Commit | Line | Data |
---|---|---|
5d1b0219 | 1 | /* |
ab5be9fa MJ |
2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> |
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); | |
88e3c2f5 | 70 | if (!sess->active || !sess->ust_session) { |
5d1b0219 JG |
71 | goto unlock_session; |
72 | } | |
73 | ||
5d1b0219 | 74 | ust_app_global_update(sess->ust_session, app); |
5d1b0219 JG |
75 | unlock_session: |
76 | session_unlock(sess); | |
77 | session_put(sess); | |
78 | } | |
70670472 JR |
79 | |
80 | unlock_rcu: | |
81 | rcu_read_unlock(); | |
5d1b0219 JG |
82 | } |
83 | ||
84 | /* | |
85 | * Sanitize the wait queue of the dispatch registration thread meaning removing | |
86 | * invalid nodes from it. This is to avoid memory leaks for the case the UST | |
87 | * notify socket is never received. | |
88 | */ | |
89 | static void sanitize_wait_queue(struct ust_reg_wait_queue *wait_queue) | |
90 | { | |
91 | int ret, nb_fd = 0, i; | |
92 | unsigned int fd_added = 0; | |
93 | struct lttng_poll_event events; | |
94 | struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node; | |
95 | ||
96 | assert(wait_queue); | |
97 | ||
98 | lttng_poll_init(&events); | |
99 | ||
100 | /* Just skip everything for an empty queue. */ | |
101 | if (!wait_queue->count) { | |
102 | goto end; | |
103 | } | |
104 | ||
105 | ret = lttng_poll_create(&events, wait_queue->count, LTTNG_CLOEXEC); | |
106 | if (ret < 0) { | |
107 | goto error_create; | |
108 | } | |
109 | ||
110 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, | |
111 | &wait_queue->head, head) { | |
112 | assert(wait_node->app); | |
113 | ret = lttng_poll_add(&events, wait_node->app->sock, | |
114 | LPOLLHUP | LPOLLERR); | |
115 | if (ret < 0) { | |
116 | goto error; | |
117 | } | |
118 | ||
119 | fd_added = 1; | |
120 | } | |
121 | ||
122 | if (!fd_added) { | |
123 | goto end; | |
124 | } | |
125 | ||
126 | /* | |
127 | * Poll but don't block so we can quickly identify the faulty events and | |
128 | * clean them afterwards from the wait queue. | |
129 | */ | |
130 | ret = lttng_poll_wait(&events, 0); | |
131 | if (ret < 0) { | |
132 | goto error; | |
133 | } | |
134 | nb_fd = ret; | |
135 | ||
136 | for (i = 0; i < nb_fd; i++) { | |
137 | /* Get faulty FD. */ | |
138 | uint32_t revents = LTTNG_POLL_GETEV(&events, i); | |
139 | int pollfd = LTTNG_POLL_GETFD(&events, i); | |
140 | ||
5d1b0219 JG |
141 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, |
142 | &wait_queue->head, head) { | |
143 | if (pollfd == wait_node->app->sock && | |
144 | (revents & (LPOLLHUP | LPOLLERR))) { | |
145 | cds_list_del(&wait_node->head); | |
146 | wait_queue->count--; | |
147 | ust_app_destroy(wait_node->app); | |
148 | free(wait_node); | |
149 | /* | |
150 | * Silence warning of use-after-free in | |
151 | * cds_list_for_each_entry_safe which uses | |
152 | * __typeof__(*wait_node). | |
153 | */ | |
154 | wait_node = NULL; | |
155 | break; | |
156 | } else { | |
157 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
158 | goto error; | |
159 | } | |
160 | } | |
161 | } | |
162 | ||
163 | if (nb_fd > 0) { | |
164 | DBG("Wait queue sanitized, %d node were cleaned up", nb_fd); | |
165 | } | |
166 | ||
167 | end: | |
168 | lttng_poll_clean(&events); | |
169 | return; | |
170 | ||
171 | error: | |
172 | lttng_poll_clean(&events); | |
173 | error_create: | |
174 | ERR("Unable to sanitize wait queue"); | |
175 | return; | |
176 | } | |
177 | ||
178 | /* | |
179 | * Send a socket to a thread This is called from the dispatch UST registration | |
180 | * thread once all sockets are set for the application. | |
181 | * | |
182 | * The sock value can be invalid, we don't really care, the thread will handle | |
183 | * it and make the necessary cleanup if so. | |
184 | * | |
185 | * On success, return 0 else a negative value being the errno message of the | |
