diff options
Diffstat (limited to 'tools')
| -rwxr-xr-x | tools/check-efi-alignment.py | 32 | ||||
| -rwxr-xr-x | tools/elf2efi.py | 252 |
2 files changed, 164 insertions, 120 deletions
diff --git a/tools/check-efi-alignment.py b/tools/check-efi-alignment.py new file mode 100755 index 0000000..bb33ac0 --- /dev/null +++ b/tools/check-efi-alignment.py @@ -0,0 +1,32 @@ +#!/usr/bin/python3 +# SPDX-License-Identifier: LGPL-2.1-or-later +# vi: set tw=110 sw=4 ts=4 et: + +import sys + +import pefile + + +def main(): + pe = pefile.PE(sys.argv[1], fast_load=True) + + for section in pe.sections: + name = section.Name.rstrip(b"\x00").decode() + file_addr = section.PointerToRawData + virt_addr = section.VirtualAddress + print(f"{name:10s} file=0x{file_addr:08x} virt=0x{virt_addr:08x}") + + if file_addr % 512 != 0: + print(f"File address of {name} section is not aligned to 512 bytes", file=sys.stderr) + return 1 + + if virt_addr % 512 != 0: + print(f"Virt address of {name} section is not aligned to 512 bytes", file=sys.stderr) + return 1 + +if __name__ == '__main__': + if len(sys.argv) != 2: + print(f"Usage: {sys.argv[0]} pe-image") + sys.exit(1) + + sys.exit(main()) diff --git a/tools/elf2efi.py b/tools/elf2efi.py index 54f64fa..cb1a284 100755 --- a/tools/elf2efi.py +++ b/tools/elf2efi.py @@ -26,6 +26,7 @@ import hashlib import io import os import pathlib +import sys import time import typing from ctypes import ( @@ -55,26 +56,26 @@ from elftools.elf.relocation import ( class PeCoffHeader(LittleEndianStructure): _fields_ = ( - ("Machine", c_uint16), - ("NumberOfSections", c_uint16), - ("TimeDateStamp", c_uint32), + ("Machine", c_uint16), + ("NumberOfSections", c_uint16), + ("TimeDateStamp", c_uint32), ("PointerToSymbolTable", c_uint32), - ("NumberOfSymbols", c_uint32), + ("NumberOfSymbols", c_uint32), ("SizeOfOptionalHeader", c_uint16), - ("Characteristics", c_uint16), + ("Characteristics", c_uint16), ) class PeDataDirectory(LittleEndianStructure): _fields_ = ( ("VirtualAddress", c_uint32), - ("Size", c_uint32), + ("Size", c_uint32), ) class PeRelocationBlock(LittleEndianStructure): _fields_ = ( - ("PageRVA", c_uint32), + ("PageRVA", c_uint32), ("BlockSize", c_uint32), ) @@ -86,62 +87,62 @@ class PeRelocationBlock(LittleEndianStructure): class PeRelocationEntry(LittleEndianStructure): _fields_ = ( ("Offset", c_uint16, 12), - ("Type", c_uint16, 4), + ("Type", c_uint16, 4), ) class PeOptionalHeaderStart(LittleEndianStructure): _fields_ = ( - ("Magic", c_uint16), - ("MajorLinkerVersion", c_uint8), - ("MinorLinkerVersion", c_uint8), - ("SizeOfCode", c_uint32), - ("SizeOfInitializedData", c_uint32), + ("Magic", c_uint16), + ("MajorLinkerVersion", c_uint8), + ("MinorLinkerVersion", c_uint8), + ("SizeOfCode", c_uint32), + ("SizeOfInitializedData", c_uint32), ("SizeOfUninitializedData", c_uint32), - ("AddressOfEntryPoint", c_uint32), - ("BaseOfCode", c_uint32), + ("AddressOfEntryPoint", c_uint32), + ("BaseOfCode", c_uint32), ) class PeOptionalHeaderMiddle(LittleEndianStructure): _fields_ = ( - ("SectionAlignment", c_uint32), - ("FileAlignment", c_uint32), + ("SectionAlignment", c_uint32), + ("FileAlignment", c_uint32), ("MajorOperatingSystemVersion", c_uint16), ("MinorOperatingSystemVersion", c_uint16), - ("MajorImageVersion", c_uint16), - ("MinorImageVersion", c_uint16), - ("MajorSubsystemVersion", c_uint16), - ("MinorSubsystemVersion", c_uint16), - ("Win32VersionValue", c_uint32), - ("SizeOfImage", c_uint32), - ("SizeOfHeaders", c_uint32), - ("CheckSum", c_uint32), - ("Subsystem", c_uint16), - ("DllCharacteristics", c_uint16), + ("MajorImageVersion", c_uint16), + ("MinorImageVersion", c_uint16), + ("MajorSubsystemVersion", c_uint16), + ("MinorSubsystemVersion", c_uint16), + ("Win32VersionValue", c_uint32), + ("SizeOfImage", c_uint32), + ("SizeOfHeaders", c_uint32), + ("CheckSum", c_uint32), + ("Subsystem", c_uint16), + ("DllCharacteristics", c_uint16), ) class PeOptionalHeaderEnd(LittleEndianStructure): _fields_ = ( - ("LoaderFlags", c_uint32), - ("NumberOfRvaAndSizes", c_uint32), - ("ExportTable", PeDataDirectory), - ("ImportTable", PeDataDirectory), - ("ResourceTable", PeDataDirectory), - ("ExceptionTable", PeDataDirectory), - ("CertificateTable", PeDataDirectory), - ("BaseRelocationTable", PeDataDirectory), - ("Debug", PeDataDirectory), - ("Architecture", PeDataDirectory), - ("GlobalPtr", PeDataDirectory), - ("TLSTable", PeDataDirectory), - ("LoadConfigTable", PeDataDirectory), - ("BoundImport", PeDataDirectory), - ("IAT", PeDataDirectory), + ("LoaderFlags", c_uint32), + ("NumberOfRvaAndSizes", c_uint32), + ("ExportTable", PeDataDirectory), + ("ImportTable", PeDataDirectory), + ("ResourceTable", PeDataDirectory), + ("ExceptionTable", PeDataDirectory), + ("CertificateTable", PeDataDirectory), + ("BaseRelocationTable", PeDataDirectory), + ("Debug", PeDataDirectory), + ("Architecture", PeDataDirectory), + ("GlobalPtr", PeDataDirectory), + ("TLSTable", PeDataDirectory), + ("LoadConfigTable", PeDataDirectory), + ("BoundImport", PeDataDirectory), + ("IAT", PeDataDirectory), ("DelayImportDescriptor", PeDataDirectory), - ("CLRRuntimeHeader", PeDataDirectory), - ("Reserved", PeDataDirectory), + ("CLRRuntimeHeader", PeDataDirectory), + ("Reserved", PeDataDirectory), ) @@ -152,44 +153,44 @@ class PeOptionalHeader(LittleEndianStructure): class PeOptionalHeader32(PeOptionalHeader): _anonymous_ = ("Start", "Middle", "End") _fields_ = ( - ("Start", PeOptionalHeaderStart), - ("BaseOfData", c_uint32), - ("ImageBase", c_uint32), - ("Middle", PeOptionalHeaderMiddle), + ("Start", PeOptionalHeaderStart), + ("BaseOfData", c_uint32), + ("ImageBase", c_uint32), + ("Middle", PeOptionalHeaderMiddle), ("SizeOfStackReserve", c_uint32), - ("SizeOfStackCommit", c_uint32), - ("SizeOfHeapReserve", c_uint32), - ("SizeOfHeapCommit", c_uint32), - ("End", PeOptionalHeaderEnd), + ("SizeOfStackCommit", c_uint32), + ("SizeOfHeapReserve", c_uint32), + ("SizeOfHeapCommit", c_uint32), + ("End", PeOptionalHeaderEnd), ) class PeOptionalHeader32Plus(PeOptionalHeader): _anonymous_ = ("Start", "Middle", "End") _fields_ = ( - ("Start", PeOptionalHeaderStart), - ("ImageBase", c_uint64), - ("Middle", PeOptionalHeaderMiddle), + ("Start", PeOptionalHeaderStart), + ("ImageBase", c_uint64), + ("Middle", PeOptionalHeaderMiddle), ("SizeOfStackReserve", c_uint64), - ("SizeOfStackCommit", c_uint64), - ("SizeOfHeapReserve", c_uint64), - ("SizeOfHeapCommit", c_uint64), - ("End", PeOptionalHeaderEnd), + ("SizeOfStackCommit", c_uint64), + ("SizeOfHeapReserve", c_uint64), + ("SizeOfHeapCommit", c_uint64), + ("End", PeOptionalHeaderEnd), ) class PeSection(LittleEndianStructure): _fields_ = ( - ("Name", c_char * 