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MachOObjectFile.cpp
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MachOObjectFile.cpp
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//===- MachOObjectFile.cpp - Mach-O object file binding -------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the MachOObjectFile class, which binds the MachOObject
// class to the generic ObjectFile wrapper.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/None.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/MachO.h"
#include "llvm/Object/Error.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/SymbolicFile.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/Host.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/SwapByteOrder.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <limits>
#include <list>
#include <memory>
#include <system_error>
using namespace llvm;
using namespace object;
namespace {
struct section_base {
char sectname[16];
char segname[16];
};
} // end anonymous namespace
static Error malformedError(const Twine &Msg) {
return make_error<GenericBinaryError>("truncated or malformed object (" +
Msg + ")",
object_error::parse_failed);
}
// 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
if (P < O.getData().begin() || P + sizeof(T) > O.getData().end())
report_fatal_error("Malformed MachO file.");
T Cmd;
memcpy(&Cmd, P, sizeof(T));
if (O.isLittleEndian() != sys::IsLittleEndianHost)
MachO::swapStruct(Cmd);
return Cmd;
}
template <typename T>
static Expected<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 malformedError("Structure read out-of-range");
T Cmd;
memcpy(&Cmd, P, sizeof(T));
if (O.isLittleEndian() != sys::IsLittleEndianHost)
MachO::swapStruct(Cmd);
return Cmd;
}
static const char *
getSectionPtr(const MachOObjectFile &O, MachOObjectFile::LoadCommandInfo L,
unsigned Sec) {
uintptr_t CommandAddr = reinterpret_cast<uintptr_t>(L.Ptr);
bool Is64 = O.is64Bit();
unsigned SegmentLoadSize = Is64 ? sizeof(MachO::segment_command_64) :
sizeof(MachO::segment_command);
unsigned SectionSize = Is64 ? sizeof(MachO::section_64) :
sizeof(MachO::section);
uintptr_t SectionAddr = CommandAddr + SegmentLoadSize + Sec * SectionSize;
return reinterpret_cast<const char*>(SectionAddr);
}
static const char *getPtr(const MachOObjectFile &O, size_t Offset) {
assert(Offset <= O.getData().size());
return O.getData().data() + Offset;
}
static MachO::nlist_base
getSymbolTableEntryBase(const MachOObjectFile &O, DataRefImpl DRI) {
const char *P = reinterpret_cast<const char *>(DRI.p);
return getStruct<MachO::nlist_base>(O, P);
}
static StringRef parseSegmentOrSectionName(const char *P) {
if (P[15] == 0)
// Null terminated.
return P;
// Not null terminated, so this is a 16 char string.
return StringRef(P, 16);
}
static unsigned getCPUType(const MachOObjectFile &O) {
return O.getHeader().cputype;
}
static unsigned getCPUSubType(const MachOObjectFile &O) {
return O.getHeader().cpusubtype;
}
static uint32_t
getPlainRelocationAddress(const MachO::any_relocation_info &RE) {
return RE.r_word0;
}
static unsigned
getScatteredRelocationAddress(const MachO::any_relocation_info &RE) {
return RE.r_word0 & 0xffffff;
}
static bool getPlainRelocationPCRel(const MachOObjectFile &O,
const MachO::any_relocation_info &RE) {
if (O.isLittleEndian())
return (RE.r_word1 >> 24) & 1;
return (RE.r_word1 >> 7) & 1;
}
static bool
getScatteredRelocationPCRel(const MachO::any_relocation_info &RE) {
return (RE.r_word0 >> 30) & 1;
}
static unsigned getPlainRelocationLength(const MachOObjectFile &O,
const MachO::any_relocation_info &RE) {
if (O.isLittleEndian())
return (RE.r_word1 >> 25) & 3;
