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; | |
44e073f5 | 84 | int global; |
7fc90dca MD |
85 | |
86 | char sock_path[PATH_MAX]; | |
87 | int socket; | |
88 | ||
89 | char wait_shm_path[PATH_MAX]; | |
90 | char *wait_shm_mmap; | |
1ea11eab | 91 | }; |
2691221a MD |
92 | |
93 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 94 | struct sock_info global_apps = { |
11ff9c7d | 95 | .name = "global", |
44e073f5 | 96 | .global = 1, |
7fc90dca | 97 | |
46050b1a | 98 | .root_handle = -1, |
8d20bf54 | 99 | .allowed = 1, |
7fc90dca MD |
100 | |
101 | .sock_path = DEFAULT_GLOBAL_APPS_UNIX_SOCK, | |
102 | .socket = -1, | |
103 | ||
104 | .wait_shm_path = DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH, | |
1ea11eab | 105 | }; |
2691221a MD |
106 | |
107 | /* TODO: allow global_apps_sock_path override */ | |
108 | ||
1ea11eab | 109 | struct sock_info local_apps = { |
11ff9c7d | 110 | .name = "local", |
44e073f5 | 111 | .global = 0, |
46050b1a | 112 | .root_handle = -1, |
8d20bf54 | 113 | .allowed = 0, /* Check setuid bit first */ |
7fc90dca MD |
114 | |
115 | .socket = -1, | |
1ea11eab | 116 | }; |
2691221a | 117 | |
edaa1431 MD |
118 | extern void ltt_ring_buffer_client_overwrite_init(void); |
119 | extern void ltt_ring_buffer_client_discard_init(void); | |
120 | extern void ltt_ring_buffer_metadata_client_init(void); | |
121 | extern void ltt_ring_buffer_client_overwrite_exit(void); | |
122 | extern void ltt_ring_buffer_client_discard_exit(void); | |
123 | extern void ltt_ring_buffer_metadata_client_exit(void); | |
124 | ||
2691221a | 125 | static |
8d20bf54 | 126 | int setup_local_apps(void) |
2691221a MD |
127 | { |
128 | const char *home_dir; | |
7fc90dca | 129 | uid_t uid; |
2691221a | 130 | |
7fc90dca | 131 | uid = getuid(); |
8d20bf54 MD |
132 | /* |
133 | * Disallow per-user tracing for setuid binaries. | |
134 | */ | |
7fc90dca | 135 | if (uid != geteuid()) { |
8d20bf54 | 136 | local_apps.allowed = 0; |
d0a1ae63 | 137 | return 0; |
8d20bf54 MD |
138 | } else { |
139 | local_apps.allowed = 1; | |
140 | } | |
2691221a MD |
141 | home_dir = (const char *) getenv("HOME"); |
142 | if (!home_dir) | |
143 | return -ENOENT; | |
1ea11eab | 144 | snprintf(local_apps.sock_path, PATH_MAX, |
2691221a | 145 | DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); |
7fc90dca MD |
146 | snprintf(local_apps.wait_shm_path, PATH_MAX, |
147 | DEFAULT_HOME_APPS_WAIT_SHM_PATH, uid); | |
2691221a MD |
148 | return 0; |
149 | } | |
150 | ||
151 | static | |
152 | int register_app_to_sessiond(int socket) | |
153 | { | |
154 | ssize_t ret; | |
2629549e | 155 | int prctl_ret; |
2691221a | 156 | struct { |
e44418f3 MD |
157 | uint32_t major; |
158 | uint32_t minor; | |
2691221a | 159 | pid_t pid; |
5c33bde8 | 160 | pid_t ppid; |
2691221a | 161 | uid_t uid; |
83610856 | 162 | gid_t gid; |
2629549e | 163 | char name[16]; /* process name */ |
2691221a MD |
164 | } reg_msg; |
165 | ||
e44418f3 MD |
166 | reg_msg.major = LTTNG_UST_COMM_VERSION_MAJOR; |
167 | reg_msg.minor = LTTNG_UST_COMM_VERSION_MINOR; | |
2691221a | 168 | reg_msg.pid = getpid(); |
5c33bde8 | 169 | reg_msg.ppid = getppid(); |
2691221a | 170 | reg_msg.uid = getuid(); |
83610856 | 171 | reg_msg.gid = getgid(); |
2629549e MD |
172 | prctl_ret = prctl(PR_GET_NAME, (unsigned long) reg_msg.name, 0, 0, 0); |
173 | if (prctl_ret) { | |
