On Mon, Aug 18, 2025 at 11:18:48AM -0700, Jakub Kicinski wrote:

[...]
header. There is a hack in scripts/headers_install.sh which
strips includes of compiler.h and compiler_types.h.

This looks like the last user of compiler_types.h in include/uapi, so
it'd probably be best to also remove portion of the hack from
scripts/headers_install.sh while you're at it.

[...]
understanding knows what that chain would be, given
kernel doesn't include uAPI stddef.h, and user space
has the compiler headers stripped.

Uh, yes it does:

$ git grep uapi/linux/stddef.h
include/linux/stddef.h:#include <uapi/linux/stddef.h>

[...]
Since nothing needs this include, let's remove it.

But yes, nothing uses compiler_types.h via uapi/linux/stddef.h. That
does seem to be true.

I find the change of subject between stddef.h ("nothing includes the
uapi header") and compiler_types.h ("nothing needs this include") to be
confusing in the commit log. :)

[...]
Builds pass on x86, arm64, csky, m68k, riscv32.
The direct motivation for the change is that the includes
of compiler.h and co. make it hard to include uAPI headers
from tools/.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

If you can clear that up and everything is building, then this change
would be fine my me.

-- 
Kees Cook