1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
| #!/usr/bin/python
#----------------------------------------------------------------------
# Be sure to add the python path that points to the LLDB shared library.
#
# # To use this in the embedded python interpreter using "lldb" just
# import it with the full path using the "command script import"
# command
# (lldb) command script import /path/to/cmdtemplate.py
#----------------------------------------------------------------------
from __future__ import print_function
import platform
import os
import re
import signal
import sys
import subprocess
try:
# Just try for LLDB in case PYTHONPATH is already correctly setup
import lldb
except ImportError:
lldb_python_dirs = list()
# lldb is not in the PYTHONPATH, try some defaults for the current platform
platform_system = platform.system()
if platform_system == 'Darwin':
# On Darwin, try the currently selected Xcode directory
xcode_dir = subprocess.check_output("xcode-select --print-path", shell=True)
if xcode_dir:
lldb_python_dirs.append(
os.path.realpath(
xcode_dir +
'/../SharedFrameworks/LLDB.framework/Resources/Python'))
lldb_python_dirs.append(
xcode_dir + '/Library/PrivateFrameworks/LLDB.framework/Resources/Python')
lldb_python_dirs.append(
'/System/Library/PrivateFrameworks/LLDB.framework/Resources/Python')
success = False
for lldb_python_dir in lldb_python_dirs:
if os.path.exists(lldb_python_dir):
if not (sys.path.__contains__(lldb_python_dir)):
sys.path.append(lldb_python_dir)
try:
import lldb
except ImportError:
pass
else:
print('imported lldb from: "%s"' % (lldb_python_dir))
success = True
break
if not success:
print("error: couldn't locate the 'lldb' module, please set PYTHONPATH correctly")
sys.exit(1)
import optparse
import shlex
import time
def regex_option_callback(option, opt_str, value, parser):
if opt_str == "--std":
value = '^std::'
regex = re.compile(value)
parser.values.skip_type_regexes.append(regex)
def create_types_options(for_lldb_command):
if for_lldb_command:
usage = "usage: %prog [options]"
description = '''This command will help check for padding in between
base classes and members in structs and classes. It will summarize the types
and how much padding was found. If no types are specified with the --types TYPENAME
option, all structure and class types will be verified. If no modules are
specified with the --module option, only the target's main executable will be
searched.
'''
else:
usage = "usage: %prog [options] EXEPATH [EXEPATH ...]"
description = '''This command will help check for padding in between
base classes and members in structures and classes. It will summarize the types
and how much padding was found. One or more paths to executable files must be
specified and targets will be created with these modules. If no types are
specified with the --types TYPENAME option, all structure and class types will
be verified in all specified modules.
'''
parser = optparse.OptionParser(
description=description,
prog='framestats',
usage=usage)
if not for_lldb_command:
parser.add_option(
'-a',
'--arch',
type='string',
dest='arch',
help='The architecture to use when creating the debug target.',
default=None)
parser.add_option(
'-p',
'--platform',
type='string',
metavar='platform',
dest='platform',
help='Specify the platform to use when creating the debug target. Valid values include "localhost", "darwin-kernel", "ios-simulator", "remote-freebsd", "remote-macosx", "remote-ios", "remote-linux".')
parser.add_option(
'-m',
'--module',
action='append',
type='string',
metavar='MODULE',
dest='modules',
help='Specify one or more modules which will be used to verify the types.',
default=[])
parser.add_option(
'-d',
'--debug',
action='store_true',
dest='debug',
help='Pause 10 seconds to wait for a debugger to attach.',
default=False)
parser.add_option(
'-t',
'--type',
action='append',
type='string',
metavar='TYPENAME',
dest='typenames',
help='Specify one or more type names which should be verified. If no type names are specified, all class and struct types will be verified.',
default=[])
parser.add_option(
'-v',
'--verbose',
action='store_true',
dest='verbose',
help='Enable verbose logging and information.',
default=False)
parser.add_option(
'-s',
'--skip-type-regex',
action="callback",
callback=regex_option_callback,
type='string',
metavar='REGEX',
dest='skip_type_regexes',
help='Regular expressions that, if they match the current member typename, will cause the type to no be recursively displayed.',
default=[])
parser.add_option(
'--std',
action="callback",
callback=regex_option_callback,
metavar='REGEX',
dest='skip_type_regexes',
help="Don't' recurse into types in the std namespace.",
default=[])
return parser
def verify_type(target, options, type):
print(type)
typename = type.GetName()
# print 'type: %s' % (typename)
(end_offset, padding) = verify_type_recursive(
target, options, type, None, 0, 0, 0)
byte_size = type.GetByteSize()
# if end_offset < byte_size:
# last_member_padding = byte_size - end_offset
# print '%+4u <%u> padding' % (end_offset, last_member_padding)
# padding += last_member_padding
print('Total byte size: %u' % (byte_size))
print('Total pad bytes: %u' % (padding))
if padding > 0:
print('Padding percentage: %2.2f %%' % ((float(padding) / float(byte_size)) * 100.0))
print()
def verify_type_recursive(
target,
options,
type,
member_name,
depth,
base_offset,
padding):
prev_end_offset = base_offset
typename = type.GetName()
byte_size = type.GetByteSize()
