The following commit has been merged into the x86/bugs branch of tip:
Commit-ID: 1dbb6b1495d472806fef1f4c94f5b3e4c89a3c1d
Gitweb: https://git.kernel.org/tip/1dbb6b1495d472806fef1f4c94f5b3e4c89a3c1d
Author: David Kaplan <david.kaplan@xxxxxxx>
AuthorDate: Wed, 04 Sep 2024 10:07:11 -05:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Thu, 05 Sep 2024 11:20:50 +02:00
x86/bugs: Fix handling when SRSO mitigation is disabled
When the SRSO mitigation is disabled, either via mitigations=off or
spec_rstack_overflow=off, the warning about the lack of IBPB-enhancing
microcode is printed anyway.
This is unnecessary since the user has turned off the mitigation.
[ bp: Massage, drop SBPB rationale as it doesn't matter because when
mitigations are disabled x86_pred_cmd is not being used anyway. ]
Signed-off-by: David Kaplan <david.kaplan@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240904150711.193022-1-david.kaplan@xxxxxxx
---
arch/x86/kernel/cpu/bugs.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 189840d..d191542 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2557,10 +2557,9 @@ static void __init srso_select_mitigation(void)
{
bool has_microcode = boot_cpu_has(X86_FEATURE_IBPB_BRTYPE);
- if (cpu_mitigations_off())
- return;
-
- if (!boot_cpu_has_bug(X86_BUG_SRSO)) {
+ if (!boot_cpu_has_bug(X86_BUG_SRSO) ||
+ cpu_mitigations_off() ||
+ srso_cmd == SRSO_CMD_OFF) {
if (boot_cpu_has(X86_FEATURE_SBPB))
x86_pred_cmd = PRED_CMD_SBPB;
return;
@@ -2591,11 +2590,6 @@ static void __init srso_select_mitigation(void)
}
switch (srso_cmd) {
- case SRSO_CMD_OFF:
- if (boot_cpu_has(X86_FEATURE_SBPB))
- x86_pred_cmd = PRED_CMD_SBPB;
- return;
-
case SRSO_CMD_MICROCODE:
if (has_microcode) {
srso_mitigation = SRSO_MITIGATION_MICROCODE;
@@ -2649,6 +2643,8 @@ static void __init srso_select_mitigation(void)
pr_err("WARNING: kernel not compiled with MITIGATION_SRSO.\n");
}
break;
+ default:
+ break;
}
out:
|