186 | * write(). | |
187 | */ | |
188 | static int send_socket_to_thread(int fd, int sock) | |
189 | { | |
190 | ssize_t ret; | |
191 | ||
192 | /* | |
193 | * It's possible that the FD is set as invalid with -1 concurrently just | |
194 | * before calling this function being a shutdown state of the thread. | |
195 | */ | |
196 | if (fd < 0) { | |
197 | ret = -EBADF; | |
198 | goto error; | |
199 | } | |
200 | ||
201 | ret = lttng_write(fd, &sock, sizeof(sock)); | |
202 | if (ret < sizeof(sock)) { | |
203 | PERROR("write apps pipe %d", fd); | |
204 | if (ret < 0) { | |
205 | ret = -errno; | |
206 | } | |
207 | goto error; | |
208 | } | |
209 | ||
210 | /* All good. Don't send back the write positive ret value. */ | |
211 | ret = 0; | |
212 | error: | |
213 | return (int) ret; | |
214 | } | |
215 | ||
216 | static void cleanup_ust_dispatch_thread(void *data) | |
217 | { | |
218 | free(data); | |
219 | } | |
220 | ||
221 | /* | |
222 | * Dispatch request from the registration threads to the application | |
223 | * communication thread. | |
224 | */ | |
225 | static void *thread_dispatch_ust_registration(void *data) | |
226 | { | |
227 | int ret, err = -1; | |
228 | struct cds_wfcq_node *node; | |
229 | struct ust_command *ust_cmd = NULL; | |
230 | struct ust_reg_wait_node *wait_node = NULL, *tmp_wait_node; | |
231 | struct ust_reg_wait_queue wait_queue = { | |
232 | .count = 0, | |
233 | }; | |
234 | struct thread_notifiers *notifiers = data; | |
235 | ||
236 | rcu_register_thread(); | |
237 | ||
412d7227 SM |
238 | health_register(the_health_sessiond, |
239 | HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH); | |
5d1b0219 JG |
240 | |
241 | if (testpoint(sessiond_thread_app_reg_dispatch)) { | |
242 | goto error_testpoint; | |
243 | } | |
244 | ||
245 | health_code_update(); | |
246 | ||
247 | CDS_INIT_LIST_HEAD(&wait_queue.head); | |
248 | ||
249 | DBG("[thread] Dispatch UST command started"); | |
250 | ||
251 | for (;;) { | |
252 | health_code_update(); | |
253 | ||
254 | /* Atomically prepare the queue futex */ | |
255 | futex_nto1_prepare(¬ifiers->ust_cmd_queue->futex); | |
256 | ||
257 | if (CMM_LOAD_SHARED(notifiers->dispatch_thread_exit)) { | |
258 | break; | |
259 | } | |
260 | ||
261 | do { | |
262 | struct ust_app *app = NULL; | |
263 | ust_cmd = NULL; | |
264 | ||
265 | /* | |
266 | * Make sure we don't have node(s) that have hung up before receiving | |
267 | * the notify socket. This is to clean the list in order to avoid | |
268 | * memory leaks from notify socket that are never seen. | |
269 | */ | |
270 | sanitize_wait_queue(&wait_queue); | |
271 | ||
272 | health_code_update(); | |
273 | /* Dequeue command for registration */ | |
274 | node = cds_wfcq_dequeue_blocking( | |
275 | ¬ifiers->ust_cmd_queue->head, | |
276 | ¬ifiers->ust_cmd_queue->tail); | |
277 | if (node == NULL) { | |
278 | DBG("Woken up but nothing in the UST command queue"); | |
279 | /* Continue thread execution */ | |
280 | break; | |
281 | } | |
282 | ||
283 | ust_cmd = caa_container_of(node, struct ust_command, node); | |
284 | ||
285 | DBG("Dispatching UST registration pid:%d ppid:%d uid:%d" | |
286 | " gid:%d sock:%d name:%s (version %d.%d)", | |
287 | ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid, | |
288 | ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid, | |
289 | ust_cmd->sock, ust_cmd->reg_msg.name, | |
290 | ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor); | |
291 | ||
b623cb6a | 292 | if (ust_cmd->reg_msg.type == LTTNG_UST_CTL_SOCKET_CMD) { |
5d1b0219 JG |
293 | wait_node = zmalloc(sizeof(*wait_node)); |
294 | if (!wait_node) { | |
295 | PERROR("zmalloc wait_node dispatch"); | |
296 | ret = close(ust_cmd->sock); | |
297 | if (ret < 0) { | |
298 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
299 | } | |
300 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
