Oilpan: Fix ASan instrumentation around heap object headers.

Source/wtf/Atomics.h

Index: Source/wtf/Atomics.h
diff --git a/Source/wtf/Atomics.h b/Source/wtf/Atomics.h
index aaad9c9e90cbe954fd9d30ec7a89488822201298..6c4b00e529b08dcf8eb175177b56e329ac1d23fd 100644
--- a/Source/wtf/Atomics.h
+++ b/Source/wtf/Atomics.h
@@ -43,6 +43,10 @@
 #include <sanitizer/tsan_interface_atomic.h>
 #endif
 
+#if defined(ADDRESS_SANITIZER)
+#include <sanitizer/asan_interface.h>
+#endif
+
 namespace WTF {
 
 #if COMPILER(MSVC)
@@ -125,6 +129,21 @@ ALWAYS_INLINE unsigned acquireLoad(volatile const unsigned* ptr)
 {
     return static_cast<unsigned>(__tsan_atomic32_load(reinterpret_cast<volatile const int*>(ptr), __tsan_memory_order_acquire));
 }
+
+#if defined(ADDRESS_SANITIZER)
+
+__attribute__((no_sanitize_address)) ALWAYS_INLINE void asanReleaseStore(volatile unsigned* ptr, unsigned value)
+{
+    __tsan_atomic32_store(reinterpret_cast<volatile int*>(ptr), static_cast<int>(value), __tsan_memory_order_release);
+}
+
+__attribute__((no_sanitize_address)) ALWAYS_INLINE unsigned asanAcquireLoad(volatile const unsigned* ptr)
+{
+    return static_cast<unsigned>(__tsan_atomic32_load(reinterpret_cast<volatile const int*>(ptr), __tsan_memory_order_acquire));
+}
+
+#endif // defined(ADDRESS_SANITIZER)
+
 #else
 
 #if CPU(X86) || CPU(X86_64)
@@ -179,6 +198,23 @@ ALWAYS_INLINE unsigned acquireLoad(volatile const unsigned* ptr)
     return value;
 }
 
+#if defined(ADDRESS_SANITIZER)
+
+__attribute__((no_sanitize_address)) ALWAYS_INLINE void asanReleaseStore(volatile unsigned* ptr, unsigned value)
+{
+    MEMORY_BARRIER();
+    *ptr = value;
+}
+
+__attribute__((no_sanitize_address)) ALWAYS_INLINE unsigned asanAcquireLoad(volatile const unsigned* ptr)
+{
+    unsigned value = *ptr;
+    MEMORY_BARRIER();
+    return value;
+}
+
+#endif
+
 #undef MEMORY_BARRIER
 

[zerny-chromium, 2014/09/09 06:01:28]

Could we add:

#if !defined(ADDRESS_SANITIZER)
ALWAYS_INLINE unsigned asanAcquireLoad(volatile const unsigned* ptr)
{
    return acquireLoad(ptr);
}
...
#endif

and then avoid the #if-def'ing at the call sites.

[Mads Ager (chromium), 2014/09/09 08:22:14]

Done.

 #endif
@@ -194,4 +230,12 @@ using WTF::atomicSetOneToZero;
 using WTF::acquireLoad;
 using WTF::releaseStore;
 
+#if defined(ADDRESS_SANITIZER)

[zerny-chromium, 2014/09/09 06:01:29]

and then remove the #if here too.

[Mads Ager (chromium), 2014/09/09 08:22:15]

Done.

+// These methods allow loading from and storing to poisoned memory. Only
+// use these methods if you know what you are doing since they will
+// silence use-after-poison errors from ASan.
+using WTF::asanAcquireLoad;
+using WTF::asanReleaseStore;
+#endif
+
 #endif // Atomics_h