You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
pwndbg/pwndbg/gdblib/vmmap.py

811 lines
28 KiB
Python

"""
Routines to enumerate mapped memory, and attempt to associate
address ranges with various ELF files and permissions.
The reason that we need robustness is that not every operating
system has /proc/$$/maps, which backs 'info proc mapping'.
"""
from __future__ import annotations
import bisect
from typing import List
from typing import Set
from typing import Tuple
import gdb
import pwndbg.auxv
import pwndbg.color.message as M
import pwndbg.gdblib.abi
import pwndbg.gdblib.elf
import pwndbg.gdblib.events
import pwndbg.gdblib.file
import pwndbg.gdblib.info
import pwndbg.gdblib.kernel
import pwndbg.gdblib.memory
import pwndbg.gdblib.proc
import pwndbg.gdblib.qemu
import pwndbg.gdblib.regs
import pwndbg.gdblib.remote
import pwndbg.gdblib.stack
import pwndbg.gdblib.typeinfo
import pwndbg.lib.cache
import pwndbg.lib.memory
# List of manually-explored pages which were discovered
# by analyzing the stack or register context.
explored_pages: List[pwndbg.lib.memory.Page] = []
# List of custom pages that can be managed manually by vmmap_* commands family
custom_pages: List[pwndbg.lib.memory.Page] = []
kernel_vmmap_via_pt = pwndbg.gdblib.config.add_param(
"kernel-vmmap-via-page-tables",
"deprecated",
"the deprecated config of the method get kernel vmmap",
help_docstring="Deprecated in favor of `kernel-vmmap`",
)
kernel_vmmap = pwndbg.gdblib.config.add_param(
"kernel-vmmap",
"page-tables",
"the method to get vmmap information when debugging via QEMU kernel",
help_docstring="""\
kernel-vmmap can be:
page-tables - read /proc/$qemu-pid/mem to parse kernel page tables to render vmmap
monitor - use QEMU's `monitor info mem` to render vmmap
none - disable vmmap rendering; useful if rendering is particularly slow
Note that the page-tables method will require the QEMU kernel process to be on the same machine and within the same PID namespace. Running QEMU kernel and GDB in different Docker containers will not work. Consider running both containers with --pid=host (meaning they will see and so be able to interact with all processes on the machine).
""",
param_class=gdb.PARAM_ENUM,
enum_sequence=["page-tables", "monitor", "none"],
)
@pwndbg.lib.cache.cache_until("objfile", "start")
def is_corefile() -> bool:
"""
For example output use:
gdb ./tests/binaries/crash_simple.out -ex run -ex 'generate-core-file ./core' -ex 'quit'
And then use:
gdb ./tests/binaries/crash_simple.out -core ./core -ex 'info target'
And:
gdb -core ./core
As the two differ in output slighty.
"""
return "Local core dump file:\n" in pwndbg.gdblib.info.target()
inside_no_proc_maps_search = False
@pwndbg.lib.cache.cache_until("start", "stop")
def get() -> Tuple[pwndbg.lib.memory.Page, ...]:
"""
Returns a tuple of `Page` objects representing the memory mappings of the
target, sorted by virtual address ascending.
"""
# Note: debugging a coredump does still show proc.alive == True
if not pwndbg.gdblib.proc.alive:
return ()
if is_corefile():
return tuple(coredump_maps())
proc_maps = None
if pwndbg.gdblib.qemu.is_qemu_usermode():
# On Qemu < 8.1 info proc maps are not supported. In that case we callback on proc_tid_maps
proc_maps = info_proc_maps()
if not proc_maps:
proc_maps = proc_tid_maps()
# The `proc_maps` is usually a tuple of Page objects but it can also be:
# None - when /proc/$tid/maps does not exist/is not available
# tuple() - when the process has no maps yet which happens only during its very early init
# (usually when we attach to a process)
if proc_maps is not None:
return proc_maps
pages: List[pwndbg.lib.memory.Page] = []
if pwndbg.gdblib.qemu.is_qemu_kernel() and pwndbg.gdblib.arch.current in (
"i386",
"x86-64",
"aarch64",
"rv32",
"rv64",
):
# If kernel_vmmap_via_pt is not set to the default value of "deprecated",
# That means the user was explicitly setting it themselves and need to
# be warned that the option is deprecated
if kernel_vmmap_via_pt != "deprecated":
print(
M.warn(
"`kernel-vmmap-via-page-tables` is deprecated, please use `kernel-vmmap` instead."
