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 |
2691221a MD |
23 | #include <sys/types.h> |
24 | #include <sys/socket.h> | |
7fc90dca MD |
25 | #include <sys/mman.h> |
26 | #include <sys/stat.h> | |
58d4b2a2 MD |
27 | #include <sys/types.h> |
28 | #include <sys/wait.h> | |
7fc90dca | 29 | #include <fcntl.h> |
2691221a MD |
30 | #include <unistd.h> |
31 | #include <errno.h> | |
d9e99d10 | 32 | #include <pthread.h> |
11ff9c7d MD |
33 | #include <semaphore.h> |
34 | #include <time.h> | |
1ea11eab | 35 | #include <assert.h> |
e822f505 | 36 | #include <signal.h> |
95259bd0 | 37 | #include <urcu/uatomic.h> |
80e2814b | 38 | #include <urcu/futex.h> |
c117fb1b | 39 | #include <urcu/compiler.h> |
1ea11eab | 40 | |
4318ae1b | 41 | #include <lttng/ust-events.h> |
4318ae1b | 42 | #include <lttng/ust-abi.h> |
4318ae1b | 43 | #include <lttng/ust.h> |
7bc53e94 | 44 | #include <lttng/ust-error.h> |
74d81a6c | 45 | #include <lttng/ust-ctl.h> |
8c90a710 | 46 | #include <urcu/tls-compat.h> |
44c72f10 MD |
47 | #include <ust-comm.h> |
48 | #include <usterr-signal-safe.h> | |
cd54f6d9 | 49 | #include <helper.h> |
44c72f10 | 50 | #include "tracepoint-internal.h" |
7dd08bec | 51 | #include "lttng-tracer-core.h" |
08114193 | 52 | #include "compat.h" |
f645cfa7 | 53 | #include "../libringbuffer/tlsfixup.h" |
394598c1 | 54 | #include "lttng-ust-baddr.h" |
9fc0207b | 55 | #include "getenv.h" |
edaa1431 MD |
56 | |
57 | /* | |
58 | * Has lttng ust comm constructor been called ? | |
59 | */ | |
60 | static int initialized; | |
61 | ||
1ea11eab | 62 | /* |
17dfb34b MD |
63 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
64 | * Held when handling a command, also held by fork() to deal with | |
65 | * removal of threads, and by exit path. | |
3327ac33 MD |
66 | * |
67 | * The UST lock is the centralized mutex across UST tracing control and | |
68 | * probe registration. | |
69 | * | |
70 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 71 | * |
4770bd47 MD |
72 | * ust_fork_mutex must never nest in ust_mutex. |
73 | * | |
d58d1454 MD |
74 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
75 | * counter lazy initialization called by events within the statedump, | |
76 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
77 | * |
78 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
79 | * it is taken within the library constructor. | |
3327ac33 MD |
80 | */ |
81 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
82 | ||
d58d1454 MD |
83 | /* Allow nesting the ust_mutex within the same thread. */ |
84 | static DEFINE_URCU_TLS(int, ust_mutex_nest); | |
85 | ||
3327ac33 MD |
86 | /* |
87 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
88 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
89 | * internal libc lock, cannot nest within ust_mutex. | |
90 | * | |
91 | * It never nests within a ust_mutex. | |
1ea11eab | 92 | */ |
3327ac33 | 93 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 94 | |
458d678c PW |
95 | /* |
96 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
97 | * prevents the dynamic loader lock to be taken (by base address statedump | |
98 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
99 | * the dynamic loader lock. | |
100 | */ | |
101 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
102 | ||
1ea11eab MD |
103 | /* Should the ust comm thread quit ? */ |
104 | static int lttng_ust_comm_should_quit; | |
105 | ||
3327ac33 | 106 | /* |
d58d1454 | 107 | * Return 0 on success, -1 if should quit. |
3327ac33 | 108 | * The lock is taken in both cases. |
d58d1454 | 109 | * Signal-safe. |
3327ac33 MD |
110 | */ |
111 | int ust_lock(void) | |
112 | { | |
d58d1454 | 113 | sigset_t sig_all_blocked, orig_mask; |
3beaf004 | 114 | int ret, oldstate; |
d58d1454 | 115 | |
3beaf004 MD |
116 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
117 | if (ret) { | |
118 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
119 | } | |
120 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
121 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
122 | } | |
d58d1454 MD |
123 | sigfillset(&sig_all_blocked); |
124 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
125 | if (ret) { | |
126 | ERR("pthread_sigmask: %s", strerror(ret)); | |
127 | } | |
128 | if (!URCU_TLS(ust_mutex_nest)++) | |
129 | pthread_mutex_lock(&ust_mutex); | |
130 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
131 | if (ret) { | |
132 | ERR("pthread_sigmask: %s", strerror(ret)); | |
133 | } | |
3327ac33 MD |
134 | if (lttng_ust_comm_should_quit) { |
135 | return -1; | |
136 | } else { | |
137 | return 0; | |
138 | } | |
139 | } | |
140 | ||
141 | /* | |
142 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
143 | * they are already nested within the dynamic loader lock, and therefore | |
144 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 145 | * Signal-safe. |
3327ac33 MD |
146 | */ |
147 | void ust_lock_nocheck(void) | |
148 | { | |
d58d1454 | 149 | sigset_t sig_all_blocked, orig_mask; |
3beaf004 | 150 | int ret, oldstate; |
d58d1454 | 151 | |
3beaf004 MD |
152 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
153 | if (ret) { | |
154 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
155 | } | |
156 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
157 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
158 | } | |
d58d1454 MD |
159 | sigfillset(&sig_all_blocked); |
160 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
161 | if (ret) { | |
162 | ERR("pthread_sigmask: %s", strerror(ret)); | |
163 | } | |
164 | if (!URCU_TLS(ust_mutex_nest)++) | |
165 | pthread_mutex_lock(&ust_mutex); | |
166 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
167 | if (ret) { | |
168 | ERR("pthread_sigmask: %s", strerror(ret)); | |
169 | } | |
3327ac33 MD |
170 | } |
171 | ||
d58d1454 MD |
172 | /* |
173 | * Signal-safe. | |
174 | */ | |
3327ac33 MD |
175 | void ust_unlock(void) |
176 | { | |
d58d1454 | 177 | sigset_t sig_all_blocked, orig_mask; |
3beaf004 | 178 | int ret, oldstate; |
d58d1454 MD |
179 | |
180 | sigfillset(&sig_all_blocked); | |
181 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
182 | if (ret) { | |
183 | ERR("pthread_sigmask: %s", strerror(ret)); | |
184 | } | |
185 | if (!--URCU_TLS(ust_mutex_nest)) | |
186 | pthread_mutex_unlock(&ust_mutex); | |
187 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
188 | if (ret) { | |
189 | ERR("pthread_sigmask: %s", strerror(ret)); | |
190 | } | |
3beaf004 MD |
191 | ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); |
192 | if (ret) { | |
193 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
194 | } | |
195 | if (oldstate != PTHREAD_CANCEL_DISABLE) { | |
196 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
197 | } | |
3327ac33 MD |
198 | } |
199 | ||
11ff9c7d MD |
200 | /* |
201 | * Wait for either of these before continuing to the main | |
202 | * program: | |
203 | * - the register_done message from sessiond daemon | |
204 | * (will let the sessiond daemon enable sessions before main | |
205 | * starts.) | |
206 | * - sessiond daemon is not reachable. | |
207 | * - timeout (ensuring applications are resilient to session | |
208 | * daemon problems). | |
209 | */ | |
210 | static sem_t constructor_wait; | |
950aab0c MD |
211 | /* |
212 | * Doing this for both the global and local sessiond. | |
213 | */ | |
95259bd0 | 214 | static int sem_count = { 2 }; |
11ff9c7d | 215 | |
e8508a49 MD |
216 | /* |
217 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
218 | * from liblttng-ust does not execute the pre/post fork handlers. | |
219 | */ | |
8c90a710 | 220 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 221 | |
1ea11eab MD |
222 | /* |
223 | * Info about socket and associated listener thread. | |
224 | */ | |
225 | struct sock_info { | |
11ff9c7d | 226 | const char *name; |
