xref: /linux/tools/perf/util/scripting-engines/trace-event-python.c (revision c54ea4918c2b7722d7242ea53271356501988a9b)
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(union perf_event *pevent __unused,
208 				 struct perf_sample *sample,
209 				 struct perf_session *session __unused,
210 				 struct thread *thread)
211 {
212 	PyObject *handler, *retval, *context, *t, *obj, *dict = NULL;
213 	static char handler_name[256];
214 	struct format_field *field;
215 	unsigned long long val;
216 	unsigned long s, ns;
217 	struct event *event;
218 	unsigned n = 0;
219 	int type;
220 	int pid;
221 	int cpu = sample->cpu;
222 	void *data = sample->raw_data;
223 	unsigned long long nsecs = sample->time;
224 	char *comm = thread->comm;
225 
226 	t = PyTuple_New(MAX_FIELDS);
227 	if (!t)
228 		Py_FatalError("couldn't create Python tuple");
229 
230 	type = trace_parse_common_type(data);
231 
232 	event = find_cache_event(type);
233 	if (!event)
234 		die("ug! no event found for type %d", type);
235 
236 	pid = trace_parse_common_pid(data);
237 
238 	sprintf(handler_name, "%s__%s", event->system, event->name);
239 
240 	handler = PyDict_GetItemString(main_dict, handler_name);
241 	if (handler && !PyCallable_Check(handler))
242 		handler = NULL;
243 	if (!handler) {
244 		dict = PyDict_New();
245 		if (!dict)
246 			Py_FatalError("couldn't create Python dict");
247 	}
248 	s = nsecs / NSECS_PER_SEC;
249 	ns = nsecs - s * NSECS_PER_SEC;
250 
251 	scripting_context->event_data = data;
252 
253 	context = PyCObject_FromVoidPtr(scripting_context, NULL);
254 
255 	PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
256 	PyTuple_SetItem(t, n++, context);
257 
258 	if (handler) {
259 		PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
260 		PyTuple_SetItem(t, n++, PyInt_FromLong(s));
261 		PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
262 		PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
263 		PyTuple_SetItem(t, n++, PyString_FromString(comm));
264 	} else {
265 		PyDict_SetItemString(dict, "common_cpu", PyInt_FromLong(cpu));
266 		PyDict_SetItemString(dict, "common_s", PyInt_FromLong(s));
267 		PyDict_SetItemString(dict, "common_ns", PyInt_FromLong(ns));
268 		PyDict_SetItemString(dict, "common_pid", PyInt_FromLong(pid));
269 		PyDict_SetItemString(dict, "common_comm", PyString_FromString(comm));
270 	}
271 	for (field = event->format.fields; field; field = field->next) {
272 		if (field->flags & FIELD_IS_STRING) {
273 			int offset;
274 			if (field->flags & FIELD_IS_DYNAMIC) {
275 				offset = *(int *)(data + field->offset);
276 				offset &= 0xffff;
277 			} else
278 				offset = field->offset;
279 			obj = PyString_FromString((char *)data + offset);
280 		} else { /* FIELD_IS_NUMERIC */
281 			val = read_size(data + field->offset, field->size);
282 			if (field->flags & FIELD_IS_SIGNED) {
283 				if ((long long)val >= LONG_MIN &&
284 				    (long long)val <= LONG_MAX)
285 					obj = PyInt_FromLong(val);
286 				else
287 					obj = PyLong_FromLongLong(val);
288 			} else {
289 				if (val <= LONG_MAX)
290 					obj = PyInt_FromLong(val);
291 				else
292 					obj = PyLong_FromUnsignedLongLong(val);
293 			}
294 		}
295 		if (handler)
296 			PyTuple_SetItem(t, n++, obj);
297 		else
298 			PyDict_SetItemString(dict, field->name, obj);
299 
300 	}
301 	if (!handler)
302 		PyTuple_SetItem(t, n++, dict);
303 
304 	if (_PyTuple_Resize(&t, n) == -1)
305 		Py_FatalError("error resizing Python tuple");
306 
307 	if (handler) {
308 		retval = PyObject_CallObject(handler, t);
309 		if (retval == NULL)
310 			handler_call_die(handler_name);
311 	} else {
312 		handler = PyDict_GetItemString(main_dict, "trace_unhandled");
313 		if (handler && PyCallable_Check(handler)) {
314 
315 			retval = PyObject_CallObject(handler, t);
