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" |
394598c1 | 55 | #include "lttng-ust-baddr.h" |
f9364363 | 56 | #include "clock.h" |
5e1b7b8b | 57 | #include "../libringbuffer/getcpu.h" |
edaa1431 MD |
58 | |
59 | /* | |
60 | * Has lttng ust comm constructor been called ? | |
61 | */ | |
62 | static int initialized; | |
63 | ||
1ea11eab | 64 | /* |
17dfb34b MD |
65 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
66 | * Held when handling a command, also held by fork() to deal with | |
67 | * removal of threads, and by exit path. | |
3327ac33 MD |
68 | * |
69 | * The UST lock is the centralized mutex across UST tracing control and | |
70 | * probe registration. | |
71 | * | |
72 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 73 | * |
4770bd47 MD |
74 | * ust_fork_mutex must never nest in ust_mutex. |
75 | * | |
d58d1454 MD |
76 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
77 | * counter lazy initialization called by events within the statedump, | |
78 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
79 | * |
80 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
81 | * it is taken within the library constructor. | |
3327ac33 MD |
82 | */ |
83 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
84 | ||
d58d1454 MD |
85 | /* Allow nesting the ust_mutex within the same thread. */ |
86 | static DEFINE_URCU_TLS(int, ust_mutex_nest); | |
87 | ||
3327ac33 MD |
88 | /* |
89 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
90 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
91 | * internal libc lock, cannot nest within ust_mutex. | |
92 | * | |
93 | * It never nests within a ust_mutex. | |
1ea11eab | 94 | */ |
3327ac33 | 95 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 96 | |
458d678c PW |
97 | /* |
98 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
99 | * prevents the dynamic loader lock to be taken (by base address statedump | |
100 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
101 | * the dynamic loader lock. | |
102 | */ | |
103 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
104 | ||
1ea11eab MD |
105 | /* Should the ust comm thread quit ? */ |
106 | static int lttng_ust_comm_should_quit; | |
107 | ||
3327ac33 | 108 | /* |
d58d1454 | 109 | * Return 0 on success, -1 if should quit. |
3327ac33 | 110 | * The lock is taken in both cases. |
d58d1454 | 111 | * Signal-safe. |
3327ac33 MD |
112 | */ |
113 | int ust_lock(void) | |
114 | { | |
d58d1454 MD |
115 | sigset_t sig_all_blocked, orig_mask; |
116 | int ret; | |
117 | ||
118 | sigfillset(&sig_all_blocked); | |
119 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
120 | if (ret) { | |
121 | ERR("pthread_sigmask: %s", strerror(ret)); | |
122 | } | |
123 | if (!URCU_TLS(ust_mutex_nest)++) | |
124 | pthread_mutex_lock(&ust_mutex); | |
125 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
126 | if (ret) { | |
127 | ERR("pthread_sigmask: %s", strerror(ret)); | |
128 | } | |
3327ac33 MD |
129 | if (lttng_ust_comm_should_quit) { |
130 | return -1; | |
131 | } else { | |
132 | return 0; | |
133 | } | |
134 | } | |
135 | ||
136 | /* | |
137 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
138 | * they are already nested within the dynamic loader lock, and therefore | |
139 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 140 | * Signal-safe. |
3327ac33 MD |
141 | */ |
142 | void ust_lock_nocheck(void) | |
143 | { | |
d58d1454 MD |
144 | sigset_t sig_all_blocked, orig_mask; |
145 | int ret; | |
146 | ||
147 | sigfillset(&sig_all_blocked); | |
148 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
149 | if (ret) { | |
150 | ERR("pthread_sigmask: %s", strerror(ret)); | |
151 | } | |
152 | if (!URCU_TLS(ust_mutex_nest)++) | |
153 | pthread_mutex_lock(&ust_mutex); | |
154 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
155 | if (ret) { | |
156 | ERR("pthread_sigmask: %s", strerror(ret)); | |
157 | } | |
3327ac33 MD |
158 | } |
159 | ||
d58d1454 MD |
160 | /* |
161 | * Signal-safe. | |
162 | */ | |
3327ac33 MD |
163 | void ust_unlock(void) |
164 | { | |
d58d1454 MD |
165 | sigset_t sig_all_blocked, orig_mask; |
166 | int ret; | |
167 | ||
168 | sigfillset(&sig_all_blocked); | |
169 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
170 | if (ret) { | |
171 | ERR("pthread_sigmask: %s", strerror(ret)); | |
172 | } | |
173 | if (!--URCU_TLS(ust_mutex_nest)) | |
174 | pthread_mutex_unlock(&ust_mutex); | |
175 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
176 | if (ret) { | |
177 | ERR("pthread_sigmask: %s", strerror(ret)); | |
178 | } | |
3327ac33 MD |
179 | } |
180 | ||
11ff9c7d MD |
181 | /* |
182 | * Wait for either of these before continuing to the main | |
183 | * program: | |
184 | * - the register_done message from sessiond daemon | |
185 | * (will let the sessiond daemon enable sessions before main | |
186 | * starts.) | |
187 | * - sessiond daemon is not reachable. | |
188 | * - timeout (ensuring applications are resilient to session | |
189 | * daemon problems). | |
190 | */ | |
191 | static sem_t constructor_wait; | |
950aab0c MD |
192 | /* |
193 | * Doing this for both the global and local sessiond. | |
