00d61432e33aea82a3d77fe17a96bdf00fad2646
[lttng-tools.git] / lttng-sessiond / trace-ust.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; only version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307, USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include <lttngerr.h>
25 #include <lttng-share.h>
26
27 #include "../common/hashtable.h"
28 #include "trace-ust.h"
29
30 /*
31 * Find the channel in the hashtable.
32 */
33 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct cds_lfht *ht,
34 char *name)
35 {
36 struct cds_lfht_node *node;
37 struct cds_lfht_iter iter;
38
39 rcu_read_lock();
40 node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
41 if (node == NULL) {
42 rcu_read_unlock();
43 goto error;
44 }
45 rcu_read_unlock();
46
47 DBG2("Trace UST channel %s found by name", name);
48
49 return caa_container_of(node, struct ltt_ust_channel, node);
50
51 error:
52 DBG2("Trace UST channel %s not found by name", name);
53 return NULL;
54 }
55
56 /*
57 * Find the event in the hashtable.
58 */
59 struct ltt_ust_event *trace_ust_find_event_by_name(struct cds_lfht *ht,
60 char *name)
61 {
62 struct cds_lfht_node *node;
63 struct cds_lfht_iter iter;
64
65 rcu_read_lock();
66 node = hashtable_lookup(ht, (void *)name, strlen(name), &iter);
67 if (node == NULL) {
68 rcu_read_unlock();
69 goto error;
70 }
71 rcu_read_unlock();
72
73 DBG2("Trace UST event found by name %s", name);
74
75 return caa_container_of(node, struct ltt_ust_event, node);
76
77 error:
78 DBG2("Trace UST event NOT found by name %s", name);
79 return NULL;
80 }
81
82 /*
83 * Allocate and initialize a ust session data structure.
84 *
85 * Return pointer to structure or NULL.
86 */
87 struct ltt_ust_session *trace_ust_create_session(char *path, int session_id,
88 struct lttng_domain *domain)
89 {
90 int ret;
91 struct ltt_ust_session *lus;
92
93 /* Allocate a new ltt ust session */
94 lus = zmalloc(sizeof(struct ltt_ust_session));
95 if (lus == NULL) {
96 PERROR("create ust session zmalloc");
97 goto error;
98 }
99
100 /* Init data structure */
101 lus->id = session_id;
102 lus->start_trace = 0;
103
104 /* Alloc UST domain hash tables */
105 lus->domain_pid = hashtable_new(0);
106 lus->domain_exec = hashtable_new_str(0);
107
108 /* Alloc UST global domain channels' HT */
109 lus->domain_global.channels = hashtable_new_str(0);
110
111 /* Set session path */
112 ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
113 if (ret < 0) {
114 PERROR("snprintf kernel traces path");
115 goto error_free_session;
116 }
117
118 DBG2("UST trace session create successful");
119
120 return lus;
121
122 error_free_session:
123 free(lus);
124 error:
125 return NULL;
126 }
127
128 /*
129 * Allocate and initialize a ust channel data structure.
130 *
131 * Return pointer to structure or NULL.
132 */
133 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
134 char *path)
135 {
136 int ret;
137 struct ltt_ust_channel *luc;
138
139 luc = zmalloc(sizeof(struct ltt_ust_channel));
140 if (luc == NULL) {
141 perror("ltt_ust_channel zmalloc");
142 goto error;
143 }
144
145 /* Copy UST channel attributes */
146 luc->attr.overwrite = chan->attr.overwrite;
147 luc->attr.subbuf_size = chan->attr.subbuf_size;
148 luc->attr.num_subbuf = chan->attr.num_subbuf;
149 luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
150 luc->attr.read_timer_interval = chan->attr.read_timer_interval;
151 luc->attr.output = chan->attr.output;
152
153 /* Translate to UST output enum */
154 switch (luc->attr.output) {
155 default:
156 luc->attr.output = LTTNG_UST_MMAP;
157 break;
158 }
159
160 /* Copy channel name */
161 strncpy(luc->name, chan->name, sizeof(luc->name));
162 luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
163
164 /* Init node */
165 hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
166 /* Alloc hash tables */
167 luc->events = hashtable_new_str(0);
168 luc->ctx = hashtable_new(0);
169
170 /* Set trace output path */
171 ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
172 if (ret < 0) {
173 perror("asprintf ust create channel");
174 goto error_free_channel;
175 }
176
177 DBG2("Trace UST channel %s created", luc->name);
178
179 return luc;
180
181 error_free_channel:
182 free(luc);
183 error:
184 return NULL;
185 }
186
187 /*
188 * Allocate and initialize a ust event. Set name and event type.
