linux-kernel - Re: Lockups due to "locking/rwsem: Make handoff bit handling more consistent"

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: <20220620140950.GB15453@techsingularity.net>
Date:   Mon, 20 Jun 2022 15:09:50 +0100
From:   Mel Gorman <mgorman@...hsingularity.net>
To:     Waiman Long <longman@...hat.com>
Cc:     Zhenhua Ma <mazhenhua@...omi.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>, Will Deacon <will@...nel.org>,
        Boqun Feng <boqun.feng@...il.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Michal Hocko <mhocko@...e.com>
Subject: Re: Lockups due to "locking/rwsem: Make handoff bit handling more
 consistent"

On Fri, Jun 17, 2022 at 10:29:20AM -0400, Waiman Long wrote:
> > The C file and shell script to run it are attached.
> > 
> Thanks for the reproducer and I will try to reproduce it locally.
> 
> It is a known issue that I have receive similar report from an Oracle
> engineer. That is the reason I posted commit 1ee326196c66 ("locking/rwsem:
> Always try to wake waiters in out_nolock path") that was merged in v5.19. I
> believe it helps but it may not be able to eliminate all possible race
> conditions. To make rwsem behave more like before commit d257cc8cb8d5
> ("locking/rwsem: Make handoff bit handling more consistent"), I posted a
> follow-up patch
> 
> https://lore.kernel.org/lkml/20220427173124.1428050-1-longman@redhat.com/
> 
> But it hasn't gotten review yet.
> 

FWIW, the patch passed the test case when applied to both 5.18 and
5.19-rc3.

-- 
Mel Gorman
SUSE Labs