Object/Minidump: Add support for reading the ModuleList stream

Summary:
The ModuleList stream consists of an integer giving the number of
entries in the list, followed by the list itself. Each entry in the list
describes a module (dynamically loaded objects which were loaded in the
process when it crashed (or when the minidump was generated).

The code for reading the list is relatively straight-forward, with a
single gotcha. Some minidump writers are emitting padding after the
"count" field in order to align the subsequent list on 8 byte boundary
(this depends on how their ModuleList type was defined and the native
alignment of various types on their platform). Fortunately, the minidump
format contains enough redundancy (in the form of the stream length
field in the stream directory), which allows us to detect this situation
and correct it.

This patch just adds the ability to parse the stream. Code for
conversion to/from yaml will come in a follow-up patch.

Reviewers: zturner, amccarth, jhenderson, clayborg

Subscribers: jdoerfert, markmentovai, lldb-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60121

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357897 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/BinaryFormat/Minidump.h

@@ -124,6 +124,37 @@ struct SystemInfo {
 };
 static_assert(sizeof(SystemInfo) == 56, "");
 
+struct VSFixedFileInfo {
+  support::ulittle32_t Signature;
+  support::ulittle32_t StructVersion;
+  support::ulittle32_t FileVersionHigh;
+  support::ulittle32_t FileVersionLow;
+  support::ulittle32_t ProductVersionHigh;
+  support::ulittle32_t ProductVersionLow;
+  support::ulittle32_t FileFlagsMask;
+  support::ulittle32_t FileFlags;
+  support::ulittle32_t FileOS;
+  support::ulittle32_t FileType;
+  support::ulittle32_t FileSubtype;
+  support::ulittle32_t FileDateHigh;
+  support::ulittle32_t FileDateLow;
+};
+static_assert(sizeof(VSFixedFileInfo) == 52, "");
+
+struct Module {
+  support::ulittle64_t BaseOfImage;
+  support::ulittle32_t SizeOfImage;
+  support::ulittle32_t Checksum;
+  support::ulittle32_t TimeDateStamp;
+  support::ulittle32_t ModuleNameRVA;
+  VSFixedFileInfo VersionInfo;
+  LocationDescriptor CvRecord;
+  LocationDescriptor MiscRecord;
+  support::ulittle64_t Reserved0;
+  support::ulittle64_t Reserved1;
+};
+static_assert(sizeof(Module) == 108, "");
+
 } // namespace minidump
 
 template <> struct DenseMapInfo<minidump::StreamType> {

include/llvm/Object/Minidump.h

@@ -55,14 +55,21 @@ public:
     return getStream<minidump::SystemInfo>(minidump::StreamType::SystemInfo);
   }
 
+  /// Returns the module list embedded in the ModuleList stream. An error is
+  /// returned if the file does not contain this stream, or if the stream is
+  /// not large enough to contain the number of modules declared in the stream
+  /// header. The consistency of the Module entries themselves is not checked in
+  /// any way.
+  Expected<ArrayRef<minidump::Module>> getModuleList() const;
+
 private:
-  static Error createError(StringRef Str,
-                           object_error Err = object_error::parse_failed) {
-    return make_error<GenericBinaryError>(Str, Err);
+  static Error createError(StringRef Str) {
+    return make_error<GenericBinaryError>(Str, object_error::parse_failed);
   }
 
   static Error createEOFError() {
-    return createError("Unexpected EOF", object_error::unexpected_eof);
+    return make_error<GenericBinaryError>("Unexpected EOF",
+                                          object_error::unexpected_eof);
   }
 
   /// Return a slice of the given data array, with bounds checking.
@@ -101,9 +108,9 @@ Expected<const T &> MinidumpFile::getStream(minidump::StreamType Stream) const {
   if (auto OptionalStream = getRawStream(Stream)) {
     if (OptionalStream->size() >= sizeof(T))
       return *reinterpret_cast<const T *>(OptionalStream->data());
-    return createError("Malformed stream", object_error::unexpected_eof);
+    return createEOFError();
   }
-  return createError("No such stream", object_error::invalid_section_index);
+  return createError("No such stream");
 }
 
 template <typename T>

lib/Object/Minidump.cpp

@@ -53,6 +53,27 @@ Expected<std::string> MinidumpFile::getString(size_t Offset) const {
   return Result;
 }
 
