Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 1 | #!/usr/bin/env python |
| 2 | # |
| 3 | # trace Trace a function and print a trace message based on its |
| 4 | # parameters, with an optional filter. |
| 5 | # |
| 6 | # USAGE: trace [-h] [-p PID] [-v] [-Z STRING_SIZE] [-S] [-M MAX_EVENTS] [-o] |
| 7 | # probe [probe ...] |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 8 | # |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 9 | # Licensed under the Apache License, Version 2.0 (the "License") |
| 10 | # Copyright (C) 2016 Sasha Goldshtein. |
| 11 | |
Sasha Goldshtein | c08c431 | 2016-03-21 03:52:09 -0700 | [diff] [blame^] | 12 | from bcc import BPF, Tracepoint, Perf |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 13 | from time import sleep, strftime |
| 14 | import argparse |
| 15 | import re |
| 16 | import ctypes as ct |
| 17 | import os |
| 18 | import traceback |
| 19 | import sys |
| 20 | |
| 21 | class Time(object): |
| 22 | # BPF timestamps come from the monotonic clock. To be able to filter |
| 23 | # and compare them from Python, we need to invoke clock_gettime. |
| 24 | # Adapted from http://stackoverflow.com/a/1205762 |
| 25 | CLOCK_MONOTONIC_RAW = 4 # see <linux/time.h> |
| 26 | |
| 27 | class timespec(ct.Structure): |
| 28 | _fields_ = [ |
| 29 | ('tv_sec', ct.c_long), |
| 30 | ('tv_nsec', ct.c_long) |
| 31 | ] |
| 32 | |
| 33 | librt = ct.CDLL('librt.so.1', use_errno=True) |
| 34 | clock_gettime = librt.clock_gettime |
| 35 | clock_gettime.argtypes = [ct.c_int, ct.POINTER(timespec)] |
| 36 | |
| 37 | @staticmethod |
| 38 | def monotonic_time(): |
| 39 | t = Time.timespec() |
| 40 | if Time.clock_gettime( |
| 41 | Time.CLOCK_MONOTONIC_RAW, ct.pointer(t)) != 0: |
| 42 | errno_ = ct.get_errno() |
| 43 | raise OSError(errno_, os.strerror(errno_)) |
| 44 | return t.tv_sec * 1e9 + t.tv_nsec |
| 45 | |
| 46 | class Probe(object): |
| 47 | probe_count = 0 |
| 48 | max_events = None |
| 49 | event_count = 0 |
| 50 | first_ts = 0 |
| 51 | use_localtime = True |
| 52 | |
| 53 | @classmethod |
| 54 | def configure(cls, args): |
| 55 | cls.max_events = args.max_events |
| 56 | cls.use_localtime = not args.offset |
| 57 | cls.first_ts = Time.monotonic_time() |
| 58 | |
| 59 | def __init__(self, probe, string_size): |
| 60 | self.raw_probe = probe |
| 61 | self.string_size = string_size |
| 62 | Probe.probe_count += 1 |
| 63 | self._parse_probe() |
| 64 | self.probe_num = Probe.probe_count |
| 65 | self.probe_name = "probe_%s_%d" % \ |
| 66 | (self.function, self.probe_num) |
| 67 | |
| 68 | def __str__(self): |
| 69 | return "%s:%s`%s FLT=%s ACT=%s/%s" % (self.probe_type, |
| 70 | self.library, self.function, self.filter, |
| 71 | self.types, self.values) |
| 72 | |
| 73 | def is_default_action(self): |
| 74 | return self.python_format == "" |
| 75 | |
| 76 | def _bail(self, error): |
| 77 | raise ValueError("error parsing probe '%s': %s" % |
| 78 | (self.raw_probe, error)) |
| 79 | |
| 80 | def _parse_probe(self): |
| 81 | text = self.raw_probe |
| 82 | |
| 83 | # Everything until the first space is the probe specifier |
| 84 | first_space = text.find(' ') |
| 85 | spec = text[:first_space] if first_space >= 0 else text |
| 86 | self._parse_spec(spec) |
| 87 | if first_space >= 0: |
| 88 | text = text[first_space:].lstrip() |
| 89 | else: |
| 90 | text = "" |
| 91 | |
| 92 | # If we now have a (, wait for the balanced closing ) and that |
| 93 | # will be the predicate |
| 94 | self.filter = None |
| 95 | if len(text) > 0 and text[0] == "(": |
| 96 | balance = 1 |
| 97 | for i in range(1, len(text)): |
| 98 | if text[i] == "(": |
| 99 | balance += 1 |
| 100 | if text[i] == ")": |
| 101 | balance -= 1 |
