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 . ;-)
