[PATCH V4 00/17] riscv: compat: Add COMPAT mode support for rv64

[PATCH V4 00/17] riscv: compat: Add COMPAT mode support for rv64

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Currently, most 64-bit architectures (x86, parisc, powerpc, arm64,
s390, mips, sparc) have supported COMPAT mode. But they all have
history issues and can't use standard linux unistd.h. RISC-V would
be first standard __SYSCALL_COMPAT user of include/uapi/asm-generic
/unistd.h.

The patchset are based on v5.17-rc1, you can compare rv64-compat32
v.s. rv32-whole in qemu with following step:

 - Prepare rv32 rootfs & fw_jump.bin by buildroot.org
   $ git clone git://git.busybox.net/buildroot
   $ cd buildroot
   $ make qemu_riscv32_virt_defconfig O=qemu_riscv32_virt_defconfig
   $ make -C qemu_riscv32_virt_defconfig
   $ make qemu_riscv64_virt_defconfig O=qemu_riscv64_virt_defconfig
   $ make -C qemu_riscv64_virt_defconfig
   (Got fw_jump.bin & rootfs.ext2 in qemu_riscvXX_virt_defconfig/images)

 - Prepare Linux rv32 & rv64 Image
   $ git clone git@github.com:c-sky/csky-linux.git -b riscv_compat_v4 linux
   $ cd linux
   $ echo "CONFIG_STRICT_KERNEL_RWX=n" >> arch/riscv/configs/defconfig
   $ echo "CONFIG_STRICT_MODULE_RWX=n" >> arch/riscv/configs/defconfig
   $ make ARCH=riscv CROSS_COMPILE=riscv32-buildroot-linux-gnu- O=../build-rv32/ rv32_defconfig
   $ make ARCH=riscv CROSS_COMPILE=riscv32-buildroot-linux-gnu- O=../build-rv32/ Image
   $ make ARCH=riscv CROSS_COMPILE=riscv64-buildroot-linux-gnu- O=../build-rv64/ defconfig
   $ make ARCH=riscv CROSS_COMPILE=riscv64-buildroot-linux-gnu- O=../build-rv64/ Image

 - Prepare Qemu: (made by LIU Zhiwei <zhiwei_liu@c-sky.com>)
   $ git clone git@github.com:alistair23/qemu.git -b riscv-to-apply.for-upstream linux
   $ cd qemu
   $ ./configure --target-list="riscv64-softmmu riscv32-softmmu"
   $ make

 - Run rv64 with rv32 rootfs in compat mode:
   $ ./build/qemu-system-riscv64 -cpu rv64,x-h=true -M virt -m 64m -nographic -bios qemu_riscv64_virt_defconfig/images/fw_jump.bin -kernel build-rv64/Image -drive file qemu_riscv32_virt_defconfig/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -append "rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi" -netdev user,id=net0 -device virtio-net-device,netdev=net0

QEMU emulator version 6.2.50 (v6.2.0-29-g196d7182c8)
OpenSBI v0.9
[    0.000000] Linux version 5.16.0-rc6-00017-g750f87086bdd-dirty (guoren@guoren-Z87-HD3) (riscv64-unknown-linux-gnu-gcc (GCC) 10.2.0, GNU ld (GNU Binutils) 2.37) #96 SMP Tue Dec 28 21:01:55 CST 2021
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Machine model: riscv-virtio,qemu
[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] efi: UEFI not found.
[    0.000000] Zone ranges:
[    0.000000]   DMA32    [mem 0x0000000080200000-0x0000000083ffffff]
[    0.000000]   Normal   empty
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080200000-0x0000000083ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080200000-0x0000000083ffffff]
[    0.000000] SBI specification v0.2 detected
[    0.000000] SBI implementation ID=0x1 Version=0x9
[    0.000000] SBI TIME extension detected
[    0.000000] SBI IPI extension detected
[    0.000000] SBI RFENCE extension detected
[    0.000000] SBI v0.2 HSM extension detected
[    0.000000] riscv: ISA extensions acdfhimsu
[    0.000000] riscv: ELF capabilities acdfim
[    0.000000] percpu: Embedded 17 pages/cpu s30696 r8192 d30744 u69632
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 15655
[    0.000000] Kernel command line: rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi
[    0.000000] Dentry cache hash table entries: 8192 (order: 4, 65536 bytes, linear)
[    0.000000] Inode-cache hash table entries: 4096 (order: 3, 32768 bytes, linear)
[    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
[    0.000000] Virtual kernel memory layout:
[    0.000000]       fixmap : 0xffffffcefee00000 - 0xffffffceff000000   (2048 kB)
[    0.000000]       pci io : 0xffffffceff000000 - 0xffffffcf00000000   (  16 MB)
[    0.000000]      vmemmap : 0xffffffcf00000000 - 0xffffffcfffffffff   (4095 MB)
[    0.000000]      vmalloc : 0xffffffd000000000 - 0xffffffdfffffffff   (65535 MB)
[    0.000000]       lowmem : 0xffffffe000000000 - 0xffffffe003e00000   (  62 MB)
[    0.000000]       kernel : 0xffffffff80000000 - 0xffffffffffffffff   (2047 MB)
[    0.000000] Memory: 52788K/63488K available (6184K kernel code, 888K rwdata, 1917K rodata, 294K init, 297K bss, 10700K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
[    0.000000] rcu:     RCU debug extended QS entry/exit.
[    0.000000]  Tracing variant of Tasks RCU enabled.
[    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
[    0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
[    0.000000] riscv-intc: 64 local interrupts mapped
[    0.000000] plic: plic@c000000: mapped 53 interrupts with 1 handlers for 2 contexts.
...
Welcome to Buildroot
buildroot login: root
# cat /proc/cpuinfo
processor       : 0
hart            : 0
isa             : rv64imafdcsuh
mmu             : sv48

# file /bin/busybox
/bin/busybox: setuid ELF 32-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped
# ca[   78.386630] random: fast init done
# cat /proc/meminfo
MemTotal:          53076 kB
MemFree:           40264 kB
MemAvailable:      40244 kB
Buffers:             236 kB
Cached:             1560 kB
SwapCached:            0 kB
Active:             1700 kB
Inactive:            516 kB
Active(anon):         40 kB
Inactive(anon):      424 kB
Active(file):       1660 kB
Inactive(file):       92 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 0 kB
Writeback:             0 kB
AnonPages:           444 kB
Mapped:             1188 kB
Shmem:                44 kB
KReclaimable:        952 kB
Slab:               5744 kB
SReclaimable:        952 kB
SUnreclaim:         4792 kB
KernelStack:         624 kB
PageTables:          156 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:       26536 kB
Committed_AS:       1748 kB
VmallocTotal:   67108863 kB
VmallocUsed:         652 kB
VmallocChunk:          0 kB
Percpu:               80 kB
#

 - Run rv32 with rv32 rootfs:
   $ ./build/qemu-system-riscv32 -cpu rv32,x-h=true -M virt -m 64m -nographic -bios qemu_riscv32_virt_defconfig/images/fw_jump.bin -kernel build-rv32/Image -drive file qemu_riscv32_virt_defconfig/images/rootfs.ext2,format=raw,id=hd0 -device virtio-blk-device,drive=hd0 -append "rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi" -netdev user,id=net0 -device virtio-net-device,netdev=net0

QEMU emulator version 6.2.50 (v6.2.0-29-g196d7182c8)
OpenSBI v0.9
[    0.000000] Linux version 5.16.0-rc6-00017-g750f87086bdd-dirty (guoren@guoren-Z87-HD3) (riscv32-buildroot-linux-gnu-gcc.br_real (Buildroot 2021.11-201-g7600ca7960-dirty) 10.3.0, GNU ld (GNU Binutils) 2.36.1) #7 SMP Tue Dec 28 21:02:21 CST 2021
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80400000
[    0.000000] Machine model: riscv-virtio,qemu
[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] efi: UEFI not found.
[    0.000000] Zone ranges:
[    0.000000]   Normal   [mem 0x0000000080400000-0x0000000083ffffff]
[    0.000000] Movable zone start for each node
[    0.000000] Early memory node ranges
[    0.000000]   node   0: [mem 0x0000000080400000-0x0000000083ffffff]
[    0.000000] Initmem setup node 0 [mem 0x0000000080400000-0x0000000083ffffff]
[    0.000000] SBI specification v0.2 detected
[    0.000000] SBI implementation ID=0x1 Version=0x9
[    0.000000] SBI TIME extension detected
[    0.000000] SBI IPI extension detected
[    0.000000] SBI RFENCE extension detected
[    0.000000] SBI v0.2 HSM extension detected
[    0.000000] riscv: ISA extensions acdfhimsu
[    0.000000] riscv: ELF capabilities acdfim
[    0.000000] percpu: Embedded 12 pages/cpu s16600 r8192 d24360 u49152
[    0.000000] Built 1 zonelists, mobility grouping on.  Total pages: 15240
[    0.000000] Kernel command line: rootwait root=/dev/vda ro console=ttyS0 earlycon=sbi
[    0.000000] Dentry cache hash table entries: 8192 (order: 3, 32768 bytes, linear)
[    0.000000] Inode-cache hash table entries: 4096 (order: 2, 16384 bytes, linear)
[    0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off
[    0.000000] Virtual kernel memory layout:
[    0.000000]       fixmap : 0x9dc00000 - 0x9e000000   (4096 kB)
[    0.000000]       pci io : 0x9e000000 - 0x9f000000   (  16 MB)
[    0.000000]      vmemmap : 0x9f000000 - 0x9fffffff   (  15 MB)
[    0.000000]      vmalloc : 0xa0000000 - 0xbfffffff   ( 511 MB)
[    0.000000]       lowmem : 0xc0000000 - 0xc3c00000   (  60 MB)
[    0.000000] Memory: 51924K/61440K available (6117K kernel code, 695K rwdata, 1594K rodata, 255K init, 241K bss, 9516K reserved, 0K cma-reserved)
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
[    0.000000] rcu: Hierarchical RCU implementation.
[    0.000000] rcu:     RCU restricting CPUs from NR_CPUS=8 to nr_cpu_ids=1.
[    0.000000] rcu:     RCU debug extended QS entry/exit.
[    0.000000]  Tracing variant of Tasks RCU enabled.
[    0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
[    0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
[    0.000000] NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
[    0.000000] riscv-intc: 32 local interrupts mapped
[    0.000000] plic: plic@c000000: mapped 53 interrupts with 1 handlers for 2 contexts.
...
Welcome to Buildroot
buildroot login: root
# cat /proc/cpuinfo
processor       : 0
hart            : 0
isa             : rv32imafdcsuh
mmu             : sv32

# file /bin/busybox
/bin/busybox: setuid ELF 32-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped
[   79.320589] random: fast init done
# cat /proc/meminfo
MemTotal:          52176 kB
MemFree:           41012 kB
MemAvailable:      42176 kB
Buffers:             644 kB
Cached:             2724 kB
SwapCached:            0 kB
Active:             3128 kB
Inactive:            752 kB
Active(anon):         40 kB
Inactive(anon):      516 kB
Active(file):       3088 kB
Inactive(file):      236 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:                 4 kB
Writeback:             0 kB
AnonPages:           556 kB
Mapped:             2172 kB
Shmem:                44 kB
KReclaimable:        656 kB
Slab:               3684 kB
SReclaimable:        656 kB
SUnreclaim:         3028 kB
KernelStack:         312 kB
PageTables:           88 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:       26088 kB
Committed_AS:       2088 kB
VmallocTotal:     524287 kB
VmallocUsed:          12 kB
VmallocChunk:          0 kB
Percpu:               60 kB
#

 Some conclusions:
 - kernel statics:
   64: Memory: 52788K/63488K available (6184K kernel code, 888K rwdata, 1917K rodata, 294K init, 297K bss, 10700K reserved)
   32: Memory: 51924K/61440K available (6117K kernel code, 695K rwdata, 1594K rodata, 255K init, 241K bss,  9516K reserved)
   rv32 better than rv64:                  1%               22%           17%          13%        19%         11%
   The code size is very similar, but data size rv32 would be better.

 - rv32 kernel runtime KernelStack, Slab... are smaller,
   rv64: MemTotal: 53076 kB,        MemFree: 40264 kB
   rv32: MemTotal: 52176 + 2048 kB, MemFree: 41012  + 2048 kB
   rv32 better than rv64:       2%                         6%

   (Because opensbi problem, we could add another 2MB for rv32.)
   Overall, rv64-compat is 6% worse than rv32-full at memory footprint.
   If the user space memory usage increases, the gap will be further
   reduced.

 - Qemu, kernel, rv32 = rv64 defconfig, rootfs, opensbi
   are the same in this comparison.

Changes in v4:
 - Rebase on linux-5.17-rc1
 - Optimize compat_sys_call_table implementation with Arnd's advice
 - Add reviewed-by for Arnd. Thx :)
 - Remove FIXME comment in elf.h
 - Optimize Cleanup duplicate definitions in compat.h with Arnd's advice

Changes in v3:
 - Rebase on newest master (pre linux-5.17-rc1)
 - Using newest qemu version v7 for test
 - Remove fcntl common modification
 - Fixup SET_PERSONALITY in elf.h by Arnd
 - Fixup KVM Kconfig
 - Update Acked-by & Reviewed-by

Changes in v2:
 - Add __ARCH_WANT_COMPAT_STAT suggested
 - Cleanup fcntl compatduplicate definitions
 - Cleanup compat.h
 - Move rv32_defconfig into Makefile
 - Fixup rv64 rootfs boot failed, remove hw_compat_mode_detect
 - Move SYSVIPC_COMPAT into init/Kconfig
 - Simplify compat_elf_check

Guo Ren (17):
  kconfig: Add SYSVIPC_COMPAT for all architectures
  fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT
  asm-generic: compat: Cleanup duplicate definitions
  syscalls: compat: Fix the missing part for __SYSCALL_COMPAT
  riscv: Fixup difference with defconfig
  riscv: compat: Add basic compat date type implementation
  riscv: compat: Re-implement TASK_SIZE for COMPAT_32BIT
  riscv: compat: syscall: Add compat_sys_call_table implementation
  riscv: compat: syscall: Add entry.S implementation
  riscv: compat: Add elf.h implementation
  riscv: compat: vdso: Add rv32 VDSO base code implementation
  riscv: compat: vdso: Add setup additional pages implementation
  riscv: compat: signal: Add rt_frame implementation
  riscv: compat: ptrace: Add compat_arch_ptrace implement
  riscv: compat: Add UXL_32 support in start_thread
  riscv: compat: Add COMPAT Kbuild skeletal support
  KVM: compat: riscv: Prevent KVM_COMPAT from being selected


Guo Ren (17):
  kconfig: Add SYSVIPC_COMPAT for all architectures
  fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT
  asm-generic: compat: Cleanup duplicate definitions
  syscalls: compat: Fix the missing part for __SYSCALL_COMPAT
  riscv: Fixup difference with defconfig
  riscv: compat: Add basic compat date type implementation
  riscv: compat: Re-implement TASK_SIZE for COMPAT_32BIT
  riscv: compat: syscall: Add compat_sys_call_table implementation
  riscv: compat: syscall: Add entry.S implementation
  riscv: compat: process: Add UXL_32 support in start_thread
  riscv: compat: Add elf.h implementation
  riscv: compat: vdso: Add rv32 VDSO base code implementation
  riscv: compat: vdso: Add setup additional pages implementation
  riscv: compat: signal: Add rt_frame implementation
  riscv: compat: ptrace: Add compat_arch_ptrace implement
  riscv: compat: Add COMPAT Kbuild skeletal support
  KVM: compat: riscv: Prevent KVM_COMPAT from being selected

 arch/arm64/Kconfig                            |   4 -
 arch/arm64/include/asm/compat.h               | 106 +-------
 arch/arm64/include/asm/unistd.h               |   1 +
 arch/mips/Kconfig                             |   5 -
 arch/mips/include/asm/compat.h                |  27 +-
 arch/mips/include/asm/unistd.h                |   2 +
 arch/parisc/Kconfig                           |   4 -
 arch/parisc/include/asm/compat.h              |  45 +---
 arch/parisc/include/asm/unistd.h              |   1 +
 arch/powerpc/Kconfig                          |   5 -
 arch/powerpc/include/asm/compat.h             |  46 +---
 arch/powerpc/include/asm/unistd.h             |   1 +
 arch/riscv/Kconfig                            |  19 ++
 arch/riscv/Makefile                           |   9 +
 arch/riscv/configs/rv32_defconfig             | 135 ----------
 arch/riscv/include/asm/compat.h               | 135 ++++++++++
 arch/riscv/include/asm/csr.h                  |   7 +
 arch/riscv/include/asm/elf.h                  |  53 +++-
 arch/riscv/include/asm/mmu.h                  |   1 +
 arch/riscv/include/asm/pgtable.h              |  13 +-
 arch/riscv/include/asm/syscall.h              |   1 +
 arch/riscv/include/asm/thread_info.h          |   1 +
 arch/riscv/include/asm/unistd.h               |  11 +
 arch/riscv/include/asm/vdso.h                 |   9 +
 arch/riscv/include/uapi/asm/unistd.h          |   2 +-
 arch/riscv/kernel/Makefile                    |   3 +
 arch/riscv/kernel/compat_signal.c             | 243 ++++++++++++++++++
 arch/riscv/kernel/compat_syscall_table.c      |  19 ++
 arch/riscv/kernel/compat_vdso/.gitignore      |   2 +
 arch/riscv/kernel/compat_vdso/Makefile        |  68 +++++
 arch/riscv/kernel/compat_vdso/compat_vdso.S   |   8 +
 .../kernel/compat_vdso/compat_vdso.lds.S      |   3 +
 arch/riscv/kernel/compat_vdso/flush_icache.S  |   3 +
 .../compat_vdso/gen_compat_vdso_offsets.sh    |   5 +
 arch/riscv/kernel/compat_vdso/getcpu.S        |   3 +
 arch/riscv/kernel/compat_vdso/note.S          |   3 +
 arch/riscv/kernel/compat_vdso/rt_sigreturn.S  |   3 +
 arch/riscv/kernel/entry.S                     |  18 +-
 arch/riscv/kernel/process.c                   |   5 +
 arch/riscv/kernel/ptrace.c                    |  87 ++++++-
 arch/riscv/kernel/signal.c                    |  13 +-
 arch/riscv/kernel/sys_riscv.c                 |   6 +-
 arch/riscv/kernel/vdso.c                      | 104 +++++---
 arch/riscv/kernel/vdso/vdso.S                 |   6 +-
 arch/s390/Kconfig                             |   3 -
 arch/s390/include/asm/compat.h                |  95 +------
 arch/s390/include/asm/unistd.h                |   1 +
 arch/sparc/Kconfig                            |   5 -
 arch/sparc/include/asm/compat.h               |  42 ++-
 arch/sparc/include/asm/unistd.h               |   1 +
 arch/x86/Kconfig                              |   4 -
 arch/x86/include/asm/compat.h                 |  89 +------
 arch/x86/include/asm/unistd.h                 |   1 +
 fs/open.c                                     |  24 ++
 fs/read_write.c                               |  16 ++
 fs/stat.c                                     |   2 +-
 fs/sync.c                                     |   9 +
 include/asm-generic/compat.h                  | 133 ++++++++++
 include/linux/compat.h                        |  37 +++
 include/uapi/asm-generic/unistd.h             |   4 +-
 init/Kconfig                                  |   4 +
 mm/fadvise.c                                  |  11 +
 mm/readahead.c                                |   7 +
 tools/include/uapi/asm-generic/unistd.h       |   4 +-
 virt/kvm/Kconfig                              |   2 +-
 65 files changed, 1141 insertions(+), 598 deletions(-)
 delete mode 100644 arch/riscv/configs/rv32_defconfig
 create mode 100644 arch/riscv/include/asm/compat.h
 create mode 100644 arch/riscv/kernel/compat_signal.c
 create mode 100644 arch/riscv/kernel/compat_syscall_table.c
 create mode 100644 arch/riscv/kernel/compat_vdso/.gitignore
 create mode 100644 arch/riscv/kernel/compat_vdso/Makefile
 create mode 100644 arch/riscv/kernel/compat_vdso/compat_vdso.S
 create mode 100644 arch/riscv/kernel/compat_vdso/compat_vdso.lds.S
 create mode 100644 arch/riscv/kernel/compat_vdso/flush_icache.S
 create mode 100755 arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh
 create mode 100644 arch/riscv/kernel/compat_vdso/getcpu.S
 create mode 100644 arch/riscv/kernel/compat_vdso/note.S
 create mode 100644 arch/riscv/kernel/compat_vdso/rt_sigreturn.S

