On Thu, Jul 29, 2021 at 02:11:27PM +0200, Daniel Vetter wrote:

On Wed, Jul 28, 2021 at 07:56:40AM +0200, Greg Kroah-Hartman wrote:

quoted

On Tue, Jul 27, 2021 at 01:58:16PM -0700, Kees Cook wrote:

quoted

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() in struct drm32_mga_init around members chipset, sgram,
maccess, fb_cpp, front_offset, front_pitch, back_offset, back_pitch,
depth_cpp, depth_offset, depth_pitch, texture_offset, and texture_size,
so they can be referenced together. This will allow memcpy() and sizeof()
to more easily reason about sizes, improve readability, and avoid future
warnings about writing beyond the end of chipset.

"pahole" shows no size nor member offset changes to struct drm32_mga_init.
"objdump -d" shows no meaningful object code changes (i.e. only source
line number induced differences and optimizations).

Note that since this includes a UAPI header, struct_group() has been
explicitly redefined local to the header.
[...]

Why can you use __struct_group in this uapi header, but not the
networking one?

If there's others, maybe we can stuff the uapi __struct_group into
linux/types.h where all the other __ uapi types hang out?

Ah yeah; it looks like include/uapi/linux/stddef.h is the place for it.

Anyway mga is very dead, I don't anyone cares.

Acked-by: Daniel Vetter <redacted>

I'm assuming this goes in through a topic pull from you?

Thanks! Yeah, my intention is to carry this as topic branch for Linus.

-Kees

-- 
Kees Cook