[WebAssembly] Implement Address Sanitizer for Emscripten
Summary:
This diff enables address sanitizer on Emscripten.
On Emscripten, real memory starts at the value passed to --global-base.
All memory before this is used as shadow memory, and thus the shadow mapping
function is simply dividing by 8.
Reviewers: tlively, aheejin, sbc100
Reviewed By: sbc100
Subscribers: dschuff, sbc100, jgravelle-google, hiraditya, sunfish, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D63742
llvm-svn: 364468
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 31900607..6821e21 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -109,6 +109,7 @@
static const uint64_t kNetBSDKasan_ShadowOffset64 = 0xdfff900000000000;
static const uint64_t kPS4CPU_ShadowOffset64 = 1ULL << 40;
static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
+static const uint64_t kEmscriptenShadowOffset = 0;
static const uint64_t kMyriadShadowScale = 5;
static const uint64_t kMyriadMemoryOffset32 = 0x80000000ULL;
@@ -433,6 +434,7 @@
bool IsWindows = TargetTriple.isOSWindows();
bool IsFuchsia = TargetTriple.isOSFuchsia();
bool IsMyriad = TargetTriple.getVendor() == llvm::Triple::Myriad;
+ bool IsEmscripten = TargetTriple.isOSEmscripten();
ShadowMapping Mapping;
@@ -454,6 +456,8 @@
Mapping.Offset = kDynamicShadowSentinel;
else if (IsWindows)
Mapping.Offset = kWindowsShadowOffset32;
+ else if (IsEmscripten)
+ Mapping.Offset = kEmscriptenShadowOffset;
else if (IsMyriad) {
uint64_t ShadowOffset = (kMyriadMemoryOffset32 + kMyriadMemorySize32 -
(kMyriadMemorySize32 >> Mapping.Scale));