diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2026-02-11 13:59:43 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-02-23 11:19:11 +0100 |
| commit | 24c8147abb39618d74fcc36e325765e8fe7bdd7a (patch) | |
| tree | b8faeb69f6921d3e84d953965ab514ad990292ee /arch/x86/include | |
| parent | a0cb371b521dde44f32cfe954b6ef6f82b407393 (diff) | |
x86/cfi: Fix CFI rewrite for odd alignments
Rustam reported his clang builds did not boot properly; turns out his
.config has: CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y set.
Fix up the FineIBT code to deal with this unusual alignment.
Fixes: 931ab63664f0 ("x86/ibt: Implement FineIBT")
Reported-by: Rustam Kovhaev <rkovhaev@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Rustam Kovhaev <rkovhaev@gmail.com>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/cfi.h | 12 | ||||
| -rw-r--r-- | arch/x86/include/asm/linkage.h | 4 |
2 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/include/asm/cfi.h b/arch/x86/include/asm/cfi.h index c40b9ebc1fb4..ab3fbbd947ed 100644 --- a/arch/x86/include/asm/cfi.h +++ b/arch/x86/include/asm/cfi.h @@ -111,6 +111,12 @@ extern bhi_thunk __bhi_args_end[]; struct pt_regs; +#ifdef CONFIG_CALL_PADDING +#define CFI_OFFSET (CONFIG_FUNCTION_PADDING_CFI+5) +#else +#define CFI_OFFSET 5 +#endif + #ifdef CONFIG_CFI enum bug_trap_type handle_cfi_failure(struct pt_regs *regs); #define __bpfcall @@ -119,11 +125,9 @@ static inline int cfi_get_offset(void) { switch (cfi_mode) { case CFI_FINEIBT: - return 16; + return /* fineibt_prefix_size */ 16; case CFI_KCFI: - if (IS_ENABLED(CONFIG_CALL_PADDING)) - return 16; - return 5; + return CFI_OFFSET; default: return 0; } diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h index 9d38ae744a2e..a7294656ad90 100644 --- a/arch/x86/include/asm/linkage.h +++ b/arch/x86/include/asm/linkage.h @@ -68,7 +68,7 @@ * Depending on -fpatchable-function-entry=N,N usage (CONFIG_CALL_PADDING) the * CFI symbol layout changes. * - * Without CALL_THUNKS: + * Without CALL_PADDING: * * .align FUNCTION_ALIGNMENT * __cfi_##name: @@ -77,7 +77,7 @@ * .long __kcfi_typeid_##name * name: * - * With CALL_THUNKS: + * With CALL_PADDING: * * .align FUNCTION_ALIGNMENT * __cfi_##name: |