return (RE.r_word1 >> 5) & 3;
}
static unsigned
getScatteredRelocationLength(const MachO::any_relocation_info &RE) {
return (RE.r_word0 >> 28) & 3;
}
static unsigned getPlainRelocationType(const MachOObjectFile &O,
const MachO::any_relocation_info &RE) {
if (O.isLittleEndian())
return RE.r_word1 >> 28;
return RE.r_word1 & 0xf;
}
static uint32_t getSectionFlags(const MachOObjectFile &O,
DataRefImpl Sec) {
if (O.is64Bit()) {
MachO::section_64 Sect = O.getSection64(Sec);
return Sect.flags;
}
MachO::section Sect = O.getSection(Sec);
return Sect.flags;
}
static Expected<MachOObjectFile::LoadCommandInfo>
getLoadCommandInfo(const MachOObjectFile &Obj, const char *Ptr,
uint32_t LoadCommandIndex) {
if (auto CmdOrErr = getStructOrErr<MachO::load_command>(Obj, Ptr)) {
if (CmdOrErr->cmdsize + Ptr > Obj.getData().end())
return malformedError("load command " + Twine(LoadCommandIndex) +
" extends past end of file");
if (CmdOrErr->cmdsize < 8)
return malformedError("load command " + Twine(LoadCommandIndex) +
" with size less than 8 bytes");
return MachOObjectFile::LoadCommandInfo({Ptr, *CmdOrErr});
} else
return CmdOrErr.takeError();
}
static Expected<MachOObjectFile::LoadCommandInfo>
getFirstLoadCommandInfo(const MachOObjectFile &Obj) {
unsigned HeaderSize = Obj.is64Bit() ? sizeof(MachO::mach_header_64)
: sizeof(MachO::mach_header);
if (sizeof(MachO::load_command) > Obj.getHeader().sizeofcmds)
return malformedError("load command 0 extends past the end all load "
"commands in the file");
return getLoadCommandInfo(Obj, getPtr(Obj, HeaderSize), 0);
}
static Expected<MachOObjectFile::LoadCommandInfo>
getNextLoadCommandInfo(const MachOObjectFile &Obj, uint32_t LoadCommandIndex,
const MachOObjectFile::LoadCommandInfo &L) {
unsigned HeaderSize = Obj.is64Bit() ? sizeof(MachO::mach_header_64)
: sizeof(MachO::mach_header);
if (L.Ptr + L.C.cmdsize + sizeof(MachO::load_command) >
Obj.getData().data() + HeaderSize + Obj.getHeader().sizeofcmds)
return malformedError("load command " + Twine(LoadCommandIndex + 1) +
" extends past the end all load commands in the file");
return getLoadCommandInfo(Obj, L.Ptr + L.C.cmdsize, LoadCommandIndex + 1);
}
template <typename T>
static void parseHeader(const MachOObjectFile &Obj, T &Header,
Error &Err) {
if (sizeof(T) > Obj.getData().size()) {
Err = malformedError("the mach header extends past the end of the "
"file");
return;
}
if (auto HeaderOrErr = getStructOrErr<T>(Obj, getPtr(Obj, 0)))
Header = *HeaderOrErr;
else
Err = HeaderOrErr.takeError();
}
// This is used to check for overlapping of Mach-O elements.
struct MachOElement {
uint64_t Offset;
uint64_t Size;
const char *Name;
};
static Error checkOverlappingElement(std::list<MachOElement> &Elements,
uint64_t Offset, uint64_t Size,
const char *Name) {
if (Size == 0)
return Error::success();
for (auto it=Elements.begin() ; it != Elements.end(); ++it) {
auto E = *it;
if ((Offset >= E.Offset && Offset < E.Offset + E.Size) ||
(Offset + Size > E.Offset && Offset + Size < E.Offset + E.Size) ||
(Offset <= E.Offset && Offset + Size >= E.Offset + E.Size))
return malformedError(Twine(Name) + " at offset " + Twine(Offset) +
" with a size of " + Twine(Size) + ", overlaps " +
E.Name + " at offset " + Twine(E.Offset) + " with "
"a size of " + Twine(E.Size));
auto nt = it;
nt++;
if (nt != Elements.end()) {
auto N = *nt;
if (Offset + Size <= N.Offset) {
Elements.insert(nt, {Offset, Size, Name});
return Error::success();
}
}
}
Elements.push_back({Offset, Size, Name});
return Error::success();
}
// Parses LC_SEGMENT or LC_SEGMENT_64 load command, adds addresses of all
// sections to \param Sections, and optionally sets
// \param IsPageZeroSegment to true.
