[PATCH v5 09/20] x86/bugs: Add attack vector controls for SRBDS
From: David Kaplan
Date: Fri May 09 2025 - 12:31:29 EST
Use attack vector controls to determine if SRBDS mitigation is required.
Signed-off-by: David Kaplan <david.kaplan@xxxxxxx>
---
arch/x86/kernel/cpu/bugs.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index e807176bc845..237ef8d0980a 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -848,13 +848,19 @@ 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
--
2.34.1