On Tue, Jun 30, 2020 at 2:55 PM Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote: > > On 2020/07/01 1:48, Alexei Starovoitov wrote: > > On Tue, Jun 30, 2020 at 03:28:49PM +0900, Tetsuo Handa wrote: > >> On 2020/06/30 5:19, Eric W. Biederman wrote: > >>> Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> writes: > >>> > >>>> On 2020/06/29 4:44, Alexei Starovoitov wrote: > >>>>> But all the defensive programming kinda goes against general kernel style. > >>>>> I wouldn't do it. Especially pr_info() ?! > >>>>> Though I don't feel strongly about it. > >>>> > >>>> Honestly speaking, caller should check for errors and print appropriate > >>>> messages. info->wd.mnt->mnt_root != info->wd.dentry indicates that something > >>>> went wrong (maybe memory corruption). But other conditions are not fatal. > >>>> That is, I consider even pr_info() here should be unnecessary. > >>> > >>> They were all should never happen cases. Which is why my patches do: > >>> if (WARN_ON_ONCE(...)) > >> > >> No. Fuzz testing (which uses panic_on_warn=1) will trivially hit them. > > > > I don't believe that's true. > > Please show fuzzing stack trace to prove your point. > > > > Please find links containing "WARNING" from https://syzkaller.appspot.com/upstream . ;-) Is it a joke? Do you understand how syzbot works? If so, please explain how it can invoke umd_* interface.
