xref: /linux/tools/perf/util/scripting-engines/trace-event-python.c (revision fb72014d98afd51e85aab9c061344ef32d615606)
1 /*
2  * trace-event-python.  Feed trace events to an embedded Python interpreter.
3  *
4  * Copyright (C) 2010 Tom Zanussi <tzanussi@gmail.com>
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19  *
20  */
21 
22 #include <Python.h>
23 
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <ctype.h>
28 #include <errno.h>
29 
30 #include "../../perf.h"
31 #include "../util.h"
32 #include "../trace-event.h"
33 
34 PyMODINIT_FUNC initperf_trace_context(void);
35 
36 #define FTRACE_MAX_EVENT				\
37 	((1 << (sizeof(unsigned short) * 8)) - 1)
38 
39 struct event *events[FTRACE_MAX_EVENT];
40 
41 #define MAX_FIELDS	64
42 #define N_COMMON_FIELDS	7
43 
44 extern struct scripting_context *scripting_context;
45 
46 static char *cur_field_name;
47 static int zero_flag_atom;
48 
49 static PyObject *main_module, *main_dict;
50 
51 static void handler_call_die(const char *handler_name)
52 {
53 	PyErr_Print();
54 	Py_FatalError("problem in Python trace event handler");
55 }
56 
57 static void define_value(enum print_arg_type field_type,
58 			 const char *ev_name,
59 			 const char *field_name,
60 			 const char *field_value,
61 			 const char *field_str)
62 {
63 	const char *handler_name = "define_flag_value";
64 	PyObject *handler, *t, *retval;
65 	unsigned long long value;
66 	unsigned n = 0;
67 
68 	if (field_type == PRINT_SYMBOL)
69 		handler_name = "define_symbolic_value";
70 
71 	t = PyTuple_New(4);
72 	if (!t)
73 		Py_FatalError("couldn't create Python tuple");
74 
75 	value = eval_flag(field_value);
76 
77 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
78 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
79 	PyTuple_SetItem(t, n++, PyInt_FromLong(value));
80 	PyTuple_SetItem(t, n++, PyString_FromString(field_str));
81 
82 	handler = PyDict_GetItemString(main_dict, handler_name);
83 	if (handler && PyCallable_Check(handler)) {
84 		retval = PyObject_CallObject(handler, t);
85 		if (retval == NULL)
86 			handler_call_die(handler_name);
87 	}
88 
89 	Py_DECREF(t);
90 }
91 
92 static void define_values(enum print_arg_type field_type,
93 			  struct print_flag_sym *field,
94 			  const char *ev_name,
95 			  const char *field_name)
96 {
97 	define_value(field_type, ev_name, field_name, field->value,
98 		     field->str);
99 
100 	if (field->next)
101 		define_values(field_type, field->next, ev_name, field_name);
102 }
103 
104 static void define_field(enum print_arg_type field_type,
105 			 const char *ev_name,
106 			 const char *field_name,
107 			 const char *delim)
108 {
109 	const char *handler_name = "define_flag_field";
110 	PyObject *handler, *t, *retval;
111 	unsigned n = 0;
112 
113 	if (field_type == PRINT_SYMBOL)
114 		handler_name = "define_symbolic_field";
115 
116 	if (field_type == PRINT_FLAGS)
117 		t = PyTuple_New(3);
118 	else
119 		t = PyTuple_New(2);
120 	if (!t)
121 		Py_FatalError("couldn't create Python tuple");
122 
123 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
124 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
125 	if (field_type == PRINT_FLAGS)
126 		PyTuple_SetItem(t, n++, PyString_FromString(delim));
