xref: /linux/tools/perf/util/scripting-engines/trace-event-python.c (revision 5a0e3ad6af8660be21ca98a971cd00f331318c05)
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;
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 			PyTuple_SetItem(t, n++,
260 				PyString_FromString((char *)data + offset));
261 		} else { /* FIELD_IS_NUMERIC */
262 			val = read_size(data + field->offset, field->size);
263 			if (field->flags & FIELD_IS_SIGNED) {
264 				PyTuple_SetItem(t, n++, PyInt_FromLong(val));
265 			} else {
266 				PyTuple_SetItem(t, n++, PyInt_FromLong(val));
267 			}
268 		}
269 	}
270 
271 	if (_PyTuple_Resize(&t, n) == -1)
272 		Py_FatalError("error resizing Python tuple");
273 
274 	handler = PyDict_GetItemString(main_dict, handler_name);
275 	if (handler && PyCallable_Check(handler)) {
276 		retval = PyObject_CallObject(handler, t);
277 		if (retval == NULL)
278 			handler_call_die(handler_name);
279 	} else {
280 		handler = PyDict_GetItemString(main_dict, "trace_unhandled");
281 		if (handler && PyCallable_Check(handler)) {
282 			if (_PyTuple_Resize(&t, N_COMMON_FIELDS) == -1)
283 				Py_FatalError("error resizing Python tuple");
284 
285 			retval = PyObject_CallObject(handler, t);
286 			if (retval == NULL)
287 				handler_call_die("trace_unhandled");
288 		}
289 	}
290 
291 	Py_DECREF(t);
292 }
293 
294 static int run_start_sub(void)
295 {
296 	PyObject *handler, *retval;
297 	int err = 0;
298 
299 	main_module = PyImport_AddModule("__main__");
300 	if (main_module == NULL)
301 		return -1;
302 	Py_INCREF(main_module);
303 
304 	main_dict = PyModule_GetDict(main_module);
305 	if (main_dict == NULL) {
306 		err = -1;
307 		goto error;
308 	}
309 	Py_INCREF(main_dict);
310 
311 	handler = PyDict_GetItemString(main_dict, "trace_begin");
312 	if (handler == NULL || !PyCallable_Check(handler))
313 		goto out;
314 
315 	retval = PyObject_CallObject(handler, NULL);
316 	if (retval == NULL)
317 		handler_call_die("trace_begin");
318 
319 	Py_DECREF(retval);
320 	return err;
321 error:
322 	Py_XDECREF(main_dict);
323 	Py_XDECREF(main_module);
324 out:
325 	return err;
326 }
327 
328 /*
329  * Start trace script
330  */
331 static int python_start_script(const char *script, int argc, const char **argv)
332 {
333 	const char **command_line;
334 	char buf[PATH_MAX];
335 	int i, err = 0;
336 	FILE *fp;
337 
338 	command_line = malloc((argc + 1) * sizeof(const char *));
339 	command_line[0] = script;
340 	for (i = 1; i < argc + 1; i++)
341 		command_line[i] = argv[i - 1];
342 
343 	Py_Initialize();
344 
345 	initperf_trace_context();
346 
347 	PySys_SetArgv(argc + 1, (char **)command_line);
348 
349 	fp = fopen(script, "r");
350 	if (!fp) {
351 		sprintf(buf, "Can't open python script \"%s\"", script);
352 		perror(buf);
353 		err = -1;
354 		goto error;
355 	}
356 
357 	err = PyRun_SimpleFile(fp, script);
358 	if (err) {
359 		fprintf(stderr, "Error running python script %s\n", script);
360 		goto error;
361 	}
362 
363 	err = run_start_sub();
364 	if (err) {
365 		fprintf(stderr, "Error starting python script %s\n", script);
366 		goto error;
367 	}
368 
369 	free(command_line);
370 	fprintf(stderr, "perf trace started with Python script %s\n\n",
371 		script);
372 
373 	return err;
374 error:
375 	Py_Finalize();
376 	free(command_line);
377 
378 	return err;
379 }
380 
381 /*
382  * Stop trace script
383  */
384 static int python_stop_script(void)
385 {
386 	PyObject *handler, *retval;
387 	int err = 0;
388 
389 	handler = PyDict_GetItemString(main_dict, "trace_end");
390 	if (handler == NULL || !PyCallable_Check(handler))
391 		goto out;
392 
393 	retval = PyObject_CallObject(handler, NULL);
394 	if (retval == NULL)
395 		handler_call_die("trace_end");
396 	else
397 		Py_DECREF(retval);
398 out:
399 	Py_XDECREF(main_dict);
400 	Py_XDECREF(main_module);
401 	Py_Finalize();
402 
403 	fprintf(stderr, "\nperf trace Python script stopped\n");
404 
405 	return err;
406 }
407 
408 static int python_generate_script(const char *outfile)
409 {
410 	struct event *event = NULL;
411 	struct format_field *f;
412 	char fname[PATH_MAX];
413 	int not_first, count;
414 	FILE *ofp;
415 
416 	sprintf(fname, "%s.py", outfile);
417 	ofp = fopen(fname, "w");
418 	if (ofp == NULL) {
419 		fprintf(stderr, "couldn't open %s\n", fname);
420 		return -1;
421 	}
422 	fprintf(ofp, "# perf trace event handlers, "
423 		"generated by perf trace -g python\n");
424 
425 	fprintf(ofp, "# Licensed under the terms of the GNU GPL"
