Re: [PATCH] x86/shstk: Change order of __user in type

From: Kees Cook
Date: Fri Aug 25 2023 - 17:22:46 EST


On Thu, Aug 24, 2023 at 06:45:54PM -0700, Rick Edgecombe wrote:
> 0day reports a sparse warning:
> arch/x86/kernel/shstk.c:295:55: sparse: sparse: cast removes address space
> '__user' of expression
>
> The __user is in the wrong spot. Move it to right spot and make sparse
> happy.
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202308222312.Jt4Tog5T-lkp@xxxxxxxxx/
> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>

Ah yeah, a good find. I with we could sanely use "address spaces" in GCC
and Clang so we didn't need to depend on sparse for these checks. I
tried to get Clang doing it[1] a few years ago, but the wall of warnings
was huge.

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

[1] https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?h=clang/address_space&id=beff911c13390a71b3f7921fd82ec6a71ca75c02

--
Kees Cook