1ea11eab | 227 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 228 | int root_handle; |
8d20bf54 MD |
229 | int constructor_sem_posted; |
230 | int allowed; | |
44e073f5 | 231 | int global; |
e33f3265 | 232 | int thread_active; |
7fc90dca MD |
233 | |
234 | char sock_path[PATH_MAX]; | |
235 | int socket; | |
32ce8569 | 236 | int notify_socket; |
7fc90dca MD |
237 | |
238 | char wait_shm_path[PATH_MAX]; | |
239 | char *wait_shm_mmap; | |
37dddb65 MD |
240 | /* Keep track of lazy state dump not performed yet. */ |
241 | int statedump_pending; | |
1ea11eab | 242 | }; |
2691221a MD |
243 | |
244 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 245 | struct sock_info global_apps = { |
11ff9c7d | 246 | .name = "global", |
44e073f5 | 247 | .global = 1, |
7fc90dca | 248 | |
46050b1a | 249 | .root_handle = -1, |
8d20bf54 | 250 | .allowed = 1, |
e33f3265 | 251 | .thread_active = 0, |
7fc90dca | 252 | |
32ce8569 | 253 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 254 | .socket = -1, |
32ce8569 | 255 | .notify_socket = -1, |
7fc90dca | 256 | |
32ce8569 | 257 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 258 | |
37dddb65 | 259 | .statedump_pending = 0, |
1ea11eab | 260 | }; |
2691221a MD |
261 | |
262 | /* TODO: allow global_apps_sock_path override */ | |
263 | ||
1ea11eab | 264 | struct sock_info local_apps = { |
11ff9c7d | 265 | .name = "local", |
44e073f5 | 266 | .global = 0, |
46050b1a | 267 | .root_handle = -1, |
8d20bf54 | 268 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 269 | .thread_active = 0, |
7fc90dca MD |
270 | |
271 | .socket = -1, | |
32ce8569 | 272 | .notify_socket = -1, |
95c25348 | 273 | |
37dddb65 | 274 | .statedump_pending = 0, |
1ea11eab | 275 | }; |
2691221a | 276 | |
37ed587a MD |
277 | static int wait_poll_fallback; |
278 | ||
74d81a6c MD |
279 | static const char *cmd_name_mapping[] = { |
280 | [ LTTNG_UST_RELEASE ] = "Release", | |
281 | [ LTTNG_UST_SESSION ] = "Create Session", | |
282 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
283 | ||
284 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
285 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
286 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
287 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
288 | ||
289 | /* Session FD commands */ | |
290 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
291 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
292 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
293 | ||
294 | /* Channel FD commands */ | |
295 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
296 | [ LTTNG_UST_EVENT ] = "Create Event", | |
297 | ||
298 | /* Event and Channel FD commands */ | |
299 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
300 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
301 | ||
302 | /* Event, Channel and Session commands */ | |
303 | [ LTTNG_UST_ENABLE ] = "Enable", | |
304 | [ LTTNG_UST_DISABLE ] = "Disable", | |
305 | ||
306 | /* Tracepoint list commands */ | |
307 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
308 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
309 | ||
310 | /* Event FD commands */ | |
311 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 312 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
74d81a6c MD |
313 | }; |
314 | ||
ff517991 MD |
315 | static const char *str_timeout; |
316 | static int got_timeout_env; | |
317 | ||
7dd08bec | 318 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 319 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 320 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 321 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
322 | extern void lttng_ring_buffer_metadata_client_init(void); |
323 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 324 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 325 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 326 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 327 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 328 | |
3c6f6263 AM |
329 | /* |
330 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
331 | * pointer. | |
332 | */ | |
333 | static | |
334 | const char *get_lttng_home_dir(void) | |
335 | { | |
336 | const char *val; | |
337 | ||
9fc0207b | 338 | val = (const char *) lttng_secure_getenv("LTTNG_HOME"); |
3c6f6263 AM |
339 | if (val != NULL) { |
340 | return val; | |
341 | } | |
9fc0207b | 342 | return (const char *) lttng_secure_getenv("HOME"); |
3c6f6263 AM |
343 | } |
344 | ||
a903623f MD |
345 | /* |
346 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
347 | */ | |
348 | static | |
349 | void lttng_fixup_nest_count_tls(void) | |
350 | { | |
8c90a710 | 351 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
352 | } |
353 | ||
d58d1454 MD |
354 | static |
355 | void lttng_fixup_ust_mutex_nest_tls(void) | |
356 | { | |
357 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
358 | } | |
359 | ||
f4695bf8 MD |
360 | /* |
361 | * Fixup urcu bp TLS. | |
362 | */ | |
363 | static | |
364 | void lttng_fixup_urcu_bp_tls(void) | |
365 | { | |
366 | rcu_read_lock(); | |
367 | rcu_read_unlock(); | |
368 | } | |
369 | ||
32ce8569 MD |
370 | int lttng_get_notify_socket(void *owner) |
371 | { | |
372 | struct sock_info *info = owner; | |
373 | ||
374 | return info->notify_socket; | |
375 | } | |
376 | ||
74d81a6c MD |
377 | static |
378 | void print_cmd(int cmd, int handle) | |
379 | { | |
380 | const char *cmd_name = "Unknown"; | |
381 | ||
fd67a004 MD |
382 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
383 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
384 | cmd_name = cmd_name_mapping[cmd]; |
385 | } | |
fd67a004 MD |
386 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
387 | cmd_name, cmd, | |
74d81a6c MD |
388 | lttng_ust_obj_get_name(handle), handle); |
389 | } | |
390 | ||
2691221a | 391 | static |
8d20bf54 | 392 | int setup_local_apps(void) |
2691221a MD |
393 | { |
394 | const char *home_dir; | |
7fc90dca | 395 | uid_t uid; |
2691221a | 396 | |
7fc90dca | 397 | uid = getuid(); |
8d20bf54 MD |
398 | /* |
399 | * Disallow per-user tracing for setuid binaries. | |
400 | */ | |
7fc90dca | 401 | if (uid != geteuid()) { |
9ec6895c | 402 | assert(local_apps.allowed == 0); |
d0a1ae63 | 403 | return 0; |
8d20bf54 | 404 | } |
3c6f6263 | 405 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
406 | if (!home_dir) { |
407 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
408 | assert(local_apps.allowed == 0); | |
2691221a | 409 | return -ENOENT; |
9ec6895c MD |
410 | } |
411 | local_apps.allowed = 1; | |
32ce8569 MD |
412 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
413 | home_dir, | |
414 | LTTNG_DEFAULT_HOME_RUNDIR, | |
415 | LTTNG_UST_SOCK_FILENAME); | |
416 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
417 | LTTNG_UST_WAIT_FILENAME, | |
418 | uid); | |
2691221a MD |
419 | return 0; |
420 | } | |
421 | ||
ff517991 MD |
422 | /* |
423 | * Get notify_sock timeout, in ms. | |
380691fa | 424 | * -1: wait forever. 0: don't wait. >0: timeout, in ms. |
ff517991 MD |
425 | */ |
426 | static | |
427 | long get_timeout(void) | |
428 | { | |
429 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
430 | ||
431 | if (!got_timeout_env) { | |
432 | str_timeout = getenv("LTTNG_UST_REGISTER_TIMEOUT"); | |
433 | got_timeout_env = 1; | |
434 | } | |
435 | if (str_timeout) | |
436 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
437 | return constructor_delay_ms; | |
438 | } | |
439 | ||
440 | static | |
441 | long get_notify_sock_timeout(void) | |
442 | { | |
443 | return get_timeout(); | |
444 | } | |
445 | ||
446 | /* | |
380691fa | 447 | * Return values: -1: wait forever. 0: don't wait. 1: timeout wait. |
ff517991 MD |
448 | */ |
449 | static | |
450 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
451 | { | |
452 | long constructor_delay_ms; | |
453 | int ret; | |