+Expected<ArrayRef<Module>> MinidumpFile::getModuleList() const {
+  auto OptionalStream = getRawStream(StreamType::ModuleList);
+  if (!OptionalStream)
+    return createError("No such stream");
+  auto ExpectedSize =
+      getDataSliceAs<support::ulittle32_t>(*OptionalStream, 0, 1);
+  if (!ExpectedSize)
+    return ExpectedSize.takeError();
+
+  size_t ListSize = ExpectedSize.get()[0];
+
+  size_t ListOffset = 4;
+  // Some producers insert additional padding bytes to align the module list to
+  // 8-byte boundary. Check for that by comparing the module list size with the
+  // overall stream size.
+  if (ListOffset + sizeof(Module) * ListSize < OptionalStream->size())
+    ListOffset = 8;
+
+  return getDataSliceAs<Module>(*OptionalStream, ListOffset, ListSize);
+}
+
 Expected<ArrayRef<uint8_t>>
 MinidumpFile::getDataSlice(ArrayRef<uint8_t> Data, size_t Offset, size_t Size) {
   // Check for overflow.

unittests/Object/MinidumpTest.cpp

@@ -284,3 +284,115 @@ TEST(MinidumpFile, getString) {
   EXPECT_THAT_EXPECTED(File.getString(ManyStrings.size() - 2),
                        Failed<BinaryError>());
 }
+
+TEST(MinidumpFile, getModuleList) {
+  std::vector<uint8_t> OneModule{
+      // Header
+      'M', 'D', 'M', 'P', 0x93, 0xa7, 0, 0, // Signature, Version
+      1, 0, 0, 0,                           // NumberOfStreams,
+      32, 0, 0, 0,                          // StreamDirectoryRVA
+      0, 1, 2, 3, 4, 5, 6, 7,               // Checksum, TimeDateStamp
+      0, 0, 0, 0, 0, 0, 0, 0,               // Flags
+                                            // Stream Directory
+      4, 0, 0, 0, 112, 0, 0, 0,             // Type, DataSize,
+      44, 0, 0, 0,                          // RVA
+      // ModuleList
+      1, 0, 0, 0,             // NumberOfModules
+      1, 2, 3, 4, 5, 6, 7, 8, // BaseOfImage
+      9, 0, 1, 2, 3, 4, 5, 6, // SizeOfImage, Checksum
+      7, 8, 9, 0, 1, 2, 3, 4, // TimeDateStamp, ModuleNameRVA
+      0, 0, 0, 0, 0, 0, 0, 0, // Signature, StructVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // FileVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // ProductVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // FileFlagsMask, FileFlags
+      0, 0, 0, 0,             // FileOS
+      0, 0, 0, 0, 0, 0, 0, 0, // FileType, FileSubType
+      0, 0, 0, 0, 0, 0, 0, 0, // FileDate
+      1, 2, 3, 4, 5, 6, 7, 8, // CvRecord
+      9, 0, 1, 2, 3, 4, 5, 6, // MiscRecord
+      7, 8, 9, 0, 1, 2, 3, 4, // Reserved0
+      5, 6, 7, 8, 9, 0, 1, 2, // Reserved1
+  };
+  // Same as before, but with a padded module list.
+  std::vector<uint8_t> PaddedModule{
+      // Header
+      'M', 'D', 'M', 'P', 0x93, 0xa7, 0, 0, // Signature, Version
+      1, 0, 0, 0,                           // NumberOfStreams,
+      32, 0, 0, 0,                          // StreamDirectoryRVA
+      0, 1, 2, 3, 4, 5, 6, 7,               // Checksum, TimeDateStamp
+      0, 0, 0, 0, 0, 0, 0, 0,               // Flags
+                                            // Stream Directory
+      4, 0, 0, 0, 116, 0, 0, 0,             // Type, DataSize,
+      44, 0, 0, 0,                          // RVA
+      // ModuleList
+      1, 0, 0, 0,             // NumberOfModules
+      0, 0, 0, 0,             // Padding
