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 MD |
48 | #include <ust-comm.h> |
49 | #include <usterr-signal-safe.h> | |
cd54f6d9 | 50 | #include <helper.h> |
44c72f10 | 51 | #include "tracepoint-internal.h" |
7dd08bec | 52 | #include "lttng-tracer-core.h" |
08114193 | 53 | #include "compat.h" |
f645cfa7 | 54 | #include "../libringbuffer/tlsfixup.h" |
cf73e0fe | 55 | #include "lttng-ust-statedump.h" |
f9364363 | 56 | #include "clock.h" |
5e1b7b8b | 57 | #include "../libringbuffer/getcpu.h" |
13efba44 | 58 | #include "getenv.h" |
edaa1431 MD |
59 | |
60 | /* | |
61 | * Has lttng ust comm constructor been called ? | |
62 | */ | |
63 | static int initialized; | |
64 | ||
1ea11eab | 65 | /* |
17dfb34b MD |
66 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
67 | * Held when handling a command, also held by fork() to deal with | |
68 | * removal of threads, and by exit path. | |
3327ac33 MD |
69 | * |
70 | * The UST lock is the centralized mutex across UST tracing control and | |
71 | * probe registration. | |
72 | * | |
73 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 74 | * |
4770bd47 MD |
75 | * ust_fork_mutex must never nest in ust_mutex. |
76 | * | |
d58d1454 MD |
77 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
78 | * counter lazy initialization called by events within the statedump, | |
79 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
80 | * |
81 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
82 | * it is taken within the library constructor. | |
3327ac33 MD |
83 | */ |
84 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
85 | ||
d58d1454 MD |
86 | /* Allow nesting the ust_mutex within the same thread. */ |
87 | static DEFINE_URCU_TLS(int, ust_mutex_nest); | |
88 | ||
3327ac33 MD |
89 | /* |
90 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
91 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
92 | * internal libc lock, cannot nest within ust_mutex. | |
93 | * | |
94 | * It never nests within a ust_mutex. | |
1ea11eab | 95 | */ |
3327ac33 | 96 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 97 | |
458d678c PW |
98 | /* |
99 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
100 | * prevents the dynamic loader lock to be taken (by base address statedump | |
101 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
102 | * the dynamic loader lock. | |
103 | */ | |
104 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
105 | ||
1ea11eab MD |
106 | /* Should the ust comm thread quit ? */ |
107 | static int lttng_ust_comm_should_quit; | |
108 | ||
3327ac33 | 109 | /* |
d58d1454 | 110 | * Return 0 on success, -1 if should quit. |
3327ac33 | 111 | * The lock is taken in both cases. |
d58d1454 | 112 | * Signal-safe. |
3327ac33 MD |
113 | */ |
114 | int ust_lock(void) | |
115 | { | |
d58d1454 | 116 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 117 | int ret, oldstate; |
d58d1454 | 118 | |
e446ad80 MD |
119 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
120 | if (ret) { | |
121 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
122 | } | |
123 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
124 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
125 | } | |
d58d1454 MD |
126 | sigfillset(&sig_all_blocked); |
127 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
128 | if (ret) { | |
129 | ERR("pthread_sigmask: %s", strerror(ret)); | |
130 | } | |
131 | if (!URCU_TLS(ust_mutex_nest)++) | |
132 | pthread_mutex_lock(&ust_mutex); | |
133 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
134 | if (ret) { | |
135 | ERR("pthread_sigmask: %s", strerror(ret)); | |
136 | } | |
3327ac33 MD |
137 | if (lttng_ust_comm_should_quit) { |
138 | return -1; | |
139 | } else { | |
140 | return 0; | |
141 | } | |
142 | } | |
143 | ||
144 | /* | |
145 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
146 | * they are already nested within the dynamic loader lock, and therefore | |
147 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 148 | * Signal-safe. |
3327ac33 MD |
149 | */ |
150 | void ust_lock_nocheck(void) | |
151 | { | |
d58d1454 | 152 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 153 | int ret, oldstate; |
d58d1454 | 154 | |
e446ad80 MD |
155 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
156 | if (ret) { | |
157 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
158 | } | |
159 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
160 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
161 | } | |
d58d1454 MD |
162 | sigfillset(&sig_all_blocked); |
163 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
164 | if (ret) { | |
165 | ERR("pthread_sigmask: %s", strerror(ret)); | |
166 | } | |
167 | if (!URCU_TLS(ust_mutex_nest)++) | |
168 | pthread_mutex_lock(&ust_mutex); | |
169 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
170 | if (ret) { | |
171 | ERR("pthread_sigmask: %s", strerror(ret)); | |
172 | } | |
3327ac33 MD |
173 | } |
174 | ||
d58d1454 MD |
175 | /* |
176 | * Signal-safe. | |
177 | */ | |
3327ac33 MD |
178 | void ust_unlock(void) |
179 | { | |
d58d1454 | 180 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 181 | int ret, oldstate; |
d58d1454 MD |
182 | |
183 | sigfillset(&sig_all_blocked); | |
184 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
185 | if (ret) { | |
186 | ERR("pthread_sigmask: %s", strerror(ret)); | |
187 | } | |
188 | if (!--URCU_TLS(ust_mutex_nest)) | |
189 | pthread_mutex_unlock(&ust_mutex); | |
190 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
191 | if (ret) { | |
192 | ERR("pthread_sigmask: %s", strerror(ret)); | |
193 | } | |
e446ad80 MD |
194 | ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); |
195 | if (ret) { | |
196 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
197 | } | |
198 | if (oldstate != PTHREAD_CANCEL_DISABLE) { | |
199 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
200 | } | |
3327ac33 MD |
201 | } |
202 | ||
11ff9c7d MD |
203 | /* |
204 | * Wait for either of these before continuing to the main | |
205 | * program: | |
206 | * - the register_done message from sessiond daemon | |
207 | * (will let the sessiond daemon enable sessions before main | |
208 | * starts.) | |
209 | * - sessiond daemon is not reachable. | |
210 | * - timeout (ensuring applications are resilient to session | |
211 | * daemon problems). | |
212 | */ | |
213 | static sem_t constructor_wait; | |
950aab0c MD |
214 | /* |
215 | * Doing this for both the global and local sessiond. | |
216 | */ | |
95259bd0 | 217 | static int sem_count = { 2 }; |
11ff9c7d | 218 | |
e8508a49 MD |
219 | /* |
220 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
221 | * from liblttng-ust does not execute the pre/post fork handlers. | |
222 | */ | |
8c90a710 | 223 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 224 | |
1ea11eab MD |
225 | /* |
226 | * Info about socket and associated listener thread. | |
227 | */ | |
228 | struct sock_info { | |
11ff9c7d | 229 | const char *name; |
1ea11eab | 230 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 231 | int root_handle; |
8d20bf54 MD |
232 | int constructor_sem_posted; |
233 | int allowed; | |
44e073f5 | 234 | int global; |
e33f3265 | 235 | int thread_active; |
7fc90dca MD |
236 | |
237 | char sock_path[PATH_MAX]; | |
238 | int socket; | |
32ce8569 | 239 | int notify_socket; |
7fc90dca MD |
240 | |
241 | char wait_shm_path[PATH_MAX]; | |
242 | char *wait_shm_mmap; | |
37dddb65 MD |
243 | /* Keep track of lazy state dump not performed yet. */ |
244 | int statedump_pending; | |
1ea11eab | 245 | }; |
2691221a MD |
246 | |
247 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 248 | struct sock_info global_apps = { |
