sessiond: implement kernel clear session
[lttng-tools.git] / src / bin / lttng-sessiond / buffer-registry.c
1 /*
2 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
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, version 2 only, as
6 * published by the Free Software Foundation.
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., 51
15 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <inttypes.h>
20
21 #include <common/common.h>
22 #include <common/hashtable/utils.h>
23
24 #include "buffer-registry.h"
25 #include "fd-limit.h"
26 #include "ust-consumer.h"
27 #include "lttng-ust-ctl.h"
28 #include "lttng-ust-error.h"
29 #include "utils.h"
30
31 /*
32 * Set in main.c during initialization process of the daemon. This contains
33 * buffer_reg_uid object which are global registry for per UID buffer. Object
34 * are indexed by session id and matched by the triplet
35 * <session_id/bits_per_long/uid>.
36 */
37 static struct lttng_ht *buffer_registry_uid;
38
39 /*
40 * Initialized at the daemon start. This contains buffer_reg_pid object and
41 * indexed by session id.
42 */
43 static struct lttng_ht *buffer_registry_pid;
44
45 /*
46 * Match function for the per UID registry hash table. It matches a registry
47 * uid object with the triplet <session_id/abi/uid>.
48 */
49 static int ht_match_reg_uid(struct cds_lfht_node *node, const void *_key)
50 {
51 struct buffer_reg_uid *reg;
52 const struct buffer_reg_uid *key;
53
54 assert(node);
55 assert(_key);
56
57 reg = caa_container_of(node, struct buffer_reg_uid, node.node);
58 assert(reg);
59 key = _key;
60
61 if (key->session_id != reg->session_id ||
62 key->bits_per_long != reg->bits_per_long ||
63 key->uid != reg->uid) {
64 goto no_match;
65 }
66
67 /* Match */
68 return 1;
69 no_match:
70 return 0;
71 }
72
73 /*
74 * Hash function for the per UID registry hash table. This XOR the triplet
75 * together.
76 */
77 static unsigned long ht_hash_reg_uid(const void *_key, unsigned long seed)
78 {
79 uint64_t xored_key;
80 const struct buffer_reg_uid *key = _key;
81
82 assert(key);
83
84 xored_key = (uint64_t)(key->session_id ^ key->bits_per_long ^ key->uid);
85 return hash_key_u64(&xored_key, seed);
86 }
87
88 /*
89 * Initialize global buffer per UID registry. Should only be called ONCE!.
90 */
91 void buffer_reg_init_uid_registry(void)
92 {
93 /* Should be called once. */
94 assert(!buffer_registry_uid);
95 buffer_registry_uid = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
96 assert(buffer_registry_uid);
97 buffer_registry_uid->match_fct = ht_match_reg_uid;
98 buffer_registry_uid->hash_fct = ht_hash_reg_uid;
99
100 DBG3("Global buffer per UID registry initialized");
101 }
102
103 /*
104 * Allocate and initialize object. Set regp with the object pointer.
105 *
106 * Return 0 on success else a negative value and regp is untouched.
