Fix: Improve the error reporting of the track/untrack command
[lttng-tools.git] / src / bin / 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
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #define _LGPL_SOURCE
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24 #include <inttypes.h>
25
26 #include <common/common.h>
27 #include <common/defaults.h>
28
29 #include "buffer-registry.h"
30 #include "trace-ust.h"
31 #include "utils.h"
32 #include "ust-app.h"
33 #include "agent.h"
34
35 /*
36 * Match function for the events hash table lookup.
37 *
38 * Matches by name only. Used by the disable command.
39 */
40 int trace_ust_ht_match_event_by_name(struct cds_lfht_node *node,
41 const void *_key)
42 {
43 struct ltt_ust_event *event;
44 const char *name;
45
46 assert(node);
47 assert(_key);
48
49 event = caa_container_of(node, struct ltt_ust_event, node.node);
50 name = _key;
51
52 /* Event name */
53 if (strncmp(event->attr.name, name, sizeof(event->attr.name)) != 0) {
54 goto no_match;
55 }
56
57 /* Match */
58 return 1;
59
60 no_match:
61 return 0;
62 }
63
64 /*
65 * Match function for the hash table lookup.
66 *
67 * It matches an ust event based on three attributes which are the event name,
68 * the filter bytecode and the loglevel.
69 */
70 int trace_ust_ht_match_event(struct cds_lfht_node *node, const void *_key)
71 {
72 struct ltt_ust_event *event;
73 const struct ltt_ust_ht_key *key;
74
75 assert(node);
76 assert(_key);
77
78 event = caa_container_of(node, struct ltt_ust_event, node.node);
79 key = _key;
80
81 /* Match the 4 elements of the key: name, filter, loglevel, exclusions. */
82
83 /* Event name */
84 if (strncmp(event->attr.name, key->name, sizeof(event->attr.name)) != 0) {
85 goto no_match;
86 }
87
88 /* Event loglevel. */
89 if (event->attr.loglevel != key->loglevel) {
90 if (event->attr.loglevel_type == LTTNG_UST_LOGLEVEL_ALL
91 && key->loglevel == 0 && event->attr.loglevel == -1) {
92 /*
93 * Match is accepted. This is because on event creation, the
94 * loglevel is set to -1 if the event loglevel type is ALL so 0 and
95 * -1 are accepted for this loglevel type since 0 is the one set by
96 * the API when receiving an enable event.
97 */
98 } else {
99 goto no_match;
100 }
101 }
102
103 /* Only one of the filters is NULL, fail. */
104 if ((key->filter && !event->filter) || (!key->filter && event->filter)) {
105 goto no_match;
106 }
107
108 if (key->filter && event->filter) {
109 /* Both filters exists, check length followed by the bytecode. */
110 if (event->filter->len != key->filter->len ||
111 memcmp(event->filter->data, key->filter->data,
112 event->filter->len) != 0) {
113 goto no_match;
114 }
115 }
116
117 /* If only one of the exclusions is NULL, fail. */
118 if ((key->exclusion && !event->exclusion) || (!key->exclusion && event->exclusion)) {
119 goto no_match;
120 }
121
122 if (key->exclusion && event->exclusion) {
123 /* Both exclusions exist; check count followed by names. */
124 if (event->exclusion->count != key->exclusion->count ||
125 memcmp(event->exclusion->names, key->exclusion->names,
126 event->exclusion->count * LTTNG_SYMBOL_NAME_LEN) != 0) {
127 goto no_match;
128 }
129 }
130 /* Match. */
131 return 1;
132
133 no_match:
134 return 0;
135 }
136
137 /*
138 * Find the channel in the hashtable and return channel pointer. RCU read side
139 * lock MUST be acquired before calling this.
140 */
141 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct lttng_ht *ht,
142 char *name)
143 {
144 struct lttng_ht_node_str *node;
145 struct lttng_ht_iter iter;
146
147 /*
148 * If we receive an empty string for channel name, it means the
149 * default channel name is requested.
