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-rw-r--r--llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp103
1 files changed, 68 insertions, 35 deletions
diff --git a/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp b/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
index 380f2e989fe4..256c830a44a4 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOLayoutBuilder.cpp
@@ -17,7 +17,7 @@ namespace macho {
uint32_t MachOLayoutBuilder::computeSizeOfCmds() const {
uint32_t Size = 0;
- for (const auto &LC : O.LoadCommands) {
+ for (const LoadCommand &LC : O.LoadCommands) {
const MachO::macho_load_command &MLC = LC.MachOLoadCommand;
auto cmd = MLC.load_command_data.cmd;
switch (cmd) {
@@ -61,15 +61,16 @@ void MachOLayoutBuilder::updateDySymTab(MachO::macho_load_command &MLC) {
assert(MLC.load_command_data.cmd == MachO::LC_DYSYMTAB);
// Make sure that nlist entries in the symbol table are sorted by the those
// types. The order is: local < defined external < undefined external.
- assert(std::is_sorted(O.SymTable.Symbols.begin(), O.SymTable.Symbols.end(),
- [](const std::unique_ptr<SymbolEntry> &A,
- const std::unique_ptr<SymbolEntry> &B) {
- bool AL = A->isLocalSymbol(), BL = B->isLocalSymbol();
- if (AL != BL)
- return AL;
- return !AL && !A->isUndefinedSymbol() &&
- B->isUndefinedSymbol();
- }) &&
+ assert(llvm::is_sorted(O.SymTable.Symbols,
+ [](const std::unique_ptr<SymbolEntry> &A,
+ const std::unique_ptr<SymbolEntry> &B) {
+ bool AL = A->isLocalSymbol(),
+ BL = B->isLocalSymbol();
+ if (AL != BL)
+ return AL;
+ return !AL && !A->isUndefinedSymbol() &&
+ B->isUndefinedSymbol();
+ }) &&
"Symbols are not sorted by their types.");
uint32_t NumLocalSymbols = 0;
@@ -107,7 +108,7 @@ uint64_t MachOLayoutBuilder::layoutSegments() {
const bool IsObjectFile =
O.Header.FileType == MachO::HeaderFileType::MH_OBJECT;
uint64_t Offset = IsObjectFile ? (HeaderSize + O.Header.SizeOfCmds) : 0;
- for (auto &LC : O.LoadCommands) {
+ for (LoadCommand &LC : O.LoadCommands) {
auto &MLC = LC.MachOLoadCommand;
StringRef Segname;
uint64_t SegmentVmAddr;
@@ -142,30 +143,30 @@ uint64_t MachOLayoutBuilder::layoutSegments() {
uint64_t SegOffset = Offset;
uint64_t SegFileSize = 0;
uint64_t VMSize = 0;
- for (auto &Sec : LC.Sections) {
+ for (std::unique_ptr<Section> &Sec : LC.Sections) {
+ assert(SegmentVmAddr <= Sec->Addr &&
+ "Section's address cannot be smaller than Segment's one");
+ uint32_t SectOffset = Sec->Addr - SegmentVmAddr;
if (IsObjectFile) {
- if (Sec.isVirtualSection()) {
- Sec.Offset = 0;
+ if (Sec->isVirtualSection()) {
+ Sec->Offset = 0;
} else {
uint64_t PaddingSize =
- offsetToAlignment(SegFileSize, Align(1ull << Sec.Align));
- Sec.Offset = SegOffset + SegFileSize + PaddingSize;
- Sec.Size = Sec.Content.size();
- SegFileSize += PaddingSize + Sec.Size;
+ offsetToAlignment(SegFileSize, Align(1ull << Sec->Align));
+ Sec->Offset = SegOffset + SegFileSize + PaddingSize;
+ Sec->Size = Sec->Content.size();
+ SegFileSize += PaddingSize + Sec->Size;
}
- VMSize = std::max(VMSize, Sec.Addr + Sec.Size);
} else {
- if (Sec.isVirtualSection()) {
- Sec.Offset = 0;
- VMSize += Sec.Size;
+ if (Sec->isVirtualSection()) {
+ Sec->Offset = 0;
} else {
- uint32_t SectOffset = Sec.Addr - SegmentVmAddr;
- Sec.Offset = SegOffset + SectOffset;
- Sec.Size = Sec.Content.size();
- SegFileSize = std::max(SegFileSize, SectOffset + Sec.Size);
- VMSize = std::max(VMSize, SegFileSize);
+ Sec->Offset = SegOffset + SectOffset;
+ Sec->Size = Sec->Content.size();
+ SegFileSize = std::max(SegFileSize, SectOffset + Sec->Size);
}
}
+ VMSize = std::max(VMSize, SectOffset + Sec->Size);
}
if (IsObjectFile) {
@@ -204,21 +205,33 @@ uint64_t MachOLayoutBuilder::layoutSegments() {
}
uint64_t MachOLayoutBuilder::layoutRelocations(uint64_t Offset) {
- for (auto &LC : O.LoadCommands)
- for (auto &Sec : LC.Sections) {
- Sec.RelOff = Sec.Relocations.empty() ? 0 : Offset;
- Sec.NReloc = Sec.Relocations.size();
- Offset += sizeof(MachO::any_relocation_info) * Sec.NReloc;
+ for (LoadCommand &LC : O.LoadCommands)
+ for (std::unique_ptr<Section> &Sec : LC.Sections) {
+ Sec->RelOff = Sec->Relocations.empty() ? 0 : Offset;
+ Sec->NReloc = Sec->Relocations.size();
+ Offset += sizeof(MachO::any_relocation_info) * Sec->NReloc;
}
return Offset;
}
Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
+ // If we are building the layout of an executable or dynamic library
+ // which does not have any segments other than __LINKEDIT,
+ // the Offset can be equal to zero by this time. It happens because of the
+ // convention that in such cases the file offsets specified by LC_SEGMENT
+ // start with zero (unlike the case of a relocatable object file).
