Pirama Arumuga Nainar | 799172d | 2016-03-03 15:50:30 -0800 | [diff] [blame^] | 1 | //===-- ubsan_type_hash_win.cc --------------------------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // Implementation of type hashing/lookup for Microsoft C++ ABI. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 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" |
| 18 | |
| 19 | #include "sanitizer_common/sanitizer_common.h" |
| 20 | |
| 21 | #include <typeinfo> |
| 22 | |
| 23 | struct CompleteObjectLocator { |
| 24 | int is_image_relative; |
| 25 | int offset_to_top; |
| 26 | int vfptr_offset; |
| 27 | int rtti_addr; |
| 28 | int chd_addr; |
| 29 | int obj_locator_addr; |
| 30 | }; |
| 31 | |
| 32 | struct CompleteObjectLocatorAbs { |
| 33 | int is_image_relative; |
| 34 | int offset_to_top; |
| 35 | int vfptr_offset; |
| 36 | std::type_info *rtti_addr; |
| 37 | void *chd_addr; |
| 38 | CompleteObjectLocator *obj_locator_addr; |
| 39 | }; |
| 40 | |
| 41 | bool __ubsan::checkDynamicType(void *Object, void *Type, HashValue Hash) { |
| 42 | // FIXME: Implement. |
| 43 | return false; |
| 44 | } |
| 45 | |
| 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); |
| 56 | |
| 57 | CompleteObjectLocator *obj_locator = *obj_locator_ptr; |
| 58 | if (!IsAccessibleMemoryRange((uptr)obj_locator, |
| 59 | sizeof(CompleteObjectLocator))) |
| 60 | return DynamicTypeInfo(0, 0, 0); |
| 61 | |
| 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; |
| 68 | else |
| 69 | // Probably not a complete object locator. |
| 70 | return DynamicTypeInfo(0, 0, 0); |
| 71 | |
| 72 | if (!IsAccessibleMemoryRange((uptr)tinfo, sizeof(std::type_info))) |
| 73 | return DynamicTypeInfo(0, 0, 0); |
| 74 | |
| 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, |
| 78 | "<unknown>"); |
| 79 | } |
| 80 | |
| 81 | #endif // CAN_SANITIZE_UB && SANITIZER_WINDOWS |