commit 9f2516f64da7dfb31a329a65c5843b8f18d8d340
author Jim Van Verth <jvanverth@google.com> Fri Nov 22 14:58:37 2019 -0500
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Fri Nov 22 20:28:17 2019 +0000
tree 473e9294ddfb6e511b0bfebb0f28a766034511fa
parent db80f6936cbca34496d87c6754167a11286f9c0c

Add checks for TextureSampler count in text GeoProcs.

Chrome is seeing unexplained segfaults when trying to access the n-1th
textureSampler while creating textOp GeoProcs -- it's possible that's
because n is 0. Also add checks to make sure n is not > kMaxTextures.

Bug: chromium:1027314
Change-Id: I65a5472980bab37d580b3f237a132a8b23794abe
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255985
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>

src/gpu/effects/GrDistanceFieldGeoProc.cpp

diff --git a/src/gpu/effects/GrDistanceFieldGeoProc.cpp b/src/gpu/effects/GrDistanceFieldGeoProc.cpp
index c1670ea..9196449 100644
--- a/src/gpu/effects/GrDistanceFieldGeoProc.cpp
+++ b/src/gpu/effects/GrDistanceFieldGeoProc.cpp
@@ -253,6 +253,8 @@
                                                  int numProxies,
                                                  const GrSamplerState& params) {
     SkASSERT(numProxies <= kMaxTextures);
+    // Just to make sure we don't try to add too many proxies
+    numProxies = SkTMin(numProxies, kMaxTextures);
 
     if (!fTextureSamplers[0].isInitialized()) {
         fAtlasDimensions = proxies[0]->dimensions();
@@ -548,6 +550,8 @@
                                                int numProxies,
                                                const GrSamplerState& params) {
     SkASSERT(numProxies <= kMaxTextures);
+    // Just to make sure we don't try to add too many proxies
+    numProxies = SkTMin(numProxies, kMaxTextures);
 
     if (!fTextureSamplers[0].isInitialized()) {
         fAtlasDimensions = proxies[0]->dimensions();
@@ -874,6 +878,8 @@
                                                   int numProxies,
                                                   const GrSamplerState& params) {
     SkASSERT(numProxies <= kMaxTextures);
+    // Just to make sure we don't try to add too many proxies
+    numProxies = SkTMin(numProxies, kMaxTextures);
 
     if (!fTextureSamplers[0].isInitialized()) {
         fAtlasDimensions = proxies[0]->dimensions();