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pwndbg/pwndbg/commands/nearpc.py

216 lines
8.3 KiB
Python

import argparse
import gdb
from capstone import *
import pwndbg.arguments
import pwndbg.color
import pwndbg.color.context as C
import pwndbg.color.disasm as D
import pwndbg.color.nearpc as N
import pwndbg.color.theme
import pwndbg.commands.comments
import pwndbg.config
import pwndbg.disasm
import pwndbg.functions
import pwndbg.ida
import pwndbg.regs
import pwndbg.strings
import pwndbg.symbol
import pwndbg.ui
import pwndbg.vmmap
from pwndbg.color import message
def ljust_padding(lst):
longest_len = max(map(len, lst)) if lst else 0
return [s.ljust(longest_len) for s in lst]
nearpc_branch_marker = pwndbg.color.theme.Parameter('nearpc-branch-marker', '', 'branch marker line for nearpc command')
nearpc_branch_marker_contiguous = pwndbg.color.theme.Parameter('nearpc-branch-marker-contiguous', ' ', 'contiguous branch marker line for nearpc command')
pwndbg.color.theme.Parameter('highlight-pc', True, 'whether to highlight the current instruction')
pwndbg.color.theme.Parameter('nearpc-prefix', '', 'prefix marker for nearpc command')
pwndbg.config.Parameter('left-pad-disasm', True, 'whether to left-pad disassembly')
nearpc_lines = pwndbg.config.Parameter('nearpc-lines', 10, 'number of additional lines to print for the nearpc command')
show_args = pwndbg.config.Parameter('nearpc-show-args', True, 'show call arguments below instruction')
parser = argparse.ArgumentParser(description='''Disassemble near a specified address.''')
parser.add_argument("pc", type=int, nargs="?", default=None, help="Address to disassemble near.")
parser.add_argument("lines", type=int, nargs="?", default=None, help="Number of lines to show on either side of the address.")
#parser.add_argument("to_string", type=bool, nargs="?", default=False, help="Whether to print it or not.") #TODO make sure this should not be exposed
parser.add_argument("emulate", type=bool, nargs="?", default=False, help="Whether to emulate instructions to find the next ones or just linearly disassemble.")
@pwndbg.commands.ArgparsedCommand(parser)
@pwndbg.commands.OnlyWhenRunning
def nearpc(pc=None, lines=None, to_string=False, emulate=False):
"""
Disassemble near a specified address.
"""
# Repeating nearpc (pressing enter) makes it show next addresses
# (writing nearpc explicitly again will reset its state)
if nearpc.repeat:
pc = nearpc.next_pc
result = []
if pc is not None:
pc = gdb.Value(pc).cast(pwndbg.typeinfo.pvoid)
# Fix the case where we only have one argument, and
# it's a small value.
if lines is None and (pc is None or int(pc) < 0x100):
lines = pc
pc = None
if pc is None:
pc = pwndbg.regs.pc
if lines is None:
lines = nearpc_lines // 2
pc = int(pc)
lines = int(lines)
# Check whether we can even read this address
if not pwndbg.memory.peek(pc):
result.append(message.error('Invalid address %#x' % pc))
# # Load source data if it's available
# pc_to_linenos = collections.defaultdict(lambda: [])
# lineno_to_src = {}
# frame = gdb.selected_frame()
# if frame:
# sal = frame.find_sal()
# if sal:
# symtab = sal.symtab
# objfile = symtab.objfile
# sourcefilename = symtab.filename
# with open(sourcefilename, 'r') as sourcefile:
# lineno_to_src = {i:l for i,l in enumerate(sourcefile.readlines())}
# for line in symtab.linetable():
# pc_to_linenos[line.pc].append(line.line)
instructions = pwndbg.disasm.near(pc, lines, emulate=emulate, show_prev_insns=not nearpc.repeat)
if pwndbg.memory.peek(pc) and not instructions:
result.append(message.error('Invalid instructions at %#x' % pc))
