mirror of
https://github.com/JakeHillion/drgn.git
synced 2024-12-23 09:43:06 +00:00
Bring back ElfFile
Instead of constructing DwarfFile with a dict of sections, pass in an ElfFile.
This commit is contained in:
Omar Sandoval
parent
68ebade7fa
commit
0adac0747c
@ -476,7 +476,7 @@ PyInit_corereader(void)
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PyObject *name;
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PyObject *m;
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name = PyUnicode_FromString("drgn.dwarf");
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name = PyUnicode_FromString("drgn.elf");
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if (!name)
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return NULL;
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@ -10,6 +10,8 @@ from typing import (
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Dict, Iterator, List, NamedTuple, Optional, Sequence, Text, Tuple, Union,
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)
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from drgn.elf import ElfFile
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class DW_AT(enum.IntEnum):
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sibling = 0x1
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@ -584,10 +586,6 @@ class DwarfAttribNotFoundError(Exception):
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pass
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class ElfFormatError(Exception):
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pass
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class _Reader:
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s8 = struct.Struct('b')
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u8 = struct.Struct('B')
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@ -666,8 +664,23 @@ class _Reader:
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class DwarfFile:
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def __init__(self, sections: Dict[str, bytes]) -> None:
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self.sections = sections
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_SECTIONS = [
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'.debug_abbrev',
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'.debug_info',
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'.debug_line',
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'.debug_str',
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]
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def __init__(self, elf_file: ElfFile) -> None:
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self.elf_file = elf_file
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self.sections: Dict[str, bytes] = {}
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for section in DwarfFile._SECTIONS:
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try:
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shdr = self.elf_file.sections[section]
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except KeyError:
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continue
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data = self.elf_file.data[shdr.sh_offset:shdr.sh_offset + shdr.sh_size]
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self.sections[section] = data
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def _get_section_reader(self, name: str) -> _Reader:
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try:
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@ -80,6 +80,7 @@ enum {
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static PyObject *DwarfFile;
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static PyObject *DwarfFormatError;
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static PyObject *ElfFile;
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static PyObject *ElfFormatError;
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#define DIE_HASH_SHIFT 17
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@ -1799,36 +1800,21 @@ err:
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static PyObject *create_file_object(DwarfIndex *self, struct file *file)
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{
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PyObject *file_obj = NULL;
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PyObject *sections;
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int i;
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PyObject *mview, *elf_file, *dwarf_file;
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sections = PyDict_New();
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if (!sections)
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/* XXX: need to reference count self */
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mview = PyMemoryView_FromMemory(file->map, file->size, PyBUF_READ);
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if (!mview)
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return NULL;
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for (i = 0; i < NUM_DEBUG_SECTIONS; i++) {
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PyObject *mview;
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elf_file = PyObject_CallFunctionObjArgs(ElfFile, mview, NULL);
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Py_DECREF(mview);
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if (!elf_file)
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return NULL;
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/* XXX: need to reference count self */
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mview = PyMemoryView_FromMemory(file->debug_sections[i].buffer,
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file->debug_sections[i].size,
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PyBUF_READ);
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if (!mview)
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goto out;
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if (PyDict_SetItemString(sections, section_names[i],
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mview) == -1) {
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Py_DECREF(mview);
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goto out;
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}
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Py_DECREF(mview);
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}
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file_obj = PyObject_CallFunctionObjArgs(DwarfFile, sections, NULL);
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out:
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Py_DECREF(sections);
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return file_obj;
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dwarf_file = PyObject_CallFunctionObjArgs(DwarfFile, elf_file, NULL);
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Py_DECREF(elf_file);
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return dwarf_file;
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}
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static PyObject *die_object_from_entry(DwarfIndex *self, struct die_hash_entry *entry)
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@ -2033,6 +2019,24 @@ PyInit_dwarfindex(void)
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Py_DECREF(m);
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return NULL;
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}
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Py_DECREF(m);
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name = PyUnicode_FromString("drgn.elf");
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if (!name)
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return NULL;
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m = PyImport_Import(name);