454 | ||
455 | constructor_delay_ms = get_timeout(); | |
456 | ||
457 | switch (constructor_delay_ms) { | |
458 | case -1:/* fall-through */ | |
459 | case 0: | |
460 | return constructor_delay_ms; | |
461 | default: | |
462 | break; | |
463 | } | |
464 | ||
465 | /* | |
466 | * If we are unable to find the current time, don't wait. | |
467 | */ | |
468 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
469 | if (ret) { | |
380691fa JG |
470 | /* Don't wait. */ |
471 | return 0; | |
ff517991 MD |
472 | } |
473 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
474 | constructor_timeout->tv_nsec += | |
475 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
476 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
477 | constructor_timeout->tv_sec++; | |
478 | constructor_timeout->tv_nsec -= 1000000000UL; | |
479 | } | |
380691fa | 480 | /* Timeout wait (constructor_delay_ms). */ |
ff517991 MD |
481 | return 1; |
482 | } | |
483 | ||
2691221a | 484 | static |
32ce8569 | 485 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 486 | { |
32ce8569 MD |
487 | return ustcomm_send_reg_msg(socket, |
488 | type, | |
489 | CAA_BITS_PER_LONG, | |
490 | lttng_alignof(uint8_t) * CHAR_BIT, | |
491 | lttng_alignof(uint16_t) * CHAR_BIT, | |
492 | lttng_alignof(uint32_t) * CHAR_BIT, | |
493 | lttng_alignof(uint64_t) * CHAR_BIT, | |
494 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
495 | } |
496 | ||
d9e99d10 | 497 | static |
57773204 | 498 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 499 | { |
9eb62b9c | 500 | ssize_t len; |
d3a492d1 | 501 | |
57773204 | 502 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 503 | switch (len) { |
a4be8962 | 504 | case sizeof(*lur): |
d3a492d1 MD |
505 | DBG("message successfully sent"); |
506 | return 0; | |
7bc53e94 MD |
507 | default: |
508 | if (len == -ECONNRESET) { | |
509 | DBG("remote end closed connection"); | |
d3a492d1 MD |
510 | return 0; |
511 | } | |
7bc53e94 MD |
512 | if (len < 0) |
513 | return len; | |
514 | DBG("incorrect message size: %zd", len); | |
515 | return -EINVAL; | |
d3a492d1 MD |
516 | } |
517 | } | |
518 | ||
519 | static | |
edaa1431 | 520 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
521 | { |
522 | int ret; | |
523 | ||
edaa1431 MD |
524 | if (sock_info->constructor_sem_posted) |
525 | return 0; | |
526 | sock_info->constructor_sem_posted = 1; | |
56cd7e2f MD |
527 | if (uatomic_read(&sem_count) <= 0) { |
528 | return 0; | |
529 | } | |
95259bd0 MD |
530 | ret = uatomic_add_return(&sem_count, -1); |
531 | if (ret == 0) { | |
532 | ret = sem_post(&constructor_wait); | |
533 | assert(!ret); | |
534 | } | |
11ff9c7d MD |
535 | return 0; |
536 | } | |
537 | ||
37dddb65 MD |
538 | /* |
539 | * Only execute pending statedump after the constructor semaphore has | |
540 | * been posted by each listener thread. This means statedump will only | |
541 | * be performed after the "registration done" command is received from | |
542 | * each session daemon the application is connected to. | |
543 | * | |
544 | * This ensures we don't run into deadlock issues with the dynamic | |
545 | * loader mutex, which is held while the constructor is called and | |
546 | * waiting on the constructor semaphore. All operations requiring this | |
547 | * dynamic loader lock need to be postponed using this mechanism. | |
548 | */ | |
549 | static | |
550 | void handle_pending_statedump(struct sock_info *sock_info) | |
551 | { | |
552 | int ctor_passed = sock_info->constructor_sem_posted; | |
553 | ||
554 | if (ctor_passed && sock_info->statedump_pending) { | |
555 | sock_info->statedump_pending = 0; | |
2932a87f | 556 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 557 | lttng_handle_pending_statedump(sock_info); |
458d678c | 558 | pthread_mutex_unlock(&ust_fork_mutex); |
37dddb65 MD |
559 | } |
560 | } | |
561 | ||
11ff9c7d MD |
562 | static |
563 | int handle_message(struct sock_info *sock_info, | |
57773204 | 564 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 565 | { |
1ea11eab | 566 | int ret = 0; |
b61ce3b2 | 567 | const struct lttng_ust_objd_ops *ops; |
57773204 | 568 | struct ustcomm_ust_reply lur; |
ef9ff354 | 569 | union ust_args args; |
40003310 | 570 | ssize_t len; |
1ea11eab | 571 | |
46050b1a MD |
572 | memset(&lur, 0, sizeof(lur)); |
573 | ||
3327ac33 | 574 | if (ust_lock()) { |
74d81a6c | 575 | ret = -LTTNG_UST_ERR_EXITING; |
7d60854f | 576 | goto error; |
1ea11eab | 577 | } |
9eb62b9c | 578 | |
46050b1a MD |
579 | ops = objd_ops(lum->handle); |
580 | if (!ops) { | |
581 | ret = -ENOENT; | |
7d60854f | 582 | goto error; |
1ea11eab | 583 | } |
46050b1a MD |
584 | |
585 | switch (lum->cmd) { | |
11ff9c7d MD |
586 | case LTTNG_UST_REGISTER_DONE: |
587 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 588 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
589 | else |
590 | ret = -EINVAL; | |
591 | break; | |
46050b1a MD |
592 | case LTTNG_UST_RELEASE: |
593 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
594 | ret = -EPERM; | |
595 | else | |
1849ef7c | 596 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 597 | break; |
2d78951a MD |
598 | case LTTNG_UST_FILTER: |
599 | { | |
600 | /* Receive filter data */ | |
f488575f | 601 | struct lttng_ust_filter_bytecode_node *bytecode; |
2d78951a | 602 | |
cd54f6d9 | 603 | if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) { |
7bc53e94 | 604 | ERR("Filter data size is too large: %u bytes", |
2d78951a MD |
605 | lum->u.filter.data_size); |
606 | ret = -EINVAL; | |
607 | goto error; | |
608 | } | |
2734ca65 | 609 | |
885b1dfd | 610 | if (lum->u.filter.reloc_offset > lum->u.filter.data_size) { |
7bc53e94 | 611 | ERR("Filter reloc offset %u is not within data", |
2734ca65 CB |
612 | lum->u.filter.reloc_offset); |
613 | ret = -EINVAL; | |
614 | goto error; | |
615 | } | |
616 | ||
cd54f6d9 MD |
617 | bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size); |
618 | if (!bytecode) { | |
619 | ret = -ENOMEM; | |
620 | goto error; | |
621 | } | |
f488575f | 622 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, |
2d78951a MD |
623 | lum->u.filter.data_size); |
624 | switch (len) { | |
625 | case 0: /* orderly shutdown */ | |
626 | ret = 0; | |
cd54f6d9 | 627 | free(bytecode); |
2d78951a | 628 | goto error; |
2d78951a MD |
629 | default: |
630 | if (len == lum->u.filter.data_size) { | |
7bc53e94 | 631 | DBG("filter data received"); |
2d78951a | 632 | break; |
7bc53e94 MD |
633 | } else if (len < 0) { |
634 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
635 | if (len == -ECONNRESET) { | |
636 | ERR("%s remote end closed connection", sock_info->name); | |
637 | ret = len; | |
638 | free(bytecode); | |
639 | goto error; | |
640 | } | |
641 | ret = len; | |
eb8bf361 | 642 | free(bytecode); |
7d60854f | 643 | goto error; |
2d78951a | 644 | } else { |
7bc53e94 | 645 | DBG("incorrect filter data message size: %zd", len); |
2d78951a | 646 | ret = -EINVAL; |
cd54f6d9 | 647 | free(bytecode); |
7d60854f | 648 | goto error; |
2d78951a MD |
649 | } |
650 | } | |
f488575f MD |
651 | bytecode->bc.len = lum->u.filter.data_size; |
652 | bytecode->bc.reloc_offset = lum->u.filter.reloc_offset; | |
3f6fd224 | 653 | bytecode->bc.seqnum = lum->u.filter.seqnum; |
cd54f6d9 | 654 | if (ops->cmd) { |
2d78951a | 655 | ret = ops->cmd(lum->handle, lum->cmd, |
cd54f6d9 | 656 | (unsigned long) bytecode, |
f59ed768 | 657 | &args, sock_info); |
cd54f6d9 MD |
658 | if (ret) { |
659 | free(bytecode); | |
660 | } | |
661 | /* don't free bytecode if everything went fine. */ | |
662 | } else { | |
2d78951a | 663 | ret = -ENOSYS; |
cd54f6d9 MD |
664 | free(bytecode); |
665 | } | |
2d78951a MD |
666 | break; |
667 | } | |
86e36163 JI |
668 | case LTTNG_UST_EXCLUSION: |
669 | { | |
670 | /* Receive exclusion names */ | |
671 | struct lttng_ust_excluder_node *node; | |
672 | unsigned int count; | |
