1//===-- ubsan_type_hash_win.cc --------------------------------------------===//
2//
3// This file is distributed under the University of Illinois Open Source
4// License. See LICENSE.TXT for details.
5//
6//===----------------------------------------------------------------------===//
7//
8// Implementation of type hashing/lookup for Microsoft C++ ABI.
9//
10//===----------------------------------------------------------------------===//
11
12#include "sanitizer_common/sanitizer_platform.h"
13#include "ubsan_platform.h"
14#if CAN_SANITIZE_UB && SANITIZER_WINDOWS
15#include "ubsan_type_hash.h"
16
17#include "sanitizer_common/sanitizer_common.h"
18
19#include <typeinfo>
20
21struct CompleteObjectLocator {
22  int is_image_relative;
23  int offset_to_top;
24  int vfptr_offset;
25  int rtti_addr;
26  int chd_addr;
27  int obj_locator_addr;
28};
29
30struct CompleteObjectLocatorAbs {
31  int is_image_relative;
32  int offset_to_top;
33  int vfptr_offset;
34  std::type_info *rtti_addr;
35  void *chd_addr;
36  CompleteObjectLocator *obj_locator_addr;
37};
38
39bool __ubsan::checkDynamicType(void *Object, void *Type, HashValue Hash) {
40  // FIXME: Implement.
41  return false;
42}
43
44__ubsan::DynamicTypeInfo
45__ubsan::getDynamicTypeInfoFromVtable(void *VtablePtr) {
46  // The virtual table may not have a complete object locator if the object
47  // was compiled without RTTI (i.e. we might be reading from some other global
48  // laid out before the virtual table), so we need to carefully validate each
49  // pointer dereference and perform sanity checks.
50  CompleteObjectLocator **obj_locator_ptr =
51    ((CompleteObjectLocator**)VtablePtr)-1;
52  if (!IsAccessibleMemoryRange((uptr)obj_locator_ptr, sizeof(void*)))
53    return DynamicTypeInfo(0, 0, 0);
54
55  CompleteObjectLocator *obj_locator = *obj_locator_ptr;
56  if (!IsAccessibleMemoryRange((uptr)obj_locator,
57                               sizeof(CompleteObjectLocator)))
58    return DynamicTypeInfo(0, 0, 0);
59
60  std::type_info *tinfo;
61  if (obj_locator->is_image_relative == 1) {
62    char *image_base = ((char *)obj_locator) - obj_locator->obj_locator_addr;
63    tinfo = (std::type_info *)(image_base + obj_locator->rtti_addr);
64  } else if (obj_locator->is_image_relative == 0)
65    tinfo = ((CompleteObjectLocatorAbs *)obj_locator)->rtti_addr;
66  else
67    // Probably not a complete object locator.
68    return DynamicTypeInfo(0, 0, 0);
69
70  if (!IsAccessibleMemoryRange((uptr)tinfo, sizeof(std::type_info)))
71    return DynamicTypeInfo(0, 0, 0);
72
73  // Okay, this is probably a std::type_info. Request its name.
74  // FIXME: Implement a base class search like we do for Itanium.
75  return DynamicTypeInfo(tinfo->name(), obj_locator->offset_to_top,
76                         "<unknown>");
77}
78
79#endif  // CAN_SANITIZE_UB && SANITIZER_WINDOWS
80