Commit | Line | Data |
---|---|---|
2691221a MD |
1 | /* |
2 | * lttng-ust-comm.c | |
3 | * | |
4 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; only | |
10 | * version 2.1 of the License. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with this library; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <sys/types.h> | |
23 | #include <sys/socket.h> | |
2629549e | 24 | #include <sys/prctl.h> |
7fc90dca MD |
25 | #include <sys/mman.h> |
26 | #include <sys/stat.h> | |
27 | #include <fcntl.h> | |
2691221a MD |
28 | #include <unistd.h> |
29 | #include <errno.h> | |
d9e99d10 | 30 | #include <pthread.h> |
11ff9c7d MD |
31 | #include <semaphore.h> |
32 | #include <time.h> | |
1ea11eab | 33 | #include <assert.h> |
e822f505 | 34 | #include <signal.h> |
95259bd0 | 35 | #include <urcu/uatomic.h> |
1ea11eab | 36 | |
edaa1431 MD |
37 | #include <lttng-ust-comm.h> |
38 | #include <ust/usterr-signal-safe.h> | |
39 | #include <ust/lttng-ust-abi.h> | |
40 | #include <ust/tracepoint.h> | |
d0a1ae63 | 41 | #include <ust/tracepoint-internal.h> |
e822f505 | 42 | #include <ust/ust.h> |
b751f722 | 43 | #include "ltt-tracer-core.h" |
edaa1431 MD |
44 | |
45 | /* | |
46 | * Has lttng ust comm constructor been called ? | |
47 | */ | |
48 | static int initialized; | |
49 | ||
1ea11eab | 50 | /* |
17dfb34b MD |
51 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
52 | * Held when handling a command, also held by fork() to deal with | |
53 | * removal of threads, and by exit path. | |
1ea11eab | 54 | */ |
1ea11eab MD |
55 | |
56 | /* Should the ust comm thread quit ? */ | |
57 | static int lttng_ust_comm_should_quit; | |
58 | ||
11ff9c7d MD |
59 | /* |
60 | * Wait for either of these before continuing to the main | |
61 | * program: | |
62 | * - the register_done message from sessiond daemon | |
63 | * (will let the sessiond daemon enable sessions before main | |
64 | * starts.) | |
65 | * - sessiond daemon is not reachable. | |
66 | * - timeout (ensuring applications are resilient to session | |
67 | * daemon problems). | |
68 | */ | |
69 | static sem_t constructor_wait; | |
950aab0c MD |
70 | /* |
71 | * Doing this for both the global and local sessiond. | |
72 | */ | |
95259bd0 | 73 | static int sem_count = { 2 }; |
11ff9c7d | 74 | |
1ea11eab MD |
75 | /* |
76 | * Info about socket and associated listener thread. | |
77 | */ | |
78 | struct sock_info { | |
11ff9c7d | 79 | const char *name; |
1ea11eab | 80 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 81 | int root_handle; |
8d20bf54 MD |
82 | int constructor_sem_posted; |
83 | int allowed; | |
7fc90dca MD |
84 | |
85 | char sock_path[PATH_MAX]; | |
86 | int socket; | |
87 | ||
88 | char wait_shm_path[PATH_MAX]; | |
89 | char *wait_shm_mmap; | |
1ea11eab | 90 | }; |
2691221a MD |
91 | |
92 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 93 | struct sock_info global_apps = { |
11ff9c7d | 94 | .name = "global", |
7fc90dca | 95 | |
46050b1a | 96 | .root_handle = -1, |
8d20bf54 | 97 | .allowed = 1, |
7fc90dca MD |
98 | |
99 | .sock_path = DEFAULT_GLOBAL_APPS_UNIX_SOCK, | |
100 | .socket = -1, | |
101 | ||
102 | .wait_shm_path = DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH, | |