174 | ERR("Error executing prctl"); | |
175 | return -errno; | |
176 | } | |
2691221a MD |
177 | |
178 | ret = lttcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg)); | |
179 | if (ret >= 0 && ret != sizeof(reg_msg)) | |
180 | return -EIO; | |
181 | return ret; | |
182 | } | |
183 | ||
d9e99d10 | 184 | static |
d3a492d1 | 185 | int send_reply(int sock, struct lttcomm_ust_reply *lur) |
d9e99d10 | 186 | { |
9eb62b9c | 187 | ssize_t len; |
d3a492d1 | 188 | |
a4be8962 | 189 | len = lttcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 190 | switch (len) { |
a4be8962 | 191 | case sizeof(*lur): |
d3a492d1 MD |
192 | DBG("message successfully sent"); |
193 | return 0; | |
194 | case -1: | |
195 | if (errno == ECONNRESET) { | |
196 | printf("remote end closed connection\n"); | |
197 | return 0; | |
198 | } | |
199 | return -1; | |
200 | default: | |
201 | printf("incorrect message size: %zd\n", len); | |
202 | return -1; | |
203 | } | |
204 | } | |
205 | ||
206 | static | |
edaa1431 | 207 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
208 | { |
209 | int ret; | |
210 | ||
edaa1431 MD |
211 | if (sock_info->constructor_sem_posted) |
212 | return 0; | |
213 | sock_info->constructor_sem_posted = 1; | |
95259bd0 MD |
214 | ret = uatomic_add_return(&sem_count, -1); |
215 | if (ret == 0) { | |
216 | ret = sem_post(&constructor_wait); | |
217 | assert(!ret); | |
218 | } | |
11ff9c7d MD |
219 | return 0; |
220 | } | |
221 | ||
222 | static | |
223 | int handle_message(struct sock_info *sock_info, | |
224 | int sock, struct lttcomm_ust_msg *lum) | |
d3a492d1 | 225 | { |
1ea11eab | 226 | int ret = 0; |
46050b1a MD |
227 | const struct objd_ops *ops; |
228 | struct lttcomm_ust_reply lur; | |
1ea11eab | 229 | |
17dfb34b | 230 | ust_lock(); |
1ea11eab | 231 | |
46050b1a MD |
232 | memset(&lur, 0, sizeof(lur)); |
233 | ||
1ea11eab | 234 | if (lttng_ust_comm_should_quit) { |
46050b1a | 235 | ret = -EPERM; |
1ea11eab MD |
236 | goto end; |
237 | } | |
9eb62b9c | 238 | |
46050b1a MD |
239 | ops = objd_ops(lum->handle); |
240 | if (!ops) { | |
241 | ret = -ENOENT; | |
242 | goto end; | |
1ea11eab | 243 | } |
46050b1a MD |
244 | |
245 | switch (lum->cmd) { | |
11ff9c7d MD |
246 | case LTTNG_UST_REGISTER_DONE: |
247 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 248 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
249 | else |
250 | ret = -EINVAL; | |
251 | break; | |
46050b1a MD |
252 | case LTTNG_UST_RELEASE: |
253 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
254 | ret = -EPERM; | |
255 | else | |
256 | ret = objd_unref(lum->handle); | |
d9e99d10 MD |
257 | break; |
258 | default: | |
46050b1a MD |
259 | if (ops->cmd) |
260 | ret = ops->cmd(lum->handle, lum->cmd, | |
261 | (unsigned long) &lum->u); | |
262 | else | |
263 | ret = -ENOSYS; | |
264 | break; | |
d9e99d10 | 265 | } |
46050b1a | 266 | |
1ea11eab | 267 | end: |
46050b1a MD |
268 | lur.handle = lum->handle; |
269 | lur.cmd = lum->cmd; | |
270 | lur.ret_val = ret; | |
271 | if (ret >= 0) { | |
272 | lur.ret_code = LTTCOMM_OK; | |
273 | } else { | |
274 | lur.ret_code = LTTCOMM_SESSION_FAIL; | |
275 | } | |
276 | ret = send_reply(sock, &lur); | |
277 | ||
17dfb34b | 278 | ust_unlock(); |
1ea11eab | 279 | return ret; |
d9e99d10 MD |
280 | } |
281 | ||
46050b1a MD |
282 | static |
283 | void cleanup_sock_info(struct sock_info *sock_info) | |
