Repository navigation
Expand file tree
/
Copy pathtrace.py
More file actions
executable file
·703 lines (635 loc) · 31.2 KB
/
Copy pathtrace.py
File metadata and controls
executable file
·703 lines (635 loc) · 31.2 KB
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
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
#!/usr/bin/env python
#
# trace Trace a function and print a trace message based on its
# parameters, with an optional filter.
#
# usage: trace [-h] [-p PID] [-L TID] [-v] [-Z STRING_SIZE] [-S]
# [-M MAX_EVENTS] [-T] [-t] [-K] [-U] [-I header]
# probe [probe ...]
#
# Licensed under the Apache License, Version 2.0 (the "License")
# Copyright (C) 2016 Sasha Goldshtein.
from bcc import BPF, USDT
from functools import partial
from time import sleep, strftime
import argparse
import re
import ctypes as ct
import os
import traceback
import sys
class Probe(object):
probe_count = 0
streq_index = 0
max_events = None
event_count = 0
first_ts = 0
use_localtime = True
tgid = -1
pid = -1
page_cnt = None
@classmethod
def configure(cls, args):
cls.max_events = args.max_events
cls.print_time = args.timestamp or args.time
cls.use_localtime = not args.timestamp
cls.first_ts = BPF.monotonic_time()
cls.tgid = args.tgid or -1
cls.pid = args.pid or -1
cls.page_cnt = args.buffer_pages
def __init__(self, probe, string_size, kernel_stack, user_stack):
self.usdt = None
self.streq_functions = ""
self.raw_probe = probe
self.string_size = string_size
self.kernel_stack = kernel_stack
self.user_stack = user_stack
Probe.probe_count += 1
self._parse_probe()
self.probe_num = Probe.probe_count
self.probe_name = "probe_%s_%d" % \
(self._display_function(), self.probe_num)
self.probe_name = re.sub(r'[^A-Za-z0-9_]', '_',
self.probe_name)
def __str__(self):
return "%s:%s:%s FLT=%s ACT=%s/%s" % (self.probe_type,
self.library, self._display_function(), self.filter,
self.types, self.values)
def is_default_action(self):
return self.python_format == ""
def _bail(self, error):
raise ValueError("error in probe '%s': %s" %
(self.raw_probe, error))
def _parse_probe(self):
text = self.raw_probe
# There might be a function signature preceding the actual
# filter/print part, or not. Find the probe specifier first --
# it ends with either a space or an open paren ( for the
# function signature part.
# opt. signature
# probespec | rest
# --------- ---------- --
(spec, sig, rest) = re.match(r'([^ \t\(]+)(\([^\(]*\))?(.*)',
text).groups()
self._parse_spec(spec)
# Remove the parens
self.signature = sig[1:-1] if sig else None
if self.signature and self.probe_type in ['u', 't']:
self._bail("USDT and tracepoint probes can't have " +
"a function signature; use arg1, arg2, " +
"... instead")
text = rest.lstrip()
# If we now have a (, wait for the balanced closing ) and that
# will be the predicate
self.filter = None
if len(text) > 0 and text[0] == "(":
balance = 1
for i in range(1, len(text)):
if text[i] == "(":
balance += 1
if text[i] == ")":
balance -= 1
if balance == 0:
self._parse_filter(text[:i + 1])
text = text[i + 1:]
break
if self.filter is None:
self._bail("unmatched end of predicate")
if self.filter is None:
self.filter = "1"
# The remainder of the text is the printf action
self._parse_action(text.lstrip())
def _parse_spec(self, spec):
parts = spec.split(":")
