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@lists.freedesktop.org>
Reviewed-by: Charmaine Lee <charmainel@vmware.com>

diff --git a/src/gallium/drivers/svga/svga_shader.c b/src/gallium/drivers/svga/svga_shader.c
index abfef0f10445aacc3ba9934525dc3a6a8a462e13..9e37e237a7d1e1a614a4ed9b67ce7390567a3ebd 100644 (file)
--- 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];
 }