127 
128 	handler = PyDict_GetItemString(main_dict, handler_name);
129 	if (handler && PyCallable_Check(handler)) {
130 		retval = PyObject_CallObject(handler, t);
131 		if (retval == NULL)
132 			handler_call_die(handler_name);
133 	}
134 
135 	Py_DECREF(t);
136 }
137 
138 static void define_event_symbols(struct event *event,
139 				 const char *ev_name,
140 				 struct print_arg *args)
141 {
142 	switch (args->type) {
143 	case PRINT_NULL:
144 		break;
145 	case PRINT_ATOM:
146 		define_value(PRINT_FLAGS, ev_name, cur_field_name, "0",
147 			     args->atom.atom);
148 		zero_flag_atom = 0;
149 		break;
150 	case PRINT_FIELD:
151 		if (cur_field_name)
152 			free(cur_field_name);
153 		cur_field_name = strdup(args->field.name);
154 		break;
155 	case PRINT_FLAGS:
156 		define_event_symbols(event, ev_name, args->flags.field);
157 		define_field(PRINT_FLAGS, ev_name, cur_field_name,
158 			     args->flags.delim);
159 		define_values(PRINT_FLAGS, args->flags.flags, ev_name,
160 			      cur_field_name);
161 		break;
162 	case PRINT_SYMBOL:
163 		define_event_symbols(event, ev_name, args->symbol.field);
164 		define_field(PRINT_SYMBOL, ev_name, cur_field_name, NULL);
165 		define_values(PRINT_SYMBOL, args->symbol.symbols, ev_name,
166 			      cur_field_name);
167 		break;
168 	case PRINT_STRING:
169 		break;
170 	case PRINT_TYPE:
171 		define_event_symbols(event, ev_name, args->typecast.item);
172 		break;
173 	case PRINT_OP:
174 		if (strcmp(args->op.op, ":") == 0)
175 			zero_flag_atom = 1;
176 		define_event_symbols(event, ev_name, args->op.left);
177 		define_event_symbols(event, ev_name, args->op.right);
178 		break;
179 	default:
180 		/* we should warn... */
181 		return;
182 	}
183 
184 	if (args->next)
185 		define_event_symbols(event, ev_name, args->next);
186 }
187 
188 static inline struct event *find_cache_event(int type)
189 {
190 	static char ev_name[256];
191 	struct event *event;
192 
193 	if (events[type])
194 		return events[type];
195 
196 	events[type] = event = trace_find_event(type);
197 	if (!event)
198 		return NULL;
199 
200 	sprintf(ev_name, "%s__%s", event->system, event->name);
201 
202 	define_event_symbols(event, ev_name, event->print_fmt.args);
203 
204 	return event;
205 }
206 
207 static void python_process_event(int cpu, void *data,
208 				 int size __unused,
209 				 unsigned long long nsecs, char *comm)
210 {
211 	PyObject *handler, *retval, *context, *t, *obj;
212 	static char handler_name[256];
213 	struct format_field *field;
214 	unsigned long long val;
215 	unsigned long s, ns;
216 	struct event *event;
217 	unsigned n = 0;
218 	int type;
219 	int pid;
220 
221 	t = PyTuple_New(MAX_FIELDS);
222 	if (!t)
223 		Py_FatalError("couldn't create Python tuple");
224 
225 	type = trace_parse_common_type(data);
226 
227 	event = find_cache_event(type);
228 	if (!event)
229 		die("ug! no event found for type %d", type);
230 
231 	pid = trace_parse_common_pid(data);
232 
233 	sprintf(handler_name, "%s__%s", event->system, event->name);
234 
235 	s = nsecs / NSECS_PER_SEC;
236 	ns = nsecs - s * NSECS_PER_SEC;
237 
238 	scripting_context->event_data = data;
239 
240 	context = PyCObject_FromVoidPtr(scripting_context, NULL);
241 
