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 | ||
80e2814b | 22 | #define _LGPL_SOURCE |
5e1b7b8b | 23 | #define _GNU_SOURCE |
2691221a MD |
24 | #include <sys/types.h> |
25 | #include <sys/socket.h> | |
7fc90dca MD |
26 | #include <sys/mman.h> |
27 | #include <sys/stat.h> | |
58d4b2a2 MD |
28 | #include <sys/types.h> |
29 | #include <sys/wait.h> | |
7fc90dca | 30 | #include <fcntl.h> |
2691221a MD |
31 | #include <unistd.h> |
32 | #include <errno.h> | |
d9e99d10 | 33 | #include <pthread.h> |
11ff9c7d MD |
34 | #include <semaphore.h> |
35 | #include <time.h> | |
1ea11eab | 36 | #include <assert.h> |
e822f505 | 37 | #include <signal.h> |
95259bd0 | 38 | #include <urcu/uatomic.h> |
80e2814b | 39 | #include <urcu/futex.h> |
c117fb1b | 40 | #include <urcu/compiler.h> |
1ea11eab | 41 | |
4318ae1b | 42 | #include <lttng/ust-events.h> |
4318ae1b | 43 | #include <lttng/ust-abi.h> |
4318ae1b | 44 | #include <lttng/ust.h> |
7bc53e94 | 45 | #include <lttng/ust-error.h> |
74d81a6c | 46 | #include <lttng/ust-ctl.h> |
8c90a710 | 47 | #include <urcu/tls-compat.h> |
44c72f10 | 48 | #include <ust-comm.h> |
6548fca4 | 49 | #include <ust-fd.h> |
44c72f10 | 50 | #include <usterr-signal-safe.h> |
cd54f6d9 | 51 | #include <helper.h> |
44c72f10 | 52 | #include "tracepoint-internal.h" |
7dd08bec | 53 | #include "lttng-tracer-core.h" |
08114193 | 54 | #include "compat.h" |
f645cfa7 | 55 | #include "../libringbuffer/tlsfixup.h" |
cf73e0fe | 56 | #include "lttng-ust-statedump.h" |
f9364363 | 57 | #include "clock.h" |
5e1b7b8b | 58 | #include "../libringbuffer/getcpu.h" |
13efba44 | 59 | #include "getenv.h" |
edaa1431 MD |
60 | |
61 | /* | |
62 | * Has lttng ust comm constructor been called ? | |
63 | */ | |
64 | static int initialized; | |
65 | ||
1ea11eab | 66 | /* |
17dfb34b MD |
67 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
68 | * Held when handling a command, also held by fork() to deal with | |
69 | * removal of threads, and by exit path. | |
3327ac33 MD |
70 | * |
71 | * The UST lock is the centralized mutex across UST tracing control and | |
72 | * probe registration. | |
73 | * | |
74 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 75 | * |
4770bd47 MD |
76 | * ust_fork_mutex must never nest in ust_mutex. |
77 | * | |
d58d1454 MD |
78 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
79 | * counter lazy initialization called by events within the statedump, | |
80 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
81 | * |
82 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
83 | * it is taken within the library constructor. | |
3327ac33 MD |
84 | */ |
85 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
86 | ||
d58d1454 MD |
87 | /* Allow nesting the ust_mutex within the same thread. */ |
88 | static DEFINE_URCU_TLS(int, ust_mutex_nest); | |
89 | ||
3327ac33 MD |
90 | /* |
91 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
92 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
93 | * internal libc lock, cannot nest within ust_mutex. | |
94 | * | |
95 | * It never nests within a ust_mutex. | |
1ea11eab | 96 | */ |
3327ac33 | 97 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 98 | |
458d678c PW |
99 | /* |
100 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
101 | * prevents the dynamic loader lock to be taken (by base address statedump | |
102 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
103 | * the dynamic loader lock. | |
104 | */ | |
105 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
106 | ||
1ea11eab MD |
107 | /* Should the ust comm thread quit ? */ |
108 | static int lttng_ust_comm_should_quit; | |
109 | ||
07b57e5e MD |
110 | /* |
111 | * This variable can be tested by applications to check whether | |
112 | * lttng-ust is loaded. They simply have to define their own | |
113 | * "lttng_ust_loaded" weak symbol, and test it. It is set to 1 by the | |
114 | * library constructor. | |
115 | */ | |
116 | int lttng_ust_loaded __attribute__((weak)); | |
117 | ||
3327ac33 | 118 | /* |
d58d1454 | 119 | * Return 0 on success, -1 if should quit. |
3327ac33 | 120 | * The lock is taken in both cases. |
d58d1454 | 121 | * Signal-safe. |
3327ac33 MD |
122 | */ |
123 | int ust_lock(void) | |
124 | { | |
d58d1454 | 125 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 126 | int ret, oldstate; |
d58d1454 | 127 | |
e446ad80 MD |
128 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
129 | if (ret) { | |
130 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
131 | } | |
132 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
133 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
134 | } | |
d58d1454 MD |
135 | sigfillset(&sig_all_blocked); |
136 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
137 | if (ret) { | |
138 | ERR("pthread_sigmask: %s", strerror(ret)); | |
139 | } | |
140 | if (!URCU_TLS(ust_mutex_nest)++) | |
141 | pthread_mutex_lock(&ust_mutex); | |
142 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
143 | if (ret) { | |
144 | ERR("pthread_sigmask: %s", strerror(ret)); | |
145 | } | |
3327ac33 MD |
146 | if (lttng_ust_comm_should_quit) { |
147 | return -1; | |
148 | } else { | |
149 | return 0; | |
150 | } | |
151 | } | |
152 | ||
153 | /* | |
154 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
155 | * they are already nested within the dynamic loader lock, and therefore | |
156 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 157 | * Signal-safe. |
3327ac33 MD |
158 | */ |
159 | void ust_lock_nocheck(void) | |
160 | { | |
d58d1454 | 161 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 162 | int ret, oldstate; |
d58d1454 | 163 | |
e446ad80 MD |
164 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
165 | if (ret) { | |
166 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
167 | } | |
168 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
169 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
170 | } | |
d58d1454 MD |
171 | sigfillset(&sig_all_blocked); |
172 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
173 | if (ret) { | |
174 | ERR("pthread_sigmask: %s", strerror(ret)); | |
175 | } | |
176 | if (!URCU_TLS(ust_mutex_nest)++) | |
177 | pthread_mutex_lock(&ust_mutex); | |
178 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
179 | if (ret) { | |
180 | ERR("pthread_sigmask: %s", strerror(ret)); | |
181 | } | |
3327ac33 MD |
182 | } |
183 | ||
d58d1454 MD |
184 | /* |
185 | * Signal-safe. | |
186 | */ | |
3327ac33 MD |
187 | void ust_unlock(void) |
188 | { | |
d58d1454 | 189 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 190 | int ret, oldstate; |
d58d1454 MD |
191 | |
192 | sigfillset(&sig_all_blocked); | |
193 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
194 | if (ret) { | |
195 | ERR("pthread_sigmask: %s", strerror(ret)); | |
196 | } | |
197 | if (!--URCU_TLS(ust_mutex_nest)) | |
198 | pthread_mutex_unlock(&ust_mutex); | |
199 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
200 | if (ret) { | |
201 | ERR("pthread_sigmask: %s", strerror(ret)); | |
202 | } | |
e446ad80 MD |
203 | ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); |
204 | if (ret) { | |
205 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
206 | } | |
207 | if (oldstate != PTHREAD_CANCEL_DISABLE) { | |
208 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
209 | } | |
3327ac33 MD |
210 | } |
211 | ||
11ff9c7d MD |
212 | /* |
213 | * Wait for either of these before continuing to the main | |
214 | * program: | |
215 | * - the register_done message from sessiond daemon | |
216 | * (will let the sessiond daemon enable sessions before main | |
217 | * starts.) | |
218 | * - sessiond daemon is not reachable. | |
219 | * - timeout (ensuring applications are resilient to session | |
220 | * daemon problems). | |
221 | */ | |
222 | static sem_t constructor_wait; | |
950aab0c MD |
223 | /* |
224 | * Doing this for both the global and local sessiond. | |
225 | */ | |
3f5339b0 GAPG |
226 | enum { |
227 | sem_count_initial_value = 4, | |
228 | }; | |
229 | ||
230 | static int sem_count = sem_count_initial_value; | |
11ff9c7d | 231 | |
e8508a49 MD |
232 | /* |
233 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
234 | * from liblttng-ust does not execute the pre/post fork handlers. | |
235 | */ | |
8c90a710 | 236 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 237 | |
1ea11eab MD |
238 | /* |
239 | * Info about socket and associated listener thread. | |
240 | */ | |
241 | struct sock_info { | |
11ff9c7d | 242 | const char *name; |
1ea11eab | 243 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 244 | int root_handle; |
3f5339b0 | 245 | int registration_done; |
8d20bf54 | 246 | int allowed; |
44e073f5 | 247 | int global; |
e33f3265 | 248 | int thread_active; |
7fc90dca MD |
249 | |
250 | char sock_path[PATH_MAX]; | |
251 | int socket; | |
32ce8569 | 252 | int notify_socket; |
7fc90dca MD |
253 | |
254 | char wait_shm_path[PATH_MAX]; | |
255 | char *wait_shm_mmap; | |
37dddb65 MD |
256 | /* Keep track of lazy state dump not performed yet. */ |
257 | int statedump_pending; | |
3f5339b0 | 258 | int initial_statedump_done; |
1ea11eab | 259 | }; |
2691221a MD |
260 | |
261 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 262 | struct sock_info global_apps = { |
