Minidump.cpp revision 360784 
1//===- Minidump.cpp - Minidump object file implementation -----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/Object/Minidump.h"
10#include "llvm/Object/Error.h"
11#include "llvm/Support/ConvertUTF.h"
12
13using namespace llvm;
14using namespace llvm::object;
15using namespace llvm::minidump;
16
17Optional<ArrayRef<uint8_t>>
18MinidumpFile::getRawStream(minidump::StreamType Type) const {
19  auto It = StreamMap.find(Type);
20  if (It != StreamMap.end())
21    return getRawStream(Streams[It->second]);
22  return None;
23}
24
25Expected<std::string> MinidumpFile::getString(size_t Offset) const {
26  // Minidump strings consist of a 32-bit length field, which gives the size of
27  // the string in *bytes*. This is followed by the actual string encoded in
28  // UTF16.
29  auto ExpectedSize =
30      getDataSliceAs<support::ulittle32_t>(getData(), Offset, 1);
31  if (!ExpectedSize)
32    return ExpectedSize.takeError();
33  size_t Size = (*ExpectedSize)[0];
34  if (Size % 2 != 0)
35    return createError("String size not even");
36  Size /= 2;
37  if (Size == 0)
38    return "";
39
40  Offset += sizeof(support::ulittle32_t);
41  auto ExpectedData =
42      getDataSliceAs<support::ulittle16_t>(getData(), Offset, Size);
43  if (!ExpectedData)
44    return ExpectedData.takeError();
45
46  SmallVector<UTF16, 32> WStr(Size);
47  copy(*ExpectedData, WStr.begin());
48
49  std::string Result;
50  if (!convertUTF16ToUTF8String(WStr, Result))
51    return createError("String decoding failed");
52
53  return Result;
54}
55
56Expected<iterator_range<MinidumpFile::MemoryInfoIterator>>
57MinidumpFile::getMemoryInfoList() const {
58  Optional<ArrayRef<uint8_t>> Stream = getRawStream(StreamType::MemoryInfoList);
59  if (!Stream)
60    return createError("No such stream");
61  auto ExpectedHeader =
62      getDataSliceAs<minidump::MemoryInfoListHeader>(*Stream, 0, 1);
63  if (!ExpectedHeader)
64    return ExpectedHeader.takeError();
65  const minidump::MemoryInfoListHeader &H = ExpectedHeader.get()[0];
66  Expected<ArrayRef<uint8_t>> Data =
67      getDataSlice(*Stream, H.SizeOfHeader, H.SizeOfEntry * H.NumberOfEntries);
68  if (!Data)
69    return Data.takeError();
70  return make_range(MemoryInfoIterator(*Data, H.SizeOfEntry),
71                    MemoryInfoIterator({}, H.SizeOfEntry));
72}
73
74template <typename T>
75Expected<ArrayRef<T>> MinidumpFile::getListStream(StreamType Type) const {
76  Optional<ArrayRef<uint8_t>> Stream = getRawStream(Type);
77  if (!Stream)
78    return createError("No such stream");
79  auto ExpectedSize = getDataSliceAs<support::ulittle32_t>(*Stream, 0, 1);
80  if (!ExpectedSize)
81    return ExpectedSize.takeError();
82
83  size_t ListSize = ExpectedSize.get()[0];
84
85  size_t ListOffset = 4;
86  // Some producers insert additional padding bytes to align the list to an
87  // 8-byte boundary. Check for that by comparing the list size with the overall
88  // stream size.
89  if (ListOffset + sizeof(T) * ListSize < Stream->size())
90    ListOffset = 8;
91
92  return getDataSliceAs<T>(*Stream, ListOffset, ListSize);
93}
94template Expected<ArrayRef<Module>>
95    MinidumpFile::getListStream(StreamType) const;
96template Expected<ArrayRef<Thread>>
97    MinidumpFile::getListStream(StreamType) const;
98template Expected<ArrayRef<MemoryDescriptor>>
99    MinidumpFile::getListStream(StreamType) const;
100
101Expected<ArrayRef<uint8_t>>
102MinidumpFile::getDataSlice(ArrayRef<uint8_t> Data, size_t Offset, size_t Size) {
103  // Check for overflow.
104  if (Offset + Size < Offset || Offset + Size < Size ||
105      Offset + Size > Data.size())
106    return createEOFError();
107  return Data.slice(Offset, Size);
108}
109
110Expected<std::unique_ptr<MinidumpFile>>
111MinidumpFile::create(MemoryBufferRef Source) {
112  ArrayRef<uint8_t> Data = arrayRefFromStringRef(Source.getBuffer());
113  auto ExpectedHeader = getDataSliceAs<minidump::Header>(Data, 0, 1);
114  if (!ExpectedHeader)
115    return ExpectedHeader.takeError();
116
117  const minidump::Header &Hdr = (*ExpectedHeader)[0];
118  if (Hdr.Signature != Header::MagicSignature)
119    return createError("Invalid signature");
120  if ((Hdr.Version & 0xffff) != Header::MagicVersion)
121    return createError("Invalid version");
122
123  auto ExpectedStreams = getDataSliceAs<Directory>(Data, Hdr.StreamDirectoryRVA,
124                                                   Hdr.NumberOfStreams);
125  if (!ExpectedStreams)
126    return ExpectedStreams.takeError();
127
128  DenseMap<StreamType, std::size_t> StreamMap;
129  for (const auto &StreamDescriptor : llvm::enumerate(*ExpectedStreams)) {
130    StreamType Type = StreamDescriptor.value().Type;
131    const LocationDescriptor &Loc = StreamDescriptor.value().Location;
132
133    Expected<ArrayRef<uint8_t>> Stream =
134        getDataSlice(Data, Loc.RVA, Loc.DataSize);
135    if (!Stream)
136      return Stream.takeError();
137
138    if (Type == StreamType::Unused && Loc.DataSize == 0) {
139      // Ignore dummy streams. This is technically ill-formed, but a number of
140      // existing minidumps seem to contain such streams.
141      continue;
142    }
143
144    if (Type == DenseMapInfo<StreamType>::getEmptyKey() ||
145        Type == DenseMapInfo<StreamType>::getTombstoneKey())
146      return createError("Cannot handle one of the minidump streams");
147
148    // Update the directory map, checking for duplicate stream types.
149    if (!StreamMap.try_emplace(Type, StreamDescriptor.index()).second)
150      return createError("Duplicate stream type");
151  }
152
153  return std::unique_ptr<MinidumpFile>(
154      new MinidumpFile(Source, Hdr, *ExpectedStreams, std::move(StreamMap)));
155}
156