The following commit has been merged into the x86/bugs branch of tip: Commit-ID: 98c7a713db91c5a9a7ffc47cd85e7158e0963cb8 Gitweb: https://git.kernel.org/tip/98c7a713db91c5a9a7ffc47cd85e7158e0963cb8 Author: David Kaplan <david.kaplan@xxxxxxx> AuthorDate: Wed, 08 Jan 2025 14:24:41 -06:00 Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx> CommitterDate: Fri, 28 Feb 2025 12:34:30 +01:00 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@xxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Link: https://lore.kernel.org/r/20250108202515.385902-2-david.kaplan@xxxxxxx --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/common.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index c8701ab..0bc4203 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 7cce91b..1e80d76 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) &&
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