linux-kernel - Re: [PATCH v2] x86/power: Fix 'nosmt' vs. hibernation triple fault during resume

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: <nycvar.YFH.7.76.1905292000310.1962@cbobk.fhfr.pm>
Date:   Wed, 29 May 2019 20:02:47 +0200 (CEST)
From:   Jiri Kosina <jikos@...nel.org>
To:     Josh Poimboeuf <jpoimboe@...hat.com>
cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Pavel Machek <pavel@....cz>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <peterz@...radead.org>, x86@...nel.org,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] x86/power: Fix 'nosmt' vs. hibernation triple fault
 during resume

On Wed, 29 May 2019, Jiri Kosina wrote:

> The target kernel only onlines the CPUs which were online at the time of 
> hibernation (and are therefore in frozen_cpus mask).

Hm, there is a catch though. After resume, the SMT siblings are now in hlt 
instead of mwait.

Which means that the resumed kernel has to do one more online/offline 
cycle for them, to push them to mwait again.

Bah.

I'll send v3 shortly, so please don't apply v2 just yet.

-- 
Jiri Kosina
SUSE Labs