242 	PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
243 	PyTuple_SetItem(t, n++,
244 			PyCObject_FromVoidPtr(scripting_context, NULL));
245 	PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
246 	PyTuple_SetItem(t, n++, PyInt_FromLong(s));
247 	PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
248 	PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
249 	PyTuple_SetItem(t, n++, PyString_FromString(comm));
250 
251 	for (field = event->format.fields; field; field = field->next) {
252 		if (field->flags & FIELD_IS_STRING) {
253 			int offset;
254 			if (field->flags & FIELD_IS_DYNAMIC) {
255 				offset = *(int *)(data + field->offset);
256 				offset &= 0xffff;
257 			} else
258 				offset = field->offset;
259 			obj = PyString_FromString((char *)data + offset);
260 		} else { /* FIELD_IS_NUMERIC */
261 			val = read_size(data + field->offset, field->size);
262 			if (field->flags & FIELD_IS_SIGNED) {
263 				if ((long long)val >= LONG_MIN &&
264 				    (long long)val <= LONG_MAX)
265 					obj = PyInt_FromLong(val);
266 				else
267 					obj = PyLong_FromLongLong(val);
268 			} else {
269 				if (val <= LONG_MAX)
270 					obj = PyInt_FromLong(val);
271 				else
272 					obj = PyLong_FromUnsignedLongLong(val);
273 			}
274 		}
275 		PyTuple_SetItem(t, n++, obj);
276 	}
277 
278 	if (_PyTuple_Resize(&t, n) == -1)
279 		Py_FatalError("error resizing Python tuple");
280 
281 	handler = PyDict_GetItemString(main_dict, handler_name);
282 	if (handler && PyCallable_Check(handler)) {
283 		retval = PyObject_CallObject(handler, t);
284 		if (retval == NULL)
285 			handler_call_die(handler_name);
286 	} else {
287 		handler = PyDict_GetItemString(main_dict, "trace_unhandled");
288 		if (handler && PyCallable_Check(handler)) {
289 			if (_PyTuple_Resize(&t, N_COMMON_FIELDS) == -1)
290 				Py_FatalError("error resizing Python tuple");
291 
292 			retval = PyObject_CallObject(handler, t);
293 			if (retval == NULL)
294 				handler_call_die("trace_unhandled");
295 		}
296 	}
297 
298 	Py_DECREF(t);
299 }
300 
301 static int run_start_sub(void)
302 {
303 	PyObject *handler, *retval;
304 	int err = 0;
305 
306 	main_module = PyImport_AddModule("__main__");
307 	if (main_module == NULL)
308 		return -1;
309 	Py_INCREF(main_module);
310 
311 	main_dict = PyModule_GetDict(main_module);
312 	if (main_dict == NULL) {
313 		err = -1;
314 		goto error;
315 	}
316 	Py_INCREF(main_dict);
317 
318 	handler = PyDict_GetItemString(main_dict, "trace_begin");
319 	if (handler == NULL || !PyCallable_Check(handler))
320 		goto out;
321 
322 	retval = PyObject_CallObject(handler, NULL);
323 	if (retval == NULL)
324 		handler_call_die("trace_begin");
325 
326 	Py_DECREF(retval);
327 	return err;
328 error:
329 	Py_XDECREF(main_dict);
330 	Py_XDECREF(main_module);
331 out:
332 	return err;
333 }
334 
335 /*
336  * Start trace script
337  */
338 static int python_start_script(const char *script, int argc, const char **argv)
339 {
340 	const char **command_line;
341 	char buf[PATH_MAX];
342 	int i, err = 0;
343 	FILE *fp;
344 
345 	command_line = malloc((argc + 1) * sizeof(const char *));
346 	command_line[0] = script;
347 	for (i = 1; i < argc + 1; i++)
348 		command_line[i] = argv[i - 1];
