xref: /linux/tools/perf/util/scripting-engines/trace-event-python.c (revision ce7240e445303de3ca66e6d08f17a2ec278a5bf6)
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 <errno.h>
28 
29 #include "../../perf.h"
30 #include "../util.h"
31 #include "../event.h"
32 #include "../thread.h"
33 #include "../trace-event.h"
34 
35 PyMODINIT_FUNC initperf_trace_context(void);
36 
37 #define FTRACE_MAX_EVENT				\
38 	((1 << (sizeof(unsigned short) * 8)) - 1)
39 
40 struct event_format *events[FTRACE_MAX_EVENT];
41 
42 #define MAX_FIELDS	64
43 #define N_COMMON_FIELDS	7
44 
45 extern struct scripting_context *scripting_context;
46 
47 static char *cur_field_name;
48 static int zero_flag_atom;
49 
50 static PyObject *main_module, *main_dict;
51 
52 static void handler_call_die(const char *handler_name)
53 {
54 	PyErr_Print();
55 	Py_FatalError("problem in Python trace event handler");
56 }
57 
58 static void define_value(enum print_arg_type field_type,
59 			 const char *ev_name,
60 			 const char *field_name,
61 			 const char *field_value,
62 			 const char *field_str)
63 {
64 	const char *handler_name = "define_flag_value";
65 	PyObject *handler, *t, *retval;
66 	unsigned long long value;
67 	unsigned n = 0;
68 
69 	if (field_type == PRINT_SYMBOL)
70 		handler_name = "define_symbolic_value";
71 
72 	t = PyTuple_New(4);
73 	if (!t)
74 		Py_FatalError("couldn't create Python tuple");
75 
76 	value = eval_flag(field_value);
77 
78 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
79 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
80 	PyTuple_SetItem(t, n++, PyInt_FromLong(value));
81 	PyTuple_SetItem(t, n++, PyString_FromString(field_str));
82 
83 	handler = PyDict_GetItemString(main_dict, handler_name);
84 	if (handler && PyCallable_Check(handler)) {
85 		retval = PyObject_CallObject(handler, t);
86 		if (retval == NULL)
87 			handler_call_die(handler_name);
88 	}
89 
90 	Py_DECREF(t);
91 }
92 
93 static void define_values(enum print_arg_type field_type,
94 			  struct print_flag_sym *field,
95 			  const char *ev_name,
96 			  const char *field_name)
97 {
98 	define_value(field_type, ev_name, field_name, field->value,
99 		     field->str);
100 
101 	if (field->next)
102 		define_values(field_type, field->next, ev_name, field_name);
103 }
104 
105 static void define_field(enum print_arg_type field_type,
106 			 const char *ev_name,
107 			 const char *field_name,
108 			 const char *delim)
109 {
110 	const char *handler_name = "define_flag_field";
111 	PyObject *handler, *t, *retval;
112 	unsigned n = 0;
113 
114 	if (field_type == PRINT_SYMBOL)
115 		handler_name = "define_symbolic_field";
116 
117 	if (field_type == PRINT_FLAGS)
118 		t = PyTuple_New(3);
119 	else
120 		t = PyTuple_New(2);
121 	if (!t)
122 		Py_FatalError("couldn't create Python tuple");
123 
124 	PyTuple_SetItem(t, n++, PyString_FromString(ev_name));
125 	PyTuple_SetItem(t, n++, PyString_FromString(field_name));
126 	if (field_type == PRINT_FLAGS)
127 		PyTuple_SetItem(t, n++, PyString_FromString(delim));
128 
129 	handler = PyDict_GetItemString(main_dict, handler_name);
130 	if (handler && PyCallable_Check(handler)) {
131 		retval = PyObject_CallObject(handler, t);
132 		if (retval == NULL)
133 			handler_call_die(handler_name);
134 	}
135 
136 	Py_DECREF(t);
137 }
138 
