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* [RFC PATCH v2 00/21] KCFI support
@ 2022-05-13 20:21 ` Sami Tolvanen
  0 siblings, 0 replies; 174+ messages in thread
From: Sami Tolvanen @ 2022-05-13 20:21 UTC (permalink / raw)
  To: linux-kernel
  Cc: Kees Cook, Josh Poimboeuf, Peter Zijlstra, x86, Catalin Marinas,
	Will Deacon, Mark Rutland, Nathan Chancellor, Nick Desaulniers,
	Joao Moreira, Sedat Dilek, Steven Rostedt, linux-hardening,
	linux-arm-kernel, llvm, Sami Tolvanen

KCFI is a proposed forward-edge control-flow integrity scheme for
Clang, which is more suitable for kernel use than the existing CFI
scheme used by CONFIG_CFI_CLANG. KCFI doesn't require LTO, doesn't
alter function references to point to a jump table, and won't break
function address equality. The latest LLVM patch is here:

  https://reviews.llvm.org/D119296

This RFC series replaces the current arm64 CFI implementation with
KCFI and adds support for x86_64.

KCFI requires assembly functions that are indirectly called from C
code to be annotated with type identifiers. As type information is
only available in C, the compiler emits expected type identifiers into
the symbol table, so they can be referenced from assembly without
having to hardcode type hashes. Patch 7 adds helper macros for
annotating functions, and patches 9 and 17 add annotations.

In case of a type mismatch, KCFI always traps. To support error
handling, the compiler generates a .kcfi_traps section for x86_64,
which contains the locations of each trap, and for arm64, encodes
the necessary register information to the ESR. Patches 10 and 20 add
arch-specific error handlers.

To test this series, you'll need to compile your own Clang toolchain
with the patches linked above. You can also find the complete source
tree here:

  https://github.com/samitolvanen/llvm-project/commits/kcfi-rfc-v2

This series is also available in GitHub:

  https://github.com/samitolvanen/linux/commits/kcfi-rfc-v2

Sami Tolvanen (21):
  efi/libstub: Filter out CC_FLAGS_CFI
  arm64/vdso: Filter out CC_FLAGS_CFI
  kallsyms: Ignore __kcfi_typeid_
  cfi: Remove CONFIG_CFI_CLANG_SHADOW
  cfi: Drop __CFI_ADDRESSABLE
  cfi: Switch to -fsanitize=kcfi
  cfi: Add type helper macros
  psci: Fix the function type for psci_initcall_t
  arm64: Add types to indirect called assembly functions
  arm64: Add CFI error handling
  arm64: Drop unneeded __nocfi attributes
  treewide: Drop function_nocfi
  treewide: Drop WARN_ON_FUNCTION_MISMATCH
  treewide: Drop __cficanonical
  objtool: Don't warn about __cfi_ preambles falling through
  x86/tools/relocs: Ignore __kcfi_typeid_ relocations
  x86: Add types to indirectly called assembly functions
  x86/purgatory: Disable CFI
  x86/vdso: Disable CFI
  x86: Add support for CONFIG_CFI_CLANG
  init: Drop __nocfi from __init

 Makefile                                  |  13 +-
 arch/Kconfig                              |  21 +-
 arch/arm64/crypto/ghash-ce-core.S         |   5 +-
 arch/arm64/crypto/sm3-ce-core.S           |   3 +-
 arch/arm64/include/asm/brk-imm.h          |   6 +
 arch/arm64/include/asm/compiler.h         |  16 -
 arch/arm64/include/asm/ftrace.h           |   2 +-
 arch/arm64/include/asm/mmu_context.h      |   4 +-
 arch/arm64/kernel/acpi_parking_protocol.c |   2 +-
 arch/arm64/kernel/alternative.c           |   2 +-
 arch/arm64/kernel/cpu-reset.S             |   5 +-
 arch/arm64/kernel/cpufeature.c            |   4 +-
 arch/arm64/kernel/ftrace.c                |   2 +-
 arch/arm64/kernel/machine_kexec.c         |   2 +-
 arch/arm64/kernel/psci.c                  |   2 +-
 arch/arm64/kernel/smp_spin_table.c        |   2 +-
 arch/arm64/kernel/traps.c                 |  46 ++-
 arch/arm64/kernel/vdso/Makefile           |   3 +-
 arch/arm64/mm/proc.S                      |   5 +-
 arch/x86/Kconfig                          |   2 +
 arch/x86/crypto/blowfish-x86_64-asm_64.S  |   5 +-
 arch/x86/entry/vdso/Makefile              |   3 +-
 arch/x86/include/asm/linkage.h            |  12 +
 arch/x86/kernel/traps.c                   |  60 +++-
 arch/x86/lib/memcpy_64.S                  |   3 +-
 arch/x86/purgatory/Makefile               |   4 +
 arch/x86/tools/relocs.c                   |   1 +
 drivers/firmware/efi/libstub/Makefile     |   2 +
 drivers/firmware/psci/psci.c              |   6 +-
 drivers/misc/lkdtm/usercopy.c             |   2 +-
 include/asm-generic/bug.h                 |  16 -
 include/asm-generic/vmlinux.lds.h         |  37 +--
 include/linux/cfi.h                       |  65 ++--
 include/linux/cfi_types.h                 |  57 ++++
 include/linux/compiler-clang.h            |   6 +-
 include/linux/compiler.h                  |  16 +-
 include/linux/compiler_types.h            |   4 -
 include/linux/init.h                      |   6 +-
 include/linux/module.h                    |  10 +-
 include/linux/pci.h                       |   4 +-
 kernel/cfi.c                              | 343 ++++------------------
 kernel/kthread.c                          |   3 +-
 kernel/module.c                           |  49 +---
 kernel/workqueue.c                        |   2 +-
 scripts/kallsyms.c                        |   1 +
 scripts/module.lds.S                      |  23 +-
 tools/objtool/check.c                     |   4 +
 47 files changed, 357 insertions(+), 534 deletions(-)
 create mode 100644 include/linux/cfi_types.h