284 | { | |
285 | int ret; | |
286 | ||
287 | if (sock_info->socket != -1) { | |
288 | ret = close(sock_info->socket); | |
289 | if (ret) { | |
7fc90dca | 290 | ERR("Error closing apps socket"); |
46050b1a MD |
291 | } |
292 | sock_info->socket = -1; | |
293 | } | |
294 | if (sock_info->root_handle != -1) { | |
295 | ret = objd_unref(sock_info->root_handle); | |
296 | if (ret) { | |
297 | ERR("Error unref root handle"); | |
298 | } | |
299 | sock_info->root_handle = -1; | |
300 | } | |
318dfea9 | 301 | sock_info->constructor_sem_posted = 0; |
7fc90dca MD |
302 | if (sock_info->wait_shm_mmap) { |
303 | ret = munmap(sock_info->wait_shm_mmap, sysconf(_SC_PAGE_SIZE)); | |
304 | if (ret) { | |
305 | ERR("Error unmapping wait shm"); | |
306 | } | |
307 | sock_info->wait_shm_mmap = NULL; | |
308 | } | |
309 | } | |
310 | ||
311 | static | |
312 | char *get_map_shm(struct sock_info *sock_info) | |
313 | { | |
314 | size_t mmap_size = sysconf(_SC_PAGE_SIZE); | |
315 | int wait_shm_fd, ret; | |
316 | char *wait_shm_mmap; | |
44e073f5 MD |
317 | int mode; |
318 | ||
319 | mode = S_IRUSR | S_IRGRP; | |
320 | if (sock_info->global) | |
321 | mode |= S_IROTH; | |
7fc90dca MD |
322 | |
323 | /* | |
324 | * Get existing (read-only) shm, or open new shm. | |
325 | * First try to open read-only. | |
326 | */ | |
327 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
44e073f5 | 328 | O_RDONLY, mode); |
7fc90dca MD |
329 | if (wait_shm_fd >= 0) |
330 | goto got_shm; | |
331 | /* | |
332 | * Real-only open did not work. If it is because it did | |
333 | * not exist, try creating it. Else it's a failure that | |
334 | * prohibits using shm. | |
335 | */ | |
336 | if (errno != ENOENT) { | |
337 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
338 | goto error; | |
339 | } | |
340 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
44e073f5 | 341 | O_RDWR | O_CREAT | O_EXCL, mode | S_IWUSR); |
7fc90dca MD |
342 | if (wait_shm_fd >= 0) |
343 | goto created_shm; | |
344 | if (errno != EEXIST) { | |
345 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
346 | goto error; | |
347 | } | |
348 | /* | |
349 | * If another process beat us to create the shm, we are | |
350 | * pretty certain the shm is available for us in | |
351 | * read-only mode. | |
352 | */ | |
353 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
44e073f5 | 354 | O_RDWR | O_CREAT | O_EXCL, mode); |
7fc90dca MD |
355 | if (wait_shm_fd >= 0) |
356 | goto got_shm; | |
357 | else | |
358 | goto error; | |
359 | ||
360 | created_shm: | |
361 | ret = ftruncate(wait_shm_fd, mmap_size); | |
362 | if (ret) { | |
363 | PERROR("ftruncate"); | |
364 | ret = close(wait_shm_fd); | |
365 | if (ret) { | |
366 | ERR("Error closing fd"); | |
367 | } | |
368 | wait_shm_fd = -1; | |
369 | goto error; | |
370 | } | |
44e073f5 MD |
371 | /* Drop write access ASAP */ |
372 | ret = chmod(sock_info->wait_shm_path, mode); | |
373 | if (ret) { | |
374 | PERROR("chmod"); | |
375 | } | |
7fc90dca MD |
376 | got_shm: |
377 | wait_shm_mmap = mmap(NULL, mmap_size, PROT_READ, | |
378 | MAP_SHARED, wait_shm_fd, 0); | |
379 | if (wait_shm_mmap == MAP_FAILED) { | |
380 | PERROR("mmap"); | |
381 | goto error; | |
382 | } | |
383 | /* close shm fd immediately after taking the mmap reference */ | |
384 | ret = close(wait_shm_fd); | |
385 | if (ret) { | |
386 | ERR("Error closing fd"); | |
