[Mesa-dev] [PATCH] i965: Initialize new chunks of realloc'd memory.

[Chris Forbes]

I think you want to move the memset after the !annotation->ann bail
out. Currently, if that allocation were to fail (and we care enough to
check...) , you'll segfault.

On Wed, Jul 9, 2014 at 3:44 PM, Matt Turner <mattst88 at gmail.com> wrote:
> Otherwise we'd compare uninitialized pointers with NULL and dereference,
> leading to crashes.
> ---
>  src/mesa/drivers/dri/i965/intel_asm_annotation.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/src/mesa/drivers/dri/i965/intel_asm_annotation.c b/src/mesa/drivers/dri/i965/intel_asm_annotation.c
> index 4717baf..d524725 100644
> --- a/src/mesa/drivers/dri/i965/intel_asm_annotation.c
> +++ b/src/mesa/drivers/dri/i965/intel_asm_annotation.c
> @@ -96,9 +96,13 @@ void annotate(struct brw_context *brw,
>                struct backend_instruction *inst, unsigned offset)
>  {
>     if (annotation->ann_size <= annotation->ann_count) {
> +      int old_size = annotation->ann_size;
>        annotation->ann_size = MAX2(1024, annotation->ann_size * 2);
>        annotation->ann = reralloc(annotation->mem_ctx, annotation->ann,
>                                   struct annotation, annotation->ann_size);
> +      memset(annotation->ann + old_size, 0,
> +             (annotation->ann_size - old_size) * sizeof(struct annotation));
> +
>        if (!annotation->ann)
>           return;
>     }
> --
> 1.8.5.5
>
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