11ff9c7d | 263 | .name = "global", |
44e073f5 | 264 | .global = 1, |
7fc90dca | 265 | |
46050b1a | 266 | .root_handle = -1, |
3f5339b0 | 267 | .registration_done = 0, |
2eab9f28 | 268 | .allowed = 0, |
e33f3265 | 269 | .thread_active = 0, |
7fc90dca | 270 | |
32ce8569 | 271 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 272 | .socket = -1, |
32ce8569 | 273 | .notify_socket = -1, |
7fc90dca | 274 | |
32ce8569 | 275 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 276 | |
37dddb65 | 277 | .statedump_pending = 0, |
3f5339b0 | 278 | .initial_statedump_done = 0, |
1ea11eab | 279 | }; |
2691221a MD |
280 | |
281 | /* TODO: allow global_apps_sock_path override */ | |
282 | ||
1ea11eab | 283 | struct sock_info local_apps = { |
11ff9c7d | 284 | .name = "local", |
44e073f5 | 285 | .global = 0, |
46050b1a | 286 | .root_handle = -1, |
3f5339b0 | 287 | .registration_done = 0, |
8d20bf54 | 288 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 289 | .thread_active = 0, |
7fc90dca MD |
290 | |
291 | .socket = -1, | |
32ce8569 | 292 | .notify_socket = -1, |
95c25348 | 293 | |
37dddb65 | 294 | .statedump_pending = 0, |
3f5339b0 | 295 | .initial_statedump_done = 0, |
1ea11eab | 296 | }; |
2691221a | 297 | |
37ed587a MD |
298 | static int wait_poll_fallback; |
299 | ||
74d81a6c MD |
300 | static const char *cmd_name_mapping[] = { |
301 | [ LTTNG_UST_RELEASE ] = "Release", | |
302 | [ LTTNG_UST_SESSION ] = "Create Session", | |
303 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
304 | ||
305 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
306 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
307 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
308 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
309 | ||
310 | /* Session FD commands */ | |
311 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
312 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
313 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
314 | ||
315 | /* Channel FD commands */ | |
316 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
317 | [ LTTNG_UST_EVENT ] = "Create Event", | |
318 | ||
319 | /* Event and Channel FD commands */ | |
320 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
321 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
322 | ||
323 | /* Event, Channel and Session commands */ | |
324 | [ LTTNG_UST_ENABLE ] = "Enable", | |
325 | [ LTTNG_UST_DISABLE ] = "Disable", | |
326 | ||
327 | /* Tracepoint list commands */ | |
328 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
329 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
330 | ||
331 | /* Event FD commands */ | |
332 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 333 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
74d81a6c MD |
334 | }; |
335 | ||
ff517991 MD |
336 | static const char *str_timeout; |
337 | static int got_timeout_env; | |
338 | ||
7dd08bec | 339 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 340 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 341 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 342 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
343 | extern void lttng_ring_buffer_metadata_client_init(void); |
344 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 345 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 346 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 347 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 348 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 349 | |
2eab9f28 JR |
350 | static char *get_map_shm(struct sock_info *sock_info); |
351 | ||
405be658 MD |
352 | ssize_t lttng_ust_read(int fd, void *buf, size_t len) |
353 | { | |
354 | ssize_t ret; | |
355 | size_t copied = 0, to_copy = len; | |
356 | ||
357 | do { | |
358 | ret = read(fd, buf + copied, to_copy); | |
359 | if (ret > 0) { | |
360 | copied += ret; | |
361 | to_copy -= ret; | |
362 | } | |
363 | } while ((ret > 0 && to_copy > 0) | |
364 | || (ret < 0 && errno == EINTR)); | |
365 | if (ret > 0) { | |
366 | ret = copied; | |
367 | } | |
368 | return ret; | |
369 | } | |
3c6f6263 AM |
370 | /* |
371 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
372 | * pointer. | |
373 | */ | |
374 | static | |
375 | const char *get_lttng_home_dir(void) | |
376 | { | |
377 | const char *val; | |
378 | ||
49254388 | 379 | val = (const char *) lttng_getenv("LTTNG_HOME"); |
3c6f6263 AM |
380 | if (val != NULL) { |
381 | return val; | |
382 | } | |
49254388 | 383 | return (const char *) lttng_getenv("HOME"); |
3c6f6263 AM |
384 | } |
385 | ||
a903623f MD |
386 | /* |
387 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
388 | */ | |
389 | static | |
390 | void lttng_fixup_nest_count_tls(void) | |
391 | { | |
8c90a710 | 392 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
393 | } |
394 | ||
d58d1454 MD |
395 | static |
396 | void lttng_fixup_ust_mutex_nest_tls(void) | |
397 | { | |
398 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
399 | } | |
400 | ||
1556a549 MD |
401 | /* |
402 | * Fixup urcu bp TLS. | |
403 | */ | |
404 | static | |
405 | void lttng_fixup_urcu_bp_tls(void) | |
406 | { | |
407 | rcu_read_lock(); | |
408 | rcu_read_unlock(); | |
409 | } | |
410 | ||
c362addf MD |
411 | void lttng_ust_fixup_tls(void) |
412 | { | |
413 | lttng_fixup_urcu_bp_tls(); | |
414 | lttng_fixup_ringbuffer_tls(); | |
415 | lttng_fixup_vtid_tls(); | |
416 | lttng_fixup_nest_count_tls(); | |
417 | lttng_fixup_procname_tls(); | |
418 | lttng_fixup_ust_mutex_nest_tls(); | |
6548fca4 | 419 | lttng_ust_fixup_fd_tracker_tls(); |
c362addf MD |
420 | } |
421 | ||
32ce8569 MD |
422 | int lttng_get_notify_socket(void *owner) |
423 | { | |
424 | struct sock_info *info = owner; | |
425 | ||
426 | return info->notify_socket; | |
427 | } | |
428 | ||
74d81a6c MD |
429 | static |
430 | void print_cmd(int cmd, int handle) | |
431 | { | |
432 | const char *cmd_name = "Unknown"; | |
433 | ||
fd67a004 MD |
434 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
435 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
436 | cmd_name = cmd_name_mapping[cmd]; |
437 | } | |
fd67a004 MD |
438 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
439 | cmd_name, cmd, | |
74d81a6c MD |
440 | lttng_ust_obj_get_name(handle), handle); |
441 | } | |
442 | ||
2eab9f28 JR |
443 | static |
444 | int setup_global_apps(void) | |
445 | { | |
446 | int ret = 0; | |
447 | assert(!global_apps.wait_shm_mmap); | |
448 | ||
449 | global_apps.wait_shm_mmap = get_map_shm(&global_apps); | |
450 | if (!global_apps.wait_shm_mmap) { | |
451 | WARN("Unable to get map shm for global apps. Disabling LTTng-UST global tracing."); | |
452 | global_apps.allowed = 0; | |
453 | ret = -EIO; | |
454 | goto error; | |
455 | } | |
456 | ||
457 | global_apps.allowed = 1; | |
458 | error: | |
459 | return ret; | |
460 | } | |
2691221a | 461 | static |
8d20bf54 | 462 | int setup_local_apps(void) |
2691221a | 463 | { |
2eab9f28 | 464 | int ret = 0; |
2691221a | 465 | const char *home_dir; |
7fc90dca | 466 | uid_t uid; |
2691221a | 467 | |
2eab9f28 JR |
468 | assert(!local_apps.wait_shm_mmap); |
469 | ||
7fc90dca | 470 | uid = getuid(); |
8d20bf54 MD |
471 | /* |
472 | * Disallow per-user tracing for setuid binaries. | |
473 | */ | |
7fc90dca | 474 | if (uid != geteuid()) { |
9ec6895c | 475 | assert(local_apps.allowed == 0); |
2eab9f28 JR |
476 | ret = 0; |
477 | goto end; | |
8d20bf54 | 478 | } |
3c6f6263 | 479 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
480 | if (!home_dir) { |
481 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
482 | assert(local_apps.allowed == 0); | |
2eab9f28 JR |
483 | ret = -ENOENT; |
484 | goto end; | |
9ec6895c MD |
485 | } |
486 | local_apps.allowed = 1; | |
32ce8569 MD |
487 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
488 | home_dir, | |
489 | LTTNG_DEFAULT_HOME_RUNDIR, | |
490 | LTTNG_UST_SOCK_FILENAME); | |
491 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
492 | LTTNG_UST_WAIT_FILENAME, | |
493 | uid); | |
2eab9f28 JR |
494 | |
495 | local_apps.wait_shm_mmap = get_map_shm(&local_apps); | |
496 | if (!local_apps.wait_shm_mmap) { | |
497 | WARN("Unable to get map shm for local apps. Disabling LTTng-UST per-user tracing."); | |
498 | local_apps.allowed = 0; | |
499 | ret = -EIO; | |
500 | goto end; | |
501 | } | |
502 | end: | |
503 | return ret; | |
2691221a MD |
504 | } |
505 | ||
ff517991 | 506 | /* |
451d66b2 | 507 | * Get socket timeout, in ms. |
28515902 | 508 | * -1: wait forever. 0: don't wait. >0: timeout, in ms. |
ff517991 MD |
509 | */ |
510 | static | |
511 | long get_timeout(void) | |
512 | { | |
513 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
514 | ||
515 | if (!got_timeout_env) { | |
49254388 | 516 | str_timeout = lttng_getenv("LTTNG_UST_REGISTER_TIMEOUT"); |
ff517991 MD |
517 | got_timeout_env = 1; |
518 | } | |
519 | if (str_timeout) | |
520 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
5cf81d53 MD |
521 | /* All negative values are considered as "-1". */ |
522 | if (constructor_delay_ms < -1) | |
523 | constructor_delay_ms = -1; | |
ff517991 MD |
524 | return constructor_delay_ms; |
525 | } | |
526 | ||
451d66b2 | 527 | /* Timeout for notify socket send and recv. */ |
ff517991 MD |
528 | static |
529 | long get_notify_sock_timeout(void) | |