150 */
151 if (name[0] == '\0')
152 name = DEFAULT_CHANNEL_NAME;
153
154 lttng_ht_lookup(ht, (void *)name, &iter);
155 node = lttng_ht_iter_get_node_str(&iter);
156 if (node == NULL) {
157 goto error;
158 }
159
160 DBG2("Trace UST channel %s found by name", name);
161
162 return caa_container_of(node, struct ltt_ust_channel, node);
163
164 error:
165 DBG2("Trace UST channel %s not found by name", name);
166 return NULL;
167 }
168
169 /*
170 * Find the event in the hashtable and return event pointer. RCU read side lock
171 * MUST be acquired before calling this.
172 */
173 struct ltt_ust_event *trace_ust_find_event(struct lttng_ht *ht,
174 char *name, struct lttng_filter_bytecode *filter, int loglevel,
175 struct lttng_event_exclusion *exclusion)
176 {
177 struct lttng_ht_node_str *node;
178 struct lttng_ht_iter iter;
179 struct ltt_ust_ht_key key;
180
181 assert(name);
182 assert(ht);
183
184 key.name = name;
185 key.filter = filter;
186 key.loglevel = loglevel;
187 key.exclusion = exclusion;
188
189 cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
190 trace_ust_ht_match_event, &key, &iter.iter);
191 node = lttng_ht_iter_get_node_str(&iter);
192 if (node == NULL) {
193 goto error;
194 }
195
196 DBG2("Trace UST event %s found", key.name);
197
198 return caa_container_of(node, struct ltt_ust_event, node);
199
200 error:
201 DBG2("Trace UST event %s NOT found", key.name);
202 return NULL;
203 }
204
205 /*
206 * Lookup an agent in the session agents hash table by domain type and return
207 * the object if found else NULL.
208 *
209 * RCU read side lock must be acquired before calling and only released
210 * once the agent is no longer in scope or being used.
211 */
212 struct agent *trace_ust_find_agent(struct ltt_ust_session *session,
213 enum lttng_domain_type domain_type)
214 {
215 struct agent *agt = NULL;
216 struct lttng_ht_node_u64 *node;
217 struct lttng_ht_iter iter;
218 uint64_t key;
219
220 assert(session);
221
222 DBG3("Trace ust agent lookup for domain %d", domain_type);
223
224 key = domain_type;
225
226 lttng_ht_lookup(session->agents, &key, &iter);
227 node = lttng_ht_iter_get_node_u64(&iter);
228 if (!node) {
229 goto end;
230 }
231 agt = caa_container_of(node, struct agent, node);
232
233 end:
234 return agt;
235 }
236
237 /*
238 * Allocate and initialize a ust session data structure.
239 *
240 * Return pointer to structure or NULL.
241 */
242 struct ltt_ust_session *trace_ust_create_session(uint64_t session_id)
243 {
244 struct ltt_ust_session *lus;
245
246 /* Allocate a new ltt ust session */
247 lus = zmalloc(sizeof(struct ltt_ust_session));
248 if (lus == NULL) {
249 PERROR("create ust session zmalloc");
250 goto error;
251 }
252
253 /* Init data structure */
254 lus->id = session_id;
255 lus->active = 0;
256
257 /* Set default metadata channel attribute. */
258 lus->metadata_attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
259 lus->metadata_attr.subbuf_size = default_get_metadata_subbuf_size();
260 lus->metadata_attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
261 lus->metadata_attr.switch_timer_interval = DEFAULT_METADATA_SWITCH_TIMER;
262 lus->metadata_attr.read_timer_interval = DEFAULT_METADATA_READ_TIMER;
263 lus->metadata_attr.output = LTTNG_UST_MMAP;
264
265 /*
266 * Default buffer type. This can be changed through an enable channel
267 * requesting a different type. Note that this can only be changed once
268 * during the session lifetime which is at the first enable channel and
269 * only before start. The flag buffer_type_changed indicates the status.
