1 #
2 # gdb helper commands and functions for Linux
3 #
4 # load kernel and module symbols
5 #
6 # Copyright (c) Siemens AG, 2011-2013
7 #
8 # Authors:
9 # Jan Kiszka <jan.kiszka@siemens.com>
10 #
11 # This work is licensed under the terms of the
12 #
13
14 import gdb
15 import os
16 import re
17
18 from linux import modules, utils, constants
19
20
21 if hasattr(gdb, 'Breakpoint'):
22 class LoadModuleBreakpoint(gdb.Breakpoint)
23 def __init__(self, spec, gdb_command):
24 super(LoadModuleBreakpoint, self).
25 self.silent = True
26 self.gdb_command = gdb_command
27
28 def stop(self):
29 module = gdb.parse_and_eval("mod")
30 module_name = module['name'].strin
31 cmd = self.gdb_command
32
33 # enforce update if object file is
34 cmd.module_files_updated = False
35
36 # Disable pagination while reporti
37 # The console input is blocked in
38 # get stuck waiting for the user t
39 show_pagination = gdb.execute("sho
40 pagination = show_pagination.endsw
41 gdb.execute("set pagination off")
42
43 if module_name in cmd.loaded_modul
44 gdb.write("refreshing all symb
45 "'{0}'\n".format(mod
46 cmd.load_all_symbols()
47 else:
48 cmd.load_module_symbols(module
49
50 # restore pagination state
51 gdb.execute("set pagination %s" %
52
53 return False
54
55
56 class LxSymbols(gdb.Command):
57 """(Re-)load symbols of Linux kernel and c
58
59 The kernel (vmlinux) is taken from the current
60 are scanned recursively, starting in the same
61 search path can be extended by a space separat
62 lx-symbols command."""
63
64 module_paths = []
65 module_files = []
66 module_files_updated = False
67 loaded_modules = []
68 breakpoint = None
69
70 def __init__(self):
71 super(LxSymbols, self).__init__("lx-sy
72 gdb.CO
73
74 def _update_module_files(self):
75 self.module_files = []
76 for path in self.module_paths:
77 gdb.write("scanning for modules in
78 for root, dirs, files in os.walk(p
79 for name in files:
80 if name.endswith(".ko") or
81 self.module_files.appe
82 self.module_files_updated = True
83
84 def _get_module_file(self, module_name):
85 module_pattern = r".*/{0}\.ko(?:.debug
86 module_name.replace("_", r"[_\-]")
87 for name in self.module_files:
88 if re.match(module_pattern, name)
89 return name
90 return None
91
92 def _section_arguments(self, module, modul
93 try:
94 sect_attrs = module['sect_attrs'].
95 except gdb.error:
96 return str(module_addr)
97
98 attrs = sect_attrs['attrs']
99 section_name_to_address = {
100 attrs[n]['battr']['attr']['name'].
101 for n in range(int(sect_attrs['nse
102
103 textaddr = section_name_to_address.get
104 args = []
105 for section_name in [".data", ".data..
106 ".text.hot", ".te
107 address = section_name_to_address.
108 if address:
109 args.append(" -s {name} {addr}
110 name=section_name, addr=st
111 return "{textaddr} {sections}".format(
112 textaddr=textaddr, sections="".joi
113
114 def load_module_symbols(self, module):
115 module_name = module['name'].string()
116 module_addr = str(module['mem'][consta
117
118 module_file = self._get_module_file(mo
119 if not module_file and not self.module
120 self._update_module_files()
121 module_file = self._get_module_fil
122
123 if module_file:
124 if utils.is_target_arch('s390'):
125 # Module text is preceded by P
126 module_arch = module['arch']
127 plt_offset = int(module_arch['
128 plt_size = int(module_arch['pl
129 module_addr = hex(int(module_a
130 gdb.write("loading @{addr}: {filen
131 addr=module_addr, filename=mod
132 cmdline = "add-symbol-file {filena
133 filename=module_file,
134 sections=self._section_argumen
135 gdb.execute(cmdline, to_string=Tru
136 if module_name not in self.loaded_
137 self.loaded_modules.append(mod
138 else:
139 gdb.write("no module object found
140
141 def load_all_symbols(self):
142 gdb.write("loading vmlinux\n")
143
144 # Dropping symbols will disable all br
145 # and restore them afterward.
146 saved_states = []
147 if hasattr(gdb, 'breakpoints') and not
148 for bp in gdb.breakpoints():
149 saved_states.append({'breakpoi
150
151 # drop all current symbols and reload
152 orig_vmlinux = 'vmlinux'
153 for obj in gdb.objfiles():
154 if (obj.filename.endswith('vmlinux
155 obj.filename.endswith('vmlinux
156 orig_vmlinux = obj.filename
157 gdb.execute("symbol-file", to_string=T
158 gdb.execute("symbol-file {0}".format(o
159
160 self.loaded_modules = []
161 module_list = modules.module_list()
162 if not module_list:
163 gdb.write("no modules found\n")
164 else:
165 [self.load_module_symbols(module)
166
167 for saved_state in saved_states:
168 saved_state['breakpoint'].enabled
169
170 def invoke(self, arg, from_tty):
171 self.module_paths = [os.path.abspath(o
172 for p in arg.spli
173 self.module_paths.append(os.getcwd())
174
175 # enforce update
176 self.module_files = []
177 self.module_files_updated = False
178
179 self.load_all_symbols()
180
181 if hasattr(gdb, 'Breakpoint'):
182 if self.breakpoint is not None:
183 self.breakpoint.delete()
184 self.breakpoint = None
185 self.breakpoint = LoadModuleBreakp
186 "kernel/module/main.c:do_init_
187 else:
188 gdb.write("Note: symbol update on
189 "with this gdb version\n
190
191
192 LxSymbols()
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