530 | { | |
531 | return get_timeout(); | |
532 | } | |
533 | ||
451d66b2 MD |
534 | /* Timeout for connecting to cmd and notify sockets. */ |
535 | static | |
536 | long get_connect_sock_timeout(void) | |
537 | { | |
538 | return get_timeout(); | |
539 | } | |
540 | ||
ff517991 | 541 | /* |
28515902 | 542 | * Return values: -1: wait forever. 0: don't wait. 1: timeout wait. |
ff517991 MD |
543 | */ |
544 | static | |
545 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
546 | { | |
547 | long constructor_delay_ms; | |
548 | int ret; | |
549 | ||
550 | constructor_delay_ms = get_timeout(); | |
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) { | |
28515902 JG |
565 | /* Don't wait. */ |
566 | return 0; | |
ff517991 MD |
567 | } |
568 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
569 | constructor_timeout->tv_nsec += | |
570 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
571 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
572 | constructor_timeout->tv_sec++; | |
573 | constructor_timeout->tv_nsec -= 1000000000UL; | |
574 | } | |
28515902 | 575 | /* Timeout wait (constructor_delay_ms). */ |
ff517991 MD |
576 | return 1; |
577 | } | |
578 | ||
2691221a | 579 | static |
32ce8569 | 580 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 581 | { |
32ce8569 MD |
582 | return ustcomm_send_reg_msg(socket, |
583 | type, | |
584 | CAA_BITS_PER_LONG, | |
585 | lttng_alignof(uint8_t) * CHAR_BIT, | |
586 | lttng_alignof(uint16_t) * CHAR_BIT, | |
587 | lttng_alignof(uint32_t) * CHAR_BIT, | |
588 | lttng_alignof(uint64_t) * CHAR_BIT, | |
589 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
590 | } |
591 | ||
d9e99d10 | 592 | static |
57773204 | 593 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 594 | { |
9eb62b9c | 595 | ssize_t len; |
d3a492d1 | 596 | |
57773204 | 597 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 598 | switch (len) { |
a4be8962 | 599 | case sizeof(*lur): |
d3a492d1 MD |
600 | DBG("message successfully sent"); |
601 | return 0; | |
7bc53e94 MD |
602 | default: |
603 | if (len == -ECONNRESET) { | |
604 | DBG("remote end closed connection"); | |
d3a492d1 MD |
605 | return 0; |
606 | } | |
7bc53e94 MD |
607 | if (len < 0) |
608 | return len; | |
609 | DBG("incorrect message size: %zd", len); | |
610 | return -EINVAL; | |
d3a492d1 MD |
611 | } |
612 | } | |
613 | ||
614 | static | |
3f5339b0 | 615 | void decrement_sem_count(unsigned int count) |
11ff9c7d MD |
616 | { |
617 | int ret; | |
618 | ||
3f5339b0 GAPG |
619 | assert(uatomic_read(&sem_count) >= count); |
620 | ||
56cd7e2f | 621 | if (uatomic_read(&sem_count) <= 0) { |
3f5339b0 | 622 | return; |
56cd7e2f | 623 | } |
3f5339b0 GAPG |
624 | |
625 | ret = uatomic_add_return(&sem_count, -count); | |
95259bd0 MD |
626 | if (ret == 0) { |
627 | ret = sem_post(&constructor_wait); | |
628 | assert(!ret); | |
629 | } | |
3f5339b0 GAPG |
630 | } |
631 | ||
632 | static | |
633 | int handle_register_done(struct sock_info *sock_info) | |
634 | { | |
635 | if (sock_info->registration_done) | |
636 | return 0; | |
637 | sock_info->registration_done = 1; | |
638 | ||
639 | decrement_sem_count(1); | |
c41cdc2a MD |
640 | if (!sock_info->statedump_pending) { |
641 | sock_info->initial_statedump_done = 1; | |
642 | decrement_sem_count(1); | |
643 | } | |
3f5339b0 GAPG |
644 | |
645 | return 0; | |
646 | } | |
647 | ||
648 | static | |
649 | int handle_register_failed(struct sock_info *sock_info) | |
650 | { | |
651 | if (sock_info->registration_done) | |
652 | return 0; | |
653 | sock_info->registration_done = 1; | |
654 | sock_info->initial_statedump_done = 1; | |
655 | ||
656 | decrement_sem_count(2); | |
657 | ||
11ff9c7d MD |
658 | return 0; |
659 | } | |
660 | ||
37dddb65 MD |
661 | /* |
662 | * Only execute pending statedump after the constructor semaphore has | |
3f5339b0 GAPG |
663 | * been posted by the current listener thread. This means statedump will |
664 | * only be performed after the "registration done" command is received | |
665 | * from this thread's session daemon. | |
37dddb65 MD |
666 | * |
667 | * This ensures we don't run into deadlock issues with the dynamic | |
668 | * loader mutex, which is held while the constructor is called and | |
669 | * waiting on the constructor semaphore. All operations requiring this | |
670 | * dynamic loader lock need to be postponed using this mechanism. | |
3f5339b0 GAPG |
671 | * |
672 | * In a scenario with two session daemons connected to the application, | |
673 | * it is possible that the first listener thread which receives the | |
674 | * registration done command issues its statedump while the dynamic | |
675 | * loader lock is still held by the application constructor waiting on | |
676 | * the semaphore. It will however be allowed to proceed when the | |
677 | * second session daemon sends the registration done command to the | |
678 | * second listener thread. This situation therefore does not produce | |
679 | * a deadlock. | |
37dddb65 MD |
680 | */ |
681 | static | |
682 | void handle_pending_statedump(struct sock_info *sock_info) | |
683 | { | |
3f5339b0 | 684 | if (sock_info->registration_done && sock_info->statedump_pending) { |
37dddb65 | 685 | sock_info->statedump_pending = 0; |
2932a87f | 686 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 687 | lttng_handle_pending_statedump(sock_info); |
458d678c | 688 | pthread_mutex_unlock(&ust_fork_mutex); |
3f5339b0 GAPG |
689 | |
690 | if (!sock_info->initial_statedump_done) { | |
691 | sock_info->initial_statedump_done = 1; | |
692 | decrement_sem_count(1); | |
693 | } | |
37dddb65 MD |
694 | } |
695 | } | |
696 | ||
11ff9c7d MD |
697 | static |
698 | int handle_message(struct sock_info *sock_info, | |
57773204 | 699 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 700 | { |
1ea11eab | 701 | int ret = 0; |
b61ce3b2 | 702 | const struct lttng_ust_objd_ops *ops; |
57773204 | 703 | struct ustcomm_ust_reply lur; |
ef9ff354 | 704 | union ust_args args; |
8e696cfa | 705 | char ctxstr[LTTNG_UST_SYM_NAME_LEN]; /* App context string. */ |
40003310 | 706 | ssize_t len; |
1ea11eab | 707 | |
46050b1a MD |
708 | memset(&lur, 0, sizeof(lur)); |
709 | ||
3327ac33 | 710 | if (ust_lock()) { |
74d81a6c | 711 | ret = -LTTNG_UST_ERR_EXITING; |
0dafcd63 | 712 | goto error; |
1ea11eab | 713 | } |
9eb62b9c | 714 | |
46050b1a MD |
715 | ops = objd_ops(lum->handle); |
716 | if (!ops) { | |
717 | ret = -ENOENT; | |
0dafcd63 | 718 | goto error; |
1ea11eab | 719 | } |
46050b1a MD |
720 | |
721 | switch (lum->cmd) { | |
11ff9c7d MD |
722 | case LTTNG_UST_REGISTER_DONE: |
723 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 724 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
725 | else |
726 | ret = -EINVAL; | |
727 | break; | |
46050b1a MD |
728 | case LTTNG_UST_RELEASE: |
729 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
730 | ret = -EPERM; | |
731 | else | |
1849ef7c | 732 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 733 | break; |
2d78951a MD |
734 | case LTTNG_UST_FILTER: |
735 | { | |
736 | /* Receive filter data */ | |
f488575f | 737 | struct lttng_ust_filter_bytecode_node *bytecode; |
2d78951a | 738 | |
cd54f6d9 | 739 | if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) { |
7bc53e94 | 740 | ERR("Filter data size is too large: %u bytes", |
2d78951a MD |
741 | lum->u.filter.data_size); |
742 | ret = -EINVAL; | |
743 | goto error; | |
744 | } | |
2734ca65 | 745 | |
885b1dfd | 746 | if (lum->u.filter.reloc_offset > lum->u.filter.data_size) { |
7bc53e94 | 747 | ERR("Filter reloc offset %u is not within data", |
2734ca65 CB |
748 | lum->u.filter.reloc_offset); |
749 | ret = -EINVAL; | |
750 | goto error; | |
751 | } | |
752 | ||
cd54f6d9 MD |
753 | bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size); |
754 | if (!bytecode) { | |
755 | ret = -ENOMEM; | |
756 | goto error; | |
757 | } | |
f488575f | 758 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, |
2d78951a MD |
759 | lum->u.filter.data_size); |
760 | switch (len) { | |
761 | case 0: /* orderly shutdown */ | |
762 | ret = 0; | |
cd54f6d9 | 763 | free(bytecode); |
2d78951a | 764 | goto error; |
2d78951a MD |
765 | default: |
766 | if (len == lum->u.filter.data_size) { | |
7bc53e94 | 767 | DBG("filter data received"); |
2d78951a | 768 | break; |
7bc53e94 MD |
769 | } else if (len < 0) { |
770 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
771 | if (len == -ECONNRESET) { | |
772 | ERR("%s remote end closed connection", sock_info->name); | |
773 | ret = len; | |
774 | free(bytecode); | |
775 | goto error; | |
776 | } | |
777 | ret = len; | |
eb8bf361 | 778 | free(bytecode); |
0dafcd63 | 779 | goto error; |
2d78951a | 780 | } else { |
7bc53e94 | 781 | DBG("incorrect filter data message size: %zd", len); |
2d78951a | 782 | ret = -EINVAL; |
cd54f6d9 | 783 | free(bytecode); |
0dafcd63 | 784 | goto error; |
2d78951a MD |
785 | } |
786 | } | |
f488575f MD |
787 | bytecode->bc.len = lum->u.filter.data_size; |
788 | bytecode->bc.reloc_offset = lum->u.filter.reloc_offset; | |
3f6fd224 | 789 | bytecode->bc.seqnum = lum->u.filter.seqnum; |
cd54f6d9 | 790 | if (ops->cmd) { |
2d78951a | 791 | ret = ops->cmd(lum->handle, lum->cmd, |
cd54f6d9 | 792 | (unsigned long) bytecode, |
f59ed768 | 793 | &args, sock_info); |