270 */
271 lus->buffer_type = LTTNG_BUFFER_PER_UID;
272 /* Once set to 1, the buffer_type is immutable for the session. */
273 lus->buffer_type_changed = 0;
274 /* Init it in case it get used after allocation. */
275 CDS_INIT_LIST_HEAD(&lus->buffer_reg_uid_list);
276
277 /* Alloc UST global domain channels' HT */
278 lus->domain_global.channels = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
279 /* Alloc agent hash table. */
280 lus->agents = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
281
282 lus->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
283 if (lus->consumer == NULL) {
284 goto error_consumer;
285 }
286
287 /*
288 * The tmp_consumer stays NULL until a set_consumer_uri command is
289 * executed. At this point, the consumer should be nullify until an
290 * enable_consumer command. This assignment is symbolic since we've zmalloc
291 * the struct.
292 */
293 lus->tmp_consumer = NULL;
294
295 DBG2("UST trace session create successful");
296
297 return lus;
298
299 error_consumer:
300 ht_cleanup_push(lus->domain_global.channels);
301 ht_cleanup_push(lus->agents);
302 free(lus);
303 error:
304 return NULL;
305 }
306
307 /*
308 * Allocate and initialize a ust channel data structure.
309 *
310 * Return pointer to structure or NULL.
311 */
312 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan)
313 {
314 struct ltt_ust_channel *luc;
315
316 assert(chan);
317
318 luc = zmalloc(sizeof(struct ltt_ust_channel));
319 if (luc == NULL) {
320 PERROR("ltt_ust_channel zmalloc");
321 goto error;
322 }
323
324 /* Copy UST channel attributes */
325 luc->attr.overwrite = chan->attr.overwrite;
326 luc->attr.subbuf_size = chan->attr.subbuf_size;
327 luc->attr.num_subbuf = chan->attr.num_subbuf;
328 luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
329 luc->attr.read_timer_interval = chan->attr.read_timer_interval;
330 luc->attr.output = (enum lttng_ust_output) chan->attr.output;
331
332 /* Translate to UST output enum */
333 switch (luc->attr.output) {
334 default:
335 luc->attr.output = LTTNG_UST_MMAP;
336 break;
337 }
338
339 /*
340 * If we receive an empty string for channel name, it means the
341 * default channel name is requested.
342 */
343 if (chan->name[0] == '\0') {
344 strncpy(luc->name, DEFAULT_CHANNEL_NAME, sizeof(luc->name));
345 } else {
346 /* Copy channel name */
347 strncpy(luc->name, chan->name, sizeof(luc->name));
348 }
349 luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
350
351 /* Init node */
352 lttng_ht_node_init_str(&luc->node, luc->name);
353 CDS_INIT_LIST_HEAD(&luc->ctx_list);
354
355 /* Alloc hash tables */
356 luc->events = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
357 luc->ctx = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
358
359 /* On-disk circular buffer parameters */
360 luc->tracefile_size = chan->attr.tracefile_size;
361 luc->tracefile_count = chan->attr.tracefile_count;
362
363 DBG2("Trace UST channel %s created", luc->name);
364
365 error:
366 return luc;
367 }
368
369 /*
370 * Allocate and initialize a ust event. Set name and event type.
371 * We own filter_expression, filter, and exclusion.
372 *
373 * Return pointer to structure or NULL.