-- 
2.25.1

[PATCH V4 01/17] kconfig: Add SYSVIPC_COMPAT for all architectures

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

The existing per-arch definitions are pretty much historic cruft.
Move SYSVIPC_COMPAT into init/Kconfig.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/arm64/Kconfig   | 4 ----
 arch/mips/Kconfig    | 5 -----
 arch/parisc/Kconfig  | 4 ----
 arch/powerpc/Kconfig | 5 -----
 arch/s390/Kconfig    | 3 ---
 arch/sparc/Kconfig   | 5 -----
 arch/x86/Kconfig     | 4 ----
 init/Kconfig         | 4 ++++
 8 files changed, 4 insertions(+), 30 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6978140edfa4..ad1beb70dc36 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2022,10 +2022,6 @@ config DMI
 
 endmenu
 
-config SYSVIPC_COMPAT
-	def_bool y
-	depends on COMPAT && SYSVIPC
-
 menu "Power management options"
 
 source "kernel/power/Kconfig"
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 058446f01487..91a17ad380c9 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -3170,16 +3170,12 @@ config MIPS32_COMPAT
 config COMPAT
 	bool
 
-config SYSVIPC_COMPAT
-	bool
-
 config MIPS32_O32
 	bool "Kernel support for o32 binaries"
 	depends on 64BIT
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT
 	select MIPS32_COMPAT
-	select SYSVIPC_COMPAT if SYSVIPC
 	help
 	  Select this option if you want to run o32 binaries.  These are pure
 	  32-bit binaries as used by the 32-bit Linux/MIPS port.  Most of
@@ -3193,7 +3189,6 @@ config MIPS32_N32
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	select COMPAT
 	select MIPS32_COMPAT
-	select SYSVIPC_COMPAT if SYSVIPC
 	help
 	  Select this option if you want to run n32 binaries.  These are
 	  64-bit binaries using 32-bit quantities for addressing and certain
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 43c1c880def6..bc56759d44a2 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -345,10 +345,6 @@ config COMPAT
 	def_bool y
 	depends on 64BIT
 
-config SYSVIPC_COMPAT
-	def_bool y
-	depends on COMPAT && SYSVIPC
-
 config AUDIT_ARCH
 	def_bool y
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b779603978e1..5a32b7f21af2 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -291,11 +291,6 @@ config COMPAT
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
 
-config SYSVIPC_COMPAT
-	bool
-	depends on COMPAT && SYSVIPC
-	default y
-
 config SCHED_OMIT_FRAME_POINTER
 	bool
 	default y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9750f92380f5..e41265c938ec 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -459,9 +459,6 @@ config COMPAT
 	  (and some other stuff like libraries and such) is needed for
 	  executing 31 bit applications.  It is safe to say "Y".
 
-config SYSVIPC_COMPAT
-	def_bool y if COMPAT && SYSVIPC
-
 config SMP
 	def_bool y
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 1cab1b284f1a..15d5725bd623 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -488,9 +488,4 @@ config COMPAT
 	select ARCH_WANT_OLD_COMPAT_IPC
 	select COMPAT_OLD_SIGACTION
 
-config SYSVIPC_COMPAT
-	bool
-	depends on COMPAT && SYSVIPC
-	default y
-
 source "drivers/sbus/char/Kconfig"
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ebe8fc76949a..9609f191719d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2859,10 +2859,6 @@ config COMPAT
 if COMPAT
 config COMPAT_FOR_U64_ALIGNMENT
 	def_bool y
-
-config SYSVIPC_COMPAT
-	def_bool y
-	depends on SYSVIPC
 endif
 
 endmenu
diff --git a/init/Kconfig b/init/Kconfig
index e9119bf54b1f..589ccec56571 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -386,6 +386,10 @@ config SYSVIPC_SYSCTL
 	depends on SYSCTL
 	default y
 
+config SYSVIPC_COMPAT
+	def_bool y
+	depends on COMPAT && SYSVIPC
+
 config POSIX_MQUEUE
 	bool "POSIX Message Queues"
 	depends on NET
-- 
2.25.1

[PATCH V4 02/17] fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

RISC-V doesn't neeed compat_stat, so using __ARCH_WANT_COMPAT_STAT
to exclude unnecessary SYSCALL functions.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/arm64/include/asm/unistd.h   | 1 +
 arch/mips/include/asm/unistd.h    | 2 ++
 arch/parisc/include/asm/unistd.h  | 1 +
 arch/powerpc/include/asm/unistd.h | 1 +
 arch/s390/include/asm/unistd.h    | 1 +
 arch/sparc/include/asm/unistd.h   | 1 +
 arch/x86/include/asm/unistd.h     | 1 +
 fs/stat.c                         | 2 +-
 8 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/unistd.h b/arch/arm64/include/asm/unistd.h
index 4e65da3445c7..037feba03a51 100644
--- a/arch/arm64/include/asm/unistd.h
+++ b/arch/arm64/include/asm/unistd.h
@@ -3,6 +3,7 @@
  * Copyright (C) 2012 ARM Ltd.
  */
 #ifdef CONFIG_COMPAT
+#define __ARCH_WANT_COMPAT_STAT
 #define __ARCH_WANT_COMPAT_STAT64
 #define __ARCH_WANT_SYS_GETHOSTNAME
 #define __ARCH_WANT_SYS_PAUSE
diff --git a/arch/mips/include/asm/unistd.h b/arch/mips/include/asm/unistd.h
index c2196b1b6604..25a5253db7f4 100644
--- a/arch/mips/include/asm/unistd.h
+++ b/arch/mips/include/asm/unistd.h
@@ -50,6 +50,8 @@
 # ifdef CONFIG_32BIT
 #  define __ARCH_WANT_STAT64
 #  define __ARCH_WANT_SYS_TIME32
+# else
+#  define __ARCH_WANT_COMPAT_STAT
 # endif
 # ifdef CONFIG_MIPS32_O32
 #  define __ARCH_WANT_SYS_TIME32
diff --git a/arch/parisc/include/asm/unistd.h b/arch/parisc/include/asm/unistd.h
index cd438e4150f6..14e0668184cb 100644
--- a/arch/parisc/include/asm/unistd.h
+++ b/arch/parisc/include/asm/unistd.h
@@ -168,6 +168,7 @@ type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, type5 arg5)	\
 #define __ARCH_WANT_SYS_CLONE
 #define __ARCH_WANT_SYS_CLONE3
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
+#define __ARCH_WANT_COMPAT_STAT
 
 #ifdef CONFIG_64BIT
 #define __ARCH_WANT_SYS_TIME
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 5eb462af6766..b1129b4ef57d 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -44,6 +44,7 @@
 #define __ARCH_WANT_SYS_TIME
 #define __ARCH_WANT_SYS_UTIME
 #define __ARCH_WANT_SYS_NEWFSTATAT
+#define __ARCH_WANT_COMPAT_STAT
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
 #endif
 #define __ARCH_WANT_SYS_FORK
diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index 9e9f75ef046a..4260bc5ce7f8 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -28,6 +28,7 @@
 #define __ARCH_WANT_SYS_SIGPENDING
 #define __ARCH_WANT_SYS_SIGPROCMASK
 # ifdef CONFIG_COMPAT
+#   define __ARCH_WANT_COMPAT_STAT
 #   define __ARCH_WANT_SYS_TIME32
 #   define __ARCH_WANT_SYS_UTIME32
 # endif
diff --git a/arch/sparc/include/asm/unistd.h b/arch/sparc/include/asm/unistd.h
index 1e66278ba4a5..d6bc76706a7a 100644
--- a/arch/sparc/include/asm/unistd.h
+++ b/arch/sparc/include/asm/unistd.h
@@ -46,6 +46,7 @@
 #define __ARCH_WANT_SYS_TIME
 #define __ARCH_WANT_SYS_UTIME
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
+#define __ARCH_WANT_COMPAT_STAT
 #endif
 
 #ifdef __32bit_syscall_numbers__
diff --git a/arch/x86/include/asm/unistd.h b/arch/x86/include/asm/unistd.h
index 80e9d5206a71..761173ccc33c 100644
--- a/arch/x86/include/asm/unistd.h
+++ b/arch/x86/include/asm/unistd.h
@@ -22,6 +22,7 @@
 #  include <asm/unistd_32_ia32.h>
 #  define __ARCH_WANT_SYS_TIME
 #  define __ARCH_WANT_SYS_UTIME
+#  define __ARCH_WANT_COMPAT_STAT
 #  define __ARCH_WANT_COMPAT_SYS_PREADV64
 #  define __ARCH_WANT_COMPAT_SYS_PWRITEV64
 #  define __ARCH_WANT_COMPAT_SYS_PREADV64V2
diff --git a/fs/stat.c b/fs/stat.c
index 28d2020ba1f4..ffdeb9065d53 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -639,7 +639,7 @@ SYSCALL_DEFINE5(statx,
 	return do_statx(dfd, filename, flags, mask, buffer);
 }
 
-#ifdef CONFIG_COMPAT
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_STAT)
 static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
 {
 	struct compat_stat tmp;
-- 
2.25.1

[PATCH V4 03/17] asm-generic: compat: Cleanup duplicate definitions

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

There are 7 64bit architectures that support Linux COMPAT mode to
run 32bit applications. A lot of definitions are duplicate:
 - COMPAT_USER_HZ
 - COMPAT_RLIM_INFINITY
 - COMPAT_OFF_T_MAX
 - __compat_uid_t, __compat_uid_t
 - compat_dev_t
 - compat_ipc_pid_t
 - struct compat_flock
 - struct compat_flock64
 - struct compat_statfs
 - struct compat_ipc64_perm, compat_semid64_ds,
	  compat_msqid64_ds, compat_shmid64_ds

Cleanup duplicate definitions and merge them into asm-generic.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/arm64/include/asm/compat.h   | 106 ++-----------------------
 arch/mips/include/asm/compat.h    |  27 ++-----
 arch/parisc/include/asm/compat.h  |  45 ++---------
 arch/powerpc/include/asm/compat.h |  46 ++---------
 arch/s390/include/asm/compat.h    |  95 +++-------------------
 arch/sparc/include/asm/compat.h   |  42 ++++------
 arch/x86/include/asm/compat.h     |  89 +++------------------
 include/asm-generic/compat.h      | 126 ++++++++++++++++++++++++++++++
 8 files changed, 193 insertions(+), 383 deletions(-)

diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index eaa6ca062d89..5b911f3625e8 100644
--- a/arch/arm64/include/asm/compat.h
+++ b/arch/arm64/include/asm/compat.h
@@ -8,6 +8,13 @@
 #define compat_mode_t compat_mode_t
 typedef u16		compat_mode_t;
 
+#define __compat_uid_t	__compat_uid_t
+typedef u16		__compat_uid_t;
+typedef u16		__compat_gid_t;
+
+#define compat_ipc_pid_t compat_ipc_pid_t
+typedef u16		 compat_ipc_pid_t;
+
 #include <asm-generic/compat.h>
 
 #ifdef CONFIG_COMPAT
@@ -19,21 +26,15 @@ typedef u16		compat_mode_t;
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
 
-#define COMPAT_USER_HZ		100
 #ifdef __AARCH64EB__
 #define COMPAT_UTS_MACHINE	"armv8b\0\0"
 #else
 #define COMPAT_UTS_MACHINE	"armv8l\0\0"
 #endif
 
-typedef u16		__compat_uid_t;
-typedef u16		__compat_gid_t;
 typedef u16		__compat_uid16_t;
 typedef u16		__compat_gid16_t;
-typedef u32		compat_dev_t;
 typedef s32		compat_nlink_t;
-typedef u16		compat_ipc_pid_t;
-typedef __kernel_fsid_t	compat_fsid_t;
 
 struct compat_stat {
 #ifdef __AARCH64EB__
@@ -65,106 +66,13 @@ struct compat_stat {
 	compat_ulong_t	__unused4[2];
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 #define F_GETLK64	12	/*  using 'struct flock64' */
 #define F_SETLK64	13
 #define F_SETLKW64	14
 
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
-struct compat_statfs {
-	int		f_type;
-	int		f_bsize;
-	int		f_blocks;
-	int		f_bfree;
-	int		f_bavail;
-	int		f_files;
-	int		f_ffree;
-	compat_fsid_t	f_fsid;
-	int		f_namelen;	/* SunOS ignores this field. */
-	int		f_frsize;
-	int		f_flags;
-	int		f_spare[4];
-};
-
-#define COMPAT_RLIM_INFINITY		0xffffffff
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
 #define compat_user_stack_pointer() (user_stack_pointer(task_pt_regs(current)))
 #define COMPAT_MINSIGSTKSZ	2048
 
-struct compat_ipc64_perm {
-	compat_key_t key;
-	__compat_uid32_t uid;
-	__compat_gid32_t gid;
-	__compat_uid32_t cuid;
-	__compat_gid32_t cgid;
-	unsigned short mode;
-	unsigned short __pad1;
-	unsigned short seq;
-	unsigned short __pad2;
-	compat_ulong_t unused1;
-	compat_ulong_t unused2;
-};
-
-struct compat_semid64_ds {
-	struct compat_ipc64_perm sem_perm;
-	compat_ulong_t sem_otime;
-	compat_ulong_t sem_otime_high;
-	compat_ulong_t sem_ctime;
-	compat_ulong_t sem_ctime_high;
-	compat_ulong_t sem_nsems;
-	compat_ulong_t __unused3;
-	compat_ulong_t __unused4;
-};
-
-struct compat_msqid64_ds {
-	struct compat_ipc64_perm msg_perm;
-	compat_ulong_t msg_stime;
-	compat_ulong_t msg_stime_high;
-	compat_ulong_t msg_rtime;
-	compat_ulong_t msg_rtime_high;
-	compat_ulong_t msg_ctime;
-	compat_ulong_t msg_ctime_high;
-	compat_ulong_t msg_cbytes;
-	compat_ulong_t msg_qnum;
-	compat_ulong_t msg_qbytes;
-	compat_pid_t   msg_lspid;
-	compat_pid_t   msg_lrpid;
-	compat_ulong_t __unused4;
-	compat_ulong_t __unused5;
-};
-
-struct compat_shmid64_ds {
-	struct compat_ipc64_perm shm_perm;
-	compat_size_t  shm_segsz;
-	compat_ulong_t shm_atime;
-	compat_ulong_t shm_atime_high;
-	compat_ulong_t shm_dtime;
-	compat_ulong_t shm_dtime_high;
-	compat_ulong_t shm_ctime;
-	compat_ulong_t shm_ctime_high;
-	compat_pid_t   shm_cpid;
-	compat_pid_t   shm_lpid;
-	compat_ulong_t shm_nattch;
-	compat_ulong_t __unused4;
-	compat_ulong_t __unused5;
-};
-
 static inline int is_compat_task(void)
 {
 	return test_thread_flag(TIF_32BIT);
diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index bbb3bc5a42fd..ceab66ba052b 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -9,28 +9,29 @@
 #include <asm/page.h>
 #include <asm/ptrace.h>
 
+#define __compat_uid_t	__compat_uid_t
 typedef s32		__compat_uid_t;
 typedef s32		__compat_gid_t;
+
 typedef __compat_uid_t	__compat_uid32_t;
 typedef __compat_gid_t	__compat_gid32_t;
 #define __compat_uid32_t __compat_uid32_t
-#define __compat_gid32_t __compat_gid32_t
+
+#define compat_flock		compat_flock
+#define compat_statfs		compat_statfs
+#define compat_ipc64_perm	compat_ipc64_perm
 
 #define _COMPAT_NSIG		128		/* Don't ask !$@#% ...	*/
 #define _COMPAT_NSIG_BPW	32
 typedef u32		compat_sigset_word;
 
+#define COMPAT_RLIM_INFINITY	0x7fffffffUL
+
 #include <asm-generic/compat.h>
 
-#define COMPAT_USER_HZ		100
 #define COMPAT_UTS_MACHINE	"mips\0\0\0"
 
-typedef u32		compat_dev_t;
 typedef u32		compat_nlink_t;
-typedef s32		compat_ipc_pid_t;
-typedef struct {
-	s32	val[2];
-} compat_fsid_t;
 
 struct compat_stat {
 	compat_dev_t	st_dev;
@@ -69,14 +70,6 @@ struct compat_flock {
 #define F_SETLK64	34
 #define F_SETLKW64	35
 
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 struct compat_statfs {
 	int		f_type;
 	int		f_bsize;
@@ -92,10 +85,6 @@ struct compat_statfs {
 	int		f_spare[5];
 };
 
-#define COMPAT_RLIM_INFINITY	0x7fffffffUL
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
 struct compat_ipc64_perm {
 	compat_key_t key;
 	__compat_uid32_t uid;
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index c04f5a637c39..339d1b833fa7 100644
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -11,16 +11,16 @@
 #define compat_mode_t compat_mode_t
 typedef u16	compat_mode_t;
 
+#define compat_ipc_pid_t compat_ipc_pid_t
+typedef u16	compat_ipc_pid_t;
+
+#define compat_ipc64_perm compat_ipc64_perm
+
 #include <asm-generic/compat.h>
 
-#define COMPAT_USER_HZ 		100
 #define COMPAT_UTS_MACHINE	"parisc\0\0"
 
-typedef u32	__compat_uid_t;
-typedef u32	__compat_gid_t;
-typedef u32	compat_dev_t;
 typedef u16	compat_nlink_t;
-typedef u16	compat_ipc_pid_t;
 
 struct compat_stat {
 	compat_dev_t		st_dev;	/* dev_t is 32 bits on parisc */
@@ -53,37 +53,6 @@ struct compat_stat {
 	u32			st_spare4[3];
 };
 
-struct compat_flock {
-	short			l_type;
-	short			l_whence;
-	compat_off_t		l_start;
-	compat_off_t		l_len;
-	compat_pid_t		l_pid;
-};
-
-struct compat_flock64 {
-	short			l_type;
-	short			l_whence;
-	compat_loff_t		l_start;
-	compat_loff_t		l_len;
-	compat_pid_t		l_pid;
-};
-
-struct compat_statfs {
-	s32		f_type;
-	s32		f_bsize;
-	s32		f_blocks;
-	s32		f_bfree;
-	s32		f_bavail;
-	s32		f_files;
-	s32		f_ffree;
-	__kernel_fsid_t	f_fsid;
-	s32		f_namelen;
-	s32		f_frsize;
-	s32		f_flags;
-	s32		f_spare[4];
-};
-
 struct compat_sigcontext {
 	compat_int_t sc_flags;
 	compat_int_t sc_gr[32]; /* PSW in sc_gr[0] */
@@ -93,10 +62,6 @@ struct compat_sigcontext {
 	compat_int_t sc_sar; /* cr11 */
 };
 
-#define COMPAT_RLIM_INFINITY 0xffffffff
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
 struct compat_ipc64_perm {
 	compat_key_t key;
 	__compat_uid_t uid;
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index 7afc96fb6524..a71d235bc5d7 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -8,21 +8,20 @@
 #include <linux/types.h>
 #include <linux/sched.h>
 
+#define compat_ipc_pid_t compat_ipc_pid_t
+typedef u16		compat_ipc_pid_t;
+
+#define compat_ipc64_perm compat_ipc64_perm
+
 #include <asm-generic/compat.h>
 
-#define COMPAT_USER_HZ		100
 #ifdef __BIG_ENDIAN__
 #define COMPAT_UTS_MACHINE	"ppc\0\0"
 #else
 #define COMPAT_UTS_MACHINE	"ppcle\0\0"
 #endif
 
