A mechanism to identify/forbid/"rewrite" non-temporal instructions (and other)

src/trusted/validator_ragel/dll_utils.c

 /*
  * Copyright (c) 2013 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 <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ skipping 27 matching lines @@
 };
 
 
 Bool ExtractRestrictedRegisterCallback(
     const uint8_t *begin,
     const uint8_t *end,
     uint32_t info,
     void *data) {
 
   struct CallbackData *callback_data = data;
+  /* UNSUPPORTED_INSTRUCTION indicates validation failure only for pnacl-mode.
+   * Since by default we are in non-pnacl-mode, the flag is simply cleared.
+   */
+  info &= ~UNSUPPORTED_INSTRUCTION;
+
   if (end <= callback_data->actual_end && (info & VALIDATION_ERRORS_MASK)) {
     callback_data->valid = FALSE;
   }
   if (end == callback_data->actual_end) {
     callback_data->restricted_register =
         (info & RESTRICTED_REGISTER_MASK) >> RESTRICTED_REGISTER_SHIFT;
   }
   if (begin < callback_data->actual_end && callback_data->actual_end < end) {
     /* Instruction crosses actual chunk boundary. */
     callback_data->valid = FALSE;
@@ skipping 32 matching lines @@
   ValidateChunkAMD64(
       codeblock, size,
       options,
       cpu_features,
       ExtractRestrictedRegisterCallback,
       &callback_data);
 
   *resulting_restricted_register = callback_data.restricted_register;
   return callback_data.valid;
 }