387 | } | |
388 | return wait_shm_mmap; | |
389 | ||
390 | error: | |
391 | return NULL; | |
392 | } | |
393 | ||
394 | static | |
395 | void wait_for_sessiond(struct sock_info *sock_info) | |
396 | { | |
397 | ust_lock(); | |
398 | if (lttng_ust_comm_should_quit) { | |
399 | goto quit; | |
400 | } | |
401 | if (!sock_info->wait_shm_mmap) { | |
402 | sock_info->wait_shm_mmap = get_map_shm(sock_info); | |
403 | if (!sock_info->wait_shm_mmap) | |
404 | goto error; | |
405 | } | |
406 | ust_unlock(); | |
407 | ||
408 | DBG("Waiting for %s apps sessiond", sock_info->name); | |
409 | /* Wait for futex wakeup TODO */ | |
410 | sleep(5); | |
411 | ||
412 | return; | |
413 | ||
414 | quit: | |
415 | ust_unlock(); | |
416 | return; | |
417 | ||
418 | error: | |
419 | ust_unlock(); | |
420 | /* Error handling: fallback on a 5 seconds sleep. */ | |
421 | sleep(5); | |
422 | return; | |
46050b1a MD |
423 | } |
424 | ||
1ea11eab MD |
425 | /* |
426 | * This thread does not allocate any resource, except within | |
427 | * handle_message, within mutex protection. This mutex protects against | |
428 | * fork and exit. | |
429 | * The other moment it allocates resources is at socket connexion, which | |
430 | * is also protected by the mutex. | |
431 | */ | |
d9e99d10 MD |
432 | static |
433 | void *ust_listener_thread(void *arg) | |
434 | { | |
1ea11eab MD |
435 | struct sock_info *sock_info = arg; |
436 | int sock, ret; | |
d9e99d10 | 437 | |
9eb62b9c MD |
438 | /* Restart trying to connect to the session daemon */ |
439 | restart: | |
17dfb34b | 440 | ust_lock(); |
1ea11eab MD |
441 | |
442 | if (lttng_ust_comm_should_quit) { | |
17dfb34b | 443 | ust_unlock(); |
1ea11eab MD |
444 | goto quit; |
445 | } | |
9eb62b9c | 446 | |
1ea11eab MD |
447 | if (sock_info->socket != -1) { |
448 | ret = close(sock_info->socket); | |
449 | if (ret) { | |
11ff9c7d | 450 | ERR("Error closing %s apps socket", sock_info->name); |
1ea11eab MD |
451 | } |
452 | sock_info->socket = -1; | |
453 | } | |
46050b1a | 454 | |
9eb62b9c | 455 | /* Register */ |
1ea11eab | 456 | ret = lttcomm_connect_unix_sock(sock_info->sock_path); |
9eb62b9c | 457 | if (ret < 0) { |
11ff9c7d MD |
458 | ERR("Error connecting to %s apps socket", sock_info->name); |
459 | /* | |
460 | * If we cannot find the sessiond daemon, don't delay | |
461 | * constructor execution. | |
462 | */ | |
edaa1431 | 463 | ret = handle_register_done(sock_info); |
11ff9c7d | 464 | assert(!ret); |
17dfb34b | 465 | ust_unlock(); |
7fc90dca MD |
466 | |
467 | /* Wait for sessiond availability with pipe */ | |
468 | wait_for_sessiond(sock_info); | |
1ea11eab | 469 | goto restart; |
46050b1a MD |
470 | } |
471 | ||
472 | sock_info->socket = sock = ret; | |
473 | ||
474 | /* | |
475 | * Create only one root handle per listener thread for the whole | |
476 | * process lifetime. | |
477 | */ | |
478 | if (sock_info->root_handle == -1) { | |
479 | ret = lttng_abi_create_root_handle(); | |
480 | if (ret) { | |
481 | ERR("Error creating root handle"); | |
17dfb34b | 482 | ust_unlock(); |
46050b1a MD |
483 | goto quit; |
484 | } | |
485 | sock_info->root_handle = ret; | |
9eb62b9c | 486 | } |
1ea11eab | 487 | |
9eb62b9c MD |
488 | ret = register_app_to_sessiond(sock); |
489 | if (ret < 0) { | |
11ff9c7d MD |
490 | ERR("Error registering to %s apps socket", sock_info->name); |
491 | /* | |