-typedef u32		__compat_uid_t;
-typedef u32		__compat_gid_t;
-typedef u32		compat_dev_t;
 typedef s16		compat_nlink_t;
-typedef u16		compat_ipc_pid_t;
-typedef __kernel_fsid_t	compat_fsid_t;
 
 struct compat_stat {
 	compat_dev_t	st_dev;
@@ -44,45 +43,10 @@ struct compat_stat {
 	u32		__unused4[2];
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 #define F_GETLK64	12	/*  using 'struct flock64' */
 #define F_SETLK64	13
 #define F_SETLKW64	14
 
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
-struct compat_statfs {
-	int		f_type;
-	int		f_bsize;
-	int		f_blocks;
-	int		f_bfree;
-	int		f_bavail;
-	int		f_files;
-	int		f_ffree;
-	compat_fsid_t	f_fsid;
-	int		f_namelen;	/* SunOS ignores this field. */
-	int		f_frsize;
-	int		f_flags;
-	int		f_spare[4];
-};
-
-#define COMPAT_RLIM_INFINITY		0xffffffff
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
 /*
  * ipc64_perm is actually 32/64bit clean but since the compat layer refers to
  * it we may as well define it.
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index cdc7ae72529d..028a79c2de00 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -12,6 +12,18 @@
 #define compat_mode_t	compat_mode_t
 typedef u16		compat_mode_t;
 
+#define __compat_uid_t	__compat_uid_t
+typedef u16		__compat_uid_t;
+typedef u16		__compat_gid_t;
+
+#define compat_dev_t	compat_dev_t
+typedef u16		compat_dev_t;
+
+#define compat_ipc_pid_t compat_ipc_pid_t
+typedef u16		 compat_ipc_pid_t;
+
+#define compat_statfs	compat_statfs
+
 #include <asm-generic/compat.h>
 
 #define __TYPE_IS_PTR(t) (!__builtin_types_compatible_p( \
@@ -53,15 +65,9 @@ typedef u16		compat_mode_t;
 			 PSW32_MASK_MCHECK | PSW32_MASK_PSTATE | \
 			 PSW32_ASC_PRIMARY)
 
-#define COMPAT_USER_HZ		100
 #define COMPAT_UTS_MACHINE	"s390\0\0\0\0"
 
-typedef u16		__compat_uid_t;
-typedef u16		__compat_gid_t;
-typedef u16		compat_dev_t;
 typedef u16		compat_nlink_t;
-typedef u16		compat_ipc_pid_t;
-typedef __kernel_fsid_t	compat_fsid_t;
 
 typedef struct {
 	u32 mask;
@@ -102,26 +108,10 @@ struct compat_stat {
 	u32		__unused5;
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 #define F_GETLK64       12
 #define F_SETLK64       13
 #define F_SETLKW64      14    
 
-struct compat_flock64 {
-	short		l_type;
-	short		l_whence;
-	compat_loff_t	l_start;
-	compat_loff_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 struct compat_statfs {
 	u32		f_type;
 	u32		f_bsize;
@@ -152,10 +142,6 @@ struct compat_statfs64 {
 	u32		f_spare[4];
 };
 
-#define COMPAT_RLIM_INFINITY		0xffffffff
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
 /*
  * A pointer passed in from user mode. This should not
  * be used for syscall parameters, just declare them
@@ -178,61 +164,4 @@ static inline int is_compat_task(void)
 
 #endif
 
-struct compat_ipc64_perm {
-	compat_key_t key;
-	__compat_uid32_t uid;
-	__compat_gid32_t gid;
-	__compat_uid32_t cuid;
-	__compat_gid32_t cgid;
-	compat_mode_t mode;
-	unsigned short __pad1;
-	unsigned short seq;
-	unsigned short __pad2;
-	unsigned int __unused1;
-	unsigned int __unused2;
-};
-
-struct compat_semid64_ds {
-	struct compat_ipc64_perm sem_perm;
-	compat_ulong_t sem_otime;
-	compat_ulong_t sem_otime_high;
-	compat_ulong_t sem_ctime;
-	compat_ulong_t sem_ctime_high;
-	compat_ulong_t sem_nsems;
-	compat_ulong_t __unused1;
-	compat_ulong_t __unused2;
-};
-
-struct compat_msqid64_ds {
-	struct compat_ipc64_perm msg_perm;
-	compat_ulong_t msg_stime;
-	compat_ulong_t msg_stime_high;
-	compat_ulong_t msg_rtime;
-	compat_ulong_t msg_rtime_high;
-	compat_ulong_t msg_ctime;
-	compat_ulong_t msg_ctime_high;
-	compat_ulong_t msg_cbytes;
-	compat_ulong_t msg_qnum;
-	compat_ulong_t msg_qbytes;
-	compat_pid_t   msg_lspid;
-	compat_pid_t   msg_lrpid;
-	compat_ulong_t __unused1;
-	compat_ulong_t __unused2;
-};
-
-struct compat_shmid64_ds {
-	struct compat_ipc64_perm shm_perm;
-	compat_size_t  shm_segsz;
-	compat_ulong_t shm_atime;
-	compat_ulong_t shm_atime_high;
-	compat_ulong_t shm_dtime;
-	compat_ulong_t shm_dtime_high;
-	compat_ulong_t shm_ctime;
-	compat_ulong_t shm_ctime_high;
-	compat_pid_t   shm_cpid;
-	compat_pid_t   shm_lpid;
-	compat_ulong_t shm_nattch;
-	compat_ulong_t __unused1;
-	compat_ulong_t __unused2;
-};
 #endif /* _ASM_S390X_COMPAT_H */
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index bd949fcf9d63..63a32f1b13c4 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -9,17 +9,28 @@
 #define compat_mode_t	compat_mode_t
 typedef u16		compat_mode_t;
 
+#define __compat_uid_t	__compat_uid_t
+typedef u16		__compat_uid_t;
+typedef u16		__compat_gid_t;
+
+#define compat_dev_t	compat_dev_t
+typedef u16		compat_dev_t;
+
+#define compat_ipc_pid_t compat_ipc_pid_t
+typedef u16		 compat_ipc_pid_t;
+
+#define compat_flock	compat_flock
+#define compat_flock64	compat_flock64
+
+#define compat_ipc64_perm compat_ipc64_perm
+
+#define COMPAT_RLIM_INFINITY 0x7fffffff
+
 #include <asm-generic/compat.h>
 
-#define COMPAT_USER_HZ		100
 #define COMPAT_UTS_MACHINE	"sparc\0\0"
 
-typedef u16		__compat_uid_t;
-typedef u16		__compat_gid_t;
-typedef u16		compat_dev_t;
 typedef s16		compat_nlink_t;
-typedef u16		compat_ipc_pid_t;
-typedef __kernel_fsid_t	compat_fsid_t;
 
 struct compat_stat {
 	compat_dev_t	st_dev;
@@ -97,25 +108,6 @@ struct compat_flock64 {
 	short		__unused;
 };
 
-struct compat_statfs {
-	int		f_type;
-	int		f_bsize;
-	int		f_blocks;
-	int		f_bfree;
-	int		f_bavail;
-	int		f_files;
-	int		f_ffree;
-	compat_fsid_t	f_fsid;
-	int		f_namelen;	/* SunOS ignores this field. */
-	int		f_frsize;
-	int		f_flags;
-	int		f_spare[4];
-};
-
-#define COMPAT_RLIM_INFINITY 0x7fffffff
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
 struct compat_ipc64_perm {
 	compat_key_t key;
 	__compat_uid32_t uid;
diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 7516e4199b3c..d3523cf1b673 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -15,17 +15,24 @@
 #define compat_mode_t	compat_mode_t
 typedef u16		compat_mode_t;
 
+#define __compat_uid_t	__compat_uid_t
+typedef u16		__compat_uid_t;
+typedef u16		__compat_gid_t;
+
+#define compat_dev_t	compat_dev_t
+typedef u16		compat_dev_t;
+
+#define compat_ipc_pid_t compat_ipc_pid_t
+typedef u16		 compat_ipc_pid_t;
+
+#define compat_flock64	compat_flock64
+#define compat_statfs	compat_statfs
+
 #include <asm-generic/compat.h>
 
-#define COMPAT_USER_HZ		100
 #define COMPAT_UTS_MACHINE	"i686\0\0"
 
-typedef u16		__compat_uid_t;
-typedef u16		__compat_gid_t;
-typedef u16		compat_dev_t;
 typedef u16		compat_nlink_t;
-typedef u16		compat_ipc_pid_t;
-typedef __kernel_fsid_t	compat_fsid_t;
 
 struct compat_stat {
 	compat_dev_t	st_dev;
@@ -50,14 +57,6 @@ struct compat_stat {
 	u32		__unused5;
 };
 
-struct compat_flock {
-	short		l_type;
-	short		l_whence;
-	compat_off_t	l_start;
-	compat_off_t	l_len;
-	compat_pid_t	l_pid;
-};
-
 #define F_GETLK64	12	/*  using 'struct flock64' */
 #define F_SETLK64	13
 #define F_SETLKW64	14
@@ -89,68 +88,6 @@ struct compat_statfs {
 	int		f_spare[4];
 };
 
-#define COMPAT_RLIM_INFINITY		0xffffffff
-
-#define COMPAT_OFF_T_MAX	0x7fffffff
-
-struct compat_ipc64_perm {
-	compat_key_t key;
-	__compat_uid32_t uid;
-	__compat_gid32_t gid;
-	__compat_uid32_t cuid;
-	__compat_gid32_t cgid;
-	unsigned short mode;
-	unsigned short __pad1;
-	unsigned short seq;
-	unsigned short __pad2;
-	compat_ulong_t unused1;
-	compat_ulong_t unused2;
-};
-
-struct compat_semid64_ds {
-	struct compat_ipc64_perm sem_perm;
-	compat_ulong_t sem_otime;
-	compat_ulong_t sem_otime_high;
-	compat_ulong_t sem_ctime;
-	compat_ulong_t sem_ctime_high;
-	compat_ulong_t sem_nsems;
-	compat_ulong_t __unused3;
-	compat_ulong_t __unused4;
-};
-
-struct compat_msqid64_ds {
-	struct compat_ipc64_perm msg_perm;
-	compat_ulong_t msg_stime;
-	compat_ulong_t msg_stime_high;
-	compat_ulong_t msg_rtime;
-	compat_ulong_t msg_rtime_high;
-	compat_ulong_t msg_ctime;
-	compat_ulong_t msg_ctime_high;
-	compat_ulong_t msg_cbytes;
-	compat_ulong_t msg_qnum;
-	compat_ulong_t msg_qbytes;
-	compat_pid_t   msg_lspid;
-	compat_pid_t   msg_lrpid;
-	compat_ulong_t __unused4;
-	compat_ulong_t __unused5;
-};
-
-struct compat_shmid64_ds {
-	struct compat_ipc64_perm shm_perm;
-	compat_size_t  shm_segsz;
-	compat_ulong_t shm_atime;
-	compat_ulong_t shm_atime_high;
-	compat_ulong_t shm_dtime;
-	compat_ulong_t shm_dtime_high;
-	compat_ulong_t shm_ctime;
-	compat_ulong_t shm_ctime_high;
-	compat_pid_t   shm_cpid;
-	compat_pid_t   shm_lpid;
-	compat_ulong_t shm_nattch;
-	compat_ulong_t __unused4;
-	compat_ulong_t __unused5;
-};
-
 #ifdef CONFIG_X86_X32_ABI
 #define COMPAT_USE_64BIT_TIME \
 	(!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))
diff --git a/include/asm-generic/compat.h b/include/asm-generic/compat.h
index d46c0201cc34..32269059058a 100644
--- a/include/asm-generic/compat.h
+++ b/include/asm-generic/compat.h
@@ -2,6 +2,18 @@
 #ifndef __ASM_GENERIC_COMPAT_H
 #define __ASM_GENERIC_COMPAT_H
 
+#ifndef COMPAT_USER_HZ
+#define COMPAT_USER_HZ		100
+#endif
+
+#ifndef COMPAT_RLIM_INFINITY
+#define COMPAT_RLIM_INFINITY	0xffffffff
+#endif
+
+#ifndef COMPAT_OFF_T_MAX
+#define COMPAT_OFF_T_MAX	0x7fffffff
+#endif
+
 /* These types are common across all compat ABIs */
 typedef u32 compat_size_t;
 typedef s32 compat_ssize_t;
@@ -24,6 +36,11 @@ typedef u32 compat_caddr_t;
 typedef u32 compat_aio_context_t;
 typedef u32 compat_old_sigset_t;
 
+#ifndef __compat_uid_t
+typedef u32 __compat_uid_t;
+typedef u32 __compat_gid_t;
+#endif
+
 #ifndef __compat_uid32_t
 typedef u32 __compat_uid32_t;
 typedef u32 __compat_gid32_t;
@@ -47,4 +64,113 @@ typedef u32 compat_sigset_word;
 #define _COMPAT_NSIG_BPW 32
 #endif
 
+#ifndef compat_dev_t
+typedef u32 compat_dev_t;
+#endif
+
+#ifndef compat_ipc_pid_t
+typedef s32 compat_ipc_pid_t;
+#endif
+
+#ifndef compat_fsid_t
+typedef __kernel_fsid_t	compat_fsid_t;
+#endif
+
+#ifndef compat_flock
+struct compat_flock {
+	compat_short_t	l_type;
+	compat_short_t	l_whence;
+	compat_off_t	l_start;
+	compat_off_t	l_len;
+	compat_pid_t	l_pid;
+};
+#endif
+
+#ifndef compat_flock64
+struct compat_flock64 {
+	compat_short_t	l_type;
+	compat_short_t	l_whence;
+	compat_loff_t	l_start;
+	compat_loff_t	l_len;
+	compat_pid_t	l_pid;
+};
+#endif
+
+#ifndef compat_statfs
+struct compat_statfs {
+	compat_int_t	f_type;
+	compat_int_t	f_bsize;
+	compat_int_t	f_blocks;
+	compat_int_t	f_bfree;
+	compat_int_t	f_bavail;
+	compat_int_t	f_files;
+	compat_int_t	f_ffree;
+	compat_fsid_t	f_fsid;
+	compat_int_t	f_namelen;
+	compat_int_t	f_frsize;
+	compat_int_t	f_flags;
+	compat_int_t	f_spare[4];
+};
+#endif
+
+#ifndef compat_ipc64_perm
+struct compat_ipc64_perm {
+	compat_key_t key;
+	__compat_uid32_t uid;
+	__compat_gid32_t gid;
+	__compat_uid32_t cuid;
+	__compat_gid32_t cgid;
+	compat_mode_t	mode;
+	unsigned char	__pad1[4 - sizeof(compat_mode_t)];
+	compat_ushort_t	seq;
+	compat_ushort_t	__pad2;
+	compat_ulong_t	unused1;
+	compat_ulong_t	unused2;
+};
+
+struct compat_semid64_ds {
+	struct compat_ipc64_perm sem_perm;
+	compat_ulong_t sem_otime;
+	compat_ulong_t sem_otime_high;
+	compat_ulong_t sem_ctime;
+	compat_ulong_t sem_ctime_high;
+	compat_ulong_t sem_nsems;
+	compat_ulong_t __unused3;
+	compat_ulong_t __unused4;
+};
+
+struct compat_msqid64_ds {
+	struct compat_ipc64_perm msg_perm;
+	compat_ulong_t msg_stime;
+	compat_ulong_t msg_stime_high;
+	compat_ulong_t msg_rtime;
+	compat_ulong_t msg_rtime_high;
+	compat_ulong_t msg_ctime;
+	compat_ulong_t msg_ctime_high;
+	compat_ulong_t msg_cbytes;
+	compat_ulong_t msg_qnum;
+	compat_ulong_t msg_qbytes;
+	compat_pid_t   msg_lspid;
+	compat_pid_t   msg_lrpid;
+	compat_ulong_t __unused4;
+	compat_ulong_t __unused5;
+};
+
+struct compat_shmid64_ds {
+	struct compat_ipc64_perm shm_perm;
+	compat_size_t  shm_segsz;
+	compat_ulong_t shm_atime;
+	compat_ulong_t shm_atime_high;
+	compat_ulong_t shm_dtime;
+	compat_ulong_t shm_dtime_high;
+	compat_ulong_t shm_ctime;
+	compat_ulong_t shm_ctime_high;
+	compat_pid_t   shm_cpid;
+	compat_pid_t   shm_lpid;
+	compat_ulong_t shm_nattch;
+	compat_ulong_t __unused4;
+	compat_ulong_t __unused5;
+};
+#endif
+
 #endif
-- 
2.25.1

[PATCH V4 04/17] syscalls: compat: Fix the missing part for __SYSCALL_COMPAT

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Make "uapi asm unistd.h" could be used for architectures' COMPAT
mode. The __SYSCALL_COMPAT is first used in riscv.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 include/uapi/asm-generic/unistd.h       | 4 ++--
 tools/include/uapi/asm-generic/unistd.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 1c48b0ae3ba3..45fa180cc56a 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -383,7 +383,7 @@ __SYSCALL(__NR_syslog, sys_syslog)
 
 /* kernel/ptrace.c */
 #define __NR_ptrace 117
-__SYSCALL(__NR_ptrace, sys_ptrace)
+__SC_COMP(__NR_ptrace, sys_ptrace, compat_sys_ptrace)
 
 /* kernel/sched/core.c */
 #define __NR_sched_setparam 118
@@ -779,7 +779,7 @@ __SYSCALL(__NR_rseq, sys_rseq)
 #define __NR_kexec_file_load 294
 __SYSCALL(__NR_kexec_file_load,     sys_kexec_file_load)
 /* 295 through 402 are unassigned to sync up with generic numbers, don't use */
-#if __BITS_PER_LONG == 32
+#if defined(__SYSCALL_COMPAT) || __BITS_PER_LONG == 32
 #define __NR_clock_gettime64 403
 __SYSCALL(__NR_clock_gettime64, sys_clock_gettime)
 #define __NR_clock_settime64 404
diff --git a/tools/include/uapi/asm-generic/unistd.h b/tools/include/uapi/asm-generic/unistd.h
index 1c48b0ae3ba3..45fa180cc56a 100644
--- a/tools/include/uapi/asm-generic/unistd.h
+++ b/tools/include/uapi/asm-generic/unistd.h
@@ -383,7 +383,7 @@ __SYSCALL(__NR_syslog, sys_syslog)
 
 /* kernel/ptrace.c */
 #define __NR_ptrace 117
-__SYSCALL(__NR_ptrace, sys_ptrace)
+__SC_COMP(__NR_ptrace, sys_ptrace, compat_sys_ptrace)
 
 /* kernel/sched/core.c */
 #define __NR_sched_setparam 118
@@ -779,7 +779,7 @@ __SYSCALL(__NR_rseq, sys_rseq)
 #define __NR_kexec_file_load 294
 __SYSCALL(__NR_kexec_file_load,     sys_kexec_file_load)
 /* 295 through 402 are unassigned to sync up with generic numbers, don't use */
-#if __BITS_PER_LONG == 32
+#if defined(__SYSCALL_COMPAT) || __BITS_PER_LONG == 32
 #define __NR_clock_gettime64 403
 __SYSCALL(__NR_clock_gettime64, sys_clock_gettime)
 #define __NR_clock_settime64 404
-- 
2.25.1

[PATCH V4 05/17] riscv: Fixup difference with defconfig

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Let's follow the origin patch's spirit:

The only difference between rv32_defconfig and defconfig is that
rv32_defconfig has  CONFIG_ARCH_RV32I=y.

This is helpful to compare rv64-compat-rv32 v.s. rv32-linux.

