diff options
| author | Borislav Petkov (AMD) <bp@alien8.de> | 2026-04-07 11:40:03 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-04-17 06:04:42 -0700 |
| commit | e55d98e7756135f32150b9b8f75d580d0d4b2dd3 (patch) | |
| tree | 237ff6781f15dcaf2047a7868a2088b29058312a /arch/x86/include | |
| parent | 43cfbdda5af60ffc6272a7b8c5c37d1d0a181ca9 (diff) | |
| download | lwn-e55d98e7756135f32150b9b8f75d580d0d4b2dd3.tar.gz lwn-e55d98e7756135f32150b9b8f75d580d0d4b2dd3.zip | |
x86/CPU: Fix FPDSS on Zen1
Zen1's hardware divider can leave, under certain circumstances, partial
results from previous operations. Those results can be leaked by
another, attacker thread.
Fix that with a chicken bit.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 9dc6b610e4e2..a14a0f43e04a 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -674,6 +674,9 @@ #define MSR_AMD64_DC_CFG 0xc0011022 #define MSR_AMD64_TW_CFG 0xc0011023 +#define MSR_AMD64_FP_CFG 0xc0011028 +#define MSR_AMD64_FP_CFG_ZEN1_DENORM_FIX_BIT 9 + #define MSR_AMD64_DE_CFG 0xc0011029 #define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT 1 #define MSR_AMD64_DE_CFG_LFENCE_SERIALIZE BIT_ULL(MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT) |