Re: Policy regarding linux-next only changes

[Tetsuo Handa]

On 2026/07/29 10:46, Theodore Tso wrote:
> On Wed, Jul 29, 2026 at 08:46:16AM -0500, Tetsuo Handa wrote:
>>>
>>> i.e. I was wondering whether the system could ignore the "WARNING:"s
>>> (and avoid the kernel panicking on them etc.) until after boot, i.e.
>>> when the fuzzing starts.
> 
> It could, but it would involve making a change in syzbot.
> Specifically, syzbot would have to be changed to boot the kernel being
> tested without the kernel.panic_on_warn=1 boot command line function,
> and then in the syzbot reproducer, to add the moral equivalent of
> 
>    echo 1 > /proc/sys/kernel/panic_on_warn

That does not help. syzbot stops not because the kernel calls panic()
but because the kernel emits "WARNING:" etc. followed by a stack trace.
The list of patterns is at
https://github.com/google/syzkaller/blob/master/pkg/report/linux.go .

For example, loop_check_io_race() in
https://lkml.kernel.org/r/30ccdd3c-6353-4a0f-bdc7-230ec3bf4765@xxxxxxxxxxxxxxxxxxx
will be sufficient to stop syzbot. Mimicking BUG*() or WARN*() using printk() +
stack dump function in order to get a difficult to reproduce problem reported by
syzbot is helpful. But unfortunately, no response to my patch for two weeks... :-(