Commit | Line | Data |
---|---|---|
5d1b0219 | 1 | /* |
21cf9b6b | 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 | ||
c9e313bc | 10 | #include "dispatch.hpp" |
c9e313bc SM |
11 | #include "fd-limit.hpp" |
12 | #include "health-sessiond.hpp" | |
13 | #include "lttng-sessiond.hpp" | |
28ab034a | 14 | #include "testpoint.hpp" |
c9e313bc | 15 | #include "thread.hpp" |
28ab034a JG |
16 | #include "ust-app.hpp" |
17 | ||
18 | #include <common/futex.hpp> | |
19 | #include <common/macros.hpp> | |
20 | ||
21 | #include <stddef.h> | |
22 | #include <stdlib.h> | |
23 | #include <urcu.h> | |
5d1b0219 | 24 | |
f1494934 | 25 | namespace { |
5d1b0219 JG |
26 | struct thread_notifiers { |
27 | struct ust_cmd_queue *ust_cmd_queue; | |
28 | int apps_cmd_pipe_write_fd; | |
29 | int apps_cmd_notify_pipe_write_fd; | |
30 | int dispatch_thread_exit; | |
31 | }; | |
f1494934 | 32 | } /* namespace */ |
5d1b0219 JG |
33 | |
34 | /* | |
35 | * For each tracing session, update newly registered apps. The session list | |
36 | * lock MUST be acquired before calling this. | |
37 | */ | |
38 | static void update_ust_app(int app_sock) | |
39 | { | |
40 | struct ltt_session *sess, *stmp; | |
41 | const struct ltt_session_list *session_list = session_get_list(); | |
70670472 | 42 | struct ust_app *app; |
5d1b0219 JG |
43 | |
44 | /* Consumer is in an ERROR state. Stop any application update. */ | |
412d7227 | 45 | if (uatomic_read(&the_ust_consumerd_state) == CONSUMER_ERROR) { |
5d1b0219 JG |
46 | /* Stop the update process since the consumer is dead. */ |
47 | return; | |
48 | } | |
49 | ||
70670472 | 50 | rcu_read_lock(); |
a0377dfe | 51 | LTTNG_ASSERT(app_sock >= 0); |
70670472 | 52 | app = ust_app_find_by_sock(app_sock); |
cd9adb8b | 53 | if (app == nullptr) { |
70670472 JR |
54 | /* |
55 | * Application can be unregistered before so | |
56 | * this is possible hence simply stopping the | |
57 | * update. | |
58 | */ | |
28ab034a | 59 | DBG3("UST app update failed to find app sock %d", app_sock); |
70670472 JR |
60 | goto unlock_rcu; |
61 | } | |
62 | ||
63 | /* Update all event notifiers for the app. */ | |
64 | ust_app_global_update_event_notifier_rules(app); | |
65 | ||
5d1b0219 | 66 | /* For all tracing session(s) */ |
28ab034a | 67 | cds_list_for_each_entry_safe (sess, stmp, &session_list->head, list) { |
5d1b0219 JG |
68 | if (!session_get(sess)) { |
69 | continue; | |
70 | } | |
71 | session_lock(sess); | |
28ab034a | 72 | if (!sess->active || !sess->ust_session || !sess->ust_session->active) { |
5d1b0219 JG |
73 | goto unlock_session; |
74 | } | |
75 | ||
5d1b0219 | 76 | ust_app_global_update(sess->ust_session, app); |
5d1b0219 JG |
77 | unlock_session: |
78 | session_unlock(sess); | |
79 | session_put(sess); | |
80 | } | |
70670472 JR |
81 | |
82 | unlock_rcu: | |
83 | rcu_read_unlock(); | |
5d1b0219 JG |
84 | } |
85 | ||
86 | /* | |
87 | * Sanitize the wait queue of the dispatch registration thread meaning removing | |
88 | * invalid nodes from it. This is to avoid memory leaks for the case the UST | |
89 | * notify socket is never received. | |
90 | */ | |