673 | ||
674 | count = lum->u.exclusion.count; | |
675 | if (count == 0) { | |
676 | /* There are no names to read */ | |
677 | ret = 0; | |
678 | goto error; | |
679 | } | |
680 | node = zmalloc(sizeof(*node) + | |
681 | count * LTTNG_UST_SYM_NAME_LEN); | |
682 | if (!node) { | |
683 | ret = -ENOMEM; | |
684 | goto error; | |
685 | } | |
686 | node->excluder.count = count; | |
687 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
688 | count * LTTNG_UST_SYM_NAME_LEN); | |
689 | switch (len) { | |
690 | case 0: /* orderly shutdown */ | |
691 | ret = 0; | |
692 | free(node); | |
693 | goto error; | |
694 | default: | |
695 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
696 | DBG("Exclusion data received"); | |
697 | break; | |
698 | } else if (len < 0) { | |
699 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
700 | if (len == -ECONNRESET) { | |
701 | ERR("%s remote end closed connection", sock_info->name); | |
702 | ret = len; | |
703 | free(node); | |
704 | goto error; | |
705 | } | |
706 | ret = len; | |
707 | free(node); | |
7d60854f | 708 | goto error; |
86e36163 JI |
709 | } else { |
710 | DBG("Incorrect exclusion data message size: %zd", len); | |
711 | ret = -EINVAL; | |
712 | free(node); | |
7d60854f | 713 | goto error; |
86e36163 JI |
714 | } |
715 | } | |
716 | if (ops->cmd) { | |
717 | ret = ops->cmd(lum->handle, lum->cmd, | |
718 | (unsigned long) node, | |
719 | &args, sock_info); | |
720 | if (ret) { | |
721 | free(node); | |
722 | } | |
723 | /* Don't free exclusion data if everything went fine. */ | |
724 | } else { | |
725 | ret = -ENOSYS; | |
726 | free(node); | |
727 | } | |
728 | break; | |
729 | } | |
74d81a6c MD |
730 | case LTTNG_UST_CHANNEL: |
731 | { | |
732 | void *chan_data; | |
ff0f5728 | 733 | int wakeup_fd; |
74d81a6c MD |
734 | |
735 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
736 | &chan_data, lum->u.channel.len, |
737 | &wakeup_fd); | |
74d81a6c MD |
738 | switch (len) { |
739 | case 0: /* orderly shutdown */ | |
740 | ret = 0; | |
741 | goto error; | |
742 | default: | |
743 | if (len == lum->u.channel.len) { | |
744 | DBG("channel data received"); | |
745 | break; | |
746 | } else if (len < 0) { | |
747 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
748 | if (len == -ECONNRESET) { | |
749 | ERR("%s remote end closed connection", sock_info->name); | |
750 | ret = len; | |
751 | goto error; | |
752 | } | |
753 | ret = len; | |
7d60854f | 754 | goto error; |
74d81a6c MD |
755 | } else { |
756 | DBG("incorrect channel data message size: %zd", len); | |
757 | ret = -EINVAL; | |
7d60854f | 758 | goto error; |
74d81a6c MD |
759 | } |
760 | } | |
761 | args.channel.chan_data = chan_data; | |
ff0f5728 | 762 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
763 | if (ops->cmd) |
764 | ret = ops->cmd(lum->handle, lum->cmd, | |
765 | (unsigned long) &lum->u, | |
766 | &args, sock_info); | |
767 | else | |
768 | ret = -ENOSYS; | |
769 | break; | |
770 | } | |
771 | case LTTNG_UST_STREAM: | |
772 | { | |
773 | /* Receive shm_fd, wakeup_fd */ | |
774 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
775 | &lum->u.stream.len, | |
776 | &args.stream.shm_fd, | |
777 | &args.stream.wakeup_fd); | |
778 | if (ret) { | |
7d60854f | 779 | goto error; |
74d81a6c MD |
780 | } |
781 | if (ops->cmd) | |
782 | ret = ops->cmd(lum->handle, lum->cmd, | |
783 | (unsigned long) &lum->u, | |
784 | &args, sock_info); | |
785 | else | |
786 | ret = -ENOSYS; | |
787 | break; | |
788 | } | |
d9e99d10 | 789 | default: |
46050b1a MD |
790 | if (ops->cmd) |
791 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 792 | (unsigned long) &lum->u, |
f59ed768 | 793 | &args, sock_info); |
46050b1a MD |
794 | else |
795 | ret = -ENOSYS; | |
796 | break; | |
d9e99d10 | 797 | } |
46050b1a | 798 | |
46050b1a MD |
799 | lur.handle = lum->handle; |
800 | lur.cmd = lum->cmd; | |
801 | lur.ret_val = ret; | |
802 | if (ret >= 0) { | |
7bc53e94 | 803 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 804 | } else { |
7bc53e94 MD |
805 | /* |
806 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
807 | * error that are not caused by the transport, except if | |
808 | * we already have a more precise error message to | |
809 | * report. | |
810 | */ | |
64b2564e DG |
811 | if (ret > -LTTNG_UST_ERR) { |
812 | /* Translate code to UST error. */ | |
813 | switch (ret) { | |
814 | case -EEXIST: | |
815 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
816 | break; | |
817 | case -EINVAL: | |
818 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
819 | break; | |
820 | case -ENOENT: | |
821 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
822 | break; | |
823 | case -EPERM: | |
824 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
825 | break; | |
826 | case -ENOSYS: | |
827 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
828 | break; | |
829 | default: | |
830 | lur.ret_code = -LTTNG_UST_ERR; | |
831 | break; | |
832 | } | |
833 | } else { | |
7bc53e94 | 834 | lur.ret_code = ret; |
64b2564e | 835 | } |
46050b1a | 836 | } |
e6ea14c5 MD |
837 | if (ret >= 0) { |
838 | switch (lum->cmd) { | |
e6ea14c5 MD |
839 | case LTTNG_UST_TRACER_VERSION: |
840 | lur.u.version = lum->u.version; | |
841 | break; | |
842 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
843 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
844 | break; | |
845 | } | |
381c0f1e | 846 | } |
74d81a6c | 847 | DBG("Return value: %d", lur.ret_val); |
46050b1a | 848 | ret = send_reply(sock, &lur); |
193183fb | 849 | if (ret < 0) { |
7bc53e94 | 850 | DBG("error sending reply"); |
193183fb MD |
851 | goto error; |
852 | } | |
46050b1a | 853 | |
40003310 MD |
854 | /* |
855 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
856 | * after the reply. | |
857 | */ | |
7bc53e94 | 858 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
859 | switch (lum->cmd) { |
860 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
861 | len = ustcomm_send_unix_sock(sock, | |
862 | &args.field_list.entry, | |
863 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
864 | if (len < 0) { |
865 | ret = len; | |
866 | goto error; | |
867 | } | |
40003310 | 868 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 869 | ret = -EINVAL; |
40003310 MD |
870 | goto error; |
871 | } | |
872 | } | |
873 | } | |
ef9ff354 | 874 | |
381c0f1e | 875 | error: |
17dfb34b | 876 | ust_unlock(); |
d9e99d10 | 877 | |
37dddb65 MD |
878 | /* |
879 | * Performed delayed statedump operations outside of the UST | |
880 | * lock. We need to take the dynamic loader lock before we take | |
881 | * the UST lock internally within handle_pending_statedump(). | |
882 | */ | |
883 | handle_pending_statedump(sock_info); | |
246be17e | 884 | |
37dddb65 | 885 | return ret; |
246be17e PW |
886 | } |
887 | ||
46050b1a | 888 | static |
efe0de09 | 889 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
890 | { |
891 | int ret; | |
892 | ||
5b14aab3 MD |
893 | if (sock_info->root_handle != -1) { |
894 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
895 | if (ret) { | |
896 | ERR("Error unref root handle"); | |
897 | } | |
898 | sock_info->root_handle = -1; | |
899 | } | |
900 | sock_info->constructor_sem_posted = 0; | |
901 | ||
902 | /* | |
903 | * wait_shm_mmap, socket and notify socket are used by listener | |
904 | * threads outside of the ust lock, so we cannot tear them down | |
905 | * ourselves, because we cannot join on these threads. Leave | |
906 | * responsibility of cleaning up these resources to the OS | |
907 | * process exit. | |
908 | */ | |
909 | if (exiting) | |
910 | return; | |
911 | ||
46050b1a | 912 | if (sock_info->socket != -1) { |
e6973a89 | 913 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 914 | if (ret) { |
32ce8569 | 915 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
916 | } |
