1 files changed, 35 insertions, 0 deletions
diff --git a/test/hwasan/TestCases/random-align-right.c b/test/hwasan/TestCases/random-align-right.c
new file mode 100644
index 0000000000000..8c524ef4784df
--- /dev/null
+++ b/test/hwasan/TestCases/random-align-right.c
@@ -0,0 +1,35 @@
+// Tests malloc_align_right=1 and 8 (randomly aligning right).
+// RUN: %clang_hwasan  %s -o %t
+//
+// RUN: %run %t
+// RUN: %env_hwasan_opts=malloc_align_right=1 not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK1
+// RUN: %env_hwasan_opts=malloc_align_right=8 not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK8
+
+// REQUIRES: stable-runtime
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <sanitizer/hwasan_interface.h>
+
+static volatile void *sink;
+
+int main(int argc, char **argv) {
+  __hwasan_enable_allocator_tagging();
+
+  // Perform 1000 buffer overflows within the 16-byte granule,
+  // so that random right-alignment has a very high chance of
+  // catching at least one of them.
+  for (int i = 0; i < 1000; i++) {
+    char *p = (char*)malloc(20);
+    sink = p;
+    fprintf(stderr, "[%d] p: %p; accessing p[20]:\n", i, p);
+    p[20 * argc] = 0;  // requires malloc_align_right=1 to catch
+    fprintf(stderr, "[%d] p: %p; accessing p[30]:\n", i, p);
+    p[30 * argc] = 0;  // requires malloc_align_right={1,8} to catch
+// CHECK1: accessing p[20]
+// CHECK1-NEXT: HWAddressSanitizer: tag-mismatch
+// CHECK8: accessing p[30]:
+// CHECK8-NEXT: HWAddressSanitizer: tag-mismatch
+  }
+}
+