Re: [PATCH] kconfig: Add kernel config option for fuzz testing.

[Sergey Senozhatsky]

On (19/12/17 08:54), Dmitry Vyukov wrote:
> On Tue, Dec 17, 2019 at 6:12 AM Sergey Senozhatsky
> <sergey.senozhatsky.work@xxxxxxxxx> wrote:
> >
> > On (19/12/16 18:59), Tetsuo Handa wrote:
> >
> > Can you fuzz test with `ignore_loglevel'?
> 
> We can set ignore_loglevel in syzbot configs, but won't it then print
> everything including verbose debug output?

What would be the most active source of debug output?

dev_dbg(), which is dev_printk(KERN_DEBUG), can be compiled out, if I'm
not mistaken. It probably depends on CONFIG_DEBUG or something similar,
unlike dev_printk(), which depends on CONFIG_PRINTK. It seems that we have
significantly more dev_dbg() users, than direct dev_printk(KERN_DEBUG).

Does fuzz tester hit pr_debug() often? File systems? Some of them
have ways to compile out debugging output as well. E.g. jbd_debug,
_debug, ext4_debug, and so on.

	-ss