917 | sock_info->socket = -1; | |
918 | } | |
32ce8569 MD |
919 | if (sock_info->notify_socket != -1) { |
920 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
921 | if (ret) { | |
922 | ERR("Error closing ust notify socket"); | |
923 | } | |
924 | sock_info->notify_socket = -1; | |
925 | } | |
5b14aab3 | 926 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
927 | long page_size; |
928 | ||
929 | page_size = sysconf(_SC_PAGE_SIZE); | |
355e3ac6 MD |
930 | if (page_size <= 0) { |
931 | if (!page_size) { | |
932 | errno = EINVAL; | |
933 | } | |
934 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
935 | } else { | |
172d6b68 MD |
936 | ret = munmap(sock_info->wait_shm_mmap, page_size); |
937 | if (ret) { | |
938 | ERR("Error unmapping wait shm"); | |
939 | } | |
7fc90dca MD |
940 | } |
941 | sock_info->wait_shm_mmap = NULL; | |
942 | } | |
943 | } | |
944 | ||
58d4b2a2 | 945 | /* |
33bbeb90 MD |
946 | * Using fork to set umask in the child process (not multi-thread safe). |
947 | * We deal with the shm_open vs ftruncate race (happening when the | |
948 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
949 | * safety against shm_unlink) by simply letting the mmap fail and | |
950 | * retrying after a few seconds. | |
951 | * For global shm, everybody has rw access to it until the sessiond | |
952 | * starts. | |
58d4b2a2 | 953 | */ |
7fc90dca | 954 | static |
58d4b2a2 | 955 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 956 | { |
7fc90dca | 957 | int wait_shm_fd, ret; |
58d4b2a2 | 958 | pid_t pid; |
44e073f5 | 959 | |
58d4b2a2 | 960 | /* |
33bbeb90 | 961 | * Try to open read-only. |
58d4b2a2 | 962 | */ |
33bbeb90 | 963 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 964 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
965 | int32_t tmp_read; |
966 | ssize_t len; | |
967 | size_t bytes_read = 0; | |
968 | ||
969 | /* | |
970 | * Try to read the fd. If unable to do so, try opening | |
971 | * it in write mode. | |
972 | */ | |
973 | do { | |
974 | len = read(wait_shm_fd, | |
975 | &((char *) &tmp_read)[bytes_read], | |
976 | sizeof(tmp_read) - bytes_read); | |
977 | if (len > 0) { | |
978 | bytes_read += len; | |
979 | } | |
980 | } while ((len < 0 && errno == EINTR) | |
981 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
982 | if (bytes_read != sizeof(tmp_read)) { | |
983 | ret = close(wait_shm_fd); | |
984 | if (ret) { | |
985 | ERR("close wait_shm_fd"); | |
986 | } | |
987 | goto open_write; | |
988 | } | |
58d4b2a2 MD |
989 | goto end; |
990 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
991 | /* | |
33bbeb90 MD |
992 | * Real-only open did not work, and it's not because the |
993 | * entry was not present. It's a failure that prohibits | |
994 | * using shm. | |
58d4b2a2 | 995 | */ |
7fc90dca | 996 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 997 | goto end; |
7fc90dca | 998 | } |
7aa76730 MD |
999 | |
1000 | open_write: | |
7fc90dca | 1001 | /* |
7aa76730 MD |
1002 | * If the open failed because the file did not exist, or because |
1003 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 1004 | */ |
8c90a710 | 1005 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 1006 | pid = fork(); |
8c90a710 | 1007 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
1008 | if (pid > 0) { |
1009 | int status; | |
1010 | ||
1011 | /* | |
1012 | * Parent: wait for child to return, in which case the | |
1013 | * shared memory map will have been created. | |
1014 | */ | |
1015 | pid = wait(&status); | |
b7d3cb32 | 1016 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
1017 | wait_shm_fd = -1; |
1018 | goto end; | |
7fc90dca | 1019 | } |
58d4b2a2 MD |
1020 | /* |
1021 | * Try to open read-only again after creation. | |
1022 | */ | |
33bbeb90 | 1023 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
1024 | if (wait_shm_fd < 0) { |
1025 | /* | |
1026 | * Real-only open did not work. It's a failure | |
1027 | * that prohibits using shm. | |
1028 | */ | |
1029 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1030 | goto end; | |
1031 | } | |
1032 | goto end; | |
1033 | } else if (pid == 0) { | |
1034 | int create_mode; | |
1035 | ||
1036 | /* Child */ | |
33bbeb90 | 1037 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1038 | if (sock_info->global) |
33bbeb90 | 1039 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1040 | /* |
1041 | * We're alone in a child process, so we can modify the | |
1042 | * process-wide umask. | |
1043 | */ | |
33bbeb90 | 1044 | umask(~create_mode); |
58d4b2a2 | 1045 | /* |
33bbeb90 MD |
1046 | * Try creating shm (or get rw access). |
1047 | * We don't do an exclusive open, because we allow other | |
1048 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1049 | */ |
1050 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1051 | O_RDWR | O_CREAT, create_mode); | |
1052 | if (wait_shm_fd >= 0) { | |
1053 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1054 | if (ret) { | |
1055 | PERROR("ftruncate"); | |
b0c1425d | 1056 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1057 | } |
b0c1425d | 1058 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1059 | } |
33bbeb90 MD |
1060 | /* |
1061 | * For local shm, we need to have rw access to accept | |
1062 | * opening it: this means the local sessiond will be | |
1063 | * able to wake us up. For global shm, we open it even | |
1064 | * if rw access is not granted, because the root.root | |
1065 | * sessiond will be able to override all rights and wake | |
1066 | * us up. | |
1067 | */ | |
1068 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1069 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1070 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1071 | } |
1072 | /* | |
33bbeb90 MD |
1073 | * The shm exists, but we cannot open it RW. Report |
1074 | * success. | |
58d4b2a2 | 1075 | */ |
5d3bc5ed | 1076 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1077 | } else { |
1078 | return -1; | |
7fc90dca | 1079 | } |
58d4b2a2 | 1080 | end: |
33bbeb90 MD |
1081 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1082 | struct stat statbuf; | |
1083 | ||
1084 | /* | |
1085 | * Ensure that our user is the owner of the shm file for | |
1086 | * local shm. If we do not own the file, it means our | |
1087 | * sessiond will not have access to wake us up (there is | |
1088 | * probably a rogue process trying to fake our | |
1089 | * sessiond). Fallback to polling method in this case. | |
1090 | */ | |
1091 | ret = fstat(wait_shm_fd, &statbuf); | |
1092 | if (ret) { | |
1093 | PERROR("fstat"); | |
1094 | goto error_close; | |
1095 | } | |
1096 | if (statbuf.st_uid != getuid()) | |
1097 | goto error_close; | |
1098 | } | |
58d4b2a2 | 1099 | return wait_shm_fd; |
33bbeb90 MD |
1100 | |
1101 | error_close: | |
1102 | ret = close(wait_shm_fd); | |
1103 | if (ret) { | |
1104 | PERROR("Error closing fd"); | |
1105 | } | |
1106 | return -1; | |
58d4b2a2 MD |
1107 | } |
1108 | ||
1109 | static | |
1110 | char *get_map_shm(struct sock_info *sock_info) | |
1111 | { | |
172d6b68 | 1112 | long page_size; |
58d4b2a2 MD |
1113 | int wait_shm_fd, ret; |
1114 | char *wait_shm_mmap; | |
1115 | ||
172d6b68 | 1116 | page_size = sysconf(_SC_PAGE_SIZE); |
355e3ac6 MD |
1117 | if (page_size <= 0) { |
1118 | if (!page_size) { | |
1119 | errno = EINVAL; | |
1120 | } | |
1121 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
172d6b68 MD |
1122 | goto error; |
1123 | } | |
1124 | ||
1125 | wait_shm_fd = get_wait_shm(sock_info, page_size); | |
58d4b2a2 MD |
1126 | if (wait_shm_fd < 0) { |
1127 | goto error; | |
44e073f5 | 1128 | } |
172d6b68 | 1129 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1130 | MAP_SHARED, wait_shm_fd, 0); |
7fc90dca MD |
1131 | /* close shm fd immediately after taking the mmap reference */ |
1132 | ret = close(wait_shm_fd); | |
1133 | if (ret) { | |
33bbeb90 MD |
