Move the Windows sandbox to sandbox/win

sandbox/src/sidestep/preamble_patcher.h

-// 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.
-
-// Definition of PreamblePatcher
-
-#ifndef SANDBOX_SRC_SIDESTEP_PREAMBLE_PATCHER_H__
-#define SANDBOX_SRC_SIDESTEP_PREAMBLE_PATCHER_H__
-
-namespace sidestep {
-
-// Maximum size of the preamble stub. We overwrite at least the first 5
-// bytes of the function. Considering the worst case scenario, we need 4
-// bytes + the max instruction size + 5 more bytes for our jump back to
-// the original code. With that in mind, 32 is a good number :)
-const size_t kMaxPreambleStubSize = 32;
-
-// Possible results of patching/unpatching
-enum SideStepError {
-  SIDESTEP_SUCCESS = 0,
-  SIDESTEP_INVALID_PARAMETER,
-  SIDESTEP_INSUFFICIENT_BUFFER,
-  SIDESTEP_JUMP_INSTRUCTION,
-  SIDESTEP_FUNCTION_TOO_SMALL,
-  SIDESTEP_UNSUPPORTED_INSTRUCTION,
-  SIDESTEP_NO_SUCH_MODULE,
-  SIDESTEP_NO_SUCH_FUNCTION,
-  SIDESTEP_ACCESS_DENIED,
-  SIDESTEP_UNEXPECTED,
-};
-
-// Implements a patching mechanism that overwrites the first few bytes of
-// a function preamble with a jump to our hook function, which is then
-// able to call the original function via a specially-made preamble-stub
-// that imitates the action of the original preamble.
-//
-// Note that there are a number of ways that this method of patching can
-// fail.  The most common are:
-//    - If there is a jump (jxx) instruction in the first 5 bytes of
-//    the function being patched, we cannot patch it because in the
-//    current implementation we do not know how to rewrite relative
-//    jumps after relocating them to the preamble-stub.  Note that
-//    if you really really need to patch a function like this, it
-//    would be possible to add this functionality (but at some cost).
-//    - If there is a return (ret) instruction in the first 5 bytes
-//    we cannot patch the function because it may not be long enough
-//    for the jmp instruction we use to inject our patch.
-//    - If there is another thread currently executing within the bytes
-//    that are copied to the preamble stub, it will crash in an undefined
-//    way.
-//
-// If you get any other error than the above, you're either pointing the
-// patcher at an invalid instruction (e.g. into the middle of a multi-
-// byte instruction, or not at memory containing executable instructions)
-// or, there may be a bug in the disassembler we use to find
-// instruction boundaries.
-class PreamblePatcher {
- public:
-  // Patches target_function to point to replacement_function using a provided
-  // preamble_stub of stub_size bytes.
-  // Returns An error code indicating the result of patching.
-  template <class T>
-  static SideStepError Patch(T target_function, T replacement_function,
-                             void* preamble_stub, size_t stub_size) {
-    return RawPatchWithStub(target_function, replacement_function,
-                            reinterpret_cast<unsigned char*>(preamble_stub),
-                            stub_size, NULL);
-  }
-
- private:
-
-  // Patches a function by overwriting its first few bytes with
-  // a jump to a different function.  This is similar to the RawPatch
-  // function except that it uses the stub allocated by the caller
-  // instead of allocating it.
-  //
-  // To use this function, you first have to call VirtualProtect to make the
-  // target function writable at least for the duration of the call.
-  //
-  // target_function: A pointer to the function that should be
-  // patched.
-  //
-  // replacement_function: A pointer to the function that should
-  // replace the target function.  The replacement function must have
-  // exactly the same calling convention and parameters as the original
-  // function.
-  //
-  // preamble_stub: A pointer to a buffer where the preamble stub
-  // should be copied. The size of the buffer should be sufficient to
-  // hold the preamble bytes.
-  //
-  // stub_size: Size in bytes of the buffer allocated for the
-  // preamble_stub
-  //
-  // bytes_needed: Pointer to a variable that receives the minimum
-  // number of bytes required for the stub.  Can be set to NULL if you're
-  // not interested.
-  //
-  // Returns An error code indicating the result of patching.
-  static SideStepError RawPatchWithStub(void* target_function,
-                                        void *replacement_function,
-                                        unsigned char* preamble_stub,
-                                        size_t stub_size,
-                                        size_t* bytes_needed);
-};
-
-};  // namespace sidestep
-
-#endif  // SANDBOX_SRC_SIDESTEP_PREAMBLE_PATCHER_H__