Commit | Line | Data |
---|---|---|
5d1b0219 | 1 | /* |
90c106c6 | 2 | * Copyright (C) 2011 EfficiOS Inc. |
ab5be9fa MJ |
3 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
4 | * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
5d1b0219 | 5 | * |
ab5be9fa | 6 | * SPDX-License-Identifier: GPL-2.0-only |
5d1b0219 | 7 | * |
5d1b0219 JG |
8 | */ |
9 | ||
10 | #include <stddef.h> | |
11 | #include <stdlib.h> | |
12 | #include <urcu.h> | |
13 | #include <common/futex.h> | |
14 | #include <common/macros.h> | |
15 | ||
16 | #include "dispatch.h" | |
17 | #include "ust-app.h" | |
18 | #include "testpoint.h" | |
19 | #include "fd-limit.h" | |
20 | #include "health-sessiond.h" | |
21 | #include "lttng-sessiond.h" | |
22 | #include "thread.h" | |
23 | ||
24 | struct thread_notifiers { | |
25 | struct ust_cmd_queue *ust_cmd_queue; | |
26 | int apps_cmd_pipe_write_fd; | |
27 | int apps_cmd_notify_pipe_write_fd; | |
28 | int dispatch_thread_exit; | |
29 | }; | |
30 | ||
31 | /* | |
32 | * For each tracing session, update newly registered apps. The session list | |
33 | * lock MUST be acquired before calling this. | |
34 | */ | |
35 | static void update_ust_app(int app_sock) | |
36 | { | |
37 | struct ltt_session *sess, *stmp; | |
38 | const struct ltt_session_list *session_list = session_get_list(); | |
70670472 | 39 | struct ust_app *app; |
5d1b0219 JG |
40 | |
41 | /* Consumer is in an ERROR state. Stop any application update. */ | |
412d7227 | 42 | if (uatomic_read(&the_ust_consumerd_state) == CONSUMER_ERROR) { |
5d1b0219 JG |
43 | /* Stop the update process since the consumer is dead. */ |
44 | return; | |
45 | } | |
46 | ||
70670472 JR |
47 | rcu_read_lock(); |
48 | assert(app_sock >= 0); | |
49 | app = ust_app_find_by_sock(app_sock); | |
50 | if (app == NULL) { | |
51 | /* | |
52 | * Application can be unregistered before so | |
53 | * this is possible hence simply stopping the | |
54 | * update. | |
55 | */ | |
56 | DBG3("UST app update failed to find app sock %d", | |
57 | app_sock); | |
58 | goto unlock_rcu; | |
59 | } | |
60 | ||
61 | /* Update all event notifiers for the app. */ | |
62 | ust_app_global_update_event_notifier_rules(app); | |
63 | ||
5d1b0219 JG |
64 | /* For all tracing session(s) */ |
65 | cds_list_for_each_entry_safe(sess, stmp, &session_list->head, list) { | |
5d1b0219 JG |
66 | if (!session_get(sess)) { |
67 | continue; | |
68 | } | |
69 | session_lock(sess); | |
c05d4d1f JR |
70 | if (!sess->active || !sess->ust_session || |
71 | !sess->ust_session->active) { | |
5d1b0219 JG |
72 | goto unlock_session; |
73 | } | |
74 | ||
5d1b0219 | 75 | ust_app_global_update(sess->ust_session, app); |
5d1b0219 JG |
76 | unlock_session: |
77 | session_unlock(sess); | |
78 | session_put(sess); | |
79 | } | |
70670472 JR |
80 | |
81 | unlock_rcu: | |
82 | rcu_read_unlock(); | |
5d1b0219 JG |
83 | } |
84 | ||
85 | /* | |
86 | * Sanitize the wait queue of the dispatch registration thread meaning removing | |
87 | * invalid nodes from it. This is to avoid memory leaks for the case the UST | |
88 | * notify socket is never received. | |
89 | */ | |
90 | static void sanitize_wait_queue(struct ust_reg_wait_queue *wait_queue) | |
91 | { | |
92 | int ret, nb_fd = 0, i; | |
93 | unsigned int fd_added = 0; | |
94 | struct lttng_poll_event events; | |
95 | struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node; | |
96 | ||
97 | assert(wait_queue); | |
98 | ||
99 | lttng_poll_init(&events); | |
100 | ||
101 | /* Just skip everything for an empty queue. */ | |
102 | if (!wait_queue->count) { | |
103 | goto end; | |
104 | } | |
105 | ||
106 | ret = lttng_poll_create(&events, wait_queue->count, LTTNG_CLOEXEC); | |
107 | if (ret < 0) { | |
108 | goto error_create; | |
