64-bit compatibility changes for the sandbox code

sandbox/src/sandbox_nt_util.cc

 // Copyright (c) 2006-2008 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.
 
 #include "sandbox/src/sandbox_nt_util.h"
 
 #include "base/pe_image.h"
 #include "sandbox/src/sandbox_factory.h"
 #include "sandbox/src/target_services.h"
 
@@ skipping 199 matching lines @@
 
   ULONG process_id;
   NTSTATUS ret = GetProcessId(process, &process_id);
   if (!NT_SUCCESS(ret))
     return false;
 
   return (process_id == s_process_id);
 }
 
 bool IsValidImageSection(HANDLE section, PVOID *base, PLARGE_INTEGER offset,
-                         PULONG view_size) {
+                         PSIZE_T view_size) {
   if (!section || !base || !view_size || offset)
     return false;
 
   HANDLE query_section;
 
   NTSTATUS ret = g_nt.DuplicateObject(NtCurrentProcess, section,
                                       NtCurrentProcess, &query_section,
                                       SECTION_QUERY, 0, 0);
   if (!NT_SUCCESS(ret))
     return false;
@@ skipping 128 matching lines @@
   if ((ix == start_pos) && sep)
     return NULL;
 
   // No path separator found. Use the entire name.
   if (!sep) {
     sep = &module_path->Buffer[-1];
   }
 
   // Add one to the size so we can null terminate the string.
   size_t size_bytes = (start_pos - ix + 1) * sizeof(wchar_t);
+
+  // Based on the code above, size_bytes should always be small enough
+  // to make the static_cast below safe.
+  DCHECK_NT(kuint16max > size_bytes);
   char* str_buffer = new(NT_ALLOC) char[size_bytes + sizeof(UNICODE_STRING)];
   if (!str_buffer)
     return NULL;
 
   UNICODE_STRING* out_string = reinterpret_cast<UNICODE_STRING*>(str_buffer);
   out_string->Buffer = reinterpret_cast<wchar_t*>(&out_string[1]);
-  out_string->Length = size_bytes - sizeof(wchar_t);
-  out_string->MaximumLength = size_bytes;
+  out_string->Length = static_cast<USHORT>(size_bytes - sizeof(wchar_t));
+  out_string->MaximumLength = static_cast<USHORT>(size_bytes);
 
   NTSTATUS ret = CopyData(out_string->Buffer, &sep[1], out_string->Length);
   if (!NT_SUCCESS(ret)) {
     operator delete(out_string, NT_ALLOC);
     return NULL;
   }
 
   out_string->Buffer[out_string->Length / sizeof(wchar_t)] = L'\0';
   return out_string;
 }
@@ skipping 107 matching lines @@
   UNREFERENCED_PARAMETER(type);
   return buffer;
 }
 
 void __cdecl operator delete(void* memory, void* buffer,
                              sandbox::AllocationType type) {
   UNREFERENCED_PARAMETER(memory);
   UNREFERENCED_PARAMETER(buffer);
   UNREFERENCED_PARAMETER(type);
 }