Re: [PATCH] mips: lib: uncached: fix uninitialized variable 'sp'

[Nick Desaulniers]

On Fri, Nov 27, 2020 at 12:39 AM Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
>
> When building mips tinyconfig with clang the following warning show up:
>
> /tmp/arch/mips/lib/uncached.c:40:18: note: initialize the variable 'sp' to silence this warning
>         register long sp __asm__("$sp");
>                         ^
>                          = 0

Hi Anders, thank you for sending the patch. Do you have the full text
of the warning; it looks like only the note was included?

>
> Rework to make an explicit inline move.
>
> Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> ---
>  arch/mips/lib/uncached.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/lib/uncached.c b/arch/mips/lib/uncached.c
> index 09d5deea747f..21a4b94a0558 100644
> --- a/arch/mips/lib/uncached.c
> +++ b/arch/mips/lib/uncached.c
> @@ -37,10 +37,11 @@
>   */
>  unsigned long run_uncached(void *func)
>  {
> -       register long sp __asm__("$sp");
>         register long ret __asm__("$2");
>         long lfunc = (long)func, ufunc;
>         long usp;
> +       long sp;
> +       asm ("move %0, $sp" : "=r" (sp));
>
>         if (sp >= (long)CKSEG0 && sp < (long)CKSEG2)
>                 usp = CKSEG1ADDR(sp);
> --
> 2.29.2
>


--
Thanks,
~Nick Desaulniers