374 */
375 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev,
376 char *filter_expression,
377 struct lttng_filter_bytecode *filter,
378 struct lttng_event_exclusion *exclusion)
379 {
380 struct ltt_ust_event *lue;
381
382 assert(ev);
383
384 lue = zmalloc(sizeof(struct ltt_ust_event));
385 if (lue == NULL) {
386 PERROR("ust event zmalloc");
387 goto error;
388 }
389
390 switch (ev->type) {
391 case LTTNG_EVENT_PROBE:
392 lue->attr.instrumentation = LTTNG_UST_PROBE;
393 break;
394 case LTTNG_EVENT_FUNCTION:
395 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
396 break;
397 case LTTNG_EVENT_FUNCTION_ENTRY:
398 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
399 break;
400 case LTTNG_EVENT_TRACEPOINT:
401 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
402 break;
403 default:
404 ERR("Unknown ust instrumentation type (%d)", ev->type);
405 goto error_free_event;
406 }
407
408 /* Copy event name */
409 strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
410 lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
411
412 switch (ev->loglevel_type) {
413 case LTTNG_EVENT_LOGLEVEL_ALL:
414 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_ALL;
415 lue->attr.loglevel = -1; /* Force to -1 */
416 break;
417 case LTTNG_EVENT_LOGLEVEL_RANGE:
418 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_RANGE;
419 lue->attr.loglevel = ev->loglevel;
420 break;
421 case LTTNG_EVENT_LOGLEVEL_SINGLE:
422 lue->attr.loglevel_type = LTTNG_UST_LOGLEVEL_SINGLE;
423 lue->attr.loglevel = ev->loglevel;
424 break;
425 default:
426 ERR("Unknown ust loglevel type (%d)", ev->loglevel_type);
427 goto error_free_event;
428 }
429
430 /* Same layout. */
431 lue->filter_expression = filter_expression;
432 lue->filter = (struct lttng_ust_filter_bytecode *) filter;
433 lue->exclusion = (struct lttng_event_exclusion *) exclusion;
434
435 /* Init node */
436 lttng_ht_node_init_str(&lue->node, lue->attr.name);
437
438 DBG2("Trace UST event %s, loglevel (%d,%d) created",
439 lue->attr.name, lue->attr.loglevel_type,
440 lue->attr.loglevel);
441
442 return lue;
443
444 error_free_event:
445 free(lue);
446 error:
447 free(filter_expression);
448 free(filter);
449 free(exclusion);
450 return NULL;
451 }
452
453 static
454 int trace_ust_context_type_event_to_ust(enum lttng_event_context_type type)
455 {
456 int utype;
457
458 switch (type) {
459 case LTTNG_EVENT_CONTEXT_VTID:
460 utype = LTTNG_UST_CONTEXT_VTID;
461 break;
462 case LTTNG_EVENT_CONTEXT_VPID:
463 utype = LTTNG_UST_CONTEXT_VPID;
464 break;
465 case LTTNG_EVENT_CONTEXT_PTHREAD_ID:
466 utype = LTTNG_UST_CONTEXT_PTHREAD_ID;
467 break;
468 case LTTNG_EVENT_CONTEXT_PROCNAME:
469 utype = LTTNG_UST_CONTEXT_PROCNAME;
470 break;
471 case LTTNG_EVENT_CONTEXT_IP:
472 utype = LTTNG_UST_CONTEXT_IP;
473 break;
474 case LTTNG_EVENT_CONTEXT_PERF_THREAD_COUNTER:
475 if (!ustctl_has_perf_counters()) {
476 utype = -1;
477 WARN("Perf counters not implemented in UST");
478 } else {
479 utype = LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER;
480 }
481 break;
482 default:
483 ERR("Invalid UST context");
484 utype = -1;
485 break;
486 }
487 return utype;
488 }
489
490 /*
491 * Return 1 if contexts match, 0 otherwise.
492 */
493 int trace_ust_match_context(struct ltt_ust_context *uctx,
494 struct lttng_event_context *ctx)
495 {
496 int utype;
497
498 utype = trace_ust_context_type_event_to_ust(ctx->ctx);
499 if (utype < 0) {
500 return 0;
501 }
502 if (uctx->ctx.ctx != utype) {
503 return 0;
504 }
505 switch (utype) {
506 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
507 if (uctx->ctx.u.perf_counter.type
508 != ctx->u.perf_counter.type) {
509 return 0;
510 }
511 if (uctx->ctx.u.perf_counter.config
512 != ctx->u.perf_counter.config) {
513 return 0;
514 }
515 if (strncmp(uctx->ctx.u.perf_counter.name,
516 ctx->u.perf_counter.name,
517 LTTNG_UST_SYM_NAME_LEN)) {
518 return 0;
519 }
520 break;
521 default:
522 break;
523
524 }
525 return 1;
526 }
527
528 /*
529 * Allocate and initialize an UST context.
530 *
531 * Return pointer to structure or NULL.
