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/Support/ConvertUTF.h"
11
12using namespace llvm;
13using namespace llvm::object;
14using namespace llvm::minidump;
15
16std::optional<ArrayRef<uint8_t>>
17MinidumpFile::getRawStream(minidump::StreamType Type) const {
18 auto It = StreamMap.find(Val: Type);
19 if (It != StreamMap.end())
20 return getRawStream(Stream: Streams[It->second]);
21 return std::nullopt;
22}
23
24Expected<std::string> MinidumpFile::getString(size_t Offset) const {
25 // Minidump strings consist of a 32-bit length field, which gives the size of
26 // the string in *bytes*. This is followed by the actual string encoded in
27 // UTF16.
28 auto ExpectedSize =
29 getDataSliceAs<support::ulittle32_t>(Data: getData(), Offset, Count: 1);
30 if (!ExpectedSize)
31 return ExpectedSize.takeError();
32 size_t Size = (*ExpectedSize)[0];
33 if (Size % 2 != 0)
34 return createError(Str: "String size not even");
35 Size /= 2;
36 if (Size == 0)
37 return "";
38
39 Offset += sizeof(support::ulittle32_t);
40 auto ExpectedData =
41 getDataSliceAs<support::ulittle16_t>(Data: getData(), Offset, Count: Size);
42 if (!ExpectedData)
43 return ExpectedData.takeError();
44
45 SmallVector<UTF16, 32> WStr(Size);
46 copy(Range&: *ExpectedData, Out: WStr.begin());
47
48 std::string Result;
49 if (!convertUTF16ToUTF8String(Src: WStr, Out&: Result))
50 return createError(Str: "String decoding failed");
51
52 return Result;
53}
54
55iterator_range<llvm::object::MinidumpFile::ExceptionStreamsIterator>
56MinidumpFile::getExceptionStreams() const {
57 return make_range(x: ExceptionStreamsIterator(ExceptionStreams, this),
58 y: ExceptionStreamsIterator({}, this));
59}
60
61Expected<iterator_range<MinidumpFile::MemoryInfoIterator>>
62MinidumpFile::getMemoryInfoList() const {
63 std::optional<ArrayRef<uint8_t>> Stream =
64 getRawStream(Type: StreamType::MemoryInfoList);
65 if (!Stream)
66 return createError(Str: "No such stream");
67 auto ExpectedHeader =
68 getDataSliceAs<minidump::MemoryInfoListHeader>(Data: *Stream, Offset: 0, Count: 1);
69 if (!ExpectedHeader)
70 return ExpectedHeader.takeError();
71 const minidump::MemoryInfoListHeader &H = ExpectedHeader.get()[0];
72 Expected<ArrayRef<uint8_t>> Data =
73 getDataSlice(Data: *Stream, Offset: H.SizeOfHeader, Size: H.SizeOfEntry * H.NumberOfEntries);
74 if (!Data)
75 return Data.takeError();
76 return make_range(x: MemoryInfoIterator(*Data, H.SizeOfEntry),
77 y: MemoryInfoIterator({}, H.SizeOfEntry));
78}
79
80Expected<ArrayRef<uint8_t>> MinidumpFile::getDataSlice(ArrayRef<uint8_t> Data,
81 uint64_t Offset,
82 uint64_t Size) {
83 // Check for overflow.
