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| author | Daniel Sneddon <daniel.sneddon@linux.intel.com> | 2024-03-13 19:47:57 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-04-08 20:27:05 +0300 |
| commit | 0f4a837615ff925ba62648d280a861adf1582df7 (patch) | |
| tree | 0dfeef27c4dbffd6e2b9afa52a5809cd92a244ae /arch/x86/kernel | |
| parent | 7390db8aea0d64e9deb28b8e1ce716f5020c7ee5 (diff) | |
| download | linux-0f4a837615ff925ba62648d280a861adf1582df7.tar.xz | |
x86/bhi: Define SPEC_CTRL_BHI_DIS_S
Newer processors supports a hardware control BHI_DIS_S to mitigate
Branch History Injection (BHI). Setting BHI_DIS_S protects the kernel
from userspace BHI attacks without having to manually overwrite the
branch history.
Define MSR_SPEC_CTRL bit BHI_DIS_S and its enumeration CPUID.BHI_CTRL.
Mitigation is enabled later.
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/scattered.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c index a515328d9d7d..af5aa2c754c2 100644 --- a/arch/x86/kernel/cpu/scattered.c +++ b/arch/x86/kernel/cpu/scattered.c @@ -28,6 +28,7 @@ static const struct cpuid_bit cpuid_bits[] = { { X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 }, { X86_FEATURE_INTEL_PPIN, CPUID_EBX, 0, 0x00000007, 1 }, { X86_FEATURE_RRSBA_CTRL, CPUID_EDX, 2, 0x00000007, 2 }, + { X86_FEATURE_BHI_CTRL, CPUID_EDX, 4, 0x00000007, 2 }, { X86_FEATURE_CQM_LLC, CPUID_EDX, 1, 0x0000000f, 0 }, { X86_FEATURE_CQM_OCCUP_LLC, CPUID_EDX, 0, 0x0000000f, 1 }, { X86_FEATURE_CQM_MBM_TOTAL, CPUID_EDX, 1, 0x0000000f, 1 }, |