diff options
| author | Josh Poimboeuf <[email protected]> | 2023-09-04 22:04:45 -0700 |
|---|---|---|
| committer | Borislav Petkov (AMD) <[email protected]> | 2023-09-19 10:53:34 +0200 |
| commit | a8cf700c17d9ca6cb8ee7dc5c9330dbac3948237 (patch) | |
| tree | 64fc44764beadcd1f303536a84a5e3ec953e93e6 | |
| parent | 10f4c9b9a33b7df000f74fa0d896351fb1a61e6a (diff) | |
x86/srso: Fix srso_show_state() side effect
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 <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Nikolay Borisov <[email protected]>
Acked-by: Borislav Petkov (AMD) <[email protected]>
Link: https://lore.kernel.org/r/27d128899cb8aee9eb2b57ddc996742b0c1d776b.1693889988.git.jpoimboe@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 f081d26616ac..bdd3e296f72b 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2717,7 +2717,7 @@ 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 gds_show_state(char *buf) |