[llvm] r364468 - [WebAssembly] Implement Address Sanitizer for Emscripten

[Guanzhong Chen via llvm-commits]

Author: quantum
Date: Wed Jun 26 13:16:14 2019
New Revision: 364468

URL: http://llvm.org/viewvc/llvm-project?rev=364468&view=rev
Log:
[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

Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=364468&r1=364467&r2=364468&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Wed Jun 26 13:16:14 2019
@@ -109,6 +109,7 @@ static const uint64_t kNetBSD_ShadowOffs
 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 @@ static ShadowMapping getShadowMapping(Tr
   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 @@ static ShadowMapping getShadowMapping(Tr
       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));