11ff9c7d | 249 | .name = "global", |
44e073f5 | 250 | .global = 1, |
7fc90dca | 251 | |
46050b1a | 252 | .root_handle = -1, |
8d20bf54 | 253 | .allowed = 1, |
e33f3265 | 254 | .thread_active = 0, |
7fc90dca | 255 | |
32ce8569 | 256 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 257 | .socket = -1, |
32ce8569 | 258 | .notify_socket = -1, |
7fc90dca | 259 | |
32ce8569 | 260 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 261 | |
37dddb65 | 262 | .statedump_pending = 0, |
1ea11eab | 263 | }; |
2691221a MD |
264 | |
265 | /* TODO: allow global_apps_sock_path override */ | |
266 | ||
1ea11eab | 267 | struct sock_info local_apps = { |
11ff9c7d | 268 | .name = "local", |
44e073f5 | 269 | .global = 0, |
46050b1a | 270 | .root_handle = -1, |
8d20bf54 | 271 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 272 | .thread_active = 0, |
7fc90dca MD |
273 | |
274 | .socket = -1, | |
32ce8569 | 275 | .notify_socket = -1, |
95c25348 | 276 | |
37dddb65 | 277 | .statedump_pending = 0, |
1ea11eab | 278 | }; |
2691221a | 279 | |
37ed587a MD |
280 | static int wait_poll_fallback; |
281 | ||
74d81a6c MD |
282 | static const char *cmd_name_mapping[] = { |
283 | [ LTTNG_UST_RELEASE ] = "Release", | |
284 | [ LTTNG_UST_SESSION ] = "Create Session", | |
285 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
286 | ||
287 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
288 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
289 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
290 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
291 | ||
292 | /* Session FD commands */ | |
293 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
294 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
295 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
296 | ||
297 | /* Channel FD commands */ | |
298 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
299 | [ LTTNG_UST_EVENT ] = "Create Event", | |
300 | ||
301 | /* Event and Channel FD commands */ | |
302 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
303 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
304 | ||
305 | /* Event, Channel and Session commands */ | |
306 | [ LTTNG_UST_ENABLE ] = "Enable", | |
307 | [ LTTNG_UST_DISABLE ] = "Disable", | |
308 | ||
309 | /* Tracepoint list commands */ | |
310 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
311 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
312 | ||
313 | /* Event FD commands */ | |
314 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 315 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
74d81a6c MD |
316 | }; |
317 | ||
ff517991 MD |
318 | static const char *str_timeout; |
319 | static int got_timeout_env; | |
320 | ||
7dd08bec | 321 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 322 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 323 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 324 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
325 | extern void lttng_ring_buffer_metadata_client_init(void); |
326 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 327 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 328 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 329 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 330 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 331 | |
3c6f6263 AM |
332 | /* |
333 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
334 | * pointer. | |
335 | */ | |
336 | static | |
337 | const char *get_lttng_home_dir(void) | |
338 | { | |
339 | const char *val; | |
340 | ||
13efba44 | 341 | val = (const char *) lttng_secure_getenv("LTTNG_HOME"); |
3c6f6263 AM |
342 | if (val != NULL) { |
343 | return val; | |
344 | } | |
13efba44 | 345 | return (const char *) lttng_secure_getenv("HOME"); |
3c6f6263 AM |
346 | } |
347 | ||
a903623f MD |
348 | /* |
349 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
350 | */ | |
351 | static | |
352 | void lttng_fixup_nest_count_tls(void) | |
353 | { | |
8c90a710 | 354 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
355 | } |
356 | ||
d58d1454 MD |
357 | static |
358 | void lttng_fixup_ust_mutex_nest_tls(void) | |
359 | { | |
360 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
361 | } | |
362 | ||
1556a549 MD |
363 | /* |
364 | * Fixup urcu bp TLS. | |
365 | */ | |
366 | static | |
367 | void lttng_fixup_urcu_bp_tls(void) | |
368 | { | |
369 | rcu_read_lock(); | |
370 | rcu_read_unlock(); | |
371 | } | |
372 | ||
32ce8569 MD |
373 | int lttng_get_notify_socket(void *owner) |
374 | { | |
375 | struct sock_info *info = owner; | |
376 | ||
377 | return info->notify_socket; | |
378 | } | |
379 | ||
74d81a6c MD |
380 | static |
381 | void print_cmd(int cmd, int handle) | |
382 | { | |
383 | const char *cmd_name = "Unknown"; | |
384 | ||
fd67a004 MD |
385 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
386 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
387 | cmd_name = cmd_name_mapping[cmd]; |
388 | } | |
fd67a004 MD |
389 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
390 | cmd_name, cmd, | |
74d81a6c MD |
391 | lttng_ust_obj_get_name(handle), handle); |
392 | } | |
393 | ||
2691221a | 394 | static |
8d20bf54 | 395 | int setup_local_apps(void) |
2691221a MD |
396 | { |
397 | const char *home_dir; | |
7fc90dca | 398 | uid_t uid; |
2691221a | 399 | |
7fc90dca | 400 | uid = getuid(); |
8d20bf54 MD |
401 | /* |
402 | * Disallow per-user tracing for setuid binaries. | |
403 | */ | |
7fc90dca | 404 | if (uid != geteuid()) { |
9ec6895c | 405 | assert(local_apps.allowed == 0); |
d0a1ae63 | 406 | return 0; |
8d20bf54 | 407 | } |
3c6f6263 | 408 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
409 | if (!home_dir) { |
410 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
411 | assert(local_apps.allowed == 0); | |
2691221a | 412 | return -ENOENT; |
9ec6895c MD |
413 | } |
414 | local_apps.allowed = 1; | |
32ce8569 MD |
415 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
416 | home_dir, | |
417 | LTTNG_DEFAULT_HOME_RUNDIR, | |
418 | LTTNG_UST_SOCK_FILENAME); | |
419 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
420 | LTTNG_UST_WAIT_FILENAME, | |
421 | uid); | |
2691221a MD |
422 | return 0; |
423 | } | |
424 | ||
ff517991 MD |
425 | /* |
426 | * Get notify_sock timeout, in ms. | |
28515902 | 427 | * -1: wait forever. 0: don't wait. >0: timeout, in ms. |
ff517991 MD |
428 | */ |
429 | static | |
430 | long get_timeout(void) | |
431 | { | |
432 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
433 | ||
434 | if (!got_timeout_env) { | |
435 | str_timeout = getenv("LTTNG_UST_REGISTER_TIMEOUT"); | |
436 | got_timeout_env = 1; | |
437 | } | |
438 | if (str_timeout) | |
439 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
440 | return constructor_delay_ms; | |
441 | } | |
442 | ||
443 | static | |
444 | long get_notify_sock_timeout(void) | |
445 | { | |
446 | return get_timeout(); | |
447 | } | |
448 | ||
449 | /* | |
28515902 | 450 | * Return values: -1: wait forever. 0: don't wait. 1: timeout wait. |
ff517991 MD |
451 | */ |
452 | static | |
453 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
454 | { | |
455 | long constructor_delay_ms; | |
456 | int ret; | |
457 | ||
458 | constructor_delay_ms = get_timeout(); | |
459 | ||
460 | switch (constructor_delay_ms) { | |
461 | case -1:/* fall-through */ | |
462 | case 0: | |
463 | return constructor_delay_ms; | |
464 | default: | |
465 | break; | |
466 | } | |
467 | ||
468 | /* | |
469 | * If we are unable to find the current time, don't wait. | |
470 | */ | |
471 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
472 | if (ret) { | |
28515902 JG |
473 | /* Don't wait. */ |
474 | return 0; | |
