[PATCH v5 00/13] kexec_file_load implementation for PowerPC

[PATCH v5 00/13] kexec_file_load implementation for PowerPC

[Thiago Jung Bauermann]

[ Andrew, since this series touches generic code, x86 and powerpc,
  Michael Ellerman and Dave Young think it should go via your tree. ]

The main differences in this version are (more detailed changelog at
the end of this email):

- The code which is not specific to loading ELF format kernels were
  moved from kexec_elf_64.c to machine_kexec_64.c.

- There is a new patch implementing support for receiving a device tree
  blob from userspace, checking it against a whitelist of allowed nodes
  and properties and copying it into the device tree for the next kernel.
  This is the only patch that depends on the "extend kexec_file_load
  system call" series. Everything else can be upstreamed independently
  of that series.

- Also, I realised that the patch "Add support for loading ELF kernels
  with kexec_file_load." was too big, so I moved some changes to other
  patches to facilitate review. Details of what went where are in the
  changelog.

Original cover letter:

This patch series implements the kexec_file_load system call on PowerPC.

This system call moves the reading of the kernel, initrd and the device tree
from the userspace kexec tool to the kernel. This is needed if you want to
do one or both of the following:

1. only allow loading of signed kernels.
2. "measure" (i.e., record the hashes of) the kernel, initrd, kernel
   command line and other boot inputs for the Integrity Measurement
   Architecture subsystem.

The above are the functions kexec already has built into kexec_file_load.
Yesterday I posted a set of patches which allows a third feature:

3. have IMA pass-on its event log (where integrity measurements are
   registered) accross kexec to the second kernel, so that the event
   history is preserved.

Because OpenPower uses an intermediary Linux instance as a boot loader
(skiroot), feature 1 is needed to implement secure boot for the platform,
while features 2 and 3 are needed to implement trusted boot.

This patch series starts by removing an x86 assumption from kexec_file:
kexec_add_buffer uses iomem to find reserved memory ranges, but PowerPC
uses the memblock subsystem.  A hook is added so that each arch can
specify how memory ranges can be found.

Also, the memory-walking logic in kexec_add_buffer is useful in this
implementation to find a free area for the purgatory's stack, so the
next patch moves that logic to kexec_locate_mem_hole.

The kexec_file_load system call needs to apply relocations to the
purgatory but adding code for that would duplicate functionality with
the module loading mechanism, which also needs to apply relocations to
the kernel modules.  Therefore, this patch series factors out the module
relocation code so that it can be shared.

One thing that is still missing is crashkernel support, which I intend
to submit shortly. For now, arch_kexec_kernel_image_probe rejects crash
kernels.

This code is based on kexec-tools, but with many modifications to adapt
it to the kernel environment and facilities. Except the purgatory,
which only has minimal changes.

Changes for v5:
- Rebased series on v4.8-rc1 + the extend kexec_file_load series.
- Patch "powerpc: Adapt elf64_apply_relocate_add for kexec_file_load."
  - New patch. These changes were previously in patch 10.
    The code itself is unchanged from v4.
- Patch "powerpc: Implement kexec_file_load."
  - Moved arch_kexec_walk_mem, arch_kexec_apply_relocations_add and
    setup_purgatory from patch 10 to this patch.
  - arch_kexec_apply_relocations_add is unchanged from v4.
  - Fixed off-by-one error in arch_kexec_walk_mem when passing range
    to func.
  - Moved setup_purgatory from kexec_elf_64.c to machine_kexec_64.c,
    and changed it to receive a pointer to the slave code directly
    rather than a struct elf_info and getting the pointer from there.
- Patch "powerpc: Add code to work with device trees in kexec_file_load."
  - New patch. These changes were previously in patch 10.
  - find_debug_console moved from kexec_elf_64.c to machine_kexec_64.c.
    The code is unchanged from v4.
  - setup_new_fdt is a new function factored out of elf64_load. The only
    code change from v4 is to create /chosen if it doesn't exist yet.
- Patch "powerpc: Add support for loading ELF kernels with kexec_file_load."
  - This patch was too big, so moved some of its changes to other patches
    to facilitate review.
  - Allow loading ELF file type ET_DYN, which is what the BE kernel uses.
  - The code adapting the device tree for booting the new kernel was moved
    out of elf64_load to setup_new_fdt.
- Patch "powerpc: Allow userspace to set device tree properties in kexec_file_load"
  - New patch.
  - The code in this patch didn't exist in v4.
  - This is the only patch that depends on the extend kexec_file_load series.
- Patch "powerpc: Enable CONFIG_KEXEC_FILE in powerpc server defconfigs."
  - New patch.

Changes for v4:
- Rebased series on today's powerpc/next.
- Patch "kexec_file: Remove unused members from struct kexec_buf.":
    - Dropped from the series.
- Patch "kexec_file: Allow arch-specific memory walking function for
  kexec_add_buffer":
    - Changed subject line to be more specific. Was: "kexec_file: Generalize
      kexec_add_buffer.".
    - Changed description to refer to x86 arch instead of Intel arch.
    - Moved documentation comments for struct kexec_buf to this patch.
- Patch "kexec_file: Change kexec_add_buffer to take kexec_buf as argument.":
    - New patch.
- Patch "kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.":
    - Changed kexec_locate_mem_hole to take kexec_buf as argument.
    - Improved description of kexec_locate_mem_hole in documentation comment.

Changes for v3:
- Rebased series on today's powerpc/next.
- Patch "kexec_file: Generalize kexec_add_buffer.":
    - Removed most arguments from arch_kexec_walk_mem and pass kbuf
      explicitly.
- Patch "powerpc: Add functions to read ELF files of any endianness.":
    - Fixed whitespace issues found by checkpatch.pl.
- Patch "powerpc: Factor out relocation code from module_64.c to
  elf_util_64.c.":
    - Changed to use the new PPC64_ELF_ABI_v2 macro.
- Patch "powerpc: Add support for loading ELF kernels with
  kexec_file_load.":
    - Adapted arch_kexec_walk_mem implementation to changes in its
      argument list.
    - Fixed whitespace and GPL header issues found by checkpatch.pl.
- Patch "powerpc: Add purgatory for kexec_file_load implementation.":
    - Fixed whitespace and GPL header issues found by checkpatch.pl.
    - Changed to use the new PPC64_ELF_ABI_v2 macro.

Changes for v2:
- All patches: forgot to add Signed-off-by lines in v1, so added them now.
- Patch "kexec_file: Generalize kexec_add_buffer.": broke in two, one
  adding arch_kexec_walk_mem and the other adding kexec_locate_mem_hole.
- Patch "powerpc: Implement kexec_file_load.":
    - Moved relocation changes and the arch_kexec_walk_mem implementation
      to the next patch in the series.
    - Removed pr_fmt from machine_kexec_64.c, since the patch doesn't add
      any call to pr_debug in that file.
    - Changed arch_kexec_kernel_image_probe to reject crash kernels.


Thiago Jung Bauermann (13):
  kexec_file: Allow arch-specific memory walking for kexec_add_buffer
  kexec_file: Change kexec_add_buffer to take kexec_buf as argument.
  kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.
  powerpc: Factor out relocation code from module_64.c to elf_util_64.c.
  powerpc: Generalize elf64_apply_relocate_add.
  powerpc: Adapt elf64_apply_relocate_add for kexec_file_load.
  powerpc: Add functions to read ELF files of any endianness.
  powerpc: Implement kexec_file_load.
  powerpc: Add code to work with device trees in kexec_file_load.
  powerpc: Add support for loading ELF kernels with kexec_file_load.
  powerpc: Allow userspace to set device tree properties in
    kexec_file_load
  powerpc: Add purgatory for kexec_file_load implementation.
  powerpc: Enable CONFIG_KEXEC_FILE in powerpc server defconfigs.

 arch/powerpc/Kconfig                      |  13 +
 arch/powerpc/Makefile                     |   4 +
 arch/powerpc/configs/powernv_defconfig    |   2 +
 arch/powerpc/configs/ppc64_defconfig      |   2 +
 arch/powerpc/configs/pseries_defconfig    |   2 +
 arch/powerpc/include/asm/elf_util.h       |  92 ++++
 arch/powerpc/include/asm/kexec.h          |  11 +
 arch/powerpc/include/asm/kexec_elf_64.h   |  10 +
 arch/powerpc/include/asm/module.h         |  14 +-
 arch/powerpc/include/asm/systbl.h         |   1 +
 arch/powerpc/include/asm/unistd.h         |   2 +-
 arch/powerpc/include/uapi/asm/unistd.h    |   1 +
 arch/powerpc/kernel/Makefile              |   7 +
 arch/powerpc/kernel/elf_util.c            | 476 ++++++++++++++++++++
 arch/powerpc/kernel/elf_util_64.c         | 374 ++++++++++++++++
 arch/powerpc/kernel/kexec_elf_64.c        | 291 ++++++++++++
 arch/powerpc/kernel/machine_kexec_64.c    | 719 ++++++++++++++++++++++++++++++
 arch/powerpc/kernel/module_64.c           | 328 ++------------
 arch/powerpc/purgatory/.gitignore         |   2 +
 arch/powerpc/purgatory/Makefile           |  36 ++
 arch/powerpc/purgatory/console-ppc64.c    |  38 ++
 arch/powerpc/purgatory/crashdump-ppc64.h  |  42 ++
 arch/powerpc/purgatory/crashdump_backup.c |  36 ++
 arch/powerpc/purgatory/crtsavres.S        |   5 +
 arch/powerpc/purgatory/hvCall.S           |  27 ++
 arch/powerpc/purgatory/hvCall.h           |   8 +
 arch/powerpc/purgatory/kexec-sha256.h     |  11 +
 arch/powerpc/purgatory/ppc64_asm.h        |  20 +
 arch/powerpc/purgatory/printf.c           | 164 +++++++
 arch/powerpc/purgatory/purgatory-ppc64.c  |  41 ++
 arch/powerpc/purgatory/purgatory-ppc64.h  |   6 +
 arch/powerpc/purgatory/purgatory.c        |  62 +++
 arch/powerpc/purgatory/purgatory.h        |  11 +
 arch/powerpc/purgatory/sha256.c           |   6 +
 arch/powerpc/purgatory/sha256.h           |   1 +
 arch/powerpc/purgatory/string.S           |   1 +
 arch/powerpc/purgatory/v2wrap.S           | 134 ++++++
 arch/x86/kernel/crash.c                   |  37 +-
 arch/x86/kernel/kexec-bzimage64.c         |  48 +-
 include/linux/kexec.h                     |  33 +-
 kernel/kexec_file.c                       | 141 +++---
 kernel/kexec_internal.h                   |  16 -
 42 files changed, 2869 insertions(+), 406 deletions(-)
 create mode 100644 arch/powerpc/include/asm/elf_util.h
 create mode 100644 arch/powerpc/include/asm/kexec_elf_64.h
 create mode 100644 arch/powerpc/kernel/elf_util.c
 create mode 100644 arch/powerpc/kernel/elf_util_64.c
 create mode 100644 arch/powerpc/kernel/kexec_elf_64.c
 create mode 100644 arch/powerpc/purgatory/.gitignore
 create mode 100644 arch/powerpc/purgatory/Makefile
 create mode 100644 arch/powerpc/purgatory/console-ppc64.c
 create mode 100644 arch/powerpc/purgatory/crashdump-ppc64.h
 create mode 100644 arch/powerpc/purgatory/crashdump_backup.c
 create mode 100644 arch/powerpc/purgatory/crtsavres.S
 create mode 100644 arch/powerpc/purgatory/hvCall.S
 create mode 100644 arch/powerpc/purgatory/hvCall.h
 create mode 100644 arch/powerpc/purgatory/kexec-sha256.h
 create mode 100644 arch/powerpc/purgatory/ppc64_asm.h
 create mode 100644 arch/powerpc/purgatory/printf.c
 create mode 100644 arch/powerpc/purgatory/purgatory-ppc64.c
 create mode 100644 arch/powerpc/purgatory/purgatory-ppc64.h
 create mode 100644 arch/powerpc/purgatory/purgatory.c
 create mode 100644 arch/powerpc/purgatory/purgatory.h
 create mode 100644 arch/powerpc/purgatory/sha256.c
 create mode 100644 arch/powerpc/purgatory/sha256.h
 create mode 100644 arch/powerpc/purgatory/string.S
 create mode 100644 arch/powerpc/purgatory/v2wrap.S

-- 
1.9.1

[PATCH v5 00/13] kexec_file_load implementation for PowerPC

[Thiago Jung Bauermann]

[ Andrew, since this series touches generic code, x86 and powerpc,
  Michael Ellerman and Dave Young think it should go via your tree. ]

The main differences in this version are (more detailed changelog at
the end of this email):

- The code which is not specific to loading ELF format kernels were
  moved from kexec_elf_64.c to machine_kexec_64.c.

- There is a new patch implementing support for receiving a device tree
  blob from userspace, checking it against a whitelist of allowed nodes
  and properties and copying it into the device tree for the next kernel.
  This is the only patch that depends on the "extend kexec_file_load
  system call" series. Everything else can be upstreamed independently
  of that series.

- Also, I realised that the patch "Add support for loading ELF kernels
  with kexec_file_load." was too big, so I moved some changes to other
  patches to facilitate review. Details of what went where are in the
  changelog.

Original cover letter:

This patch series implements the kexec_file_load system call on PowerPC.

This system call moves the reading of the kernel, initrd and the device tree
from the userspace kexec tool to the kernel. This is needed if you want to
do one or both of the following:

1. only allow loading of signed kernels.
2. "measure" (i.e., record the hashes of) the kernel, initrd, kernel
   command line and other boot inputs for the Integrity Measurement
   Architecture subsystem.

The above are the functions kexec already has built into kexec_file_load.
Yesterday I posted a set of patches which allows a third feature:

3. have IMA pass-on its event log (where integrity measurements are
   registered) accross kexec to the second kernel, so that the event
   history is preserved.

Because OpenPower uses an intermediary Linux instance as a boot loader
(skiroot), feature 1 is needed to implement secure boot for the platform,
while features 2 and 3 are needed to implement trusted boot.

This patch series starts by removing an x86 assumption from kexec_file:
kexec_add_buffer uses iomem to find reserved memory ranges, but PowerPC
uses the memblock subsystem.  A hook is added so that each arch can
specify how memory ranges can be found.

Also, the memory-walking logic in kexec_add_buffer is useful in this
implementation to find a free area for the purgatory's stack, so the
next patch moves that logic to kexec_locate_mem_hole.

The kexec_file_load system call needs to apply relocations to the
purgatory but adding code for that would duplicate functionality with
the module loading mechanism, which also needs to apply relocations to
the kernel modules.  Therefore, this patch series factors out the module
relocation code so that it can be shared.

One thing that is still missing is crashkernel support, which I intend
to submit shortly. For now, arch_kexec_kernel_image_probe rejects crash
kernels.

This code is based on kexec-tools, but with many modifications to adapt
it to the kernel environment and facilities. Except the purgatory,
which only has minimal changes.

Changes for v5:
- Rebased series on v4.8-rc1 + the extend kexec_file_load series.
- Patch "powerpc: Adapt elf64_apply_relocate_add for kexec_file_load."
  - New patch. These changes were previously in patch 10.
    The code itself is unchanged from v4.
- Patch "powerpc: Implement kexec_file_load."
  - Moved arch_kexec_walk_mem, arch_kexec_apply_relocations_add and
    setup_purgatory from patch 10 to this patch.
  - arch_kexec_apply_relocations_add is unchanged from v4.
  - Fixed off-by-one error in arch_kexec_walk_mem when passing range
    to func.
  - Moved setup_purgatory from kexec_elf_64.c to machine_kexec_64.c,
    and changed it to receive a pointer to the slave code directly
    rather than a struct elf_info and getting the pointer from there.
- Patch "powerpc: Add code to work with device trees in kexec_file_load."
  - New patch. These changes were previously in patch 10.
  - find_debug_console moved from kexec_elf_64.c to machine_kexec_64.c.
    The code is unchanged from v4.
  - setup_new_fdt is a new function factored out of elf64_load. The only
    code change from v4 is to create /chosen if it doesn't exist yet.
- Patch "powerpc: Add support for loading ELF kernels with kexec_file_load."
  - This patch was too big, so moved some of its changes to other patches
    to facilitate review.
  - Allow loading ELF file type ET_DYN, which is what the BE kernel uses.
  - The code adapting the device tree for booting the new kernel was moved
    out of elf64_load to setup_new_fdt.
- Patch "powerpc: Allow userspace to set device tree properties in kexec_file_load"
  - New patch.
  - The code in this patch didn't exist in v4.
  - This is the only patch that depends on the extend kexec_file_load series.
- Patch "powerpc: Enable CONFIG_KEXEC_FILE in powerpc server defconfigs."
  - New patch.

Changes for v4:
- Rebased series on today's powerpc/next.
- Patch "kexec_file: Remove unused members from struct kexec_buf.":
    - Dropped from the series.
- Patch "kexec_file: Allow arch-specific memory walking function for
  kexec_add_buffer":
    - Changed subject line to be more specific. Was: "kexec_file: Generalize
      kexec_add_buffer.".
    - Changed description to refer to x86 arch instead of Intel arch.
    - Moved documentation comments for struct kexec_buf to this patch.
- Patch "kexec_file: Change kexec_add_buffer to take kexec_buf as argument.":
    - New patch.
- Patch "kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.":
    - Changed kexec_locate_mem_hole to take kexec_buf as argument.
    - Improved description of kexec_locate_mem_hole in documentation comment.

Changes for v3:
- Rebased series on today's powerpc/next.
- Patch "kexec_file: Generalize kexec_add_buffer.":
    - Removed most arguments from arch_kexec_walk_mem and pass kbuf
      explicitly.
- Patch "powerpc: Add functions to read ELF files of any endianness.":
    - Fixed whitespace issues found by checkpatch.pl.
- Patch "powerpc: Factor out relocation code from module_64.c to
  elf_util_64.c.":
    - Changed to use the new PPC64_ELF_ABI_v2 macro.
- Patch "powerpc: Add support for loading ELF kernels with
  kexec_file_load.":
    - Adapted arch_kexec_walk_mem implementation to changes in its
      argument list.
    - Fixed whitespace and GPL header issues found by checkpatch.pl.
- Patch "powerpc: Add purgatory for kexec_file_load implementation.":
    - Fixed whitespace and GPL header issues found by checkpatch.pl.
    - Changed to use the new PPC64_ELF_ABI_v2 macro.

Changes for v2:
- All patches: forgot to add Signed-off-by lines in v1, so added them now.
- Patch "kexec_file: Generalize kexec_add_buffer.": broke in two, one
  adding arch_kexec_walk_mem and the other adding kexec_locate_mem_hole.
- Patch "powerpc: Implement kexec_file_load.":
    - Moved relocation changes and the arch_kexec_walk_mem implementation
      to the next patch in the series.
    - Removed pr_fmt from machine_kexec_64.c, since the patch doesn't add
      any call to pr_debug in that file.
    - Changed arch_kexec_kernel_image_probe to reject crash kernels.


Thiago Jung Bauermann (13):
  kexec_file: Allow arch-specific memory walking for kexec_add_buffer
  kexec_file: Change kexec_add_buffer to take kexec_buf as argument.
  kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.
  powerpc: Factor out relocation code from module_64.c to elf_util_64.c.
  powerpc: Generalize elf64_apply_relocate_add.
  powerpc: Adapt elf64_apply_relocate_add for kexec_file_load.
  powerpc: Add functions to read ELF files of any endianness.
  powerpc: Implement kexec_file_load.
  powerpc: Add code to work with device trees in kexec_file_load.
  powerpc: Add support for loading ELF kernels with kexec_file_load.
  powerpc: Allow userspace to set device tree properties in
    kexec_file_load
  powerpc: Add purgatory for kexec_file_load implementation.
  powerpc: Enable CONFIG_KEXEC_FILE in powerpc server defconfigs.

 arch/powerpc/Kconfig                      |  13 +
 arch/powerpc/Makefile                     |   4 +
 arch/powerpc/configs/powernv_defconfig    |   2 +
 arch/powerpc/configs/ppc64_defconfig      |   2 +
 arch/powerpc/configs/pseries_defconfig    |   2 +
 arch/powerpc/include/asm/elf_util.h       |  92 ++++
 arch/powerpc/include/asm/kexec.h          |  11 +
 arch/powerpc/include/asm/kexec_elf_64.h   |  10 +
 arch/powerpc/include/asm/module.h         |  14 +-
 arch/powerpc/include/asm/systbl.h         |   1 +
 arch/powerpc/include/asm/unistd.h         |   2 +-
 arch/powerpc/include/uapi/asm/unistd.h    |   1 +
 arch/powerpc/kernel/Makefile              |   7 +
 arch/powerpc/kernel/elf_util.c            | 476 ++++++++++++++++++++
 arch/powerpc/kernel/elf_util_64.c         | 374 ++++++++++++++++
 arch/powerpc/kernel/kexec_elf_64.c        | 291 ++++++++++++
 arch/powerpc/kernel/machine_kexec_64.c    | 719 ++++++++++++++++++++++++++++++
 arch/powerpc/kernel/module_64.c           | 328 ++------------
 arch/powerpc/purgatory/.gitignore         |   2 +
 arch/powerpc/purgatory/Makefile           |  36 ++
 arch/powerpc/purgatory/console-ppc64.c    |  38 ++
 arch/powerpc/purgatory/crashdump-ppc64.h  |  42 ++
 arch/powerpc/purgatory/crashdump_backup.c |  36 ++
 arch/powerpc/purgatory/crtsavres.S        |   5 +
 arch/powerpc/purgatory/hvCall.S           |  27 ++
 arch/powerpc/purgatory/hvCall.h           |   8 +
 arch/powerpc/purgatory/kexec-sha256.h     |  11 +
 arch/powerpc/purgatory/ppc64_asm.h        |  20 +
 arch/powerpc/purgatory/printf.c           | 164 +++++++
 arch/powerpc/purgatory/purgatory-ppc64.c  |  41 ++
 arch/powerpc/purgatory/purgatory-ppc64.h  |   6 +
 arch/powerpc/purgatory/purgatory.c        |  62 +++
 arch/powerpc/purgatory/purgatory.h        |  11 +
 arch/powerpc/purgatory/sha256.c           |   6 +
 arch/powerpc/purgatory/sha256.h           |   1 +
 arch/powerpc/purgatory/string.S           |   1 +
 arch/powerpc/purgatory/v2wrap.S           | 134 ++++++
 arch/x86/kernel/crash.c                   |  37 +-
 arch/x86/kernel/kexec-bzimage64.c         |  48 +-
 include/linux/kexec.h                     |  33 +-
 kernel/kexec_file.c                       | 141 +++---
 kernel/kexec_internal.h                   |  16 -
 42 files changed, 2869 insertions(+), 406 deletions(-)
 create mode 100644 arch/powerpc/include/asm/elf_util.h
 create mode 100644 arch/powerpc/include/asm/kexec_elf_64.h
 create mode 100644 arch/powerpc/kernel/elf_util.c
 create mode 100644 arch/powerpc/kernel/elf_util_64.c
 create mode 100644 arch/powerpc/kernel/kexec_elf_64.c
 create mode 100644 arch/powerpc/purgatory/.gitignore
 create mode 100644 arch/powerpc/purgatory/Makefile
 create mode 100644 arch/powerpc/purgatory/console-ppc64.c
 create mode 100644 arch/powerpc/purgatory/crashdump-ppc64.h
 create mode 100644 arch/powerpc/purgatory/crashdump_backup.c
 create mode 100644 arch/powerpc/purgatory/crtsavres.S
 create mode 100644 arch/powerpc/purgatory/hvCall.S
 create mode 100644 arch/powerpc/purgatory/hvCall.h
 create mode 100644 arch/powerpc/purgatory/kexec-sha256.h
 create mode 100644 arch/powerpc/purgatory/ppc64_asm.h
 create mode 100644 arch/powerpc/purgatory/printf.c
 create mode 100644 arch/powerpc/purgatory/purgatory-ppc64.c
 create mode 100644 arch/powerpc/purgatory/purgatory-ppc64.h
 create mode 100644 arch/powerpc/purgatory/purgatory.c
 create mode 100644 arch/powerpc/purgatory/purgatory.h
 create mode 100644 arch/powerpc/purgatory/sha256.c
 create mode 100644 arch/powerpc/purgatory/sha256.h
 create mode 100644 arch/powerpc/purgatory/string.S
 create mode 100644 arch/powerpc/purgatory/v2wrap.S

-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 01/13] kexec_file: Allow arch-specific memory walking for kexec_add_buffer

[Thiago Jung Bauermann]

Allow architectures to specify a different memory walking function for
kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
PowerPC uses the memblock subsystem.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
---
 include/linux/kexec.h   | 26 ++++++++++++++++++++++++++
 kernel/kexec_file.c     | 30 ++++++++++++++++++++++--------
 kernel/kexec_internal.h | 16 ----------------
 3 files changed, 48 insertions(+), 24 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 29202935055d..5ffd0011395c 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -149,6 +149,32 @@ struct kexec_file_ops {
 #endif
 };
 
+/**
+ * struct kexec_buf - parameters for finding a place for a buffer in memory
+ * @image:	kexec image in which memory to search.
+ * @buffer:	Contents which will be copied to the allocated memory.
+ * @bufsz:	Size of @buffer.
+ * @mem:	On return will have address of the buffer in memory.
+ * @memsz:	Size for the buffer in memory.
+ * @buf_align:	Minimum alignment needed.
+ * @buf_min:	The buffer can't be placed below this address.
+ * @buf_max:	The buffer can't be placed above this address.
+ * @top_down:	Allocate from top of memory.
+ */
+struct kexec_buf {
+	struct kimage *image;
+	char *buffer;
+	unsigned long bufsz;
+	unsigned long mem;
+	unsigned long memsz;
+	unsigned long buf_align;
+	unsigned long buf_min;
+	unsigned long buf_max;
+	bool top_down;
+};
+
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+			       int (*func)(u64, u64, void *));
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
 				    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index c32d1d65bb77..e63fd4592e20 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -502,6 +502,27 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
 	return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @kbuf:	Context info for the search. Also passed to @func.
+ * @func:	Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+			       int (*func)(u64, u64, void *))
+{
+	if (kbuf->image->type == KEXEC_TYPE_CRASH)
+		return walk_iomem_res_desc(crashk_res.desc,
+					   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+					   crashk_res.start, crashk_res.end,
+					   kbuf, func);
+	else
+		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
 /*
  * Helper function for placing a buffer in a kexec segment. This assumes
  * that kexec_mutex is held.
@@ -548,14 +569,7 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	kbuf->top_down = top_down;
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
-	if (image->type == KEXEC_TYPE_CRASH)
-		ret = walk_iomem_res_desc(crashk_res.desc,
-				IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
-				crashk_res.start, crashk_res.end, kbuf,
-				locate_mem_hole_callback);
-	else
-		ret = walk_system_ram_res(0, -1, kbuf,
-					  locate_mem_hole_callback);
+	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
 	if (ret != 1) {
 		/* A suitable memory range could not be found for buffer */
 		return -EADDRNOTAVAIL;
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 0a52315d9c62..4cef7e4706b0 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -20,22 +20,6 @@ struct kexec_sha_region {
 	unsigned long len;
 };
 
-/*
- * Keeps track of buffer parameters as provided by caller for requesting
- * memory placement of buffer.
- */
-struct kexec_buf {
-	struct kimage *image;
-	char *buffer;
-	unsigned long bufsz;
-	unsigned long mem;
-	unsigned long memsz;
-	unsigned long buf_align;
-	unsigned long buf_min;
-	unsigned long buf_max;
-	bool top_down;		/* allocate from top of memory hole */
-};
-
 void kimage_file_post_load_cleanup(struct kimage *image);
 #else /* CONFIG_KEXEC_FILE */
 static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
-- 
1.9.1

[PATCH v5 01/13] kexec_file: Allow arch-specific memory walking for kexec_add_buffer

[Thiago Jung Bauermann]

Allow architectures to specify a different memory walking function for
kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
PowerPC uses the memblock subsystem.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
---
 include/linux/kexec.h   | 26 ++++++++++++++++++++++++++
 kernel/kexec_file.c     | 30 ++++++++++++++++++++++--------
 kernel/kexec_internal.h | 16 ----------------
 3 files changed, 48 insertions(+), 24 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 29202935055d..5ffd0011395c 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -149,6 +149,32 @@ struct kexec_file_ops {
 #endif
 };
 
+/**
+ * struct kexec_buf - parameters for finding a place for a buffer in memory
+ * @image:	kexec image in which memory to search.
+ * @buffer:	Contents which will be copied to the allocated memory.
+ * @bufsz:	Size of @buffer.
+ * @mem:	On return will have address of the buffer in memory.
+ * @memsz:	Size for the buffer in memory.
+ * @buf_align:	Minimum alignment needed.
+ * @buf_min:	The buffer can't be placed below this address.
+ * @buf_max:	The buffer can't be placed above this address.
+ * @top_down:	Allocate from top of memory.
+ */
+struct kexec_buf {
+	struct kimage *image;
+	char *buffer;
+	unsigned long bufsz;
+	unsigned long mem;
+	unsigned long memsz;
+	unsigned long buf_align;
+	unsigned long buf_min;
+	unsigned long buf_max;
+	bool top_down;
+};
+
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+			       int (*func)(u64, u64, void *));
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
 				    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index c32d1d65bb77..e63fd4592e20 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -502,6 +502,27 @@ static int locate_mem_hole_callback(u64 start, u64 end, void *arg)
 	return locate_mem_hole_bottom_up(start, end, kbuf);
 }
 
+/**
+ * arch_kexec_walk_mem - call func(data) on free memory regions
+ * @kbuf:	Context info for the search. Also passed to @func.
+ * @func:	Function to call for each memory region.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
+			       int (*func)(u64, u64, void *))
+{
+	if (kbuf->image->type == KEXEC_TYPE_CRASH)
+		return walk_iomem_res_desc(crashk_res.desc,
+					   IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
+					   crashk_res.start, crashk_res.end,
+					   kbuf, func);
+	else
+		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
+}
+
 /*
  * Helper function for placing a buffer in a kexec segment. This assumes
  * that kexec_mutex is held.
@@ -548,14 +569,7 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	kbuf->top_down = top_down;
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
-	if (image->type == KEXEC_TYPE_CRASH)
-		ret = walk_iomem_res_desc(crashk_res.desc,
-				IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY,
-				crashk_res.start, crashk_res.end, kbuf,
-				locate_mem_hole_callback);
-	else
-		ret = walk_system_ram_res(0, -1, kbuf,
-					  locate_mem_hole_callback);
+	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
 	if (ret != 1) {
 		/* A suitable memory range could not be found for buffer */
 		return -EADDRNOTAVAIL;
diff --git a/kernel/kexec_internal.h b/kernel/kexec_internal.h
index 0a52315d9c62..4cef7e4706b0 100644
--- a/kernel/kexec_internal.h
+++ b/kernel/kexec_internal.h
@@ -20,22 +20,6 @@ struct kexec_sha_region {
 	unsigned long len;
 };
 
-/*
- * Keeps track of buffer parameters as provided by caller for requesting
- * memory placement of buffer.
- */
-struct kexec_buf {
-	struct kimage *image;
-	char *buffer;
-	unsigned long bufsz;
-	unsigned long mem;
-	unsigned long memsz;
-	unsigned long buf_align;
-	unsigned long buf_min;
-	unsigned long buf_max;
-	bool top_down;		/* allocate from top of memory hole */
-};
-
 void kimage_file_post_load_cleanup(struct kimage *image);
 #else /* CONFIG_KEXEC_FILE */
 static inline void kimage_file_post_load_cleanup(struct kimage *image) { }
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Thiago Jung Bauermann]

Adapt all callers to the new function prototype.

In addition, change the type of kexec_buf.buffer from char * to void *.
There is no particular reason for it to be a char *, and the change
allows us to get rid of 3 existing casts to char * in the code.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
---
 arch/x86/kernel/crash.c           | 37 ++++++++--------
 arch/x86/kernel/kexec-bzimage64.c | 48 +++++++++++----------
 include/linux/kexec.h             |  8 +---
 kernel/kexec_file.c               | 88 ++++++++++++++++++---------------------
 4 files changed, 87 insertions(+), 94 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 9616cf76940c..38a1cdf6aa05 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -615,9 +615,9 @@ static int determine_backup_region(u64 start, u64 end, void *arg)
 
 int crash_load_segments(struct kimage *image)
 {
-	unsigned long src_start, src_sz, elf_sz;
-	void *elf_addr;
 	int ret;
+	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ULONG_MAX, .top_down = false };
 
 	/*
 	 * Determine and load a segment for backup area. First 640K RAM
@@ -631,43 +631,44 @@ int crash_load_segments(struct kimage *image)
 	if (ret < 0)
 		return ret;
 
-	src_start = image->arch.backup_src_start;
-	src_sz = image->arch.backup_src_sz;
-
 	/* Add backup segment. */
-	if (src_sz) {
+	if (image->arch.backup_src_sz) {
+		kbuf.buffer = &crash_zero_bytes;
+		kbuf.bufsz = sizeof(crash_zero_bytes);
+		kbuf.memsz = image->arch.backup_src_sz;
+		kbuf.buf_align = PAGE_SIZE;
 		/*
 		 * Ideally there is no source for backup segment. This is
 		 * copied in purgatory after crash. Just add a zero filled
 		 * segment for now to make sure checksum logic works fine.
 		 */
-		ret = kexec_add_buffer(image, (char *)&crash_zero_bytes,
-				       sizeof(crash_zero_bytes), src_sz,
-				       PAGE_SIZE, 0, -1, 0,
-				       &image->arch.backup_load_addr);
+		ret = kexec_add_buffer(&kbuf);
 		if (ret)
 			return ret;
+		image->arch.backup_load_addr = kbuf.mem;
 		pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n",
-			 image->arch.backup_load_addr, src_start, src_sz);
+			 image->arch.backup_load_addr,
+			 image->arch.backup_src_start, kbuf.memsz);
 	}
 
 	/* Prepare elf headers and add a segment */
-	ret = prepare_elf_headers(image, &elf_addr, &elf_sz);
+	ret = prepare_elf_headers(image, &kbuf.buffer, &kbuf.bufsz);
 	if (ret)
 		return ret;
 
-	image->arch.elf_headers = elf_addr;
-	image->arch.elf_headers_sz = elf_sz;
+	image->arch.elf_headers = kbuf.buffer;
+	image->arch.elf_headers_sz = kbuf.bufsz;
 
-	ret = kexec_add_buffer(image, (char *)elf_addr, elf_sz, elf_sz,
-			ELF_CORE_HEADER_ALIGN, 0, -1, 0,
-			&image->arch.elf_load_addr);
+	kbuf.memsz = kbuf.bufsz;
+	kbuf.buf_align = ELF_CORE_HEADER_ALIGN;
+	ret = kexec_add_buffer(&kbuf);
 	if (ret) {
 		vfree((void *)image->arch.elf_headers);
 		return ret;
 	}
+	image->arch.elf_load_addr = kbuf.mem;
 	pr_debug("Loaded ELF headers at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-		 image->arch.elf_load_addr, elf_sz, elf_sz);
+		 image->arch.elf_load_addr, kbuf.bufsz, kbuf.bufsz);
 
 	return ret;
 }
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index f2356bda2b05..4b3a75329fb6 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -331,17 +331,17 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 
 	struct setup_header *header;
 	int setup_sects, kern16_size, ret = 0;
-	unsigned long setup_header_size, params_cmdline_sz, params_misc_sz;
+	unsigned long setup_header_size, params_cmdline_sz;
 	struct boot_params *params;
 	unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
 	unsigned long purgatory_load_addr;
-	unsigned long kernel_bufsz, kernel_memsz, kernel_align;
-	char *kernel_buf;
 	struct bzimage64_data *ldata;
 	struct kexec_entry64_regs regs64;
 	void *stack;
 	unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
 	unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
+	struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
+				  .top_down = true };
 
 	header = (struct setup_header *)(kernel + setup_hdr_offset);
 	setup_sects = header->setup_sects;
@@ -402,11 +402,11 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 	params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
 				MAX_ELFCOREHDR_STR_LEN;
 	params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
-	params_misc_sz = params_cmdline_sz + efi_map_sz +
+	kbuf.bufsz = params_cmdline_sz + efi_map_sz +
 				sizeof(struct setup_data) +
 				sizeof(struct efi_setup_data);
 
-	params = kzalloc(params_misc_sz, GFP_KERNEL);
+	params = kzalloc(kbuf.bufsz, GFP_KERNEL);
 	if (!params)
 		return ERR_PTR(-ENOMEM);
 	efi_map_offset = params_cmdline_sz;
@@ -418,37 +418,41 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 	/* Is there a limit on setup header size? */
 	memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
 
-	ret = kexec_add_buffer(image, (char *)params, params_misc_sz,
-			       params_misc_sz, 16, MIN_BOOTPARAM_ADDR,
-			       ULONG_MAX, 1, &bootparam_load_addr);
+	kbuf.buffer = params;
+	kbuf.memsz = kbuf.bufsz;
+	kbuf.buf_align = 16;
+	kbuf.buf_min = MIN_BOOTPARAM_ADDR;
+	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out_free_params;
+	bootparam_load_addr = kbuf.mem;
 	pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-		 bootparam_load_addr, params_misc_sz, params_misc_sz);
+		 bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);
 
 	/* Load kernel */
-	kernel_buf = kernel + kern16_size;
-	kernel_bufsz =  kernel_len - kern16_size;
-	kernel_memsz = PAGE_ALIGN(header->init_size);
-	kernel_align = header->kernel_alignment;
-
-	ret = kexec_add_buffer(image, kernel_buf,
-			       kernel_bufsz, kernel_memsz, kernel_align,
-			       MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1,
-			       &kernel_load_addr);
+	kbuf.buffer = kernel + kern16_size;
+	kbuf.bufsz =  kernel_len - kern16_size;
+	kbuf.memsz = PAGE_ALIGN(header->init_size);
+	kbuf.buf_align = header->kernel_alignment;
+	kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
+	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out_free_params;
+	kernel_load_addr = kbuf.mem;
 
 	pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-		 kernel_load_addr, kernel_memsz, kernel_memsz);
+		 kernel_load_addr, kbuf.bufsz, kbuf.memsz);
 
 	/* Load initrd high */
 	if (initrd) {
-		ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len,
-				       PAGE_SIZE, MIN_INITRD_LOAD_ADDR,
-				       ULONG_MAX, 1, &initrd_load_addr);
+		kbuf.buffer = initrd;
+		kbuf.bufsz = kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
+		ret = kexec_add_buffer(&kbuf);
 		if (ret)
 			goto out_free_params;
+		initrd_load_addr = kbuf.mem;
 
 		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 				initrd_load_addr, initrd_len, initrd_len);
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 5ffd0011395c..28bc9f335d0d 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -163,7 +163,7 @@ struct kexec_file_ops {
  */
 struct kexec_buf {
 	struct kimage *image;
-	char *buffer;
+	void *buffer;
 	unsigned long bufsz;
 	unsigned long mem;
 	unsigned long memsz;
@@ -175,6 +175,7 @@ struct kexec_buf {
 
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			       int (*func)(u64, u64, void *));
+extern int kexec_add_buffer(struct kexec_buf *kbuf);
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
 				    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
@@ -244,11 +245,6 @@ extern asmlinkage long sys_kexec_load(unsigned long entry,
 					struct kexec_segment __user *segments,
 					unsigned long flags);
 extern int kernel_kexec(void);
-extern int kexec_add_buffer(struct kimage *image, char *buffer,
-			    unsigned long bufsz, unsigned long memsz,
-			    unsigned long buf_align, unsigned long buf_min,
-			    unsigned long buf_max, bool top_down,
-			    unsigned long *load_addr);
 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 						unsigned int order);
 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index e63fd4592e20..58818264ad0e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -523,25 +523,27 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
 }
 
-/*
- * Helper function for placing a buffer in a kexec segment. This assumes
- * that kexec_mutex is held.
+/**
+ * kexec_add_buffer - place a buffer in a kexec segment
+ * @kbuf:	Buffer contents and memory parameters.
+ *
+ * This function assumes that kexec_mutex is held.
+ * On successful return, @kbuf->mem will have the physical address of
+ * the buffer in memory.
+ *
+ * Return: 0 on success, negative errno on error.
  */
-int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
-		     unsigned long memsz, unsigned long buf_align,
-		     unsigned long buf_min, unsigned long buf_max,
-		     bool top_down, unsigned long *load_addr)
+int kexec_add_buffer(struct kexec_buf *kbuf)
 {
 
 	struct kexec_segment *ksegment;
-	struct kexec_buf buf, *kbuf;
 	int ret;
 
 	/* Currently adding segment this way is allowed only in file mode */
-	if (!image->file_mode)
+	if (!kbuf->image->file_mode)
 		return -EINVAL;
 
-	if (image->nr_segments >= KEXEC_SEGMENT_MAX)
+	if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
 		return -EINVAL;
 
 	/*
@@ -551,22 +553,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	 * logic goes through list of segments to make sure there are
 	 * no destination overlaps.
 	 */
-	if (!list_empty(&image->control_pages)) {
+	if (!list_empty(&kbuf->image->control_pages)) {
 		WARN_ON(1);
 		return -EINVAL;
 	}
 
-	memset(&buf, 0, sizeof(struct kexec_buf));
-	kbuf = &buf;
-	kbuf->image = image;
-	kbuf->buffer = buffer;
-	kbuf->bufsz = bufsz;
-
-	kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
-	kbuf->buf_align = max(buf_align, PAGE_SIZE);
-	kbuf->buf_min = buf_min;
-	kbuf->buf_max = buf_max;
-	kbuf->top_down = top_down;
+	/* Ensure minimum alignment needed for segments. */
+	kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
+	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
 	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
@@ -576,13 +570,12 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	}
 
 	/* Found a suitable memory range */
-	ksegment = &image->segment[image->nr_segments];
+	ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
 	ksegment->kbuf = kbuf->buffer;
 	ksegment->bufsz = kbuf->bufsz;
 	ksegment->mem = kbuf->mem;
 	ksegment->memsz = kbuf->memsz;
-	image->nr_segments++;
-	*load_addr = ksegment->mem;
+	kbuf->image->nr_segments++;
 	return 0;
 }
 
@@ -704,13 +697,15 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 				  unsigned long max, int top_down)
 {
 	struct purgatory_info *pi = &image->purgatory_info;
-	unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
-	unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
+	unsigned long align, bss_align, bss_sz, bss_pad;
+	unsigned long entry, load_addr, curr_load_addr, bss_addr, offset;
 	unsigned char *buf_addr, *src;
 	int i, ret = 0, entry_sidx = -1;
 	const Elf_Shdr *sechdrs_c;
 	Elf_Shdr *sechdrs = NULL;
-	void *purgatory_buf = NULL;
+	struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1,
+				  .buf_min = min, .buf_max = max,
+				  .top_down = top_down };
 
 	/*
 	 * sechdrs_c points to section headers in purgatory and are read
@@ -776,9 +771,7 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 	}
 
 	/* Determine how much memory is needed to load relocatable object. */
-	buf_align = 1;
 	bss_align = 1;
-	buf_sz = 0;
 	bss_sz = 0;
 
 	for (i = 0; i < pi->ehdr->e_shnum; i++) {
@@ -787,10 +780,10 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 
 		align = sechdrs[i].sh_addralign;
 		if (sechdrs[i].sh_type != SHT_NOBITS) {
-			if (buf_align < align)
-				buf_align = align;
-			buf_sz = ALIGN(buf_sz, align);
-			buf_sz += sechdrs[i].sh_size;
+			if (kbuf.buf_align < align)
+				kbuf.buf_align = align;
+			kbuf.bufsz = ALIGN(kbuf.bufsz, align);
+			kbuf.bufsz += sechdrs[i].sh_size;
 		} else {
 			/* bss section */
 			if (bss_align < align)
@@ -802,32 +795,31 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 
 	/* Determine the bss padding required to align bss properly */
 	bss_pad = 0;
-	if (buf_sz & (bss_align - 1))
-		bss_pad = bss_align - (buf_sz & (bss_align - 1));
+	if (kbuf.bufsz & (bss_align - 1))
+		bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1));
 
-	memsz = buf_sz + bss_pad + bss_sz;
+	kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz;
 
 	/* Allocate buffer for purgatory */
-	purgatory_buf = vzalloc(buf_sz);
-	if (!purgatory_buf) {
+	kbuf.buffer = vzalloc(kbuf.bufsz);
+	if (!kbuf.buffer) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	if (buf_align < bss_align)
-		buf_align = bss_align;
+	if (kbuf.buf_align < bss_align)
+		kbuf.buf_align = bss_align;
 
 	/* Add buffer to segment list */
-	ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
-				buf_align, min, max, top_down,
-				&pi->purgatory_load_addr);
+	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out;
+	pi->purgatory_load_addr = kbuf.mem;
 
 	/* Load SHF_ALLOC sections */
-	buf_addr = purgatory_buf;
+	buf_addr = kbuf.buffer;
 	load_addr = curr_load_addr = pi->purgatory_load_addr;
-	bss_addr = load_addr + buf_sz + bss_pad;
+	bss_addr = load_addr + kbuf.bufsz + bss_pad;
 
 	for (i = 0; i < pi->ehdr->e_shnum; i++) {
 		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -873,11 +865,11 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 	 * Used later to identify which section is purgatory and skip it
 	 * from checksumming.
 	 */
-	pi->purgatory_buf = purgatory_buf;
+	pi->purgatory_buf = kbuf.buffer;
 	return ret;
 out:
 	vfree(sechdrs);
-	vfree(purgatory_buf);
+	vfree(kbuf.buffer);
 	return ret;
 }
 
-- 
1.9.1

[PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Thiago Jung Bauermann]

Adapt all callers to the new function prototype.