template <typename Segment, typename Section>
static Error parseSegmentLoadCommand(
const MachOObjectFile &Obj, const MachOObjectFile::LoadCommandInfo &Load,
SmallVectorImpl<const char *> &Sections, bool &IsPageZeroSegment,
uint32_t LoadCommandIndex, const char *CmdName, uint64_t SizeOfHeaders,
std::list<MachOElement> &Elements) {
const unsigned SegmentLoadSize = sizeof(Segment);
if (Load.C.cmdsize < SegmentLoadSize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" " + CmdName + " cmdsize too small");
if (auto SegOrErr = getStructOrErr<Segment>(Obj, Load.Ptr)) {
Segment S = SegOrErr.get();
const unsigned SectionSize = sizeof(Section);
uint64_t FileSize = Obj.getData().size();
if (S.nsects > std::numeric_limits<uint32_t>::max() / SectionSize ||
S.nsects * SectionSize > Load.C.cmdsize - SegmentLoadSize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" inconsistent cmdsize in " + CmdName +
" for the number of sections");
for (unsigned J = 0; J < S.nsects; ++J) {
const char *Sec = getSectionPtr(Obj, Load, J);
Sections.push_back(Sec);
auto SectionOrErr = getStructOrErr<Section>(Obj, Sec);
if (!SectionOrErr)
return SectionOrErr.takeError();
Section s = SectionOrErr.get();
if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
Obj.getHeader().filetype != MachO::MH_DSYM &&
s.flags != MachO::S_ZEROFILL &&
s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
s.offset > FileSize)
return malformedError("offset field of section " + Twine(J) + " in " +
CmdName + " command " + Twine(LoadCommandIndex) +
" extends past the end of the file");
if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
Obj.getHeader().filetype != MachO::MH_DSYM &&
s.flags != MachO::S_ZEROFILL &&
s.flags != MachO::S_THREAD_LOCAL_ZEROFILL && S.fileoff == 0 &&
s.offset < SizeOfHeaders && s.size != 0)
return malformedError("offset field of section " + Twine(J) + " in " +
CmdName + " command " + Twine(LoadCommandIndex) +
" not past the headers of the file");
uint64_t BigSize = s.offset;
BigSize += s.size;
if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
Obj.getHeader().filetype != MachO::MH_DSYM &&
s.flags != MachO::S_ZEROFILL &&
s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
BigSize > FileSize)
return malformedError("offset field plus size field of section " +
Twine(J) + " in " + CmdName + " command " +
Twine(LoadCommandIndex) +
" extends past the end of the file");
if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
Obj.getHeader().filetype != MachO::MH_DSYM &&
s.flags != MachO::S_ZEROFILL &&
s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
s.size > S.filesize)
return malformedError("size field of section " +
Twine(J) + " in " + CmdName + " command " +
Twine(LoadCommandIndex) +
" greater than the segment");
if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
Obj.getHeader().filetype != MachO::MH_DSYM && s.size != 0 &&
s.addr < S.vmaddr)
return malformedError("addr field of section " + Twine(J) + " in " +
CmdName + " command " + Twine(LoadCommandIndex) +
" less than the segment's vmaddr");
BigSize = s.addr;
BigSize += s.size;
uint64_t BigEnd = S.vmaddr;
BigEnd += S.vmsize;
if (S.vmsize != 0 && s.size != 0 && BigSize > BigEnd)
return malformedError("addr field plus size of section " + Twine(J) +
" in " + CmdName + " command " +
Twine(LoadCommandIndex) +
" greater than than "
"the segment's vmaddr plus vmsize");
if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
Obj.getHeader().filetype != MachO::MH_DSYM &&
s.flags != MachO::S_ZEROFILL &&
s.flags != MachO::S_THREAD_LOCAL_ZEROFILL)
if (Error Err = checkOverlappingElement(Elements, s.offset, s.size,
"section contents"))
return Err;
if (s.reloff > FileSize)
return malformedError("reloff field of section " + Twine(J) + " in " +
CmdName + " command " + Twine(LoadCommandIndex) +
" extends past the end of the file");
BigSize = s.nreloc;
BigSize *= sizeof(struct MachO::relocation_info);
BigSize += s.reloff;
if (BigSize > FileSize)
return malformedError("reloff field plus nreloc field times sizeof("
"struct relocation_info) of section " +
Twine(J) + " in " + CmdName + " command " +
Twine(LoadCommandIndex) +
