scripts/gdb/linux/proc.py

   1 #
   2 # gdb helper commands and functions for Linux kernel debugging
   3 #
   4 #  Kernel proc information reader
   5 #
   6 # Copyright (c) 2016 Linaro Ltd
   7 #
   8 # Authors:
   9 #  Kieran Bingham <kieran.bingham@linaro.org>
  10 #
  11 # This work is licensed under the terms of the GNU GPL version 2.
  12 #
  13
  14 import gdb
  15 from linux import constants
  16 from linux import utils
  17 from linux import tasks
  18 from linux import lists
  19
  20
  21 class LxCmdLine(gdb.Command):
  22     """ Report the Linux Commandline used in the current kernel.
  23         Equivalent to cat /proc/cmdline on a running target"""
  24
  25     def __init__(self):
  26         super(LxCmdLine, self).__init__("lx-cmdline", gdb.COMMAND_DATA)
  27
  28     def invoke(self, arg, from_tty):
  29         gdb.write(gdb.parse_and_eval("saved_command_line").string() + "\n")
  30
  31 LxCmdLine()
  32
  33
  34 class LxVersion(gdb.Command):
  35     """ Report the Linux Version of the current kernel.
  36         Equivalent to cat /proc/version on a running target"""
  37
  38     def __init__(self):
  39         super(LxVersion, self).__init__("lx-version", gdb.COMMAND_DATA)
  40
  41     def invoke(self, arg, from_tty):
  42         # linux_banner should contain a newline
  43         gdb.write(gdb.parse_and_eval("linux_banner").string())
  44
  45 LxVersion()
  46
  47
  48 # Resource Structure Printers
  49 #  /proc/iomem
  50 #  /proc/ioports
  51
  52 def get_resources(resource, depth):
  53     while resource:
  54         yield resource, depth
  55
  56         child = resource['child']
  57         if child:
  58             for res, deep in get_resources(child, depth + 1):
  59                 yield res, deep
  60
  61         resource = resource['sibling']
  62
  63
  64 def show_lx_resources(resource_str):
  65         resource = gdb.parse_and_eval(resource_str)
  66         width = 4 if resource['end'] < 0x10000 else 8
  67         # Iterate straight to the first child
  68         for res, depth in get_resources(resource['child'], 0):
  69             start = int(res['start'])
  70             end = int(res['end'])
  71             gdb.write(" " * depth * 2 +
  72                       "{0:0{1}x}-".format(start, width) +
  73                       "{0:0{1}x} : ".format(end, width) +
  74                       res['name'].string() + "\n")
  75
  76
  77 class LxIOMem(gdb.Command):
  78     """Identify the IO memory resource locations defined by the kernel
  79
  80 Equivalent to cat /proc/iomem on a running target"""
  81
  82     def __init__(self):
  83         super(LxIOMem, self).__init__("lx-iomem", gdb.COMMAND_DATA)
  84
  85     def invoke(self, arg, from_tty):
  86         return show_lx_resources("iomem_resource")
  87
  88 LxIOMem()
  89
  90
  91 class LxIOPorts(gdb.Command):
  92     """Identify the IO port resource locations defined by the kernel
  93
  94 Equivalent to cat /proc/ioports on a running target"""
  95
  96     def __init__(self):
  97         super(LxIOPorts, self).__init__("lx-ioports", gdb.COMMAND_DATA)
  98
  99     def invoke(self, arg, from_tty):
 100         return show_lx_resources("ioport_resource")
 101
 102 LxIOPorts()
 103
 104
 105 # Mount namespace viewer
 106 #  /proc/mounts
 107
 108 def info_opts(lst, opt):
 109     opts = ""
 110     for key, string in lst.items():
 111         if opt & key:
 112             opts += string
 113     return opts
 114
 115
 116 FS_INFO = {constants.LX_MS_SYNCHRONOUS: ",sync",
 117            constants.LX_MS_MANDLOCK: ",mand",
 118            constants.LX_MS_DIRSYNC: ",dirsync",
 119            constants.LX_MS_NOATIME: ",noatime",
 120            constants.LX_MS_NODIRATIME: ",nodiratime"}
 121
 122 MNT_INFO = {constants.LX_MNT_NOSUID: ",nosuid",
 123             constants.LX_MNT_NODEV: ",nodev",
 124             constants.LX_MNT_NOEXEC: ",noexec",
 125             constants.LX_MNT_NOATIME: ",noatime",
 126             constants.LX_MNT_NODIRATIME: ",nodiratime",
 127             constants.LX_MNT_RELATIME: ",relatime"}
 128
 129 mount_type = utils.CachedType("struct mount")
 130 mount_ptr_type = mount_type.get_type().pointer()
 131
 132
 133 class LxMounts(gdb.Command):
 134     """Report the VFS mounts of the current process namespace.
 135
 136 Equivalent to cat /proc/mounts on a running target
 137 An integer value can be supplied to display the mount
 138 values of that process namespace"""
 139
 140     def __init__(self):
 141         super(LxMounts, self).__init__("lx-mounts", gdb.COMMAND_DATA)
 142
 143     # Equivalent to proc_namespace.c:show_vfsmnt
 144     # However, that has the ability to call into s_op functions
 145     # whereas we cannot and must make do with the information we can obtain.
 146     def invoke(self, arg, from_tty):
 147         argv = gdb.string_to_argv(arg)
 148         if len(argv) >= 1:
 149             try:
 150                 pid = int(argv[0])
 151             except:
 152                 raise gdb.GdbError("Provide a PID as integer value")
 153         else:
 154             pid = 1
 155
 156         task = tasks.get_task_by_pid(pid)
 157         if not task:
 158             raise gdb.GdbError("Couldn't find a process with PID {}"
 159                                .format(pid))
 160
 161         namespace = task['nsproxy']['mnt_ns']
 162         if not namespace:
 163             raise gdb.GdbError("No namespace for current process")
 164
 165         for vfs in lists.list_for_each_entry(namespace['list'],
 166                                              mount_ptr_type, "mnt_list"):
 167             devname = vfs['mnt_devname'].string()
 168             devname = devname if devname else "none"
 169
 170             pathname = ""
 171             parent = vfs
 172             while True:
 173                 mntpoint = parent['mnt_mountpoint']
 174                 pathname = utils.dentry_name(mntpoint) + pathname
 175                 if (parent == parent['mnt_parent']):
 176                     break
 177                 parent = parent['mnt_parent']
 178
 179             if (pathname == ""):
 180                 pathname = "/"
 181
 182             superblock = vfs['mnt']['mnt_sb']
 183             fstype = superblock['s_type']['name'].string()
 184             s_flags = int(superblock['s_flags'])
 185             m_flags = int(vfs['mnt']['mnt_flags'])
 186             rd = "ro" if (s_flags & constants.LX_MS_RDONLY) else "rw"
 187
 188             gdb.write(
 189                 "{} {} {} {}{}{} 0 0\n"
 190                 .format(devname,
 191                         pathname,
 192                         fstype,
 193                         rd,
 194                         info_opts(FS_INFO, s_flags),
 195                         info_opts(MNT_INFO, m_flags)))
 196
 197 LxMounts()