1ea11eab | 103 | }; |
2691221a MD |
104 | |
105 | /* TODO: allow global_apps_sock_path override */ | |
106 | ||
1ea11eab | 107 | struct sock_info local_apps = { |
11ff9c7d | 108 | .name = "local", |
46050b1a | 109 | .root_handle = -1, |
8d20bf54 | 110 | .allowed = 0, /* Check setuid bit first */ |
7fc90dca MD |
111 | |
112 | .socket = -1, | |
1ea11eab | 113 | }; |
2691221a | 114 | |
edaa1431 MD |
115 | extern void ltt_ring_buffer_client_overwrite_init(void); |
116 | extern void ltt_ring_buffer_client_discard_init(void); | |
117 | extern void ltt_ring_buffer_metadata_client_init(void); | |
118 | extern void ltt_ring_buffer_client_overwrite_exit(void); | |
119 | extern void ltt_ring_buffer_client_discard_exit(void); | |
120 | extern void ltt_ring_buffer_metadata_client_exit(void); | |
121 | ||
2691221a | 122 | static |
8d20bf54 | 123 | int setup_local_apps(void) |
2691221a MD |
124 | { |
125 | const char *home_dir; | |
7fc90dca | 126 | uid_t uid; |
2691221a | 127 | |
7fc90dca | 128 | uid = getuid(); |
8d20bf54 MD |
129 | /* |
130 | * Disallow per-user tracing for setuid binaries. | |
131 | */ | |
7fc90dca | 132 | if (uid != geteuid()) { |
8d20bf54 | 133 | local_apps.allowed = 0; |
d0a1ae63 | 134 | return 0; |
8d20bf54 MD |
135 | } else { |
136 | local_apps.allowed = 1; | |
137 | } | |
2691221a MD |
138 | home_dir = (const char *) getenv("HOME"); |
139 | if (!home_dir) | |
140 | return -ENOENT; | |
1ea11eab | 141 | snprintf(local_apps.sock_path, PATH_MAX, |
2691221a | 142 | DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); |
7fc90dca MD |
143 | snprintf(local_apps.wait_shm_path, PATH_MAX, |
144 | DEFAULT_HOME_APPS_WAIT_SHM_PATH, uid); | |
2691221a MD |
145 | return 0; |
146 | } | |
147 | ||
148 | static | |
149 | int register_app_to_sessiond(int socket) | |
150 | { | |
151 | ssize_t ret; | |
2629549e | 152 | int prctl_ret; |
2691221a | 153 | struct { |
e44418f3 MD |
154 | uint32_t major; |
155 | uint32_t minor; | |
2691221a | 156 | pid_t pid; |
5c33bde8 | 157 | pid_t ppid; |
2691221a | 158 | uid_t uid; |
83610856 | 159 | gid_t gid; |
2629549e | 160 | char name[16]; /* process name */ |
2691221a MD |
161 | } reg_msg; |
162 | ||
e44418f3 MD |
163 | reg_msg.major = LTTNG_UST_COMM_VERSION_MAJOR; |
164 | reg_msg.minor = LTTNG_UST_COMM_VERSION_MINOR; | |
2691221a | 165 | reg_msg.pid = getpid(); |
5c33bde8 | 166 | reg_msg.ppid = getppid(); |
2691221a | 167 | reg_msg.uid = getuid(); |
83610856 | 168 | reg_msg.gid = getgid(); |
2629549e MD |
169 | prctl_ret = prctl(PR_GET_NAME, (unsigned long) reg_msg.name, 0, 0, 0); |
170 | if (prctl_ret) { | |
171 | ERR("Error executing prctl"); | |
172 | return -errno; | |
173 | } | |
2691221a MD |
174 | |
175 | ret = lttcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg)); | |
176 | if (ret >= 0 && ret != sizeof(reg_msg)) | |
177 | return -EIO; | |
178 | return ret; | |
179 | } | |
180 | ||
d9e99d10 | 181 | static |
d3a492d1 | 182 | int send_reply(int sock, struct lttcomm_ust_reply *lur) |
d9e99d10 | 183 | { |
9eb62b9c | 184 | ssize_t len; |
d3a492d1 | 185 | |
a4be8962 | 186 | len = lttcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 187 | switch (len) { |
a4be8962 | 188 | case sizeof(*lur): |