# In case $pc is in a new map we don't know about,
# this will trigger an exploratory search.
pwndbg.vmmap.find(pc)
# Gather all addresses and symbols for each instruction
symbols = [pwndbg.symbol.get(i.address) for i in instructions]
addresses = ['%#x' % i.address for i in instructions]
nearpc.next_pc = instructions[-1].address + instructions[-1].size if instructions else 0
# Format the symbol name for each instruction
symbols = ['<%s> ' % sym if sym else '' for sym in symbols]
# Pad out all of the symbols and addresses
if pwndbg.config.left_pad_disasm and not nearpc.repeat:
symbols = ljust_padding(symbols)
addresses = ljust_padding(addresses)
prev = None
first_pc = True
# Print out each instruction
for address_str, symbol, instr in zip(addresses, symbols, instructions):
asm = D.instruction(instr)
prefix_sign = pwndbg.config.nearpc_prefix
# Show prefix only on the specified address and don't show it while in repeat-mode
# or when showing current instruction for the second time
show_prefix = instr.address == pc and not nearpc.repeat and first_pc
prefix = ' %s' % (prefix_sign if show_prefix else ' ' * len(prefix_sign))
prefix = N.prefix(prefix)
pre = pwndbg.ida.Anterior(instr.address)
if pre:
result.append(N.ida_anterior(pre))
# Colorize address and symbol if not highlighted
# symbol is fetched from gdb and it can be e.g. '<main+8>'
if instr.address != pc or not pwndbg.config.highlight_pc or nearpc.repeat:
address_str = N.address(address_str)
symbol = N.symbol(symbol)
elif pwndbg.config.highlight_pc and first_pc:
prefix = C.highlight(prefix)
address_str = C.highlight(address_str)
symbol = C.highlight(symbol)
first_pc = False
line = ' '.join((prefix, address_str, symbol, asm))
# If there was a branch before this instruction which was not
# contiguous, put in some ellipses.
if prev and prev.address + prev.size != instr.address:
result.append(N.branch_marker('%s' % nearpc_branch_marker))
# Otherwise if it's a branch and it *is* contiguous, just put
# and empty line.
elif prev and any(g in prev.groups for g in (CS_GRP_CALL, CS_GRP_JUMP, CS_GRP_RET)):
if len('%s' % nearpc_branch_marker_contiguous) > 0:
result.append('%s' % nearpc_branch_marker_contiguous)
# For syscall instructions, put the name on the side
if instr.address == pc:
syscall_name = pwndbg.arguments.get_syscall_name(instr)
if syscall_name:
line += ' <%s>' % N.syscall_name('SYS_' + syscall_name)
# For Comment Function
try:
line += " "*10 + C.comment(pwndbg.commands.comments.file_lists[pwndbg.proc.exe][hex(instr.address)])
except Exception:
pass
result.append(line)
# For call instructions, attempt to resolve the target and
# determine the number of arguments.
if show_args:
result.extend(('%8s%s' % ('', arg) for arg in pwndbg.arguments.format_args(instruction=instr)))
prev = instr
if not to_string:
print('\n'.join(result))
return result
parser = argparse.ArgumentParser(description='''Like nearpc, but will emulate instructions from the current $PC forward.''')
parser.add_argument("pc", type=int, nargs="?", default=None, help="Address to emulate near.")
parser.add_argument("lines", type=int, nargs="?", default=None, help="Number of lines to show on either side of the address.")
@pwndbg.commands.ArgparsedCommand(parser)
@pwndbg.commands.OnlyWhenRunning
def emulate(pc=None, lines=None, to_string=False, emulate=True):
"""
Like nearpc, but will emulate instructions from the current $PC forward.
"""
nearpc.repeat = emulate_command.repeat
return nearpc(pc, lines, to_string, emulate)
emulate_command = emulate
parser = argparse.ArgumentParser(description='''Compatibility layer for PEDA's pdisass command.''')
parser.add_argument("pc", type=int, nargs="?", default=None, help="Address to disassemble near.")
parser.add_argument("lines", type=int, nargs="?", default=None, help="Number of lines to show on either side of the address.")
@pwndbg.commands.ArgparsedCommand(parser)
@pwndbg.commands.OnlyWhenRunning
def pdisass(pc=None, lines=None, to_string=False):
"""
Compatibility layer for PEDA's pdisass command
"""
nearpc.repeat = pdisass.repeat
return nearpc(pc, lines, to_string, False)
nearpc.next_pc = 0