189 *
190 * Return pointer to structure or NULL.
191 */
192 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
193 {
194 struct ltt_ust_event *lue;
195
196 lue = zmalloc(sizeof(struct ltt_ust_event));
197 if (lue == NULL) {
198 PERROR("ust event zmalloc");
199 goto error;
200 }
201
202 switch (ev->type) {
203 case LTTNG_EVENT_PROBE:
204 lue->attr.instrumentation = LTTNG_UST_PROBE;
205 break;
206 case LTTNG_EVENT_FUNCTION:
207 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
208 break;
209 case LTTNG_EVENT_FUNCTION_ENTRY:
210 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
211 break;
212 case LTTNG_EVENT_TRACEPOINT:
213 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
214 break;
215 case LTTNG_EVENT_TRACEPOINT_LOGLEVEL:
216 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT_LOGLEVEL;
217 break;
218 default:
219 ERR("Unknown ust instrumentation type (%d)", ev->type);
220 goto error_free_event;
221 }
222
223 /* Copy event name */
224 strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
225 lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
226
227 /* Init node */
228 hashtable_node_init(&lue->node, (void *) lue->attr.name,
229 strlen(lue->attr.name));
230 /* Alloc context hash tables */
231 lue->ctx = hashtable_new(0);
232
233 DBG2("Trace UST event %s created", lue->attr.name);
234
235 return lue;
236
237 error_free_event:
238 free(lue);
239 error:
240 return NULL;
241 }
242
243 /*
244 * Allocate and initialize a ust metadata.
245 *
246 * Return pointer to structure or NULL.
247 */
248 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
249 {
250 int ret;
251 struct ltt_ust_metadata *lum;
252
253 lum = zmalloc(sizeof(struct ltt_ust_metadata));
254 if (lum == NULL) {
255 perror("ust metadata zmalloc");
256 goto error;
257 }
258
259 /* Set default attributes */
260 lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
261 lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
262 lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
263 lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
264 lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
265 lum->attr.output = LTTNG_UST_MMAP;
266
267 lum->handle = -1;
268 /* Set metadata trace path */
269 ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
270 if (ret < 0) {
271 perror("asprintf ust metadata");
272 goto error_free_metadata;
273 }
274
275 return lum;
276
277 error_free_metadata:
278 free(lum);
279 error:
280 return NULL;
281 }
282
283 /*
284 * Allocate and initialize an UST context.
285 *
286 * Return pointer to structure or NULL.
287 */
288 struct ltt_ust_context *trace_ust_create_context(
289 struct lttng_event_context *ctx)
290 {
291 struct ltt_ust_context *uctx;
292
293 uctx = zmalloc(sizeof(struct ltt_ust_context));
294 if (uctx == NULL) {
295 PERROR("zmalloc ltt_ust_context");
296 goto error;
297 }
298
299 uctx->ctx.ctx = ctx->ctx;
300 hashtable_node_init(&uctx->node, (void *)((unsigned long) uctx->ctx.ctx),
301 sizeof(void *));
302
303 return uctx;
304
305 error:
306 return NULL;
307 }
308
309 /*
310 * RCU safe free context structure.
311 */
312 static void destroy_context_rcu(struct rcu_head *head)
313 {
314 struct cds_lfht_node *node =
315 caa_container_of(head, struct cds_lfht_node, head);
316 struct ltt_ust_context *ctx =
317 caa_container_of(node, struct ltt_ust_context, node);
318
319 free(ctx);
320 }
321
322 /*
323 * Cleanup UST context hash table.
324 */
325 static void destroy_context(struct cds_lfht *ht)
326 {
327 int ret;
328 struct cds_lfht_node *node;
329 struct cds_lfht_iter iter;
330
331 cds_lfht_for_each(ht, &iter, node) {
332 ret = hashtable_del(ht, &iter);
333 if (!ret) {
334 call_rcu(&node->head, destroy_context_rcu);
335 }
336 }
337
338 hashtable_destroy(ht);
339 }
340
341 /*
342 * Cleanup ust event structure.
343 */
344 void trace_ust_destroy_event(struct ltt_ust_event *event)
345 {
346 DBG2("Trace destroy UST event %s", event->attr.name);
347 destroy_context(event->ctx);
348
349 free(event);
350 }
351
352 /*
353 * URCU intermediate call to complete destroy event.
