Index: llvm/include/llvm/TextAPI/ELF/ELFStub.h =================================================================== --- llvm/include/llvm/TextAPI/ELF/ELFStub.h +++ llvm/include/llvm/TextAPI/ELF/ELFStub.h @@ -38,6 +38,7 @@ ELFSymbol(std::string SymbolName) : Name(SymbolName) {} std::string Name; uint64_t Size; + uint64_t Alignment; ELFSymbolType Type; bool Undefined; bool Weak; Index: llvm/llvm/test/tools/llvm-elfabi/binary-write-neededlibs.test =================================================================== --- /dev/null +++ llvm/llvm/test/tools/llvm-elfabi/binary-write-neededlibs.test @@ -0,0 +1,20 @@ +# This test ensures .dynamic strings are added to .dynstr with suffix matching. +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj --dynamic %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +SoName: libsomething.so +Arch: x86_64 +NeededLibs: + - libc.so + - libclang.so + - thing.so +Symbols: {} +... + +# CHECK: STRSZ 37 (bytes) +# CHECK: SONAME Library soname: [libsomething.so] +# CHECK: NEEDED Shared library: [libc.so] +# CHECK: NEEDED Shared library: [libclang.so] +# CHECK: NEEDED Shared library: [thing.so] Index: llvm/llvm/test/tools/llvm-elfabi/binary-write-pheaders.test =================================================================== --- /dev/null +++ llvm/llvm/test/tools/llvm-elfabi/binary-write-pheaders.test @@ -0,0 +1,38 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj -h %t | FileCheck %s --check-prefix=ELFHEADER +# RUN: llvm-readobj -l %t | FileCheck %s --check-prefix=PHDRS + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# ELFHEADER: ProgramHeaderCount: 2{{$}} + +# PHDRS: ProgramHeader { +# PHDRS-NEXT: Type: PT_LOAD (0x1) +# PHDRS-NEXT: Offset: 0x0{{$}} +# PHDRS-NEXT: VirtualAddress: 0x0{{$}} +# PHDRS-NEXT: PhysicalAddress: 0x0{{$}} +# PHDRS-NEXT: FileSize: {{.*$}} +# PHDRS-NEXT: MemSize: {{.*$}} +# PHDRS-NEXT: Flags [ (0x5) +# PHDRS-NEXT: PF_R (0x4) +# PHDRS-NEXT: PF_X (0x1) +# PHDRS-NEXT: ] +# PHDRS-NEXT: Alignment: 4096{{$}} +# PHDRS-NEXT: } +# PHDRS-NEXT: ProgramHeader { +# PHDRS-NEXT: Type: PT_DYNAMIC (0x2) +# PHDRS-NEXT: Offset: {{.*$}} +# PHDRS-NEXT: VirtualAddress: {{.*$}} +# PHDRS-NEXT: PhysicalAddress: {{.*$}} +# PHDRS-NEXT: FileSize: 48{{$}} +# PHDRS-NEXT: MemSize: 48{{$}} +# PHDRS-NEXT: Flags [ (0x6) +# PHDRS-NEXT: PF_R (0x4) +# PHDRS-NEXT: PF_W (0x2) +# PHDRS-NEXT: ] +# PHDRS-NEXT: Alignment: 8{{$}} +# PHDRS-NEXT: } Index: llvm/llvm/test/tools/llvm-elfabi/binary-write-sheaders.test =================================================================== --- /dev/null +++ llvm/llvm/test/tools/llvm-elfabi/binary-write-sheaders.test @@ -0,0 +1,71 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj -h %t | FileCheck %s --check-prefix=ELFHEADER +# RUN: llvm-readobj -S %t | FileCheck %s --check-prefix=SECTIONS + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# ELFHEADER: SectionHeaderCount: 4{{$}} +# ELFHEADER: StringTableSectionIndex: 3{{$}} + +# SECTIONS: Section { +# SECTIONS-NEXT: Index: 0{{$}} +# SECTIONS-NEXT: Name: (0) +# SECTIONS-NEXT: Type: SHT_NULL (0x0) +# SECTIONS-NEXT: Flags [ (0x0) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: 0x0{{$}} +# SECTIONS-NEXT: Offset: 0x0{{$}} +# SECTIONS-NEXT: Size: 4{{$}} +# SECTIONS-NEXT: Link: 3{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 0{{$}} +# SECTIONS-NEXT: EntrySize: 0{{$}} +# SECTIONS-NEXT: } +# SECTIONS-NEXT: Section { +# SECTIONS-NEXT: Index: 1{{$}} +# SECTIONS-NEXT: Name: .dynstr (1) +# SECTIONS-NEXT: Type: SHT_STRTAB (0x3) +# SECTIONS-NEXT: Flags [ (0x2) +# SECTIONS-NEXT: SHF_ALLOC (0x2) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: {{.*$}} +# SECTIONS-NEXT: Offset: {{.*$}} +# SECTIONS-NEXT: Size: 1{{$}} +# SECTIONS-NEXT: Link: 0{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 1{{$}} +# SECTIONS-NEXT: EntrySize: 0{{$}} +# SECTIONS-NEXT: } +# SECTIONS-NEXT: Section { +# SECTIONS-NEXT: Index: 2{{$}} +# SECTIONS-NEXT: Name: .dynamic (9) +# SECTIONS-NEXT: Type: SHT_DYNAMIC (0x6) +# SECTIONS-NEXT: Flags [ (0x2) +# SECTIONS-NEXT: SHF_ALLOC (0x2) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: {{.*$}} +# SECTIONS-NEXT: Offset: {{.*$}} +# SECTIONS-NEXT: Size: 48{{$}} +# SECTIONS-NEXT: Link: 1{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 8{{$}} +# SECTIONS-NEXT: EntrySize: 16{{$}} +# SECTIONS-NEXT: } +# SECTIONS-NEXT: Section { +# SECTIONS-NEXT: Index: 3{{$}} +# SECTIONS-NEXT: Name: .shstrtab (18) +# SECTIONS-NEXT: Type: SHT_STRTAB (0x3) +# SECTIONS-NEXT: Flags [ (0x0) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: 0x0{{$}} +# SECTIONS-NEXT: Offset: {{.