win: support x64 reading x86 (wow64)

util/win/process_structs.h

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 265 matching lines @@
   typename Traits::UnsignedIntegral MinimumStackCommit;
   typename Traits::Pointer FlsCallback;
   LIST_ENTRY<Traits> FlsListHead;
   typename Traits::Pointer FlsBitmap;
   DWORD FlsBitmapBits[4];
   DWORD FlsHighIndex;
 };
 
 template <class Traits>
 struct NT_TIB {
-  typename Traits::Pointer ExceptionList;
+  union {
+    typename Traits::Pointer ExceptionList;
+    // See https://msdn.microsoft.com/en-us/library/dn424783.aspx.

[Mark Mentovai, 2015/09/18 15:44:07]

But the rest of NT_TIB isn’t right for WoW64 either, is it? Maybe this:

  union {
    struct {
      ExceptionList;
      StackBase;
    };
    Wow64Teb;
  };

[scottmg, 2015/09/18 19:45:26]

I'm not sure if it is. I think it probably has the associated 64 bit data? But
we don't care about that, so seems reasonable.

[Mark Mentovai, 2015/09/18 22:10:50]

scottmg wrote:
Well, if each thread has its own distinct 64-bit stack, then what you had is
maybe more correct. Your call. Like you said, we don’t actually use anything
else in the WoW64 case, so there’s no practical difference.

+    typename Traits::Pointer Wow64Teb;
+  };
   typename Traits::Pointer StackBase;
   typename Traits::Pointer StackLimit;
   typename Traits::Pointer SubSystemTib;
   union {
     typename Traits::Pointer FiberData;
     BYTE Version[4];
   };
   typename Traits::Pointer ArbitraryUserPointer;
   typename Traits::Pointer Self;
 };
@@ skipping 113 matching lines @@
     LARGE_INTEGER alignment_for_x86[6];
   };
   IO_COUNTERS IoCounters;
   SYSTEM_THREAD_INFORMATION<Traits> Threads[1];
 };
 
 // http://undocumented.ntinternals.net/source/usermode/structures/thread_basic_information.html
 template <class Traits>
 struct THREAD_BASIC_INFORMATION {
   union {
-    NTSTATUS ExitStatus;
+    LONG ExitStatus;
     typename Traits::Pad padding_for_x64_0;
   };
   typename Traits::Pointer TebBaseAddress;
   CLIENT_ID<Traits> ClientId;
   typename Traits::Pointer AffinityMask;
   ULONG Priority;
   LONG BasePriority;
 };
 
+template <class Traits>
+struct EXCEPTION_POINTERS {
+  typename Traits::Pointer ExceptionRecord;
+  typename Traits::Pointer ContextRecord;
+};
+
 #pragma pack(pop)
 
 //! \}
 
 }  // namespace process_types
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_WIN_PROCESS_STRUCTS_H_