linux-kernel - Re: [PATCH v4 4/4] mm: convert page kmemcg type to a page memcg flag

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: <20201002132557.GA525590@cmpxchg.org>
Date:   Fri, 2 Oct 2020 09:25:57 -0400
From:   Johannes Weiner <hannes@...xchg.org>
To:     Michal Koutný <mkoutny@...e.com>
Cc:     Roman Gushchin <guro@...com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Shakeel Butt <shakeelb@...gle.com>,
        Michal Hocko <mhocko@...nel.org>, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, kernel-team@...com
Subject: Re: [PATCH v4 4/4] mm: convert page kmemcg type to a page memcg flag

On Fri, Oct 02, 2020 at 12:03:50PM +0200, Michal Koutný wrote:
> On Thu, Oct 01, 2020 at 01:27:13PM -0400, Johannes Weiner <hannes@...xchg.org> wrote:
> > I do think there is a bug, though: mem_cgroup_move_account() should
> > use WRITE_ONCE() on page->mem_cgroup.
> If this were a bug, wouldn't be the proper approach
> rcu_assign_pointer()/rcu_dereference() pair?

Yes, you're right.

I'll double check these code paths and follow up with a patch if
necessary.