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