[Mesa-dev] [PATCH] draw: Avoid NULL pointer dereference when binding NULL fragment shaders.

[Brian Paul]

On 02/02/2012 06:20 AM, jfonseca at vmware.com wrote:
> From: José Fonseca<jfonseca at vmware.com>
>
> Now that the draw module avoids flushing, it may flush precisely when
> binding a NULL shader, so care must be taken when restoring the original
> fragment shader.
> ---
>   src/gallium/auxiliary/draw/draw_pipe_aaline.c   |    2 +-
>   src/gallium/auxiliary/draw/draw_pipe_aapoint.c  |    2 +-
>   src/gallium/auxiliary/draw/draw_pipe_pstipple.c |    2 +-
>   3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/src/gallium/auxiliary/draw/draw_pipe_aaline.c b/src/gallium/auxiliary/draw/draw_pipe_aaline.c
> index 0b368da..ea0a4fb 100644
> --- a/src/gallium/auxiliary/draw/draw_pipe_aaline.c
> +++ b/src/gallium/auxiliary/draw/draw_pipe_aaline.c
> @@ -738,7 +738,7 @@ aaline_flush(struct draw_stage *stage, unsigned flags)
>
>      /* restore original frag shader, texture, sampler state */
>      draw->suspend_flushing = TRUE;
> -   aaline->driver_bind_fs_state(pipe, aaline->fs->driver_fs);
> +   aaline->driver_bind_fs_state(pipe, aaline->fs ? aaline->fs->driver_fs : NULL);
>      aaline->driver_bind_sampler_states(pipe, aaline->num_samplers,
>                                         aaline->state.sampler);
>      aaline->driver_set_sampler_views(pipe,
> diff --git a/src/gallium/auxiliary/draw/draw_pipe_aapoint.c b/src/gallium/auxiliary/draw/draw_pipe_aapoint.c
> index 248f26b..a900dd3 100644
> --- a/src/gallium/auxiliary/draw/draw_pipe_aapoint.c
> +++ b/src/gallium/auxiliary/draw/draw_pipe_aapoint.c
> @@ -744,7 +744,7 @@ aapoint_flush(struct draw_stage *stage, unsigned flags)
>
>      /* restore original frag shader */
>      draw->suspend_flushing = TRUE;
> -   aapoint->driver_bind_fs_state(pipe, aapoint->fs->driver_fs);
> +   aapoint->driver_bind_fs_state(pipe, aapoint->fs ? aapoint->fs->driver_fs : NULL);
>
>      /* restore original rasterizer state */
>      if (draw->rast_handle) {
> diff --git a/src/gallium/auxiliary/draw/draw_pipe_pstipple.c b/src/gallium/auxiliary/draw/draw_pipe_pstipple.c
> index 0401a45..62c54b3 100644
> --- a/src/gallium/auxiliary/draw/draw_pipe_pstipple.c
> +++ b/src/gallium/auxiliary/draw/draw_pipe_pstipple.c
> @@ -565,7 +565,7 @@ pstip_flush(struct draw_stage *stage, unsigned flags)
>
>      /* restore original frag shader, texture, sampler state */
>      draw->suspend_flushing = TRUE;
> -   pstip->driver_bind_fs_state(pipe, pstip->fs->driver_fs);
> +   pstip->driver_bind_fs_state(pipe, pstip->fs ? pstip->fs->driver_fs : NULL);
>      pstip->driver_bind_sampler_states(pipe, pstip->num_samplers,
>                                        pstip->state.samplers);
>      pstip->driver_set_sampler_views(pipe,

Reviewed-by: Brian Paul <brianp at vmware.com>