mprotect system call exposed to the untrusted code.

src/untrusted/irt/irt_memory.c

 /*
  * Copyright (c) 2011 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <errno.h>
 #include <stdint.h>
 
 #include "native_client/src/untrusted/irt/irt.h"
@@ skipping 27 matching lines @@
   if ((uint32_t) rv > 0xffff0000u)
     return -(int32_t) rv;
   *addr = (void *) (uintptr_t) rv;
   return 0;
 }
 
 static int nacl_irt_munmap(void *addr, size_t len) {
   return -NACL_SYSCALL(munmap)(addr, len);
 }
 
+static int nacl_irt_mprotect(void *addr, size_t len, int prot) {
+  return -NACL_SYSCALL(mprotect)(addr, len, prot);
+}
+
 const struct nacl_irt_memory nacl_irt_memory = {
   nacl_irt_sysbrk,
   nacl_irt_mmap,
   nacl_irt_munmap,
+  nacl_irt_mprotect,
 };