linux-kernel - Re: [PATCH] x86/apic: Fix the issues in x2apic

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: <87a5hhsspm.ffs@tglx>
Date: Mon, 12 Aug 2024 16:48:05 +0200
From: Thomas Gleixner <tglx@...utronix.de>
To: Yuntao Wang <yuntao.wang@...ux.dev>, linux-kernel@...r.kernel.org,
 x86@...nel.org
Cc: Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, Dave
 Hansen <dave.hansen@...ux.intel.com>, "H. Peter Anvin" <hpa@...or.com>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>, Thorsten Blum
 <thorsten.blum@...lux.com>, Tony Luck <tony.luck@...el.com>, Daniel
 Sneddon <daniel.sneddon@...ux.intel.com>, Yuntao Wang
 <yuntao.wang@...ux.dev>
Subject: Re: [PATCH] x86/apic: Fix the issues in x2apic_disable()

On Mon, Aug 12 2024 at 18:08, Yuntao Wang wrote:
>  static __init void x2apic_disable(void)
>  {
> -	u32 x2apic_id, state = x2apic_state;
> +	u32 x2apic_id;
>  
> -	x2apic_mode = 0;
> -	x2apic_state = X2APIC_DISABLED;
> -
> -	if (state != X2APIC_ON)
> -		return;
> +	if (x2apic_state < X2APIC_ON)
> +		goto out;

There is no point in overwriting the state in case it is < ON, no?

Thanks,

        tglx