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Py_DECREF(name);
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if (!m)
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return NULL;
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ElfFile = PyObject_GetAttrString(m, "ElfFile");
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if (!ElfFile) {
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Py_DECREF(m);
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return NULL;
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}
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ElfFormatError = PyObject_GetAttrString(m, "ElfFormatError");
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if (!ElfFormatError) {
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Py_DECREF(m);
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289
drgn/elf.py
Normal file
289
drgn/elf.py
Normal file
@ -0,0 +1,289 @@
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# Copyright 2018 - Omar Sandoval
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# SPDX-License-Identifier: GPL-3.0+
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from collections import namedtuple
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import struct
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from typing import Dict, List, NamedTuple, Optional, Tuple, Union
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# Automatically generated from elf.h
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EI_NIDENT = (16)
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EI_MAG0 = 0
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ELFMAG0 = 0x7f
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EI_MAG1 = 1
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ELFMAG1 = 0x45
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EI_MAG2 = 2
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ELFMAG2 = 0x4c
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EI_MAG3 = 3
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ELFMAG3 = 0x46
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EI_CLASS = 4
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ELFCLASSNONE = 0
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ELFCLASS32 = 1
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ELFCLASS64 = 2
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ELFCLASSNUM = 3
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EI_DATA = 5
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ELFDATANONE = 0
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ELFDATA2LSB = 1
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ELFDATA2MSB = 2
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ELFDATANUM = 3
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EI_VERSION = 6
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EI_OSABI = 7
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EI_ABIVERSION = 8
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EI_PAD = 9
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EV_NONE = 0
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EV_CURRENT = 1
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EV_NUM = 2
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SHN_UNDEF = 0
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SHN_LORESERVE = 0xff00
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SHN_LOPROC = 0xff00
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SHN_BEFORE = 0xff00
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SHN_AFTER = 0xff01
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SHN_HIPROC = 0xff1f
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SHN_LOOS = 0xff20
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SHN_HIOS = 0xff3f
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SHN_ABS = 0xfff1
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SHN_COMMON = 0xfff2
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SHN_XINDEX = 0xffff
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SHN_HIRESERVE = 0xffff
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SHT_NULL = 0
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SHT_PROGBITS = 1
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SHT_SYMTAB = 2
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SHT_STRTAB = 3
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SHT_RELA = 4
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SHT_HASH = 5
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SHT_DYNAMIC = 6
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SHT_NOTE = 7
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SHT_NOBITS = 8
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SHT_REL = 9
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SHT_SHLIB = 10
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SHT_DYNSYM = 11
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SHT_INIT_ARRAY = 14
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SHT_FINI_ARRAY = 15
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SHT_PREINIT_ARRAY = 16
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SHT_GROUP = 17
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SHT_SYMTAB_SHNDX = 18
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SHT_NUM = 19
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SHT_LOOS = 0x60000000
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SHT_GNU_ATTRIBUTES = 0x6ffffff5
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SHT_GNU_HASH = 0x6ffffff6
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SHT_GNU_LIBLIST = 0x6ffffff7
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SHT_CHECKSUM = 0x6ffffff8
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SHT_LOSUNW = 0x6ffffffa
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SHT_SUNW_move = 0x6ffffffa
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SHT_SUNW_COMDAT = 0x6ffffffb
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SHT_SUNW_syminfo = 0x6ffffffc
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SHT_GNU_verdef = 0x6ffffffd
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SHT_GNU_verneed = 0x6ffffffe
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SHT_GNU_versym = 0x6fffffff
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SHT_HISUNW = 0x6fffffff
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SHT_HIOS = 0x6fffffff
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SHT_LOPROC = 0x70000000
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SHT_HIPROC = 0x7fffffff
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SHT_LOUSER = 0x80000000
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SHT_HIUSER = 0x8fffffff
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SHN_MIPS_ACOMMON = 0xff00
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SHN_MIPS_TEXT = 0xff01
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SHN_MIPS_DATA = 0xff02
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SHN_MIPS_SCOMMON = 0xff03
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SHN_MIPS_SUNDEFINED = 0xff04
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SHT_MIPS_LIBLIST = 0x70000000
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SHT_MIPS_MSYM = 0x70000001
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SHT_MIPS_CONFLICT = 0x70000002
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SHT_MIPS_GPTAB = 0x70000003
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SHT_MIPS_UCODE = 0x70000004
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SHT_MIPS_DEBUG = 0x70000005
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SHT_MIPS_REGINFO = 0x70000006
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SHT_MIPS_PACKAGE = 0x70000007
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SHT_MIPS_PACKSYM = 0x70000008
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SHT_MIPS_RELD = 0x70000009