91 | static void sanitize_wait_queue(struct ust_reg_wait_queue *wait_queue) | |
92 | { | |
93 | int ret, nb_fd = 0, i; | |
94 | unsigned int fd_added = 0; | |
95 | struct lttng_poll_event events; | |
cd9adb8b | 96 | struct ust_reg_wait_node *wait_node = nullptr, *tmp_wait_node; |
5d1b0219 | 97 | |
a0377dfe | 98 | LTTNG_ASSERT(wait_queue); |
5d1b0219 JG |
99 | |
100 | lttng_poll_init(&events); | |
101 | ||
102 | /* Just skip everything for an empty queue. */ | |
103 | if (!wait_queue->count) { | |
104 | goto end; | |
105 | } | |
106 | ||
107 | ret = lttng_poll_create(&events, wait_queue->count, LTTNG_CLOEXEC); | |
108 | if (ret < 0) { | |
109 | goto error_create; | |
110 | } | |
111 | ||
28ab034a | 112 | cds_list_for_each_entry_safe (wait_node, tmp_wait_node, &wait_queue->head, head) { |
a0377dfe | 113 | LTTNG_ASSERT(wait_node->app); |
1524f98c | 114 | ret = lttng_poll_add(&events, wait_node->app->sock, LPOLLIN); |
5d1b0219 JG |
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 | ||
28ab034a JG |
141 | cds_list_for_each_entry_safe (wait_node, tmp_wait_node, &wait_queue->head, head) { |
142 | if (pollfd == wait_node->app->sock && (revents & (LPOLLHUP | LPOLLERR))) { | |
5d1b0219 JG |
143 | cds_list_del(&wait_node->head); |
144 | wait_queue->count--; | |
145 | ust_app_destroy(wait_node->app); | |
146 | free(wait_node); | |
147 | /* | |
148 | * Silence warning of use-after-free in | |
149 | * cds_list_for_each_entry_safe which uses | |
150 | * __typeof__(*wait_node). | |
151 | */ | |
cd9adb8b | 152 | wait_node = nullptr; |
5d1b0219 JG |
153 | break; |
154 | } else { | |
155 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
156 | goto error; | |
157 | } | |
158 | } | |
159 | } | |
160 | ||
161 | if (nb_fd > 0) { | |
162 | DBG("Wait queue sanitized, %d node were cleaned up", nb_fd); | |
163 | } | |
164 | ||
165 | end: | |
166 | lttng_poll_clean(&events); | |
167 | return; | |
168 | ||
169 | error: | |
170 | lttng_poll_clean(&events); | |
171 | error_create: | |
172 | ERR("Unable to sanitize wait queue"); | |
173 | return; | |
174 | } | |
175 | ||
176 | /* | |
177 | * Send a socket to a thread This is called from the dispatch UST registration | |
178 | * thread once all sockets are set for the application. | |
179 | * | |
180 | * The sock value can be invalid, we don't really care, the thread will handle | |
181 | * it and make the necessary cleanup if so. | |
182 | * | |
183 | * On success, return 0 else a negative value being the errno message of the | |
184 | * write(). | |
185 | */ | |
186 | static int send_socket_to_thread(int fd, int sock) | |
187 | { | |
188 | ssize_t ret; | |
189 | ||
190 | /* | |
191 | * It's possible that the FD is set as invalid with -1 concurrently just | |
192 | * before calling this function being a shutdown state of the thread. | |
193 | */ | |
194 | if (fd < 0) { | |
195 | ret = -EBADF; | |
196 | goto error; | |
197 | } | |
198 | ||
199 | ret = lttng_write(fd, &sock, sizeof(sock)); | |
200 | if (ret < sizeof(sock)) { | |
201 | PERROR("write apps pipe %d", fd); | |
202 | if (ret < 0) { | |
203 | ret = -errno; | |
204 | } | |
205 | goto error; | |
206 | } | |
