Re: [PATCH] selftests: sigaltstack: fix -Wuninitialized

[Kees Cook]

On Wed, Mar 08, 2023 at 11:59:33AM -0800, Nick Desaulniers wrote:
> Building sigaltstack with clang via:
> $ ARCH=x86 make LLVM=1 -C tools/testing/selftests/sigaltstack/
> 
> produces the following warning:
>   warning: variable 'sp' is uninitialized when used here [-Wuninitialized]
>   if (sp < (unsigned long)sstack ||
>       ^~
> 
> Clang expects these to be declared at global scope; we've fixed this in
> the kernel proper by using the macro `current_stack_pointer`. This is
> defined in different headers for different target architectures, so just
> create a new header that defines the arch-specific register names for
> the stack pointer register, and define it for more targets (at least the
> ones that support current_stack_pointer/ARCH_HAS_CURRENT_STACK_POINTER).
> 
> Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>
> Link: https://lore.kernel.org/lkml/CA+G9fYsi3OOu7yCsMutpzKDnBMAzJBCPimBp86LhGBa0eCnEpA@xxxxxxxxxxxxxx/
> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

Looks good!

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-- 
Kees Cook