linux-kernel - Re: [PATCH v2 2/2] fscache: Add the missing smp_mb__after_atomic() before wake_up

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: <2432456.1673454299@warthog.procyon.org.uk>
Date:   Wed, 11 Jan 2023 16:24:59 +0000
From:   David Howells <dhowells@...hat.com>
To:     unlisted-recipients:; (no To-header on input)
Cc:     dhowells@...hat.com, Hou Tao <houtao@...weicloud.com>,
        linux-cachefs@...hat.com, Jeff Layton <jlayton@...nel.org>,
        linux-erofs@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
        Jingbo Xu <jefflexu@...ux.alibaba.com>, houtao1@...wei.com
Subject: Re: [PATCH v2 2/2] fscache: Add the missing smp_mb__after_atomic() before wake_up_bit()

David Howells <dhowells@...hat.com> wrote:

> What two values are you ordering?
> 
> If we're using this to create a critical section, then yes, we would need a
> barrier to order the changes inside the critical section before changing the
> memory location that forms the lock - but this is not a critical section.

Actually, that said, the ordering is probably between the bit being cleared
and the task state.

David