ff517991 MD |
475 | } |
476 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
477 | constructor_timeout->tv_nsec += | |
478 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
479 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
480 | constructor_timeout->tv_sec++; | |
481 | constructor_timeout->tv_nsec -= 1000000000UL; | |
482 | } | |
28515902 | 483 | /* Timeout wait (constructor_delay_ms). */ |
ff517991 MD |
484 | return 1; |
485 | } | |
486 | ||
2691221a | 487 | static |
32ce8569 | 488 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 489 | { |
32ce8569 MD |
490 | return ustcomm_send_reg_msg(socket, |
491 | type, | |
492 | CAA_BITS_PER_LONG, | |
493 | lttng_alignof(uint8_t) * CHAR_BIT, | |
494 | lttng_alignof(uint16_t) * CHAR_BIT, | |
495 | lttng_alignof(uint32_t) * CHAR_BIT, | |
496 | lttng_alignof(uint64_t) * CHAR_BIT, | |
497 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
498 | } |
499 | ||
d9e99d10 | 500 | static |
57773204 | 501 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 502 | { |
9eb62b9c | 503 | ssize_t len; |
d3a492d1 | 504 | |
57773204 | 505 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 506 | switch (len) { |
a4be8962 | 507 | case sizeof(*lur): |
d3a492d1 MD |
508 | DBG("message successfully sent"); |
509 | return 0; | |
7bc53e94 MD |
510 | default: |
511 | if (len == -ECONNRESET) { | |
512 | DBG("remote end closed connection"); | |
d3a492d1 MD |
513 | return 0; |
514 | } | |
7bc53e94 MD |
515 | if (len < 0) |
516 | return len; | |
517 | DBG("incorrect message size: %zd", len); | |
518 | return -EINVAL; | |
d3a492d1 MD |
519 | } |
520 | } | |
521 | ||
522 | static | |
edaa1431 | 523 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
524 | { |
525 | int ret; | |
526 | ||
edaa1431 MD |
527 | if (sock_info->constructor_sem_posted) |
528 | return 0; | |
529 | sock_info->constructor_sem_posted = 1; | |
56cd7e2f MD |
530 | if (uatomic_read(&sem_count) <= 0) { |
531 | return 0; | |
532 | } | |
95259bd0 MD |
533 | ret = uatomic_add_return(&sem_count, -1); |
534 | if (ret == 0) { | |
535 | ret = sem_post(&constructor_wait); | |
536 | assert(!ret); | |
537 | } | |
11ff9c7d MD |
538 | return 0; |
539 | } | |
540 | ||
37dddb65 MD |
541 | /* |
542 | * Only execute pending statedump after the constructor semaphore has | |
543 | * been posted by each listener thread. This means statedump will only | |
544 | * be performed after the "registration done" command is received from | |
545 | * each session daemon the application is connected to. | |
546 | * | |
547 | * This ensures we don't run into deadlock issues with the dynamic | |
548 | * loader mutex, which is held while the constructor is called and | |
549 | * waiting on the constructor semaphore. All operations requiring this | |
550 | * dynamic loader lock need to be postponed using this mechanism. | |
551 | */ | |
552 | static | |
553 | void handle_pending_statedump(struct sock_info *sock_info) | |
554 | { | |
555 | int ctor_passed = sock_info->constructor_sem_posted; | |
556 | ||
557 | if (ctor_passed && sock_info->statedump_pending) { | |
558 | sock_info->statedump_pending = 0; | |
2932a87f | 559 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 560 | lttng_handle_pending_statedump(sock_info); |
458d678c | 561 | pthread_mutex_unlock(&ust_fork_mutex); |
37dddb65 MD |
562 | } |
563 | } | |
564 | ||
11ff9c7d MD |
565 | static |
566 | int handle_message(struct sock_info *sock_info, | |
57773204 | 567 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 568 | { |
1ea11eab | 569 | int ret = 0; |
b61ce3b2 | 570 | const struct lttng_ust_objd_ops *ops; |
57773204 | 571 | struct ustcomm_ust_reply lur; |
ef9ff354 | 572 | union ust_args args; |
40003310 | 573 | ssize_t len; |
1ea11eab | 574 | |
46050b1a MD |
575 | memset(&lur, 0, sizeof(lur)); |
576 | ||
3327ac33 | 577 | if (ust_lock()) { |
74d81a6c | 578 | ret = -LTTNG_UST_ERR_EXITING; |
1ea11eab MD |
579 | goto end; |
580 | } | |
9eb62b9c | 581 | |
46050b1a MD |
582 | ops = objd_ops(lum->handle); |
583 | if (!ops) { | |
584 | ret = -ENOENT; | |
585 | goto end; | |
1ea11eab | 586 | } |
46050b1a MD |
587 | |
588 | switch (lum->cmd) { | |
11ff9c7d MD |
589 | case LTTNG_UST_REGISTER_DONE: |
590 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 591 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
592 | else |
593 | ret = -EINVAL; | |
594 | break; | |
46050b1a MD |
595 | case LTTNG_UST_RELEASE: |
596 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
597 | ret = -EPERM; | |
598 | else | |
1849ef7c | 599 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 600 | break; |
2d78951a MD |
601 | case LTTNG_UST_FILTER: |
602 | { | |
603 | /* Receive filter data */ | |
f488575f | 604 | struct lttng_ust_filter_bytecode_node *bytecode; |
2d78951a | 605 | |
cd54f6d9 | 606 | if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) { |
7bc53e94 | 607 | ERR("Filter data size is too large: %u bytes", |
2d78951a MD |
608 | lum->u.filter.data_size); |
609 | ret = -EINVAL; | |
610 | goto error; | |
611 | } | |
2734ca65 | 612 | |
885b1dfd | 613 | if (lum->u.filter.reloc_offset > lum->u.filter.data_size) { |
7bc53e94 | 614 | ERR("Filter reloc offset %u is not within data", |
2734ca65 CB |
615 | lum->u.filter.reloc_offset); |
616 | ret = -EINVAL; | |
617 | goto error; | |
618 | } | |
619 | ||
cd54f6d9 MD |
620 | bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size); |
621 | if (!bytecode) { | |
622 | ret = -ENOMEM; | |
623 | goto error; | |
624 | } | |
f488575f | 625 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, |
2d78951a MD |
626 | lum->u.filter.data_size); |
627 | switch (len) { | |
628 | case 0: /* orderly shutdown */ | |
629 | ret = 0; | |
cd54f6d9 | 630 | free(bytecode); |
2d78951a | 631 | goto error; |
2d78951a MD |
632 | default: |
633 | if (len == lum->u.filter.data_size) { | |
7bc53e94 | 634 | DBG("filter data received"); |
2d78951a | 635 | break; |
7bc53e94 MD |
636 | } else if (len < 0) { |
637 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
638 | if (len == -ECONNRESET) { | |
639 | ERR("%s remote end closed connection", sock_info->name); | |
640 | ret = len; | |
641 | free(bytecode); | |
642 | goto error; | |
643 | } | |
644 | ret = len; | |
eb8bf361 | 645 | free(bytecode); |
7bc53e94 | 646 | goto end; |
2d78951a | 647 | } else { |
7bc53e94 | 648 | DBG("incorrect filter data message size: %zd", len); |
2d78951a | 649 | ret = -EINVAL; |
cd54f6d9 | 650 | free(bytecode); |
2d78951a MD |
651 | goto end; |
652 | } | |
653 | } | |
f488575f MD |
654 | bytecode->bc.len = lum->u.filter.data_size; |
655 | bytecode->bc.reloc_offset = lum->u.filter.reloc_offset; | |
3f6fd224 | 656 | bytecode->bc.seqnum = lum->u.filter.seqnum; |
cd54f6d9 | 657 | if (ops->cmd) { |
2d78951a | 658 | ret = ops->cmd(lum->handle, lum->cmd, |
cd54f6d9 | 659 | (unsigned long) bytecode, |
f59ed768 | 660 | &args, sock_info); |
cd54f6d9 MD |
661 | if (ret) { |
662 | free(bytecode); | |
663 | } | |
664 | /* don't free bytecode if everything went fine. */ | |
665 | } else { | |
2d78951a | 666 | ret = -ENOSYS; |
cd54f6d9 MD |
667 | free(bytecode); |
668 | } | |
2d78951a MD |
669 | break; |
670 | } | |
86e36163 JI |
671 | case LTTNG_UST_EXCLUSION: |
672 | { | |
673 | /* Receive exclusion names */ | |
674 | struct lttng_ust_excluder_node *node; | |
675 | unsigned int count; | |
676 | ||
677 | count = lum->u.exclusion.count; | |
678 | if (count == 0) { | |
679 | /* There are no names to read */ | |
680 | ret = 0; | |
681 | goto error; | |
682 | } | |
683 | node = zmalloc(sizeof(*node) + | |
684 | count * LTTNG_UST_SYM_NAME_LEN); | |
685 | if (!node) { | |
686 | ret = -ENOMEM; | |
687 | goto error; | |
688 | } | |
