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
14import gdb
15
16from linux import cpus, utils, lists, constants
17
18
19module_type = utils.CachedType("struct module")
20
21
22def 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
34def 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
41class 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
45of 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
59LxModule()
60
61
62class 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
100LxLsmod()
101
102def 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
108class 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
131LxFindTextAddrinMod()
132