Unverified Commit 42a67bc7 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!5281 printk: avoid deadlock in panic 

Merge Pull Request from: @ci-robot 
 
PR sync from: Ye Weihua <yeweihua4@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/GPYHNG6NF2QOJIGOT7BQKZEJ5GSLKL27/ 
 
https://gitee.com/openeuler/kernel/issues/I991OV 
 
Link:https://gitee.com/openeuler/kernel/pulls/5281

 

Reviewed-by: default avatarXu Kuohai <xukuohai@huawei.com>
Reviewed-by: default avatarLiu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: default avatarZhang Changzhong <zhangchangzhong@huawei.com>
parents 72d884f2 e6471ff3

kernel/printk/printk.c

+7 −4
Original line number Diff line number Diff line
@@ -2426,7 +2426,7 @@ void console_unlock(void) 
	static char text[LOG_LINE_MAX + PREFIX_MAX];

	static int panic_console_dropped;

	unsigned long flags;

	bool do_cond_resched, retry;

	bool do_cond_resched, retry, locked = false;



	if (console_suspended) {

		up_console_sem();
@@ -2469,6 +2469,7 @@ void console_unlock(void) 


		printk_safe_enter_irqsave(flags);

		raw_spin_lock(&logbuf_lock);

		locked = true;

		if (console_seq < log_first_seq) {

			len = snprintf(text, sizeof(text),

				       "** %llu printk messages dropped **\n",
@@ -2520,6 +2521,7 @@ void console_unlock(void) 
		}

		console_idx = log_next(console_idx);

		console_seq++;

		locked = false;

		raw_spin_unlock(&logbuf_lock);



		/*
@@ -2539,18 +2541,19 @@ void console_unlock(void) 
			return;

		}



		printk_safe_exit_irqrestore(flags);



		/* Allow panic_cpu to take over the consoles safely */

		if (abandon_console_lock_in_panic())

			break;



		printk_safe_exit_irqrestore(flags);



		if (do_cond_resched)

			cond_resched();

	}



	console_locked = 0;



	if (likely(locked))

		raw_spin_unlock(&logbuf_lock);



	up_console_sem();