In addition, change the type of kexec_buf.buffer from char * to void *.
There is no particular reason for it to be a char *, and the change
allows us to get rid of 3 existing casts to char * in the code.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
---
 arch/x86/kernel/crash.c           | 37 ++++++++--------
 arch/x86/kernel/kexec-bzimage64.c | 48 +++++++++++----------
 include/linux/kexec.h             |  8 +---
 kernel/kexec_file.c               | 88 ++++++++++++++++++---------------------
 4 files changed, 87 insertions(+), 94 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 9616cf76940c..38a1cdf6aa05 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -615,9 +615,9 @@ static int determine_backup_region(u64 start, u64 end, void *arg)
 
 int crash_load_segments(struct kimage *image)
 {
-	unsigned long src_start, src_sz, elf_sz;
-	void *elf_addr;
 	int ret;
+	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ULONG_MAX, .top_down = false };
 
 	/*
 	 * Determine and load a segment for backup area. First 640K RAM
@@ -631,43 +631,44 @@ int crash_load_segments(struct kimage *image)
 	if (ret < 0)
 		return ret;
 
-	src_start = image->arch.backup_src_start;
-	src_sz = image->arch.backup_src_sz;
-
 	/* Add backup segment. */
-	if (src_sz) {
+	if (image->arch.backup_src_sz) {
+		kbuf.buffer = &crash_zero_bytes;
+		kbuf.bufsz = sizeof(crash_zero_bytes);
+		kbuf.memsz = image->arch.backup_src_sz;
+		kbuf.buf_align = PAGE_SIZE;
 		/*
 		 * Ideally there is no source for backup segment. This is
 		 * copied in purgatory after crash. Just add a zero filled
 		 * segment for now to make sure checksum logic works fine.
 		 */
-		ret = kexec_add_buffer(image, (char *)&crash_zero_bytes,
-				       sizeof(crash_zero_bytes), src_sz,
-				       PAGE_SIZE, 0, -1, 0,
-				       &image->arch.backup_load_addr);
+		ret = kexec_add_buffer(&kbuf);
 		if (ret)
 			return ret;
+		image->arch.backup_load_addr = kbuf.mem;
 		pr_debug("Loaded backup region at 0x%lx backup_start=0x%lx memsz=0x%lx\n",
-			 image->arch.backup_load_addr, src_start, src_sz);
+			 image->arch.backup_load_addr,
+			 image->arch.backup_src_start, kbuf.memsz);
 	}
 
 	/* Prepare elf headers and add a segment */
-	ret = prepare_elf_headers(image, &elf_addr, &elf_sz);
+	ret = prepare_elf_headers(image, &kbuf.buffer, &kbuf.bufsz);
 	if (ret)
 		return ret;
 
-	image->arch.elf_headers = elf_addr;
-	image->arch.elf_headers_sz = elf_sz;
+	image->arch.elf_headers = kbuf.buffer;
+	image->arch.elf_headers_sz = kbuf.bufsz;
 
-	ret = kexec_add_buffer(image, (char *)elf_addr, elf_sz, elf_sz,
-			ELF_CORE_HEADER_ALIGN, 0, -1, 0,
-			&image->arch.elf_load_addr);
+	kbuf.memsz = kbuf.bufsz;
+	kbuf.buf_align = ELF_CORE_HEADER_ALIGN;
+	ret = kexec_add_buffer(&kbuf);
 	if (ret) {
 		vfree((void *)image->arch.elf_headers);
 		return ret;
 	}
+	image->arch.elf_load_addr = kbuf.mem;
 	pr_debug("Loaded ELF headers at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-		 image->arch.elf_load_addr, elf_sz, elf_sz);
+		 image->arch.elf_load_addr, kbuf.bufsz, kbuf.bufsz);
 
 	return ret;
 }
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index f2356bda2b05..4b3a75329fb6 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -331,17 +331,17 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 
 	struct setup_header *header;
 	int setup_sects, kern16_size, ret = 0;
-	unsigned long setup_header_size, params_cmdline_sz, params_misc_sz;
+	unsigned long setup_header_size, params_cmdline_sz;
 	struct boot_params *params;
 	unsigned long bootparam_load_addr, kernel_load_addr, initrd_load_addr;
 	unsigned long purgatory_load_addr;
-	unsigned long kernel_bufsz, kernel_memsz, kernel_align;
-	char *kernel_buf;
 	struct bzimage64_data *ldata;
 	struct kexec_entry64_regs regs64;
 	void *stack;
 	unsigned int setup_hdr_offset = offsetof(struct boot_params, hdr);
 	unsigned int efi_map_offset, efi_map_sz, efi_setup_data_offset;
+	struct kexec_buf kbuf = { .image = image, .buf_max = ULONG_MAX,
+				  .top_down = true };
 
 	header = (struct setup_header *)(kernel + setup_hdr_offset);
 	setup_sects = header->setup_sects;
@@ -402,11 +402,11 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 	params_cmdline_sz = sizeof(struct boot_params) + cmdline_len +
 				MAX_ELFCOREHDR_STR_LEN;
 	params_cmdline_sz = ALIGN(params_cmdline_sz, 16);
-	params_misc_sz = params_cmdline_sz + efi_map_sz +
+	kbuf.bufsz = params_cmdline_sz + efi_map_sz +
 				sizeof(struct setup_data) +
 				sizeof(struct efi_setup_data);
 
-	params = kzalloc(params_misc_sz, GFP_KERNEL);
+	params = kzalloc(kbuf.bufsz, GFP_KERNEL);
 	if (!params)
 		return ERR_PTR(-ENOMEM);
 	efi_map_offset = params_cmdline_sz;
@@ -418,37 +418,41 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
 	/* Is there a limit on setup header size? */
 	memcpy(&params->hdr, (kernel + setup_hdr_offset), setup_header_size);
 
-	ret = kexec_add_buffer(image, (char *)params, params_misc_sz,
-			       params_misc_sz, 16, MIN_BOOTPARAM_ADDR,
-			       ULONG_MAX, 1, &bootparam_load_addr);
+	kbuf.buffer = params;
+	kbuf.memsz = kbuf.bufsz;
+	kbuf.buf_align = 16;
+	kbuf.buf_min = MIN_BOOTPARAM_ADDR;
+	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out_free_params;
+	bootparam_load_addr = kbuf.mem;
 	pr_debug("Loaded boot_param, command line and misc at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-		 bootparam_load_addr, params_misc_sz, params_misc_sz);
+		 bootparam_load_addr, kbuf.bufsz, kbuf.bufsz);
 
 	/* Load kernel */
-	kernel_buf = kernel + kern16_size;
-	kernel_bufsz =  kernel_len - kern16_size;
-	kernel_memsz = PAGE_ALIGN(header->init_size);
-	kernel_align = header->kernel_alignment;
-
-	ret = kexec_add_buffer(image, kernel_buf,
-			       kernel_bufsz, kernel_memsz, kernel_align,
-			       MIN_KERNEL_LOAD_ADDR, ULONG_MAX, 1,
-			       &kernel_load_addr);
+	kbuf.buffer = kernel + kern16_size;
+	kbuf.bufsz =  kernel_len - kern16_size;
+	kbuf.memsz = PAGE_ALIGN(header->init_size);
+	kbuf.buf_align = header->kernel_alignment;
+	kbuf.buf_min = MIN_KERNEL_LOAD_ADDR;
+	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out_free_params;
+	kernel_load_addr = kbuf.mem;
 
 	pr_debug("Loaded 64bit kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
-		 kernel_load_addr, kernel_memsz, kernel_memsz);
+		 kernel_load_addr, kbuf.bufsz, kbuf.memsz);
 
 	/* Load initrd high */
 	if (initrd) {
-		ret = kexec_add_buffer(image, initrd, initrd_len, initrd_len,
-				       PAGE_SIZE, MIN_INITRD_LOAD_ADDR,
-				       ULONG_MAX, 1, &initrd_load_addr);
+		kbuf.buffer = initrd;
+		kbuf.bufsz = kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		kbuf.buf_min = MIN_INITRD_LOAD_ADDR;
+		ret = kexec_add_buffer(&kbuf);
 		if (ret)
 			goto out_free_params;
+		initrd_load_addr = kbuf.mem;
 
 		pr_debug("Loaded initrd at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
 				initrd_load_addr, initrd_len, initrd_len);
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 5ffd0011395c..28bc9f335d0d 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -163,7 +163,7 @@ struct kexec_file_ops {
  */
 struct kexec_buf {
 	struct kimage *image;
-	char *buffer;
+	void *buffer;
 	unsigned long bufsz;
 	unsigned long mem;
 	unsigned long memsz;
@@ -175,6 +175,7 @@ struct kexec_buf {
 
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			       int (*func)(u64, u64, void *));
+extern int kexec_add_buffer(struct kexec_buf *kbuf);
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
 				    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
@@ -244,11 +245,6 @@ extern asmlinkage long sys_kexec_load(unsigned long entry,
 					struct kexec_segment __user *segments,
 					unsigned long flags);
 extern int kernel_kexec(void);
-extern int kexec_add_buffer(struct kimage *image, char *buffer,
-			    unsigned long bufsz, unsigned long memsz,
-			    unsigned long buf_align, unsigned long buf_min,
-			    unsigned long buf_max, bool top_down,
-			    unsigned long *load_addr);
 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 						unsigned int order);
 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index e63fd4592e20..58818264ad0e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -523,25 +523,27 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
 }
 
-/*
- * Helper function for placing a buffer in a kexec segment. This assumes
- * that kexec_mutex is held.
+/**
+ * kexec_add_buffer - place a buffer in a kexec segment
+ * @kbuf:	Buffer contents and memory parameters.
+ *
+ * This function assumes that kexec_mutex is held.
+ * On successful return, @kbuf->mem will have the physical address of
+ * the buffer in memory.
+ *
+ * Return: 0 on success, negative errno on error.
  */
-int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
-		     unsigned long memsz, unsigned long buf_align,
-		     unsigned long buf_min, unsigned long buf_max,
-		     bool top_down, unsigned long *load_addr)
+int kexec_add_buffer(struct kexec_buf *kbuf)
 {
 
 	struct kexec_segment *ksegment;
-	struct kexec_buf buf, *kbuf;
 	int ret;
 
 	/* Currently adding segment this way is allowed only in file mode */
-	if (!image->file_mode)
+	if (!kbuf->image->file_mode)
 		return -EINVAL;
 
-	if (image->nr_segments >= KEXEC_SEGMENT_MAX)
+	if (kbuf->image->nr_segments >= KEXEC_SEGMENT_MAX)
 		return -EINVAL;
 
 	/*
@@ -551,22 +553,14 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	 * logic goes through list of segments to make sure there are
 	 * no destination overlaps.
 	 */
-	if (!list_empty(&image->control_pages)) {
+	if (!list_empty(&kbuf->image->control_pages)) {
 		WARN_ON(1);
 		return -EINVAL;
 	}
 
-	memset(&buf, 0, sizeof(struct kexec_buf));
-	kbuf = &buf;
-	kbuf->image = image;
-	kbuf->buffer = buffer;
-	kbuf->bufsz = bufsz;
-
-	kbuf->memsz = ALIGN(memsz, PAGE_SIZE);
-	kbuf->buf_align = max(buf_align, PAGE_SIZE);
-	kbuf->buf_min = buf_min;
-	kbuf->buf_max = buf_max;
-	kbuf->top_down = top_down;
+	/* Ensure minimum alignment needed for segments. */
+	kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
+	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
 	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
@@ -576,13 +570,12 @@ int kexec_add_buffer(struct kimage *image, char *buffer, unsigned long bufsz,
 	}
 
 	/* Found a suitable memory range */
-	ksegment = &image->segment[image->nr_segments];
+	ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
 	ksegment->kbuf = kbuf->buffer;
 	ksegment->bufsz = kbuf->bufsz;
 	ksegment->mem = kbuf->mem;
 	ksegment->memsz = kbuf->memsz;
-	image->nr_segments++;
-	*load_addr = ksegment->mem;
+	kbuf->image->nr_segments++;
 	return 0;
 }
 
@@ -704,13 +697,15 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 				  unsigned long max, int top_down)
 {
 	struct purgatory_info *pi = &image->purgatory_info;
-	unsigned long align, buf_align, bss_align, buf_sz, bss_sz, bss_pad;
-	unsigned long memsz, entry, load_addr, curr_load_addr, bss_addr, offset;
+	unsigned long align, bss_align, bss_sz, bss_pad;
+	unsigned long entry, load_addr, curr_load_addr, bss_addr, offset;
 	unsigned char *buf_addr, *src;
 	int i, ret = 0, entry_sidx = -1;
 	const Elf_Shdr *sechdrs_c;
 	Elf_Shdr *sechdrs = NULL;
-	void *purgatory_buf = NULL;
+	struct kexec_buf kbuf = { .image = image, .bufsz = 0, .buf_align = 1,
+				  .buf_min = min, .buf_max = max,
+				  .top_down = top_down };
 
 	/*
 	 * sechdrs_c points to section headers in purgatory and are read
@@ -776,9 +771,7 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 	}
 
 	/* Determine how much memory is needed to load relocatable object. */
-	buf_align = 1;
 	bss_align = 1;
-	buf_sz = 0;
 	bss_sz = 0;
 
 	for (i = 0; i < pi->ehdr->e_shnum; i++) {
@@ -787,10 +780,10 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 
 		align = sechdrs[i].sh_addralign;
 		if (sechdrs[i].sh_type != SHT_NOBITS) {
-			if (buf_align < align)
-				buf_align = align;
-			buf_sz = ALIGN(buf_sz, align);
-			buf_sz += sechdrs[i].sh_size;
+			if (kbuf.buf_align < align)
+				kbuf.buf_align = align;
+			kbuf.bufsz = ALIGN(kbuf.bufsz, align);
+			kbuf.bufsz += sechdrs[i].sh_size;
 		} else {
 			/* bss section */
 			if (bss_align < align)
@@ -802,32 +795,31 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 
 	/* Determine the bss padding required to align bss properly */
 	bss_pad = 0;
-	if (buf_sz & (bss_align - 1))
-		bss_pad = bss_align - (buf_sz & (bss_align - 1));
+	if (kbuf.bufsz & (bss_align - 1))
+		bss_pad = bss_align - (kbuf.bufsz & (bss_align - 1));
 
-	memsz = buf_sz + bss_pad + bss_sz;
+	kbuf.memsz = kbuf.bufsz + bss_pad + bss_sz;
 
 	/* Allocate buffer for purgatory */
-	purgatory_buf = vzalloc(buf_sz);
-	if (!purgatory_buf) {
+	kbuf.buffer = vzalloc(kbuf.bufsz);
+	if (!kbuf.buffer) {
 		ret = -ENOMEM;
 		goto out;
 	}
 
-	if (buf_align < bss_align)
-		buf_align = bss_align;
+	if (kbuf.buf_align < bss_align)
+		kbuf.buf_align = bss_align;
 
 	/* Add buffer to segment list */
-	ret = kexec_add_buffer(image, purgatory_buf, buf_sz, memsz,
-				buf_align, min, max, top_down,
-				&pi->purgatory_load_addr);
+	ret = kexec_add_buffer(&kbuf);
 	if (ret)
 		goto out;
+	pi->purgatory_load_addr = kbuf.mem;
 
 	/* Load SHF_ALLOC sections */
-	buf_addr = purgatory_buf;
+	buf_addr = kbuf.buffer;
 	load_addr = curr_load_addr = pi->purgatory_load_addr;
-	bss_addr = load_addr + buf_sz + bss_pad;
+	bss_addr = load_addr + kbuf.bufsz + bss_pad;
 
 	for (i = 0; i < pi->ehdr->e_shnum; i++) {
 		if (!(sechdrs[i].sh_flags & SHF_ALLOC))
@@ -873,11 +865,11 @@ static int __kexec_load_purgatory(struct kimage *image, unsigned long min,
 	 * Used later to identify which section is purgatory and skip it
 	 * from checksumming.
 	 */
-	pi->purgatory_buf = purgatory_buf;
+	pi->purgatory_buf = kbuf.buffer;
 	return ret;
 out:
 	vfree(sechdrs);
-	vfree(purgatory_buf);
+	vfree(kbuf.buffer);
 	return ret;
 }
 
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 03/13] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.

[Thiago Jung Bauermann]

kexec_locate_mem_hole will be used by the PowerPC kexec_file_load
implementation to find free memory for the purgatory stack.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
---
 include/linux/kexec.h |  1 +
 kernel/kexec_file.c   | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 28bc9f335d0d..ceccc5856aab 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -176,6 +176,7 @@ struct kexec_buf {
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			       int (*func)(u64, u64, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
+int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
 				    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 58818264ad0e..772cb491715e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -524,6 +524,23 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 }
 
 /**
+ * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
+ * @kbuf:	Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+	int ret;
+
+	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
+
+	return ret == 1 ? 0 : -EADDRNOTAVAIL;
+}
+
+/**
  * kexec_add_buffer - place a buffer in a kexec segment
  * @kbuf:	Buffer contents and memory parameters.
  *
@@ -563,11 +580,9 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
 	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
-	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
-	if (ret != 1) {
-		/* A suitable memory range could not be found for buffer */
-		return -EADDRNOTAVAIL;
-	}
+	ret = kexec_locate_mem_hole(kbuf);
+	if (ret)
+		return ret;
 
 	/* Found a suitable memory range */
 	ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
-- 
1.9.1

[PATCH v5 03/13] kexec_file: Factor out kexec_locate_mem_hole from kexec_add_buffer.

[Thiago Jung Bauermann]

kexec_locate_mem_hole will be used by the PowerPC kexec_file_load
implementation to find free memory for the purgatory stack.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
---
 include/linux/kexec.h |  1 +
 kernel/kexec_file.c   | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 28bc9f335d0d..ceccc5856aab 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -176,6 +176,7 @@ struct kexec_buf {
 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 			       int (*func)(u64, u64, void *));
 extern int kexec_add_buffer(struct kexec_buf *kbuf);
+int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 int __weak arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
 				    unsigned long size);
 #endif /* CONFIG_KEXEC_FILE */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 58818264ad0e..772cb491715e 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -524,6 +524,23 @@ int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 }
 
 /**
+ * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
+ * @kbuf:	Parameters for the memory search.
+ *
+ * On success, kbuf->mem will have the start address of the memory region found.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int kexec_locate_mem_hole(struct kexec_buf *kbuf)
+{
+	int ret;
+
+	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
+
+	return ret == 1 ? 0 : -EADDRNOTAVAIL;
+}
+
+/**
  * kexec_add_buffer - place a buffer in a kexec segment
  * @kbuf:	Buffer contents and memory parameters.
  *
@@ -563,11 +580,9 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
 	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
-	ret = arch_kexec_walk_mem(kbuf, locate_mem_hole_callback);
-	if (ret != 1) {
-		/* A suitable memory range could not be found for buffer */
-		return -EADDRNOTAVAIL;
-	}
+	ret = kexec_locate_mem_hole(kbuf);
+	if (ret)
+		return ret;
 
 	/* Found a suitable memory range */
 	ksegment = &kbuf->image->segment[kbuf->image->nr_segments];
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

The kexec_file_load system call needs to relocate the purgatory, so
factor out the module relocation code so that it can be shared.

This patch's purpose is to move the ELF relocation logic from
apply_relocate_add to elf_util_64.c with as few changes as
possible. The following changes were needed:

To avoid having module-specific code in a general purpose utility
function, struct elf_info was created to contain the information
needed for ELF binaries manipulation.

my_r2, stub_for_addr and create_stub were changed to use it instead of
having to receive a struct module, since they are called from
elf64_apply_relocate_add.

local_entry_offset and squash_toc_save_inst were only used by
apply_rellocate_add, so they were moved to elf_util_64.c as well.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  70 ++++++++
 arch/powerpc/include/asm/module.h   |  14 +-
 arch/powerpc/kernel/Makefile        |   4 +
 arch/powerpc/kernel/elf_util_64.c   | 269 +++++++++++++++++++++++++++++++
 arch/powerpc/kernel/module_64.c     | 312 ++++--------------------------------
 5 files changed, 386 insertions(+), 283 deletions(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
new file mode 100644
index 000000000000..37372559fe62
--- /dev/null
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -0,0 +1,70 @@
+/*
+ * Utility functions to work with ELF files.
+ *
+ * Copyright (C) 2016, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _ASM_POWERPC_ELF_UTIL_H
+#define _ASM_POWERPC_ELF_UTIL_H
+
+#include <linux/elf.h>
+
+struct elf_info {
+	struct elf_shdr *sechdrs;
+
+	/* Index of stubs section. */
+	unsigned int stubs_section;
+	/* Index of TOC section. */
+	unsigned int toc_section;
+};
+
+#ifdef __powerpc64__
+#ifdef PPC64_ELF_ABI_v2
+
+/* An address is simply the address of the function. */
+typedef unsigned long func_desc_t;
+#else
+
+/* An address is address of the OPD entry, which contains address of fn. */
+typedef struct ppc64_opd_entry func_desc_t;
+#endif /* PPC64_ELF_ABI_v2 */
+
+/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
+   the kernel itself).  But on PPC64, these need to be used for every
+   jump, actually, to reset r2 (TOC+0x8000). */
+struct ppc64_stub_entry
+{
+	/* 28 byte jump instruction sequence (7 instructions). We only
+	 * need 6 instructions on ABIv2 but we always allocate 7 so
+	 * so we don't have to modify the trampoline load instruction. */
+	u32 jump[7];
+	/* Used by ftrace to identify stubs */
+	u32 magic;
+	/* Data for the above code */
+	func_desc_t funcdata;
+};
+#endif
+
+/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
+   gives the value maximum span in an instruction which uses a signed
+   offset) */
+static inline unsigned long my_r2(const struct elf_info *elf_info)
+{
+	return elf_info->sechdrs[elf_info->toc_section].sh_addr + 0x8000;
+}
+
+int elf64_apply_relocate_add(const struct elf_info *elf_info,
+			     const char *strtab, unsigned int symindex,
+			     unsigned int relsec, const char *obj_name);
+
+#endif /* _ASM_POWERPC_ELF_UTIL_H */
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index cd4ffd86765f..f2073115d518 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -12,7 +12,14 @@
 #include <linux/list.h>
 #include <asm/bug.h>
 #include <asm-generic/module.h>
+#include <asm/elf_util.h>
 
+/* Both low and high 16 bits are added as SIGNED additions, so if low
+   16 bits has high bit set, high 16 bits must be adjusted.  These
+   macros do that (stolen from binutils). */
+#define PPC_LO(v) ((v) & 0xffff)
+#define PPC_HI(v) (((v) >> 16) & 0xffff)
+#define PPC_HA(v) PPC_HI ((v) + 0x8000)
 
 #ifndef __powerpc64__
 /*
@@ -33,8 +40,7 @@ struct ppc_plt_entry {
 
 struct mod_arch_specific {
 #ifdef __powerpc64__
-	unsigned int stubs_section;	/* Index of stubs section in module */
-	unsigned int toc_section;	/* What section is the TOC? */
+	struct elf_info elf_info;
 	bool toc_fixed;			/* Have we fixed up .TOC.? */
 #ifdef CONFIG_DYNAMIC_FTRACE
 	unsigned long toc;
@@ -90,6 +96,10 @@ static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sec
 }
 #endif
 
+unsigned long stub_for_addr(const struct elf_info *elf_info, unsigned long addr,
+			    const char *obj_name);
+int restore_r2(u32 *instruction, const char *obj_name);
+
 struct exception_table_entry;
 void sort_ex_table(struct exception_table_entry *start,
 		   struct exception_table_entry *finish);
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index b2027a5cf508..e38aace0a6e7 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -123,6 +123,10 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y				+= iomap.o
 endif
 
+ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
+obj-y				+= elf_util_64.o
+endif
+
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
 
 obj-$(CONFIG_PPC64)		+= $(obj64-y)
diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
new file mode 100644
index 000000000000..decad2c34f38
--- /dev/null
+++ b/arch/powerpc/kernel/elf_util_64.c
@@ -0,0 +1,269 @@
+/*
+ * Utility functions to work with ELF files.
+ *
+ * Copyright (C) 2016, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/ppc-opcode.h>
+#include <asm/elf_util.h>
+
+/*
+ * We just need to use the functions defined in <asm/module.h>, so just declare
+ * struct module here and avoid having to import <linux/module.h>.
+ */
+struct module;
+#include <asm/module.h>
+
+#ifdef PPC64_ELF_ABI_v2
+/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
+#define STO_PPC64_LOCAL_BIT	5
+#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
+#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
+ (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
+
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+	/* sym->st_other indicates offset to local entry point
+	 * (otherwise it will assume r12 is the address of the start
+	 * of function and try to derive r2 from it). */
+	return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
+}
+#else
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+	return 0;
+}
+#endif
+
+#ifdef CC_USING_MPROFILE_KERNEL
+/*
+ * In case of _mcount calls, do not save the current callee's TOC (in r2) into
+ * the original caller's stack frame. If we did we would clobber the saved TOC
+ * value of the original caller.
+ */
+static void squash_toc_save_inst(const char *name, unsigned long addr)
+{
+	struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
+
+	/* Only for calls to _mcount */
+	if (strcmp("_mcount", name) != 0)
+		return;
+
+	stub->jump[2] = PPC_INST_NOP;
+}
+#else
+static void squash_toc_save_inst(const char *name, unsigned long addr) { }
+#endif
+
+/**
+ * elf64_apply_relocate_add - apply 64 bit RELA relocations
+ * @elf_info:		Support information for the ELF binary being relocated.
+ * @strtab:		String table for the associated symbol table.
+ * @symindex:		Section header index for the associated symbol table.
+ * @relsec:		Section header index for the relocations to apply.
+ * @obj_name:		The name of the ELF binary, for information messages.
+ */
+int elf64_apply_relocate_add(const struct elf_info *elf_info,
+			     const char *strtab, unsigned int symindex,
+			     unsigned int relsec, const char *obj_name)
+{
+	unsigned int i;
+	Elf64_Shdr *sechdrs = elf_info->sechdrs;
+	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
+	Elf64_Sym *sym;
+	unsigned long *location;
+	unsigned long value;
+
+
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
+		/* This is where to make the change */
+		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+			+ rela[i].r_offset;
+		/* This is the symbol it is referring to */
+		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+			+ ELF64_R_SYM(rela[i].r_info);
+
+		pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
+		       location, (long)ELF64_R_TYPE(rela[i].r_info),
+		       strtab + sym->st_name, (unsigned long)sym->st_value,
+		       (long)rela[i].r_addend);
+
+		/* `Everything is relative'. */
+		value = sym->st_value + rela[i].r_addend;
+
+		switch (ELF64_R_TYPE(rela[i].r_info)) {
+		case R_PPC64_ADDR32:
+			/* Simply set it */
+			*(u32 *)location = value;
+			break;
+
+		case R_PPC64_ADDR64:
+			/* Simply set it */
+			*(unsigned long *)location = value;
+			break;
+
+		case R_PPC64_TOC:
+			*(unsigned long *)location = my_r2(elf_info);
+			break;
+
+		case R_PPC64_TOC16:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			if (value + 0x8000 > 0xffff) {
+				pr_err("%s: bad TOC16 relocation (0x%lx)\n",
+				       obj_name, value);
+				return -ENOEXEC;
+			}
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC64_TOC16_LO:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC64_TOC16_DS:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			if ((value & 3) != 0 || value + 0x8000 > 0xffff) {
+				pr_err("%s: bad TOC16_DS relocation (0x%lx)\n",
+				       obj_name, value);
+				return -ENOEXEC;
+			}
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xfffc)
+				| (value & 0xfffc);
+			break;
+
+		case R_PPC64_TOC16_LO_DS:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			if ((value & 3) != 0) {
+				pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n",
+				       obj_name, value);
+				return -ENOEXEC;
+			}
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xfffc)
+				| (value & 0xfffc);
+			break;
+
+		case R_PPC64_TOC16_HA:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			value = ((value + 0x8000) >> 16);
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC_REL24:
+			/* FIXME: Handle weak symbols here --RR */
+			if (sym->st_shndx == SHN_UNDEF) {
+				/* External: go via stub */
+				value = stub_for_addr(elf_info, value, obj_name);
+				if (!value)
+					return -ENOENT;
+				if (!restore_r2((u32 *)location + 1, obj_name))
+					return -ENOEXEC;
+
+				squash_toc_save_inst(strtab + sym->st_name, value);
+			} else
+				value += local_entry_offset(sym);
+
+			/* Convert value to relative */
+			value -= (unsigned long)location;
+			if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
+				pr_err("%s: REL24 %li out of range!\n",
+				       obj_name, (long int)value);
+				return -ENOEXEC;
+			}
+
+			/* Only replace bits 2 through 26 */
+			*(uint32_t *)location
+				= (*(uint32_t *)location & ~0x03fffffc)
+				| (value & 0x03fffffc);
+			break;
+
+		case R_PPC64_REL64:
+			/* 64 bits relative (used by features fixups) */
+			*location = value - (unsigned long)location;
+			break;
+
+		case R_PPC64_TOCSAVE:
+			/*
+			 * Marker reloc indicates we don't have to save r2.
+			 * That would only save us one instruction, so ignore
+			 * it.
+			 */
+			break;
+
+		case R_PPC64_ENTRY:
+			/*
+			 * Optimize ELFv2 large code model entry point if
+			 * the TOC is within 2GB range of current location.
+			 */
+			value = my_r2(elf_info) - (unsigned long)location;
+			if (value + 0x80008000 > 0xffffffff)
+				break;
+			/*
+			 * Check for the large code model prolog sequence:
+			 *	ld r2, ...(r12)
+			 *	add r2, r2, r12
+			 */
+			if ((((uint32_t *)location)[0] & ~0xfffc)
+			    != 0xe84c0000)
+				break;
+			if (((uint32_t *)location)[1] != 0x7c426214)
+				break;
+			/*
+			 * If found, replace it with:
+			 *	addis r2, r12, (.TOC.-func)@ha
+			 *	addi r2, r12, (.TOC.-func)@l
+			 */
+			((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
+			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
+			break;
+
+		case R_PPC64_REL16_HA:
+			/* Subtract location pointer */
+			value -= (unsigned long)location;
+			value = ((value + 0x8000) >> 16);
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC64_REL16_LO:
+			/* Subtract location pointer */
+			value -= (unsigned long)location;
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		default:
+			pr_err("%s: Unknown ADD relocation: %lu\n",
+			       obj_name,
+			       (unsigned long)ELF64_R_TYPE(rela[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+
+	return 0;
+}
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 183368e008cf..b929560ecd5b 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -19,7 +19,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/module.h>
-#include <linux/elf.h>
+#include <asm/elf_util.h>
 #include <linux/moduleloader.h>
 #include <linux/err.h>
 #include <linux/vmalloc.h>
@@ -43,9 +43,6 @@
 
 #ifdef PPC64_ELF_ABI_v2
 
-/* An address is simply the address of the function. */
-typedef unsigned long func_desc_t;
-
 static func_desc_t func_desc(unsigned long addr)
 {
 	return addr;
@@ -58,25 +55,8 @@ static unsigned long stub_func_addr(func_desc_t func)
 {
 	return func;
 }
-
-/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
-#define STO_PPC64_LOCAL_BIT	5
-#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
-#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
- (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
-
-static unsigned int local_entry_offset(const Elf64_Sym *sym)
-{
-	/* sym->st_other indicates offset to local entry point
-	 * (otherwise it will assume r12 is the address of the start
-	 * of function and try to derive r2 from it). */
-	return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
-}
 #else
 
-/* An address is address of the OPD entry, which contains address of fn. */
-typedef struct ppc64_opd_entry func_desc_t;
-
 static func_desc_t func_desc(unsigned long addr)
 {
 	return *(struct ppc64_opd_entry *)addr;
@@ -89,29 +69,10 @@ static unsigned long stub_func_addr(func_desc_t func)
 {
 	return func.funcaddr;
 }
-static unsigned int local_entry_offset(const Elf64_Sym *sym)
-{
-	return 0;
-}
 #endif
 
 #define STUB_MAGIC 0x73747562 /* stub */
 
-/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
-   the kernel itself).  But on PPC64, these need to be used for every
-   jump, actually, to reset r2 (TOC+0x8000). */
-struct ppc64_stub_entry
-{
-	/* 28 byte jump instruction sequence (7 instructions). We only
-	 * need 6 instructions on ABIv2 but we always allocate 7 so
-	 * so we don't have to modify the trampoline load instruction. */
-	u32 jump[7];
-	/* Used by ftrace to identify stubs */
-	u32 magic;
-	/* Data for the above code */
-	func_desc_t funcdata;
-};
-
 /*
  * PPC64 uses 24 bit jumps, but we need to jump into other modules or
  * the kernel which may be further.  So we jump to a stub.
@@ -346,9 +307,9 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
 	for (i = 1; i < hdr->e_shnum; i++) {
 		char *p;
 		if (strcmp(secstrings + sechdrs[i].sh_name, ".stubs") == 0)
-			me->arch.stubs_section = i;
+			me->arch.elf_info.stubs_section = i;
 		else if (strcmp(secstrings + sechdrs[i].sh_name, ".toc") == 0)
-			me->arch.toc_section = i;
+			me->arch.elf_info.toc_section = i;
 		else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
 			dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
 					  sechdrs[i].sh_size);
@@ -364,7 +325,7 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
 				 + sechdrs[sechdrs[i].sh_link].sh_offset);
 	}
 
-	if (!me->arch.stubs_section) {
+	if (!me->arch.elf_info.stubs_section) {
 		pr_err("%s: doesn't contain .stubs.\n", me->name);
 		return -ENOEXEC;
 	}
@@ -373,44 +334,32 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
 	   to some reasonable value in case the module calls out to
 	   other functions via a stub, or if a function pointer escapes
 	   the module by some means.  */
-	if (!me->arch.toc_section)
-		me->arch.toc_section = me->arch.stubs_section;
+	if (!me->arch.elf_info.toc_section)
+		me->arch.elf_info.toc_section = me->arch.elf_info.stubs_section;
 
 	/* Override the stubs size */
-	sechdrs[me->arch.stubs_section].sh_size = get_stubs_size(hdr, sechdrs);
-	return 0;
-}
+	sechdrs[me->arch.elf_info.stubs_section].sh_size = get_stubs_size(hdr, sechdrs);
 
-/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
-   gives the value maximum span in an instruction which uses a signed
-   offset) */
-static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me)
-{
-	return sechdrs[me->arch.toc_section].sh_addr + 0x8000;
-}
+	/* For the elf_util functions. */
+	me->arch.elf_info.sechdrs = sechdrs;
 
-/* Both low and high 16 bits are added as SIGNED additions, so if low
-   16 bits has high bit set, high 16 bits must be adjusted.  These
-   macros do that (stolen from binutils). */
-#define PPC_LO(v) ((v) & 0xffff)
-#define PPC_HI(v) (((v) >> 16) & 0xffff)
-#define PPC_HA(v) PPC_HI ((v) + 0x8000)
+	return 0;
+}
 
 /* Patch stub to reference function and correct r2 value. */
-static inline int create_stub(const Elf64_Shdr *sechdrs,
+static inline int create_stub(const struct elf_info *elf_info,
 			      struct ppc64_stub_entry *entry,
-			      unsigned long addr,
-			      struct module *me)
+			      unsigned long addr, const char *obj_name)
 {
 	long reladdr;
 
 	memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns));
 
 	/* Stub uses address relative to r2. */
-	reladdr = (unsigned long)entry - my_r2(sechdrs, me);
+	reladdr = (unsigned long)entry - my_r2(elf_info);
 	if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
 		pr_err("%s: Address %p of stub out of range of %p.\n",
-		       me->name, (void *)reladdr, (void *)my_r2);
+		       obj_name, (void *)reladdr, (void *)my_r2);
 		return 0;
 	}
 	pr_debug("Stub %p get data from reladdr %li\n", entry, reladdr);
@@ -425,17 +374,17 @@ static inline int create_stub(const Elf64_Shdr *sechdrs,
 
 /* Create stub to jump to function described in this OPD/ptr: we need the
    stub to set up the TOC ptr (r2) for the function. */
-static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
-				   unsigned long addr,
-				   struct module *me)
+unsigned long stub_for_addr(const struct elf_info *elf_info, unsigned long addr,
+			    const char *obj_name)
 {
+	struct elf_shdr *stubs_sec = &elf_info->sechdrs[elf_info->stubs_section];
 	struct ppc64_stub_entry *stubs;
 	unsigned int i, num_stubs;
 
-	num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs);
+	num_stubs = stubs_sec->sh_size / sizeof(*stubs);
 
 	/* Find this stub, or if that fails, the next avail. entry */
-	stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr;
+	stubs = (void *) stubs_sec->sh_addr;
 	for (i = 0; stub_func_addr(stubs[i].funcdata); i++) {
 		BUG_ON(i >= num_stubs);
 
@@ -443,7 +392,7 @@ static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
 			return (unsigned long)&stubs[i];
 	}
 
-	if (!create_stub(sechdrs, &stubs[i], addr, me))
+	if (!create_stub(elf_info, &stubs[i], addr, obj_name))
 		return 0;
 
 	return (unsigned long)&stubs[i];
@@ -465,24 +414,7 @@ static bool is_early_mcount_callsite(u32 *instruction)
 	return false;
 }
 
-/*
- * In case of _mcount calls, do not save the current callee's TOC (in r2) into
- * the original caller's stack frame. If we did we would clobber the saved TOC
- * value of the original caller.
- */
-static void squash_toc_save_inst(const char *name, unsigned long addr)
-{
-	struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
-
-	/* Only for calls to _mcount */
-	if (strcmp("_mcount", name) != 0)
-		return;
-
-	stub->jump[2] = PPC_INST_NOP;
-}
 #else
-static void squash_toc_save_inst(const char *name, unsigned long addr) { }
-
 /* without -mprofile-kernel, mcount calls are never early */
 static bool is_early_mcount_callsite(u32 *instruction)
 {
@@ -492,14 +424,14 @@ static bool is_early_mcount_callsite(u32 *instruction)
 
 /* We expect a noop next: if it is, replace it with instruction to
    restore r2. */
-static int restore_r2(u32 *instruction, struct module *me)
+int restore_r2(u32 *instruction, const char *obj_name)
 {
 	if (is_early_mcount_callsite(instruction - 1))
 		return 1;
 
 	if (*instruction != PPC_INST_NOP) {
 		pr_err("%s: Expect noop after relocate, got %08x\n",
-		       me->name, *instruction);
+		       obj_name, *instruction);
 		return 0;
 	}
 	/* ld r2,R2_STACK_OFFSET(r1) */
@@ -513,11 +445,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 		       unsigned int relsec,
 		       struct module *me)
 {
-	unsigned int i;
-	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
 	Elf64_Sym *sym;
-	unsigned long *location;
-	unsigned long value;
 
 	pr_debug("Applying ADD relocate section %u to %u\n", relsec,
 	       sechdrs[relsec].sh_info);
@@ -528,191 +456,12 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 		/* It's theoretically possible that a module doesn't want a
 		 * .TOC. so don't fail it just for that. */
 		if (sym)
-			sym->st_value = my_r2(sechdrs, me);
+			sym->st_value = my_r2(&me->arch.elf_info);
 		me->arch.toc_fixed = true;
 	}
 
-	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
-		/* This is where to make the change */
-		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
-			+ rela[i].r_offset;
-		/* This is the symbol it is referring to */
-		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
-			+ ELF64_R_SYM(rela[i].r_info);
-
-		pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
-		       location, (long)ELF64_R_TYPE(rela[i].r_info),
-		       strtab + sym->st_name, (unsigned long)sym->st_value,
-		       (long)rela[i].r_addend);
-
-		/* `Everything is relative'. */
-		value = sym->st_value + rela[i].r_addend;
-
-		switch (ELF64_R_TYPE(rela[i].r_info)) {
-		case R_PPC64_ADDR32:
-			/* Simply set it */
-			*(u32 *)location = value;
-			break;
-
-		case R_PPC64_ADDR64:
-			/* Simply set it */
-			*(unsigned long *)location = value;
-			break;
-
-		case R_PPC64_TOC:
-			*(unsigned long *)location = my_r2(sechdrs, me);
-			break;
-
-		case R_PPC64_TOC16:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			if (value + 0x8000 > 0xffff) {
-				pr_err("%s: bad TOC16 relocation (0x%lx)\n",
-				       me->name, value);
-				return -ENOEXEC;
-			}
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC64_TOC16_LO:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC64_TOC16_DS:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			if ((value & 3) != 0 || value + 0x8000 > 0xffff) {
-				pr_err("%s: bad TOC16_DS relocation (0x%lx)\n",
-				       me->name, value);
-				return -ENOEXEC;
-			}
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xfffc)
-				| (value & 0xfffc);
-			break;
-
-		case R_PPC64_TOC16_LO_DS:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			if ((value & 3) != 0) {
-				pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n",
-				       me->name, value);
-				return -ENOEXEC;
-			}
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xfffc)
-				| (value & 0xfffc);
-			break;
-
-		case R_PPC64_TOC16_HA:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			value = ((value + 0x8000) >> 16);
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC_REL24:
-			/* FIXME: Handle weak symbols here --RR */
-			if (sym->st_shndx == SHN_UNDEF) {
-				/* External: go via stub */
-				value = stub_for_addr(sechdrs, value, me);
-				if (!value)
-					return -ENOENT;
-				if (!restore_r2((u32 *)location + 1, me))
-					return -ENOEXEC;
-
-				squash_toc_save_inst(strtab + sym->st_name, value);
-			} else
-				value += local_entry_offset(sym);
-
-			/* Convert value to relative */
-			value -= (unsigned long)location;
-			if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
-				pr_err("%s: REL24 %li out of range!\n",
-				       me->name, (long int)value);
-				return -ENOEXEC;
-			}
-
-			/* Only replace bits 2 through 26 */
-			*(uint32_t *)location
-				= (*(uint32_t *)location & ~0x03fffffc)
-				| (value & 0x03fffffc);
-			break;
-
-		case R_PPC64_REL64:
-			/* 64 bits relative (used by features fixups) */
-			*location = value - (unsigned long)location;
-			break;
-
-		case R_PPC64_TOCSAVE:
-			/*
-			 * Marker reloc indicates we don't have to save r2.
-			 * That would only save us one instruction, so ignore
-			 * it.
-			 */
-			break;
-
-		case R_PPC64_ENTRY:
-			/*
-			 * Optimize ELFv2 large code model entry point if
-			 * the TOC is within 2GB range of current location.
-			 */
-			value = my_r2(sechdrs, me) - (unsigned long)location;
-			if (value + 0x80008000 > 0xffffffff)
-				break;
-			/*
-			 * Check for the large code model prolog sequence:
-		         *	ld r2, ...(r12)
-			 *	add r2, r2, r12
-			 */
-			if ((((uint32_t *)location)[0] & ~0xfffc)
-			    != 0xe84c0000)
-				break;
-			if (((uint32_t *)location)[1] != 0x7c426214)
-				break;
-			/*
-			 * If found, replace it with:
-			 *	addis r2, r12, (.TOC.-func)@ha
-			 *	addi r2, r12, (.TOC.-func)@l
-			 */
-			((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
-			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
-			break;
-
-		case R_PPC64_REL16_HA:
-			/* Subtract location pointer */
-			value -= (unsigned long)location;
-			value = ((value + 0x8000) >> 16);
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC64_REL16_LO:
-			/* Subtract location pointer */
-			value -= (unsigned long)location;
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		default:
-			pr_err("%s: Unknown ADD relocation: %lu\n",
-			       me->name,
-			       (unsigned long)ELF64_R_TYPE(rela[i].r_info));
-			return -ENOEXEC;
-		}
-	}
-
-	return 0;
+	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, symindex,
+					relsec, me->name);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -746,10 +495,10 @@ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module
 	};
 	long reladdr;
 
-	num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry);
+	num_stubs = sechdrs[me->arch.elf_info.stubs_section].sh_size / sizeof(*entry);
 
 	/* Find the next available stub entry */
-	entry = (void *)sechdrs[me->arch.stubs_section].sh_addr;
+	entry = (void *)sechdrs[me->arch.elf_info.stubs_section].sh_addr;
 	for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++);
 
 	if (i >= num_stubs) {
@@ -778,13 +527,14 @@ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module
 #else
 static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me)
 {
-	return stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me);
+	return stub_for_addr(&me->arch.elf_info, (unsigned long)ftrace_caller,
+			     me->name);
 }
 #endif
 
 int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
 {
-	mod->arch.toc = my_r2(sechdrs, mod);
+	mod->arch.toc = my_r2(&mod->arch.elf_info);
 	mod->arch.tramp = create_ftrace_stub(sechdrs, mod);
 
 	if (!mod->arch.tramp)
-- 
1.9.1

[PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

The kexec_file_load system call needs to relocate the purgatory, so
factor out the module relocation code so that it can be shared.