# Two special cases: 'func' means 'p::func', 'lib:func' means
# 'p:lib:func'. Other combinations need to provide an empty
# value between delimiters, e.g. 'r::func' for a kretprobe on
# the function func.
if len(parts) == 1:
parts = ["p", "", parts[0]]
elif len(parts) == 2:
parts = ["p", parts[0], parts[1]]
if len(parts[0]) == 0:
self.probe_type = "p"
elif parts[0] in ["p", "r", "t", "u"]:
self.probe_type = parts[0]
else:
self._bail("probe type must be '', 'p', 't', 'r', " +
"or 'u', but got '%s'" % parts[0])
if self.probe_type == "t":
self.tp_category = parts[1]
self.tp_event = parts[2]
self.library = "" # kernel
self.function = "" # from TRACEPOINT_PROBE
elif self.probe_type == "u":
self.library = ':'.join(parts[1:-1])
self.usdt_name = parts[-1]
self.function = "" # no function, just address
# We will discover the USDT provider by matching on
# the USDT name in the specified library
self._find_usdt_probe()
else:
self.library = ':'.join(parts[1:-1])
self.function = parts[-1]
def _find_usdt_probe(self):
target = Probe.pid if Probe.pid and Probe.pid != -1 \
else Probe.tgid
self.usdt = USDT(path=self.library, pid=target)
for probe in self.usdt.enumerate_probes():
if probe.name == self.usdt_name:
return # Found it, will enable later
self._bail("unrecognized USDT probe %s" % self.usdt_name)
def _parse_filter(self, filt):
self.filter = self._rewrite_expr(filt)
def _parse_types(self, fmt):
for match in re.finditer(
r'[^%]%(s|u|d|llu|lld|hu|hd|x|llx|c|K|U)', fmt):
self.types.append(match.group(1))
fmt = re.sub(r'([^%]%)(u|d|llu|lld|hu|hd)', r'\1d', fmt)
fmt = re.sub(r'([^%]%)(x|llx)', r'\1x', fmt)
fmt = re.sub('%K|%U', '%s', fmt)
self.python_format = fmt.strip('"')
def _parse_action(self, action):
self.values = []
self.types = []
self.python_format = ""
if len(action) == 0:
return
action = action.strip()
match = re.search(r'(\".*?\"),?(.*)', action)
if match is None:
self._bail("expected format string in \"s")
self.raw_format = match.group(1)
self._parse_types(self.raw_format)
for part in re.split('(?<!"),', match.group(2)):
part = self._rewrite_expr(part)
if len(part) > 0:
self.values.append(part)
aliases = {
"retval": "PT_REGS_RC(ctx)",
"arg1": "PT_REGS_PARM1(ctx)",
"arg2": "PT_REGS_PARM2(ctx)",
"arg3": "PT_REGS_PARM3(ctx)",
"arg4": "PT_REGS_PARM4(ctx)",
"arg5": "PT_REGS_PARM5(ctx)",
"arg6": "PT_REGS_PARM6(ctx)",
"$uid": "(unsigned)(bpf_get_current_uid_gid() & 0xffffffff)",
"$gid": "(unsigned)(bpf_get_current_uid_gid() >> 32)",
"$pid": "(unsigned)(bpf_get_current_pid_tgid() & 0xffffffff)",
"$tgid": "(unsigned)(bpf_get_current_pid_tgid() >> 32)",
"$cpu": "bpf_get_smp_processor_id()"
}
def _generate_streq_function(self, string):
fname = "streq_%d" % Probe.streq_index
Probe.streq_index += 1
self.streq_functions += """
static inline bool %s(char const *ignored, uintptr_t str) {
char needle[] = %s;
char haystack[sizeof(needle)];
bpf_probe_read(&haystack, sizeof(haystack), (void *)str);
for (int i = 0; i < sizeof(needle) - 1; ++i) {
if (needle[i] != haystack[i]) {
return false;
}
}
return true;
}
""" % (fname, string)
return fname
def _rewrite_expr(self, expr):
for alias, replacement in Probe.aliases.items():
