[compiler-rt] r185621 - [ASan] Do not protect the malloc zone created by malloc_zone_create() on Snow Leopard and earlier systems.

[Alexander Potapenko]

Author: glider
Date: Thu Jul  4 05:16:12 2013
New Revision: 185621

URL: http://llvm.org/viewvc/llvm-project?rev=185621&view=rev
Log:
[ASan] Do not protect the malloc zone created by malloc_zone_create() on Snow Leopard and earlier systems.
Fixes https://code.google.com/p/address-sanitizer/issues/detail?id=208

Modified:
    compiler-rt/trunk/lib/asan/asan_malloc_mac.cc

Modified: compiler-rt/trunk/lib/asan/asan_malloc_mac.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_malloc_mac.cc?rev=185621&r1=185620&r2=185621&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_malloc_mac.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_malloc_mac.cc Thu Jul  4 05:16:12 2013
@@ -50,9 +50,12 @@ INTERCEPTOR(malloc_zone_t *, malloc_crea
                                     &stack, FROM_MALLOC);
   internal_memcpy(new_zone, &asan_zone, sizeof(asan_zone));
   new_zone->zone_name = NULL;  // The name will be changed anyway.
-  // Prevent the client app from overwriting the zone contents.
-  // Library functions that need to modify the zone will set PROT_WRITE on it.
-  mprotect(new_zone, allocated_size, PROT_READ);
+  if (GetMacosVersion() >= MACOS_VERSION_LION) {
+    // Prevent the client app from overwriting the zone contents.
+    // Library functions that need to modify the zone will set PROT_WRITE on it.
+    // This matches the behavior of malloc_create_zone() on OSX 10.7 and higher.
+    mprotect(new_zone, allocated_size, PROT_READ);
+  }
   return new_zone;
 }