139 static void define_event_symbols(struct event_format *event,
140 				 const char *ev_name,
141 				 struct print_arg *args)
142 {
143 	switch (args->type) {
144 	case PRINT_NULL:
145 		break;
146 	case PRINT_ATOM:
147 		define_value(PRINT_FLAGS, ev_name, cur_field_name, "0",
148 			     args->atom.atom);
149 		zero_flag_atom = 0;
150 		break;
151 	case PRINT_FIELD:
152 		if (cur_field_name)
153 			free(cur_field_name);
154 		cur_field_name = strdup(args->field.name);
155 		break;
156 	case PRINT_FLAGS:
157 		define_event_symbols(event, ev_name, args->flags.field);
158 		define_field(PRINT_FLAGS, ev_name, cur_field_name,
159 			     args->flags.delim);
160 		define_values(PRINT_FLAGS, args->flags.flags, ev_name,
161 			      cur_field_name);
162 		break;
163 	case PRINT_SYMBOL:
164 		define_event_symbols(event, ev_name, args->symbol.field);
165 		define_field(PRINT_SYMBOL, ev_name, cur_field_name, NULL);
166 		define_values(PRINT_SYMBOL, args->symbol.symbols, ev_name,
167 			      cur_field_name);
168 		break;
169 	case PRINT_STRING:
170 		break;
171 	case PRINT_TYPE:
172 		define_event_symbols(event, ev_name, args->typecast.item);
173 		break;
174 	case PRINT_OP:
175 		if (strcmp(args->op.op, ":") == 0)
176 			zero_flag_atom = 1;
177 		define_event_symbols(event, ev_name, args->op.left);
178 		define_event_symbols(event, ev_name, args->op.right);
179 		break;
180 	default:
181 		/* gcc warns for these? */
182 	case PRINT_BSTRING:
183 	case PRINT_DYNAMIC_ARRAY:
184 	case PRINT_FUNC:
185 		/* we should warn... */
186 		return;
187 	}
188 
189 	if (args->next)
190 		define_event_symbols(event, ev_name, args->next);
191 }
192 
193 static inline struct event_format *find_cache_event(int type)
194 {
195 	static char ev_name[256];
196 	struct event_format *event;
197 
198 	if (events[type])
199 		return events[type];
200 
201 	events[type] = event = trace_find_event(type);
202 	if (!event)
203 		return NULL;
204 
205 	sprintf(ev_name, "%s__%s", event->system, event->name);
206 
207 	define_event_symbols(event, ev_name, event->print_fmt.args);
208 
209 	return event;
210 }
211 
212 static void python_process_event(union perf_event *pevent __unused,
213 				 struct perf_sample *sample,
214 				 struct perf_evsel *evsel __unused,
215 				 struct machine *machine __unused,
216 				 struct thread *thread)
217 {
218 	PyObject *handler, *retval, *context, *t, *obj, *dict = NULL;
219 	static char handler_name[256];
220 	struct format_field *field;
221 	unsigned long long val;
222 	unsigned long s, ns;
223 	struct event_format *event;
224 	unsigned n = 0;
225 	int type;
226 	int pid;
227 	int cpu = sample->cpu;
228 	void *data = sample->raw_data;
229 	unsigned long long nsecs = sample->time;
230 	char *comm = thread->comm;
231 
232 	t = PyTuple_New(MAX_FIELDS);
233 	if (!t)
234 		Py_FatalError("couldn't create Python tuple");
235 
236 	type = trace_parse_common_type(data);
237 
238 	event = find_cache_event(type);
239 	if (!event)
240 		die("ug! no event found for type %d", type);
241 
242 	pid = trace_parse_common_pid(data);
243 
244 	sprintf(handler_name, "%s__%s", event->system, event->name);
245 
246 	handler = PyDict_GetItemString(main_dict, handler_name);
247 	if (handler && !PyCallable_Check(handler))
248 		handler = NULL;
249 	if (!handler) {
250 		dict = PyDict_New();
251 		if (!dict)