d3a492d1 MD |
189 | DBG("message successfully sent"); |
190 | return 0; | |
191 | case -1: | |
192 | if (errno == ECONNRESET) { | |
193 | printf("remote end closed connection\n"); | |
194 | return 0; | |
195 | } | |
196 | return -1; | |
197 | default: | |
198 | printf("incorrect message size: %zd\n", len); | |
199 | return -1; | |
200 | } | |
201 | } | |
202 | ||
203 | static | |
edaa1431 | 204 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
205 | { |
206 | int ret; | |
207 | ||
edaa1431 MD |
208 | if (sock_info->constructor_sem_posted) |
209 | return 0; | |
210 | sock_info->constructor_sem_posted = 1; | |
95259bd0 MD |
211 | ret = uatomic_add_return(&sem_count, -1); |
212 | if (ret == 0) { | |
213 | ret = sem_post(&constructor_wait); | |
214 | assert(!ret); | |
215 | } | |
11ff9c7d MD |
216 | return 0; |
217 | } | |
218 | ||
219 | static | |
220 | int handle_message(struct sock_info *sock_info, | |
221 | int sock, struct lttcomm_ust_msg *lum) | |
d3a492d1 | 222 | { |
1ea11eab | 223 | int ret = 0; |
46050b1a MD |
224 | const struct objd_ops *ops; |
225 | struct lttcomm_ust_reply lur; | |
1ea11eab | 226 | |
17dfb34b | 227 | ust_lock(); |
1ea11eab | 228 | |
46050b1a MD |
229 | memset(&lur, 0, sizeof(lur)); |
230 | ||
1ea11eab | 231 | if (lttng_ust_comm_should_quit) { |
46050b1a | 232 | ret = -EPERM; |
1ea11eab MD |
233 | goto end; |
234 | } | |
9eb62b9c | 235 | |
46050b1a MD |
236 | ops = objd_ops(lum->handle); |
237 | if (!ops) { | |
238 | ret = -ENOENT; | |
239 | goto end; | |
1ea11eab | 240 | } |
46050b1a MD |
241 | |
242 | switch (lum->cmd) { | |
11ff9c7d MD |
243 | case LTTNG_UST_REGISTER_DONE: |
244 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 245 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
246 | else |
247 | ret = -EINVAL; | |
248 | break; | |
46050b1a MD |
249 | case LTTNG_UST_RELEASE: |
250 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
251 | ret = -EPERM; | |
252 | else | |
253 | ret = objd_unref(lum->handle); | |
d9e99d10 MD |
254 | break; |
255 | default: | |
46050b1a MD |
256 | if (ops->cmd) |
257 | ret = ops->cmd(lum->handle, lum->cmd, | |
258 | (unsigned long) &lum->u); | |
259 | else | |
260 | ret = -ENOSYS; | |
261 | break; | |
d9e99d10 | 262 | } |
46050b1a | 263 | |
1ea11eab | 264 | end: |
46050b1a MD |
265 | lur.handle = lum->handle; |
266 | lur.cmd = lum->cmd; | |
267 | lur.ret_val = ret; | |
268 | if (ret >= 0) { | |
269 | lur.ret_code = LTTCOMM_OK; | |
270 | } else { | |
271 | lur.ret_code = LTTCOMM_SESSION_FAIL; | |
272 | } | |
273 | ret = send_reply(sock, &lur); | |
274 | ||
17dfb34b | 275 | ust_unlock(); |
1ea11eab | 276 | return ret; |
d9e99d10 MD |
277 | } |
278 | ||
46050b1a MD |
279 | static |
280 | void cleanup_sock_info(struct sock_info *sock_info) | |
281 | { | |
282 | int ret; | |
283 | ||
284 | if (sock_info->socket != -1) { | |
285 | ret = close(sock_info->socket); | |
286 | if (ret) { | |
7fc90dca | 287 | ERR("Error closing apps socket"); |
46050b1a MD |
288 | } |
289 | sock_info->socket = -1; | |
290 | } | |
291 | if (sock_info->root_handle != -1) { | |
292 | ret = objd_unref(sock_info->root_handle); | |
293 | if (ret) { | |
294 | ERR("Error unref root handle"); | |
