diff options
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 23 |
2 files changed, 25 insertions, 1 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index 573a137f5ac3..31fa631c8587 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -185,7 +185,8 @@ * where we have a stack but before any RET instruction. */ .macro UNTRAIN_RET -#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) +#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \ + defined(CONFIG_CPU_SRSO) ANNOTATE_UNRET_END ALTERNATIVE_2 "", \ CALL_ZEN_UNTRAIN_RET, X86_FEATURE_UNRET, \ diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 1be4f7186ba8..82417ce310cc 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -2315,18 +2315,21 @@ enum srso_mitigation { SRSO_MITIGATION_NONE, SRSO_MITIGATION_MICROCODE, SRSO_MITIGATION_SAFE_RET, + SRSO_MITIGATION_IBPB, }; enum srso_mitigation_cmd { SRSO_CMD_OFF, SRSO_CMD_MICROCODE, SRSO_CMD_SAFE_RET, + SRSO_CMD_IBPB, }; static const char * const srso_strings[] = { [SRSO_MITIGATION_NONE] = "Vulnerable", [SRSO_MITIGATION_MICROCODE] = "Mitigation: microcode", [SRSO_MITIGATION_SAFE_RET] = "Mitigation: safe RET", + [SRSO_MITIGATION_IBPB] = "Mitigation: IBPB", }; static enum srso_mitigation srso_mitigation __ro_after_init = SRSO_MITIGATION_NONE; @@ -2343,6 +2346,8 @@ static int __init srso_parse_cmdline(char *str) srso_cmd = SRSO_CMD_MICROCODE; else if (!strcmp(str, "safe-ret")) srso_cmd = SRSO_CMD_SAFE_RET; + else if (!strcmp(str, "ibpb")) + srso_cmd = SRSO_CMD_IBPB; else pr_err("Ignoring unknown SRSO option (%s).", str); @@ -2384,6 +2389,14 @@ static void __init srso_select_mitigation(void) setup_force_cpu_cap(X86_FEATURE_SRSO_NO); } + if (retbleed_mitigation == RETBLEED_MITIGATION_IBPB) { + if (has_microcode) { + pr_err("Retbleed IBPB mitigation enabled, using same for SRSO\n"); + srso_mitigation = SRSO_MITIGATION_IBPB; + goto pred_cmd; + } + } + switch (srso_cmd) { case SRSO_CMD_OFF: return; @@ -2408,6 +2421,16 @@ static void __init srso_select_mitigation(void) } break; + case SRSO_CMD_IBPB: + if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) { + if (has_microcode) { + setup_force_cpu_cap(X86_FEATURE_ENTRY_IBPB); + srso_mitigation = SRSO_MITIGATION_IBPB; + } + } else { + pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n"); + goto pred_cmd; + } default: break; } |