From: Bart Van Assche <bvanassche@acm.org> To: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@linutronix.de>, Linus Torvalds <torvalds@linux-foundation.org>, linux-kernel@vger.kernel.org, Bart Van Assche <bvanassche@acm.org>, Tejun Heo <tj@kernel.org>, Qian Cai <cai@lca.pw>, syzbot+be0c198232f86389c3dd@syzkaller.appspotmail.com Subject: [PATCH] kernel/workqueue: Only unregister a lockdep key if it has been registered first Date: Mon, 11 Mar 2019 16:02:55 -0700 Message-ID: <20190311230255.176081-1-bvanassche@acm.org> (raw) Only call wq_unregister_lockdep() if wq_register_lockdep() has been called first. This patch avoids that the following warning is reported: WARNING: CPU: 1 PID: 6970 at kernel/locking/lockdep.c:4925 lockdep_unregister_key+0x21c/0x4e0 That warning refers to the following source code statement: WARN_ON_ONCE(!found); Cc: Tejun Heo <tj@kernel.org> Cc: Qian Cai <cai@lca.pw> Reported-by: syzbot+be0c198232f86389c3dd@syzkaller.appspotmail.com Fixes: 009bb421b6ce ("workqueue, lockdep: Fix an alloc_workqueue() error path") Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- kernel/workqueue.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4026d1871407..ddee541ea97a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4266,7 +4266,7 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, INIT_LIST_HEAD(&wq->list); if (alloc_and_link_pwqs(wq) < 0) - goto err_free_wq; + goto err_unreg_lockdep; if (wq_online && init_rescuer(wq) < 0) goto err_destroy; @@ -4292,9 +4292,10 @@ struct workqueue_struct *alloc_workqueue(const char *fmt, return wq; -err_free_wq: +err_unreg_lockdep: wq_unregister_lockdep(wq); wq_free_lockdep(wq); +err_free_wq: free_workqueue_attrs(wq->unbound_attrs); kfree(wq); return NULL; -- 2.21.0
next reply index Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-03-11 23:02 Bart Van Assche [this message] 2019-03-21 11:04 ` [tip:locking/urgent] workqueue: Only unregister a registered lockdep key tip-bot for Bart Van Assche
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