)
)
if kernel_vmmap == "page-tables":
pages.extend(kernel_vmmap_via_page_tables())
elif kernel_vmmap == "monitor":
pages.extend(kernel_vmmap_via_monitor_info_mem())
# TODO/FIXME: Add tests for QEMU-user targets when this is needed
global inside_no_proc_maps_search
if not pages and not inside_no_proc_maps_search:
inside_no_proc_maps_search = True
# If debuggee is launched from a symlink the debuggee memory maps will be
# labeled with symlink path while in normal scenario the /proc/pid/maps
# labels debuggee memory maps with real path (after symlinks).
# This is because the exe path in AUXV (and so `info auxv`) is before
# following links.
pages.extend(info_auxv())
if pages:
pages.extend(info_sharedlibrary())
else:
if pwndbg.gdblib.qemu.is_qemu():
return (pwndbg.lib.memory.Page(0, pwndbg.gdblib.arch.ptrmask, 7, 0, "[qemu]"),)
pages.extend(info_files())
pages.extend(pwndbg.gdblib.stack.get().values())
inside_no_proc_maps_search = False
pages.extend(explored_pages)
pages.extend(custom_pages)
pages.sort()
return tuple(pages)
@pwndbg.lib.cache.cache_until("stop")
def find(address: int | None) -> pwndbg.lib.memory.Page | None:
if address is None:
return None
address = int(address)
for page in get():
if address in page:
return page
return explore(address)
@pwndbg.gdblib.abi.LinuxOnly()
def explore(address_maybe: int) -> pwndbg.lib.memory.Page | None:
"""
Given a potential address, check to see what permissions it has.
Returns:
Page object
Note:
Adds the Page object to a persistent list of pages which are
only reset when the process dies. This means pages which are
added this way will not be removed when unmapped.
Also assumes the entire contiguous section has the same permission.
"""
if proc_tid_maps():
return None
address_maybe = pwndbg.lib.memory.page_align(address_maybe)
flags = 4 if pwndbg.gdblib.memory.peek(address_maybe) else 0
if not flags:
return None
flags |= 2 if pwndbg.gdblib.memory.poke(address_maybe) else 0
flags |= 1 if not pwndbg.gdblib.stack.is_executable() else 0
page = find_boundaries(address_maybe)
page.objfile = "<explored>"
page.flags = flags
explored_pages.append(page)
return page
# Automatically ensure that all registers are explored on each stop
# @pwndbg.gdblib.events.stop
def explore_registers() -> None:
for regname in pwndbg.gdblib.regs.common:
find(pwndbg.gdblib.regs[regname])
# @pwndbg.gdblib.events.exit
def clear_explored_pages() -> None:
while explored_pages:
explored_pages.pop()
def add_custom_page(page: pwndbg.lib.memory.Page) -> None:
bisect.insort(custom_pages, page)
# Reset all the cache
# We can not reset get() only, since the result may be used by others.
# TODO: avoid flush all caches
pwndbg.lib.cache.clear_caches()
def clear_custom_page() -> None:
while custom_pages:
custom_pages.pop()