689 | node->excluder.count = count; | |
690 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
691 | count * LTTNG_UST_SYM_NAME_LEN); | |
692 | switch (len) { | |
693 | case 0: /* orderly shutdown */ | |
694 | ret = 0; | |
695 | free(node); | |
696 | goto error; | |
697 | default: | |
698 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
699 | DBG("Exclusion data received"); | |
700 | break; | |
701 | } else if (len < 0) { | |
702 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
703 | if (len == -ECONNRESET) { | |
704 | ERR("%s remote end closed connection", sock_info->name); | |
705 | ret = len; | |
706 | free(node); | |
707 | goto error; | |
708 | } | |
709 | ret = len; | |
710 | free(node); | |
711 | goto end; | |
712 | } else { | |
713 | DBG("Incorrect exclusion data message size: %zd", len); | |
714 | ret = -EINVAL; | |
715 | free(node); | |
716 | goto end; | |
717 | } | |
718 | } | |
719 | if (ops->cmd) { | |
720 | ret = ops->cmd(lum->handle, lum->cmd, | |
721 | (unsigned long) node, | |
722 | &args, sock_info); | |
723 | if (ret) { | |
724 | free(node); | |
725 | } | |
726 | /* Don't free exclusion data if everything went fine. */ | |
727 | } else { | |
728 | ret = -ENOSYS; | |
729 | free(node); | |
730 | } | |
731 | break; | |
732 | } | |
74d81a6c MD |
733 | case LTTNG_UST_CHANNEL: |
734 | { | |
735 | void *chan_data; | |
ff0f5728 | 736 | int wakeup_fd; |
74d81a6c MD |
737 | |
738 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
739 | &chan_data, lum->u.channel.len, |
740 | &wakeup_fd); | |
74d81a6c MD |
741 | switch (len) { |
742 | case 0: /* orderly shutdown */ | |
743 | ret = 0; | |
744 | goto error; | |
745 | default: | |
746 | if (len == lum->u.channel.len) { | |
747 | DBG("channel data received"); | |
748 | break; | |
749 | } else if (len < 0) { | |
750 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
751 | if (len == -ECONNRESET) { | |
752 | ERR("%s remote end closed connection", sock_info->name); | |
753 | ret = len; | |
754 | goto error; | |
755 | } | |
756 | ret = len; | |
757 | goto end; | |
758 | } else { | |
759 | DBG("incorrect channel data message size: %zd", len); | |
760 | ret = -EINVAL; | |
761 | goto end; | |
762 | } | |
763 | } | |
764 | args.channel.chan_data = chan_data; | |
ff0f5728 | 765 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
766 | if (ops->cmd) |
767 | ret = ops->cmd(lum->handle, lum->cmd, | |
768 | (unsigned long) &lum->u, | |
769 | &args, sock_info); | |
770 | else | |
771 | ret = -ENOSYS; | |
772 | break; | |
773 | } | |
774 | case LTTNG_UST_STREAM: | |
775 | { | |
776 | /* Receive shm_fd, wakeup_fd */ | |
777 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
778 | &lum->u.stream.len, | |
779 | &args.stream.shm_fd, | |
780 | &args.stream.wakeup_fd); | |
781 | if (ret) { | |
782 | goto end; | |
783 | } | |
784 | if (ops->cmd) | |
785 | ret = ops->cmd(lum->handle, lum->cmd, | |
786 | (unsigned long) &lum->u, | |
787 | &args, sock_info); | |
788 | else | |
789 | ret = -ENOSYS; | |
790 | break; | |
791 | } | |
d9e99d10 | 792 | default: |
46050b1a MD |
793 | if (ops->cmd) |
794 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 795 | (unsigned long) &lum->u, |
f59ed768 | 796 | &args, sock_info); |
46050b1a MD |
797 | else |
798 | ret = -ENOSYS; | |
799 | break; | |
d9e99d10 | 800 | } |
46050b1a | 801 | |
1ea11eab | 802 | end: |
46050b1a MD |
803 | lur.handle = lum->handle; |
804 | lur.cmd = lum->cmd; | |
805 | lur.ret_val = ret; | |
806 | if (ret >= 0) { | |
7bc53e94 | 807 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 808 | } else { |
7bc53e94 MD |
809 | /* |
810 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
811 | * error that are not caused by the transport, except if | |
812 | * we already have a more precise error message to | |
813 | * report. | |
814 | */ | |
64b2564e DG |
815 | if (ret > -LTTNG_UST_ERR) { |
816 | /* Translate code to UST error. */ | |
817 | switch (ret) { | |
818 | case -EEXIST: | |
819 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
820 | break; | |
821 | case -EINVAL: | |
822 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
823 | break; | |
824 | case -ENOENT: | |
825 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
826 | break; | |
827 | case -EPERM: | |
828 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
829 | break; | |
830 | case -ENOSYS: | |
831 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
832 | break; | |
833 | default: | |
834 | lur.ret_code = -LTTNG_UST_ERR; | |
835 | break; | |
836 | } | |
837 | } else { | |
7bc53e94 | 838 | lur.ret_code = ret; |
64b2564e | 839 | } |
46050b1a | 840 | } |
e6ea14c5 MD |
841 | if (ret >= 0) { |
842 | switch (lum->cmd) { | |
e6ea14c5 MD |
843 | case LTTNG_UST_TRACER_VERSION: |
844 | lur.u.version = lum->u.version; | |
845 | break; | |
846 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
847 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
848 | break; | |
849 | } | |
381c0f1e | 850 | } |
74d81a6c | 851 | DBG("Return value: %d", lur.ret_val); |
46050b1a | 852 | ret = send_reply(sock, &lur); |
193183fb | 853 | if (ret < 0) { |
7bc53e94 | 854 | DBG("error sending reply"); |
193183fb MD |
855 | goto error; |
856 | } | |
46050b1a | 857 | |
40003310 MD |
858 | /* |
859 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
860 | * after the reply. | |
861 | */ | |
7bc53e94 | 862 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
863 | switch (lum->cmd) { |
864 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
865 | len = ustcomm_send_unix_sock(sock, | |
866 | &args.field_list.entry, | |
867 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
868 | if (len < 0) { |
869 | ret = len; | |
870 | goto error; | |
871 | } | |
40003310 | 872 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 873 | ret = -EINVAL; |
40003310 MD |
874 | goto error; |
875 | } | |
876 | } | |
877 | } | |
ef9ff354 | 878 | |
381c0f1e | 879 | error: |
17dfb34b | 880 | ust_unlock(); |
d9e99d10 | 881 | |
37dddb65 MD |
882 | /* |
883 | * Performed delayed statedump operations outside of the UST | |
884 | * lock. We need to take the dynamic loader lock before we take | |
885 | * the UST lock internally within handle_pending_statedump(). | |
886 | */ | |
887 | handle_pending_statedump(sock_info); | |
246be17e | 888 | |
37dddb65 | 889 | return ret; |
246be17e PW |
890 | } |
891 | ||
46050b1a | 892 | static |
efe0de09 | 893 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
894 | { |
895 | int ret; | |
896 | ||
5b14aab3 MD |
897 | if (sock_info->root_handle != -1) { |
898 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
899 | if (ret) { | |
900 | ERR("Error unref root handle"); | |
901 | } | |
902 | sock_info->root_handle = -1; | |
903 | } | |
904 | sock_info->constructor_sem_posted = 0; | |
905 | ||
906 | /* | |
907 | * wait_shm_mmap, socket and notify socket are used by listener | |
908 | * threads outside of the ust lock, so we cannot tear them down | |
909 | * ourselves, because we cannot join on these threads. Leave | |
910 | * responsibility of cleaning up these resources to the OS | |
911 | * process exit. | |
912 | */ | |
913 | if (exiting) | |
914 | return; | |
915 | ||
46050b1a | 916 | if (sock_info->socket != -1) { |
e6973a89 | 917 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 918 | if (ret) { |
32ce8569 | 919 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
920 | } |
921 | sock_info->socket = -1; | |
922 | } | |
32ce8569 MD |
923 | if (sock_info->notify_socket != -1) { |
924 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
925 | if (ret) { | |
926 | ERR("Error closing ust notify socket"); | |
927 | } | |
928 | sock_info->notify_socket = -1; | |
929 | } | |
