| # |
| # SPDX-License-Identifier: GPL-2.0-only |
| # |
| |
| import os, struct, mmap |
| |
| class NotELFFileError(Exception): |
| pass |
| |
| class ELFFile: |
| EI_NIDENT = 16 |
| |
| EI_CLASS = 4 |
| EI_DATA = 5 |
| EI_VERSION = 6 |
| EI_OSABI = 7 |
| EI_ABIVERSION = 8 |
| |
| E_MACHINE = 0x12 |
| |
| # possible values for EI_CLASS |
| ELFCLASSNONE = 0 |
| ELFCLASS32 = 1 |
| ELFCLASS64 = 2 |
| |
| # possible value for EI_VERSION |
| EV_CURRENT = 1 |
| |
| # possible values for EI_DATA |
| EI_DATA_NONE = 0 |
| EI_DATA_LSB = 1 |
| EI_DATA_MSB = 2 |
| |
| PT_INTERP = 3 |
| |
| def my_assert(self, expectation, result): |
| if not expectation == result: |
| #print "'%x','%x' %s" % (ord(expectation), ord(result), self.name) |
| raise NotELFFileError("%s is not an ELF" % self.name) |
| |
| def __init__(self, name): |
| self.name = name |
| self.objdump_output = {} |
| self.data = None |
| |
| # Context Manager functions to close the mmap explicitly |
| def __enter__(self): |
| return self |
| |
| def __exit__(self, exc_type, exc_value, traceback): |
| self.close() |
| |
| def close(self): |
| if self.data: |
| self.data.close() |
| |
| def open(self): |
| with open(self.name, "rb") as f: |
| try: |
| self.data = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ) |
| except ValueError: |
| # This means the file is empty |
| raise NotELFFileError("%s is empty" % self.name) |
| |
| # Check the file has the minimum number of ELF table entries |
| if len(self.data) < ELFFile.EI_NIDENT + 4: |
| raise NotELFFileError("%s is not an ELF" % self.name) |
| |
| # ELF header |
| self.my_assert(self.data[0], 0x7f) |
| self.my_assert(self.data[1], ord('E')) |
| self.my_assert(self.data[2], ord('L')) |
| self.my_assert(self.data[3], ord('F')) |
| if self.data[ELFFile.EI_CLASS] == ELFFile.ELFCLASS32: |
| self.bits = 32 |
| elif self.data[ELFFile.EI_CLASS] == ELFFile.ELFCLASS64: |
| self.bits = 64 |
| else: |
| # Not 32-bit or 64.. lets assert |
| raise NotELFFileError("ELF but not 32 or 64 bit.") |
| self.my_assert(self.data[ELFFile.EI_VERSION], ELFFile.EV_CURRENT) |
| |
| self.endian = self.data[ELFFile.EI_DATA] |
| if self.endian not in (ELFFile.EI_DATA_LSB, ELFFile.EI_DATA_MSB): |
| raise NotELFFileError("Unexpected EI_DATA %x" % self.endian) |
| |
| def osAbi(self): |
| return self.data[ELFFile.EI_OSABI] |
| |
| def abiVersion(self): |
| return self.data[ELFFile.EI_ABIVERSION] |
| |
| def abiSize(self): |
| return self.bits |
| |
| def isLittleEndian(self): |
| return self.endian == ELFFile.EI_DATA_LSB |
| |
| def isBigEndian(self): |
| return self.endian == ELFFile.EI_DATA_MSB |
| |
| def getStructEndian(self): |
| return {ELFFile.EI_DATA_LSB: "<", |
| ELFFile.EI_DATA_MSB: ">"}[self.endian] |
| |
| def getShort(self, offset): |
| return struct.unpack_from(self.getStructEndian() + "H", self.data, offset)[0] |
| |
| def getWord(self, offset): |
| return struct.unpack_from(self.getStructEndian() + "i", self.data, offset)[0] |
| |
| def isDynamic(self): |
| """ |
| Return True if there is a .interp segment (therefore dynamically |
