Re: [PATCH] tmpfs: fix uninitialized return value in shmem_link

From: Darrick J. Wong
Date: Mon Feb 25 2019 - 19:29:19 EST


On Mon, Feb 25, 2019 at 04:07:12PM -0800, Linus Torvalds wrote:
> On Mon, Feb 25, 2019 at 4:03 PM Qian Cai <cai@xxxxxx> wrote:
> > >
> > > Of course, that's just gcc. I have no idea what llvm ends up doing.
> >
> > Clang 7.0:
> >
> > # clang -O2 -S -Wall /tmp/test.c
> > /tmp/test.c:46:6: warning: variable 'ret' is used uninitialized whenever 'if'
> > condition is false [-Wsometimes-uninitialized]
>
> Ok, good.
>
> Do we have any clang builds in any of the zero-day robot
> infrastructure or something? Should we?
>
> And maybe this was how Dan noticed the problem in the first place? Or
> is it just because of his eagle-eyes?

He didn't say specifically how he found it, but I would guess he was
running smatch...?

--D

> Linus