316 			if (retval == NULL)
317 				handler_call_die("trace_unhandled");
318 		}
319 		Py_DECREF(dict);
320 	}
321 
322 	Py_DECREF(t);
323 }
324 
325 static int run_start_sub(void)
326 {
327 	PyObject *handler, *retval;
328 	int err = 0;
329 
330 	main_module = PyImport_AddModule("__main__");
331 	if (main_module == NULL)
332 		return -1;
333 	Py_INCREF(main_module);
334 
335 	main_dict = PyModule_GetDict(main_module);
336 	if (main_dict == NULL) {
337 		err = -1;
338 		goto error;
339 	}
340 	Py_INCREF(main_dict);
341 
342 	handler = PyDict_GetItemString(main_dict, "trace_begin");
343 	if (handler == NULL || !PyCallable_Check(handler))
344 		goto out;
345 
346 	retval = PyObject_CallObject(handler, NULL);
347 	if (retval == NULL)
348 		handler_call_die("trace_begin");
349 
350 	Py_DECREF(retval);
351 	return err;
352 error:
353 	Py_XDECREF(main_dict);
354 	Py_XDECREF(main_module);
355 out:
356 	return err;
357 }
358 
359 /*
360  * Start trace script
361  */
362 static int python_start_script(const char *script, int argc, const char **argv)
363 {
364 	const char **command_line;
365 	char buf[PATH_MAX];
366 	int i, err = 0;
367 	FILE *fp;
368 
369 	command_line = malloc((argc + 1) * sizeof(const char *));
370 	command_line[0] = script;
371 	for (i = 1; i < argc + 1; i++)
372 		command_line[i] = argv[i - 1];
373 
374 	Py_Initialize();
375 
376 	initperf_trace_context();
377 
378 	PySys_SetArgv(argc + 1, (char **)command_line);
379 
380 	fp = fopen(script, "r");
381 	if (!fp) {
382 		sprintf(buf, "Can't open python script \"%s\"", script);
383 		perror(buf);
384 		err = -1;
385 		goto error;
386 	}
387 
388 	err = PyRun_SimpleFile(fp, script);
389 	if (err) {
390 		fprintf(stderr, "Error running python script %s\n", script);
391 		goto error;
392 	}
393 
394 	err = run_start_sub();
395 	if (err) {
396 		fprintf(stderr, "Error starting python script %s\n", script);
397 		goto error;
398 	}
399 
400 	free(command_line);
401 
402 	return err;
403 error:
404 	Py_Finalize();
405 	free(command_line);
406 
407 	return err;
408 }
409 
410 /*
411  * Stop trace script
412  */
413 static int python_stop_script(void)
414 {
415 	PyObject *handler, *retval;
416 	int err = 0;
417 
418 	handler = PyDict_GetItemString(main_dict, "trace_end");
419 	if (handler == NULL || !PyCallable_Check(handler))
420 		goto out;
421 
422 	retval = PyObject_CallObject(handler, NULL);
423 	if (retval == NULL)
424 		handler_call_die("trace_end");
425 	else
426 		Py_DECREF(retval);
427 out:
428 	Py_XDECREF(main_dict);
429 	Py_XDECREF(main_module);
430 	Py_Finalize();
431 
432 	return err;
433 }
434 
435 static int python_generate_script(const char *outfile)
436 {
437 	struct event *event = NULL;
438 	struct format_field *f;
439 	char fname[PATH_MAX];
440 	int not_first, count;
441 	FILE *ofp;
442 
443 	sprintf(fname, "%s.py", outfile);
444 	ofp = fopen(fname, "w");
445 	if (ofp == NULL) {
446 		fprintf(stderr, "couldn't open %s\n", fname);
447 		return -1;
448 	}
449 	fprintf(ofp, "# perf script event handlers, "
450 		"generated by perf script -g python\n");
451 
452 	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
453 		" License version 2\n\n");
454 
455 	fprintf(ofp, "# The common_* event handler fields are the most useful "
456 		"fields common to\n");
457 
458 	fprintf(ofp, "# all events.  They don't necessarily correspond to "
459 		"the 'common_*' fields\n");
460 
461 	fprintf(ofp, "# in the format files.  Those fields not available as "
462 		"handler params can\n");
463 
464 	fprintf(ofp, "# be retrieved using Python functions of the form "
465 		"common_*(context).\n");
466 
467 	fprintf(ofp, "# See the perf-trace-python Documentation for the list "
468 		"of available functions.\n\n");
469 
470 	fprintf(ofp, "import os\n");