+      1, 2, 3, 4, 5, 6, 7, 8, // BaseOfImage
+      9, 0, 1, 2, 3, 4, 5, 6, // SizeOfImage, Checksum
+      7, 8, 9, 0, 1, 2, 3, 4, // TimeDateStamp, ModuleNameRVA
+      0, 0, 0, 0, 0, 0, 0, 0, // Signature, StructVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // FileVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // ProductVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // FileFlagsMask, FileFlags
+      0, 0, 0, 0,             // FileOS
+      0, 0, 0, 0, 0, 0, 0, 0, // FileType, FileSubType
+      0, 0, 0, 0, 0, 0, 0, 0, // FileDate
+      1, 2, 3, 4, 5, 6, 7, 8, // CvRecord
+      9, 0, 1, 2, 3, 4, 5, 6, // MiscRecord
+      7, 8, 9, 0, 1, 2, 3, 4, // Reserved0
+      5, 6, 7, 8, 9, 0, 1, 2, // Reserved1
+  };
+
+  for (const std::vector<uint8_t> &Data : {OneModule, PaddedModule}) {
+    auto ExpectedFile = create(Data);
+    ASSERT_THAT_EXPECTED(ExpectedFile, Succeeded());
+    const MinidumpFile &File = **ExpectedFile;
+    Expected<ArrayRef<Module>> ExpectedModule = File.getModuleList();
+    ASSERT_THAT_EXPECTED(ExpectedModule, Succeeded());
+    ASSERT_EQ(1u, ExpectedModule->size());
+    const Module &M = ExpectedModule.get()[0];
+    EXPECT_EQ(0x0807060504030201u, M.BaseOfImage);
+    EXPECT_EQ(0x02010009u, M.SizeOfImage);
+    EXPECT_EQ(0x06050403u, M.Checksum);
+    EXPECT_EQ(0x00090807u, M.TimeDateStamp);
+    EXPECT_EQ(0x04030201u, M.ModuleNameRVA);
+    EXPECT_EQ(0x04030201u, M.CvRecord.DataSize);
+    EXPECT_EQ(0x08070605u, M.CvRecord.RVA);
+    EXPECT_EQ(0x02010009u, M.MiscRecord.DataSize);
+    EXPECT_EQ(0x06050403u, M.MiscRecord.RVA);
+    EXPECT_EQ(0x0403020100090807u, M.Reserved0);
+    EXPECT_EQ(0x0201000908070605u, M.Reserved1);
+  }
+
+  std::vector<uint8_t> StreamTooShort{
+      // Header
+      'M', 'D', 'M', 'P', 0x93, 0xa7, 0, 0, // Signature, Version
+      1, 0, 0, 0,                           // NumberOfStreams,
+      32, 0, 0, 0,                          // StreamDirectoryRVA
+      0, 1, 2, 3, 4, 5, 6, 7,               // Checksum, TimeDateStamp
+      0, 0, 0, 0, 0, 0, 0, 0,               // Flags
+                                            // Stream Directory
+      4, 0, 0, 0, 111, 0, 0, 0,             // Type, DataSize,
+      44, 0, 0, 0,                          // RVA
+      // ModuleList
+      1, 0, 0, 0,             // NumberOfModules
+      1, 2, 3, 4, 5, 6, 7, 8, // BaseOfImage
+      9, 0, 1, 2, 3, 4, 5, 6, // SizeOfImage, Checksum
+      7, 8, 9, 0, 1, 2, 3, 4, // TimeDateStamp, ModuleNameRVA
+      0, 0, 0, 0, 0, 0, 0, 0, // Signature, StructVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // FileVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // ProductVersion
+      0, 0, 0, 0, 0, 0, 0, 0, // FileFlagsMask, FileFlags
+      0, 0, 0, 0,             // FileOS
+      0, 0, 0, 0, 0, 0, 0, 0, // FileType, FileSubType
+      0, 0, 0, 0, 0, 0, 0, 0, // FileDate
+      1, 2, 3, 4, 5, 6, 7, 8, // CvRecord
+      9, 0, 1, 2, 3, 4, 5, 6, // MiscRecord
+      7, 8, 9, 0, 1, 2, 3, 4, // Reserved0
+      5, 6, 7, 8, 9, 0, 1, 2, // Reserved1
+  };
+  auto ExpectedFile = create(StreamTooShort);
+  ASSERT_THAT_EXPECTED(ExpectedFile, Succeeded());
+  const MinidumpFile &File = **ExpectedFile;
+  EXPECT_THAT_EXPECTED(File.getModuleList(), Failed<BinaryError>());
+}