This patch's purpose is to move the ELF relocation logic from
apply_relocate_add to elf_util_64.c with as few changes as
possible. The following changes were needed:

To avoid having module-specific code in a general purpose utility
function, struct elf_info was created to contain the information
needed for ELF binaries manipulation.

my_r2, stub_for_addr and create_stub were changed to use it instead of
having to receive a struct module, since they are called from
elf64_apply_relocate_add.

local_entry_offset and squash_toc_save_inst were only used by
apply_rellocate_add, so they were moved to elf_util_64.c as well.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  70 ++++++++
 arch/powerpc/include/asm/module.h   |  14 +-
 arch/powerpc/kernel/Makefile        |   4 +
 arch/powerpc/kernel/elf_util_64.c   | 269 +++++++++++++++++++++++++++++++
 arch/powerpc/kernel/module_64.c     | 312 ++++--------------------------------
 5 files changed, 386 insertions(+), 283 deletions(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
new file mode 100644
index 000000000000..37372559fe62
--- /dev/null
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -0,0 +1,70 @@
+/*
+ * Utility functions to work with ELF files.
+ *
+ * Copyright (C) 2016, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _ASM_POWERPC_ELF_UTIL_H
+#define _ASM_POWERPC_ELF_UTIL_H
+
+#include <linux/elf.h>
+
+struct elf_info {
+	struct elf_shdr *sechdrs;
+
+	/* Index of stubs section. */
+	unsigned int stubs_section;
+	/* Index of TOC section. */
+	unsigned int toc_section;
+};
+
+#ifdef __powerpc64__
+#ifdef PPC64_ELF_ABI_v2
+
+/* An address is simply the address of the function. */
+typedef unsigned long func_desc_t;
+#else
+
+/* An address is address of the OPD entry, which contains address of fn. */
+typedef struct ppc64_opd_entry func_desc_t;
+#endif /* PPC64_ELF_ABI_v2 */
+
+/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
+   the kernel itself).  But on PPC64, these need to be used for every
+   jump, actually, to reset r2 (TOC+0x8000). */
+struct ppc64_stub_entry
+{
+	/* 28 byte jump instruction sequence (7 instructions). We only
+	 * need 6 instructions on ABIv2 but we always allocate 7 so
+	 * so we don't have to modify the trampoline load instruction. */
+	u32 jump[7];
+	/* Used by ftrace to identify stubs */
+	u32 magic;
+	/* Data for the above code */
+	func_desc_t funcdata;
+};
+#endif
+
+/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
+   gives the value maximum span in an instruction which uses a signed
+   offset) */
+static inline unsigned long my_r2(const struct elf_info *elf_info)
+{
+	return elf_info->sechdrs[elf_info->toc_section].sh_addr + 0x8000;
+}
+
+int elf64_apply_relocate_add(const struct elf_info *elf_info,
+			     const char *strtab, unsigned int symindex,
+			     unsigned int relsec, const char *obj_name);
+
+#endif /* _ASM_POWERPC_ELF_UTIL_H */
diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
index cd4ffd86765f..f2073115d518 100644
--- a/arch/powerpc/include/asm/module.h
+++ b/arch/powerpc/include/asm/module.h
@@ -12,7 +12,14 @@
 #include <linux/list.h>
 #include <asm/bug.h>
 #include <asm-generic/module.h>
+#include <asm/elf_util.h>
 
+/* Both low and high 16 bits are added as SIGNED additions, so if low
+   16 bits has high bit set, high 16 bits must be adjusted.  These
+   macros do that (stolen from binutils). */
+#define PPC_LO(v) ((v) & 0xffff)
+#define PPC_HI(v) (((v) >> 16) & 0xffff)
+#define PPC_HA(v) PPC_HI ((v) + 0x8000)
 
 #ifndef __powerpc64__
 /*
@@ -33,8 +40,7 @@ struct ppc_plt_entry {
 
 struct mod_arch_specific {
 #ifdef __powerpc64__
-	unsigned int stubs_section;	/* Index of stubs section in module */
-	unsigned int toc_section;	/* What section is the TOC? */
+	struct elf_info elf_info;
 	bool toc_fixed;			/* Have we fixed up .TOC.? */
 #ifdef CONFIG_DYNAMIC_FTRACE
 	unsigned long toc;
@@ -90,6 +96,10 @@ static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sec
 }
 #endif
 
+unsigned long stub_for_addr(const struct elf_info *elf_info, unsigned long addr,
+			    const char *obj_name);
+int restore_r2(u32 *instruction, const char *obj_name);
+
 struct exception_table_entry;
 void sort_ex_table(struct exception_table_entry *start,
 		   struct exception_table_entry *finish);
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index b2027a5cf508..e38aace0a6e7 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -123,6 +123,10 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y				+= iomap.o
 endif
 
+ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
+obj-y				+= elf_util_64.o
+endif
+
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
 
 obj-$(CONFIG_PPC64)		+= $(obj64-y)
diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
new file mode 100644
index 000000000000..decad2c34f38
--- /dev/null
+++ b/arch/powerpc/kernel/elf_util_64.c
@@ -0,0 +1,269 @@
+/*
+ * Utility functions to work with ELF files.
+ *
+ * Copyright (C) 2016, IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <asm/ppc-opcode.h>
+#include <asm/elf_util.h>
+
+/*
+ * We just need to use the functions defined in <asm/module.h>, so just declare
+ * struct module here and avoid having to import <linux/module.h>.
+ */
+struct module;
+#include <asm/module.h>
+
+#ifdef PPC64_ELF_ABI_v2
+/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
+#define STO_PPC64_LOCAL_BIT	5
+#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
+#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
+ (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
+
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+	/* sym->st_other indicates offset to local entry point
+	 * (otherwise it will assume r12 is the address of the start
+	 * of function and try to derive r2 from it). */
+	return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
+}
+#else
+static unsigned int local_entry_offset(const Elf64_Sym *sym)
+{
+	return 0;
+}
+#endif
+
+#ifdef CC_USING_MPROFILE_KERNEL
+/*
+ * In case of _mcount calls, do not save the current callee's TOC (in r2) into
+ * the original caller's stack frame. If we did we would clobber the saved TOC
+ * value of the original caller.
+ */
+static void squash_toc_save_inst(const char *name, unsigned long addr)
+{
+	struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
+
+	/* Only for calls to _mcount */
+	if (strcmp("_mcount", name) != 0)
+		return;
+
+	stub->jump[2] = PPC_INST_NOP;
+}
+#else
+static void squash_toc_save_inst(const char *name, unsigned long addr) { }
+#endif
+
+/**
+ * elf64_apply_relocate_add - apply 64 bit RELA relocations
+ * @elf_info:		Support information for the ELF binary being relocated.
+ * @strtab:		String table for the associated symbol table.
+ * @symindex:		Section header index for the associated symbol table.
+ * @relsec:		Section header index for the relocations to apply.
+ * @obj_name:		The name of the ELF binary, for information messages.
+ */
+int elf64_apply_relocate_add(const struct elf_info *elf_info,
+			     const char *strtab, unsigned int symindex,
+			     unsigned int relsec, const char *obj_name)
+{
+	unsigned int i;
+	Elf64_Shdr *sechdrs = elf_info->sechdrs;
+	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
+	Elf64_Sym *sym;
+	unsigned long *location;
+	unsigned long value;
+
+
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
+		/* This is where to make the change */
+		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+			+ rela[i].r_offset;
+		/* This is the symbol it is referring to */
+		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+			+ ELF64_R_SYM(rela[i].r_info);
+
+		pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
+		       location, (long)ELF64_R_TYPE(rela[i].r_info),
+		       strtab + sym->st_name, (unsigned long)sym->st_value,
+		       (long)rela[i].r_addend);
+
+		/* `Everything is relative'. */
+		value = sym->st_value + rela[i].r_addend;
+
+		switch (ELF64_R_TYPE(rela[i].r_info)) {
+		case R_PPC64_ADDR32:
+			/* Simply set it */
+			*(u32 *)location = value;
+			break;
+
+		case R_PPC64_ADDR64:
+			/* Simply set it */
+			*(unsigned long *)location = value;
+			break;
+
+		case R_PPC64_TOC:
+			*(unsigned long *)location = my_r2(elf_info);
+			break;
+
+		case R_PPC64_TOC16:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			if (value + 0x8000 > 0xffff) {
+				pr_err("%s: bad TOC16 relocation (0x%lx)\n",
+				       obj_name, value);
+				return -ENOEXEC;
+			}
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC64_TOC16_LO:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC64_TOC16_DS:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			if ((value & 3) != 0 || value + 0x8000 > 0xffff) {
+				pr_err("%s: bad TOC16_DS relocation (0x%lx)\n",
+				       obj_name, value);
+				return -ENOEXEC;
+			}
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xfffc)
+				| (value & 0xfffc);
+			break;
+
+		case R_PPC64_TOC16_LO_DS:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			if ((value & 3) != 0) {
+				pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n",
+				       obj_name, value);
+				return -ENOEXEC;
+			}
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xfffc)
+				| (value & 0xfffc);
+			break;
+
+		case R_PPC64_TOC16_HA:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			value = ((value + 0x8000) >> 16);
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC_REL24:
+			/* FIXME: Handle weak symbols here --RR */
+			if (sym->st_shndx == SHN_UNDEF) {
+				/* External: go via stub */
+				value = stub_for_addr(elf_info, value, obj_name);
+				if (!value)
+					return -ENOENT;
+				if (!restore_r2((u32 *)location + 1, obj_name))
+					return -ENOEXEC;
+
+				squash_toc_save_inst(strtab + sym->st_name, value);
+			} else
+				value += local_entry_offset(sym);
+
+			/* Convert value to relative */
+			value -= (unsigned long)location;
+			if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
+				pr_err("%s: REL24 %li out of range!\n",
+				       obj_name, (long int)value);
+				return -ENOEXEC;
+			}
+
+			/* Only replace bits 2 through 26 */
+			*(uint32_t *)location
+				= (*(uint32_t *)location & ~0x03fffffc)
+				| (value & 0x03fffffc);
+			break;
+
+		case R_PPC64_REL64:
+			/* 64 bits relative (used by features fixups) */
+			*location = value - (unsigned long)location;
+			break;
+
+		case R_PPC64_TOCSAVE:
+			/*
+			 * Marker reloc indicates we don't have to save r2.
+			 * That would only save us one instruction, so ignore
+			 * it.
+			 */
+			break;
+
+		case R_PPC64_ENTRY:
+			/*
+			 * Optimize ELFv2 large code model entry point if
+			 * the TOC is within 2GB range of current location.
+			 */
+			value = my_r2(elf_info) - (unsigned long)location;
+			if (value + 0x80008000 > 0xffffffff)
+				break;
+			/*
+			 * Check for the large code model prolog sequence:
+			 *	ld r2, ...(r12)
+			 *	add r2, r2, r12
+			 */
+			if ((((uint32_t *)location)[0] & ~0xfffc)
+			    != 0xe84c0000)
+				break;
+			if (((uint32_t *)location)[1] != 0x7c426214)
+				break;
+			/*
+			 * If found, replace it with:
+			 *	addis r2, r12, (.TOC.-func)@ha
+			 *	addi r2, r12, (.TOC.-func)@l
+			 */
+			((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
+			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
+			break;
+
+		case R_PPC64_REL16_HA:
+			/* Subtract location pointer */
+			value -= (unsigned long)location;
+			value = ((value + 0x8000) >> 16);
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		case R_PPC64_REL16_LO:
+			/* Subtract location pointer */
+			value -= (unsigned long)location;
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+			break;
+
+		default:
+			pr_err("%s: Unknown ADD relocation: %lu\n",
+			       obj_name,
+			       (unsigned long)ELF64_R_TYPE(rela[i].r_info));
+			return -ENOEXEC;
+		}
+	}
+
+	return 0;
+}
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 183368e008cf..b929560ecd5b 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -19,7 +19,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/module.h>
-#include <linux/elf.h>
+#include <asm/elf_util.h>
 #include <linux/moduleloader.h>
 #include <linux/err.h>
 #include <linux/vmalloc.h>
@@ -43,9 +43,6 @@
 
 #ifdef PPC64_ELF_ABI_v2
 
-/* An address is simply the address of the function. */
-typedef unsigned long func_desc_t;
-
 static func_desc_t func_desc(unsigned long addr)
 {
 	return addr;
@@ -58,25 +55,8 @@ static unsigned long stub_func_addr(func_desc_t func)
 {
 	return func;
 }
-
-/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
-#define STO_PPC64_LOCAL_BIT	5
-#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
-#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
- (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
-
-static unsigned int local_entry_offset(const Elf64_Sym *sym)
-{
-	/* sym->st_other indicates offset to local entry point
-	 * (otherwise it will assume r12 is the address of the start
-	 * of function and try to derive r2 from it). */
-	return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
-}
 #else
 
-/* An address is address of the OPD entry, which contains address of fn. */
-typedef struct ppc64_opd_entry func_desc_t;
-
 static func_desc_t func_desc(unsigned long addr)
 {
 	return *(struct ppc64_opd_entry *)addr;
@@ -89,29 +69,10 @@ static unsigned long stub_func_addr(func_desc_t func)
 {
 	return func.funcaddr;
 }
-static unsigned int local_entry_offset(const Elf64_Sym *sym)
-{
-	return 0;
-}
 #endif
 
 #define STUB_MAGIC 0x73747562 /* stub */
 
-/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
-   the kernel itself).  But on PPC64, these need to be used for every
-   jump, actually, to reset r2 (TOC+0x8000). */
-struct ppc64_stub_entry
-{
-	/* 28 byte jump instruction sequence (7 instructions). We only
-	 * need 6 instructions on ABIv2 but we always allocate 7 so
-	 * so we don't have to modify the trampoline load instruction. */
-	u32 jump[7];
-	/* Used by ftrace to identify stubs */
-	u32 magic;
-	/* Data for the above code */
-	func_desc_t funcdata;
-};
-
 /*
  * PPC64 uses 24 bit jumps, but we need to jump into other modules or
  * the kernel which may be further.  So we jump to a stub.
@@ -346,9 +307,9 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
 	for (i = 1; i < hdr->e_shnum; i++) {
 		char *p;
 		if (strcmp(secstrings + sechdrs[i].sh_name, ".stubs") == 0)
-			me->arch.stubs_section = i;
+			me->arch.elf_info.stubs_section = i;
 		else if (strcmp(secstrings + sechdrs[i].sh_name, ".toc") == 0)
-			me->arch.toc_section = i;
+			me->arch.elf_info.toc_section = i;
 		else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
 			dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
 					  sechdrs[i].sh_size);
@@ -364,7 +325,7 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
 				 + sechdrs[sechdrs[i].sh_link].sh_offset);
 	}
 
-	if (!me->arch.stubs_section) {
+	if (!me->arch.elf_info.stubs_section) {
 		pr_err("%s: doesn't contain .stubs.\n", me->name);
 		return -ENOEXEC;
 	}
@@ -373,44 +334,32 @@ int module_frob_arch_sections(Elf64_Ehdr *hdr,
 	   to some reasonable value in case the module calls out to
 	   other functions via a stub, or if a function pointer escapes
 	   the module by some means.  */
-	if (!me->arch.toc_section)
-		me->arch.toc_section = me->arch.stubs_section;
+	if (!me->arch.elf_info.toc_section)
+		me->arch.elf_info.toc_section = me->arch.elf_info.stubs_section;
 
 	/* Override the stubs size */
-	sechdrs[me->arch.stubs_section].sh_size = get_stubs_size(hdr, sechdrs);
-	return 0;
-}
+	sechdrs[me->arch.elf_info.stubs_section].sh_size = get_stubs_size(hdr, sechdrs);
 
-/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
-   gives the value maximum span in an instruction which uses a signed
-   offset) */
-static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me)
-{
-	return sechdrs[me->arch.toc_section].sh_addr + 0x8000;
-}
+	/* For the elf_util functions. */
+	me->arch.elf_info.sechdrs = sechdrs;
 
-/* Both low and high 16 bits are added as SIGNED additions, so if low
-   16 bits has high bit set, high 16 bits must be adjusted.  These
-   macros do that (stolen from binutils). */
-#define PPC_LO(v) ((v) & 0xffff)
-#define PPC_HI(v) (((v) >> 16) & 0xffff)
-#define PPC_HA(v) PPC_HI ((v) + 0x8000)
+	return 0;
+}
 
 /* Patch stub to reference function and correct r2 value. */
-static inline int create_stub(const Elf64_Shdr *sechdrs,
+static inline int create_stub(const struct elf_info *elf_info,
 			      struct ppc64_stub_entry *entry,
-			      unsigned long addr,
-			      struct module *me)
+			      unsigned long addr, const char *obj_name)
 {
 	long reladdr;
 
 	memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns));
 
 	/* Stub uses address relative to r2. */
-	reladdr = (unsigned long)entry - my_r2(sechdrs, me);
+	reladdr = (unsigned long)entry - my_r2(elf_info);
 	if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
 		pr_err("%s: Address %p of stub out of range of %p.\n",
-		       me->name, (void *)reladdr, (void *)my_r2);
+		       obj_name, (void *)reladdr, (void *)my_r2);
 		return 0;
 	}
 	pr_debug("Stub %p get data from reladdr %li\n", entry, reladdr);
@@ -425,17 +374,17 @@ static inline int create_stub(const Elf64_Shdr *sechdrs,
 
 /* Create stub to jump to function described in this OPD/ptr: we need the
    stub to set up the TOC ptr (r2) for the function. */
-static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
-				   unsigned long addr,
-				   struct module *me)
+unsigned long stub_for_addr(const struct elf_info *elf_info, unsigned long addr,
+			    const char *obj_name)
 {
+	struct elf_shdr *stubs_sec = &elf_info->sechdrs[elf_info->stubs_section];
 	struct ppc64_stub_entry *stubs;
 	unsigned int i, num_stubs;
 
-	num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs);
+	num_stubs = stubs_sec->sh_size / sizeof(*stubs);
 
 	/* Find this stub, or if that fails, the next avail. entry */
-	stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr;
+	stubs = (void *) stubs_sec->sh_addr;
 	for (i = 0; stub_func_addr(stubs[i].funcdata); i++) {
 		BUG_ON(i >= num_stubs);
 
@@ -443,7 +392,7 @@ static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs,
 			return (unsigned long)&stubs[i];
 	}
 
-	if (!create_stub(sechdrs, &stubs[i], addr, me))
+	if (!create_stub(elf_info, &stubs[i], addr, obj_name))
 		return 0;
 
 	return (unsigned long)&stubs[i];
@@ -465,24 +414,7 @@ static bool is_early_mcount_callsite(u32 *instruction)
 	return false;
 }
 
-/*
- * In case of _mcount calls, do not save the current callee's TOC (in r2) into
- * the original caller's stack frame. If we did we would clobber the saved TOC
- * value of the original caller.
- */
-static void squash_toc_save_inst(const char *name, unsigned long addr)
-{
-	struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
-
-	/* Only for calls to _mcount */
-	if (strcmp("_mcount", name) != 0)
-		return;
-
-	stub->jump[2] = PPC_INST_NOP;
-}
 #else
-static void squash_toc_save_inst(const char *name, unsigned long addr) { }
-
 /* without -mprofile-kernel, mcount calls are never early */
 static bool is_early_mcount_callsite(u32 *instruction)
 {
@@ -492,14 +424,14 @@ static bool is_early_mcount_callsite(u32 *instruction)
 
 /* We expect a noop next: if it is, replace it with instruction to
    restore r2. */
-static int restore_r2(u32 *instruction, struct module *me)
+int restore_r2(u32 *instruction, const char *obj_name)
 {
 	if (is_early_mcount_callsite(instruction - 1))
 		return 1;
 
 	if (*instruction != PPC_INST_NOP) {
 		pr_err("%s: Expect noop after relocate, got %08x\n",
-		       me->name, *instruction);
+		       obj_name, *instruction);
 		return 0;
 	}
 	/* ld r2,R2_STACK_OFFSET(r1) */
@@ -513,11 +445,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 		       unsigned int relsec,
 		       struct module *me)
 {
-	unsigned int i;
-	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
 	Elf64_Sym *sym;
-	unsigned long *location;
-	unsigned long value;
 
 	pr_debug("Applying ADD relocate section %u to %u\n", relsec,
 	       sechdrs[relsec].sh_info);
@@ -528,191 +456,12 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 		/* It's theoretically possible that a module doesn't want a
 		 * .TOC. so don't fail it just for that. */
 		if (sym)
-			sym->st_value = my_r2(sechdrs, me);
+			sym->st_value = my_r2(&me->arch.elf_info);
 		me->arch.toc_fixed = true;
 	}
 
-	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
-		/* This is where to make the change */
-		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
-			+ rela[i].r_offset;
-		/* This is the symbol it is referring to */
-		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
-			+ ELF64_R_SYM(rela[i].r_info);
-
-		pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
-		       location, (long)ELF64_R_TYPE(rela[i].r_info),
-		       strtab + sym->st_name, (unsigned long)sym->st_value,
-		       (long)rela[i].r_addend);
-
-		/* `Everything is relative'. */
-		value = sym->st_value + rela[i].r_addend;
-
-		switch (ELF64_R_TYPE(rela[i].r_info)) {
-		case R_PPC64_ADDR32:
-			/* Simply set it */
-			*(u32 *)location = value;
-			break;
-
-		case R_PPC64_ADDR64:
-			/* Simply set it */
-			*(unsigned long *)location = value;
-			break;
-
-		case R_PPC64_TOC:
-			*(unsigned long *)location = my_r2(sechdrs, me);
-			break;
-
-		case R_PPC64_TOC16:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			if (value + 0x8000 > 0xffff) {
-				pr_err("%s: bad TOC16 relocation (0x%lx)\n",
-				       me->name, value);
-				return -ENOEXEC;
-			}
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC64_TOC16_LO:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC64_TOC16_DS:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			if ((value & 3) != 0 || value + 0x8000 > 0xffff) {
-				pr_err("%s: bad TOC16_DS relocation (0x%lx)\n",
-				       me->name, value);
-				return -ENOEXEC;
-			}
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xfffc)
-				| (value & 0xfffc);
-			break;
-
-		case R_PPC64_TOC16_LO_DS:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			if ((value & 3) != 0) {
-				pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n",
-				       me->name, value);
-				return -ENOEXEC;
-			}
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xfffc)
-				| (value & 0xfffc);
-			break;
-
-		case R_PPC64_TOC16_HA:
-			/* Subtract TOC pointer */
-			value -= my_r2(sechdrs, me);
-			value = ((value + 0x8000) >> 16);
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC_REL24:
-			/* FIXME: Handle weak symbols here --RR */
-			if (sym->st_shndx == SHN_UNDEF) {
-				/* External: go via stub */
-				value = stub_for_addr(sechdrs, value, me);
-				if (!value)
-					return -ENOENT;
-				if (!restore_r2((u32 *)location + 1, me))
-					return -ENOEXEC;
-
-				squash_toc_save_inst(strtab + sym->st_name, value);
-			} else
-				value += local_entry_offset(sym);
-
-			/* Convert value to relative */
-			value -= (unsigned long)location;
-			if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
-				pr_err("%s: REL24 %li out of range!\n",
-				       me->name, (long int)value);
-				return -ENOEXEC;
-			}
-
-			/* Only replace bits 2 through 26 */
-			*(uint32_t *)location
-				= (*(uint32_t *)location & ~0x03fffffc)
-				| (value & 0x03fffffc);
-			break;
-
-		case R_PPC64_REL64:
-			/* 64 bits relative (used by features fixups) */
-			*location = value - (unsigned long)location;
-			break;
-
-		case R_PPC64_TOCSAVE:
-			/*
-			 * Marker reloc indicates we don't have to save r2.
-			 * That would only save us one instruction, so ignore
-			 * it.
-			 */
-			break;
-
-		case R_PPC64_ENTRY:
-			/*
-			 * Optimize ELFv2 large code model entry point if
-			 * the TOC is within 2GB range of current location.
-			 */
-			value = my_r2(sechdrs, me) - (unsigned long)location;
-			if (value + 0x80008000 > 0xffffffff)
-				break;
-			/*
-			 * Check for the large code model prolog sequence:
-		         *	ld r2, ...(r12)
-			 *	add r2, r2, r12
-			 */
-			if ((((uint32_t *)location)[0] & ~0xfffc)
-			    != 0xe84c0000)
-				break;
-			if (((uint32_t *)location)[1] != 0x7c426214)
-				break;
-			/*
-			 * If found, replace it with:
-			 *	addis r2, r12, (.TOC.-func)@ha
-			 *	addi r2, r12, (.TOC.-func)@l
-			 */
-			((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value);
-			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
-			break;
-
-		case R_PPC64_REL16_HA:
-			/* Subtract location pointer */
-			value -= (unsigned long)location;
-			value = ((value + 0x8000) >> 16);
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		case R_PPC64_REL16_LO:
-			/* Subtract location pointer */
-			value -= (unsigned long)location;
-			*((uint16_t *) location)
-				= (*((uint16_t *) location) & ~0xffff)
-				| (value & 0xffff);
-			break;
-
-		default:
-			pr_err("%s: Unknown ADD relocation: %lu\n",
-			       me->name,
-			       (unsigned long)ELF64_R_TYPE(rela[i].r_info));
-			return -ENOEXEC;
-		}
-	}
-
-	return 0;
+	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, symindex,
+					relsec, me->name);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -746,10 +495,10 @@ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module
 	};
 	long reladdr;
 
-	num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry);
+	num_stubs = sechdrs[me->arch.elf_info.stubs_section].sh_size / sizeof(*entry);
 
 	/* Find the next available stub entry */
-	entry = (void *)sechdrs[me->arch.stubs_section].sh_addr;
+	entry = (void *)sechdrs[me->arch.elf_info.stubs_section].sh_addr;
 	for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++);
 
 	if (i >= num_stubs) {
@@ -778,13 +527,14 @@ static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module
 #else
 static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me)
 {
-	return stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me);
+	return stub_for_addr(&me->arch.elf_info, (unsigned long)ftrace_caller,
+			     me->name);
 }
 #endif
 
 int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs)
 {
-	mod->arch.toc = my_r2(sechdrs, mod);
+	mod->arch.toc = my_r2(&mod->arch.elf_info);
 	mod->arch.tramp = create_ftrace_stub(sechdrs, mod);
 
 	if (!mod->arch.tramp)
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 05/13] powerpc: Generalize elf64_apply_relocate_add.

[Thiago Jung Bauermann]

When apply_relocate_add is called, modules are already loaded at their
final location in memory so Elf64_Shdr.sh_addr can be used for accessing
the section contents as well as the base address for relocations.

This is not the case for kexec's purgatory, because it will only be
copied to its final location right before being executed. Therefore,
it needs to be relocated while it is still in a temporary buffer. In
this case, Elf64_Shdr.sh_addr can't be used to access the sections'
contents.

This patch allows elf64_apply_relocate_add to be used when the ELF
binary is not yet at its final location by adding an addr_base argument
to specify the address at which the section will be loaded, and rela,
loc_base and syms_base to point to the sections' contents.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  6 ++--
 arch/powerpc/kernel/elf_util_64.c   | 63 +++++++++++++++++++++++++------------
 arch/powerpc/kernel/module_64.c     | 17 ++++++++--
 3 files changed, 61 insertions(+), 25 deletions(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
index 37372559fe62..a012ba03282d 100644
--- a/arch/powerpc/include/asm/elf_util.h
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -64,7 +64,9 @@ static inline unsigned long my_r2(const struct elf_info *elf_info)
 }
 
 int elf64_apply_relocate_add(const struct elf_info *elf_info,
-			     const char *strtab, unsigned int symindex,
-			     unsigned int relsec, const char *obj_name);
+			     const char *strtab, const Elf64_Rela *rela,
+			     unsigned int num_rela, void *syms_base,
+			     void *loc_base, Elf64_Addr addr_base,
+			     const char *obj_name);
 
 #endif /* _ASM_POWERPC_ELF_UTIL_H */
diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
index decad2c34f38..8e5d400ac9f2 100644
--- a/arch/powerpc/kernel/elf_util_64.c
+++ b/arch/powerpc/kernel/elf_util_64.c
@@ -69,33 +69,56 @@ static void squash_toc_save_inst(const char *name, unsigned long addr) { }
  * elf64_apply_relocate_add - apply 64 bit RELA relocations
  * @elf_info:		Support information for the ELF binary being relocated.
  * @strtab:		String table for the associated symbol table.
- * @symindex:		Section header index for the associated symbol table.
- * @relsec:		Section header index for the relocations to apply.
+ * @rela:		Contents of the section with the relocations to apply.
+ * @num_rela:		Number of relocation entries in the section.
+ * @syms_base:		Contents of the associated symbol table.
+ * @loc_base:		Contents of the section to which relocations apply.
+ * @addr_base:		The address where the section will be loaded in memory.
  * @obj_name:		The name of the ELF binary, for information messages.
+ *
+ * Applies RELA relocations to an ELF file already at its final location
+ * in memory (in which case loc_base == addr_base), or still in a temporary
+ * buffer.
  */
 int elf64_apply_relocate_add(const struct elf_info *elf_info,
-			     const char *strtab, unsigned int symindex,
-			     unsigned int relsec, const char *obj_name)
+			     const char *strtab, const Elf64_Rela *rela,
+			     unsigned int num_rela, void *syms_base,
+			     void *loc_base, Elf64_Addr addr_base,
+			     const char *obj_name)
 {
 	unsigned int i;
-	Elf64_Shdr *sechdrs = elf_info->sechdrs;
-	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
-	Elf64_Sym *sym;
 	unsigned long *location;
+	unsigned long address;
 	unsigned long value;
+	const char *name;
+	Elf64_Sym *sym;
+
+	for (i = 0; i < num_rela; i++) {
+		/*
+		 * rels[i].r_offset contains the byte offset from the beginning
+		 * of section to the storage unit affected.
+		 *
+		 * This is the location to update in the temporary buffer where
+		 * the section is currently loaded. The section will finally
+		 * be loaded to a different address later, pointed to by
+		 * addr_base.
+		 */
+		location = loc_base + rela[i].r_offset;
+
+		/* Final address of the location. */
+		address = addr_base + rela[i].r_offset;
 
+		/* This is the symbol the relocation is referring to. */
+		sym = (Elf64_Sym *) syms_base + ELF64_R_SYM(rela[i].r_info);
 
-	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
-		/* This is where to make the change */
-		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
-			+ rela[i].r_offset;
-		/* This is the symbol it is referring to */
-		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
-			+ ELF64_R_SYM(rela[i].r_info);
+		if (sym->st_name)
+			name = strtab + sym->st_name;
+		else
+			name = "<unnamed symbol>";
 
 		pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
 		       location, (long)ELF64_R_TYPE(rela[i].r_info),
-		       strtab + sym->st_name, (unsigned long)sym->st_value,
+		       name, (unsigned long)sym->st_value,
 		       (long)rela[i].r_addend);
 
 		/* `Everything is relative'. */
@@ -187,7 +210,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 				value += local_entry_offset(sym);
 
 			/* Convert value to relative */
-			value -= (unsigned long)location;
+			value -= address;
 			if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
 				pr_err("%s: REL24 %li out of range!\n",
 				       obj_name, (long int)value);
@@ -202,7 +225,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 
 		case R_PPC64_REL64:
 			/* 64 bits relative (used by features fixups) */
-			*location = value - (unsigned long)location;
+			*location = value - address;
 			break;
 
 		case R_PPC64_TOCSAVE:
@@ -218,7 +241,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			 * Optimize ELFv2 large code model entry point if
 			 * the TOC is within 2GB range of current location.
 			 */
-			value = my_r2(elf_info) - (unsigned long)location;
+			value = my_r2(elf_info) - address;
 			if (value + 0x80008000 > 0xffffffff)
 				break;
 			/*
@@ -242,7 +265,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 
 		case R_PPC64_REL16_HA:
 			/* Subtract location pointer */
-			value -= (unsigned long)location;
+			value -= address;
 			value = ((value + 0x8000) >> 16);
 			*((uint16_t *) location)
 				= (*((uint16_t *) location) & ~0xffff)
@@ -251,7 +274,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 
 		case R_PPC64_REL16_LO:
 			/* Subtract location pointer */
-			value -= (unsigned long)location;
+			value -= address;
 			*((uint16_t *) location)
 				= (*((uint16_t *) location) & ~0xffff)
 				| (value & 0xffff);
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index b929560ecd5b..590e2413974f 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -439,16 +439,26 @@ int restore_r2(u32 *instruction, const char *obj_name)
 	return 1;
 }
 
+/*
+ * When this function is called, the module is already at its final location in
+ * memory, so Elf64_Shdr.sh_addr can be used for accessing the section
+ * contents as well as the base address for relocations.
+ */
 int apply_relocate_add(Elf64_Shdr *sechdrs,
 		       const char *strtab,
 		       unsigned int symindex,
 		       unsigned int relsec,
 		       struct module *me)
 {
+	Elf64_Shdr *rel_section = &sechdrs[relsec];
+	void *syms_base = (void *) sechdrs[symindex].sh_addr;
+	Elf64_Addr addr_base = sechdrs[rel_section->sh_info].sh_addr;
+	const Elf64_Rela *rela = (const Elf64_Rela *) rel_section->sh_addr;
+	unsigned int num_rela = rel_section->sh_size / sizeof(Elf64_Rela);
 	Elf64_Sym *sym;
 
 	pr_debug("Applying ADD relocate section %u to %u\n", relsec,
-	       sechdrs[relsec].sh_info);
+		 rel_section->sh_info);
 
 	/* First time we're called, we can fix up .TOC. */
 	if (!me->arch.toc_fixed) {
@@ -460,8 +470,9 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 		me->arch.toc_fixed = true;
 	}
 
-	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, symindex,
-					relsec, me->name);
+	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, rela,
+					num_rela, syms_base, (void *) addr_base,
+					addr_base, me->name);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-- 
1.9.1

[PATCH v5 05/13] powerpc: Generalize elf64_apply_relocate_add.

[Thiago Jung Bauermann]

When apply_relocate_add is called, modules are already loaded at their
final location in memory so Elf64_Shdr.sh_addr can be used for accessing
the section contents as well as the base address for relocations.

This is not the case for kexec's purgatory, because it will only be
copied to its final location right before being executed. Therefore,
it needs to be relocated while it is still in a temporary buffer. In
this case, Elf64_Shdr.sh_addr can't be used to access the sections'
contents.

This patch allows elf64_apply_relocate_add to be used when the ELF
binary is not yet at its final location by adding an addr_base argument
to specify the address at which the section will be loaded, and rela,
loc_base and syms_base to point to the sections' contents.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  6 ++--
 arch/powerpc/kernel/elf_util_64.c   | 63 +++++++++++++++++++++++++------------
 arch/powerpc/kernel/module_64.c     | 17 ++++++++--
 3 files changed, 61 insertions(+), 25 deletions(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
index 37372559fe62..a012ba03282d 100644
--- a/arch/powerpc/include/asm/elf_util.h
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -64,7 +64,9 @@ static inline unsigned long my_r2(const struct elf_info *elf_info)
 }
 
 int elf64_apply_relocate_add(const struct elf_info *elf_info,
-			     const char *strtab, unsigned int symindex,
-			     unsigned int relsec, const char *obj_name);
+			     const char *strtab, const Elf64_Rela *rela,
+			     unsigned int num_rela, void *syms_base,
+			     void *loc_base, Elf64_Addr addr_base,
+			     const char *obj_name);
 
 #endif /* _ASM_POWERPC_ELF_UTIL_H */
diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
index decad2c34f38..8e5d400ac9f2 100644
--- a/arch/powerpc/kernel/elf_util_64.c
+++ b/arch/powerpc/kernel/elf_util_64.c
@@ -69,33 +69,56 @@ static void squash_toc_save_inst(const char *name, unsigned long addr) { }
  * elf64_apply_relocate_add - apply 64 bit RELA relocations
  * @elf_info:		Support information for the ELF binary being relocated.
  * @strtab:		String table for the associated symbol table.
- * @symindex:		Section header index for the associated symbol table.
- * @relsec:		Section header index for the relocations to apply.
+ * @rela:		Contents of the section with the relocations to apply.
+ * @num_rela:		Number of relocation entries in the section.
+ * @syms_base:		Contents of the associated symbol table.
+ * @loc_base:		Contents of the section to which relocations apply.
+ * @addr_base:		The address where the section will be loaded in memory.
  * @obj_name:		The name of the ELF binary, for information messages.
+ *
+ * Applies RELA relocations to an ELF file already at its final location
+ * in memory (in which case loc_base == addr_base), or still in a temporary
+ * buffer.
  */
 int elf64_apply_relocate_add(const struct elf_info *elf_info,
-			     const char *strtab, unsigned int symindex,
-			     unsigned int relsec, const char *obj_name)
+			     const char *strtab, const Elf64_Rela *rela,
+			     unsigned int num_rela, void *syms_base,
+			     void *loc_base, Elf64_Addr addr_base,
+			     const char *obj_name)
 {
 	unsigned int i;
-	Elf64_Shdr *sechdrs = elf_info->sechdrs;
-	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
-	Elf64_Sym *sym;
 	unsigned long *location;
+	unsigned long address;
 	unsigned long value;
+	const char *name;
+	Elf64_Sym *sym;
+
+	for (i = 0; i < num_rela; i++) {
+		/*
+		 * rels[i].r_offset contains the byte offset from the beginning
+		 * of section to the storage unit affected.
+		 *
+		 * This is the location to update in the temporary buffer where
+		 * the section is currently loaded. The section will finally
+		 * be loaded to a different address later, pointed to by
+		 * addr_base.
+		 */
+		location = loc_base + rela[i].r_offset;
+
+		/* Final address of the location. */
+		address = addr_base + rela[i].r_offset;
 
+		/* This is the symbol the relocation is referring to. */
+		sym = (Elf64_Sym *) syms_base + ELF64_R_SYM(rela[i].r_info);
 
-	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
-		/* This is where to make the change */
-		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
-			+ rela[i].r_offset;
-		/* This is the symbol it is referring to */
-		sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
-			+ ELF64_R_SYM(rela[i].r_info);
+		if (sym->st_name)
+			name = strtab + sym->st_name;
+		else
+			name = "<unnamed symbol>";
 
 		pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n",
 		       location, (long)ELF64_R_TYPE(rela[i].r_info),
-		       strtab + sym->st_name, (unsigned long)sym->st_value,
+		       name, (unsigned long)sym->st_value,
 		       (long)rela[i].r_addend);
 
 		/* `Everything is relative'. */
@@ -187,7 +210,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 				value += local_entry_offset(sym);
 
 			/* Convert value to relative */
-			value -= (unsigned long)location;
+			value -= address;
 			if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){
 				pr_err("%s: REL24 %li out of range!\n",
 				       obj_name, (long int)value);
@@ -202,7 +225,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 
 		case R_PPC64_REL64:
 			/* 64 bits relative (used by features fixups) */
-			*location = value - (unsigned long)location;
+			*location = value - address;
 			break;
 
 		case R_PPC64_TOCSAVE:
@@ -218,7 +241,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			 * Optimize ELFv2 large code model entry point if
 			 * the TOC is within 2GB range of current location.
 			 */
-			value = my_r2(elf_info) - (unsigned long)location;
+			value = my_r2(elf_info) - address;
 			if (value + 0x80008000 > 0xffffffff)
 				break;
 			/*
@@ -242,7 +265,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 
 		case R_PPC64_REL16_HA:
 			/* Subtract location pointer */
-			value -= (unsigned long)location;
+			value -= address;
 			value = ((value + 0x8000) >> 16);
 			*((uint16_t *) location)
 				= (*((uint16_t *) location) & ~0xffff)
@@ -251,7 +274,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 
 		case R_PPC64_REL16_LO:
 			/* Subtract location pointer */
-			value -= (unsigned long)location;
+			value -= address;
 			*((uint16_t *) location)
 				= (*((uint16_t *) location) & ~0xffff)
 				| (value & 0xffff);
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index b929560ecd5b..590e2413974f 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -439,16 +439,26 @@ int restore_r2(u32 *instruction, const char *obj_name)
 	return 1;
 }
 
+/*
+ * When this function is called, the module is already at its final location in
+ * memory, so Elf64_Shdr.sh_addr can be used for accessing the section
+ * contents as well as the base address for relocations.
+ */
 int apply_relocate_add(Elf64_Shdr *sechdrs,
 		       const char *strtab,
 		       unsigned int symindex,
 		       unsigned int relsec,
 		       struct module *me)
 {
+	Elf64_Shdr *rel_section = &sechdrs[relsec];
+	void *syms_base = (void *) sechdrs[symindex].sh_addr;
+	Elf64_Addr addr_base = sechdrs[rel_section->sh_info].sh_addr;
+	const Elf64_Rela *rela = (const Elf64_Rela *) rel_section->sh_addr;
+	unsigned int num_rela = rel_section->sh_size / sizeof(Elf64_Rela);
 	Elf64_Sym *sym;
 
 	pr_debug("Applying ADD relocate section %u to %u\n", relsec,
-	       sechdrs[relsec].sh_info);
+		 rel_section->sh_info);
 
 	/* First time we're called, we can fix up .TOC. */
 	if (!me->arch.toc_fixed) {
@@ -460,8 +470,9 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 		me->arch.toc_fixed = true;
 	}
 
-	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, symindex,
-					relsec, me->name);
+	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, rela,
+					num_rela, syms_base, (void *) addr_base,
+					addr_base, me->name);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 06/13] powerpc: Adapt elf64_apply_relocate_add for kexec_file_load.

[Thiago Jung Bauermann]

Extend elf64_apply_relocate_add to support relative symbols. This is
necessary because there is a difference between how the module loading
mechanism and the kexec purgatory loading code use Elf64_Sym.st_value
at relocation time: the former changes st_value to point to the absolute
memory address before relocating the module, while the latter does that
adjustment during relocation of the purgatory.

Also, add a check_symbols argument so that the kexec code can be stricter
about undefined symbols.

Finally, add relocation types used by the purgatory.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  1 +
 arch/powerpc/kernel/elf_util_64.c   | 84 ++++++++++++++++++++++++++++++++++++-
 arch/powerpc/kernel/module_64.c     |  5 ++-
 3 files changed, 88 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
index a012ba03282d..3405eeabe542 100644
--- a/arch/powerpc/include/asm/elf_util.h
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -67,6 +67,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			     const char *strtab, const Elf64_Rela *rela,
 			     unsigned int num_rela, void *syms_base,
 			     void *loc_base, Elf64_Addr addr_base,
+			     bool relative_symbols, bool check_symbols,
 			     const char *obj_name);
 
 #endif /* _ASM_POWERPC_ELF_UTIL_H */
diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
index 8e5d400ac9f2..80f209a42abd 100644
--- a/arch/powerpc/kernel/elf_util_64.c
+++ b/arch/powerpc/kernel/elf_util_64.c
@@ -74,6 +74,8 @@ static void squash_toc_save_inst(const char *name, unsigned long addr) { }
  * @syms_base:		Contents of the associated symbol table.
  * @loc_base:		Contents of the section to which relocations apply.
  * @addr_base:		The address where the section will be loaded in memory.
+ * @relative_symbols:	Are the symbols' st_value members relative?
+ * @check_symbols:	Fail if an unexpected symbol is found?
  * @obj_name:		The name of the ELF binary, for information messages.
  *
  * Applies RELA relocations to an ELF file already at its final location
@@ -84,11 +86,13 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			     const char *strtab, const Elf64_Rela *rela,
 			     unsigned int num_rela, void *syms_base,
 			     void *loc_base, Elf64_Addr addr_base,
+			     bool relative_symbols, bool check_symbols,
 			     const char *obj_name)
 {
 	unsigned int i;
 	unsigned long *location;
 	unsigned long address;
+	unsigned long sec_base;
 	unsigned long value;
 	const char *name;
 	Elf64_Sym *sym;
@@ -121,8 +125,36 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 		       name, (unsigned long)sym->st_value,
 		       (long)rela[i].r_addend);
 
+		if (check_symbols) {
+			/*
+			 * TOC symbols appear as undefined but should be
+			 * resolved as well, so allow them to be processed.
+			 */
+			if (sym->st_shndx == SHN_UNDEF &&
+					strcmp(name, ".TOC.") != 0) {
+				pr_err("Undefined symbol: %s\n", name);
+				return -ENOEXEC;
+			} else if (sym->st_shndx == SHN_COMMON) {
+				pr_err("Symbol '%s' in common section.\n", name);
+				return -ENOEXEC;
+			}
+		}
+
+		if (relative_symbols && sym->st_shndx != SHN_ABS) {
+			if (sym->st_shndx >= elf_info->ehdr->e_shnum) {
+				pr_err("Invalid section %d for symbol %s\n",
+				       sym->st_shndx, name);
+				return -ENOEXEC;
+			} else {
+				struct elf_shdr *sechdrs = elf_info->sechdrs;
+
+				sec_base = sechdrs[sym->st_shndx].sh_addr;
+			}
+		} else
+			sec_base = 0;
+
 		/* `Everything is relative'. */
-		value = sym->st_value + rela[i].r_addend;
+		value = sym->st_value + sec_base + rela[i].r_addend;
 
 		switch (ELF64_R_TYPE(rela[i].r_info)) {
 		case R_PPC64_ADDR32:
@@ -135,6 +167,10 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			*(unsigned long *)location = value;
 			break;
 
+		case R_PPC64_REL32:
+			*(uint32_t *)location = value - (uint32_t)(uint64_t)location;
+			break;
+
 		case R_PPC64_TOC:
 			*(unsigned long *)location = my_r2(elf_info);
 			break;
@@ -186,6 +222,14 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 				| (value & 0xfffc);
 			break;
 
+		case R_PPC64_TOC16_HI:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			value = value >> 16;
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+
 		case R_PPC64_TOC16_HA:
 			/* Subtract TOC pointer */
 			value -= my_r2(elf_info);
@@ -195,6 +239,21 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 				| (value & 0xffff);
 			break;
 
+		case R_PPC64_REL14:
+			/* Convert value to relative */
+			value -= address;
+			if (value + 0x8000 > 0xffff || (value & 3) != 0) {
+				pr_err("%s: REL14 %li out of range!\n", obj_name,
+				       (long int)value);
+				return -ENOEXEC;
+			}
+
+			/* Only replace bits 2 through 16 */
+			*(uint32_t *)location
+				= (*(uint32_t *)location & ~0xfffc)
+				| (value & 0xfffc);
+			break;
+
 		case R_PPC_REL24:
 			/* FIXME: Handle weak symbols here --RR */
 			if (sym->st_shndx == SHN_UNDEF) {
@@ -263,6 +322,29 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
 			break;
 
+		case R_PPC64_ADDR16_LO:
+			*(uint16_t *)location = value & 0xffff;
+			break;
+
+		case R_PPC64_ADDR16_HI:
+			*(uint16_t *)location = (value >> 16) & 0xffff;
+			break;
+
+		case R_PPC64_ADDR16_HA:
+			*(uint16_t *)location = (((value + 0x8000) >> 16) &
+							0xffff);
+			break;
+
+		case R_PPC64_ADDR16_HIGHER:
+			*(uint16_t *)location = (((uint64_t)value >> 32) &
+							0xffff);
+			break;
+
+		case R_PPC64_ADDR16_HIGHEST:
+			*(uint16_t *)location = (((uint64_t)value >> 48) &
+							0xffff);
+			break;
+
 		case R_PPC64_REL16_HA:
 			/* Subtract location pointer */
 			value -= address;
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 590e2413974f..10745ac6b004 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -443,6 +443,9 @@ int restore_r2(u32 *instruction, const char *obj_name)
  * When this function is called, the module is already at its final location in
  * memory, so Elf64_Shdr.sh_addr can be used for accessing the section
  * contents as well as the base address for relocations.
+ *
+ * Also, simplify_symbols already changed all symbols' st_value members
+ * to absolute addresses.
  */
 int apply_relocate_add(Elf64_Shdr *sechdrs,
 		       const char *strtab,
@@ -472,7 +475,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 
 	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, rela,
 					num_rela, syms_base, (void *) addr_base,
-					addr_base, me->name);
+					addr_base, false, false, me->name);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-- 
1.9.1

[PATCH v5 06/13] powerpc: Adapt elf64_apply_relocate_add for kexec_file_load.

[Thiago Jung Bauermann]

Extend elf64_apply_relocate_add to support relative symbols. This is
necessary because there is a difference between how the module loading
mechanism and the kexec purgatory loading code use Elf64_Sym.st_value
at relocation time: the former changes st_value to point to the absolute
memory address before relocating the module, while the latter does that
adjustment during relocation of the purgatory.

Also, add a check_symbols argument so that the kexec code can be stricter
about undefined symbols.

Finally, add relocation types used by the purgatory.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  1 +
 arch/powerpc/kernel/elf_util_64.c   | 84 ++++++++++++++++++++++++++++++++++++-
 arch/powerpc/kernel/module_64.c     |  5 ++-
 3 files changed, 88 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
index a012ba03282d..3405eeabe542 100644
--- a/arch/powerpc/include/asm/elf_util.h
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -67,6 +67,7 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			     const char *strtab, const Elf64_Rela *rela,
 			     unsigned int num_rela, void *syms_base,
 			     void *loc_base, Elf64_Addr addr_base,
+			     bool relative_symbols, bool check_symbols,
 			     const char *obj_name);
 
 #endif /* _ASM_POWERPC_ELF_UTIL_H */
diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
index 8e5d400ac9f2..80f209a42abd 100644
--- a/arch/powerpc/kernel/elf_util_64.c
+++ b/arch/powerpc/kernel/elf_util_64.c
@@ -74,6 +74,8 @@ static void squash_toc_save_inst(const char *name, unsigned long addr) { }
  * @syms_base:		Contents of the associated symbol table.
  * @loc_base:		Contents of the section to which relocations apply.
  * @addr_base:		The address where the section will be loaded in memory.
+ * @relative_symbols:	Are the symbols' st_value members relative?
+ * @check_symbols:	Fail if an unexpected symbol is found?
  * @obj_name:		The name of the ELF binary, for information messages.
  *
  * Applies RELA relocations to an ELF file already at its final location
@@ -84,11 +86,13 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			     const char *strtab, const Elf64_Rela *rela,
 			     unsigned int num_rela, void *syms_base,
 			     void *loc_base, Elf64_Addr addr_base,
+			     bool relative_symbols, bool check_symbols,
 			     const char *obj_name)
 {
 	unsigned int i;
 	unsigned long *location;
 	unsigned long address;
+	unsigned long sec_base;
 	unsigned long value;
 	const char *name;
 	Elf64_Sym *sym;
@@ -121,8 +125,36 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 		       name, (unsigned long)sym->st_value,
 		       (long)rela[i].r_addend);
 
+		if (check_symbols) {
+			/*
+			 * TOC symbols appear as undefined but should be
+			 * resolved as well, so allow them to be processed.
+			 */
+			if (sym->st_shndx == SHN_UNDEF &&
+					strcmp(name, ".TOC.") != 0) {
+				pr_err("Undefined symbol: %s\n", name);
+				return -ENOEXEC;
+			} else if (sym->st_shndx == SHN_COMMON) {
+				pr_err("Symbol '%s' in common section.\n", name);
+				return -ENOEXEC;
+			}
+		}
+
+		if (relative_symbols && sym->st_shndx != SHN_ABS) {
+			if (sym->st_shndx >= elf_info->ehdr->e_shnum) {
+				pr_err("Invalid section %d for symbol %s\n",
+				       sym->st_shndx, name);
+				return -ENOEXEC;
+			} else {
+				struct elf_shdr *sechdrs = elf_info->sechdrs;
+
+				sec_base = sechdrs[sym->st_shndx].sh_addr;
+			}
+		} else
+			sec_base = 0;
+
 		/* `Everything is relative'. */
-		value = sym->st_value + rela[i].r_addend;
+		value = sym->st_value + sec_base + rela[i].r_addend;
 
 		switch (ELF64_R_TYPE(rela[i].r_info)) {
 		case R_PPC64_ADDR32:
@@ -135,6 +167,10 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			*(unsigned long *)location = value;
 			break;
 
+		case R_PPC64_REL32:
+			*(uint32_t *)location = value - (uint32_t)(uint64_t)location;
+			break;
+
 		case R_PPC64_TOC:
 			*(unsigned long *)location = my_r2(elf_info);
 			break;
@@ -186,6 +222,14 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 				| (value & 0xfffc);
 			break;
 
+		case R_PPC64_TOC16_HI:
+			/* Subtract TOC pointer */
+			value -= my_r2(elf_info);
+			value = value >> 16;
+			*((uint16_t *) location)
+				= (*((uint16_t *) location) & ~0xffff)
+				| (value & 0xffff);
+
 		case R_PPC64_TOC16_HA:
 			/* Subtract TOC pointer */
 			value -= my_r2(elf_info);
@@ -195,6 +239,21 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 				| (value & 0xffff);
 			break;
 
+		case R_PPC64_REL14:
+			/* Convert value to relative */
+			value -= address;
+			if (value + 0x8000 > 0xffff || (value & 3) != 0) {
+				pr_err("%s: REL14 %li out of range!\n", obj_name,
+				       (long int)value);
+				return -ENOEXEC;
+			}
+
+			/* Only replace bits 2 through 16 */
+			*(uint32_t *)location
+				= (*(uint32_t *)location & ~0xfffc)
+				| (value & 0xfffc);
+			break;
+
 		case R_PPC_REL24:
 			/* FIXME: Handle weak symbols here --RR */
 			if (sym->st_shndx == SHN_UNDEF) {
@@ -263,6 +322,29 @@ int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value);
 			break;
 
+		case R_PPC64_ADDR16_LO:
+			*(uint16_t *)location = value & 0xffff;
+			break;
+
+		case R_PPC64_ADDR16_HI:
+			*(uint16_t *)location = (value >> 16) & 0xffff;
+			break;
+
+		case R_PPC64_ADDR16_HA:
+			*(uint16_t *)location = (((value + 0x8000) >> 16) &
+							0xffff);
+			break;
+
+		case R_PPC64_ADDR16_HIGHER:
+			*(uint16_t *)location = (((uint64_t)value >> 32) &
+							0xffff);
+			break;
+
+		case R_PPC64_ADDR16_HIGHEST:
+			*(uint16_t *)location = (((uint64_t)value >> 48) &
+							0xffff);
+			break;
+
 		case R_PPC64_REL16_HA:
 			/* Subtract location pointer */
 			value -= address;
diff --git a/arch/powerpc/kernel/module_64.c b/arch/powerpc/kernel/module_64.c
index 590e2413974f..10745ac6b004 100644
--- a/arch/powerpc/kernel/module_64.c
+++ b/arch/powerpc/kernel/module_64.c
@@ -443,6 +443,9 @@ int restore_r2(u32 *instruction, const char *obj_name)
  * When this function is called, the module is already at its final location in
  * memory, so Elf64_Shdr.sh_addr can be used for accessing the section
  * contents as well as the base address for relocations.
+ *
+ * Also, simplify_symbols already changed all symbols' st_value members
+ * to absolute addresses.
  */
 int apply_relocate_add(Elf64_Shdr *sechdrs,
 		       const char *strtab,
@@ -472,7 +475,7 @@ int apply_relocate_add(Elf64_Shdr *sechdrs,
 
 	return elf64_apply_relocate_add(&me->arch.elf_info, strtab, rela,
 					num_rela, syms_base, (void *) addr_base,
-					addr_base, me->name);
+					addr_base, false, false, me->name);
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 07/13] powerpc: Add functions to read ELF files of any endianness.