349 
350 	Py_Initialize();
351 
352 	initperf_trace_context();
353 
354 	PySys_SetArgv(argc + 1, (char **)command_line);
355 
356 	fp = fopen(script, "r");
357 	if (!fp) {
358 		sprintf(buf, "Can't open python script \"%s\"", script);
359 		perror(buf);
360 		err = -1;
361 		goto error;
362 	}
363 
364 	err = PyRun_SimpleFile(fp, script);
365 	if (err) {
366 		fprintf(stderr, "Error running python script %s\n", script);
367 		goto error;
368 	}
369 
370 	err = run_start_sub();
371 	if (err) {
372 		fprintf(stderr, "Error starting python script %s\n", script);
373 		goto error;
374 	}
375 
376 	free(command_line);
377 	fprintf(stderr, "perf trace started with Python script %s\n\n",
378 		script);
379 
380 	return err;
381 error:
382 	Py_Finalize();
383 	free(command_line);
384 
385 	return err;
386 }
387 
388 /*
389  * Stop trace script
390  */
391 static int python_stop_script(void)
392 {
393 	PyObject *handler, *retval;
394 	int err = 0;
395 
396 	handler = PyDict_GetItemString(main_dict, "trace_end");
397 	if (handler == NULL || !PyCallable_Check(handler))
398 		goto out;
399 
400 	retval = PyObject_CallObject(handler, NULL);
401 	if (retval == NULL)
402 		handler_call_die("trace_end");
403 	else
404 		Py_DECREF(retval);
405 out:
406 	Py_XDECREF(main_dict);
407 	Py_XDECREF(main_module);
408 	Py_Finalize();
409 
410 	fprintf(stderr, "\nperf trace Python script stopped\n");
411 
412 	return err;
413 }
414 
415 static int python_generate_script(const char *outfile)
416 {
417 	struct event *event = NULL;
418 	struct format_field *f;
419 	char fname[PATH_MAX];
420 	int not_first, count;
421 	FILE *ofp;
422 
423 	sprintf(fname, "%s.py", outfile);
424 	ofp = fopen(fname, "w");
425 	if (ofp == NULL) {
426 		fprintf(stderr, "couldn't open %s\n", fname);
427 		return -1;
428 	}
429 	fprintf(ofp, "# perf trace event handlers, "
430 		"generated by perf trace -g python\n");
431 
432 	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
433 		" License version 2\n\n");
434 
435 	fprintf(ofp, "# The common_* event handler fields are the most useful "
436 		"fields common to\n");
437 
438 	fprintf(ofp, "# all events.  They don't necessarily correspond to "
439 		"the 'common_*' fields\n");
440 
441 	fprintf(ofp, "# in the format files.  Those fields not available as "
442 		"handler params can\n");
443 
444 	fprintf(ofp, "# be retrieved using Python functions of the form "
445 		"common_*(context).\n");
446 
447 	fprintf(ofp, "# See the perf-trace-python Documentation for the list "
448 		"of available functions.\n\n");
449 
450 	fprintf(ofp, "import os\n");
451 	fprintf(ofp, "import sys\n\n");
452 
453 	fprintf(ofp, "sys.path.append(os.environ['PERF_EXEC_PATH'] + \\\n");
454 	fprintf(ofp, "\t'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')\n");
455 	fprintf(ofp, "\nfrom perf_trace_context import *\n");
456 	fprintf(ofp, "from Core import *\n\n\n");
457 
458 	fprintf(ofp, "def trace_begin():\n");
459 	fprintf(ofp, "\tprint \"in trace_begin\"\n\n");
460 
461 	fprintf(ofp, "def trace_end():\n");
462 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
463 
464 	while ((event = trace_find_next_event(event))) {
465 		fprintf(ofp, "def %s__%s(", event->system, event->name);