" extends past the end of the file");
if (Error Err = checkOverlappingElement(Elements, s.reloff, s.nreloc *
sizeof(struct
MachO::relocation_info),
"section relocation entries"))
return Err;
}
if (S.fileoff > FileSize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" fileoff field in " + CmdName +
" extends past the end of the file");
uint64_t BigSize = S.fileoff;
BigSize += S.filesize;
if (BigSize > FileSize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" fileoff field plus filesize field in " +
CmdName + " extends past the end of the file");
if (S.vmsize != 0 && S.filesize > S.vmsize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" filesize field in " + CmdName +
" greater than vmsize field");
IsPageZeroSegment |= StringRef("__PAGEZERO").equals(S.segname);
} else
return SegOrErr.takeError();
return Error::success();
}
static Error checkSymtabCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
const char **SymtabLoadCmd,
std::list<MachOElement> &Elements) {
if (Load.C.cmdsize < sizeof(MachO::symtab_command))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_SYMTAB cmdsize too small");
if (*SymtabLoadCmd != nullptr)
return malformedError("more than one LC_SYMTAB command");
auto SymtabOrErr = getStructOrErr<MachO::symtab_command>(Obj, Load.Ptr);
if (!SymtabOrErr)
return SymtabOrErr.takeError();
MachO::symtab_command Symtab = SymtabOrErr.get();
if (Symtab.cmdsize != sizeof(MachO::symtab_command))
return malformedError("LC_SYMTAB command " + Twine(LoadCommandIndex) +
" has incorrect cmdsize");
uint64_t FileSize = Obj.getData().size();
if (Symtab.symoff > FileSize)
return malformedError("symoff field of LC_SYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end "
"of the file");
uint64_t SymtabSize = Symtab.nsyms;
const char *struct_nlist_name;
if (Obj.is64Bit()) {
SymtabSize *= sizeof(MachO::nlist_64);
struct_nlist_name = "struct nlist_64";
} else {
SymtabSize *= sizeof(MachO::nlist);
struct_nlist_name = "struct nlist";
}
uint64_t BigSize = SymtabSize;
BigSize += Symtab.symoff;
if (BigSize > FileSize)
return malformedError("symoff field plus nsyms field times sizeof(" +
Twine(struct_nlist_name) + ") of LC_SYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end "
"of the file");
if (Error Err = checkOverlappingElement(Elements, Symtab.symoff, SymtabSize,
"symbol table"))
return Err;
if (Symtab.stroff > FileSize)
return malformedError("stroff field of LC_SYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end "
"of the file");
BigSize = Symtab.stroff;
BigSize += Symtab.strsize;
if (BigSize > FileSize)
return malformedError("stroff field plus strsize field of LC_SYMTAB "
"command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
if (Error Err = checkOverlappingElement(Elements, Symtab.stroff,
Symtab.strsize, "string table"))
return Err;
*SymtabLoadCmd = Load.Ptr;
return Error::success();
}
static Error checkDysymtabCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
const char **DysymtabLoadCmd,
std::list<MachOElement> &Elements) {
if (Load.C.cmdsize < sizeof(MachO::dysymtab_command))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_DYSYMTAB cmdsize too small");
if (*DysymtabLoadCmd != nullptr)
return malformedError("more than one LC_DYSYMTAB command");
auto DysymtabOrErr =
getStructOrErr<MachO::dysymtab_command>(Obj, Load.Ptr);
if (!DysymtabOrErr)
return DysymtabOrErr.takeError();
MachO::dysymtab_command Dysymtab = DysymtabOrErr.get();
if (Dysymtab.cmdsize != sizeof(MachO::dysymtab_command))
return malformedError("LC_DYSYMTAB command " + Twine(LoadCommandIndex) +
" has incorrect cmdsize");
uint64_t FileSize = Obj.getData().size();
if (Dysymtab.tocoff > FileSize)
return malformedError("tocoff field of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
uint64_t BigSize = Dysymtab.ntoc;
BigSize *= sizeof(MachO::dylib_table_of_contents);
BigSize += Dysymtab.tocoff;
if (BigSize > FileSize)
return malformedError("tocoff field plus ntoc field times sizeof(struct "
"dylib_table_of_contents) of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, Dysymtab.tocoff,
Dysymtab.ntoc * sizeof(struct
MachO::dylib_table_of_contents),
"table of contents"))