[Thiago Jung Bauermann]

A little endian kernel might need to kexec a big endian kernel (the
opposite is less likely but could happen as well), so we can't just cast
the buffer with the binary to ELF structs and use them as is done
elsewhere.

This patch adds functions which do byte-swapping as necessary when
populating the ELF structs. These functions will be used in the next
patch in the series.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  19 ++
 arch/powerpc/kernel/Makefile        |   2 +-
 arch/powerpc/kernel/elf_util.c      | 476 ++++++++++++++++++++++++++++++++++++
 3 files changed, 496 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
index 3405eeabe542..18703d56eabd 100644
--- a/arch/powerpc/include/asm/elf_util.h
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -20,6 +20,14 @@
 #include <linux/elf.h>
 
 struct elf_info {
+	/*
+	 * Where the ELF binary contents are kept.
+	 * Memory managed by the user of the struct.
+	 */
+	const char *buffer;
+
+	const struct elfhdr *ehdr;
+	const struct elf_phdr *proghdrs;
 	struct elf_shdr *sechdrs;
 
 	/* Index of stubs section. */
@@ -63,6 +71,17 @@ static inline unsigned long my_r2(const struct elf_info *elf_info)
 	return elf_info->sechdrs[elf_info->toc_section].sh_addr + 0x8000;
 }
 
+static inline bool elf_is_elf_file(const struct elfhdr *ehdr)
+{
+	return memcmp(ehdr->e_ident, ELFMAG, SELFMAG) == 0;
+}
+
+int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr,
+			 struct elf_info *elf_info);
+void elf_init_elf_info(const struct elfhdr *ehdr, struct elf_shdr *sechdrs,
+		       struct elf_info *elf_info);
+void elf_free_info(struct elf_info *elf_info);
+
 int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			     const char *strtab, const Elf64_Rela *rela,
 			     unsigned int num_rela, void *syms_base,
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index e38aace0a6e7..6159ec6ac032 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -124,7 +124,7 @@ obj-y				+= iomap.o
 endif
 
 ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
-obj-y				+= elf_util_64.o
+obj-y				+= elf_util.o elf_util_64.o
 endif
 
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
diff --git a/arch/powerpc/kernel/elf_util.c b/arch/powerpc/kernel/elf_util.c
new file mode 100644
index 000000000000..1df4a116ad90
--- /dev/null
+++ b/arch/powerpc/kernel/elf_util.c
@@ -0,0 +1,476 @@
+/*
+ * Utility functions to work with ELF files.
+ *
+ * Copyright (C) 2016, IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf.c. Heavily modified for the
+ * kernel by Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <asm/elf_util.h>
+#include <asm-generic/module.h>
+
+#if ELF_CLASS == ELFCLASS32
+#define elf_addr_to_cpu	elf32_to_cpu
+
+#ifndef Elf_Rel
+#define Elf_Rel		Elf32_Rel
+#endif /* Elf_Rel */
+#else /* ELF_CLASS == ELFCLASS32 */
+#define elf_addr_to_cpu	elf64_to_cpu
+
+#ifndef Elf_Rel
+#define Elf_Rel		Elf64_Rel
+#endif /* Elf_Rel */
+
+static uint64_t elf64_to_cpu(const struct elfhdr *ehdr, uint64_t value)
+{
+	if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
+		value = le64_to_cpu(value);
+	else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
+		value = be64_to_cpu(value);
+
+	return value;
+}
+#endif /* ELF_CLASS == ELFCLASS32 */
+
+static uint16_t elf16_to_cpu(const struct elfhdr *ehdr, uint16_t value)
+{
+	if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
+		value = le16_to_cpu(value);
+	else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
+		value = be16_to_cpu(value);
+
+	return value;
+}
+
+static uint32_t elf32_to_cpu(const struct elfhdr *ehdr, uint32_t value)
+{
+	if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
+		value = le32_to_cpu(value);
+	else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
+		value = be32_to_cpu(value);
+
+	return value;
+}
+
+/**
+ * elf_is_ehdr_sane - check that it is safe to use the ELF header
+ * @buf_len:	size of the buffer in which the ELF file is loaded.
+ */
+static bool elf_is_ehdr_sane(const struct elfhdr *ehdr, size_t buf_len)
+{
+	if (ehdr->e_phnum > 0 && ehdr->e_phentsize != sizeof(struct elf_phdr)) {
+		pr_debug("Bad program header size.\n");
+		return false;
+	} else if (ehdr->e_shnum > 0 &&
+		   ehdr->e_shentsize != sizeof(struct elf_shdr)) {
+		pr_debug("Bad section header size.\n");
+		return false;
+	} else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
+		   ehdr->e_version != EV_CURRENT) {
+		pr_debug("Unknown ELF version.\n");
+		return false;
+	}
+
+	if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) {
+		size_t phdr_size;
+
+		/*
+		 * e_phnum is at most 65535 so calculating the size of the
+		 * program header cannot overflow.
+		 */
+		phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum;
+
+		/* Sanity check the program header table location. */
+		if (ehdr->e_phoff + phdr_size < ehdr->e_phoff) {
+			pr_debug("Program headers at invalid location.\n");
+			return false;
+		} else if (ehdr->e_phoff + phdr_size > buf_len) {
+			pr_debug("Program headers truncated.\n");
+			return false;
+		}
+	}
+
+	if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) {
+		size_t shdr_size;
+
+		/*
+		 * e_shnum is at most 65536 so calculating
+		 * the size of the section header cannot overflow.
+		 */
+		shdr_size = sizeof(struct elf_shdr) * ehdr->e_shnum;
+
+		/* Sanity check the section header table location. */
+		if (ehdr->e_shoff + shdr_size < ehdr->e_shoff) {
+			pr_debug("Section headers at invalid location.\n");
+			return false;
+		} else if (ehdr->e_shoff + shdr_size > buf_len) {
+			pr_debug("Section headers truncated.\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int elf_read_ehdr(const char *buf, size_t len, struct elfhdr *ehdr)
+{
+	struct elfhdr *buf_ehdr;
+
+	if (len < sizeof(*buf_ehdr)) {
+		pr_debug("Buffer is too small to hold ELF header.\n");
+		return -ENOEXEC;
+	}
+
+	memset(ehdr, 0, sizeof(*ehdr));
+	memcpy(ehdr->e_ident, buf, sizeof(ehdr->e_ident));
+	if (!elf_is_elf_file(ehdr)) {
+		pr_debug("No ELF header magic.\n");
+		return -ENOEXEC;
+	}
+
+	if (ehdr->e_ident[EI_CLASS] != ELF_CLASS) {
+		pr_debug("Not a supported ELF class.\n");
+		return -1;
+	} else  if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB &&
+		ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
+		pr_debug("Not a supported ELF data format.\n");
+		return -ENOEXEC;
+	}
+
+	buf_ehdr = (struct elfhdr *) buf;
+	if (elf16_to_cpu(ehdr, buf_ehdr->e_ehsize) != sizeof(*buf_ehdr)) {
+		pr_debug("Bad ELF header size.\n");
+		return -ENOEXEC;
+	}
+
+	ehdr->e_type      = elf16_to_cpu(ehdr, buf_ehdr->e_type);
+	ehdr->e_machine   = elf16_to_cpu(ehdr, buf_ehdr->e_machine);
+	ehdr->e_version   = elf32_to_cpu(ehdr, buf_ehdr->e_version);
+	ehdr->e_entry     = elf_addr_to_cpu(ehdr, buf_ehdr->e_entry);
+	ehdr->e_phoff     = elf_addr_to_cpu(ehdr, buf_ehdr->e_phoff);
+	ehdr->e_shoff     = elf_addr_to_cpu(ehdr, buf_ehdr->e_shoff);
+	ehdr->e_flags     = elf32_to_cpu(ehdr, buf_ehdr->e_flags);
+	ehdr->e_phentsize = elf16_to_cpu(ehdr, buf_ehdr->e_phentsize);
+	ehdr->e_phnum     = elf16_to_cpu(ehdr, buf_ehdr->e_phnum);
+	ehdr->e_shentsize = elf16_to_cpu(ehdr, buf_ehdr->e_shentsize);
+	ehdr->e_shnum     = elf16_to_cpu(ehdr, buf_ehdr->e_shnum);
+	ehdr->e_shstrndx  = elf16_to_cpu(ehdr, buf_ehdr->e_shstrndx);
+
+	return elf_is_ehdr_sane(ehdr, len) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_is_phdr_sane - check that it is safe to use the program header
+ * @buf_len:	size of the buffer in which the ELF file is loaded.
+ */
+static bool elf_is_phdr_sane(const struct elf_phdr *phdr, size_t buf_len)
+{
+
+	if (phdr->p_offset + phdr->p_filesz < phdr->p_offset) {
+		pr_debug("ELF segment location wraps around.\n");
+		return false;
+	} else if (phdr->p_offset + phdr->p_filesz > buf_len) {
+		pr_debug("ELF segment not in file.\n");
+		return false;
+	} else if (phdr->p_paddr + phdr->p_memsz < phdr->p_paddr) {
+		pr_debug("ELF segment address wraps around.\n");
+		return false;
+	}
+
+	return true;
+}
+
+static int elf_read_phdr(const char *buf, size_t len, struct elf_info *elf_info,
+			 int idx)
+{
+	/* Override the const in proghdrs, we are the ones doing the loading. */
+	struct elf_phdr *phdr = (struct elf_phdr *) &elf_info->proghdrs[idx];
+	const char *pbuf;
+	struct elf_phdr *buf_phdr;
+
+	pbuf = buf + elf_info->ehdr->e_phoff + (idx * sizeof(*buf_phdr));
+	buf_phdr = (struct elf_phdr *) pbuf;
+
+	phdr->p_type   = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_type);
+	phdr->p_offset = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_offset);
+	phdr->p_paddr  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_paddr);
+	phdr->p_vaddr  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_vaddr);
+	phdr->p_flags  = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_flags);
+
+	/*
+	 * The following fields have a type equivalent to Elf_Addr
+	 * both in 32 bit and 64 bit ELF.
+	 */
+	phdr->p_filesz = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_filesz);
+	phdr->p_memsz  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_memsz);
+	phdr->p_align  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_align);
+
+	return elf_is_phdr_sane(phdr, len) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_read_phdrs - read the program headers from the buffer
+ *
+ * This function assumes that the program header table was checked for sanity.
+ * Use elf_is_ehdr_sane() if it wasn't.
+ */
+static int elf_read_phdrs(const char *buf, size_t len,
+			  struct elf_info *elf_info)
+{
+	size_t phdr_size, i;
+	const struct elfhdr *ehdr = elf_info->ehdr;
+
+	/*
+	 * e_phnum is at most 65535 so calculating the size of the
+	 * program header cannot overflow.
+	 */
+	phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum;
+
+	elf_info->proghdrs = kzalloc(phdr_size, GFP_KERNEL);
+	if (!elf_info->proghdrs)
+		return -ENOMEM;
+
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		int ret;
+
+		ret = elf_read_phdr(buf, len, elf_info, i);
+		if (ret) {
+			kfree(elf_info->proghdrs);
+			elf_info->proghdrs = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * elf_is_shdr_sane - check that it is safe to use the section header
+ * @buf_len:	size of the buffer in which the ELF file is loaded.
+ */
+static bool elf_is_shdr_sane(const struct elf_shdr *shdr, size_t buf_len)
+{
+	bool size_ok;
+
+	/* SHT_NULL headers have undefined values, so we can't check them. */
+	if (shdr->sh_type == SHT_NULL)
+		return true;
+
+	/* Now verify sh_entsize */
+	switch (shdr->sh_type) {
+	case SHT_SYMTAB:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Sym);
+		break;
+	case SHT_RELA:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Rela);
+		break;
+	case SHT_DYNAMIC:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Dyn);
+		break;
+	case SHT_REL:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Rel);
+		break;
+	case SHT_NOTE:
+	case SHT_PROGBITS:
+	case SHT_HASH:
+	case SHT_NOBITS:
+	default:
+		/*
+		 * This is a section whose entsize requirements
+		 * I don't care about.  If I don't know about
+		 * the section I can't care about it's entsize
+		 * requirements.
+		 */
+		size_ok = true;
+		break;
+	}
+
+	if (!size_ok) {
+		pr_debug("ELF section with wrong entry size.\n");
+		return false;
+	} else if (shdr->sh_addr + shdr->sh_size < shdr->sh_addr) {
+		pr_debug("ELF section address wraps around.\n");
+		return false;
+	}
+
+	if (shdr->sh_type != SHT_NOBITS) {
+		if (shdr->sh_offset + shdr->sh_size < shdr->sh_offset) {
+			pr_debug("ELF section location wraps around.\n");
+			return false;
+		} else if (shdr->sh_offset + shdr->sh_size > buf_len) {
+			pr_debug("ELF section not in file.\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int elf_read_shdr(const char *buf, size_t len, struct elf_info *elf_info,
+			 int idx)
+{
+	struct elf_shdr *shdr = &elf_info->sechdrs[idx];
+	const struct elfhdr *ehdr = elf_info->ehdr;
+	const char *sbuf;
+	struct elf_shdr *buf_shdr;
+
+	sbuf = buf + ehdr->e_shoff + idx * sizeof(*buf_shdr);
+	buf_shdr = (struct elf_shdr *) sbuf;
+
+	shdr->sh_name      = elf32_to_cpu(ehdr, buf_shdr->sh_name);
+	shdr->sh_type      = elf32_to_cpu(ehdr, buf_shdr->sh_type);
+	shdr->sh_addr      = elf_addr_to_cpu(ehdr, buf_shdr->sh_addr);
+	shdr->sh_offset    = elf_addr_to_cpu(ehdr, buf_shdr->sh_offset);
+	shdr->sh_link      = elf32_to_cpu(ehdr, buf_shdr->sh_link);
+	shdr->sh_info      = elf32_to_cpu(ehdr, buf_shdr->sh_info);
+
+	/*
+	 * The following fields have a type equivalent to Elf_Addr
+	 * both in 32 bit and 64 bit ELF.
+	 */
+	shdr->sh_flags     = elf_addr_to_cpu(ehdr, buf_shdr->sh_flags);
+	shdr->sh_size      = elf_addr_to_cpu(ehdr, buf_shdr->sh_size);
+	shdr->sh_addralign = elf_addr_to_cpu(ehdr, buf_shdr->sh_addralign);
+	shdr->sh_entsize   = elf_addr_to_cpu(ehdr, buf_shdr->sh_entsize);
+
+	return elf_is_shdr_sane(shdr, len) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_read_shdrs - read the section headers from the buffer
+ *
+ * This function assumes that the section header table was checked for sanity.
+ * Use elf_is_ehdr_sane() if it wasn't.
+ */
+static int elf_read_shdrs(const char *buf, size_t len,
+			  struct elf_info *elf_info)
+{
+	size_t shdr_size, i;
+
+	/*
+	 * e_shnum is at most 65536 so calculating
+	 * the size of the section header cannot overflow.
+	 */
+	shdr_size = sizeof(struct elf_shdr) * elf_info->ehdr->e_shnum;
+
+	elf_info->sechdrs = kzalloc(shdr_size, GFP_KERNEL);
+	if (!elf_info->sechdrs)
+		return -ENOMEM;
+
+	for (i = 0; i < elf_info->ehdr->e_shnum; i++) {
+		int ret;
+
+		ret = elf_read_shdr(buf, len, elf_info, i);
+		if (ret) {
+			kfree(elf_info->sechdrs);
+			elf_info->sechdrs = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * elf_read_from_buffer - read ELF file and sets up ELF header and ELF info
+ * @buf:	Buffer to read ELF file from.
+ * @len:	Size of @buf.
+ * @ehdr:	Pointer to existing struct which will be populated.
+ * @elf_info:	Pointer to existing struct which will be populated.
+ *
+ * This function allows reading ELF files with different byte order than
+ * the kernel, byte-swapping the fields as needed.
+ *
+ * Return:
+ * On success returns 0, and the caller should call elf_free_info(elf_info) to
+ * free the memory allocated for the section and program headers.
+ */
+int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr,
+			 struct elf_info *elf_info)
+{
+	int ret;
+
+	ret = elf_read_ehdr(buf, len, ehdr);
+	if (ret)
+		return ret;
+
+	elf_info->buffer = buf;
+	elf_info->ehdr = ehdr;
+	if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) {
+		ret = elf_read_phdrs(buf, len, elf_info);
+		if (ret)
+			return ret;
+	}
+	if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) {
+		ret = elf_read_shdrs(buf, len, elf_info);
+		if (ret) {
+			kfree(elf_info->proghdrs);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * elf_init_elf_info - initialize elf_info from existing information
+ * @ehdr:	Pointer to already loaded ELF header.
+ * @sechdrs:	Pointer to already loaded section headers contents.
+ * @elf_info:	Pointer to existing struct which will be populated.
+ *
+ * If the ELF binary was not loaded using elf_read_from_buffer, this function
+ * can be used to obtain a struct elf_info for use with other ELF utility
+ * functions.
+ *
+ * The caller is responsible for managing @sechdrs memory, users of this
+ * function don't need to call elf_free_info() if they free this memory
+ * separately.
+ */
+void elf_init_elf_info(const struct elfhdr *ehdr, struct elf_shdr *sechdrs,
+		       struct elf_info *elf_info)
+{
+	int i;
+	const char *shstrtab;
+
+	memset(elf_info, 0, sizeof(*elf_info));
+
+	/* Section header string table. */
+	shstrtab = (const char *) sechdrs[ehdr->e_shstrndx].sh_offset;
+
+	for (i = 0; i < ehdr->e_shnum; i++) {
+		if (sechdrs[i].sh_size == 0)
+			continue;
+
+		if (!strcmp(&shstrtab[sechdrs[i].sh_name], ".stubs"))
+			elf_info->stubs_section = i;
+		else if (!strcmp(&shstrtab[sechdrs[i].sh_name], ".toc"))
+			elf_info->toc_section = i;
+	}
+
+	elf_info->ehdr = ehdr;
+	elf_info->sechdrs = sechdrs;
+}
+
+/**
+ * elf_free_info - free memory allocated by elf_read_from_buffer
+ */
+void elf_free_info(struct elf_info *elf_info)
+{
+	kfree(elf_info->proghdrs);
+	kfree(elf_info->sechdrs);
+	memset(elf_info, 0, sizeof(*elf_info));
+}
-- 
1.9.1

[PATCH v5 07/13] powerpc: Add functions to read ELF files of any endianness.

[Thiago Jung Bauermann]

A little endian kernel might need to kexec a big endian kernel (the
opposite is less likely but could happen as well), so we can't just cast
the buffer with the binary to ELF structs and use them as is done
elsewhere.

This patch adds functions which do byte-swapping as necessary when
populating the ELF structs. These functions will be used in the next
patch in the series.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/elf_util.h |  19 ++
 arch/powerpc/kernel/Makefile        |   2 +-
 arch/powerpc/kernel/elf_util.c      | 476 ++++++++++++++++++++++++++++++++++++
 3 files changed, 496 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
index 3405eeabe542..18703d56eabd 100644
--- a/arch/powerpc/include/asm/elf_util.h
+++ b/arch/powerpc/include/asm/elf_util.h
@@ -20,6 +20,14 @@
 #include <linux/elf.h>
 
 struct elf_info {
+	/*
+	 * Where the ELF binary contents are kept.
+	 * Memory managed by the user of the struct.
+	 */
+	const char *buffer;
+
+	const struct elfhdr *ehdr;
+	const struct elf_phdr *proghdrs;
 	struct elf_shdr *sechdrs;
 
 	/* Index of stubs section. */
@@ -63,6 +71,17 @@ static inline unsigned long my_r2(const struct elf_info *elf_info)
 	return elf_info->sechdrs[elf_info->toc_section].sh_addr + 0x8000;
 }
 
+static inline bool elf_is_elf_file(const struct elfhdr *ehdr)
+{
+	return memcmp(ehdr->e_ident, ELFMAG, SELFMAG) == 0;
+}
+
+int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr,
+			 struct elf_info *elf_info);
+void elf_init_elf_info(const struct elfhdr *ehdr, struct elf_shdr *sechdrs,
+		       struct elf_info *elf_info);
+void elf_free_info(struct elf_info *elf_info);
+
 int elf64_apply_relocate_add(const struct elf_info *elf_info,
 			     const char *strtab, const Elf64_Rela *rela,
 			     unsigned int num_rela, void *syms_base,
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index e38aace0a6e7..6159ec6ac032 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -124,7 +124,7 @@ obj-y				+= iomap.o
 endif
 
 ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
-obj-y				+= elf_util_64.o
+obj-y				+= elf_util.o elf_util_64.o
 endif
 
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
diff --git a/arch/powerpc/kernel/elf_util.c b/arch/powerpc/kernel/elf_util.c
new file mode 100644
index 000000000000..1df4a116ad90
--- /dev/null
+++ b/arch/powerpc/kernel/elf_util.c
@@ -0,0 +1,476 @@
+/*
+ * Utility functions to work with ELF files.
+ *
+ * Copyright (C) 2016, IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf.c. Heavily modified for the
+ * kernel by Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/slab.h>
+#include <asm/elf_util.h>
+#include <asm-generic/module.h>
+
+#if ELF_CLASS == ELFCLASS32
+#define elf_addr_to_cpu	elf32_to_cpu
+
+#ifndef Elf_Rel
+#define Elf_Rel		Elf32_Rel
+#endif /* Elf_Rel */
+#else /* ELF_CLASS == ELFCLASS32 */
+#define elf_addr_to_cpu	elf64_to_cpu
+
+#ifndef Elf_Rel
+#define Elf_Rel		Elf64_Rel
+#endif /* Elf_Rel */
+
+static uint64_t elf64_to_cpu(const struct elfhdr *ehdr, uint64_t value)
+{
+	if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
+		value = le64_to_cpu(value);
+	else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
+		value = be64_to_cpu(value);
+
+	return value;
+}
+#endif /* ELF_CLASS == ELFCLASS32 */
+
+static uint16_t elf16_to_cpu(const struct elfhdr *ehdr, uint16_t value)
+{
+	if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
+		value = le16_to_cpu(value);
+	else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
+		value = be16_to_cpu(value);
+
+	return value;
+}
+
+static uint32_t elf32_to_cpu(const struct elfhdr *ehdr, uint32_t value)
+{
+	if (ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
+		value = le32_to_cpu(value);
+	else if (ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
+		value = be32_to_cpu(value);
+
+	return value;
+}
+
+/**
+ * elf_is_ehdr_sane - check that it is safe to use the ELF header
+ * @buf_len:	size of the buffer in which the ELF file is loaded.
+ */
+static bool elf_is_ehdr_sane(const struct elfhdr *ehdr, size_t buf_len)
+{
+	if (ehdr->e_phnum > 0 && ehdr->e_phentsize != sizeof(struct elf_phdr)) {
+		pr_debug("Bad program header size.\n");
+		return false;
+	} else if (ehdr->e_shnum > 0 &&
+		   ehdr->e_shentsize != sizeof(struct elf_shdr)) {
+		pr_debug("Bad section header size.\n");
+		return false;
+	} else if (ehdr->e_ident[EI_VERSION] != EV_CURRENT ||
+		   ehdr->e_version != EV_CURRENT) {
+		pr_debug("Unknown ELF version.\n");
+		return false;
+	}
+
+	if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) {
+		size_t phdr_size;
+
+		/*
+		 * e_phnum is at most 65535 so calculating the size of the
+		 * program header cannot overflow.
+		 */
+		phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum;
+
+		/* Sanity check the program header table location. */
+		if (ehdr->e_phoff + phdr_size < ehdr->e_phoff) {
+			pr_debug("Program headers at invalid location.\n");
+			return false;
+		} else if (ehdr->e_phoff + phdr_size > buf_len) {
+			pr_debug("Program headers truncated.\n");
+			return false;
+		}
+	}
+
+	if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) {
+		size_t shdr_size;
+
+		/*
+		 * e_shnum is at most 65536 so calculating
+		 * the size of the section header cannot overflow.
+		 */
+		shdr_size = sizeof(struct elf_shdr) * ehdr->e_shnum;
+
+		/* Sanity check the section header table location. */
+		if (ehdr->e_shoff + shdr_size < ehdr->e_shoff) {
+			pr_debug("Section headers at invalid location.\n");
+			return false;
+		} else if (ehdr->e_shoff + shdr_size > buf_len) {
+			pr_debug("Section headers truncated.\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int elf_read_ehdr(const char *buf, size_t len, struct elfhdr *ehdr)
+{
+	struct elfhdr *buf_ehdr;
+
+	if (len < sizeof(*buf_ehdr)) {
+		pr_debug("Buffer is too small to hold ELF header.\n");
+		return -ENOEXEC;
+	}
+
+	memset(ehdr, 0, sizeof(*ehdr));
+	memcpy(ehdr->e_ident, buf, sizeof(ehdr->e_ident));
+	if (!elf_is_elf_file(ehdr)) {
+		pr_debug("No ELF header magic.\n");
+		return -ENOEXEC;
+	}
+
+	if (ehdr->e_ident[EI_CLASS] != ELF_CLASS) {
+		pr_debug("Not a supported ELF class.\n");
+		return -1;
+	} else  if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB &&
+		ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
+		pr_debug("Not a supported ELF data format.\n");
+		return -ENOEXEC;
+	}
+
+	buf_ehdr = (struct elfhdr *) buf;
+	if (elf16_to_cpu(ehdr, buf_ehdr->e_ehsize) != sizeof(*buf_ehdr)) {
+		pr_debug("Bad ELF header size.\n");
+		return -ENOEXEC;
+	}
+
+	ehdr->e_type      = elf16_to_cpu(ehdr, buf_ehdr->e_type);
+	ehdr->e_machine   = elf16_to_cpu(ehdr, buf_ehdr->e_machine);
+	ehdr->e_version   = elf32_to_cpu(ehdr, buf_ehdr->e_version);
+	ehdr->e_entry     = elf_addr_to_cpu(ehdr, buf_ehdr->e_entry);
+	ehdr->e_phoff     = elf_addr_to_cpu(ehdr, buf_ehdr->e_phoff);
+	ehdr->e_shoff     = elf_addr_to_cpu(ehdr, buf_ehdr->e_shoff);
+	ehdr->e_flags     = elf32_to_cpu(ehdr, buf_ehdr->e_flags);
+	ehdr->e_phentsize = elf16_to_cpu(ehdr, buf_ehdr->e_phentsize);
+	ehdr->e_phnum     = elf16_to_cpu(ehdr, buf_ehdr->e_phnum);
+	ehdr->e_shentsize = elf16_to_cpu(ehdr, buf_ehdr->e_shentsize);
+	ehdr->e_shnum     = elf16_to_cpu(ehdr, buf_ehdr->e_shnum);
+	ehdr->e_shstrndx  = elf16_to_cpu(ehdr, buf_ehdr->e_shstrndx);
+
+	return elf_is_ehdr_sane(ehdr, len) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_is_phdr_sane - check that it is safe to use the program header
+ * @buf_len:	size of the buffer in which the ELF file is loaded.
+ */
+static bool elf_is_phdr_sane(const struct elf_phdr *phdr, size_t buf_len)
+{
+
+	if (phdr->p_offset + phdr->p_filesz < phdr->p_offset) {
+		pr_debug("ELF segment location wraps around.\n");
+		return false;
+	} else if (phdr->p_offset + phdr->p_filesz > buf_len) {
+		pr_debug("ELF segment not in file.\n");
+		return false;
+	} else if (phdr->p_paddr + phdr->p_memsz < phdr->p_paddr) {
+		pr_debug("ELF segment address wraps around.\n");
+		return false;
+	}
+
+	return true;
+}
+
+static int elf_read_phdr(const char *buf, size_t len, struct elf_info *elf_info,
+			 int idx)
+{
+	/* Override the const in proghdrs, we are the ones doing the loading. */
+	struct elf_phdr *phdr = (struct elf_phdr *) &elf_info->proghdrs[idx];
+	const char *pbuf;
+	struct elf_phdr *buf_phdr;
+
+	pbuf = buf + elf_info->ehdr->e_phoff + (idx * sizeof(*buf_phdr));
+	buf_phdr = (struct elf_phdr *) pbuf;
+
+	phdr->p_type   = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_type);
+	phdr->p_offset = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_offset);
+	phdr->p_paddr  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_paddr);
+	phdr->p_vaddr  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_vaddr);
+	phdr->p_flags  = elf32_to_cpu(elf_info->ehdr, buf_phdr->p_flags);
+
+	/*
+	 * The following fields have a type equivalent to Elf_Addr
+	 * both in 32 bit and 64 bit ELF.
+	 */
+	phdr->p_filesz = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_filesz);
+	phdr->p_memsz  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_memsz);
+	phdr->p_align  = elf_addr_to_cpu(elf_info->ehdr, buf_phdr->p_align);
+
+	return elf_is_phdr_sane(phdr, len) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_read_phdrs - read the program headers from the buffer
+ *
+ * This function assumes that the program header table was checked for sanity.
+ * Use elf_is_ehdr_sane() if it wasn't.
+ */
+static int elf_read_phdrs(const char *buf, size_t len,
+			  struct elf_info *elf_info)
+{
+	size_t phdr_size, i;
+	const struct elfhdr *ehdr = elf_info->ehdr;
+
+	/*
+	 * e_phnum is at most 65535 so calculating the size of the
+	 * program header cannot overflow.
+	 */
+	phdr_size = sizeof(struct elf_phdr) * ehdr->e_phnum;
+
+	elf_info->proghdrs = kzalloc(phdr_size, GFP_KERNEL);
+	if (!elf_info->proghdrs)
+		return -ENOMEM;
+
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		int ret;
+
+		ret = elf_read_phdr(buf, len, elf_info, i);
+		if (ret) {
+			kfree(elf_info->proghdrs);
+			elf_info->proghdrs = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * elf_is_shdr_sane - check that it is safe to use the section header
+ * @buf_len:	size of the buffer in which the ELF file is loaded.
+ */
+static bool elf_is_shdr_sane(const struct elf_shdr *shdr, size_t buf_len)
+{
+	bool size_ok;
+
+	/* SHT_NULL headers have undefined values, so we can't check them. */
+	if (shdr->sh_type == SHT_NULL)
+		return true;
+
+	/* Now verify sh_entsize */
+	switch (shdr->sh_type) {
+	case SHT_SYMTAB:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Sym);
+		break;
+	case SHT_RELA:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Rela);
+		break;
+	case SHT_DYNAMIC:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Dyn);
+		break;
+	case SHT_REL:
+		size_ok = shdr->sh_entsize == sizeof(Elf_Rel);
+		break;
+	case SHT_NOTE:
+	case SHT_PROGBITS:
+	case SHT_HASH:
+	case SHT_NOBITS:
+	default:
+		/*
+		 * This is a section whose entsize requirements
+		 * I don't care about.  If I don't know about
+		 * the section I can't care about it's entsize
+		 * requirements.
+		 */
+		size_ok = true;
+		break;
+	}
+
+	if (!size_ok) {
+		pr_debug("ELF section with wrong entry size.\n");
+		return false;
+	} else if (shdr->sh_addr + shdr->sh_size < shdr->sh_addr) {
+		pr_debug("ELF section address wraps around.\n");
+		return false;
+	}
+
+	if (shdr->sh_type != SHT_NOBITS) {
+		if (shdr->sh_offset + shdr->sh_size < shdr->sh_offset) {
+			pr_debug("ELF section location wraps around.\n");
+			return false;
+		} else if (shdr->sh_offset + shdr->sh_size > buf_len) {
+			pr_debug("ELF section not in file.\n");
+			return false;
+		}
+	}
+
+	return true;
+}
+
+static int elf_read_shdr(const char *buf, size_t len, struct elf_info *elf_info,
+			 int idx)
+{
+	struct elf_shdr *shdr = &elf_info->sechdrs[idx];
+	const struct elfhdr *ehdr = elf_info->ehdr;
+	const char *sbuf;
+	struct elf_shdr *buf_shdr;
+
+	sbuf = buf + ehdr->e_shoff + idx * sizeof(*buf_shdr);
+	buf_shdr = (struct elf_shdr *) sbuf;
+
+	shdr->sh_name      = elf32_to_cpu(ehdr, buf_shdr->sh_name);
+	shdr->sh_type      = elf32_to_cpu(ehdr, buf_shdr->sh_type);
+	shdr->sh_addr      = elf_addr_to_cpu(ehdr, buf_shdr->sh_addr);
+	shdr->sh_offset    = elf_addr_to_cpu(ehdr, buf_shdr->sh_offset);
+	shdr->sh_link      = elf32_to_cpu(ehdr, buf_shdr->sh_link);
+	shdr->sh_info      = elf32_to_cpu(ehdr, buf_shdr->sh_info);
+
+	/*
+	 * The following fields have a type equivalent to Elf_Addr
+	 * both in 32 bit and 64 bit ELF.
+	 */
+	shdr->sh_flags     = elf_addr_to_cpu(ehdr, buf_shdr->sh_flags);
+	shdr->sh_size      = elf_addr_to_cpu(ehdr, buf_shdr->sh_size);
+	shdr->sh_addralign = elf_addr_to_cpu(ehdr, buf_shdr->sh_addralign);
+	shdr->sh_entsize   = elf_addr_to_cpu(ehdr, buf_shdr->sh_entsize);
+
+	return elf_is_shdr_sane(shdr, len) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_read_shdrs - read the section headers from the buffer
+ *
+ * This function assumes that the section header table was checked for sanity.
+ * Use elf_is_ehdr_sane() if it wasn't.
+ */
+static int elf_read_shdrs(const char *buf, size_t len,
+			  struct elf_info *elf_info)
+{
+	size_t shdr_size, i;
+
+	/*
+	 * e_shnum is at most 65536 so calculating
+	 * the size of the section header cannot overflow.
+	 */
+	shdr_size = sizeof(struct elf_shdr) * elf_info->ehdr->e_shnum;
+
+	elf_info->sechdrs = kzalloc(shdr_size, GFP_KERNEL);
+	if (!elf_info->sechdrs)
+		return -ENOMEM;
+
+	for (i = 0; i < elf_info->ehdr->e_shnum; i++) {
+		int ret;
+
+		ret = elf_read_shdr(buf, len, elf_info, i);
+		if (ret) {
+			kfree(elf_info->sechdrs);
+			elf_info->sechdrs = NULL;
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * elf_read_from_buffer - read ELF file and sets up ELF header and ELF info
+ * @buf:	Buffer to read ELF file from.
+ * @len:	Size of @buf.
+ * @ehdr:	Pointer to existing struct which will be populated.
+ * @elf_info:	Pointer to existing struct which will be populated.
+ *
+ * This function allows reading ELF files with different byte order than
+ * the kernel, byte-swapping the fields as needed.
+ *
+ * Return:
+ * On success returns 0, and the caller should call elf_free_info(elf_info) to
+ * free the memory allocated for the section and program headers.
+ */
+int elf_read_from_buffer(const char *buf, size_t len, struct elfhdr *ehdr,
+			 struct elf_info *elf_info)
+{
+	int ret;
+
+	ret = elf_read_ehdr(buf, len, ehdr);
+	if (ret)
+		return ret;
+
+	elf_info->buffer = buf;
+	elf_info->ehdr = ehdr;
+	if (ehdr->e_phoff > 0 && ehdr->e_phnum > 0) {
+		ret = elf_read_phdrs(buf, len, elf_info);
+		if (ret)
+			return ret;
+	}
+	if (ehdr->e_shoff > 0 && ehdr->e_shnum > 0) {
+		ret = elf_read_shdrs(buf, len, elf_info);
+		if (ret) {
+			kfree(elf_info->proghdrs);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * elf_init_elf_info - initialize elf_info from existing information
+ * @ehdr:	Pointer to already loaded ELF header.
+ * @sechdrs:	Pointer to already loaded section headers contents.
+ * @elf_info:	Pointer to existing struct which will be populated.
+ *
+ * If the ELF binary was not loaded using elf_read_from_buffer, this function
+ * can be used to obtain a struct elf_info for use with other ELF utility
+ * functions.
+ *
+ * The caller is responsible for managing @sechdrs memory, users of this
+ * function don't need to call elf_free_info() if they free this memory
+ * separately.
+ */
+void elf_init_elf_info(const struct elfhdr *ehdr, struct elf_shdr *sechdrs,
+		       struct elf_info *elf_info)
+{
+	int i;
+	const char *shstrtab;
+
+	memset(elf_info, 0, sizeof(*elf_info));
+
+	/* Section header string table. */
+	shstrtab = (const char *) sechdrs[ehdr->e_shstrndx].sh_offset;
+
+	for (i = 0; i < ehdr->e_shnum; i++) {
+		if (sechdrs[i].sh_size == 0)
+			continue;
+
+		if (!strcmp(&shstrtab[sechdrs[i].sh_name], ".stubs"))
+			elf_info->stubs_section = i;
+		else if (!strcmp(&shstrtab[sechdrs[i].sh_name], ".toc"))
+			elf_info->toc_section = i;
+	}
+
+	elf_info->ehdr = ehdr;
+	elf_info->sechdrs = sechdrs;
+}
+
+/**
+ * elf_free_info - free memory allocated by elf_read_from_buffer
+ */
+void elf_free_info(struct elf_info *elf_info)
+{
+	kfree(elf_info->proghdrs);
+	kfree(elf_info->sechdrs);
+	memset(elf_info, 0, sizeof(*elf_info));
+}
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 08/13] powerpc: Implement kexec_file_load.

[Thiago Jung Bauermann]

arch_kexec_walk_mem and arch_kexec_apply_relocations_add are used by
generic kexec code, while setup_purgatory is powerpc-specific and sets
runtime variables needed by the powerpc purgatory implementation.

Signed-off-by: Josh Sklar <sklar@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/Kconfig                   |  13 ++
 arch/powerpc/include/asm/kexec.h       |   7 +
 arch/powerpc/include/asm/systbl.h      |   1 +
 arch/powerpc/include/asm/unistd.h      |   2 +-
 arch/powerpc/include/uapi/asm/unistd.h |   1 +
 arch/powerpc/kernel/Makefile           |   4 +-
 arch/powerpc/kernel/machine_kexec_64.c | 252 +++++++++++++++++++++++++++++++++
 7 files changed, 278 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ec4047e170a0..ff362ca60d1b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -459,6 +459,19 @@ config KEXEC
 	  interface is strongly in flux, so no good recommendation can be
 	  made.
 
+config KEXEC_FILE
+	bool "kexec file based system call"
+	select KEXEC_CORE
+	select BUILD_BIN2C
+	depends on PPC64
+	depends on CRYPTO=y
+	depends on CRYPTO_SHA256=y
+	help
+	  This is a new version of the kexec system call. This call is
+	  file based and takes in file descriptors as system call arguments
+	  for kernel and initramfs as opposed to a list of segments as is the
+	  case for the older kexec call.
+
 config RELOCATABLE
 	bool "Build a relocatable kernel"
 	depends on (PPC64 && !COMPILE_TEST) || (FLATMEM && (44x || FSL_BOOKE))
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index a46f5f45570c..83b81b7bdca1 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -91,6 +91,13 @@ static inline bool kdump_in_progress(void)
 	return crashing_cpu >= 0;
 }
 
+#ifdef CONFIG_KEXEC_FILE
+int setup_purgatory(struct kimage *image, const void *slave_code,
+		    const void *fdt, unsigned long kernel_load_addr,
+		    unsigned long fdt_load_addr, unsigned long stack_top,
+		    int debug);
+#endif /* CONFIG_KEXEC_FILE */
+
 #else /* !CONFIG_KEXEC */
 static inline void crash_kexec_secondary(struct pt_regs *regs) { }
 
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index 2fc5d4db503c..4b369d83fe9c 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -386,3 +386,4 @@ SYSCALL(mlock2)
 SYSCALL(copy_file_range)
 COMPAT_SYS_SPU(preadv2)
 COMPAT_SYS_SPU(pwritev2)
+SYSCALL(kexec_file_load)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index cf12c580f6b2..a01e97d3f305 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls		382
+#define NR_syscalls		383
 
 #define __NR__exit __NR_exit
 
diff --git a/arch/powerpc/include/uapi/asm/unistd.h b/arch/powerpc/include/uapi/asm/unistd.h
index e9f5f41aa55a..2f26335a3c42 100644
--- a/arch/powerpc/include/uapi/asm/unistd.h
+++ b/arch/powerpc/include/uapi/asm/unistd.h
@@ -392,5 +392,6 @@
 #define __NR_copy_file_range	379
 #define __NR_preadv2		380
 #define __NR_pwritev2		381
+#define __NR_kexec_file_load	382
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 6159ec6ac032..ce18a985bcfc 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -123,9 +123,11 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y				+= iomap.o
 endif
 
-ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
+ifneq ($(CONFIG_MODULES)$(CONFIG_KEXEC_FILE),)
+ifeq ($(CONFIG_WORD_SIZE),64)
 obj-y				+= elf_util.o elf_util_64.o
 endif
+endif
 
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
 
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 4c780a342282..1e678dc5096a 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -18,6 +18,8 @@
 #include <linux/kernel.h>
 #include <linux/cpu.h>
 #include <linux/hardirq.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
 
 #include <asm/page.h>
 #include <asm/current.h>
@@ -31,6 +33,12 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/asm-prototypes.h>
 
+#define SLAVE_CODE_SIZE		256
+
+#ifdef CONFIG_KEXEC_FILE
+static struct kexec_file_ops *kexec_file_loaders[] = { };
+#endif
+
 #ifdef CONFIG_PPC_BOOK3E
 int default_machine_kexec_prepare(struct kimage *image)
 {
@@ -432,3 +440,247 @@ static int __init export_htab_values(void)
 }
 late_initcall(export_htab_values);
 #endif /* CONFIG_PPC_STD_MMU_64 */
+
+#ifdef CONFIG_KEXEC_FILE
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+				  unsigned long buf_len)
+{
+	int i, ret = -ENOEXEC;
+	struct kexec_file_ops *fops;
+
+	/* We don't support crash kernels yet. */
+	if (image->type == KEXEC_TYPE_CRASH)
+		return -ENOTSUPP;
+
+	for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+		fops = kexec_file_loaders[i];
+		if (!fops || !fops->probe)
+			continue;
+
+		ret = fops->probe(buf, buf_len);
+		if (!ret) {
+			image->fops = fops;
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+	if (!image->fops || !image->fops->load)
+		return ERR_PTR(-ENOEXEC);
+
+	return image->fops->load(image, image->kernel_buf,
+				 image->kernel_buf_len, image->initrd_buf,
+				 image->initrd_buf_len, image->cmdline_buf,
+				 image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+	if (!image->fops || !image->fops->cleanup)
+		return 0;
+
+	return image->fops->cleanup(image->image_loader_data);
+}
+
+/**
+ * arch_kexec_walk_mem() - call func(data) for each unreserved memory block
+ * @kbuf:	Context info for the search. Also passed to @func.
+ * @func:	Function to call for each memory block.
+ *
+ * This function is used by kexec_add_buffer and kexec_locate_mem_hole
+ * to find unreserved memory to load kexec segments into.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+	int ret = 0;
+	u64 i;
+	phys_addr_t mstart, mend;
+
+	if (kbuf->top_down) {
+		for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
+						&mstart, &mend, NULL) {
+			/*
+			 * In memblock, end points to the first byte after the
+			 * range while in kexec, end points to the last byte
+			 * in the range.
+			 */
+			ret = func(mstart, mend - 1, kbuf);
+			if (ret)
+				break;
+		}
+	} else {
+		for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
+					NULL) {
+			/*
+			 * In memblock, end points to the first byte after the
+			 * range while in kexec, end points to the last byte
+			 * in the range.
+			 */
+			ret = func(mstart, mend - 1, kbuf);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+/**
+ * arch_kexec_apply_relocations_add() - apply purgatory relocations
+ * @ehdr:	Pointer to ELF headers.
+ * @sechdrs:	Pointer to section headers.
+ * @relsec:	Section index of SHT_RELA section.
+ *
+ * Elf64_Shdr.sh_offset has been modified to keep the pointer to the section
+ * contents, while Elf64_Shdr.sh_addr points to the final address of the
+ * section in memory.
+ */
+int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
+				     Elf64_Shdr *sechdrs, unsigned int relsec)
+{
+	/* Section containing the relocation entries. */
+	Elf64_Shdr *rel_section = &sechdrs[relsec];
+	const Elf64_Rela *rela = (const Elf64_Rela *) rel_section->sh_offset;
+	unsigned int num_rela = rel_section->sh_size / sizeof(Elf64_Rela);
+	/* Section to which relocations apply. */
+	Elf64_Shdr *target_section = &sechdrs[rel_section->sh_info];
+	/* Associated symbol table. */
+	Elf64_Shdr *symtabsec = &sechdrs[rel_section->sh_link];
+	void *syms_base = (void *) symtabsec->sh_offset;
+	void *loc_base = (void *) target_section->sh_offset;
+	Elf64_Addr addr_base = target_section->sh_addr;
+	struct elf_info elf_info;
+	const char *strtab;
+
+	if (symtabsec->sh_link >= ehdr->e_shnum) {
+		/* Invalid strtab section number */
+		pr_err("Invalid string table section index %d\n",
+		       symtabsec->sh_link);
+		return -ENOEXEC;
+	}
+	/* String table for the associated symbol table. */
+	strtab = (const char *) sechdrs[symtabsec->sh_link].sh_offset;
+
+	elf_init_elf_info(ehdr, sechdrs, &elf_info);
+
+	return elf64_apply_relocate_add(&elf_info, strtab, rela, num_rela,
+					syms_base, loc_base, addr_base,
+					true, true, "kexec purgatory");
+}
+
+/**
+ * setup_purgatory() - setup the purgatory runtime variables
+ * @image:		kexec image.
+ * @slave_code:		Slave code for the purgatory.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @kernel_load_addr:	Address where the kernel is loaded.
+ * @fdt_load_addr:	Address where the flattened device tree is loaded.
+ * @stack_top:		Address where the purgatory can place its stack.
+ * @debug:		Can the purgatory print messages to the console?
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_purgatory(struct kimage *image, const void *slave_code,
+		    const void *fdt, unsigned long kernel_load_addr,
+		    unsigned long fdt_load_addr, unsigned long stack_top,
+		    int debug)
+{
+	int ret, tree_node;
+	const void *prop;
+	unsigned long opal_base, opal_entry;
+	uint64_t toc;
+	unsigned int *slave_code_buf, master_entry;
+	struct elf_info purg_info;
+
+	slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
+	if (!slave_code_buf)
+		return -ENOMEM;
+
+	/* Get the slave code from the new kernel and put it in purgatory. */
+	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+					     slave_code_buf, SLAVE_CODE_SIZE,
+					     true);
+	if (ret) {
+		kfree(slave_code_buf);
+		return ret;
+	}
+
+	master_entry = slave_code_buf[0];
+	memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
+	slave_code_buf[0] = master_entry;
+	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+					     slave_code_buf, SLAVE_CODE_SIZE,
+					     false);
+	kfree(slave_code_buf);
+
+	ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
+					     sizeof(kernel_load_addr), false);
+	if (ret)
+		return ret;
+	ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
+					     sizeof(fdt_load_addr), false);
+	if (ret)
+		return ret;
+
+	tree_node = fdt_path_offset(fdt, "/ibm,opal");
+	if (tree_node >= 0) {
+		prop = fdt_getprop(fdt, tree_node, "opal-base-address", NULL);
+		if (!prop) {
+			pr_err("OPAL address not found in the device tree.\n");
+			return -EINVAL;
+		}
+		opal_base = fdt64_to_cpu((const fdt64_t *) prop);
+
+		prop = fdt_getprop(fdt, tree_node, "opal-entry-address", NULL);
+		if (!prop) {
+			pr_err("OPAL address not found in the device tree.\n");
+			return -EINVAL;
+		}
+		opal_entry = fdt64_to_cpu((const fdt64_t *) prop);
+
+		ret = kexec_purgatory_get_set_symbol(image, "opal_base",
+						     &opal_base,
+						     sizeof(opal_base), false);
+		if (ret)
+			return ret;
+		ret = kexec_purgatory_get_set_symbol(image, "opal_entry",
+						     &opal_entry,
+						     sizeof(opal_entry), false);
+		if (ret)
+			return ret;
+	}
+
+	ret = kexec_purgatory_get_set_symbol(image, "stack", &stack_top,
+					     sizeof(stack_top), false);
+	if (ret)
+		return ret;
+
+	elf_init_elf_info(image->purgatory_info.ehdr,
+			  image->purgatory_info.sechdrs, &purg_info);
+	toc = my_r2(&purg_info);
+	ret = kexec_purgatory_get_set_symbol(image, "my_toc", &toc, sizeof(toc),
+					     false);
+	if (ret)
+		return ret;
+
+	pr_debug("Purgatory TOC is at 0x%llx\n", toc);
+
+	ret = kexec_purgatory_get_set_symbol(image, "debug", &debug,
+					     sizeof(debug), false);
+	if (ret)
+		return ret;
+	if (!debug)
+		pr_debug("Disabling purgatory output.\n");
+
+	return 0;
+}
+
+#endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1

[PATCH v5 08/13] powerpc: Implement kexec_file_load.

