From: David Kaplan Date: Mon, 7 Jul 2025 18:33:04 +0000 (-0500) Subject: x86/bugs: Add attack vector controls for SRBDS X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=71dc301c26e9503350cf4e736022cc1eb8e986a7;p=users%2Fjedix%2Flinux-maple.git x86/bugs: Add attack vector controls for SRBDS Use attack vector controls to determine if SRBDS mitigation is required. Signed-off-by: David Kaplan Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/20250707183316.1349127-10-david.kaplan@amd.com --- diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index a557d174a7519..de0b5efb0652e 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -870,13 +870,19 @@ void update_srbds_msr(void) static void __init srbds_select_mitigation(void) { - if (!boot_cpu_has_bug(X86_BUG_SRBDS) || cpu_mitigations_off()) { + if (!boot_cpu_has_bug(X86_BUG_SRBDS)) { srbds_mitigation = SRBDS_MITIGATION_OFF; return; } - if (srbds_mitigation == SRBDS_MITIGATION_AUTO) - srbds_mitigation = SRBDS_MITIGATION_FULL; + if (srbds_mitigation == SRBDS_MITIGATION_AUTO) { + if (should_mitigate_vuln(X86_BUG_SRBDS)) + srbds_mitigation = SRBDS_MITIGATION_FULL; + else { + srbds_mitigation = SRBDS_MITIGATION_OFF; + return; + } + } /* * Check to see if this is one of the MDS_NO systems supporting TSX that