207 | ||
208 | /* All good. Don't send back the write positive ret value. */ | |
209 | ret = 0; | |
210 | error: | |
211 | return (int) ret; | |
212 | } | |
213 | ||
214 | static void cleanup_ust_dispatch_thread(void *data) | |
215 | { | |
216 | free(data); | |
217 | } | |
218 | ||
219 | /* | |
220 | * Dispatch request from the registration threads to the application | |
221 | * communication thread. | |
222 | */ | |
223 | static void *thread_dispatch_ust_registration(void *data) | |
224 | { | |
225 | int ret, err = -1; | |
226 | struct cds_wfcq_node *node; | |
cd9adb8b JG |
227 | struct ust_command *ust_cmd = nullptr; |
228 | struct ust_reg_wait_node *wait_node = nullptr, *tmp_wait_node; | |
5d1b0219 JG |
229 | struct ust_reg_wait_queue wait_queue = { |
230 | .count = 0, | |
1c9a0b0e | 231 | .head = {}, |
5d1b0219 | 232 | }; |
7966af57 | 233 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
5d1b0219 JG |
234 | |
235 | rcu_register_thread(); | |
236 | ||
28ab034a | 237 | health_register(the_health_sessiond, HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH); |
5d1b0219 JG |
238 | |
239 | if (testpoint(sessiond_thread_app_reg_dispatch)) { | |
240 | goto error_testpoint; | |
241 | } | |
242 | ||
243 | health_code_update(); | |
244 | ||
245 | CDS_INIT_LIST_HEAD(&wait_queue.head); | |
246 | ||
247 | DBG("[thread] Dispatch UST command started"); | |
248 | ||
249 | for (;;) { | |
250 | health_code_update(); | |
251 | ||
252 | /* Atomically prepare the queue futex */ | |
253 | futex_nto1_prepare(¬ifiers->ust_cmd_queue->futex); | |
254 | ||
255 | if (CMM_LOAD_SHARED(notifiers->dispatch_thread_exit)) { | |
256 | break; | |
257 | } | |
258 | ||
259 | do { | |
cd9adb8b JG |
260 | struct ust_app *app = nullptr; |
261 | ust_cmd = nullptr; | |
5d1b0219 JG |
262 | |
263 | /* | |
264 | * Make sure we don't have node(s) that have hung up before receiving | |
265 | * the notify socket. This is to clean the list in order to avoid | |
266 | * memory leaks from notify socket that are never seen. | |
267 | */ | |
268 | sanitize_wait_queue(&wait_queue); | |
269 | ||
270 | health_code_update(); | |
271 | /* Dequeue command for registration */ | |
28ab034a JG |
272 | node = cds_wfcq_dequeue_blocking(¬ifiers->ust_cmd_queue->head, |
273 | ¬ifiers->ust_cmd_queue->tail); | |
cd9adb8b | 274 | if (node == nullptr) { |
5d1b0219 JG |
275 | DBG("Woken up but nothing in the UST command queue"); |
276 | /* Continue thread execution */ | |
277 | break; | |
278 | } | |
279 | ||
0114db0e | 280 | ust_cmd = lttng::utils::container_of(node, &ust_command::node); |
5d1b0219 JG |
281 | |
282 | DBG("Dispatching UST registration pid:%d ppid:%d uid:%d" | |
28ab034a JG |
283 | " gid:%d sock:%d name:%s (version %d.%d)", |
284 | ust_cmd->reg_msg.pid, | |
285 | ust_cmd->reg_msg.ppid, | |
286 | ust_cmd->reg_msg.uid, | |
287 | ust_cmd->reg_msg.gid, | |
288 | ust_cmd->sock, | |
289 | ust_cmd->reg_msg.name, | |
290 | ust_cmd->reg_msg.major, | |
291 | ust_cmd->reg_msg.minor); | |
5d1b0219 | 292 | |
b623cb6a | 293 | if (ust_cmd->reg_msg.type == LTTNG_UST_CTL_SOCKET_CMD) { |
64803277 | 294 | wait_node = zmalloc<ust_reg_wait_node>(); |