+ const uint64_t HeaderSize =
+ Is64Bit ? sizeof(MachO::mach_header_64) : sizeof(MachO::mach_header);
+ assert((!(O.Header.FileType == MachO::HeaderFileType::MH_OBJECT) ||
+ Offset >= HeaderSize + O.Header.SizeOfCmds) &&
+ "Incorrect tail offset");
+ Offset = std::max(Offset, HeaderSize + O.Header.SizeOfCmds);
+
// The order of LINKEDIT elements is as follows:
// rebase info, binding info, weak binding info, lazy binding info, export
// trie, data-in-code, symbol table, indirect symbol table, symbol table
- // strings.
+ // strings, code signature.
uint64_t NListSize = Is64Bit ? sizeof(MachO::nlist_64) : sizeof(MachO::nlist);
uint64_t StartOfLinkEdit = Offset;
uint64_t StartOfRebaseInfo = StartOfLinkEdit;
@@ -237,8 +250,10 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
uint64_t StartOfSymbolStrings =
StartOfIndirectSymbols +
sizeof(uint32_t) * O.IndirectSymTable.Symbols.size();
+ uint64_t StartOfCodeSignature =
+ StartOfSymbolStrings + StrTableBuilder.getSize();
uint64_t LinkEditSize =
- (StartOfSymbolStrings + StrTableBuilder.getSize()) - StartOfLinkEdit;
+ (StartOfCodeSignature + O.CodeSignature.Data.size()) - StartOfLinkEdit;
// Now we have determined the layout of the contents of the __LINKEDIT
// segment. Update its load command.
@@ -260,10 +275,14 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
}
}
- for (auto &LC : O.LoadCommands) {
+ for (LoadCommand &LC : O.LoadCommands) {
auto &MLC = LC.MachOLoadCommand;
auto cmd = MLC.load_command_data.cmd;
switch (cmd) {
+ case MachO::LC_CODE_SIGNATURE:
+ MLC.linkedit_data_command_data.dataoff = StartOfCodeSignature;
+ MLC.linkedit_data_command_data.datasize = O.CodeSignature.Data.size();
+ break;
case MachO::LC_SYMTAB:
MLC.symtab_command_data.symoff = StartOfSymbols;
MLC.symtab_command_data.nsyms = O.SymTable.Symbols.size();
@@ -314,6 +333,19 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
O.Exports.Trie.empty() ? 0 : StartOfExportTrie;
MLC.dyld_info_command_data.export_size = O.Exports.Trie.size();
break;
+ // Note that LC_ENCRYPTION_INFO.cryptoff despite its name and the comment in
+ // <mach-o/loader.h> is not an offset in the binary file, instead, it is a
+ // relative virtual address. At the moment modification of the __TEXT
+ // segment of executables isn't supported anyway (e.g. data in code entries
+ // are not recalculated). Moreover, in general
+ // LC_ENCRYPT_INFO/LC_ENCRYPTION_INFO_64 are nontrivial to update because
+ // without making additional assumptions (e.g. that the entire __TEXT
+ // segment should be encrypted) we do not know how to recalculate the
+ // boundaries of the encrypted part. For now just copy over these load
+ // commands until we encounter a real world usecase where
+ // LC_ENCRYPT_INFO/LC_ENCRYPTION_INFO_64 need to be adjusted.
+ case MachO::LC_ENCRYPTION_INFO:
+ case MachO::LC_ENCRYPTION_INFO_64:
case MachO::LC_LOAD_DYLINKER:
case MachO::LC_MAIN:
case MachO::LC_RPATH:
@@ -326,6 +358,7 @@ Error MachOLayoutBuilder::layoutTail(uint64_t Offset) {
case MachO::LC_BUILD_VERSION:
case MachO::LC_ID_DYLIB:
case MachO::LC_LOAD_DYLIB:
+ case MachO::LC_LOAD_WEAK_DYLIB:
case MachO::LC_UUID:
case MachO::LC_SOURCE_VERSION:
// Nothing to update.
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-28 20:32:31 +0000