# For USDT probes, we replace argN values with the
# actual arguments for that probe obtained using
# bpf_readarg_N macros emitted at BPF construction.
if alias.startswith("arg") and self.probe_type == "u":
continue
expr = expr.replace(alias, replacement)
matches = re.finditer('STRCMP\\(("[^"]+\\")', expr)
for match in matches:
string = match.group(1)
fname = self._generate_streq_function(string)
expr = expr.replace("STRCMP", fname, 1)
return expr
p_type = {"u": ct.c_uint, "d": ct.c_int,
"llu": ct.c_ulonglong, "lld": ct.c_longlong,
"hu": ct.c_ushort, "hd": ct.c_short,
"x": ct.c_uint, "llx": ct.c_ulonglong, "c": ct.c_ubyte,
"K": ct.c_ulonglong, "U": ct.c_ulonglong}
def _generate_python_field_decl(self, idx, fields):
field_type = self.types[idx]
if field_type == "s":
ptype = ct.c_char * self.string_size
else:
ptype = Probe.p_type[field_type]
fields.append(("v%d" % idx, ptype))
def _generate_python_data_decl(self):
self.python_struct_name = "%s_%d_Data" % \
(self._display_function(), self.probe_num)
fields = [
("timestamp_ns", ct.c_ulonglong),
("tgid", ct.c_uint),
("pid", ct.c_uint),
("comm", ct.c_char * 16) # TASK_COMM_LEN
]
for i in range(0, len(self.types)):
self._generate_python_field_decl(i, fields)
if self.kernel_stack:
fields.append(("kernel_stack_id", ct.c_int))
if self.user_stack:
fields.append(("user_stack_id", ct.c_int))
return type(self.python_struct_name, (ct.Structure,),
dict(_fields_=fields))
c_type = {"u": "unsigned int", "d": "int",
"llu": "unsigned long long", "lld": "long long",
"hu": "unsigned short", "hd": "short",
"x": "unsigned int", "llx": "unsigned long long",
"c": "char", "K": "unsigned long long",
"U": "unsigned long long"}
fmt_types = c_type.keys()
def _generate_field_decl(self, idx):
field_type = self.types[idx]
if field_type == "s":
return "char v%d[%d];\n" % (idx, self.string_size)
if field_type in Probe.fmt_types:
return "%s v%d;\n" % (Probe.c_type[field_type], idx)
self._bail("unrecognized format specifier %s" % field_type)
def _generate_data_decl(self):
# The BPF program will populate values into the struct
# according to the format string, and the Python program will
# construct the final display string.
self.events_name = "%s_events" % self.probe_name
self.struct_name = "%s_data_t" % self.probe_name
self.stacks_name = "%s_stacks" % self.probe_name
stack_table = "BPF_STACK_TRACE(%s, 1024);" % self.stacks_name \
if (self.kernel_stack or self.user_stack) else ""
data_fields = ""
for i, field_type in enumerate(self.types):
data_fields += " " + \
self._generate_field_decl(i)
kernel_stack_str = " int kernel_stack_id;" \
if self.kernel_stack else ""
user_stack_str = " int user_stack_id;" \
if self.user_stack else ""
text = """
struct %s
{
u64 timestamp_ns;
u32 tgid;
u32 pid;
char comm[TASK_COMM_LEN];
%s
%s
%s
};
BPF_PERF_OUTPUT(%s);
%s
"""
return text % (self.struct_name, data_fields,
kernel_stack_str, user_stack_str,
self.events_name, stack_table)
def _generate_field_assign(self, idx):
field_type = self.types[idx]
expr = self.values[idx].strip()
text = ""
if self.probe_type == "u" and expr[0:3] == "arg":
arg_index = int(expr[3])
arg_ctype = self.usdt.get_probe_arg_ctype(
self.usdt_name, arg_index - 1)
text = (" %s %s = 0;\n" +
" bpf_usdt_readarg(%s, ctx, &%s);\n") \
% (arg_ctype, expr, expr[3], expr)
if field_type == "s":
return text + """
if (%s != 0) {
bpf_probe_read(&__data.v%d, sizeof(__data.v%d), (void *)%s);
}
""" % (expr, idx, idx, expr)
if field_type in Probe.fmt_types:
return text + " __data.v%d = (%s)%s;\n" % \
(idx, Probe.c_type[field_type], expr)
