On Fri, Nov 09, 2018 at 03:58:56PM +0000, Will Deacon wrote: > On Fri, Nov 09, 2018 at 02:37:51PM +0000, Jan Glauber wrote: > > I'm seeing the following oops reproducible with upstream kernel on arm64 > > (ThunderX2): > > [...] > > > It happens after 1-3 hours of running 'stress-ng --dev 128'. This testcase > > does a scandir of /dev and then calls random stuff like ioctl, lseek, > > open/close etc. on the entries. I assume no files are deleted under /dev > > during the testcase. > > > > The NULL pointer is the inode pointer of next. The next dentry->d_flags is > > DCACHE_RCUACCESS when this happens. > > > > Any hints on how to further debug this? > > Can you reproduce the issue with vanilla -rc1 and do you have a "known good" > kernel? I can try out -rc1, but IIRC this wasn't bisectible as the bug was present at least back to 4.14. I need to double check that as there were other issues that are resolved now so I may confuse things here. I've defintely seen the same bug with 4.18. Unfortunately I lost access to the machine as our data center seems to be moving currently so it might take some days until I can try -rc1. thanks, Jan
