Mesa (master): svga: handle mismatched number of samplers, sampler views

[Brian Paul]

Module: Mesa
Branch: master
Commit: 50a669de4e216d2e3bea3ec1148c7e79f77ecb27
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=50a669de4e216d2e3bea3ec1148c7e79f77ecb27

Author: Brian Paul <brianp at vmware.com>
Date:   Fri Jul 15 07:08:13 2016 -0600

svga: handle mismatched number of samplers, sampler views

in svga_init_shader_key_common().  Since the CSO module only tracks
sampler views for fragment shaders, the number of samplers and sampler
views can be mismatched for other types of shaders.  This situation
triggered an assertion in Chrome with maps.google.com

This patch adds defensive code to handle that situation.

Fixes VMware bug 1694027
Cc: <mesa-stable at lists.freedesktop.org>
Reviewed-by: Charmaine Lee <charmainel at vmware.com>

---

 src/gallium/drivers/svga/svga_shader.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/svga/svga_shader.c b/src/gallium/drivers/svga/svga_shader.c
index abfef0f..9e37e23 100644
--- a/src/gallium/drivers/svga/svga_shader.c
+++ b/src/gallium/drivers/svga/svga_shader.c
@@ -173,10 +173,16 @@ svga_init_shader_key_common(const struct svga_context *svga, unsigned shader,
 
    assert(shader < ARRAY_SIZE(svga->curr.num_sampler_views));
 
-   for (i = 0; i < svga->curr.num_sampler_views[shader]; i++) {
+   /* In case the number of samplers and sampler_views doesn't match,
+    * loop over the lower of the two counts.
+    */
+   key->num_textures = MIN2(svga->curr.num_sampler_views[shader],
+                            svga->curr.num_samplers[shader]);
+
+   for (i = 0; i < key->num_textures; i++) {
       struct pipe_sampler_view *view = svga->curr.sampler_views[shader][i];
-      if (view) {
-         assert(svga->curr.sampler[shader][i]);
+      const struct svga_sampler_state *sampler = svga->curr.sampler[shader][i];
+      if (view && sampler) {
          assert(view->texture);
          assert(view->texture->target < (1 << 4)); /* texture_target:4 */
 
@@ -195,7 +201,7 @@ svga_init_shader_key_common(const struct svga_context *svga, unsigned shader,
             }
          }
 
-         if (!svga->curr.sampler[shader][i]->normalized_coords) {
+         if (!sampler->normalized_coords) {
             assert(idx < (1 << 5));  /* width_height_idx:5 bitfield */
             key->tex[i].width_height_idx = idx++;
             key->tex[i].unnormalized = TRUE;
@@ -208,7 +214,6 @@ svga_init_shader_key_common(const struct svga_context *svga, unsigned shader,
          key->tex[i].swizzle_a = view->swizzle_a;
       }
    }
-   key->num_textures = svga->curr.num_sampler_views[shader];
 }