[Mesa-dev] [PATCH] st/mesa: avoid integer overflows with buffers >= 512MB

[Ilia Mirkin]

On Wed, Sep 16, 2015 at 9:21 AM, Roland Scheidegger <sroland at vmware.com> wrote:
> Since there are no formats where block.bits isn't a multiple of 8 (and I
> wouldn't expect that to change), you could theoretically fix that by
> dividing by block.bits / 8 instead of multiplying base (or size) by 8.
> Ought to be faster at least on 32bit systems...

Why didn't I think of that... I even tried playing with a few other
expression orderings, and gave up.

> Unless you wanted to support >= 4GB buffers (I think though for that
> we're missing way more things).

No. In fact my piglit test explicitly skips situations that would
cause it to create >= 2G buffers.

> Either way though,
> Reviewed-by: Roland Scheidegger <sroland at vmware.com>

Thanks!

>
> Am 16.09.2015 um 01:32 schrieb Ilia Mirkin:
>> This fixes failures with the newly-submitted max-size texture buffer
>> piglit test for GPUs exposing >= 128M max texels.
>>
>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>> Cc: "10.6 11.0" <mesa-stable at lists.freedesktop.org>
>> ---
>>  src/mesa/state_tracker/st_atom_texture.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/src/mesa/state_tracker/st_atom_texture.c b/src/mesa/state_tracker/st_atom_texture.c
>> index 31e0f6b..62312af 100644
>> --- a/src/mesa/state_tracker/st_atom_texture.c
>> +++ b/src/mesa/state_tracker/st_atom_texture.c
>> @@ -264,7 +264,7 @@ st_create_texture_sampler_view_from_stobj(struct pipe_context *pipe,
>>                                     format);
>>
>>     if (stObj->pt->target == PIPE_BUFFER) {
>> -      unsigned base, size;
>> +      uint64_t base, size;
>>        unsigned f, n;
>>        const struct util_format_description *desc
>>           = util_format_description(templ.format);
>>
>