1134 | PERROR("Error closing fd"); |
1135 | } | |
1136 | if (wait_shm_mmap == MAP_FAILED) { | |
1137 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1138 | goto error; | |
7fc90dca MD |
1139 | } |
1140 | return wait_shm_mmap; | |
1141 | ||
1142 | error: | |
1143 | return NULL; | |
1144 | } | |
1145 | ||
1146 | static | |
1147 | void wait_for_sessiond(struct sock_info *sock_info) | |
1148 | { | |
3327ac33 | 1149 | if (ust_lock()) { |
7fc90dca MD |
1150 | goto quit; |
1151 | } | |
37ed587a MD |
1152 | if (wait_poll_fallback) { |
1153 | goto error; | |
1154 | } | |
7fc90dca MD |
1155 | if (!sock_info->wait_shm_mmap) { |
1156 | sock_info->wait_shm_mmap = get_map_shm(sock_info); | |
1157 | if (!sock_info->wait_shm_mmap) | |
1158 | goto error; | |
1159 | } | |
1160 | ust_unlock(); | |
1161 | ||
1162 | DBG("Waiting for %s apps sessiond", sock_info->name); | |
80e2814b | 1163 | /* Wait for futex wakeup */ |
faccc28a MD |
1164 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) |
1165 | goto end_wait; | |
1166 | ||
1167 | while (futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1168 | FUTEX_WAIT, 0, NULL, NULL, 0)) { | |
1169 | switch (errno) { | |
1170 | case EWOULDBLOCK: | |
1171 | /* Value already changed. */ | |
1172 | goto end_wait; | |
1173 | case EINTR: | |
1174 | /* Retry if interrupted by signal. */ | |
1175 | break; /* Get out of switch. */ | |
1176 | case EFAULT: | |
1177 | wait_poll_fallback = 1; | |
1178 | DBG( | |
37ed587a MD |
1179 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1180 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1181 | "Please upgrade your kernel " | |
1182 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1183 | "mainline). LTTng-UST will use polling mode fallback."); | |
faccc28a MD |
1184 | if (ust_debug()) |
1185 | PERROR("futex"); | |
1186 | goto end_wait; | |
80e2814b MD |
1187 | } |
1188 | } | |
faccc28a | 1189 | end_wait: |
7fc90dca MD |
1190 | return; |
1191 | ||
1192 | quit: | |
1193 | ust_unlock(); | |
1194 | return; | |
1195 | ||
1196 | error: | |
1197 | ust_unlock(); | |
7fc90dca | 1198 | return; |
46050b1a MD |
1199 | } |
1200 | ||
1ea11eab MD |
1201 | /* |
1202 | * This thread does not allocate any resource, except within | |
1203 | * handle_message, within mutex protection. This mutex protects against | |
1204 | * fork and exit. | |
98bf993f | 1205 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1206 | * is also protected by the mutex. |
1207 | */ | |
d9e99d10 MD |
1208 | static |
1209 | void *ust_listener_thread(void *arg) | |
1210 | { | |
1ea11eab | 1211 | struct sock_info *sock_info = arg; |
c0eedf81 | 1212 | int sock, ret, prev_connect_failed = 0, has_waited = 0; |
ff517991 | 1213 | long timeout; |
d9e99d10 | 1214 | |
9eb62b9c MD |
1215 | /* Restart trying to connect to the session daemon */ |
1216 | restart: | |
c0eedf81 MD |
1217 | if (prev_connect_failed) { |
1218 | /* Wait for sessiond availability with pipe */ | |
1219 | wait_for_sessiond(sock_info); | |
1220 | if (has_waited) { | |
1221 | has_waited = 0; | |
1222 | /* | |
1223 | * Sleep for 5 seconds before retrying after a | |
1224 | * sequence of failure / wait / failure. This | |
1225 | * deals with a killed or broken session daemon. | |
1226 | */ | |
1227 | sleep(5); | |
1228 | } | |
1229 | has_waited = 1; | |
1230 | prev_connect_failed = 0; | |
1231 | } | |
9eb62b9c | 1232 | |
1ea11eab | 1233 | if (sock_info->socket != -1) { |
e6973a89 | 1234 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1235 | if (ret) { |
32ce8569 MD |
1236 | ERR("Error closing %s ust cmd socket", |
1237 | sock_info->name); | |
1ea11eab MD |
1238 | } |
1239 | sock_info->socket = -1; | |
1240 | } | |
32ce8569 MD |
1241 | if (sock_info->notify_socket != -1) { |
1242 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1243 | if (ret) { | |
1244 | ERR("Error closing %s ust notify socket", | |
1245 | sock_info->name); | |
1246 | } | |
1247 | sock_info->notify_socket = -1; | |
1248 | } | |
46050b1a | 1249 | |
321f2351 MD |
1250 | /* |
1251 | * Register. We need to perform both connect and sending | |
1252 | * registration message before doing the next connect otherwise | |
1253 | * we may reach unix socket connect queue max limits and block | |
1254 | * on the 2nd connect while the session daemon is awaiting the | |
1255 | * first connect registration message. | |
1256 | */ | |
1257 | /* Connect cmd socket */ | |
1258 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1259 | if (ret < 0) { | |
1260 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1261 | prev_connect_failed = 1; | |
5b14aab3 | 1262 | |
3327ac33 | 1263 | if (ust_lock()) { |
321f2351 | 1264 | goto quit; |
32ce8569 | 1265 | } |
46050b1a | 1266 | |
e3426ddc | 1267 | /* |
321f2351 MD |
1268 | * If we cannot find the sessiond daemon, don't delay |
1269 | * constructor execution. | |
e3426ddc | 1270 | */ |
321f2351 MD |
1271 | ret = handle_register_done(sock_info); |
1272 | assert(!ret); | |
1273 | ust_unlock(); | |
1274 | goto restart; | |
27fe9f21 | 1275 | } |
321f2351 | 1276 | sock_info->socket = ret; |
27fe9f21 | 1277 | |
3327ac33 | 1278 | if (ust_lock()) { |
5b14aab3 MD |
1279 | goto quit; |
1280 | } | |
1281 | ||
46050b1a MD |
1282 | /* |
1283 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1284 | * process lifetime, so we ensure we get ID which is statically |
1285 | * assigned to the root handle. | |
46050b1a MD |
1286 | */ |
1287 | if (sock_info->root_handle == -1) { | |
1288 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1289 | if (ret < 0) { |
46050b1a | 1290 | ERR("Error creating root handle"); |
46050b1a MD |
1291 | goto quit; |
1292 | } | |
1293 | sock_info->root_handle = ret; | |
9eb62b9c | 1294 | } |
1ea11eab | 1295 | |
32ce8569 | 1296 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1297 | if (ret < 0) { |
32ce8569 MD |
1298 | ERR("Error registering to %s ust cmd socket", |
1299 | sock_info->name); | |
c0eedf81 | 1300 | prev_connect_failed = 1; |
11ff9c7d MD |
1301 | /* |
1302 | * If we cannot register to the sessiond daemon, don't | |
1303 | * delay constructor execution. | |
1304 | */ | |
edaa1431 | 1305 | ret = handle_register_done(sock_info); |
11ff9c7d | 1306 | assert(!ret); |
17dfb34b | 1307 | ust_unlock(); |
9eb62b9c MD |
1308 | goto restart; |
1309 | } | |
321f2351 MD |
1310 | |
1311 | ust_unlock(); | |
1312 | ||
1313 | /* Connect notify socket */ | |
1314 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1315 | if (ret < 0) { | |
1316 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1317 | prev_connect_failed = 1; | |
1318 | ||
3327ac33 | 1319 | if (ust_lock()) { |
321f2351 MD |
1320 | goto quit; |
1321 | } | |
1322 | ||
1323 | /* | |
1324 | * If we cannot find the sessiond daemon, don't delay | |
1325 | * constructor execution. | |
1326 | */ | |
1327 | ret = handle_register_done(sock_info); | |
1328 | assert(!ret); | |
1329 | ust_unlock(); | |
1330 | goto restart; | |
1331 | } | |
1332 | sock_info->notify_socket = ret; | |
1333 | ||
1334 | timeout = get_notify_sock_timeout(); | |
1335 | if (timeout >= 0) { | |
1336 | /* | |
1337 | * Give at least 10ms to sessiond to reply to | |
1338 | * notifications. | |
1339 | */ | |
1340 | if (timeout < 10) | |
1341 | timeout = 10; | |
1342 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1343 | timeout); | |
1344 | if (ret < 0) { | |
1345 | WARN("Error setting socket receive timeout"); | |
1346 | } | |
1347 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1348 | timeout); | |
1349 | if (ret < 0) { | |
1350 | WARN("Error setting socket send timeout"); | |
1351 | } | |
1352 | } else if (timeout < -1) { | |
1353 | WARN("Unsupported timeout value %ld", timeout); | |
1354 | } | |
1355 | ||
3327ac33 | 1356 | if (ust_lock()) { |
321f2351 MD |
1357 | goto quit; |
1358 | } | |
1359 | ||
32ce8569 MD |
1360 | ret = register_to_sessiond(sock_info->notify_socket, |
