Re: [GIT PULL] overflow updates for v5.15-rc1

[Kees Cook]

On Mon, Sep 06, 2021 at 03:27:31PM +1000, Stephen Rothwell wrote:
> Hi Linus,
> 
> On Sun, 5 Sep 2021 10:36:22 -0700 Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Sun, Sep 5, 2021 at 12:38 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > >
> > > Yeech. Yeah, no, that was not expected at all. I even did test merge builds against your latest tree before sending the Pull Request. This has been in -next for weeks, too.  
> > 
> > Sadly, I don't think linux-next checks for warnings.
> 
> Yes, I do.  And report them.  I did not get these warnings for some
> reason.  One of my builds is an X86_64 allmodconfig, currently using
> 
> x86_64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110

FWIW, the difference turned out to be LANG=C.UTF-8 in Fedora (vs LANG=C or
LANG=en_US.UTF-8), and the warning analysis being done in the self-tests
I added got unlucky when I tried to avoid setting "LANG". (i.e. I didn't
want to depend on matching English output, and used the trailing "'" in
the function name matcher -- which is a "`" under C.UTF-8.)

This has been fixed now -- I just got fantastically unlucky, it seems,
as literally only Linus appears to have been building with LANG=C.UTF-8.
(None of the other build bots warned about this for the weeks it's been
in -next). :(

-- 
Kees Cook