if member_name and member_name != typename:
print('%+4u <%3u> %s%s %s;' % (base_offset, byte_size, ' ' * depth, typename, member_name))
else:
print('%+4u {%3u} %s%s' % (base_offset, byte_size, ' ' * depth, typename))
for type_regex in options.skip_type_regexes:
match = type_regex.match(typename)
if match:
return (base_offset + byte_size, padding)
members = type.members
if members:
for member_idx, member in enumerate(members):
member_type = member.GetType()
member_canonical_type = member_type.GetCanonicalType()
member_type_class = member_canonical_type.GetTypeClass()
member_name = member.GetName()
member_offset = member.GetOffsetInBytes()
member_total_offset = member_offset + base_offset
member_byte_size = member_type.GetByteSize()
member_is_class_or_struct = False
if member_type_class == lldb.eTypeClassStruct or member_type_class == lldb.eTypeClassClass:
member_is_class_or_struct = True
if member_idx == 0 and member_offset == target.GetAddressByteSize(
) and type.IsPolymorphicClass():
ptr_size = target.GetAddressByteSize()
print('%+4u <%3u> %s__vtbl_ptr_type * _vptr;' % (prev_end_offset, ptr_size, ' ' * (depth + 1)))
prev_end_offset = ptr_size
else:
if prev_end_offset < member_total_offset:
member_padding = member_total_offset - prev_end_offset
padding = padding + member_padding
print('%+4u <%3u> %s<PADDING>' % (prev_end_offset, member_padding, ' ' * (depth + 1)))
if member_is_class_or_struct:
(prev_end_offset,
padding) = verify_type_recursive(target,
options,
member_canonical_type,
member_name,
depth + 1,
member_total_offset,
padding)
else:
prev_end_offset = member_total_offset + member_byte_size
member_typename = member_type.GetName()
if member.IsBitfield():
print('%+4u <%3u> %s%s:%u %s;' % (member_total_offset, member_byte_size, ' ' * (depth + 1), member_typename, member.GetBitfieldSizeInBits(), member_name))
else:
print('%+4u <%3u> %s%s %s;' % (member_total_offset, member_byte_size, ' ' * (depth + 1), member_typename, member_name))
if prev_end_offset < byte_size:
last_member_padding = byte_size - prev_end_offset
print('%+4u <%3u> %s<PADDING>' % (prev_end_offset, last_member_padding, ' ' * (depth + 1)))
padding += last_member_padding
else:
if type.IsPolymorphicClass():
ptr_size = target.GetAddressByteSize()
print('%+4u <%3u> %s__vtbl_ptr_type * _vptr;' % (prev_end_offset, ptr_size, ' ' * (depth + 1)))
prev_end_offset = ptr_size
prev_end_offset = base_offset + byte_size
return (prev_end_offset, padding)
def check_padding_command(debugger, command, result, dict):
# Use the Shell Lexer to properly parse up command options just like a
# shell would
command_args = shlex.split(command)
parser = create_types_options(True)
try:
(options, args) = parser.parse_args(command_args)
except:
# if you don't handle exceptions, passing an incorrect argument to the OptionParser will cause LLDB to exit
# (courtesy of OptParse dealing with argument errors by throwing SystemExit)
result.SetStatus(lldb.eReturnStatusFailed)
# returning a string is the same as returning an error whose
# description is the string
return "option parsing failed"
verify_types(debugger.GetSelectedTarget(), options)
@lldb.command("parse_all_struct_class_types")
def parse_all_struct_class_types(debugger, command, result, dict):
command_args = shlex.split(command)
for f in command_args:
error = lldb.SBError()
target = debugger.CreateTarget(f, None, None, False, error)
module = target.GetModuleAtIndex(0)
print("Parsing all types in '%s'" % (module))
types = module.GetTypes(lldb.eTypeClassClass | lldb.eTypeClassStruct)
for t in types:
print(t)
print("")
def verify_types(target, options):
if not target:
print('error: invalid target')
return
modules = list()
if len(options.modules) == 0:
# Append just the main executable if nothing was specified
module = target.modules[0]
if module:
modules.append(module)
else:
for module_name in options.modules:
module = lldb.target.module[module_name]
if module:
modules.append(module)
if modules:
for module in modules:
print('module: %s' % (module.file))
if options.typenames:
for typename in options.typenames:
types = module.FindTypes(typename)
if types.GetSize():
print('Found %u types matching "%s" in "%s"' % (len(types), typename, module.file))
for type in types:
verify_type(target, options, type)
else:
print('error: no type matches "%s" in "%s"' % (typename, module.file))
else:
types = module.GetTypes(
lldb.eTypeClassClass | lldb.eTypeClassStruct)
print('Found %u types in "%s"' % (len(types), module.file))
for type in types:
verify_type(target, options, type)
else:
print('error: no modules')
if __name__ == '__main__':
debugger = lldb.SBDebugger.Create()
parser = create_types_options(False)
# try:
(options, args) = parser.parse_args(sys.argv[1:])
# except:
# print "error: option parsing failed"
# sys.exit(1)
if options.debug:
print("Waiting for debugger to attach to process %d" % os.getpid())
os.kill(os.getpid(), signal.SIGSTOP)
for path in args:
# in a command - the lldb.* convenience variables are not to be used
# and their values (if any) are undefined
# this is the best practice to access those objects from within a
# command
error = lldb.SBError()
target = debugger.CreateTarget(path,
options.arch,
options.platform,
True,
error)
if error.Fail():
print(error.GetCString())
continue
verify_types(target, options)
elif getattr(lldb, 'debugger', None):
lldb.debugger.HandleCommand(
'command script add -f types.check_padding_command check_padding')
print('"check_padding" command installed, use the "--help" option for detailed help')
|