1//===-- ubsan_type_hash_win.cpp -------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Implementation of type hashing/lookup for Microsoft C++ ABI.
10//
11//===----------------------------------------------------------------------===//
12
13#include "sanitizer_common/sanitizer_platform.h"
14#include "ubsan_platform.h"
15#if CAN_SANITIZE_UB && defined(_MSC_VER)
16#include "ubsan_type_hash.h"
17
18#include "sanitizer_common/sanitizer_common.h"
19
20#include <typeinfo>
21
22struct CompleteObjectLocator {
23 int is_image_relative;
24 int offset_to_top;
25 int vfptr_offset;
26 int rtti_addr;
27 int chd_addr;
28 int obj_locator_addr;
29};
30
31struct CompleteObjectLocatorAbs {
32 int is_image_relative;
33 int offset_to_top;
34 int vfptr_offset;
35 std::type_info *rtti_addr;
36 void *chd_addr;
37 CompleteObjectLocator *obj_locator_addr;
38};
39
40bool __ubsan::checkDynamicType(void *Object, void *Type, HashValue Hash) {
41 // FIXME: Implement.
42 return false;
43}
44
45__ubsan::DynamicTypeInfo
46__ubsan::getDynamicTypeInfoFromVtable(void *VtablePtr) {
47 // The virtual table may not have a complete object locator if the object
48 // was compiled without RTTI (i.e. we might be reading from some other global
49 // laid out before the virtual table), so we need to carefully validate each
50 // pointer dereference and perform sanity checks.
51 CompleteObjectLocator **obj_locator_ptr =
52 ((CompleteObjectLocator**)VtablePtr)-1;
53 if (!IsAccessibleMemoryRange((uptr)obj_locator_ptr, sizeof(void*)))
54 return DynamicTypeInfo(0, 0, 0);
55
56 CompleteObjectLocator *obj_locator = *obj_locator_ptr;
57 if (!IsAccessibleMemoryRange((uptr)obj_locator,
58 sizeof(CompleteObjectLocator)))
59 return DynamicTypeInfo(0, 0, 0);
60
61 std::type_info *tinfo;
62 if (obj_locator->is_image_relative == 1) {
63 char *image_base = ((char *)obj_locator) - obj_locator->obj_locator_addr;
64 tinfo = (std::type_info *)(image_base + obj_locator->rtti_addr);
65 } else if (obj_locator->is_image_relative == 0)
66 tinfo = ((CompleteObjectLocatorAbs *)obj_locator)->rtti_addr;
67 else
68 // Probably not a complete object locator.
69 return DynamicTypeInfo(0, 0, 0);
70
71 if (!IsAccessibleMemoryRange((uptr)tinfo, sizeof(std::type_info)))
72 return DynamicTypeInfo(0, 0, 0);
73
74 // Okay, this is probably a std::type_info. Request its name.
75 // FIXME: Implement a base class search like we do for Itanium.
76 return DynamicTypeInfo(tinfo->name(), obj_locator->offset_to_top,
77 "<unknown>");
78}
79
80bool __ubsan::checkTypeInfoEquality(const void *, const void *) {
81 return false;
82}
83
84#endif // CAN_SANITIZE_UB && SANITIZER_WINDOWS
85

source code of compiler-rt/lib/ubsan/ubsan_type_hash_win.cpp