Re: [PATCH v2][next] cgroup: Avoid -Wstringop-overflow warnings

From: Kees Cook
Date: Wed Aug 16 2023 - 16:58:12 EST


On Wed, Aug 16, 2023 at 10:51:12AM -1000, Tejun Heo wrote:
> Hello,
>
> On Wed, Aug 16, 2023 at 02:50:16PM -0600, Gustavo A. R. Silva wrote:
> > Change the notation from pointer-to-array to pointer-to-pointer.
> > With this, we avoid the compiler complaining about trying
> > to access a region of size zero as an argument during function
> > calls.
>
> Haha, I thought the functions were actually accessing the memory. This can't
> be an intended behavior on the compiler's side, right?

I think it's a result of inlining -- the compiler ends up with a case
where it looks like it might be possible to index a zero-sized array,
but it is "accidentally safe".

--
Kees Cook