5b14aab3 | 930 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
931 | long page_size; |
932 | ||
933 | page_size = sysconf(_SC_PAGE_SIZE); | |
934 | if (page_size > 0) { | |
935 | ret = munmap(sock_info->wait_shm_mmap, page_size); | |
936 | if (ret) { | |
937 | ERR("Error unmapping wait shm"); | |
938 | } | |
7fc90dca MD |
939 | } |
940 | sock_info->wait_shm_mmap = NULL; | |
941 | } | |
942 | } | |
943 | ||
58d4b2a2 | 944 | /* |
33bbeb90 MD |
945 | * Using fork to set umask in the child process (not multi-thread safe). |
946 | * We deal with the shm_open vs ftruncate race (happening when the | |
947 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
948 | * safety against shm_unlink) by simply letting the mmap fail and | |
949 | * retrying after a few seconds. | |
950 | * For global shm, everybody has rw access to it until the sessiond | |
951 | * starts. | |
58d4b2a2 | 952 | */ |
7fc90dca | 953 | static |
58d4b2a2 | 954 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 955 | { |
7fc90dca | 956 | int wait_shm_fd, ret; |
58d4b2a2 | 957 | pid_t pid; |
44e073f5 | 958 | |
58d4b2a2 | 959 | /* |
33bbeb90 | 960 | * Try to open read-only. |
58d4b2a2 | 961 | */ |
33bbeb90 | 962 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 963 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
964 | int32_t tmp_read; |
965 | ssize_t len; | |
966 | size_t bytes_read = 0; | |
967 | ||
968 | /* | |
969 | * Try to read the fd. If unable to do so, try opening | |
970 | * it in write mode. | |
971 | */ | |
972 | do { | |
973 | len = read(wait_shm_fd, | |
974 | &((char *) &tmp_read)[bytes_read], | |
975 | sizeof(tmp_read) - bytes_read); | |
976 | if (len > 0) { | |
977 | bytes_read += len; | |
978 | } | |
979 | } while ((len < 0 && errno == EINTR) | |
980 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
981 | if (bytes_read != sizeof(tmp_read)) { | |
982 | ret = close(wait_shm_fd); | |
983 | if (ret) { | |
984 | ERR("close wait_shm_fd"); | |
985 | } | |
986 | goto open_write; | |
987 | } | |
58d4b2a2 MD |
988 | goto end; |
989 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
990 | /* | |
33bbeb90 MD |
991 | * Real-only open did not work, and it's not because the |
992 | * entry was not present. It's a failure that prohibits | |
993 | * using shm. | |
58d4b2a2 | 994 | */ |
7fc90dca | 995 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 996 | goto end; |
7fc90dca | 997 | } |
7aa76730 MD |
998 | |
999 | open_write: | |
7fc90dca | 1000 | /* |
7aa76730 MD |
1001 | * If the open failed because the file did not exist, or because |
1002 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 1003 | */ |
8c90a710 | 1004 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 1005 | pid = fork(); |
8c90a710 | 1006 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
1007 | if (pid > 0) { |
1008 | int status; | |
1009 | ||
1010 | /* | |
1011 | * Parent: wait for child to return, in which case the | |
1012 | * shared memory map will have been created. | |
1013 | */ | |
1014 | pid = wait(&status); | |
b7d3cb32 | 1015 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
1016 | wait_shm_fd = -1; |
1017 | goto end; | |
7fc90dca | 1018 | } |
58d4b2a2 MD |
1019 | /* |
1020 | * Try to open read-only again after creation. | |
1021 | */ | |
33bbeb90 | 1022 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
1023 | if (wait_shm_fd < 0) { |
1024 | /* | |
1025 | * Real-only open did not work. It's a failure | |
1026 | * that prohibits using shm. | |
1027 | */ | |
1028 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1029 | goto end; | |
1030 | } | |
1031 | goto end; | |
1032 | } else if (pid == 0) { | |
1033 | int create_mode; | |
1034 | ||
1035 | /* Child */ | |
33bbeb90 | 1036 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1037 | if (sock_info->global) |
33bbeb90 | 1038 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1039 | /* |
1040 | * We're alone in a child process, so we can modify the | |
1041 | * process-wide umask. | |
1042 | */ | |
33bbeb90 | 1043 | umask(~create_mode); |
58d4b2a2 | 1044 | /* |
33bbeb90 MD |
1045 | * Try creating shm (or get rw access). |
1046 | * We don't do an exclusive open, because we allow other | |
1047 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1048 | */ |
1049 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1050 | O_RDWR | O_CREAT, create_mode); | |
1051 | if (wait_shm_fd >= 0) { | |
1052 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1053 | if (ret) { | |
1054 | PERROR("ftruncate"); | |
b0c1425d | 1055 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1056 | } |
b0c1425d | 1057 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1058 | } |
33bbeb90 MD |
1059 | /* |
1060 | * For local shm, we need to have rw access to accept | |
1061 | * opening it: this means the local sessiond will be | |
1062 | * able to wake us up. For global shm, we open it even | |
1063 | * if rw access is not granted, because the root.root | |
1064 | * sessiond will be able to override all rights and wake | |
1065 | * us up. | |
1066 | */ | |
1067 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1068 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1069 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1070 | } |
1071 | /* | |
33bbeb90 MD |
1072 | * The shm exists, but we cannot open it RW. Report |
1073 | * success. | |
58d4b2a2 | 1074 | */ |
5d3bc5ed | 1075 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1076 | } else { |
1077 | return -1; | |
7fc90dca | 1078 | } |
58d4b2a2 | 1079 | end: |
33bbeb90 MD |
1080 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1081 | struct stat statbuf; | |
1082 | ||
1083 | /* | |
1084 | * Ensure that our user is the owner of the shm file for | |
1085 | * local shm. If we do not own the file, it means our | |
1086 | * sessiond will not have access to wake us up (there is | |
1087 | * probably a rogue process trying to fake our | |
1088 | * sessiond). Fallback to polling method in this case. | |
1089 | */ | |
1090 | ret = fstat(wait_shm_fd, &statbuf); | |
1091 | if (ret) { | |
1092 | PERROR("fstat"); | |
1093 | goto error_close; | |
1094 | } | |
1095 | if (statbuf.st_uid != getuid()) | |
1096 | goto error_close; | |
1097 | } | |
58d4b2a2 | 1098 | return wait_shm_fd; |
33bbeb90 MD |
1099 | |
1100 | error_close: | |
1101 | ret = close(wait_shm_fd); | |
1102 | if (ret) { | |
1103 | PERROR("Error closing fd"); | |
1104 | } | |
1105 | return -1; | |
58d4b2a2 MD |
1106 | } |
1107 | ||
1108 | static | |
1109 | char *get_map_shm(struct sock_info *sock_info) | |
1110 | { | |
172d6b68 | 1111 | long page_size; |
58d4b2a2 MD |
1112 | int wait_shm_fd, ret; |
1113 | char *wait_shm_mmap; | |
1114 | ||
172d6b68 MD |
1115 | page_size = sysconf(_SC_PAGE_SIZE); |
1116 | if (page_size < 0) { | |
1117 | goto error; | |
1118 | } | |
1119 | ||
1120 | wait_shm_fd = get_wait_shm(sock_info, page_size); | |
58d4b2a2 MD |
1121 | if (wait_shm_fd < 0) { |
1122 | goto error; | |
44e073f5 | 1123 | } |
172d6b68 | 1124 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1125 | MAP_SHARED, wait_shm_fd, 0); |
7fc90dca MD |
1126 | /* close shm fd immediately after taking the mmap reference */ |
1127 | ret = close(wait_shm_fd); | |
1128 | if (ret) { | |
33bbeb90 MD |
1129 | PERROR("Error closing fd"); |
1130 | } | |
1131 | if (wait_shm_mmap == MAP_FAILED) { | |
1132 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1133 | goto error; | |
7fc90dca MD |
1134 | } |
1135 | return wait_shm_mmap; | |
1136 | ||
1137 | error: | |
1138 | return NULL; | |
1139 | } | |
1140 | ||
1141 | static | |
1142 | void wait_for_sessiond(struct sock_info *sock_info) | |
1143 | { | |
3327ac33 | 1144 | if (ust_lock()) { |
