Re: [syzbot] [mm?] [input?] [usb?] INFO: rcu detected stall in devtmpfsd (3)

[Hillf Danton]

> Date: Sun, 20 Jul 2025 07:21:33 -0700	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    155a3c003e55 Merge tag 'for-6.16/dm-fixes-2' of git://git...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15d3658c580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f62a2ef17395702a
> dashboard link: https://syzkaller.appspot.com/bug?extid=5583f599fe40b819b3e7
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1096f58c580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1686a382580000

#syz test upstream  master

--- x/kernel/time/hrtimer.c
+++ y/kernel/time/hrtimer.c
@@ -1942,7 +1942,7 @@ retry:
 	else
 		expires_next = ktime_add(now, delta);
 	tick_program_event(expires_next, 1);
-	pr_warn_once("hrtimer: interrupt took %llu ns\n", ktime_to_ns(delta));
+	WARN(1, "hrtimer: interrupt took %llu ns on cpu%u\n", ktime_to_ns(delta), cpu_base->cpu);
 }
 #endif /* !CONFIG_HIGH_RES_TIMERS */
 
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