194 | */ | |
95259bd0 | 195 | static int sem_count = { 2 }; |
11ff9c7d | 196 | |
e8508a49 MD |
197 | /* |
198 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
199 | * from liblttng-ust does not execute the pre/post fork handlers. | |
200 | */ | |
8c90a710 | 201 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 202 | |
1ea11eab MD |
203 | /* |
204 | * Info about socket and associated listener thread. | |
205 | */ | |
206 | struct sock_info { | |
11ff9c7d | 207 | const char *name; |
1ea11eab | 208 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 209 | int root_handle; |
8d20bf54 MD |
210 | int constructor_sem_posted; |
211 | int allowed; | |
44e073f5 | 212 | int global; |
e33f3265 | 213 | int thread_active; |
7fc90dca MD |
214 | |
215 | char sock_path[PATH_MAX]; | |
216 | int socket; | |
32ce8569 | 217 | int notify_socket; |
7fc90dca MD |
218 | |
219 | char wait_shm_path[PATH_MAX]; | |
220 | char *wait_shm_mmap; | |
37dddb65 MD |
221 | /* Keep track of lazy state dump not performed yet. */ |
222 | int statedump_pending; | |
1ea11eab | 223 | }; |
2691221a MD |
224 | |
225 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 226 | struct sock_info global_apps = { |
11ff9c7d | 227 | .name = "global", |
44e073f5 | 228 | .global = 1, |
7fc90dca | 229 | |
46050b1a | 230 | .root_handle = -1, |
8d20bf54 | 231 | .allowed = 1, |
e33f3265 | 232 | .thread_active = 0, |
7fc90dca | 233 | |
32ce8569 | 234 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 235 | .socket = -1, |
32ce8569 | 236 | .notify_socket = -1, |
7fc90dca | 237 | |
32ce8569 | 238 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 239 | |
37dddb65 | 240 | .statedump_pending = 0, |
1ea11eab | 241 | }; |
2691221a MD |
242 | |
243 | /* TODO: allow global_apps_sock_path override */ | |
244 | ||
1ea11eab | 245 | struct sock_info local_apps = { |
11ff9c7d | 246 | .name = "local", |
44e073f5 | 247 | .global = 0, |
46050b1a | 248 | .root_handle = -1, |
8d20bf54 | 249 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 250 | .thread_active = 0, |
7fc90dca MD |
251 | |
252 | .socket = -1, | |
32ce8569 | 253 | .notify_socket = -1, |
95c25348 | 254 | |
37dddb65 | 255 | .statedump_pending = 0, |
1ea11eab | 256 | }; |
2691221a | 257 | |
37ed587a MD |
258 | static int wait_poll_fallback; |
259 | ||
74d81a6c MD |
260 | static const char *cmd_name_mapping[] = { |
261 | [ LTTNG_UST_RELEASE ] = "Release", | |
262 | [ LTTNG_UST_SESSION ] = "Create Session", | |
263 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
264 | ||
265 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
266 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
267 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
268 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
269 | ||
270 | /* Session FD commands */ | |
271 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
272 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
273 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
274 | ||
275 | /* Channel FD commands */ | |
276 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
277 | [ LTTNG_UST_EVENT ] = "Create Event", | |
278 | ||
279 | /* Event and Channel FD commands */ | |
280 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
281 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
282 | ||
283 | /* Event, Channel and Session commands */ | |
284 | [ LTTNG_UST_ENABLE ] = "Enable", | |
285 | [ LTTNG_UST_DISABLE ] = "Disable", | |
286 | ||
287 | /* Tracepoint list commands */ | |
288 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
289 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
290 | ||
291 | /* Event FD commands */ | |
292 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 293 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
74d81a6c MD |
294 | }; |
295 | ||
ff517991 MD |
296 | static const char *str_timeout; |
297 | static int got_timeout_env; | |
298 | ||
7dd08bec | 299 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 300 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 301 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 302 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
303 | extern void lttng_ring_buffer_metadata_client_init(void); |
304 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 305 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 306 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 307 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 308 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 309 | |
3c6f6263 AM |
310 | /* |
311 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
312 | * pointer. | |
313 | */ | |
314 | static | |
315 | const char *get_lttng_home_dir(void) | |
316 | { | |
317 | const char *val; | |
318 | ||
319 | val = (const char *) getenv("LTTNG_HOME"); | |
320 | if (val != NULL) { | |
321 | return val; | |
322 | } | |
323 | return (const char *) getenv("HOME"); | |
324 | } | |
325 | ||
a903623f MD |
326 | /* |
327 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
328 | */ | |
329 | static | |
330 | void lttng_fixup_nest_count_tls(void) | |