| linked), otherwise False (statically linked). |
| """ |
| offset = self.getWord(self.bits == 32 and 0x1C or 0x20) |
| size = self.getShort(self.bits == 32 and 0x2A or 0x36) |
| count = self.getShort(self.bits == 32 and 0x2C or 0x38) |
| |
| for i in range(0, count): |
| p_type = self.getWord(offset + i * size) |
| if p_type == ELFFile.PT_INTERP: |
| return True |
| return False |
| |
| def machine(self): |
| """ |
| We know the endian stored in self.endian and we |
| know the position |
| """ |
| return self.getShort(ELFFile.E_MACHINE) |
| |
| def set_objdump(self, cmd, output): |
| self.objdump_output[cmd] = output |
| |
| def run_objdump(self, cmd, d): |
| import bb.process |
| import sys |
| |
| if cmd in self.objdump_output: |
| return self.objdump_output[cmd] |
| |
| objdump = d.getVar('OBJDUMP') |
| |
| env = os.environ.copy() |
| env["LC_ALL"] = "C" |
| env["PATH"] = d.getVar('PATH') |
| |
| try: |
| bb.note("%s %s %s" % (objdump, cmd, self.name)) |
| self.objdump_output[cmd] = bb.process.run([objdump, cmd, self.name], env=env, shell=False)[0] |
| return self.objdump_output[cmd] |
| except Exception as e: |
| bb.note("%s %s %s failed: %s" % (objdump, cmd, self.name, e)) |
| return "" |
| |
| def elf_machine_to_string(machine): |
| """ |
| Return the name of a given ELF e_machine field or the hex value as a string |
| if it isn't recognised. |
| """ |
| try: |
| return { |
| 0x00: "Unset", |
| 0x02: "SPARC", |
| 0x03: "x86", |
| 0x08: "MIPS", |
| 0x14: "PowerPC", |
| 0x28: "ARM", |
| 0x2A: "SuperH", |
| 0x32: "IA-64", |
| 0x3E: "x86-64", |
| 0xB7: "AArch64", |
| 0xF7: "BPF" |
| }[machine] |
| except: |
| return "Unknown (%s)" % repr(machine) |
| |
| def write_error(type, error, d): |
| logfile = d.getVar('QA_LOGFILE') |
| if logfile: |
| p = d.getVar('P') |
| with open(logfile, "a+") as f: |
| f.write("%s: %s [%s]\n" % (p, error, type)) |
| |
| def handle_error(error_class, error_msg, d): |
| if error_class in (d.getVar("ERROR_QA") or "").split(): |
| write_error(error_class, error_msg, d) |
| bb.error("QA Issue: %s [%s]" % (error_msg, error_class)) |
| d.setVar("QA_ERRORS_FOUND", "True") |
| return False |
| elif error_class in (d.getVar("WARN_QA") or "").split(): |
| write_error(error_class, error_msg, d) |
| bb.warn("QA Issue: %s [%s]" % (error_msg, error_class)) |
| else: |
| bb.note("QA Issue: %s [%s]" % (error_msg, error_class)) |
| return True |
| |
| def add_message(messages, section, new_msg): |
| if section not in messages: |
| messages[section] = new_msg |
| else: |
| messages[section] = messages[section] + "\n" + new_msg |
| |
| def exit_with_message_if_errors(message, d): |
| qa_fatal_errors = bb.utils.to_boolean(d.getVar("QA_ERRORS_FOUND"), False) |
| if qa_fatal_errors: |
| bb.fatal(message) |
| |
| def exit_if_errors(d): |
| exit_with_message_if_errors("Fatal QA errors were found, failing task.", d) |
| |
| if __name__ == "__main__": |
| import sys |
| |
| with ELFFile(sys.argv[1]) as elf: |
| elf.open() |
| print(elf.isDynamic()) |