[PATCH v5 09/20] x86/bugs: Add attack vector controls for SRBDS

David Kaplan posted 20 patches 7 months, 1 week ago
There is a newer version of this series
[PATCH v5 09/20] x86/bugs: Add attack vector controls for SRBDS
Posted by David Kaplan 7 months, 1 week ago
Use attack vector controls to determine if SRBDS mitigation is required.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
 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