Dmitry Vyukov wrote:
> On Sat, Apr 7, 2018 at 5:39 PM, Peter Zijlstra <pet...@infradead.org> wrote:
> > On Sat, Apr 07, 2018 at 09:31:19PM +0900, Tetsuo Handa wrote:
> >> are for replacing debug_show_all_locks() in check_hung_task() for cases
> >> like
> >> https://syzkaller.appspot.com/bug?id=26aa22915f5e3b7ca2cfca76a939f12c25d624db
> >> because we are interested in only threads holding locks.
> >> SysRq-t is too much but SysRq-w is useless for killable/interruptible
> >> threads...
> > Or use a script to process the sysrq-t output? I mean, we can add all
> > sorts, but where does it end?
Maybe allow khungtaskd to call call_usermode_helper() to run arbitrary
instead of just calling panic()?
> Good question.
> We are talking about few dozen more stacks, right?
> Not all kernel bugs are well reproducible, so it's not always possible
> to go back and hit sysrq-t. And this come up in the context of syzbot,
> which is an automated system. It reported a bunch of hangs and most of
> them are real bugs, but not all of them are easily actionable.
> Can it be a config or a command line argument, which will make syzbot
> capture more useful context for each such hang?
It will be nice if syzbot testing is done with kdump configured, and the
result of automated scripting on vmcore (such as "foreach bt -s -l") is