On Tue, Jan 22, 2019 at 2:52 PM Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > > On Tue, Jan 22, 2019 at 11:32 AM Tetsuo Handa > <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On 2019/01/22 19:12, Dmitry Vyukov wrote: > > > On Tue, Jan 22, 2019 at 11:02 AM Tetsuo Handa > > > <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote: > > >> > > >> On 2018/09/22 8:21, Andrew Morton wrote: > > >>> On Thu, 20 Sep 2018 19:33:15 -0400 Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote: > > >>> > > >>>> On Thu, Sep 20, 2018 at 5:12 PM Todd Kjos <tkjos@xxxxxxxxxx> wrote: > > >>>>> > > >>>>> +Joel Fernandes > > >>>>> > > >>>>> On Thu, Sep 20, 2018 at 2:11 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> 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. > > Right. Let's do this. > > As with any kernel changes only you really know how to apply it, git > tree/base commit info is missing, so let's do guessing and > finger-crossing as usual: > > #syz fix: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git > master This of course should be: #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