109 | } | |
110 | ||
111 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, | |
112 | &wait_queue->head, head) { | |
113 | assert(wait_node->app); | |
114 | ret = lttng_poll_add(&events, wait_node->app->sock, | |
115 | LPOLLHUP | LPOLLERR); | |
116 | if (ret < 0) { | |
117 | goto error; | |
118 | } | |
119 | ||
120 | fd_added = 1; | |
121 | } | |
122 | ||
123 | if (!fd_added) { | |
124 | goto end; | |
125 | } | |
126 | ||
127 | /* | |
128 | * Poll but don't block so we can quickly identify the faulty events and | |
129 | * clean them afterwards from the wait queue. | |
130 | */ | |
131 | ret = lttng_poll_wait(&events, 0); | |
132 | if (ret < 0) { | |
133 | goto error; | |
134 | } | |
135 | nb_fd = ret; | |
136 | ||
137 | for (i = 0; i < nb_fd; i++) { | |
138 | /* Get faulty FD. */ | |
139 | uint32_t revents = LTTNG_POLL_GETEV(&events, i); | |
140 | int pollfd = LTTNG_POLL_GETFD(&events, i); | |
141 | ||
5d1b0219 JG |
142 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, |
143 | &wait_queue->head, head) { | |
144 | if (pollfd == wait_node->app->sock && | |
145 | (revents & (LPOLLHUP | LPOLLERR))) { | |
146 | cds_list_del(&wait_node->head); | |
147 | wait_queue->count--; | |
148 | ust_app_destroy(wait_node->app); | |
149 | free(wait_node); | |
150 | /* | |
151 | * Silence warning of use-after-free in | |
152 | * cds_list_for_each_entry_safe which uses | |
153 | * __typeof__(*wait_node). | |
154 | */ | |
155 | wait_node = NULL; | |
156 | break; | |
157 | } else { | |
158 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
159 | goto error; | |
160 | } | |
161 | } | |
162 | } | |
163 | ||
164 | if (nb_fd > 0) { | |
165 | DBG("Wait queue sanitized, %d node were cleaned up", nb_fd); | |
166 | } | |
167 | ||
168 | end: | |
169 | lttng_poll_clean(&events); | |
170 | return; | |
171 | ||
172 | error: | |
173 | lttng_poll_clean(&events); | |
174 | error_create: | |
175 | ERR("Unable to sanitize wait queue"); | |
176 | return; | |
177 | } | |
178 | ||
179 | /* | |
180 | * Send a socket to a thread This is called from the dispatch UST registration | |
181 | * thread once all sockets are set for the application. | |
182 | * | |
183 | * The sock value can be invalid, we don't really care, the thread will handle | |
184 | * it and make the necessary cleanup if so. | |
185 | * | |
186 | * On success, return 0 else a negative value being the errno message of the | |
187 | * write(). | |
188 | */ | |
189 | static int send_socket_to_thread(int fd, int sock) | |
190 | { | |
191 | ssize_t ret; | |
192 | ||
193 | /* | |
194 | * It's possible that the FD is set as invalid with -1 concurrently just | |
195 | * before calling this function being a shutdown state of the thread. | |
196 | */ | |
197 | if (fd < 0) { | |
198 | ret = -EBADF; | |
199 | goto error; | |
200 | } | |
201 | ||
202 | ret = lttng_write(fd, &sock, sizeof(sock)); | |
203 | if (ret < sizeof(sock)) { | |
204 | PERROR("write apps pipe %d", fd); | |
205 | if (ret < 0) { | |
206 | ret = -errno; | |
207 | } | |
208 | goto error; | |
209 | } | |
210 | ||
211 | /* All good. Don't send back the write positive ret value. */ | |
212 | ret = 0; | |
213 | error: | |
214 | return (int) ret; | |
215 | } | |
216 | ||
217 | static void cleanup_ust_dispatch_thread(void *data) | |
218 | { | |
219 | free(data); | |
220 | } | |
221 | ||
222 | /* | |
223 | * Dispatch request from the registration threads to the application | |
224 | * communication thread. | |
225 | */ | |
226 | static void *thread_dispatch_ust_registration(void *data) | |
227 | { | |
228 | int ret, err = -1; | |
229 | struct cds_wfcq_node *node; | |
230 | struct ust_command *ust_cmd = NULL; | |
231 | struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node; | |