Fixes: 1b937e8faa87ccfb ("RISC-V: Add separate defconfig for 32bit systems")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anup Patel <anup.patel@wdc.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/Makefile               |   4 +
 arch/riscv/configs/rv32_defconfig | 135 ------------------------------
 2 files changed, 4 insertions(+), 135 deletions(-)
 delete mode 100644 arch/riscv/configs/rv32_defconfig

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 8a107ed18b0d..a02e588c4947 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -148,3 +148,7 @@ PHONY += rv64_randconfig
 rv64_randconfig:
 	$(Q)$(MAKE) KCONFIG_ALLCONFIG=$(srctree)/arch/riscv/configs/64-bit.config \
 		-f $(srctree)/Makefile randconfig
+
+PHONY += rv32_defconfig
+rv32_defconfig:
+	$(Q)$(MAKE) -f $(srctree)/Makefile defconfig 32-bit.config
diff --git a/arch/riscv/configs/rv32_defconfig b/arch/riscv/configs/rv32_defconfig
deleted file mode 100644
index 8b56a7f1eb06..000000000000
--- a/arch/riscv/configs/rv32_defconfig
+++ /dev/null
@@ -1,135 +0,0 @@
-CONFIG_SYSVIPC=y
-CONFIG_POSIX_MQUEUE=y
-CONFIG_NO_HZ_IDLE=y
-CONFIG_HIGH_RES_TIMERS=y
-CONFIG_BPF_SYSCALL=y
-CONFIG_IKCONFIG=y
-CONFIG_IKCONFIG_PROC=y
-CONFIG_CGROUPS=y
-CONFIG_CGROUP_SCHED=y
-CONFIG_CFS_BANDWIDTH=y
-CONFIG_CGROUP_BPF=y
-CONFIG_NAMESPACES=y
-CONFIG_USER_NS=y
-CONFIG_CHECKPOINT_RESTORE=y
-CONFIG_BLK_DEV_INITRD=y
-CONFIG_EXPERT=y
-# CONFIG_SYSFS_SYSCALL is not set
-CONFIG_SOC_SIFIVE=y
-CONFIG_SOC_VIRT=y
-CONFIG_ARCH_RV32I=y
-CONFIG_SMP=y
-CONFIG_HOTPLUG_CPU=y
-CONFIG_VIRTUALIZATION=y
-CONFIG_KVM=m
-CONFIG_JUMP_LABEL=y
-CONFIG_MODULES=y
-CONFIG_MODULE_UNLOAD=y
-CONFIG_NET=y
-CONFIG_PACKET=y
-CONFIG_UNIX=y
-CONFIG_INET=y
-CONFIG_IP_MULTICAST=y
-CONFIG_IP_ADVANCED_ROUTER=y
-CONFIG_IP_PNP=y
-CONFIG_IP_PNP_DHCP=y
-CONFIG_IP_PNP_BOOTP=y
-CONFIG_IP_PNP_RARP=y
-CONFIG_NETLINK_DIAG=y
-CONFIG_NET_9P=y
-CONFIG_NET_9P_VIRTIO=y
-CONFIG_PCI=y
-CONFIG_PCIEPORTBUS=y
-CONFIG_PCI_HOST_GENERIC=y
-CONFIG_PCIE_XILINX=y
-CONFIG_DEVTMPFS=y
-CONFIG_DEVTMPFS_MOUNT=y
-CONFIG_BLK_DEV_LOOP=y
-CONFIG_VIRTIO_BLK=y
-CONFIG_BLK_DEV_SD=y
-CONFIG_BLK_DEV_SR=y
-CONFIG_SCSI_VIRTIO=y
-CONFIG_ATA=y
-CONFIG_SATA_AHCI=y
-CONFIG_SATA_AHCI_PLATFORM=y
-CONFIG_NETDEVICES=y
-CONFIG_VIRTIO_NET=y
-CONFIG_MACB=y
-CONFIG_E1000E=y
-CONFIG_R8169=y
-CONFIG_MICROSEMI_PHY=y
-CONFIG_INPUT_MOUSEDEV=y
-CONFIG_SERIAL_8250=y
-CONFIG_SERIAL_8250_CONSOLE=y
-CONFIG_SERIAL_OF_PLATFORM=y
-CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
-CONFIG_HVC_RISCV_SBI=y
-CONFIG_VIRTIO_CONSOLE=y
-CONFIG_HW_RANDOM=y
-CONFIG_HW_RANDOM_VIRTIO=y
-CONFIG_SPI=y
-CONFIG_SPI_SIFIVE=y
-# CONFIG_PTP_1588_CLOCK is not set
-CONFIG_DRM=y
-CONFIG_DRM_RADEON=y
-CONFIG_DRM_VIRTIO_GPU=y
-CONFIG_FB=y
-CONFIG_FRAMEBUFFER_CONSOLE=y
-CONFIG_USB=y
-CONFIG_USB_XHCI_HCD=y
-CONFIG_USB_XHCI_PLATFORM=y
-CONFIG_USB_EHCI_HCD=y
-CONFIG_USB_EHCI_HCD_PLATFORM=y
-CONFIG_USB_OHCI_HCD=y
-CONFIG_USB_OHCI_HCD_PLATFORM=y
-CONFIG_USB_STORAGE=y
-CONFIG_USB_UAS=y
-CONFIG_MMC=y
-CONFIG_MMC_SPI=y
-CONFIG_RTC_CLASS=y
-CONFIG_VIRTIO_PCI=y
-CONFIG_VIRTIO_BALLOON=y
-CONFIG_VIRTIO_INPUT=y
-CONFIG_VIRTIO_MMIO=y
-CONFIG_RPMSG_CHAR=y
-CONFIG_RPMSG_VIRTIO=y
-CONFIG_EXT4_FS=y
-CONFIG_EXT4_FS_POSIX_ACL=y
-CONFIG_AUTOFS4_FS=y
-CONFIG_MSDOS_FS=y
-CONFIG_VFAT_FS=y
-CONFIG_TMPFS=y
-CONFIG_TMPFS_POSIX_ACL=y
-CONFIG_NFS_FS=y
-CONFIG_NFS_V4=y
-CONFIG_NFS_V4_1=y
-CONFIG_NFS_V4_2=y
-CONFIG_ROOT_NFS=y
-CONFIG_9P_FS=y
-CONFIG_CRYPTO_USER_API_HASH=y
-CONFIG_CRYPTO_DEV_VIRTIO=y
-CONFIG_PRINTK_TIME=y
-CONFIG_DEBUG_FS=y
-CONFIG_DEBUG_PAGEALLOC=y
-CONFIG_SCHED_STACK_END_CHECK=y
-CONFIG_DEBUG_VM=y
-CONFIG_DEBUG_VM_PGFLAGS=y
-CONFIG_DEBUG_MEMORY_INIT=y
-CONFIG_DEBUG_PER_CPU_MAPS=y
-CONFIG_SOFTLOCKUP_DETECTOR=y
-CONFIG_WQ_WATCHDOG=y
-CONFIG_DEBUG_TIMEKEEPING=y
-CONFIG_DEBUG_RT_MUTEXES=y
-CONFIG_DEBUG_SPINLOCK=y
-CONFIG_DEBUG_MUTEXES=y
-CONFIG_DEBUG_RWSEMS=y
-CONFIG_DEBUG_ATOMIC_SLEEP=y
-CONFIG_STACKTRACE=y
-CONFIG_DEBUG_LIST=y
-CONFIG_DEBUG_PLIST=y
-CONFIG_DEBUG_SG=y
-# CONFIG_RCU_TRACE is not set
-CONFIG_RCU_EQS_DEBUG=y
-# CONFIG_FTRACE is not set
-# CONFIG_RUNTIME_TESTING_MENU is not set
-CONFIG_MEMTEST=y
-- 
2.25.1

[PATCH V4 06/17] riscv: compat: Add basic compat date type implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Implement asm/compat.h for struct compat_xxx, RLIM_INFINITY,
OFF_T_MAX, is_compat_task, compat_user_regset, regset convert.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/riscv/include/asm/compat.h      | 135 +++++++++++++++++++++++++++
 arch/riscv/include/asm/thread_info.h |   1 +
 2 files changed, 136 insertions(+)
 create mode 100644 arch/riscv/include/asm/compat.h

diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
new file mode 100644
index 000000000000..3d3e89629e3b
--- /dev/null
+++ b/arch/riscv/include/asm/compat.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_COMPAT_H
+#define __ASM_COMPAT_H
+
+#define COMPAT_UTS_MACHINE	"riscv\0\0"
+
+#define COMPAT_RLIM_INFINITY	0x7fffffff
+
+/*
+ * Architecture specific compatibility types
+ */
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <asm-generic/compat.h>
+
+#define F_GETLK64	12
+#define F_SETLK64	13
+#define F_SETLKW64	14
+
+static inline int is_compat_task(void)
+{
+	return test_thread_flag(TIF_32BIT);
+}
+
+struct compat_user_regs_struct {
+	compat_ulong_t pc;
+	compat_ulong_t ra;
+	compat_ulong_t sp;
+	compat_ulong_t gp;
+	compat_ulong_t tp;
+	compat_ulong_t t0;
+	compat_ulong_t t1;
+	compat_ulong_t t2;
+	compat_ulong_t s0;
+	compat_ulong_t s1;
+	compat_ulong_t a0;
+	compat_ulong_t a1;
+	compat_ulong_t a2;
+	compat_ulong_t a3;
+	compat_ulong_t a4;
+	compat_ulong_t a5;
+	compat_ulong_t a6;
+	compat_ulong_t a7;
+	compat_ulong_t s2;
+	compat_ulong_t s3;
+	compat_ulong_t s4;
+	compat_ulong_t s5;
+	compat_ulong_t s6;
+	compat_ulong_t s7;
+	compat_ulong_t s8;
+	compat_ulong_t s9;
+	compat_ulong_t s10;
+	compat_ulong_t s11;
+	compat_ulong_t t3;
+	compat_ulong_t t4;
+	compat_ulong_t t5;
+	compat_ulong_t t6;
+};
+
+static inline void regs_to_cregs(struct compat_user_regs_struct *cregs,
+				 struct pt_regs *regs)
+{
+	cregs->pc	= (compat_ulong_t) regs->epc;
+	cregs->ra	= (compat_ulong_t) regs->ra;
+	cregs->sp	= (compat_ulong_t) regs->sp;
+	cregs->gp	= (compat_ulong_t) regs->gp;
+	cregs->tp	= (compat_ulong_t) regs->tp;
+	cregs->t0	= (compat_ulong_t) regs->t0;
+	cregs->t1	= (compat_ulong_t) regs->t1;
+	cregs->t2	= (compat_ulong_t) regs->t2;
+	cregs->s0	= (compat_ulong_t) regs->s0;
+	cregs->s1	= (compat_ulong_t) regs->s1;
+	cregs->a0	= (compat_ulong_t) regs->a0;
+	cregs->a1	= (compat_ulong_t) regs->a1;
+	cregs->a2	= (compat_ulong_t) regs->a2;
+	cregs->a3	= (compat_ulong_t) regs->a3;
+	cregs->a4	= (compat_ulong_t) regs->a4;
+	cregs->a5	= (compat_ulong_t) regs->a5;
+	cregs->a6	= (compat_ulong_t) regs->a6;
+	cregs->a7	= (compat_ulong_t) regs->a7;
+	cregs->s2	= (compat_ulong_t) regs->s2;
+	cregs->s3	= (compat_ulong_t) regs->s3;
+	cregs->s4	= (compat_ulong_t) regs->s4;
+	cregs->s5	= (compat_ulong_t) regs->s5;
+	cregs->s6	= (compat_ulong_t) regs->s6;
+	cregs->s7	= (compat_ulong_t) regs->s7;
+	cregs->s8	= (compat_ulong_t) regs->s8;
+	cregs->s9	= (compat_ulong_t) regs->s9;
+	cregs->s10	= (compat_ulong_t) regs->s10;
+	cregs->s11	= (compat_ulong_t) regs->s11;
+	cregs->t3	= (compat_ulong_t) regs->t3;
+	cregs->t4	= (compat_ulong_t) regs->t4;
+	cregs->t5	= (compat_ulong_t) regs->t5;
+	cregs->t6	= (compat_ulong_t) regs->t6;
+};
+
+static inline void cregs_to_regs(struct compat_user_regs_struct *cregs,
+				 struct pt_regs *regs)
+{
+	regs->epc	= (unsigned long) cregs->pc;
+	regs->ra	= (unsigned long) cregs->ra;
+	regs->sp	= (unsigned long) cregs->sp;
+	regs->gp	= (unsigned long) cregs->gp;
+	regs->tp	= (unsigned long) cregs->tp;
+	regs->t0	= (unsigned long) cregs->t0;
+	regs->t1	= (unsigned long) cregs->t1;
+	regs->t2	= (unsigned long) cregs->t2;
+	regs->s0	= (unsigned long) cregs->s0;
+	regs->s1	= (unsigned long) cregs->s1;
+	regs->a0	= (unsigned long) cregs->a0;
+	regs->a1	= (unsigned long) cregs->a1;
+	regs->a2	= (unsigned long) cregs->a2;
+	regs->a3	= (unsigned long) cregs->a3;
+	regs->a4	= (unsigned long) cregs->a4;
+	regs->a5	= (unsigned long) cregs->a5;
+	regs->a6	= (unsigned long) cregs->a6;
+	regs->a7	= (unsigned long) cregs->a7;
+	regs->s2	= (unsigned long) cregs->s2;
+	regs->s3	= (unsigned long) cregs->s3;
+	regs->s4	= (unsigned long) cregs->s4;
+	regs->s5	= (unsigned long) cregs->s5;
+	regs->s6	= (unsigned long) cregs->s6;
+	regs->s7	= (unsigned long) cregs->s7;
+	regs->s8	= (unsigned long) cregs->s8;
+	regs->s9	= (unsigned long) cregs->s9;
+	regs->s10	= (unsigned long) cregs->s10;
+	regs->s11	= (unsigned long) cregs->s11;
+	regs->t3	= (unsigned long) cregs->t3;
+	regs->t4	= (unsigned long) cregs->t4;
+	regs->t5	= (unsigned long) cregs->t5;
+	regs->t6	= (unsigned long) cregs->t6;
+};
+
+#endif /* __ASM_COMPAT_H */
diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index 60da0dcacf14..9392e35c689d 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -91,6 +91,7 @@ struct thread_info {
 #define TIF_SECCOMP		8	/* syscall secure computing */
 #define TIF_NOTIFY_SIGNAL	9	/* signal notifications exist */
 #define TIF_UPROBE		10	/* uprobe breakpoint or singlestep */
+#define TIF_32BIT		11	/* 32bit process */
 
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
-- 
2.25.1

[PATCH V4 07/17] riscv: compat: Re-implement TASK_SIZE for COMPAT_32BIT

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Make TASK_SIZE from const to dynamic detect TIF_32BIT flag
function. Refer to arm64 to implement DEFAULT_MAP_WINDOW_64 for
efi-stub.

Limit 32-bit compatible process in 0-2GB virtual address range
(which is enough for real scenarios), because it could avoid
address sign extend problem when 32-bit enter 64-bit and ease
software design.

The standard 32-bit TASK_SIZE is 0x9dc00000:FIXADDR_START, and
compared to a compatible 32-bit, it increases 476MB for the
application's virtual address.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/riscv/include/asm/pgtable.h | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 7e949f25c933..f0d125ea3ceb 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -704,8 +704,17 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
  */
 #ifdef CONFIG_64BIT
-#define TASK_SIZE      (PGDIR_SIZE * PTRS_PER_PGD / 2)
-#define TASK_SIZE_MIN  (PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
+#define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
+#define TASK_SIZE_MIN	(PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
+
+#ifdef CONFIG_COMPAT
+#define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
+#define TASK_SIZE	(test_thread_flag(TIF_32BIT) ? \
+			 TASK_SIZE_32 : TASK_SIZE_64)
+#else
+#define TASK_SIZE	TASK_SIZE_64
+#endif
+
 #else
 #define TASK_SIZE	FIXADDR_START
 #define TASK_SIZE_MIN	TASK_SIZE
-- 
2.25.1

[PATCH V4 08/17] riscv: compat: syscall: Add compat_sys_call_table implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Implement compat sys_call_table and some system call functions:
truncate64, ftruncate64, fallocate, pread64, pwrite64,
sync_file_range, readahead, fadvise64_64 which need argument
translation.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/riscv/include/asm/syscall.h         |  1 +
 arch/riscv/include/asm/unistd.h          | 11 +++++++
 arch/riscv/include/uapi/asm/unistd.h     |  2 +-
 arch/riscv/kernel/Makefile               |  1 +
 arch/riscv/kernel/compat_syscall_table.c | 19 ++++++++++++
 arch/riscv/kernel/sys_riscv.c            |  6 ++--
 fs/open.c                                | 24 +++++++++++++++
 fs/read_write.c                          | 16 ++++++++++
 fs/sync.c                                |  9 ++++++
 include/asm-generic/compat.h             |  7 +++++
 include/linux/compat.h                   | 37 ++++++++++++++++++++++++
 mm/fadvise.c                             | 11 +++++++
 mm/readahead.c                           |  7 +++++
 13 files changed, 148 insertions(+), 3 deletions(-)
 create mode 100644 arch/riscv/kernel/compat_syscall_table.c

diff --git a/arch/riscv/include/asm/syscall.h b/arch/riscv/include/asm/syscall.h
index 7ac6a0e275f2..384a63b86420 100644
--- a/arch/riscv/include/asm/syscall.h
+++ b/arch/riscv/include/asm/syscall.h
@@ -16,6 +16,7 @@
 
 /* The array of function pointers for syscalls. */
 extern void * const sys_call_table[];
+extern void * const compat_sys_call_table[];
 
 /*
  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
diff --git a/arch/riscv/include/asm/unistd.h b/arch/riscv/include/asm/unistd.h
index 6c316093a1e5..5ddac412b578 100644
--- a/arch/riscv/include/asm/unistd.h
+++ b/arch/riscv/include/asm/unistd.h
@@ -11,6 +11,17 @@
 #define __ARCH_WANT_SYS_CLONE
 #define __ARCH_WANT_MEMFD_SECRET
 
+#ifdef CONFIG_COMPAT
+#define __ARCH_WANT_COMPAT_TRUNCATE64
+#define __ARCH_WANT_COMPAT_FTRUNCATE64
+#define __ARCH_WANT_COMPAT_FALLOCATE
+#define __ARCH_WANT_COMPAT_PREAD64
+#define __ARCH_WANT_COMPAT_PWRITE64
+#define __ARCH_WANT_COMPAT_SYNC_FILE_RANGE
+#define __ARCH_WANT_COMPAT_READAHEAD
+#define __ARCH_WANT_COMPAT_FADVISE64_64
+#endif
+
 #include <uapi/asm/unistd.h>
 
 #define NR_syscalls (__NR_syscalls)
diff --git a/arch/riscv/include/uapi/asm/unistd.h b/arch/riscv/include/uapi/asm/unistd.h
index 8062996c2dfd..c9e50eed14aa 100644
--- a/arch/riscv/include/uapi/asm/unistd.h
+++ b/arch/riscv/include/uapi/asm/unistd.h
@@ -15,7 +15,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-#ifdef __LP64__
+#if defined(__LP64__) && !defined(__SYSCALL_COMPAT)
 #define __ARCH_WANT_NEW_STAT
 #define __ARCH_WANT_SET_GET_RLIMIT
 #endif /* __LP64__ */
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 612556faa527..954dc7043ad2 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -66,3 +66,4 @@ obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 
 obj-$(CONFIG_EFI)		+= efi.o
+obj-$(CONFIG_COMPAT)		+= compat_syscall_table.o
diff --git a/arch/riscv/kernel/compat_syscall_table.c b/arch/riscv/kernel/compat_syscall_table.c
new file mode 100644
index 000000000000..651f2b009c28
--- /dev/null
+++ b/arch/riscv/kernel/compat_syscall_table.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#define __SYSCALL_COMPAT
+
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <asm-generic/mman-common.h>
+#include <asm-generic/syscalls.h>
+#include <asm/syscall.h>
+
+#undef __SYSCALL
+#define __SYSCALL(nr, call)      [nr] = (call),
+
+asmlinkage long compat_sys_rt_sigreturn(void);
+
+void * const compat_sys_call_table[__NR_syscalls] = {
+	[0 ... __NR_syscalls - 1] = sys_ni_syscall,
+#include <asm/unistd.h>
+};
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index 12f8a7fce78b..9c0194f176fc 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -33,7 +33,9 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
 {
 	return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 0);
 }
-#else
+#endif
+
+#if defined(CONFIG_32BIT) || defined(CONFIG_COMPAT)
 SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
 	unsigned long, prot, unsigned long, flags,
 	unsigned long, fd, off_t, offset)
@@ -44,7 +46,7 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, unsigned long, len,
 	 */
 	return riscv_sys_mmap(addr, len, prot, flags, fd, offset, 12);
 }
-#endif /* !CONFIG_64BIT */
+#endif
 