| 102 | if balance == 0: |
| 103 | self._parse_filter(text[:i+1]) |
| 104 | text = text[i+1:] |
| 105 | break |
| 106 | if self.filter is None: |
| 107 | self._bail("unmatched end of predicate") |
| 108 | |
| 109 | if self.filter is None: |
| 110 | self.filter = "1" |
| 111 | |
| 112 | # The remainder of the text is the printf action |
| 113 | self._parse_action(text.lstrip()) |
| 114 | |
| 115 | def _parse_spec(self, spec): |
| 116 | parts = spec.split(":") |
| 117 | # Two special cases: 'func' means 'p::func', 'lib:func' means |
| 118 | # 'p:lib:func'. Other combinations need to provide an empty |
| 119 | # value between delimiters, e.g. 'r::func' for a kretprobe on |
| 120 | # the function func. |
| 121 | if len(parts) == 1: |
| 122 | parts = ["p", "", parts[0]] |
| 123 | elif len(parts) == 2: |
| 124 | parts = ["p", parts[0], parts[1]] |
| 125 | if len(parts[0]) == 0: |
| 126 | self.probe_type = "p" |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 127 | elif parts[0] in ["p", "r", "t"]: |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 128 | self.probe_type = parts[0] |
| 129 | else: |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 130 | self._bail("expected '', 'p', 't', or 'r', got '%s'" % |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 131 | parts[0]) |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 132 | if self.probe_type == "t": |
| 133 | self.tp_category = parts[1] |
| 134 | self.tp_event = parts[2] |
Sasha Goldshtein | c08c431 | 2016-03-21 03:52:09 -0700 | [diff] [blame^] | 135 | self.tp = Tracepoint.enable_tracepoint( |
| 136 | self.tp_category, self.tp_event) |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 137 | self.library = "" # kernel |
| 138 | self.function = "perf_trace_%s" % self.tp_event |
| 139 | else: |
| 140 | self.library = parts[1] |
| 141 | self.function = parts[2] |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 142 | |
| 143 | def _parse_filter(self, filt): |
| 144 | self.filter = self._replace_args(filt) |
| 145 | |
| 146 | def _parse_types(self, fmt): |
| 147 | for match in re.finditer( |
| 148 | r'[^%]%(s|u|d|llu|lld|hu|hd|x|llx|c)', fmt): |
| 149 | self.types.append(match.group(1)) |
| 150 | fmt = re.sub(r'([^%]%)(u|d|llu|lld|hu|hd)', r'\1d', fmt) |
| 151 | fmt = re.sub(r'([^%]%)(x|llx)', r'\1x', fmt) |
| 152 | self.python_format = fmt.strip('"') |
| 153 | |
| 154 | def _parse_action(self, action): |
| 155 | self.values = [] |
| 156 | self.types = [] |
| 157 | self.python_format = "" |
| 158 | if len(action) == 0: |
| 159 | return |
| 160 | |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 161 | action = action.strip() |
| 162 | match = re.search(r'(\".*\"),?(.*)', action) |
| 163 | if match is None: |
| 164 | self._bail("expected format string in \"s") |
| 165 | |
| 166 | self.raw_format = match.group(1) |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 167 | self._parse_types(self.raw_format) |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 168 | for part in match.group(2).split(','): |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 169 | part = self._replace_args(part) |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 170 | if len(part) > 0: |
| 171 | self.values.append(part) |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 172 | |
| 173 | aliases = { |
| 174 | "retval": "ctx->ax", |
| 175 | "arg1": "ctx->di", |
| 176 | "arg2": "ctx->si", |
| 177 | "arg3": "ctx->dx", |
| 178 | "arg4": "ctx->cx", |
| 179 | "arg5": "ctx->r8", |
| 180 | "arg6": "ctx->r9", |
| 181 | "$uid": "(unsigned)(bpf_get_current_uid_gid() & 0xffffffff)", |
| 182 | "$gid": "(unsigned)(bpf_get_current_uid_gid() >> 32)", |
| 183 | "$pid": "(unsigned)(bpf_get_current_pid_tgid() & 0xffffffff)", |