252 			Py_FatalError("couldn't create Python dict");
253 	}
254 	s = nsecs / NSECS_PER_SEC;
255 	ns = nsecs - s * NSECS_PER_SEC;
256 
257 	scripting_context->event_data = data;
258 
259 	context = PyCObject_FromVoidPtr(scripting_context, NULL);
260 
261 	PyTuple_SetItem(t, n++, PyString_FromString(handler_name));
262 	PyTuple_SetItem(t, n++, context);
263 
264 	if (handler) {
265 		PyTuple_SetItem(t, n++, PyInt_FromLong(cpu));
266 		PyTuple_SetItem(t, n++, PyInt_FromLong(s));
267 		PyTuple_SetItem(t, n++, PyInt_FromLong(ns));
268 		PyTuple_SetItem(t, n++, PyInt_FromLong(pid));
269 		PyTuple_SetItem(t, n++, PyString_FromString(comm));
270 	} else {
271 		PyDict_SetItemString(dict, "common_cpu", PyInt_FromLong(cpu));
272 		PyDict_SetItemString(dict, "common_s", PyInt_FromLong(s));
273 		PyDict_SetItemString(dict, "common_ns", PyInt_FromLong(ns));
274 		PyDict_SetItemString(dict, "common_pid", PyInt_FromLong(pid));
275 		PyDict_SetItemString(dict, "common_comm", PyString_FromString(comm));
276 	}
277 	for (field = event->format.fields; field; field = field->next) {
278 		if (field->flags & FIELD_IS_STRING) {
279 			int offset;
280 			if (field->flags & FIELD_IS_DYNAMIC) {
281 				offset = *(int *)(data + field->offset);
282 				offset &= 0xffff;
283 			} else
284 				offset = field->offset;
285 			obj = PyString_FromString((char *)data + offset);
286 		} else { /* FIELD_IS_NUMERIC */
287 			val = read_size(data + field->offset, field->size);
288 			if (field->flags & FIELD_IS_SIGNED) {
289 				if ((long long)val >= LONG_MIN &&
290 				    (long long)val <= LONG_MAX)
291 					obj = PyInt_FromLong(val);
292 				else
293 					obj = PyLong_FromLongLong(val);
294 			} else {
295 				if (val <= LONG_MAX)
296 					obj = PyInt_FromLong(val);
297 				else
298 					obj = PyLong_FromUnsignedLongLong(val);
299 			}
300 		}
301 		if (handler)
302 			PyTuple_SetItem(t, n++, obj);
303 		else
304 			PyDict_SetItemString(dict, field->name, obj);
305 
306 	}
307 	if (!handler)
308 		PyTuple_SetItem(t, n++, dict);
309 
310 	if (_PyTuple_Resize(&t, n) == -1)
311 		Py_FatalError("error resizing Python tuple");
312 
313 	if (handler) {
314 		retval = PyObject_CallObject(handler, t);
315 		if (retval == NULL)
316 			handler_call_die(handler_name);
317 	} else {
318 		handler = PyDict_GetItemString(main_dict, "trace_unhandled");
319 		if (handler && PyCallable_Check(handler)) {
320 
321 			retval = PyObject_CallObject(handler, t);
322 			if (retval == NULL)
323 				handler_call_die("trace_unhandled");
324 		}
325 		Py_DECREF(dict);
326 	}
327 
328 	Py_DECREF(t);
329 }
330 
331 static int run_start_sub(void)
332 {
333 	PyObject *handler, *retval;
334 	int err = 0;
335 
336 	main_module = PyImport_AddModule("__main__");
337 	if (main_module == NULL)
338 		return -1;
339 	Py_INCREF(main_module);
340 
341 	main_dict = PyModule_GetDict(main_module);
342 	if (main_dict == NULL) {
343 		err = -1;
344 		goto error;
345 	}
346 	Py_INCREF(main_dict);
347 
348 	handler = PyDict_GetItemString(main_dict, "trace_begin");
349 	if (handler == NULL || !PyCallable_Check(handler))
350 		goto out;
351 
352 	retval = PyObject_CallObject(handler, NULL);
353 	if (retval == NULL)
354 		handler_call_die("trace_begin");
355 
356 	Py_DECREF(retval);
357 	return err;
358 error:
359 	Py_XDECREF(main_dict);
360 	Py_XDECREF(main_module);