295 | } | |
296 | sock_info->root_handle = -1; | |
297 | } | |
318dfea9 | 298 | sock_info->constructor_sem_posted = 0; |
7fc90dca MD |
299 | if (sock_info->wait_shm_mmap) { |
300 | ret = munmap(sock_info->wait_shm_mmap, sysconf(_SC_PAGE_SIZE)); | |
301 | if (ret) { | |
302 | ERR("Error unmapping wait shm"); | |
303 | } | |
304 | sock_info->wait_shm_mmap = NULL; | |
305 | } | |
306 | } | |
307 | ||
308 | static | |
309 | char *get_map_shm(struct sock_info *sock_info) | |
310 | { | |
311 | size_t mmap_size = sysconf(_SC_PAGE_SIZE); | |
312 | int wait_shm_fd, ret; | |
313 | char *wait_shm_mmap; | |
314 | ||
315 | /* | |
316 | * Get existing (read-only) shm, or open new shm. | |
317 | * First try to open read-only. | |
318 | */ | |
319 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
320 | O_RDONLY, 0700); | |
321 | if (wait_shm_fd >= 0) | |
322 | goto got_shm; | |
323 | /* | |
324 | * Real-only open did not work. If it is because it did | |
325 | * not exist, try creating it. Else it's a failure that | |
326 | * prohibits using shm. | |
327 | */ | |
328 | if (errno != ENOENT) { | |
329 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
330 | goto error; | |
331 | } | |
332 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
333 | O_RDWR | O_CREAT | O_EXCL, 0700); | |
334 | if (wait_shm_fd >= 0) | |
335 | goto created_shm; | |
336 | if (errno != EEXIST) { | |
337 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
338 | goto error; | |
339 | } | |
340 | /* | |
341 | * If another process beat us to create the shm, we are | |
342 | * pretty certain the shm is available for us in | |
343 | * read-only mode. | |
344 | */ | |
345 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
346 | O_RDWR | O_CREAT | O_EXCL, 0700); | |
347 | if (wait_shm_fd >= 0) | |
348 | goto got_shm; | |
349 | else | |
350 | goto error; | |
351 | ||
352 | created_shm: | |
353 | ret = ftruncate(wait_shm_fd, mmap_size); | |
354 | if (ret) { | |
355 | PERROR("ftruncate"); | |
356 | ret = close(wait_shm_fd); | |
357 | if (ret) { | |
358 | ERR("Error closing fd"); | |
359 | } | |
360 | wait_shm_fd = -1; | |
361 | goto error; | |
362 | } | |
363 | got_shm: | |
364 | wait_shm_mmap = mmap(NULL, mmap_size, PROT_READ, | |
365 | MAP_SHARED, wait_shm_fd, 0); | |
366 | if (wait_shm_mmap == MAP_FAILED) { | |
367 | PERROR("mmap"); | |
368 | goto error; | |
369 | } | |
370 | /* close shm fd immediately after taking the mmap reference */ | |
371 | ret = close(wait_shm_fd); | |
372 | if (ret) { | |
373 | ERR("Error closing fd"); | |
374 | } | |
375 | return wait_shm_mmap; | |
376 | ||
377 | error: | |
378 | return NULL; | |
379 | } | |
380 | ||
381 | static | |
382 | void wait_for_sessiond(struct sock_info *sock_info) | |
383 | { | |
384 | ust_lock(); | |
385 | if (lttng_ust_comm_should_quit) { | |
386 | goto quit; | |
387 | } | |
388 | if (!sock_info->wait_shm_mmap) { | |
389 | sock_info->wait_shm_mmap = get_map_shm(sock_info); | |
390 | if (!sock_info->wait_shm_mmap) | |
391 | goto error; | |
392 | } | |
393 | ust_unlock(); | |
394 | ||
395 | DBG("Waiting for %s apps sessiond", sock_info->name); | |
396 | /* Wait for futex wakeup TODO */ | |
397 | sleep(5); | |
398 | ||