331 | { | |
8c90a710 | 332 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
333 | } |
334 | ||
d58d1454 MD |
335 | static |
336 | void lttng_fixup_ust_mutex_nest_tls(void) | |
337 | { | |
338 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
339 | } | |
340 | ||
1556a549 MD |
341 | /* |
342 | * Fixup urcu bp TLS. | |
343 | */ | |
344 | static | |
345 | void lttng_fixup_urcu_bp_tls(void) | |
346 | { | |
347 | rcu_read_lock(); | |
348 | rcu_read_unlock(); | |
349 | } | |
350 | ||
32ce8569 MD |
351 | int lttng_get_notify_socket(void *owner) |
352 | { | |
353 | struct sock_info *info = owner; | |
354 | ||
355 | return info->notify_socket; | |
356 | } | |
357 | ||
74d81a6c MD |
358 | static |
359 | void print_cmd(int cmd, int handle) | |
360 | { | |
361 | const char *cmd_name = "Unknown"; | |
362 | ||
fd67a004 MD |
363 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
364 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
365 | cmd_name = cmd_name_mapping[cmd]; |
366 | } | |
fd67a004 MD |
367 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
368 | cmd_name, cmd, | |
74d81a6c MD |
369 | lttng_ust_obj_get_name(handle), handle); |
370 | } | |
371 | ||
2691221a | 372 | static |
8d20bf54 | 373 | int setup_local_apps(void) |
2691221a MD |
374 | { |
375 | const char *home_dir; | |
7fc90dca | 376 | uid_t uid; |
2691221a | 377 | |
7fc90dca | 378 | uid = getuid(); |
8d20bf54 MD |
379 | /* |
380 | * Disallow per-user tracing for setuid binaries. | |
381 | */ | |
7fc90dca | 382 | if (uid != geteuid()) { |
9ec6895c | 383 | assert(local_apps.allowed == 0); |
d0a1ae63 | 384 | return 0; |
8d20bf54 | 385 | } |
3c6f6263 | 386 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
387 | if (!home_dir) { |
388 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
389 | assert(local_apps.allowed == 0); | |
2691221a | 390 | return -ENOENT; |
9ec6895c MD |
391 | } |
392 | local_apps.allowed = 1; | |
32ce8569 MD |
393 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
394 | home_dir, | |
395 | LTTNG_DEFAULT_HOME_RUNDIR, | |
396 | LTTNG_UST_SOCK_FILENAME); | |
397 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
398 | LTTNG_UST_WAIT_FILENAME, | |
399 | uid); | |
2691221a MD |
400 | return 0; |
401 | } | |
402 | ||
ff517991 MD |
403 | /* |
404 | * Get notify_sock timeout, in ms. | |
405 | * -1: don't wait. 0: wait forever. >0: timeout, in ms. | |
406 | */ | |
407 | static | |
408 | long get_timeout(void) | |
409 | { | |
410 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
411 | ||
412 | if (!got_timeout_env) { | |
413 | str_timeout = getenv("LTTNG_UST_REGISTER_TIMEOUT"); | |
414 | got_timeout_env = 1; | |
415 | } | |
416 | if (str_timeout) | |
417 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
418 | return constructor_delay_ms; | |
419 | } | |
420 | ||
421 | static | |
422 | long get_notify_sock_timeout(void) | |
423 | { | |
424 | return get_timeout(); | |
425 | } | |
426 | ||
427 | /* | |
428 | * Return values: -1: don't wait. 0: wait forever. 1: timeout wait. | |
429 | */ | |
430 | static | |
431 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
432 | { | |
433 | long constructor_delay_ms; | |
434 | int ret; | |
435 | ||
436 | constructor_delay_ms = get_timeout(); | |
437 | ||
438 | switch (constructor_delay_ms) { | |
439 | case -1:/* fall-through */ | |
440 | case 0: | |
441 | return constructor_delay_ms; | |
442 | default: | |
443 | break; | |
444 | } | |
445 | ||
446 | /* | |
447 | * If we are unable to find the current time, don't wait. | |
448 | */ | |
449 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
450 | if (ret) { | |
451 | return -1; | |
452 | } | |
453 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
454 | constructor_timeout->tv_nsec += | |
455 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
456 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
457 | constructor_timeout->tv_sec++; | |
458 | constructor_timeout->tv_nsec -= 1000000000UL; | |
459 | } | |
460 | return 1; | |
461 | } | |
462 | ||
2691221a | 463 | static |
32ce8569 | 464 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 465 | { |
32ce8569 MD |
466 | return ustcomm_send_reg_msg(socket, |
467 | type, | |
468 | CAA_BITS_PER_LONG, | |
469 | lttng_alignof(uint8_t) * CHAR_BIT, | |
470 | lttng_alignof(uint16_t) * CHAR_BIT, | |
471 | lttng_alignof(uint32_t) * CHAR_BIT, | |
472 | lttng_alignof(uint64_t) * CHAR_BIT, | |
473 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
474 | } |
475 | ||
d9e99d10 | 476 | static |
57773204 | 477 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 478 | { |
9eb62b9c | 479 | ssize_t len; |
d3a492d1 | 480 | |
57773204 | 481 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 482 | switch (len) { |
a4be8962 | 483 | case sizeof(*lur): |
d3a492d1 MD |
484 | DBG("message successfully sent"); |
485 | return 0; | |
7bc53e94 MD |
486 | default: |
487 | if (len == -ECONNRESET) { | |
488 | DBG("remote end closed connection"); | |
d3a492d1 MD |
489 | return 0; |
490 | } | |
7bc53e94 MD |
491 | if (len < 0) |
492 | return len; | |
493 | DBG("incorrect message size: %zd", len); | |