# Reset all the cache
# We can not reset get() only, since the result may be used by others.
# TODO: avoid flush all caches
pwndbg.lib.cache.clear_caches()
@pwndbg.lib.cache.cache_until("objfile", "start")
def coredump_maps() -> Tuple[pwndbg.lib.memory.Page, ...]:
"""
Parses `info proc mappings` and `maintenance info sections`
and tries to make sense out of the result :)
"""
pages: List[pwndbg.lib.memory.Page] = []
try:
info_proc_mappings = pwndbg.gdblib.info.proc_mappings().splitlines()
except gdb.error:
# On qemu user emulation, we may get: gdb.error: Not supported on this target.
info_proc_mappings = []
for line in info_proc_mappings:
# We look for lines like:
# ['0x555555555000', '0x555555556000', '0x1000', '0x1000', '/home/user/a.out']
try:
start, _end, size, offset, objfile = line.split()
start, size, offset = int(start, 16), int(size, 16), int(offset, 16)
except (IndexError, ValueError):
continue
# Note: we set flags=0 because we do not have this information here
pages.append(pwndbg.lib.memory.Page(start, size, 0, offset, objfile))
started_sections = False
for line in gdb.execute("maintenance info sections", to_string=True).splitlines():
if not started_sections:
if "Core file:" in line:
started_sections = True
continue
# We look for lines like:
# ['[9]', '0x00000000->0x00000150', 'at', '0x00098c40:', '.auxv', 'HAS_CONTENTS']
# ['[15]', '0x555555555000->0x555555556000', 'at', '0x00001430:', 'load2', 'ALLOC', 'LOAD', 'READONLY', 'CODE', 'HAS_CONTENTS']
try:
_idx, start_end, _at_str, _at, name, *flags_list = line.split()
start, end = (int(v, 16) for v in start_end.split("->"))
# Skip pages with start=0x0, this is unlikely this is valid vmmap
if start == 0:
continue
# Tried taking this from the 'at 0x...' value
# but it turns out to be invalid, so keep it 0 until we find better way
offset = 0
except (IndexError, ValueError):
continue
# Note: can we deduce anything from 'ALLOC', 'HAS_CONTENTS' or 'LOAD' flags?
flags = 0
if "READONLY" in flags_list:
flags |= 4
if "DATA" in flags_list:
flags |= 2
if "CODE" in flags_list:
flags |= 1
# Now, if the section is already in pages, just add its perms
known_page = False
for page in pages:
if start in page:
page.flags |= flags
known_page = True
break
if known_page:
continue
pages.append(pwndbg.lib.memory.Page(start, end - start, flags, offset, name))
if not pages:
return ()
# If the last page starts on e.g. 0xffffffffff600000 it must be vsyscall
vsyscall_page = pages[-1]
if vsyscall_page.start > 0xFFFFFFFFFF000000 and vsyscall_page.flags & 1:
vsyscall_page.objfile = "[vsyscall]"
vsyscall_page.offset = 0
# Detect stack based on addresses in AUXV from stack memory
stack_addr = None
# TODO/FIXME: Can we uxe `pwndbg.auxv.get()` for this somehow?
auxv = pwndbg.gdblib.info.auxv().splitlines()
for line in auxv:
if "AT_EXECFN" in line:
try:
stack_addr = int(line.split()[-2], 16)
except Exception as e:
pass
break
if stack_addr is not None:
for page in pages:
if stack_addr in page:
page.objfile = "[stack]"
page.flags |= 6
page.offset = 0
break
return tuple(pages)
@pwndbg.lib.cache.cache_until("start", "stop")
def info_proc_maps() -> Tuple[pwndbg.lib.memory.Page, ...]:
"""
Parse the result of info proc mappings.
Note: this may return no pages due to a bug/behavior of GDB.
See https://sourceware.org/bugzilla/show_bug.cgi?id=31207
for more information.
Returns:
A tuple of pwndbg.lib.memory.Page objects or None if
info proc mapping is not supported on the target.