| 184 | "$tgid": "(unsigned)(bpf_get_current_pid_tgid() >> 32)", |
| 185 | "$cpu": "bpf_get_smp_processor_id()" |
| 186 | } |
| 187 | |
| 188 | def _replace_args(self, expr): |
| 189 | for alias, replacement in Probe.aliases.items(): |
| 190 | expr = expr.replace(alias, replacement) |
| 191 | return expr |
| 192 | |
| 193 | p_type = { "u": ct.c_uint, "d": ct.c_int, |
| 194 | "llu": ct.c_ulonglong, "lld": ct.c_longlong, |
| 195 | "hu": ct.c_ushort, "hd": ct.c_short, |
| 196 | "x": ct.c_uint, "llx": ct.c_ulonglong, |
| 197 | "c": ct.c_ubyte } |
| 198 | |
| 199 | def _generate_python_field_decl(self, idx, fields): |
| 200 | field_type = self.types[idx] |
| 201 | if field_type == "s": |
| 202 | ptype = ct.c_char * self.string_size |
| 203 | else: |
| 204 | ptype = Probe.p_type[field_type] |
| 205 | fields.append(("v%d" % idx, ptype)) |
| 206 | |
| 207 | def _generate_python_data_decl(self): |
| 208 | self.python_struct_name = "%s_%d_Data" % \ |
| 209 | (self.function, self.probe_num) |
| 210 | fields = [ |
| 211 | ("timestamp_ns", ct.c_ulonglong), |
| 212 | ("pid", ct.c_uint), |
| 213 | ("comm", ct.c_char * 16) # TASK_COMM_LEN |
| 214 | ] |
| 215 | for i in range(0, len(self.types)): |
| 216 | self._generate_python_field_decl(i, fields) |
| 217 | return type(self.python_struct_name, (ct.Structure,), |
| 218 | dict(_fields_=fields)) |
| 219 | |
| 220 | c_type = { "u": "unsigned int", "d": "int", |
| 221 | "llu": "unsigned long long", "lld": "long long", |
| 222 | "hu": "unsigned short", "hd": "short", |
| 223 | "x": "unsigned int", "llx": "unsigned long long", |
| 224 | "c": "char" } |
| 225 | fmt_types = c_type.keys() |
| 226 | |
| 227 | def _generate_field_decl(self, idx): |
| 228 | field_type = self.types[idx] |
| 229 | if field_type == "s": |
| 230 | return "char v%d[%d];\n" % (idx, self.string_size) |
| 231 | if field_type in Probe.fmt_types: |
| 232 | return "%s v%d;\n" % (Probe.c_type[field_type], idx) |
| 233 | self._bail("unrecognized format specifier %s" % field_type) |
| 234 | |
| 235 | def _generate_data_decl(self): |
| 236 | # The BPF program will populate values into the struct |
| 237 | # according to the format string, and the Python program will |
| 238 | # construct the final display string. |
| 239 | self.events_name = "%s_events" % self.probe_name |
| 240 | self.struct_name = "%s_data_t" % self.probe_name |
| 241 | |
| 242 | data_fields = "" |
| 243 | for i, field_type in enumerate(self.types): |
| 244 | data_fields += " " + \ |
| 245 | self._generate_field_decl(i) |
| 246 | |
| 247 | text = """ |
| 248 | struct %s |
| 249 | { |
| 250 | u64 timestamp_ns; |
| 251 | u32 pid; |
| 252 | char comm[TASK_COMM_LEN]; |
| 253 | %s |
| 254 | }; |
| 255 | |
| 256 | BPF_PERF_OUTPUT(%s); |
| 257 | """ |
| 258 | return text % (self.struct_name, data_fields, self.events_name) |
| 259 | |
| 260 | def _generate_field_assign(self, idx): |
| 261 | field_type = self.types[idx] |
| 262 | expr = self.values[idx] |
| 263 | if field_type == "s": |
| 264 | return """ |
| 265 | if (%s != 0) { |
| 266 | bpf_probe_read(&__data.v%d, sizeof(__data.v%d), (void *)%s); |
| 267 | } |
| 268 | """ % (expr, idx, idx, expr) |
| 269 | # return ("bpf_probe_read(&__data.v%d, " + \ |
| 270 | # "sizeof(__data.v%d), (char*)%s);\n") % (idx, idx, expr) |
| 271 | # return ("__builtin_memcpy(&__data.v%d, (void *)%s, " + \ |
| 272 | # "sizeof(__data.v%d));\n") % (idx, expr, idx) |
| 273 | if field_type in Probe.fmt_types: |
| 274 | return " __data.v%d = (%s)%s;\n" % \ |
| 275 | (idx, Probe.c_type[field_type], expr) |
| 276 | self._bail("unrecognized field type %s" % field_type) |
| 277 | |
| 278 | def generate_program(self, pid, include_self): |