494 | return -EINVAL; | |
d3a492d1 MD |
495 | } |
496 | } | |
497 | ||
498 | static | |
edaa1431 | 499 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
500 | { |
501 | int ret; | |
502 | ||
edaa1431 MD |
503 | if (sock_info->constructor_sem_posted) |
504 | return 0; | |
505 | sock_info->constructor_sem_posted = 1; | |
56cd7e2f MD |
506 | if (uatomic_read(&sem_count) <= 0) { |
507 | return 0; | |
508 | } | |
95259bd0 MD |
509 | ret = uatomic_add_return(&sem_count, -1); |
510 | if (ret == 0) { | |
511 | ret = sem_post(&constructor_wait); | |
512 | assert(!ret); | |
513 | } | |
11ff9c7d MD |
514 | return 0; |
515 | } | |
516 | ||
37dddb65 MD |
517 | /* |
518 | * Only execute pending statedump after the constructor semaphore has | |
519 | * been posted by each listener thread. This means statedump will only | |
520 | * be performed after the "registration done" command is received from | |
521 | * each session daemon the application is connected to. | |
522 | * | |
523 | * This ensures we don't run into deadlock issues with the dynamic | |
524 | * loader mutex, which is held while the constructor is called and | |
525 | * waiting on the constructor semaphore. All operations requiring this | |
526 | * dynamic loader lock need to be postponed using this mechanism. | |
527 | */ | |
528 | static | |
529 | void handle_pending_statedump(struct sock_info *sock_info) | |
530 | { | |
531 | int ctor_passed = sock_info->constructor_sem_posted; | |
532 | ||
533 | if (ctor_passed && sock_info->statedump_pending) { | |
534 | sock_info->statedump_pending = 0; | |
2932a87f | 535 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 536 | lttng_handle_pending_statedump(sock_info); |
458d678c | 537 | pthread_mutex_unlock(&ust_fork_mutex); |
37dddb65 MD |
538 | } |
539 | } | |
540 | ||
11ff9c7d MD |
541 | static |
542 | int handle_message(struct sock_info *sock_info, | |
57773204 | 543 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 544 | { |
1ea11eab | 545 | int ret = 0; |
b61ce3b2 | 546 | const struct lttng_ust_objd_ops *ops; |
57773204 | 547 | struct ustcomm_ust_reply lur; |
ef9ff354 | 548 | union ust_args args; |
40003310 | 549 | ssize_t len; |
1ea11eab | 550 | |
46050b1a MD |
551 | memset(&lur, 0, sizeof(lur)); |
552 | ||
3327ac33 | 553 | if (ust_lock()) { |
74d81a6c | 554 | ret = -LTTNG_UST_ERR_EXITING; |
1ea11eab MD |
555 | goto end; |
556 | } | |
9eb62b9c | 557 | |
46050b1a MD |
558 | ops = objd_ops(lum->handle); |
559 | if (!ops) { | |
560 | ret = -ENOENT; | |
561 | goto end; | |
1ea11eab | 562 | } |
46050b1a MD |
563 | |
564 | switch (lum->cmd) { | |
11ff9c7d MD |
565 | case LTTNG_UST_REGISTER_DONE: |
566 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 567 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
568 | else |
569 | ret = -EINVAL; | |
570 | break; | |
46050b1a MD |
571 | case LTTNG_UST_RELEASE: |
572 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
573 | ret = -EPERM; | |
574 | else | |
1849ef7c | 575 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 576 | break; |
2d78951a MD |
577 | case LTTNG_UST_FILTER: |
578 | { | |
579 | /* Receive filter data */ | |
f488575f | 580 | struct lttng_ust_filter_bytecode_node *bytecode; |
2d78951a | 581 | |
cd54f6d9 | 582 | if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) { |
7bc53e94 | 583 | ERR("Filter data size is too large: %u bytes", |
2d78951a MD |
584 | lum->u.filter.data_size); |
585 | ret = -EINVAL; | |
586 | goto error; | |
587 | } | |
2734ca65 | 588 | |
885b1dfd | 589 | if (lum->u.filter.reloc_offset > lum->u.filter.data_size) { |
7bc53e94 | 590 | ERR("Filter reloc offset %u is not within data", |
2734ca65 CB |
591 | lum->u.filter.reloc_offset); |
592 | ret = -EINVAL; | |
593 | goto error; | |
594 | } | |
595 | ||
cd54f6d9 MD |
596 | bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size); |
597 | if (!bytecode) { | |
598 | ret = -ENOMEM; | |
599 | goto error; | |
600 | } | |
f488575f | 601 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, |
2d78951a MD |
602 | lum->u.filter.data_size); |
603 | switch (len) { | |
604 | case 0: /* orderly shutdown */ | |
605 | ret = 0; | |
cd54f6d9 | 606 | free(bytecode); |
2d78951a | 607 | goto error; |
2d78951a MD |
608 | default: |
609 | if (len == lum->u.filter.data_size) { | |
7bc53e94 | 610 | DBG("filter data received"); |
2d78951a | 611 | break; |
7bc53e94 MD |
612 | } else if (len < 0) { |
613 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
614 | if (len == -ECONNRESET) { | |
615 | ERR("%s remote end closed connection", sock_info->name); | |
616 | ret = len; | |
617 | free(bytecode); | |
618 | goto error; | |
619 | } | |
620 | ret = len; | |
eb8bf361 | 621 | free(bytecode); |
7bc53e94 | 622 | goto end; |
2d78951a | 623 | } else { |
7bc53e94 | 624 | DBG("incorrect filter data message size: %zd", len); |
2d78951a | 625 | ret = -EINVAL; |
cd54f6d9 | 626 | free(bytecode); |
2d78951a MD |
627 | goto end; |
628 | } | |
629 | } | |
f488575f MD |
630 | bytecode->bc.len = lum->u.filter.data_size; |
631 | bytecode->bc.reloc_offset = lum->u.filter.reloc_offset; | |
3f6fd224 | 632 | bytecode->bc.seqnum = lum->u.filter.seqnum; |