"""
try:
info_proc_mappings = pwndbg.gdblib.info.proc_mappings().splitlines()
except gdb.error:
# On qemu user emulation, we may get: gdb.error: Not supported on this target.
info_proc_mappings = []
pages: List[pwndbg.lib.memory.Page] = []
for line in info_proc_mappings:
# We look for lines like:
# ['0x555555555000', '0x555555556000', '0x1000', '0x1000', 'rw-p', '/home/user/a.out']
try:
split_line = line.split()
# Permission info is only available in GDB versions >=12.1
# https://github.com/bminor/binutils-gdb/commit/29ef4c0699e1b46d41ade00ae07a54f979ea21cc
# Assume "rw-p" on older gdb versions
if len(split_line) < 6:
start, _end, size, offset, objfile = split_line
perm = "rwxp"
else:
start, _end, size, offset, perm, objfile = split_line
start, size, offset = int(start, 16), int(size, 16), int(offset, 16)
except (IndexError, ValueError):
continue
flags = 0
if "r" in perm:
flags |= 4
if "w" in perm:
flags |= 2
if "x" in perm:
flags |= 1
pages.append(pwndbg.lib.memory.Page(start, size, flags, offset, objfile))
return tuple(pages)
@pwndbg.lib.cache.cache_until("start", "stop")
def proc_tid_maps() -> Tuple[pwndbg.lib.memory.Page, ...] | None:
"""
Parse the contents of /proc/$TID/maps on the server.
(TID == Thread Identifier. We do not use PID since it may not be correct)
Returns:
A tuple of pwndbg.lib.memory.Page objects or None if
/proc/$tid/maps doesn't exist or when we debug a qemu-user target
"""
# If we debug remotely a qemu-user or qemu-system target,
# there is no point of hitting things further
if pwndbg.gdblib.qemu.is_qemu():
return None
# Example /proc/$tid/maps
# 7f95266fa000-7f95268b5000 r-xp 00000000 08:01 418404 /lib/x86_64-linux-gnu/libc-2.19.so
# 7f95268b5000-7f9526ab5000 ---p 001bb000 08:01 418404 /lib/x86_64-linux-gnu/libc-2.19.so
# 7f9526ab5000-7f9526ab9000 r--p 001bb000 08:01 418404 /lib/x86_64-linux-gnu/libc-2.19.so
# 7f9526ab9000-7f9526abb000 rw-p 001bf000 08:01 418404 /lib/x86_64-linux-gnu/libc-2.19.so
# 7f9526abb000-7f9526ac0000 rw-p 00000000 00:00 0
# 7f9526ac0000-7f9526ae3000 r-xp 00000000 08:01 418153 /lib/x86_64-linux-gnu/ld-2.19.so
# 7f9526cbe000-7f9526cc1000 rw-p 00000000 00:00 0
# 7f9526ce0000-7f9526ce2000 rw-p 00000000 00:00 0
# 7f9526ce2000-7f9526ce3000 r--p 00022000 08:01 418153 /lib/x86_64-linux-gnu/ld-2.19.so
# 7f9526ce3000-7f9526ce4000 rw-p 00023000 08:01 418153 /lib/x86_64-linux-gnu/ld-2.19.so
# 7f9526ce4000-7f9526ce5000 rw-p 00000000 00:00 0
# 7f9526ce5000-7f9526d01000 r-xp 00000000 08:01 786466 /bin/dash
# 7f9526f00000-7f9526f02000 r--p 0001b000 08:01 786466 /bin/dash
# 7f9526f02000-7f9526f03000 rw-p 0001d000 08:01 786466 /bin/dash
# 7f9526f03000-7f9526f05000 rw-p 00000000 00:00 0
# 7f95279fe000-7f9527a1f000 rw-p 00000000 00:00 0 [heap]
# 7fff3c177000-7fff3c199000 rw-p 00000000 00:00 0 [stack]
# 7fff3c1e8000-7fff3c1ea000 r-xp 00000000 00:00 0 [vdso]
# ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
tid = pwndbg.gdblib.proc.tid
locations = [
f"/proc/{tid}/maps",
f"/proc/{tid}/map",
f"/usr/compat/linux/proc/{tid}/maps",
]
for location in locations:
try:
data = pwndbg.gdblib.file.get(location).decode()
break
except (OSError, gdb.error):
continue
else:
return None
# Process hasn't been fully created yet; it is in Z (zombie) state
if data == "":