426 		" License version 2\n\n");
427 
428 	fprintf(ofp, "# The common_* event handler fields are the most useful "
429 		"fields common to\n");
430 
431 	fprintf(ofp, "# all events.  They don't necessarily correspond to "
432 		"the 'common_*' fields\n");
433 
434 	fprintf(ofp, "# in the format files.  Those fields not available as "
435 		"handler params can\n");
436 
437 	fprintf(ofp, "# be retrieved using Python functions of the form "
438 		"common_*(context).\n");
439 
440 	fprintf(ofp, "# See the perf-trace-python Documentation for the list "
441 		"of available functions.\n\n");
442 
443 	fprintf(ofp, "import os\n");
444 	fprintf(ofp, "import sys\n\n");
445 
446 	fprintf(ofp, "sys.path.append(os.environ['PERF_EXEC_PATH'] + \\\n");
447 	fprintf(ofp, "\t'/scripts/python/Perf-Trace-Util/lib/Perf/Trace')\n");
448 	fprintf(ofp, "\nfrom perf_trace_context import *\n");
449 	fprintf(ofp, "from Core import *\n\n\n");
450 
451 	fprintf(ofp, "def trace_begin():\n");
452 	fprintf(ofp, "\tprint \"in trace_begin\"\n\n");
453 
454 	fprintf(ofp, "def trace_end():\n");
455 	fprintf(ofp, "\tprint \"in trace_end\"\n\n");
456 
457 	while ((event = trace_find_next_event(event))) {
458 		fprintf(ofp, "def %s__%s(", event->system, event->name);
459 		fprintf(ofp, "event_name, ");
460 		fprintf(ofp, "context, ");
461 		fprintf(ofp, "common_cpu,\n");
462 		fprintf(ofp, "\tcommon_secs, ");
463 		fprintf(ofp, "common_nsecs, ");
464 		fprintf(ofp, "common_pid, ");
465 		fprintf(ofp, "common_comm,\n\t");
466 
467 		not_first = 0;
468 		count = 0;
469 
470 		for (f = event->format.fields; f; f = f->next) {
471 			if (not_first++)
472 				fprintf(ofp, ", ");
473 			if (++count % 5 == 0)
474 				fprintf(ofp, "\n\t");
475 
476 			fprintf(ofp, "%s", f->name);
477 		}
478 		fprintf(ofp, "):\n");
479 
480 		fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
481 			"common_secs, common_nsecs,\n\t\t\t"
482 			"common_pid, common_comm)\n\n");
483 
484 		fprintf(ofp, "\t\tprint \"");
485 
486 		not_first = 0;
487 		count = 0;
488 
489 		for (f = event->format.fields; f; f = f->next) {
490 			if (not_first++)
491 				fprintf(ofp, ", ");
492 			if (count && count % 3 == 0) {
493 				fprintf(ofp, "\" \\\n\t\t\"");
494 			}
495 			count++;
496 
497 			fprintf(ofp, "%s=", f->name);
498 			if (f->flags & FIELD_IS_STRING ||
499 			    f->flags & FIELD_IS_FLAG ||
500 			    f->flags & FIELD_IS_SYMBOLIC)
501 				fprintf(ofp, "%%s");
502 			else if (f->flags & FIELD_IS_SIGNED)
503 				fprintf(ofp, "%%d");
504 			else
505 				fprintf(ofp, "%%u");
506 		}
507 
508 		fprintf(ofp, "\\n\" %% \\\n\t\t(");
509 
510 		not_first = 0;
511 		count = 0;
512 
513 		for (f = event->format.fields; f; f = f->next) {
514 			if (not_first++)
515 				fprintf(ofp, ", ");
516 
517 			if (++count % 5 == 0)
518 				fprintf(ofp, "\n\t\t");
519 
520 			if (f->flags & FIELD_IS_FLAG) {
521 				if ((count - 1) % 5 != 0) {
522 					fprintf(ofp, "\n\t\t");
523 					count = 4;
524 				}
525 				fprintf(ofp, "flag_str(\"");
526 				fprintf(ofp, "%s__%s\", ", event->system,
527 					event->name);
528 				fprintf(ofp, "\"%s\", %s)", f->name,
529 					f->name);
530 			} else if (f->flags & FIELD_IS_SYMBOLIC) {
531 				if ((count - 1) % 5 != 0) {
532 					fprintf(ofp, "\n\t\t");
533 					count = 4;
534 				}
535 				fprintf(ofp, "symbol_str(\"");
536 				fprintf(ofp, "%s__%s\", ", event->system,
537 					event->name);
538 				fprintf(ofp, "\"%s\", %s)", f->name,
539 					f->name);
540 			} else
541 				fprintf(ofp, "%s", f->name);
542 		}
543 
544 		fprintf(ofp, "),\n\n");
545 	}
546 
547 	fprintf(ofp, "def trace_unhandled(event_name, context, "
548 		"common_cpu, common_secs, common_nsecs,\n\t\t"
549 		"common_pid, common_comm):\n");
550 
551 	fprintf(ofp, "\t\tprint_header(event_name, common_cpu, "
552 		"common_secs, common_nsecs,\n\t\tcommon_pid, "
553 		"common_comm)\n\n");
554 
555 	fprintf(ofp, "def print_header("
556 		"event_name, cpu, secs, nsecs, pid, comm):\n"
557 		"\tprint \"%%-20s %%5u %%05u.%%09u %%8u %%-20s \" %% \\\n\t"
558 		"(event_name, cpu, secs, nsecs, pid, comm),\n");
559 
560 	fclose(ofp);
561 
562 	fprintf(stderr, "generated Python script: %s\n", fname);
563 
564 	return 0;
565 }
566 
567 struct scripting_ops python_scripting_ops = {
568 	.name = "Python",
569 	.start_script = python_start_script,
570 	.stop_script = python_stop_script,
571 	.process_event = python_process_event,
572 	.generate_script = python_generate_script,
573 };
574