Re: [Qemu-ppc] [Qemu-devel] [PATCH] Revert "Update OpenBIOS images"

[Mark Cave-Ayland]

On 14/02/13 00:17, Alexander Graf wrote:

> With the following patch fixing the issue at hand for me. Though I don't fully 
> understand why str would be NULL yet:
>
>
> diff --git a/packages/mac-parts.c b/packages/mac-parts.c
> index a286870..443455e 100644
> --- a/packages/mac-parts.c
> +++ b/packages/mac-parts.c
> @@ -140,7 +140,7 @@ macparts_open( macparts_info_t *di )
>           * Implement partition selection as per the PowerPC Microprocessor 
> CHRP bindings
>           */
>
> -       if (parnum == 0) {
> +       if (str == NULL || parnum == 0) {
>                  /* According to the spec, partition 0 as well as no arguments 
> means the whole disk */
>                  offs = (long long)0;
>                  size = (long long)__be32_to_cpu(dmap.sbBlkCount) * bs;
>
> Alex

Ah okay. It's actually caused by this bit of logic in 
libopenbios/bindings.c and assuming that my_args() is a zero length 
Forth string:

char *
pop_fstr_copy( void )
{
        int len = POP();
        char *str, *p = (char*)cell2pointer(POP());
        if( !len )
                return NULL;
        str = malloc( len + 1 );
        if( !str )
                return NULL;
        memcpy( str, p, len );
        str[len] = 0;
        return str;
}

The check for a zero length string and returning NULL has caused me 
problems before when round-tripping strings between Forth and C.

Without testing the patch myself, I'd say that it looks good. I can run 
it over my complete set of test images tomorrow evening if that would be 
acceptable? Can you post a git diff version to the OpenBIOS mailing list 
too?


ATB,

Mark.