7fc90dca MD |
1145 | goto quit; |
1146 | } | |
37ed587a MD |
1147 | if (wait_poll_fallback) { |
1148 | goto error; | |
1149 | } | |
7fc90dca MD |
1150 | if (!sock_info->wait_shm_mmap) { |
1151 | sock_info->wait_shm_mmap = get_map_shm(sock_info); | |
1152 | if (!sock_info->wait_shm_mmap) | |
1153 | goto error; | |
1154 | } | |
1155 | ust_unlock(); | |
1156 | ||
1157 | DBG("Waiting for %s apps sessiond", sock_info->name); | |
80e2814b | 1158 | /* Wait for futex wakeup */ |
ee7fcec8 MD |
1159 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) |
1160 | goto end_wait; | |
1161 | ||
1162 | while (futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1163 | FUTEX_WAIT, 0, NULL, NULL, 0)) { | |
1164 | switch (errno) { | |
1165 | case EWOULDBLOCK: | |
1166 | /* Value already changed. */ | |
1167 | goto end_wait; | |
1168 | case EINTR: | |
1169 | /* Retry if interrupted by signal. */ | |
1170 | break; /* Get out of switch. */ | |
1171 | case EFAULT: | |
1172 | wait_poll_fallback = 1; | |
1173 | DBG( | |
37ed587a MD |
1174 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1175 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1176 | "Please upgrade your kernel " | |
1177 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1178 | "mainline). LTTng-UST will use polling mode fallback."); | |
ee7fcec8 MD |
1179 | if (ust_debug()) |
1180 | PERROR("futex"); | |
1181 | goto end_wait; | |
80e2814b MD |
1182 | } |
1183 | } | |
ee7fcec8 | 1184 | end_wait: |
7fc90dca MD |
1185 | return; |
1186 | ||
1187 | quit: | |
1188 | ust_unlock(); | |
1189 | return; | |
1190 | ||
1191 | error: | |
1192 | ust_unlock(); | |
7fc90dca | 1193 | return; |
46050b1a MD |
1194 | } |
1195 | ||
1ea11eab MD |
1196 | /* |
1197 | * This thread does not allocate any resource, except within | |
1198 | * handle_message, within mutex protection. This mutex protects against | |
1199 | * fork and exit. | |
98bf993f | 1200 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1201 | * is also protected by the mutex. |
1202 | */ | |
d9e99d10 MD |
1203 | static |
1204 | void *ust_listener_thread(void *arg) | |
1205 | { | |
1ea11eab | 1206 | struct sock_info *sock_info = arg; |
c0eedf81 | 1207 | int sock, ret, prev_connect_failed = 0, has_waited = 0; |
ff517991 | 1208 | long timeout; |
d9e99d10 | 1209 | |
9eb62b9c MD |
1210 | /* Restart trying to connect to the session daemon */ |
1211 | restart: | |
c0eedf81 MD |
1212 | if (prev_connect_failed) { |
1213 | /* Wait for sessiond availability with pipe */ | |
1214 | wait_for_sessiond(sock_info); | |
1215 | if (has_waited) { | |
1216 | has_waited = 0; | |
1217 | /* | |
1218 | * Sleep for 5 seconds before retrying after a | |
1219 | * sequence of failure / wait / failure. This | |
1220 | * deals with a killed or broken session daemon. | |
1221 | */ | |
1222 | sleep(5); | |
1223 | } | |
1224 | has_waited = 1; | |
1225 | prev_connect_failed = 0; | |
1226 | } | |
9eb62b9c | 1227 | |
1ea11eab | 1228 | if (sock_info->socket != -1) { |
e6973a89 | 1229 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1230 | if (ret) { |
32ce8569 MD |
1231 | ERR("Error closing %s ust cmd socket", |
1232 | sock_info->name); | |
1ea11eab MD |
1233 | } |
1234 | sock_info->socket = -1; | |
1235 | } | |
32ce8569 MD |
1236 | if (sock_info->notify_socket != -1) { |
1237 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1238 | if (ret) { | |
1239 | ERR("Error closing %s ust notify socket", | |
1240 | sock_info->name); | |
1241 | } | |
1242 | sock_info->notify_socket = -1; | |
1243 | } | |
46050b1a | 1244 | |
321f2351 MD |
1245 | /* |
1246 | * Register. We need to perform both connect and sending | |
1247 | * registration message before doing the next connect otherwise | |
1248 | * we may reach unix socket connect queue max limits and block | |
1249 | * on the 2nd connect while the session daemon is awaiting the | |
1250 | * first connect registration message. | |
1251 | */ | |
1252 | /* Connect cmd socket */ | |
1253 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1254 | if (ret < 0) { | |
1255 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1256 | prev_connect_failed = 1; | |
5b14aab3 | 1257 | |
3327ac33 | 1258 | if (ust_lock()) { |
321f2351 | 1259 | goto quit; |
32ce8569 | 1260 | } |
46050b1a | 1261 | |
e3426ddc | 1262 | /* |
321f2351 MD |
1263 | * If we cannot find the sessiond daemon, don't delay |
1264 | * constructor execution. | |
e3426ddc | 1265 | */ |
321f2351 MD |
1266 | ret = handle_register_done(sock_info); |
1267 | assert(!ret); | |
1268 | ust_unlock(); | |
1269 | goto restart; | |
27fe9f21 | 1270 | } |
321f2351 | 1271 | sock_info->socket = ret; |
27fe9f21 | 1272 | |
3327ac33 | 1273 | if (ust_lock()) { |
5b14aab3 MD |
1274 | goto quit; |
1275 | } | |
1276 | ||
46050b1a MD |
1277 | /* |
1278 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1279 | * process lifetime, so we ensure we get ID which is statically |
1280 | * assigned to the root handle. | |
46050b1a MD |
1281 | */ |
1282 | if (sock_info->root_handle == -1) { | |
1283 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1284 | if (ret < 0) { |
46050b1a | 1285 | ERR("Error creating root handle"); |
46050b1a MD |
1286 | goto quit; |
1287 | } | |
1288 | sock_info->root_handle = ret; | |
9eb62b9c | 1289 | } |
1ea11eab | 1290 | |
32ce8569 | 1291 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1292 | if (ret < 0) { |
32ce8569 MD |
1293 | ERR("Error registering to %s ust cmd socket", |
1294 | sock_info->name); | |
c0eedf81 | 1295 | prev_connect_failed = 1; |
11ff9c7d MD |
1296 | /* |
1297 | * If we cannot register to the sessiond daemon, don't | |
1298 | * delay constructor execution. | |
1299 | */ | |
edaa1431 | 1300 | ret = handle_register_done(sock_info); |
11ff9c7d | 1301 | assert(!ret); |
17dfb34b | 1302 | ust_unlock(); |
9eb62b9c MD |
1303 | goto restart; |
1304 | } | |
321f2351 MD |
1305 | |
1306 | ust_unlock(); | |
1307 | ||
1308 | /* Connect notify socket */ | |
1309 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1310 | if (ret < 0) { | |
1311 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1312 | prev_connect_failed = 1; | |
1313 | ||
3327ac33 | 1314 | if (ust_lock()) { |
321f2351 MD |
1315 | goto quit; |
1316 | } | |
1317 | ||
1318 | /* | |
1319 | * If we cannot find the sessiond daemon, don't delay | |
1320 | * constructor execution. | |
1321 | */ | |
1322 | ret = handle_register_done(sock_info); | |
1323 | assert(!ret); | |
1324 | ust_unlock(); | |
1325 | goto restart; | |
1326 | } | |
1327 | sock_info->notify_socket = ret; | |
1328 | ||
1329 | timeout = get_notify_sock_timeout(); | |
1330 | if (timeout >= 0) { | |
1331 | /* | |
1332 | * Give at least 10ms to sessiond to reply to | |
1333 | * notifications. | |
1334 | */ | |
1335 | if (timeout < 10) | |
1336 | timeout = 10; | |
1337 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1338 | timeout); | |
1339 | if (ret < 0) { | |
1340 | WARN("Error setting socket receive timeout"); | |
1341 | } | |
1342 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1343 | timeout); | |
1344 | if (ret < 0) { | |
1345 | WARN("Error setting socket send timeout"); | |
1346 | } | |
1347 | } else if (timeout < -1) { | |
1348 | WARN("Unsupported timeout value %ld", timeout); | |
1349 | } | |
1350 | ||
3327ac33 | 1351 | if (ust_lock()) { |
321f2351 MD |
1352 | goto quit; |
1353 | } | |
1354 | ||
32ce8569 MD |
1355 | ret = register_to_sessiond(sock_info->notify_socket, |
1356 | USTCTL_SOCKET_NOTIFY); | |
1357 | if (ret < 0) { | |
1358 | ERR("Error registering to %s ust notify socket", | |
1359 | sock_info->name); | |
1360 | prev_connect_failed = 1; | |
1361 | /* | |
1362 | * If we cannot register to the sessiond daemon, don't | |