| 279 | data_decl = self._generate_data_decl() |
| 280 | self.pid = pid |
| 281 | # kprobes don't have built-in pid filters, so we have to add |
| 282 | # it to the function body: |
| 283 | if len(self.library) == 0 and pid != -1: |
| 284 | pid_filter = """ |
| 285 | u32 __pid = bpf_get_current_pid_tgid(); |
| 286 | if (__pid != %d) { return 0; } |
| 287 | """ % pid |
| 288 | elif not include_self: |
| 289 | pid_filter = """ |
| 290 | u32 __pid = bpf_get_current_pid_tgid(); |
| 291 | if (__pid == %d) { return 0; } |
| 292 | """ % os.getpid() |
| 293 | else: |
| 294 | pid_filter = "" |
| 295 | |
| 296 | data_fields = "" |
| 297 | for i, expr in enumerate(self.values): |
| 298 | data_fields += self._generate_field_assign(i) |
| 299 | |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 300 | prefix = "" |
| 301 | if self.probe_type == "t": |
Sasha Goldshtein | c08c431 | 2016-03-21 03:52:09 -0700 | [diff] [blame^] | 302 | data_decl += self.tp.generate_struct() |
| 303 | prefix = self.tp.generate_get_struct() |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 304 | |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 305 | text = """ |
| 306 | int %s(struct pt_regs *ctx) |
| 307 | { |
| 308 | %s |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 309 | %s |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 310 | if (!(%s)) return 0; |
| 311 | |
| 312 | struct %s __data = {0}; |
| 313 | __data.timestamp_ns = bpf_ktime_get_ns(); |
| 314 | __data.pid = bpf_get_current_pid_tgid(); |
| 315 | bpf_get_current_comm(&__data.comm, sizeof(__data.comm)); |
| 316 | %s |
| 317 | %s.perf_submit(ctx, &__data, sizeof(__data)); |
| 318 | return 0; |
| 319 | } |
| 320 | """ |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 321 | text = text % (self.probe_name, pid_filter, prefix, |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 322 | self.filter, self.struct_name, |
| 323 | data_fields, self.events_name) |
| 324 | |
| 325 | return data_decl + "\n" + text |
| 326 | |
| 327 | @classmethod |
| 328 | def _time_off_str(cls, timestamp_ns): |
| 329 | return "%.6f" % (1e-9 * (timestamp_ns - cls.first_ts)) |
| 330 | |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 331 | auto_includes = { |
| 332 | "linux/time.h" : ["time"], |
| 333 | "linux/fs.h" : ["fs", "file"], |
| 334 | "linux/blkdev.h" : ["bio", "request"], |
| 335 | "linux/slab.h" : ["alloc"], |
| 336 | "linux/netdevice.h" : ["sk_buff"] |
| 337 | } |
| 338 | |
| 339 | @classmethod |
| 340 | def generate_auto_includes(cls, probes): |
| 341 | headers = "" |
| 342 | for header, keywords in cls.auto_includes.items(): |
| 343 | for keyword in keywords: |
| 344 | for probe in probes: |
| 345 | if keyword in probe: |
| 346 | headers += "#include <%s>\n" \ |
| 347 | % header |
| 348 | return headers |
| 349 | |
| 350 | def _display_function(self): |
| 351 | if self.probe_type != 't': |
| 352 | return self.function |
| 353 | else: |
| 354 | return self.function.replace("perf_trace_", "") |
| 355 | |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 356 | def print_event(self, cpu, data, size): |
| 357 | # Cast as the generated structure type and display |
| 358 | # according to the format string in the probe. |
| 359 | event = ct.cast(data, ct.POINTER(self.python_struct)).contents |
| 360 | values = map(lambda i: getattr(event, "v%d" % i), |
| 361 | range(0, len(self.values))) |
| 362 | msg = self.python_format % tuple(values) |
| 363 | time = strftime("%H:%M:%S") if Probe.use_localtime else \ |
| 364 | Probe._time_off_str(event.timestamp_ns) |
| 365 | print("%-8s %-6d %-12s %-16s %s" % \ |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 366 | (time[:8], event.pid, event.comm[:12], |
