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authorLinus Torvalds <torvalds@linux-foundation.org>2021-10-12 02:59:49 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-10-12 02:59:49 +0300
commit0a5d6c641b671370f019cbe20fe51ee3ef00264c (patch)
treee4837d29b156e0bf09c84caf2fbcb3043a63c2b6 /kernel
parent1986c10acc9c906e453fb19d86e6342e8e525824 (diff)
parent57116ce17b04fde2fe30f0859df69d8dbe5809f6 (diff)
downloadlinux-0a5d6c641b671370f019cbe20fe51ee3ef00264c.tar.xz
Merge branch 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixes from Tejun Heo: "One patch to add a missing __printf annotation and the other to enable deferred printing for debug dumps to avoid deadlocks when triggered from some contexts (e.g. console drivers)" * 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix state-dump console deadlock workqueue: annotate alloc_workqueue() as printf
Diffstat (limited to 'kernel')
-rw-r--r--kernel/workqueue.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 33a6b4a2443d..1b3eb1e9531f 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4830,8 +4830,16 @@ void show_workqueue_state(void)
for_each_pwq(pwq, wq) {
raw_spin_lock_irqsave(&pwq->pool->lock, flags);
- if (pwq->nr_active || !list_empty(&pwq->inactive_works))
+ if (pwq->nr_active || !list_empty(&pwq->inactive_works)) {
+ /*
+ * Defer printing to avoid deadlocks in console
+ * drivers that queue work while holding locks
+ * also taken in their write paths.
+ */
+ printk_deferred_enter();
show_pwq(pwq);
+ printk_deferred_exit();
+ }
raw_spin_unlock_irqrestore(&pwq->pool->lock, flags);
/*
* We could be printing a lot from atomic context, e.g.
@@ -4849,7 +4857,12 @@ void show_workqueue_state(void)
raw_spin_lock_irqsave(&pool->lock, flags);
if (pool->nr_workers == pool->nr_idle)
goto next_pool;
-
+ /*
+ * Defer printing to avoid deadlocks in console drivers that
+ * queue work while holding locks also taken in their write
+ * paths.
+ */
+ printk_deferred_enter();
pr_info("pool %d:", pool->id);
pr_cont_pool_info(pool);
pr_cont(" hung=%us workers=%d",
@@ -4864,6 +4877,7 @@ void show_workqueue_state(void)
first = false;
}
pr_cont("\n");
+ printk_deferred_exit();
next_pool:
raw_spin_unlock_irqrestore(&pool->lock, flags);
/*