cd54f6d9 | 633 | if (ops->cmd) { |
2d78951a | 634 | ret = ops->cmd(lum->handle, lum->cmd, |
cd54f6d9 | 635 | (unsigned long) bytecode, |
f59ed768 | 636 | &args, sock_info); |
cd54f6d9 MD |
637 | if (ret) { |
638 | free(bytecode); | |
639 | } | |
640 | /* don't free bytecode if everything went fine. */ | |
641 | } else { | |
2d78951a | 642 | ret = -ENOSYS; |
cd54f6d9 MD |
643 | free(bytecode); |
644 | } | |
2d78951a MD |
645 | break; |
646 | } | |
86e36163 JI |
647 | case LTTNG_UST_EXCLUSION: |
648 | { | |
649 | /* Receive exclusion names */ | |
650 | struct lttng_ust_excluder_node *node; | |
651 | unsigned int count; | |
652 | ||
653 | count = lum->u.exclusion.count; | |
654 | if (count == 0) { | |
655 | /* There are no names to read */ | |
656 | ret = 0; | |
657 | goto error; | |
658 | } | |
659 | node = zmalloc(sizeof(*node) + | |
660 | count * LTTNG_UST_SYM_NAME_LEN); | |
661 | if (!node) { | |
662 | ret = -ENOMEM; | |
663 | goto error; | |
664 | } | |
665 | node->excluder.count = count; | |
666 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
667 | count * LTTNG_UST_SYM_NAME_LEN); | |
668 | switch (len) { | |
669 | case 0: /* orderly shutdown */ | |
670 | ret = 0; | |
671 | free(node); | |
672 | goto error; | |
673 | default: | |
674 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
675 | DBG("Exclusion data received"); | |
676 | break; | |
677 | } else if (len < 0) { | |
678 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
679 | if (len == -ECONNRESET) { | |
680 | ERR("%s remote end closed connection", sock_info->name); | |
681 | ret = len; | |
682 | free(node); | |
683 | goto error; | |
684 | } | |
685 | ret = len; | |
686 | free(node); | |
687 | goto end; | |
688 | } else { | |
689 | DBG("Incorrect exclusion data message size: %zd", len); | |
690 | ret = -EINVAL; | |
691 | free(node); | |
692 | goto end; | |
693 | } | |
694 | } | |
695 | if (ops->cmd) { | |
696 | ret = ops->cmd(lum->handle, lum->cmd, | |
697 | (unsigned long) node, | |
698 | &args, sock_info); | |
699 | if (ret) { | |
700 | free(node); | |
701 | } | |
702 | /* Don't free exclusion data if everything went fine. */ | |
703 | } else { | |
704 | ret = -ENOSYS; | |
705 | free(node); | |
706 | } | |
707 | break; | |
708 | } | |
74d81a6c MD |
709 | case LTTNG_UST_CHANNEL: |
710 | { | |
711 | void *chan_data; | |
ff0f5728 | 712 | int wakeup_fd; |
74d81a6c MD |
713 | |
714 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
715 | &chan_data, lum->u.channel.len, |
716 | &wakeup_fd); | |
74d81a6c MD |
717 | switch (len) { |
718 | case 0: /* orderly shutdown */ | |
719 | ret = 0; | |
720 | goto error; | |
721 | default: | |
722 | if (len == lum->u.channel.len) { | |
723 | DBG("channel data received"); | |
724 | break; | |
725 | } else if (len < 0) { | |
726 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
727 | if (len == -ECONNRESET) { | |
728 | ERR("%s remote end closed connection", sock_info->name); | |
729 | ret = len; | |
730 | goto error; | |
731 | } | |
732 | ret = len; | |
733 | goto end; | |
734 | } else { | |
735 | DBG("incorrect channel data message size: %zd", len); | |
736 | ret = -EINVAL; | |
737 | goto end; | |
738 | } | |
739 | } | |
740 | args.channel.chan_data = chan_data; | |
ff0f5728 | 741 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
742 | if (ops->cmd) |
743 | ret = ops->cmd(lum->handle, lum->cmd, | |
744 | (unsigned long) &lum->u, | |
745 | &args, sock_info); | |
746 | else | |
747 | ret = -ENOSYS; | |
748 | break; | |
749 | } | |
750 | case LTTNG_UST_STREAM: | |
751 | { | |
752 | /* Receive shm_fd, wakeup_fd */ | |
753 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
754 | &lum->u.stream.len, | |
755 | &args.stream.shm_fd, | |
756 | &args.stream.wakeup_fd); | |
757 | if (ret) { | |
758 | goto end; | |
759 | } | |
760 | if (ops->cmd) | |
761 | ret = ops->cmd(lum->handle, lum->cmd, | |
762 | (unsigned long) &lum->u, | |
763 | &args, sock_info); | |
764 | else | |
765 | ret = -ENOSYS; | |
766 | break; | |
767 | } | |
d9e99d10 | 768 | default: |
46050b1a MD |
769 | if (ops->cmd) |
770 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 771 | (unsigned long) &lum->u, |
f59ed768 | 772 | &args, sock_info); |
46050b1a MD |
773 | else |
774 | ret = -ENOSYS; | |
775 | break; | |
d9e99d10 | 776 | } |
46050b1a | 777 | |
1ea11eab | 778 | end: |
46050b1a MD |
779 | lur.handle = lum->handle; |
780 | lur.cmd = lum->cmd; | |
781 | lur.ret_val = ret; | |
782 | if (ret >= 0) { | |
7bc53e94 | 783 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 784 | } else { |
7bc53e94 MD |
785 | /* |
786 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
787 | * error that are not caused by the transport, except if | |
788 | * we already have a more precise error message to | |
789 | * report. | |
790 | */ | |
64b2564e DG |
791 | if (ret > -LTTNG_UST_ERR) { |
792 | /* Translate code to UST error. */ | |
793 | switch (ret) { | |
794 | case -EEXIST: | |
795 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
796 | break; | |
797 | case -EINVAL: | |
798 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