[Thiago Jung Bauermann]

arch_kexec_walk_mem and arch_kexec_apply_relocations_add are used by
generic kexec code, while setup_purgatory is powerpc-specific and sets
runtime variables needed by the powerpc purgatory implementation.

Signed-off-by: Josh Sklar <sklar@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/Kconfig                   |  13 ++
 arch/powerpc/include/asm/kexec.h       |   7 +
 arch/powerpc/include/asm/systbl.h      |   1 +
 arch/powerpc/include/asm/unistd.h      |   2 +-
 arch/powerpc/include/uapi/asm/unistd.h |   1 +
 arch/powerpc/kernel/Makefile           |   4 +-
 arch/powerpc/kernel/machine_kexec_64.c | 252 +++++++++++++++++++++++++++++++++
 7 files changed, 278 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ec4047e170a0..ff362ca60d1b 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -459,6 +459,19 @@ config KEXEC
 	  interface is strongly in flux, so no good recommendation can be
 	  made.
 
+config KEXEC_FILE
+	bool "kexec file based system call"
+	select KEXEC_CORE
+	select BUILD_BIN2C
+	depends on PPC64
+	depends on CRYPTO=y
+	depends on CRYPTO_SHA256=y
+	help
+	  This is a new version of the kexec system call. This call is
+	  file based and takes in file descriptors as system call arguments
+	  for kernel and initramfs as opposed to a list of segments as is the
+	  case for the older kexec call.
+
 config RELOCATABLE
 	bool "Build a relocatable kernel"
 	depends on (PPC64 && !COMPILE_TEST) || (FLATMEM && (44x || FSL_BOOKE))
diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index a46f5f45570c..83b81b7bdca1 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -91,6 +91,13 @@ static inline bool kdump_in_progress(void)
 	return crashing_cpu >= 0;
 }
 
+#ifdef CONFIG_KEXEC_FILE
+int setup_purgatory(struct kimage *image, const void *slave_code,
+		    const void *fdt, unsigned long kernel_load_addr,
+		    unsigned long fdt_load_addr, unsigned long stack_top,
+		    int debug);
+#endif /* CONFIG_KEXEC_FILE */
+
 #else /* !CONFIG_KEXEC */
 static inline void crash_kexec_secondary(struct pt_regs *regs) { }
 
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index 2fc5d4db503c..4b369d83fe9c 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -386,3 +386,4 @@ SYSCALL(mlock2)
 SYSCALL(copy_file_range)
 COMPAT_SYS_SPU(preadv2)
 COMPAT_SYS_SPU(pwritev2)
+SYSCALL(kexec_file_load)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index cf12c580f6b2..a01e97d3f305 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls		382
+#define NR_syscalls		383
 
 #define __NR__exit __NR_exit
 
diff --git a/arch/powerpc/include/uapi/asm/unistd.h b/arch/powerpc/include/uapi/asm/unistd.h
index e9f5f41aa55a..2f26335a3c42 100644
--- a/arch/powerpc/include/uapi/asm/unistd.h
+++ b/arch/powerpc/include/uapi/asm/unistd.h
@@ -392,5 +392,6 @@
 #define __NR_copy_file_range	379
 #define __NR_preadv2		380
 #define __NR_pwritev2		381
+#define __NR_kexec_file_load	382
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 6159ec6ac032..ce18a985bcfc 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -123,9 +123,11 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
 obj-y				+= iomap.o
 endif
 
-ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
+ifneq ($(CONFIG_MODULES)$(CONFIG_KEXEC_FILE),)
+ifeq ($(CONFIG_WORD_SIZE),64)
 obj-y				+= elf_util.o elf_util_64.o
 endif
+endif
 
 obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
 
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 4c780a342282..1e678dc5096a 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -18,6 +18,8 @@
 #include <linux/kernel.h>
 #include <linux/cpu.h>
 #include <linux/hardirq.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
 
 #include <asm/page.h>
 #include <asm/current.h>
@@ -31,6 +33,12 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/asm-prototypes.h>
 
+#define SLAVE_CODE_SIZE		256
+
+#ifdef CONFIG_KEXEC_FILE
+static struct kexec_file_ops *kexec_file_loaders[] = { };
+#endif
+
 #ifdef CONFIG_PPC_BOOK3E
 int default_machine_kexec_prepare(struct kimage *image)
 {
@@ -432,3 +440,247 @@ static int __init export_htab_values(void)
 }
 late_initcall(export_htab_values);
 #endif /* CONFIG_PPC_STD_MMU_64 */
+
+#ifdef CONFIG_KEXEC_FILE
+int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
+				  unsigned long buf_len)
+{
+	int i, ret = -ENOEXEC;
+	struct kexec_file_ops *fops;
+
+	/* We don't support crash kernels yet. */
+	if (image->type == KEXEC_TYPE_CRASH)
+		return -ENOTSUPP;
+
+	for (i = 0; i < ARRAY_SIZE(kexec_file_loaders); i++) {
+		fops = kexec_file_loaders[i];
+		if (!fops || !fops->probe)
+			continue;
+
+		ret = fops->probe(buf, buf_len);
+		if (!ret) {
+			image->fops = fops;
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+void *arch_kexec_kernel_image_load(struct kimage *image)
+{
+	if (!image->fops || !image->fops->load)
+		return ERR_PTR(-ENOEXEC);
+
+	return image->fops->load(image, image->kernel_buf,
+				 image->kernel_buf_len, image->initrd_buf,
+				 image->initrd_buf_len, image->cmdline_buf,
+				 image->cmdline_buf_len);
+}
+
+int arch_kimage_file_post_load_cleanup(struct kimage *image)
+{
+	if (!image->fops || !image->fops->cleanup)
+		return 0;
+
+	return image->fops->cleanup(image->image_loader_data);
+}
+
+/**
+ * arch_kexec_walk_mem() - call func(data) for each unreserved memory block
+ * @kbuf:	Context info for the search. Also passed to @func.
+ * @func:	Function to call for each memory block.
+ *
+ * This function is used by kexec_add_buffer and kexec_locate_mem_hole
+ * to find unreserved memory to load kexec segments into.
+ *
+ * Return: The memory walk will stop when func returns a non-zero value
+ * and that value will be returned. If all free regions are visited without
+ * func returning non-zero, then zero will be returned.
+ */
+int arch_kexec_walk_mem(struct kexec_buf *kbuf, int (*func)(u64, u64, void *))
+{
+	int ret = 0;
+	u64 i;
+	phys_addr_t mstart, mend;
+
+	if (kbuf->top_down) {
+		for_each_free_mem_range_reverse(i, NUMA_NO_NODE, 0,
+						&mstart, &mend, NULL) {
+			/*
+			 * In memblock, end points to the first byte after the
+			 * range while in kexec, end points to the last byte
+			 * in the range.
+			 */
+			ret = func(mstart, mend - 1, kbuf);
+			if (ret)
+				break;
+		}
+	} else {
+		for_each_free_mem_range(i, NUMA_NO_NODE, 0, &mstart, &mend,
+					NULL) {
+			/*
+			 * In memblock, end points to the first byte after the
+			 * range while in kexec, end points to the last byte
+			 * in the range.
+			 */
+			ret = func(mstart, mend - 1, kbuf);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+/**
+ * arch_kexec_apply_relocations_add() - apply purgatory relocations
+ * @ehdr:	Pointer to ELF headers.
+ * @sechdrs:	Pointer to section headers.
+ * @relsec:	Section index of SHT_RELA section.
+ *
+ * Elf64_Shdr.sh_offset has been modified to keep the pointer to the section
+ * contents, while Elf64_Shdr.sh_addr points to the final address of the
+ * section in memory.
+ */
+int arch_kexec_apply_relocations_add(const Elf64_Ehdr *ehdr,
+				     Elf64_Shdr *sechdrs, unsigned int relsec)
+{
+	/* Section containing the relocation entries. */
+	Elf64_Shdr *rel_section = &sechdrs[relsec];
+	const Elf64_Rela *rela = (const Elf64_Rela *) rel_section->sh_offset;
+	unsigned int num_rela = rel_section->sh_size / sizeof(Elf64_Rela);
+	/* Section to which relocations apply. */
+	Elf64_Shdr *target_section = &sechdrs[rel_section->sh_info];
+	/* Associated symbol table. */
+	Elf64_Shdr *symtabsec = &sechdrs[rel_section->sh_link];
+	void *syms_base = (void *) symtabsec->sh_offset;
+	void *loc_base = (void *) target_section->sh_offset;
+	Elf64_Addr addr_base = target_section->sh_addr;
+	struct elf_info elf_info;
+	const char *strtab;
+
+	if (symtabsec->sh_link >= ehdr->e_shnum) {
+		/* Invalid strtab section number */
+		pr_err("Invalid string table section index %d\n",
+		       symtabsec->sh_link);
+		return -ENOEXEC;
+	}
+	/* String table for the associated symbol table. */
+	strtab = (const char *) sechdrs[symtabsec->sh_link].sh_offset;
+
+	elf_init_elf_info(ehdr, sechdrs, &elf_info);
+
+	return elf64_apply_relocate_add(&elf_info, strtab, rela, num_rela,
+					syms_base, loc_base, addr_base,
+					true, true, "kexec purgatory");
+}
+
+/**
+ * setup_purgatory() - setup the purgatory runtime variables
+ * @image:		kexec image.
+ * @slave_code:		Slave code for the purgatory.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @kernel_load_addr:	Address where the kernel is loaded.
+ * @fdt_load_addr:	Address where the flattened device tree is loaded.
+ * @stack_top:		Address where the purgatory can place its stack.
+ * @debug:		Can the purgatory print messages to the console?
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_purgatory(struct kimage *image, const void *slave_code,
+		    const void *fdt, unsigned long kernel_load_addr,
+		    unsigned long fdt_load_addr, unsigned long stack_top,
+		    int debug)
+{
+	int ret, tree_node;
+	const void *prop;
+	unsigned long opal_base, opal_entry;
+	uint64_t toc;
+	unsigned int *slave_code_buf, master_entry;
+	struct elf_info purg_info;
+
+	slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
+	if (!slave_code_buf)
+		return -ENOMEM;
+
+	/* Get the slave code from the new kernel and put it in purgatory. */
+	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+					     slave_code_buf, SLAVE_CODE_SIZE,
+					     true);
+	if (ret) {
+		kfree(slave_code_buf);
+		return ret;
+	}
+
+	master_entry = slave_code_buf[0];
+	memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
+	slave_code_buf[0] = master_entry;
+	ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
+					     slave_code_buf, SLAVE_CODE_SIZE,
+					     false);
+	kfree(slave_code_buf);
+
+	ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
+					     sizeof(kernel_load_addr), false);
+	if (ret)
+		return ret;
+	ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
+					     sizeof(fdt_load_addr), false);
+	if (ret)
+		return ret;
+
+	tree_node = fdt_path_offset(fdt, "/ibm,opal");
+	if (tree_node >= 0) {
+		prop = fdt_getprop(fdt, tree_node, "opal-base-address", NULL);
+		if (!prop) {
+			pr_err("OPAL address not found in the device tree.\n");
+			return -EINVAL;
+		}
+		opal_base = fdt64_to_cpu((const fdt64_t *) prop);
+
+		prop = fdt_getprop(fdt, tree_node, "opal-entry-address", NULL);
+		if (!prop) {
+			pr_err("OPAL address not found in the device tree.\n");
+			return -EINVAL;
+		}
+		opal_entry = fdt64_to_cpu((const fdt64_t *) prop);
+
+		ret = kexec_purgatory_get_set_symbol(image, "opal_base",
+						     &opal_base,
+						     sizeof(opal_base), false);
+		if (ret)
+			return ret;
+		ret = kexec_purgatory_get_set_symbol(image, "opal_entry",
+						     &opal_entry,
+						     sizeof(opal_entry), false);
+		if (ret)
+			return ret;
+	}
+
+	ret = kexec_purgatory_get_set_symbol(image, "stack", &stack_top,
+					     sizeof(stack_top), false);
+	if (ret)
+		return ret;
+
+	elf_init_elf_info(image->purgatory_info.ehdr,
+			  image->purgatory_info.sechdrs, &purg_info);
+	toc = my_r2(&purg_info);
+	ret = kexec_purgatory_get_set_symbol(image, "my_toc", &toc, sizeof(toc),
+					     false);
+	if (ret)
+		return ret;
+
+	pr_debug("Purgatory TOC is at 0x%llx\n", toc);
+
+	ret = kexec_purgatory_get_set_symbol(image, "debug", &debug,
+					     sizeof(debug), false);
+	if (ret)
+		return ret;
+	if (!debug)
+		pr_debug("Disabling purgatory output.\n");
+
+	return 0;
+}
+
+#endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 09/13] powerpc: Add code to work with device trees in kexec_file_load.

[Thiago Jung Bauermann]

kexec_file_load needs to set up the device tree that will be used
by the next kernel and check whether it provides a console
that can be used by the purgatory.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kexec.h       |   3 +
 arch/powerpc/kernel/machine_kexec_64.c | 222 +++++++++++++++++++++++++++++++++
 2 files changed, 225 insertions(+)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 83b81b7bdca1..f263cc867891 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -96,6 +96,9 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 		    const void *fdt, unsigned long kernel_load_addr,
 		    unsigned long fdt_load_addr, unsigned long stack_top,
 		    int debug);
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+		  unsigned long initrd_len, const char *cmdline);
+bool find_debug_console(const void *fdt, int chosen_node);
 #endif /* CONFIG_KEXEC_FILE */
 
 #else /* !CONFIG_KEXEC */
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 1e678dc5096a..897b724ea9fd 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -683,4 +683,226 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 	return 0;
 }
 
+/*
+ * setup_new_fdt() - modify /chosen and memory reservation for the next kernel
+ * @fdt:
+ * @initrd_load_addr:	Address where the next initrd will be loaded.
+ * @initrd_len:		Size of the next initrd, or 0 if there will be none.
+ * @cmdline:		Command line for the next kernel, or NULL if there will
+ * 			be none.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+		  unsigned long initrd_len, const char *cmdline)
+{
+	uint64_t oldfdt_addr;
+	int i, ret, chosen_node;
+	const void *prop;
+
+	/* Remove memory reservation for the current device tree. */
+	oldfdt_addr = __pa(initial_boot_params);
+	for (i = 0; i < fdt_num_mem_rsv(fdt); i++) {
+		uint64_t rsv_start, rsv_size;
+
+		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+		if (ret) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+
+		if (rsv_start == oldfdt_addr &&
+		    rsv_size == fdt_totalsize(initial_boot_params)) {
+			ret = fdt_del_mem_rsv(fdt, i);
+			if (ret) {
+				pr_err("Error deleting fdt reservation.\n");
+				return -EINVAL;
+			}
+
+			pr_debug("Removed old device tree reservation.\n");
+			break;
+		}
+	}
+
+	chosen_node = fdt_path_offset(fdt, "/chosen");
+	if (chosen_node == -FDT_ERR_NOTFOUND) {
+		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+					      "chosen");
+		if (chosen_node < 0) {
+			pr_err("Error creating /chosen.\n");
+			return -EINVAL;
+		}
+	} else if (chosen_node < 0) {
+		pr_err("Malformed device tree: error reading /chosen.\n");
+		return -EINVAL;
+	}
+
+	/* Did we boot using an initrd? */
+	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
+	if (prop) {
+		uint64_t tmp_start, tmp_end, tmp_size, tmp_sizepg;
+
+		tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
+		if (!prop) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+		tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+		/*
+		 * kexec reserves exact initrd size, while firmware may
+		 * reserve a multiple of PAGE_SIZE, so check for both.
+		 */
+		tmp_size = tmp_end - tmp_start;
+		tmp_sizepg = round_up(tmp_size, PAGE_SIZE);
+
+		/* Remove memory reservation for the current initrd. */
+		for (i = 0; i < fdt_num_mem_rsv(fdt); i++) {
+			uint64_t rsv_start, rsv_size;
+
+			ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+			if (ret) {
+				pr_err("Malformed device tree.\n");
+				return -EINVAL;
+			}
+
+			if (rsv_start == tmp_start &&
+			    (rsv_size == tmp_size || rsv_size == tmp_sizepg)) {
+				ret = fdt_del_mem_rsv(fdt, i);
+				if (ret) {
+					pr_err("Error deleting fdt reservation.\n");
+					return -EINVAL;
+				}
+				pr_debug("Removed old initrd reservation.\n");
+
+				/* fdt was modified, offsets may have changed. */
+				chosen_node = fdt_path_offset(fdt, "/chosen");
+				if (chosen_node < 0) {
+					pr_err("Malformed device tree.\n");
+					return -EINVAL;
+				}
+
+				break;
+			}
+		}
+
+		/* If there's no new initrd, delete the old initrd's info. */
+		if (initrd_len == 0) {
+			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-start");
+			if (ret) {
+				pr_err("Error deleting linux,initrd-start.\n");
+				return -EINVAL;
+			}
+
+			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
+			if (ret) {
+				pr_err("Error deleting linux,initrd-end.\n");
+				return -EINVAL;
+			}
+		}
+	}
+
+	if (initrd_len) {
+		ret = fdt_setprop_u64(fdt, chosen_node,
+				      "linux,initrd-start",
+				      initrd_load_addr);
+		if (ret < 0) {
+			pr_err("Error setting up the new device tree.\n");
+			return -EINVAL;
+		}
+
+		/* initrd-end is the first address after the initrd image. */
+		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
+				      initrd_load_addr + initrd_len);
+		if (ret < 0) {
+			pr_err("Error setting up the new device tree.\n");
+			return -EINVAL;
+		}
+
+		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+		if (ret) {
+			pr_err("Error reserving initrd memory: %s\n",
+			       fdt_strerror(ret));
+			return -EINVAL;
+		}
+	}
+
+	if (cmdline != NULL) {
+		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
+		if (ret < 0) {
+			pr_err("Error setting up the new device tree.\n");
+			return -EINVAL;
+		}
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, "bootargs");
+		if (ret && ret != -FDT_ERR_NOTFOUND) {
+			pr_err("Error deleting bootargs.\n");
+			return -EINVAL;
+		}
+	}
+
+	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+	if (ret) {
+		pr_err("Error setting up the new device tree.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * find_debug_console() - find out whether there is a console for the purgatory
+ * @fdt:		Flattened device tree to search.
+ * @chosen_node:	Offset of /chosen in @fdt.
+ */
+bool find_debug_console(const void *fdt, int chosen_node)
+{
+	int len;
+	int console_node;
+	const void *prop, *colon;
+
+	prop = fdt_getprop(fdt, chosen_node, "stdout-path", &len);
+	if (prop == NULL) {
+		if (len == -FDT_ERR_NOTFOUND) {
+			prop = fdt_getprop(fdt, chosen_node, "linux,stdout-path",
+					   &len);
+			if (prop == NULL) {
+				pr_debug("Unable to find [linux,]stdout-path.\n");
+				return false;
+			}
+		} else {
+			pr_debug("Error finding console: %s\n",
+				 fdt_strerror(len));
+			return false;
+		}
+	}
+
+	/*
+	 * stdout-path can have a ':' separating the path from device-specific
+	 * information, so we should only consider what's before it.
+	 */
+	colon = strchr(prop, ':');
+	if (colon != NULL)
+		len = colon - prop;
+	else
+		len -= 1;	/* Ignore the terminating NUL. */
+
+	console_node = fdt_path_offset_namelen(fdt, prop, len);
+	if (console_node < 0) {
+		pr_debug("Error finding console: %s\n",
+			 fdt_strerror(console_node));
+		return false;
+	}
+
+	if (fdt_node_check_compatible(fdt, console_node, "hvterm1") == 0)
+		return true;
+	else if (fdt_node_check_compatible(fdt, console_node,
+					   "hvterm-protocol") == 0)
+		return true;
+
+	return false;
+}
+
 #endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1

[PATCH v5 09/13] powerpc: Add code to work with device trees in kexec_file_load.

[Thiago Jung Bauermann]

kexec_file_load needs to set up the device tree that will be used
by the next kernel and check whether it provides a console
that can be used by the purgatory.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kexec.h       |   3 +
 arch/powerpc/kernel/machine_kexec_64.c | 222 +++++++++++++++++++++++++++++++++
 2 files changed, 225 insertions(+)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index 83b81b7bdca1..f263cc867891 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -96,6 +96,9 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 		    const void *fdt, unsigned long kernel_load_addr,
 		    unsigned long fdt_load_addr, unsigned long stack_top,
 		    int debug);
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+		  unsigned long initrd_len, const char *cmdline);
+bool find_debug_console(const void *fdt, int chosen_node);
 #endif /* CONFIG_KEXEC_FILE */
 
 #else /* !CONFIG_KEXEC */
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 1e678dc5096a..897b724ea9fd 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -683,4 +683,226 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 	return 0;
 }
 
+/*
+ * setup_new_fdt() - modify /chosen and memory reservation for the next kernel
+ * @fdt:
+ * @initrd_load_addr:	Address where the next initrd will be loaded.
+ * @initrd_len:		Size of the next initrd, or 0 if there will be none.
+ * @cmdline:		Command line for the next kernel, or NULL if there will
+ * 			be none.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
+		  unsigned long initrd_len, const char *cmdline)
+{
+	uint64_t oldfdt_addr;
+	int i, ret, chosen_node;
+	const void *prop;
+
+	/* Remove memory reservation for the current device tree. */
+	oldfdt_addr = __pa(initial_boot_params);
+	for (i = 0; i < fdt_num_mem_rsv(fdt); i++) {
+		uint64_t rsv_start, rsv_size;
+
+		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+		if (ret) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+
+		if (rsv_start == oldfdt_addr &&
+		    rsv_size == fdt_totalsize(initial_boot_params)) {
+			ret = fdt_del_mem_rsv(fdt, i);
+			if (ret) {
+				pr_err("Error deleting fdt reservation.\n");
+				return -EINVAL;
+			}
+
+			pr_debug("Removed old device tree reservation.\n");
+			break;
+		}
+	}
+
+	chosen_node = fdt_path_offset(fdt, "/chosen");
+	if (chosen_node == -FDT_ERR_NOTFOUND) {
+		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+					      "chosen");
+		if (chosen_node < 0) {
+			pr_err("Error creating /chosen.\n");
+			return -EINVAL;
+		}
+	} else if (chosen_node < 0) {
+		pr_err("Malformed device tree: error reading /chosen.\n");
+		return -EINVAL;
+	}
+
+	/* Did we boot using an initrd? */
+	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", NULL);
+	if (prop) {
+		uint64_t tmp_start, tmp_end, tmp_size, tmp_sizepg;
+
+		tmp_start = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", NULL);
+		if (!prop) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+		tmp_end = fdt64_to_cpu(*((const fdt64_t *) prop));
+
+		/*
+		 * kexec reserves exact initrd size, while firmware may
+		 * reserve a multiple of PAGE_SIZE, so check for both.
+		 */
+		tmp_size = tmp_end - tmp_start;
+		tmp_sizepg = round_up(tmp_size, PAGE_SIZE);
+
+		/* Remove memory reservation for the current initrd. */
+		for (i = 0; i < fdt_num_mem_rsv(fdt); i++) {
+			uint64_t rsv_start, rsv_size;
+
+			ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+			if (ret) {
+				pr_err("Malformed device tree.\n");
+				return -EINVAL;
+			}
+
+			if (rsv_start == tmp_start &&
+			    (rsv_size == tmp_size || rsv_size == tmp_sizepg)) {
+				ret = fdt_del_mem_rsv(fdt, i);
+				if (ret) {
+					pr_err("Error deleting fdt reservation.\n");
+					return -EINVAL;
+				}
+				pr_debug("Removed old initrd reservation.\n");
+
+				/* fdt was modified, offsets may have changed. */
+				chosen_node = fdt_path_offset(fdt, "/chosen");
+				if (chosen_node < 0) {
+					pr_err("Malformed device tree.\n");
+					return -EINVAL;
+				}
+
+				break;
+			}
+		}
+
+		/* If there's no new initrd, delete the old initrd's info. */
+		if (initrd_len == 0) {
+			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-start");
+			if (ret) {
+				pr_err("Error deleting linux,initrd-start.\n");
+				return -EINVAL;
+			}
+
+			ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
+			if (ret) {
+				pr_err("Error deleting linux,initrd-end.\n");
+				return -EINVAL;
+			}
+		}
+	}
+
+	if (initrd_len) {
+		ret = fdt_setprop_u64(fdt, chosen_node,
+				      "linux,initrd-start",
+				      initrd_load_addr);
+		if (ret < 0) {
+			pr_err("Error setting up the new device tree.\n");
+			return -EINVAL;
+		}
+
+		/* initrd-end is the first address after the initrd image. */
+		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
+				      initrd_load_addr + initrd_len);
+		if (ret < 0) {
+			pr_err("Error setting up the new device tree.\n");
+			return -EINVAL;
+		}
+
+		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+		if (ret) {
+			pr_err("Error reserving initrd memory: %s\n",
+			       fdt_strerror(ret));
+			return -EINVAL;
+		}
+	}
+
+	if (cmdline != NULL) {
+		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
+		if (ret < 0) {
+			pr_err("Error setting up the new device tree.\n");
+			return -EINVAL;
+		}
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, "bootargs");
+		if (ret && ret != -FDT_ERR_NOTFOUND) {
+			pr_err("Error deleting bootargs.\n");
+			return -EINVAL;
+		}
+	}
+
+	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+	if (ret) {
+		pr_err("Error setting up the new device tree.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * find_debug_console() - find out whether there is a console for the purgatory
+ * @fdt:		Flattened device tree to search.
+ * @chosen_node:	Offset of /chosen in @fdt.
+ */
+bool find_debug_console(const void *fdt, int chosen_node)
+{
+	int len;
+	int console_node;
+	const void *prop, *colon;
+
+	prop = fdt_getprop(fdt, chosen_node, "stdout-path", &len);
+	if (prop == NULL) {
+		if (len == -FDT_ERR_NOTFOUND) {
+			prop = fdt_getprop(fdt, chosen_node, "linux,stdout-path",
+					   &len);
+			if (prop == NULL) {
+				pr_debug("Unable to find [linux,]stdout-path.\n");
+				return false;
+			}
+		} else {
+			pr_debug("Error finding console: %s\n",
+				 fdt_strerror(len));
+			return false;
+		}
+	}
+
+	/*
+	 * stdout-path can have a ':' separating the path from device-specific
+	 * information, so we should only consider what's before it.
+	 */
+	colon = strchr(prop, ':');
+	if (colon != NULL)
+		len = colon - prop;
+	else
+		len -= 1;	/* Ignore the terminating NUL. */
+
+	console_node = fdt_path_offset_namelen(fdt, prop, len);
+	if (console_node < 0) {
+		pr_debug("Error finding console: %s\n",
+			 fdt_strerror(console_node));
+		return false;
+	}
+
+	if (fdt_node_check_compatible(fdt, console_node, "hvterm1") == 0)
+		return true;
+	else if (fdt_node_check_compatible(fdt, console_node,
+					   "hvterm-protocol") == 0)
+		return true;
+
+	return false;
+}
+
 #endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 10/13] powerpc: Add support for loading ELF kernels with kexec_file_load.

[Thiago Jung Bauermann]

This uses all the infrastructure built up by the previous patches
in the series to load an ELF vmlinux file and an initrd. It uses the
flattened device tree at initial_boot_params as a base and adjusts memory
reservations and its /chosen node for the next kernel.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kexec_elf_64.h |  10 ++
 arch/powerpc/kernel/Makefile            |   1 +
 arch/powerpc/kernel/kexec_elf_64.c      | 284 ++++++++++++++++++++++++++++++++
 arch/powerpc/kernel/machine_kexec_64.c  |   5 +-
 4 files changed, 299 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/kexec_elf_64.h b/arch/powerpc/include/asm/kexec_elf_64.h
new file mode 100644
index 000000000000..30da6bc0ccf8
--- /dev/null
+++ b/arch/powerpc/include/asm/kexec_elf_64.h
@@ -0,0 +1,10 @@
+#ifndef __POWERPC_KEXEC_ELF_64_H__
+#define __POWERPC_KEXEC_ELF_64_H__
+
+#ifdef CONFIG_KEXEC_FILE
+
+extern struct kexec_file_ops kexec_elf64_ops;
+
+#endif /* CONFIG_KEXEC_FILE */
+
+#endif /* __POWERPC_KEXEC_ELF_64_H__ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index ce18a985bcfc..d149f5ebac90 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_PCI)		+= pci_$(CONFIG_WORD_SIZE).o $(pci64-y) \
 obj-$(CONFIG_PCI_MSI)		+= msi.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec.o crash.o \
 				   machine_kexec_$(CONFIG_WORD_SIZE).o
+obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf_$(CONFIG_WORD_SIZE).o
 obj-$(CONFIG_AUDIT)		+= audit.o
 obj64-$(CONFIG_AUDIT)		+= compat_audit.o
 
diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
new file mode 100644
index 000000000000..49cba9509464
--- /dev/null
+++ b/arch/powerpc/kernel/kexec_elf_64.c
@@ -0,0 +1,284 @@
+/*
+ * Load ELF vmlinux file for the kexec_file_load syscall.
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2016  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf-exec.c and kexec-elf-ppc64.c.
+ * Heavily modified for the kernel by
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt)	"kexec_elf: " fmt
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/elf.h>
+#include <linux/kexec.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <asm/elf_util.h>
+
+extern size_t kexec_purgatory_size;
+
+#define PURGATORY_STACK_SIZE	(16 * 1024)
+
+/**
+ * build_elf_exec_info - read ELF executable and check that we can use it
+ */
+static int build_elf_exec_info(const char *buf, size_t len, struct elfhdr *ehdr,
+			       struct elf_info *elf_info)
+{
+	int i;
+	int ret;
+
+	ret = elf_read_from_buffer(buf, len, ehdr, elf_info);
+	if (ret)
+		return ret;
+
+	/* Big endian vmlinux has type ET_DYN. */
+	if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
+		pr_err("Not an ELF executable.\n");
+		goto error;
+	} else if (!elf_info->proghdrs) {
+		pr_err("No ELF program header.\n");
+		goto error;
+	}
+
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		/*
+		 * Kexec does not support loading interpreters.
+		 * In addition this check keeps us from attempting
+		 * to kexec ordinay executables.
+		 */
+		if (elf_info->proghdrs[i].p_type == PT_INTERP) {
+			pr_err("Requires an ELF interpreter.\n");
+			goto error;
+		}
+	}
+
+	return 0;
+error:
+	elf_free_info(elf_info);
+	return -ENOEXEC;
+}
+
+static int elf64_probe(const char *buf, unsigned long len)
+{
+	struct elfhdr ehdr;
+	struct elf_info elf_info;
+	int ret;
+
+	ret = build_elf_exec_info(buf, len, &ehdr, &elf_info);
+	if (ret)
+		return ret;
+
+	elf_free_info(&elf_info);
+
+	return elf_check_arch(&ehdr) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_exec_load - load ELF executable image
+ * @lowest_load_addr:	On return, will be the address where the first PT_LOAD
+ *			section will be loaded in memory.
+ *
+ * Return:
+ * 0 on success, negative value on failure.
+ */
+static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr,
+			 struct elf_info *elf_info,
+			 unsigned long *lowest_load_addr)
+{
+	unsigned long base = 0, lowest_addr = UINT_MAX;
+	int ret;
+	size_t i;
+	struct kexec_buf kbuf = { .image = image, .buf_max = ppc64_rma_size,
+				  .top_down = false };
+
+	/* Read in the PT_LOAD segments. */
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		unsigned long load_addr;
+		size_t size;
+		const struct elf_phdr *phdr;
+
+		phdr = &elf_info->proghdrs[i];
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		size = phdr->p_filesz;
+		if (size > phdr->p_memsz)
+			size = phdr->p_memsz;
+
+		kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset;
+		kbuf.bufsz = size;
+		kbuf.memsz = phdr->p_memsz;
+		kbuf.buf_align = phdr->p_align;
+		kbuf.buf_min = phdr->p_paddr + base;
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out;
+		load_addr = kbuf.mem;
+
+		if (load_addr < lowest_addr)
+			lowest_addr = load_addr;
+	}
+
+	/* Update entry point to reflect new load address. */
+	ehdr->e_entry += base;
+
+	*lowest_load_addr = lowest_addr;
+	ret = 0;
+ out:
+	return ret;
+}
+
+void *elf64_load(struct kimage *image, char *kernel_buf,
+		 unsigned long kernel_len, char *initrd,
+		 unsigned long initrd_len, char *cmdline,
+		 unsigned long cmdline_len)
+{
+	int i;
+	int ret = 0, chosen_node;
+	unsigned int fdt_size;
+	unsigned long kernel_load_addr, purgatory_load_addr;
+	unsigned long initrd_load_addr, fdt_load_addr, stack_top;
+	void *fdt;
+	const void *slave_code;
+	struct elfhdr ehdr;
+	struct elf_info elf_info;
+	struct fdt_reserve_entry *rsvmap;
+	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ppc64_rma_size };
+
+	ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info);
+	if (ret)
+		goto out;
+
+	ret = elf_exec_load(image, &ehdr, &elf_info, &kernel_load_addr);
+	if (ret)
+		goto out;
+
+	pr_debug("Loaded the kernel at 0x%lx\n", kernel_load_addr);
+
+	ret = kexec_load_purgatory(image, 0, ppc64_rma_size, true,
+				   &purgatory_load_addr);
+	if (ret) {
+		pr_err("Loading purgatory failed.\n");
+		goto out;
+	}
+
+	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+
+	if (initrd != NULL) {
+		kbuf.buffer = initrd;
+		kbuf.bufsz = kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		kbuf.top_down = false;
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out;
+		initrd_load_addr = kbuf.mem;
+
+		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
+	}
+
+	fdt_size = fdt_totalsize(initial_boot_params) * 2;
+	fdt = kmalloc(fdt_size, GFP_KERNEL);
+	if (!fdt) {
+		pr_err("Not enough memory for the device tree.\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+	if (ret < 0) {
+		pr_err("Error setting up the new device tree.\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
+	if (ret)
+		goto out;
+
+	/*
+	 * Documentation/devicetree/booting-without-of.txt says we need to
+	 * add a reservation entry for the device tree block, but
+	 * early_init_fdt_reserve_self reserves the memory even if there's no
+	 * such entry. We'll add a reservation entry anyway, to be safe and
+	 * compliant.
+	 *
+	 * Use dummy values, we will correct them in a moment.
+	 */
+	ret = fdt_add_mem_rsv(fdt, 1, 1);
+	if (ret) {
+		pr_err("Error reserving device tree memory: %s\n",
+		       fdt_strerror(ret));
+		ret = -EINVAL;
+		goto out;
+	}
+	fdt_pack(fdt);
+
+	kbuf.buffer = fdt;
+	kbuf.bufsz = kbuf.memsz = fdt_size;
+	kbuf.buf_align = PAGE_SIZE;
+	kbuf.top_down = true;
+	ret = kexec_add_buffer(&kbuf);
+	if (ret)
+		goto out;
+	fdt_load_addr = kbuf.mem;
+
+	/*
+	 * Fix fdt reservation, now that we now where it will be loaded
+	 * and how big it is.
+	 */
+	rsvmap = fdt + fdt_off_mem_rsvmap(fdt);
+	i = fdt_num_mem_rsv(fdt) - 1;
+	rsvmap[i].address = cpu_to_fdt64(fdt_load_addr);
+	rsvmap[i].size = cpu_to_fdt64(fdt_totalsize(fdt));
+
+	pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
+
+	kbuf.memsz = PURGATORY_STACK_SIZE;
+	kbuf.buf_align = PAGE_SIZE;
+	kbuf.top_down = true;
+	ret = kexec_locate_mem_hole(&kbuf);
+	if (ret) {
+		pr_err("Couldn't find free memory for the purgatory stack.\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+	stack_top = kbuf.mem + PURGATORY_STACK_SIZE - 1;
+	pr_debug("Purgatory stack is at 0x%lx\n", stack_top);
+
+	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
+	ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
+			      fdt_load_addr, stack_top,
+			      find_debug_console(fdt, chosen_node));
+	if (ret)
+		pr_err("Error setting up the purgatory.\n");
+
+out:
+	elf_free_info(&elf_info);
+
+	/* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
+	return ret ? ERR_PTR(ret) : fdt;
+}
+
+struct kexec_file_ops kexec_elf64_ops = {
+	.probe = elf64_probe,
+	.load = elf64_load,
+};
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 897b724ea9fd..527f98efe651 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -32,11 +32,14 @@
 #include <asm/smp.h>
 #include <asm/hw_breakpoint.h>
 #include <asm/asm-prototypes.h>
+#include <asm/kexec_elf_64.h>
 
 #define SLAVE_CODE_SIZE		256
 
 #ifdef CONFIG_KEXEC_FILE
-static struct kexec_file_ops *kexec_file_loaders[] = { };
+static struct kexec_file_ops *kexec_file_loaders[] = {
+	&kexec_elf64_ops,
+};
 #endif
 
 #ifdef CONFIG_PPC_BOOK3E
-- 
1.9.1

[PATCH v5 10/13] powerpc: Add support for loading ELF kernels with kexec_file_load.

[Thiago Jung Bauermann]

This uses all the infrastructure built up by the previous patches
in the series to load an ELF vmlinux file and an initrd. It uses the
flattened device tree at initial_boot_params as a base and adjusts memory
reservations and its /chosen node for the next kernel.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kexec_elf_64.h |  10 ++
 arch/powerpc/kernel/Makefile            |   1 +
 arch/powerpc/kernel/kexec_elf_64.c      | 284 ++++++++++++++++++++++++++++++++
 arch/powerpc/kernel/machine_kexec_64.c  |   5 +-
 4 files changed, 299 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/kexec_elf_64.h b/arch/powerpc/include/asm/kexec_elf_64.h
new file mode 100644
index 000000000000..30da6bc0ccf8
--- /dev/null
+++ b/arch/powerpc/include/asm/kexec_elf_64.h
@@ -0,0 +1,10 @@
+#ifndef __POWERPC_KEXEC_ELF_64_H__
+#define __POWERPC_KEXEC_ELF_64_H__
+
+#ifdef CONFIG_KEXEC_FILE
+
+extern struct kexec_file_ops kexec_elf64_ops;
+
+#endif /* CONFIG_KEXEC_FILE */
+
+#endif /* __POWERPC_KEXEC_ELF_64_H__ */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index ce18a985bcfc..d149f5ebac90 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_PCI)		+= pci_$(CONFIG_WORD_SIZE).o $(pci64-y) \
 obj-$(CONFIG_PCI_MSI)		+= msi.o
 obj-$(CONFIG_KEXEC)		+= machine_kexec.o crash.o \
 				   machine_kexec_$(CONFIG_WORD_SIZE).o
+obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf_$(CONFIG_WORD_SIZE).o
 obj-$(CONFIG_AUDIT)		+= audit.o
 obj64-$(CONFIG_AUDIT)		+= compat_audit.o
 
diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
new file mode 100644
index 000000000000..49cba9509464
--- /dev/null
+++ b/arch/powerpc/kernel/kexec_elf_64.c
@@ -0,0 +1,284 @@
+/*
+ * Load ELF vmlinux file for the kexec_file_load syscall.
+ *
+ * Copyright (C) 2004  Adam Litke (agl@us.ibm.com)
+ * Copyright (C) 2004  IBM Corp.
+ * Copyright (C) 2005  R Sharada (sharada@in.ibm.com)
+ * Copyright (C) 2006  Mohan Kumar M (mohan@in.ibm.com)
+ * Copyright (C) 2016  IBM Corporation
+ *
+ * Based on kexec-tools' kexec-elf-exec.c and kexec-elf-ppc64.c.
+ * Heavily modified for the kernel by
+ * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt)	"kexec_elf: " fmt
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/elf.h>
+#include <linux/kexec.h>
+#include <linux/of_fdt.h>
+#include <linux/libfdt.h>
+#include <asm/elf_util.h>
+
+extern size_t kexec_purgatory_size;
+
+#define PURGATORY_STACK_SIZE	(16 * 1024)
+
+/**
+ * build_elf_exec_info - read ELF executable and check that we can use it
+ */
+static int build_elf_exec_info(const char *buf, size_t len, struct elfhdr *ehdr,
+			       struct elf_info *elf_info)
+{
+	int i;
+	int ret;
+
+	ret = elf_read_from_buffer(buf, len, ehdr, elf_info);
+	if (ret)
+		return ret;
+
+	/* Big endian vmlinux has type ET_DYN. */
+	if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
+		pr_err("Not an ELF executable.\n");
+		goto error;
+	} else if (!elf_info->proghdrs) {
+		pr_err("No ELF program header.\n");
+		goto error;
+	}
+
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		/*
+		 * Kexec does not support loading interpreters.
+		 * In addition this check keeps us from attempting
+		 * to kexec ordinay executables.
+		 */
+		if (elf_info->proghdrs[i].p_type == PT_INTERP) {
+			pr_err("Requires an ELF interpreter.\n");
+			goto error;
+		}
+	}
+
+	return 0;
+error:
+	elf_free_info(elf_info);
+	return -ENOEXEC;
+}
+
+static int elf64_probe(const char *buf, unsigned long len)
+{
+	struct elfhdr ehdr;
+	struct elf_info elf_info;
+	int ret;
+
+	ret = build_elf_exec_info(buf, len, &ehdr, &elf_info);
+	if (ret)
+		return ret;
+
+	elf_free_info(&elf_info);
+
+	return elf_check_arch(&ehdr) ? 0 : -ENOEXEC;
+}
+
+/**
+ * elf_exec_load - load ELF executable image
+ * @lowest_load_addr:	On return, will be the address where the first PT_LOAD
+ *			section will be loaded in memory.
+ *
+ * Return:
+ * 0 on success, negative value on failure.
+ */
+static int elf_exec_load(struct kimage *image, struct elfhdr *ehdr,
+			 struct elf_info *elf_info,
+			 unsigned long *lowest_load_addr)
+{
+	unsigned long base = 0, lowest_addr = UINT_MAX;
+	int ret;
+	size_t i;
+	struct kexec_buf kbuf = { .image = image, .buf_max = ppc64_rma_size,
+				  .top_down = false };
+
+	/* Read in the PT_LOAD segments. */
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		unsigned long load_addr;
+		size_t size;
+		const struct elf_phdr *phdr;
+
+		phdr = &elf_info->proghdrs[i];
+		if (phdr->p_type != PT_LOAD)
+			continue;
+
+		size = phdr->p_filesz;
+		if (size > phdr->p_memsz)
+			size = phdr->p_memsz;
+
+		kbuf.buffer = (void *) elf_info->buffer + phdr->p_offset;
+		kbuf.bufsz = size;
+		kbuf.memsz = phdr->p_memsz;
+		kbuf.buf_align = phdr->p_align;
+		kbuf.buf_min = phdr->p_paddr + base;
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out;
+		load_addr = kbuf.mem;
+
+		if (load_addr < lowest_addr)
+			lowest_addr = load_addr;
+	}
+
+	/* Update entry point to reflect new load address. */
+	ehdr->e_entry += base;
+
+	*lowest_load_addr = lowest_addr;
+	ret = 0;
+ out:
+	return ret;
+}
+
+void *elf64_load(struct kimage *image, char *kernel_buf,
+		 unsigned long kernel_len, char *initrd,
+		 unsigned long initrd_len, char *cmdline,
+		 unsigned long cmdline_len)
+{
+	int i;
+	int ret = 0, chosen_node;
+	unsigned int fdt_size;
+	unsigned long kernel_load_addr, purgatory_load_addr;
+	unsigned long initrd_load_addr, fdt_load_addr, stack_top;
+	void *fdt;
+	const void *slave_code;
+	struct elfhdr ehdr;
+	struct elf_info elf_info;
+	struct fdt_reserve_entry *rsvmap;
+	struct kexec_buf kbuf = { .image = image, .buf_min = 0,
+				  .buf_max = ppc64_rma_size };
+
+	ret = build_elf_exec_info(kernel_buf, kernel_len, &ehdr, &elf_info);
+	if (ret)
+		goto out;
+
+	ret = elf_exec_load(image, &ehdr, &elf_info, &kernel_load_addr);
+	if (ret)
+		goto out;
+
+	pr_debug("Loaded the kernel at 0x%lx\n", kernel_load_addr);
+
+	ret = kexec_load_purgatory(image, 0, ppc64_rma_size, true,
+				   &purgatory_load_addr);
+	if (ret) {
+		pr_err("Loading purgatory failed.\n");
+		goto out;
+	}
+
+	pr_debug("Loaded purgatory at 0x%lx\n", purgatory_load_addr);
+
+	if (initrd != NULL) {
+		kbuf.buffer = initrd;
+		kbuf.bufsz = kbuf.memsz = initrd_len;
+		kbuf.buf_align = PAGE_SIZE;
+		kbuf.top_down = false;
+		ret = kexec_add_buffer(&kbuf);
+		if (ret)
+			goto out;
+		initrd_load_addr = kbuf.mem;
+
+		pr_debug("Loaded initrd at 0x%lx\n", initrd_load_addr);
+	}
+
+	fdt_size = fdt_totalsize(initial_boot_params) * 2;
+	fdt = kmalloc(fdt_size, GFP_KERNEL);
+	if (!fdt) {
+		pr_err("Not enough memory for the device tree.\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+	if (ret < 0) {
+		pr_err("Error setting up the new device tree.\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
+	if (ret)
+		goto out;
+
+	/*
+	 * Documentation/devicetree/booting-without-of.txt says we need to
+	 * add a reservation entry for the device tree block, but
+	 * early_init_fdt_reserve_self reserves the memory even if there's no
+	 * such entry. We'll add a reservation entry anyway, to be safe and
+	 * compliant.
+	 *
+	 * Use dummy values, we will correct them in a moment.
+	 */
+	ret = fdt_add_mem_rsv(fdt, 1, 1);
+	if (ret) {
+		pr_err("Error reserving device tree memory: %s\n",
+		       fdt_strerror(ret));
+		ret = -EINVAL;
+		goto out;
+	}
+	fdt_pack(fdt);
+
+	kbuf.buffer = fdt;
+	kbuf.bufsz = kbuf.memsz = fdt_size;
+	kbuf.buf_align = PAGE_SIZE;
+	kbuf.top_down = true;
+	ret = kexec_add_buffer(&kbuf);
+	if (ret)
+		goto out;
+	fdt_load_addr = kbuf.mem;
+
+	/*
+	 * Fix fdt reservation, now that we now where it will be loaded
+	 * and how big it is.
+	 */
+	rsvmap = fdt + fdt_off_mem_rsvmap(fdt);
+	i = fdt_num_mem_rsv(fdt) - 1;
+	rsvmap[i].address = cpu_to_fdt64(fdt_load_addr);
+	rsvmap[i].size = cpu_to_fdt64(fdt_totalsize(fdt));
+
+	pr_debug("Loaded device tree at 0x%lx\n", fdt_load_addr);
+
+	kbuf.memsz = PURGATORY_STACK_SIZE;
+	kbuf.buf_align = PAGE_SIZE;
+	kbuf.top_down = true;
+	ret = kexec_locate_mem_hole(&kbuf);
+	if (ret) {
+		pr_err("Couldn't find free memory for the purgatory stack.\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+	stack_top = kbuf.mem + PURGATORY_STACK_SIZE - 1;
+	pr_debug("Purgatory stack is at 0x%lx\n", stack_top);
+
+	slave_code = elf_info.buffer + elf_info.proghdrs[0].p_offset;
+	ret = setup_purgatory(image, slave_code, fdt, kernel_load_addr,
+			      fdt_load_addr, stack_top,
+			      find_debug_console(fdt, chosen_node));
+	if (ret)
+		pr_err("Error setting up the purgatory.\n");
+
+out:
+	elf_free_info(&elf_info);
+
+	/* Make kimage_file_post_load_cleanup free the fdt buffer for us. */
+	return ret ? ERR_PTR(ret) : fdt;
+}
+
+struct kexec_file_ops kexec_elf64_ops = {
+	.probe = elf64_probe,
+	.load = elf64_load,
+};
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 897b724ea9fd..527f98efe651 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -32,11 +32,14 @@
 #include <asm/smp.h>
 #include <asm/hw_breakpoint.h>
 #include <asm/asm-prototypes.h>
+#include <asm/kexec_elf_64.h>
 
 #define SLAVE_CODE_SIZE		256
 
 #ifdef CONFIG_KEXEC_FILE
-static struct kexec_file_ops *kexec_file_loaders[] = { };
+static struct kexec_file_ops *kexec_file_loaders[] = {
+	&kexec_elf64_ops,
+};
 #endif
 
 #ifdef CONFIG_PPC_BOOK3E
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Thiago Jung Bauermann]

Implement the arch_kexec_verify_buffer hook to verify that a device
tree blob passed by userspace via kexec_file_load contains only nodes
and properties from a whitelist.