8), - ("VirtualSize", c_uint32), - ("VirtualAddress", c_uint32), - ("SizeOfRawData", c_uint32), - ("PointerToRawData", c_uint32), + ("Name", c_char * 8), + ("VirtualSize", c_uint32), + ("VirtualAddress", c_uint32), + ("SizeOfRawData", c_uint32), + ("PointerToRawData", c_uint32), ("PointerToRelocations", c_uint32), ("PointerToLinenumbers", c_uint32), - ("NumberOfRelocations", c_uint16), - ("NumberOfLinenumbers", c_uint16), - ("Characteristics", c_uint32), + ("NumberOfRelocations", c_uint16), + ("NumberOfLinenumbers", c_uint16), + ("Characteristics", c_uint32), ) def __init__(self): @@ -206,12 +207,13 @@ assert sizeof(PeOptionalHeader32Plus) == 240 PE_CHARACTERISTICS_RX = 0x60000020 # CNT_CODE|MEM_READ|MEM_EXECUTE PE_CHARACTERISTICS_RW = 0xC0000040 # CNT_INITIALIZED_DATA|MEM_READ|MEM_WRITE -PE_CHARACTERISTICS_R = 0x40000040 # CNT_INITIALIZED_DATA|MEM_READ +PE_CHARACTERISTICS_R = 0x40000040 # CNT_INITIALIZED_DATA|MEM_READ IGNORE_SECTIONS = [ ".eh_frame", ".eh_frame_hdr", ".ARM.exidx", + ".relro_padding", ] IGNORE_SECTION_TYPES = [ @@ -246,9 +248,12 @@ def align_down(x: int, align: int) -> int: def next_section_address(sections: typing.List[PeSection]) -> int: - return align_to( - sections[-1].VirtualAddress + sections[-1].VirtualSize, SECTION_ALIGNMENT - ) + return align_to(sections[-1].VirtualAddress + sections[-1].VirtualSize, + SECTION_ALIGNMENT) + + +class BadSectionError(ValueError): + "One of the sections is in a bad state" def iter_copy_sections(elf: ELFFile) -> typing.Iterator[PeSection]: @@ -261,8 +266,9 @@ def iter_copy_sections(elf: ELFFile) -> typing.Iterator[PeSection]: relro = None for elf_seg in elf.iter_segments(): if elf_seg["p_type"] == "PT_LOAD" and elf_seg["p_align"] != SECTION_ALIGNMENT: - raise RuntimeError("ELF segments are not properly aligned.") - elif elf_seg["p_type"] == "PT_GNU_RELRO": + raise BadSectionError(f"ELF segment {elf_seg['p_type']} is not properly aligned" + f" ({elf_seg['p_align']} != {SECTION_ALIGNMENT})") + if elf_seg["p_type"] == "PT_GNU_RELRO": relro = elf_seg for elf_s in elf.iter_sections(): @@ -270,10 +276,14 @@ def iter_copy_sections(elf: ELFFile) -> typing.Iterator[PeSection]: elf_s["sh_flags"] & SH_FLAGS.SHF_ALLOC == 0 or elf_s["sh_type"] in IGNORE_SECTION_TYPES or elf_s.name in IGNORE_SECTIONS + or elf_s["sh_size"] == 0 ): continue if elf_s["sh_type"] not in ["SHT_PROGBITS", "SHT_NOBITS"]: - raise RuntimeError(f"Unknown section {elf_s.name}.") + raise BadSectionError(f"Unknown section {elf_s.name} with type {elf_s['sh_type']}") + if elf_s.name == '.got': + # FIXME: figure out why those sections are inserted + print("WARNING: Non-empty .got section", file=sys.stderr) if elf_s["sh_flags"] & SH_FLAGS.SHF_EXECINSTR: rwx = PE_CHARACTERISTICS_RX @@ -305,7 +315,7 @@ def iter_copy_sections(elf: ELFFile) -> typing.Iterator[PeSection]: def convert_sections(elf: ELFFile, opt: PeOptionalHeader) -> typing.List[PeSection]: - last_vma = 0 + last_vma = (0, 0) sections = [] for pe_s in iter_copy_sections(elf): @@ -325,10 +335,11 @@ def convert_sections(elf: ELFFile, opt: PeOptionalHeader) -> typing.List[PeSecti PE_CHARACTERISTICS_R: b".rodata", }[pe_s.Characteristics] - # This can happen if not building with `-z separate-code`. - if pe_s.VirtualAddress < last_vma: - raise RuntimeError("Overlapping PE sections.") - last_vma = pe_s.VirtualAddress + pe_s.VirtualSize + # This can happen if not building with '-z