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SHT_MIPS_IFACE = 0x7000000b
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SHT_MIPS_CONTENT = 0x7000000c
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SHT_MIPS_OPTIONS = 0x7000000d
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SHT_MIPS_SHDR = 0x70000010
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SHT_MIPS_FDESC = 0x70000011
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SHT_MIPS_EXTSYM = 0x70000012
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SHT_MIPS_DENSE = 0x70000013
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SHT_MIPS_PDESC = 0x70000014
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SHT_MIPS_LOCSYM = 0x70000015
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SHT_MIPS_AUXSYM = 0x70000016
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SHT_MIPS_OPTSYM = 0x70000017
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SHT_MIPS_LOCSTR = 0x70000018
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SHT_MIPS_LINE = 0x70000019
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SHT_MIPS_RFDESC = 0x7000001a
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SHT_MIPS_DELTASYM = 0x7000001b
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SHT_MIPS_DELTAINST = 0x7000001c
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SHT_MIPS_DELTACLASS = 0x7000001d
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SHT_MIPS_DWARF = 0x7000001e
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SHT_MIPS_DELTADECL = 0x7000001f
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SHT_MIPS_SYMBOL_LIB = 0x70000020
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SHT_MIPS_EVENTS = 0x70000021
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SHT_MIPS_TRANSLATE = 0x70000022
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SHT_MIPS_PIXIE = 0x70000023
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SHT_MIPS_XLATE = 0x70000024
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SHT_MIPS_XLATE_DEBUG = 0x70000025
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SHT_MIPS_WHIRL = 0x70000026
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SHT_MIPS_EH_REGION = 0x70000027
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SHT_MIPS_XLATE_OLD = 0x70000028
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SHT_MIPS_PDR_EXCEPTION = 0x70000029
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SHN_PARISC_ANSI_COMMON = 0xff00
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SHN_PARISC_HUGE_COMMON = 0xff01
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SHT_PARISC_EXT = 0x70000000
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SHT_PARISC_UNWIND = 0x70000001
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SHT_PARISC_DOC = 0x70000002
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SHT_ALPHA_DEBUG = 0x70000001
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SHT_ALPHA_REGINFO = 0x70000002
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SHT_ARM_EXIDX = (SHT_LOPROC + 1)
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SHT_ARM_PREEMPTMAP = (SHT_LOPROC + 2)
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SHT_ARM_ATTRIBUTES = (SHT_LOPROC + 3)
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SHT_IA_64_EXT = (SHT_LOPROC + 0)
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SHT_IA_64_UNWIND = (SHT_LOPROC + 1)
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class ElfFormatError(Exception):
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pass
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class Elf_Ehdr(NamedTuple):
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e_ident: bytes
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e_type: int
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e_machine: int
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e_version: int
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e_entry: int
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e_phoff: int
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e_shoff: int
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e_flags: int
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e_ehsize: int
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e_phentsize: int
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e_phnum: int
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e_shentsize: int
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e_shnum: int
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e_shstrndx: int
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class Elf_Shdr(NamedTuple):
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sh_name: int
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sh_type: int
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sh_flags: int
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sh_addr: int
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sh_offset: int
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sh_size: int
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sh_link: int
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sh_info: int
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sh_addralign: int
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sh_entsize: int
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name: str
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class Elf_Sym(NamedTuple):
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st_name: int
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st_info: int
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st_other: int
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st_shndx: int
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st_value: int
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st_size: int
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class ElfFile:
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def __init__(self, data: bytes) -> None:
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self.data = data
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self.ehdr = self._ehdr()
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self.shdrs = self._shdrs()
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self.sections = {shdr.name: shdr for shdr in self.shdrs}
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self._symbols: Optional[Dict[str, List[Elf_Sym]]] = None
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def _ehdr(self) -> Elf_Ehdr:
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if (self.data[EI_MAG0] != ELFMAG0 or self.data[EI_MAG1] != ELFMAG1 or
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self.data[EI_MAG2] != ELFMAG2 or self.data[EI_MAG3] != ELFMAG3):
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raise ValueError('not an ELF file')
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if self.data[EI_VERSION] != EV_CURRENT:
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raise ValueError('ELF version is not EV_CURRENT')
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if self.data[EI_DATA] == ELFDATA2LSB:
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fmt = '<'
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elif self.data[EI_DATA] == ELFDATA2MSB:
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fmt = '>'
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else:
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raise ValueError(f'unknown ELF data encoding {self.data[EI_DATA]}')
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if self.data[EI_CLASS] == ELFCLASS64:
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fmt += '16sHHLQQQLHHHHHH'
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elif self.data[EI_CLASS] == ELFCLASS32:
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raise NotImplementedError('32-bit ELF is not implemented')
