Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform.h
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform.h
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_platform.h
@@ -282,5 +282,10 @@
 # define SANITIZER_SUPPRESS_LEAK_ON_PTHREAD_EXIT 0
 #endif
 
+#if SANITIZER_FREEBSD || SANITIZER_MAC || SANITIZER_NETBSD
+# define SANITIZER_MADVISE_DONTNEED MADV_FREE
+#else
+# define SANITIZER_MADVISE_DONTNEED MADV_DONTNEED
+#endif
 
 #endif // SANITIZER_PLATFORM_H
Index: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
===================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix_libcdep.cc
@@ -62,7 +62,8 @@
   uptr beg_aligned = RoundUpTo(beg, page_size);
   uptr end_aligned = RoundDownTo(end, page_size);
   if (beg_aligned < end_aligned)
-    madvise((void*)beg_aligned, end_aligned - beg_aligned, MADV_DONTNEED);
+    madvise((void *)beg_aligned, end_aligned - beg_aligned,
+            SANITIZER_MADVISE_DONTNEED);
 }
 
 void NoHugePagesInRegion(uptr addr, uptr size) {