Use zero-based shadow by default on Android.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157317 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index b43b9e5..7fb33f7 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -22,6 +22,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/Function.h"
 #include "llvm/IntrinsicInst.h"
 #include "llvm/LLVMContext.h"
@@ -47,6 +48,7 @@ using namespace llvm;
 static const uint64_t kDefaultShadowScale = 3;
 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
+static const uint64_t kDefaultShadowOffsetAndroid = 0;
 
 static const size_t kMaxStackMallocSize = 1 << 16;  // 64K
 static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
@@ -556,8 +558,11 @@ bool AddressSanitizer::runOnModule(Module &M) {
   AsanInitFunction->setLinkage(Function::ExternalLinkage);
   IRB.CreateCall(AsanInitFunction);
 
-  MappingOffset = LongSize == 32
-      ? kDefaultShadowOffset32 : kDefaultShadowOffset64;
+  llvm::Triple targetTriple(M.getTargetTriple());
+  bool isAndroid = targetTriple.getEnvironment() == llvm::Triple::ANDROIDEABI;
+
+  MappingOffset = isAndroid ? kDefaultShadowOffsetAndroid :
+    (LongSize == 32 ? kDefaultShadowOffset32 : kDefaultShadowOffset64);
   if (ClMappingOffsetLog >= 0) {
     if (ClMappingOffsetLog == 0) {
       // special case