From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
"Joel Fernandes" <joel@joelfernandes.org>,
"Todd Kjos" <tkjos@google.com>,
"Joel Fernandes" <joelaf@google.com>,
syzbot+a76129f18c89f3e2ddd4@syzkaller.appspotmail.com,
"Andi Kleen" <ak@linux.intel.com>,
"Johannes Weiner" <hannes@cmpxchg.org>, "Jan Kara" <jack@suse.cz>,
"Souptick Joarder" <jrdr.linux@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"Matthew Wilcox" <mawilcox@microsoft.com>,
"Mel Gorman" <mgorman@techsingularity.net>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
"Arve Hjønnevåg" <arve@android.com>,
"Todd Kjos" <tkjos@android.com>,
"Martijn Coenen" <maco@android.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
Subject: Re: possible deadlock in __do_page_fault
Date: Tue, 22 Jan 2019 19:32:34 +0900 [thread overview]
Message-ID: <c56d4d0b-8ecc-059d-69cb-4f3e91f9410c@i-love.sakura.ne.jp> (raw)
In-Reply-To: <CACT4Y+ZTjCGd9XYUCUoqv+AqXrPwX4OqWMC0jFgjNxZRFkNYXw@mail.gmail.com>
On 2019/01/22 19:12, Dmitry Vyukov wrote:
> On Tue, Jan 22, 2019 at 11:02 AM Tetsuo Handa
> <penguin-kernel@i-love.sakura.ne.jp> wrote:
>>
>> On 2018/09/22 8:21, Andrew Morton wrote:
>>> On Thu, 20 Sep 2018 19:33:15 -0400 Joel Fernandes <joel@joelfernandes.org> wrote:
>>>
>>>> On Thu, Sep 20, 2018 at 5:12 PM Todd Kjos <tkjos@google.com> wrote:
>>>>>
>>>>> +Joel Fernandes
>>>>>
>>>>> On Thu, Sep 20, 2018 at 2:11 PM Andrew Morton <akpm@linux-foundation.org> wrote:
>>>>>>
>>>>>>
>>>>>> Thanks. Let's cc the ashmem folks.
>>>>>>
>>>>
>>>> This should be fixed by https://patchwork.kernel.org/patch/10572477/
>>>>
>>>> It has Neil Brown's Reviewed-by but looks like didn't yet appear in
>>>> anyone's tree, could Greg take this patch?
>>>
>>> All is well. That went into mainline yesterday, with a cc:stable.
>>>
>>
>> This problem was not fixed at all.
>
> There are at least 2 other open deadlocks involving ashmem:
Yes, they involve ashmem_shrink_scan() => {shmem|vfs}_fallocate() sequence.
This approach tries to eliminate this sequence.
>
> https://syzkaller.appspot.com/bug?extid=148c2885d71194f18d28
> https://syzkaller.appspot.com/bug?extid=4b8b031b89e6b96c4b2e
>
> Does this fix any of these too?
I need checks from ashmem folks whether this approach is possible/correct.
But you can ask syzbot to test this patch before ashmem folks respond.
next prev parent reply other threads:[~2019-01-22 10:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-20 21:04 possible deadlock in __do_page_fault syzbot
2018-09-20 21:10 ` Andrew Morton
2018-09-20 21:12 ` Todd Kjos
2018-09-20 23:33 ` Joel Fernandes
2018-09-21 6:37 ` Dmitry Vyukov
2018-09-21 23:21 ` Andrew Morton
2019-01-22 10:02 ` Tetsuo Handa
2019-01-22 10:12 ` Dmitry Vyukov
2019-01-22 10:32 ` Tetsuo Handa [this message]
2019-01-22 13:52 ` Dmitry Vyukov
2019-01-22 13:54 ` Dmitry Vyukov
2019-01-22 14:08 ` syzbot
2019-01-22 15:32 ` Joel Fernandes
2019-01-23 2:01 ` Tetsuo Handa
2019-01-23 15:57 ` Joel Fernandes
2019-01-24 1:52 ` Tetsuo Handa
2019-01-24 13:46 ` Joel Fernandes
2019-01-25 16:02 ` Tetsuo Handa
2019-01-28 16:45 ` Joel Fernandes
2019-01-29 10:44 ` Tetsuo Handa
2019-01-26 1:57 ` Tetsuo Handa
2018-10-01 5:23 ` syzbot
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