cd54f6d9 MD |
794 | if (ret) { |
795 | free(bytecode); | |
796 | } | |
797 | /* don't free bytecode if everything went fine. */ | |
798 | } else { | |
2d78951a | 799 | ret = -ENOSYS; |
cd54f6d9 MD |
800 | free(bytecode); |
801 | } | |
2d78951a MD |
802 | break; |
803 | } | |
86e36163 JI |
804 | case LTTNG_UST_EXCLUSION: |
805 | { | |
806 | /* Receive exclusion names */ | |
807 | struct lttng_ust_excluder_node *node; | |
808 | unsigned int count; | |
809 | ||
810 | count = lum->u.exclusion.count; | |
811 | if (count == 0) { | |
812 | /* There are no names to read */ | |
813 | ret = 0; | |
814 | goto error; | |
815 | } | |
816 | node = zmalloc(sizeof(*node) + | |
817 | count * LTTNG_UST_SYM_NAME_LEN); | |
818 | if (!node) { | |
819 | ret = -ENOMEM; | |
820 | goto error; | |
821 | } | |
822 | node->excluder.count = count; | |
823 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
824 | count * LTTNG_UST_SYM_NAME_LEN); | |
825 | switch (len) { | |
826 | case 0: /* orderly shutdown */ | |
827 | ret = 0; | |
828 | free(node); | |
829 | goto error; | |
830 | default: | |
831 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
832 | DBG("Exclusion data received"); | |
833 | break; | |
834 | } else if (len < 0) { | |
835 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
836 | if (len == -ECONNRESET) { | |
837 | ERR("%s remote end closed connection", sock_info->name); | |
838 | ret = len; | |
839 | free(node); | |
840 | goto error; | |
841 | } | |
842 | ret = len; | |
843 | free(node); | |
0dafcd63 | 844 | goto error; |
86e36163 JI |
845 | } else { |
846 | DBG("Incorrect exclusion data message size: %zd", len); | |
847 | ret = -EINVAL; | |
848 | free(node); | |
0dafcd63 | 849 | goto error; |
86e36163 JI |
850 | } |
851 | } | |
852 | if (ops->cmd) { | |
853 | ret = ops->cmd(lum->handle, lum->cmd, | |
854 | (unsigned long) node, | |
855 | &args, sock_info); | |
856 | if (ret) { | |
857 | free(node); | |
858 | } | |
859 | /* Don't free exclusion data if everything went fine. */ | |
860 | } else { | |
861 | ret = -ENOSYS; | |
862 | free(node); | |
863 | } | |
864 | break; | |
865 | } | |
74d81a6c MD |
866 | case LTTNG_UST_CHANNEL: |
867 | { | |
868 | void *chan_data; | |
ff0f5728 | 869 | int wakeup_fd; |
74d81a6c MD |
870 | |
871 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
872 | &chan_data, lum->u.channel.len, |
873 | &wakeup_fd); | |
74d81a6c MD |
874 | switch (len) { |
875 | case 0: /* orderly shutdown */ | |
876 | ret = 0; | |
877 | goto error; | |
878 | default: | |
879 | if (len == lum->u.channel.len) { | |
880 | DBG("channel data received"); | |
881 | break; | |
882 | } else if (len < 0) { | |
883 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
884 | if (len == -ECONNRESET) { | |
885 | ERR("%s remote end closed connection", sock_info->name); | |
886 | ret = len; | |
887 | goto error; | |
888 | } | |
889 | ret = len; | |
0dafcd63 | 890 | goto error; |
74d81a6c MD |
891 | } else { |
892 | DBG("incorrect channel data message size: %zd", len); | |
893 | ret = -EINVAL; | |
0dafcd63 | 894 | goto error; |
74d81a6c MD |
895 | } |
896 | } | |
897 | args.channel.chan_data = chan_data; | |
ff0f5728 | 898 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
899 | if (ops->cmd) |
900 | ret = ops->cmd(lum->handle, lum->cmd, | |
901 | (unsigned long) &lum->u, | |
902 | &args, sock_info); | |
903 | else | |
904 | ret = -ENOSYS; | |
905 | break; | |
906 | } | |
907 | case LTTNG_UST_STREAM: | |
908 | { | |
909 | /* Receive shm_fd, wakeup_fd */ | |
910 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
acafe8d8 | 911 | NULL, |
74d81a6c MD |
912 | &args.stream.shm_fd, |
913 | &args.stream.wakeup_fd); | |
914 | if (ret) { | |
0dafcd63 | 915 | goto error; |
74d81a6c | 916 | } |
61973368 | 917 | |
74d81a6c MD |
918 | if (ops->cmd) |
919 | ret = ops->cmd(lum->handle, lum->cmd, | |
920 | (unsigned long) &lum->u, | |
921 | &args, sock_info); | |
922 | else | |
923 | ret = -ENOSYS; | |
924 | break; | |
925 | } | |
8e696cfa MD |
926 | case LTTNG_UST_CONTEXT: |
927 | switch (lum->u.context.ctx) { | |
928 | case LTTNG_UST_CONTEXT_APP_CONTEXT: | |
929 | { | |
930 | char *p; | |
931 | size_t ctxlen, recvlen; | |
932 | ||
933 | ctxlen = strlen("$app.") + lum->u.context.u.app_ctx.provider_name_len - 1 | |
934 | + strlen(":") + lum->u.context.u.app_ctx.ctx_name_len; | |
935 | if (ctxlen >= LTTNG_UST_SYM_NAME_LEN) { | |
936 | ERR("Application context string length size is too large: %zu bytes", | |
937 | ctxlen); | |
938 | ret = -EINVAL; | |
939 | goto error; | |
940 | } | |
941 | strcpy(ctxstr, "$app."); | |
942 | p = &ctxstr[strlen("$app.")]; | |
943 | recvlen = ctxlen - strlen("$app."); | |
944 | len = ustcomm_recv_unix_sock(sock, p, recvlen); | |
945 | switch (len) { | |
946 | case 0: /* orderly shutdown */ | |
947 | ret = 0; | |
948 | goto error; | |
949 | default: | |
950 | if (len == recvlen) { | |
951 | DBG("app context data received"); | |
952 | break; | |
953 | } else if (len < 0) { | |
954 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
955 | if (len == -ECONNRESET) { | |
956 | ERR("%s remote end closed connection", sock_info->name); | |
957 | ret = len; | |
958 | goto error; | |
959 | } | |
960 | ret = len; | |
961 | goto error; | |
962 | } else { | |
963 | DBG("incorrect app context data message size: %zd", len); | |
964 | ret = -EINVAL; | |
965 | goto error; | |
966 | } | |
967 | } | |
968 | /* Put : between provider and ctxname. */ | |
969 | p[lum->u.context.u.app_ctx.provider_name_len - 1] = ':'; | |
970 | args.app_context.ctxname = ctxstr; | |
971 | break; | |
972 | } | |
973 | default: | |
974 | break; | |
975 | } | |
976 | if (ops->cmd) { | |
977 | ret = ops->cmd(lum->handle, lum->cmd, | |
978 | (unsigned long) &lum->u, | |
979 | &args, sock_info); | |
980 | } else { | |
981 | ret = -ENOSYS; | |
982 | } | |
983 | break; | |
d9e99d10 | 984 | default: |
46050b1a MD |
985 | if (ops->cmd) |
986 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 987 | (unsigned long) &lum->u, |
f59ed768 | 988 | &args, sock_info); |
46050b1a MD |
989 | else |
990 | ret = -ENOSYS; | |
991 | break; | |
d9e99d10 | 992 | } |
46050b1a | 993 | |
46050b1a MD |
994 | lur.handle = lum->handle; |
995 | lur.cmd = lum->cmd; | |
996 | lur.ret_val = ret; | |
997 | if (ret >= 0) { | |
7bc53e94 | 998 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 999 | } else { |
7bc53e94 MD |
1000 | /* |
1001 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
1002 | * error that are not caused by the transport, except if | |
1003 | * we already have a more precise error message to | |
1004 | * report. | |
1005 | */ | |
64b2564e DG |
1006 | if (ret > -LTTNG_UST_ERR) { |
1007 | /* Translate code to UST error. */ | |
1008 | switch (ret) { | |
1009 | case -EEXIST: | |
1010 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
1011 | break; | |
1012 | case -EINVAL: | |
1013 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
1014 | break; | |
1015 | case -ENOENT: | |
1016 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
1017 | break; | |
1018 | case -EPERM: | |
1019 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
1020 | break; | |
1021 | case -ENOSYS: | |
1022 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
1023 | break; | |
1024 | default: | |
1025 | lur.ret_code = -LTTNG_UST_ERR; | |
1026 | break; | |
1027 | } | |
1028 | } else { | |
7bc53e94 | 1029 | lur.ret_code = ret; |
64b2564e | 1030 | } |
46050b1a | 1031 | } |
e6ea14c5 MD |
1032 | if (ret >= 0) { |
1033 | switch (lum->cmd) { | |
e6ea14c5 MD |
1034 | case LTTNG_UST_TRACER_VERSION: |
1035 | lur.u.version = lum->u.version; | |
1036 | break; | |
1037 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
1038 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
1039 | break; | |
1040 | } | |
381c0f1e | 1041 | } |
74d81a6c | 1042 | DBG("Return value: %d", lur.ret_val); |
4c62d8d1 MD |
1043 | |
1044 | ust_unlock(); | |
1045 | ||
1046 | /* | |
1047 | * Performed delayed statedump operations outside of the UST | |
1048 | * lock. We need to take the dynamic loader lock before we take | |
1049 | * the UST lock internally within handle_pending_statedump(). | |
1050 | */ | |
1051 | handle_pending_statedump(sock_info); | |
1052 | ||
1053 | if (ust_lock()) { | |
1054 | ret = -LTTNG_UST_ERR_EXITING; | |
1055 | goto error; | |
1056 | } | |
1057 | ||
46050b1a | 1058 | ret = send_reply(sock, &lur); |
193183fb | 1059 | if (ret < 0) { |
7bc53e94 | 1060 | DBG("error sending reply"); |
193183fb MD |
1061 | goto error; |
1062 | } | |
46050b1a | 1063 | |
40003310 MD |
1064 | /* |
1065 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
1066 | * after the reply. | |
1067 | */ | |
7bc53e94 | 1068 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
1069 | switch (lum->cmd) { |
1070 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
1071 | len = ustcomm_send_unix_sock(sock, | |
1072 | &args.field_list.entry, | |
1073 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
1074 | if (len < 0) { |
1075 | ret = len; | |
1076 | goto error; | |
1077 | } | |
40003310 | 1078 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 1079 | ret = -EINVAL; |
40003310 MD |
1080 | goto error; |
1081 | } | |
1082 | } | |
1083 | } | |
ef9ff354 | 1084 | |
381c0f1e | 1085 | error: |