 /*
  * Allows the instruction cache to be flushed from userspace.  Despite RISC-V
diff --git a/fs/open.c b/fs/open.c
index 9ff2f621b760..b25613f7c0a7 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -224,6 +224,21 @@ SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
 }
 #endif /* BITS_PER_LONG == 32 */
 
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_TRUNCATE64)
+COMPAT_SYSCALL_DEFINE3(truncate64, const char __user *, pathname,
+		       compat_arg_u64_dual(length))
+{
+	return ksys_truncate(pathname, compat_arg_u64_glue(length));
+}
+#endif
+
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FTRUNCATE64)
+COMPAT_SYSCALL_DEFINE3(ftruncate64, unsigned int, fd,
+		       compat_arg_u64_dual(length))
+{
+	return ksys_ftruncate(fd, compat_arg_u64_glue(length));
+}
+#endif
 
 int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 {
@@ -339,6 +354,15 @@ SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
 	return ksys_fallocate(fd, mode, offset, len);
 }
 
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FALLOCATE)
+COMPAT_SYSCALL_DEFINE6(fallocate, int, fd, int, mode, compat_arg_u64_dual(offset),
+		       compat_arg_u64_dual(len))
+{
+	return ksys_fallocate(fd, mode, compat_arg_u64_glue(offset),
+			      compat_arg_u64_glue(len));
+}
+#endif
+
 /*
  * access() needs to use the real uid/gid, not the effective uid/gid.
  * We do this by temporarily clearing all FS-related capabilities and
diff --git a/fs/read_write.c b/fs/read_write.c
index 0074afa7ecb3..548657c462e8 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -681,6 +681,14 @@ SYSCALL_DEFINE4(pread64, unsigned int, fd, char __user *, buf,
 	return ksys_pread64(fd, buf, count, pos);
 }
 
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PREAD64)
+COMPAT_SYSCALL_DEFINE5(pread64, unsigned int, fd, char __user *, buf,
+		       size_t, count, compat_arg_u64_dual(pos))
+{
+	return ksys_pread64(fd, buf, count, compat_arg_u64_glue(pos));
+}
+#endif
+
 ssize_t ksys_pwrite64(unsigned int fd, const char __user *buf,
 		      size_t count, loff_t pos)
 {
@@ -707,6 +715,14 @@ SYSCALL_DEFINE4(pwrite64, unsigned int, fd, const char __user *, buf,
 	return ksys_pwrite64(fd, buf, count, pos);
 }
 
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_PWRITE64)
+COMPAT_SYSCALL_DEFINE5(pwrite64, unsigned int, fd, const char __user *, buf,
+		       size_t, count, compat_arg_u64_dual(pos))
+{
+	return ksys_pwrite64(fd, buf, count, compat_arg_u64_glue(pos));
+}
+#endif
+
 static ssize_t do_iter_readv_writev(struct file *filp, struct iov_iter *iter,
 		loff_t *ppos, int type, rwf_t flags)
 {
diff --git a/fs/sync.c b/fs/sync.c
index 3ce8e2137f31..75edb7a664e5 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -367,6 +367,15 @@ SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
 	return ksys_sync_file_range(fd, offset, nbytes, flags);
 }
 
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_SYNC_FILE_RANGE)
+COMPAT_SYSCALL_DEFINE6(sync_file_range, int, fd, compat_arg_u64_dual(offset),
+		       compat_arg_u64_dual(nbytes), unsigned int, flags)
+{
+	return ksys_sync_file_range(fd, compat_arg_u64_glue(offset),
+				    compat_arg_u64_glue(nbytes), flags);
+}
+#endif
+
 /* It would be nice if people remember that not all the world's an i386
    when they introduce new system calls */
 SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags,
diff --git a/include/asm-generic/compat.h b/include/asm-generic/compat.h
index 32269059058a..cdf1124a4883 100644
--- a/include/asm-generic/compat.h
+++ b/include/asm-generic/compat.h
@@ -14,6 +14,13 @@
 #define COMPAT_OFF_T_MAX	0x7fffffff
 #endif
 
+#ifndef compat_arg_u64
+#define compat_arg_u64(name)		u32  name##_lo, u32  name##_hi
+#define compat_arg_u64_dual(name)	u32, name##_lo, u32, name##_hi
+#define compat_arg_u64_glue(name)	(((u64)name##_hi << 32) | \
+					 ((u64)name##_lo & 0xffffffffUL))
+#endif
+
 /* These types are common across all compat ABIs */
 typedef u32 compat_size_t;
 typedef s32 compat_ssize_t;
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 1c758b0e0359..841d882c41e2 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -895,6 +895,43 @@ asmlinkage long compat_sys_sigaction(int sig,
 /* obsolete: net/socket.c */
 asmlinkage long compat_sys_socketcall(int call, u32 __user *args);
 
+#ifdef __ARCH_WANT_COMPAT_TRUNCATE64
+asmlinkage long compat_sys_truncate64(const char __user *pathname, compat_arg_u64(len));
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_FTRUNCATE64
+asmlinkage long compat_sys_ftruncate64(unsigned int fd, compat_arg_u64(len));
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_FALLOCATE
+asmlinkage long compat_sys_fallocate(int fd, int mode, compat_arg_u64(offset),
+				     compat_arg_u64(len));
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_PREAD64
+asmlinkage long compat_sys_pread64(unsigned int fd, char __user * buf, size_t count,
+				   compat_arg_u64(pos));
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_PWRITE64
+asmlinkage long compat_sys_pwrite64(unsigned int fd, const char __user * buf, size_t count,
+				    compat_arg_u64(pos));
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_SYNC_FILE_RANGE
+asmlinkage long compat_sys_sync_file_range(int fd, compat_arg_u64(pos),
+					   compat_arg_u64(nbytes), unsigned int flags);
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_FADVISE64_64
+asmlinkage long compat_sys_fadvise64_64(int fd, int advice, compat_arg_u64(pos),
+					compat_arg_u64(len));
+#endif
+
+#ifdef __ARCH_WANT_COMPAT_READAHEAD
+asmlinkage long compat_sys_readahead(int fd, compat_arg_u64(offset), size_t count);
+#endif
+
 #endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
 
 /**
diff --git a/mm/fadvise.c b/mm/fadvise.c
index d6baa4f451c5..8950f7c05d20 100644
--- a/mm/fadvise.c
+++ b/mm/fadvise.c
@@ -215,5 +215,16 @@ SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
 	return ksys_fadvise64_64(fd, offset, len, advice);
 }
 
+#endif
+
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_FADVISE64_64)
+
+COMPAT_SYSCALL_DEFINE6(fadvise64_64, int, fd, int, advice, compat_arg_u64_dual(offset),
+		       compat_arg_u64_dual(len))
+{
+	return ksys_fadvise64_64(fd, compat_arg_u64_glue(offset),
+				 compat_arg_u64_glue(len), advice);
+}
+
 #endif
 #endif
diff --git a/mm/readahead.c b/mm/readahead.c
index cf0dcf89eb69..9adf57044299 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -640,6 +640,13 @@ SYSCALL_DEFINE3(readahead, int, fd, loff_t, offset, size_t, count)
 	return ksys_readahead(fd, offset, count);
 }
 
+#if defined(CONFIG_COMPAT) && defined(__ARCH_WANT_COMPAT_READAHEAD)
+COMPAT_SYSCALL_DEFINE4(readahead, int, fd, compat_arg_u64_dual(offset), size_t, count)
+{
+	return ksys_readahead(fd, compat_arg_u64_glue(offset), count);
+}
+#endif
+
 /**
  * readahead_expand - Expand a readahead request
  * @ractl: The request to be expanded
-- 
2.25.1

[PATCH V4 09/17] riscv: compat: syscall: Add entry.S implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Implement the entry of compat_sys_call_table[] in asm. Ref to
riscv-privileged spec 4.1.1 Supervisor Status Register (sstatus):

 BIT[32:33] = UXL[1:0]:
 - 1:32
 - 2:64
 - 3:128

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/riscv/include/asm/csr.h |  7 +++++++
 arch/riscv/kernel/entry.S    | 18 ++++++++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index ae711692eec9..eed96fa62d66 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -36,6 +36,13 @@
 #define SR_SD		_AC(0x8000000000000000, UL) /* FS/XS dirty */
 #endif
 
+#ifdef CONFIG_COMPAT
+#define SR_UXL		_AC(0x300000000, UL) /* XLEN mask for U-mode */
+#define SR_UXL_32	_AC(0x100000000, UL) /* XLEN = 32 for U-mode */
+#define SR_UXL_64	_AC(0x200000000, UL) /* XLEN = 64 for U-mode */
+#define SR_UXL_SHIFT	32
+#endif
+
 /* SATP flags */
 #ifndef CONFIG_64BIT
 #define SATP_PPN	_AC(0x003FFFFF, UL)
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index ed29e9c8f660..1951743f09b3 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -207,13 +207,27 @@ check_syscall_nr:
 	 * Syscall number held in a7.
 	 * If syscall number is above allowed value, redirect to ni_syscall.
 	 */
-	bgeu a7, t0, 1f
+	bgeu a7, t0, 3f
+#ifdef CONFIG_COMPAT
+	REG_L s0, PT_STATUS(sp)
+	srli s0, s0, SR_UXL_SHIFT
+	andi s0, s0, (SR_UXL >> SR_UXL_SHIFT)
+	li t0, (SR_UXL_32 >> SR_UXL_SHIFT)
+	sub t0, s0, t0
+	bnez t0, 1f
+
+	/* Call compat_syscall */
+	la s0, compat_sys_call_table
+	j 2f
+1:
+#endif
 	/* Call syscall */
 	la s0, sys_call_table
+2:
 	slli t0, a7, RISCV_LGPTR
 	add s0, s0, t0
 	REG_L s0, 0(s0)
-1:
+3:
 	jalr s0
 
 ret_from_syscall:
-- 
2.25.1

[PATCH V4 10/17] riscv: compat: process: Add UXL_32 support in start_thread

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

If the current task is in COMPAT mode, set SR_UXL_32 in status for
returning userspace. We need CONFIG _COMPAT to prevent compiling
errors with rv32 defconfig.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/kernel/process.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 03ac3aa611f5..1a666ad299b4 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -97,6 +97,11 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 	}
 	regs->epc = pc;
 	regs->sp = sp;
+
+#ifdef CONFIG_COMPAT
+	if (is_compat_task())
+		regs->status |= SR_UXL_32;
+#endif
 }
 
 void flush_thread(void)
-- 
2.25.1

[PATCH V4 11/17] riscv: compat: Add elf.h implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Implement necessary type and macro for compat elf. See the code
comment for detail.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/riscv/include/asm/elf.h | 48 +++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index f53c40026c7a..c1fc31629d40 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -8,6 +8,8 @@
 #ifndef _ASM_RISCV_ELF_H
 #define _ASM_RISCV_ELF_H
 
+#include <uapi/linux/elf.h>
+#include <linux/compat.h>
 #include <uapi/asm/elf.h>
 #include <asm/auxvec.h>
 #include <asm/byteorder.h>
@@ -18,11 +20,13 @@
  */
 #define ELF_ARCH	EM_RISCV
 
+#ifndef ELF_CLASS
 #ifdef CONFIG_64BIT
 #define ELF_CLASS	ELFCLASS64
 #else
 #define ELF_CLASS	ELFCLASS32
 #endif
+#endif
 
 #define ELF_DATA	ELFDATA2LSB
 
@@ -31,6 +35,15 @@
  */
 #define elf_check_arch(x) ((x)->e_machine == EM_RISCV)
 
+#ifdef CONFIG_COMPAT
+/*
+ * Use the same code with elf_check_arch, because elf32_hdr &
+ * elf64_hdr e_machine's offset are different. The checker is
+ * a little bit simple compare to other architectures.
+ */
+#define compat_elf_check_arch(x) ((x)->e_machine == EM_RISCV)
+#endif
+
 #define CORE_DUMP_USE_REGSET
 #define ELF_EXEC_PAGESIZE	(PAGE_SIZE)
 
@@ -43,8 +56,14 @@
 #define ELF_ET_DYN_BASE		((TASK_SIZE / 3) * 2)
 
 #ifdef CONFIG_64BIT
+#ifdef CONFIG_COMPAT
+#define STACK_RND_MASK		(test_thread_flag(TIF_32BIT) ? \
+				 0x7ff >> (PAGE_SHIFT - 12) : \
+				 0x3ffff >> (PAGE_SHIFT - 12))
+#else
 #define STACK_RND_MASK		(0x3ffff >> (PAGE_SHIFT - 12))
 #endif
+#endif
 /*
  * This yields a mask that user programs can use to figure out what
  * instruction set this CPU supports.  This could be done in user space,
@@ -60,11 +79,19 @@ extern unsigned long elf_hwcap;
  */
 #define ELF_PLATFORM	(NULL)
 
+#define COMPAT_ELF_PLATFORM	(NULL)
+
 #ifdef CONFIG_MMU
 #define ARCH_DLINFO						\
 do {								\
+	/*							\
+	 * Note that we add ulong after elf_addr_t because	\
+	 * casting current->mm->context.vdso triggers a cast	\
+	 * warning of cast from pointer to integer for		\
+	 * COMPAT ELFCLASS32.					\
+	 */							\
 	NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
-		(elf_addr_t)current->mm->context.vdso);		\
+		(elf_addr_t)(ulong)current->mm->context.vdso);	\
 	NEW_AUX_ENT(AT_L1I_CACHESIZE,				\
 		get_cache_size(1, CACHE_TYPE_INST));		\
 	NEW_AUX_ENT(AT_L1I_CACHEGEOMETRY,			\
@@ -90,4 +117,23 @@ do {							\
 		*(struct user_regs_struct *)regs;	\
 } while (0);
 
+#ifdef CONFIG_COMPAT
+
+#define SET_PERSONALITY(ex)					\
+do {    if ((ex).e_ident[EI_CLASS] == ELFCLASS32)		\
+		set_thread_flag(TIF_32BIT);			\
+	else							\
+		clear_thread_flag(TIF_32BIT);			\
+	if (personality(current->personality) != PER_LINUX32)	\
+		set_personality(PER_LINUX |			\
+			(current->personality & (~PER_MASK)));	\
+} while (0)
+
+#define COMPAT_ELF_ET_DYN_BASE		((TASK_SIZE_32 / 3) * 2)
+
+/* rv32 registers */
+typedef compat_ulong_t			compat_elf_greg_t;
+typedef compat_elf_greg_t		compat_elf_gregset_t[ELF_NGREG];
+
+#endif /* CONFIG_COMPAT */
 #endif /* _ASM_RISCV_ELF_H */
-- 
2.25.1

[PATCH V4 12/17] riscv: compat: vdso: Add rv32 VDSO base code implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

There is no vgettimeofday supported in rv32 that makes simple to
generate rv32 vdso code which only needs riscv64 compiler. Other
architectures need change compiler or -m (machine parameter) to
support vdso32 compiling. If rv32 support vgettimeofday (which
cause C compile) in future, we would add CROSS_COMPILE to support
that makes more requirement on compiler enviornment.

linux-rv64/arch/riscv/kernel/compat_vdso/compat_vdso.so.dbg:
file format elf64-littleriscv

Disassembly of section .text:

0000000000000800 <__vdso_rt_sigreturn>:
 800:   08b00893                li      a7,139
 804:   00000073                ecall
 808:   0000                    unimp
        ...

000000000000080c <__vdso_getcpu>:
 80c:   0a800893                li      a7,168
 810:   00000073                ecall
 814:   8082                    ret
        ...

0000000000000818 <__vdso_flush_icache>:
 818:   10300893                li      a7,259
 81c:   00000073                ecall
 820:   8082                    ret

linux-rv32/arch/riscv/kernel/vdso/vdso.so.dbg:
file format elf32-littleriscv

Disassembly of section .text:

00000800 <__vdso_rt_sigreturn>:
 800:   08b00893                li      a7,139
 804:   00000073                ecall
 808:   0000                    unimp
        ...

0000080c <__vdso_getcpu>:
 80c:   0a800893                li      a7,168
 810:   00000073                ecall
 814:   8082                    ret
        ...

00000818 <__vdso_flush_icache>:
 818:   10300893                li      a7,259
 81c:   00000073                ecall
 820:   8082                    ret

Finally, reuse all *.S from vdso in compat_vdso that makes
implementation clear and readable.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/Makefile                           |  5 ++
 arch/riscv/include/asm/vdso.h                 |  9 +++
 arch/riscv/kernel/Makefile                    |  1 +
 arch/riscv/kernel/compat_vdso/.gitignore      |  2 +
 arch/riscv/kernel/compat_vdso/Makefile        | 68 +++++++++++++++++++
 arch/riscv/kernel/compat_vdso/compat_vdso.S   |  8 +++
 .../kernel/compat_vdso/compat_vdso.lds.S      |  3 +
 arch/riscv/kernel/compat_vdso/flush_icache.S  |  3 +
 .../compat_vdso/gen_compat_vdso_offsets.sh    |  5 ++
 arch/riscv/kernel/compat_vdso/getcpu.S        |  3 +
 arch/riscv/kernel/compat_vdso/note.S          |  3 +
 arch/riscv/kernel/compat_vdso/rt_sigreturn.S  |  3 +
 arch/riscv/kernel/vdso/vdso.S                 |  6 +-
 13 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/kernel/compat_vdso/.gitignore
 create mode 100644 arch/riscv/kernel/compat_vdso/Makefile
 create mode 100644 arch/riscv/kernel/compat_vdso/compat_vdso.S
 create mode 100644 arch/riscv/kernel/compat_vdso/compat_vdso.lds.S
 create mode 100644 arch/riscv/kernel/compat_vdso/flush_icache.S
 create mode 100755 arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh
 create mode 100644 arch/riscv/kernel/compat_vdso/getcpu.S
 create mode 100644 arch/riscv/kernel/compat_vdso/note.S
 create mode 100644 arch/riscv/kernel/compat_vdso/rt_sigreturn.S

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index a02e588c4947..f73d50552e09 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -106,12 +106,17 @@ libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 PHONY += vdso_install
 vdso_install:
 	$(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso $@
+	$(if $(CONFIG_COMPAT),$(Q)$(MAKE) \
+		$(build)=arch/riscv/kernel/compat_vdso $@)
 
 ifeq ($(KBUILD_EXTMOD),)
 ifeq ($(CONFIG_MMU),y)
 prepare: vdso_prepare
 vdso_prepare: prepare0
 	$(Q)$(MAKE) $(build)=arch/riscv/kernel/vdso include/generated/vdso-offsets.h
+	$(if $(CONFIG_COMPAT),$(Q)$(MAKE) \
+		$(build)=arch/riscv/kernel/compat_vdso include/generated/compat_vdso-offsets.h)
+
 endif
 endif
 
diff --git a/arch/riscv/include/asm/vdso.h b/arch/riscv/include/asm/vdso.h
index bc6f75f3a199..af981426fe0f 100644
--- a/arch/riscv/include/asm/vdso.h
+++ b/arch/riscv/include/asm/vdso.h
@@ -21,6 +21,15 @@
 