492 | * If we cannot register to the sessiond daemon, don't | |
493 | * delay constructor execution. | |
494 | */ | |
edaa1431 | 495 | ret = handle_register_done(sock_info); |
11ff9c7d | 496 | assert(!ret); |
17dfb34b | 497 | ust_unlock(); |
7fc90dca | 498 | wait_for_sessiond(sock_info); |
9eb62b9c MD |
499 | goto restart; |
500 | } | |
17dfb34b | 501 | ust_unlock(); |
46050b1a | 502 | |
d9e99d10 MD |
503 | for (;;) { |
504 | ssize_t len; | |
e7723462 | 505 | struct lttcomm_ust_msg lum; |
d9e99d10 | 506 | |
e7723462 | 507 | len = lttcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
508 | switch (len) { |
509 | case 0: /* orderly shutdown */ | |
11ff9c7d | 510 | DBG("%s ltt-sessiond has performed an orderly shutdown\n", sock_info->name); |
d9e99d10 | 511 | goto end; |
e7723462 | 512 | case sizeof(lum): |
d9e99d10 | 513 | DBG("message received\n"); |
11ff9c7d | 514 | ret = handle_message(sock_info, sock, &lum); |
2a80c9d8 | 515 | if (ret < 0) { |
11ff9c7d | 516 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
517 | } |
518 | continue; | |
519 | case -1: | |
520 | if (errno == ECONNRESET) { | |
11ff9c7d | 521 | ERR("%s remote end closed connection\n", sock_info->name); |
d9e99d10 MD |
522 | goto end; |
523 | } | |
524 | goto end; | |
525 | default: | |
11ff9c7d | 526 | ERR("incorrect message size (%s socket): %zd\n", sock_info->name, len); |
d9e99d10 MD |
527 | continue; |
528 | } | |
529 | ||
530 | } | |
531 | end: | |
9eb62b9c | 532 | goto restart; /* try to reconnect */ |
1ea11eab | 533 | quit: |
d9e99d10 MD |
534 | return NULL; |
535 | } | |
536 | ||
cf12a773 MD |
537 | /* |
538 | * Return values: -1: don't wait. 0: wait forever. 1: timeout wait. | |
539 | */ | |
11ff9c7d MD |
540 | static |
541 | int get_timeout(struct timespec *constructor_timeout) | |
542 | { | |
cf12a773 MD |
543 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; |
544 | char *str_delay; | |
11ff9c7d MD |
545 | int ret; |
546 | ||
cf12a773 MD |
547 | str_delay = getenv("UST_REGISTER_TIMEOUT"); |
548 | if (str_delay) { | |
549 | constructor_delay_ms = strtol(str_delay, NULL, 10); | |
550 | } | |
551 | ||
552 | switch (constructor_delay_ms) { | |
553 | case -1:/* fall-through */ | |
554 | case 0: | |
555 | return constructor_delay_ms; | |
556 | default: | |
557 | break; | |
558 | } | |
559 | ||
560 | /* | |
561 | * If we are unable to find the current time, don't wait. | |
562 | */ | |
563 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
564 | if (ret) { | |
565 | return -1; | |
566 | } | |
95259bd0 MD |
567 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; |
568 | constructor_timeout->tv_nsec += | |
569 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
11ff9c7d MD |
570 | if (constructor_timeout->tv_nsec >= 1000000000UL) { |
571 | constructor_timeout->tv_sec++; | |
572 | constructor_timeout->tv_nsec -= 1000000000UL; | |
573 | } | |
cf12a773 | 574 | return 1; |
11ff9c7d | 575 | } |
d9e99d10 | 576 | |
2691221a MD |
577 | /* |
578 | * sessiond monitoring thread: monitor presence of global and per-user | |
579 | * sessiond by polling the application common named pipe. | |
580 | */ | |
581 | /* TODO */ | |
582 | ||
edaa1431 | 583 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 584 | { |
11ff9c7d | 585 | struct timespec constructor_timeout; |
cf12a773 | 586 | int timeout_mode; |
2691221a MD |