107 */
108 int buffer_reg_uid_create(uint64_t session_id, uint32_t bits_per_long, uid_t uid,
109 enum lttng_domain_type domain, struct buffer_reg_uid **regp,
110 const char *root_shm_path, const char *shm_path)
111 {
112 int ret = 0;
113 struct buffer_reg_uid *reg = NULL;
114
115 assert(regp);
116
117 reg = zmalloc(sizeof(*reg));
118 if (!reg) {
119 PERROR("zmalloc buffer registry uid");
120 ret = -ENOMEM;
121 goto error;
122 }
123
124 reg->registry = zmalloc(sizeof(struct buffer_reg_session));
125 if (!reg->registry) {
126 PERROR("zmalloc buffer registry uid session");
127 ret = -ENOMEM;
128 goto error;
129 }
130
131 reg->session_id = session_id;
132 reg->bits_per_long = bits_per_long;
133 reg->uid = uid;
134 reg->domain = domain;
135 if (shm_path[0]) {
136 strncpy(reg->root_shm_path, root_shm_path, sizeof(reg->root_shm_path));
137 reg->root_shm_path[sizeof(reg->root_shm_path) - 1] = '\0';
138 strncpy(reg->shm_path, shm_path, sizeof(reg->shm_path));
139 reg->shm_path[sizeof(reg->shm_path) - 1] = '\0';
140 DBG3("shm path '%s' is assigned to uid buffer registry for session id %" PRIu64,
141 reg->shm_path, session_id);
142 }
143 reg->registry->channels = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
144 if (!reg->registry->channels) {
145 ret = -ENOMEM;
146 goto error_session;
147 }
148
149 cds_lfht_node_init(&reg->node.node);
150 *regp = reg;
151
152 DBG3("Buffer registry per UID created id: %" PRIu64 ", ABI: %u, uid: %d, domain: %d",
153 session_id, bits_per_long, uid, domain);
154
155 return 0;
156
157 error_session:
158 free(reg->registry);
159 error:
160 free(reg);
161 return ret;
162 }
163
164 /*
165 * Add a buffer registry per UID object to the global registry.
166 */
167 void buffer_reg_uid_add(struct buffer_reg_uid *reg)
168 {
169 struct cds_lfht_node *nodep;
170 struct lttng_ht *ht = buffer_registry_uid;
171
172 assert(reg);
173
174 DBG3("Buffer registry per UID adding to global registry with id: %" PRIu64 ,
175 reg->session_id);
176
177 rcu_read_lock();
178 nodep = cds_lfht_add_unique(ht->ht, ht->hash_fct(reg, lttng_ht_seed),
179 ht->match_fct, reg, &reg->node.node);
180 assert(nodep == &reg->node.node);
181 rcu_read_unlock();
182 }
183
184 /*
185 * Find a buffer registry per UID object with given params. RCU read side lock
186 * MUST be acquired before calling this and hold on to protect the object.
187 *
188 * Return the object pointer or NULL on error.
189 */
190 struct buffer_reg_uid *buffer_reg_uid_find(uint64_t session_id,
191 uint32_t bits_per_long, uid_t uid)
192 {
193 struct lttng_ht_node_u64 *node;
194 struct lttng_ht_iter iter;
195 struct buffer_reg_uid *reg = NULL, key;
196 struct lttng_ht *ht = buffer_registry_uid;
197
198 /* Setup key we are looking for. */
199 key.session_id = session_id;
200 key.bits_per_long = bits_per_long;
201 key.uid = uid;
202
203 DBG3("Buffer registry per UID find id: %" PRIu64 ", ABI: %u, uid: %d",
204 session_id, bits_per_long, uid);
205
206 /* Custom lookup function since it's a different key. */
207 cds_lfht_lookup(ht->ht, ht->hash_fct(&key, lttng_ht_seed), ht->match_fct,
208 &key, &iter.iter);
209 node = lttng_ht_iter_get_node_u64(&iter);
210 if (!node) {
211 goto end;
212 }
213 reg = caa_container_of(node, struct buffer_reg_uid, node);
214
215 end:
216 return reg;
217 }
218
219 /*
220 * Initialize global buffer per PID registry. Should only be called ONCE!.
221 */
222 void buffer_reg_init_pid_registry(void)
223 {
224 /* Should be called once. */
225 assert(!buffer_registry_pid);
226 buffer_registry_pid = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
227 assert(buffer_registry_pid);
228
229 DBG3("Global buffer per PID registry initialized");
230 }
231
232 /*
233 * Allocate and initialize object. Set regp with the object pointer.
234 *
235 * Return 0 on success else a negative value and regp is untouched.