799 | break; | |
800 | case -ENOENT: | |
801 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
802 | break; | |
803 | case -EPERM: | |
804 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
805 | break; | |
806 | case -ENOSYS: | |
807 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
808 | break; | |
809 | default: | |
810 | lur.ret_code = -LTTNG_UST_ERR; | |
811 | break; | |
812 | } | |
813 | } else { | |
7bc53e94 | 814 | lur.ret_code = ret; |
64b2564e | 815 | } |
46050b1a | 816 | } |
e6ea14c5 MD |
817 | if (ret >= 0) { |
818 | switch (lum->cmd) { | |
e6ea14c5 MD |
819 | case LTTNG_UST_TRACER_VERSION: |
820 | lur.u.version = lum->u.version; | |
821 | break; | |
822 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
823 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
824 | break; | |
825 | } | |
381c0f1e | 826 | } |
74d81a6c | 827 | DBG("Return value: %d", lur.ret_val); |
46050b1a | 828 | ret = send_reply(sock, &lur); |
193183fb | 829 | if (ret < 0) { |
7bc53e94 | 830 | DBG("error sending reply"); |
193183fb MD |
831 | goto error; |
832 | } | |
46050b1a | 833 | |
40003310 MD |
834 | /* |
835 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
836 | * after the reply. | |
837 | */ | |
7bc53e94 | 838 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
839 | switch (lum->cmd) { |
840 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
841 | len = ustcomm_send_unix_sock(sock, | |
842 | &args.field_list.entry, | |
843 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
844 | if (len < 0) { |
845 | ret = len; | |
846 | goto error; | |
847 | } | |
40003310 | 848 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 849 | ret = -EINVAL; |
40003310 MD |
850 | goto error; |
851 | } | |
852 | } | |
853 | } | |
ef9ff354 | 854 | |
381c0f1e | 855 | error: |
17dfb34b | 856 | ust_unlock(); |
d9e99d10 | 857 | |
37dddb65 MD |
858 | /* |
859 | * Performed delayed statedump operations outside of the UST | |
860 | * lock. We need to take the dynamic loader lock before we take | |
861 | * the UST lock internally within handle_pending_statedump(). | |
862 | */ | |
863 | handle_pending_statedump(sock_info); | |
246be17e | 864 | |
37dddb65 | 865 | return ret; |
246be17e PW |
866 | } |
867 | ||
46050b1a | 868 | static |
efe0de09 | 869 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
870 | { |
871 | int ret; | |
872 | ||
5b14aab3 MD |
873 | if (sock_info->root_handle != -1) { |
874 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
875 | if (ret) { | |
876 | ERR("Error unref root handle"); | |
877 | } | |
878 | sock_info->root_handle = -1; | |
879 | } | |
880 | sock_info->constructor_sem_posted = 0; | |
881 | ||
882 | /* | |
883 | * wait_shm_mmap, socket and notify socket are used by listener | |
884 | * threads outside of the ust lock, so we cannot tear them down | |
885 | * ourselves, because we cannot join on these threads. Leave | |
886 | * responsibility of cleaning up these resources to the OS | |
887 | * process exit. | |
888 | */ | |
889 | if (exiting) | |
890 | return; | |
891 | ||
46050b1a | 892 | if (sock_info->socket != -1) { |
e6973a89 | 893 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 894 | if (ret) { |
32ce8569 | 895 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
896 | } |
897 | sock_info->socket = -1; | |
898 | } | |
32ce8569 MD |
899 | if (sock_info->notify_socket != -1) { |
900 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
901 | if (ret) { | |
902 | ERR("Error closing ust notify socket"); | |
903 | } | |
904 | sock_info->notify_socket = -1; | |
905 | } | |
5b14aab3 | 906 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
907 | long page_size; |
908 | ||
909 | page_size = sysconf(_SC_PAGE_SIZE); | |
910 | if (page_size > 0) { | |
911 | ret = munmap(sock_info->wait_shm_mmap, page_size); | |
912 | if (ret) { | |
913 | ERR("Error unmapping wait shm"); | |
914 | } | |
7fc90dca MD |
915 | } |
916 | sock_info->wait_shm_mmap = NULL; | |
917 | } | |
918 | } | |
919 | ||
58d4b2a2 | 920 | /* |
33bbeb90 MD |
921 | * Using fork to set umask in the child process (not multi-thread safe). |
922 | * We deal with the shm_open vs ftruncate race (happening when the | |
923 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
924 | * safety against shm_unlink) by simply letting the mmap fail and | |
925 | * retrying after a few seconds. | |
926 | * For global shm, everybody has rw access to it until the sessiond | |
927 | * starts. | |
58d4b2a2 | 928 | */ |
7fc90dca | 929 | static |
58d4b2a2 | 930 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 931 | { |
7fc90dca | 932 | int wait_shm_fd, ret; |
58d4b2a2 | 933 | pid_t pid; |
44e073f5 | 934 | |
58d4b2a2 | 935 | /* |
33bbeb90 | 936 | * Try to open read-only. |
58d4b2a2 | 937 | */ |
33bbeb90 | 938 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 939 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
940 | int32_t tmp_read; |
941 | ssize_t len; | |
942 | size_t bytes_read = 0; | |
943 | ||
944 | /* | |
945 | * Try to read the fd. If unable to do so, try opening | |
946 | * it in write mode. | |
947 | */ | |
948 | do { | |