separate-code'. + if pe_s.VirtualAddress < sum(last_vma): + raise BadSectionError(f"Section {pe_s.Name.decode()!r} @0x{pe_s.VirtualAddress:x} overlaps" + f" previous section @0x{last_vma[0]:x}+0x{last_vma[1]:x}=@0x{sum(last_vma):x}") + last_vma = (pe_s.VirtualAddress, pe_s.VirtualSize) if pe_s.Name == b".text": opt.BaseOfCode = pe_s.VirtualAddress @@ -355,9 +366,9 @@ def copy_sections( if not elf_s: continue if elf_s.data_alignment > 1 and SECTION_ALIGNMENT % elf_s.data_alignment != 0: - raise RuntimeError(f"ELF section {name} is not aligned.") + raise BadSectionError(f"ELF section {name} is not aligned") if elf_s["sh_flags"] & (SH_FLAGS.SHF_EXECINSTR | SH_FLAGS.SHF_WRITE) != 0: - raise RuntimeError(f"ELF section {name} is not read-only data.") + raise BadSectionError(f"ELF section {name} is not read-only data") pe_s = PeSection() pe_s.Name = name.encode() @@ -376,12 +387,8 @@ def apply_elf_relative_relocation( sections: typing.List[PeSection], addend_size: int, ): - # fmt: off - [target] = [ - pe_s for pe_s in sections - if pe_s.VirtualAddress <= reloc["r_offset"] < pe_s.VirtualAddress + len(pe_s.data) - ] - # fmt: on + [target] = [pe_s for pe_s in sections + if pe_s.VirtualAddress <= reloc["r_offset"] < pe_s.VirtualAddress + len(pe_s.data)] addend_offset = reloc["r_offset"] - target.VirtualAddress @@ -425,9 +432,10 @@ def convert_elf_reloc_table( continue if reloc["r_info_type"] == RELATIVE_RELOC: - apply_elf_relative_relocation( - reloc, elf_image_base, sections, elf.elfclass // 8 - ) + apply_elf_relative_relocation(reloc, + elf_image_base, + sections, + elf.elfclass // 8) # Now that the ELF relocation has been applied, we can create a PE relocation. block_rva = reloc["r_offset"] & ~0xFFF @@ -442,7 +450,7 @@ def convert_elf_reloc_table( continue - raise RuntimeError(f"Unsupported relocation {reloc}") + raise BadSectionError(f"Unsupported relocation {reloc}") def convert_elf_relocations( @@ -453,27 +461,25 @@ def convert_elf_relocations( ) -> typing.Optional[PeSection]: dynamic = elf.get_section_by_name(".dynamic") if dynamic is None: - raise RuntimeError("ELF .dynamic section is missing.") + raise BadSectionError("ELF .dynamic section is missing") [flags_tag] = dynamic.iter_tags("DT_FLAGS_1") if not flags_tag["d_val"] & ENUM_DT_FLAGS_1["DF_1_PIE"]: - raise RuntimeError("ELF file is not a PIE.") + raise ValueError("ELF file is not a PIE") # This checks that the ELF image base is 0. symtab = elf.get_section_by_name(".symtab") if symtab: exe_start = symtab.get_symbol_by_name("__executable_start") if exe_start and exe_start[0]["st_value"] != 0: - raise RuntimeError("Unexpected ELF image base.") - - opt.SizeOfHeaders = align_to( - PE_OFFSET - + len(PE_MAGIC) - + sizeof(PeCoffHeader) - + sizeof(opt) - + sizeof(PeSection) * max(len(sections) + 1, minimum_sections), - FILE_ALIGNMENT, - ) + raise ValueError("Unexpected ELF image base") + + opt.SizeOfHeaders = align_to(PE_OFFSET + + len(PE_MAGIC) + + sizeof(PeCoffHeader) + + sizeof(opt) + + sizeof(PeSection) * max(len(sections) + 1, minimum_sections), + FILE_ALIGNMENT) # We use the basic VMA layout from the ELF image in the PE image. This could cause the first # section to overlap the PE image headers during runtime at VMA 0. We can simply apply a fixed @@ -482,9 +488,8 @@ def convert_elf_relocations( # the ELF portions of the image. segment_offset = 0 