return ()
pages: List[pwndbg.lib.memory.Page] = []
for line in data.splitlines():
maps, perm, offset, dev, inode_objfile = line.split(maxsplit=4)
start, stop = maps.split("-")
try:
inode, objfile = inode_objfile.split(maxsplit=1)
except Exception:
# Name unnamed anonymous pages so they can be used e.g. with search commands
objfile = "[anon_" + start[:-3] + "]"
start = int(start, 16)
stop = int(stop, 16)
offset = int(offset, 16)
size = stop - start
flags = 0
if "r" in perm:
flags |= 4
if "w" in perm:
flags |= 2
if "x" in perm:
flags |= 1
page = pwndbg.lib.memory.Page(start, size, flags, offset, objfile)
pages.append(page)
return tuple(pages)
@pwndbg.lib.cache.cache_until("stop")
def kernel_vmmap_via_page_tables() -> Tuple[pwndbg.lib.memory.Page, ...]:
import pt
retpages: List[pwndbg.lib.memory.Page] = []
p = pt.PageTableDump()
try:
p.lazy_init()
except Exception:
print(
M.error(
"Permission error when attempting to parse page tables with gdb-pt-dump.\n"
"Either change the kernel-vmmap setting, re-run GDB as root, or disable "
"`ptrace_scope` (`echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope`)"
)
)
return tuple(retpages)
# If paging is not enabled, we shouldn't attempt to parse page tables
if not pwndbg.gdblib.kernel.paging_enabled():
return tuple(retpages)
pages = p.backend.parse_tables(p.cache, p.parser.parse_args(""))
for page in pages:
start = page.va
size = page.page_size
flags = 4 # IMPLY ALWAYS READ
if page.pwndbg_is_writeable():
flags |= 2
if page.pwndbg_is_executable():
flags |= 1
objfile = f"[pt_{hex(start)[2:-3]}]"
retpages.append(pwndbg.lib.memory.Page(start, size, flags, 0, objfile))
return tuple(retpages)
monitor_info_mem_not_warned = True
def kernel_vmmap_via_monitor_info_mem() -> Tuple[pwndbg.lib.memory.Page, ...]:
"""
Returns Linux memory maps information by parsing `monitor info mem` output
from QEMU kernel GDB stub.
Works only on X86/X64/RISC-V as this is what QEMU supports.
Consider using the `kernel_vmmap_via_page_tables` method
as it is probably more reliable/better.
See also: https://github.com/pwndbg/pwndbg/pull/685
(TODO: revisit with future QEMU versions)
# Example output from the command:
# pwndbg> monitor info mem
# ffff903580000000-ffff903580099000 0000000000099000 -rw
# ffff903580099000-ffff90358009b000 0000000000002000 -r-
# ffff90358009b000-ffff903582200000 0000000002165000 -rw
# ffff903582200000-ffff903582803000 0000000000603000 -r-
"""
global monitor_info_mem_not_warned
monitor_info_mem = None
try:
monitor_info_mem = gdb.execute("monitor info mem", to_string=True)
finally:
# Older versions of QEMU/GDB may throw `gdb.error: "monitor" command
# not supported by this target`. Newer versions will not throw, but will
# return a string starting with 'unknown command:'. We handle both of
# these cases in a `finally` block instead of an `except` block.
if monitor_info_mem is None or "unknown command" in monitor_info_mem:
# TODO: Find out which other architectures don't support this command
if pwndbg.gdblib.arch.name == "aarch64":
print(
M.error(
f"The {pwndbg.gdblib.arch.name} architecture does"
" not support the `monitor info mem` command. Run "
"`help show kernel-vmmap` for other options."