-- 
2.36.0.550.gb090851708-goog


^ permalink raw reply	[flat|nested] 174+ messages in thread

end of thread, other threads:[~2022-05-25 20:04 UTC | newest]

Thread overview: 174+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-13 20:21 [RFC PATCH v2 00/21] KCFI support Sami Tolvanen
2022-05-13 20:21 ` Sami Tolvanen
2022-05-13 20:21 ` [RFC PATCH v2 01/21] efi/libstub: Filter out CC_FLAGS_CFI Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:42   ` Kees Cook
2022-05-14 21:42     ` Kees Cook
2022-05-16 15:44     ` Sami Tolvanen
2022-05-16 15:44       ` Sami Tolvanen
2022-05-13 20:21 ` [RFC PATCH v2 02/21] arm64/vdso: " Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:42   ` Kees Cook
2022-05-14 21:42     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 03/21] kallsyms: Ignore __kcfi_typeid_ Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:43   ` Kees Cook
2022-05-14 21:43     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 04/21] cfi: Remove CONFIG_CFI_CLANG_SHADOW Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:43   ` Kees Cook
2022-05-14 21:43     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 05/21] cfi: Drop __CFI_ADDRESSABLE Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:44   ` Kees Cook
2022-05-14 21:44     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 06/21] cfi: Switch to -fsanitize=kcfi Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:46   ` Kees Cook
2022-05-14 21:46     ` Kees Cook
2022-05-15  3:41   ` Kees Cook
2022-05-15  3:41     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 07/21] cfi: Add type helper macros Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:49   ` Kees Cook
2022-05-14 21:49     ` Kees Cook
2022-05-16 12:28     ` Rasmus Villemoes
2022-05-16 12:28       ` Rasmus Villemoes
2022-05-16 16:23       ` Sami Tolvanen
2022-05-16 16:23         ` Sami Tolvanen
2022-05-16 16:04     ` Sami Tolvanen
2022-05-16 16:04       ` Sami Tolvanen
2022-05-13 20:21 ` [RFC PATCH v2 08/21] psci: Fix the function type for psci_initcall_t Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:50   ` Kees Cook
2022-05-14 21:50     ` Kees Cook
2022-05-16 15:44     ` Sami Tolvanen
2022-05-16 15:44       ` Sami Tolvanen
2022-05-17  8:47   ` Mark Rutland
2022-05-17  8:47     ` Mark Rutland
2022-05-13 20:21 ` [RFC PATCH v2 09/21] arm64: Add types to indirect called assembly functions Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:50   ` Kees Cook
2022-05-14 21:50     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 10/21] arm64: Add CFI error handling Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:51   ` Kees Cook
2022-05-14 21:51     ` Kees Cook
2022-05-16 16:24     ` Sami Tolvanen
2022-05-16 16:24       ` Sami Tolvanen
2022-05-13 20:21 ` [RFC PATCH v2 11/21] arm64: Drop unneeded __nocfi attributes Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:54   ` Kees Cook
2022-05-14 21:54     ` Kees Cook
2022-05-16 16:28     ` Sami Tolvanen
2022-05-16 16:28       ` Sami Tolvanen
2022-05-13 20:21 ` [RFC PATCH v2 12/21] treewide: Drop function_nocfi Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:54   ` Kees Cook
2022-05-14 21:54     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 13/21] treewide: Drop WARN_ON_FUNCTION_MISMATCH Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:54   ` Kees Cook
2022-05-14 21:54     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 14/21] treewide: Drop __cficanonical Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:56   ` Kees Cook
2022-05-14 21:56     ` Kees Cook
2022-05-16 16:32     ` Sami Tolvanen
2022-05-16 16:32       ` Sami Tolvanen
2022-05-13 20:21 ` [RFC PATCH v2 15/21] objtool: Don't warn about __cfi_ preambles falling through Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:56   ` Kees Cook
2022-05-14 21:56     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 16/21] x86/tools/relocs: Ignore __kcfi_typeid_ relocations Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:57   ` Kees Cook
