Re: possible deadlock in aio_poll

2018-10-26 Thread syzbot
syzbot has found a reproducer for the following crash on: HEAD commit:18d0eae30e6a Merge tag 'char-misc-4.20-rc1' of git://git.k.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14728be540 kernel config: https://syzkaller.appspot.com/x/.config?x=342f43

Re: possible deadlock in aio_poll

2018-10-17 Thread Andrea Arcangeli
On Mon, Sep 10, 2018 at 09:53:17AM -0700, Christoph Hellwig wrote: > On Mon, Sep 10, 2018 at 12:41:05AM -0700, syzbot wrote: > > = > > WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected > > 4.19.0-rc2+ #229 Not tainted > > ---

Re: possible deadlock in aio_poll

2018-09-11 Thread Miklos Szeredi
On Tue, Sep 11, 2018 at 8:33 AM, Christoph Hellwig wrote: > On Mon, Sep 10, 2018 at 08:14:20PM +0200, Miklos Szeredi wrote: >> Why do pollable waitqueues need to disable interrupts generally? > > Any waitqueue needs to disable interrupts for consistency. We > always use spin_lock_irqsave in __wak

Re: possible deadlock in aio_poll

2018-09-10 Thread Christoph Hellwig
On Mon, Sep 10, 2018 at 08:14:20PM +0200, Miklos Szeredi wrote: > Why do pollable waitqueues need to disable interrupts generally? Any waitqueue needs to disable interrupts for consistency. We always use spin_lock_irqsave in __wake_up_common_lock() for example.

Re: possible deadlock in aio_poll

2018-09-10 Thread Miklos Szeredi
On Mon, Sep 10, 2018 at 6:53 PM, Christoph Hellwig wrote: > On Mon, Sep 10, 2018 at 12:41:05AM -0700, syzbot wrote: >> = >> WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected >> 4.19.0-rc2+ #229 Not tainted >> ---

Re: possible deadlock in aio_poll

2018-09-10 Thread Christoph Hellwig
On Mon, Sep 10, 2018 at 12:41:05AM -0700, syzbot wrote: > = > WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected > 4.19.0-rc2+ #229 Not tainted > - > syz-executor2/9399 [HC0[0]:SC0[0]:HE

possible deadlock in aio_poll

2018-09-10 Thread syzbot
Hello, syzbot found the following crash on: HEAD commit:f8f65382c98a Merge tag 'for-linus' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1587e26640 kernel config: https://syzkaller.appspot.com/x/.config?x=8f59875069d721b6 da