diff options
| author | Josh Poimboeuf | 2023-09-04 22:04:45 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-10-06 14:56:40 +0200 |
| commit | 755195b2d2df4d70952e5e5122c2cd590821be80 (patch) | |
| tree | 09dbc97f87172f6ba735ad305dc75528d95712f7 | |
| parent | 7f301aa243b9df34a7a2aa7c166a0cd79b37dd43 (diff) | |
x86/srso: Fix srso_show_state() side effect
[ Upstream commit a8cf700c17d9ca6cb8ee7dc5c9330dbac3948237 ]
Reading the 'spec_rstack_overflow' sysfs file can trigger an unnecessary
MSR write, and possibly even a (handled) exception if the microcode
hasn't been updated.
Avoid all that by just checking X86_FEATURE_IBPB_BRTYPE instead, which
gets set by srso_select_mitigation() if the updated microcode exists.
Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/27d128899cb8aee9eb2b57ddc996742b0c1d776b.1693889988.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 3a893ab398a0..5f38d60532a9 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2692,7 +2692,7 @@ static ssize_t srso_show_state(char *buf) return sysfs_emit(buf, "%s%s\n", srso_strings[srso_mitigation], - (cpu_has_ibpb_brtype_microcode() ? "" : ", no microcode")); + boot_cpu_has(X86_FEATURE_IBPB_BRTYPE) ? "" : ", no microcode"); } static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr, |