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 from struct import *
  20
  21
  22 class LxCmdLine(gdb.Command):
  23     """ Report the Linux Commandline used in the current kernel.
  24         Equivalent to cat /proc/cmdline on a running target"""
  25
  26     def __init__(self):
  27         super(LxCmdLine, self).__init__("lx-cmdline", gdb.COMMAND_DATA)
  28
  29     def invoke(self, arg, from_tty):
  30         gdb.write(gdb.parse_and_eval("saved_command_line").string() + "\n")
  31
  32 LxCmdLine()
  33
  34
  35 class LxVersion(gdb.Command):
  36     """ Report the Linux Version of the current kernel.
  37         Equivalent to cat /proc/version on a running target"""
  38
  39     def __init__(self):
  40         super(LxVersion, self).__init__("lx-version", gdb.COMMAND_DATA)
  41
  42     def invoke(self, arg, from_tty):
  43         # linux_banner should contain a newline
  44         gdb.write(gdb.parse_and_eval("linux_banner").string())
  45
  46 LxVersion()
  47
  48
  49 # Resource Structure Printers
  50 #  /proc/iomem
  51 #  /proc/ioports
  52
  53 def get_resources(resource, depth):
  54     while resource:
  55         yield resource, depth
  56
  57         child = resource['child']
  58         if child:
  59             for res, deep in get_resources(child, depth + 1):
  60                 yield res, deep
  61
  62         resource = resource['sibling']
  63
  64
  65 def show_lx_resources(resource_str):
  66         resource = gdb.parse_and_eval(resource_str)
  67         width = 4 if resource['end'] < 0x10000 else 8
  68         # Iterate straight to the first child
  69         for res, depth in get_resources(resource['child'], 0):
  70             start = int(res['start'])
  71             end = int(res['end'])
  72             gdb.write(" " * depth * 2 +
  73                       "{0:0{1}x}-".format(start, width) +
  74                       "{0:0{1}x} : ".format(end, width) +
  75                       res['name'].string() + "\n")
  76
  77
  78 class LxIOMem(gdb.Command):
  79     """Identify the IO memory resource locations defined by the kernel
  80
  81 Equivalent to cat /proc/iomem on a running target"""
  82
  83     def __init__(self):
  84         super(LxIOMem, self).__init__("lx-iomem", gdb.COMMAND_DATA)
  85
  86     def invoke(self, arg, from_tty):
  87         return show_lx_resources("iomem_resource")
  88
  89 LxIOMem()
  90
  91
  92 class LxIOPorts(gdb.Command):
  93     """Identify the IO port resource locations defined by the kernel
  94
  95 Equivalent to cat /proc/ioports on a running target"""
  96
  97     def __init__(self):
  98         super(LxIOPorts, self).__init__("lx-ioports", gdb.COMMAND_DATA)
  99
 100     def invoke(self, arg, from_tty):
 101         return show_lx_resources("ioport_resource")
 102
 103 LxIOPorts()
 104
 105
 106 # Mount namespace viewer
 107 #  /proc/mounts
 108
 109 def info_opts(lst, opt):
 110     opts = ""
 111     for key, string in lst.items():
 112         if opt & key:
 113             opts += string
 114     return opts
 115
 116
 117 FS_INFO = {constants.LX_MS_SYNCHRONOUS: ",sync",
 118            constants.LX_MS_MANDLOCK: ",mand",
 119            constants.LX_MS_DIRSYNC: ",dirsync",
 120            constants.LX_MS_NOATIME: ",noatime",
 121            constants.LX_MS_NODIRATIME: ",nodiratime"}
 122
 123 MNT_INFO = {constants.LX_MNT_NOSUID: ",nosuid",
 124             constants.LX_MNT_NODEV: ",nodev",
 125             constants.LX_MNT_NOEXEC: ",noexec",
 126             constants.LX_MNT_NOATIME: ",noatime",
 127             constants.LX_MNT_NODIRATIME: ",nodiratime",
 128             constants.LX_MNT_RELATIME: ",relatime"}
 129
 130 mount_type = utils.CachedType("struct mount")
 131 mount_ptr_type = mount_type.get_type().pointer()
 132
 133
 134 class LxMounts(gdb.Command):
 135     """Report the VFS mounts of the current process namespace.
 136
 137 Equivalent to cat /proc/mounts on a running target
 138 An integer value can be supplied to display the mount
 139 values of that process namespace"""
 140
 141     def __init__(self):
 142         super(LxMounts, self).__init__("lx-mounts", gdb.COMMAND_DATA)
 143
 144     # Equivalent to proc_namespace.c:show_vfsmnt
 145     # However, that has the ability to call into s_op functions
 146     # whereas we cannot and must make do with the information we can obtain.
