diff --git a/libc/bionic/setjmp_cookie.cpp b/libc/bionic/setjmp_cookie.cpp
new file mode 100644
index 0000000..cf79e83
--- /dev/null
+++ b/libc/bionic/setjmp_cookie.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/auxv.h>
+#include <sys/cdefs.h>
+
+#include "private/libc_logging.h"
+
+extern "C" __LIBC_HIDDEN__ int getentropy(void*, size_t);
+static long __bionic_setjmp_cookie;
+
+extern "C" void __bionic_setjmp_cookie_init() {
+  char* random_data = reinterpret_cast<char*>(getauxval(AT_RANDOM));
+  long value = *reinterpret_cast<long*>(random_data + 8);
+
+  // Mask off the last bit to store the signal flag.
+  __bionic_setjmp_cookie = value & ~1;
+}
+
+extern "C" long __bionic_setjmp_cookie_get(long sigflag) {
+  if (sigflag & ~1) {
+    __libc_fatal("unexpected sigflag value: %ld", sigflag);
+  }
+
+  return __bionic_setjmp_cookie | sigflag;
+}
+
+// Aborts if cookie doesn't match, returns the signal flag otherwise.
+extern "C" long __bionic_setjmp_cookie_check(long cookie) {
+  if (__bionic_setjmp_cookie != (cookie & ~1)) {
+    __libc_fatal("setjmp cookie mismatch");
+  }
+
+  return cookie & 1;
+}