self._bail("unrecognized field type %s" % field_type)
def _generate_usdt_filter_read(self):
text = ""
if self.probe_type != "u":
return text
for arg, _ in Probe.aliases.items():
if not (arg.startswith("arg") and
(arg in self.filter)):
continue
arg_index = int(arg.replace("arg", ""))
arg_ctype = self.usdt.get_probe_arg_ctype(
self.usdt_name, arg_index - 1)
if not arg_ctype:
self._bail("Unable to determine type of {} "
"in the filter".format(arg))
text += """
{} {}_filter;
bpf_usdt_readarg({}, ctx, &{}_filter);
""".format(arg_ctype, arg, arg_index, arg)
self.filter = self.filter.replace(
arg, "{}_filter".format(arg))
return text
def generate_program(self, include_self):
data_decl = self._generate_data_decl()
if Probe.pid != -1:
pid_filter = """
if (__pid != %d) { return 0; }
""" % Probe.pid
# uprobes can have a built-in tgid filter passed to
# attach_uprobe, hence the check here -- for kprobes, we
# need to do the tgid test by hand:
elif len(self.library) == 0 and Probe.tgid != -1:
pid_filter = """
if (__tgid != %d) { return 0; }
""" % Probe.tgid
elif not include_self:
pid_filter = """
if (__tgid == %d) { return 0; }
""" % os.getpid()
else:
pid_filter = ""
prefix = ""
signature = "struct pt_regs *ctx"
if self.signature:
signature += ", " + self.signature
data_fields = ""
for i, expr in enumerate(self.values):
data_fields += self._generate_field_assign(i)
if self.probe_type == "t":
heading = "TRACEPOINT_PROBE(%s, %s)" % \
(self.tp_category, self.tp_event)
ctx_name = "args"
else:
heading = "int %s(%s)" % (self.probe_name, signature)
ctx_name = "ctx"
stack_trace = ""
if self.user_stack:
stack_trace += """
__data.user_stack_id = %s.get_stackid(
%s, BPF_F_REUSE_STACKID | BPF_F_USER_STACK
);""" % (self.stacks_name, ctx_name)
if self.kernel_stack:
stack_trace += """
__data.kernel_stack_id = %s.get_stackid(
%s, BPF_F_REUSE_STACKID
);""" % (self.stacks_name, ctx_name)
text = heading + """
{
u64 __pid_tgid = bpf_get_current_pid_tgid();
u32 __tgid = __pid_tgid >> 32;
u32 __pid = __pid_tgid; // implicit cast to u32 for bottom half
%s
%s
%s
if (!(%s)) return 0;
struct %s __data = {0};
__data.timestamp_ns = bpf_ktime_get_ns();
__data.tgid = __tgid;
__data.pid = __pid;
bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
%s
%s
%s.perf_submit(%s, &__data, sizeof(__data));
return 0;
}
"""
text = text % (pid_filter, prefix,
self._generate_usdt_filter_read(), self.filter,
self.struct_name, data_fields,
stack_trace, self.events_name, ctx_name)
return self.streq_functions + data_decl + "\n" + text
@classmethod
def _time_off_str(cls, timestamp_ns):
return "%.6f" % (1e-9 * (timestamp_ns - cls.first_ts))
def _display_function(self):
if self.probe_type == 'p' or self.probe_type == 'r':
return self.function
elif self.probe_type == 'u':
return self.usdt_name
else: # self.probe_type == 't'
return self.tp_event
def print_stack(self, bpf, stack_id, tgid):
if stack_id < 0:
print(" %d" % stack_id)
return
stack = list(bpf.get_table(self.stacks_name).walk(stack_id))
for addr in stack:
print(" %s" % (bpf.sym(addr, tgid,
show_module=True, show_offset=True)))
def _format_message(self, bpf, tgid, values):
# Replace each %K with kernel sym and %U with user sym in tgid
kernel_placeholders = [i for i, t in enumerate(self.types)
if t == 'K']
user_placeholders = [i for i, t in enumerate(self.types)
if t == 'U']
for kp in kernel_placeholders:
values[kp] = bpf.ksym(values[kp], show_offset=True)
for up in user_placeholders:
values[up] = bpf.sym(values[up], tgid,
show_module=True, show_offset=True)
return self.python_format % tuple(values)
def print_event(self, bpf, cpu, data, size):
