Re: WARNING in collapse_file

[Andrew Morton]

On Fri, 25 Oct 2019 01:27:07 -0700 syzbot <syzbot+742a9c5d4ab05d343c49@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

> syzbot found the following crash on:
> 
> HEAD commit:    a6fcdcd9 Add linux-next specific files for 20191021
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=11145ed8e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=32434321999f01e9
> dashboard link: https://syzkaller.appspot.com/bug?extid=742a9c5d4ab05d343c49
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> 
> Unfortunately, I don't have any reproducer for this crash yet.
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+742a9c5d4ab05d343c49@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1080 at mm/khugepaged.c:1643  

Yup, thanks, this was addressed in v4:

https://ozlabs.org/~akpm/mmotm/broken-out/mmthp-recheck-each-page-before-collapsing-file-thp-v4.patch