return Err;
if (Dysymtab.modtaboff > FileSize)
return malformedError("modtaboff field of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
BigSize = Dysymtab.nmodtab;
const char *struct_dylib_module_name;
uint64_t sizeof_modtab;
if (Obj.is64Bit()) {
sizeof_modtab = sizeof(MachO::dylib_module_64);
struct_dylib_module_name = "struct dylib_module_64";
} else {
sizeof_modtab = sizeof(MachO::dylib_module);
struct_dylib_module_name = "struct dylib_module";
}
BigSize *= sizeof_modtab;
BigSize += Dysymtab.modtaboff;
if (BigSize > FileSize)
return malformedError("modtaboff field plus nmodtab field times sizeof(" +
Twine(struct_dylib_module_name) + ") of LC_DYSYMTAB "
"command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
if (Error Err = checkOverlappingElement(Elements, Dysymtab.modtaboff,
Dysymtab.nmodtab * sizeof_modtab,
"module table"))
return Err;
if (Dysymtab.extrefsymoff > FileSize)
return malformedError("extrefsymoff field of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
BigSize = Dysymtab.nextrefsyms;
BigSize *= sizeof(MachO::dylib_reference);
BigSize += Dysymtab.extrefsymoff;
if (BigSize > FileSize)
return malformedError("extrefsymoff field plus nextrefsyms field times "
"sizeof(struct dylib_reference) of LC_DYSYMTAB "
"command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
if (Error Err = checkOverlappingElement(Elements, Dysymtab.extrefsymoff,
Dysymtab.nextrefsyms *
sizeof(MachO::dylib_reference),
"reference table"))
return Err;
if (Dysymtab.indirectsymoff > FileSize)
return malformedError("indirectsymoff field of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
BigSize = Dysymtab.nindirectsyms;
BigSize *= sizeof(uint32_t);
BigSize += Dysymtab.indirectsymoff;
if (BigSize > FileSize)
return malformedError("indirectsymoff field plus nindirectsyms field times "
"sizeof(uint32_t) of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, Dysymtab.indirectsymoff,
Dysymtab.nindirectsyms *
sizeof(uint32_t),
"indirect table"))
return Err;
if (Dysymtab.extreloff > FileSize)
return malformedError("extreloff field of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
BigSize = Dysymtab.nextrel;
BigSize *= sizeof(MachO::relocation_info);
BigSize += Dysymtab.extreloff;
if (BigSize > FileSize)
return malformedError("extreloff field plus nextrel field times sizeof"
"(struct relocation_info) of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, Dysymtab.extreloff,
Dysymtab.nextrel *
sizeof(MachO::relocation_info),
"external relocation table"))
return Err;
if (Dysymtab.locreloff > FileSize)
return malformedError("locreloff field of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
BigSize = Dysymtab.nlocrel;
BigSize *= sizeof(MachO::relocation_info);
BigSize += Dysymtab.locreloff;
if (BigSize > FileSize)
return malformedError("locreloff field plus nlocrel field times sizeof"
"(struct relocation_info) of LC_DYSYMTAB command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, Dysymtab.locreloff,
Dysymtab.nlocrel *
sizeof(MachO::relocation_info),
"local relocation table"))
return Err;
*DysymtabLoadCmd = Load.Ptr;
return Error::success();
}
static Error checkLinkeditDataCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
const char **LoadCmd, const char *CmdName,
std::list<MachOElement> &Elements,
const char *ElementName) {
if (Load.C.cmdsize < sizeof(MachO::linkedit_data_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " cmdsize too small");
if (*LoadCmd != nullptr)
return malformedError("more than one " + Twine(CmdName) + " command");
auto LinkDataOrError =
getStructOrErr<MachO::linkedit_data_command>(Obj, Load.Ptr);
if (!LinkDataOrError)
return LinkDataOrError.takeError();
MachO::linkedit_data_command LinkData = LinkDataOrError.get();
if (LinkData.cmdsize != sizeof(MachO::linkedit_data_command))
return malformedError(Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " has incorrect cmdsize");
uint64_t FileSize = Obj.getData().size();
if (LinkData.dataoff > FileSize)
return malformedError("dataoff field of " + Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
uint64_t BigSize = LinkData.dataoff;
BigSize += LinkData.datasize;
if (BigSize > FileSize)
