Enable check for DEP / NX page protection

src/trusted/service_runtime/sel_main_chrome.c

Index: src/trusted/service_runtime/sel_main_chrome.c
===================================================================
--- src/trusted/service_runtime/sel_main_chrome.c	(revision 3470)
+++ src/trusted/service_runtime/sel_main_chrome.c	(working copy)
@@ -25,6 +25,7 @@
 #include "native_client/src/trusted/service_runtime/nacl_debug.h"
 #include "native_client/src/trusted/service_runtime/nacl_signal.h"
 #include "native_client/src/trusted/service_runtime/sel_ldr.h"
+#include "native_client/src/trusted/platform_qualify/nacl_dep_qualify.h"
 #include "native_client/src/trusted/platform_qualify/nacl_os_qualify.h"
 
 static int const kSrpcFd = 5;
@@ -122,6 +123,16 @@
             NaClErrorString(errcode));
   }
 
+  /*
+   * Ensure this platform has Data Execution Prevention enabled.
+   */
+  if (!NaClCheckDEP()) {
+    errcode = LOAD_DEP_UNSUPPORTED;
+    nap->module_load_status = errcode;
+    fprintf(stderr, "Error while loading in SelMain: %s\n",
+            NaClErrorString(errcode));
+  }
+
   /* Give debuggers a well known point at which xlate_base is known.  */
   StopForDebuggerInit(&state);