Re: WARNING in print_bfs_bug

[Peter Zijlstra]

On Sun, Sep 27, 2020 at 10:57:24AM +0200, Dmitry Vyukov wrote:
> On Thu, Oct 31, 2019 at 9:39 PM syzbot
> <syzbot+62ebe501c1ce9a91f68c@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > syzbot has found a reproducer for the following crash on:
> >
> > HEAD commit:    49afce6d Add linux-next specific files for 20191031
> > git tree:       linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=11eea36ce00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=3c5f119b33031056
> > dashboard link: https://syzkaller.appspot.com/bug?extid=62ebe501c1ce9a91f68c
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14c162f4e00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=131b5eb8e00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+62ebe501c1ce9a91f68c@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> This is another LOCKDEP-related top crasher. syzkaller finds just this
> one (see below).
> I think we need to disable LOCKDEP temporary until this and other
> LOCKDEP issues are resolved. I've filed
> https://github.com/google/syzkaller/issues/2140 to track
> disabling/enabling.

There is a potential patch for it:

  https://lkml.kernel.org/r/20200917080210.108095-1-boqun.feng@xxxxxxxxx

Let me try and digest it.