Re: [syzbot? printk?] no WARN_ON() messages printed before "Kernel panic - not syncing: panic_on_warn set ..."

[Dmitry Vyukov]

On Sat, Mar 16, 2019 at 3:53 PM Tetsuo Handa
<penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On 2019/03/16 23:16, Dmitry Vyukov wrote:
> >>> Maybe try running with "ignore_loglevel" kernel command line option added?
> >>
> >> Right, that's something I would expect 0-day and syzkaller to do.
> >
> > to double-check: enabling this won't lead to verbose/debug level of logging?
> >
>
> I don't know what "verbose/debug level" means. But enabling this option causes
> KERN_{EMERG,ALERT,CRIT,ERR,WARNING,NOTICE,INFO,DEBUG} be printed equally.
>
>   "ignore loglevel setting (prints all kernel messages to the console)"
>
> static bool suppress_message_printing(int level)
> {
>         return (level >= console_loglevel && !ignore_loglevel);
> }

Then I don't think it's suitable: there will be too much output.