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authorDavid Kaplan <david.kaplan@amd.com>2025-01-08 14:24:41 -0600
committerBorislav Petkov (AMD) <bp@alien8.de>2025-02-28 12:34:30 +0100
commit98c7a713db91c5a9a7ffc47cd85e7158e0963cb8 (patch)
treeef411f3eb9b069dcdcd1fb372859c4803208534a
parent8f64eee70cdd3bb8c3ec7d30f0d1f52922aaef7c (diff)
x86/bugs: Add X86_BUG_SPECTRE_V2_USER
All CPU vulnerabilities with command line options map to a single X86_BUG bit except for Spectre V2 where both the spectre_v2 and spectre_v2_user command line options are related to the same bug. The spectre_v2 command line options mostly relate to user->kernel and guest->host mitigations, while the spectre_v2_user command line options relate to user->user or guest->guest protections. Define a new X86_BUG bit for spectre_v2_user so each *_select_mitigation() function in bugs.c is related to a unique X86_BUG bit. No functional changes. Signed-off-by: David Kaplan <david.kaplan@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/20250108202515.385902-2-david.kaplan@amd.com
-rw-r--r--arch/x86/include/asm/cpufeatures.h1
-rw-r--r--arch/x86/kernel/cpu/common.c4
2 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index c8701abb7752..0bc420319ee2 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -537,4 +537,5 @@
#define X86_BUG_RFDS X86_BUG(1*32 + 2) /* "rfds" CPU is vulnerable to Register File Data Sampling */
#define X86_BUG_BHI X86_BUG(1*32 + 3) /* "bhi" CPU is affected by Branch History Injection */
#define X86_BUG_IBPB_NO_RET X86_BUG(1*32 + 4) /* "ibpb_no_ret" IBPB omits return target predictions */
+#define X86_BUG_SPECTRE_V2_USER X86_BUG(1*32 + 5) /* "spectre_v2_user" CPU is affected by Spectre variant 2 attack between user processes */
#endif /* _ASM_X86_CPUFEATURES_H */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7cce91b19fb2..1e80d76dc9c1 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1331,8 +1331,10 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
setup_force_cpu_bug(X86_BUG_SPECTRE_V1);
- if (!cpu_matches(cpu_vuln_whitelist, NO_SPECTRE_V2))
+ if (!cpu_matches(cpu_vuln_whitelist, NO_SPECTRE_V2)) {
setup_force_cpu_bug(X86_BUG_SPECTRE_V2);
+ setup_force_cpu_bug(X86_BUG_SPECTRE_V2_USER);
+ }
if (!cpu_matches(cpu_vuln_whitelist, NO_SSB) &&
!(x86_arch_cap_msr & ARCH_CAP_SSB_NO) &&