def BuildIdFromElf(elf_path, tool_prefix):
"""Returns the Build ID for the given binary."""
args = [path_util.GetReadElfPath(tool_prefix), '-n', elf_path]
stdout = subprocess.check_output(args, encoding='ascii')
match = re.search(r'Build ID: (\w+)', stdout)
assert match, 'Build ID not found from running: ' + ' '.join(args)
return match.group(1)
def CollectRelocationAddresses(elf_path, tool_prefix):
"""Returns the list of addresses that are targets for relative relocations."""
cmd = [path_util.GetReadElfPath(tool_prefix), '--relocs', elf_path]
ret = subprocess.check_output(cmd, encoding='ascii').splitlines()
# Grab first column from (sample output) '02de6d5c 00000017 R_ARM_RELATIVE'
return [
int(l.split(maxsplit=1)[0], 16) for l in ret if 'R_ARM_RELATIVE' in l
]
def _SectionSizesFromElf(elf_path, tool_prefix):
args = [path_util.GetReadElfPath(tool_prefix), '-S', '--wide', elf_path]
stdout = subprocess.check_output(args)
section_sizes = {}
# Matches [ 2] .hash HASH 00000000006681f0 0001f0 003154 04 A 3 0 8
for match in re.finditer(r'\[[\s\d]+\] (\..*)$', stdout, re.MULTILINE):
items = match.group(1).split()
section_sizes[items[0]] = int(items[4], 16)
return section_sizes
def LookupElfRodataInfo(elf_path, tool_prefix):
"""Returns (address, offset, size) for the .rodata section."""
args = [path_util.GetReadElfPath(tool_prefix), '-S', '--wide', elf_path]
output = subprocess.check_output(args)
lines = output.splitlines()
for line in lines:
# [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
# [07] .rodata PROGBITS 025e7000 237c000 5ec4f6 00 A 0 0 256
if '.rodata ' in line:
fields = line[line.index(models.SECTION_RODATA):].split()
return int(fields[2], 16), int(fields[3], 16), int(fields[4], 16)
raise AssertionError('No .rodata for command: ' + repr(args))
def _ArchFromElf(elf_path, tool_prefix):
args = [path_util.GetReadElfPath(tool_prefix), '-h', elf_path]
stdout = subprocess.check_output(args)
machine = re.search('Machine:\s*(.+)', stdout).group(1)
if machine == 'Intel 80386':
return 'x86'
if machine == 'Advanced Micro Devices X86-64':
return 'x64'
elif machine == 'ARM':
return 'arm'
elif machine == 'AArch64':
return 'arm64'
return machine
def SectionInfoFromElf(elf_path, tool_prefix):
"""Finds the address and size of all ELF sections
Returns:
A dict of section_name->(start_address, size).
"""
args = [path_util.GetReadElfPath(tool_prefix), '-S', '--wide', elf_path]
stdout = subprocess.check_output(args, encoding='ascii')
section_ranges = {}
# Matches [ 2] .hash HASH 00000000006681f0 0001f0 003154 04 A 3 0 8
for match in re.finditer(r'\[[\s\d]+\] (\..*)$', stdout, re.MULTILINE):
items = match.group(1).split()
section_ranges[items[0]] = (int(items[2], 16), int(items[4], 16))
return section_ranges
def ArchFromElf(elf_path, tool_prefix):
"""Returns the GN architecture for the given binary."""
args = [path_util.GetReadElfPath(tool_prefix), '-h', elf_path]
stdout = subprocess.check_output(args, encoding='ascii')
machine = re.search('Machine:\s*(.+)', stdout).group(1)
if machine == 'Intel 80386':
return 'x86'
if machine == 'Advanced Micro Devices X86-64':
return 'x64'
elif machine == 'ARM':
return 'arm'
elif machine == 'AArch64':
return 'arm64'
return machine
def _LookupStringSectionPositions(target, tool_prefix, output_directory):
"""Returns a dict of object_path -> [(offset, size)...] of .rodata sections.
Args:
target: An archive path string (e.g., "foo.a") or a list of object paths.
"""
is_archive = isinstance(target, str)
args = [path_util.GetReadElfPath(tool_prefix), '-S', '--wide']
if is_archive:
args.append(target)
else:
# Assign path for when len(target) == 1, (no File: line exists).
path = target[0]
args.extend(target)
output = subprocess.check_output(args,
cwd=output_directory).decode('ascii')
lines = output.splitlines()
section_positions_by_path = {}
cur_offsets = []
for line in lines:
# File: base/third_party/libevent/libevent.a(buffer.o)
# [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
# [11] .rodata.str1.1 PROGBITS 00000000 0000b4 000004 01 AMS 0 0 1
# [11] .rodata.str4.4 PROGBITS 00000000 0000b4 000004 01 AMS 0 0 4
# [11] .rodata.str8.8 PROGBITS 00000000 0000b4 000004 01 AMS 0 0 8
# [80] .rodata..L.str PROGBITS 00000000 000530 000002 00 A 0 0 1
# The various string sections differ by alignment.
# The presence of a wchar_t literal (L"asdf") seems to make a str4 section.
# When multiple sections exist, nm gives us no indication as to which
# section each string corresponds to.
if line.startswith('File: '):
if cur_offsets:
section_positions_by_path[path] = cur_offsets
cur_offsets = []
path = line[6:]
elif '.rodata.' in line:
progbits_idx = line.find('PROGBITS ')
if progbits_idx != -1:
fields = line[progbits_idx:].split()
position = (int(fields[2], 16), int(fields[3], 16))
# The heuristics in _IterStringLiterals rely on str1 coming first.
if fields[-1] == '1':
cur_offsets.insert(0, position)
else:
cur_offsets.append(position)
if cur_offsets:
section_positions_by_path[path] = cur_offsets
return section_positions_by_path
def BuildIdFromElf(elf_path, tool_prefix): args = [path_util.GetReadElfPath(tool_prefix), '-n', elf_path] stdout = subprocess.check_output(args) match = re.search(r'Build ID: (\w+)', stdout) assert match, 'Build ID not found from running: ' + ' '.join(args) return match.group(1)