949 | len = read(wait_shm_fd, | |
950 | &((char *) &tmp_read)[bytes_read], | |
951 | sizeof(tmp_read) - bytes_read); | |
952 | if (len > 0) { | |
953 | bytes_read += len; | |
954 | } | |
955 | } while ((len < 0 && errno == EINTR) | |
956 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
957 | if (bytes_read != sizeof(tmp_read)) { | |
958 | ret = close(wait_shm_fd); | |
959 | if (ret) { | |
960 | ERR("close wait_shm_fd"); | |
961 | } | |
962 | goto open_write; | |
963 | } | |
58d4b2a2 MD |
964 | goto end; |
965 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
966 | /* | |
33bbeb90 MD |
967 | * Real-only open did not work, and it's not because the |
968 | * entry was not present. It's a failure that prohibits | |
969 | * using shm. | |
58d4b2a2 | 970 | */ |
7fc90dca | 971 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 972 | goto end; |
7fc90dca | 973 | } |
7aa76730 MD |
974 | |
975 | open_write: | |
7fc90dca | 976 | /* |
7aa76730 MD |
977 | * If the open failed because the file did not exist, or because |
978 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 979 | */ |
8c90a710 | 980 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 981 | pid = fork(); |
8c90a710 | 982 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
983 | if (pid > 0) { |
984 | int status; | |
985 | ||
986 | /* | |
987 | * Parent: wait for child to return, in which case the | |
988 | * shared memory map will have been created. | |
989 | */ | |
990 | pid = wait(&status); | |
b7d3cb32 | 991 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
992 | wait_shm_fd = -1; |
993 | goto end; | |
7fc90dca | 994 | } |
58d4b2a2 MD |
995 | /* |
996 | * Try to open read-only again after creation. | |
997 | */ | |
33bbeb90 | 998 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
999 | if (wait_shm_fd < 0) { |
1000 | /* | |
1001 | * Real-only open did not work. It's a failure | |
1002 | * that prohibits using shm. | |
1003 | */ | |
1004 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1005 | goto end; | |
1006 | } | |
1007 | goto end; | |
1008 | } else if (pid == 0) { | |
1009 | int create_mode; | |
1010 | ||
1011 | /* Child */ | |
33bbeb90 | 1012 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1013 | if (sock_info->global) |
33bbeb90 | 1014 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1015 | /* |
1016 | * We're alone in a child process, so we can modify the | |
1017 | * process-wide umask. | |
1018 | */ | |
33bbeb90 | 1019 | umask(~create_mode); |
58d4b2a2 | 1020 | /* |
33bbeb90 MD |
1021 | * Try creating shm (or get rw access). |
1022 | * We don't do an exclusive open, because we allow other | |
1023 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1024 | */ |
1025 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1026 | O_RDWR | O_CREAT, create_mode); | |
1027 | if (wait_shm_fd >= 0) { | |
1028 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1029 | if (ret) { | |
1030 | PERROR("ftruncate"); | |
b0c1425d | 1031 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1032 | } |
b0c1425d | 1033 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1034 | } |
33bbeb90 MD |
1035 | /* |
1036 | * For local shm, we need to have rw access to accept | |
1037 | * opening it: this means the local sessiond will be | |
1038 | * able to wake us up. For global shm, we open it even | |
1039 | * if rw access is not granted, because the root.root | |
1040 | * sessiond will be able to override all rights and wake | |
1041 | * us up. | |
1042 | */ | |
1043 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1044 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1045 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1046 | } |
1047 | /* | |
33bbeb90 MD |
1048 | * The shm exists, but we cannot open it RW. Report |
1049 | * success. | |
58d4b2a2 | 1050 | */ |
5d3bc5ed | 1051 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1052 | } else { |
1053 | return -1; | |
7fc90dca | 1054 | } |
58d4b2a2 | 1055 | end: |
33bbeb90 MD |
1056 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1057 | struct stat statbuf; | |
1058 | ||
1059 | /* | |
1060 | * Ensure that our user is the owner of the shm file for | |
1061 | * local shm. If we do not own the file, it means our | |
1062 | * sessiond will not have access to wake us up (there is | |
1063 | * probably a rogue process trying to fake our | |
1064 | * sessiond). Fallback to polling method in this case. | |
1065 | */ | |
1066 | ret = fstat(wait_shm_fd, &statbuf); | |
1067 | if (ret) { | |
1068 | PERROR("fstat"); | |
1069 | goto error_close; | |
1070 | } | |
1071 | if (statbuf.st_uid != getuid()) | |
1072 | goto error_close; | |
1073 | } | |
58d4b2a2 | 1074 | return wait_shm_fd; |
33bbeb90 MD |
1075 | |
1076 | error_close: | |
1077 | ret = close(wait_shm_fd); | |
1078 | if (ret) { | |
1079 | PERROR("Error closing fd"); | |
1080 | } | |
1081 | return -1; | |
58d4b2a2 MD |
1082 | } |
1083 | ||
1084 | static | |
1085 | char *get_map_shm(struct sock_info *sock_info) | |
1086 | { | |
172d6b68 | 1087 | long page_size; |
58d4b2a2 MD |
1088 | int wait_shm_fd, ret; |
1089 | char *wait_shm_mmap; | |