if sections[0].VirtualAddress < opt.SizeOfHeaders: - segment_offset = align_to( - opt.SizeOfHeaders - sections[0].VirtualAddress, SECTION_ALIGNMENT - ) + segment_offset = align_to(opt.SizeOfHeaders - sections[0].VirtualAddress, + SECTION_ALIGNMENT) opt.AddressOfEntryPoint = elf["e_entry"] + segment_offset opt.BaseOfCode += segment_offset @@ -494,10 +499,12 @@ def convert_elf_relocations( pe_reloc_blocks: typing.Dict[int, PeRelocationBlock] = {} for reloc_type, reloc_table in dynamic.get_relocation_tables().items(): if reloc_type not in ["REL", "RELA"]: - raise RuntimeError("Unsupported relocation type {elf_reloc_type}.") - convert_elf_reloc_table( - elf, reloc_table, opt.ImageBase + segment_offset, sections, pe_reloc_blocks - ) + raise BadSectionError(f"Unsupported relocation type {reloc_type}") + convert_elf_reloc_table(elf, + reloc_table, + opt.ImageBase + segment_offset, + sections, + pe_reloc_blocks) for pe_s in sections: pe_s.VirtualAddress += segment_offset @@ -517,9 +524,7 @@ def convert_elf_relocations( block.entries.append(PeRelocationEntry()) block.PageRVA += segment_offset - block.BlockSize = ( - sizeof(PeRelocationBlock) + sizeof(PeRelocationEntry) * n_relocs - ) + block.BlockSize = sizeof(PeRelocationBlock) + sizeof(PeRelocationEntry) * n_relocs data += block for entry in sorted(block.entries, key=lambda e: e.Offset): data += entry @@ -539,7 +544,10 @@ def convert_elf_relocations( def write_pe( - file, coff: PeCoffHeader, opt: PeOptionalHeader, sections: typing.List[PeSection] + file, + coff: PeCoffHeader, + opt: PeOptionalHeader, + sections: typing.List[PeSection], ): file.write(b"MZ") file.seek(0x3C, io.SEEK_SET) @@ -552,8 +560,8 @@ def write_pe( offset = opt.SizeOfHeaders for pe_s in sorted(sections, key=lambda s: s.VirtualAddress): if pe_s.VirtualAddress < opt.SizeOfHeaders: - # Linker script should make sure this does not happen. - raise RuntimeError(f"Section {pe_s.Name} overlapping PE headers.") + raise BadSectionError(f"Section {pe_s.Name} @0x{pe_s.VirtualAddress:x} overlaps" + " PE headers ending at 0x{opt.SizeOfHeaders:x}") pe_s.PointerToRawData = offset file.write(pe_s) @@ -571,9 +579,9 @@ def write_pe( def elf2efi(args: argparse.Namespace): elf = ELFFile(args.ELF) if not elf.little_endian: - raise RuntimeError("ELF file is not little-endian.") + raise ValueError("ELF file is not little-endian") if elf["e_type"] not in ["ET_DYN", "ET_EXEC"]: - raise RuntimeError("Unsupported ELF type.") + raise ValueError(f"Unsupported ELF type {elf['e_type']}") pe_arch = { "EM_386": 0x014C, @@ -584,7 +592,7 @@ def elf2efi(args: argparse.Namespace): "EM_X86_64": 0x8664, }.get(elf["e_machine"]) if pe_arch is None: - raise RuntimeError(f"Unsupported ELF arch {elf['e_machine']}") + raise ValueError(f"Unsupported ELF architecture {elf['e_machine']}") coff = PeCoffHeader() opt = PeOptionalHeader32() if elf.elfclass == 32 else PeOptionalHeader32Plus() @@ -637,7 +645,7 @@ def elf2efi(args: argparse.Namespace): write_pe(args.PE, coff, opt, sections) -def main(): +def create_parser() -> argparse.ArgumentParser: parser = argparse.ArgumentParser(description="Convert ELF binaries to PE/EFI") parser.add_argument( "--version-major", @@ -691,7 +699,11 @@ def main(): default="", help="Copy these sections if found", ) + return parser + +def main(): + parser = create_parser() elf2efi(parser.parse_args()) |