All of lore.kernel.org
 help / color / mirror / Atom feed
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.

  reply	other threads:[~2019-01-22 10:32 UTC|newest]

Thread overview: 25+ 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 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
2019-01-25 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
2019-01-26  1:57                       ` Tetsuo Handa
2018-10-01  5:23 ` syzbot

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c56d4d0b-8ecc-059d-69cb-4f3e91f9410c@i-love.sakura.ne.jp \
    --to=penguin-kernel@i-love.sakura.ne.jp \
    --cc=ak@linux.intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=arve@android.com \
    --cc=dvyukov@google.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hannes@cmpxchg.org \
    --cc=jack@suse.cz \
    --cc=joel@joelfernandes.org \
    --cc=joelaf@google.com \
    --cc=jrdr.linux@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=maco@android.com \
    --cc=mawilcox@microsoft.com \
    --cc=mgorman@techsingularity.net \
    --cc=syzbot+a76129f18c89f3e2ddd4@syzkaller.appspotmail.com \
    --cc=syzkaller-bugs@googlegroups.com \
    --cc=tkjos@android.com \
    --cc=tkjos@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.