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else:
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raise ValueError(f'unknown ELF class {self.data[EI_CLASS]}')
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return Elf_Ehdr._make(struct.unpack_from(fmt, self.data))
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def _shdrs(self) -> List[Elf_Shdr]:
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if self.ehdr.e_ident[EI_DATA] == ELFDATA2LSB:
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fmt = '<'
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else:
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fmt = '>'
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if self.ehdr.e_ident[EI_CLASS] == ELFCLASS64:
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fmt += 'LLQQQQLLQQ'
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else:
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assert False
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# TODO: e_shnum == 0
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buf = self.data[self.ehdr.e_shoff:
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self.ehdr.e_shoff + self.ehdr.e_shnum * self.ehdr.e_shentsize]
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raw_shdrs = list(struct.iter_unpack(fmt, buf))
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if self.ehdr.e_shstrndx == SHN_UNDEF:
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raise ValueError('no string table index in ELF header')
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elif self.ehdr.e_shstrndx == SHN_XINDEX:
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sh_link = raw_shdrs[0][6]
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shstrtab_shdr = raw_shdrs[sh_link]
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else:
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if self.ehdr.e_shstrndx >= SHN_LORESERVE:
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raise ValueError('invalid string table index in ELF header')
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shstrtab_shdr = raw_shdrs[self.ehdr.e_shstrndx]
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sh_offset = shstrtab_shdr[4]
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sh_size = shstrtab_shdr[5]
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shstrtab = bytes(self.data[sh_offset:sh_offset + sh_size])
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shdrs = []
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for raw_shdr in raw_shdrs:
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sh_name = raw_shdr[0]
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if sh_name:
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end = shstrtab.index(b'\0', sh_name)
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section_name = shstrtab[sh_name:end].decode()
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else:
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section_name = ''
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# mypy claims 'Too many arguments for "Elf_Shdr"'
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shdrs.append(Elf_Shdr(*raw_shdr, section_name)) # type: ignore
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return shdrs
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@property
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def symbols(self) -> Dict[str, List[Elf_Sym]]:
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if self._symbols is None:
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if self.ehdr.e_ident[EI_DATA] == ELFDATA2LSB:
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fmt = '<'
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else:
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fmt = '>'
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if self.ehdr.e_ident[EI_CLASS] == ELFCLASS64:
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fmt += 'LBBHQQ'
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else:
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assert False
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shdr = self.sections['.symtab']
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buf = self.data[shdr.sh_offset:shdr.sh_offset + shdr.sh_size]
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symtab = [Elf_Sym._make(sym) for sym in struct.iter_unpack(fmt, buf)]
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strtab_shdr = self.sections['.strtab']
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strtab = bytes(self.data[strtab_shdr.sh_offset:
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strtab_shdr.sh_offset + strtab_shdr.sh_size])
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symbols: Dict[str, List[Elf_Sym]] = {}
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for sym in symtab:
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if not sym.st_name:
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continue
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end = strtab.index(b'\0', sym.st_name)
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symbol_name = strtab[sym.st_name:end].decode()
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try:
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symbols[symbol_name].append(sym)
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except KeyError:
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symbols[symbol_name] = [sym]
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self._symbols = symbols
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return self._symbols
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37
scripts/generate_elf_constants.py
Executable file
37
scripts/generate_elf_constants.py
Executable file
@ -0,0 +1,37 @@
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#!/usr/bin/env python3
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import re
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constant_prefixes = [
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'EI_',
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'ELFCLASS',
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'ELFDATA',
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'ELFMAG',
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'EV_',
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'SHN_',
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'SHT_',
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]
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if __name__ == '__main__':
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with open('/usr/include/elf.h', 'r') as f:
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elf_h = f.read()
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elf_h = re.sub(r'/\*.*?\*/', '', elf_h, flags=re.DOTALL)
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elf_h = re.sub(r'\\\n', '', elf_h)
|
||||
matches = re.findall(r'^#define\s+((?:' + '|'.join(constant_prefixes) + r')\w*)\s+(.+?)\s*$',
|
||||
elf_h, re.MULTILINE)
|
||||
|
||||
print('# Automatically generated from elf.h')
|
||||
for constant, value in matches:
|
||||
if value.startswith("'"):
|
||||
assert len(value) == 3 and value.endswith("'")
|
||||
value = hex(ord(value[1]))
|
||||
elif value.startswith('"'):
|
||||
continue
|
||||
if constant == 'DT_PROCNUM':
|
||||
value = next(match[1] for match in matches if match[0] == value)
|
||||
# Special case for SHF_EXCLUDE.
|
||||
if value == '(1U << 31)':
|
||||
value = '(1 << 31)'
|
||||
print(f'{constant} = {value}')
|
||||
@ -5,7 +5,7 @@ import tempfile
|
||||
import unittest
|
||||
|
||||
from drgn.corereader import CoreReader
|
||||
from drgn.dwarf import ElfFormatError
|
||||
from drgn.elf import ElfFormatError
|
||||
|
||||
|
||||
@contextlib.contextmanager
|
||||
|
||||
Loading…
Reference in New Issue
Block a user