[Mesa-dev] [Mesa-stable] [PATCH 1/4] glsl: Fix crash due to negative array index

[Chris Forbes]

Patches 1 & 2 are:

Reviewed-by: Chris Forbes <chrisf at ijw.co.nz>

I'm not convinced about patch 3. From the GLSL 4.50 spec, section
4.1.9 Arrays p31 (p37 of the PDF):

"It is a compile-time error to declare an array with a size, and then
later (in the same shader) index the same array with an integral
constant expression greater than or equal to the declared size."


-- Chris

On Thu, Oct 23, 2014 at 8:33 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> Hi Anuj,
>
> Afaics the series is yet to land on master, this I've not pulled it for
> the stable branch. Is the lack of review holding it back ?
>
> Gents can anyone take a look at/review the series ?
>
> Thanks
> Emil
>
> On 22/09/14 23:57, Anuj Phogat wrote:
>> Currently Mesa crashes with a shader like this:
>>
>> [fragmnet shader]
>> float[5] array;
>> int idx = -2;
>> void main()
>> {
>>    gl_FragColor = vec4(0.0, 1.0, 0.0, array[idx]);
>> }
>>
>> Cc: <mesa-stable at lists.freedesktop.org>
>> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
>> ---
>>  src/glsl/opt_array_splitting.cpp | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/src/glsl/opt_array_splitting.cpp b/src/glsl/opt_array_splitting.cpp
>> index ebb076b..9e73f3c 100644
>> --- a/src/glsl/opt_array_splitting.cpp
>> +++ b/src/glsl/opt_array_splitting.cpp
>> @@ -295,7 +295,7 @@ ir_array_splitting_visitor::split_deref(ir_dereference **deref)
>>     ir_constant *constant = deref_array->array_index->as_constant();
>>     assert(constant);
>>
>> -   if (constant->value.i[0] < (int)entry->size) {
>> +   if (constant->value.i[0] >= 0 && constant->value.i[0] < (int)entry->size) {
>>        *deref = new(entry->mem_ctx)
>>        ir_dereference_variable(entry->components[constant->value.i[0]]);
>>     } else {
>>
>
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