public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

x86/bugs: Add X86_BUG_SPECTRE_V2_USER

Browse source 
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
This commit is contained in:
David Kaplan 2025-01-08 14:24:41 -06:00 • committed by Borislav Petkov (AMD)
parent 8f64eee70c
commit 98c7a713db
2 changed files with 4 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
arch/x86/include/asm/cpufeatures.h
View file

@ -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 */

4
arch/x86/kernel/cpu/common.c
View file

@ -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) &&