*$}} +# SECTIONS-NEXT: Size: 28{{$}} +# SECTIONS-NEXT: Link: 0{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 1{{$}} +# SECTIONS-NEXT: EntrySize: 0{{$}} +# SECTIONS-NEXT: } Index: llvm/llvm/test/tools/llvm-elfabi/binary-write-soname.test =================================================================== --- /dev/null +++ llvm/llvm/test/tools/llvm-elfabi/binary-write-soname.test @@ -0,0 +1,12 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj --dynamic %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +SoName: somelib.so +Arch: x86_64 +Symbols: {} +... + +# CHECK: STRSZ 12 (bytes) +# CHECK: SONAME Library soname: [somelib.so] Index: llvm/test/tools/llvm-elfabi/binary-write-neededlibs.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/binary-write-neededlibs.test @@ -0,0 +1,20 @@ +# This test ensures .dynamic strings are added to .dynstr with suffix matching. +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj --dynamic %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +SoName: libsomething.so +Arch: x86_64 +NeededLibs: + - libc.so + - libclang.so + - thing.so +Symbols: {} +... + +# CHECK: STRSZ 37 (bytes) +# CHECK: SONAME Library soname: [libsomething.so] +# CHECK: NEEDED Shared library: [libc.so] +# CHECK: NEEDED Shared library: [libclang.so] +# CHECK: NEEDED Shared library: [thing.so] Index: llvm/test/tools/llvm-elfabi/binary-write-pheaders.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/binary-write-pheaders.test @@ -0,0 +1,38 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj -h %t | FileCheck %s --check-prefix=ELFHEADER +# RUN: llvm-readobj -l %t | FileCheck %s --check-prefix=PHDRS + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# ELFHEADER: ProgramHeaderCount: 2{{$}} + +# PHDRS: ProgramHeader { +# PHDRS-NEXT: Type: PT_LOAD (0x1) +# PHDRS-NEXT: Offset: 0x0{{$}} +# PHDRS-NEXT: VirtualAddress: 0x0{{$}} +# PHDRS-NEXT: PhysicalAddress: 0x0{{$}} +# PHDRS-NEXT: FileSize: {{.*$}} +# PHDRS-NEXT: MemSize: {{.*$}} +# PHDRS-NEXT: Flags [ (0x5) +# PHDRS-NEXT: PF_R (0x4) +# PHDRS-NEXT: PF_X (0x1) +# PHDRS-NEXT: ] +# PHDRS-NEXT: Alignment: 4096{{$}} +# PHDRS-NEXT: } +# PHDRS-NEXT: ProgramHeader { +# PHDRS-NEXT: Type: PT_DYNAMIC (0x2) +# PHDRS-NEXT: Offset: {{.*$}} +# PHDRS-NEXT: VirtualAddress: {{.*$}} +# PHDRS-NEXT: PhysicalAddress: {{.*$}} +# PHDRS-NEXT: FileSize: 48{{$}} +# PHDRS-NEXT: MemSize: 48{{$}} +# PHDRS-NEXT: Flags [ (0x6) +# PHDRS-NEXT: PF_R (0x4) +# PHDRS-NEXT: PF_W (0x2) +# PHDRS-NEXT: ] +# PHDRS-NEXT: Alignment: 8{{$}} +# PHDRS-NEXT: } Index: llvm/test/tools/llvm-elfabi/binary-write-sheaders.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/binary-write-sheaders.test @@ -0,0 +1,71 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj -h %t | FileCheck %s --check-prefix=ELFHEADER +# RUN: llvm-readobj -S %t | FileCheck %s --check-prefix=SECTIONS + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# ELFHEADER: SectionHeaderCount: 4{{$}} +# ELFHEADER: StringTableSectionIndex: 3{{$}} + +# SECTIONS: Section { +# SECTIONS-NEXT: Index: 0{{$}} +# SECTIONS-NEXT: Name: (0) +# SECTIONS-NEXT: Type: SHT_NULL (0x0) +# SECTIONS-NEXT: Flags [ (0x0) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: 0x0{{$}} +# SECTIONS-NEXT: Offset: 0x0{{$}} +# SECTIONS-NEXT: Size: 4{{$}} +# SECTIONS-NEXT: Link: 3{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 0{{$}} +# SECTIONS-NEXT: EntrySize: 0{{$}} +# SECTIONS-NEXT: } +# SECTIONS-NEXT: Section { +# SECTIONS-NEXT: Index: 1{{$}} +# SECTIONS-NEXT: Name: .dynstr (1) +# SECTIONS-NEXT: Type: SHT_STRTAB (0x3) +# SECTIONS-NEXT: Flags [ (0x2) +# SECTIONS-NEXT: SHF_ALLOC (0x2) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: {{.*$}} +# SECTIONS-NEXT: Offset: {{.*$}} +# SECTIONS-NEXT: Size: 1{{$}} +# SECTIONS-NEXT: Link: 0{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 1{{$}} +# SECTIONS-NEXT: EntrySize: 0{{$}} +# SECTIONS-NEXT: } +# SECTIONS-NEXT: Section { +# SECTIONS-NEXT: Index: 2{{$}} +# SECTIONS-NEXT: Name: .dynamic (9) +# SECTIONS-NEXT: Type: SHT_DYNAMIC (0x6) +# SECTIONS-NEXT: Flags [ (0x2) +# SECTIONS-NEXT: SHF_ALLOC (0x2) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: {{.*$}} +# SECTIONS-NEXT: Offset: {{.