return malformedError("dataoff field plus datasize field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, LinkData.dataoff,
LinkData.datasize, ElementName))
return Err;
*LoadCmd = Load.Ptr;
return Error::success();
}
static Error checkDyldInfoCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
const char **LoadCmd, const char *CmdName,
std::list<MachOElement> &Elements) {
if (Load.C.cmdsize < sizeof(MachO::dyld_info_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " cmdsize too small");
if (*LoadCmd != nullptr)
return malformedError("more than one LC_DYLD_INFO and or LC_DYLD_INFO_ONLY "
"command");
auto DyldInfoOrErr =
getStructOrErr<MachO::dyld_info_command>(Obj, Load.Ptr);
if (!DyldInfoOrErr)
return DyldInfoOrErr.takeError();
MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
if (DyldInfo.cmdsize != sizeof(MachO::dyld_info_command))
return malformedError(Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " has incorrect cmdsize");
uint64_t FileSize = Obj.getData().size();
if (DyldInfo.rebase_off > FileSize)
return malformedError("rebase_off field of " + Twine(CmdName) +
" command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
uint64_t BigSize = DyldInfo.rebase_off;
BigSize += DyldInfo.rebase_size;
if (BigSize > FileSize)
return malformedError("rebase_off field plus rebase_size field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, DyldInfo.rebase_off,
DyldInfo.rebase_size,
"dyld rebase info"))
return Err;
if (DyldInfo.bind_off > FileSize)
return malformedError("bind_off field of " + Twine(CmdName) +
" command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
BigSize = DyldInfo.bind_off;
BigSize += DyldInfo.bind_size;
if (BigSize > FileSize)
return malformedError("bind_off field plus bind_size field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, DyldInfo.bind_off,
DyldInfo.bind_size,
"dyld bind info"))
return Err;
if (DyldInfo.weak_bind_off > FileSize)
return malformedError("weak_bind_off field of " + Twine(CmdName) +
" command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
BigSize = DyldInfo.weak_bind_off;
BigSize += DyldInfo.weak_bind_size;
if (BigSize > FileSize)
return malformedError("weak_bind_off field plus weak_bind_size field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, DyldInfo.weak_bind_off,
DyldInfo.weak_bind_size,
"dyld weak bind info"))
return Err;
if (DyldInfo.lazy_bind_off > FileSize)
return malformedError("lazy_bind_off field of " + Twine(CmdName) +
" command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
BigSize = DyldInfo.lazy_bind_off;
BigSize += DyldInfo.lazy_bind_size;
if (BigSize > FileSize)
return malformedError("lazy_bind_off field plus lazy_bind_size field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, DyldInfo.lazy_bind_off,
DyldInfo.lazy_bind_size,
"dyld lazy bind info"))
return Err;
if (DyldInfo.export_off > FileSize)
return malformedError("export_off field of " + Twine(CmdName) +
" command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
BigSize = DyldInfo.export_off;
BigSize += DyldInfo.export_size;
if (BigSize > FileSize)
return malformedError("export_off field plus export_size field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, DyldInfo.export_off,
DyldInfo.export_size,
"dyld export info"))
return Err;
*LoadCmd = Load.Ptr;
return Error::success();
}
static Error checkDylibCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex, const char *CmdName) {
if (Load.C.cmdsize < sizeof(MachO::dylib_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " cmdsize too small");
auto CommandOrErr = getStructOrErr<MachO::dylib_command>(Obj, Load.Ptr);
if (!CommandOrErr)
return CommandOrErr.takeError();
MachO::dylib_command D = CommandOrErr.get();
if (D.dylib.name < sizeof(MachO::dylib_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " name.offset field too small, not past "
"the end of the dylib_command struct");
if (D.dylib.name >= D.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " name.offset field extends past the end "
"of the load command");
// Make sure there is a null between the starting offset of the name and
// the end of the load command.
