[Mesa-dev] [PATCH] mesa/vbo: fix invalid min/max indexes

[Rob Clark]

On Mon, May 8, 2017 at 4:57 PM, Marek Olšák <maraeo at gmail.com> wrote:
> I personally find the assertions unnecessary because the bug has been
> discovered and fixed by this patch, and this code is unlikely to
> change. Anyway:
>
> Reviewed-by: Marek Olšák <marek.olsak at amd.com>

I don't suppose there is something like debug_assert() (ie. only
defined for --enable-debug builds) for mesa code?  That was really
what I wanted there.  Maybe I'll just put #ifdef DEBUG / #endif around
it..

(I am a fan of asserts, even just so that next time I read the code I
remember that some case shouldn't happen ;-))

BR,
-R

> Marek
>
> On Mon, May 8, 2017 at 10:37 PM, Rob Clark <robdclark at gmail.com> wrote:
>> Fixes: c3f37e9b ("st/mesa: use min_index and max_index directly from vbo")
>> Signed-off-by: Rob Clark <robdclark at gmail.com>
>> ---
>> I haven't had a chance to piglit this yet, but it does fix the
>> regression w/ 'glmark2 -b ideas'.
>>
>>  src/mesa/vbo/vbo_exec_array.c | 22 ++++++++++++++++------
>>  1 file changed, 16 insertions(+), 6 deletions(-)
>>
>> diff --git a/src/mesa/vbo/vbo_exec_array.c b/src/mesa/vbo/vbo_exec_array.c
>> index 0fcaefe..437d260 100644
>> --- a/src/mesa/vbo/vbo_exec_array.c
>> +++ b/src/mesa/vbo/vbo_exec_array.c
>> @@ -855,6 +855,11 @@ vbo_validated_drawrangeelements(struct gl_context *ctx, GLenum mode,
>>     struct _mesa_index_buffer ib;
>>     struct _mesa_prim prim;
>>
>> +   if (!index_bounds_valid) {
>> +      assert(start == 0u);
>> +      assert(end == ~0u);
>> +   }
>> +
>>     if (skip_draw_elements(ctx, count, indices))
>>        return;
>>
>> @@ -999,6 +1004,11 @@ vbo_exec_DrawRangeElementsBaseVertex(GLenum mode, GLuint start, GLuint end,
>>     (void) check_draw_elements_data;
>>  #endif
>>
>> +   if (!index_bounds_valid) {
>> +      start = 0;
>> +      end = ~0;
>> +   }
>> +
>>     vbo_validated_drawrangeelements(ctx, mode, index_bounds_valid, start, end,
>>                                     count, type, indices, basevertex, 1, 0);
>>  }
>> @@ -1048,7 +1058,7 @@ vbo_exec_DrawElements(GLenum mode, GLsizei count, GLenum type,
>>           return;
>>     }
>>
>> -   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
>> +   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, 0, ~0,
>>                                     count, type, indices, 0, 1, 0);
>>  }
>>
>> @@ -1077,7 +1087,7 @@ vbo_exec_DrawElementsBaseVertex(GLenum mode, GLsizei count, GLenum type,
>>           return;
>>     }
>>
>> -   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
>> +   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, 0, ~0,
>>                                     count, type, indices, basevertex, 1, 0);
>>  }
>>
>> @@ -1107,7 +1117,7 @@ vbo_exec_DrawElementsInstanced(GLenum mode, GLsizei count, GLenum type,
>>           return;
>>     }
>>
>> -   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
>> +   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, 0, ~0,
>>                                     count, type, indices, 0, numInstances, 0);
>>  }
>>
>> @@ -1142,7 +1152,7 @@ vbo_exec_DrawElementsInstancedBaseVertex(GLenum mode, GLsizei count,
>>           return;
>>     }
>>
>> -   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
>> +   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, 0, ~0,
>>                                     count, type, indices,
>>                                     basevertex, numInstances, 0);
>>  }
>> @@ -1179,7 +1189,7 @@ vbo_exec_DrawElementsInstancedBaseInstance(GLenum mode, GLsizei count,
>>           return;
>>     }
>>
>> -   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
>> +   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, 0, ~0,
>>                                     count, type, indices, 0, numInstances,
>>                                     baseInstance);
>>  }
>> @@ -1218,7 +1228,7 @@ vbo_exec_DrawElementsInstancedBaseVertexBaseInstance(GLenum mode,
>>           return;
>>     }
>>
>> -   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, ~0, ~0,
>> +   vbo_validated_drawrangeelements(ctx, mode, GL_FALSE, 0, ~0,
>>                                     count, type, indices, basevertex,
>>                                     numInstances, baseInstance);
>>  }
>> --
>> 2.9.3
>>