399 | return; | |
400 | ||
401 | quit: | |
402 | ust_unlock(); | |
403 | return; | |
404 | ||
405 | error: | |
406 | ust_unlock(); | |
407 | /* Error handling: fallback on a 5 seconds sleep. */ | |
408 | sleep(5); | |
409 | return; | |
46050b1a MD |
410 | } |
411 | ||
1ea11eab MD |
412 | /* |
413 | * This thread does not allocate any resource, except within | |
414 | * handle_message, within mutex protection. This mutex protects against | |
415 | * fork and exit. | |
416 | * The other moment it allocates resources is at socket connexion, which | |
417 | * is also protected by the mutex. | |
418 | */ | |
d9e99d10 MD |
419 | static |
420 | void *ust_listener_thread(void *arg) | |
421 | { | |
1ea11eab MD |
422 | struct sock_info *sock_info = arg; |
423 | int sock, ret; | |
d9e99d10 | 424 | |
9eb62b9c MD |
425 | /* Restart trying to connect to the session daemon */ |
426 | restart: | |
17dfb34b | 427 | ust_lock(); |
1ea11eab MD |
428 | |
429 | if (lttng_ust_comm_should_quit) { | |
17dfb34b | 430 | ust_unlock(); |
1ea11eab MD |
431 | goto quit; |
432 | } | |
9eb62b9c | 433 | |
1ea11eab MD |
434 | if (sock_info->socket != -1) { |
435 | ret = close(sock_info->socket); | |
436 | if (ret) { | |
11ff9c7d | 437 | ERR("Error closing %s apps socket", sock_info->name); |
1ea11eab MD |
438 | } |
439 | sock_info->socket = -1; | |
440 | } | |
46050b1a | 441 | |
9eb62b9c | 442 | /* Register */ |
1ea11eab | 443 | ret = lttcomm_connect_unix_sock(sock_info->sock_path); |
9eb62b9c | 444 | if (ret < 0) { |
11ff9c7d MD |
445 | ERR("Error connecting to %s apps socket", sock_info->name); |
446 | /* | |
447 | * If we cannot find the sessiond daemon, don't delay | |
448 | * constructor execution. | |
449 | */ | |
edaa1431 | 450 | ret = handle_register_done(sock_info); |
11ff9c7d | 451 | assert(!ret); |
17dfb34b | 452 | ust_unlock(); |
7fc90dca MD |
453 | |
454 | /* Wait for sessiond availability with pipe */ | |
455 | wait_for_sessiond(sock_info); | |
1ea11eab | 456 | goto restart; |
46050b1a MD |
457 | } |
458 | ||
459 | sock_info->socket = sock = ret; | |
460 | ||
461 | /* | |
462 | * Create only one root handle per listener thread for the whole | |
463 | * process lifetime. | |
464 | */ | |
465 | if (sock_info->root_handle == -1) { | |
466 | ret = lttng_abi_create_root_handle(); | |
467 | if (ret) { | |
468 | ERR("Error creating root handle"); | |
17dfb34b | 469 | ust_unlock(); |
46050b1a MD |
470 | goto quit; |
471 | } | |
472 | sock_info->root_handle = ret; | |
9eb62b9c | 473 | } |
1ea11eab | 474 | |
9eb62b9c MD |
475 | ret = register_app_to_sessiond(sock); |
476 | if (ret < 0) { | |
11ff9c7d MD |
477 | ERR("Error registering to %s apps socket", sock_info->name); |
478 | /* | |
479 | * If we cannot register to the sessiond daemon, don't | |
480 | * delay constructor execution. | |
481 | */ | |
edaa1431 | 482 | ret = handle_register_done(sock_info); |
11ff9c7d | 483 | assert(!ret); |
17dfb34b | 484 | ust_unlock(); |
7fc90dca | 485 | wait_for_sessiond(sock_info); |
9eb62b9c MD |
486 | goto restart; |
487 | } | |
17dfb34b | 488 | ust_unlock(); |
46050b1a | 489 | |
d9e99d10 MD |
490 | for (;;) { |
491 | ssize_t len; | |
e7723462 | 492 | struct lttcomm_ust_msg lum; |