1361 | USTCTL_SOCKET_NOTIFY); | |
1362 | if (ret < 0) { | |
1363 | ERR("Error registering to %s ust notify socket", | |
1364 | sock_info->name); | |
1365 | prev_connect_failed = 1; | |
1366 | /* | |
1367 | * If we cannot register to the sessiond daemon, don't | |
1368 | * delay constructor execution. | |
1369 | */ | |
1370 | ret = handle_register_done(sock_info); | |
1371 | assert(!ret); | |
1372 | ust_unlock(); | |
1373 | goto restart; | |
1374 | } | |
1375 | sock = sock_info->socket; | |
1376 | ||
17dfb34b | 1377 | ust_unlock(); |
46050b1a | 1378 | |
d9e99d10 MD |
1379 | for (;;) { |
1380 | ssize_t len; | |
57773204 | 1381 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1382 | |
57773204 | 1383 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1384 | switch (len) { |
1385 | case 0: /* orderly shutdown */ | |
7dd08bec | 1386 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1387 | if (ust_lock()) { |
d5e1fea6 MD |
1388 | goto quit; |
1389 | } | |
8236ba10 MD |
1390 | /* |
1391 | * Either sessiond has shutdown or refused us by closing the socket. | |
1392 | * In either case, we don't want to delay construction execution, | |
1393 | * and we need to wait before retry. | |
1394 | */ | |
1395 | prev_connect_failed = 1; | |
1396 | /* | |
1397 | * If we cannot register to the sessiond daemon, don't | |
1398 | * delay constructor execution. | |
1399 | */ | |
1400 | ret = handle_register_done(sock_info); | |
1401 | assert(!ret); | |
1402 | ust_unlock(); | |
d9e99d10 | 1403 | goto end; |
e7723462 | 1404 | case sizeof(lum): |
74d81a6c | 1405 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1406 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1407 | if (ret) { |
7d60854f MD |
1408 | ERR("Error handling message for %s socket", |
1409 | sock_info->name); | |
1410 | /* | |
1411 | * Close socket if protocol error is | |
1412 | * detected. | |
1413 | */ | |
1414 | goto end; | |
d9e99d10 MD |
1415 | } |
1416 | continue; | |
7bc53e94 MD |
1417 | default: |
1418 | if (len < 0) { | |
1419 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1420 | } else { | |
1421 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1422 | } | |
1423 | if (len == -ECONNRESET) { | |
1424 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1425 | goto end; |
1426 | } | |
1427 | goto end; | |
d9e99d10 MD |
1428 | } |
1429 | ||
1430 | } | |
1431 | end: | |
3327ac33 | 1432 | if (ust_lock()) { |
d5e1fea6 MD |
1433 | goto quit; |
1434 | } | |
f59ed768 MD |
1435 | /* Cleanup socket handles before trying to reconnect */ |
1436 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1437 | ust_unlock(); | |
9eb62b9c | 1438 | goto restart; /* try to reconnect */ |
e33f3265 | 1439 | |
1ea11eab | 1440 | quit: |
e33f3265 | 1441 | ust_unlock(); |
3327ac33 MD |
1442 | |
1443 | pthread_mutex_lock(&ust_exit_mutex); | |
1444 | sock_info->thread_active = 0; | |
1445 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1446 | return NULL; |
1447 | } | |
1448 | ||
2594a5b4 MD |
1449 | /* |
1450 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1451 | */ | |
1452 | __attribute__((weak)) | |
1453 | void lttng_ust_malloc_wrapper_init(void) | |
1454 | { | |
1455 | } | |
1456 | ||
2691221a MD |
1457 | /* |
1458 | * sessiond monitoring thread: monitor presence of global and per-user | |
1459 | * sessiond by polling the application common named pipe. | |
1460 | */ | |
edaa1431 | 1461 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1462 | { |
11ff9c7d | 1463 | struct timespec constructor_timeout; |
ae6a58bf | 1464 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1465 | pthread_attr_t thread_attr; |
cf12a773 | 1466 | int timeout_mode; |
2691221a MD |
1467 | int ret; |
1468 | ||
edaa1431 MD |
1469 | if (uatomic_xchg(&initialized, 1) == 1) |
1470 | return; | |
1471 | ||
eddd8d5d MD |
1472 | /* |
1473 | * Fixup interdependency between TLS fixup mutex (which happens | |
1474 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1475 | * the ust lock. | |
1476 | */ | |
f4695bf8 | 1477 | lttng_fixup_urcu_bp_tls(); |
f645cfa7 | 1478 | lttng_fixup_ringbuffer_tls(); |
4158a15a | 1479 | lttng_fixup_vtid_tls(); |
a903623f | 1480 | lttng_fixup_nest_count_tls(); |
009745db | 1481 | lttng_fixup_procname_tls(); |
d58d1454 | 1482 | lttng_fixup_ust_mutex_nest_tls(); |
eddd8d5d | 1483 | |
edaa1431 MD |
1484 | /* |
1485 | * We want precise control over the order in which we construct | |
1486 | * our sub-libraries vs starting to receive commands from | |
1487 | * sessiond (otherwise leading to errors when trying to create | |
1488 | * sessiond before the init functions are completed). | |
1489 | */ | |
2691221a | 1490 | init_usterr(); |
edaa1431 | 1491 | init_tracepoint(); |
bd703713 | 1492 | lttng_ust_baddr_statedump_init(); |
7dd08bec MD |
1493 | lttng_ring_buffer_metadata_client_init(); |
1494 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1495 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1496 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1497 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1498 | lttng_perf_counter_init(); |
a0a3bef9 | 1499 | lttng_context_init(); |
2594a5b4 MD |
1500 | /* |
1501 | * Invoke ust malloc wrapper init before starting other threads. | |
1502 | */ | |
1503 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1504 | |
ff517991 | 1505 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1506 | |
95259bd0 | 1507 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
1508 | assert(!ret); |
1509 | ||
8d20bf54 | 1510 | ret = setup_local_apps(); |
2691221a | 1511 | if (ret) { |
9ec6895c | 1512 | DBG("local apps setup returned %d", ret); |
2691221a | 1513 | } |
ae6a58bf WP |
1514 | |
1515 | /* A new thread created by pthread_create inherits the signal mask | |
1516 | * from the parent. To avoid any signal being received by the | |
1517 | * listener thread, we block all signals temporarily in the parent, | |
1518 | * while we create the listener thread. | |
1519 | */ | |
1520 | sigfillset(&sig_all_blocked); | |
1521 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1522 | if (ret) { | |
d94d802c | 1523 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1524 | } |
1525 | ||
1879f67f MG |
1526 | ret = pthread_attr_init(&thread_attr); |
1527 | if (ret) { | |
1528 | ERR("pthread_attr_init: %s", strerror(ret)); | |
1529 | } | |
1530 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
1531 | if (ret) { | |
1532 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
1533 | } | |
1534 | ||
c0bbbd5a | 1535 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1536 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, |
dde70ea0 | 1537 | ust_listener_thread, &global_apps); |
d94d802c MD |
1538 | if (ret) { |
1539 | ERR("pthread_create global: %s", strerror(ret)); | |
1540 | } | |
e33f3265 | 1541 | global_apps.thread_active = 1; |
c0bbbd5a | 1542 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1543 | |
8d20bf54 | 1544 | if (local_apps.allowed) { |
c0bbbd5a | 1545 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1546 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 1547 | ust_listener_thread, &local_apps); |
d94d802c MD |
1548 | if (ret) { |
1549 | ERR("pthread_create local: %s", strerror(ret)); | |
1550 | } | |
e33f3265 | 1551 | local_apps.thread_active = 1; |
c0bbbd5a | 1552 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
1553 | } else { |
1554 | handle_register_done(&local_apps); | |
1555 | } | |
1879f67f MG |
1556 | ret = pthread_attr_destroy(&thread_attr); |
1557 | if (ret) { | |
1558 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
1559 | } | |
8d20bf54 | 1560 | |
ae6a58bf WP |
1561 | /* Restore original signal mask in parent */ |
1562 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
1563 | if (ret) { | |
d94d802c | 1564 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1565 | } |