17dfb34b | 1086 | ust_unlock(); |
d9e99d10 | 1087 | |
37dddb65 | 1088 | return ret; |
246be17e PW |
1089 | } |
1090 | ||
46050b1a | 1091 | static |
efe0de09 | 1092 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
1093 | { |
1094 | int ret; | |
1095 | ||
5b14aab3 MD |
1096 | if (sock_info->root_handle != -1) { |
1097 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
1098 | if (ret) { | |
1099 | ERR("Error unref root handle"); | |
1100 | } | |
1101 | sock_info->root_handle = -1; | |
1102 | } | |
3f5339b0 GAPG |
1103 | sock_info->registration_done = 0; |
1104 | sock_info->initial_statedump_done = 0; | |
5b14aab3 MD |
1105 | |
1106 | /* | |
1107 | * wait_shm_mmap, socket and notify socket are used by listener | |
1108 | * threads outside of the ust lock, so we cannot tear them down | |
1109 | * ourselves, because we cannot join on these threads. Leave | |
1110 | * responsibility of cleaning up these resources to the OS | |
1111 | * process exit. | |
1112 | */ | |
1113 | if (exiting) | |
1114 | return; | |
1115 | ||
46050b1a | 1116 | if (sock_info->socket != -1) { |
e6973a89 | 1117 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 1118 | if (ret) { |
32ce8569 | 1119 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
1120 | } |
1121 | sock_info->socket = -1; | |
1122 | } | |
32ce8569 MD |
1123 | if (sock_info->notify_socket != -1) { |
1124 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1125 | if (ret) { | |
1126 | ERR("Error closing ust notify socket"); | |
1127 | } | |
1128 | sock_info->notify_socket = -1; | |
1129 | } | |
5b14aab3 | 1130 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
1131 | long page_size; |
1132 | ||
1133 | page_size = sysconf(_SC_PAGE_SIZE); | |
2657d1ba MD |
1134 | if (page_size <= 0) { |
1135 | if (!page_size) { | |
1136 | errno = EINVAL; | |
1137 | } | |
1138 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
1139 | } else { | |
172d6b68 MD |
1140 | ret = munmap(sock_info->wait_shm_mmap, page_size); |
1141 | if (ret) { | |
1142 | ERR("Error unmapping wait shm"); | |
1143 | } | |
7fc90dca MD |
1144 | } |
1145 | sock_info->wait_shm_mmap = NULL; | |
1146 | } | |
1147 | } | |
1148 | ||
58d4b2a2 | 1149 | /* |
33bbeb90 MD |
1150 | * Using fork to set umask in the child process (not multi-thread safe). |
1151 | * We deal with the shm_open vs ftruncate race (happening when the | |
1152 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
1153 | * safety against shm_unlink) by simply letting the mmap fail and | |
1154 | * retrying after a few seconds. | |
1155 | * For global shm, everybody has rw access to it until the sessiond | |
1156 | * starts. | |
58d4b2a2 | 1157 | */ |
7fc90dca | 1158 | static |
58d4b2a2 | 1159 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 1160 | { |
7fc90dca | 1161 | int wait_shm_fd, ret; |
58d4b2a2 | 1162 | pid_t pid; |
44e073f5 | 1163 | |
58d4b2a2 | 1164 | /* |
33bbeb90 | 1165 | * Try to open read-only. |
58d4b2a2 | 1166 | */ |
33bbeb90 | 1167 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 1168 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
1169 | int32_t tmp_read; |
1170 | ssize_t len; | |
1171 | size_t bytes_read = 0; | |
1172 | ||
1173 | /* | |
1174 | * Try to read the fd. If unable to do so, try opening | |
1175 | * it in write mode. | |
1176 | */ | |
1177 | do { | |
1178 | len = read(wait_shm_fd, | |
1179 | &((char *) &tmp_read)[bytes_read], | |
1180 | sizeof(tmp_read) - bytes_read); | |
1181 | if (len > 0) { | |
1182 | bytes_read += len; | |
1183 | } | |
1184 | } while ((len < 0 && errno == EINTR) | |
1185 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
1186 | if (bytes_read != sizeof(tmp_read)) { | |
1187 | ret = close(wait_shm_fd); | |
1188 | if (ret) { | |
1189 | ERR("close wait_shm_fd"); | |
1190 | } | |
1191 | goto open_write; | |
1192 | } | |
58d4b2a2 MD |
1193 | goto end; |
1194 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
1195 | /* | |
33bbeb90 MD |
1196 | * Real-only open did not work, and it's not because the |
1197 | * entry was not present. It's a failure that prohibits | |
1198 | * using shm. | |
58d4b2a2 | 1199 | */ |
7fc90dca | 1200 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 1201 | goto end; |
7fc90dca | 1202 | } |
7aa76730 MD |
1203 | |
1204 | open_write: | |
7fc90dca | 1205 | /* |
7aa76730 MD |
1206 | * If the open failed because the file did not exist, or because |
1207 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 1208 | */ |
8c90a710 | 1209 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 1210 | pid = fork(); |
8c90a710 | 1211 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
1212 | if (pid > 0) { |
1213 | int status; | |
1214 | ||
1215 | /* | |
1216 | * Parent: wait for child to return, in which case the | |
1217 | * shared memory map will have been created. | |
1218 | */ | |
1219 | pid = wait(&status); | |
b7d3cb32 | 1220 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
1221 | wait_shm_fd = -1; |
1222 | goto end; | |
7fc90dca | 1223 | } |
58d4b2a2 MD |
1224 | /* |
1225 | * Try to open read-only again after creation. | |
1226 | */ | |
33bbeb90 | 1227 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
1228 | if (wait_shm_fd < 0) { |
1229 | /* | |
1230 | * Real-only open did not work. It's a failure | |
1231 | * that prohibits using shm. | |
1232 | */ | |
1233 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1234 | goto end; | |
1235 | } | |
1236 | goto end; | |
1237 | } else if (pid == 0) { | |
1238 | int create_mode; | |
1239 | ||
1240 | /* Child */ | |
33bbeb90 | 1241 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1242 | if (sock_info->global) |
33bbeb90 | 1243 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1244 | /* |
1245 | * We're alone in a child process, so we can modify the | |
1246 | * process-wide umask. | |
1247 | */ | |
33bbeb90 | 1248 | umask(~create_mode); |
58d4b2a2 | 1249 | /* |
33bbeb90 MD |
1250 | * Try creating shm (or get rw access). |
1251 | * We don't do an exclusive open, because we allow other | |
1252 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1253 | */ |
1254 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1255 | O_RDWR | O_CREAT, create_mode); | |
1256 | if (wait_shm_fd >= 0) { | |
1257 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1258 | if (ret) { | |
1259 | PERROR("ftruncate"); | |
b0c1425d | 1260 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1261 | } |
b0c1425d | 1262 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1263 | } |
33bbeb90 MD |
1264 | /* |
1265 | * For local shm, we need to have rw access to accept | |
1266 | * opening it: this means the local sessiond will be | |
1267 | * able to wake us up. For global shm, we open it even | |
1268 | * if rw access is not granted, because the root.root | |
1269 | * sessiond will be able to override all rights and wake | |
1270 | * us up. | |
1271 | */ | |
1272 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1273 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1274 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1275 | } |
1276 | /* | |
33bbeb90 MD |
1277 | * The shm exists, but we cannot open it RW. Report |
1278 | * success. | |
58d4b2a2 | 1279 | */ |
5d3bc5ed | 1280 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1281 | } else { |
1282 | return -1; | |
7fc90dca | 1283 | } |
58d4b2a2 | 1284 | end: |
33bbeb90 MD |
1285 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1286 | struct stat statbuf; | |
1287 | ||
1288 | /* | |
1289 | * Ensure that our user is the owner of the shm file for | |
1290 | * local shm. If we do not own the file, it means our | |
1291 | * sessiond will not have access to wake us up (there is | |
1292 | * probably a rogue process trying to fake our | |
1293 | * sessiond). Fallback to polling method in this case. | |
1294 | */ | |
1295 | ret = fstat(wait_shm_fd, &statbuf); | |
1296 | if (ret) { | |
1297 | PERROR("fstat"); | |
1298 | goto error_close; | |
1299 | } | |
1300 | if (statbuf.st_uid != getuid()) | |
1301 | goto error_close; | |
1302 | } | |
58d4b2a2 | 1303 | return wait_shm_fd; |
33bbeb90 MD |
1304 | |
1305 | error_close: | |
1306 | ret = close(wait_shm_fd); | |
1307 | if (ret) { | |
1308 | PERROR("Error closing fd"); | |
1309 | } | |
1310 | return -1; | |
58d4b2a2 MD |
1311 | } |
1312 | ||
1313 | static | |
1314 | char *get_map_shm(struct sock_info *sock_info) | |
1315 | { | |
172d6b68 | 1316 | long page_size; |
58d4b2a2 MD |
1317 | int wait_shm_fd, ret; |
1318 | char *wait_shm_mmap; | |
1319 | ||
172d6b68 | 1320 | page_size = sysconf(_SC_PAGE_SIZE); |
2657d1ba MD |
1321 | if (page_size <= 0) { |
1322 | if (!page_size) { | |
1323 | errno = EINVAL; | |
1324 | } | |
1325 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
172d6b68 MD |
1326 | goto error; |
1327 | } | |
1328 | ||
6548fca4 | 1329 | lttng_ust_lock_fd_tracker(); |
172d6b68 | 1330 | wait_shm_fd = get_wait_shm(sock_info, page_size); |
58d4b2a2 | 1331 | if (wait_shm_fd < 0) { |
6548fca4 | 1332 | lttng_ust_unlock_fd_tracker(); |
58d4b2a2 | 1333 | goto error; |
44e073f5 | 1334 | } |
fc9a0ccb JR |
1335 | |
1336 | ret = lttng_ust_add_fd_to_tracker(wait_shm_fd); | |
1337 | if (ret < 0) { | |
1338 | ret = close(wait_shm_fd); | |
1339 | if (!ret) { | |
1340 | PERROR("Error closing fd"); | |
