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[Object, MachO] Don't crash on parsing invalid MachO header.

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Summary: Instead, properly report this error from MachOObjectFile constructor.

Test Plan: regression test suite

Reviewers: rafael

Subscribers: llvm-commits
llvm-svn: 239078
This commit is contained in:
Alexey Samsonov
2015-06-04 19:45:22 +00:00
parent 4fdbed3885
commit 9f336636fe
3 changed files with 32 additions and 4 deletions
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33
llvm/lib/Object/MachOObjectFile.cpp
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@@ -38,6 +38,7 @@ namespace {
};
}
// FIXME: Replace all uses of this function with getStructOrErr.
template <typename T>
static T getStruct(const MachOObjectFile *O, const char *P) {
// Don't read before the beginning or past the end of the file
@@ -51,6 +52,19 @@ static T getStruct(const MachOObjectFile *O, const char *P) {
return Cmd;
}
template <typename T>
static ErrorOr<T> getStructOrErr(const MachOObjectFile *O, const char *P) {
// Don't read before the beginning or past the end of the file
if (P < O->getData().begin() || P + sizeof(T) > O->getData().end())
return object_error::parse_failed;
T Cmd;
memcpy(&Cmd, P, sizeof(T));
if (O->isLittleEndian() != sys::IsLittleEndianHost)
MachO::swapStruct(Cmd);
return Cmd;
}
template <typename SegmentCmd>
static uint32_t getSegmentLoadCommandNumSections(const SegmentCmd &S,
uint32_t Cmdsize) {
@@ -203,6 +217,16 @@ getNextLoadCommandInfo(const MachOObjectFile *Obj,
return getLoadCommandInfo(Obj, L.Ptr + L.C.cmdsize);
}
template <typename T>
static void parseHeader(const MachOObjectFile *Obj, T &Header,
std::error_code &EC) {
auto HeaderOrErr = getStructOrErr<T>(Obj, getPtr(Obj, 0));
if (HeaderOrErr)
Header = HeaderOrErr.get();
else
EC = HeaderOrErr.getError();
}
MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
bool Is64bits, std::error_code &EC)
: ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object),
@@ -210,14 +234,15 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian,
DataInCodeLoadCmd(nullptr), LinkOptHintsLoadCmd(nullptr),
DyldInfoLoadCmd(nullptr), UuidLoadCmd(nullptr),
HasPageZeroSegment(false) {
// Parse header.
if (is64Bit())
Header64 = getStruct<MachO::mach_header_64>(this, getPtr(this, 0));
parseHeader(this, Header64, EC);
else
// First fields of MachO::mach_header_64 are the same as
// in MachO::mach_header.
*reinterpret_cast<MachO::mach_header *>(&this->Header64) =
getStruct<MachO::mach_header>(this, getPtr(this, 0));
parseHeader(this, *reinterpret_cast<MachO::mach_header *>(&this->Header64),
EC);
if (EC)
return;
uint32_t LoadCommandCount = getHeader().ncmds;
if (LoadCommandCount == 0)