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