1341 | } | |
1342 | lttng_ust_unlock_fd_tracker(); | |
1343 | goto error; | |
1344 | } | |
1345 | ||
1346 | wait_shm_fd = ret; | |
6548fca4 MD |
1347 | lttng_ust_unlock_fd_tracker(); |
1348 | ||
172d6b68 | 1349 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1350 | MAP_SHARED, wait_shm_fd, 0); |
6548fca4 | 1351 | |
7fc90dca | 1352 | /* close shm fd immediately after taking the mmap reference */ |
6548fca4 | 1353 | lttng_ust_lock_fd_tracker(); |
7fc90dca | 1354 | ret = close(wait_shm_fd); |
6548fca4 MD |
1355 | if (!ret) { |
1356 | lttng_ust_delete_fd_from_tracker(wait_shm_fd); | |
1357 | } else { | |
33bbeb90 MD |
1358 | PERROR("Error closing fd"); |
1359 | } | |
6548fca4 MD |
1360 | lttng_ust_unlock_fd_tracker(); |
1361 | ||
33bbeb90 MD |
1362 | if (wait_shm_mmap == MAP_FAILED) { |
1363 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1364 | goto error; | |
7fc90dca MD |
1365 | } |
1366 | return wait_shm_mmap; | |
1367 | ||
1368 | error: | |
1369 | return NULL; | |
1370 | } | |
1371 | ||
1372 | static | |
1373 | void wait_for_sessiond(struct sock_info *sock_info) | |
1374 | { | |
2eab9f28 | 1375 | /* Use ust_lock to check if we should quit. */ |
3327ac33 | 1376 | if (ust_lock()) { |
7fc90dca MD |
1377 | goto quit; |
1378 | } | |
37ed587a MD |
1379 | if (wait_poll_fallback) { |
1380 | goto error; | |
1381 | } | |
7fc90dca MD |
1382 | ust_unlock(); |
1383 | ||
2eab9f28 JR |
1384 | assert(sock_info->wait_shm_mmap); |
1385 | ||
7fc90dca | 1386 | DBG("Waiting for %s apps sessiond", sock_info->name); |
80e2814b | 1387 | /* Wait for futex wakeup */ |
ee7fcec8 MD |
1388 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) |
1389 | goto end_wait; | |
1390 | ||
1391 | while (futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1392 | FUTEX_WAIT, 0, NULL, NULL, 0)) { | |
1393 | switch (errno) { | |
1394 | case EWOULDBLOCK: | |
1395 | /* Value already changed. */ | |
1396 | goto end_wait; | |
1397 | case EINTR: | |
1398 | /* Retry if interrupted by signal. */ | |
1399 | break; /* Get out of switch. */ | |
1400 | case EFAULT: | |
1401 | wait_poll_fallback = 1; | |
1402 | DBG( | |
37ed587a MD |
1403 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1404 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1405 | "Please upgrade your kernel " | |
1406 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1407 | "mainline). LTTng-UST will use polling mode fallback."); | |
ee7fcec8 MD |
1408 | if (ust_debug()) |
1409 | PERROR("futex"); | |
1410 | goto end_wait; | |
80e2814b MD |
1411 | } |
1412 | } | |
ee7fcec8 | 1413 | end_wait: |
7fc90dca MD |
1414 | return; |
1415 | ||
1416 | quit: | |
1417 | ust_unlock(); | |
1418 | return; | |
1419 | ||
1420 | error: | |
1421 | ust_unlock(); | |
7fc90dca | 1422 | return; |
46050b1a MD |
1423 | } |
1424 | ||
1ea11eab MD |
1425 | /* |
1426 | * This thread does not allocate any resource, except within | |
1427 | * handle_message, within mutex protection. This mutex protects against | |
1428 | * fork and exit. | |
98bf993f | 1429 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1430 | * is also protected by the mutex. |
1431 | */ | |
d9e99d10 MD |
1432 | static |
1433 | void *ust_listener_thread(void *arg) | |
1434 | { | |
1ea11eab | 1435 | struct sock_info *sock_info = arg; |
fc9a0ccb | 1436 | int sock, ret, prev_connect_failed = 0, has_waited = 0, fd; |
ff517991 | 1437 | long timeout; |
d9e99d10 | 1438 | |
c362addf | 1439 | lttng_ust_fixup_tls(); |
01f0e40c RB |
1440 | /* |
1441 | * If available, add '-ust' to the end of this thread's | |
1442 | * process name | |
1443 | */ | |
1444 | ret = lttng_ust_setustprocname(); | |
1445 | if (ret) { | |
1446 | ERR("Unable to set UST process name"); | |
1447 | } | |
1448 | ||
9eb62b9c MD |
1449 | /* Restart trying to connect to the session daemon */ |
1450 | restart: | |
c0eedf81 MD |
1451 | if (prev_connect_failed) { |
1452 | /* Wait for sessiond availability with pipe */ | |
1453 | wait_for_sessiond(sock_info); | |
1454 | if (has_waited) { | |
1455 | has_waited = 0; | |
1456 | /* | |
1457 | * Sleep for 5 seconds before retrying after a | |
1458 | * sequence of failure / wait / failure. This | |
1459 | * deals with a killed or broken session daemon. | |
1460 | */ | |
1461 | sleep(5); | |
eacc4aa4 MD |
1462 | } else { |
1463 | has_waited = 1; | |
c0eedf81 | 1464 | } |
c0eedf81 MD |
1465 | prev_connect_failed = 0; |
1466 | } | |
9eb62b9c | 1467 | |
005aeac5 JR |
1468 | if (ust_lock()) { |
1469 | goto quit; | |
1470 | } | |
1471 | ||
1ea11eab | 1472 | if (sock_info->socket != -1) { |
6548fca4 | 1473 | /* FD tracker is updated by ustcomm_close_unix_sock() */ |
e6973a89 | 1474 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1475 | if (ret) { |
32ce8569 MD |
1476 | ERR("Error closing %s ust cmd socket", |
1477 | sock_info->name); | |
1ea11eab MD |
1478 | } |
1479 | sock_info->socket = -1; | |
1480 | } | |
32ce8569 | 1481 | if (sock_info->notify_socket != -1) { |
6548fca4 | 1482 | /* FD tracker is updated by ustcomm_close_unix_sock() */ |
32ce8569 MD |
1483 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); |
1484 | if (ret) { | |
1485 | ERR("Error closing %s ust notify socket", | |
1486 | sock_info->name); | |
1487 | } | |
1488 | sock_info->notify_socket = -1; | |
1489 | } | |
46050b1a | 1490 | |
6548fca4 | 1491 | |
321f2351 MD |
1492 | /* |
1493 | * Register. We need to perform both connect and sending | |
1494 | * registration message before doing the next connect otherwise | |
1495 | * we may reach unix socket connect queue max limits and block | |
1496 | * on the 2nd connect while the session daemon is awaiting the | |
1497 | * first connect registration message. | |
1498 | */ | |
1499 | /* Connect cmd socket */ | |
6548fca4 | 1500 | lttng_ust_lock_fd_tracker(); |
451d66b2 MD |
1501 | ret = ustcomm_connect_unix_sock(sock_info->sock_path, |
1502 | get_connect_sock_timeout()); | |
321f2351 | 1503 | if (ret < 0) { |
6548fca4 | 1504 | lttng_ust_unlock_fd_tracker(); |
321f2351 MD |
1505 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); |
1506 | prev_connect_failed = 1; | |
5b14aab3 | 1507 | |
e3426ddc | 1508 | /* |
321f2351 MD |
1509 | * If we cannot find the sessiond daemon, don't delay |
1510 | * constructor execution. | |
e3426ddc | 1511 | */ |
3f5339b0 | 1512 | ret = handle_register_failed(sock_info); |
321f2351 MD |
1513 | assert(!ret); |
1514 | ust_unlock(); | |
1515 | goto restart; | |
27fe9f21 | 1516 | } |
fc9a0ccb JR |
1517 | fd = ret; |
1518 | ret = lttng_ust_add_fd_to_tracker(fd); | |
1519 | if (ret < 0) { | |
1520 | ret = close(fd); | |
1521 | if (ret) { | |
1522 | PERROR("close on sock_info->socket"); | |
1523 | } | |
1524 | ret = -1; | |
1525 | lttng_ust_unlock_fd_tracker(); | |
1526 | ust_unlock(); | |
1527 | goto quit; | |
1528 | } | |
1529 | ||
321f2351 | 1530 | sock_info->socket = ret; |
fc9a0ccb | 1531 | lttng_ust_unlock_fd_tracker(); |
27fe9f21 | 1532 | |
6548fca4 MD |
1533 | ust_unlock(); |
1534 | /* | |
1535 | * Unlock/relock ust lock because connect is blocking (with | |
1536 | * timeout). Don't delay constructors on the ust lock for too | |
1537 | * long. | |
1538 | */ | |
3327ac33 | 1539 | if (ust_lock()) { |
5b14aab3 MD |
1540 | goto quit; |
1541 | } | |
1542 | ||
46050b1a MD |
1543 | /* |
1544 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1545 | * process lifetime, so we ensure we get ID which is statically |
1546 | * assigned to the root handle. | |
46050b1a MD |
1547 | */ |
1548 | if (sock_info->root_handle == -1) { | |
1549 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1550 | if (ret < 0) { |
46050b1a | 1551 | ERR("Error creating root handle"); |
46050b1a MD |
1552 | goto quit; |
1553 | } | |
1554 | sock_info->root_handle = ret; | |
9eb62b9c | 1555 | } |
1ea11eab | 1556 | |
32ce8569 | 1557 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1558 | if (ret < 0) { |
32ce8569 MD |
1559 | ERR("Error registering to %s ust cmd socket", |
1560 | sock_info->name); | |
c0eedf81 | 1561 | prev_connect_failed = 1; |
11ff9c7d MD |
1562 | /* |
1563 | * If we cannot register to the sessiond daemon, don't | |
1564 | * delay constructor execution. | |
1565 | */ | |
3f5339b0 | 1566 | ret = handle_register_failed(sock_info); |
11ff9c7d | 1567 | assert(!ret); |
17dfb34b | 1568 | ust_unlock(); |
9eb62b9c MD |
1569 | goto restart; |
1570 | } | |
321f2351 MD |
1571 | |
1572 | ust_unlock(); | |
6548fca4 MD |
1573 | /* |
1574 | * Unlock/relock ust lock because connect is blocking (with | |
1575 | * timeout). Don't delay constructors on the ust lock for too | |
1576 | * long. | |
1577 | */ | |
1578 | if (ust_lock()) { | |
1579 | goto quit; | |
1580 | } | |
321f2351 MD |
1581 | |
1582 | /* Connect notify socket */ | |
6548fca4 | 1583 | lttng_ust_lock_fd_tracker(); |
451d66b2 MD |
1584 | ret = ustcomm_connect_unix_sock(sock_info->sock_path, |
1585 | get_connect_sock_timeout()); | |
321f2351 | 1586 | if (ret < 0) { |
6548fca4 | 1587 | lttng_ust_unlock_fd_tracker(); |
321f2351 MD |
1588 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); |
1589 | prev_connect_failed = 1; | |
1590 | ||
321f2351 MD |
1591 | /* |
1592 | * If we cannot find the sessiond daemon, don't delay | |
1593 | * constructor execution. | |
1594 | */ | |
3f5339b0 | 1595 | ret = handle_register_failed(sock_info); |