232 | struct ust_reg_wait_queue wait_queue = { | |
233 | .count = 0, | |
234 | }; | |
235 | struct thread_notifiers *notifiers = data; | |
236 | ||
237 | rcu_register_thread(); | |
238 | ||
412d7227 SM |
239 | health_register(the_health_sessiond, |
240 | HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH); | |
5d1b0219 JG |
241 | |
242 | if (testpoint(sessiond_thread_app_reg_dispatch)) { | |
243 | goto error_testpoint; | |
244 | } | |
245 | ||
246 | health_code_update(); | |
247 | ||
248 | CDS_INIT_LIST_HEAD(&wait_queue.head); | |
249 | ||
250 | DBG("[thread] Dispatch UST command started"); | |
251 | ||
252 | for (;;) { | |
253 | health_code_update(); | |
254 | ||
255 | /* Atomically prepare the queue futex */ | |
256 | futex_nto1_prepare(¬ifiers->ust_cmd_queue->futex); | |
257 | ||
258 | if (CMM_LOAD_SHARED(notifiers->dispatch_thread_exit)) { | |
259 | break; | |
260 | } | |
261 | ||
262 | do { | |
263 | struct ust_app *app = NULL; | |
264 | ust_cmd = NULL; | |
265 | ||
266 | /* | |
267 | * Make sure we don't have node(s) that have hung up before receiving | |
268 | * the notify socket. This is to clean the list in order to avoid | |
269 | * memory leaks from notify socket that are never seen. | |
270 | */ | |
271 | sanitize_wait_queue(&wait_queue); | |
272 | ||
273 | health_code_update(); | |
274 | /* Dequeue command for registration */ | |
275 | node = cds_wfcq_dequeue_blocking( | |
276 | ¬ifiers->ust_cmd_queue->head, | |
277 | ¬ifiers->ust_cmd_queue->tail); | |
278 | if (node == NULL) { | |
279 | DBG("Woken up but nothing in the UST command queue"); | |
280 | /* Continue thread execution */ | |
281 | break; | |
282 | } | |
283 | ||
284 | ust_cmd = caa_container_of(node, struct ust_command, node); | |
285 | ||
286 | DBG("Dispatching UST registration pid:%d ppid:%d uid:%d" | |
287 | " gid:%d sock:%d name:%s (version %d.%d)", | |
288 | ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid, | |
289 | ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid, | |
290 | ust_cmd->sock, ust_cmd->reg_msg.name, | |
291 | ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor); | |
292 | ||
b623cb6a | 293 | if (ust_cmd->reg_msg.type == LTTNG_UST_CTL_SOCKET_CMD) { |
5d1b0219 JG |
294 | wait_node = zmalloc(sizeof(*wait_node)); |
295 | if (!wait_node) { | |
296 | PERROR("zmalloc wait_node dispatch"); | |
297 | ret = close(ust_cmd->sock); | |
298 | if (ret < 0) { | |
299 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
300 | } | |
301 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
302 | free(ust_cmd); | |
58f835e1 | 303 | ust_cmd = NULL; |
5d1b0219 JG |
304 | goto error; |
305 | } | |
306 | CDS_INIT_LIST_HEAD(&wait_node->head); | |
307 | ||
308 | /* Create application object if socket is CMD. */ | |
309 | wait_node->app = ust_app_create(&ust_cmd->reg_msg, | |
310 | ust_cmd->sock); | |
311 | if (!wait_node->app) { | |
312 | ret = close(ust_cmd->sock); | |
313 | if (ret < 0) { | |
314 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
315 | } | |
316 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
317 | free(wait_node); | |
58f835e1 | 318 | wait_node = NULL; |
5d1b0219 | 319 | free(ust_cmd); |
58f835e1 | 320 | ust_cmd = NULL; |
5d1b0219 JG |
321 | continue; |
322 | } | |
323 | /* | |
324 | * Add application to the wait queue so we can set the notify | |
325 | * socket before putting this object in the global ht. | |
326 | */ | |
327 | cds_list_add(&wait_node->head, &wait_queue.head); | |
328 | wait_queue.count++; | |
329 | ||
330 | free(ust_cmd); | |
58f835e1 | 331 | ust_cmd = NULL; |
5d1b0219 JG |
332 | /* |
333 | * We have to continue here since we don't have the notify | |
334 | * socket and the application MUST be added to the hash table | |
