[asan,tsan,msan] move the memcmp interceptor from asan/tsan to sanitizer_common. This may potentially lead to more reports from msan as it now sees the reads inside memcmp. To disable, use the flag intercept_memcmp=0. Likewise, it may potentially cause new races to appear due to more strict memcmp checking (flag strict_memcmp=1)

llvm-svn: 243595

1 files changed, 15 insertions, 0 deletions

diff --git a/compiler-rt/test/msan/memcmp_test.cc b/compiler-rt/test/msan/memcmp_test.cc
new file mode 100644
index 00000000000..95228eb127d
--- /dev/null
+++ b/compiler-rt/test/msan/memcmp_test.cc
@@ -0,0 +1,15 @@
+// RUN: %clangxx_msan -O0 -g %s -o %t
+// RUN: not %run %t 2>&1 | FileCheck %s
+// RUN: MSAN_OPTIONS=intercept_memcmp=0 %run %t
+
+#include <string.h>
+int main(int argc, char **argv) {
+  char a1[4];
+  char a2[4];
+  for (int i = 0; i < argc * 3; i++)
+    a2[i] = a1[i] = i;
+  int res = memcmp(a1, a2, 4);
+  return res;
+  // CHECK: Uninitialized bytes in __interceptor_memcmp at offset 3
+  // CHECK: MemorySanitizer: use-of-uninitialized-value
+}