In elf64_load we merge those properties into the device tree that
will be passed to the next kernel.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kexec.h       |   1 +
 arch/powerpc/kernel/kexec_elf_64.c     |   9 ++
 arch/powerpc/kernel/machine_kexec_64.c | 242 +++++++++++++++++++++++++++++++++
 3 files changed, 252 insertions(+)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index f263cc867891..31bc64e07c8f 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -99,6 +99,7 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
 		  unsigned long initrd_len, const char *cmdline);
 bool find_debug_console(const void *fdt, int chosen_node);
+int merge_partial_dtb(void *to, const void *from);
 #endif /* CONFIG_KEXEC_FILE */
 
 #else /* !CONFIG_KEXEC */
diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
index 49cba9509464..1b902ad66e2a 100644
--- a/arch/powerpc/kernel/kexec_elf_64.c
+++ b/arch/powerpc/kernel/kexec_elf_64.c
@@ -210,6 +210,15 @@ void *elf64_load(struct kimage *image, char *kernel_buf,
 		goto out;
 	}
 
+	/* Add nodes and properties from the DTB passed by userspace. */
+	if (image->dtb_buf) {
+		ret = merge_partial_dtb(fdt, image->dtb_buf);
+		if (ret) {
+			pr_err("Error merging partial device tree.\n");
+			goto out;
+		}
+	}
+
 	ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
 	if (ret)
 		goto out;
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 527f98efe651..a484a6346146 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -35,6 +35,7 @@
 #include <asm/kexec_elf_64.h>
 
 #define SLAVE_CODE_SIZE		256
+#define MAX_DT_PATH		512
 
 #ifdef CONFIG_KEXEC_FILE
 static struct kexec_file_ops *kexec_file_loaders[] = {
@@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int chosen_node)
 	return false;
 }
 
+/**
+ * struct allowed_node - a node in the whitelist and its allowed properties.
+ * @name:		node name or full node path
+ * @properties:		NULL-terminated array of names or name=value pairs
+ *
+ * If name starts with /, then the node has to be at the specified path in
+ * the device tree (including unit addresses for all nodes in the path).
+ * If it doesn't, then the node can be anywhere in the device tree.
+ *
+ * An entry in properties can specify a string value that the property must
+ * have by using the "name=value" format. If the entry ends with =, it means
+ * that the property must be empty.
+ */
+static struct allowed_node {
+	const char *name;
+	const char *properties[9];
+} allowed_nodes[] = {
+	{
+		.name = "/chosen",
+		.properties = {
+			"stdout-path",
+			"linux,stdout-path",
+			NULL,
+		}
+	},
+	{
+		.name = "vga",
+		.properties = {
+			"device_type=display",
+			"assigned-addresses",
+			"width",
+			"height",
+			"depth",
+			"little-endian=",
+			"linux,opened=",
+			"linux,boot-display=",
+			NULL,
+		}
+	},
+};
+
+/**
+ * verify_properties() - verify that all properties in a node are allowed
+ * @properties:	Array of allowed properties in the node.
+ * @fdt:	Device tree blob.
+ * @node:	Offset to node being verified.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int verify_properties(const char *properties[], const void *fdt, int node)
+{
+	int prop;
+
+	for (prop = fdt_first_property_offset(fdt, node); prop >= 0;
+	     prop = fdt_next_property_offset(fdt, prop)) {
+		const char *prop_name;
+		const void *prop_val;
+		int i;
+
+		prop_val = fdt_getprop_by_offset(fdt, prop, &prop_name, NULL);
+		if (prop_val == NULL) {
+			pr_debug("Error reading device tree.\n");
+			return -EINVAL;
+		}
+
+		for (i = 0; properties[i] != NULL; i++) {
+			size_t len;
+			const char *allowed_prop = properties[i];
+
+			len = strchrnul(allowed_prop, '=') - allowed_prop;
+			if (!strncmp(allowed_prop, prop_name, len)) {
+				if (strchr(allowed_prop, '=') != NULL)
+					/* We only support checking strings. */
+					if (strcmp(allowed_prop + len + 1, prop_val)) {
+						pr_debug("Device tree property %s has an invalid value for node %s.\n",
+							 prop_name, fdt_get_name(fdt, node, NULL));
+						return -EINVAL;
+					}
+
+				break;
+			}
+		}
+
+		if (properties[i] == NULL) {
+			pr_debug("Device tree property not allowed for node %s: %s\n",
+				 fdt_get_name(fdt, node, NULL), prop_name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+int arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
+			     unsigned long size)
+{
+	int node;
+
+	if (type != KEXEC_FILE_TYPE_PARTIAL_DTB) {
+		pr_debug("Invalid file type.\n");
+		return -EINVAL;
+	}
+
+	if (fdt_check_header(buf)) {
+		pr_debug("Malformed device tree.\n");
+		return -EINVAL;
+	}
+
+	if (fdt_num_mem_rsv(buf) != 0) {
+		pr_debug("Device tree has memory reservations.\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Check that the device tree only has nodes and properties listed
+	 * in the whitelist.
+	 */
+	for (node = fdt_next_node(buf, -1, NULL); node >= 0;
+	     node = fdt_next_node(buf, node, NULL)) {
+		int i;
+
+		for (i = 0; i < ARRAY_SIZE(allowed_nodes); i++) {
+			int ret;
+
+			if (allowed_nodes[i].name[0] == '/') {
+				char path[MAX_DT_PATH];
+
+				if (fdt_get_path(buf, node, path, sizeof(path))) {
+					pr_debug("Error reading device tree.\n");
+					return -EINVAL;
+				}
+
+				if (!strcmp(allowed_nodes[i].name, path)) {
+					ret = verify_properties(allowed_nodes[i].properties,
+								buf, node);
+					if (ret)
+						return ret;
+
+					break;
+				}
+			} else {
+				const char *name;
+				size_t len;
+
+				name = fdt_get_name(buf, node, NULL);
+				if (name == NULL) {
+					pr_debug("Error reading device tree.\n");
+					return -EINVAL;
+				}
+
+				len = strchrnul(name, '@') - name;
+				if (!strncmp(allowed_nodes[i].name, name, len)) {
+					ret = verify_properties(allowed_nodes[i].properties,
+								buf, node);
+					if (ret)
+						return ret;
+
+					break;
+				}
+			}
+		}
+
+		/*
+		 * If a node isn't in the whitelist but has at least one subnode
+		 * and no properties we allow it, since there may be a
+		 * whitelisted node under it.
+		 */
+		if (i == ARRAY_SIZE(allowed_nodes) &&
+		    (fdt_first_property_offset(buf, node) != -FDT_ERR_NOTFOUND ||
+		     fdt_first_subnode(buf, node) == -FDT_ERR_NOTFOUND)) {
+			pr_debug("Device tree node not allowed: %s\n",
+				 fdt_get_name(buf, node, NULL));
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * merge_partial_dtb() - copy all nodes and properties from one DTB to another
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int merge_partial_dtb(void *to, const void *from)
+{
+	int from_node;
+
+	for (from_node = fdt_next_node(from, -1, NULL); from_node >= 0;
+	     from_node = fdt_next_node(from, from_node, NULL)) {
+		int prop, to_node;
+		char path[MAX_DT_PATH];
+
+		if (fdt_get_path(from, from_node, path, sizeof(path))) {
+			pr_debug("Error reading device tree.\n");
+			return -EINVAL;
+		}
+
+		to_node = fdt_path_offset(to, path);
+		if (to_node == -FDT_ERR_NOTFOUND) {
+			/* We allow creating /chosen if it doesn't exist. */
+			if (strcmp(path, "/chosen")) {
+				pr_debug("%s doesn't exist in the device tree.\n",
+					 path);
+				return -EINVAL;
+			}
+
+			to_node = fdt_add_subnode(to, fdt_path_offset(to, "/"),
+						  "chosen");
+			if (to_node < 0) {
+				pr_debug("Error creating the /chosen node.\n");
+				return -EINVAL;
+			}
+		} else if (to_node < 0) {
+			pr_debug("Error reading device tree.\n");
+			return -EINVAL;
+		}
+
+		for (prop = fdt_first_property_offset(from, from_node); prop >= 0;
+		     prop = fdt_next_property_offset(from, prop)) {
+			const char *name;
+			const void *val;
+			int len, ret;
+
+			val = fdt_getprop_by_offset(from, prop, &name, &len);
+			if (val == NULL) {
+				pr_debug("Error reading device tree.\n");
+				return -EINVAL;
+			}
+
+			ret = fdt_setprop(to, to_node, name, val, len);
+			if (ret) {
+				pr_debug("Error writing new device tree.\n");
+				return -EINVAL;
+			}
+		}
+	}
+
+	return 0;
+}
+
 #endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1

[PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Thiago Jung Bauermann]

Implement the arch_kexec_verify_buffer hook to verify that a device
tree blob passed by userspace via kexec_file_load contains only nodes
and properties from a whitelist.

In elf64_load we merge those properties into the device tree that
will be passed to the next kernel.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kexec.h       |   1 +
 arch/powerpc/kernel/kexec_elf_64.c     |   9 ++
 arch/powerpc/kernel/machine_kexec_64.c | 242 +++++++++++++++++++++++++++++++++
 3 files changed, 252 insertions(+)

diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
index f263cc867891..31bc64e07c8f 100644
--- a/arch/powerpc/include/asm/kexec.h
+++ b/arch/powerpc/include/asm/kexec.h
@@ -99,6 +99,7 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
 int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
 		  unsigned long initrd_len, const char *cmdline);
 bool find_debug_console(const void *fdt, int chosen_node);
+int merge_partial_dtb(void *to, const void *from);
 #endif /* CONFIG_KEXEC_FILE */
 
 #else /* !CONFIG_KEXEC */
diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
index 49cba9509464..1b902ad66e2a 100644
--- a/arch/powerpc/kernel/kexec_elf_64.c
+++ b/arch/powerpc/kernel/kexec_elf_64.c
@@ -210,6 +210,15 @@ void *elf64_load(struct kimage *image, char *kernel_buf,
 		goto out;
 	}
 
+	/* Add nodes and properties from the DTB passed by userspace. */
+	if (image->dtb_buf) {
+		ret = merge_partial_dtb(fdt, image->dtb_buf);
+		if (ret) {
+			pr_err("Error merging partial device tree.\n");
+			goto out;
+		}
+	}
+
 	ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
 	if (ret)
 		goto out;
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index 527f98efe651..a484a6346146 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -35,6 +35,7 @@
 #include <asm/kexec_elf_64.h>
 
 #define SLAVE_CODE_SIZE		256
+#define MAX_DT_PATH		512
 
 #ifdef CONFIG_KEXEC_FILE
 static struct kexec_file_ops *kexec_file_loaders[] = {
@@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int chosen_node)
 	return false;
 }
 
+/**
+ * struct allowed_node - a node in the whitelist and its allowed properties.
+ * @name:		node name or full node path
+ * @properties:		NULL-terminated array of names or name=value pairs
+ *
+ * If name starts with /, then the node has to be at the specified path in
+ * the device tree (including unit addresses for all nodes in the path).
+ * If it doesn't, then the node can be anywhere in the device tree.
+ *
+ * An entry in properties can specify a string value that the property must
+ * have by using the "name=value" format. If the entry ends with =, it means
+ * that the property must be empty.
+ */
+static struct allowed_node {
+	const char *name;
+	const char *properties[9];
+} allowed_nodes[] = {
+	{
+		.name = "/chosen",
+		.properties = {
+			"stdout-path",
+			"linux,stdout-path",
+			NULL,
+		}
+	},
+	{
+		.name = "vga",
+		.properties = {
+			"device_type=display",
+			"assigned-addresses",
+			"width",
+			"height",
+			"depth",
+			"little-endian=",
+			"linux,opened=",
+			"linux,boot-display=",
+			NULL,
+		}
+	},
+};
+
+/**
+ * verify_properties() - verify that all properties in a node are allowed
+ * @properties:	Array of allowed properties in the node.
+ * @fdt:	Device tree blob.
+ * @node:	Offset to node being verified.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+static int verify_properties(const char *properties[], const void *fdt, int node)
+{
+	int prop;
+
+	for (prop = fdt_first_property_offset(fdt, node); prop >= 0;
+	     prop = fdt_next_property_offset(fdt, prop)) {
+		const char *prop_name;
+		const void *prop_val;
+		int i;
+
+		prop_val = fdt_getprop_by_offset(fdt, prop, &prop_name, NULL);
+		if (prop_val == NULL) {
+			pr_debug("Error reading device tree.\n");
+			return -EINVAL;
+		}
+
+		for (i = 0; properties[i] != NULL; i++) {
+			size_t len;
+			const char *allowed_prop = properties[i];
+
+			len = strchrnul(allowed_prop, '=') - allowed_prop;
+			if (!strncmp(allowed_prop, prop_name, len)) {
+				if (strchr(allowed_prop, '=') != NULL)
+					/* We only support checking strings. */
+					if (strcmp(allowed_prop + len + 1, prop_val)) {
+						pr_debug("Device tree property %s has an invalid value for node %s.\n",
+							 prop_name, fdt_get_name(fdt, node, NULL));
+						return -EINVAL;
+					}
+
+				break;
+			}
+		}
+
+		if (properties[i] == NULL) {
+			pr_debug("Device tree property not allowed for node %s: %s\n",
+				 fdt_get_name(fdt, node, NULL), prop_name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+int arch_kexec_verify_buffer(enum kexec_file_type type, const void *buf,
+			     unsigned long size)
+{
+	int node;
+
+	if (type != KEXEC_FILE_TYPE_PARTIAL_DTB) {
+		pr_debug("Invalid file type.\n");
+		return -EINVAL;
+	}
+
+	if (fdt_check_header(buf)) {
+		pr_debug("Malformed device tree.\n");
+		return -EINVAL;
+	}
+
+	if (fdt_num_mem_rsv(buf) != 0) {
+		pr_debug("Device tree has memory reservations.\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Check that the device tree only has nodes and properties listed
+	 * in the whitelist.
+	 */
+	for (node = fdt_next_node(buf, -1, NULL); node >= 0;
+	     node = fdt_next_node(buf, node, NULL)) {
+		int i;
+
+		for (i = 0; i < ARRAY_SIZE(allowed_nodes); i++) {
+			int ret;
+
+			if (allowed_nodes[i].name[0] == '/') {
+				char path[MAX_DT_PATH];
+
+				if (fdt_get_path(buf, node, path, sizeof(path))) {
+					pr_debug("Error reading device tree.\n");
+					return -EINVAL;
+				}
+
+				if (!strcmp(allowed_nodes[i].name, path)) {
+					ret = verify_properties(allowed_nodes[i].properties,
+								buf, node);
+					if (ret)
+						return ret;
+
+					break;
+				}
+			} else {
+				const char *name;
+				size_t len;
+
+				name = fdt_get_name(buf, node, NULL);
+				if (name == NULL) {
+					pr_debug("Error reading device tree.\n");
+					return -EINVAL;
+				}
+
+				len = strchrnul(name, '@') - name;
+				if (!strncmp(allowed_nodes[i].name, name, len)) {
+					ret = verify_properties(allowed_nodes[i].properties,
+								buf, node);
+					if (ret)
+						return ret;
+
+					break;
+				}
+			}
+		}
+
+		/*
+		 * If a node isn't in the whitelist but has at least one subnode
+		 * and no properties we allow it, since there may be a
+		 * whitelisted node under it.
+		 */
+		if (i == ARRAY_SIZE(allowed_nodes) &&
+		    (fdt_first_property_offset(buf, node) != -FDT_ERR_NOTFOUND ||
+		     fdt_first_subnode(buf, node) == -FDT_ERR_NOTFOUND)) {
+			pr_debug("Device tree node not allowed: %s\n",
+				 fdt_get_name(buf, node, NULL));
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * merge_partial_dtb() - copy all nodes and properties from one DTB to another
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int merge_partial_dtb(void *to, const void *from)
+{
+	int from_node;
+
+	for (from_node = fdt_next_node(from, -1, NULL); from_node >= 0;
+	     from_node = fdt_next_node(from, from_node, NULL)) {
+		int prop, to_node;
+		char path[MAX_DT_PATH];
+
+		if (fdt_get_path(from, from_node, path, sizeof(path))) {
+			pr_debug("Error reading device tree.\n");
+			return -EINVAL;
+		}
+
+		to_node = fdt_path_offset(to, path);
+		if (to_node == -FDT_ERR_NOTFOUND) {
+			/* We allow creating /chosen if it doesn't exist. */
+			if (strcmp(path, "/chosen")) {
+				pr_debug("%s doesn't exist in the device tree.\n",
+					 path);
+				return -EINVAL;
+			}
+
+			to_node = fdt_add_subnode(to, fdt_path_offset(to, "/"),
+						  "chosen");
+			if (to_node < 0) {
+				pr_debug("Error creating the /chosen node.\n");
+				return -EINVAL;
+			}
+		} else if (to_node < 0) {
+			pr_debug("Error reading device tree.\n");
+			return -EINVAL;
+		}
+
+		for (prop = fdt_first_property_offset(from, from_node); prop >= 0;
+		     prop = fdt_next_property_offset(from, prop)) {
+			const char *name;
+			const void *val;
+			int len, ret;
+
+			val = fdt_getprop_by_offset(from, prop, &name, &len);
+			if (val == NULL) {
+				pr_debug("Error reading device tree.\n");
+				return -EINVAL;
+			}
+
+			ret = fdt_setprop(to, to_node, name, val, len);
+			if (ret) {
+				pr_debug("Error writing new device tree.\n");
+				return -EINVAL;
+			}
+		}
+	}
+
+	return 0;
+}
+
 #endif /* CONFIG_KEXEC_FILE */
-- 
1.9.1


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 12/13] powerpc: Add purgatory for kexec_file_load implementation.

[Thiago Jung Bauermann]

This purgatory implementation comes from kexec-tools, almost unchanged.

The only changes were that the sha256_regions global variable was
renamed to sha_regions to match what kexec_file_load expects, and to
use the sha256.c file from x86's purgatory to avoid adding yet another
SHA-256 implementation.

Also, some formatting warnings found by checkpatch.pl were fixed.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/Makefile                     |   4 +
 arch/powerpc/purgatory/.gitignore         |   2 +
 arch/powerpc/purgatory/Makefile           |  36 +++++++
 arch/powerpc/purgatory/console-ppc64.c    |  38 +++++++
 arch/powerpc/purgatory/crashdump-ppc64.h  |  42 ++++++++
 arch/powerpc/purgatory/crashdump_backup.c |  36 +++++++
 arch/powerpc/purgatory/crtsavres.S        |   5 +
 arch/powerpc/purgatory/hvCall.S           |  27 +++++
 arch/powerpc/purgatory/hvCall.h           |   8 ++
 arch/powerpc/purgatory/kexec-sha256.h     |  11 ++
 arch/powerpc/purgatory/ppc64_asm.h        |  20 ++++
 arch/powerpc/purgatory/printf.c           | 164 ++++++++++++++++++++++++++++++
 arch/powerpc/purgatory/purgatory-ppc64.c  |  41 ++++++++
 arch/powerpc/purgatory/purgatory-ppc64.h  |   6 ++
 arch/powerpc/purgatory/purgatory.c        |  62 +++++++++++
 arch/powerpc/purgatory/purgatory.h        |  11 ++
 arch/powerpc/purgatory/sha256.c           |   6 ++
 arch/powerpc/purgatory/sha256.h           |   1 +
 arch/powerpc/purgatory/string.S           |   1 +
 arch/powerpc/purgatory/v2wrap.S           | 134 ++++++++++++++++++++++++
 20 files changed, 655 insertions(+)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index ca254546cd05..beb928ff6b77 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -254,6 +254,7 @@ core-y				+= arch/powerpc/kernel/ \
 core-$(CONFIG_XMON)		+= arch/powerpc/xmon/
 core-$(CONFIG_KVM) 		+= arch/powerpc/kvm/
 core-$(CONFIG_PERF_EVENTS)	+= arch/powerpc/perf/
+core-$(CONFIG_KEXEC_FILE)	+= arch/powerpc/purgatory/
 
 drivers-$(CONFIG_OPROFILE)	+= arch/powerpc/oprofile/
 
@@ -375,6 +376,9 @@ archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)
 
 archprepare: checkbin
+ifeq ($(CONFIG_KEXEC_FILE),y)
+	$(Q)$(MAKE) $(build)=arch/powerpc/purgatory arch/powerpc/purgatory/kexec-purgatory.c
+endif
 
 # Use the file '.tmp_gas_check' for binutils tests, as gas won't output
 # to stdout and these checks are run even on install targets.
diff --git a/arch/powerpc/purgatory/.gitignore b/arch/powerpc/purgatory/.gitignore
new file mode 100644
index 000000000000..e9e66f178a6d
--- /dev/null
+++ b/arch/powerpc/purgatory/.gitignore
@@ -0,0 +1,2 @@
+kexec-purgatory.c
+purgatory.ro
diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile
new file mode 100644
index 000000000000..63daf95e5703
--- /dev/null
+++ b/arch/powerpc/purgatory/Makefile
@@ -0,0 +1,36 @@
+purgatory-y := purgatory.o printf.o string.o v2wrap.o hvCall.o \
+		purgatory-ppc64.o console-ppc64.o crashdump_backup.o \
+		crtsavres.o sha256.o
+
+targets += $(purgatory-y)
+PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
+
+LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostartfiles \
+			-nostdlib -nodefaultlibs
+targets += purgatory.ro
+
+# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
+# in turn leaves some undefined symbols like __fentry__ in purgatory and not
+# sure how to relocate those. Like kexec-tools, use custom flags.
+
+KBUILD_CFLAGS := -Wall -Wstrict-prototypes -fno-strict-aliasing \
+		-fno-zero-initialized-in-bss -fno-builtin -ffreestanding \
+		-fno-PIC -fno-PIE -fno-stack-protector  -fno-exceptions \
+		-msoft-float -MD -Os
+KBUILD_CFLAGS += -m$(CONFIG_WORD_SIZE)
+
+$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
+		$(call if_changed,ld)
+
+targets += kexec-purgatory.c
+
+CMD_BIN2C = $(objtree)/scripts/basic/bin2c
+quiet_cmd_bin2c = BIN2C   $@
+      cmd_bin2c = $(CMD_BIN2C) kexec_purgatory < $< > $@
+
+$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE
+	$(call if_changed,bin2c)
+	@:
+
+
+obj-$(CONFIG_KEXEC_FILE)	+= kexec-purgatory.o
diff --git a/arch/powerpc/purgatory/console-ppc64.c b/arch/powerpc/purgatory/console-ppc64.c
new file mode 100644
index 000000000000..3d07be0b5d08
--- /dev/null
+++ b/arch/powerpc/purgatory/console-ppc64.c
@@ -0,0 +1,38 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Mohan Kumar M (mohan@in.ibm.com)
+ *
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ *
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "hvCall.h"
+#include <asm/byteorder.h>
+
+extern int debug;
+
+void putchar(int c)
+{
+	char buff[8];
+	unsigned long *lbuf = (unsigned long *)buff;
+
+	if (!debug) /* running on non pseries */
+		return;
+
+	if (c == '\n')
+		putchar('\r');
+
+	buff[0] = c;
+	plpar_hcall_norets(H_PUT_TERM_CHAR, 0, 1, __cpu_to_be64(*lbuf), 0);
+}
diff --git a/arch/powerpc/purgatory/crashdump-ppc64.h b/arch/powerpc/purgatory/crashdump-ppc64.h
new file mode 100644
index 000000000000..90064b49ebfe
--- /dev/null
+++ b/arch/powerpc/purgatory/crashdump-ppc64.h
@@ -0,0 +1,42 @@
+#ifndef CRASHDUMP_PPC64_H
+#define CRASHDUMP_PPC64_H
+
+#include <linux/types.h>
+
+struct kexec_info;
+int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
+				uint64_t max_addr, unsigned long min_base);
+void add_usable_mem_rgns(unsigned long long base, unsigned long long size);
+
+#define PAGE_OFFSET     0xC000000000000000ULL
+#define KERNELBASE      PAGE_OFFSET
+#define VMALLOCBASE     0xD000000000000000ULL
+
+#define __pa(x)         ((unsigned long)(x)-PAGE_OFFSET)
+#define MAXMEM          (-KERNELBASE-VMALLOCBASE)
+
+#define COMMAND_LINE_SIZE       512 /* from kernel */
+/* Backup Region, First 64K of System RAM. */
+#define BACKUP_SRC_START    0x0000
+#define BACKUP_SRC_END      0xffff
+#define BACKUP_SRC_SIZE     (BACKUP_SRC_END - BACKUP_SRC_START + 1)
+
+#define KDUMP_BACKUP_LIMIT	BACKUP_SRC_SIZE
+
+#define KERNEL_RUN_AT_ZERO_MAGIC 0x72756e30	/* "run0" */
+
+extern uint64_t crash_base;
+extern uint64_t crash_size;
+extern uint64_t memory_limit;
+extern unsigned int rtas_base;
+extern unsigned int rtas_size;
+extern uint64_t opal_base;
+extern uint64_t opal_size;
+
+uint64_t lmb_size;
+unsigned int num_of_lmbs;
+
+#define DRCONF_ADDR	0
+#define DRCONF_FLAGS	20
+
+#endif /* CRASHDUMP_PPC64_H */
diff --git a/arch/powerpc/purgatory/crashdump_backup.c b/arch/powerpc/purgatory/crashdump_backup.c
new file mode 100644
index 000000000000..11ccafdcc9ad
--- /dev/null
+++ b/arch/powerpc/purgatory/crashdump_backup.c
@@ -0,0 +1,36 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Mohan Kumar M (mohan@in.ibm.com)
+ *
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ *
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "../boot/string.h"
+#include "crashdump-ppc64.h"
+
+extern unsigned long backup_start;
+
+/* Backup first 32KB of memory to backup region reserved by kexec */
+void crashdump_backup_memory(void)
+{
+	void *dest, *src;
+
+	src = (void *)BACKUP_SRC_START;
+
+	if (backup_start) {
+		dest = (void *)(backup_start);
+		memcpy(dest, src, BACKUP_SRC_SIZE);
+	}
+}
diff --git a/arch/powerpc/purgatory/crtsavres.S b/arch/powerpc/purgatory/crtsavres.S
new file mode 100644
index 000000000000..5d17e1c0d575
--- /dev/null
+++ b/arch/powerpc/purgatory/crtsavres.S
@@ -0,0 +1,5 @@
+#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
+#define CONFIG_CC_OPTIMIZE_FOR_SIZE 1
+#endif
+
+#include "../lib/crtsavres.S"
diff --git a/arch/powerpc/purgatory/hvCall.S b/arch/powerpc/purgatory/hvCall.S
new file mode 100644
index 000000000000..a96c4898f1d8
--- /dev/null
+++ b/arch/powerpc/purgatory/hvCall.S
@@ -0,0 +1,27 @@
+/*
+ * This file contains the generic function to perform a call to the
+ * pSeries LPAR hypervisor.
+ *
+ * Taken from linux/arch/powerpc/platforms/pseries/hvCall.S
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include "ppc64_asm.h"
+
+#define HVSC	.long 0x44000022
+.text
+	.machine ppc64
+.globl DOTSYM(plpar_hcall_norets)
+DOTSYM(plpar_hcall_norets):
+	or	6,6,6			# medium low priority
+        mfcr	0
+        stw	0,8(1)
+
+        HVSC 				/* invoke the hypervisor */
+
+        lwz	0,8(1)
+        mtcrf	0xff,0
+        blr                             /* return r3 = status */
diff --git a/arch/powerpc/purgatory/hvCall.h b/arch/powerpc/purgatory/hvCall.h
new file mode 100644
index 000000000000..187e24d8b964
--- /dev/null
+++ b/arch/powerpc/purgatory/hvCall.h
@@ -0,0 +1,8 @@
+#ifndef HVCALL_H
+#define HVCALL_H
+
+#define H_PUT_TERM_CHAR	0x58
+
+long plpar_hcall_norets(unsigned long opcode, ...);
+
+#endif
diff --git a/arch/powerpc/purgatory/kexec-sha256.h b/arch/powerpc/purgatory/kexec-sha256.h
new file mode 100644
index 000000000000..4418ed02c052
--- /dev/null
+++ b/arch/powerpc/purgatory/kexec-sha256.h
@@ -0,0 +1,11 @@
+#ifndef KEXEC_SHA256_H
+#define KEXEC_SHA256_H
+
+struct kexec_sha_region {
+	unsigned long start;
+	unsigned long len;
+};
+
+#define SHA256_REGIONS 16
+
+#endif /* KEXEC_SHA256_H */
diff --git a/arch/powerpc/purgatory/ppc64_asm.h b/arch/powerpc/purgatory/ppc64_asm.h
new file mode 100644
index 000000000000..95d721718237
--- /dev/null
+++ b/arch/powerpc/purgatory/ppc64_asm.h
@@ -0,0 +1,20 @@
+/*
+ * ppc64_asm.h - common defines for PPC64 assembly parts
+ *
+ * Code taken from kexec-tools.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <asm/types.h>
+
+/*
+ * ABIv1 requires dot symbol while ABIv2 does not.
+ */
+#ifdef PPC64_ELF_ABI_v2
+#define DOTSYM(a)	a
+#else
+#define GLUE(a, b)	a##b
+#define DOTSYM(a)	GLUE(., a)
+#endif
diff --git a/arch/powerpc/purgatory/printf.c b/arch/powerpc/purgatory/printf.c
new file mode 100644
index 000000000000..c5f425b55fd5
--- /dev/null
+++ b/arch/powerpc/purgatory/printf.c
@@ -0,0 +1,164 @@
+/*
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdarg.h>
+#include "purgatory.h"
+#include "../boot/string.h"
+
+#define CHAR_BIT 8
+
+/*
+ * Output
+ * =============================================================================
+ */
+
+#define LONG_LONG_SHIFT  ((int)((sizeof(unsigned long long)*CHAR_BIT) - 4))
+#define LONG_SHIFT  ((int)((sizeof(unsigned long)*CHAR_BIT) - 4))
+#define INT_SHIFT   ((int)((sizeof(unsigned int)*CHAR_BIT) - 4))
+#define SHRT_SHIFT  ((int)((sizeof(unsigned short)*CHAR_BIT) - 4))
+#define CHAR_SHIFT  ((int)((sizeof(unsigned char)*CHAR_BIT) - 4))
+
+/**************************************************************************
+PRINTF and friends
+
+	Formats:
+		%x	- 4 bytes int (8 hex digits, lower case)
+		%X	- 4 bytes int (8 hex digits, upper case)
+		%lx     - 8 bytes long (16 hex digits, lower case)
+		%lX     - 8 bytes long (16 hex digits, upper case)
+		%hx	- 2 bytes int (4 hex digits, lower case)
+		%hX	- 2 bytes int (4 hex digits, upper case)
+		%hhx	- 1 byte int (2 hex digits, lower case)
+		%hhX	- 1 byte int (2 hex digits, upper case)
+			- optional # prefixes 0x or 0X
+		%d	- decimal int
+		%c	- char
+		%s	- string
+	Note: width specification not supported
+**************************************************************************/
+void vsprintf(char *buffer, const char *fmt, va_list args)
+{
+	char *p;
+
+	for ( ; *fmt != '\0'; ++fmt) {
+		if (*fmt != '%') {
+			if (buffer)
+				*buffer++ = *fmt;
+			else
+				putchar(*fmt);
+			continue;
+		}
+		if (*++fmt == 's') {
+			for (p = va_arg(args, char *); *p != '\0'; p++)
+				if (buffer)
+					*buffer++ = *p;
+				else
+					putchar(*p);
+		} else {	/* Length of item is bounded */
+			char tmp[40], *q = tmp;
+			int shift = INT_SHIFT;
+
+			if (*fmt == 'L') {
+				shift = LONG_LONG_SHIFT;
+				fmt++;
+			} else if (*fmt == 'l') {
+				shift = LONG_SHIFT;
+				fmt++;
+			} else if (*fmt == 'h') {
+				shift = SHRT_SHIFT;
+				fmt++;
+				if (*fmt == 'h') {
+					shift = CHAR_SHIFT;
+					fmt++;
+				}
+			}
+
+			/*
+			 * Before each format q points to tmp buffer
+			 * After each format q points past end of item
+			 */
+			if ((*fmt | 0x20) == 'x') {
+				/* With x86 gcc, sizeof(long) == sizeof(int) */
+				unsigned long long h;
+				int ncase;
+
+				if (shift > LONG_SHIFT)
+					h = va_arg(args, unsigned long long);
+				else if (shift > INT_SHIFT)
+					h = va_arg(args, unsigned long);
+				else
+					h = va_arg(args, unsigned int);
+
+				ncase = (*fmt & 0x20);
+				for ( ; shift >= 0; shift -= 4)
+					*q++ = "0123456789ABCDEF"[(h >> shift) & 0xF] | ncase;
+			} else if (*fmt == 'd') {
+				char *r;
+				long i;
+
+				if (shift > LONG_SHIFT)
+					i = va_arg(args, long long);
+				else if (shift > INT_SHIFT)
+					i = va_arg(args, long);
+				else
+					i = va_arg(args, int);
+
+				if (i < 0) {
+					*q++ = '-';
+					i = -i;
+				}
+				p = q;		/* save beginning of digits */
+				do {
+					*q++ = '0' + (i % 10);
+					i /= 10;
+				} while (i);
+				/* reverse digits, stop in middle */
+				r = q;		/* don't alter q */
+				while (--r > p) {
+					i = *r;
+					*r = *p;
+					*p++ = i;
+				}
+			} else if (*fmt == 'c')
+				*q++ = va_arg(args, int);
+			else
+				*q++ = *fmt;
+			/* now output the saved string */
+			for (p = tmp; p < q; ++p)
+				if (buffer)
+					*buffer++ = *p;
+				else
+					putchar(*p);
+		}
+	}
+	if (buffer)
+		*buffer = '\0';
+}
+
+void sprintf(char *buffer, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vsprintf(buffer, fmt, args);
+	va_end(args);
+}
+
+void printf(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vsprintf(0, fmt, args);
+	va_end(args);
+}
diff --git a/arch/powerpc/purgatory/purgatory-ppc64.c b/arch/powerpc/purgatory/purgatory-ppc64.c
new file mode 100644
index 000000000000..0be65a424ab1
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory-ppc64.c
@@ -0,0 +1,41 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Mohan Kumar M (mohan@in.ibm.com)
+ *
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ *
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "purgatory.h"
+#include "purgatory-ppc64.h"
+
+unsigned int panic_kernel = 0;
+unsigned long backup_start = 0;
+unsigned long stack = 0;
+unsigned long dt_offset = 0;
+unsigned long my_toc = 0;
+unsigned long kernel = 0;
+unsigned int debug = 0;
+unsigned long opal_base = 0;
+unsigned long opal_entry = 0;
+
+void setup_arch(void)
+{
+}
+
+void post_verification_setup_arch(void)
+{
+	if (panic_kernel)
+		crashdump_backup_memory();
+}
diff --git a/arch/powerpc/purgatory/purgatory-ppc64.h b/arch/powerpc/purgatory/purgatory-ppc64.h
new file mode 100644
index 000000000000..52eaf4394c48
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory-ppc64.h
@@ -0,0 +1,6 @@
+#ifndef PURGATORY_PPC64_H
+#define PURGATORY_PPC64_H
+
+void crashdump_backup_memory(void);
+
+#endif /* PURGATORY_PPC64_H */
diff --git a/arch/powerpc/purgatory/purgatory.c b/arch/powerpc/purgatory/purgatory.c
new file mode 100644
index 000000000000..5b006d685cf2
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory.c
@@ -0,0 +1,62 @@
+/*
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "purgatory.h"
+#include "sha256.h"
+#include "../boot/string.h"
+#include "kexec-sha256.h"
+
+struct kexec_sha_region sha_regions[SHA256_REGIONS] = {};
+u8 sha256_digest[SHA256_DIGEST_SIZE] = { 0 };
+
+int verify_sha256_digest(void)
+{
+	struct kexec_sha_region *ptr, *end;
+	u8 digest[SHA256_DIGEST_SIZE];
+	size_t i;
+	struct sha256_state sctx;
+
+	sha256_init(&sctx);
+	end = &sha_regions[sizeof(sha_regions)/sizeof(sha_regions[0])];
+	for (ptr = sha_regions; ptr < end; ptr++)
+		sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
+	sha256_final(&sctx, digest);
+
+	if (memcmp(digest, sha256_digest, sizeof(digest)) != 0) {
+		printf("sha256 digests do not match :(\n");
+		printf("       digest: ");
+		for (i = 0; i < sizeof(digest); i++)
+			printf("%hhx ", digest[i]);
+		printf("\n");
+
+		printf("sha256_digest: ");
+		for (i = 0; i < sizeof(sha256_digest); i++)
+			printf("%hhx ", sha256_digest[i]);
+
+		printf("\n");
+		return 1;
+	}
+	return 0;
+}
+
+void purgatory(void)
+{
+	printf("I'm in purgatory\n");
+	setup_arch();
+	if (verify_sha256_digest()) {
+		/* loop forever */
+		for (;;)
+			;
+	}
+	post_verification_setup_arch();
+}
diff --git a/arch/powerpc/purgatory/purgatory.h b/arch/powerpc/purgatory/purgatory.h
new file mode 100644
index 000000000000..788ce4930a30
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory.h
@@ -0,0 +1,11 @@
+#ifndef PURGATORY_H
+#define PURGATORY_H
+
+void putchar(int ch);
+void sprintf(char *buffer, const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3)));
+void printf(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
+void setup_arch(void);
+void post_verification_setup_arch(void);
+
+#endif /* PURGATORY_H */
diff --git a/arch/powerpc/purgatory/sha256.c b/arch/powerpc/purgatory/sha256.c
new file mode 100644
index 000000000000..6abee1877d56
--- /dev/null
+++ b/arch/powerpc/purgatory/sha256.c
@@ -0,0 +1,6 @@
+#include "../boot/string.h"
+
+/* Avoid including x86's boot/string.h in sha256.c. */
+#define BOOT_STRING_H
+
+#include "../../x86/purgatory/sha256.c"
diff --git a/arch/powerpc/purgatory/sha256.h b/arch/powerpc/purgatory/sha256.h
new file mode 100644
index 000000000000..72818f3a207e
--- /dev/null
+++ b/arch/powerpc/purgatory/sha256.h
@@ -0,0 +1 @@
+#include "../../x86/purgatory/sha256.h"
diff --git a/arch/powerpc/purgatory/string.S b/arch/powerpc/purgatory/string.S
new file mode 100644
index 000000000000..3a1e23ff4017
--- /dev/null
+++ b/arch/powerpc/purgatory/string.S
@@ -0,0 +1 @@
+#include "../boot/string.S"
diff --git a/arch/powerpc/purgatory/v2wrap.S b/arch/powerpc/purgatory/v2wrap.S
new file mode 100644
index 000000000000..c9a981c39a78
--- /dev/null
+++ b/arch/powerpc/purgatory/v2wrap.S
@@ -0,0 +1,134 @@
+#
+#  kexec: Linux boots Linux
+#
+#  Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
+#  Copyright (C) 2006, Mohan Kumar M (mohan@in.ibm.com), IBM Corporation
+#
+# Code taken from kexec-tools.
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation (version 2 of the License).
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+
+#include "ppc64_asm.h"
+
+# v2wrap.S
+# a wrapper to call purgatory code to backup first
+# 32kB of first kernel into the backup region
+# reserved by kexec-tools.
+# Invokes ppc64 kernel with the expected arguments
+# of kernel(device-tree, phys-offset, 0)
+
+#
+# calling convention:
+#   r3 = physical number of this cpu (all cpus)
+#   r4 = address of this chunk (master only)
+# master enters at purgatory_start (aka first byte of this chunk)
+# slaves (additional cpus), if any, enter a copy of the
+# first 0x100 bytes of this code relocated to 0x0
+#
+# in other words,
+#   a copy of the first 0x100 bytes of this code is copied to 0
+#   and the slaves are sent to address 0x60
+#   with r3 = their physical cpu number.
+
+#define LOADADDR(rn,name) \
+	lis     rn,name##@highest;      \
+	ori     rn,rn,name##@higher;    \
+	rldicr  rn,rn,32,31;            \
+	oris    rn,rn,name##@h;         \
+	ori     rn,rn,name##@l
+
+	.machine ppc64
+	.align 8
+	.globl purgatory_start
+purgatory_start:	b	master
+	.org purgatory_start + 0x5c     # ABI: possible run_at_load flag at 0x5c
+	.globl run_at_load
+run_at_load:
+	.long 0
+	.size run_at_load, . - run_at_load
+	.org purgatory_start + 0x60     # ABI: slaves start at 60 with r3=phys
+slave:	b $
+	.org purgatory_start + 0x100    # ABI: end of copied region
+	.size purgatory_start, . - purgatory_start
+
+#
+# The above 0x100 bytes at purgatory_start are replaced with the
+# code from the kernel (or next stage) by kexec/arch/ppc64/kexec-elf-ppc64.c
+#
+
+master:
+	or	1,1,1		# low priority to let other threads catchup
+	isync
+	mr      17,3            # save cpu id to r17
+	mr      15,4            # save physical address in reg15
+
+	LOADADDR(6,my_toc)
+	ld      2,0(6)          #setup toc
+
+	LOADADDR(6,stack)
+	ld      1,0(6)          #setup stack
+
+	subi    1,1,112
+	bl      DOTSYM(purgatory)
+	nop
+
+	or	3,3,3		# ok now to high priority, lets boot
+	lis	6,0x1
+	mtctr	6		# delay a bit for slaves to catch up
+83:	bdnz	83b		# before we overwrite 0-100 again
+
+	LOADADDR(16, dt_offset)
+	ld      3,0(16)         # load device-tree address
+	mr      16,3            # save dt address in reg16
+#ifdef __BIG_ENDIAN__
+	lwz     6,20(3)         # fetch version number
+#else
+	li	4,20
+	lwbrx	6,3,4		# fetch BE version number
+#endif
+	cmpwi   0,6,2           # v2 ?
+	blt     80f
+#ifdef __BIG_ENDIAN__
+	stw     17,28(3)        # save my cpu number as boot_cpu_phys
+#else
+	li	4,28
+	stwbrx	17,3,4		# Store my cpu as BE value
+#endif
+80:
+	LOADADDR(6,opal_base)	# For OPAL early debug
+	ld      8,0(6)          # load the OPAL base address in r8
+	LOADADDR(6,opal_entry)	# For OPAL early debug
+	ld      9,0(6)          # load the OPAL entry address in r9
+	LOADADDR(6,kernel)
+	ld      4,0(6)          # load the kernel address
+	LOADADDR(6,run_at_load) # the load flag
+	lwz	7,0(6)		# possibly patched by kexec-elf-ppc64
+	stw	7,0x5c(4)	# and patch it into the kernel
+	mr      3,16            # restore dt address
+
+	mfmsr	5
+	andi.	10,5,1		# test MSR_LE
+	bne	little_endian
+
+	li	5,0		# r5 will be 0 for kernel
+	mtctr	4		# prepare branch to
+	bctr			# start kernel
+
+little_endian:			# book3s-only
+	mtsrr0	4		# prepare branch to
+
+	clrrdi	5,5,1		# clear MSR_LE
+	mtsrr1	5
+
+	li	5,0		# r5 will be 0 for kernel
+
+				# skip cache flush, do we care?
+
+	rfid			# update MSR and start kernel
-- 
1.9.1

[PATCH v5 12/13] powerpc: Add purgatory for kexec_file_load implementation.

