diff options
| author | Borislav Petkov (AMD) <bp@alien8.de> | 2023-08-05 01:06:43 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-08-09 17:55:00 +0300 |
| commit | 77245f1c3c6495521f6a3af082696ee2f8ce3921 (patch) | |
| tree | fca77ee5bfe3c557f190f201e39a82688f9ac9b4 /arch/x86/include/asm/processor.h | |
| parent | 13b9372068660fe4f7023f43081067376582ef3c (diff) | |
| download | linux-77245f1c3c6495521f6a3af082696ee2f8ce3921.tar.xz | |
x86/CPU/AMD: Do not leak quotient data after a division by 0
Under certain circumstances, an integer division by 0 which faults, can
leave stale quotient data from a previous division operation on Zen1
microarchitectures.
Do a dummy division 0/1 before returning from the #DE exception handler
in order to avoid any leaks of potentially sensitive data.
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 7c67db7c9f53..973db0406528 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -683,10 +683,12 @@ extern u16 get_llc_id(unsigned int cpu); extern u32 amd_get_nodes_per_socket(void); extern u32 amd_get_highest_perf(void); extern bool cpu_has_ibpb_brtype_microcode(void); +extern void amd_clear_divider(void); #else static inline u32 amd_get_nodes_per_socket(void) { return 0; } static inline u32 amd_get_highest_perf(void) { return 0; } static inline bool cpu_has_ibpb_brtype_microcode(void) { return false; } +static inline void amd_clear_divider(void) { } #endif extern unsigned long arch_align_stack(unsigned long sp); |