ubsan_handlers_cxx.cc revision 288943 
1//===-- ubsan_handlers_cxx.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// Error logging entry points for the UBSan runtime, which are only used for C++
11// compilations. This file is permitted to use language features which require
12// linking against a C++ ABI library.
13//
14//===----------------------------------------------------------------------===//
15
16#include "ubsan_platform.h"
17#if CAN_SANITIZE_UB
18#include "ubsan_handlers_cxx.h"
19#include "ubsan_diag.h"
20#include "ubsan_type_hash.h"
21
22#include "sanitizer_common/sanitizer_common.h"
23#include "sanitizer_common/sanitizer_suppressions.h"
24
25using namespace __sanitizer;
26using namespace __ubsan;
27
28namespace __ubsan {
29  extern const char *TypeCheckKinds[];
30}
31
32static void HandleDynamicTypeCacheMiss(
33    DynamicTypeCacheMissData *Data, ValueHandle Pointer, ValueHandle Hash,
34    ReportOptions Opts) {
35  if (checkDynamicType((void*)Pointer, Data->TypeInfo, Hash))
36    // Just a cache miss. The type matches after all.
37    return;
38
39  // Check if error report should be suppressed.
40  DynamicTypeInfo DTI = getDynamicTypeInfoFromObject((void*)Pointer);
41  if (DTI.isValid() && IsVptrCheckSuppressed(DTI.getMostDerivedTypeName()))
42    return;
43
44  SourceLocation Loc = Data->Loc.acquire();
45  if (Loc.isDisabled())
46    return;
47
48  ScopedReport R(Opts, Loc);
49
50  Diag(Loc, DL_Error,
51       "%0 address %1 which does not point to an object of type %2")
52    << TypeCheckKinds[Data->TypeCheckKind] << (void*)Pointer << Data->Type;
53
54  // If possible, say what type it actually points to.
55  if (!DTI.isValid())
56    Diag(Pointer, DL_Note, "object has invalid vptr")
57        << TypeName(DTI.getMostDerivedTypeName())
58        << Range(Pointer, Pointer + sizeof(uptr), "invalid vptr");
59  else if (!DTI.getOffset())
60    Diag(Pointer, DL_Note, "object is of type %0")
61        << TypeName(DTI.getMostDerivedTypeName())
62        << Range(Pointer, Pointer + sizeof(uptr), "vptr for %0");
63  else
64    // FIXME: Find the type at the specified offset, and include that
65    //        in the note.
66    Diag(Pointer - DTI.getOffset(), DL_Note,
67         "object is base class subobject at offset %0 within object of type %1")
68        << DTI.getOffset() << TypeName(DTI.getMostDerivedTypeName())
69        << TypeName(DTI.getSubobjectTypeName())
70        << Range(Pointer, Pointer + sizeof(uptr),
71                 "vptr for %2 base class of %1");
72}
73
74void __ubsan::__ubsan_handle_dynamic_type_cache_miss(
75    DynamicTypeCacheMissData *Data, ValueHandle Pointer, ValueHandle Hash) {
76  GET_REPORT_OPTIONS(false);
77  HandleDynamicTypeCacheMiss(Data, Pointer, Hash, Opts);
78}
79void __ubsan::__ubsan_handle_dynamic_type_cache_miss_abort(
80    DynamicTypeCacheMissData *Data, ValueHandle Pointer, ValueHandle Hash) {
81  GET_REPORT_OPTIONS(true);
82  HandleDynamicTypeCacheMiss(Data, Pointer, Hash, Opts);
83}
84
85static void HandleCFIBadType(CFIBadTypeData *Data, ValueHandle Vtable,
86                             ReportOptions Opts) {
87  SourceLocation Loc = Data->Loc.acquire();
88  ScopedReport R(Opts, Loc);
89  DynamicTypeInfo DTI = getDynamicTypeInfoFromVtable((void*)Vtable);
90
91  static const char *TypeCheckKinds[] = {
92    "virtual call",
93    "non-virtual call",
94    "base-to-derived cast",
95    "cast to unrelated type",
96  };
97
98  Diag(Loc, DL_Error, "control flow integrity check for type %0 failed during "
99                      "%1 (vtable address %2)")
100      << Data->Type << TypeCheckKinds[Data->TypeCheckKind] << (void *)Vtable;
101
102  // If possible, say what type it actually points to.
103  if (!DTI.isValid())
104    Diag(Vtable, DL_Note, "invalid vtable");
105  else
106    Diag(Vtable, DL_Note, "vtable is of type %0")
107        << TypeName(DTI.getMostDerivedTypeName());
108}
109
110void __ubsan::__ubsan_handle_cfi_bad_type(CFIBadTypeData *Data,
111                                          ValueHandle Vtable) {
112  GET_REPORT_OPTIONS(false);
113  HandleCFIBadType(Data, Vtable, Opts);
114}
115
116void __ubsan::__ubsan_handle_cfi_bad_type_abort(CFIBadTypeData *Data,
117                                                ValueHandle Vtable) {
118  GET_REPORT_OPTIONS(true);
119  HandleCFIBadType(Data, Vtable, Opts);
120}
121
122#endif  // CAN_SANITIZE_UB
123