)
)
return () # pylint: disable=lost-exception
lines = monitor_info_mem.splitlines()
# Handle disabled PG
# This will prevent a crash on abstract architectures
if len(lines) == 1 and lines[0] == "PG disabled":
return ()
pages: List[pwndbg.lib.memory.Page] = []
for line in lines:
dash_idx = line.index("-")
space_idx = line.index(" ")
rspace_idx = line.rindex(" ")
start = int(line[:dash_idx], 16)
end = int(line[dash_idx + 1 : space_idx], 16)
size = int(line[space_idx + 1 : rspace_idx], 16)
if end - start != size and monitor_info_mem_not_warned:
print(
M.warn(
(
"The vmmap output may be incorrect as `monitor info mem` output assertion/assumption\n"
"that end-start==size failed. The values are:\n"
"end=%#x; start=%#x; size=%#x; end-start=%#x\n"
"Note that this warning will not show up again in this Pwndbg/GDB session."
)
% (end, start, size, end - start)
)
)
monitor_info_mem_not_warned = False
perm = line[rspace_idx + 1 :]
flags = 0
if "r" in perm:
flags |= 4
if "w" in perm:
flags |= 2
# QEMU does not expose X/NX bit, see #685
# if 'x' in perm: flags |= 1
flags |= 1
pages.append(pwndbg.lib.memory.Page(start, size, flags, 0, "<qemu>"))
return tuple(pages)
@pwndbg.lib.cache.cache_until("stop")
def info_sharedlibrary() -> Tuple[pwndbg.lib.memory.Page, ...]:
"""
Parses the output of `info sharedlibrary`.
Specifically, all we really want is any valid pointer into each library,
and the path to the library on disk.
With this information, we can use the ELF parser to get all of the
page permissions for every mapped page in the ELF.
Returns:
A list of pwndbg.lib.memory.Page objects.
"""
# Example of `info sharedlibrary` on FreeBSD
# From To Syms Read Shared Object Library
# 0x280fbea0 0x2810e570 Yes (*) /libexec/ld-elf.so.1
# 0x281260a0 0x281495c0 Yes (*) /lib/libncurses.so.8
# 0x28158390 0x2815dcf0 Yes (*) /usr/local/lib/libintl.so.9
# 0x28188b00 0x2828e060 Yes (*) /lib/libc.so.7
# (*): Shared library is missing debugging information.
# Example of `info sharedlibrary` on Linux
# From To Syms Read Shared Object Library
# 0x00007ffff7ddaae0 0x00007ffff7df54e0 Yes /lib64/ld-linux-x86-64.so.2
# 0x00007ffff7bbd3d0 0x00007ffff7bc9028 Yes (*) /lib/x86_64-linux-gnu/libtinfo.so.5
# 0x00007ffff79aded0 0x00007ffff79ae9ce Yes /lib/x86_64-linux-gnu/libdl.so.2
# 0x00007ffff76064a0 0x00007ffff774c113 Yes /lib/x86_64-linux-gnu/libc.so.6
# (*): Shared library is missing debugging information.
pages: List[pwndbg.lib.memory.Page] = []
for line in pwndbg.gdblib.info.sharedlibrary().splitlines():
if not line.startswith("0x"):
continue
tokens = line.split()
text = int(tokens[0], 16)
obj = tokens[-1]
pages.extend(pwndbg.gdblib.elf.map(text, obj))
return tuple(sorted(pages))
@pwndbg.lib.cache.cache_until("stop")
def info_files() -> Tuple[pwndbg.lib.memory.Page, ...]:
