Re: [PATCH 01/64] media: omap3isp: Extract struct group for memcpy() region

Kees Cook
2021-07-30T19:18:32Z

On Fri, Jul 30, 2021 at 10:08:03AM -0700, Nick Desaulniers wrote:
> On Fri, Jul 30, 2021 at 9:44 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > On Fri, Jul 30, 2021 at 12:00:54PM +0300, Dan Carpenter wrote:
> > > On Fri, Jul 30, 2021 at 10:38:45AM +0200, David Sterba wrote:
> > > > Then is explicit memset the only reliable way accross all compiler
> > > > flavors and supported versions?
> > > >
> > >
> > > The = { } initializer works. It's only when you start partially
> > > initializing the struct that it doesn't initialize holes.
> >
> > No, partial works. It's when you _fully_ initialize the struct where the
> > padding doesn't get initialized. *sob*
>
> I'm pretty sure that this has more to do with whether or not the
> compiler applies SROA then observes uses of the individual members or
> not.

Ultimately, it's just not consistent, so thank goodness for
-ftrivial-auto-var-init=zero. :)

--
Kees Cook