From a026dc61cffd98541e048f3c88d3280bcd105bd4 Mon Sep 17 00:00:00 2001 From: David Kaplan Date: Mon, 7 Jul 2025 13:33:15 -0500 Subject: [PATCH] x86/bugs: Print enabled attack vectors Print the status of enabled attack vectors and SMT mitigation status in the boot log for easier reporting and debugging. This information will also be available through sysfs. Signed-off-by: David Kaplan Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/20250707183316.1349127-21-david.kaplan@amd.com --- arch/x86/kernel/cpu/bugs.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index b9d0509e5e5ee..b74bf937cd9fb 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -189,6 +189,39 @@ DEFINE_STATIC_KEY_FALSE(switch_mm_cond_l1d_flush); DEFINE_STATIC_KEY_FALSE(cpu_buf_vm_clear); EXPORT_SYMBOL_GPL(cpu_buf_vm_clear); +#undef pr_fmt +#define pr_fmt(fmt) "mitigations: " fmt + +static void __init cpu_print_attack_vectors(void) +{ + pr_info("Enabled attack vectors: "); + + if (cpu_attack_vector_mitigated(CPU_MITIGATE_USER_KERNEL)) + pr_cont("user_kernel, "); + + if (cpu_attack_vector_mitigated(CPU_MITIGATE_USER_USER)) + pr_cont("user_user, "); + + if (cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_HOST)) + pr_cont("guest_host, "); + + if (cpu_attack_vector_mitigated(CPU_MITIGATE_GUEST_GUEST)) + pr_cont("guest_guest, "); + + pr_cont("SMT mitigations: "); + + switch (smt_mitigations) { + case SMT_MITIGATIONS_OFF: + pr_cont("off\n"); + break; + case SMT_MITIGATIONS_AUTO: + pr_cont("auto\n"); + break; + case SMT_MITIGATIONS_ON: + pr_cont("on\n"); + } +} + void __init cpu_select_mitigations(void) { /* @@ -209,6 +242,8 @@ void __init cpu_select_mitigations(void) x86_arch_cap_msr = x86_read_arch_cap_msr(); + cpu_print_attack_vectors(); + /* Select the proper CPU mitigations before patching alternatives: */ spectre_v1_select_mitigation(); spectre_v2_select_mitigation(); -- 2.47.2