diff --git a/libc/bionic/ioctl.c b/libc/bionic/ioctl.cpp
similarity index 85%
rename from libc/bionic/ioctl.c
rename to libc/bionic/ioctl.cpp
index 6dd95d0..db85132 100644
--- a/libc/bionic/ioctl.c
+++ b/libc/bionic/ioctl.cpp
@@ -25,19 +25,16 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
+#include <sys/ioctl.h>
 #include <stdarg.h>
 
-extern int __ioctl(int, int, void *);
+extern "C" int __ioctl(int, int, void *);
 
-int ioctl(int fd, int request, ...)
-{
-    va_list ap;
-    void * arg;
-
-    va_start(ap, request);
-    arg = va_arg(ap, void *);
-    va_end(ap);
-
-    return __ioctl(fd, request, arg);
+int ioctl(int fd, int request, ...) {
+  va_list ap;
+  va_start(ap, request);
+  void* arg = va_arg(ap, void*);
+  va_end(ap);
+  return __ioctl(fd, request, arg);
 }
-
diff --git a/libc/bionic/ioctl.c b/libc/bionic/mremap.cpp
similarity index 71%
copy from libc/bionic/ioctl.c
copy to libc/bionic/mremap.cpp
index 6dd95d0..4892b1d 100644
--- a/libc/bionic/ioctl.c
+++ b/libc/bionic/mremap.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008 The Android Open Source Project
+ * Copyright (C) 2015 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,19 +25,21 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
+#include <sys/mman.h>
 #include <stdarg.h>
 
-extern int __ioctl(int, int, void *);
+extern "C" void* ___mremap(void*, size_t, size_t, int, void*);
 
-int ioctl(int fd, int request, ...)
-{
+void* mremap(void* old_address, size_t old_size, size_t new_size, int flags, ...) {
+  void* new_address = nullptr;
+  // The optional argument is only valid if the MREMAP_FIXED flag is set,
+  // so we assume it's not present otherwise.
+  if ((flags & MREMAP_FIXED) != 0) {
     va_list ap;
-    void * arg;
-
-    va_start(ap, request);
-    arg = va_arg(ap, void *);
+    va_start(ap, flags);
+    new_address = va_arg(ap, void*);
     va_end(ap);
-
-    return __ioctl(fd, request, arg);
+  }
+  return ___mremap(old_address, old_size, new_size, flags, new_address);
 }
-