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 
25 using namespace __sanitizer;
26 using namespace __ubsan;
27 
28 namespace __ubsan {
29   extern const char *TypeCheckKinds[];
30 }
31 
HandleDynamicTypeCacheMiss(DynamicTypeCacheMissData * Data,ValueHandle Pointer,ValueHandle Hash,ReportOptions Opts)32 static 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 = getDynamicTypeInfo((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         << MangledName(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         << MangledName(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() << MangledName(DTI.getMostDerivedTypeName())
69         << MangledName(DTI.getSubobjectTypeName())
70         << Range(Pointer, Pointer + sizeof(uptr),
71                  "vptr for %2 base class of %1");
72 }
73 
__ubsan_handle_dynamic_type_cache_miss(DynamicTypeCacheMissData * Data,ValueHandle Pointer,ValueHandle Hash)74 void __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 }
__ubsan_handle_dynamic_type_cache_miss_abort(DynamicTypeCacheMissData * Data,ValueHandle Pointer,ValueHandle Hash)79 void __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 
85 #endif  // CAN_SANITIZE_UB
86