Commit 0a5d6c64 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 1986c10a 57116ce1

include/linux/workqueue.h

+2 −3
Original line number Diff line number Diff line
@@ -399,9 +399,8 @@ extern struct workqueue_struct *system_freezable_power_efficient_wq; 
 * RETURNS:

 * Pointer to the allocated workqueue on success, %NULL on failure.

 */

struct workqueue_struct *alloc_workqueue(const char *fmt,

					 unsigned int flags,

					 int max_active, ...);

__printf(1, 4) struct workqueue_struct *

alloc_workqueue(const char *fmt, unsigned int flags, int max_active, ...);



/**

 * alloc_ordered_workqueue - allocate an ordered workqueue

kernel/workqueue.c

+16 −2
Original line number Diff line number Diff line
@@ -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);

		/*