 #define VDSO_SYMBOL(base, name)							\
 	(void __user *)((unsigned long)(base) + __vdso_##name##_offset)
+
+#ifdef CONFIG_COMPAT
+#include <generated/compat_vdso-offsets.h>
+
+#define COMPAT_VDSO_SYMBOL(base, name)						\
+	(void __user *)((unsigned long)(base) + compat__vdso_##name##_offset)
+
+#endif /* CONFIG_COMPAT */
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* CONFIG_MMU */
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 954dc7043ad2..88e79f481c21 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -67,3 +67,4 @@ obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 
 obj-$(CONFIG_EFI)		+= efi.o
 obj-$(CONFIG_COMPAT)		+= compat_syscall_table.o
+obj-$(CONFIG_COMPAT)		+= compat_vdso/
diff --git a/arch/riscv/kernel/compat_vdso/.gitignore b/arch/riscv/kernel/compat_vdso/.gitignore
new file mode 100644
index 000000000000..19d83d846c1e
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+compat_vdso.lds
diff --git a/arch/riscv/kernel/compat_vdso/Makefile b/arch/riscv/kernel/compat_vdso/Makefile
new file mode 100644
index 000000000000..7bbbbf94307f
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/Makefile
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
+# the inclusion of generic Makefile.
+ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
+include $(srctree)/lib/vdso/Makefile
+# Symbols present in the compat_vdso
+compat_vdso-syms  = rt_sigreturn
+compat_vdso-syms += getcpu
+compat_vdso-syms += flush_icache
+
+# Files to link into the compat_vdso
+obj-compat_vdso = $(patsubst %, %.o, $(compat_vdso-syms)) note.o
+
+ccflags-y := -fno-stack-protector
+
+# Build rules
+targets := $(obj-compat_vdso) compat_vdso.so compat_vdso.so.dbg compat_vdso.lds
+obj-compat_vdso := $(addprefix $(obj)/, $(obj-compat_vdso))
+
+obj-y += compat_vdso.o
+CPPFLAGS_compat_vdso.lds += -P -C -U$(ARCH)
+
+# Disable profiling and instrumentation for VDSO code
+GCOV_PROFILE := n
+KCOV_INSTRUMENT := n
+KASAN_SANITIZE := n
+UBSAN_SANITIZE := n
+
+# Force dependency
+$(obj)/compat_vdso.o: $(obj)/compat_vdso.so
+
+# link rule for the .so file, .lds has to be first
+$(obj)/compat_vdso.so.dbg: $(obj)/compat_vdso.lds $(obj-compat_vdso) FORCE
+	$(call if_changed,compat_vdsold)
+LDFLAGS_compat_vdso.so.dbg = -shared -S -soname=linux-compat_vdso.so.1 \
+	--build-id=sha1 --hash-style=both --eh-frame-hdr
+
+# strip rule for the .so file
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+	$(call if_changed,objcopy)
+
+# Generate VDSO offsets using helper script
+gen-compat_vdsosym := $(srctree)/$(src)/gen_compat_vdso_offsets.sh
+quiet_cmd_compat_vdsosym = VDSOSYM $@
+	cmd_compat_vdsosym = $(NM) $< | $(gen-compat_vdsosym) | LC_ALL=C sort > $@
+
+include/generated/compat_vdso-offsets.h: $(obj)/compat_vdso.so.dbg FORCE
+	$(call if_changed,compat_vdsosym)
+
+# actual build commands
+# The DSO images are built using a special linker script
+# Make sure only to export the intended __compat_vdso_xxx symbol offsets.
+quiet_cmd_compat_vdsold = VDSOLD  $@
+      cmd_compat_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
+                   $(OBJCOPY) $(patsubst %, -G __compat_vdso_%, $(compat_vdso-syms)) $@.tmp $@ && \
+                   rm $@.tmp
+
+# install commands for the unstripped file
+quiet_cmd_compat_vdso_install = INSTALL $@
+      cmd_compat_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/compat_vdso/$@
+
+compat_vdso.so: $(obj)/compat_vdso.so.dbg
+	@mkdir -p $(MODLIB)/compat_vdso
+	$(call cmd,compat_vdso_install)
+
+compat_vdso_install: compat_vdso.so
diff --git a/arch/riscv/kernel/compat_vdso/compat_vdso.S b/arch/riscv/kernel/compat_vdso/compat_vdso.S
new file mode 100644
index 000000000000..fea4a8b0c45d
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/compat_vdso.S
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#define	vdso_start	compat_vdso_start
+#define	vdso_end	compat_vdso_end
+
+#define	__VDSO_PATH	"arch/riscv/kernel/compat_vdso/compat_vdso.so"
+
+#include <../vdso/vdso.S>
diff --git a/arch/riscv/kernel/compat_vdso/compat_vdso.lds.S b/arch/riscv/kernel/compat_vdso/compat_vdso.lds.S
new file mode 100644
index 000000000000..02a9ec5dc7f6
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/compat_vdso.lds.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <../vdso/vdso.lds.S>
diff --git a/arch/riscv/kernel/compat_vdso/flush_icache.S b/arch/riscv/kernel/compat_vdso/flush_icache.S
new file mode 100644
index 000000000000..88e21a84a974
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/flush_icache.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <../vdso/flush_icache.S>
diff --git a/arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh b/arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh
new file mode 100755
index 000000000000..8ac070c783b3
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/gen_compat_vdso_offsets.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+LC_ALL=C
+sed -n -e 's/^[0]\+\(0[0-9a-fA-F]*\) . \(__vdso_[a-zA-Z0-9_]*\)$/\#define compat\2_offset\t0x\1/p'
diff --git a/arch/riscv/kernel/compat_vdso/getcpu.S b/arch/riscv/kernel/compat_vdso/getcpu.S
new file mode 100644
index 000000000000..946449a15a94
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/getcpu.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <../vdso/getcpu.S>
diff --git a/arch/riscv/kernel/compat_vdso/note.S b/arch/riscv/kernel/compat_vdso/note.S
new file mode 100644
index 000000000000..67c50898b8e5
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/note.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <../vdso/note.S>
diff --git a/arch/riscv/kernel/compat_vdso/rt_sigreturn.S b/arch/riscv/kernel/compat_vdso/rt_sigreturn.S
new file mode 100644
index 000000000000..f4c98f18c053
--- /dev/null
+++ b/arch/riscv/kernel/compat_vdso/rt_sigreturn.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <../vdso/rt_sigreturn.S>
diff --git a/arch/riscv/kernel/vdso/vdso.S b/arch/riscv/kernel/vdso/vdso.S
index df222245be05..83f1c899e8d8 100644
--- a/arch/riscv/kernel/vdso/vdso.S
+++ b/arch/riscv/kernel/vdso/vdso.S
@@ -7,12 +7,16 @@
 #include <linux/linkage.h>
 #include <asm/page.h>
 
+#ifndef __VDSO_PATH
+#define __VDSO_PATH "arch/riscv/kernel/vdso/vdso.so"
+#endif
+
 	__PAGE_ALIGNED_DATA
 
 	.globl vdso_start, vdso_end
 	.balign PAGE_SIZE
 vdso_start:
-	.incbin "arch/riscv/kernel/vdso/vdso.so"
+	.incbin __VDSO_PATH
 	.balign PAGE_SIZE
 vdso_end:
 
-- 
2.25.1

[PATCH V4 13/17] riscv: compat: vdso: Add setup additional pages implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Reconstruct __setup_additional_pages() by appending vdso info
pointer argument to meet compat_vdso_info requirement. And change
vm_special_mapping *dm, *cm initialization into static.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/include/asm/elf.h |   5 ++
 arch/riscv/include/asm/mmu.h |   1 +
 arch/riscv/kernel/vdso.c     | 104 +++++++++++++++++++++++++----------
 3 files changed, 81 insertions(+), 29 deletions(-)

diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index c1fc31629d40..6f374e6bc786 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -135,5 +135,10 @@ do {    if ((ex).e_ident[EI_CLASS] == ELFCLASS32)		\
 typedef compat_ulong_t			compat_elf_greg_t;
 typedef compat_elf_greg_t		compat_elf_gregset_t[ELF_NGREG];
 
+extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+					      int uses_interp);
+#define compat_arch_setup_additional_pages \
+				compat_arch_setup_additional_pages
+
 #endif /* CONFIG_COMPAT */
 #endif /* _ASM_RISCV_ELF_H */
diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h
index 0099dc116168..cedcf8ea3c76 100644
--- a/arch/riscv/include/asm/mmu.h
+++ b/arch/riscv/include/asm/mmu.h
@@ -16,6 +16,7 @@ typedef struct {
 	atomic_long_t id;
 #endif
 	void *vdso;
+	void *vdso_info;
 #ifdef CONFIG_SMP
 	/* A local icache flush is needed before user execution can resume. */
 	cpumask_t icache_stale_mask;
diff --git a/arch/riscv/kernel/vdso.c b/arch/riscv/kernel/vdso.c
index a9436a65161a..deca69524799 100644
--- a/arch/riscv/kernel/vdso.c
+++ b/arch/riscv/kernel/vdso.c
@@ -23,6 +23,9 @@ struct vdso_data {
 #endif
 
 extern char vdso_start[], vdso_end[];
+#ifdef CONFIG_COMPAT
+extern char compat_vdso_start[], compat_vdso_end[];
+#endif
 
 enum vvar_pages {
 	VVAR_DATA_PAGE_OFFSET,
@@ -30,6 +33,11 @@ enum vvar_pages {
 	VVAR_NR_PAGES,
 };
 
+enum rv_vdso_map {
+	RV_VDSO_MAP_VVAR,
+	RV_VDSO_MAP_VDSO,
+};
+
 #define VVAR_SIZE  (VVAR_NR_PAGES << PAGE_SHIFT)
 
 /*
@@ -52,12 +60,6 @@ struct __vdso_info {
 	struct vm_special_mapping *cm;
 };
 
-static struct __vdso_info vdso_info __ro_after_init = {
-	.name = "vdso",
-	.vdso_code_start = vdso_start,
-	.vdso_code_end = vdso_end,
-};
-
 static int vdso_mremap(const struct vm_special_mapping *sm,
 		       struct vm_area_struct *new_vma)
 {
@@ -66,35 +68,35 @@ static int vdso_mremap(const struct vm_special_mapping *sm,
 	return 0;
 }
 
-static int __init __vdso_init(void)
+static int __init __vdso_init(struct __vdso_info *vdso_info)
 {
 	unsigned int i;
 	struct page **vdso_pagelist;
 	unsigned long pfn;
 
-	if (memcmp(vdso_info.vdso_code_start, "\177ELF", 4)) {
+	if (memcmp(vdso_info->vdso_code_start, "\177ELF", 4)) {
 		pr_err("vDSO is not a valid ELF object!\n");
 		return -EINVAL;
 	}
 
-	vdso_info.vdso_pages = (
-		vdso_info.vdso_code_end -
-		vdso_info.vdso_code_start) >>
+	vdso_info->vdso_pages = (
+		vdso_info->vdso_code_end -
+		vdso_info->vdso_code_start) >>
 		PAGE_SHIFT;
 
-	vdso_pagelist = kcalloc(vdso_info.vdso_pages,
+	vdso_pagelist = kcalloc(vdso_info->vdso_pages,
 				sizeof(struct page *),
 				GFP_KERNEL);
 	if (vdso_pagelist == NULL)
 		return -ENOMEM;
 
 	/* Grab the vDSO code pages. */
-	pfn = sym_to_pfn(vdso_info.vdso_code_start);
+	pfn = sym_to_pfn(vdso_info->vdso_code_start);
 
-	for (i = 0; i < vdso_info.vdso_pages; i++)
+	for (i = 0; i < vdso_info->vdso_pages; i++)
 		vdso_pagelist[i] = pfn_to_page(pfn + i);
 
-	vdso_info.cm->pages = vdso_pagelist;
+	vdso_info->cm->pages = vdso_pagelist;
 
 	return 0;
 }
@@ -116,13 +118,14 @@ int vdso_join_timens(struct task_struct *task, struct time_namespace *ns)
 {
 	struct mm_struct *mm = task->mm;
 	struct vm_area_struct *vma;
+	struct __vdso_info *vdso_info = mm->context.vdso_info;
 
 	mmap_read_lock(mm);
 
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
 		unsigned long size = vma->vm_end - vma->vm_start;
 
-		if (vma_is_special_mapping(vma, vdso_info.dm))
+		if (vma_is_special_mapping(vma, vdso_info->dm))
 			zap_page_range(vma, vma->vm_start, size);
 	}
 
@@ -187,11 +190,6 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	return vmf_insert_pfn(vma, vmf->address, pfn);
 }
 
-enum rv_vdso_map {
-	RV_VDSO_MAP_VVAR,
-	RV_VDSO_MAP_VDSO,
-};
-
 static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
 	[RV_VDSO_MAP_VVAR] = {
 		.name   = "[vvar]",
@@ -203,25 +201,53 @@ static struct vm_special_mapping rv_vdso_maps[] __ro_after_init = {
 	},
 };
 
+static struct __vdso_info vdso_info __ro_after_init = {
+	.name = "vdso",
+	.vdso_code_start = vdso_start,
+	.vdso_code_end = vdso_end,
+	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
+	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
+};
+
+#ifdef CONFIG_COMPAT
+static struct __vdso_info compat_vdso_info __ro_after_init = {
+	.name = "compat_vdso",
+	.vdso_code_start = compat_vdso_start,
+	.vdso_code_end = compat_vdso_end,
+	.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR],
+	.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO],
+};
+#endif
+
 static int __init vdso_init(void)
 {
-	vdso_info.dm = &rv_vdso_maps[RV_VDSO_MAP_VVAR];
-	vdso_info.cm = &rv_vdso_maps[RV_VDSO_MAP_VDSO];
+	int ret;
+
+	ret = __vdso_init(&vdso_info);
+	if (ret)
+		goto out;
 
-	return __vdso_init();
+#ifdef CONFIG_COMPAT
+	ret = __vdso_init(&compat_vdso_info);
+	if (ret)
+		goto out;
+#endif
+out:
+	return ret;
 }
 arch_initcall(vdso_init);
 
 static int __setup_additional_pages(struct mm_struct *mm,
 				    struct linux_binprm *bprm,
-				    int uses_interp)
+				    int uses_interp,
+				    struct __vdso_info *vdso_info)
 {
 	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
 	void *ret;
 
 	BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
 
-	vdso_text_len = vdso_info.vdso_pages << PAGE_SHIFT;
+	vdso_text_len = vdso_info->vdso_pages << PAGE_SHIFT;
 	/* Be sure to map the data page */
 	vdso_mapping_len = vdso_text_len + VVAR_SIZE;
 
@@ -232,16 +258,18 @@ static int __setup_additional_pages(struct mm_struct *mm,
 	}
 
 	ret = _install_special_mapping(mm, vdso_base, VVAR_SIZE,
-		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info.dm);
+		(VM_READ | VM_MAYREAD | VM_PFNMAP), vdso_info->dm);
 	if (IS_ERR(ret))
 		goto up_fail;
 
 	vdso_base += VVAR_SIZE;
 	mm->context.vdso = (void *)vdso_base;
+	mm->context.vdso_info = (void *)vdso_info;
+
 	ret =
 	   _install_special_mapping(mm, vdso_base, vdso_text_len,
 		(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
-		vdso_info.cm);
+		vdso_info->cm);
 
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -253,6 +281,24 @@ static int __setup_additional_pages(struct mm_struct *mm,
 	return PTR_ERR(ret);
 }
 
+#ifdef CONFIG_COMPAT
+int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
+				       int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	int ret;
+
+	if (mmap_write_lock_killable(mm))
+		return -EINTR;
+
+	ret = __setup_additional_pages(mm, bprm, uses_interp,
+							&compat_vdso_info);
+	mmap_write_unlock(mm);
+
+	return ret;
+}
+#endif
+
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
 	struct mm_struct *mm = current->mm;
@@ -261,7 +307,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
-	ret = __setup_additional_pages(mm, bprm, uses_interp);
+	ret = __setup_additional_pages(mm, bprm, uses_interp, &vdso_info);
 	mmap_write_unlock(mm);
 
 	return ret;
-- 
2.25.1

[PATCH V4 14/17] riscv: compat: signal: Add rt_frame implementation

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Implement compat_setup_rt_frame for sigcontext save & restore. The
main process is the same with signal, but the rv32 pt_regs' size
is different from rv64's, so we needs convert them.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/kernel/Makefile        |   1 +
 arch/riscv/kernel/compat_signal.c | 243 ++++++++++++++++++++++++++++++
 arch/riscv/kernel/signal.c        |  13 +-
 3 files changed, 256 insertions(+), 1 deletion(-)
 create mode 100644 arch/riscv/kernel/compat_signal.c

diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 88e79f481c21..a46f9807c59e 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -67,4 +67,5 @@ obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o
 
 obj-$(CONFIG_EFI)		+= efi.o
 obj-$(CONFIG_COMPAT)		+= compat_syscall_table.o
+obj-$(CONFIG_COMPAT)		+= compat_signal.o
 obj-$(CONFIG_COMPAT)		+= compat_vdso/
diff --git a/arch/riscv/kernel/compat_signal.c b/arch/riscv/kernel/compat_signal.c
new file mode 100644
index 000000000000..7041742ded08
--- /dev/null
+++ b/arch/riscv/kernel/compat_signal.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/compat.h>
+#include <linux/signal.h>
+#include <linux/uaccess.h>
+#include <linux/syscalls.h>
+#include <linux/tracehook.h>
+#include <linux/linkage.h>
+
+#include <asm/ucontext.h>
+#include <asm/vdso.h>
+#include <asm/switch_to.h>
+#include <asm/csr.h>
+
+#define COMPAT_DEBUG_SIG 0
+
+struct compat_sigcontext {
+	struct compat_user_regs_struct sc_regs;
+	union __riscv_fp_state sc_fpregs;
+};
+
+struct compat_ucontext {
+	compat_ulong_t		uc_flags;
+	struct compat_ucontext	*uc_link;
+	compat_stack_t		uc_stack;
+	sigset_t		uc_sigmask;
+	/* There's some padding here to allow sigset_t to be expanded in the
+	 * future.  Though this is unlikely, other architectures put uc_sigmask
+	 * at the end of this structure and explicitly state it can be
+	 * expanded, so we didn't want to box ourselves in here. */
+	__u8		  __unused[1024 / 8 - sizeof(sigset_t)];
+	/* We can't put uc_sigmask at the end of this structure because we need
+	 * to be able to expand sigcontext in the future.  For example, the
+	 * vector ISA extension will almost certainly add ISA state.  We want
+	 * to ensure all user-visible ISA state can be saved and restored via a
+	 * ucontext, so we're putting this at the end in order to allow for
+	 * infinite extensibility.  Since we know this will be extended and we
+	 * assume sigset_t won't be extended an extreme amount, we're
+	 * prioritizing this. */
+	struct compat_sigcontext uc_mcontext;
+};
+
+struct compat_rt_sigframe {
+	struct compat_siginfo info;
+	struct compat_ucontext uc;
+};
+
+#ifdef CONFIG_FPU
+static long compat_restore_fp_state(struct pt_regs *regs,
+	union __riscv_fp_state __user *sc_fpregs)
+{
+	long err;
+	struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
+	size_t i;
+
+	err = __copy_from_user(&current->thread.fstate, state, sizeof(*state));
+	if (unlikely(err))
+		return err;
+
+	fstate_restore(current, regs);
+
+	/* We support no other extension state at this time. */
+	for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
+		u32 value;
+
+		err = __get_user(value, &sc_fpregs->q.reserved[i]);
+		if (unlikely(err))
+			break;
+		if (value != 0)
+			return -EINVAL;
+	}
+
+	return err;
+}
+
+static long compat_save_fp_state(struct pt_regs *regs,
+			  union __riscv_fp_state __user *sc_fpregs)
+{
+	long err;
+	struct __riscv_d_ext_state __user *state = &sc_fpregs->d;
+	size_t i;
+
+	fstate_save(current, regs);
+	err = __copy_to_user(state, &current->thread.fstate, sizeof(*state));
+	if (unlikely(err))
+		return err;
+
+	/* We support no other extension state at this time. */
+	for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) {
+		err = __put_user(0, &sc_fpregs->q.reserved[i]);
+		if (unlikely(err))
+			break;
+	}
+
+	return err;
+}
+#else
+#define compat_save_fp_state(task, regs) (0)
+#define compat_restore_fp_state(task, regs) (0)
+#endif
+
+static long compat_restore_sigcontext(struct pt_regs *regs,
+	struct compat_sigcontext __user *sc)
+{
+	long err;
+	struct compat_user_regs_struct cregs;
+
+	/* sc_regs is structured the same as the start of pt_regs */
+	err = __copy_from_user(&cregs, &sc->sc_regs, sizeof(sc->sc_regs));
+
+	cregs_to_regs(&cregs, regs);
+
+	/* Restore the floating-point state. */
+	if (has_fpu())
+		err |= compat_restore_fp_state(regs, &sc->sc_fpregs);
+	return err;
+}
+
+COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct compat_rt_sigframe __user *frame;
+	struct task_struct *task;
+	sigset_t set;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	frame = (struct compat_rt_sigframe __user *)regs->sp;
+
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (compat_restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	if (compat_restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->a0;
+
+badframe:
+	task = current;
+	if (show_unhandled_signals) {
+		pr_info_ratelimited(
+			"%s[%d]: bad frame in %s: frame=%p pc=%p sp=%p\n",
+			task->comm, task_pid_nr(task), __func__,
+			frame, (void *)regs->epc, (void *)regs->sp);
+	}
+	force_sig(SIGSEGV);
+	return 0;
+}
+
+static long compat_setup_sigcontext(struct compat_rt_sigframe __user *frame,
+	struct pt_regs *regs)
+{
+	struct compat_sigcontext __user *sc = &frame->uc.uc_mcontext;
+	struct compat_user_regs_struct cregs;
+	long err;
+
+	regs_to_cregs(&cregs, regs);
+
+	/* sc_regs is structured the same as the start of pt_regs */
+	err = __copy_to_user(&sc->sc_regs, &cregs, sizeof(sc->sc_regs));
+	/* Save the floating-point state. */
+	if (has_fpu())
+		err |= compat_save_fp_state(regs, &sc->sc_fpregs);
+	return err;
+}
+
+static inline void __user *compat_get_sigframe(struct ksignal *ksig,
+	struct pt_regs *regs, size_t framesize)
+{
+	unsigned long sp;
+	/* Default to using normal stack */
+	sp = regs->sp;
+
+	/*
+	 * If we are on the alternate signal stack and would overflow it, don't.
+	 * Return an always-bogus address instead so we will die with SIGSEGV.
+	 */
+	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+		return (void __user __force *)(-1UL);
+
+	/* This is the X/Open sanctioned signal stack switching. */
+	sp = sigsp(sp, ksig) - framesize;
+
+	/* Align the stack frame. */
+	sp &= ~0xfUL;
+
+	return (void __user *)sp;
+}
+
+int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+	struct pt_regs *regs)
+{
+	struct compat_rt_sigframe __user *frame;
+	long err = 0;
+
+	frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
+	if (!access_ok(frame, sizeof(*frame)))
+		return -EFAULT;
+
+	err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
+
+	/* Create the ucontext. */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp);
+	err |= compat_setup_sigcontext(frame, regs);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	if (err)
+		return -EFAULT;
+
+	regs->ra = (unsigned long)COMPAT_VDSO_SYMBOL(
+			current->mm->context.vdso, rt_sigreturn);
+
+	/*
+	 * Set up registers for signal handler.
+	 * Registers that we don't modify keep the value they had from
+	 * user-space at the time we took the signal.
+	 * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+	 * since some things rely on this (e.g. glibc's debug/segfault.c).
+	 */
+	regs->epc = (unsigned long)ksig->ka.sa.sa_handler;
+	regs->sp = (unsigned long)frame;
+	regs->a0 = ksig->sig;                     /* a0: signal number */
+	regs->a1 = (unsigned long)(&frame->info); /* a1: siginfo pointer */
+	regs->a2 = (unsigned long)(&frame->uc);   /* a2: ucontext pointer */
+
+#if COMPAT_DEBUG_SIG
+	pr_info("SIG deliver (%s:%d): sig=%d pc=%p ra=%p sp=%p\n",
+		current->comm, task_pid_nr(current), ksig->sig,
+		(void *)regs->epc, (void *)regs->ra, frame);
+#endif
+
+	return 0;
+}
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index c2d5ecbe5526..27d8f39228c4 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2012 Regents of the University of California
  */
 