361 out:
362 	return err;
363 }
364 
365 /*
366  * Start trace script
367  */
368 static int python_start_script(const char *script, int argc, const char **argv)
369 {
370 	const char **command_line;
371 	char buf[PATH_MAX];
372 	int i, err = 0;
373 	FILE *fp;
374 
375 	command_line = malloc((argc + 1) * sizeof(const char *));
376 	command_line[0] = script;
377 	for (i = 1; i < argc + 1; i++)
378 		command_line[i] = argv[i - 1];
379 
380 	Py_Initialize();
381 
382 	initperf_trace_context();
383 
384 	PySys_SetArgv(argc + 1, (char **)command_line);
385 
386 	fp = fopen(script, "r");
387 	if (!fp) {
388 		sprintf(buf, "Can't open python script \"%s\"", script);
389 		perror(buf);
390 		err = -1;
391 		goto error;
392 	}
393 
394 	err = PyRun_SimpleFile(fp, script);
395 	if (err) {
396 		fprintf(stderr, "Error running python script %s\n", script);
397 		goto error;
398 	}
399 
400 	err = run_start_sub();
401 	if (err) {
402 		fprintf(stderr, "Error starting python script %s\n", script);
403 		goto error;
404 	}
405 
406 	free(command_line);
407 
408 	return err;
409 error:
410 	Py_Finalize();
411 	free(command_line);
412 
413 	return err;
414 }
415 
416 /*
417  * Stop trace script
418  */
419 static int python_stop_script(void)
420 {
421 	PyObject *handler, *retval;
422 	int err = 0;
423 
424 	handler = PyDict_GetItemString(main_dict, "trace_end");
425 	if (handler == NULL || !PyCallable_Check(handler))
426 		goto out;
427 
428 	retval = PyObject_CallObject(handler, NULL);
429 	if (retval == NULL)
430 		handler_call_die("trace_end");
431 	else
432 		Py_DECREF(retval);
433 out:
434 	Py_XDECREF(main_dict);
435 	Py_XDECREF(main_module);
436 	Py_Finalize();
437 
438 	return err;
439 }
440 
441 static int python_generate_script(const char *outfile)
442 {
443 	struct event_format *event = NULL;
444 	struct format_field *f;
445 	char fname[PATH_MAX];
446 	int not_first, count;
447 	FILE *ofp;
448 
449 	sprintf(fname, "%s.py", outfile);
450 	ofp = fopen(fname, "w");
451 	if (ofp == NULL) {
452 		fprintf(stderr, "couldn't open %s\n", fname);
453 		return -1;
454 	}
455 	fprintf(ofp, "# perf script event handlers, "
456 		"generated by perf script -g python\n");
457 
458 	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
459 		" License version 2\n\n");
460 
461 	fprintf(ofp, "# The common_* event handler fields are the most useful "
462 		"fields common to\n");
463 
464 	fprintf(ofp, "# all events.  They don't necessarily correspond to "
465 		"the 'common_*' fields\n");
466 
467 	fprintf(ofp, "# in the format files.  Those fields not available as "
468 		"handler params can\n");
469 
470 	fprintf(ofp, "# be retrieved using Python functions of the form "
471 		"common_*(context).\n");
472 
473 	fprintf(ofp, "# See the perf-trace-python Documentation for the list "
474 		"of available functions.\n\n");
475 
476 	fprintf(ofp, "import os\n");
477 	fprintf(ofp, "import sys\n\n");
478 
479 	fprintf(ofp, "sys.path.append(os.environ['PERF_EXEC_PATH'] + \\\n");
480 	fprintf(ofp, "\t'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')\n");
481 	fprintf(ofp, "\nfrom perf_trace_context import *\n");
482 	fprintf(ofp, "from Core import *\n\n\n");
483 
484 	fprintf(ofp, "def trace_begin():\n");
485 	fprintf(ofp, "\tprint \"in trace_begin\"\n\n");
486 
487 	fprintf(ofp, "def trace_end():\n");