321f2351 MD |
1596 | assert(!ret); |
1597 | ust_unlock(); | |
1598 | goto restart; | |
1599 | } | |
fc9a0ccb JR |
1600 | |
1601 | fd = ret; | |
1602 | ret = lttng_ust_add_fd_to_tracker(fd); | |
1603 | if (ret < 0) { | |
1604 | ret = close(fd); | |
1605 | if (ret) { | |
1606 | PERROR("close on sock_info->notify_socket"); | |
1607 | } | |
1608 | ret = -1; | |
1609 | lttng_ust_unlock_fd_tracker(); | |
1610 | ust_unlock(); | |
1611 | goto quit; | |
1612 | } | |
1613 | ||
321f2351 | 1614 | sock_info->notify_socket = ret; |
fc9a0ccb | 1615 | lttng_ust_unlock_fd_tracker(); |
321f2351 | 1616 | |
6548fca4 MD |
1617 | ust_unlock(); |
1618 | /* | |
1619 | * Unlock/relock ust lock because connect is blocking (with | |
1620 | * timeout). Don't delay constructors on the ust lock for too | |
1621 | * long. | |
1622 | */ | |
1623 | if (ust_lock()) { | |
1624 | goto quit; | |
1625 | } | |
1626 | ||
321f2351 MD |
1627 | timeout = get_notify_sock_timeout(); |
1628 | if (timeout >= 0) { | |
1629 | /* | |
1630 | * Give at least 10ms to sessiond to reply to | |
1631 | * notifications. | |
1632 | */ | |
1633 | if (timeout < 10) | |
1634 | timeout = 10; | |
1635 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1636 | timeout); | |
1637 | if (ret < 0) { | |
1638 | WARN("Error setting socket receive timeout"); | |
1639 | } | |
1640 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1641 | timeout); | |
1642 | if (ret < 0) { | |
1643 | WARN("Error setting socket send timeout"); | |
1644 | } | |
1645 | } else if (timeout < -1) { | |
1646 | WARN("Unsupported timeout value %ld", timeout); | |
1647 | } | |
1648 | ||
32ce8569 MD |
1649 | ret = register_to_sessiond(sock_info->notify_socket, |
1650 | USTCTL_SOCKET_NOTIFY); | |
1651 | if (ret < 0) { | |
1652 | ERR("Error registering to %s ust notify socket", | |
1653 | sock_info->name); | |
1654 | prev_connect_failed = 1; | |
1655 | /* | |
1656 | * If we cannot register to the sessiond daemon, don't | |
1657 | * delay constructor execution. | |
1658 | */ | |
3f5339b0 | 1659 | ret = handle_register_failed(sock_info); |
32ce8569 MD |
1660 | assert(!ret); |
1661 | ust_unlock(); | |
1662 | goto restart; | |
1663 | } | |
1664 | sock = sock_info->socket; | |
1665 | ||
17dfb34b | 1666 | ust_unlock(); |
46050b1a | 1667 | |
d9e99d10 MD |
1668 | for (;;) { |
1669 | ssize_t len; | |
57773204 | 1670 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1671 | |
57773204 | 1672 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1673 | switch (len) { |
1674 | case 0: /* orderly shutdown */ | |
7dd08bec | 1675 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1676 | if (ust_lock()) { |
d5e1fea6 MD |
1677 | goto quit; |
1678 | } | |
8236ba10 MD |
1679 | /* |
1680 | * Either sessiond has shutdown or refused us by closing the socket. | |
1681 | * In either case, we don't want to delay construction execution, | |
1682 | * and we need to wait before retry. | |
1683 | */ | |
1684 | prev_connect_failed = 1; | |
1685 | /* | |
1686 | * If we cannot register to the sessiond daemon, don't | |
1687 | * delay constructor execution. | |
1688 | */ | |
3f5339b0 | 1689 | ret = handle_register_failed(sock_info); |
8236ba10 MD |
1690 | assert(!ret); |
1691 | ust_unlock(); | |
d9e99d10 | 1692 | goto end; |
e7723462 | 1693 | case sizeof(lum): |
74d81a6c | 1694 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1695 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1696 | if (ret) { |
0dafcd63 MD |
1697 | ERR("Error handling message for %s socket", |
1698 | sock_info->name); | |
1699 | /* | |
1700 | * Close socket if protocol error is | |
1701 | * detected. | |
1702 | */ | |
1703 | goto end; | |
d9e99d10 MD |
1704 | } |
1705 | continue; | |
7bc53e94 MD |
1706 | default: |
1707 | if (len < 0) { | |
1708 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1709 | } else { | |
1710 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1711 | } | |
1712 | if (len == -ECONNRESET) { | |
1713 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1714 | goto end; |
1715 | } | |
1716 | goto end; | |
d9e99d10 MD |
1717 | } |
1718 | ||
1719 | } | |
1720 | end: | |
3327ac33 | 1721 | if (ust_lock()) { |
d5e1fea6 MD |
1722 | goto quit; |
1723 | } | |
f59ed768 MD |
1724 | /* Cleanup socket handles before trying to reconnect */ |
1725 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1726 | ust_unlock(); | |
9eb62b9c | 1727 | goto restart; /* try to reconnect */ |
e33f3265 | 1728 | |
1ea11eab | 1729 | quit: |
e33f3265 | 1730 | ust_unlock(); |
3327ac33 MD |
1731 | |
1732 | pthread_mutex_lock(&ust_exit_mutex); | |
1733 | sock_info->thread_active = 0; | |
1734 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1735 | return NULL; |
1736 | } | |
1737 | ||
2594a5b4 MD |
1738 | /* |
1739 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1740 | */ | |
1741 | __attribute__((weak)) | |
1742 | void lttng_ust_malloc_wrapper_init(void) | |
1743 | { | |
1744 | } | |
1745 | ||
2691221a MD |
1746 | /* |
1747 | * sessiond monitoring thread: monitor presence of global and per-user | |
1748 | * sessiond by polling the application common named pipe. | |
1749 | */ | |
edaa1431 | 1750 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1751 | { |
11ff9c7d | 1752 | struct timespec constructor_timeout; |
ae6a58bf | 1753 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1754 | pthread_attr_t thread_attr; |
cf12a773 | 1755 | int timeout_mode; |
2691221a MD |
1756 | int ret; |
1757 | ||
edaa1431 MD |
1758 | if (uatomic_xchg(&initialized, 1) == 1) |
1759 | return; | |
1760 | ||
eddd8d5d MD |
1761 | /* |
1762 | * Fixup interdependency between TLS fixup mutex (which happens | |
1763 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1764 | * the ust lock. | |
1765 | */ | |
c362addf | 1766 | lttng_ust_fixup_tls(); |
eddd8d5d | 1767 | |
07b57e5e MD |
1768 | lttng_ust_loaded = 1; |
1769 | ||
edaa1431 MD |
1770 | /* |
1771 | * We want precise control over the order in which we construct | |
1772 | * our sub-libraries vs starting to receive commands from | |
1773 | * sessiond (otherwise leading to errors when trying to create | |
1774 | * sessiond before the init functions are completed). | |
1775 | */ | |
2691221a | 1776 | init_usterr(); |
49254388 | 1777 | lttng_ust_getenv_init(); /* Needs init_usterr() to be completed. */ |
edaa1431 | 1778 | init_tracepoint(); |
6548fca4 | 1779 | lttng_ust_init_fd_tracker(); |
f9364363 | 1780 | lttng_ust_clock_init(); |
5e1b7b8b | 1781 | lttng_ust_getcpu_init(); |
cf73e0fe | 1782 | lttng_ust_statedump_init(); |
7dd08bec MD |
1783 | lttng_ring_buffer_metadata_client_init(); |
1784 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1785 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1786 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1787 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1788 | lttng_perf_counter_init(); |
2594a5b4 MD |
1789 | /* |
1790 | * Invoke ust malloc wrapper init before starting other threads. | |
1791 | */ | |
1792 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1793 | |
ff517991 | 1794 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1795 | |
95259bd0 | 1796 | ret = sem_init(&constructor_wait, 0, 0); |
8aadb54a MD |
1797 | if (ret) { |
1798 | PERROR("sem_init"); | |
1799 | } | |
11ff9c7d | 1800 | |
2eab9f28 JR |
1801 | ret = setup_global_apps(); |
1802 | if (ret) { | |
1803 | assert(global_apps.allowed == 0); | |
1804 | DBG("global apps setup returned %d", ret); | |
1805 | } | |
1806 | ||
8d20bf54 | 1807 | ret = setup_local_apps(); |
2691221a | 1808 | if (ret) { |
2eab9f28 | 1809 | assert(local_apps.allowed == 0); |
9ec6895c | 1810 | DBG("local apps setup returned %d", ret); |
2691221a | 1811 | } |
ae6a58bf WP |
1812 | |
1813 | /* A new thread created by pthread_create inherits the signal mask | |
1814 | * from the parent. To avoid any signal being received by the | |
1815 | * listener thread, we block all signals temporarily in the parent, | |
1816 | * while we create the listener thread. | |
1817 | */ | |
1818 | sigfillset(&sig_all_blocked); | |
1819 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1820 | if (ret) { | |
d94d802c | 1821 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1822 | } |
1823 | ||
1879f67f MG |
1824 | ret = pthread_attr_init(&thread_attr); |
1825 | if (ret) { | |
1826 | ERR("pthread_attr_init: %s", strerror(ret)); | |
1827 | } | |
1828 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
1829 | if (ret) { | |
1830 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
1831 | } | |
1832 | ||
2eab9f28 JR |
1833 | if (global_apps.allowed) { |
1834 | pthread_mutex_lock(&ust_exit_mutex); | |
1835 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, | |
1836 | ust_listener_thread, &global_apps); | |
1837 | if (ret) { | |
1838 | ERR("pthread_create global: %s", strerror(ret)); | |
1839 | } | |
1840 | global_apps.thread_active = 1; | |
1841 | pthread_mutex_unlock(&ust_exit_mutex); | |
1842 | } else { | |
1843 | handle_register_done(&global_apps); | |
d94d802c | 1844 | } |
e33f3265 | 1845 | |
8d20bf54 | 1846 | if (local_apps.allowed) { |
c0bbbd5a | 1847 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1848 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 1849 | ust_listener_thread, &local_apps); |
d94d802c MD |
