[PATCH] D21202: Unpoison stack memory in use-after-return + use-after-scope mode

[Kostya Serebryany via llvm-commits]

kcc accepted this revision.
kcc added a comment.
This revision is now accepted and ready to land.

LGTM


================
Comment at: lib/Transforms/Instrumentation/AddressSanitizer.cpp:2183-2195
@@ -2179,9 +2182,15 @@
       IRBuilder<> IRBElse(ElseTerm);
-      poisonRedZones(L.ShadowBytes, IRBElse, ShadowBase, false);
+      if (HavePoisonedAllocas) {
+        // If we fallback to static alloca at runtime, we still need to
+        // unpoison allocas poisoned for llvm.lifetime analysis.
+        poisonAlloca(LocalStackBase, LocalStackSize, IRBElse, false);
+      } else {
+        poisonRedZones(L.ShadowBytes, IRBElse, ShadowBase, false);
+      }
     } else if (HavePoisonedAllocas) {
       // If we poisoned some allocas in llvm.lifetime analysis,
       // unpoison whole stack frame now.
       poisonAlloca(LocalStackBase, LocalStackSize, IRBRet, false);
     } else {
       poisonRedZones(L.ShadowBytes, IRBRet, ShadowBase, false);
     }
----------------
we have a bit of code duplication here. Up to you if you want to eliminate it or keep it as is. 


http://reviews.llvm.org/D21202