From 2ff908525e42580e410d9d0f7831c20645006b56 Mon Sep 17 00:00:00 2001
From: Christian Holler <choller@mozilla.com>
Date: Mon, 29 Jul 2013 02:44:00 +0200
Subject: [PATCH] Bug 898230 - Disable alloc-dealloc checking under
 AddressSanitizer. r=glandium

---
 js/src/ion/AsmJSSignalHandlers.cpp | 11 -----------
 mozglue/build/AsanOptions.cpp      | 24 ++++++++++++++++++++++++
 mozglue/build/moz.build            |  4 ++++
 3 files changed, 28 insertions(+), 11 deletions(-)
 create mode 100644 mozglue/build/AsanOptions.cpp

diff --git a/js/src/ion/AsmJSSignalHandlers.cpp b/js/src/ion/AsmJSSignalHandlers.cpp
index c32a952241a..c6105b6372e 100644
--- a/js/src/ion/AsmJSSignalHandlers.cpp
+++ b/js/src/ion/AsmJSSignalHandlers.cpp
@@ -996,14 +996,3 @@ js::TriggerOperationCallbackForAsmJSCode(JSRuntime *rt)
         MOZ_CRASH();
 #endif
 }
-
-#ifdef MOZ_ASAN
-// When running with asm.js under AddressSanitizer, we need to explicitely
-// tell AddressSanitizer to allow custom signal handlers because it will 
-// otherwise trigger ASan's SIGSEGV handler for the internal SIGSEGVs that 
-// asm.js would otherwise handle.
-extern "C" MOZ_ASAN_BLACKLIST
-const char* __asan_default_options() {
-    return "allow_user_segv_handler=1";
-}
-#endif
diff --git a/mozglue/build/AsanOptions.cpp b/mozglue/build/AsanOptions.cpp
new file mode 100644
index 00000000000..0b516e0c68f
--- /dev/null
+++ b/mozglue/build/AsanOptions.cpp
@@ -0,0 +1,24 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/Attributes.h"
+
+// When running with AddressSanitizer, we need to explicitely set some
+// options specific to our codebase to prevent errors during runtime.
+// 
+// Currently, these are:
+//
+//   allow_user_segv_handler=1 - Tell ASan to allow our code to use its
+//   own SIGSEGV handlers. This is required by ASM.js internally.
+//
+//   alloc_dealloc_mismatch=0 - Disable alloc-dealloc mismatch checking
+//   in ASan. This is required because we define our own new/delete
+//   operators that are backed by malloc/free. If one of them gets inlined
+//   while the other doesn't, ASan will report false positives.
+//
+extern "C" MOZ_ASAN_BLACKLIST
+const char* __asan_default_options() {
+    return "allow_user_segv_handler=1:alloc_dealloc_mismatch=0";
+}
diff --git a/mozglue/build/moz.build b/mozglue/build/moz.build
index f2b3f2d54bd..99b88f85f6f 100644
--- a/mozglue/build/moz.build
+++ b/mozglue/build/moz.build
@@ -45,6 +45,10 @@ if CONFIG['CPU_ARCH'] == 'arm':
         'arm.cpp',
     ]
 
+if CONFIG['MOZ_ASAN']:
+    CPP_SOURCES += [
+        'AsanOptions.cpp',
+    ]
 
 
 LIBRARY_NAME = 'mozglue'