[tip: x86/urgent] x86/srso: Fix SBPB enablement for spec_rstack_overflow=off

From: tip-bot2 for Josh Poimboeuf
Date: Tue Sep 19 2023 - 05:45:15 EST


The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 01b057b2f4cc2d905a0bd92195657dbd9a7005ab
Gitweb: https://git.kernel.org/tip/01b057b2f4cc2d905a0bd92195657dbd9a7005ab
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Mon, 04 Sep 2023 22:04:48 -07:00
Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Tue, 19 Sep 2023 10:54:39 +02:00

x86/srso: Fix SBPB enablement for spec_rstack_overflow=off

If the user has requested no SRSO mitigation, other mitigations can use
the lighter-weight SBPB instead of IBPB.

Fixes: fb3bd914b3ec ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Acked-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/r/b20820c3cfd1003171135ec8d762a0b957348497.1693889988.git.jpoimboe@xxxxxxxxxx
---
arch/x86/kernel/cpu/bugs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index b0ae985..10499bc 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2433,7 +2433,7 @@ static void __init srso_select_mitigation(void)

switch (srso_cmd) {
case SRSO_CMD_OFF:
- return;
+ goto pred_cmd;

case SRSO_CMD_MICROCODE:
if (has_microcode) {