[tsan] Fix the memcpy interceptor to be memmove compatible on OS X

On OS X, memcpy and memmove are actually aliases of the same implementation, which means the interceptor of memcpy is also invoked when memmove is called. The current implementation of the interceptor uses `internal_memcpy` to perform the actual memory operation, which can produce an incorrect result when memmove semantics are expected. Let's call `internal_memmove` instead.

Differential Revision: http://reviews.llvm.org/D14336

llvm-svn: 252162

1 files changed, 4 insertions, 1 deletions

diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
index 7d2194d8368..8308afb7c24 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
@@ -626,7 +626,10 @@ TSAN_INTERCEPTOR(void*, memcpy, void *dst, const void *src, uptr size) {
     MemoryAccessRange(thr, pc, (uptr)dst, size, true);
     MemoryAccessRange(thr, pc, (uptr)src, size, false);
   }
-  return internal_memcpy(dst, src, size);
+  // On OS X, calling internal_memcpy here will cause memory corruptions,
+  // because memcpy and memmove are actually aliases of the same implementation.
+  // We need to use internal_memmove here.
+  return internal_memmove(dst, src, size);
 }
 
 TSAN_INTERCEPTOR(void*, memmove, void *dst, void *src, uptr n) {