+#include <linux/compat.h>
 #include <linux/signal.h>
 #include <linux/uaccess.h>
 #include <linux/syscalls.h>
@@ -229,6 +230,11 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+extern int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+				 struct pt_regs *regs);
+#endif
+
 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
 	sigset_t *oldset = sigmask_to_save();
@@ -258,8 +264,13 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 		}
 	}
 
+#ifdef CONFIG_COMPAT
 	/* Set up the stack frame */
-	ret = setup_rt_frame(ksig, oldset, regs);
+	if (is_compat_task())
+		ret = compat_setup_rt_frame(ksig, oldset, regs);
+	else
+#endif
+		ret = setup_rt_frame(ksig, oldset, regs);
 
 	signal_setup_done(ret, ksig, 0);
 }
-- 
2.25.1

[PATCH V4 15/17] riscv: compat: ptrace: Add compat_arch_ptrace implement

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Now, you can use native gdb on riscv64 for rv32 app debugging.

$ uname -a
Linux buildroot 5.16.0-rc4-00036-gbef6b82fdf23-dirty #53 SMP Mon Dec 20 23:06:53 CST 2021 riscv64 GNU/Linux
$ cat /proc/cpuinfo
processor       : 0
hart            : 0
isa             : rv64imafdcsuh
mmu             : sv48

$ file /bin/busybox
/bin/busybox: setuid ELF 32-bit LSB shared object, UCB RISC-V, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped
$ file /usr/bin/gdb
/usr/bin/gdb: ELF 32-bit LSB shared object, UCB RISC-V, version 1 (GNU/Linux), dynamically linked, interpreter /lib/ld-linux-riscv32-ilp32d.so.1, for GNU/Linux 5.15.0, stripped
$ /usr/bin/gdb /bin/busybox
GNU gdb (GDB) 10.2
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
...
Reading symbols from /bin/busybox...
(No debugging symbols found in /bin/busybox)
(gdb) b main
Breakpoint 1 at 0x8ddc
(gdb) r
Starting program: /bin/busybox
Failed to read a valid object file image from memory.

Breakpoint 1, 0x555a8ddc in main ()
(gdb) i r
ra             0x77df0b74       0x77df0b74
sp             0x7fdd3d10       0x7fdd3d10
gp             0x5567e800       0x5567e800 <bb_common_bufsiz1+160>
tp             0x77f64280       0x77f64280
t0             0x0      0
t1             0x555a6fac       1431990188
t2             0x77dd8db4       2011008436
fp             0x7fdd3e34       0x7fdd3e34
s1             0x7fdd3e34       2145205812
a0             0xffffffff       -1
a1             0x2000   8192
a2             0x7fdd3e3c       2145205820
a3             0x0      0
a4             0x7fdd3d30       2145205552
a5             0x555a8dc0       1431997888
a6             0x77f2c170       2012397936
a7             0x6a7c7a2f       1786542639
s2             0x0      0
s3             0x0      0
s4             0x555a8dc0       1431997888
s5             0x77f8a3a8       2012783528
s6             0x7fdd3e3c       2145205820
s7             0x5567cecc       1432866508
--Type <RET> for more, q to quit, c to continue without paging--
s8             0x1      1
s9             0x0      0
s10            0x55634448       1432568904
s11            0x0      0
t3             0x77df0bb8       2011106232
t4             0x42fc   17148
t5             0x0      0
t6             0x40     64
pc             0x555a8ddc       0x555a8ddc <main+28>
(gdb) si
0x555a78f0 in mallopt@plt ()
(gdb) c
Continuing.
BusyBox v1.34.1 (2021-12-19 22:39:48 CST) multi-call binary.
BusyBox is copyrighted by many authors between 1998-2015.
Licensed under GPLv2. See source distribution for detailed
copyright notices.

Usage: busybox [function [arguments]...]
   or: busybox --list[-full]
...
[Inferior 1 (process 107) exited normally]
(gdb) q

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/kernel/ptrace.c | 87 +++++++++++++++++++++++++++++++++++---
 1 file changed, 82 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c
index a89243730153..bb387593a121 100644
--- a/arch/riscv/kernel/ptrace.c
+++ b/arch/riscv/kernel/ptrace.c
@@ -12,6 +12,7 @@
 #include <asm/thread_info.h>
 #include <asm/switch_to.h>
 #include <linux/audit.h>
+#include <linux/compat.h>
 #include <linux/ptrace.h>
 #include <linux/elf.h>
 #include <linux/regset.h>
@@ -111,11 +112,6 @@ static const struct user_regset_view riscv_user_native_view = {
 	.n = ARRAY_SIZE(riscv_user_regset),
 };
 
-const struct user_regset_view *task_user_regset_view(struct task_struct *task)
-{
-	return &riscv_user_native_view;
-}
-
 struct pt_regs_offset {
 	const char *name;
 	int offset;
@@ -273,3 +269,84 @@ __visible void do_syscall_trace_exit(struct pt_regs *regs)
 		trace_sys_exit(regs, regs_return_value(regs));
 #endif
 }
+
+#ifdef CONFIG_COMPAT
+static int compat_riscv_gpr_get(struct task_struct *target,
+				const struct user_regset *regset,
+				struct membuf to)
+{
+	struct compat_user_regs_struct cregs;
+
+	regs_to_cregs(&cregs, task_pt_regs(target));
+
+	return membuf_write(&to, &cregs,
+			    sizeof(struct compat_user_regs_struct));
+}
+
+static int compat_riscv_gpr_set(struct task_struct *target,
+				const struct user_regset *regset,
+				unsigned int pos, unsigned int count,
+				const void *kbuf, const void __user *ubuf)
+{
+	int ret;
+	struct compat_user_regs_struct cregs;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &cregs, 0, -1);
+
+	cregs_to_regs(&cregs, task_pt_regs(target));
+
+	return ret;
+}
+
+static const struct user_regset compat_riscv_user_regset[] = {
+	[REGSET_X] = {
+		.core_note_type = NT_PRSTATUS,
+		.n = ELF_NGREG,
+		.size = sizeof(compat_elf_greg_t),
+		.align = sizeof(compat_elf_greg_t),
+		.regset_get = compat_riscv_gpr_get,
+		.set = compat_riscv_gpr_set,
+	},
+#ifdef CONFIG_FPU
+	[REGSET_F] = {
+		.core_note_type = NT_PRFPREG,
+		.n = ELF_NFPREG,
+		.size = sizeof(elf_fpreg_t),
+		.align = sizeof(elf_fpreg_t),
+		.regset_get = riscv_fpr_get,
+		.set = riscv_fpr_set,
+	},
+#endif
+};
+
+static const struct user_regset_view compat_riscv_user_native_view = {
+	.name = "riscv",
+	.e_machine = EM_RISCV,
+	.regsets = compat_riscv_user_regset,
+	.n = ARRAY_SIZE(compat_riscv_user_regset),
+};
+
+long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
+			compat_ulong_t caddr, compat_ulong_t cdata)
+{
+	long ret = -EIO;
+
+	switch (request) {
+	default:
+		ret = compat_ptrace_request(child, request, caddr, cdata);
+		break;
+	}
+
+	return ret;
+}
+#endif /* CONFIG_COMPAT */
+
+const struct user_regset_view *task_user_regset_view(struct task_struct *task)
+{
+#ifdef CONFIG_COMPAT
+	if (test_tsk_thread_flag(task, TIF_32BIT))
+		return &compat_riscv_user_native_view;
+	else
+#endif
+		return &riscv_user_native_view;
+}
-- 
2.25.1

[PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Adds initial skeletal COMPAT Kbuild (Runing 32bit U-mode on 64bit
S-mode) support.
 - Setup kconfig & dummy functions for compiling.
 - Implement compat_start_thread by the way.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
---
 arch/riscv/Kconfig | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 5adcbd9b5e88..6f11df8c189f 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -73,6 +73,7 @@ config RISCV
 	select HAVE_ARCH_KGDB if !XIP_KERNEL
 	select HAVE_ARCH_KGDB_QXFER_PKT
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
+	select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU
@@ -123,12 +124,18 @@ config ARCH_MMAP_RND_BITS_MIN
 	default 18 if 64BIT
 	default 8
 
+config ARCH_MMAP_RND_COMPAT_BITS_MIN
+	default 8
+
 # max bits determined by the following formula:
 #  VA_BITS - PAGE_SHIFT - 3
 config ARCH_MMAP_RND_BITS_MAX
 	default 24 if 64BIT # SV39 based
 	default 17
 
+config ARCH_MMAP_RND_COMPAT_BITS_MAX
+	default 17
+
 # set if we run in machine mode, cleared if we run in supervisor mode
 config RISCV_M_MODE
 	bool
@@ -406,6 +413,18 @@ config CRASH_DUMP
 
 	  For more details see Documentation/admin-guide/kdump/kdump.rst
 
+config COMPAT
+	bool "Kernel support for 32-bit U-mode"
+	default 64BIT
+	depends on 64BIT && MMU
+	help
+	  This option enables support for a 32-bit U-mode running under a 64-bit
+	  kernel at S-mode. riscv32-specific components such as system calls,
+	  the user helper functions (vdso), signal rt_frame functions and the
+	  ptrace interface are handled appropriately by the kernel.
+
+	  If you want to execute 32-bit userspace applications, say Y.
+
 endmenu
 
 menu "Boot options"
-- 
2.25.1

[PATCH V4 17/17] KVM: compat: riscv: Prevent KVM_COMPAT from being selected

[guoren]

From: Guo Ren <guoren@linux.alibaba.com>

Current riscv doesn't support the 32bit KVM API. Let's make it
clear by not selecting KVM_COMPAT.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 virt/kvm/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index f4834c20e4a6..a8c5c9f06b3c 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -53,7 +53,7 @@ config KVM_GENERIC_DIRTYLOG_READ_PROTECT
 
 config KVM_COMPAT
        def_bool y
-       depends on KVM && COMPAT && !(S390 || ARM64)
+       depends on KVM && COMPAT && !(S390 || ARM64 || RISCV)
 
 config HAVE_KVM_IRQ_BYPASS
        bool
-- 
2.25.1

Re: [PATCH V4 03/17] asm-generic: compat: Cleanup duplicate definitions

[Arnd Bergmann]

On Sat, Jan 29, 2022 at 1:17 PM <guoren@kernel.org> wrote:
>
> From: Guo Ren <guoren@linux.alibaba.com>
>
> There are 7 64bit architectures that support Linux COMPAT mode to
> run 32bit applications. A lot of definitions are duplicate:
>  - COMPAT_USER_HZ
>  - COMPAT_RLIM_INFINITY
>  - COMPAT_OFF_T_MAX
>  - __compat_uid_t, __compat_uid_t
>  - compat_dev_t
>  - compat_ipc_pid_t
>  - struct compat_flock
>  - struct compat_flock64
>  - struct compat_statfs
>  - struct compat_ipc64_perm, compat_semid64_ds,
>           compat_msqid64_ds, compat_shmid64_ds
>
> Cleanup duplicate definitions and merge them into asm-generic.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Palmer Dabbelt <palmer@dabbelt.com>

Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Re: [PATCH V4 06/17] riscv: compat: Add basic compat date type implementation

[Arnd Bergmann]

On Sat, Jan 29, 2022 at 1:17 PM <guoren@kernel.org> wrote:
> +
> +#define COMPAT_RLIM_INFINITY   0x7fffffff
>
> +#define F_GETLK64      12
> +#define F_SETLK64      13
> +#define F_SETLKW64     14

These now come from the generic definitions I think. The flock definitions
are just the normal ones, and AFAICT the RLIM_INIFINITY definition here
is actually wrong and should be the default 0xffffffffu to match the
native (~0UL) definition.

            Arnd

Re: [PATCH V4 08/17] riscv: compat: syscall: Add compat_sys_call_table implementation

[Arnd Bergmann]

> Implement compat sys_call_table and some system call functions:
> truncate64, ftruncate64, fallocate, pread64, pwrite64,
> sync_file_range, readahead, fadvise64_64 which need argument
> translation.
>
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Cc: Arnd Bergmann <arnd@arndb.de>

This all looks really good, but I would change one detail:

> +#ifndef compat_arg_u64
> +#define compat_arg_u64(name)           u32  name##_lo, u32  name##_hi
> +#define compat_arg_u64_dual(name)      u32, name##_lo, u32, name##_hi
> +#define compat_arg_u64_glue(name)      (((u64)name##_hi << 32) | \
> +                                        ((u64)name##_lo & 0xffffffffUL))
> +#endif

I would make these endian-specific, and reverse them on big-endian
architectures. That way it
should be possible to share them across all compat architectures
without needing the override
option.

        Arnd

Re: [PATCH V4 06/17] riscv: compat: Add basic compat date type implementation

[Guo Ren]

On Sun, Jan 30, 2022 at 5:56 AM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Sat, Jan 29, 2022 at 1:17 PM <guoren@kernel.org> wrote:
> > +
> > +#define COMPAT_RLIM_INFINITY   0x7fffffff
> >
> > +#define F_GETLK64      12
> > +#define F_SETLK64      13
> > +#define F_SETLKW64     14
>
> These now come from the generic definitions I think. The flock definitions
> are just the normal ones,
Yes, it could be removed after Christoph Hellwig's patch merged.

> and AFAICT the RLIM_INIFINITY definition here
> is actually wrong and should be the default 0xffffffffu to match the
> native (~0UL) definition.
Yes, native rv32 used ~0UL, although its task_size is only 2.4GB.

I would remove #define COMPAT_RLIM_INFINITY   0x7fffffff

>
>             Arnd



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 08/17] riscv: compat: syscall: Add compat_sys_call_table implementation

[Guo Ren]

On Sun, Jan 30, 2022 at 6:41 AM Arnd Bergmann <arnd@arndb.de> wrote:
>
> > Implement compat sys_call_table and some system call functions:
> > truncate64, ftruncate64, fallocate, pread64, pwrite64,
> > sync_file_range, readahead, fadvise64_64 which need argument
> > translation.
> >
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
> > Cc: Arnd Bergmann <arnd@arndb.de>
>
> This all looks really good, but I would change one detail:
>
> > +#ifndef compat_arg_u64
> > +#define compat_arg_u64(name)           u32  name##_lo, u32  name##_hi
> > +#define compat_arg_u64_dual(name)      u32, name##_lo, u32, name##_hi
> > +#define compat_arg_u64_glue(name)      (((u64)name##_hi << 32) | \
> > +                                        ((u64)name##_lo & 0xffffffffUL))
> > +#endif
>
> I would make these endian-specific, and reverse them on big-endian
> architectures. That way it
> should be possible to share them across all compat architectures
> without needing the override
> option.
I hope it could be another patch. Because it's not clear to
_LITTLE_ENDIAN definition in archs.

eg: Names could be __ORDER_LITTLE_ENDIAN__ CPU_LITTLE_ENDIAN
SYS_SUPPORTS_LITTLE_ENDIAN __LITTLE_ENDIAN

riscv is little-endian, but no any LITTLE_ENDIAN definition.

So let's keep them in the patch, first, Thx

>
>         Arnd



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 08/17] riscv: compat: syscall: Add compat_sys_call_table implementation

[Arnd Bergmann]

On Sun, Jan 30, 2022 at 6:54 AM Guo Ren <guoren@kernel.org> wrote:
> On Sun, Jan 30, 2022 at 6:41 AM Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > I would make these endian-specific, and reverse them on big-endian
> > architectures. That way it
> > should be possible to share them across all compat architectures
> > without needing the override
> > option.
> I hope it could be another patch. Because it's not clear to
> _LITTLE_ENDIAN definition in archs.
>
> eg: Names could be __ORDER_LITTLE_ENDIAN__ CPU_LITTLE_ENDIAN
> SYS_SUPPORTS_LITTLE_ENDIAN __LITTLE_ENDIAN
>
> riscv is little-endian, but no any LITTLE_ENDIAN definition.
>
> So let's keep them in the patch, first, Thx

The correct way to do it is to check for CONFIG_CPU_BIG_ENDIAN,
which works on all architectures. Since nothing else selects the
__ARCH_WANT_COMPAT_* symbols, there is also no risk for
regressions, so just use this and leave the #ifndef compat_arg_u64
check in place.

      Arnd

Re: [PATCH V4 06/17] riscv: compat: Add basic compat date type implementation

[Arnd Bergmann]

On Sun, Jan 30, 2022 at 6:47 AM Guo Ren <guoren@kernel.org> wrote:
>
> On Sun, Jan 30, 2022 at 5:56 AM Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > On Sat, Jan 29, 2022 at 1:17 PM <guoren@kernel.org> wrote:
> > > +
> > > +#define COMPAT_RLIM_INFINITY   0x7fffffff
> > >
> > > +#define F_GETLK64      12
> > > +#define F_SETLK64      13
> > > +#define F_SETLKW64     14
> >
> > These now come from the generic definitions I think. The flock definitions
> > are just the normal ones,
> Yes, it could be removed after Christoph Hellwig's patch merged.