466 		fprintf(ofp, "event_name, ");
467 		fprintf(ofp, "context, ");
468 		fprintf(ofp, "common_cpu,\n");
469 		fprintf(ofp, "\tcommon_secs, ");
470 		fprintf(ofp, "common_nsecs, ");
471 		fprintf(ofp, "common_pid, ");
472 		fprintf(ofp, "common_comm,\n\t");
473 
474 		not_first = 0;
475 		count = 0;
476 
477 		for (f = event->format.fields; f; f = f->next) {
478 			if (not_first++)
479 				fprintf(ofp, ", ");
480 			if (++count % 5 == 0)
481 				fprintf(ofp, "\n\t");
482 
483 			fprintf(ofp, "%s", f->name);
484 		}
485 		fprintf(ofp, "):\n");
486 
487 		fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
488 			"common_secs, common_nsecs,\n\t\t\t"
489 			"common_pid, common_comm)\n\n");
490 
491 		fprintf(ofp, "\t\tprint \"");
492 
493 		not_first = 0;
494 		count = 0;
495 
496 		for (f = event->format.fields; f; f = f->next) {
497 			if (not_first++)
498 				fprintf(ofp, ", ");
499 			if (count && count % 3 == 0) {
500 				fprintf(ofp, "\" \\\n\t\t\"");
501 			}
502 			count++;
503 
504 			fprintf(ofp, "%s=", f->name);
505 			if (f->flags & FIELD_IS_STRING ||
506 			    f->flags & FIELD_IS_FLAG ||
507 			    f->flags & FIELD_IS_SYMBOLIC)
508 				fprintf(ofp, "%%s");
509 			else if (f->flags & FIELD_IS_SIGNED)
510 				fprintf(ofp, "%%d");
511 			else
512 				fprintf(ofp, "%%u");
513 		}
514 
515 		fprintf(ofp, "\\n\" %% \\\n\t\t(");
516 
517 		not_first = 0;
518 		count = 0;
519 
520 		for (f = event->format.fields; f; f = f->next) {
521 			if (not_first++)
522 				fprintf(ofp, ", ");
523 
524 			if (++count % 5 == 0)
525 				fprintf(ofp, "\n\t\t");
526 
527 			if (f->flags & FIELD_IS_FLAG) {
528 				if ((count - 1) % 5 != 0) {
529 					fprintf(ofp, "\n\t\t");
530 					count = 4;
531 				}
532 				fprintf(ofp, "flag_str(\"");
533 				fprintf(ofp, "%s__%s\", ", event->system,
534 					event->name);
535 				fprintf(ofp, "\"%s\", %s)", f->name,
536 					f->name);
537 			} else if (f->flags & FIELD_IS_SYMBOLIC) {
538 				if ((count - 1) % 5 != 0) {
539 					fprintf(ofp, "\n\t\t");
540 					count = 4;
541 				}
542 				fprintf(ofp, "symbol_str(\"");
543 				fprintf(ofp, "%s__%s\", ", event->system,
544 					event->name);
545 				fprintf(ofp, "\"%s\", %s)", f->name,
546 					f->name);
547 			} else
548 				fprintf(ofp, "%s", f->name);
549 		}
550 
551 		fprintf(ofp, "),\n\n");
552 	}
553 
554 	fprintf(ofp, "def trace_unhandled(event_name, context, "
555 		"common_cpu, common_secs, common_nsecs,\n\t\t"
556 		"common_pid, common_comm):\n");
557 
558 	fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
559 		"common_secs, common_nsecs,\n\t\tcommon_pid, "
560 		"common_comm)\n\n");
561 
562 	fprintf(ofp, "def print_header("
563 		"event_name, cpu, secs, nsecs, pid, comm):\n"
564 		"\tprint \"%%-20s %%5u %%05u.%%09u %%8u %%-20s \" %% \\\n\t"
565 		"(event_name, cpu, secs, nsecs, pid, comm),\n");
566 
567 	fclose(ofp);
568 
569 	fprintf(stderr, "generated Python script: %s\n", fname);
570 
571 	return 0;
572 }
573 
574 struct scripting_ops python_scripting_ops = {
575 	.name = "Python",
576 	.start_script = python_start_script,
577 	.stop_script = python_stop_script,
578 	.process_event = python_process_event,
579 	.generate_script = python_generate_script,
580 };
581