From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Yao HongBo <yaohongbo@huawei.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
linuxarm@huawei.com, linux-kernel@vger.kernel.org
Subject: Re: possible deadlock in console_unlock
Date: Tue, 19 Feb 2019 10:32:54 +0900 [thread overview]
Message-ID: <20190219013254.GA20023@jagdpanzerIV> (raw)
In-Reply-To: <3fece106-baed-92f6-1389-62b8f2c4578b@huawei.com>
On (02/18/19 22:07), Yao HongBo wrote:
> >> I have tried GFP_NOWARN, but the problem still exists.
> >> Only print_safe contexts for tty locks can solve the problem.
> >> My test scenario is falt-injection.
> >
> > Oh, I see. Yes, fault-injection is special.
> >
> > I suspect that this patch series can be helpful then
> > https://lore.kernel.org/lkml/20181016050428.17966-1-sergey.senozhatsky@gmail.com/T/#u
>
> hi, sergey.
Hello,
> I merged this patch series on linux-4.19.18, but it didn't work for the fault-injection cases.
Thanks!
> The failure seems to be the same as before.
OK... So tty_port lock must switch to printk_safe, after all...
I had it in one of the previous versions of the patchset which you
have tested, but people were strictly against new locking rules
in TTY, so I dropped that part. Need to think what we can do here.
BTW,
we are now looking at a completely new printk implementation; which
would not use printk_safe at all:
https://lore.kernel.org/lkml/20190212143003.48446-1-john.ogness@linutronix.de/T/#u
-ss
next prev parent reply other threads:[~2019-02-19 1:33 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-16 6:36 possible deadlock in console_unlock Yao HongBo
2019-02-16 7:21 ` Sergey Senozhatsky
2019-02-16 7:46 ` Sergey Senozhatsky
2019-02-16 7:59 ` Yao HongBo
2019-02-18 5:46 ` Sergey Senozhatsky
2019-02-18 12:09 ` Yao HongBo
2019-02-18 14:07 ` Yao HongBo
2019-02-19 1:32 ` Sergey Senozhatsky [this message]
2019-02-19 2:48 ` Yao HongBo
-- strict thread matches above, loose matches on Subject: below --
2018-06-06 13:17 syzbot
2018-06-07 4:44 ` syzbot
2018-06-07 5:10 ` Sergey Senozhatsky
2018-06-07 11:00 ` Petr Mladek
2018-06-07 11:40 ` Tetsuo Handa
2018-06-07 14:03 ` Sergey Senozhatsky
2018-06-07 14:01 ` Sergey Senozhatsky
2018-06-08 8:18 ` Petr Mladek
2018-06-15 8:38 ` Sergey Senozhatsky
2018-06-19 8:04 ` Petr Mladek
2018-06-19 8:08 ` Sergey Senozhatsky
2019-02-20 10:52 ` Tetsuo Handa
2019-11-25 2:41 ` syzbot
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