301 | free(ust_cmd); | |
58f835e1 | 302 | ust_cmd = NULL; |
5d1b0219 JG |
303 | goto error; |
304 | } | |
305 | CDS_INIT_LIST_HEAD(&wait_node->head); | |
306 | ||
307 | /* Create application object if socket is CMD. */ | |
308 | wait_node->app = ust_app_create(&ust_cmd->reg_msg, | |
309 | ust_cmd->sock); | |
310 | if (!wait_node->app) { | |
311 | ret = close(ust_cmd->sock); | |
312 | if (ret < 0) { | |
313 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
314 | } | |
315 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
316 | free(wait_node); | |
58f835e1 | 317 | wait_node = NULL; |
5d1b0219 | 318 | free(ust_cmd); |
58f835e1 | 319 | ust_cmd = NULL; |
5d1b0219 JG |
320 | continue; |
321 | } | |
322 | /* | |
323 | * Add application to the wait queue so we can set the notify | |
324 | * socket before putting this object in the global ht. | |
325 | */ | |
326 | cds_list_add(&wait_node->head, &wait_queue.head); | |
327 | wait_queue.count++; | |
328 | ||
329 | free(ust_cmd); | |
58f835e1 | 330 | ust_cmd = NULL; |
5d1b0219 JG |
331 | /* |
332 | * We have to continue here since we don't have the notify | |
333 | * socket and the application MUST be added to the hash table | |
334 | * only at that moment. | |
335 | */ | |
336 | continue; | |
337 | } else { | |
338 | /* | |
339 | * Look for the application in the local wait queue and set the | |
340 | * notify socket if found. | |
341 | */ | |
342 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, | |
343 | &wait_queue.head, head) { | |
344 | health_code_update(); | |
345 | if (wait_node->app->pid == ust_cmd->reg_msg.pid) { | |
346 | wait_node->app->notify_sock = ust_cmd->sock; | |
347 | cds_list_del(&wait_node->head); | |
348 | wait_queue.count--; | |
349 | app = wait_node->app; | |
350 | free(wait_node); | |
58f835e1 | 351 | wait_node = NULL; |
5d1b0219 JG |
352 | DBG3("UST app notify socket %d is set", ust_cmd->sock); |
353 | break; | |
354 | } | |
355 | } | |
356 | ||
357 | /* | |
358 | * With no application at this stage the received socket is | |
359 | * basically useless so close it before we free the cmd data | |
360 | * structure for good. | |
361 | */ | |
362 | if (!app) { | |
363 | ret = close(ust_cmd->sock); | |
364 | if (ret < 0) { | |
365 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
366 | } | |
367 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
368 | } | |
369 | free(ust_cmd); | |
58f835e1 | 370 | ust_cmd = NULL; |
5d1b0219 JG |
371 | } |
372 | ||
373 | if (app) { | |
374 | /* | |
375 | * @session_lock_list | |
376 | * | |
377 | * Lock the global session list so from the register up to the | |
378 | * registration done message, no thread can see the application | |
379 | * and change its state. | |
380 | */ | |
381 | session_lock_list(); | |
382 | rcu_read_lock(); | |
383 | ||
384 | /* | |
385 | * Add application to the global hash table. This needs to be | |
386 | * done before the update to the UST registry can locate the | |
387 | * application. | |
388 | */ | |
389 | ust_app_add(app); | |
390 | ||
391 | /* Set app version. This call will print an error if needed. */ | |
392 | (void) ust_app_version(app); | |
393 | ||
da873412 JR |
394 | (void) ust_app_setup_event_notifier_group(app); |
395 | ||
5d1b0219 JG |
396 | /* Send notify socket through the notify pipe. */ |
397 | ret = send_socket_to_thread( | |
398 | notifiers->apps_cmd_notify_pipe_write_fd, | |
399 | app->notify_sock); | |
400 | if (ret < 0) { | |
401 | rcu_read_unlock(); | |
402 | session_unlock_list(); | |
403 | /* | |
404 | * No notify thread, stop the UST tracing. However, this is | |
405 | * not an internal error of the this thread thus setting | |
406 | * the health error code to a normal exit. | |
407 | */ | |
408 | err = 0; | |
409 | goto error; | |
410 | } | |
411 | ||
412 | /* | |
413 | * Update newly registered application with the tracing | |