1363 | * delay constructor execution. | |
1364 | */ | |
1365 | ret = handle_register_done(sock_info); | |
1366 | assert(!ret); | |
1367 | ust_unlock(); | |
1368 | goto restart; | |
1369 | } | |
1370 | sock = sock_info->socket; | |
1371 | ||
17dfb34b | 1372 | ust_unlock(); |
46050b1a | 1373 | |
d9e99d10 MD |
1374 | for (;;) { |
1375 | ssize_t len; | |
57773204 | 1376 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1377 | |
57773204 | 1378 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1379 | switch (len) { |
1380 | case 0: /* orderly shutdown */ | |
7dd08bec | 1381 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1382 | if (ust_lock()) { |
d5e1fea6 MD |
1383 | goto quit; |
1384 | } | |
8236ba10 MD |
1385 | /* |
1386 | * Either sessiond has shutdown or refused us by closing the socket. | |
1387 | * In either case, we don't want to delay construction execution, | |
1388 | * and we need to wait before retry. | |
1389 | */ | |
1390 | prev_connect_failed = 1; | |
1391 | /* | |
1392 | * If we cannot register to the sessiond daemon, don't | |
1393 | * delay constructor execution. | |
1394 | */ | |
1395 | ret = handle_register_done(sock_info); | |
1396 | assert(!ret); | |
1397 | ust_unlock(); | |
d9e99d10 | 1398 | goto end; |
e7723462 | 1399 | case sizeof(lum): |
74d81a6c | 1400 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1401 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1402 | if (ret) { |
11ff9c7d | 1403 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
1404 | } |
1405 | continue; | |
7bc53e94 MD |
1406 | default: |
1407 | if (len < 0) { | |
1408 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1409 | } else { | |
1410 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1411 | } | |
1412 | if (len == -ECONNRESET) { | |
1413 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1414 | goto end; |
1415 | } | |
1416 | goto end; | |
d9e99d10 MD |
1417 | } |
1418 | ||
1419 | } | |
1420 | end: | |
3327ac33 | 1421 | if (ust_lock()) { |
d5e1fea6 MD |
1422 | goto quit; |
1423 | } | |
f59ed768 MD |
1424 | /* Cleanup socket handles before trying to reconnect */ |
1425 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1426 | ust_unlock(); | |
9eb62b9c | 1427 | goto restart; /* try to reconnect */ |
e33f3265 | 1428 | |
1ea11eab | 1429 | quit: |
e33f3265 | 1430 | ust_unlock(); |
3327ac33 MD |
1431 | |
1432 | pthread_mutex_lock(&ust_exit_mutex); | |
1433 | sock_info->thread_active = 0; | |
1434 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1435 | return NULL; |
1436 | } | |
1437 | ||
2594a5b4 MD |
1438 | /* |
1439 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1440 | */ | |
1441 | __attribute__((weak)) | |
1442 | void lttng_ust_malloc_wrapper_init(void) | |
1443 | { | |
1444 | } | |
1445 | ||
2691221a MD |
1446 | /* |
1447 | * sessiond monitoring thread: monitor presence of global and per-user | |
1448 | * sessiond by polling the application common named pipe. | |
1449 | */ | |
edaa1431 | 1450 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1451 | { |
11ff9c7d | 1452 | struct timespec constructor_timeout; |
ae6a58bf | 1453 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1454 | pthread_attr_t thread_attr; |
cf12a773 | 1455 | int timeout_mode; |
2691221a MD |
1456 | int ret; |
1457 | ||
edaa1431 MD |
1458 | if (uatomic_xchg(&initialized, 1) == 1) |
1459 | return; | |
1460 | ||
eddd8d5d MD |
1461 | /* |
1462 | * Fixup interdependency between TLS fixup mutex (which happens | |
1463 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1464 | * the ust lock. | |
1465 | */ | |
1556a549 | 1466 | lttng_fixup_urcu_bp_tls(); |
f645cfa7 | 1467 | lttng_fixup_ringbuffer_tls(); |
4158a15a | 1468 | lttng_fixup_vtid_tls(); |
a903623f | 1469 | lttng_fixup_nest_count_tls(); |
009745db | 1470 | lttng_fixup_procname_tls(); |
d58d1454 | 1471 | lttng_fixup_ust_mutex_nest_tls(); |
eddd8d5d | 1472 | |
edaa1431 MD |
1473 | /* |
1474 | * We want precise control over the order in which we construct | |
1475 | * our sub-libraries vs starting to receive commands from | |
1476 | * sessiond (otherwise leading to errors when trying to create | |
1477 | * sessiond before the init functions are completed). | |
1478 | */ | |
2691221a | 1479 | init_usterr(); |
edaa1431 | 1480 | init_tracepoint(); |
f9364363 | 1481 | lttng_ust_clock_init(); |
5e1b7b8b | 1482 | lttng_ust_getcpu_init(); |
cf73e0fe | 1483 | lttng_ust_statedump_init(); |
7dd08bec MD |
1484 | lttng_ring_buffer_metadata_client_init(); |
1485 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1486 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1487 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1488 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1489 | lttng_perf_counter_init(); |
a0a3bef9 | 1490 | lttng_context_init(); |
2594a5b4 MD |
1491 | /* |
1492 | * Invoke ust malloc wrapper init before starting other threads. | |
1493 | */ | |
1494 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1495 | |
ff517991 | 1496 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1497 | |
95259bd0 | 1498 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
1499 | assert(!ret); |
1500 | ||
8d20bf54 | 1501 | ret = setup_local_apps(); |
2691221a | 1502 | if (ret) { |
9ec6895c | 1503 | DBG("local apps setup returned %d", ret); |
2691221a | 1504 | } |
ae6a58bf WP |
1505 | |
1506 | /* A new thread created by pthread_create inherits the signal mask | |
1507 | * from the parent. To avoid any signal being received by the | |
1508 | * listener thread, we block all signals temporarily in the parent, | |
1509 | * while we create the listener thread. | |
1510 | */ | |
1511 | sigfillset(&sig_all_blocked); | |
1512 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1513 | if (ret) { | |
d94d802c | 1514 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1515 | } |
1516 | ||
1879f67f MG |
1517 | ret = pthread_attr_init(&thread_attr); |
1518 | if (ret) { | |
1519 | ERR("pthread_attr_init: %s", strerror(ret)); | |
1520 | } | |
1521 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
1522 | if (ret) { | |
1523 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
1524 | } | |
1525 | ||
c0bbbd5a | 1526 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1527 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, |
dde70ea0 | 1528 | ust_listener_thread, &global_apps); |
d94d802c MD |
1529 | if (ret) { |
1530 | ERR("pthread_create global: %s", strerror(ret)); | |
1531 | } | |
e33f3265 | 1532 | global_apps.thread_active = 1; |
c0bbbd5a | 1533 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1534 | |
8d20bf54 | 1535 | if (local_apps.allowed) { |
c0bbbd5a | 1536 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1537 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 1538 | ust_listener_thread, &local_apps); |
d94d802c MD |
1539 | if (ret) { |
1540 | ERR("pthread_create local: %s", strerror(ret)); | |
1541 | } | |
e33f3265 | 1542 | local_apps.thread_active = 1; |
c0bbbd5a | 1543 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
1544 | } else { |
1545 | handle_register_done(&local_apps); | |
1546 | } | |
1879f67f MG |
1547 | ret = pthread_attr_destroy(&thread_attr); |
1548 | if (ret) { | |
1549 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
1550 | } | |
8d20bf54 | 1551 | |
ae6a58bf WP |
1552 | /* Restore original signal mask in parent */ |
1553 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
1554 | if (ret) { | |
d94d802c | 1555 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1556 | } |
1557 | ||
cf12a773 MD |
1558 | switch (timeout_mode) { |
1559 | case 1: /* timeout wait */ | |
95259bd0 MD |
1560 | do { |
