diff options
| author | Borislav Petkov (AMD) <bp@alien8.de> | 2023-08-13 12:39:34 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-26 13:27:00 +0200 |
| commit | dae93ed961a8a315cefe64491e8573c5d9e3484e (patch) | |
| tree | 5a7e6c3188811cc9949b02117d3cb1b3a855474e /arch/x86 | |
| parent | e4679a0342e05a962639a6ec3781f257f417f0ff (diff) | |
| download | linux-dae93ed961a8a315cefe64491e8573c5d9e3484e.tar.gz | |
x86/srso: Disable the mitigation on unaffected configurations
commit e9fbc47b818b964ddff5df5b2d5c0f5f32f4a147 upstream.
Skip the srso cmd line parsing which is not needed on Zen1/2 with SMT
disabled and with the proper microcode applied (latter should be the
case anyway) as those are not affected.
Fixes: 5a15d8348881 ("x86/srso: Tie SBPB bit setting to microcode patch detection")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230813104517.3346-1-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index c2f8f98f20d5..971f28944037 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2399,8 +2399,10 @@ static void __init srso_select_mitigation(void) * IBPB microcode has been applied. */ if ((boot_cpu_data.x86 < 0x19) && - (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) + (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) { setup_force_cpu_cap(X86_FEATURE_SRSO_NO); + return; + } } if (retbleed_mitigation == RETBLEED_MITIGATION_IBPB) { @@ -2686,6 +2688,9 @@ static ssize_t gds_show_state(char *buf) static ssize_t srso_show_state(char *buf) { + if (boot_cpu_has(X86_FEATURE_SRSO_NO)) + return sysfs_emit(buf, "Not affected\n"); + return sysfs_emit(buf, "%s%s\n", srso_strings[srso_mitigation], (cpu_has_ibpb_brtype_microcode() ? "" : ", no microcode")); |