On 2019/03/16 23:57, Dmitry Vyukov wrote: > On Sat, Mar 16, 2019 at 3:53 PM Tetsuo Handa > <penguin-ker...@i-love.sakura.ne.jp> 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. >
Then, we need to find what test is changing console_loglevel. Maybe add debug BUG_ON() in linux-next.git using CONFIG_DEBUG_AID_FOR_SYZBOT ?