libsanitizer/ubsan/ubsan_type_hash_win.cc

   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
  21 struct 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
  30 struct 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
  39 bool __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