| 367 | self._display_function(), msg)) |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 368 | |
| 369 | Probe.event_count += 1 |
| 370 | if Probe.max_events is not None and \ |
| 371 | Probe.event_count >= Probe.max_events: |
| 372 | exit() |
| 373 | |
| 374 | def attach(self, bpf, verbose): |
| 375 | if len(self.library) == 0: |
| 376 | self._attach_k(bpf) |
| 377 | else: |
| 378 | self._attach_u(bpf) |
| 379 | self.python_struct = self._generate_python_data_decl() |
| 380 | bpf[self.events_name].open_perf_buffer(self.print_event) |
| 381 | |
| 382 | def _attach_k(self, bpf): |
| 383 | if self.probe_type == "r": |
| 384 | bpf.attach_kretprobe(event=self.function, |
| 385 | fn_name=self.probe_name) |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 386 | elif self.probe_type == "p" or self.probe_type == "t": |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 387 | bpf.attach_kprobe(event=self.function, |
| 388 | fn_name=self.probe_name) |
| 389 | |
| 390 | def _attach_u(self, bpf): |
| 391 | libpath = BPF.find_library(self.library) |
| 392 | if libpath is None: |
| 393 | # This might be an executable (e.g. 'bash') |
| 394 | with os.popen("/usr/bin/which %s 2>/dev/null" % |
| 395 | self.library) as w: |
| 396 | libpath = w.read().strip() |
| 397 | if libpath is None or len(libpath) == 0: |
| 398 | self._bail("unable to find library %s" % self.library) |
| 399 | |
| 400 | if self.probe_type == "r": |
| 401 | bpf.attach_uretprobe(name=libpath, |
| 402 | sym=self.function, |
| 403 | fn_name=self.probe_name, |
| 404 | pid=self.pid) |
| 405 | else: |
| 406 | bpf.attach_uprobe(name=libpath, |
| 407 | sym=self.function, |
| 408 | fn_name=self.probe_name, |
| 409 | pid=self.pid) |
| 410 | |
| 411 | class Tool(object): |
| 412 | examples = """ |
| 413 | EXAMPLES: |
| 414 | |
Sasha Goldshtein | 8acd015 | 2016-02-22 02:25:03 -0800 | [diff] [blame] | 415 | trace do_sys_open |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 416 | Trace the open syscall and print a default trace message when entered |
Sasha Goldshtein | 8acd015 | 2016-02-22 02:25:03 -0800 | [diff] [blame] | 417 | trace 'do_sys_open "%s", arg2' |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 418 | Trace the open syscall and print the filename being opened |
Sasha Goldshtein | 8acd015 | 2016-02-22 02:25:03 -0800 | [diff] [blame] | 419 | trace 'sys_read (arg3 > 20000) "read %d bytes", arg3' |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 420 | Trace the read syscall and print a message for reads >20000 bytes |
| 421 | trace 'r::do_sys_return "%llx", retval' |
| 422 | Trace the return from the open syscall and print the return value |
Sasha Goldshtein | 8acd015 | 2016-02-22 02:25:03 -0800 | [diff] [blame] | 423 | trace 'c:open (arg2 == 42) "%s %d", arg1, arg2' |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 424 | Trace the open() call from libc only if the flags (arg2) argument is 42 |
Sasha Goldshtein | 8acd015 | 2016-02-22 02:25:03 -0800 | [diff] [blame] | 425 | trace 'c:malloc "size = %d", arg1' |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 426 | Trace malloc calls and print the size being allocated |
Sasha Goldshtein | 8acd015 | 2016-02-22 02:25:03 -0800 | [diff] [blame] | 427 | trace 'p:c:write (arg1 == 1) "writing %d bytes to STDOUT", arg3' |
| 428 | Trace the write() call from libc to monitor writes to STDOUT |
| 429 | trace 'r::__kmalloc (retval == 0) "kmalloc failed!" |
| 430 | Trace returns from __kmalloc which returned a null pointer |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 431 | trace 'r:c:malloc (retval) "allocated = %p", retval |