5d1b0219 JG |
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); | |
cd9adb8b | 303 | ust_cmd = nullptr; |
5d1b0219 JG |
304 | goto error; |
305 | } | |
306 | CDS_INIT_LIST_HEAD(&wait_node->head); | |
307 | ||
308 | /* Create application object if socket is CMD. */ | |
28ab034a | 309 | wait_node->app = ust_app_create(&ust_cmd->reg_msg, ust_cmd->sock); |
5d1b0219 JG |
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); | |
cd9adb8b | 317 | wait_node = nullptr; |
5d1b0219 | 318 | free(ust_cmd); |
cd9adb8b | 319 | ust_cmd = nullptr; |
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); | |
cd9adb8b | 330 | ust_cmd = nullptr; |
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 | */ | |
28ab034a JG |
342 | cds_list_for_each_entry_safe ( |
343 | wait_node, tmp_wait_node, &wait_queue.head, head) { | |
5d1b0219 JG |
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); | |
cd9adb8b | 351 | wait_node = nullptr; |
28ab034a JG |
352 | DBG3("UST app notify socket %d is set", |
353 | ust_cmd->sock); | |
5d1b0219 JG |
354 | break; |
355 | } | |
356 | } | |
357 | ||
358 | /* | |
359 | * With no application at this stage the received socket is | |
360 | * basically useless so close it before we free the cmd data | |
361 | * structure for good. | |
362 | */ | |
363 | if (!app) { | |
364 | ret = close(ust_cmd->sock); | |
365 | if (ret < 0) { | |
366 | PERROR("close ust sock dispatch %d", ust_cmd->sock); | |
367 | } | |
368 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
369 | } | |
370 | free(ust_cmd); | |
cd9adb8b | 371 | ust_cmd = nullptr; |
5d1b0219 JG |
372 | } |
373 | ||
374 | if (app) { | |
375 | /* | |
376 | * @session_lock_list | |
377 | * | |
378 | * Lock the global session list so from the register up to the | |
379 | * registration done message, no thread can see the application | |
380 | * and change its state. | |
381 | */ | |
382 | session_lock_list(); | |
383 | rcu_read_lock(); | |
384 | ||
385 | /* | |
386 | * Add application to the global hash table. This needs to be | |
387 | * done before the update to the UST registry can locate the | |
388 | * application. | |
389 | */ | |
390 | ust_app_add(app); | |
391 | ||
392 | /* Set app version. This call will print an error if needed. */ | |
393 | (void) ust_app_version(app); | |
394 | ||
da873412 JR |
395 | (void) ust_app_setup_event_notifier_group(app); |
396 | ||
5d1b0219 JG |
397 | /* Send notify socket through the notify pipe. */ |
398 | ret = send_socket_to_thread( | |
28ab034a | 399 | notifiers->apps_cmd_notify_pipe_write_fd, app->notify_sock); |
5d1b0219 JG |
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 | */ | |
28ab034a JG |
429 | ret = send_socket_to_thread(notifiers->apps_cmd_pipe_write_fd, |
430 | app->sock); | |
5d1b0219 JG |
431 | if (ret < 0) { |
432 | rcu_read_unlock(); | |
433 | session_unlock_list(); | |
434 | /* | |
435 | * No apps. thread, stop the UST tracing. However, this is | |
436 | * not an internal error of the this thread thus setting | |
437 | * the health error code to a normal exit. | |
438 | */ | |
439 | err = 0; | |
440 | goto error; | |