236 */
237 int buffer_reg_pid_create(uint64_t session_id, struct buffer_reg_pid **regp,
238 const char *root_shm_path, const char *shm_path)
239 {
240 int ret = 0;
241 struct buffer_reg_pid *reg = NULL;
242
243 assert(regp);
244
245 reg = zmalloc(sizeof(*reg));
246 if (!reg) {
247 PERROR("zmalloc buffer registry pid");
248 ret = -ENOMEM;
249 goto error;
250 }
251
252 reg->registry = zmalloc(sizeof(struct buffer_reg_session));
253 if (!reg->registry) {
254 PERROR("zmalloc buffer registry pid session");
255 ret = -ENOMEM;
256 goto error;
257 }
258
259 /* A cast is done here so we can use the session ID as a u64 ht node. */
260 reg->session_id = session_id;
261 if (shm_path[0]) {
262 strncpy(reg->root_shm_path, root_shm_path, sizeof(reg->root_shm_path));
263 reg->root_shm_path[sizeof(reg->root_shm_path) - 1] = '\0';
264 strncpy(reg->shm_path, shm_path, sizeof(reg->shm_path));
265 reg->shm_path[sizeof(reg->shm_path) - 1] = '\0';
266 DBG3("shm path '%s' is assigned to pid buffer registry for session id %" PRIu64,
267 reg->shm_path, session_id);
268 }
269 reg->registry->channels = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
270 if (!reg->registry->channels) {
271 ret = -ENOMEM;
272 goto error_session;
273 }
274
275 lttng_ht_node_init_u64(&reg->node, reg->session_id);
276 *regp = reg;
277
278 DBG3("Buffer registry per PID created with session id: %" PRIu64,
279 session_id);
280
281 return 0;
282
283 error_session:
284 free(reg->registry);
285 error:
286 free(reg);
287 return ret;
288 }
289
290 /*
291 * Add a buffer registry per PID object to the global registry.
292 */
293 void buffer_reg_pid_add(struct buffer_reg_pid *reg)
294 {
295 assert(reg);
296
297 DBG3("Buffer registry per PID adding to global registry with id: %" PRIu64,
298 reg->session_id);
299
300 rcu_read_lock();
301 lttng_ht_add_unique_u64(buffer_registry_pid, &reg->node);
302 rcu_read_unlock();
303 }
304
305 /*
306 * Find a buffer registry per PID object with given params. RCU read side lock
307 * MUST be acquired before calling this and hold on to protect the object.
308 *
309 * Return the object pointer or NULL on error.
310 */
311 struct buffer_reg_pid *buffer_reg_pid_find(uint64_t session_id)
312 {
313 struct lttng_ht_node_u64 *node;
314 struct lttng_ht_iter iter;
315 struct buffer_reg_pid *reg = NULL;
316 struct lttng_ht *ht = buffer_registry_pid;
317
318 DBG3("Buffer registry per PID find id: %" PRIu64, session_id);
319
320 lttng_ht_lookup(ht, &session_id, &iter);
321 node = lttng_ht_iter_get_node_u64(&iter);
322 if (!node) {
323 goto end;
324 }
325 reg = caa_container_of(node, struct buffer_reg_pid, node);
326
327 end:
328 return reg;
329 }
330
331 /*
332 * Find the consumer channel key from a UST session per-uid channel key.
333 *
334 * Return the matching key or -1 if not found.
335 */
336 int buffer_reg_uid_consumer_channel_key(
337 struct cds_list_head *buffer_reg_uid_list,
338 uint64_t chan_key, uint64_t *consumer_chan_key)
339 {
340 struct lttng_ht_iter iter;
341 struct buffer_reg_uid *uid_reg = NULL;
342 struct buffer_reg_session *session_reg = NULL;
343 struct buffer_reg_channel *reg_chan;
344 int ret = -1;
345
346 rcu_read_lock();
347 /*
348 * For the per-uid registry, we have to iterate since we don't have the
349 * uid and bitness key.
350 */
351 cds_list_for_each_entry(uid_reg, buffer_reg_uid_list, lnode) {
352 session_reg = uid_reg->registry;
353 cds_lfht_for_each_entry(session_reg->channels->ht,
354 &iter.iter, reg_chan, node.node) {
355 if (reg_chan->key == chan_key) {
356 *consumer_chan_key = reg_chan->consumer_key;
357 ret = 0;
358 goto end;
359 }
360 }
361 }
362
363 end:
364 rcu_read_unlock();
365 return ret;
366 }
367
368 /*
369 * Allocate and initialize a buffer registry channel with the given key. Set
370 * regp with the object pointer.
