On (02/16/19 16:21), Sergey Senozhatsky wrote: > On (02/16/19 14:36), Yao HongBo wrote: > > hi, sergey: > > > > As shown in that link, https://lkml.org/lkml/2018/6/6/397 > > > > On the linux kernel 5.0-rc6, Syzkaller also hit 'possible deadlock in > > console_unlock' > > bug for several times in my environment. > > > > This solution fixes things for me. Do you have a plan to submit patches to > > solve this problem. > > > > diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c > > __printk_safe_enter(); > > kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC); > > __printk_safe_exit(); > > I would probably try the following:
Yao HongBo, could you please post the lockdep splat? GFP_NOWARN is probably the best option for now. Yes, it, maybe, will not work for fault-injection cases; but printk_safe approach is harder to push for, especially given that printk_safe maybe will not even exist in the future. -ss