d9e99d10 | 493 | |
e7723462 | 494 | len = lttcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
495 | switch (len) { |
496 | case 0: /* orderly shutdown */ | |
11ff9c7d | 497 | DBG("%s ltt-sessiond has performed an orderly shutdown\n", sock_info->name); |
d9e99d10 | 498 | goto end; |
e7723462 | 499 | case sizeof(lum): |
d9e99d10 | 500 | DBG("message received\n"); |
11ff9c7d | 501 | ret = handle_message(sock_info, sock, &lum); |
2a80c9d8 | 502 | if (ret < 0) { |
11ff9c7d | 503 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
504 | } |
505 | continue; | |
506 | case -1: | |
507 | if (errno == ECONNRESET) { | |
11ff9c7d | 508 | ERR("%s remote end closed connection\n", sock_info->name); |
d9e99d10 MD |
509 | goto end; |
510 | } | |
511 | goto end; | |
512 | default: | |
11ff9c7d | 513 | ERR("incorrect message size (%s socket): %zd\n", sock_info->name, len); |
d9e99d10 MD |
514 | continue; |
515 | } | |
516 | ||
517 | } | |
518 | end: | |
9eb62b9c | 519 | goto restart; /* try to reconnect */ |
1ea11eab | 520 | quit: |
d9e99d10 MD |
521 | return NULL; |
522 | } | |
523 | ||
cf12a773 MD |
524 | /* |
525 | * Return values: -1: don't wait. 0: wait forever. 1: timeout wait. | |
526 | */ | |
11ff9c7d MD |
527 | static |
528 | int get_timeout(struct timespec *constructor_timeout) | |
529 | { | |
cf12a773 MD |
530 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; |
531 | char *str_delay; | |
11ff9c7d MD |
532 | int ret; |
533 | ||
cf12a773 MD |
534 | str_delay = getenv("UST_REGISTER_TIMEOUT"); |
535 | if (str_delay) { | |
536 | constructor_delay_ms = strtol(str_delay, NULL, 10); | |
537 | } | |
538 | ||
539 | switch (constructor_delay_ms) { | |
540 | case -1:/* fall-through */ | |
541 | case 0: | |
542 | return constructor_delay_ms; | |
543 | default: | |
544 | break; | |
545 | } | |
546 | ||
547 | /* | |
548 | * If we are unable to find the current time, don't wait. | |
549 | */ | |
550 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
551 | if (ret) { | |
552 | return -1; | |
553 | } | |
95259bd0 MD |
554 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; |
555 | constructor_timeout->tv_nsec += | |
556 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
11ff9c7d MD |
557 | if (constructor_timeout->tv_nsec >= 1000000000UL) { |
558 | constructor_timeout->tv_sec++; | |
559 | constructor_timeout->tv_nsec -= 1000000000UL; | |
560 | } | |
cf12a773 | 561 | return 1; |
11ff9c7d | 562 | } |
d9e99d10 | 563 | |
2691221a MD |
564 | /* |
565 | * sessiond monitoring thread: monitor presence of global and per-user | |
566 | * sessiond by polling the application common named pipe. | |
567 | */ | |
568 | /* TODO */ | |
569 | ||
edaa1431 | 570 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 571 | { |
11ff9c7d | 572 | struct timespec constructor_timeout; |
cf12a773 | 573 | int timeout_mode; |
2691221a MD |
574 | int ret; |
575 | ||
edaa1431 MD |
576 | if (uatomic_xchg(&initialized, 1) == 1) |
577 | return; | |
578 | ||
579 | /* | |
580 | * We want precise control over the order in which we construct | |
581 | * our sub-libraries vs starting to receive commands from | |
582 | * sessiond (otherwise leading to errors when trying to create | |