371 *
372 * Return 0 on success or else a negative value keeping regp untouched.
373 */
374 int buffer_reg_channel_create(uint64_t key, struct buffer_reg_channel **regp)
375 {
376 struct buffer_reg_channel *reg;
377
378 assert(regp);
379
380 DBG3("Buffer registry channel create with key: %" PRIu64, key);
381
382 reg = zmalloc(sizeof(*reg));
383 if (!reg) {
384 PERROR("zmalloc buffer registry channel");
385 return -ENOMEM;
386 }
387
388 reg->key = key;
389 CDS_INIT_LIST_HEAD(&reg->streams);
390 pthread_mutex_init(&reg->stream_list_lock, NULL);
391
392 lttng_ht_node_init_u64(&reg->node, key);
393 *regp = reg;
394
395 return 0;
396 }
397
398 /*
399 * Allocate and initialize a buffer registry stream. Set regp with the object
400 * pointer.
401 *
402 * Return 0 on success or else a negative value keeping regp untouched.
403 */
404 int buffer_reg_stream_create(struct buffer_reg_stream **regp)
405 {
406 struct buffer_reg_stream *reg;
407
408 assert(regp);
409
410 DBG3("Buffer registry creating stream");
411
412 reg = zmalloc(sizeof(*reg));
413 if (!reg) {
414 PERROR("zmalloc buffer registry stream");
415 return -ENOMEM;
416 }
417
418 *regp = reg;
419
420 return 0;
421 }
422
423 /*
424 * Add stream to the list in the channel.
425 */
426 void buffer_reg_stream_add(struct buffer_reg_stream *stream,
427 struct buffer_reg_channel *channel)
428 {
429 assert(stream);
430 assert(channel);
431
432 pthread_mutex_lock(&channel->stream_list_lock);
433 cds_list_add_tail(&stream->lnode, &channel->streams);
434 channel->stream_count++;
435 pthread_mutex_unlock(&channel->stream_list_lock);
436 }
437
438 /*
439 * Add a buffer registry channel object to the given session.
440 */
441 void buffer_reg_channel_add(struct buffer_reg_session *session,
442 struct buffer_reg_channel *channel)
443 {
444 assert(session);
445 assert(channel);
446
447 rcu_read_lock();
448 lttng_ht_add_unique_u64(session->channels, &channel->node);
449 rcu_read_unlock();
450 }
451
452 /*
453 * Find a buffer registry channel object with the given key. RCU read side lock
454 * MUST be acquired and hold on until the object reference is not needed
455 * anymore.
456 *
457 * Return the object pointer or NULL on error.
458 */
459 struct buffer_reg_channel *buffer_reg_channel_find(uint64_t key,
460 struct buffer_reg_uid *reg)
461 {
462 struct lttng_ht_node_u64 *node;
463 struct lttng_ht_iter iter;
464 struct buffer_reg_channel *chan = NULL;
465 struct lttng_ht *ht;
466
467 assert(reg);
468
469 switch (reg->domain) {
470 case LTTNG_DOMAIN_UST:
471 ht = reg->registry->channels;
472 break;
473 default:
474 assert(0);
475 goto end;
476 }
477
478 lttng_ht_lookup(ht, &key, &iter);
479 node = lttng_ht_iter_get_node_u64(&iter);
480 if (!node) {
481 goto end;
482 }
483 chan = caa_container_of(node, struct buffer_reg_channel, node);
484
485 end:
486 return chan;
487 }
488
489 /*
490 * Destroy a buffer registry stream with the given domain.
