Make command buffer commands and immediate data volatile

gpu/command_buffer/service/cmd_parser.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains the implementation of the command parser.
 
 #include "gpu/command_buffer/service/cmd_parser.h"
 
 #include <stddef.h>
 
@@ skipping 58 matching lines @@
       return error;
   }
   return error::kNoError;
 }
 
 // Decode multiple commands, and call the corresponding GL functions.
 // NOTE: buffer is a pointer to the command buffer. As such, it could be
 // changed by a (malicious) client at any time, so if validation has to happen,
 // it should operate on a copy of them.
 error::Error AsyncAPIInterface::DoCommands(unsigned int num_commands,
-                                           const void* buffer,
+                                           const volatile void* buffer,
                                            int num_entries,
                                            int* entries_processed) {
   int commands_to_process = num_commands;
   error::Error result = error::kNoError;
-  const CommandBufferEntry* cmd_data =
-      static_cast<const CommandBufferEntry*>(buffer);
+  const volatile CommandBufferEntry* cmd_data =
+      static_cast<const volatile CommandBufferEntry*>(buffer);
   int process_pos = 0;
 
   while (process_pos < num_entries && result == error::kNoError &&
          commands_to_process--) {
-    CommandHeader header = cmd_data->value_header;
+    CommandHeader header = CommandHeader::FromVolatile(cmd_data->value_header);
     if (header.size == 0) {
       DVLOG(1) << "Error: zero sized command in command buffer";
       return error::kInvalidSize;
     }
 
     if (static_cast<int>(header.size) + process_pos > num_entries) {
       DVLOG(1) << "Error: get offset out of bounds";
       return error::kOutOfBounds;
     }
 
     const unsigned int command = header.command;
     const unsigned int arg_count = header.size - 1;
 
     result = DoCommand(command, arg_count, cmd_data);
 
     if (result != error::kDeferCommandUntilLater) {
       process_pos += header.size;
       cmd_data += header.size;
     }
   }
 
   if (entries_processed)
     *entries_processed = process_pos;
 
   return result;
 }
 
 }  // namespace gpu