1566 | ||
cf12a773 MD |
1567 | switch (timeout_mode) { |
1568 | case 1: /* timeout wait */ | |
95259bd0 MD |
1569 | do { |
1570 | ret = sem_timedwait(&constructor_wait, | |
1571 | &constructor_timeout); | |
1572 | } while (ret < 0 && errno == EINTR); | |
cf12a773 | 1573 | if (ret < 0 && errno == ETIMEDOUT) { |
7dd08bec | 1574 | ERR("Timed out waiting for lttng-sessiond"); |
cf12a773 MD |
1575 | } else { |
1576 | assert(!ret); | |
1577 | } | |
1578 | break; | |
7b766b16 | 1579 | case -1:/* wait forever */ |
95259bd0 MD |
1580 | do { |
1581 | ret = sem_wait(&constructor_wait); | |
1582 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 1583 | assert(!ret); |
cf12a773 | 1584 | break; |
7b766b16 | 1585 | case 0: /* no timeout */ |
cf12a773 | 1586 | break; |
11ff9c7d | 1587 | } |
2691221a MD |
1588 | } |
1589 | ||
17dfb34b MD |
1590 | static |
1591 | void lttng_ust_cleanup(int exiting) | |
1592 | { | |
efe0de09 | 1593 | cleanup_sock_info(&global_apps, exiting); |
1e5c497c | 1594 | cleanup_sock_info(&local_apps, exiting); |
efe0de09 MD |
1595 | /* |
1596 | * The teardown in this function all affect data structures | |
1597 | * accessed under the UST lock by the listener thread. This | |
1598 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
1599 | * that none of these threads are accessing this data at this | |
1600 | * point. | |
1601 | */ | |
17dfb34b | 1602 | lttng_ust_abi_exit(); |
003fedf4 | 1603 | lttng_ust_events_exit(); |
a0a3bef9 | 1604 | lttng_context_exit(); |
d58d1454 | 1605 | lttng_perf_counter_exit(); |
34a91bdb | 1606 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 1607 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 1608 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
1609 | lttng_ring_buffer_client_overwrite_exit(); |
1610 | lttng_ring_buffer_metadata_client_exit(); | |
bd703713 | 1611 | lttng_ust_baddr_statedump_destroy(); |
17dfb34b MD |
1612 | exit_tracepoint(); |
1613 | if (!exiting) { | |
1614 | /* Reinitialize values for fork */ | |
1615 | sem_count = 2; | |
1616 | lttng_ust_comm_should_quit = 0; | |
1617 | initialized = 0; | |
1618 | } | |
1619 | } | |
1620 | ||
edaa1431 | 1621 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
1622 | { |
1623 | int ret; | |
1624 | ||
9eb62b9c MD |
1625 | /* |
1626 | * Using pthread_cancel here because: | |
1627 | * A) we don't want to hang application teardown. | |
1628 | * B) the thread is not allocating any resource. | |
1629 | */ | |
1ea11eab MD |
1630 | |
1631 | /* | |
1632 | * Require the communication thread to quit. Synchronize with | |
1633 | * mutexes to ensure it is not in a mutex critical section when | |
1634 | * pthread_cancel is later called. | |
1635 | */ | |
3327ac33 | 1636 | ust_lock_nocheck(); |
1ea11eab | 1637 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 1638 | ust_unlock(); |
1ea11eab | 1639 | |
3327ac33 | 1640 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 1641 | /* cancel threads */ |
e33f3265 MD |
1642 | if (global_apps.thread_active) { |
1643 | ret = pthread_cancel(global_apps.ust_listener); | |
1644 | if (ret) { | |
1645 | ERR("Error cancelling global ust listener thread: %s", | |
1646 | strerror(ret)); | |
1647 | } else { | |
1648 | global_apps.thread_active = 0; | |
1649 | } | |
2691221a | 1650 | } |
e33f3265 | 1651 | if (local_apps.thread_active) { |
8d20bf54 MD |
1652 | ret = pthread_cancel(local_apps.ust_listener); |
1653 | if (ret) { | |
d94d802c MD |
1654 | ERR("Error cancelling local ust listener thread: %s", |
1655 | strerror(ret)); | |
e33f3265 MD |
1656 | } else { |
1657 | local_apps.thread_active = 0; | |
8d20bf54 | 1658 | } |
8d20bf54 | 1659 | } |
3327ac33 | 1660 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1661 | |
efe0de09 MD |
1662 | /* |
1663 | * Do NOT join threads: use of sys_futex makes it impossible to | |
1664 | * join the threads without using async-cancel, but async-cancel | |
1665 | * is delivered by a signal, which could hit the target thread | |
1666 | * anywhere in its code path, including while the ust_lock() is | |
1667 | * held, causing a deadlock for the other thread. Let the OS | |
1668 | * cleanup the threads if there are stalled in a syscall. | |
1669 | */ | |
17dfb34b | 1670 | lttng_ust_cleanup(1); |
2691221a | 1671 | } |
e822f505 MD |
1672 | |
1673 | /* | |
1674 | * We exclude the worker threads across fork and clone (except | |
1675 | * CLONE_VM), because these system calls only keep the forking thread | |
1676 | * running in the child. Therefore, we don't want to call fork or clone | |
1677 | * in the middle of an tracepoint or ust tracing state modification. | |
1678 | * Holding this mutex protects these structures across fork and clone. | |
1679 | */ | |
b728d87e | 1680 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
1681 | { |
1682 | /* | |
1683 | * Disable signals. This is to avoid that the child intervenes | |
1684 | * before it is properly setup for tracing. It is safer to | |
1685 | * disable all signals, because then we know we are not breaking | |
1686 | * anything by restoring the original mask. | |
1687 | */ | |
1688 | sigset_t all_sigs; | |
1689 | int ret; | |
1690 | ||
8c90a710 | 1691 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1692 | return; |
e822f505 MD |
1693 | /* Disable signals */ |
1694 | sigfillset(&all_sigs); | |
b728d87e | 1695 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
1696 | if (ret == -1) { |
1697 | PERROR("sigprocmask"); | |
1698 | } | |
458d678c PW |
1699 | |
1700 | pthread_mutex_lock(&ust_fork_mutex); | |
1701 | ||
3327ac33 | 1702 | ust_lock_nocheck(); |
e822f505 MD |
1703 | rcu_bp_before_fork(); |
1704 | } | |
1705 | ||
b728d87e | 1706 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
1707 | { |
1708 | int ret; | |
1709 | ||
17dfb34b MD |
1710 | DBG("process %d", getpid()); |
1711 | ust_unlock(); | |
458d678c PW |
1712 | |
1713 | pthread_mutex_unlock(&ust_fork_mutex); | |
1714 | ||
e822f505 | 1715 | /* Restore signals */ |
23c8854a | 1716 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
1717 | if (ret == -1) { |
1718 | PERROR("sigprocmask"); | |
1719 | } | |
1720 | } | |
1721 | ||
b728d87e | 1722 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 1723 | { |
8c90a710 | 1724 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1725 | return; |
17dfb34b | 1726 | DBG("process %d", getpid()); |
e822f505 MD |
1727 | rcu_bp_after_fork_parent(); |
1728 | /* Release mutexes and reenable signals */ | |
b728d87e | 1729 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
1730 | } |
1731 | ||
17dfb34b MD |
1732 | /* |
1733 | * After fork, in the child, we need to cleanup all the leftover state, | |
1734 | * except the worker thread which already magically disappeared thanks | |
1735 | * to the weird Linux fork semantics. After tyding up, we call | |
1736 | * lttng_ust_init() again to start over as a new PID. | |
1737 | * | |
1738 | * This is meant for forks() that have tracing in the child between the | |
1739 | * fork and following exec call (if there is any). | |
1740 | */ | |
b728d87e | 1741 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 1742 | { |
8c90a710 | 1743 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1744 | return; |
17dfb34b | 1745 | DBG("process %d", getpid()); |
e822f505 MD |
1746 | /* Release urcu mutexes */ |
1747 | rcu_bp_after_fork_child(); | |
17dfb34b | 1748 | lttng_ust_cleanup(0); |
a93bfc45 | 1749 | lttng_context_vtid_reset(); |
e822f505 | 1750 | /* Release mutexes and reenable signals */ |
b728d87e | 1751 | ust_after_fork_common(restore_sigset); |
318dfea9 | 1752 | lttng_ust_init(); |
e822f505 | 1753 | } |
95c25348 | 1754 | |
246be17e | 1755 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
1756 | { |
1757 | struct sock_info *sock_info = owner; | |
37dddb65 | 1758 | sock_info->statedump_pending = 1; |
95c25348 | 1759 | } |