583 | * sessiond before the init functions are completed). | |
584 | */ | |
2691221a | 585 | init_usterr(); |
edaa1431 MD |
586 | init_tracepoint(); |
587 | ltt_ring_buffer_metadata_client_init(); | |
588 | ltt_ring_buffer_client_overwrite_init(); | |
589 | ltt_ring_buffer_client_discard_init(); | |
2691221a | 590 | |
cf12a773 | 591 | timeout_mode = get_timeout(&constructor_timeout); |
11ff9c7d | 592 | |
95259bd0 | 593 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
594 | assert(!ret); |
595 | ||
8d20bf54 | 596 | ret = setup_local_apps(); |
2691221a | 597 | if (ret) { |
8d20bf54 | 598 | ERR("Error setting up to local apps"); |
2691221a | 599 | } |
1ea11eab MD |
600 | ret = pthread_create(&local_apps.ust_listener, NULL, |
601 | ust_listener_thread, &local_apps); | |
11ff9c7d | 602 | |
8d20bf54 MD |
603 | if (local_apps.allowed) { |
604 | ret = pthread_create(&global_apps.ust_listener, NULL, | |
605 | ust_listener_thread, &global_apps); | |
606 | } else { | |
607 | handle_register_done(&local_apps); | |
608 | } | |
609 | ||
cf12a773 MD |
610 | switch (timeout_mode) { |
611 | case 1: /* timeout wait */ | |
95259bd0 MD |
612 | do { |
613 | ret = sem_timedwait(&constructor_wait, | |
614 | &constructor_timeout); | |
615 | } while (ret < 0 && errno == EINTR); | |
cf12a773 MD |
616 | if (ret < 0 && errno == ETIMEDOUT) { |
617 | ERR("Timed out waiting for ltt-sessiond"); | |
618 | } else { | |
619 | assert(!ret); | |
620 | } | |
621 | break; | |
7b766b16 | 622 | case -1:/* wait forever */ |
95259bd0 MD |
623 | do { |
624 | ret = sem_wait(&constructor_wait); | |
625 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 626 | assert(!ret); |
cf12a773 | 627 | break; |
7b766b16 | 628 | case 0: /* no timeout */ |
cf12a773 | 629 | break; |
11ff9c7d | 630 | } |
2691221a MD |
631 | } |
632 | ||
17dfb34b MD |
633 | static |
634 | void lttng_ust_cleanup(int exiting) | |
635 | { | |
636 | cleanup_sock_info(&global_apps); | |
637 | if (local_apps.allowed) { | |
638 | cleanup_sock_info(&local_apps); | |
639 | } | |
640 | lttng_ust_abi_exit(); | |
641 | ltt_events_exit(); | |
642 | ltt_ring_buffer_client_discard_exit(); | |
643 | ltt_ring_buffer_client_overwrite_exit(); | |
644 | ltt_ring_buffer_metadata_client_exit(); | |
645 | exit_tracepoint(); | |
646 | if (!exiting) { | |
647 | /* Reinitialize values for fork */ | |
648 | sem_count = 2; | |
649 | lttng_ust_comm_should_quit = 0; | |
650 | initialized = 0; | |
651 | } | |
652 | } | |
653 | ||
edaa1431 | 654 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
655 | { |
656 | int ret; | |
657 | ||
9eb62b9c MD |
658 | /* |
659 | * Using pthread_cancel here because: | |
660 | * A) we don't want to hang application teardown. | |
661 | * B) the thread is not allocating any resource. | |
662 | */ | |
1ea11eab MD |
663 | |
664 | /* | |
665 | * Require the communication thread to quit. Synchronize with | |
666 | * mutexes to ensure it is not in a mutex critical section when | |
667 | * pthread_cancel is later called. | |
668 | */ | |
17dfb34b | 669 | ust_lock(); |
1ea11eab | 670 | lttng_ust_comm_should_quit = 1; |
17dfb34b | 671 | ust_unlock(); |
1ea11eab | 672 | |
1ea11eab | 673 | ret = pthread_cancel(global_apps.ust_listener); |
