blob: 09cd871925a5fcdbd15ffed9f4fb260a33fa2b5d [file] [log] [blame]
# gdb helper commands and functions for Linux kernel debugging
# Kernel proc information reader
# Copyright (c) 2016 Linaro Ltd
# Authors:
# Kieran Bingham <>
# This work is licensed under the terms of the GNU GPL version 2.
import gdb
from linux import constants
from linux import utils
from linux import tasks
from linux import lists
from struct import *
class LxCmdLine(gdb.Command):
""" Report the Linux Commandline used in the current kernel.
Equivalent to cat /proc/cmdline on a running target"""
def __init__(self):
super(LxCmdLine, self).__init__("lx-cmdline", gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
gdb.write(gdb.parse_and_eval("saved_command_line").string() + "\n")
class LxVersion(gdb.Command):
""" Report the Linux Version of the current kernel.
Equivalent to cat /proc/version on a running target"""
def __init__(self):
super(LxVersion, self).__init__("lx-version", gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
# linux_banner should contain a newline
gdb.write(gdb.parse_and_eval("(char *)linux_banner").string())
# Resource Structure Printers
# /proc/iomem
# /proc/ioports
def get_resources(resource, depth):
while resource:
yield resource, depth
child = resource['child']
if child:
for res, deep in get_resources(child, depth + 1):
yield res, deep
resource = resource['sibling']
def show_lx_resources(resource_str):
resource = gdb.parse_and_eval(resource_str)
width = 4 if resource['end'] < 0x10000 else 8
# Iterate straight to the first child
for res, depth in get_resources(resource['child'], 0):
start = int(res['start'])
end = int(res['end'])
gdb.write(" " * depth * 2 +
"{0:0{1}x}-".format(start, width) +
"{0:0{1}x} : ".format(end, width) +
res['name'].string() + "\n")
class LxIOMem(gdb.Command):
"""Identify the IO memory resource locations defined by the kernel
Equivalent to cat /proc/iomem on a running target"""
def __init__(self):
super(LxIOMem, self).__init__("lx-iomem", gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
return show_lx_resources("iomem_resource")
class LxIOPorts(gdb.Command):
"""Identify the IO port resource locations defined by the kernel
Equivalent to cat /proc/ioports on a running target"""
def __init__(self):
super(LxIOPorts, self).__init__("lx-ioports", gdb.COMMAND_DATA)
def invoke(self, arg, from_tty):
return show_lx_resources("ioport_resource")
# Mount namespace viewer
# /proc/mounts
def info_opts(lst, opt):
opts = ""
for key, string in lst.items():
if opt & key:
opts += string
return opts
FS_INFO = {constants.LX_SB_SYNCHRONOUS: ",sync",
constants.LX_SB_MANDLOCK: ",mand",
constants.LX_SB_DIRSYNC: ",dirsync",
constants.LX_SB_NOATIME: ",noatime",
constants.LX_SB_NODIRATIME: ",nodiratime"}
MNT_INFO = {constants.LX_MNT_NOSUID: ",nosuid",
constants.LX_MNT_NODEV: ",nodev",
constants.LX_MNT_NOEXEC: ",noexec",
constants.LX_MNT_NOATIME: ",noatime",
constants.LX_MNT_NODIRATIME: ",nodiratime",
constants.LX_MNT_RELATIME: ",relatime"}
mount_type = utils.CachedType("struct mount")
mount_ptr_type = mount_type.get_type().pointer()
class LxMounts(gdb.Command):
"""Report the VFS mounts of the current process namespace.
