[llvm] r279222 - [asan] Fix size of shadow incorrectly calculated in r279178

[Vitaly Buka via llvm-commits]

Author: vitalybuka
Date: Fri Aug 19 03:33:53 2016
New Revision: 279222

URL: http://llvm.org/viewvc/llvm-project?rev=279222&view=rev
Log:
[asan] Fix size of shadow incorrectly calculated in r279178

Summary: r279178 generates 8 times more stores than necessary.

Reviewers: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23708

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
    llvm/trunk/test/Instrumentation/AddressSanitizer/stack-poisoning.ll

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=279222&r1=279221&r2=279222&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Fri Aug 19 03:33:53 2016
@@ -2237,10 +2237,8 @@ void FunctionStackPoisoner::poisonStack(
       IRBuilder<> IRBPoison(ThenTerm);
       if (StackMallocIdx <= 4) {
         int ClassSize = kMinStackMallocSize << StackMallocIdx;
-        if ((int)ShadowBytesAfterReturn.size() != ClassSize) {
-          ShadowBytesAfterReturn.resize(ClassSize,
-                                        kAsanStackUseAfterReturnMagic);
-        }
+        ShadowBytesAfterReturn.resize(ClassSize >> Mapping.Scale,
+                                      kAsanStackUseAfterReturnMagic);
         poisonRedZones(ShadowBytesAfterReturn, IRBPoison, ShadowBase, true);
         Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
             FakeStack,

Modified: llvm/trunk/test/Instrumentation/AddressSanitizer/stack-poisoning.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/stack-poisoning.ll?rev=279222&r1=279221&r2=279222&view=diff
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/stack-poisoning.ll (original)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/stack-poisoning.ll Fri Aug 19 03:33:53 2016
@@ -44,6 +44,7 @@ entry:
   ; CHECK-UAR: store i64 -723401728380766731
   ; CHECK-UAR: store i64 -723401728380766731
   ; CHECK-UAR: store i64 -723401728380766731
+  ; CHECK-UAR-NOT: store i64
   ; CHECK-UAR: store i8 0
   ; CHECK-UAR-NOT: store
   ; CHECK-UAR: label