Rgiht, I keep forgetting that this is a separate series, so this is fine.

> > and AFAICT the RLIM_INIFINITY definition here
> > is actually wrong and should be the default 0xffffffffu to match the
> > native (~0UL) definition.
> Yes, native rv32 used ~0UL, although its task_size is only 2.4GB.

The rlimit range has very little to do with the virtual memory address
limits, it is used for a number of other things that are typically more
limited in practice.

> I would remove #define COMPAT_RLIM_INFINITY   0x7fffffff

Ok.

       Arnd

Re: [PATCH V4 08/17] riscv: compat: syscall: Add compat_sys_call_table implementation

[Guo Ren]

On Sun, Jan 30, 2022 at 7:32 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Sun, Jan 30, 2022 at 6:54 AM Guo Ren <guoren@kernel.org> wrote:
> > On Sun, Jan 30, 2022 at 6:41 AM Arnd Bergmann <arnd@arndb.de> wrote:
> > >
> > > I would make these endian-specific, and reverse them on big-endian
> > > architectures. That way it
> > > should be possible to share them across all compat architectures
> > > without needing the override
> > > option.
> > I hope it could be another patch. Because it's not clear to
> > _LITTLE_ENDIAN definition in archs.
> >
> > eg: Names could be __ORDER_LITTLE_ENDIAN__ CPU_LITTLE_ENDIAN
> > SYS_SUPPORTS_LITTLE_ENDIAN __LITTLE_ENDIAN
> >
> > riscv is little-endian, but no any LITTLE_ENDIAN definition.
> >
> > So let's keep them in the patch, first, Thx
>
> The correct way to do it is to check for CONFIG_CPU_BIG_ENDIAN,
> which works on all architectures. Since nothing else selects the
> __ARCH_WANT_COMPAT_* symbols, there is also no risk for
> regressions, so just use this and leave the #ifndef compat_arg_u64
> check in place.
Okay, got it.

>
>       Arnd



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 01/17] kconfig: Add SYSVIPC_COMPAT for all architectures

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH V4 02/17] fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH V4 03/17] asm-generic: compat: Cleanup duplicate definitions

[Christoph Hellwig]

On Sat, Jan 29, 2022 at 08:17:14PM +0800, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> There are 7 64bit architectures that support Linux COMPAT mode to
> run 32bit applications. A lot of definitions are duplicate:
>  - COMPAT_USER_HZ
>  - COMPAT_RLIM_INFINITY
>  - COMPAT_OFF_T_MAX
>  - __compat_uid_t, __compat_uid_t
>  - compat_dev_t
>  - compat_ipc_pid_t
>  - struct compat_flock
>  - struct compat_flock64
>  - struct compat_statfs
>  - struct compat_ipc64_perm, compat_semid64_ds,
> 	  compat_msqid64_ds, compat_shmid64_ds
> 
> Cleanup duplicate definitions and merge them into asm-generic.

The flock part seems to clash with the general compat_flock
consolidation.  Otherwise this looks like a good idea.

Re: [PATCH V4 04/17] syscalls: compat: Fix the missing part for __SYSCALL_COMPAT

[Christoph Hellwig]

On Sat, Jan 29, 2022 at 08:17:15PM +0800, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> Make "uapi asm unistd.h" could be used for architectures' COMPAT
> mode. The __SYSCALL_COMPAT is first used in riscv.
> 
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH V4 05/17] riscv: Fixup difference with defconfig

[Christoph Hellwig]

On Sat, Jan 29, 2022 at 08:17:16PM +0800, guoren@kernel.org wrote:
> From: Guo Ren <guoren@linux.alibaba.com>
> 
> Let's follow the origin patch's spirit:
> 
> The only difference between rv32_defconfig and defconfig is that
> rv32_defconfig has  CONFIG_ARCH_RV32I=y.
> 
> This is helpful to compare rv64-compat-rv32 v.s. rv32-linux.
> 
> Fixes: 1b937e8faa87ccfb ("RISC-V: Add separate defconfig for 32bit systems")
> Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> Signed-off-by: Guo Ren <guoren@kernel.org>

Wouldn't a common.config that generats both the 32-bit and 64-bit
configs a better idea?

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Christoph Hellwig]

Given that most rv64 implementations can't run in rv32 mode, what is the
failure mode if someone tries it with the compat mode enabled?

Re: [PATCH V4 05/17] riscv: Fixup difference with defconfig

[Arnd Bergmann]

On Mon, Jan 31, 2022 at 1:23 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Sat, Jan 29, 2022 at 08:17:16PM +0800, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > Let's follow the origin patch's spirit:
> >
> > The only difference between rv32_defconfig and defconfig is that
> > rv32_defconfig has  CONFIG_ARCH_RV32I=y.
> >
> > This is helpful to compare rv64-compat-rv32 v.s. rv32-linux.
> >
> > Fixes: 1b937e8faa87ccfb ("RISC-V: Add separate defconfig for 32bit systems")
> > Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
> > Signed-off-by: Guo Ren <guoren@kernel.org>
>
> Wouldn't a common.config that generats both the 32-bit and 64-bit
> configs a better idea?

I thought that is what the patch does, there is already the normal 64-bit
defconfig, and the new makefile target makes this shared with 32-bit
to prevent them from diverging again.

        Arnd

Re: [PATCH V4 05/17] riscv: Fixup difference with defconfig

[Christoph Hellwig]

On Mon, Jan 31, 2022 at 01:48:58PM +0100, Arnd Bergmann wrote:
> I thought that is what the patch does, there is already the normal 64-bit
> defconfig, and the new makefile target makes this shared with 32-bit
> to prevent them from diverging again.

I ment using a common fragment and the deriving both 32-bit and 64-bit
configs from it. The 64-bit specific fragment will be empty for now,
but we will sooner or later have an option that can only go into the
64-bit defconfig.

Re: [PATCH V4 05/17] riscv: Fixup difference with defconfig

[Arnd Bergmann]

On Mon, Jan 31, 2022 at 2:00 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Mon, Jan 31, 2022 at 01:48:58PM +0100, Arnd Bergmann wrote:
> > I thought that is what the patch does, there is already the normal 64-bit
> > defconfig, and the new makefile target makes this shared with 32-bit
> > to prevent them from diverging again.
>
> I ment using a common fragment and the deriving both 32-bit and 64-bit
> configs from it. The 64-bit specific fragment will be empty for now,
> but we will sooner or later have an option that can only go into the
> 64-bit defconfig.

Ah right, that should work as well, not sure if it makes much of a difference.

I suggested this method because it is the same thing we do on powerpc.

        Arnd

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Guo Ren]

On Mon, Jan 31, 2022 at 8:26 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> Given that most rv64 implementations can't run in rv32 mode, what is the
> failure mode if someone tries it with the compat mode enabled?
A static linked simple hello_world could still run on a non-compat
support hardware. But most rv32 apps would meet different userspace
segment faults.

Current code would let the machine try the rv32 apps without detecting
whether hw support or not.


-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 03/17] asm-generic: compat: Cleanup duplicate definitions

[Guo Ren]

On Mon, Jan 31, 2022 at 8:21 PM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Sat, Jan 29, 2022 at 08:17:14PM +0800, guoren@kernel.org wrote:
> > From: Guo Ren <guoren@linux.alibaba.com>
> >
> > There are 7 64bit architectures that support Linux COMPAT mode to
> > run 32bit applications. A lot of definitions are duplicate:
> >  - COMPAT_USER_HZ
> >  - COMPAT_RLIM_INFINITY
> >  - COMPAT_OFF_T_MAX
> >  - __compat_uid_t, __compat_uid_t
> >  - compat_dev_t
> >  - compat_ipc_pid_t
> >  - struct compat_flock
> >  - struct compat_flock64
> >  - struct compat_statfs
> >  - struct compat_ipc64_perm, compat_semid64_ds,
> >         compat_msqid64_ds, compat_shmid64_ds
> >
> > Cleanup duplicate definitions and merge them into asm-generic.
>
> The flock part seems to clash with the general compat_flock
> consolidation.  Otherwise this looks like a good idea.
Okay, In the next version, I would rebase on general compat_flock
consolidation v4.



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Christoph Hellwig]

On Mon, Jan 31, 2022 at 09:50:58PM +0800, Guo Ren wrote:
> On Mon, Jan 31, 2022 at 8:26 PM Christoph Hellwig <hch@infradead.org> wrote:
> >
> > Given that most rv64 implementations can't run in rv32 mode, what is the
> > failure mode if someone tries it with the compat mode enabled?
> A static linked simple hello_world could still run on a non-compat
> support hardware. But most rv32 apps would meet different userspace
> segment faults.
> 
> Current code would let the machine try the rv32 apps without detecting
> whether hw support or not.

Hmm, we probably want some kind of check for not even offer running
rv32 binaries.  I guess trying to write UXL some time during early
boot and catching the resulting exception would be the way to go?

> 
> 
> -- 
> Best Regards
>  Guo Ren
> 
> ML: https://lore.kernel.org/linux-csky/
---end quoted text---

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Guo Ren]

On Tue, Feb 1, 2022 at 3:45 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Mon, Jan 31, 2022 at 09:50:58PM +0800, Guo Ren wrote:
> > On Mon, Jan 31, 2022 at 8:26 PM Christoph Hellwig <hch@infradead.org> wrote:
> > >
> > > Given that most rv64 implementations can't run in rv32 mode, what is the
> > > failure mode if someone tries it with the compat mode enabled?
> > A static linked simple hello_world could still run on a non-compat
> > support hardware. But most rv32 apps would meet different userspace
> > segment faults.
> >
> > Current code would let the machine try the rv32 apps without detecting
> > whether hw support or not.
>
> Hmm, we probably want some kind of check for not even offer running
> rv32 binaries.  I guess trying to write UXL some time during early
> boot and catching the resulting exception would be the way to go?

Emm... I think it's unnecessary. Free rv32 app running won't cause
system problem, just as a wrong elf running. They are U-mode
privileged.
>
> >
> >
> > --
> > Best Regards
> >  Guo Ren
> >
> > ML: https://lore.kernel.org/linux-csky/
> ---end quoted text---



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Arnd Bergmann]

On Tue, Feb 1, 2022 at 10:13 AM Guo Ren <guoren@kernel.org> wrote:
> On Tue, Feb 1, 2022 at 3:45 PM Christoph Hellwig <hch@lst.de> wrote:
> > On Mon, Jan 31, 2022 at 09:50:58PM +0800, Guo Ren wrote:
> > > On Mon, Jan 31, 2022 at 8:26 PM Christoph Hellwig <hch@infradead.org> wrote:
> > > >
> > > > Given that most rv64 implementations can't run in rv32 mode, what is the
> > > > failure mode if someone tries it with the compat mode enabled?
> > > A static linked simple hello_world could still run on a non-compat
> > > support hardware. But most rv32 apps would meet different userspace
> > > segment faults.
> > >
> > > Current code would let the machine try the rv32 apps without detecting
> > > whether hw support or not.
> >
> > Hmm, we probably want some kind of check for not even offer running
> > rv32 binaries.  I guess trying to write UXL some time during early
> > boot and catching the resulting exception would be the way to go?
>
> Emm... I think it's unnecessary. Free rv32 app running won't cause
> system problem, just as a wrong elf running. They are U-mode
> privileged.

While it's not a security issue, I think it would be helpful to get a
user-readable error message and a machine-readable /proc/cpuinfo
flag to see if a particular system can run rv32 binaries rather than
relying on SIGILL to kill a process.

        Arnd

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Guo Ren]

Hi Arnd & Christoph,

The UXL field controls the value of XLEN for U-mode, termed UXLEN,
which may differ from the
value of XLEN for S-mode, termed SXLEN. The encoding of UXL is the
same as that of the MXL
field of misa, shown in Table 3.1.

Here is the patch. (We needn't exception helper, because we are in
S-mode and UXL wouldn't affect.)

 arch/riscv/include/asm/elf.h       |  5 ++++-
 arch/riscv/include/asm/processor.h |  1 +
 arch/riscv/kernel/process.c        | 22 ++++++++++++++++++++++
 arch/riscv/kernel/setup.c          |  5 +++++
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index 37f1cbdaa242..6baa49c4fba1 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -35,7 +35,10 @@
  */
 #define elf_check_arch(x) ((x)->e_machine == EM_RISCV)

-#define compat_elf_check_arch(x) ((x)->e_machine == EM_RISCV)
+#ifdef CONFIG_COMPAT
+#define compat_elf_check_arch compat_elf_check_arch
+extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
+#endif

 #define CORE_DUMP_USE_REGSET
 #define ELF_EXEC_PAGESIZE (PAGE_SIZE)
diff --git a/arch/riscv/include/asm/processor.h
b/arch/riscv/include/asm/processor.h
index 9544c138d9ce..8b288ac0d704 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -64,6 +64,7 @@ extern void start_thread(struct pt_regs *regs,
 #ifdef CONFIG_COMPAT
 extern void compat_start_thread(struct pt_regs *regs,
  unsigned long pc, unsigned long sp);
+extern void compat_mode_detect(void);

 #define DEFAULT_MAP_WINDOW_64 TASK_SIZE_64
 #else
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 9ebf9a95e5ea..496d09c5d384 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -101,6 +101,28 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 }

 #ifdef CONFIG_COMPAT
+static bool compat_mode_support __read_mostly = false;
+
+bool compat_elf_check_arch(Elf32_Ehdr *hdr)
+{
+ if (compat_mode_support && (hdr->e_machine == EM_RISCV))
+ return true;
+
+ return false;
+}
+
+void compat_mode_detect(void)
+{
+ unsigned long tmp = csr_read(CSR_STATUS);
+ csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
+
+ if ((csr_read(CSR_STATUS) & SR_UXL) != SR_UXL_32) {
+ csr_write(CSR_STATUS, tmp);
+ return;
+ }
+
+ csr_write(CSR_STATUS, tmp);
+ compat_mode_support = true;
+
+ pr_info("riscv: compat: 32bit U-mode applications support\n");
+}
+
 void compat_start_thread(struct pt_regs *regs, unsigned long pc,
  unsigned long sp)
 {
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index b42bfdc67482..be131219d549 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -12,6 +12,7 @@
 #include <linux/mm.h>
 #include <linux/memblock.h>
 #include <linux/sched.h>
+#include <linux/compat.h>
 #include <linux/console.h>
 #include <linux/screen_info.h>
 #include <linux/of_fdt.h>
@@ -294,6 +295,10 @@ void __init setup_arch(char **cmdline_p)
  setup_smp();
 #endif

+#ifdef CONFIG_COMPAT
+ compat_mode_detect();
+#endif
+
  riscv_fill_hwcap();
 }
On Tue, Feb 1, 2022 at 5:36 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Tue, Feb 1, 2022 at 10:13 AM Guo Ren <guoren@kernel.org> wrote:
> > On Tue, Feb 1, 2022 at 3:45 PM Christoph Hellwig <hch@lst.de> wrote:
> > > On Mon, Jan 31, 2022 at 09:50:58PM +0800, Guo Ren wrote:
> > > > On Mon, Jan 31, 2022 at 8:26 PM Christoph Hellwig <hch@infradead.org> wrote:
> > > > >
> > > > > Given that most rv64 implementations can't run in rv32 mode, what is the
> > > > > failure mode if someone tries it with the compat mode enabled?
> > > > A static linked simple hello_world could still run on a non-compat
> > > > support hardware. But most rv32 apps would meet different userspace
> > > > segment faults.
> > > >
> > > > Current code would let the machine try the rv32 apps without detecting
> > > > whether hw support or not.
> > >
> > > Hmm, we probably want some kind of check for not even offer running
> > > rv32 binaries.  I guess trying to write UXL some time during early
> > > boot and catching the resulting exception would be the way to go?
> >
> > Emm... I think it's unnecessary. Free rv32 app running won't cause
> > system problem, just as a wrong elf running. They are U-mode
> > privileged.
>
> While it's not a security issue, I think it would be helpful to get a
> user-readable error message and a machine-readable /proc/cpuinfo
> flag to see if a particular system can run rv32 binaries rather than
> relying on SIGILL to kill a process.
--
2.25.1


>
>         Arnd



--
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Arnd Bergmann]

On Tue, Feb 1, 2022 at 11:26 AM Guo Ren <guoren@kernel.org> wrote:
>
> Hi Arnd & Christoph,
>
> The UXL field controls the value of XLEN for U-mode, termed UXLEN,
> which may differ from the
> value of XLEN for S-mode, termed SXLEN. The encoding of UXL is the
> same as that of the MXL
> field of misa, shown in Table 3.1.
>
> Here is the patch. (We needn't exception helper, because we are in
> S-mode and UXL wouldn't affect.)

Looks good to me, just a few details that could be improved

> -#define compat_elf_check_arch(x) ((x)->e_machine == EM_RISCV)
> +#ifdef CONFIG_COMPAT
> +#define compat_elf_check_arch compat_elf_check_arch
> +extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
> +#endif

No need for the #ifdef
> +}

> +void compat_mode_detect(void)

__init

> +{
> + unsigned long tmp = csr_read(CSR_STATUS);
> + csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
> +
> + if ((csr_read(CSR_STATUS) & SR_UXL) != SR_UXL_32) {
> + csr_write(CSR_STATUS, tmp);
> + return;
> + }
> +
> + csr_write(CSR_STATUS, tmp);
> + compat_mode_support = true;
> +
> + pr_info("riscv: compat: 32bit U-mode applications support\n");
> +}

I think an entry in /proc/cpuinfo would be more helpful than the pr_info at
boot time. Maybe a follow-up patch though, as there is no obvious place
to put it. On other architectures, you typically have a set of space
separated feature names, but riscv has a single string that describes
the ISA, and this feature is technically the support for a second ISA.

         Arnd

Re: [PATCH V4 16/17] riscv: compat: Add COMPAT Kbuild skeletal support

[Guo Ren]

On Tue, Feb 1, 2022 at 7:48 PM Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Tue, Feb 1, 2022 at 11:26 AM Guo Ren <guoren@kernel.org> wrote:
> >
> > Hi Arnd & Christoph,
> >
> > The UXL field controls the value of XLEN for U-mode, termed UXLEN,
> > which may differ from the
> > value of XLEN for S-mode, termed SXLEN. The encoding of UXL is the
> > same as that of the MXL
> > field of misa, shown in Table 3.1.
> >
> > Here is the patch. (We needn't exception helper, because we are in
> > S-mode and UXL wouldn't affect.)
>
> Looks good to me, just a few details that could be improved
>
> > -#define compat_elf_check_arch(x) ((x)->e_machine == EM_RISCV)
> > +#ifdef CONFIG_COMPAT
> > +#define compat_elf_check_arch compat_elf_check_arch
> > +extern bool compat_elf_check_arch(Elf32_Ehdr *hdr);
> > +#endif
>
> No need for the #ifdef
Okay

> > +}
>
> > +void compat_mode_detect(void)
>
> __init
Okay

>
> > +{
> > + unsigned long tmp = csr_read(CSR_STATUS);
> > + csr_write(CSR_STATUS, (tmp & ~SR_UXL) | SR_UXL_32);
> > +
> > + if ((csr_read(CSR_STATUS) & SR_UXL) != SR_UXL_32) {
> > + csr_write(CSR_STATUS, tmp);
> > + return;
> > + }
> > +
> > + csr_write(CSR_STATUS, tmp);
> > + compat_mode_support = true;
> > +
> > + pr_info("riscv: compat: 32bit U-mode applications support\n");
> > +}
>
> I think an entry in /proc/cpuinfo would be more helpful than the pr_info at
> boot time. Maybe a follow-up patch though, as there is no obvious place
> to put it. On other architectures, you typically have a set of space
> separated feature names, but riscv has a single string that describes
> the ISA, and this feature is technically the support for a second ISA.
Yes, it should be another patch after discussion.

>
>          Arnd



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/