# Cast as the generated structure type and display
# according to the format string in the probe.
event = ct.cast(data, ct.POINTER(self.python_struct)).contents
values = map(lambda i: getattr(event, "v%d" % i),
range(0, len(self.values)))
msg = self._format_message(bpf, event.tgid, values)
if not Probe.print_time:
print("%-6d %-6d %-12s %-16s %s" %
(event.tgid, event.pid, event.comm.decode(),
self._display_function(), msg))
else:
time = strftime("%H:%M:%S") if Probe.use_localtime else \
Probe._time_off_str(event.timestamp_ns)
print("%-8s %-6d %-6d %-12s %-16s %s" %
(time[:8], event.tgid, event.pid, event.comm.decode(),
self._display_function(), msg))
if self.kernel_stack:
self.print_stack(bpf, event.kernel_stack_id, -1)
if self.user_stack:
self.print_stack(bpf, event.user_stack_id, event.tgid)
if self.user_stack or self.kernel_stack:
print("")
Probe.event_count += 1
if Probe.max_events is not None and \
Probe.event_count >= Probe.max_events:
exit()
def attach(self, bpf, verbose):
if len(self.library) == 0:
self._attach_k(bpf)
else:
self._attach_u(bpf)
self.python_struct = self._generate_python_data_decl()
callback = partial(self.print_event, bpf)
bpf[self.events_name].open_perf_buffer(callback,
page_cnt=self.page_cnt)
def _attach_k(self, bpf):
if self.probe_type == "r":
bpf.attach_kretprobe(event=self.function,
fn_name=self.probe_name)
elif self.probe_type == "p":
bpf.attach_kprobe(event=self.function,
fn_name=self.probe_name)
# Note that tracepoints don't need an explicit attach
def _attach_u(self, bpf):
libpath = BPF.find_library(self.library)
if libpath is None:
# This might be an executable (e.g. 'bash')
libpath = BPF.find_exe(self.library)
if libpath is None or len(libpath) == 0:
self._bail("unable to find library %s" % self.library)
if self.probe_type == "u":
pass # Was already enabled by the BPF constructor
elif self.probe_type == "r":
bpf.attach_uretprobe(name=libpath,
sym=self.function,
fn_name=self.probe_name,
pid=Probe.tgid)
else:
bpf.attach_uprobe(name=libpath,
sym=self.function,
fn_name=self.probe_name,
pid=Probe.tgid)
class Tool(object):
DEFAULT_PERF_BUFFER_PAGES = 64
examples = """
EXAMPLES:
trace do_sys_open
Trace the open syscall and print a default trace message when entered
trace 'do_sys_open "%s", arg2'
Trace the open syscall and print the filename being opened
trace 'sys_read (arg3 > 20000) "read %d bytes", arg3'
Trace the read syscall and print a message for reads >20000 bytes
trace 'r::do_sys_open "%llx", retval'
Trace the return from the open syscall and print the return value
trace 'c:open (arg2 == 42) "%s %d", arg1, arg2'
Trace the open() call from libc only if the flags (arg2) argument is 42
trace 'c:malloc "size = %d", arg1'
Trace malloc calls and print the size being allocated
trace 'p:c:write (arg1 == 1) "writing %d bytes to STDOUT", arg3'
Trace the write() call from libc to monitor writes to STDOUT
trace 'r::__kmalloc (retval == 0) "kmalloc failed!"'