uint32_t i;
const char *P = (const char *)Load.Ptr;
for (i = D.dylib.name; i < D.cmdsize; i++)
if (P[i] == '\0')
break;
if (i >= D.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " library name extends past the end of the "
"load command");
return Error::success();
}
static Error checkDylibIdCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
const char **LoadCmd) {
if (Error Err = checkDylibCommand(Obj, Load, LoadCommandIndex,
"LC_ID_DYLIB"))
return Err;
if (*LoadCmd != nullptr)
return malformedError("more than one LC_ID_DYLIB command");
if (Obj.getHeader().filetype != MachO::MH_DYLIB &&
Obj.getHeader().filetype != MachO::MH_DYLIB_STUB)
return malformedError("LC_ID_DYLIB load command in non-dynamic library "
"file type");
*LoadCmd = Load.Ptr;
return Error::success();
}
static Error checkDyldCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex, const char *CmdName) {
if (Load.C.cmdsize < sizeof(MachO::dylinker_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " cmdsize too small");
auto CommandOrErr = getStructOrErr<MachO::dylinker_command>(Obj, Load.Ptr);
if (!CommandOrErr)
return CommandOrErr.takeError();
MachO::dylinker_command D = CommandOrErr.get();
if (D.name < sizeof(MachO::dylinker_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " name.offset field too small, not past "
"the end of the dylinker_command struct");
if (D.name >= D.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " name.offset field extends past the end "
"of the load command");
// Make sure there is a null between the starting offset of the name and
// the end of the load command.
uint32_t i;
const char *P = (const char *)Load.Ptr;
for (i = D.name; i < D.cmdsize; i++)
if (P[i] == '\0')
break;
if (i >= D.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " dyld name extends past the end of the "
"load command");
return Error::success();
}
static Error checkVersCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
const char **LoadCmd, const char *CmdName) {
if (Load.C.cmdsize != sizeof(MachO::version_min_command))
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " has incorrect cmdsize");
if (*LoadCmd != nullptr)
return malformedError("more than one LC_VERSION_MIN_MACOSX, "
"LC_VERSION_MIN_IPHONEOS, LC_VERSION_MIN_TVOS or "
"LC_VERSION_MIN_WATCHOS command");
*LoadCmd = Load.Ptr;
return Error::success();
}
static Error checkNoteCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
std::list<MachOElement> &Elements) {
if (Load.C.cmdsize != sizeof(MachO::note_command))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_NOTE has incorrect cmdsize");
auto NoteCmdOrErr = getStructOrErr<MachO::note_command>(Obj, Load.Ptr);
if (!NoteCmdOrErr)
return NoteCmdOrErr.takeError();
MachO::note_command Nt = NoteCmdOrErr.get();
uint64_t FileSize = Obj.getData().size();
if (Nt.offset > FileSize)
return malformedError("offset field of LC_NOTE command " +
Twine(LoadCommandIndex) + " extends "
"past the end of the file");
uint64_t BigSize = Nt.offset;
BigSize += Nt.size;
if (BigSize > FileSize)
return malformedError("size field plus offset field of LC_NOTE command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
if (Error Err = checkOverlappingElement(Elements, Nt.offset, Nt.size,
"LC_NOTE data"))
return Err;
return Error::success();
}
static Error
parseBuildVersionCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
SmallVectorImpl<const char*> &BuildTools,
uint32_t LoadCommandIndex) {
auto BVCOrErr =
getStructOrErr<MachO::build_version_command>(Obj, Load.Ptr);
if (!BVCOrErr)
return BVCOrErr.takeError();
MachO::build_version_command BVC = BVCOrErr.get();
if (Load.C.cmdsize !=
sizeof(MachO::build_version_command) +
BVC.ntools * sizeof(MachO::build_tool_version))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_BUILD_VERSION_COMMAND has incorrect cmdsize");
auto Start = Load.Ptr + sizeof(MachO::build_version_command);
BuildTools.resize(BVC.ntools);
for (unsigned i = 0; i < BVC.ntools; ++i)
BuildTools[i] = Start + i * sizeof(MachO::build_tool_version);
return Error::success();
}
static Error checkRpathCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex) {
if (Load.C.cmdsize < sizeof(MachO::rpath_command))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_RPATH cmdsize too small");
auto ROrErr = getStructOrErr<MachO::rpath_command>(Obj, Load.Ptr);
if (!ROrErr)
return ROrErr.takeError();
MachO::rpath_command R = ROrErr.get();
if (R.path < sizeof(MachO::rpath_command))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_RPATH path.offset field too small, not past "
"the end of the rpath_command struct");
if (R.path >= R.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_RPATH path.offset field extends past the end "
"of the load command");
// Make sure there is a null between the starting offset of the path and
// the end of the load command.