532 */
533 struct ltt_ust_context *trace_ust_create_context(
534 struct lttng_event_context *ctx)
535 {
536 struct ltt_ust_context *uctx;
537 int utype;
538
539 assert(ctx);
540
541 utype = trace_ust_context_type_event_to_ust(ctx->ctx);
542 if (utype < 0) {
543 return NULL;
544 }
545
546 uctx = zmalloc(sizeof(struct ltt_ust_context));
547 if (uctx == NULL) {
548 PERROR("zmalloc ltt_ust_context");
549 goto error;
550 }
551
552 uctx->ctx.ctx = (enum lttng_ust_context_type) utype;
553 switch (utype) {
554 case LTTNG_UST_CONTEXT_PERF_THREAD_COUNTER:
555 uctx->ctx.u.perf_counter.type = ctx->u.perf_counter.type;
556 uctx->ctx.u.perf_counter.config = ctx->u.perf_counter.config;
557 strncpy(uctx->ctx.u.perf_counter.name, ctx->u.perf_counter.name,
558 LTTNG_UST_SYM_NAME_LEN);
559 uctx->ctx.u.perf_counter.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
560 break;
561 default:
562 break;
563 }
564 lttng_ht_node_init_ulong(&uctx->node, (unsigned long) uctx->ctx.ctx);
565
566 return uctx;
567
568 error:
569 return NULL;
570 }
571
572 static
573 void destroy_pid_tracker_node_rcu(struct rcu_head *head)
574 {
575 struct ust_pid_tracker_node *tracker_node =
576 caa_container_of(head, struct ust_pid_tracker_node, node.head);
577 free(tracker_node);
578 }
579
580 static
581 void destroy_pid_tracker_node(struct ust_pid_tracker_node *tracker_node)
582 {
583
584 call_rcu(&tracker_node->node.head, destroy_pid_tracker_node_rcu);
585 }
586
587 static
588 int init_pid_tracker(struct ust_pid_tracker *pid_tracker)
589 {
590 int ret = 0;
591
592 pid_tracker->ht = lttng_ht_new(0, LTTNG_HT_TYPE_ULONG);
593 if (!pid_tracker->ht) {
594 ret = -1;
595 goto end;
596 }
597
598 end:
599 return ret;
600 }
601
602 /*
603 * Teardown pid tracker content, but don't free pid_tracker object.
604 */
605 static
606 void fini_pid_tracker(struct ust_pid_tracker *pid_tracker)
607 {
608 struct ust_pid_tracker_node *tracker_node;
609 struct lttng_ht_iter iter;
610
611 if (!pid_tracker->ht) {
612 return;
613 }
614 rcu_read_lock();
615 cds_lfht_for_each_entry(pid_tracker->ht->ht,
616 &iter.iter, tracker_node, node.node) {
617 int ret = lttng_ht_del(pid_tracker->ht, &iter);
618
619 assert(!ret);
620 destroy_pid_tracker_node(tracker_node);
621 }
622 rcu_read_unlock();
623 ht_cleanup_push(pid_tracker->ht);
624 pid_tracker->ht = NULL;
625 }
626
627 static
628 struct ust_pid_tracker_node *pid_tracker_lookup(
629 struct ust_pid_tracker *pid_tracker, int pid,
630 struct lttng_ht_iter *iter)
631 {
632 unsigned long _pid = (unsigned long) pid;
633 struct lttng_ht_node_ulong *node;
634
635 lttng_ht_lookup(pid_tracker->ht, (void *) _pid, iter);
636 node = lttng_ht_iter_get_node_ulong(iter);
637 if (node) {
638 return caa_container_of(node, struct ust_pid_tracker_node,
639 node);
640 } else {
641 return NULL;
642 }
643 }
644
645 static
646 int pid_tracker_add_pid(struct ust_pid_tracker *pid_tracker, int pid)
647 {
648 int retval = LTTNG_OK;
649 struct ust_pid_tracker_node *tracker_node;
650 struct lttng_ht_iter iter;
651
652 if (pid < 0) {
653 retval = LTTNG_ERR_INVALID;
654 goto end;
655 }
656 tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
657 if (tracker_node) {
658 /* Already exists. */
659 retval = LTTNG_ERR_PID_TRACKED;
660 goto end;
661 }
662 tracker_node = zmalloc(sizeof(*tracker_node));
663 if (!tracker_node) {
664 retval = LTTNG_ERR_NOMEM;
665 goto end;
666 }
667 lttng_ht_node_init_ulong(&tracker_node->node, (unsigned long) pid);
668 lttng_ht_add_unique_ulong(pid_tracker->ht, &tracker_node->node);
669 end:
670 return retval;
671 }
672
673 static
674 int pid_tracker_del_pid(struct ust_pid_tracker *pid_tracker, int pid)
675 {
676 int retval = LTTNG_OK, ret;
677 struct ust_pid_tracker_node *tracker_node;
678 struct lttng_ht_iter iter;
679
680 if (pid < 0) {
681 retval = LTTNG_ERR_INVALID;
682 goto end;
683 }
684 tracker_node = pid_tracker_lookup(pid_tracker, pid, &iter);
685 if (!tracker_node) {
686 /* Not found */
687 retval = LTTNG_ERR_PID_NOT_TRACKED;
688 goto end;
689 }
690 ret = lttng_ht_del(pid_tracker->ht, &iter);
691 assert(!ret);
692
693 destroy_pid_tracker_node(tracker_node);
694 end:
695 return retval;
696 }
697
698 /*
699 * The session lock is held when calling this function.