 147     def invoke(self, arg, from_tty):
 148         argv = gdb.string_to_argv(arg)
 149         if len(argv) >= 1:
 150             try:
 151                 pid = int(argv[0])
 152             except:
 153                 raise gdb.GdbError("Provide a PID as integer value")
 154         else:
 155             pid = 1
 156
 157         task = tasks.get_task_by_pid(pid)
 158         if not task:
 159             raise gdb.GdbError("Couldn't find a process with PID {}"
 160                                .format(pid))
 161
 162         namespace = task['nsproxy']['mnt_ns']
 163         if not namespace:
 164             raise gdb.GdbError("No namespace for current process")
 165
 166         for vfs in lists.list_for_each_entry(namespace['list'],
 167                                              mount_ptr_type, "mnt_list"):
 168             devname = vfs['mnt_devname'].string()
 169             devname = devname if devname else "none"
 170
 171             pathname = ""
 172             parent = vfs
 173             while True:
 174                 mntpoint = parent['mnt_mountpoint']
 175                 pathname = utils.dentry_name(mntpoint) + pathname
 176                 if (parent == parent['mnt_parent']):
 177                     break
 178                 parent = parent['mnt_parent']
 179
 180             if (pathname == ""):
 181                 pathname = "/"
 182
 183             superblock = vfs['mnt']['mnt_sb']
 184             fstype = superblock['s_type']['name'].string()
 185             s_flags = int(superblock['s_flags'])
 186             m_flags = int(vfs['mnt']['mnt_flags'])
 187             rd = "ro" if (s_flags & constants.LX_MS_RDONLY) else "rw"
 188
 189             gdb.write(
 190                 "{} {} {} {}{}{} 0 0\n"
 191                 .format(devname,
 192                         pathname,
 193                         fstype,
 194                         rd,
 195                         info_opts(FS_INFO, s_flags),
 196                         info_opts(MNT_INFO, m_flags)))
 197
 198 LxMounts()
 199
 200
 201 class LxFdtDump(gdb.Command):
 202     """Output Flattened Device Tree header and dump FDT blob to the filename
 203        specified as the command argument. Equivalent to
 204        'cat /proc/fdt > fdtdump.dtb' on a running target"""
 205
 206     def __init__(self):
 207         super(LxFdtDump, self).__init__("lx-fdtdump", gdb.COMMAND_DATA,
 208                                         gdb.COMPLETE_FILENAME)
 209
 210     def fdthdr_to_cpu(self, fdt_header):
 211
 212         fdt_header_be = ">IIIIIII"
 213         fdt_header_le = "<IIIIIII"
 214
 215         if utils.get_target_endianness() == 1:
 216             output_fmt = fdt_header_le
 217         else:
 218             output_fmt = fdt_header_be
 219
 220         return unpack(output_fmt, pack(fdt_header_be,
 221                                        fdt_header['magic'],
 222                                        fdt_header['totalsize'],
 223                                        fdt_header['off_dt_struct'],
 224                                        fdt_header['off_dt_strings'],
 225                                        fdt_header['off_mem_rsvmap'],
 226                                        fdt_header['version'],
 227                                        fdt_header['last_comp_version']))
 228
 229     def invoke(self, arg, from_tty):
 230
 231         if not constants.LX_CONFIG_OF:
 232             raise gdb.GdbError("Kernel not compiled with CONFIG_OF\n")
 233
 234         if len(arg) == 0:
 235             filename = "fdtdump.dtb"
 236         else:
 237             filename = arg
 238
 239         py_fdt_header_ptr = gdb.parse_and_eval(
 240             "(const struct fdt_header *) initial_boot_params")
 241         py_fdt_header = py_fdt_header_ptr.dereference()
 242
 243         fdt_header = self.fdthdr_to_cpu(py_fdt_header)
 244
 245         if fdt_header[0] != constants.LX_OF_DT_HEADER:
 246             raise gdb.GdbError("No flattened device tree magic found\n")
 247
 248         gdb.write("fdt_magic:         0x{:02X}\n".format(fdt_header[0]))
 249         gdb.write("fdt_totalsize:     0x{:02X}\n".format(fdt_header[1]))
 250         gdb.write("off_dt_struct:     0x{:02X}\n".format(fdt_header[2]))
 251         gdb.write("off_dt_strings:    0x{:02X}\n".format(fdt_header[3]))
 252         gdb.write("off_mem_rsvmap:    0x{:02X}\n".format(fdt_header[4]))
 253         gdb.write("version:           {}\n".format(fdt_header[5]))
 254         gdb.write("last_comp_version: {}\n".format(fdt_header[6]))
 255
 256         inf = gdb.inferiors()[0]
 257         fdt_buf = utils.read_memoryview(inf, py_fdt_header_ptr,
 258                                         fdt_header[1]).tobytes()
 259
 260         try:
 261             f = open(filename, 'wb')
 262         except:
 263             raise gdb.GdbError("Could not open file to dump fdt")
 264
 265         f.write(fdt_buf)
 266         f.close()
 267
 268         gdb.write("Dumped fdt blob to " + filename + "\n")
 269
 270 LxFdtDump()