*$}} +# SECTIONS-NEXT: Size: 48{{$}} +# SECTIONS-NEXT: Link: 1{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 8{{$}} +# SECTIONS-NEXT: EntrySize: 16{{$}} +# SECTIONS-NEXT: } +# SECTIONS-NEXT: Section { +# SECTIONS-NEXT: Index: 3{{$}} +# SECTIONS-NEXT: Name: .shstrtab (18) +# SECTIONS-NEXT: Type: SHT_STRTAB (0x3) +# SECTIONS-NEXT: Flags [ (0x0) +# SECTIONS-NEXT: ] +# SECTIONS-NEXT: Address: 0x0{{$}} +# SECTIONS-NEXT: Offset: {{.*$}} +# SECTIONS-NEXT: Size: 28{{$}} +# SECTIONS-NEXT: Link: 0{{$}} +# SECTIONS-NEXT: Info: 0{{$}} +# SECTIONS-NEXT: AddressAlignment: 1{{$}} +# SECTIONS-NEXT: EntrySize: 0{{$}} +# SECTIONS-NEXT: } Index: llvm/test/tools/llvm-elfabi/binary-write-soname.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/binary-write-soname.test @@ -0,0 +1,12 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj --dynamic %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +SoName: somelib.so +Arch: x86_64 +Symbols: {} +... + +# CHECK: STRSZ 12 (bytes) +# CHECK: SONAME Library soname: [somelib.so] Index: llvm/test/tools/llvm-elfabi/invalid-bin-target.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/invalid-bin-target.test @@ -0,0 +1,10 @@ +# RUN: not llvm-elfabi %s --output-target=nope %t 2>&1 | FileCheck %s + +--- !tapi-tbe +SoName: somelib.so +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# CHECK: llvm-elfabi: for the -output-target option: Cannot find option named 'nope'! Index: llvm/test/tools/llvm-elfabi/missing-bin-target.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/missing-bin-target.test @@ -0,0 +1,10 @@ +# RUN: not llvm-elfabi %s %t 2>&1 | FileCheck %s + +--- !tapi-tbe +SoName: somelib.so +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# CHECK: No binary output target specified. Index: llvm/test/tools/llvm-elfabi/write-elf32be-ehdr.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/write-elf32be-ehdr.test @@ -0,0 +1,28 @@ +# RUN: llvm-elfabi %s --output-target=elf32-big %t +# RUN: llvm-readobj --file-headers %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# CHECK: ElfHeader { +# CHECK-NEXT: Ident { +# CHECK-NEXT: Magic: (7F 45 4C 46) +# CHECK-NEXT: Class: 32-bit (0x1) +# CHECK-NEXT: DataEncoding: BigEndian (0x2) +# CHECK-NEXT: FileVersion: 1{{$}} +# CHECK-NEXT: OS/ABI: SystemV (0x0) +# CHECK-NEXT: ABIVersion: 0{{$}} +# CHECK-NEXT: Unused: (00 00 00 00 00 00 00) +# CHECK-NEXT: } +# CHECK-NEXT: Type: SharedObject (0x3) +# CHECK-NEXT: Machine: EM_X86_64 (0x3E) +# CHECK-NEXT: Version: 1{{$}} +# CHECK-NEXT: Entry: 0x0{{$}} +# CHECK: Flags [ (0x0) +# CHECK-NEXT: ] +# CHECK-NEXT: HeaderSize: 52{{$}} +# CHECK-NEXT: ProgramHeaderEntrySize: 32{{$}} +# CHECK: SectionHeaderEntrySize: 40{{$}} Index: llvm/test/tools/llvm-elfabi/write-elf32le-ehdr.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/write-elf32le-ehdr.test @@ -0,0 +1,28 @@ +# RUN: llvm-elfabi %s --output-target=elf32-little %t +# RUN: llvm-readobj --file-headers %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# CHECK: ElfHeader { +# CHECK-NEXT: Ident { +# CHECK-NEXT: Magic: (7F 45 4C 46) +# CHECK-NEXT: Class: 32-bit (0x1) +# CHECK-NEXT: DataEncoding: LittleEndian (0x1) +# CHECK-NEXT: FileVersion: 1{{$}} +# CHECK-NEXT: OS/ABI: SystemV (0x0) +# CHECK-NEXT: ABIVersion: 0{{$}} +# CHECK-NEXT: Unused: (00 00 00 00 00 00 00) +# CHECK-NEXT: } +# CHECK-NEXT: Type: SharedObject (0x3) +# CHECK-NEXT: Machine: EM_X86_64 (0x3E) +# CHECK-NEXT: Version: 1{{$}} +# CHECK-NEXT: Entry: 0x0{{$}} +# CHECK: Flags [ (0x0) +# CHECK-NEXT: ] +# CHECK-NEXT: HeaderSize: 52{{$}} +# CHECK-NEXT: ProgramHeaderEntrySize: 32{{$}} +# CHECK: SectionHeaderEntrySize: 40{{$}} Index: llvm/test/tools/llvm-elfabi/write-elf64be-ehdr.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/write-elf64be-ehdr.test @@ -0,0 +1,28 @@ +# RUN: llvm-elfabi %s --output-target=elf64-big %t +# RUN: llvm-readobj --file-headers %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: x86_64 +Symbols: {} +... + +# CHECK: ElfHeader { +# CHECK-NEXT: Ident { +# CHECK-NEXT: Magic: (7F 45 4C 46) +# CHECK-NEXT: Class: 64-bit (0x2) +# CHECK-NEXT: DataEncoding: BigEndian (0x2) +# CHECK-NEXT: FileVersion: 1{{$}} +# CHECK-NEXT: OS/ABI: SystemV (0x0) +# CHECK-NEXT: ABIVersion: 0{{$}} +# CHECK-NEXT: Unused: (00 00 00 00 00 00 00) +# CHECK-NEXT: } +# CHECK-NEXT: Type: SharedObject (0x3) +# CHECK-NEXT: Machine: EM_X86_64 (0x3E) +# CHECK-NEXT: Version: 1{{$}} +# CHECK-NEXT: Entry: 0x0{{$}} +# CHECK: Flags [ (0x0) +# CHECK-NEXT: ] +# CHECK-NEXT: HeaderSize: 64{{$}} +# CHECK-NEXT: ProgramHeaderEntrySize: 56{{$}} +# CHECK: SectionHeaderEntrySize: 64{{$}} Index: llvm/test/tools/llvm-elfabi/write-elf64le-ehdr.test =================================================================== --- /dev/null +++ llvm/test/tools/llvm-elfabi/write-elf64le-ehdr.test @@ -0,0 +1,28 @@ +# RUN: llvm-elfabi %s --output-target=elf64-little %t +# RUN: llvm-readobj --file-headers %t | FileCheck %s + +--- !tapi-tbe +TbeVersion: 1.0 +Arch: AArch64 +Symbols: {} +... + +# CHECK: ElfHeader { +# CHECK-NEXT: Ident { +# CHECK-NEXT: Magic: (7F 45 4C 46) +# CHECK-NEXT: Class: 64-bit (0x2) +# CHECK-NEXT: DataEncoding: LittleEndian (0x1) +# CHECK-NEXT: FileVersion: 1{{$}} +# CHECK-NEXT: OS/ABI: SystemV (0x0) +# CHECK-NEXT: ABIVersion: 0{{$}} +# CHECK-NEXT: Unused: (00 00 00 00 00 00 00) +# CHECK-NEXT: } +# CHECK-NEXT: Type: SharedObject (0x3) +# CHECK-NEXT: Machine: EM_AARCH64 (0xB7) +# CHECK-NEXT: Version: 1{{$}} +# CHECK-NEXT: Entry: 0x0{{$}} +# CHECK: Flags [ (0x0) +# CHECK-NEXT: ] +# CHECK-NEXT: HeaderSize: 64{{$}} +# CHECK-NEXT: ProgramHeaderEntrySize: 56{{$}} +# CHECK: SectionHeaderEntrySize: 64{{$}} Index: llvm/tools/llvm-elfabi/ELFObjHandler.h =================================================================== --- llvm/tools/llvm-elfabi/ELFObjHandler.h +++ llvm/tools/llvm-elfabi/ELFObjHandler.h @@ -23,9 +23,26 @@ namespace elfabi { +enum class ELFTarget { + ELF32LE, + ELF32BE, + ELF64LE, + ELF64BE +}; + /// Attempt to read a binary ELF file from a MemoryBuffer. Expected> readELFFile(MemoryBufferRef Buf); +/// Attempt to write a binary ELF stub. +/// This function determines appropriate ELFType using the passed ELFTarget and +/// then writes a binary ELF stub to a specified file path. +/// +/// @param FilePath File path for writing the ELF binary. +/// @param Stub Source ELFStub to generate a binary ELF stub from. +/// @param OutputFormat Target ELFType to write binary as. +Error writeBinaryStub(StringRef FilePath, const ELFStub &Stub, + ELFTarget OutputFormat); + } // end namespace elfabi } // end namespace llvm Index: llvm/tools/llvm-elfabi/ELFObjHandler.cpp =================================================================== --- llvm/tools/llvm-elfabi/ELFObjHandler.cpp +++ llvm/tools/llvm-elfabi/ELFObjHandler.cpp @@ -7,14 +7,19 @@ //===-----------------------------------------------------------------------===/ #include "ELFObjHandler.h" +#include "llvm/Support/MathExtras.h" +#include "llvm/MC/StringTableBuilder.h" #include "llvm/Object/Binary.h" #include "llvm/Object/ELFObjectFile.h" #include "llvm/Object/ELFTypes.h" #include "llvm/Support/Errc.h" #include "llvm/Support/Error.h" +#include "llvm/Support/FileOutputBuffer.h" #include "llvm/Support/MemoryBuffer.h" #include "llvm/TextAPI/ELF/ELFStub.h" +#include + using llvm::MemoryBufferRef; using llvm::object::ELFObjectFile; @@ -22,8 +27,9 @@ using namespace llvm::object; using namespace llvm::ELF; -namespace llvm { -namespace elfabi { +namespace { + +using namespace llvm::elfabi; // Simple struct to hold relevant .dynamic entries. struct DynamicEntries { @@ -38,13 +44,71 @@ Optional GnuHash; }; +// Lazy assumes that T is default constructable. +// Lazy also acts like a read-only, move-only type. +template +class Lazy { +private: + std::function Func; + mutable Optional Value; + mutable bool Blackhole = false; + +public: + Lazy(const Lazy&) = delete; + Lazy(Lazy&&) = default; + // Allow Lazy values to be default constructed to an empty state. + Lazy() = default; + explicit Lazy(std::function&& F) : Func(std::move(F)) {} + + Lazy& operator=(std::function&& F) { + // Once a thunk has been assigned don't allow it to change. + assert(!Value && !Func); + Func = F; + return *this; + } + Lazy& operator=(T&& Val) { + assert(!Value && !Func); + Value = std::move(Val); + return *this; + } + Lazy& operator=(const T& Val) { + assert(!Value && !Func); + Value = Val; + return *this; + } + + const T &operator*() const { + // Assert that a value has been assigned, lazy or otherwise. + assert(Value || Func); + if (Blackhole) + llvm_unreachable("cycle detected"); + if (Value) + return *Value; + else { + Blackhole = true; + Value = T(); + Func(*Value); + Blackhole = false; + return *Value; + } + } + const T *operator->() const { + return &**this; + } +}; + +template +Lazy makeLazy(std::function&& F) { + return Lazy{std::move(F)}; +} + /// This function behaves similarly to StringRef::substr(), but attempts to /// terminate the returned StringRef at the first null terminator. If no null /// terminator is found, an error is returned. /// /// @param Str Source string to create a substring from. /// @param Offset The start index of the desired substring. -static Expected terminatedSubstr(StringRef Str, size_t Offset) { +Expected terminatedSubstr(StringRef Str, size_t Offset) { size_t StrEnd = Str.find('\0', Offset); if (StrEnd == StringLiteral::npos) { return createError( @@ -78,7 +142,7 @@ /// @param Dyn Target DynamicEntries struct to populate. /// @param DynTable Source dynamic table. template -static Error populateDynamic(DynamicEntries &Dyn, +Error populateDynamic(DynamicEntries &Dyn, typename ELFT::DynRange DynTable) { if (DynTable.empty()) return createError("No .dynamic section found"); @@ -151,7 +215,7 @@ /// /// @param Table The GNU hash table for .dynsym. template -static uint64_t getDynSymtabSize(const typename ELFT::GnuHash &Table) { +uint64_t getDynSymtabSize(const typename ELFT::GnuHash &Table) { using Elf_Word = typename ELFT::Word; if (Table.nbuckets == 0) return Table.symndx + 1; @@ -179,7 +243,7 @@ /// @param Dyn Entries with the locations of hash tables. /// @param ElfFile The ElfFile that the section contents reside in. template -static Expected getNumSyms(DynamicEntries &Dyn, +Expected getNumSyms(DynamicEntries &Dyn, const ELFFile &ElfFile) { using Elf_Hash = typename ELFT::Hash; using Elf_GnuHash = typename ELFT::GnuHash; @@ -209,7 +273,7 @@ /// Other symbol types are mapped to ELFSymbolType::Unknown. /// /// @param Info Binary symbol st_info to extract symbol type from. -static ELFSymbolType convertInfoToType(uint8_t Info) { +ELFSymbolType convertInfoToType(uint8_t Info) { Info = Info & 0xf; switch (Info) { case ELF::STT_NOTYPE: @@ -231,7 +295,7 @@ /// @param SymName The desired name of the ELFSymbol. /// @param RawSym ELFT::Sym to extract symbol information from. template -static ELFSymbol createELFSym(StringRef SymName, +ELFSymbol createELFSym(StringRef SymName, const typename ELFT::Sym &RawSym) { ELFSymbol TargetSym(SymName); uint8_t Binding = RawSym.getBinding(); @@ -258,7 +322,7 @@ /// @param DynSym Range of dynamic symbols to add to TargetStub. /// @param DynStr StringRef to the dynamic string table. template -static Error populateSymbols(ELFStub &TargetStub, +Error populateSymbols(ELFStub &TargetStub, const typename ELFT::SymRange DynSym, StringRef DynStr) { // Skips the first symbol since it's the NULL symbol. @@ -286,7 +350,7 @@ /// Returns a new ELFStub with all members populated from an ELFObjectFile. /// @param ElfObj Source ELFObjectFile. template -static Expected> +Expected> buildStub(const ELFObjectFile &ElfObj) { using Elf_Dyn_Range = typename ELFT::DynRange; using Elf_Phdr_Range = typename ELFT::PhdrRange; @@ -367,6 +431,398 @@ return std::move(DestStub); } +/// This initializes an ELF file header with information specific to a binary +/// dynamic shared object. +/// Offsets, indexes, links, etc. for section and program headers are just +/// zero-initialized as they will be updated elsewhere. +/// +/// @param ElfHeader Target ELFT::Ehdr to populate. +/// @param Machine Target architecture (e_machine from ELF specifications). +template +void initELFHeader(typename ELFT::Ehdr &ElfHeader, uint16_t Machine) { + using Elf_Ehdr = typename ELFT::Ehdr; + using Elf_Shdr = typename ELFT::Shdr; + + memset(&ElfHeader, 0, sizeof(Elf_Ehdr)); + // ELF identification. + ElfHeader.e_ident[EI_MAG0] = 0x7f; // ELFMAG0 + ElfHeader.e_ident[EI_MAG1] = 'E'; // ELFMAG1 + ElfHeader.e_ident[EI_MAG2] = 'L'; // ELFMAG2 + ElfHeader.e_ident[EI_MAG3] = 'F'; // ELFMAG3 + ElfHeader.e_ident[EI_CLASS] = ELFT::Is64Bits ? ELFCLASS64 : ELFCLASS32; + bool IsLittleEndian = ELFT::TargetEndianness == support::little; + ElfHeader.e_ident[EI_DATA] = IsLittleEndian ? ELFDATA2LSB : ELFDATA2MSB; + ElfHeader.e_ident[EI_VERSION] = EV_CURRENT; + ElfHeader.e_ident[EI_OSABI] = ELFOSABI_NONE; + ElfHeader.e_ident[EI_ABIVERSION] = 0; + + // Remainder of ELF header. + ElfHeader.e_type = ET_DYN; + ElfHeader.e_machine = Machine; + ElfHeader.e_version = EV_CURRENT; + ElfHeader.e_entry = 0; + ElfHeader.e_flags = 0; + ElfHeader.e_ehsize = sizeof(Elf_Ehdr); + ElfHeader.e_phentsize = 0; + ElfHeader.e_shentsize = sizeof(Elf_Shdr); +} + +template +struct OutputSection { + using Elf_Shdr = typename ELFT::Shdr; + std::string Name; + Lazy Shdr; + Lazy Addr; + Lazy Offset; + Lazy Size; + Lazy Align; + uint32_t Index; +}; + +template +struct ContentSection : public OutputSection { + Lazy Content; +}; + +class ELFStringTableBuilder : public StringTableBuilder { +public: + ELFStringTableBuilder() : StringTableBuilder(StringTableBuilder::ELF) {} +}; + +template +struct SymbolInformation { + using Elf_Sym = typename ELFT::Sym; + std::vector Symbols; + uint64_t MaxAlign = 0; + uint64_t MaxAddr = 0; + uint64_t MaxTLSAlign = 0; + uint64_t MaxTLSAddr = 0; +}; + +template +class ELFBuilder { +public: + using Elf_Ehdr = typename ELFT::Ehdr; + using Elf_Shdr = typename ELFT::Shdr; + using Elf_Phdr = typename ELFT::Phdr; + using Elf_Sym = typename ELFT::Sym; + using Elf_Addr = typename ELFT::Addr; + using Elf_Dyn = typename ELFT::Dyn; + +private: + Lazy ElfHeader; + ContentSection StrTab; + ContentSection, ELFT> DynSym; + OutputSection DefSec; + OutputSection TlsSec; + ContentSection, ELFT> Dynamic; + Lazy> ProgramHeaders; + + template + static void Write(uint8_t *Data, const T& Value) { + *reinterpret_cast(Data) = Value; + } + template + static void WriteVector(uint8_t *Data, const std::vector& Vec) { + std::copy(Vec.begin(), Vec.end(), reinterpret_cast(Data)); + } + uint64_t ShdrOffset(const OutputSection& Sec) const { + return ElfHeader->e_shoff + Sec.Index * sizeof(Elf_Shdr); + } + void WriteShdr(uint8_t *Data, const OutputSection& Sec) const { + Write(Data + ShdrOffset(Sec), *Sec.Shdr); + } +public: + ELFBuilder(const ELFBuilder&) = delete; + ELFBuilder(ELFBuilder&&) = default; + explicit ELFBuilder(const ELFStub& Stub) { + // New sections can be added here + std::vector*> Sections; + Sections.push_back(&StrTab); + Sections.push_back(&DynSym); + Sections.push_back(&Dynamic); + + // Manually set the indexes of these. + uint64_t Index = 1; + const OutputSection *Prev = nullptr; + DefSec.Index = Index++; + TlsSec.Index = Index++; + // Now set the Index, Offset, and Addr of everything. + for (auto Sec : Sections) { + Sec->Index = Index++; + Sec->Offset = [Sec, Prev](uint64_t &Offset) { + uint64_t Align = *Sec->Align ? *Sec->Align : 1; + if (!Prev) + Offset = alignTo(sizeof(Elf_Ehdr), Align); + else + Offset = alignTo(*Prev->Offset + *Prev->Size, Align); + }; + if (Prev == nullptr) + Prev = &DefSec; + Sec->Addr = [Sec, Prev](uint64_t &Addr) { + uint64_t Align = *Sec->Align ? *Sec->Align : 1; + Addr = alignTo(*Prev->Addr + *Prev->Size, Align); + }; + Prev = Sec; + } + // We manually set the addresses and offsets of these. + DefSec.Addr = 0x0; + TlsSec.Addr = 0x0; + DefSec.Offset = 0x0; + TlsSec.Offset = 0x0; + + // Prev is now the last section so we can define the ELF header. + ElfHeader = [this, &Stub, Prev](Elf_Ehdr& Ehdr) { + initELFHeader(Ehdr, Stub.Arch); + Ehdr.e_shstrndx = StrTab.Index; + Ehdr.e_shoff = alignTo(*Prev->Offset + *Prev->Size, sizeof(Elf_Addr)); + Ehdr.e_shnum = 6; + }; + + // Define the non-TLS section. + DefSec.Name = ".def"; + DefSec.Shdr = [this](Elf_Shdr& Shdr) { + Shdr.sh_name = StrTab.Content->getOffset(DefSec.Name); + Shdr.sh_type = SHT_NOBITS; + Shdr.sh_flags = SHF_ALLOC; + Shdr.sh_size = *DefSec.Size; + Shdr.sh_addralign = *DefSec.Align; + }; + DefSec.Size = [this](uint64_t &Size) { + Size = DynSym.Content->MaxAddr; + }; + DefSec.Align = [this](uint64_t &Align) { + Align = DynSym.Content->MaxAlign; + }; + + // Define the TLS section. + TlsSec.Name = ".tls"; + TlsSec.Shdr = [this](Elf_Shdr& Shdr) { + Shdr.sh_name = StrTab.Content->getOffset(TlsSec.Name); + Shdr.sh_type = SHT_NOBITS; + Shdr.sh_flags = SHF_ALLOC; + Shdr.sh_size = *TlsSec.Size; + Shdr.sh_addralign = *TlsSec.Align; + }; + TlsSec.Size = [this](uint64_t &Size) { + Size = DynSym.Content->MaxTLSAddr; + }; + TlsSec.Align = [this](uint64_t &Align) { + Align = DynSym.Content->MaxTLSAlign; + }; + + // Define the string table. + StrTab.Name = ".dynstr"; + StrTab.Shdr = [this](Elf_Shdr& Shdr) { + Shdr.sh_name = StrTab.Content->getOffset(StrTab.Name); + Shdr.sh_type = SHT_STRTAB; + Shdr.sh_flags = SHF_ALLOC; + Shdr.sh_size = *StrTab.Size; + Shdr.sh_addr = *StrTab.Addr; + Shdr.sh_offset = *StrTab.Offset; + }; + StrTab.Size = [this](uint64_t &Size) { + Size = StrTab.Content->getSize(); + }; + StrTab.Align = 0; + StrTab.Content = [this, &Stub](ELFStringTableBuilder& Builder) { + Builder.add(StrTab.Name); + Builder.add(DynSym.Name); + Builder.add(DefSec.Name); + Builder.add(TlsSec.Name); + Builder.add(Dynamic.Name); + for (const auto& Sym : Stub.Symbols) + Builder.add(Sym.Name); + if (Stub.SoName) + Builder.add(*Stub.SoName); + for (const auto& Needed : Stub.NeededLibs) + Builder.add(Needed); + Builder.finalize(); + }; + + // Define the symbol table. + DynSym.Name = ".dynsym"; + DynSym.Shdr = [this](Elf_Shdr& Shdr) { + Shdr.sh_name = StrTab.Content->getOffset(DynSym.Name); + Shdr.sh_type = SHT_DYNSYM; + Shdr.sh_flags = SHF_ALLOC; + Shdr.sh_size = *DynSym.Size; + Shdr.sh_addralign = sizeof(Elf_Addr); + Shdr.sh_addr = *DynSym.Addr; + Shdr.sh_offset = *DynSym.Offset; + Shdr.sh_link = StrTab.Index; + Shdr.sh_entsize = sizeof(Elf_Sym); + }; + DynSym.Align = sizeof(Elf_Addr); + DynSym.Size = Stub.Symbols.size() * sizeof(Elf_Sym); + DynSym.Content = [this, &Stub](SymbolInformation& SymbolInfo) { + // Process each symbol. We'll set the name index in a second loop. + // We treat TLS symbols like they're in a different address space. + // We will adjust the addresses later by adding a bias in the second loop. + uint64_t Addr = 0x0; + uint64_t MaxAlign = 0x0; + uint64_t TLSAddr = 0x0; + uint64_t MaxTLSAlign = 0x0; + // TODO: Explore not allocating Symbols and instead writing directly + // into the output buffer. The challenge here is computing MaxAddr + // and friends. It seems like we'd still need this loop. + for (const auto &Symbol : Stub.Symbols) { + SymbolInfo.Symbols.emplace_back(); + Elf_Sym& ElfSym = SymbolInfo.Symbols.back(); + ElfSym.st_name = StrTab.Content->getOffset(Symbol.Name); + if (!Symbol.Undefined) { + switch (Symbol.Type) { + case ELFSymbolType::Func: + ElfSym.st_shndx = DefSec.Index; + ElfSym.st_value = Addr++; + break; + case ELFSymbolType::Object: + ElfSym.st_shndx = DefSec.Index; + // TODO: When bumping to alignment ensure that we hit exactly the + // minimum alignment. This ensures that copy relocations will have + // exactly the alignment they need rather than anything larger. + Addr = alignTo(Addr, Symbol.Alignment ? Symbol.Alignment : 1); + ElfSym.st_value = Addr; + Addr += Symbol.Size; + ElfSym.st_size = Symbol.Size; + MaxAlign = std::max(Symbol.Alignment, MaxAlign); + break; + case ELFSymbolType::TLS: + ElfSym.st_shndx = TlsSec.Index; + // This doesn't really matter but it feels nice and doesn't cost us + // anything. Alignment defaults to zero when absent and it will + // have no effect. + TLSAddr = alignTo(TLSAddr, Symbol.Alignment ? Symbol.Alignment : 1); + ElfSym.st_value = TLSAddr; + TLSAddr += Symbol.Size; + ElfSym.st_size = Symbol.Size; + MaxTLSAlign = std::max(Symbol.Alignment, MaxTLSAlign); + break; + default: + break; + } + } + ElfSym.setType(static_cast(Symbol.Type)); + if (Symbol.Weak) + ElfSym.setBinding(STB_WEAK); + else + ElfSym.setBinding(STB_GLOBAL); + } + SymbolInfo.MaxAddr = Addr; + SymbolInfo.MaxAlign = MaxAlign; + SymbolInfo.MaxTLSAddr = TLSAddr; + SymbolInfo.MaxTLSAlign = MaxTLSAlign; + }; + + // Construct the .dynamic table. + Dynamic.Name = ".dynamic"; + Dynamic.Shdr = [this](Elf_Shdr& Shdr) { + Shdr.sh_name = StrTab.Content->getOffset(Dynamic.Name); + Shdr.sh_type = SHT_DYNAMIC; + Shdr.sh_flags = SHF_ALLOC; + Shdr.sh_addr = *Dynamic.Addr; + Shdr.sh_offset = *Dynamic.Offset; + Shdr.sh_size = *Dynamic.Size; + Shdr.sh_link = StrTab.Index; + Shdr.sh_addralign = sizeof(Elf_Addr); + Shdr.sh_entsize = sizeof(Elf_Dyn); + }; + Dynamic.Align = sizeof(Elf_Addr); + Dynamic.Size = [this](uint64_t &Size) { + // TODO: This can be calculated without knowing the Content. + Size = Dynamic.Content->size() * sizeof(Elf_Dyn); + }; + Dynamic.Content = [this, &Stub](std::vector& Entries) { + auto Add = [&Entries](uint16_t Tag) -> Elf_Dyn& { + Entries.emplace_back(); + Elf_Dyn& Dyn = Entries.back(); + Dyn.d_tag = Tag; + return Dyn; + }; + if (Stub.SoName) + Add(DT_SONAME).d_un.d_val = StrTab.Content->getOffset(*Stub.SoName); + for (const auto& Needed : Stub.NeededLibs) + Add(DT_NEEDED).d_un.d_val = StrTab.Content->getOffset(Needed); + Add(DT_STRTAB).d_un.d_ptr = *StrTab.Addr; + Add(DT_STRSZ).d_un.d_ptr = *StrTab.Size; + Add(DT_SYMTAB).d_un.d_ptr = *DynSym.Addr; + Add(DT_SYMENT).d_un.d_ptr = sizeof(Elf_Sym); + Add(DT_NULL); + }; + } + + // GetSize will effectivelly compute the whole