471 	fprintf(ofp, "import sys\n\n");
472 
473 	fprintf(ofp, "sys.path.append(os.environ['PERF_EXEC_PATH'] + \\\n");
474 	fprintf(ofp, "\t'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')\n");
475 	fprintf(ofp, "\nfrom perf_trace_context import *\n");
476 	fprintf(ofp, "from Core import *\n\n\n");
477 
478 	fprintf(ofp, "def trace_begin():\n");
479 	fprintf(ofp, "\tprint \"in trace_begin\"\n\n");
480 
481 	fprintf(ofp, "def trace_end():\n");
482 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
483 
484 	while ((event = trace_find_next_event(event))) {
485 		fprintf(ofp, "def %s__%s(", event->system, event->name);
486 		fprintf(ofp, "event_name, ");
487 		fprintf(ofp, "context, ");
488 		fprintf(ofp, "common_cpu,\n");
489 		fprintf(ofp, "\tcommon_secs, ");
490 		fprintf(ofp, "common_nsecs, ");
491 		fprintf(ofp, "common_pid, ");
492 		fprintf(ofp, "common_comm,\n\t");
493 
494 		not_first = 0;
495 		count = 0;
496 
497 		for (f = event->format.fields; f; f = f->next) {
498 			if (not_first++)
499 				fprintf(ofp, ", ");
500 			if (++count % 5 == 0)
501 				fprintf(ofp, "\n\t");
502 
503 			fprintf(ofp, "%s", f->name);
504 		}
505 		fprintf(ofp, "):\n");
506 
507 		fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
508 			"common_secs, common_nsecs,\n\t\t\t"
509 			"common_pid, common_comm)\n\n");
510 
511 		fprintf(ofp, "\t\tprint \"");
512 
513 		not_first = 0;
514 		count = 0;
515 
516 		for (f = event->format.fields; f; f = f->next) {
517 			if (not_first++)
518 				fprintf(ofp, ", ");
519 			if (count && count % 3 == 0) {
520 				fprintf(ofp, "\" \\\n\t\t\"");
521 			}
522 			count++;
523 
524 			fprintf(ofp, "%s=", f->name);
525 			if (f->flags & FIELD_IS_STRING ||
526 			    f->flags & FIELD_IS_FLAG ||
527 			    f->flags & FIELD_IS_SYMBOLIC)
528 				fprintf(ofp, "%%s");
529 			else if (f->flags & FIELD_IS_SIGNED)
530 				fprintf(ofp, "%%d");
531 			else
532 				fprintf(ofp, "%%u");
533 		}
534 
535 		fprintf(ofp, "\\n\" %% \\\n\t\t(");
536 
537 		not_first = 0;
538 		count = 0;
539 
540 		for (f = event->format.fields; f; f = f->next) {
541 			if (not_first++)
542 				fprintf(ofp, ", ");
543 
544 			if (++count % 5 == 0)
545 				fprintf(ofp, "\n\t\t");
546 
547 			if (f->flags & FIELD_IS_FLAG) {
548 				if ((count - 1) % 5 != 0) {
549 					fprintf(ofp, "\n\t\t");
550 					count = 4;
551 				}
552 				fprintf(ofp, "flag_str(\"");
553 				fprintf(ofp, "%s__%s\", ", event->system,
554 					event->name);
555 				fprintf(ofp, "\"%s\", %s)", f->name,
556 					f->name);
557 			} else if (f->flags & FIELD_IS_SYMBOLIC) {
558 				if ((count - 1) % 5 != 0) {
559 					fprintf(ofp, "\n\t\t");
560 					count = 4;
561 				}
562 				fprintf(ofp, "symbol_str(\"");
563 				fprintf(ofp, "%s__%s\", ", event->system,
564 					event->name);
565 				fprintf(ofp, "\"%s\", %s)", f->name,
566 					f->name);
567 			} else
568 				fprintf(ofp, "%s", f->name);
569 		}
570 
571 		fprintf(ofp, "),\n\n");
572 	}
573 
574 	fprintf(ofp, "def trace_unhandled(event_name, context, "
575 		"event_fields_dict):\n");
576 
577 	fprintf(ofp, "\t\tprint ' '.join(['%%s=%%s'%%(k,str(v))"
578 		"for k,v in sorted(event_fields_dict.items())])\n\n");
579 
580 	fprintf(ofp, "def print_header("
581 		"event_name, cpu, secs, nsecs, pid, comm):\n"
582 		"\tprint \"%%-20s %%5u %%05u.%%09u %%8u %%-20s \" %% \\\n\t"
583 		"(event_name, cpu, secs, nsecs, pid, comm),\n");
584 
585 	fclose(ofp);
586 
587 	fprintf(stderr, "generated Python script: %s\n", fname);
588 
589 	return 0;
590 }
591 
592 struct scripting_ops python_scripting_ops = {
593 	.name = "Python",
594 	.start_script = python_start_script,
595 	.stop_script = python_stop_script,
596 	.process_event = python_process_event,
597 	.generate_script = python_generate_script,
598 };
599