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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2024-03-11 12:29:43 -0700 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2024-03-11 13:13:48 -0700 |
| commit | 8076fcde016c9c0e0660543e67bff86cb48a7c9c (patch) | |
| tree | b07933926b045b08a417655be3f4310cebdbb1a6 /arch/x86/include/asm/cpufeatures.h | |
| parent | 4e42765d1be01111df0c0275bbaf1db1acef346e (diff) | |
| download | linux-8076fcde016c9c0e0660543e67bff86cb48a7c9c.tar.gz linux-8076fcde016c9c0e0660543e67bff86cb48a7c9c.tar.bz2 linux-8076fcde016c9c0e0660543e67bff86cb48a7c9c.zip | |
x86/rfds: Mitigate Register File Data Sampling (RFDS)
RFDS is a CPU vulnerability that may allow userspace to infer kernel
stale data previously used in floating point registers, vector registers
and integer registers. RFDS only affects certain Intel Atom processors.
Intel released a microcode update that uses VERW instruction to clear
the affected CPU buffers. Unlike MDS, none of the affected cores support
SMT.
Add RFDS bug infrastructure and enable the VERW based mitigation by
default, that clears the affected buffers just before exiting to
userspace. Also add sysfs reporting and cmdline parameter
"reg_file_data_sampling" to control the mitigation.
For details see:
Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/cpufeatures.h')
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 2b62cdd8dd12..8511aad59581 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -503,4 +503,5 @@ /* BUG word 2 */ #define X86_BUG_SRSO X86_BUG(1*32 + 0) /* AMD SRSO bug */ #define X86_BUG_DIV0 X86_BUG(1*32 + 1) /* AMD DIV0 speculation bug */ +#define X86_BUG_RFDS X86_BUG(1*32 + 2) /* CPU is vulnerable to Register File Data Sampling */ #endif /* _ASM_X86_CPUFEATURES_H */ |