587 | int ret; |
588 | ||
edaa1431 MD |
589 | if (uatomic_xchg(&initialized, 1) == 1) |
590 | return; | |
591 | ||
592 | /* | |
593 | * We want precise control over the order in which we construct | |
594 | * our sub-libraries vs starting to receive commands from | |
595 | * sessiond (otherwise leading to errors when trying to create | |
596 | * sessiond before the init functions are completed). | |
597 | */ | |
2691221a | 598 | init_usterr(); |
edaa1431 MD |
599 | init_tracepoint(); |
600 | ltt_ring_buffer_metadata_client_init(); | |
601 | ltt_ring_buffer_client_overwrite_init(); | |
602 | ltt_ring_buffer_client_discard_init(); | |
2691221a | 603 | |
cf12a773 | 604 | timeout_mode = get_timeout(&constructor_timeout); |
11ff9c7d | 605 | |
95259bd0 | 606 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
607 | assert(!ret); |
608 | ||
8d20bf54 | 609 | ret = setup_local_apps(); |
2691221a | 610 | if (ret) { |
8d20bf54 | 611 | ERR("Error setting up to local apps"); |
2691221a | 612 | } |
1ea11eab MD |
613 | ret = pthread_create(&local_apps.ust_listener, NULL, |
614 | ust_listener_thread, &local_apps); | |
11ff9c7d | 615 | |
8d20bf54 MD |
616 | if (local_apps.allowed) { |
617 | ret = pthread_create(&global_apps.ust_listener, NULL, | |
618 | ust_listener_thread, &global_apps); | |
619 | } else { | |
620 | handle_register_done(&local_apps); | |
621 | } | |
622 | ||
cf12a773 MD |
623 | switch (timeout_mode) { |
624 | case 1: /* timeout wait */ | |
95259bd0 MD |
625 | do { |
626 | ret = sem_timedwait(&constructor_wait, | |
627 | &constructor_timeout); | |
628 | } while (ret < 0 && errno == EINTR); | |
cf12a773 MD |
629 | if (ret < 0 && errno == ETIMEDOUT) { |
630 | ERR("Timed out waiting for ltt-sessiond"); | |
631 | } else { | |
632 | assert(!ret); | |
633 | } | |
634 | break; | |
7b766b16 | 635 | case -1:/* wait forever */ |
95259bd0 MD |
636 | do { |
637 | ret = sem_wait(&constructor_wait); | |
638 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 639 | assert(!ret); |
cf12a773 | 640 | break; |
7b766b16 | 641 | case 0: /* no timeout */ |
cf12a773 | 642 | break; |
11ff9c7d | 643 | } |
2691221a MD |
644 | } |
645 | ||
17dfb34b MD |
646 | static |
647 | void lttng_ust_cleanup(int exiting) | |
648 | { | |
649 | cleanup_sock_info(&global_apps); | |
650 | if (local_apps.allowed) { | |
651 | cleanup_sock_info(&local_apps); | |
652 | } | |
653 | lttng_ust_abi_exit(); | |
654 | ltt_events_exit(); | |
655 | ltt_ring_buffer_client_discard_exit(); | |
656 | ltt_ring_buffer_client_overwrite_exit(); | |
657 | ltt_ring_buffer_metadata_client_exit(); | |
658 | exit_tracepoint(); | |
659 | if (!exiting) { | |
660 | /* Reinitialize values for fork */ | |
661 | sem_count = 2; | |
662 | lttng_ust_comm_should_quit = 0; | |
663 | initialized = 0; | |
664 | } | |
665 | } | |
666 | ||
edaa1431 | 667 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
668 | { |
669 | int ret; | |
670 | ||
9eb62b9c MD |
671 | /* |
672 | * Using pthread_cancel here because: | |
673 | * A) we don't want to hang application teardown. | |
674 | * B) the thread is not allocating any resource. | |
675 | */ | |
1ea11eab MD |
676 | |
677 | /* | |
678 | * Require the communication thread to quit. Synchronize with | |
679 | * mutexes to ensure it is not in a mutex critical section when | |
680 | * pthread_cancel is later called. | |
681 | */ | |
