def compile_dwarf(dies, little_endian=True, bits=64):
if isinstance(dies, DwarfDie):
dies = (dies, )
assert all(isinstance(die, DwarfDie) for die in dies)
cu_die = DwarfDie(DW_TAG.compile_unit, [
DwarfAttrib(DW_AT.comp_dir, DW_FORM.string, '/usr/src'),
DwarfAttrib(DW_AT.stmt_list, DW_FORM.sec_offset, 0),
], dies)
return create_elf_file(ET.EXEC, [
ElfSection(
name='.debug_abbrev',
sh_type=SHT.PROGBITS,
data=_compile_debug_abbrev(cu_die),
),
ElfSection(
name='.debug_info',
sh_type=SHT.PROGBITS,
data=_compile_debug_info(cu_die, little_endian, bits),
),
ElfSection(
name='.debug_line',
sh_type=SHT.PROGBITS,
data=_compile_debug_line(cu_die, little_endian),
),
ElfSection(
name='.debug_str',
sh_type=SHT.PROGBITS,
data=b'\0',
),
],
little_endian=little_endian,
bits=bits)
def dwarf_sections(
dies, little_endian=True, bits=64, *, lang=None, use_dw_form_indirect=False
):
if isinstance(dies, DwarfDie):
dies = (dies,)
assert all(isinstance(die, DwarfDie) for die in dies)
if dies and dies[0].tag in UNIT_HEADER_TYPES:
unit_dies = dies
else:
unit_dies = (DwarfDie(DW_TAG.compile_unit, (), dies),)
assert all(die.tag in UNIT_HEADER_TYPES for die in unit_dies)
unit_attribs = [DwarfAttrib(DW_AT.stmt_list, DW_FORM.sec_offset, 0)]
if lang is not None:
unit_attribs.append(DwarfAttrib(DW_AT.language, DW_FORM.data1, lang))
cu_attribs = unit_attribs + [
DwarfAttrib(DW_AT.comp_dir, DW_FORM.string, "/usr/src")
]
unit_dies = [
DwarfDie(
die.tag,
list(die.attribs)
+ (cu_attribs if die.tag == DW_TAG.compile_unit else unit_attribs),
die.children,
)
for die in unit_dies
]
debug_info, debug_types = _compile_debug_info(
unit_dies, little_endian, bits, use_dw_form_indirect
)
sections = [
ElfSection(
name=".debug_abbrev",
sh_type=SHT.PROGBITS,
data=_compile_debug_abbrev(unit_dies, use_dw_form_indirect),
),
ElfSection(name=".debug_info", sh_type=SHT.PROGBITS, data=debug_info),
ElfSection(
name=".debug_line",
sh_type=SHT.PROGBITS,
data=_compile_debug_line(unit_dies, little_endian),
),
ElfSection(name=".debug_str", sh_type=SHT.PROGBITS, data=b"\0"),
]
if debug_types:
sections.append(
ElfSection(name=".debug_types", sh_type=SHT.PROGBITS, data=debug_types)
)
return sections
def compile_dwarf(dies, little_endian=True, bits=64, *, lang=None):
if isinstance(dies, DwarfDie):
dies = (dies, )
assert all(isinstance(die, DwarfDie) for die in dies)
cu_attribs = [
DwarfAttrib(DW_AT.comp_dir, DW_FORM.string, "/usr/src"),
DwarfAttrib(DW_AT.stmt_list, DW_FORM.sec_offset, 0),
]
if lang is not None:
cu_attribs.append(DwarfAttrib(DW_AT.language, DW_FORM.data1, lang))
cu_die = DwarfDie(DW_TAG.compile_unit, cu_attribs, dies)
return create_elf_file(
ET.EXEC,
[
ElfSection(
p_type=PT.LOAD,
vaddr=0xFFFF0000,
data=b"",
),
ElfSection(
name=".debug_abbrev",
sh_type=SHT.PROGBITS,
data=_compile_debug_abbrev(cu_die),
),
ElfSection(
name=".debug_info",
sh_type=SHT.PROGBITS,
data=_compile_debug_info(cu_die, little_endian, bits),
),
ElfSection(
name=".debug_line",
sh_type=SHT.PROGBITS,
data=_compile_debug_line(cu_die, little_endian),
),
ElfSection(
name=".debug_str",
sh_type=SHT.PROGBITS,
data=b"\0",
),
],
little_endian=little_endian,
bits=bits,
)
def test_simple(self):
data = b"hello, world"
prog = Program()
with tempfile.NamedTemporaryFile() as f:
f.write(
create_elf_file(
ET.CORE,
[ElfSection(p_type=PT.LOAD, vaddr=0xFFFF0000, data=data)]))
f.flush()
prog.set_core_dump(f.name)
self.assertEqual(prog.read(0xFFFF0000, len(data)), data)
self.assertRaises(FaultError, prog.read, 0x0, len(data), physical=True)
def test_zero_fill(self):
data = b'hello, world'
prog = Program()
with tempfile.NamedTemporaryFile() as f:
f.write(
create_elf_file(ET.CORE, [
ElfSection(
p_type=PT.LOAD,
vaddr=0xffff0000,
data=data,
memsz=len(data) + 4,
),
]))
f.flush()
prog.set_core_dump(f.name)
self.assertEqual(prog.read(0xffff0000, len(data) + 4), data + bytes(4))
def test_physical(self):
data = b'hello, world'
prog = Program()
with tempfile.NamedTemporaryFile() as f:
f.write(
create_elf_file(ET.CORE, [
ElfSection(
p_type=PT.LOAD,
vaddr=0xffff0000,
paddr=0xa0,
data=data,
),
]))
f.flush()
prog.set_core_dump(f.name)
self.assertEqual(prog.read(0xffff0000, len(data)), data)
self.assertEqual(prog.read(0xa0, len(data), physical=True), data)
def create_elf_symbol_file(symbols):
# We need some DWARF data so that libdwfl will load the file.
sections = dwarf_sections(())
# Create a section for the symbols to reference and the corresponding
# segment for address lookups.
min_address = min(symbol.value for symbol in symbols)
max_address = max(symbol.value + symbol.size for symbol in symbols)
sections.append(
ElfSection(
name=".foo",
sh_type=SHT.NOBITS,
p_type=PT.LOAD,
vaddr=min_address,
memsz=max_address - min_address,
))
symbols = [
symbol._replace(shindex=len(sections)
if symbol.shindex is None else symbol.shindex)
for symbol in symbols
]
return create_elf_file(ET.EXEC, sections, symbols)
def test_unsaved(self):
data = b"hello, world"
prog = Program()
with tempfile.NamedTemporaryFile() as f:
f.write(
create_elf_file(
ET.CORE,
[
ElfSection(
p_type=PT.LOAD,
vaddr=0xFFFF0000,
data=data,
memsz=len(data) + 4,
),
],
)
)
f.flush()
prog.set_core_dump(f.name)
with self.assertRaisesRegex(FaultError, "memory not saved in core dump") as cm:
prog.read(0xFFFF0000, len(data) + 4)
self.assertEqual(cm.exception.address, 0xFFFF000C)