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authorPawan Gupta <pawan.kumar.gupta@linux.intel.com>2022-08-04 00:41:32 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-08-31 18:15:22 +0300
commit14cbbb9c9914663d0eeca6b59c1c9d4f5a547ee0 (patch)
treeaea9ba3d69a383956662d8055b20821fa5929532 /arch/x86/include
parente3e0d117294dfd80ae788b375912e7fc307c51dd (diff)
downloadlinux-14cbbb9c9914663d0eeca6b59c1c9d4f5a547ee0.tar.xz
x86/bugs: Add "unknown" reporting for MMIO Stale Data
commit 7df548840c496b0141fb2404b889c346380c2b22 upstream. Older Intel CPUs that are not in the affected processor list for MMIO Stale Data vulnerabilities currently report "Not affected" in sysfs, which may not be correct. Vulnerability status for these older CPUs is unknown. Add known-not-affected CPUs to the whitelist. Report "unknown" mitigation status for CPUs that are not in blacklist, whitelist and also don't enumerate MSR ARCH_CAPABILITIES bits that reflect hardware immunity to MMIO Stale Data vulnerabilities. Mitigation is not deployed when the status is unknown. [ bp: Massage, fixup. ] Fixes: 8d50cdf8b834 ("x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data") Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com> Suggested-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/a932c154772f2121794a5f2eded1a11013114711.1657846269.git.pawan.kumar.gupta@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/cpufeatures.h5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 37ba0cdf99aa..f507ad7c7fd7 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -429,7 +429,8 @@
#define X86_BUG_ITLB_MULTIHIT X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
#define X86_BUG_SRBDS X86_BUG(24) /* CPU may leak RNG bits if not mitigated */
#define X86_BUG_MMIO_STALE_DATA X86_BUG(25) /* CPU is affected by Processor MMIO Stale Data vulnerabilities */
-#define X86_BUG_RETBLEED X86_BUG(26) /* CPU is affected by RETBleed */
-#define X86_BUG_EIBRS_PBRSB X86_BUG(27) /* EIBRS is vulnerable to Post Barrier RSB Predictions */
+#define X86_BUG_MMIO_UNKNOWN X86_BUG(26) /* CPU is too old and its MMIO Stale Data status is unknown */
+#define X86_BUG_RETBLEED X86_BUG(27) /* CPU is affected by RETBleed */
+#define X86_BUG_EIBRS_PBRSB X86_BUG(28) /* EIBRS is vulnerable to Post Barrier RSB Predictions */
#endif /* _ASM_X86_CPUFEATURES_H */