netdev - Re: [PATCH 1/2] workqueue: Catch more locking problems with flush

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]

Date:	Fri, 20 Apr 2012 16:15:01 -0700
From:	Stephen Boyd <sboyd@...eaurora.org>
To:	Tejun Heo <tj@...nel.org>
CC:	linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
	Ben Dooks <ben-linux@...ff.org>
Subject: Re: [PATCH 1/2] workqueue: Catch more locking problems with flush_work()

On 4/20/2012 10:35 AM, Tejun Heo wrote:
>
> All that's necessary is acquiring and releasing work->lockdep_map.
> There's no need to nest start_flush_work() inside it.  Without
> nesting, there's nothing to worry about ABBA lockdeps.

Yes I see. This patch should work then?

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 5abf42f..038cf64 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2506,6 +2506,9 @@ bool flush_work(struct work_struct *work)
 {
        struct wq_barrier barr;

+       lock_map_acquire(&work->lockdep_map);
+       lock_map_release(&work->lockdep_map);
+
        if (start_flush_work(work, &barr, true)) {
                wait_for_completion(&barr.done);
                destroy_work_on_stack(&barr.work);


-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html