uint32_t i;
const char *P = (const char *)Load.Ptr;
for (i = R.path; i < R.cmdsize; i++)
if (P[i] == '\0')
break;
if (i >= R.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_RPATH library name extends past the end of the "
"load command");
return Error::success();
}
static Error checkEncryptCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex,
uint64_t cryptoff, uint64_t cryptsize,
const char **LoadCmd, const char *CmdName) {
if (*LoadCmd != nullptr)
return malformedError("more than one LC_ENCRYPTION_INFO and or "
"LC_ENCRYPTION_INFO_64 command");
uint64_t FileSize = Obj.getData().size();
if (cryptoff > FileSize)
return malformedError("cryptoff field of " + Twine(CmdName) +
" command " + Twine(LoadCommandIndex) + " extends "
"past the end of the file");
uint64_t BigSize = cryptoff;
BigSize += cryptsize;
if (BigSize > FileSize)
return malformedError("cryptoff field plus cryptsize field of " +
Twine(CmdName) + " command " +
Twine(LoadCommandIndex) + " extends past the end of "
"the file");
*LoadCmd = Load.Ptr;
return Error::success();
}
static Error checkLinkerOptCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex) {
if (Load.C.cmdsize < sizeof(MachO::linker_option_command))
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_LINKER_OPTION cmdsize too small");
auto LinkOptionOrErr =
getStructOrErr<MachO::linker_option_command>(Obj, Load.Ptr);
if (!LinkOptionOrErr)
return LinkOptionOrErr.takeError();
MachO::linker_option_command L = LinkOptionOrErr.get();
// Make sure the count of strings is correct.
const char *string = (const char *)Load.Ptr +
sizeof(struct MachO::linker_option_command);
uint32_t left = L.cmdsize - sizeof(struct MachO::linker_option_command);
uint32_t i = 0;
while (left > 0) {
while (*string == '\0' && left > 0) {
string++;
left--;
}
if (left > 0) {
i++;
uint32_t NullPos = StringRef(string, left).find('\0');
if (0xffffffff == NullPos)
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_LINKER_OPTION string #" + Twine(i) +
" is not NULL terminated");
uint32_t len = std::min(NullPos, left) + 1;
string += len;
left -= len;
}
}
if (L.count != i)
return malformedError("load command " + Twine(LoadCommandIndex) +
" LC_LINKER_OPTION string count " + Twine(L.count) +
" does not match number of strings");
return Error::success();
}
static Error checkSubCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,
uint32_t LoadCommandIndex, const char *CmdName,
size_t SizeOfCmd, const char *CmdStructName,
uint32_t PathOffset, const char *PathFieldName) {
if (PathOffset < SizeOfCmd)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " " + PathFieldName + ".offset field too "
"small, not past the end of the " + CmdStructName);
if (PathOffset >= Load.C.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " " + PathFieldName + ".offset field "
"extends past the end of the load command");
// Make sure there is a null between the starting offset of the path and
// the end of the load command.
uint32_t i;
const char *P = (const char *)Load.Ptr;
for (i = PathOffset; i < Load.C.cmdsize; i++)
if (P[i] == '\0')
break;
if (i >= Load.C.cmdsize)
return malformedError("load command " + Twine(LoadCommandIndex) + " " +
CmdName + " " + PathFieldName + " name extends past "
"the end of the load command");
return Error::success();
}
static Error checkThreadCommand(const MachOObjectFile &Obj,
const MachOObjectFile::LoadCommandInfo &Load,