414 | * registry info already enabled information. | |
415 | */ | |
416 | update_ust_app(app->sock); | |
417 | ||
418 | /* | |
419 | * Don't care about return value. Let the manage apps threads | |
420 | * handle app unregistration upon socket close. | |
421 | */ | |
422 | (void) ust_app_register_done(app); | |
423 | ||
424 | /* | |
425 | * Even if the application socket has been closed, send the app | |
426 | * to the thread and unregistration will take place at that | |
427 | * place. | |
428 | */ | |
429 | ret = send_socket_to_thread( | |
430 | notifiers->apps_cmd_pipe_write_fd, | |
431 | app->sock); | |
432 | if (ret < 0) { | |
433 | rcu_read_unlock(); | |
434 | session_unlock_list(); | |
435 | /* | |
436 | * No apps. thread, stop the UST tracing. However, this is | |
437 | * not an internal error of the this thread thus setting | |
438 | * the health error code to a normal exit. | |
439 | */ | |
440 | err = 0; | |
441 | goto error; | |
442 | } | |
443 | ||
444 | rcu_read_unlock(); | |
445 | session_unlock_list(); | |
446 | } | |
447 | } while (node != NULL); | |
448 | ||
449 | health_poll_entry(); | |
450 | /* Futex wait on queue. Blocking call on futex() */ | |
451 | futex_nto1_wait(¬ifiers->ust_cmd_queue->futex); | |
452 | health_poll_exit(); | |
453 | } | |
454 | /* Normal exit, no error */ | |
455 | err = 0; | |
456 | ||
457 | error: | |
458 | /* Clean up wait queue. */ | |
459 | cds_list_for_each_entry_safe(wait_node, tmp_wait_node, | |
460 | &wait_queue.head, head) { | |
461 | cds_list_del(&wait_node->head); | |
462 | wait_queue.count--; | |
463 | free(wait_node); | |
464 | } | |
465 | ||
466 | /* Empty command queue. */ | |
467 | for (;;) { | |
468 | /* Dequeue command for registration */ | |
469 | node = cds_wfcq_dequeue_blocking( | |
470 | ¬ifiers->ust_cmd_queue->head, | |
471 | ¬ifiers->ust_cmd_queue->tail); | |
472 | if (node == NULL) { | |
473 | break; | |
474 | } | |
475 | ust_cmd = caa_container_of(node, struct ust_command, node); | |
476 | ret = close(ust_cmd->sock); | |
477 | if (ret < 0) { | |
478 | PERROR("close ust sock exit dispatch %d", ust_cmd->sock); | |
479 | } | |
480 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
481 | free(ust_cmd); | |
482 | } | |
483 | ||
484 | error_testpoint: | |
485 | DBG("Dispatch thread dying"); | |
486 | if (err) { | |
487 | health_error(); | |
488 | ERR("Health error occurred in %s", __func__); | |
489 | } | |
412d7227 | 490 | health_unregister(the_health_sessiond); |
5d1b0219 JG |
491 | rcu_unregister_thread(); |
492 | return NULL; | |
493 | } | |
494 | ||
495 | static bool shutdown_ust_dispatch_thread(void *data) | |
496 | { | |
497 | struct thread_notifiers *notifiers = data; | |
498 | ||
499 | CMM_STORE_SHARED(notifiers->dispatch_thread_exit, 1); | |
500 | futex_nto1_wake(¬ifiers->ust_cmd_queue->futex); | |
501 | return true; | |
502 | } | |
503 | ||
504 | bool launch_ust_dispatch_thread(struct ust_cmd_queue *cmd_queue, | |
505 | int apps_cmd_pipe_write_fd, | |
506 | int apps_cmd_notify_pipe_write_fd) | |
507 | { | |
508 | struct lttng_thread *thread; | |
509 | struct thread_notifiers *notifiers; | |
510 | ||
511 | notifiers = zmalloc(sizeof(*notifiers)); | |
512 | if (!notifiers) { | |
513 | goto error; | |
514 | } | |
515 | notifiers->ust_cmd_queue = cmd_queue; | |
516 | notifiers->apps_cmd_pipe_write_fd = apps_cmd_pipe_write_fd; | |
517 | notifiers->apps_cmd_notify_pipe_write_fd = apps_cmd_notify_pipe_write_fd; | |
518 | ||
519 | thread = lttng_thread_create("UST registration dispatch", | |
520 | thread_dispatch_ust_registration, | |
521 | shutdown_ust_dispatch_thread, | |
522 | cleanup_ust_dispatch_thread, | |
523 | notifiers); | |
524 | if (!thread) { | |
525 | goto error; | |
526 | } | |
527 | lttng_thread_put(thread); | |
528 | return true; | |
529 | error: | |
530 | free(notifiers); | |
531 | return false; | |
532 | } |