[Thiago Jung Bauermann]

This purgatory implementation comes from kexec-tools, almost unchanged.

The only changes were that the sha256_regions global variable was
renamed to sha_regions to match what kexec_file_load expects, and to
use the sha256.c file from x86's purgatory to avoid adding yet another
SHA-256 implementation.

Also, some formatting warnings found by checkpatch.pl were fixed.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/Makefile                     |   4 +
 arch/powerpc/purgatory/.gitignore         |   2 +
 arch/powerpc/purgatory/Makefile           |  36 +++++++
 arch/powerpc/purgatory/console-ppc64.c    |  38 +++++++
 arch/powerpc/purgatory/crashdump-ppc64.h  |  42 ++++++++
 arch/powerpc/purgatory/crashdump_backup.c |  36 +++++++
 arch/powerpc/purgatory/crtsavres.S        |   5 +
 arch/powerpc/purgatory/hvCall.S           |  27 +++++
 arch/powerpc/purgatory/hvCall.h           |   8 ++
 arch/powerpc/purgatory/kexec-sha256.h     |  11 ++
 arch/powerpc/purgatory/ppc64_asm.h        |  20 ++++
 arch/powerpc/purgatory/printf.c           | 164 ++++++++++++++++++++++++++++++
 arch/powerpc/purgatory/purgatory-ppc64.c  |  41 ++++++++
 arch/powerpc/purgatory/purgatory-ppc64.h  |   6 ++
 arch/powerpc/purgatory/purgatory.c        |  62 +++++++++++
 arch/powerpc/purgatory/purgatory.h        |  11 ++
 arch/powerpc/purgatory/sha256.c           |   6 ++
 arch/powerpc/purgatory/sha256.h           |   1 +
 arch/powerpc/purgatory/string.S           |   1 +
 arch/powerpc/purgatory/v2wrap.S           | 134 ++++++++++++++++++++++++
 20 files changed, 655 insertions(+)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index ca254546cd05..beb928ff6b77 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -254,6 +254,7 @@ core-y				+= arch/powerpc/kernel/ \
 core-$(CONFIG_XMON)		+= arch/powerpc/xmon/
 core-$(CONFIG_KVM) 		+= arch/powerpc/kvm/
 core-$(CONFIG_PERF_EVENTS)	+= arch/powerpc/perf/
+core-$(CONFIG_KEXEC_FILE)	+= arch/powerpc/purgatory/
 
 drivers-$(CONFIG_OPROFILE)	+= arch/powerpc/oprofile/
 
@@ -375,6 +376,9 @@ archclean:
 	$(Q)$(MAKE) $(clean)=$(boot)
 
 archprepare: checkbin
+ifeq ($(CONFIG_KEXEC_FILE),y)
+	$(Q)$(MAKE) $(build)=arch/powerpc/purgatory arch/powerpc/purgatory/kexec-purgatory.c
+endif
 
 # Use the file '.tmp_gas_check' for binutils tests, as gas won't output
 # to stdout and these checks are run even on install targets.
diff --git a/arch/powerpc/purgatory/.gitignore b/arch/powerpc/purgatory/.gitignore
new file mode 100644
index 000000000000..e9e66f178a6d
--- /dev/null
+++ b/arch/powerpc/purgatory/.gitignore
@@ -0,0 +1,2 @@
+kexec-purgatory.c
+purgatory.ro
diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile
new file mode 100644
index 000000000000..63daf95e5703
--- /dev/null
+++ b/arch/powerpc/purgatory/Makefile
@@ -0,0 +1,36 @@
+purgatory-y := purgatory.o printf.o string.o v2wrap.o hvCall.o \
+		purgatory-ppc64.o console-ppc64.o crashdump_backup.o \
+		crtsavres.o sha256.o
+
+targets += $(purgatory-y)
+PURGATORY_OBJS = $(addprefix $(obj)/,$(purgatory-y))
+
+LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined -nostartfiles \
+			-nostdlib -nodefaultlibs
+targets += purgatory.ro
+
+# Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
+# in turn leaves some undefined symbols like __fentry__ in purgatory and not
+# sure how to relocate those. Like kexec-tools, use custom flags.
+
+KBUILD_CFLAGS := -Wall -Wstrict-prototypes -fno-strict-aliasing \
+		-fno-zero-initialized-in-bss -fno-builtin -ffreestanding \
+		-fno-PIC -fno-PIE -fno-stack-protector  -fno-exceptions \
+		-msoft-float -MD -Os
+KBUILD_CFLAGS += -m$(CONFIG_WORD_SIZE)
+
+$(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
+		$(call if_changed,ld)
+
+targets += kexec-purgatory.c
+
+CMD_BIN2C = $(objtree)/scripts/basic/bin2c
+quiet_cmd_bin2c = BIN2C   $@
+      cmd_bin2c = $(CMD_BIN2C) kexec_purgatory < $< > $@
+
+$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro FORCE
+	$(call if_changed,bin2c)
+	@:
+
+
+obj-$(CONFIG_KEXEC_FILE)	+= kexec-purgatory.o
diff --git a/arch/powerpc/purgatory/console-ppc64.c b/arch/powerpc/purgatory/console-ppc64.c
new file mode 100644
index 000000000000..3d07be0b5d08
--- /dev/null
+++ b/arch/powerpc/purgatory/console-ppc64.c
@@ -0,0 +1,38 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Mohan Kumar M (mohan@in.ibm.com)
+ *
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ *
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "hvCall.h"
+#include <asm/byteorder.h>
+
+extern int debug;
+
+void putchar(int c)
+{
+	char buff[8];
+	unsigned long *lbuf = (unsigned long *)buff;
+
+	if (!debug) /* running on non pseries */
+		return;
+
+	if (c == '\n')
+		putchar('\r');
+
+	buff[0] = c;
+	plpar_hcall_norets(H_PUT_TERM_CHAR, 0, 1, __cpu_to_be64(*lbuf), 0);
+}
diff --git a/arch/powerpc/purgatory/crashdump-ppc64.h b/arch/powerpc/purgatory/crashdump-ppc64.h
new file mode 100644
index 000000000000..90064b49ebfe
--- /dev/null
+++ b/arch/powerpc/purgatory/crashdump-ppc64.h
@@ -0,0 +1,42 @@
+#ifndef CRASHDUMP_PPC64_H
+#define CRASHDUMP_PPC64_H
+
+#include <linux/types.h>
+
+struct kexec_info;
+int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
+				uint64_t max_addr, unsigned long min_base);
+void add_usable_mem_rgns(unsigned long long base, unsigned long long size);
+
+#define PAGE_OFFSET     0xC000000000000000ULL
+#define KERNELBASE      PAGE_OFFSET
+#define VMALLOCBASE     0xD000000000000000ULL
+
+#define __pa(x)         ((unsigned long)(x)-PAGE_OFFSET)
+#define MAXMEM          (-KERNELBASE-VMALLOCBASE)
+
+#define COMMAND_LINE_SIZE       512 /* from kernel */
+/* Backup Region, First 64K of System RAM. */
+#define BACKUP_SRC_START    0x0000
+#define BACKUP_SRC_END      0xffff
+#define BACKUP_SRC_SIZE     (BACKUP_SRC_END - BACKUP_SRC_START + 1)
+
+#define KDUMP_BACKUP_LIMIT	BACKUP_SRC_SIZE
+
+#define KERNEL_RUN_AT_ZERO_MAGIC 0x72756e30	/* "run0" */
+
+extern uint64_t crash_base;
+extern uint64_t crash_size;
+extern uint64_t memory_limit;
+extern unsigned int rtas_base;
+extern unsigned int rtas_size;
+extern uint64_t opal_base;
+extern uint64_t opal_size;
+
+uint64_t lmb_size;
+unsigned int num_of_lmbs;
+
+#define DRCONF_ADDR	0
+#define DRCONF_FLAGS	20
+
+#endif /* CRASHDUMP_PPC64_H */
diff --git a/arch/powerpc/purgatory/crashdump_backup.c b/arch/powerpc/purgatory/crashdump_backup.c
new file mode 100644
index 000000000000..11ccafdcc9ad
--- /dev/null
+++ b/arch/powerpc/purgatory/crashdump_backup.c
@@ -0,0 +1,36 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Mohan Kumar M (mohan@in.ibm.com)
+ *
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ *
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "../boot/string.h"
+#include "crashdump-ppc64.h"
+
+extern unsigned long backup_start;
+
+/* Backup first 32KB of memory to backup region reserved by kexec */
+void crashdump_backup_memory(void)
+{
+	void *dest, *src;
+
+	src = (void *)BACKUP_SRC_START;
+
+	if (backup_start) {
+		dest = (void *)(backup_start);
+		memcpy(dest, src, BACKUP_SRC_SIZE);
+	}
+}
diff --git a/arch/powerpc/purgatory/crtsavres.S b/arch/powerpc/purgatory/crtsavres.S
new file mode 100644
index 000000000000..5d17e1c0d575
--- /dev/null
+++ b/arch/powerpc/purgatory/crtsavres.S
@@ -0,0 +1,5 @@
+#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
+#define CONFIG_CC_OPTIMIZE_FOR_SIZE 1
+#endif
+
+#include "../lib/crtsavres.S"
diff --git a/arch/powerpc/purgatory/hvCall.S b/arch/powerpc/purgatory/hvCall.S
new file mode 100644
index 000000000000..a96c4898f1d8
--- /dev/null
+++ b/arch/powerpc/purgatory/hvCall.S
@@ -0,0 +1,27 @@
+/*
+ * This file contains the generic function to perform a call to the
+ * pSeries LPAR hypervisor.
+ *
+ * Taken from linux/arch/powerpc/platforms/pseries/hvCall.S
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include "ppc64_asm.h"
+
+#define HVSC	.long 0x44000022
+.text
+	.machine ppc64
+.globl DOTSYM(plpar_hcall_norets)
+DOTSYM(plpar_hcall_norets):
+	or	6,6,6			# medium low priority
+        mfcr	0
+        stw	0,8(1)
+
+        HVSC 				/* invoke the hypervisor */
+
+        lwz	0,8(1)
+        mtcrf	0xff,0
+        blr                             /* return r3 = status */
diff --git a/arch/powerpc/purgatory/hvCall.h b/arch/powerpc/purgatory/hvCall.h
new file mode 100644
index 000000000000..187e24d8b964
--- /dev/null
+++ b/arch/powerpc/purgatory/hvCall.h
@@ -0,0 +1,8 @@
+#ifndef HVCALL_H
+#define HVCALL_H
+
+#define H_PUT_TERM_CHAR	0x58
+
+long plpar_hcall_norets(unsigned long opcode, ...);
+
+#endif
diff --git a/arch/powerpc/purgatory/kexec-sha256.h b/arch/powerpc/purgatory/kexec-sha256.h
new file mode 100644
index 000000000000..4418ed02c052
--- /dev/null
+++ b/arch/powerpc/purgatory/kexec-sha256.h
@@ -0,0 +1,11 @@
+#ifndef KEXEC_SHA256_H
+#define KEXEC_SHA256_H
+
+struct kexec_sha_region {
+	unsigned long start;
+	unsigned long len;
+};
+
+#define SHA256_REGIONS 16
+
+#endif /* KEXEC_SHA256_H */
diff --git a/arch/powerpc/purgatory/ppc64_asm.h b/arch/powerpc/purgatory/ppc64_asm.h
new file mode 100644
index 000000000000..95d721718237
--- /dev/null
+++ b/arch/powerpc/purgatory/ppc64_asm.h
@@ -0,0 +1,20 @@
+/*
+ * ppc64_asm.h - common defines for PPC64 assembly parts
+ *
+ * Code taken from kexec-tools.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#include <asm/types.h>
+
+/*
+ * ABIv1 requires dot symbol while ABIv2 does not.
+ */
+#ifdef PPC64_ELF_ABI_v2
+#define DOTSYM(a)	a
+#else
+#define GLUE(a, b)	a##b
+#define DOTSYM(a)	GLUE(., a)
+#endif
diff --git a/arch/powerpc/purgatory/printf.c b/arch/powerpc/purgatory/printf.c
new file mode 100644
index 000000000000..c5f425b55fd5
--- /dev/null
+++ b/arch/powerpc/purgatory/printf.c
@@ -0,0 +1,164 @@
+/*
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdarg.h>
+#include "purgatory.h"
+#include "../boot/string.h"
+
+#define CHAR_BIT 8
+
+/*
+ * Output
+ * =============================================================================
+ */
+
+#define LONG_LONG_SHIFT  ((int)((sizeof(unsigned long long)*CHAR_BIT) - 4))
+#define LONG_SHIFT  ((int)((sizeof(unsigned long)*CHAR_BIT) - 4))
+#define INT_SHIFT   ((int)((sizeof(unsigned int)*CHAR_BIT) - 4))
+#define SHRT_SHIFT  ((int)((sizeof(unsigned short)*CHAR_BIT) - 4))
+#define CHAR_SHIFT  ((int)((sizeof(unsigned char)*CHAR_BIT) - 4))
+
+/**************************************************************************
+PRINTF and friends
+
+	Formats:
+		%x	- 4 bytes int (8 hex digits, lower case)
+		%X	- 4 bytes int (8 hex digits, upper case)
+		%lx     - 8 bytes long (16 hex digits, lower case)
+		%lX     - 8 bytes long (16 hex digits, upper case)
+		%hx	- 2 bytes int (4 hex digits, lower case)
+		%hX	- 2 bytes int (4 hex digits, upper case)
+		%hhx	- 1 byte int (2 hex digits, lower case)
+		%hhX	- 1 byte int (2 hex digits, upper case)
+			- optional # prefixes 0x or 0X
+		%d	- decimal int
+		%c	- char
+		%s	- string
+	Note: width specification not supported
+**************************************************************************/
+void vsprintf(char *buffer, const char *fmt, va_list args)
+{
+	char *p;
+
+	for ( ; *fmt != '\0'; ++fmt) {
+		if (*fmt != '%') {
+			if (buffer)
+				*buffer++ = *fmt;
+			else
+				putchar(*fmt);
+			continue;
+		}
+		if (*++fmt == 's') {
+			for (p = va_arg(args, char *); *p != '\0'; p++)
+				if (buffer)
+					*buffer++ = *p;
+				else
+					putchar(*p);
+		} else {	/* Length of item is bounded */
+			char tmp[40], *q = tmp;
+			int shift = INT_SHIFT;
+
+			if (*fmt == 'L') {
+				shift = LONG_LONG_SHIFT;
+				fmt++;
+			} else if (*fmt == 'l') {
+				shift = LONG_SHIFT;
+				fmt++;
+			} else if (*fmt == 'h') {
+				shift = SHRT_SHIFT;
+				fmt++;
+				if (*fmt == 'h') {
+					shift = CHAR_SHIFT;
+					fmt++;
+				}
+			}
+
+			/*
+			 * Before each format q points to tmp buffer
+			 * After each format q points past end of item
+			 */
+			if ((*fmt | 0x20) == 'x') {
+				/* With x86 gcc, sizeof(long) == sizeof(int) */
+				unsigned long long h;
+				int ncase;
+
+				if (shift > LONG_SHIFT)
+					h = va_arg(args, unsigned long long);
+				else if (shift > INT_SHIFT)
+					h = va_arg(args, unsigned long);
+				else
+					h = va_arg(args, unsigned int);
+
+				ncase = (*fmt & 0x20);
+				for ( ; shift >= 0; shift -= 4)
+					*q++ = "0123456789ABCDEF"[(h >> shift) & 0xF] | ncase;
+			} else if (*fmt == 'd') {
+				char *r;
+				long i;
+
+				if (shift > LONG_SHIFT)
+					i = va_arg(args, long long);
+				else if (shift > INT_SHIFT)
+					i = va_arg(args, long);
+				else
+					i = va_arg(args, int);
+
+				if (i < 0) {
+					*q++ = '-';
+					i = -i;
+				}
+				p = q;		/* save beginning of digits */
+				do {
+					*q++ = '0' + (i % 10);
+					i /= 10;
+				} while (i);
+				/* reverse digits, stop in middle */
+				r = q;		/* don't alter q */
+				while (--r > p) {
+					i = *r;
+					*r = *p;
+					*p++ = i;
+				}
+			} else if (*fmt == 'c')
+				*q++ = va_arg(args, int);
+			else
+				*q++ = *fmt;
+			/* now output the saved string */
+			for (p = tmp; p < q; ++p)
+				if (buffer)
+					*buffer++ = *p;
+				else
+					putchar(*p);
+		}
+	}
+	if (buffer)
+		*buffer = '\0';
+}
+
+void sprintf(char *buffer, const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vsprintf(buffer, fmt, args);
+	va_end(args);
+}
+
+void printf(const char *fmt, ...)
+{
+	va_list args;
+
+	va_start(args, fmt);
+	vsprintf(0, fmt, args);
+	va_end(args);
+}
diff --git a/arch/powerpc/purgatory/purgatory-ppc64.c b/arch/powerpc/purgatory/purgatory-ppc64.c
new file mode 100644
index 000000000000..0be65a424ab1
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory-ppc64.c
@@ -0,0 +1,41 @@
+/*
+ * kexec: Linux boots Linux
+ *
+ * Created by: Mohan Kumar M (mohan@in.ibm.com)
+ *
+ * Copyright (C) IBM Corporation, 2005. All rights reserved
+ *
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "purgatory.h"
+#include "purgatory-ppc64.h"
+
+unsigned int panic_kernel = 0;
+unsigned long backup_start = 0;
+unsigned long stack = 0;
+unsigned long dt_offset = 0;
+unsigned long my_toc = 0;
+unsigned long kernel = 0;
+unsigned int debug = 0;
+unsigned long opal_base = 0;
+unsigned long opal_entry = 0;
+
+void setup_arch(void)
+{
+}
+
+void post_verification_setup_arch(void)
+{
+	if (panic_kernel)
+		crashdump_backup_memory();
+}
diff --git a/arch/powerpc/purgatory/purgatory-ppc64.h b/arch/powerpc/purgatory/purgatory-ppc64.h
new file mode 100644
index 000000000000..52eaf4394c48
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory-ppc64.h
@@ -0,0 +1,6 @@
+#ifndef PURGATORY_PPC64_H
+#define PURGATORY_PPC64_H
+
+void crashdump_backup_memory(void);
+
+#endif /* PURGATORY_PPC64_H */
diff --git a/arch/powerpc/purgatory/purgatory.c b/arch/powerpc/purgatory/purgatory.c
new file mode 100644
index 000000000000..5b006d685cf2
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory.c
@@ -0,0 +1,62 @@
+/*
+ * Code taken from kexec-tools.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (version 2 of the License).
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "purgatory.h"
+#include "sha256.h"
+#include "../boot/string.h"
+#include "kexec-sha256.h"
+
+struct kexec_sha_region sha_regions[SHA256_REGIONS] = {};
+u8 sha256_digest[SHA256_DIGEST_SIZE] = { 0 };
+
+int verify_sha256_digest(void)
+{
+	struct kexec_sha_region *ptr, *end;
+	u8 digest[SHA256_DIGEST_SIZE];
+	size_t i;
+	struct sha256_state sctx;
+
+	sha256_init(&sctx);
+	end = &sha_regions[sizeof(sha_regions)/sizeof(sha_regions[0])];
+	for (ptr = sha_regions; ptr < end; ptr++)
+		sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len);
+	sha256_final(&sctx, digest);
+
+	if (memcmp(digest, sha256_digest, sizeof(digest)) != 0) {
+		printf("sha256 digests do not match :(\n");
+		printf("       digest: ");
+		for (i = 0; i < sizeof(digest); i++)
+			printf("%hhx ", digest[i]);
+		printf("\n");
+
+		printf("sha256_digest: ");
+		for (i = 0; i < sizeof(sha256_digest); i++)
+			printf("%hhx ", sha256_digest[i]);
+
+		printf("\n");
+		return 1;
+	}
+	return 0;
+}
+
+void purgatory(void)
+{
+	printf("I'm in purgatory\n");
+	setup_arch();
+	if (verify_sha256_digest()) {
+		/* loop forever */
+		for (;;)
+			;
+	}
+	post_verification_setup_arch();
+}
diff --git a/arch/powerpc/purgatory/purgatory.h b/arch/powerpc/purgatory/purgatory.h
new file mode 100644
index 000000000000..788ce4930a30
--- /dev/null
+++ b/arch/powerpc/purgatory/purgatory.h
@@ -0,0 +1,11 @@
+#ifndef PURGATORY_H
+#define PURGATORY_H
+
+void putchar(int ch);
+void sprintf(char *buffer, const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3)));
+void printf(const char *fmt, ...) __attribute__ ((format (printf, 1, 2)));
+void setup_arch(void);
+void post_verification_setup_arch(void);
+
+#endif /* PURGATORY_H */
diff --git a/arch/powerpc/purgatory/sha256.c b/arch/powerpc/purgatory/sha256.c
new file mode 100644
index 000000000000..6abee1877d56
--- /dev/null
+++ b/arch/powerpc/purgatory/sha256.c
@@ -0,0 +1,6 @@
+#include "../boot/string.h"
+
+/* Avoid including x86's boot/string.h in sha256.c. */
+#define BOOT_STRING_H
+
+#include "../../x86/purgatory/sha256.c"
diff --git a/arch/powerpc/purgatory/sha256.h b/arch/powerpc/purgatory/sha256.h
new file mode 100644
index 000000000000..72818f3a207e
--- /dev/null
+++ b/arch/powerpc/purgatory/sha256.h
@@ -0,0 +1 @@
+#include "../../x86/purgatory/sha256.h"
diff --git a/arch/powerpc/purgatory/string.S b/arch/powerpc/purgatory/string.S
new file mode 100644
index 000000000000..3a1e23ff4017
--- /dev/null
+++ b/arch/powerpc/purgatory/string.S
@@ -0,0 +1 @@
+#include "../boot/string.S"
diff --git a/arch/powerpc/purgatory/v2wrap.S b/arch/powerpc/purgatory/v2wrap.S
new file mode 100644
index 000000000000..c9a981c39a78
--- /dev/null
+++ b/arch/powerpc/purgatory/v2wrap.S
@@ -0,0 +1,134 @@
+#
+#  kexec: Linux boots Linux
+#
+#  Copyright (C) 2004 - 2005, Milton D Miller II, IBM Corporation
+#  Copyright (C) 2006, Mohan Kumar M (mohan@in.ibm.com), IBM Corporation
+#
+# Code taken from kexec-tools.
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation (version 2 of the License).
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+
+#include "ppc64_asm.h"
+
+# v2wrap.S
+# a wrapper to call purgatory code to backup first
+# 32kB of first kernel into the backup region
+# reserved by kexec-tools.
+# Invokes ppc64 kernel with the expected arguments
+# of kernel(device-tree, phys-offset, 0)
+
+#
+# calling convention:
+#   r3 = physical number of this cpu (all cpus)
+#   r4 = address of this chunk (master only)
+# master enters at purgatory_start (aka first byte of this chunk)
+# slaves (additional cpus), if any, enter a copy of the
+# first 0x100 bytes of this code relocated to 0x0
+#
+# in other words,
+#   a copy of the first 0x100 bytes of this code is copied to 0
+#   and the slaves are sent to address 0x60
+#   with r3 = their physical cpu number.
+
+#define LOADADDR(rn,name) \
+	lis     rn,name##@highest;      \
+	ori     rn,rn,name##@higher;    \
+	rldicr  rn,rn,32,31;            \
+	oris    rn,rn,name##@h;         \
+	ori     rn,rn,name##@l
+
+	.machine ppc64
+	.align 8
+	.globl purgatory_start
+purgatory_start:	b	master
+	.org purgatory_start + 0x5c     # ABI: possible run_at_load flag at 0x5c
+	.globl run_at_load
+run_at_load:
+	.long 0
+	.size run_at_load, . - run_at_load
+	.org purgatory_start + 0x60     # ABI: slaves start at 60 with r3=phys
+slave:	b $
+	.org purgatory_start + 0x100    # ABI: end of copied region
+	.size purgatory_start, . - purgatory_start
+
+#
+# The above 0x100 bytes at purgatory_start are replaced with the
+# code from the kernel (or next stage) by kexec/arch/ppc64/kexec-elf-ppc64.c
+#
+
+master:
+	or	1,1,1		# low priority to let other threads catchup
+	isync
+	mr      17,3            # save cpu id to r17
+	mr      15,4            # save physical address in reg15
+
+	LOADADDR(6,my_toc)
+	ld      2,0(6)          #setup toc
+
+	LOADADDR(6,stack)
+	ld      1,0(6)          #setup stack
+
+	subi    1,1,112
+	bl      DOTSYM(purgatory)
+	nop
+
+	or	3,3,3		# ok now to high priority, lets boot
+	lis	6,0x1
+	mtctr	6		# delay a bit for slaves to catch up
+83:	bdnz	83b		# before we overwrite 0-100 again
+
+	LOADADDR(16, dt_offset)
+	ld      3,0(16)         # load device-tree address
+	mr      16,3            # save dt address in reg16
+#ifdef __BIG_ENDIAN__
+	lwz     6,20(3)         # fetch version number
+#else
+	li	4,20
+	lwbrx	6,3,4		# fetch BE version number
+#endif
+	cmpwi   0,6,2           # v2 ?
+	blt     80f
+#ifdef __BIG_ENDIAN__
+	stw     17,28(3)        # save my cpu number as boot_cpu_phys
+#else
+	li	4,28
+	stwbrx	17,3,4		# Store my cpu as BE value
+#endif
+80:
+	LOADADDR(6,opal_base)	# For OPAL early debug
+	ld      8,0(6)          # load the OPAL base address in r8
+	LOADADDR(6,opal_entry)	# For OPAL early debug
+	ld      9,0(6)          # load the OPAL entry address in r9
+	LOADADDR(6,kernel)
+	ld      4,0(6)          # load the kernel address
+	LOADADDR(6,run_at_load) # the load flag
+	lwz	7,0(6)		# possibly patched by kexec-elf-ppc64
+	stw	7,0x5c(4)	# and patch it into the kernel
+	mr      3,16            # restore dt address
+
+	mfmsr	5
+	andi.	10,5,1		# test MSR_LE
+	bne	little_endian
+
+	li	5,0		# r5 will be 0 for kernel
+	mtctr	4		# prepare branch to
+	bctr			# start kernel
+
+little_endian:			# book3s-only
+	mtsrr0	4		# prepare branch to
+
+	clrrdi	5,5,1		# clear MSR_LE
+	mtsrr1	5
+
+	li	5,0		# r5 will be 0 for kernel
+
+				# skip cache flush, do we care?
+
+	rfid			# update MSR and start kernel
-- 
1.9.1


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http://lists.infradead.org/mailman/listinfo/kexec

[PATCH v5 13/13] powerpc: Enable CONFIG_KEXEC_FILE in powerpc server defconfigs.

[Thiago Jung Bauermann]

Enable CONFIG_KEXEC_FILE in powernv_defconfig, ppc64_defconfig and
pseries_defconfig.

It depends on CONFIG_CRYPTO_SHA256=y, so add that as well.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/configs/powernv_defconfig | 2 ++
 arch/powerpc/configs/ppc64_defconfig   | 2 ++
 arch/powerpc/configs/pseries_defconfig | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig
index dce352e9153b..319e1fb7b0c9 100644
--- a/arch/powerpc/configs/powernv_defconfig
+++ b/arch/powerpc/configs/powernv_defconfig
@@ -47,6 +47,7 @@ CONFIG_BINFMT_MISC=m
 CONFIG_PPC_TRANSACTIONAL_MEM=y
 CONFIG_HOTPLUG_CPU=y
 CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_NUMA=y
 CONFIG_MEMORY_HOTPLUG=y
@@ -298,6 +299,7 @@ CONFIG_CRYPTO_CCM=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index 0a8d250cb97e..a0355ccc7f55 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -44,6 +44,7 @@ CONFIG_HZ_100=y
 CONFIG_BINFMT_MISC=m
 CONFIG_PPC_TRANSACTIONAL_MEM=y
 CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
 CONFIG_CRASH_DUMP=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_MEMORY_HOTREMOVE=y
@@ -333,6 +334,7 @@ CONFIG_CRYPTO_TEST=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
index 654aeffc57ef..23af4a72930e 100644
--- a/arch/powerpc/configs/pseries_defconfig
+++ b/arch/powerpc/configs/pseries_defconfig
@@ -50,6 +50,7 @@ CONFIG_HZ_100=y
 CONFIG_BINFMT_MISC=m
 CONFIG_PPC_TRANSACTIONAL_MEM=y
 CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_MEMORY_HOTPLUG=y
 CONFIG_MEMORY_HOTREMOVE=y
@@ -300,6 +301,7 @@ CONFIG_CRYPTO_TEST=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
-- 
1.9.1

[PATCH v5 13/13] powerpc: Enable CONFIG_KEXEC_FILE in powerpc server defconfigs.

[Thiago Jung Bauermann]

Enable CONFIG_KEXEC_FILE in powernv_defconfig, ppc64_defconfig and
pseries_defconfig.

It depends on CONFIG_CRYPTO_SHA256=y, so add that as well.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
---
 arch/powerpc/configs/powernv_defconfig | 2 ++
 arch/powerpc/configs/ppc64_defconfig   | 2 ++
 arch/powerpc/configs/pseries_defconfig | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig
index dce352e9153b..319e1fb7b0c9 100644
--- a/arch/powerpc/configs/powernv_defconfig
+++ b/arch/powerpc/configs/powernv_defconfig
@@ -47,6 +47,7 @@ CONFIG_BINFMT_MISC=m
 CONFIG_PPC_TRANSACTIONAL_MEM=y
 CONFIG_HOTPLUG_CPU=y
 CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_NUMA=y
 CONFIG_MEMORY_HOTPLUG=y
@@ -298,6 +299,7 @@ CONFIG_CRYPTO_CCM=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index 0a8d250cb97e..a0355ccc7f55 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -44,6 +44,7 @@ CONFIG_HZ_100=y
 CONFIG_BINFMT_MISC=m
 CONFIG_PPC_TRANSACTIONAL_MEM=y
 CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
 CONFIG_CRASH_DUMP=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_MEMORY_HOTREMOVE=y
@@ -333,6 +334,7 @@ CONFIG_CRYPTO_TEST=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
index 654aeffc57ef..23af4a72930e 100644
--- a/arch/powerpc/configs/pseries_defconfig
+++ b/arch/powerpc/configs/pseries_defconfig
@@ -50,6 +50,7 @@ CONFIG_HZ_100=y
 CONFIG_BINFMT_MISC=m
 CONFIG_PPC_TRANSACTIONAL_MEM=y
 CONFIG_KEXEC=y
+CONFIG_KEXEC_FILE=y
 CONFIG_IRQ_ALL_CPUS=y
 CONFIG_MEMORY_HOTPLUG=y
 CONFIG_MEMORY_HOTREMOVE=y
@@ -300,6 +301,7 @@ CONFIG_CRYPTO_TEST=m
 CONFIG_CRYPTO_PCBC=m
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_MICHAEL_MIC=m
+CONFIG_CRYPTO_SHA256=y
 CONFIG_CRYPTO_TGR192=m
 CONFIG_CRYPTO_WP512=m
 CONFIG_CRYPTO_ANUBIS=m
-- 
1.9.1


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Re: [PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Samuel Mendoza-Jonas]

On Thu, 2016-08-11 at 20:08 -0300, Thiago Jung Bauermann wrote:
> Implement the arch_kexec_verify_buffer hook to verify that a device
> tree blob passed by userspace via kexec_file_load contains only nodes
> and properties from a whitelist.
> 
> In elf64_load we merge those properties into the device tree that
> will be passed to the next kernel.
> 
> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/kexec.h       |   1 +
>  arch/powerpc/kernel/kexec_elf_64.c     |   9 ++
>  arch/powerpc/kernel/machine_kexec_64.c | 242 +++++++++++++++++++++++++++++++++
>  3 files changed, 252 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
> index f263cc867891..31bc64e07c8f 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -99,6 +99,7 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
>  int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
>                   unsigned long initrd_len, const char *cmdline);
>  bool find_debug_console(const void *fdt, int chosen_node);
> +int merge_partial_dtb(void *to, const void *from);
>  #endif /* CONFIG_KEXEC_FILE */
>  
>  #else /* !CONFIG_KEXEC */
> diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
> index 49cba9509464..1b902ad66e2a 100644
> --- a/arch/powerpc/kernel/kexec_elf_64.c
> +++ b/arch/powerpc/kernel/kexec_elf_64.c
> @@ -210,6 +210,15 @@ void *elf64_load(struct kimage *image, char *kernel_buf,
>                 goto out;
>         }
>  
> +       /* Add nodes and properties from the DTB passed by userspace. */
> +       if (image->dtb_buf) {
> +               ret = merge_partial_dtb(fdt, image->dtb_buf);
> +               if (ret) {
> +                       pr_err("Error merging partial device tree.\n");
> +                       goto out;
> +               }
> +       }
> +
>         ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
>         if (ret)
>                 goto out;
> diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
> index 527f98efe651..a484a6346146 100644
> --- a/arch/powerpc/kernel/machine_kexec_64.c
> +++ b/arch/powerpc/kernel/machine_kexec_64.c
> @@ -35,6 +35,7 @@
>  #include <asm/kexec_elf_64.h>
>  
>  #define SLAVE_CODE_SIZE                256
> +#define MAX_DT_PATH            512
>  
>  #ifdef CONFIG_KEXEC_FILE
>  static struct kexec_file_ops *kexec_file_loaders[] = {
> @@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int chosen_node)
>         return false;
>  }
>  
> +/**
> + * struct allowed_node - a node in the whitelist and its allowed properties.
> + * @name:              node name or full node path
> + * @properties:                NULL-terminated array of names or name=value pairs
> + *
> + * If name starts with /, then the node has to be at the specified path in
> + * the device tree (including unit addresses for all nodes in the path).
> + * If it doesn't, then the node can be anywhere in the device tree.
> + *
> + * An entry in properties can specify a string value that the property must
> + * have by using the "name=value" format. If the entry ends with =, it means
> + * that the property must be empty.
> + */
> +static struct allowed_node {
> +       const char *name;
> +       const char *properties[9];
> +} allowed_nodes[] = {
> +       {
> +               .name = "/chosen",
> +               .properties = {
> +                       "stdout-path",
> +                       "linux,stdout-path",
> +                       NULL,
> +               }
> +       },
> +       {
> +               .name = "vga",
> +               .properties = {
> +                       "device_type=display",
> +                       "assigned-addresses",
> +                       "width",
> +                       "height",
> +                       "depth",
> +                       "little-endian=",
> +                       "linux,opened=",
> +                       "linux,boot-display=",ss
> +                       NULL,
> +               }
> +       },
> +};

Hi Thiago,

As much as this solves problems for *me*, I suspect adding 'vga' here
might be the subject of some discussion. Having /chosen whitelisted makes
sense on it's own, but 'vga' and its properties are very specific without
much explanation.

If everyone's happy to have it there, cool! If not, I have the majority
of a patch that handles the original reason for these property updates
separately in the kernel rather than from userspace. If needed I'll clean
it up and we can handle it that way.

Cheers,
Sam

Re: [PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Samuel Mendoza-Jonas]

On Thu, 2016-08-11 at 20:08 -0300, Thiago Jung Bauermann wrote:
> Implement the arch_kexec_verify_buffer hook to verify that a device
> tree blob passed by userspace via kexec_file_load contains only nodes
> and properties from a whitelist.
> 
> In elf64_load we merge those properties into the device tree that
> will be passed to the next kernel.
> 
> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/kexec.h       |   1 +
>  arch/powerpc/kernel/kexec_elf_64.c     |   9 ++
>  arch/powerpc/kernel/machine_kexec_64.c | 242 +++++++++++++++++++++++++++++++++
>  3 files changed, 252 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
> index f263cc867891..31bc64e07c8f 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -99,6 +99,7 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
>  int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
>                   unsigned long initrd_len, const char *cmdline);
>  bool find_debug_console(const void *fdt, int chosen_node);
> +int merge_partial_dtb(void *to, const void *from);
>  #endif /* CONFIG_KEXEC_FILE */
>  
>  #else /* !CONFIG_KEXEC */
> diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
> index 49cba9509464..1b902ad66e2a 100644
> --- a/arch/powerpc/kernel/kexec_elf_64.c
> +++ b/arch/powerpc/kernel/kexec_elf_64.c
> @@ -210,6 +210,15 @@ void *elf64_load(struct kimage *image, char *kernel_buf,
>                 goto out;
>         }
>  
> +       /* Add nodes and properties from the DTB passed by userspace. */
> +       if (image->dtb_buf) {
> +               ret = merge_partial_dtb(fdt, image->dtb_buf);
> +               if (ret) {
> +                       pr_err("Error merging partial device tree.\n");
> +                       goto out;
> +               }
> +       }
> +
>         ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
>         if (ret)
>                 goto out;
> diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
> index 527f98efe651..a484a6346146 100644
> --- a/arch/powerpc/kernel/machine_kexec_64.c
> +++ b/arch/powerpc/kernel/machine_kexec_64.c
> @@ -35,6 +35,7 @@
>  #include <asm/kexec_elf_64.h>
>  
>  #define SLAVE_CODE_SIZE                256
> +#define MAX_DT_PATH            512
>  
>  #ifdef CONFIG_KEXEC_FILE
>  static struct kexec_file_ops *kexec_file_loaders[] = {
> @@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int chosen_node)
>         return false;
>  }
>  
> +/**
> + * struct allowed_node - a node in the whitelist and its allowed properties.
> + * @name:              node name or full node path
> + * @properties:                NULL-terminated array of names or name=value pairs
> + *
> + * If name starts with /, then the node has to be at the specified path in
> + * the device tree (including unit addresses for all nodes in the path).
> + * If it doesn't, then the node can be anywhere in the device tree.
> + *
> + * An entry in properties can specify a string value that the property must
> + * have by using the "name=value" format. If the entry ends with =, it means
> + * that the property must be empty.
> + */
> +static struct allowed_node {
> +       const char *name;
> +       const char *properties[9];
> +} allowed_nodes[] = {
> +       {
> +               .name = "/chosen",
> +               .properties = {
> +                       "stdout-path",
> +                       "linux,stdout-path",
> +                       NULL,
> +               }
> +       },
> +       {
> +               .name = "vga",
> +               .properties = {
> +                       "device_type=display",
> +                       "assigned-addresses",
> +                       "width",
> +                       "height",
> +                       "depth",
> +                       "little-endian=",
> +                       "linux,opened=",
> +                       "linux,boot-display=",ss
> +                       NULL,
> +               }
> +       },
> +};

Hi Thiago,

As much as this solves problems for *me*, I suspect adding 'vga' here
might be the subject of some discussion. Having /chosen whitelisted makes
sense on it's own, but 'vga' and its properties are very specific without
much explanation.

If everyone's happy to have it there, cool! If not, I have the majority
of a patch that handles the original reason for these property updates
separately in the kernel rather than from userspace. If needed I'll clean
it up and we can handle it that way.

Cheers,
Sam

Re: [PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Samuel Mendoza-Jonas]

On Thu, 2016-08-11 at 20:08 -0300, Thiago Jung Bauermann wrote:
> Implement the arch_kexec_verify_buffer hook to verify that a device
> tree blob passed by userspace via kexec_file_load contains only nodes
> and properties from a whitelist.
> 
> In elf64_load we merge those properties into the device tree that
> will be passed to the next kernel.
> 
> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/kexec.h       |   1 +
>  arch/powerpc/kernel/kexec_elf_64.c     |   9 ++
>  arch/powerpc/kernel/machine_kexec_64.c | 242 +++++++++++++++++++++++++++++++++
>  3 files changed, 252 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h
> index f263cc867891..31bc64e07c8f 100644
> --- a/arch/powerpc/include/asm/kexec.h
> +++ b/arch/powerpc/include/asm/kexec.h
> @@ -99,6 +99,7 @@ int setup_purgatory(struct kimage *image, const void *slave_code,
>  int setup_new_fdt(void *fdt, unsigned long initrd_load_addr,
>                   unsigned long initrd_len, const char *cmdline);
>  bool find_debug_console(const void *fdt, int chosen_node);
> +int merge_partial_dtb(void *to, const void *from);
>  #endif /* CONFIG_KEXEC_FILE */
>  
>  #else /* !CONFIG_KEXEC */
> diff --git a/arch/powerpc/kernel/kexec_elf_64.c b/arch/powerpc/kernel/kexec_elf_64.c
> index 49cba9509464..1b902ad66e2a 100644
> --- a/arch/powerpc/kernel/kexec_elf_64.c
> +++ b/arch/powerpc/kernel/kexec_elf_64.c
> @@ -210,6 +210,15 @@ void *elf64_load(struct kimage *image, char *kernel_buf,
>                 goto out;
>         }
>  
> +       /* Add nodes and properties from the DTB passed by userspace. */
> +       if (image->dtb_buf) {
> +               ret = merge_partial_dtb(fdt, image->dtb_buf);
> +               if (ret) {
> +                       pr_err("Error merging partial device tree.\n");
> +                       goto out;
> +               }
> +       }
> +
>         ret = setup_new_fdt(fdt, initrd_load_addr, initrd_len, cmdline);
>         if (ret)
>                 goto out;
> diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
> index 527f98efe651..a484a6346146 100644
> --- a/arch/powerpc/kernel/machine_kexec_64.c
> +++ b/arch/powerpc/kernel/machine_kexec_64.c
> @@ -35,6 +35,7 @@
>  #include <asm/kexec_elf_64.h>
>  
>  #define SLAVE_CODE_SIZE                256
> +#define MAX_DT_PATH            512
>  
>  #ifdef CONFIG_KEXEC_FILE
>  static struct kexec_file_ops *kexec_file_loaders[] = {
> @@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int chosen_node)
>         return false;
>  }
>  
> +/**
> + * struct allowed_node - a node in the whitelist and its allowed properties.
> + * @name:              node name or full node path
> + * @properties:                NULL-terminated array of names or name=value pairs
> + *
> + * If name starts with /, then the node has to be at the specified path in
> + * the device tree (including unit addresses for all nodes in the path).
> + * If it doesn't, then the node can be anywhere in the device tree.
> + *
> + * An entry in properties can specify a string value that the property must
> + * have by using the "name=value" format. If the entry ends with =, it means
> + * that the property must be empty.
> + */
> +static struct allowed_node {
> +       const char *name;
> +       const char *properties[9];
> +} allowed_nodes[] = {
> +       {
> +               .name = "/chosen",
> +               .properties = {
> +                       "stdout-path",
> +                       "linux,stdout-path",
> +                       NULL,
> +               }
> +       },
> +       {
> +               .name = "vga",
> +               .properties = {
> +                       "device_type=display",
> +                       "assigned-addresses",
> +                       "width",
> +                       "height",
> +                       "depth",
> +                       "little-endian=",
> +                       "linux,opened=",
> +                       "linux,boot-display=",ss
> +                       NULL,
> +               }
> +       },
> +};

Hi Thiago,

As much as this solves problems for *me*, I suspect adding 'vga' here
might be the subject of some discussion. Having /chosen whitelisted makes
sense on it's own, but 'vga' and its properties are very specific without
much explanation.

If everyone's happy to have it there, cool! If not, I have the majority
of a patch that handles the original reason for these property updates
separately in the kernel rather than from userspace. If needed I'll clean
it up and we can handle it that way.

Cheers,
Sam

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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Re: [PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Thiago Jung Bauermann]

Hello Sam,

Thanks for the quick response.

Am Freitag, 12 August 2016, 10:45:00 schrieb Samuel Mendoza-Jonas:
> On Thu, 2016-08-11 at 20:08 -0300, Thiago Jung Bauermann wrote:
> > @@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int
> > chosen_node) return false;
> >  }
> >  
> > +/**
> > + * struct allowed_node - a node in the whitelist and its allowed
> > properties. + * @name:              node name or full node path
> > + * @properties:                NULL-terminated array of names or
> > name=value pairs + *
> > + * If name starts with /, then the node has to be at the specified path
> > in + * the device tree (including unit addresses for all nodes in the
> > path). + * If it doesn't, then the node can be anywhere in the device
> > tree. + *
> > + * An entry in properties can specify a string value that the property
> > must + * have by using the "name=value" format. If the entry ends with
> > =, it means + * that the property must be empty.
> > + */
> > +static struct allowed_node {
> > +       const char *name;
> > +       const char *properties[9];
> > +} allowed_nodes[] = {
> > +       {
> > +               .name = "/chosen",
> > +               .properties = {
> > +                       "stdout-path",
> > +                       "linux,stdout-path",
> > +                       NULL,
> > +               }
> > +       },
> > +       {
> > +               .name = "vga",
> > +               .properties = {
> > +                       "device_type=display",
> > +                       "assigned-addresses",
> > +                       "width",
> > +                       "height",
> > +                       "depth",
> > +                       "little-endian=",
> > +                       "linux,opened=",
> > +                       "linux,boot-display=",ss
> > +                       NULL,
> > +               }
> > +       },
> > +};
> 
> Hi Thiago,
> 
> As much as this solves problems for *me*, I suspect adding 'vga' here
> might be the subject of some discussion. Having /chosen whitelisted makes
> sense on it's own, but 'vga' and its properties are very specific without
> much explanation.
> 
> If everyone's happy to have it there, cool! If not, I have the majority
> of a patch that handles the original reason for these property updates
> separately in the kernel rather than from userspace. If needed I'll clean
> it up and we can handle it that way.

Ok, that's good to know. I'm fine with it either way. In any case, 'vga' in 
this patch also serves a good real-life example of a non-trivial binding 
outside of /chosen that we might want to whitelist in the future.

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v5 11/13] powerpc: Allow userspace to set device tree properties in kexec_file_load

[Thiago Jung Bauermann]

Hello Sam,

Thanks for the quick response.

Am Freitag, 12 August 2016, 10:45:00 schrieb Samuel Mendoza-Jonas:
> On Thu, 2016-08-11 at 20:08 -0300, Thiago Jung Bauermann wrote:
> > @@ -908,4 +909,245 @@ bool find_debug_console(const void *fdt, int
> > chosen_node) return false;
> >  }
> >  
> > +/**
> > + * struct allowed_node - a node in the whitelist and its allowed
> > properties. + * @name:              node name or full node path
> > + * @properties:                NULL-terminated array of names or
> > name=value pairs + *
> > + * If name starts with /, then the node has to be at the specified path
> > in + * the device tree (including unit addresses for all nodes in the
> > path). + * If it doesn't, then the node can be anywhere in the device
> > tree. + *
> > + * An entry in properties can specify a string value that the property
> > must + * have by using the "name=value" format. If the entry ends with
> > =, it means + * that the property must be empty.
> > + */
> > +static struct allowed_node {
> > +       const char *name;
> > +       const char *properties[9];
> > +} allowed_nodes[] = {
> > +       {
> > +               .name = "/chosen",
> > +               .properties = {
> > +                       "stdout-path",
> > +                       "linux,stdout-path",
> > +                       NULL,
> > +               }
> > +       },
> > +       {
> > +               .name = "vga",
> > +               .properties = {
> > +                       "device_type=display",
> > +                       "assigned-addresses",
> > +                       "width",
> > +                       "height",
> > +                       "depth",
> > +                       "little-endian=",
> > +                       "linux,opened=",
> > +                       "linux,boot-display=",ss
> > +                       NULL,
> > +               }
> > +       },
> > +};
> 
> Hi Thiago,
> 
> As much as this solves problems for *me*, I suspect adding 'vga' here
> might be the subject of some discussion. Having /chosen whitelisted makes
> sense on it's own, but 'vga' and its properties are very specific without
> much explanation.
> 
> If everyone's happy to have it there, cool! If not, I have the majority
> of a patch that handles the original reason for these property updates
> separately in the kernel rather than from userspace. If needed I'll clean
> it up and we can handle it that way.