700 */
701 int trace_ust_pid_tracker_lookup(struct ltt_ust_session *session, int pid)
702 {
703 struct lttng_ht_iter iter;
704
705 if (!session->pid_tracker.ht) {
706 return 1;
707 }
708 if (pid_tracker_lookup(&session->pid_tracker, pid, &iter)) {
709 return 1;
710 }
711 return 0;
712 }
713
714 /*
715 * Called with the session lock held.
716 */
717 int trace_ust_track_pid(struct ltt_ust_session *session, int pid)
718 {
719 int retval = LTTNG_OK;
720
721 if (pid == -1) {
722 /* Track all pids: destroy tracker if exists. */
723 if (session->pid_tracker.ht) {
724 fini_pid_tracker(&session->pid_tracker);
725 /* Ensure all apps have session. */
726 ust_app_global_update_all(session);
727 }
728 } else {
729 int ret;
730
731 if (!session->pid_tracker.ht) {
732 /* Create tracker. */
733 if (init_pid_tracker(&session->pid_tracker)) {
734 ERR("Error initializing PID tracker");
735 retval = LTTNG_ERR_NOMEM;
736 goto end;
737 }
738 ret = pid_tracker_add_pid(&session->pid_tracker, pid);
739 if (ret != LTTNG_OK) {
740 retval = ret;
741 fini_pid_tracker(&session->pid_tracker);
742 goto end;
743 }
744 /* Remove all apps from session except pid. */
745 ust_app_global_update_all(session);
746 } else {
747 struct ust_app *app;
748
749 ret = pid_tracker_add_pid(&session->pid_tracker, pid);
750 if (ret != LTTNG_OK) {
751 retval = ret;
752 goto end;
753 }
754 /* Add session to application */
755 app = ust_app_find_by_pid(pid);
756 if (app) {
757 ust_app_global_update(session, app);
758 }
759 }
760 }
761 end:
762 return retval;
763 }
764
765 /*
766 * Called with the session lock held.
767 */
768 int trace_ust_untrack_pid(struct ltt_ust_session *session, int pid)
769 {
770 int retval = LTTNG_OK;
771
772 if (pid == -1) {
773 /* Create empty tracker, replace old tracker. */
774 struct ust_pid_tracker tmp_tracker;
775
776 tmp_tracker = session->pid_tracker;
777 if (init_pid_tracker(&session->pid_tracker)) {
778 ERR("Error initializing PID tracker");
779 retval = LTTNG_ERR_NOMEM;
780 /* Rollback operation. */
781 session->pid_tracker = tmp_tracker;
782 goto end;
783 }
784 fini_pid_tracker(&tmp_tracker);
785
786 /* Remove session from all applications */
787 ust_app_global_update_all(session);
788 } else {
789 int ret;
790 struct ust_app *app;
791
792 if (!session->pid_tracker.ht) {
793 retval = LTTNG_ERR_INVALID;
794 goto end;
795 }
796 /* Remove PID from tracker */
797 ret = pid_tracker_del_pid(&session->pid_tracker, pid);
798 if (ret != LTTNG_OK) {
799 retval = ret;
800 goto end;
801 }
802 /* Remove session from application. */
803 app = ust_app_find_by_pid(pid);
804 if (app) {
805 ust_app_global_update(session, app);
806 }
807 }
808 end:
809 return retval;
810 }
811
812 /*
813 * Called with session lock held.
