linux-kernel - Re: [PATCH v7 15/21] x86/split_lock: Add a sysfs interface to enable/disable split lock detection during run time

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]

Date:   Thu, 18 Apr 2019 00:47:24 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Fenghua Yu <fenghua.yu@...el.com>
cc:     Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        H Peter Anvin <hpa@...or.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Ashok Raj <ashok.raj@...el.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ravi V Shankar <ravi.v.shankar@...el.com>,
        Xiaoyao Li <xiaoyao.li@...el.com>,
        Christopherson Sean J <sean.j.christopherson@...el.com>,
        Kalle Valo <kvalo@...eaurora.org>,
        Michael Chan <michael.chan@...adcom.com>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        x86 <x86@...nel.org>, kvm@...r.kernel.org,
        netdev@...r.kernel.org, linux-wireless@...r.kernel.org
Subject: Re: [PATCH v7 15/21] x86/split_lock: Add a sysfs interface to
 enable/disable split lock detection during run time

On Wed, 17 Apr 2019, Fenghua Yu wrote:

> The interface /sys/device/system/cpu/split_lock_detect is added
> to allow user to control split lock detection and show current split
> lock detection setting.
> 
> Writing [yY1] or [oO][nN] to the file enables split lock detection and
> writing [nN0] or [oO][fF] disables split lock detection. Split lock
> detection is enabled or disabled on all CPUs.
> 
> Reading the file returns current global split lock detection setting:
> 0: disabled
> 1: enabled

Again, You explain WHAT this patch does and still there is zero
justification why this sysfs knob is needed at all. I still do not see any
reason why this knob should exist.

Thanks,

	tglx