335 | * only at that moment. | |
336 | */ | |
337 | continue; | |
338 | } else { | |
339 | /* | |
340 | * Look for the application in the local wait queue and set the | |
341 | * notify socket if found. | |
342 | */ | |
343 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, | |
344 | &wait_queue.head, head) { | |
345 | health_code_update(); | |
0b6b8118 JR |
346 | /* |
347 | * Only using the pid number to match | |
348 | * notify socket is not enough when | |
349 | * dealing with multiple instances of | |
350 | * lttng-ust for a given process. A | |
351 | * similar problem will rise up when | |
352 | * dealing with multiple similar pid | |
353 | * across namespaces in the futur. | |
354 | */ | |
355 | if (wait_node->app->pid == | |
356 | ust_cmd->reg_msg.pid) { | |
357 | if ((wait_node->app->v_major != | |
358 | ust_cmd->reg_msg.major) && | |
359 | (wait_node->app->v_minor != | |
360 | ust_cmd->reg_msg.minor)) { | |
361 | DBG("Skipping notify socket assignment (pid: %d) based on version mismatch. Notify socket registration version %d.%d, under iteration app version %d.%d.", | |
362 | wait_node->app->pid, | |
363 | ust_cmd->reg_msg.major, | |
364 | ust_cmd->reg_msg.minor, | |
365 | wait_node->app->v_major, | |
366 | wait_node->app->v_minor); | |
367 | continue; | |
368 | } | |
5d1b0219 JG |
369 | wait_node->app->notify_sock = ust_cmd->sock; |
370 | cds_list_del(&wait_node->head); | |
371 | wait_queue.count--; | |
372 | app = wait_node->app; | |
373 | free(wait_node); | |
58f835e1 | 374 | wait_node = NULL; |
0b6b8118 | 375 | DBG3("UST app notify socket %d is set for app sock %d", ust_cmd->sock, app->sock); |
5d1b0219 JG |
376 | break; |
377 | } | |
378 | } | |
379 | ||
380 | /* | |
381 | * With no application at this stage the received socket is | |
382 | * basically useless so close it before we free the cmd data | |
383 | * structure for good. | |
384 | */ | |
385 | if (!app) { | |
386 | ret = close(ust_cmd->sock); | |
387 | if (ret < 0) { | |
388 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
389 | } | |
390 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
391 | } | |
392 | free(ust_cmd); | |
58f835e1 | 393 | ust_cmd = NULL; |
5d1b0219 JG |
394 | } |
395 | ||
396 | if (app) { | |
397 | /* | |
398 | * @session_lock_list | |
399 | * | |
400 | * Lock the global session list so from the register up to the | |
401 | * registration done message, no thread can see the application | |
402 | * and change its state. | |
403 | */ | |
404 | session_lock_list(); | |
405 | rcu_read_lock(); | |
406 | ||
407 | /* | |
408 | * Add application to the global hash table. This needs to be | |
409 | * done before the update to the UST registry can locate the | |
410 | * application. | |
411 | */ | |
412 | ust_app_add(app); | |
413 | ||
414 | /* Set app version. This call will print an error if needed. */ | |
415 | (void) ust_app_version(app); | |
416 | ||
da873412 JR |
417 | (void) ust_app_setup_event_notifier_group(app); |
418 | ||
5d1b0219 JG |
419 | /* Send notify socket through the notify pipe. */ |
420 | ret = send_socket_to_thread( | |
421 | notifiers->apps_cmd_notify_pipe_write_fd, | |
422 | app->notify_sock); | |
423 | if (ret < 0) { | |
424 | rcu_read_unlock(); | |
425 | session_unlock_list(); | |
426 | /* | |
427 | * No notify thread, stop the UST tracing. However, this is | |
428 | * not an internal error of the this thread thus setting | |
429 | * the health error code to a normal exit. | |
430 | */ | |
431 | err = 0; | |
432 | goto error; | |
433 | } | |
434 | ||
435 | /* | |
436 | * Update newly registered application with the tracing | |
437 | * registry info already enabled information. | |
438 | */ | |
439 | update_ust_app(app->sock); | |
440 | ||
441 | /* | |
