mprotect system call exposed to the untrusted code.

src/untrusted/irt/irt_dev_mprotect.c

 /*
  * Copyright (c) 2012 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 "native_client/src/untrusted/irt/irt.h"
 #include "native_client/src/untrusted/irt/irt_interfaces.h"
 #include "native_client/src/untrusted/nacl/syscall_bindings_trampoline.h"
 
-static int nacl_irt_dev_getpid_func(int *pid) {
-  int rv = NACL_SYSCALL(getpid)();
-  if (rv < 0)
-    return -rv;
-  *pid = rv;
-  return 0;
+static int nacl_irt_mprotect(void *addr, size_t len, int prot) {
+  return -NACL_SYSCALL(mprotect)(addr, len, prot);
 }
 
-const struct nacl_irt_dev_getpid nacl_irt_dev_getpid = {
-  nacl_irt_dev_getpid_func,
+const struct nacl_irt_dev_mprotect nacl_irt_dev_mprotect = {
+  nacl_irt_mprotect,
 };