Equivalent to cat /proc/mounts on a running target
An integer value can be supplied to display the mount
values of that process namespace"""
def __init__(self):
super(LxMounts, self).__init__("lx-mounts", gdb.COMMAND_DATA)
# Equivalent to proc_namespace.c:show_vfsmnt
# However, that has the ability to call into s_op functions
# whereas we cannot and must make do with the information we can obtain.
def invoke(self, arg, from_tty):
argv = gdb.string_to_argv(arg)
if len(argv) >= 1:
pid = int(argv[0])
except gdb.error:
raise gdb.GdbError("Provide a PID as integer value")
pid = 1
task = tasks.get_task_by_pid(pid)
if not task:
raise gdb.GdbError("Couldn't find a process with PID {}"
namespace = task['nsproxy']['mnt_ns']
if not namespace:
raise gdb.GdbError("No namespace for current process")
gdb.write("{:^18} {:^15} {:>9} {} {} options\n".format(
"mount", "super_block", "devname", "pathname", "fstype"))
for vfs in lists.list_for_each_entry(namespace['list'],
mount_ptr_type, "mnt_list"):
devname = vfs['mnt_devname'].string()
devname = devname if devname else "none"
pathname = ""
parent = vfs
while True:
mntpoint = parent['mnt_mountpoint']
pathname = utils.dentry_name(mntpoint) + pathname
if (parent == parent['mnt_parent']):
parent = parent['mnt_parent']
if (pathname == ""):
pathname = "/"
superblock = vfs['mnt']['mnt_sb']
fstype = superblock['s_type']['name'].string()
s_flags = int(superblock['s_flags'])
m_flags = int(vfs['mnt']['mnt_flags'])
rd = "ro" if (s_flags & constants.LX_SB_RDONLY) else "rw"
gdb.write("{} {} {} {} {} {}{}{} 0 0\n".format(
vfs.format_string(), superblock.format_string(), devname,
pathname, fstype, rd, info_opts(FS_INFO, s_flags),
info_opts(MNT_INFO, m_flags)))
class LxFdtDump(gdb.Command):
"""Output Flattened Device Tree header and dump FDT blob to the filename
specified as the command argument. Equivalent to
'cat /proc/fdt > fdtdump.dtb' on a running target"""
def __init__(self):
super(LxFdtDump, self).__init__("lx-fdtdump", gdb.COMMAND_DATA,
def fdthdr_to_cpu(self, fdt_header):
fdt_header_be = ">IIIIIII"
fdt_header_le = "<IIIIIII"
if utils.get_target_endianness() == 1:
output_fmt = fdt_header_le
output_fmt = fdt_header_be
return unpack(output_fmt, pack(fdt_header_be,
def invoke(self, arg, from_tty):
if not constants.LX_CONFIG_OF:
raise gdb.GdbError("Kernel not compiled with CONFIG_OF\n")
if len(arg) == 0:
filename = "fdtdump.dtb"
filename = arg
py_fdt_header_ptr = gdb.parse_and_eval(
"(const struct fdt_header *) initial_boot_params")
py_fdt_header = py_fdt_header_ptr.dereference()
fdt_header = self.fdthdr_to_cpu(py_fdt_header)
if fdt_header[0] != constants.LX_OF_DT_HEADER:
raise gdb.GdbError("No flattened device tree magic found\n")
gdb.write("fdt_magic: 0x{:02X}\n".format(fdt_header[0]))
gdb.write("fdt_totalsize: 0x{:02X}\n".format(fdt_header[1]))
gdb.write("off_dt_struct: 0x{:02X}\n".format(fdt_header[2]))
gdb.write("off_dt_strings: 0x{:02X}\n".format(fdt_header[3]))
gdb.write("off_mem_rsvmap: 0x{:02X}\n".format(fdt_header[4]))
gdb.write("version: {}\n".format(fdt_header[5]))
gdb.write("last_comp_version: {}\n".format(fdt_header[6]))
inf = gdb.inferiors()[0]
fdt_buf = utils.read_memoryview(inf, py_fdt_header_ptr,
f = open(filename, 'wb')
except gdb.error:
raise gdb.GdbError("Could not open file to dump fdt")
gdb.write("Dumped fdt blob to " + filename + "\n")