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| author |   Peter Zijlstra <peterz@infradead.org> | 2022-06-14 23:15:37 +0200 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2022-06-27 10:33:58 +0200 |
| commit | 15e67227c49a57837108acfe1c80570e1bd9f962 (patch) | |
| tree | 1fd03816aa33ce35c51505a235fdf1f9fb58962d /arch/x86/include | |
| parent | x86/retpoline: Use -mfunction-return (diff) | |
| download | linux-dev-15e67227c49a57837108acfe1c80570e1bd9f962.tar.xz linux-dev-15e67227c49a57837108acfe1c80570e1bd9f962.zip | |
x86: Undo return-thunk damage
Introduce X86_FEATURE_RETHUNK for those afflicted with needing this.
[ bp: Do only INT3 padding - simpler. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/disabled-features.h | 3 |
3 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 9b10c8c76087..9542c582d546 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -76,6 +76,7 @@ extern int alternatives_patched; extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); extern void apply_retpolines(s32 *start, s32 *end); +extern void apply_returns(s32 *start, s32 *end); extern void apply_ibt_endbr(s32 *start, s32 *end); struct module; diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 4807302a32d9..295e69090fb8 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -300,6 +300,7 @@ /* FREE! (11*32+11) */ #define X86_FEATURE_RETPOLINE (11*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */ #define X86_FEATURE_RETPOLINE_LFENCE (11*32+13) /* "" Use LFENCE for Spectre variant 2 */ +#define X86_FEATURE_RETHUNK (11*32+14) /* "" Use REturn THUNK */ /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 4061f4907c92..641c479cca17 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -54,7 +54,8 @@ # define DISABLE_RETPOLINE 0 #else # define DISABLE_RETPOLINE ((1 << (X86_FEATURE_RETPOLINE & 31)) | \ - (1 << (X86_FEATURE_RETPOLINE_LFENCE & 31))) + (1 << (X86_FEATURE_RETPOLINE_LFENCE & 31)) | \ + (1 << (X86_FEATURE_RETHUNK & 31))) #endif #ifdef CONFIG_INTEL_IOMMU_SVM |