linux-kernel - [PATCH v2 02/10] x86/apic: fix panic message when x2APIC is not supported

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: <20220911084711.13694-3-mat.jonczyk@o2.pl>
Date:   Sun, 11 Sep 2022 10:47:03 +0200
From:   Mateusz Jończyk <mat.jonczyk@...pl>
To:     linux-kernel@...r.kernel.org, x86@...nel.org
Cc:     Mateusz Jończyk <mat.jonczyk@...pl>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "H. Peter Anvin" <hpa@...or.com>, Johan Hovold <johan@...nel.org>,
        "Maciej W. Rozycki" <macro@...am.me.uk>,
        Yinghai Lu <yinghai@...nel.org>
Subject: [PATCH v2 02/10] x86/apic: fix panic message when x2APIC is not supported

The correct course of action is to enable x2APIC support in the kernel,
not to disable it in the BIOS (which may be impossible).
x2APIC has performance and functionality benefits, so it is best to use
it if it is available on the platform.

Signed-off-by: Mateusz Jończyk <mat.jonczyk@...pl>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: x86@...nel.org
Cc: "H. Peter Anvin" <hpa@...or.com>
Cc: Johan Hovold <johan@...nel.org>
Cc: "Maciej W. Rozycki" <macro@...am.me.uk>
Cc: Yinghai Lu <yinghai@...nel.org>
---
v2: add a newline at the end of the text

 arch/x86/kernel/apic/apic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 6d303d1d276c..206a2693a27a 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1902,7 +1902,7 @@ static int __init validate_x2apic(void)
 	/*
 	 * Checkme: Can we simply turn off x2apic here instead of panic?
 	 */
-	panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
+	panic("Kernel does not support x2APIC, please recompile with CONFIG_X86_X2APIC or disable x2APIC in BIOS.\n");
 }
 early_initcall(validate_x2apic);
 
-- 
2.25.1