scripts/gdb/linux/modules.py

   1 #
   2 # gdb helper commands and functions for Linux kernel debugging
   3 #
   4 #  module tools
   5 #
   6 # Copyright (c) Siemens AG, 2013
   7 #
   8 # Authors:
   9 #  Jan Kiszka <jan.kiszka@siemens.com>
  10 #
  11 # This work is licensed under the terms of the GNU GPL version 2.
  12 #
  13
  14 import gdb
  15
  16 from linux import cpus, utils, lists, constants
  17
  18
  19 module_type = utils.CachedType("struct module")
  20
  21
  22 def module_list():
  23     global module_type
  24     modules = utils.gdb_eval_or_none("modules")
  25     if modules is None:
  26         return
  27
  28     module_ptr_type = module_type.get_type().pointer()
  29
  30     for module in lists.list_for_each_entry(modules, module_ptr_type, "list"):
  31         yield module
  32
  33
  34 def find_module_by_name(name):
  35     for module in module_list():
  36         if module['name'].string() == name:
  37             return module
  38     return None
  39
  40
  41 class LxModule(gdb.Function):
  42     """Find module by name and return the module variable.
  43
  44 $lx_module("MODULE"): Given the name MODULE, iterate over all loaded modules
  45 of the target and return that module variable which MODULE matches."""
  46
  47     def __init__(self):
  48         super(LxModule, self).__init__("lx_module")
  49
  50     def invoke(self, mod_name):
  51         mod_name = mod_name.string()
  52         module = find_module_by_name(mod_name)
  53         if module:
  54             return module.dereference()
  55         else:
  56             raise gdb.GdbError("Unable to find MODULE " + mod_name)
  57
  58
  59 LxModule()
  60
  61
  62 class LxLsmod(gdb.Command):
  63     """List currently loaded modules."""
  64
  65     _module_use_type = utils.CachedType("struct module_use")
  66
  67     def __init__(self):
  68         super(LxLsmod, self).__init__("lx-lsmod", gdb.COMMAND_DATA)
  69
  70     def invoke(self, arg, from_tty):
  71         gdb.write(
  72             "Address{0}    Module                  Size  Used by\n".format(
  73                 "        " if utils.get_long_type().sizeof == 8 else ""))
  74
  75         for module in module_list():
  76             text = module['mem'][constants.LX_MOD_TEXT]
  77             text_addr = str(text['base']).split()[0]
  78             total_size = 0
  79
  80             for i in range(constants.LX_MOD_TEXT, constants.LX_MOD_RO_AFTER_INIT + 1):
  81                 total_size += module['mem'][i]['size']
  82
  83             gdb.write("{address} {name:<19} {size:>8}  {ref}".format(
  84                 address=text_addr,
  85                 name=module['name'].string(),
  86                 size=str(total_size),
  87                 ref=str(module['refcnt']['counter'] - 1)))
  88
  89             t = self._module_use_type.get_type().pointer()
  90             first = True
  91             sources = module['source_list']
  92             for use in lists.list_for_each_entry(sources, t, "source_list"):
  93                 gdb.write("{separator}{name}".format(
  94                     separator=" " if first else ",",
  95                     name=use['source']['name'].string()))
  96                 first = False
  97
  98             gdb.write("\n")
  99
 100 LxLsmod()
 101
 102 def help():
 103     t = """Usage: lx-getmod-by-textaddr [Heximal Address]
 104     Example: lx-getmod-by-textaddr 0xffff800002d305ac\n"""
 105     gdb.write("Unrecognized command\n")
 106     raise gdb.GdbError(t)
 107
 108 class LxFindTextAddrinMod(gdb.Command):
 109     '''Look up loaded kernel module by text address.'''
 110
 111     def __init__(self):
 112         super(LxFindTextAddrinMod, self).__init__('lx-getmod-by-textaddr', gdb.COMMAND_SUPPORT)
 113
 114     def invoke(self, arg, from_tty):
 115         args = gdb.string_to_argv(arg)
 116
 117         if len(args) != 1:
 118             help()
 119
 120         addr = gdb.Value(int(args[0], 16)).cast(utils.get_ulong_type())
 121         for mod in module_list():
 122             mod_text_start = mod['mem'][constants.LX_MOD_TEXT]['base']
 123             mod_text_end = mod_text_start + mod['mem'][constants.LX_MOD_TEXT]['size'].cast(utils.get_ulong_type())
 124
 125             if addr >= mod_text_start and addr < mod_text_end:
 126                 s = "0x%x" % addr + " is in " + mod['name'].string() + ".ko\n"
 127                 gdb.write(s)
 128                 return
 129         gdb.write("0x%x is not in any module text section\n" % addr)
 130
 131 LxFindTextAddrinMod()