1561 | ret = sem_timedwait(&constructor_wait, | |
1562 | &constructor_timeout); | |
1563 | } while (ret < 0 && errno == EINTR); | |
cf12a773 | 1564 | if (ret < 0 && errno == ETIMEDOUT) { |
7dd08bec | 1565 | ERR("Timed out waiting for lttng-sessiond"); |
cf12a773 MD |
1566 | } else { |
1567 | assert(!ret); | |
1568 | } | |
1569 | break; | |
7b766b16 | 1570 | case -1:/* wait forever */ |
95259bd0 MD |
1571 | do { |
1572 | ret = sem_wait(&constructor_wait); | |
1573 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 1574 | assert(!ret); |
cf12a773 | 1575 | break; |
7b766b16 | 1576 | case 0: /* no timeout */ |
cf12a773 | 1577 | break; |
11ff9c7d | 1578 | } |
2691221a MD |
1579 | } |
1580 | ||
17dfb34b MD |
1581 | static |
1582 | void lttng_ust_cleanup(int exiting) | |
1583 | { | |
efe0de09 | 1584 | cleanup_sock_info(&global_apps, exiting); |
932cfadb | 1585 | cleanup_sock_info(&local_apps, exiting); |
efe0de09 MD |
1586 | /* |
1587 | * The teardown in this function all affect data structures | |
1588 | * accessed under the UST lock by the listener thread. This | |
1589 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
1590 | * that none of these threads are accessing this data at this | |
1591 | * point. | |
1592 | */ | |
17dfb34b | 1593 | lttng_ust_abi_exit(); |
003fedf4 | 1594 | lttng_ust_events_exit(); |
a0a3bef9 | 1595 | lttng_context_exit(); |
d58d1454 | 1596 | lttng_perf_counter_exit(); |
34a91bdb | 1597 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 1598 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 1599 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
1600 | lttng_ring_buffer_client_overwrite_exit(); |
1601 | lttng_ring_buffer_metadata_client_exit(); | |
cf73e0fe | 1602 | lttng_ust_statedump_destroy(); |
17dfb34b MD |
1603 | exit_tracepoint(); |
1604 | if (!exiting) { | |
1605 | /* Reinitialize values for fork */ | |
1606 | sem_count = 2; | |
1607 | lttng_ust_comm_should_quit = 0; | |
1608 | initialized = 0; | |
1609 | } | |
1610 | } | |
1611 | ||
edaa1431 | 1612 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
1613 | { |
1614 | int ret; | |
1615 | ||
9eb62b9c MD |
1616 | /* |
1617 | * Using pthread_cancel here because: | |
1618 | * A) we don't want to hang application teardown. | |
1619 | * B) the thread is not allocating any resource. | |
1620 | */ | |
1ea11eab MD |
1621 | |
1622 | /* | |
1623 | * Require the communication thread to quit. Synchronize with | |
1624 | * mutexes to ensure it is not in a mutex critical section when | |
1625 | * pthread_cancel is later called. | |
1626 | */ | |
3327ac33 | 1627 | ust_lock_nocheck(); |
1ea11eab | 1628 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 1629 | ust_unlock(); |
1ea11eab | 1630 | |
3327ac33 | 1631 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 1632 | /* cancel threads */ |
e33f3265 MD |
1633 | if (global_apps.thread_active) { |
1634 | ret = pthread_cancel(global_apps.ust_listener); | |
1635 | if (ret) { | |
1636 | ERR("Error cancelling global ust listener thread: %s", | |
1637 | strerror(ret)); | |
1638 | } else { | |
1639 | global_apps.thread_active = 0; | |
1640 | } | |
2691221a | 1641 | } |
e33f3265 | 1642 | if (local_apps.thread_active) { |
8d20bf54 MD |
1643 | ret = pthread_cancel(local_apps.ust_listener); |
1644 | if (ret) { | |
d94d802c MD |
1645 | ERR("Error cancelling local ust listener thread: %s", |
1646 | strerror(ret)); | |
e33f3265 MD |
1647 | } else { |
1648 | local_apps.thread_active = 0; | |
8d20bf54 | 1649 | } |
8d20bf54 | 1650 | } |
3327ac33 | 1651 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1652 | |
efe0de09 MD |
1653 | /* |
1654 | * Do NOT join threads: use of sys_futex makes it impossible to | |
1655 | * join the threads without using async-cancel, but async-cancel | |
1656 | * is delivered by a signal, which could hit the target thread | |
1657 | * anywhere in its code path, including while the ust_lock() is | |
1658 | * held, causing a deadlock for the other thread. Let the OS | |
1659 | * cleanup the threads if there are stalled in a syscall. | |
1660 | */ | |
17dfb34b | 1661 | lttng_ust_cleanup(1); |
2691221a | 1662 | } |
e822f505 MD |
1663 | |
1664 | /* | |
1665 | * We exclude the worker threads across fork and clone (except | |
1666 | * CLONE_VM), because these system calls only keep the forking thread | |
1667 | * running in the child. Therefore, we don't want to call fork or clone | |
1668 | * in the middle of an tracepoint or ust tracing state modification. | |
1669 | * Holding this mutex protects these structures across fork and clone. | |
1670 | */ | |
b728d87e | 1671 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
1672 | { |
1673 | /* | |
1674 | * Disable signals. This is to avoid that the child intervenes | |
1675 | * before it is properly setup for tracing. It is safer to | |
1676 | * disable all signals, because then we know we are not breaking | |
1677 | * anything by restoring the original mask. | |
1678 | */ | |
1679 | sigset_t all_sigs; | |
1680 | int ret; | |
1681 | ||
8c90a710 | 1682 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1683 | return; |
e822f505 MD |
1684 | /* Disable signals */ |
1685 | sigfillset(&all_sigs); | |
b728d87e | 1686 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
1687 | if (ret == -1) { |
1688 | PERROR("sigprocmask"); | |
1689 | } | |
458d678c PW |
1690 | |
1691 | pthread_mutex_lock(&ust_fork_mutex); | |
1692 | ||
3327ac33 | 1693 | ust_lock_nocheck(); |
e822f505 MD |
1694 | rcu_bp_before_fork(); |
1695 | } | |
1696 | ||
b728d87e | 1697 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
1698 | { |
1699 | int ret; | |
1700 | ||
17dfb34b MD |
1701 | DBG("process %d", getpid()); |
1702 | ust_unlock(); | |
458d678c PW |
1703 | |
1704 | pthread_mutex_unlock(&ust_fork_mutex); | |
1705 | ||
e822f505 | 1706 | /* Restore signals */ |
23c8854a | 1707 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
1708 | if (ret == -1) { |
1709 | PERROR("sigprocmask"); | |
1710 | } | |
1711 | } | |
1712 | ||
b728d87e | 1713 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 1714 | { |
8c90a710 | 1715 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1716 | return; |
17dfb34b | 1717 | DBG("process %d", getpid()); |
e822f505 MD |
1718 | rcu_bp_after_fork_parent(); |
1719 | /* Release mutexes and reenable signals */ | |
b728d87e | 1720 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
1721 | } |
1722 | ||
17dfb34b MD |
1723 | /* |
1724 | * After fork, in the child, we need to cleanup all the leftover state, | |
1725 | * except the worker thread which already magically disappeared thanks | |
1726 | * to the weird Linux fork semantics. After tyding up, we call | |
1727 | * lttng_ust_init() again to start over as a new PID. | |
1728 | * | |
1729 | * This is meant for forks() that have tracing in the child between the | |
1730 | * fork and following exec call (if there is any). | |
1731 | */ | |
b728d87e | 1732 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 1733 | { |
8c90a710 | 1734 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1735 | return; |
17dfb34b | 1736 | DBG("process %d", getpid()); |
e822f505 MD |
1737 | /* Release urcu mutexes */ |
1738 | rcu_bp_after_fork_child(); | |
17dfb34b | 1739 | lttng_ust_cleanup(0); |
a93bfc45 | 1740 | lttng_context_vtid_reset(); |
e822f505 | 1741 | /* Release mutexes and reenable signals */ |
b728d87e | 1742 | ust_after_fork_common(restore_sigset); |
318dfea9 | 1743 | lttng_ust_init(); |
e822f505 | 1744 | } |
95c25348 | 1745 | |
246be17e | 1746 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
1747 | { |
1748 | struct sock_info *sock_info = owner; | |
37dddb65 | 1749 | sock_info->statedump_pending = 1; |
95c25348 | 1750 | } |