linux-kernel - Re: [PATCH v2] sched/core: fix illegal RCU from offline CPUs

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: <A72A7F42-A166-4403-B12C-32B2D7A662C4@lca.pw>
Date:   Thu, 23 Jan 2020 23:21:35 -0500
From:   Qian Cai <cai@....pw>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     mingo@...hat.com, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        paulmck@...nel.org, tglx@...utronix.de, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] sched/core: fix illegal RCU from offline CPUs



> On Jan 21, 2020, at 5:35 AM, Peter Zijlstra <peterz@...radead.org> wrote:
> 
> Something like this; except you'll need to go audit archs to make sure
> they all call idle_task_exit() and/or put in comments on why they don't
> have to (perhaps their bringup switches them to &init_mm unconditionally
> and the switch_mm() is not required).

Damn, I am having a hard time to motivate myself to learn all about those two “dead“ arches from scratch. I suppose the first step we could put a dummy finish_cpu() for alpha and parisc if they don’t call idle_task_exit() in the first place anyway, so if it is a bug there it is another issue that could be dealt with in a separate patch later?