488 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
489 
490 	while ((event = trace_find_next_event(event))) {
491 		fprintf(ofp, "def %s__%s(", event->system, event->name);
492 		fprintf(ofp, "event_name, ");
493 		fprintf(ofp, "context, ");
494 		fprintf(ofp, "common_cpu,\n");
495 		fprintf(ofp, "\tcommon_secs, ");
496 		fprintf(ofp, "common_nsecs, ");
497 		fprintf(ofp, "common_pid, ");
498 		fprintf(ofp, "common_comm,\n\t");
499 
500 		not_first = 0;
501 		count = 0;
502 
503 		for (f = event->format.fields; f; f = f->next) {
504 			if (not_first++)
505 				fprintf(ofp, ", ");
506 			if (++count % 5 == 0)
507 				fprintf(ofp, "\n\t");
508 
509 			fprintf(ofp, "%s", f->name);
510 		}
511 		fprintf(ofp, "):\n");
512 
513 		fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
514 			"common_secs, common_nsecs,\n\t\t\t"
515 			"common_pid, common_comm)\n\n");
516 
517 		fprintf(ofp, "\t\tprint \"");
518 
519 		not_first = 0;
520 		count = 0;
521 
522 		for (f = event->format.fields; f; f = f->next) {
523 			if (not_first++)
524 				fprintf(ofp, ", ");
525 			if (count && count % 3 == 0) {
526 				fprintf(ofp, "\" \\\n\t\t\"");
527 			}
528 			count++;
529 
530 			fprintf(ofp, "%s=", f->name);
531 			if (f->flags & FIELD_IS_STRING ||
532 			    f->flags & FIELD_IS_FLAG ||
533 			    f->flags & FIELD_IS_SYMBOLIC)
534 				fprintf(ofp, "%%s");
535 			else if (f->flags & FIELD_IS_SIGNED)
536 				fprintf(ofp, "%%d");
537 			else
538 				fprintf(ofp, "%%u");
539 		}
540 
541 		fprintf(ofp, "\\n\" %% \\\n\t\t(");
542 
543 		not_first = 0;
544 		count = 0;
545 
546 		for (f = event->format.fields; f; f = f->next) {
547 			if (not_first++)
548 				fprintf(ofp, ", ");
549 
550 			if (++count % 5 == 0)
551 				fprintf(ofp, "\n\t\t");
552 
553 			if (f->flags & FIELD_IS_FLAG) {
554 				if ((count - 1) % 5 != 0) {
555 					fprintf(ofp, "\n\t\t");
556 					count = 4;
557 				}
558 				fprintf(ofp, "flag_str(\"");
559 				fprintf(ofp, "%s__%s\", ", event->system,
560 					event->name);
561 				fprintf(ofp, "\"%s\", %s)", f->name,
562 					f->name);
563 			} else if (f->flags & FIELD_IS_SYMBOLIC) {
564 				if ((count - 1) % 5 != 0) {
565 					fprintf(ofp, "\n\t\t");
566 					count = 4;
567 				}
568 				fprintf(ofp, "symbol_str(\"");
569 				fprintf(ofp, "%s__%s\", ", event->system,
570 					event->name);
571 				fprintf(ofp, "\"%s\", %s)", f->name,
572 					f->name);
573 			} else
574 				fprintf(ofp, "%s", f->name);
575 		}
576 
577 		fprintf(ofp, "),\n\n");
578 	}
579 
580 	fprintf(ofp, "def trace_unhandled(event_name, context, "
581 		"event_fields_dict):\n");
582 
583 	fprintf(ofp, "\t\tprint ' '.join(['%%s=%%s'%%(k,str(v))"
584 		"for k,v in sorted(event_fields_dict.items())])\n\n");
585 
586 	fprintf(ofp, "def print_header("
587 		"event_name, cpu, secs, nsecs, pid, comm):\n"
588 		"\tprint \"%%-20s %%5u %%05u.%%09u %%8u %%-20s \" %% \\\n\t"
589 		"(event_name, cpu, secs, nsecs, pid, comm),\n");
590 
591 	fclose(ofp);
592 
593 	fprintf(stderr, "generated Python script: %s\n", fname);
594 
595 	return 0;
596 }
597 
598 struct scripting_ops python_scripting_ops = {
599 	.name = "Python",
600 	.start_script = python_start_script,
601 	.stop_script = python_stop_script,
602 	.process_event = python_process_event,
603 	.generate_script = python_generate_script,
604 };
605