# Example of `info files` output:
# Symbols from "/bin/bash".
# Unix child process:
# Using the running image of child process 5903.
# While running this, GDB does not access memory from...
# Local exec file:
# `/bin/bash', file type elf64-x86-64.
# Entry point: 0x42020b
# 0x0000000000400238 - 0x0000000000400254 is .interp
# 0x0000000000400254 - 0x0000000000400274 is .note.ABI-tag
# ...
# 0x00000000006f06c0 - 0x00000000006f8ca8 is .data
# 0x00000000006f8cc0 - 0x00000000006fe898 is .bss
# 0x00007ffff7dda1c8 - 0x00007ffff7dda1ec is .note.gnu.build-id in /lib64/ld-linux-x86-64.so.2
# 0x00007ffff7dda1f0 - 0x00007ffff7dda2ac is .hash in /lib64/ld-linux-x86-64.so.2
# 0x00007ffff7dda2b0 - 0x00007ffff7dda38c is .gnu.hash in /lib64/ld-linux-x86-64.so.2
seen_files: Set[str] = set()
pages: List[pwndbg.lib.memory.Page] = []
main_exe = ""
for line in pwndbg.gdblib.info.files().splitlines():
line = line.strip()
# The name of the main executable
if line.startswith("`"):
exename, filetype = line.split(maxsplit=1)
main_exe = exename.strip("`,'")
continue
# Everything else should be addresses
if not line.startswith("0x"):
continue
# start, stop, _, segment, _, filename = line.split(maxsplit=6)
fields = line.split(maxsplit=6)
vaddr = int(fields[0], 16)
if len(fields) == 5:
objfile = main_exe
elif len(fields) == 7:
objfile = fields[6]
else:
print("Bad data: %r" % line)
continue
if objfile not in seen_files:
seen_files.add(objfile)
pages.extend(pwndbg.gdblib.elf.map(vaddr, objfile))
return tuple(pages)
@pwndbg.lib.cache.cache_until("exit")
def info_auxv(skip_exe: bool = False) -> Tuple[pwndbg.lib.memory.Page, ...]:
"""
Extracts the name of the executable from the output of the command
"info auxv". Note that if the executable path is a symlink,
it is not dereferenced by `info auxv` and we also don't dereference it.
Arguments:
skip_exe(bool): Do not return any mappings that belong to the exe.
Returns:
A list of pwndbg.lib.memory.Page objects.
"""
auxv = pwndbg.auxv.get()
if not auxv:
return ()
pages: List[pwndbg.lib.memory.Page] = []
exe_name = auxv.AT_EXECFN or "main.exe"
entry = auxv.AT_ENTRY
base = auxv.AT_BASE
vdso = auxv.AT_SYSINFO_EHDR or auxv.AT_SYSINFO
phdr = auxv.AT_PHDR
if not skip_exe and (entry or phdr):
for addr in [entry, phdr]:
if not addr:
continue
new_pages = pwndbg.gdblib.elf.map(addr, exe_name)
if new_pages:
pages.extend(new_pages)
break
if base:
pages.extend(pwndbg.gdblib.elf.map(base, "[linker]"))
if vdso:
pages.extend(pwndbg.gdblib.elf.map(vdso, "[vdso]"))
return tuple(sorted(pages))
def find_boundaries(addr: int, name: str = "", min: int = 0) -> pwndbg.lib.memory.Page:
"""
Given a single address, find all contiguous pages
which are mapped.
"""
start = pwndbg.gdblib.memory.find_lower_boundary(addr)
end = pwndbg.gdblib.memory.find_upper_boundary(addr)
start = max(start, min)
return pwndbg.lib.memory.Page(start, end - start, 4, 0, name)
def check_aslr() -> Tuple[bool | None, str]:
"""
Detects the ASLR status. Returns True, False or None.
None is returned when we can't detect ASLR.
"""
# QEMU does not support this concept.
if pwndbg.gdblib.qemu.is_qemu():
return None, "Could not detect ASLR on QEMU targets"
# Systemwide ASLR is disabled
try:
data = pwndbg.gdblib.file.get("/proc/sys/kernel/randomize_va_space")
if b"0" in data:
return False, "kernel.randomize_va_space == 0"
except Exception:
print("Could not check ASLR: can't read randomize_va_space")
# Check the personality of the process
if pwndbg.gdblib.proc.alive:
try:
data = pwndbg.gdblib.file.get("/proc/%i/personality" % pwndbg.gdblib.proc.tid)
personality = int(data, 16)
return (personality & 0x40000 == 0), "read status from process' personality"
except Exception:
print("Could not check ASLR: can't read process' personality")
# Just go with whatever GDB says it did.
#
# This should usually be identical to the above, but we may not have
# access to procfs.
output = gdb.execute("show disable-randomization", to_string=True)
return ("is off." in output), "show disable-randomization"