442 | * Don't care about return value. Let the manage apps threads | |
443 | * handle app unregistration upon socket close. | |
444 | */ | |
445 | (void) ust_app_register_done(app); | |
446 | ||
447 | /* | |
448 | * Even if the application socket has been closed, send the app | |
449 | * to the thread and unregistration will take place at that | |
450 | * place. | |
451 | */ | |
452 | ret = send_socket_to_thread( | |
453 | notifiers->apps_cmd_pipe_write_fd, | |
454 | app->sock); | |
455 | if (ret < 0) { | |
456 | rcu_read_unlock(); | |
457 | session_unlock_list(); | |
458 | /* | |
459 | * No apps. thread, stop the UST tracing. However, this is | |
460 | * not an internal error of the this thread thus setting | |
461 | * the health error code to a normal exit. | |
462 | */ | |
463 | err = 0; | |
464 | goto error; | |
465 | } | |
466 | ||
467 | rcu_read_unlock(); | |
468 | session_unlock_list(); | |
469 | } | |
470 | } while (node != NULL); | |
471 | ||
472 | health_poll_entry(); | |
473 | /* Futex wait on queue. Blocking call on futex() */ | |
474 | futex_nto1_wait(¬ifiers->ust_cmd_queue->futex); | |
475 | health_poll_exit(); | |
476 | } | |
477 | /* Normal exit, no error */ | |
478 | err = 0; | |
479 | ||
480 | error: | |
481 | /* Clean up wait queue. */ | |
482 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, | |
483 | &wait_queue.head, head) { | |
484 | cds_list_del(&wait_node->head); | |
485 | wait_queue.count--; | |
486 | free(wait_node); | |
487 | } | |
488 | ||
489 | /* Empty command queue. */ | |
490 | for (;;) { | |
491 | /* Dequeue command for registration */ | |
492 | node = cds_wfcq_dequeue_blocking( | |
493 | ¬ifiers->ust_cmd_queue->head, | |
494 | ¬ifiers->ust_cmd_queue->tail); | |
495 | if (node == NULL) { | |
496 | break; | |
497 | } | |
498 | ust_cmd = caa_container_of(node, struct ust_command, node); | |
499 | ret = close(ust_cmd->sock); | |
500 | if (ret < 0) { | |
501 | PERROR("close ust sock exit dispatch %d", ust_cmd->sock); | |
502 | } | |
503 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
504 | free(ust_cmd); | |
505 | } | |
506 | ||
507 | error_testpoint: | |
508 | DBG("Dispatch thread dying"); | |
509 | if (err) { | |
510 | health_error(); | |
511 | ERR("Health error occurred in %s", __func__); | |
512 | } | |
412d7227 | 513 | health_unregister(the_health_sessiond); |
5d1b0219 JG |
514 | rcu_unregister_thread(); |
515 | return NULL; | |
516 | } | |
517 | ||
518 | static bool shutdown_ust_dispatch_thread(void *data) | |
519 | { | |
520 | struct thread_notifiers *notifiers = data; | |
521 | ||
522 | CMM_STORE_SHARED(notifiers->dispatch_thread_exit, 1); | |
523 | futex_nto1_wake(¬ifiers->ust_cmd_queue->futex); | |
524 | return true; | |
525 | } | |
526 | ||
527 | bool launch_ust_dispatch_thread(struct ust_cmd_queue *cmd_queue, | |
528 | int apps_cmd_pipe_write_fd, | |
529 | int apps_cmd_notify_pipe_write_fd) | |
530 | { | |
531 | struct lttng_thread *thread; | |
532 | struct thread_notifiers *notifiers; | |
533 | ||
534 | notifiers = zmalloc(sizeof(*notifiers)); | |
535 | if (!notifiers) { | |
536 | goto error; | |
537 | } | |
538 | notifiers->ust_cmd_queue = cmd_queue; | |
539 | notifiers->apps_cmd_pipe_write_fd = apps_cmd_pipe_write_fd; | |
540 | notifiers->apps_cmd_notify_pipe_write_fd = apps_cmd_notify_pipe_write_fd; | |
541 | ||
542 | thread = lttng_thread_create("UST registration dispatch", | |
543 | thread_dispatch_ust_registration, | |
544 | shutdown_ust_dispatch_thread, | |
545 | cleanup_ust_dispatch_thread, | |
546 | notifiers); | |
547 | if (!thread) { | |
548 | goto error; | |
549 | } | |
550 | lttng_thread_put(thread); | |
551 | return true; | |
552 | error: | |
553 | free(notifiers); | |
554 | return false; | |
555 | } |