linux-kernel - [PATCH v3 4/7] x86/bugs: Remove uses of cpu_mitigations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250915134706.3201818-5-david.kaplan@amd.com>
Date: Mon, 15 Sep 2025 08:47:03 -0500
From: David Kaplan <david.kaplan@....com>
To: Thomas Gleixner <tglx@...utronix.de>, Borislav Petkov <bp@...en8.de>,
	Peter Zijlstra <peterz@...radead.org>, Josh Poimboeuf <jpoimboe@...nel.org>,
	Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>, Ingo Molnar
	<mingo@...hat.com>, Dave Hansen <dave.hansen@...ux.intel.com>,
	<x86@...nel.org>, "H . Peter Anvin" <hpa@...or.com>
CC: <linux-kernel@...r.kernel.org>
Subject: [PATCH v3 4/7] x86/bugs: Remove uses of cpu_mitigations_off()

cpu_mitigations_off() is no longer needed because all bugs use attack
vector controls to select a mitigation, and cpu_mitigations_off() is
equivalent to no attack vectors being selected.

Remove the few remaining unnecessary uses of this function in this file.

Signed-off-by: David Kaplan <david.kaplan@....com>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
---
 arch/x86/kernel/cpu/bugs.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index fe57e890d56c..d52600b89d60 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -687,8 +687,7 @@ static const char * const mmio_strings[] = {
 
 static void __init mmio_select_mitigation(void)
 {
-	if (!boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA) ||
-	     cpu_mitigations_off()) {
+	if (!boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) {
 		mmio_mitigation = MMIO_MITIGATION_OFF;
 		return;
 	}
@@ -3130,14 +3129,15 @@ static void __init srso_select_mitigation(void)
 
 static void __init srso_update_mitigation(void)
 {
+	if (!boot_cpu_has_bug(X86_BUG_SRSO))
+		return;
+
 	/* If retbleed is using IBPB, that works for SRSO as well */
 	if (retbleed_mitigation == RETBLEED_MITIGATION_IBPB &&
 	    boot_cpu_has(X86_FEATURE_IBPB_BRTYPE))
 		srso_mitigation = SRSO_MITIGATION_IBPB;
 
-	if (boot_cpu_has_bug(X86_BUG_SRSO) &&
-	    !cpu_mitigations_off())
-		pr_info("%s\n", srso_strings[srso_mitigation]);
+	pr_info("%s\n", srso_strings[srso_mitigation]);
 }
 
 static void __init srso_apply_mitigation(void)
-- 
2.34.1