layout. + size_t GetSize() const { + return ElfHeader->e_shoff + ElfHeader->e_shnum * sizeof(Elf_Shdr); + } + + void Write(uint8_t *Data) const { + Write(Data, *ElfHeader); + StrTab.Content->write(Data + StrTab.Shdr->sh_offset); + // TODO: It would be preety cool if we didn't need DynSym.Content->Symbols + // and could just write into the Data directly. + WriteVector(Data + DynSym.Shdr->sh_offset, DynSym.Content->Symbols); + WriteVector(Data + Dynamic.Shdr->sh_offset, *Dynamic.Content); + WriteShdr(Data, StrTab); + WriteShdr(Data, DynSym); + WriteShdr(Data, DefSec); + WriteShdr(Data, TlsSec); + WriteShdr(Data, Dynamic); + } +}; + +/// This function opens a file for writing and then writes a binary ELF stub to +/// the file. +/// +/// @param FilePath File path for writing the ELF binary. +/// @param Stub Source ELFStub to generate a binary ELF stub from. +template +Error writeELFBinaryToFile(StringRef FilePath, const ELFStub &Stub) { + ELFBuilder Builder{Stub}; + Expected> BufOrError = + FileOutputBuffer::create(FilePath, Builder.GetSize()); + if (!BufOrError) { + Error FileReadError = BufOrError.takeError(); + std::string Message; + raw_string_ostream Stream(Message); + Stream << FileReadError; + Stream << " when trying to open `" << FilePath <<"` for writing"; + consumeError(std::move(FileReadError)); + return createStringError(errc::invalid_argument, Stream.str().c_str()); + } + + // Write binary to file. + std::unique_ptr Buf = std::move(*BufOrError); + Builder.Write(Buf->getBufferStart()); + + if (Error FileWriteError = Buf->commit()) + return FileWriteError; + + return Error::success(); +} + +} // end namespace + +namespace llvm { +namespace elfabi { + +// This function wraps the ELFT writeELFBinaryToFile() so writeBinaryStub() +// can be called without having to use ELFType templates directly. +Error writeBinaryStub(StringRef FilePath, const ELFStub &Stub, + ELFTarget OutputFormat) { + if (OutputFormat == ELFTarget::ELF32LE) { + return writeELFBinaryToFile(FilePath, Stub); + } else if (OutputFormat == ELFTarget::ELF32BE) { + return writeELFBinaryToFile(FilePath, Stub); + } else if (OutputFormat == ELFTarget::ELF64LE) { + return writeELFBinaryToFile(FilePath, Stub); + } else if (OutputFormat == ELFTarget::ELF64BE) { + return writeELFBinaryToFile(FilePath, Stub); + } + return createStringError(errc::invalid_argument, + "Invalid binary output target"); +} + Expected> readELFFile(MemoryBufferRef Buf) { Expected> BinOrErr = createBinary(Buf); if (!BinOrErr) { Index: llvm/tools/llvm-elfabi/llvm-elfabi.cpp =================================================================== --- llvm/tools/llvm-elfabi/llvm-elfabi.cpp +++ llvm/tools/llvm-elfabi/llvm-elfabi.cpp @@ -49,6 +49,17 @@ "soname", cl::desc("Manually set the DT_SONAME entry of any emitted files"), cl::value_desc("name")); +cl::opt BinaryOutputTarget( + "output-target", cl::desc("Create a binary stub for the specified target"), + cl::values(clEnumValN(ELFTarget::ELF32LE, "elf32-little", + "32-bit little-endian ELF stub"), + clEnumValN(ELFTarget::ELF32BE, "elf32-big", + "32-bit big-endian ELF stub"), + clEnumValN(ELFTarget::ELF64LE, "elf64-little", + "64-bit little-endian ELF stub"), + clEnumValN(ELFTarget::ELF64BE, "elf64-big", + "64-bit big-endian ELF stub"))); +cl::opt BinaryOutputFilePath(cl::Positional, cl::desc("output")); /// writeTBE() writes a Text-Based ELF stub to a file using the latest version /// of the YAML parser. @@ -127,16 +138,32 @@ std::unique_ptr TargetStub = std::move(StubOrErr.get()); + // Change SoName before emitting stubs. + if (SOName.getNumOccurrences() == 1) { + TargetStub->SoName = SOName; + } + // Write out .tbe file. if (EmitTBE.getNumOccurrences() == 1) { TargetStub->TbeVersion = TBEVersionCurrent; - if (SOName.getNumOccurrences() == 1) { - TargetStub->SoName = SOName; - } Error TBEWriteError = writeTBE(EmitTBE, *TargetStub); if (TBEWriteError) { WithColor::error() << TBEWriteError << "\n"; exit(1); } } + + // Write out binary ELF stub. + if (BinaryOutputFilePath.getNumOccurrences() == 1) { + if (BinaryOutputTarget.getNumOccurrences() == 0) { + WithColor::error() << "No binary output target specified.\n"; + exit(1); + } + Error BinaryWriteError = writeBinaryStub(BinaryOutputFilePath, *TargetStub, + BinaryOutputTarget); + if (BinaryWriteError) { + WithColor::error() << BinaryWriteError << "\n"; + exit(1); + } + } }