Trace returns from __kmalloc which returned a null pointer
trace 'r:c:malloc (retval) "allocated = %x", retval'
Trace returns from malloc and print non-NULL allocated buffers
trace 't:block:block_rq_complete "sectors=%d", args->nr_sector'
Trace the block_rq_complete kernel tracepoint and print # of tx sectors
trace 'u:pthread:pthread_create (arg4 != 0)'
Trace the USDT probe pthread_create when its 4th argument is non-zero
trace 'p::SyS_nanosleep(struct timespec *ts) "sleep for %lld ns", ts->tv_nsec'
Trace the nanosleep syscall and print the sleep duration in ns
"""
def __init__(self):
parser = argparse.ArgumentParser(description="Attach to " +
"functions and print trace messages.",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=Tool.examples)
parser.add_argument("-b", "--buffer-pages", type=int,
default=Tool.DEFAULT_PERF_BUFFER_PAGES,
help="number of pages to use for perf_events ring buffer "
"(default: %(default)d)")
# we'll refer to the userspace concepts of "pid" and "tid" by
# their kernel names -- tgid and pid -- inside the script
parser.add_argument("-p", "--pid", type=int, metavar="PID",
dest="tgid", help="id of the process to trace (optional)")
parser.add_argument("-L", "--tid", type=int, metavar="TID",
dest="pid", help="id of the thread to trace (optional)")
parser.add_argument("-v", "--verbose", action="store_true",
help="print resulting BPF program code before executing")
parser.add_argument("-Z", "--string-size", type=int,
default=80, help="maximum size to read from strings")
parser.add_argument("-S", "--include-self",
action="store_true",
help="do not filter trace's own pid from the trace")
parser.add_argument("-M", "--max-events", type=int,
help="number of events to print before quitting")
parser.add_argument("-t", "--timestamp", action="store_true",
help="print timestamp column (offset from trace start)")
parser.add_argument("-T", "--time", action="store_true",
help="print time column")
parser.add_argument("-K", "--kernel-stack",
action="store_true", help="output kernel stack trace")
parser.add_argument("-U", "--user-stack",
action="store_true", help="output user stack trace")
parser.add_argument(metavar="probe", dest="probes", nargs="+",
help="probe specifier (see examples)")
parser.add_argument("-I", "--include", action="append",
metavar="header",
help="additional header files to include in the BPF program "
"as either full path, or relative to '/usr/include'")
self.args = parser.parse_args()
if self.args.tgid and self.args.pid:
parser.error("only one of -p and -t may be specified")
def _create_probes(self):
Probe.configure(self.args)
self.probes = []
for probe_spec in self.args.probes:
self.probes.append(Probe(
probe_spec, self.args.string_size,
self.args.kernel_stack, self.args.user_stack))
def _generate_program(self):
self.program = """
#include <linux/ptrace.h>
#include <linux/sched.h> /* For TASK_COMM_LEN */
"""
for include in (self.args.include or []):
if include.startswith((".", "/")):
include = os.path.abspath(include)
self.program += "#include \"%s\"\n" % include
else:
self.program += "#include <%s>\n" % include
self.program += BPF.generate_auto_includes(
map(lambda p: p.raw_probe, self.probes))
for probe in self.probes:
self.program += probe.generate_program(
self.args.include_self)
if self.args.verbose:
print(self.program)
def _attach_probes(self):
usdt_contexts = []
for probe in self.probes:
if probe.usdt:
# USDT probes must be enabled before the BPF object
# is initialized, because that's where the actual
# uprobe is being attached.
probe.usdt.enable_probe(
probe.usdt_name, probe.probe_name)
if self.args.verbose:
print(probe.usdt.get_text())
usdt_contexts.append(probe.usdt)
self.bpf = BPF(text=self.program, usdt_contexts=usdt_contexts)
for probe in self.probes:
if self.args.verbose:
print(probe)
probe.attach(self.bpf, self.args.verbose)
def _main_loop(self):
all_probes_trivial = all(map(Probe.is_default_action,
self.probes))
# Print header
if self.args.timestamp or self.args.time:
print("%-8s %-6s %-6s %-12s %-16s %s" %
("TIME", "PID", "TID", "COMM", "FUNC",
"-" if not all_probes_trivial else ""))
else:
print("%-6s %-6s %-12s %-16s %s" %
("PID", "TID", "COMM", "FUNC",
"-" if not all_probes_trivial else ""))
while True:
self.bpf.kprobe_poll()
def run(self):
try:
self._create_probes()
self._generate_program()
self._attach_probes()
self._main_loop()
except:
exc_info = sys.exc_info()
sys_exit = exc_info[0] is SystemExit
if self.args.verbose:
traceback.print_exc()
elif not sys_exit:
print(exc_info[1])
exit(0 if sys_exit else 1)
if __name__ == "__main__":
Tool().run()