491 */
492 void buffer_reg_stream_destroy(struct buffer_reg_stream *regp,
493 enum lttng_domain_type domain)
494 {
495 if (!regp) {
496 return;
497 }
498
499 DBG3("Buffer registry stream destroy with handle %d",
500 regp->obj.ust->handle);
501
502 switch (domain) {
503 case LTTNG_DOMAIN_UST:
504 {
505 int ret;
506
507 ret = ust_app_release_object(NULL, regp->obj.ust);
508 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
509 ERR("Buffer reg stream release obj handle %d failed with ret %d",
510 regp->obj.ust->handle, ret);
511 }
512 free(regp->obj.ust);
513 lttng_fd_put(LTTNG_FD_APPS, 2);
514 break;
515 }
516 default:
517 assert(0);
518 }
519
520 free(regp);
521 return;
522 }
523
524 /*
525 * Remove buffer registry channel object from the session hash table. RCU read
526 * side lock MUST be acquired before calling this.
527 */
528 void buffer_reg_channel_remove(struct buffer_reg_session *session,
529 struct buffer_reg_channel *regp)
530 {
531 int ret;
532 struct lttng_ht_iter iter;
533
534 assert(session);
535 assert(regp);
536
537 iter.iter.node = &regp->node.node;
538 ret = lttng_ht_del(session->channels, &iter);
539 assert(!ret);
540 }
541
542 /*
543 * Destroy a buffer registry channel with the given domain.
544 */
545 void buffer_reg_channel_destroy(struct buffer_reg_channel *regp,
546 enum lttng_domain_type domain)
547 {
548 if (!regp) {
549 return;
550 }
551
552 DBG3("Buffer registry channel destroy with key %" PRIu32, regp->key);
553
554 switch (domain) {
555 case LTTNG_DOMAIN_UST:
556 {
557 int ret;
558 struct buffer_reg_stream *sreg, *stmp;
559 /* Wipe stream */
560 cds_list_for_each_entry_safe(sreg, stmp, &regp->streams, lnode) {
561 cds_list_del(&sreg->lnode);
562 regp->stream_count--;
563 buffer_reg_stream_destroy(sreg, domain);
564 }
565
566 if (regp->obj.ust) {
567 ret = ust_app_release_object(NULL, regp->obj.ust);
568 if (ret < 0 && ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
569 ERR("Buffer reg channel release obj handle %d failed with ret %d",
570 regp->obj.ust->handle, ret);
571 }
572 free(regp->obj.ust);
573 }
574 lttng_fd_put(LTTNG_FD_APPS, 1);
575 break;
576 }
577 default:
578 assert(0);
579 }
580
581 free(regp);
582 return;
583 }
584
585 /*
586 * Destroy a buffer registry session with the given domain.
587 *
588 * Should *NOT* be called with RCU read-side lock held.
589 */
590 static void buffer_reg_session_destroy(struct buffer_reg_session *regp,
591 enum lttng_domain_type domain)
592 {
593 int ret;
594 struct lttng_ht_iter iter;
595 struct buffer_reg_channel *reg_chan;
596
597 DBG3("Buffer registry session destroy");
598
599 /* Destroy all channels. */
600 rcu_read_lock();
601 cds_lfht_for_each_entry(regp->channels->ht, &iter.iter, reg_chan,
602 node.node) {
603 ret = lttng_ht_del(regp->channels, &iter);
604 assert(!ret);
605 buffer_reg_channel_destroy(reg_chan, domain);
606 }
607 rcu_read_unlock();
608
609 ht_cleanup_push(regp->channels);
610
611 switch (domain) {
612 case LTTNG_DOMAIN_UST:
613 ust_registry_session_destroy(regp->reg.ust);
614 free(regp->reg.ust);
615 break;
616 default:
617 assert(0);
618 }
619
620 free(regp);
621 return;
622 }
623
624 /*
625 * Remove buffer registry UID object from the global hash table.