814 */
815 ssize_t trace_ust_list_tracker_pids(struct ltt_ust_session *session,
816 int32_t **_pids)
817 {
818 struct ust_pid_tracker_node *tracker_node;
819 struct lttng_ht_iter iter;
820 unsigned long count, i = 0;
821 long approx[2];
822 int32_t *pids;
823 int ret = 0;
824
825 if (!session->pid_tracker.ht) {
826 /* Tracker disabled. Set first entry to -1. */
827 pids = zmalloc(sizeof(*pids));
828 if (!pids) {
829 ret = -1;
830 goto end;
831 }
832 pids[0] = -1;
833 *_pids = pids;
834 return 1;
835 }
836
837 rcu_read_lock();
838 cds_lfht_count_nodes(session->pid_tracker.ht->ht,
839 &approx[0], &count, &approx[1]);
840 pids = zmalloc(sizeof(*pids) * count);
841 if (!pids) {
842 ret = -1;
843 goto end;
844 }
845 cds_lfht_for_each_entry(session->pid_tracker.ht->ht,
846 &iter.iter, tracker_node, node.node) {
847 pids[i++] = tracker_node->node.key;
848 }
849 *_pids = pids;
850 ret = count;
851 end:
852 rcu_read_unlock();
853 return ret;
854 }
855
856 /*
857 * RCU safe free context structure.
858 */
859 static void destroy_context_rcu(struct rcu_head *head)
860 {
861 struct lttng_ht_node_ulong *node =
862 caa_container_of(head, struct lttng_ht_node_ulong, head);
863 struct ltt_ust_context *ctx =
864 caa_container_of(node, struct ltt_ust_context, node);
865
866 free(ctx);
867 }
868
869 /*
870 * Cleanup UST context hash table.
871 */
872 static void destroy_contexts(struct lttng_ht *ht)
873 {
874 int ret;
875 struct lttng_ht_node_ulong *node;
876 struct lttng_ht_iter iter;
877 struct ltt_ust_context *ctx;
878
879 assert(ht);
880
881 rcu_read_lock();
882 cds_lfht_for_each_entry(ht->ht, &iter.iter, node, node) {
883 /* Remove from ordered list. */
884 ctx = caa_container_of(node, struct ltt_ust_context, node);
885 cds_list_del(&ctx->list);
886 /* Remove from channel's hash table. */
887 ret = lttng_ht_del(ht, &iter);
888 if (!ret) {
889 call_rcu(&node->head, destroy_context_rcu);
890 }
891 }
892 rcu_read_unlock();
893
894 ht_cleanup_push(ht);
895 }
896
897 /*
898 * Cleanup ust event structure.
899 */
900 void trace_ust_destroy_event(struct ltt_ust_event *event)
901 {
902 assert(event);
903
904 DBG2("Trace destroy UST event %s", event->attr.name);
905 free(event->filter_expression);
906 free(event->filter);
907 free(event->exclusion);
908 free(event);
909 }
910
911 /*
912 * URCU intermediate call to complete destroy event.
913 */
914 static void destroy_event_rcu(struct rcu_head *head)
915 {
916 struct lttng_ht_node_str *node =
917 caa_container_of(head, struct lttng_ht_node_str, head);
918 struct ltt_ust_event *event =
919 caa_container_of(node, struct ltt_ust_event, node);
920
921 trace_ust_destroy_event(event);
922 }
923
924 /*
925 * Cleanup UST events hashtable.
926 */
927 static void destroy_events(struct lttng_ht *events)
928 {
929 int ret;
930 struct lttng_ht_node_str *node;
931 struct lttng_ht_iter iter;
932
933 assert(events);
934
935 rcu_read_lock();
936 cds_lfht_for_each_entry(events->ht, &iter.iter, node, node) {
937 ret = lttng_ht_del(events, &iter);
938 assert(!ret);
939 call_rcu(&node->head, destroy_event_rcu);
940 }
941 rcu_read_unlock();
942
943 ht_cleanup_push(events);
944 }
945
946 /*
947 * Cleanup ust channel structure.