| 432 | Trace returns from malloc and print non-NULL allocated buffers |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 433 | trace 't:block:block_rq_complete "sectors=%d", tp.nr_sector' |
| 434 | Trace the block_rq_complete kernel tracepoint and print # of tx sectors |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 435 | """ |
| 436 | |
| 437 | def __init__(self): |
| 438 | parser = argparse.ArgumentParser(description= |
| 439 | "Attach to functions and print trace messages.", |
| 440 | formatter_class=argparse.RawDescriptionHelpFormatter, |
| 441 | epilog=Tool.examples) |
| 442 | parser.add_argument("-p", "--pid", type=int, |
| 443 | help="id of the process to trace (optional)") |
| 444 | parser.add_argument("-v", "--verbose", action="store_true", |
| 445 | help="print resulting BPF program code before executing") |
| 446 | parser.add_argument("-Z", "--string-size", type=int, |
| 447 | default=80, help="maximum size to read from strings") |
| 448 | parser.add_argument("-S", "--include-self", action="store_true", |
| 449 | help="do not filter trace's own pid from the trace") |
| 450 | parser.add_argument("-M", "--max-events", type=int, |
| 451 | help="number of events to print before quitting") |
| 452 | parser.add_argument("-o", "--offset", action="store_true", |
| 453 | help="use relative time from first traced message") |
| 454 | parser.add_argument(metavar="probe", dest="probes", nargs="+", |
| 455 | help="probe specifier (see examples)") |
| 456 | self.args = parser.parse_args() |
| 457 | |
| 458 | def _create_probes(self): |
| 459 | Probe.configure(self.args) |
| 460 | self.probes = [] |
| 461 | for probe_spec in self.args.probes: |
| 462 | self.probes.append(Probe( |
| 463 | probe_spec, self.args.string_size)) |
| 464 | |
| 465 | def _generate_program(self): |
| 466 | self.program = """ |
| 467 | #include <linux/ptrace.h> |
| 468 | #include <linux/sched.h> /* For TASK_COMM_LEN */ |
| 469 | |
| 470 | """ |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 471 | self.program += Probe.generate_auto_includes( |
| 472 | map(lambda p: p.raw_probe, self.probes)) |
| 473 | self.program += Tracepoint.generate_decl() |
| 474 | self.program += Tracepoint.generate_entry_probe() |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 475 | for probe in self.probes: |
| 476 | self.program += probe.generate_program( |
| 477 | self.args.pid or -1, self.args.include_self) |
| 478 | |
| 479 | if self.args.verbose: |
| 480 | print(self.program) |
| 481 | |
| 482 | def _attach_probes(self): |
| 483 | self.bpf = BPF(text=self.program) |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 484 | Tracepoint.attach(self.bpf) |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 485 | for probe in self.probes: |
| 486 | if self.args.verbose: |
| 487 | print(probe) |
| 488 | probe.attach(self.bpf, self.args.verbose) |
| 489 | |
| 490 | def _main_loop(self): |
| 491 | all_probes_trivial = all(map(Probe.is_default_action, |
| 492 | self.probes)) |
| 493 | |
| 494 | # Print header |
| 495 | print("%-8s %-6s %-12s %-16s %s" % \ |
| 496 | ("TIME", "PID", "COMM", "FUNC", |
| 497 | "-" if not all_probes_trivial else "")) |
| 498 | |
| 499 | while True: |
| 500 | self.bpf.kprobe_poll() |
| 501 | |
| 502 | def run(self): |
| 503 | try: |
| 504 | self._create_probes() |
| 505 | self._generate_program() |
| 506 | self._attach_probes() |
| 507 | self._main_loop() |
| 508 | except: |
| 509 | if self.args.verbose: |
| 510 | traceback.print_exc() |
Sasha Goldshtein | fd60d55 | 2016-03-01 12:15:34 -0800 | [diff] [blame] | 511 | elif sys.exc_type is not SystemExit: |
Sasha Goldshtein | 38847f0 | 2016-02-22 02:19:24 -0800 | [diff] [blame] | 512 | print(sys.exc_value) |
| 513 | |
| 514 | if __name__ == "__main__": |
| 515 | Tool().run() |