linux-kernel - [tip: x86/urgent] x86/srso: Fix SBPB enablement for spec_rstack

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Message-ID: <169511670491.27769.1578583529325282203.tip-bot2@tip-bot2>
Date:   Tue, 19 Sep 2023 09:45:04 -0000
From:   "tip-bot2 for Josh Poimboeuf" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Josh Poimboeuf <jpoimboe@...nel.org>,
        Ingo Molnar <mingo@...nel.org>,
        "Borislav Petkov (AMD)" <bp@...en8.de>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/urgent] x86/srso: Fix SBPB enablement for spec_rstack_overflow=off

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@...nel.org>
AuthorDate:    Mon, 04 Sep 2023 22:04:48 -07:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
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@...nel.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Acked-by: Borislav Petkov (AMD) <bp@...en8.de>
Link: https://lore.kernel.org/r/b20820c3cfd1003171135ec8d762a0b957348497.1693889988.git.jpoimboe@kernel.org
---
 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) {