948 *
949 * Should _NOT_ be called with RCU read lock held.
950 */
951 static void _trace_ust_destroy_channel(struct ltt_ust_channel *channel)
952 {
953 assert(channel);
954
955 DBG2("Trace destroy UST channel %s", channel->name);
956
957 /* Destroying all events of the channel */
958 destroy_events(channel->events);
959 /* Destroying all context of the channel */
960 destroy_contexts(channel->ctx);
961
962 free(channel);
963 }
964
965 /*
966 * URCU intermediate call to complete destroy channel.
967 */
968 static void destroy_channel_rcu(struct rcu_head *head)
969 {
970 struct lttng_ht_node_str *node =
971 caa_container_of(head, struct lttng_ht_node_str, head);
972 struct ltt_ust_channel *channel =
973 caa_container_of(node, struct ltt_ust_channel, node);
974
975 _trace_ust_destroy_channel(channel);
976 }
977
978 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
979 {
980 call_rcu(&channel->node.head, destroy_channel_rcu);
981 }
982
983 /*
984 * Remove an UST channel from a channel HT.
985 */
986 void trace_ust_delete_channel(struct lttng_ht *ht,
987 struct ltt_ust_channel *channel)
988 {
989 int ret;
990 struct lttng_ht_iter iter;
991
992 assert(ht);
993 assert(channel);
994
995 iter.iter.node = &channel->node.node;
996 ret = lttng_ht_del(ht, &iter);
997 assert(!ret);
998 }
999
1000 /*
1001 * Iterate over a hash table containing channels and cleanup safely.
1002 */
1003 static void destroy_channels(struct lttng_ht *channels)
1004 {
1005 int ret;
1006 struct lttng_ht_node_str *node;
1007 struct lttng_ht_iter iter;
1008
1009 assert(channels);
1010
1011 rcu_read_lock();
1012
1013 cds_lfht_for_each_entry(channels->ht, &iter.iter, node, node) {
1014 ret = lttng_ht_del(channels, &iter);
1015 assert(!ret);
1016 call_rcu(&node->head, destroy_channel_rcu);
1017 }
1018 rcu_read_unlock();
1019
1020 ht_cleanup_push(channels);
1021 }
1022
1023 /*
1024 * Cleanup UST global domain.
1025 */
1026 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
1027 {
1028 assert(dom);
1029
1030 destroy_channels(dom->channels);
1031 }
1032
1033 /*
1034 * Cleanup ust session structure
1035 *
1036 * Should *NOT* be called with RCU read-side lock held.
1037 */
1038 void trace_ust_destroy_session(struct ltt_ust_session *session)
1039 {
1040 struct agent *agt;
1041 struct buffer_reg_uid *reg, *sreg;
1042 struct lttng_ht_iter iter;
1043
1044 assert(session);
1045
1046 DBG2("Trace UST destroy session %" PRIu64, session->id);
1047
1048 /* Cleaning up UST domain */
1049 destroy_domain_global(&session->domain_global);
1050
1051 rcu_read_lock();
1052 cds_lfht_for_each_entry(session->agents->ht, &iter.iter, agt, node.node) {
1053 int ret = lttng_ht_del(session->agents, &iter);
1054
1055 assert(!ret);
1056 agent_destroy(agt);
1057 }
1058 rcu_read_unlock();
1059
1060 ht_cleanup_push(session->agents);
1061
1062 /* Cleanup UID buffer registry object(s). */
1063 cds_list_for_each_entry_safe(reg, sreg, &session->buffer_reg_uid_list,
1064 lnode) {
1065 cds_list_del(&reg->lnode);
1066 buffer_reg_uid_remove(reg);
1067 buffer_reg_uid_destroy(reg, session->consumer);
1068 }
1069
1070 consumer_destroy_output(session->consumer);
1071 consumer_destroy_output(session->tmp_consumer);
1072
1073 fini_pid_tracker(&session->pid_tracker);
1074
1075 free(session);
1076 }
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