--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/compiler-rt/test/hwasan/TestCases/tail-magic.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,36 @@
+// Tests free_checks_tail_magic=1.
+// RUN: %clang_hwasan  %s -o %t
+// RUN: %env_hwasan_opts=free_checks_tail_magic=0     %run %t
+// RUN: %env_hwasan_opts=free_checks_tail_magic=1 not %run %t 2>&1 | FileCheck %s
+// RUN:                                           not %run %t 2>&1 | FileCheck %s
+
+// REQUIRES: stable-runtime
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sanitizer/hwasan_interface.h>
+
+#include "utils.h"
+
+static volatile char *sink;
+
+// Overwrite the tail in a non-hwasan function so that we don't detect the
+// stores as OOB.
+__attribute__((no_sanitize("hwaddress"))) void overwrite_tail() {
+  (*UNTAG(&sink))[20] = 0x42;
+  (*UNTAG(&sink))[24] = 0x66;
+}
+
+int main(int argc, char **argv) {
+  __hwasan_enable_allocator_tagging();
+
+  char *p = (char*)malloc(20);
+  sink = UNTAG(p);
+  overwrite_tail();
+  free(p);
+// CHECK: ERROR: HWAddressSanitizer: allocation-tail-overwritten; heap object [{{.*}}) of size 20
+// CHECK: in main {{.*}}tail-magic.c:[[@LINE-2]]
+// CHECK: allocated here:
+// CHECK: in main {{.*}}tail-magic.c:[[@LINE-7]]
+// CHECK: Tail contains: .. .. .. .. 42 {{.. .. ..}} 66
+}