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| author | Gatlin Newhouse <gatlin.newhouse@gmail.com> | 2024-07-24 00:01:55 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-08-06 13:42:40 +0200 |
| commit | 7424fc6b86c8980a87169e005f5cd4438d18efe6 (patch) | |
| tree | 090afe00201332780aef7b4a16369caf7ed17ba4 /arch/x86/include/asm/bug.h | |
| parent | 8400291e289ee6b2bf9779ff1c83a291501f017b (diff) | |
| download | lwn-7424fc6b86c8980a87169e005f5cd4438d18efe6.tar.gz lwn-7424fc6b86c8980a87169e005f5cd4438d18efe6.zip | |
x86/traps: Enable UBSAN traps on x86
Currently ARM64 extracts which specific sanitizer has caused a trap via
encoded data in the trap instruction. Clang on x86 currently encodes the
same data in the UD1 instruction but x86 handle_bug() and
is_valid_bugaddr() currently only look at UD2.
Bring x86 to parity with ARM64, similar to commit 25b84002afb9 ("arm64:
Support Clang UBSAN trap codes for better reporting"). See the llvm
links for information about the code generation.
Enable the reporting of UBSAN sanitizer details on x86 compiled with clang
when CONFIG_UBSAN_TRAP=y by analysing UD1 and retrieving the type immediate
which is encoded by the compiler after the UD1.
[ tglx: Simplified it by moving the printk() into handle_bug() ]
Signed-off-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20240724000206.451425-1-gatlin.newhouse@gmail.com
Link: https://github.com/llvm/llvm-project/commit/c5978f42ec8e9#diff-bb68d7cd885f41cfc35843998b0f9f534adb60b415f647109e597ce448e92d9f
Link: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/X86/X86InstrSystem.td#L27
Diffstat (limited to 'arch/x86/include/asm/bug.h')
| -rw-r--r-- | arch/x86/include/asm/bug.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index a3ec87d198ac..806649c7f23d 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -13,6 +13,18 @@ #define INSN_UD2 0x0b0f #define LEN_UD2 2 +/* + * In clang we have UD1s reporting UBSAN failures on X86, 64 and 32bit. + */ +#define INSN_ASOP 0x67 +#define OPCODE_ESCAPE 0x0f +#define SECOND_BYTE_OPCODE_UD1 0xb9 +#define SECOND_BYTE_OPCODE_UD2 0x0b + +#define BUG_NONE 0xffff +#define BUG_UD1 0xfffe +#define BUG_UD2 0xfffd + #ifdef CONFIG_GENERIC_BUG #ifdef CONFIG_X86_32 |