626 */
627 void buffer_reg_uid_remove(struct buffer_reg_uid *regp)
628 {
629 int ret;
630 struct lttng_ht_iter iter;
631
632 assert(regp);
633
634 rcu_read_lock();
635 iter.iter.node = &regp->node.node;
636 ret = lttng_ht_del(buffer_registry_uid, &iter);
637 assert(!ret);
638 rcu_read_unlock();
639 }
640
641 static void rcu_free_buffer_reg_uid(struct rcu_head *head)
642 {
643 struct lttng_ht_node_u64 *node =
644 caa_container_of(head, struct lttng_ht_node_u64, head);
645 struct buffer_reg_uid *reg =
646 caa_container_of(node, struct buffer_reg_uid, node);
647
648 buffer_reg_session_destroy(reg->registry, reg->domain);
649 free(reg);
650 }
651
652 static void rcu_free_buffer_reg_pid(struct rcu_head *head)
653 {
654 struct lttng_ht_node_u64 *node =
655 caa_container_of(head, struct lttng_ht_node_u64, head);
656 struct buffer_reg_pid *reg =
657 caa_container_of(node, struct buffer_reg_pid, node);
658
659 buffer_reg_session_destroy(reg->registry, LTTNG_DOMAIN_UST);
660 free(reg);
661 }
662
663 /*
664 * Destroy buffer registry per UID. The given pointer is NOT removed from any
665 * list or hash table. Use buffer_reg_pid_remove() before calling this function
666 * for the case that the object is in the global hash table.
667 */
668 void buffer_reg_uid_destroy(struct buffer_reg_uid *regp,
669 struct consumer_output *consumer)
670 {
671 struct consumer_socket *socket;
672
673 if (!regp) {
674 return;
675 }
676
677 DBG3("Buffer registry per UID destroy with id: %" PRIu64 ", ABI: %u, uid: %d",
678 regp->session_id, regp->bits_per_long, regp->uid);
679
680 if (!consumer) {
681 goto destroy;
682 }
683
684 rcu_read_lock();
685 /* Get the right socket from the consumer object. */
686 socket = consumer_find_socket_by_bitness(regp->bits_per_long,
687 consumer);
688 if (!socket) {
689 goto unlock;
690 }
691
692 switch (regp->domain) {
693 case LTTNG_DOMAIN_UST:
694 if (regp->registry->reg.ust->metadata_key) {
695 /* Return value does not matter. This call will print errors. */
696 (void) consumer_close_metadata(socket,
697 regp->registry->reg.ust->metadata_key);
698 }
699 break;
700 default:
701 assert(0);
702 rcu_read_unlock();
703 return;
704 }
705
706 unlock:
707 rcu_read_unlock();
708 destroy:
709 call_rcu(&regp->node.head, rcu_free_buffer_reg_uid);
710 }
711
712 /*
713 * Remove buffer registry UID object from the global hash table. RCU read side
714 * lock MUST be acquired before calling this.
715 */
716 void buffer_reg_pid_remove(struct buffer_reg_pid *regp)
717 {
718 int ret;
719 struct lttng_ht_iter iter;
720
721 assert(regp);
722
723 iter.iter.node = &regp->node.node;
724 ret = lttng_ht_del(buffer_registry_pid, &iter);
725 assert(!ret);
726 }
727
728 /*
729 * Destroy buffer registry per PID. The pointer is NOT removed from the global
730 * hash table. Call buffer_reg_pid_remove() before that if the object was
731 * previously added to the global hash table.
732 */
733 void buffer_reg_pid_destroy(struct buffer_reg_pid *regp)
734 {
735 if (!regp) {
736 return;
737 }
738
739 DBG3("Buffer registry per PID destroy with id: %" PRIu64,
740 regp->session_id);
741
742 /* This registry is only used by UST. */
743 call_rcu(&regp->node.head, rcu_free_buffer_reg_pid);
744 }
745
746 /*
747 * Destroy per PID and UID registry hash table.
748 *
749 * Should *NOT* be called with RCU read-side lock held.
750 */
751 void buffer_reg_destroy_registries(void)
752 {
753 DBG3("Buffer registry destroy all registry");
754 ht_cleanup_push(buffer_registry_uid);
755 ht_cleanup_push(buffer_registry_pid);
756 }
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