ASan support for the Zone

src/zone-inl.h

Index: src/zone-inl.h
diff --git a/src/zone-inl.h b/src/zone-inl.h
index f257382a2dba5b118cadb98e83c1da68b58ad27a..faf99e3d1fd88b8545db94b2fb1bfa0b57b6f390 100644
--- a/src/zone-inl.h
+++ b/src/zone-inl.h
@@ -30,6 +30,10 @@
 
 #include "zone.h"
 
+#ifdef ADDRESS_SANITIZER
+#include <sanitizer/asan_interface.h>

[kcc1, 2014/03/26 06:43:41]

A style nit. I would do 
#ifdef ADDRESS_SANITIZER
# include <...>
#else
// define a few macros as empty
#endif

Then, instead of 
#ifdef ADDRESS_SANITIZER
ASAN_MACRO(...)
#endif

I would use 
  ASAN_MACRO(...)

This is just to make less ifdefs in the code. 
Otherwise looks good.
(I can't give a proper comment on the build file changes)

[Jakob Kummerow, 2014/03/26 09:59:12]

Good idea, done for ASAN_UNPOISON_MEMORY_REGION, keeping zone.cc free of
additional #ifdefs. For the changes in this file below, however, I don't think
pulling stuff out into a #define would improve readability.

+#endif
+
 #include "counters.h"
 #include "isolate.h"
 #include "utils.h"
@@ -39,6 +43,9 @@ namespace v8 {
 namespace internal {
 
 
+static const int kASanRedzoneBytes = 24;  // Must be a multiple of 8.
+
+
 inline void* Zone::New(int size) {
   // Round up the requested size to fit the alignment.
   size = RoundUp(size, kAlignment);
@@ -54,12 +61,25 @@ inline void* Zone::New(int size) {
   // Check if the requested size is available without expanding.
   Address result = position_;
 
-  if (size > limit_ - position_) {
-     result = NewExpand(size);
+  int size_with_redzone =
+#ifdef ADDRESS_SANITIZER
+      size + kASanRedzoneBytes;
+#else
+      size;
+#endif
+
+  if (size_with_redzone > limit_ - position_) {
+     result = NewExpand(size_with_redzone);
   } else {
-     position_ += size;
+     position_ += size_with_redzone;
   }
 
+#ifdef ADDRESS_SANITIZER
+  Address redzone_position = result + size;
+  ASSERT(redzone_position + kASanRedzoneBytes == position_);
+  ASAN_POISON_MEMORY_REGION(redzone_position, kASanRedzoneBytes);
+#endif
+
   // Check that the result has the proper alignment and return it.
   ASSERT(IsAddressAligned(result, kAlignment, 0));
   allocation_size_ += size;
@@ -69,6 +89,7 @@ inline void* Zone::New(int size) {
 
 template <typename T>
 T* Zone::NewArray(int length) {
+  CHECK(std::numeric_limits<int>::max() / static_cast<int>(sizeof(T)) > length);
   return static_cast<T*>(New(length * sizeof(T)));
 }