Re: [PATCH v4] checkpatch: check for missing Fixes tags

Kees Cook
2023-07-11T15:48:40Z

On Tue, Jul 11, 2023 at 04:48:14PM +0300, Dan Carpenter wrote:
> This check looks for common words that probably indicate a patch
> is a fix. For now the regex is:
>
> (?:(?:BUG: K.|UB)SAN: |Call Trace:|stable\@|syzkaller)/)
>
> Why are stable patches encouraged to have a fixes tag? Some people mark
> their stable patches as "# 5.10" etc. This is useful but a Fixes tag is
> still a good idea. For example, the Fixes tag helps in review. It
> helps people to not cherry-pick buggy patches without also
> cherry-picking the fix.
>
> Also if a bug affects the 5.7 kernel some people will round it up to
> 5.10+ because 5.7 is not supported on kernel.org. It's possible the Bad
> Binder bug was caused by this sort of gap where companies outside of
> kernel.org are supporting different kernels from kernel.org.
>
> Should it be counted as a Fix when a patch just silences harmless
> WARN_ON() stack trace. Yes. Definitely.
>
> Is silencing compiler warnings a fix? It seems unfair to the original
> authors, but we use -Werror now, and warnings break the build so let's
> just add Fixes tags. I tell people that silencing static checker
> warnings is not a fix but the rules on this vary by subsystem.
>
> Is fixing a minor LTP issue (Linux Test Project) a fix? Probably? It's
> hard to know what to do if the LTP test has technically always been
> broken.
>
> One clear false positive from this check is when someone updated their
> debug output and included before and after Call Traces. Or when crashes
> are introduced deliberately for testing. In those cases, you should
> just ignore checkpatch.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

--
Kees Cook