Enable check for DEP / NX page protection

src/trusted/service_runtime/sel_main.c

Index: src/trusted/service_runtime/sel_main.c
===================================================================
--- src/trusted/service_runtime/sel_main.c	(revision 3470)
+++ src/trusted/service_runtime/sel_main.c	(working copy)
@@ -28,6 +28,7 @@
 #include "native_client/src/shared/platform/nacl_sync_checked.h"
 #include "native_client/src/shared/srpc/nacl_srpc.h"
 
+#include "native_client/src/trusted/platform_qualify/nacl_dep_qualify.h"
 #include "native_client/src/trusted/platform_qualify/nacl_os_qualify.h"
 
 #ifdef NACL_BREAKPAD
@@ -450,6 +451,17 @@
             NaClErrorString(errcode));
   }
 
+  /*
+   * Ensure this platform has Data Execution Prevention enabled.
+   */
+  if (!skip_qualification && !NaClCheckDEP()) {
+    errcode = LOAD_DEP_UNSUPPORTED;
+    nap->module_load_status = errcode;
+    fprintf(stderr, "Error while loading \"%s\": %s\n",
+            nacl_file,
+            NaClErrorString(errcode));
+  }
+
   if (LOAD_OK == errcode) {
     errcode = NaClAppLoadFile((struct Gio *) &gf, nap, check_abi);
     if (LOAD_OK != errcode) {