9eb62b9c MD |
674 | if (ret) { |
675 | ERR("Error cancelling global ust listener thread"); | |
2691221a | 676 | } |
8d20bf54 MD |
677 | if (local_apps.allowed) { |
678 | ret = pthread_cancel(local_apps.ust_listener); | |
679 | if (ret) { | |
680 | ERR("Error cancelling local ust listener thread"); | |
681 | } | |
8d20bf54 | 682 | } |
17dfb34b | 683 | lttng_ust_cleanup(1); |
2691221a | 684 | } |
e822f505 MD |
685 | |
686 | /* | |
687 | * We exclude the worker threads across fork and clone (except | |
688 | * CLONE_VM), because these system calls only keep the forking thread | |
689 | * running in the child. Therefore, we don't want to call fork or clone | |
690 | * in the middle of an tracepoint or ust tracing state modification. | |
691 | * Holding this mutex protects these structures across fork and clone. | |
692 | */ | |
693 | void ust_before_fork(ust_fork_info_t *fork_info) | |
694 | { | |
695 | /* | |
696 | * Disable signals. This is to avoid that the child intervenes | |
697 | * before it is properly setup for tracing. It is safer to | |
698 | * disable all signals, because then we know we are not breaking | |
699 | * anything by restoring the original mask. | |
700 | */ | |
701 | sigset_t all_sigs; | |
702 | int ret; | |
703 | ||
704 | /* Disable signals */ | |
705 | sigfillset(&all_sigs); | |
706 | ret = sigprocmask(SIG_BLOCK, &all_sigs, &fork_info->orig_sigs); | |
707 | if (ret == -1) { | |
708 | PERROR("sigprocmask"); | |
709 | } | |
17dfb34b | 710 | ust_lock(); |
e822f505 MD |
711 | rcu_bp_before_fork(); |
712 | } | |
713 | ||
714 | static void ust_after_fork_common(ust_fork_info_t *fork_info) | |
715 | { | |
716 | int ret; | |
717 | ||
17dfb34b MD |
718 | DBG("process %d", getpid()); |
719 | ust_unlock(); | |
e822f505 MD |
720 | /* Restore signals */ |
721 | ret = sigprocmask(SIG_SETMASK, &fork_info->orig_sigs, NULL); | |
722 | if (ret == -1) { | |
723 | PERROR("sigprocmask"); | |
724 | } | |
725 | } | |
726 | ||
727 | void ust_after_fork_parent(ust_fork_info_t *fork_info) | |
728 | { | |
17dfb34b | 729 | DBG("process %d", getpid()); |
e822f505 MD |
730 | rcu_bp_after_fork_parent(); |
731 | /* Release mutexes and reenable signals */ | |
732 | ust_after_fork_common(fork_info); | |
733 | } | |
734 | ||
17dfb34b MD |
735 | /* |
736 | * After fork, in the child, we need to cleanup all the leftover state, | |
737 | * except the worker thread which already magically disappeared thanks | |
738 | * to the weird Linux fork semantics. After tyding up, we call | |
739 | * lttng_ust_init() again to start over as a new PID. | |
740 | * | |
741 | * This is meant for forks() that have tracing in the child between the | |
742 | * fork and following exec call (if there is any). | |
743 | */ | |
e822f505 MD |
744 | void ust_after_fork_child(ust_fork_info_t *fork_info) |
745 | { | |
17dfb34b | 746 | DBG("process %d", getpid()); |
e822f505 MD |
747 | /* Release urcu mutexes */ |
748 | rcu_bp_after_fork_child(); | |
17dfb34b | 749 | lttng_ust_cleanup(0); |
e822f505 MD |
750 | /* Release mutexes and reenable signals */ |
751 | ust_after_fork_common(fork_info); | |
318dfea9 | 752 | lttng_ust_init(); |
e822f505 | 753 | } |