[OpenBIOS] [PATCH v2] sparc32: fix __context corruption in __switch_context_nosave

[Blue Swirl]

On Fri, Feb 11, 2011 at 9:35 PM, Artyom Tarasenko <atar4qemu at gmail.com> wrote:
>  __switch_context_nosave shall not write to __context, only read it.
>
> Signed-off-by: Artyom Tarasenko <atar4qemu at gmail.com>
> --- arch/sparc32/switch.S       (revision 1024)
> +++ arch/sparc32/switch.S       (working copy)
> @@ -79,11 +79,15 @@
>        set     (PSR_PS | PSR_S | PSR_PIL | PSR_EF), %g2
>        wr      %g2, 0x0, %psr
>  #endif
> -
> -__switch_context_nosave:
> -       set     __context, %g1
> +        set     __context, %g1
>         /* Swap ctx pointer with %fp */
>         swap      [%g1], %fp
> +        ba     __set_context

This will execute also 'sethi' part of the following 'set', please add
a 'nop' (with indent increased by one space).

> +__switch_context_nosave:
> +        set     __context, %g1
> +        /* Load %fp from ctx pointer */
> +        ld      [%g1], %fp
> +__set_context:
>        /* Load all registers */
>         /* offset 0: %g0, no need to load */
>         ld      [%fp + 4], %g1
> ---
> Regards,
> Artyom Tarasenko
>
> solaris/sparc under qemu blog: http://tyom.blogspot.com/
>