linux-kernel - [tip: x86/bugs] x86/srso: Remove redundant X86_FEATURE_ENTRY

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Message-ID: <169295876899.27769.15911339219433317921.tip-bot2@tip-bot2>
Date:   Fri, 25 Aug 2023 10:19:28 -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>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/bugs] x86/srso: Remove redundant X86_FEATURE_ENTRY_IBPB check

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

Commit-ID:     071fcf6c28adcee293addd7258097949b8b54819
Gitweb:        https://git.kernel.org/tip/071fcf6c28adcee293addd7258097949b8b54819
Author:        Josh Poimboeuf <jpoimboe@...nel.org>
AuthorDate:    Fri, 25 Aug 2023 00:01:49 -07:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Fri, 25 Aug 2023 11:22:01 +02:00

x86/srso: Remove redundant X86_FEATURE_ENTRY_IBPB check

The X86_FEATURE_ENTRY_IBPB check is redundant here due to the above
RETBLEED_MITIGATION_IBPB check.  RETBLEED_MITIGATION_IBPB already
implies X86_FEATURE_ENTRY_IBPB.  So if we got here and 'has_microcode'
is true, it means X86_FEATURE_ENTRY_IBPB is not set.

Signed-off-by: Josh Poimboeuf <jpoimboe@...nel.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Link: https://lore.kernel.org/r/9b671422643939792afe05c625e93ef40d9b57b5.1692919072.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 b086fd4..563f09b 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2494,7 +2494,7 @@ static void __init srso_select_mitigation(void)
 
 	case SRSO_CMD_IBPB_ON_VMEXIT:
 		if (IS_ENABLED(CONFIG_CPU_SRSO)) {
-			if (!boot_cpu_has(X86_FEATURE_ENTRY_IBPB) && has_microcode) {
+			if (has_microcode) {
 				setup_force_cpu_cap(X86_FEATURE_IBPB_ON_VMEXIT);
 				srso_mitigation = SRSO_MITIGATION_IBPB_ON_VMEXIT;
 			}