linux-kernel - [PATCH] x86,spinlock: make disabling virt_spin_lock_key contingent on CONFIG

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-next>] [day] [month] [year] [list]

Message-ID: <20240715131853.313c3bae@imladris.surriel.com>
Date: Mon, 15 Jul 2024 13:18:53 -0400
From: Rik van Riel <riel@...riel.com>
To: Juergen Gross <jgross@...e.com>
Cc: Thomas Gleixner <tglx@...utronix.de>, Arnd Bergmann <arnd@...db.de>,
 linux-kernel@...r.kernel.org, x86@...nel.org, Ingo Molnar
 <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, Dave Hansen
 <dave.hansen@...ux.intel.com>, kernel-team@...a.com
Subject: [PATCH] x86,spinlock: make disabling virt_spin_lock_key contingent
 on CONFIG_PARAVIRT

The existence of virt_spin_lock_key is contingent only on CONFIG_PARAVIRT, not 
on CONFIG_PARAVIRT_SPINLOCKS.

As a result, a kernel with CONFIG_PARAVIRT enabled, but CONFIG_PARAVIRT_SPINLOCKS
disabled will end up disabling queued spinlocks when running on bare metal.

Making the disabling of virt_spin_lock_key contingent on CONFIG_PARAVIRT, which 
controls whether the key exists, results in queued spinlocks being enabled on
bare metal again.

Signed-off-by: Rik van Riel <riel@...riel.com>
Cc: stable@...r.kernel.org
Fixes: ce0a1b608bfc ("x86/paravirt: Silence unused native_pv_lock_init() function warning")
---
 arch/x86/kernel/paravirt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 5358d43886ad..dd542a9c6667 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -55,7 +55,7 @@ DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
 
 void __init native_pv_lock_init(void)
 {
-	if (IS_ENABLED(CONFIG_PARAVIRT_SPINLOCKS) &&
+	if (IS_ENABLED(CONFIG_PARAVIRT) &&
 	    !boot_cpu_has(X86_FEATURE_HYPERVISOR))
 		static_branch_disable(&virt_spin_lock_key);
 }
-- 
2.45.2