2022-05-14 21:57     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 17/21] x86: Add types to indirectly called assembly functions Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:58   ` Kees Cook
2022-05-14 21:58     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 18/21] x86/purgatory: Disable CFI Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:58   ` Kees Cook
2022-05-14 21:58     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 19/21] x86/vdso: " Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 21:58   ` Kees Cook
2022-05-14 21:58     ` Kees Cook
2022-05-13 20:21 ` [RFC PATCH v2 20/21] x86: Add support for CONFIG_CFI_CLANG Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 22:02   ` Kees Cook
2022-05-14 22:02     ` Kees Cook
2022-05-16 18:57     ` Sami Tolvanen
2022-05-16 18:57       ` Sami Tolvanen
2022-05-15  3:19   ` Kees Cook
2022-05-15  3:19     ` Kees Cook
2022-05-16  8:32   ` David Laight
2022-05-16  8:32     ` David Laight
2022-05-16 16:39     ` Sami Tolvanen
2022-05-16 16:39       ` Sami Tolvanen
2022-05-16 21:32       ` David Laight
2022-05-16 21:32         ` David Laight
2022-05-16 21:44         ` Peter Zijlstra
2022-05-16 21:44           ` Peter Zijlstra
2022-05-16 22:03           ` Sami Tolvanen
2022-05-16 22:03             ` Sami Tolvanen
2022-05-17  6:44             ` Peter Zijlstra
2022-05-17  6:44               ` Peter Zijlstra
2022-05-17 20:36               ` Sami Tolvanen
2022-05-17 20:36                 ` Sami Tolvanen
2022-05-17  7:56             ` David Laight
2022-05-17  7:56               ` David Laight
2022-05-16  9:54   ` Peter Zijlstra
2022-05-16  9:54     ` Peter Zijlstra
2022-05-16 11:45     ` Peter Zijlstra
2022-05-16 11:45       ` Peter Zijlstra
2022-05-16 12:58       ` Peter Zijlstra
2022-05-16 12:58         ` Peter Zijlstra
2022-05-20 13:49         ` Matthew Wilcox
2022-05-20 13:49           ` Matthew Wilcox
2022-05-16 17:15     ` Sami Tolvanen
2022-05-16 17:15       ` Sami Tolvanen
2022-05-16 18:30       ` Peter Zijlstra
2022-05-16 18:30         ` Peter Zijlstra
2022-05-16 19:39         ` Sami Tolvanen
2022-05-16 19:39           ` Sami Tolvanen
2022-05-16 20:37           ` Peter Zijlstra
2022-05-16 20:37             ` Peter Zijlstra
2022-05-25 20:02             ` Kees Cook
2022-05-25 20:02               ` Kees Cook
2022-05-16 22:59         ` Kees Cook
2022-05-16 22:59           ` Kees Cook
2022-05-17  8:05           ` Peter Zijlstra
2022-05-17  8:05             ` Peter Zijlstra
2022-05-17  8:32             ` Joao Moreira
2022-05-17  8:32               ` Joao Moreira
2022-05-17  8:40             ` Peter Zijlstra
2022-05-17  8:40               ` Peter Zijlstra
2022-05-17  8:48               ` David Laight
2022-05-17  8:48                 ` David Laight
2022-05-17  9:38                 ` Peter Zijlstra
2022-05-17  9:38                   ` Peter Zijlstra
2022-05-13 20:21 ` [RFC PATCH v2 21/21] init: Drop __nocfi from __init Sami Tolvanen
2022-05-13 20:21   ` Sami Tolvanen
2022-05-14 22:03   ` Kees Cook
2022-05-14 22:03     ` Kees Cook
2022-05-16 17:16     ` Sami Tolvanen
2022-05-16 17:16       ` Sami Tolvanen
     [not found] ` <CA+icZUWr+-HjMvY1VZf+nqjTadxSTDciux0Y5Y-+p_j4o7CmXg@mail.gmail.com>
2022-05-16 17:57   ` [RFC PATCH v2 00/21] KCFI support Sami Tolvanen
2022-05-16 17:57     ` Sami Tolvanen
2022-05-17  7:33     ` Sedat Dilek
2022-05-17  7:33       ` Sedat Dilek
2022-05-17 18:49       ` Nathan Chancellor
2022-05-17 18:49         ` Nathan Chancellor
2022-05-19  9:01         ` Sedat Dilek
2022-05-19  9:01           ` Sedat Dilek
2022-05-19 20:26           ` Nathan Chancellor
2022-05-19 20:26             ` Nathan Chancellor
2022-05-19 20:41             ` Sami Tolvanen
2022-05-19 20:41               ` Sami Tolvanen
2022-05-17  8:57 ` Peter Zijlstra
2022-05-17  8:57   ` Peter Zijlstra
2022-05-17 20:25   ` Sami Tolvanen
2022-05-17 20:25     ` Sami Tolvanen

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