441 | } | |
442 | ||
443 | rcu_read_unlock(); | |
444 | session_unlock_list(); | |
445 | } | |
cd9adb8b | 446 | } while (node != nullptr); |
5d1b0219 JG |
447 | |
448 | health_poll_entry(); | |
449 | /* Futex wait on queue. Blocking call on futex() */ | |
450 | futex_nto1_wait(¬ifiers->ust_cmd_queue->futex); | |
451 | health_poll_exit(); | |
452 | } | |
453 | /* Normal exit, no error */ | |
454 | err = 0; | |
455 | ||
456 | error: | |
457 | /* Clean up wait queue. */ | |
28ab034a | 458 | cds_list_for_each_entry_safe (wait_node, tmp_wait_node, &wait_queue.head, head) { |
5d1b0219 JG |
459 | cds_list_del(&wait_node->head); |
460 | wait_queue.count--; | |
461 | free(wait_node); | |
462 | } | |
463 | ||
464 | /* Empty command queue. */ | |
465 | for (;;) { | |
466 | /* Dequeue command for registration */ | |
28ab034a JG |
467 | node = cds_wfcq_dequeue_blocking(¬ifiers->ust_cmd_queue->head, |
468 | ¬ifiers->ust_cmd_queue->tail); | |
cd9adb8b | 469 | if (node == nullptr) { |
5d1b0219 JG |
470 | break; |
471 | } | |
0114db0e | 472 | ust_cmd = lttng::utils::container_of(node, &ust_command::node); |
5d1b0219 JG |
473 | ret = close(ust_cmd->sock); |
474 | if (ret < 0) { | |
475 | PERROR("close ust sock exit dispatch %d", ust_cmd->sock); | |
476 | } | |
477 | lttng_fd_put(LTTNG_FD_APPS, 1); | |
478 | free(ust_cmd); | |
479 | } | |
480 | ||
481 | error_testpoint: | |
482 | DBG("Dispatch thread dying"); | |
483 | if (err) { | |
484 | health_error(); | |
485 | ERR("Health error occurred in %s", __func__); | |
486 | } | |
412d7227 | 487 | health_unregister(the_health_sessiond); |
5d1b0219 | 488 | rcu_unregister_thread(); |
cd9adb8b | 489 | return nullptr; |
5d1b0219 JG |
490 | } |
491 | ||
492 | static bool shutdown_ust_dispatch_thread(void *data) | |
493 | { | |
7966af57 | 494 | struct thread_notifiers *notifiers = (thread_notifiers *) data; |
5d1b0219 JG |
495 | |
496 | CMM_STORE_SHARED(notifiers->dispatch_thread_exit, 1); | |
497 | futex_nto1_wake(¬ifiers->ust_cmd_queue->futex); | |
498 | return true; | |
499 | } | |
500 | ||
501 | bool launch_ust_dispatch_thread(struct ust_cmd_queue *cmd_queue, | |
28ab034a JG |
502 | int apps_cmd_pipe_write_fd, |
503 | int apps_cmd_notify_pipe_write_fd) | |
5d1b0219 JG |
504 | { |
505 | struct lttng_thread *thread; | |
506 | struct thread_notifiers *notifiers; | |
507 | ||
64803277 | 508 | notifiers = zmalloc<thread_notifiers>(); |
5d1b0219 JG |
509 | if (!notifiers) { |
510 | goto error; | |
511 | } | |
512 | notifiers->ust_cmd_queue = cmd_queue; | |
513 | notifiers->apps_cmd_pipe_write_fd = apps_cmd_pipe_write_fd; | |
514 | notifiers->apps_cmd_notify_pipe_write_fd = apps_cmd_notify_pipe_write_fd; | |
515 | ||
516 | thread = lttng_thread_create("UST registration dispatch", | |
28ab034a JG |
517 | thread_dispatch_ust_registration, |
518 | shutdown_ust_dispatch_thread, | |
519 | cleanup_ust_dispatch_thread, | |
520 | notifiers); | |
5d1b0219 JG |
521 | if (!thread) { |
522 | goto error; | |
523 | } | |
524 | lttng_thread_put(thread); | |
525 | return true; | |
526 | error: | |
527 | free(notifiers); | |
528 | return false; | |
529 | } |