Ok, that's good to know. I'm fine with it either way. In any case, 'vga' in 
this patch also serves a good real-life example of a non-trivial binding 
outside of /chosen that we might want to whitelist in the future.

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


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Re: [PATCH v5 01/13] kexec_file: Allow arch-specific memory walking for kexec_add_buffer

[Balbir Singh]

On Thu, Aug 11, 2016 at 08:08:06PM -0300, Thiago Jung Bauermann wrote:
> Allow architectures to specify a different memory walking function for
> kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
> PowerPC uses the memblock subsystem.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> Acked-by: Dave Young <dyoung@redhat.com>
> ---

Acked-by: Balbir Singh <bsingharora@gmail.com>

Re: [PATCH v5 01/13] kexec_file: Allow arch-specific memory walking for kexec_add_buffer

[Balbir Singh]

On Thu, Aug 11, 2016 at 08:08:06PM -0300, Thiago Jung Bauermann wrote:
> Allow architectures to specify a different memory walking function for
> kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
> PowerPC uses the memblock subsystem.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> Acked-by: Dave Young <dyoung@redhat.com>
> ---

Acked-by: Balbir Singh <bsingharora@gmail.com>

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Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Balbir Singh]

On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
> Adapt all callers to the new function prototype.
>

Could you please expand on this?
 
> In addition, change the type of kexec_buf.buffer from char * to void *.
> There is no particular reason for it to be a char *, and the change
> allows us to get rid of 3 existing casts to char * in the code.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> Acked-by: Dave Young <dyoung@redhat.com>
> ---

Looks good otherwise

Acked-by: Balbir Singh <bsingharora@gmail.com>

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Balbir Singh]

On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
> Adapt all callers to the new function prototype.
>

Could you please expand on this?
 
> In addition, change the type of kexec_buf.buffer from char * to void *.
> There is no particular reason for it to be a char *, and the change
> allows us to get rid of 3 existing casts to char * in the code.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> Acked-by: Dave Young <dyoung@redhat.com>
> ---

Looks good otherwise

Acked-by: Balbir Singh <bsingharora@gmail.com>

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Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Balbir Singh]

On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
> The kexec_file_load system call needs to relocate the purgatory, so
> factor out the module relocation code so that it can be shared.
> 
> This patch's purpose is to move the ELF relocation logic from
> apply_relocate_add to elf_util_64.c with as few changes as
> possible. The following changes were needed:
> 
> To avoid having module-specific code in a general purpose utility
> function, struct elf_info was created to contain the information
> needed for ELF binaries manipulation.
> 
> my_r2, stub_for_addr and create_stub were changed to use it instead of
> having to receive a struct module, since they are called from
> elf64_apply_relocate_add.
> 
> local_entry_offset and squash_toc_save_inst were only used by
> apply_rellocate_add, so they were moved to elf_util_64.c as well.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/elf_util.h |  70 ++++++++
>  arch/powerpc/include/asm/module.h   |  14 +-
>  arch/powerpc/kernel/Makefile        |   4 +
>  arch/powerpc/kernel/elf_util_64.c   | 269 +++++++++++++++++++++++++++++++
>  arch/powerpc/kernel/module_64.c     | 312 ++++--------------------------------
>  5 files changed, 386 insertions(+), 283 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
> new file mode 100644
> index 000000000000..37372559fe62
> --- /dev/null
> +++ b/arch/powerpc/include/asm/elf_util.h
> @@ -0,0 +1,70 @@
> +/*
> + * Utility functions to work with ELF files.
> + *
> + * Copyright (C) 2016, IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2, or (at your option)
> + * any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _ASM_POWERPC_ELF_UTIL_H
> +#define _ASM_POWERPC_ELF_UTIL_H
> +
> +#include <linux/elf.h>
> +
> +struct elf_info {
> +	struct elf_shdr *sechdrs;
> +
> +	/* Index of stubs section. */
> +	unsigned int stubs_section;
> +	/* Index of TOC section. */
> +	unsigned int toc_section;
> +};
> +
> +#ifdef __powerpc64__
> +#ifdef PPC64_ELF_ABI_v2
> +
> +/* An address is simply the address of the function. */
> +typedef unsigned long func_desc_t;
> +#else
> +
> +/* An address is address of the OPD entry, which contains address of fn. */
> +typedef struct ppc64_opd_entry func_desc_t;
> +#endif /* PPC64_ELF_ABI_v2 */
> +
> +/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
> +   the kernel itself).  But on PPC64, these need to be used for every
> +   jump, actually, to reset r2 (TOC+0x8000). */
> +struct ppc64_stub_entry
> +{
> +	/* 28 byte jump instruction sequence (7 instructions). We only
> +	 * need 6 instructions on ABIv2 but we always allocate 7 so
> +	 * so we don't have to modify the trampoline load instruction. */
> +	u32 jump[7];
> +	/* Used by ftrace to identify stubs */
> +	u32 magic;
> +	/* Data for the above code */
> +	func_desc_t funcdata;
> +};
> +#endif
> +
> +/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
> +   gives the value maximum span in an instruction which uses a signed
> +   offset) */
> +static inline unsigned long my_r2(const struct elf_info *elf_info)
> +{
> +	return elf_info->sechdrs[elf_info->toc_section].sh_addr + 0x8000;
> +}
> +
> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> +			     const char *strtab, unsigned int symindex,
> +			     unsigned int relsec, const char *obj_name);
> +
> +#endif /* _ASM_POWERPC_ELF_UTIL_H */
> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
> index cd4ffd86765f..f2073115d518 100644
> --- a/arch/powerpc/include/asm/module.h
> +++ b/arch/powerpc/include/asm/module.h
> @@ -12,7 +12,14 @@
>  #include <linux/list.h>
>  #include <asm/bug.h>
>  #include <asm-generic/module.h>
> +#include <asm/elf_util.h>
>  
> +/* Both low and high 16 bits are added as SIGNED additions, so if low
> +   16 bits has high bit set, high 16 bits must be adjusted.  These
> +   macros do that (stolen from binutils). */
> +#define PPC_LO(v) ((v) & 0xffff)
> +#define PPC_HI(v) (((v) >> 16) & 0xffff)
> +#define PPC_HA(v) PPC_HI ((v) + 0x8000)
>  
>  #ifndef __powerpc64__
>  /*
> @@ -33,8 +40,7 @@ struct ppc_plt_entry {
>  
>  struct mod_arch_specific {
>  #ifdef __powerpc64__
> -	unsigned int stubs_section;	/* Index of stubs section in module */
> -	unsigned int toc_section;	/* What section is the TOC? */
> +	struct elf_info elf_info;
>  	bool toc_fixed;			/* Have we fixed up .TOC.? */
>  #ifdef CONFIG_DYNAMIC_FTRACE
>  	unsigned long toc;
> @@ -90,6 +96,10 @@ static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sec
>  }
>  #endif
>  
> +unsigned long stub_for_addr(const struct elf_info *elf_info, unsigned long addr,
> +			    const char *obj_name);
> +int restore_r2(u32 *instruction, const char *obj_name);
> +
>  struct exception_table_entry;
>  void sort_ex_table(struct exception_table_entry *start,
>  		   struct exception_table_entry *finish);
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index b2027a5cf508..e38aace0a6e7 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -123,6 +123,10 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
>  obj-y				+= iomap.o
>  endif
>  
> +ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
> +obj-y				+= elf_util_64.o
> +endif
> +
>  obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
>  
>  obj-$(CONFIG_PPC64)		+= $(obj64-y)
> diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
> new file mode 100644
> index 000000000000..decad2c34f38
> --- /dev/null
> +++ b/arch/powerpc/kernel/elf_util_64.c
> @@ -0,0 +1,269 @@
> +/*
> + * Utility functions to work with ELF files.
> + *
> + * Copyright (C) 2016, IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2, or (at your option)
> + * any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <asm/ppc-opcode.h>
> +#include <asm/elf_util.h>
> +
> +/*
> + * We just need to use the functions defined in <asm/module.h>, so just declare
> + * struct module here and avoid having to import <linux/module.h>.
> + */
> +struct module;
> +#include <asm/module.h>
> +
> +#ifdef PPC64_ELF_ABI_v2
> +/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
> +#define STO_PPC64_LOCAL_BIT	5
> +#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
> +#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
> + (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
> +
> +static unsigned int local_entry_offset(const Elf64_Sym *sym)
> +{
> +	/* sym->st_other indicates offset to local entry point
> +	 * (otherwise it will assume r12 is the address of the start
> +	 * of function and try to derive r2 from it). */
> +	return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
> +}
> +#else
> +static unsigned int local_entry_offset(const Elf64_Sym *sym)
> +{
> +	return 0;
> +}
> +#endif
> +
> +#ifdef CC_USING_MPROFILE_KERNEL
> +/*
> + * In case of _mcount calls, do not save the current callee's TOC (in r2) into
> + * the original caller's stack frame. If we did we would clobber the saved TOC
> + * value of the original caller.
> + */
> +static void squash_toc_save_inst(const char *name, unsigned long addr)
> +{
> +	struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
> +
> +	/* Only for calls to _mcount */
> +	if (strcmp("_mcount", name) != 0)
> +		return;
> +
> +	stub->jump[2] = PPC_INST_NOP;
> +}
> +#else
> +static void squash_toc_save_inst(const char *name, unsigned long addr) { }
> +#endif
> +
> +/**
> + * elf64_apply_relocate_add - apply 64 bit RELA relocations
> + * @elf_info:		Support information for the ELF binary being relocated.
> + * @strtab:		String table for the associated symbol table.
> + * @symindex:		Section header index for the associated symbol table.
> + * @relsec:		Section header index for the relocations to apply.
> + * @obj_name:		The name of the ELF binary, for information messages.
> + */
> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> +			     const char *strtab, unsigned int symindex,
> +			     unsigned int relsec, const char *obj_name)
> +{
> +	unsigned int i;
> +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
> +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
> +	Elf64_Sym *sym;
> +	unsigned long *location;
> +	unsigned long value;
> +


For the relocatable kernel we expect only

R_PPC64_RELATIVE
R_PPC64_NONE
R_PPC64_ADDR64

In the future we can use this to check/assert the usage of this
for the core kernel (vmlinux) when loaded.

Did we check elf64_apply_relocate_add with zImage and vmlinux?

Balbir Singh

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Balbir Singh]

On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
> The kexec_file_load system call needs to relocate the purgatory, so
> factor out the module relocation code so that it can be shared.
> 
> This patch's purpose is to move the ELF relocation logic from
> apply_relocate_add to elf_util_64.c with as few changes as
> possible. The following changes were needed:
> 
> To avoid having module-specific code in a general purpose utility
> function, struct elf_info was created to contain the information
> needed for ELF binaries manipulation.
> 
> my_r2, stub_for_addr and create_stub were changed to use it instead of
> having to receive a struct module, since they are called from
> elf64_apply_relocate_add.
> 
> local_entry_offset and squash_toc_save_inst were only used by
> apply_rellocate_add, so they were moved to elf_util_64.c as well.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/elf_util.h |  70 ++++++++
>  arch/powerpc/include/asm/module.h   |  14 +-
>  arch/powerpc/kernel/Makefile        |   4 +
>  arch/powerpc/kernel/elf_util_64.c   | 269 +++++++++++++++++++++++++++++++
>  arch/powerpc/kernel/module_64.c     | 312 ++++--------------------------------
>  5 files changed, 386 insertions(+), 283 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/elf_util.h b/arch/powerpc/include/asm/elf_util.h
> new file mode 100644
> index 000000000000..37372559fe62
> --- /dev/null
> +++ b/arch/powerpc/include/asm/elf_util.h
> @@ -0,0 +1,70 @@
> +/*
> + * Utility functions to work with ELF files.
> + *
> + * Copyright (C) 2016, IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2, or (at your option)
> + * any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#ifndef _ASM_POWERPC_ELF_UTIL_H
> +#define _ASM_POWERPC_ELF_UTIL_H
> +
> +#include <linux/elf.h>
> +
> +struct elf_info {
> +	struct elf_shdr *sechdrs;
> +
> +	/* Index of stubs section. */
> +	unsigned int stubs_section;
> +	/* Index of TOC section. */
> +	unsigned int toc_section;
> +};
> +
> +#ifdef __powerpc64__
> +#ifdef PPC64_ELF_ABI_v2
> +
> +/* An address is simply the address of the function. */
> +typedef unsigned long func_desc_t;
> +#else
> +
> +/* An address is address of the OPD entry, which contains address of fn. */
> +typedef struct ppc64_opd_entry func_desc_t;
> +#endif /* PPC64_ELF_ABI_v2 */
> +
> +/* Like PPC32, we need little trampolines to do > 24-bit jumps (into
> +   the kernel itself).  But on PPC64, these need to be used for every
> +   jump, actually, to reset r2 (TOC+0x8000). */
> +struct ppc64_stub_entry
> +{
> +	/* 28 byte jump instruction sequence (7 instructions). We only
> +	 * need 6 instructions on ABIv2 but we always allocate 7 so
> +	 * so we don't have to modify the trampoline load instruction. */
> +	u32 jump[7];
> +	/* Used by ftrace to identify stubs */
> +	u32 magic;
> +	/* Data for the above code */
> +	func_desc_t funcdata;
> +};
> +#endif
> +
> +/* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this
> +   gives the value maximum span in an instruction which uses a signed
> +   offset) */
> +static inline unsigned long my_r2(const struct elf_info *elf_info)
> +{
> +	return elf_info->sechdrs[elf_info->toc_section].sh_addr + 0x8000;
> +}
> +
> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> +			     const char *strtab, unsigned int symindex,
> +			     unsigned int relsec, const char *obj_name);
> +
> +#endif /* _ASM_POWERPC_ELF_UTIL_H */
> diff --git a/arch/powerpc/include/asm/module.h b/arch/powerpc/include/asm/module.h
> index cd4ffd86765f..f2073115d518 100644
> --- a/arch/powerpc/include/asm/module.h
> +++ b/arch/powerpc/include/asm/module.h
> @@ -12,7 +12,14 @@
>  #include <linux/list.h>
>  #include <asm/bug.h>
>  #include <asm-generic/module.h>
> +#include <asm/elf_util.h>
>  
> +/* Both low and high 16 bits are added as SIGNED additions, so if low
> +   16 bits has high bit set, high 16 bits must be adjusted.  These
> +   macros do that (stolen from binutils). */
> +#define PPC_LO(v) ((v) & 0xffff)
> +#define PPC_HI(v) (((v) >> 16) & 0xffff)
> +#define PPC_HA(v) PPC_HI ((v) + 0x8000)
>  
>  #ifndef __powerpc64__
>  /*
> @@ -33,8 +40,7 @@ struct ppc_plt_entry {
>  
>  struct mod_arch_specific {
>  #ifdef __powerpc64__
> -	unsigned int stubs_section;	/* Index of stubs section in module */
> -	unsigned int toc_section;	/* What section is the TOC? */
> +	struct elf_info elf_info;
>  	bool toc_fixed;			/* Have we fixed up .TOC.? */
>  #ifdef CONFIG_DYNAMIC_FTRACE
>  	unsigned long toc;
> @@ -90,6 +96,10 @@ static inline int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sec
>  }
>  #endif
>  
> +unsigned long stub_for_addr(const struct elf_info *elf_info, unsigned long addr,
> +			    const char *obj_name);
> +int restore_r2(u32 *instruction, const char *obj_name);
> +
>  struct exception_table_entry;
>  void sort_ex_table(struct exception_table_entry *start,
>  		   struct exception_table_entry *finish);
> diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
> index b2027a5cf508..e38aace0a6e7 100644
> --- a/arch/powerpc/kernel/Makefile
> +++ b/arch/powerpc/kernel/Makefile
> @@ -123,6 +123,10 @@ ifneq ($(CONFIG_PPC_INDIRECT_PIO),y)
>  obj-y				+= iomap.o
>  endif
>  
> +ifeq ($(CONFIG_MODULES)$(CONFIG_WORD_SIZE),y64)
> +obj-y				+= elf_util_64.o
> +endif
> +
>  obj64-$(CONFIG_PPC_TRANSACTIONAL_MEM)	+= tm.o
>  
>  obj-$(CONFIG_PPC64)		+= $(obj64-y)
> diff --git a/arch/powerpc/kernel/elf_util_64.c b/arch/powerpc/kernel/elf_util_64.c
> new file mode 100644
> index 000000000000..decad2c34f38
> --- /dev/null
> +++ b/arch/powerpc/kernel/elf_util_64.c
> @@ -0,0 +1,269 @@
> +/*
> + * Utility functions to work with ELF files.
> + *
> + * Copyright (C) 2016, IBM Corporation
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2, or (at your option)
> + * any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <asm/ppc-opcode.h>
> +#include <asm/elf_util.h>
> +
> +/*
> + * We just need to use the functions defined in <asm/module.h>, so just declare
> + * struct module here and avoid having to import <linux/module.h>.
> + */
> +struct module;
> +#include <asm/module.h>
> +
> +#ifdef PPC64_ELF_ABI_v2
> +/* PowerPC64 specific values for the Elf64_Sym st_other field.  */
> +#define STO_PPC64_LOCAL_BIT	5
> +#define STO_PPC64_LOCAL_MASK	(7 << STO_PPC64_LOCAL_BIT)
> +#define PPC64_LOCAL_ENTRY_OFFSET(other)					\
> + (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2)
> +
> +static unsigned int local_entry_offset(const Elf64_Sym *sym)
> +{
> +	/* sym->st_other indicates offset to local entry point
> +	 * (otherwise it will assume r12 is the address of the start
> +	 * of function and try to derive r2 from it). */
> +	return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other);
> +}
> +#else
> +static unsigned int local_entry_offset(const Elf64_Sym *sym)
> +{
> +	return 0;
> +}
> +#endif
> +
> +#ifdef CC_USING_MPROFILE_KERNEL
> +/*
> + * In case of _mcount calls, do not save the current callee's TOC (in r2) into
> + * the original caller's stack frame. If we did we would clobber the saved TOC
> + * value of the original caller.
> + */
> +static void squash_toc_save_inst(const char *name, unsigned long addr)
> +{
> +	struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr;
> +
> +	/* Only for calls to _mcount */
> +	if (strcmp("_mcount", name) != 0)
> +		return;
> +
> +	stub->jump[2] = PPC_INST_NOP;
> +}
> +#else
> +static void squash_toc_save_inst(const char *name, unsigned long addr) { }
> +#endif
> +
> +/**
> + * elf64_apply_relocate_add - apply 64 bit RELA relocations
> + * @elf_info:		Support information for the ELF binary being relocated.
> + * @strtab:		String table for the associated symbol table.
> + * @symindex:		Section header index for the associated symbol table.
> + * @relsec:		Section header index for the relocations to apply.
> + * @obj_name:		The name of the ELF binary, for information messages.
> + */
> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> +			     const char *strtab, unsigned int symindex,
> +			     unsigned int relsec, const char *obj_name)
> +{
> +	unsigned int i;
> +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
> +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
> +	Elf64_Sym *sym;
> +	unsigned long *location;
> +	unsigned long value;
> +


For the relocatable kernel we expect only

R_PPC64_RELATIVE
R_PPC64_NONE
R_PPC64_ADDR64

In the future we can use this to check/assert the usage of this
for the core kernel (vmlinux) when loaded.

Did we check elf64_apply_relocate_add with zImage and vmlinux?

Balbir Singh

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Thiago Jung Bauermann]

Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
> > Adapt all callers to the new function prototype.
> 
> Could you please expand on this?

Is the following better?

Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.

> Looks good otherwise
> 
> Acked-by: Balbir Singh <bsingharora@gmail.com>

Thank you for reviewing this series!

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Thiago Jung Bauermann]

Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
> > Adapt all callers to the new function prototype.
> 
> Could you please expand on this?

Is the following better?

Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.

> Looks good otherwise
> 
> Acked-by: Balbir Singh <bsingharora@gmail.com>

Thank you for reviewing this series!

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

Am Montag, 15 August 2016, 17:46:34 schrieb Balbir Singh:
> On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
> > +/**
> > + * elf64_apply_relocate_add - apply 64 bit RELA relocations
> > + * @elf_info:		Support information for the ELF binary being 
relocated.
> > + * @strtab:		String table for the associated symbol 
table.
> > + * @symindex:		Section header index for the associated 
symbol table.
> > + * @relsec:		Section header index for the relocations to 
apply.
> > + * @obj_name:		The name of the ELF binary, for information 
messages.
> > + */
> > +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> > +			     const char *strtab, unsigned int symindex,
> > +			     unsigned int relsec, const char *obj_name)
> > +{
> > +	unsigned int i;
> > +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
> > +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
> > +	Elf64_Sym *sym;
> > +	unsigned long *location;
> > +	unsigned long value;
> > +
> 
> For the relocatable kernel we expect only
> 
> R_PPC64_RELATIVE
> R_PPC64_NONE
> R_PPC64_ADDR64
> 
> In the future we can use this to check/assert the usage of this
> for the core kernel (vmlinux) when loaded.
> 
> Did we check elf64_apply_relocate_add with zImage and vmlinux?

kexec_file_load doesn't call call elf64_apply_relocate_add on the kernel 
image, it only uses it to relocate the purgatory. So whether it is loading a 
zImage or a vmlinux file, the function will work in the same way since the 
purgatory binary is the same regardless of the kernel image format.

For the same reason, as it currently stands kexec_file_load can't check the 
relocation types used in the kernel image. But it is possible to add such a 
check/assertion in kexec_elf_64.c:build_elf_exec_info if we want.

I tested kexec_file_load on both relocatable and non-relocatable vmlinux and 
it works correctly.

I hadn't tested with zImage yet. I just did, and I had two problems:

1. For some reason, it has an INTERP segment. This patch series doesn't 
support loading program interpreters for ELF binaries, so 
kexec_elf_64.c:build_elf_exec_info refuses to load them.

2. If I disable the check for the INTERP segment, the zImage file loads 
correctly, but then I get an exception during reboot when loading the kexec 
image, right before jumping into the purgatory. I suspect this is because 
the LOAD segment has a virtual address of 0, and the first kernel is not 
coping well with that. But I still have to debug it further.

Is there a reason for the zImage ELF header to request an interpreter and to 
have a virtual address of 0?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

Am Montag, 15 August 2016, 17:46:34 schrieb Balbir Singh:
> On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
> > +/**
> > + * elf64_apply_relocate_add - apply 64 bit RELA relocations
> > + * @elf_info:		Support information for the ELF binary being 
relocated.
> > + * @strtab:		String table for the associated symbol 
table.
> > + * @symindex:		Section header index for the associated 
symbol table.
> > + * @relsec:		Section header index for the relocations to 
apply.
> > + * @obj_name:		The name of the ELF binary, for information 
messages.
> > + */
> > +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> > +			     const char *strtab, unsigned int symindex,
> > +			     unsigned int relsec, const char *obj_name)
> > +{
> > +	unsigned int i;
> > +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
> > +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
> > +	Elf64_Sym *sym;
> > +	unsigned long *location;
> > +	unsigned long value;
> > +
> 
> For the relocatable kernel we expect only
> 
> R_PPC64_RELATIVE
> R_PPC64_NONE
> R_PPC64_ADDR64
> 
> In the future we can use this to check/assert the usage of this
> for the core kernel (vmlinux) when loaded.
> 
> Did we check elf64_apply_relocate_add with zImage and vmlinux?

kexec_file_load doesn't call call elf64_apply_relocate_add on the kernel 
image, it only uses it to relocate the purgatory. So whether it is loading a 
zImage or a vmlinux file, the function will work in the same way since the 
purgatory binary is the same regardless of the kernel image format.

For the same reason, as it currently stands kexec_file_load can't check the 
relocation types used in the kernel image. But it is possible to add such a 
check/assertion in kexec_elf_64.c:build_elf_exec_info if we want.

I tested kexec_file_load on both relocatable and non-relocatable vmlinux and 
it works correctly.

I hadn't tested with zImage yet. I just did, and I had two problems:

1. For some reason, it has an INTERP segment. This patch series doesn't 
support loading program interpreters for ELF binaries, so 
kexec_elf_64.c:build_elf_exec_info refuses to load them.

2. If I disable the check for the INTERP segment, the zImage file loads 
correctly, but then I get an exception during reboot when loading the kexec 
image, right before jumping into the purgatory. I suspect this is because 
the LOAD segment has a virtual address of 0, and the first kernel is not 
coping well with that. But I still have to debug it further.

Is there a reason for the zImage ELF header to request an interpreter and to 
have a virtual address of 0?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Balbir Singh]

On 16/08/16 00:49, Thiago Jung Bauermann wrote:
> Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
>> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
>>> Adapt all callers to the new function prototype.
>>
>> Could you please expand on this?
> 
> Is the following better?
> 
> Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.

Yes and the reason for doing so? Consolidation/clarity of implementation?

> 
>> Looks good otherwise
>>
>> Acked-by: Balbir Singh <bsingharora@gmail.com>
> 
> Thank you for reviewing this series!
> 

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Balbir Singh]

On 16/08/16 00:49, Thiago Jung Bauermann wrote:
> Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
>> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
>>> Adapt all callers to the new function prototype.
>>
>> Could you please expand on this?
> 
> Is the following better?
> 
> Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.

Yes and the reason for doing so? Consolidation/clarity of implementation?

> 
>> Looks good otherwise
>>
>> Acked-by: Balbir Singh <bsingharora@gmail.com>
> 
> Thank you for reviewing this series!
> 

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Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Balbir Singh]

On 16/08/16 09:25, Thiago Jung Bauermann wrote:
> Am Montag, 15 August 2016, 17:46:34 schrieb Balbir Singh:
>> On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
>>> +/**
>>> + * elf64_apply_relocate_add - apply 64 bit RELA relocations
>>> + * @elf_info:		Support information for the ELF binary being 
> relocated.
>>> + * @strtab:		String table for the associated symbol 
> table.
>>> + * @symindex:		Section header index for the associated 
> symbol table.
>>> + * @relsec:		Section header index for the relocations to 
> apply.
>>> + * @obj_name:		The name of the ELF binary, for information 
> messages.
>>> + */
>>> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
>>> +			     const char *strtab, unsigned int symindex,
>>> +			     unsigned int relsec, const char *obj_name)
>>> +{
>>> +	unsigned int i;
>>> +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
>>> +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
>>> +	Elf64_Sym *sym;
>>> +	unsigned long *location;
>>> +	unsigned long value;
>>> +
>>
>> For the relocatable kernel we expect only
>>
>> R_PPC64_RELATIVE
>> R_PPC64_NONE
>> R_PPC64_ADDR64
>>
>> In the future we can use this to check/assert the usage of this
>> for the core kernel (vmlinux) when loaded.
>>
>> Did we check elf64_apply_relocate_add with zImage and vmlinux?
> 
> kexec_file_load doesn't call call elf64_apply_relocate_add on the kernel 
> image, it only uses it to relocate the purgatory. So whether it is loading a 
> zImage or a vmlinux file, the function will work in the same way since the 
> purgatory binary is the same regardless of the kernel image format.

Thanks for clarifying.

> 
> For the same reason, as it currently stands kexec_file_load can't check the 
> relocation types used in the kernel image. But it is possible to add such a 
> check/assertion in kexec_elf_64.c:build_elf_exec_info if we want.
> 
> I tested kexec_file_load on both relocatable and non-relocatable vmlinux and 
> it works correctly.
> 
> I hadn't tested with zImage yet. I just did, and I had two problems:
> 
> 1. For some reason, it has an INTERP segment. This patch series doesn't 
> support loading program interpreters for ELF binaries, so 
> kexec_elf_64.c:build_elf_exec_info refuses to load them.
> 
> 2. If I disable the check for the INTERP segment, the zImage file loads 
> correctly, but then I get an exception during reboot when loading the kexec 
> image, right before jumping into the purgatory. I suspect this is because 
> the LOAD segment has a virtual address of 0, and the first kernel is not 
> coping well with that. But I still have to debug it further.
> 
> Is there a reason for the zImage ELF header to request an interpreter and to 
> have a virtual address of 0?
> 

Not that I am aware of. 

Balbir Singh

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Balbir Singh]

On 16/08/16 09:25, Thiago Jung Bauermann wrote:
> Am Montag, 15 August 2016, 17:46:34 schrieb Balbir Singh:
>> On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
>>> +/**
>>> + * elf64_apply_relocate_add - apply 64 bit RELA relocations
>>> + * @elf_info:		Support information for the ELF binary being 
> relocated.
>>> + * @strtab:		String table for the associated symbol 
> table.
>>> + * @symindex:		Section header index for the associated 
> symbol table.
>>> + * @relsec:		Section header index for the relocations to 
> apply.
>>> + * @obj_name:		The name of the ELF binary, for information 
> messages.
>>> + */
>>> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
>>> +			     const char *strtab, unsigned int symindex,
>>> +			     unsigned int relsec, const char *obj_name)
>>> +{
>>> +	unsigned int i;
>>> +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
>>> +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
>>> +	Elf64_Sym *sym;
>>> +	unsigned long *location;
>>> +	unsigned long value;
>>> +
>>
>> For the relocatable kernel we expect only
>>
>> R_PPC64_RELATIVE
>> R_PPC64_NONE
>> R_PPC64_ADDR64
>>
>> In the future we can use this to check/assert the usage of this
>> for the core kernel (vmlinux) when loaded.
>>
>> Did we check elf64_apply_relocate_add with zImage and vmlinux?
> 
> kexec_file_load doesn't call call elf64_apply_relocate_add on the kernel 
> image, it only uses it to relocate the purgatory. So whether it is loading a 
> zImage or a vmlinux file, the function will work in the same way since the 
> purgatory binary is the same regardless of the kernel image format.

Thanks for clarifying.

> 
> For the same reason, as it currently stands kexec_file_load can't check the 
> relocation types used in the kernel image. But it is possible to add such a 
> check/assertion in kexec_elf_64.c:build_elf_exec_info if we want.
> 
> I tested kexec_file_load on both relocatable and non-relocatable vmlinux and 
> it works correctly.
> 
> I hadn't tested with zImage yet. I just did, and I had two problems:
> 
> 1. For some reason, it has an INTERP segment. This patch series doesn't 
> support loading program interpreters for ELF binaries, so 
> kexec_elf_64.c:build_elf_exec_info refuses to load them.
> 
> 2. If I disable the check for the INTERP segment, the zImage file loads 
> correctly, but then I get an exception during reboot when loading the kexec 
> image, right before jumping into the purgatory. I suspect this is because 
> the LOAD segment has a virtual address of 0, and the first kernel is not 
> coping well with that. But I still have to debug it further.
> 
> Is there a reason for the zImage ELF header to request an interpreter and to 
> have a virtual address of 0?
> 

Not that I am aware of. 

Balbir Singh

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Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Thiago Jung Bauermann]

Am Dienstag, 16 August 2016, 16:15:55 schrieb Balbir Singh:
> On 16/08/16 00:49, Thiago Jung Bauermann wrote:
> > Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
> >> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
> >>> Adapt all callers to the new function prototype.
> >> 
> >> Could you please expand on this?
> > 
> > Is the following better?
> > 
> > Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.
> 
> Yes and the reason for doing so? Consolidation/clarity of implementation?

Indeed. What about this commit message?

Subject: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take  
 kexec_buf as argument.

This is done to simplify the kexec_add_buffer argument list.
Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.

In addition, change the type of kexec_buf.buffer from char * to void *.
There is no particular reason for it to be a char *, and the change
allows us to get rid of 3 existing casts to char * in the code.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Thiago Jung Bauermann]

Am Dienstag, 16 August 2016, 16:15:55 schrieb Balbir Singh:
> On 16/08/16 00:49, Thiago Jung Bauermann wrote:
> > Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
> >> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
> >>> Adapt all callers to the new function prototype.
> >> 
> >> Could you please expand on this?
> > 
> > Is the following better?
> > 
> > Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.
> 
> Yes and the reason for doing so? Consolidation/clarity of implementation?

Indeed. What about this commit message?

Subject: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take  
 kexec_buf as argument.

This is done to simplify the kexec_add_buffer argument list.
Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.

In addition, change the type of kexec_buf.buffer from char * to void *.
There is no particular reason for it to be a char *, and the change
allows us to get rid of 3 existing casts to char * in the code.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


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Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Balbir Singh]

On 17/08/16 04:49, Thiago Jung Bauermann wrote:
> Am Dienstag, 16 August 2016, 16:15:55 schrieb Balbir Singh:
>> On 16/08/16 00:49, Thiago Jung Bauermann wrote:
>>> Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
>>>> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
>>>>> Adapt all callers to the new function prototype.
>>>>
>>>> Could you please expand on this?
>>>
>>> Is the following better?
>>>
>>> Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.
>>
>> Yes and the reason for doing so? Consolidation/clarity of implementation?
> 
> Indeed. What about this commit message?
> 
> Subject: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take  
>  kexec_buf as argument.
> 
> This is done to simplify the kexec_add_buffer argument list.
> Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.
> 
> In addition, change the type of kexec_buf.buffer from char * to void *.
> There is no particular reason for it to be a char *, and the change
> allows us to get rid of 3 existing casts to char * in the code.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> Acked-by: Dave Young <dyoung@redhat.com>
> Acked-by: Balbir Singh <bsingharora@gmail.com>
> 


Looks good

Balbir

Re: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take kexec_buf as argument.

[Balbir Singh]

On 17/08/16 04:49, Thiago Jung Bauermann wrote:
> Am Dienstag, 16 August 2016, 16:15:55 schrieb Balbir Singh:
>> On 16/08/16 00:49, Thiago Jung Bauermann wrote:
>>> Am Montag, 15 August 2016, 17:30:49 schrieb Balbir Singh:
>>>> On Thu, Aug 11, 2016 at 08:08:07PM -0300, Thiago Jung Bauermann wrote:
>>>>> Adapt all callers to the new function prototype.
>>>>
>>>> Could you please expand on this?
>>>
>>> Is the following better?
>>>
>>> Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.
>>
>> Yes and the reason for doing so? Consolidation/clarity of implementation?
> 
> Indeed. What about this commit message?
> 
> Subject: [PATCH v5 02/13] kexec_file: Change kexec_add_buffer to take  
>  kexec_buf as argument.
> 
> This is done to simplify the kexec_add_buffer argument list.
> Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.
> 
> In addition, change the type of kexec_buf.buffer from char * to void *.
> There is no particular reason for it to be a char *, and the change
> allows us to get rid of 3 existing casts to char * in the code.
> 
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
> Acked-by: Dave Young <dyoung@redhat.com>
> Acked-by: Balbir Singh <bsingharora@gmail.com>
> 


Looks good

Balbir

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Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

Am Dienstag, 16 August 2016, 16:52:54 schrieb Balbir Singh:
> On 16/08/16 09:25, Thiago Jung Bauermann wrote:
> > Am Montag, 15 August 2016, 17:46:34 schrieb Balbir Singh:
> >> On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
> >>> +/**
> >>> + * elf64_apply_relocate_add - apply 64 bit RELA relocations
> >>> + * @elf_info:		Support information for the ELF binary being
> > 
> > relocated.
> > 
> >>> + * @strtab:		String table for the associated symbol
> > 
> > table.
> > 
> >>> + * @symindex:		Section header index for the associated
> > 
> > symbol table.
> > 
> >>> + * @relsec:		Section header index for the relocations to
> > 
> > apply.
> > 
> >>> + * @obj_name:		The name of the ELF binary, for information
> > 
> > messages.
> > 
> >>> + */
> >>> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> >>> +			     const char *strtab, unsigned int symindex,
> >>> +			     unsigned int relsec, const char *obj_name)
> >>> +{
> >>> +	unsigned int i;
> >>> +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
> >>> +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
> >>> +	Elf64_Sym *sym;
> >>> +	unsigned long *location;
> >>> +	unsigned long value;
> >>> +
> >> 
> >> For the relocatable kernel we expect only
> >> 
> >> R_PPC64_RELATIVE
> >> R_PPC64_NONE
> >> R_PPC64_ADDR64
> >> 
> >> In the future we can use this to check/assert the usage of this
> >> for the core kernel (vmlinux) when loaded.
> >> 
> >> Did we check elf64_apply_relocate_add with zImage and vmlinux?
> > 
> > kexec_file_load doesn't call call elf64_apply_relocate_add on the kernel
> > image, it only uses it to relocate the purgatory. So whether it is
> > loading a zImage or a vmlinux file, the function will work in the same
> > way since the purgatory binary is the same regardless of the kernel
> > image format.
> Thanks for clarifying.
> 
> > For the same reason, as it currently stands kexec_file_load can't check
> > the relocation types used in the kernel image. But it is possible to
> > add such a check/assertion in kexec_elf_64.c:build_elf_exec_info if we
> > want.
> > 
> > I tested kexec_file_load on both relocatable and non-relocatable vmlinux
> > and it works correctly.
> > 
> > I hadn't tested with zImage yet. I just did, and I had two problems:
> > 
> > 1. For some reason, it has an INTERP segment. This patch series doesn't
> > support loading program interpreters for ELF binaries, so
> > kexec_elf_64.c:build_elf_exec_info refuses to load them.
> > 
> > 2. If I disable the check for the INTERP segment, the zImage file loads
> > correctly, but then I get an exception during reboot when loading the
> > kexec image, right before jumping into the purgatory. I suspect this is
> > because the LOAD segment has a virtual address of 0, and the first
> > kernel is not coping well with that. But I still have to debug it
> > further.
> > 
> > Is there a reason for the zImage ELF header to request an interpreter
> > and to have a virtual address of 0?
> 
> Not that I am aware of.

zImage on ppc64 BE is an ELF32 file. This patch set only supports loading 
ELF files of the same class as the kernel, so a 64 bit kernel can't load an 
ELF32 file. It would be possible to add such support, but it would be a new 
feature.

The distros I was able to check on ppc64 LE and BE all use vmlinux.
kexec-tools with kexec_load also doesn't support zImage. Do you think it is 
important to support zImage?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

Am Dienstag, 16 August 2016, 16:52:54 schrieb Balbir Singh:
> On 16/08/16 09:25, Thiago Jung Bauermann wrote:
> > Am Montag, 15 August 2016, 17:46:34 schrieb Balbir Singh:
> >> On Thu, Aug 11, 2016 at 08:08:09PM -0300, Thiago Jung Bauermann wrote:
> >>> +/**
> >>> + * elf64_apply_relocate_add - apply 64 bit RELA relocations
> >>> + * @elf_info:		Support information for the ELF binary being
> > 
> > relocated.
> > 
> >>> + * @strtab:		String table for the associated symbol
> > 
> > table.
> > 
> >>> + * @symindex:		Section header index for the associated
> > 
> > symbol table.
> > 
> >>> + * @relsec:		Section header index for the relocations to
> > 
> > apply.
> > 
> >>> + * @obj_name:		The name of the ELF binary, for information
> > 
> > messages.
> > 
> >>> + */
> >>> +int elf64_apply_relocate_add(const struct elf_info *elf_info,
> >>> +			     const char *strtab, unsigned int symindex,
> >>> +			     unsigned int relsec, const char *obj_name)
> >>> +{
> >>> +	unsigned int i;
> >>> +	Elf64_Shdr *sechdrs = elf_info->sechdrs;
> >>> +	Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr;
> >>> +	Elf64_Sym *sym;
> >>> +	unsigned long *location;
> >>> +	unsigned long value;
> >>> +
> >> 
> >> For the relocatable kernel we expect only
> >> 
> >> R_PPC64_RELATIVE
> >> R_PPC64_NONE
> >> R_PPC64_ADDR64
> >> 
> >> In the future we can use this to check/assert the usage of this
> >> for the core kernel (vmlinux) when loaded.
> >> 
> >> Did we check elf64_apply_relocate_add with zImage and vmlinux?
> > 
> > kexec_file_load doesn't call call elf64_apply_relocate_add on the kernel
> > image, it only uses it to relocate the purgatory. So whether it is
> > loading a zImage or a vmlinux file, the function will work in the same
> > way since the purgatory binary is the same regardless of the kernel
> > image format.
> Thanks for clarifying.
> 
> > For the same reason, as it currently stands kexec_file_load can't check
> > the relocation types used in the kernel image. But it is possible to
> > add such a check/assertion in kexec_elf_64.c:build_elf_exec_info if we
> > want.
> > 
> > I tested kexec_file_load on both relocatable and non-relocatable vmlinux
> > and it works correctly.
> > 
> > I hadn't tested with zImage yet. I just did, and I had two problems:
> > 
> > 1. For some reason, it has an INTERP segment. This patch series doesn't
> > support loading program interpreters for ELF binaries, so
> > kexec_elf_64.c:build_elf_exec_info refuses to load them.
> > 
> > 2. If I disable the check for the INTERP segment, the zImage file loads
> > correctly, but then I get an exception during reboot when loading the
> > kexec image, right before jumping into the purgatory. I suspect this is
> > because the LOAD segment has a virtual address of 0, and the first
> > kernel is not coping well with that. But I still have to debug it
> > further.
> > 
> > Is there a reason for the zImage ELF header to request an interpreter
> > and to have a virtual address of 0?
> 
> Not that I am aware of.

zImage on ppc64 BE is an ELF32 file. This patch set only supports loading 
ELF files of the same class as the kernel, so a 64 bit kernel can't load an 
ELF32 file. It would be possible to add such support, but it would be a new 
feature.

The distros I was able to check on ppc64 LE and BE all use vmlinux.
kexec-tools with kexec_load also doesn't support zImage. Do you think it is 
important to support zImage?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


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Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Balbir Singh]

> zImage on ppc64 BE is an ELF32 file. This patch set only supports loading 
> ELF files of the same class as the kernel, so a 64 bit kernel can't load an 
> ELF32 file. It would be possible to add such support, but it would be a new 
> feature.
> 
> The distros I was able to check on ppc64 LE and BE all use vmlinux.
> kexec-tools with kexec_load also doesn't support zImage. Do you think it is 
> important to support zImage?
> 

Well if it didn't work already, I think its low priority. Michael should be
able to confirm this. Oliver's been trying to cleanup the zImage to get rid
the old zImage limitation, cc'ing him

Balbir Singh

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Balbir Singh]

> zImage on ppc64 BE is an ELF32 file. This patch set only supports loading 
> ELF files of the same class as the kernel, so a 64 bit kernel can't load an 
> ELF32 file. It would be possible to add such support, but it would be a new 
> feature.
> 
> The distros I was able to check on ppc64 LE and BE all use vmlinux.
> kexec-tools with kexec_load also doesn't support zImage. Do you think it is 
> important to support zImage?
> 

Well if it didn't work already, I think its low priority. Michael should be
able to confirm this. Oliver's been trying to cleanup the zImage to get rid
the old zImage limitation, cc'ing him

Balbir Singh

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Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Oliver O'Halloran]

On Tue, Aug 23, 2016 at 1:21 PM, Balbir Singh <bsingharora@gmail.com> wrote:
>
>> zImage on ppc64 BE is an ELF32 file. This patch set only supports loading
>> ELF files of the same class as the kernel, so a 64 bit kernel can't load an
>> ELF32 file. It would be possible to add such support, but it would be a new
>> feature.
>>
>> The distros I was able to check on ppc64 LE and BE all use vmlinux.
>> kexec-tools with kexec_load also doesn't support zImage. Do you think it is
>> important to support zImage?
>
> Well if it didn't work already, I think its low priority. Michael should be
> able to confirm this. Oliver's been trying to cleanup the zImage to get rid
> the old zImage limitation, cc'ing him

I don't think it's ever worked so I wouldn't worry too much about
supporting it. Fixing kexec-into-zImage and fixing the 32bit wrapper
on 64bit BE kernel problem has been on my TODO list for a while, but
it's not a priority.

oliver

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Oliver O'Halloran]

On Tue, Aug 23, 2016 at 1:21 PM, Balbir Singh <bsingharora@gmail.com> wrote:
>
>> zImage on ppc64 BE is an ELF32 file. This patch set only supports loading
>> ELF files of the same class as the kernel, so a 64 bit kernel can't load an
>> ELF32 file. It would be possible to add such support, but it would be a new
>> feature.
>>
>> The distros I was able to check on ppc64 LE and BE all use vmlinux.
>> kexec-tools with kexec_load also doesn't support zImage. Do you think it is
>> important to support zImage?
>
> Well if it didn't work already, I think its low priority. Michael should be
> able to confirm this. Oliver's been trying to cleanup the zImage to get rid
> the old zImage limitation, cc'ing him

I don't think it's ever worked so I wouldn't worry too much about
supporting it. Fixing kexec-into-zImage and fixing the 32bit wrapper
on 64bit BE kernel problem has been on my TODO list for a while, but
it's not a priority.

oliver

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Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

Am Mittwoch, 24 August 2016, 10:50:26 schrieb Oliver O'Halloran:
> On Tue, Aug 23, 2016 at 1:21 PM, Balbir Singh <bsingharora@gmail.com> 
wrote:
> >> zImage on ppc64 BE is an ELF32 file. This patch set only supports
> >> loading
> >> ELF files of the same class as the kernel, so a 64 bit kernel can't
> >> load an ELF32 file. It would be possible to add such support, but it
> >> would be a new feature.
> >> 
> >> The distros I was able to check on ppc64 LE and BE all use vmlinux.
> >> kexec-tools with kexec_load also doesn't support zImage. Do you think
> >> it is important to support zImage?
> > 
> > Well if it didn't work already, I think its low priority. Michael should
> > be able to confirm this. Oliver's been trying to cleanup the zImage to
> > get rid the old zImage limitation, cc'ing him
> 
> I don't think it's ever worked so I wouldn't worry too much about
> supporting it. Fixing kexec-into-zImage and fixing the 32bit wrapper
> on 64bit BE kernel problem has been on my TODO list for a while, but
> it's not a priority.

Ok, thanks for your input.

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v5 04/13] powerpc: Factor out relocation code from module_64.c to elf_util_64.c.

[Thiago Jung Bauermann]

Am Mittwoch, 24 August 2016, 10:50:26 schrieb Oliver O'Halloran:
> On Tue, Aug 23, 2016 at 1:21 PM, Balbir Singh <bsingharora@gmail.com> 
wrote:
> >> zImage on ppc64 BE is an ELF32 file. This patch set only supports
> >> loading
> >> ELF files of the same class as the kernel, so a 64 bit kernel can't
> >> load an ELF32 file. It would be possible to add such support, but it
> >> would be a new feature.
> >> 
> >> The distros I was able to check on ppc64 LE and BE all use vmlinux.
> >> kexec-tools with kexec_load also doesn't support zImage. Do you think
> >> it is important to support zImage?
> > 
> > Well if it didn't work already, I think its low priority. Michael should
> > be able to confirm this. Oliver's been trying to cleanup the zImage to
> > get rid the old zImage limitation, cc'ing him
> 
> I don't think it's ever worked so I wouldn't worry too much about
> supporting it. Fixing kexec-into-zImage and fixing the 32bit wrapper
> on 64bit BE kernel problem has been on my TODO list for a while, but
> it's not a priority.

Ok, thanks for your input.

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


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