From: Sebastian Andrzej Siewior Date: Fri, 15 Nov 2019 18:01:25 +0000 (+0100) Subject: workqueue: Add RCU annotation for pwq list walk X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=49e9d1a9faf2f71fdfd80a30697ee9a15070626d;p=uclinux-h8%2Flinux.git workqueue: Add RCU annotation for pwq list walk An additional check has been recently added to ensure that a RCU related lock is held while the RCU list is iterated. The `pwqs' are sometimes iterated without a RCU lock but with the &wq->mutex acquired leading to a warning. Teach list_for_each_entry_rcu() that the RCU usage is okay if &wq->mutex is acquired during the list traversal. Fixes: 28875945ba98d ("rcu: Add support for consolidated-RCU reader checking") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tejun Heo --- diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 4dc8270326d7..914b845ad4ff 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -426,7 +426,8 @@ static void show_pwq(struct pool_workqueue *pwq); * ignored. */ #define for_each_pwq(pwq, wq) \ - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \ + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \ + lockdep_is_held(&wq->mutex)) \ if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \ else