diff options
Diffstat (limited to 'arch/x86/kernel/cpu/bugs.c')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index b74bf937cd9f..af838b8d845c 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -386,7 +386,6 @@ static bool __init should_mitigate_vuln(unsigned int bug) case X86_BUG_SPECTRE_V2: case X86_BUG_RETBLEED: - case X86_BUG_SRSO: case X86_BUG_L1TF: case X86_BUG_ITS: return cpu_attack_vector_mitigated(CPU_MITIGATE_USER_KERNEL) || @@ -417,6 +416,10 @@ static bool __init should_mitigate_vuln(unsigned int bug) cpu_attack_vector_mitigated(CPU_MITIGATE_USER_USER) || cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_GUEST) || (smt_mitigations != SMT_MITIGATIONS_OFF); + + case X86_BUG_SPEC_STORE_BYPASS: + return cpu_attack_vector_mitigated(CPU_MITIGATE_USER_USER); + default: WARN(1, "Unknown bug %x\n", bug); return false; @@ -1069,10 +1072,8 @@ static void __init gds_select_mitigation(void) if (gds_mitigation == GDS_MITIGATION_AUTO) { if (should_mitigate_vuln(X86_BUG_GDS)) gds_mitigation = GDS_MITIGATION_FULL; - else { + else gds_mitigation = GDS_MITIGATION_OFF; - return; - } } /* No microcode */ @@ -2713,6 +2714,11 @@ static void __init ssb_select_mitigation(void) ssb_mode = SPEC_STORE_BYPASS_DISABLE; break; case SPEC_STORE_BYPASS_CMD_AUTO: + if (should_mitigate_vuln(X86_BUG_SPEC_STORE_BYPASS)) + ssb_mode = SPEC_STORE_BYPASS_PRCTL; + else + ssb_mode = SPEC_STORE_BYPASS_NONE; + break; case SPEC_STORE_BYPASS_CMD_PRCTL: ssb_mode = SPEC_STORE_BYPASS_PRCTL; break; @@ -3184,8 +3190,18 @@ static void __init srso_select_mitigation(void) } if (srso_mitigation == SRSO_MITIGATION_AUTO) { - if (should_mitigate_vuln(X86_BUG_SRSO)) { + /* + * Use safe-RET if user->kernel or guest->host protection is + * required. Otherwise the 'microcode' mitigation is sufficient + * to protect the user->user and guest->guest vectors. + */ + if (cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_HOST) || + (cpu_attack_vector_mitigated(CPU_MITIGATE_USER_KERNEL) && + !boot_cpu_has(X86_FEATURE_SRSO_USER_KERNEL_NO))) { srso_mitigation = SRSO_MITIGATION_SAFE_RET; + } else if (cpu_attack_vector_mitigated(CPU_MITIGATE_USER_USER) || + cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_GUEST)) { + srso_mitigation = SRSO_MITIGATION_MICROCODE; } else { srso_mitigation = SRSO_MITIGATION_NONE; return; |