354 */
355 static void destroy_event_rcu(struct rcu_head *head)
356 {
357 struct cds_lfht_node *node =
358 caa_container_of(head, struct cds_lfht_node, head);
359 struct ltt_ust_event *event =
360 caa_container_of(node, struct ltt_ust_event, node);
361
362 trace_ust_destroy_event(event);
363 }
364
365 /*
366 * Cleanup UST events hashtable.
367 */
368 static void destroy_event(struct cds_lfht *events)
369 {
370 int ret;
371 struct cds_lfht_node *node;
372 struct cds_lfht_iter iter;
373
374 cds_lfht_for_each(events, &iter, node) {
375 ret = hashtable_del(events, &iter);
376 if (!ret) {
377 call_rcu(&node->head, destroy_event_rcu);
378 }
379 }
380
381 hashtable_destroy(events);
382 }
383
384 /*
385 * Cleanup ust channel structure.
386 */
387 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
388 {
389 int ret;
390 struct cds_lfht_node *node;
391 struct cds_lfht_iter iter;
392
393 DBG2("Trace destroy UST channel %s", channel->name);
394
395 rcu_read_lock();
396
397 cds_lfht_for_each(channel->events, &iter, node) {
398 ret = hashtable_del(channel->events, &iter);
399 if (!ret) {
400 destroy_event(channel->events);
401 }
402 }
403
404 destroy_context(channel->ctx);
405 free(channel);
406
407 rcu_read_unlock();
408 }
409
410 /*
411 * URCU intermediate call to complete destroy channel.
412 */
413 static void destroy_channel_rcu(struct rcu_head *head)
414 {
415 struct cds_lfht_node *node =
416 caa_container_of(head, struct cds_lfht_node, head);
417 struct ltt_ust_channel *channel =
418 caa_container_of(node, struct ltt_ust_channel, node);
419
420 trace_ust_destroy_channel(channel);
421 }
422
423 /*
424 * Cleanup ust metadata structure.
425 */
426 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
427 {
428 DBG2("Trace UST destroy metadata %d", metadata->handle);
429
430 free(metadata);
431 }
432
433 /*
434 * Iterate over a hash table containing channels and cleanup safely.
435 */
436 static void destroy_channels(struct cds_lfht *channels)
437 {
438 int ret;
439 struct cds_lfht_node *node;
440 struct cds_lfht_iter iter;
441
442 cds_lfht_for_each(channels, &iter, node) {
443 ret = hashtable_del(channels, &iter);
444 if (!ret) {
445 call_rcu(&node->head, destroy_channel_rcu);
446 }
447 }
448
449 hashtable_destroy(channels);
450 }
451
452 /*
453 * Cleanup UST pid domain.
454 */
455 static void destroy_domain_pid(struct cds_lfht *ht)
456 {
457 int ret;
458 struct cds_lfht_iter iter;
459 struct ltt_ust_domain_pid *dpid;
460
461 cds_lfht_for_each_entry(ht, &iter, dpid, node) {
462 ret = hashtable_del(ht , &iter);
463 if (!ret) {
464 destroy_channels(dpid->channels);
465 }
466 }
467
468 hashtable_destroy(ht);
469 }
470
471 /*
472 * Cleanup UST exec name domain.
473 */
474 static void destroy_domain_exec(struct cds_lfht *ht)
475 {
476 int ret;
477 struct cds_lfht_iter iter;
478 struct ltt_ust_domain_exec *dexec;
479
480 cds_lfht_for_each_entry(ht, &iter, dexec, node) {
481 ret = hashtable_del(ht , &iter);
482 if (!ret) {
483 destroy_channels(dexec->channels);
484 }
485 }
486
487 hashtable_destroy(ht);
488 }
489
490 /*
491 * Cleanup UST global domain.
492 */
493 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
494 {
495 destroy_channels(dom->channels);
496 }
497
498 /*
499 * Cleanup ust session structure
500 */
501 void trace_ust_destroy_session(struct ltt_ust_session *session)
502 {
503 /* Extra protection */
504 if (session == NULL) {
505 return;
506 }
507
508 rcu_read_lock();
509
510 DBG2("Trace UST destroy session %d", session->id);
511
512 /* Cleaning up UST domain */
513 destroy_domain_global(&session->domain_global);
514 destroy_domain_pid(session->domain_pid);
515 destroy_domain_exec(session->domain_exec);
516
517 free(session);
518
519 rcu_read_unlock();
520 }
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