xref: /freebsd/contrib/llvm-project/llvm/lib/Object/Minidump.cpp (revision ccb59683b98360afaf5b5bb641a68fea22c68d0b)
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 
13 using namespace llvm;
14 using namespace llvm::object;
15 using namespace llvm::minidump;
16 
17 Optional<ArrayRef<uint8_t>>
18 MinidumpFile::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 
25 Expected<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 
56 Expected<iterator_range<MinidumpFile::MemoryInfoIterator>>
57 MinidumpFile::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 
74 template <typename T>
75 Expected<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 }
94 template Expected<ArrayRef<Module>>
95     MinidumpFile::getListStream(StreamType) const;
96 template Expected<ArrayRef<Thread>>
97     MinidumpFile::getListStream(StreamType) const;
98 template Expected<ArrayRef<MemoryDescriptor>>
99     MinidumpFile::getListStream(StreamType) const;
100 
101 Expected<ArrayRef<uint8_t>>
102 MinidumpFile::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 
110 Expected<std::unique_ptr<MinidumpFile>>
111 MinidumpFile::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