17dfb34b | 682 | ust_lock(); |
1ea11eab | 683 | lttng_ust_comm_should_quit = 1; |
17dfb34b | 684 | ust_unlock(); |
1ea11eab | 685 | |
1ea11eab | 686 | ret = pthread_cancel(global_apps.ust_listener); |
9eb62b9c MD |
687 | if (ret) { |
688 | ERR("Error cancelling global ust listener thread"); | |
2691221a | 689 | } |
8d20bf54 MD |
690 | if (local_apps.allowed) { |
691 | ret = pthread_cancel(local_apps.ust_listener); | |
692 | if (ret) { | |
693 | ERR("Error cancelling local ust listener thread"); | |
694 | } | |
8d20bf54 | 695 | } |
17dfb34b | 696 | lttng_ust_cleanup(1); |
2691221a | 697 | } |
e822f505 MD |
698 | |
699 | /* | |
700 | * We exclude the worker threads across fork and clone (except | |
701 | * CLONE_VM), because these system calls only keep the forking thread | |
702 | * running in the child. Therefore, we don't want to call fork or clone | |
703 | * in the middle of an tracepoint or ust tracing state modification. | |
704 | * Holding this mutex protects these structures across fork and clone. | |
705 | */ | |
706 | void ust_before_fork(ust_fork_info_t *fork_info) | |
707 | { | |
708 | /* | |
709 | * Disable signals. This is to avoid that the child intervenes | |
710 | * before it is properly setup for tracing. It is safer to | |
711 | * disable all signals, because then we know we are not breaking | |
712 | * anything by restoring the original mask. | |
713 | */ | |
714 | sigset_t all_sigs; | |
715 | int ret; | |
716 | ||
717 | /* Disable signals */ | |
718 | sigfillset(&all_sigs); | |
719 | ret = sigprocmask(SIG_BLOCK, &all_sigs, &fork_info->orig_sigs); | |
720 | if (ret == -1) { | |
721 | PERROR("sigprocmask"); | |
722 | } | |
17dfb34b | 723 | ust_lock(); |
e822f505 MD |
724 | rcu_bp_before_fork(); |
725 | } | |
726 | ||
727 | static void ust_after_fork_common(ust_fork_info_t *fork_info) | |
728 | { | |
729 | int ret; | |
730 | ||
17dfb34b MD |
731 | DBG("process %d", getpid()); |
732 | ust_unlock(); | |
e822f505 MD |
733 | /* Restore signals */ |
734 | ret = sigprocmask(SIG_SETMASK, &fork_info->orig_sigs, NULL); | |
735 | if (ret == -1) { | |
736 | PERROR("sigprocmask"); | |
737 | } | |
738 | } | |
739 | ||
740 | void ust_after_fork_parent(ust_fork_info_t *fork_info) | |
741 | { | |
17dfb34b | 742 | DBG("process %d", getpid()); |
e822f505 MD |
743 | rcu_bp_after_fork_parent(); |
744 | /* Release mutexes and reenable signals */ | |
745 | ust_after_fork_common(fork_info); | |
746 | } | |
747 | ||
17dfb34b MD |
748 | /* |
749 | * After fork, in the child, we need to cleanup all the leftover state, | |
750 | * except the worker thread which already magically disappeared thanks | |
751 | * to the weird Linux fork semantics. After tyding up, we call | |
752 | * lttng_ust_init() again to start over as a new PID. | |
753 | * | |
754 | * This is meant for forks() that have tracing in the child between the | |
755 | * fork and following exec call (if there is any). | |
756 | */ | |
e822f505 MD |
757 | void ust_after_fork_child(ust_fork_info_t *fork_info) |
758 | { | |
17dfb34b | 759 | DBG("process %d", getpid()); |
e822f505 MD |
760 | /* Release urcu mutexes */ |
761 | rcu_bp_after_fork_child(); | |
17dfb34b | 762 | lttng_ust_cleanup(0); |
e822f505 MD |
763 | /* Release mutexes and reenable signals */ |
764 | ust_after_fork_common(fork_info); | |
318dfea9 | 765 | lttng_ust_init(); |
e822f505 | 766 | } |