1850 | if (ret) { |
1851 | ERR("pthread_create local: %s", strerror(ret)); | |
1852 | } | |
e33f3265 | 1853 | local_apps.thread_active = 1; |
c0bbbd5a | 1854 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
1855 | } else { |
1856 | handle_register_done(&local_apps); | |
1857 | } | |
1879f67f MG |
1858 | ret = pthread_attr_destroy(&thread_attr); |
1859 | if (ret) { | |
1860 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
1861 | } | |
8d20bf54 | 1862 | |
ae6a58bf WP |
1863 | /* Restore original signal mask in parent */ |
1864 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
1865 | if (ret) { | |
d94d802c | 1866 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1867 | } |
1868 | ||
cf12a773 MD |
1869 | switch (timeout_mode) { |
1870 | case 1: /* timeout wait */ | |
95259bd0 MD |
1871 | do { |
1872 | ret = sem_timedwait(&constructor_wait, | |
1873 | &constructor_timeout); | |
1874 | } while (ret < 0 && errno == EINTR); | |
8aadb54a MD |
1875 | if (ret < 0) { |
1876 | switch (errno) { | |
1877 | case ETIMEDOUT: | |
1878 | ERR("Timed out waiting for lttng-sessiond"); | |
1879 | break; | |
1880 | case EINVAL: | |
1881 | PERROR("sem_timedwait"); | |
1882 | break; | |
1883 | default: | |
1884 | ERR("Unexpected error \"%s\" returned by sem_timedwait", | |
1885 | strerror(errno)); | |
1886 | } | |
cf12a773 MD |
1887 | } |
1888 | break; | |
7b766b16 | 1889 | case -1:/* wait forever */ |
95259bd0 MD |
1890 | do { |
1891 | ret = sem_wait(&constructor_wait); | |
1892 | } while (ret < 0 && errno == EINTR); | |
8aadb54a MD |
1893 | if (ret < 0) { |
1894 | switch (errno) { | |
1895 | case EINVAL: | |
1896 | PERROR("sem_wait"); | |
1897 | break; | |
1898 | default: | |
1899 | ERR("Unexpected error \"%s\" returned by sem_wait", | |
1900 | strerror(errno)); | |
1901 | } | |
1902 | } | |
cf12a773 | 1903 | break; |
7b766b16 | 1904 | case 0: /* no timeout */ |
cf12a773 | 1905 | break; |
11ff9c7d | 1906 | } |
2691221a MD |
1907 | } |
1908 | ||
17dfb34b MD |
1909 | static |
1910 | void lttng_ust_cleanup(int exiting) | |
1911 | { | |
efe0de09 | 1912 | cleanup_sock_info(&global_apps, exiting); |
932cfadb | 1913 | cleanup_sock_info(&local_apps, exiting); |
74f98bc9 | 1914 | local_apps.allowed = 0; |
2eab9f28 | 1915 | global_apps.allowed = 0; |
efe0de09 MD |
1916 | /* |
1917 | * The teardown in this function all affect data structures | |
1918 | * accessed under the UST lock by the listener thread. This | |
1919 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
1920 | * that none of these threads are accessing this data at this | |
1921 | * point. | |
1922 | */ | |
17dfb34b | 1923 | lttng_ust_abi_exit(); |
003fedf4 | 1924 | lttng_ust_events_exit(); |
d58d1454 | 1925 | lttng_perf_counter_exit(); |
34a91bdb | 1926 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 1927 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 1928 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
1929 | lttng_ring_buffer_client_overwrite_exit(); |
1930 | lttng_ring_buffer_metadata_client_exit(); | |
cf73e0fe | 1931 | lttng_ust_statedump_destroy(); |
17dfb34b MD |
1932 | exit_tracepoint(); |
1933 | if (!exiting) { | |
1934 | /* Reinitialize values for fork */ | |
3f5339b0 | 1935 | sem_count = sem_count_initial_value; |
17dfb34b MD |
1936 | lttng_ust_comm_should_quit = 0; |
1937 | initialized = 0; | |
1938 | } | |
1939 | } | |
1940 | ||
edaa1431 | 1941 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
1942 | { |
1943 | int ret; | |
1944 | ||
9eb62b9c MD |
1945 | /* |
1946 | * Using pthread_cancel here because: | |
1947 | * A) we don't want to hang application teardown. | |
1948 | * B) the thread is not allocating any resource. | |
1949 | */ | |
1ea11eab MD |
1950 | |
1951 | /* | |
1952 | * Require the communication thread to quit. Synchronize with | |
1953 | * mutexes to ensure it is not in a mutex critical section when | |
1954 | * pthread_cancel is later called. | |
1955 | */ | |
3327ac33 | 1956 | ust_lock_nocheck(); |
1ea11eab | 1957 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 1958 | ust_unlock(); |
1ea11eab | 1959 | |
3327ac33 | 1960 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 1961 | /* cancel threads */ |
e33f3265 MD |
1962 | if (global_apps.thread_active) { |
1963 | ret = pthread_cancel(global_apps.ust_listener); | |
1964 | if (ret) { | |
1965 | ERR("Error cancelling global ust listener thread: %s", | |
1966 | strerror(ret)); | |
1967 | } else { | |
1968 | global_apps.thread_active = 0; | |
1969 | } | |
2691221a | 1970 | } |
e33f3265 | 1971 | if (local_apps.thread_active) { |
8d20bf54 MD |
1972 | ret = pthread_cancel(local_apps.ust_listener); |
1973 | if (ret) { | |
d94d802c MD |
1974 | ERR("Error cancelling local ust listener thread: %s", |
1975 | strerror(ret)); | |
e33f3265 MD |
1976 | } else { |
1977 | local_apps.thread_active = 0; | |
8d20bf54 | 1978 | } |
8d20bf54 | 1979 | } |
3327ac33 | 1980 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1981 | |
efe0de09 MD |
1982 | /* |
1983 | * Do NOT join threads: use of sys_futex makes it impossible to | |
1984 | * join the threads without using async-cancel, but async-cancel | |
1985 | * is delivered by a signal, which could hit the target thread | |
1986 | * anywhere in its code path, including while the ust_lock() is | |
1987 | * held, causing a deadlock for the other thread. Let the OS | |
1988 | * cleanup the threads if there are stalled in a syscall. | |
1989 | */ | |
17dfb34b | 1990 | lttng_ust_cleanup(1); |
2691221a | 1991 | } |
e822f505 MD |
1992 | |
1993 | /* | |
1994 | * We exclude the worker threads across fork and clone (except | |
1995 | * CLONE_VM), because these system calls only keep the forking thread | |
1996 | * running in the child. Therefore, we don't want to call fork or clone | |
1997 | * in the middle of an tracepoint or ust tracing state modification. | |
1998 | * Holding this mutex protects these structures across fork and clone. | |
1999 | */ | |
b728d87e | 2000 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
2001 | { |
2002 | /* | |
2003 | * Disable signals. This is to avoid that the child intervenes | |
2004 | * before it is properly setup for tracing. It is safer to | |
2005 | * disable all signals, because then we know we are not breaking | |
2006 | * anything by restoring the original mask. | |
2007 | */ | |
2008 | sigset_t all_sigs; | |
2009 | int ret; | |
2010 | ||
c362addf MD |
2011 | /* Fixup lttng-ust TLS. */ |
2012 | lttng_ust_fixup_tls(); | |
2013 | ||
8c90a710 | 2014 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2015 | return; |
e822f505 MD |
2016 | /* Disable signals */ |
2017 | sigfillset(&all_sigs); | |
b728d87e | 2018 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
2019 | if (ret == -1) { |
2020 | PERROR("sigprocmask"); | |
2021 | } | |
458d678c PW |
2022 | |
2023 | pthread_mutex_lock(&ust_fork_mutex); | |
2024 | ||
3327ac33 | 2025 | ust_lock_nocheck(); |
e822f505 MD |
2026 | rcu_bp_before_fork(); |
2027 | } | |
2028 | ||
b728d87e | 2029 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
2030 | { |
2031 | int ret; | |
2032 | ||
17dfb34b MD |
2033 | DBG("process %d", getpid()); |
2034 | ust_unlock(); | |
458d678c PW |
2035 | |
2036 | pthread_mutex_unlock(&ust_fork_mutex); | |
2037 | ||
e822f505 | 2038 | /* Restore signals */ |
23c8854a | 2039 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
2040 | if (ret == -1) { |
2041 | PERROR("sigprocmask"); | |
2042 | } | |
2043 | } | |
2044 | ||
b728d87e | 2045 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 2046 | { |
8c90a710 | 2047 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2048 | return; |
17dfb34b | 2049 | DBG("process %d", getpid()); |
e822f505 MD |
2050 | rcu_bp_after_fork_parent(); |
2051 | /* Release mutexes and reenable signals */ | |
b728d87e | 2052 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
2053 | } |
2054 | ||
17dfb34b MD |
2055 | /* |
2056 | * After fork, in the child, we need to cleanup all the leftover state, | |
2057 | * except the worker thread which already magically disappeared thanks | |
2058 | * to the weird Linux fork semantics. After tyding up, we call | |
2059 | * lttng_ust_init() again to start over as a new PID. | |
2060 | * | |
2061 | * This is meant for forks() that have tracing in the child between the | |
2062 | * fork and following exec call (if there is any). | |
2063 | */ | |
b728d87e | 2064 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 2065 | { |
8c90a710 | 2066 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2067 | return; |
77971c85 | 2068 | lttng_context_vpid_reset(); |
8478887d | 2069 | lttng_context_vtid_reset(); |
efe79472 | 2070 | lttng_context_procname_reset(); |
17dfb34b | 2071 | DBG("process %d", getpid()); |
e822f505 MD |
2072 | /* Release urcu mutexes */ |
2073 | rcu_bp_after_fork_child(); | |
17dfb34b | 2074 | lttng_ust_cleanup(0); |
e822f505 | 2075 | /* Release mutexes and reenable signals */ |
b728d87e | 2076 | ust_after_fork_common(restore_sigset); |
318dfea9 | 2077 | lttng_ust_init(); |
e822f505 | 2078 | } |
95c25348 | 2079 | |
246be17e | 2080 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
2081 | { |
2082 | struct sock_info *sock_info = owner; | |
37dddb65 | 2083 | sock_info->statedump_pending = 1; |
95c25348 | 2084 | } |