84 if (Offset + Size < Offset || Offset + Size < Size ||
85 Offset + Size > Data.size())
86 return createEOFError();
87 return Data.slice(N: Offset, M: Size);
88}
89
90Expected<std::unique_ptr<MinidumpFile>>
91MinidumpFile::create(MemoryBufferRef Source) {
92 ArrayRef<uint8_t> Data = arrayRefFromStringRef(Input: Source.getBuffer());
93 auto ExpectedHeader = getDataSliceAs<minidump::Header>(Data, Offset: 0, Count: 1);
94 if (!ExpectedHeader)
95 return ExpectedHeader.takeError();
96
97 const minidump::Header &Hdr = (*ExpectedHeader)[0];
98 if (Hdr.Signature != Header::MagicSignature)
99 return createError(Str: "Invalid signature");
100 if ((Hdr.Version & 0xffff) != Header::MagicVersion)
101 return createError(Str: "Invalid version");
102
103 auto ExpectedStreams = getDataSliceAs<Directory>(Data, Offset: Hdr.StreamDirectoryRVA,
104 Count: Hdr.NumberOfStreams);
105 if (!ExpectedStreams)
106 return ExpectedStreams.takeError();
107
108 DenseMap<StreamType, std::size_t> StreamMap;
109 std::vector<Directory> ExceptionStreams;
110 for (const auto &StreamDescriptor : llvm::enumerate(First&: *ExpectedStreams)) {
111 StreamType Type = StreamDescriptor.value().Type;
112 const LocationDescriptor &Loc = StreamDescriptor.value().Location;
113
114 Expected<ArrayRef<uint8_t>> Stream =
115 getDataSlice(Data, Offset: Loc.RVA, Size: Loc.DataSize);
116 if (!Stream)
117 return Stream.takeError();
118
119 if (Type == StreamType::Unused && Loc.DataSize == 0) {
120 // Ignore dummy streams. This is technically ill-formed, but a number of
121 // existing minidumps seem to contain such streams.
122 continue;
123 }
124
125 // Exceptions can be treated as a special case of streams. Other streams
126 // represent a list of entities, but exceptions are unique per stream.
127 if (Type == StreamType::Exception) {
128 ExceptionStreams.push_back(x: StreamDescriptor.value());
129 continue;
130 }
131
132 if (Type == DenseMapInfo<StreamType>::getEmptyKey() ||
133 Type == DenseMapInfo<StreamType>::getTombstoneKey())
134 return createError(Str: "Cannot handle one of the minidump streams");
135
136 // Update the directory map, checking for duplicate stream types.
137 if (!StreamMap.try_emplace(Key: Type, Args: StreamDescriptor.index()).second)
138 return createError(Str: "Duplicate stream type");
139 }
140
141 return std::unique_ptr<MinidumpFile>(
142 new MinidumpFile(Source, Hdr, *ExpectedStreams, std::move(StreamMap),
143 std::move(ExceptionStreams)));
144}
145
146iterator_range<MinidumpFile::FallibleMemory64Iterator>
147MinidumpFile::getMemory64List(Error &Err) const {
148 ErrorAsOutParameter ErrAsOutParam(Err);
149 auto end = FallibleMemory64Iterator::end(I: Memory64Iterator::end());
150 Expected<minidump::Memory64ListHeader> ListHeader = getMemoryList64Header();
151 if (!ListHeader) {
152 Err = ListHeader.takeError();
153 return make_range(x: end, y: end);
154 }
155
156 std::optional<ArrayRef<uint8_t>> Stream =
157 getRawStream(Type: StreamType::Memory64List);
158 if (!Stream) {
159 Err = createError(Str: "No such stream");
160 return make_range(x: end, y: end);
161 }
162
163 Expected<ArrayRef<minidump::MemoryDescriptor_64>> Descriptors =
164 getDataSliceAs<minidump::MemoryDescriptor_64>(
165 Data: *Stream, Offset: sizeof(Memory64ListHeader),
166 Count: ListHeader->NumberOfMemoryRanges);
167
168 if (!Descriptors) {
169 Err = Descriptors.takeError();
170 return make_range(x: end, y: end);
171 }
172
173 if (!Descriptors->empty() &&
174 ListHeader->BaseRVA + Descriptors->front().DataSize > getData().size()) {
175 Err = createError(Str: "Memory64List header RVA out of range");
176 return make_range(x: end, y: end);
177 }
178
179 return make_range(x: FallibleMemory64Iterator::itr(
180 I: Memory64Iterator::begin(
181 Storage: getData().slice(N: ListHeader->BaseRVA), Descriptors: *Descriptors),
182 Err),
183 y: FallibleMemory64Iterator::end(I: Memory64Iterator::end()));
184}
185