1090 | ||
172d6b68 MD |
1091 | page_size = sysconf(_SC_PAGE_SIZE); |
1092 | if (page_size < 0) { | |
1093 | goto error; | |
1094 | } | |
1095 | ||
1096 | wait_shm_fd = get_wait_shm(sock_info, page_size); | |
58d4b2a2 MD |
1097 | if (wait_shm_fd < 0) { |
1098 | goto error; | |
44e073f5 | 1099 | } |
172d6b68 | 1100 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1101 | MAP_SHARED, wait_shm_fd, 0); |
7fc90dca MD |
1102 | /* close shm fd immediately after taking the mmap reference */ |
1103 | ret = close(wait_shm_fd); | |
1104 | if (ret) { | |
33bbeb90 MD |
1105 | PERROR("Error closing fd"); |
1106 | } | |
1107 | if (wait_shm_mmap == MAP_FAILED) { | |
1108 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1109 | goto error; | |
7fc90dca MD |
1110 | } |
1111 | return wait_shm_mmap; | |
1112 | ||
1113 | error: | |
1114 | return NULL; | |
1115 | } | |
1116 | ||
1117 | static | |
1118 | void wait_for_sessiond(struct sock_info *sock_info) | |
1119 | { | |
efe0de09 | 1120 | int ret; |
80e2814b | 1121 | |
3327ac33 | 1122 | if (ust_lock()) { |
7fc90dca MD |
1123 | goto quit; |
1124 | } | |
37ed587a MD |
1125 | if (wait_poll_fallback) { |
1126 | goto error; | |
1127 | } | |
7fc90dca MD |
1128 | if (!sock_info->wait_shm_mmap) { |
1129 | sock_info->wait_shm_mmap = get_map_shm(sock_info); | |
1130 | if (!sock_info->wait_shm_mmap) | |
1131 | goto error; | |
1132 | } | |
1133 | ust_unlock(); | |
1134 | ||
1135 | DBG("Waiting for %s apps sessiond", sock_info->name); | |
80e2814b MD |
1136 | /* Wait for futex wakeup */ |
1137 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap) == 0) { | |
1138 | ret = futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1139 | FUTEX_WAIT, 0, NULL, NULL, 0); | |
80e2814b | 1140 | if (ret < 0) { |
37ed587a MD |
1141 | if (errno == EFAULT) { |
1142 | wait_poll_fallback = 1; | |
a8b870ad | 1143 | DBG( |
37ed587a MD |
1144 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1145 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1146 | "Please upgrade your kernel " | |
1147 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1148 | "mainline). LTTng-UST will use polling mode fallback."); | |
cd27263b MD |
1149 | if (ust_debug()) |
1150 | PERROR("futex"); | |
37ed587a | 1151 | } |
80e2814b MD |
1152 | } |
1153 | } | |
7fc90dca MD |
1154 | return; |
1155 | ||
1156 | quit: | |
1157 | ust_unlock(); | |
1158 | return; | |
1159 | ||
1160 | error: | |
1161 | ust_unlock(); | |
7fc90dca | 1162 | return; |
46050b1a MD |
1163 | } |
1164 | ||
1ea11eab MD |
1165 | /* |
1166 | * This thread does not allocate any resource, except within | |
1167 | * handle_message, within mutex protection. This mutex protects against | |
1168 | * fork and exit. | |
98bf993f | 1169 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1170 | * is also protected by the mutex. |
1171 | */ | |
d9e99d10 MD |
1172 | static |
1173 | void *ust_listener_thread(void *arg) | |
1174 | { | |
1ea11eab | 1175 | struct sock_info *sock_info = arg; |
c0eedf81 | 1176 | int sock, ret, prev_connect_failed = 0, has_waited = 0; |
ff517991 | 1177 | long timeout; |
d9e99d10 | 1178 | |
9eb62b9c MD |
1179 | /* Restart trying to connect to the session daemon */ |
1180 | restart: | |
c0eedf81 MD |
1181 | if (prev_connect_failed) { |
1182 | /* Wait for sessiond availability with pipe */ | |
1183 | wait_for_sessiond(sock_info); | |
1184 | if (has_waited) { | |
1185 | has_waited = 0; | |
1186 | /* | |
1187 | * Sleep for 5 seconds before retrying after a | |
1188 | * sequence of failure / wait / failure. This | |
1189 | * deals with a killed or broken session daemon. | |
1190 | */ | |
1191 | sleep(5); | |
1192 | } | |
1193 | has_waited = 1; | |
1194 | prev_connect_failed = 0; | |
1195 | } | |
9eb62b9c | 1196 | |
1ea11eab | 1197 | if (sock_info->socket != -1) { |
e6973a89 | 1198 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1199 | if (ret) { |
32ce8569 MD |
1200 | ERR("Error closing %s ust cmd socket", |
1201 | sock_info->name); | |
1ea11eab MD |
1202 | } |
1203 | sock_info->socket = -1; | |
1204 | } | |
32ce8569 MD |
1205 | if (sock_info->notify_socket != -1) { |
1206 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1207 | if (ret) { | |
1208 | ERR("Error closing %s ust notify socket", | |
1209 | sock_info->name); | |
1210 | } | |
1211 | sock_info->notify_socket = -1; | |
1212 | } | |
46050b1a | 1213 | |
321f2351 MD |
1214 | /* |
1215 | * Register. We need to perform both connect and sending | |
1216 | * registration message before doing the next connect otherwise | |
1217 | * we may reach unix socket connect queue max limits and block | |
1218 | * on the 2nd connect while the session daemon is awaiting the | |
1219 | * first connect registration message. | |
1220 | */ | |
1221 | /* Connect cmd socket */ | |
1222 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1223 | if (ret < 0) { | |
1224 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1225 | prev_connect_failed = 1; | |
5b14aab3 | 1226 | |
3327ac33 | 1227 | if (ust_lock()) { |
321f2351 | 1228 | goto quit; |
32ce8569 | 1229 | } |
46050b1a | 1230 | |
e3426ddc | 1231 | /* |
321f2351 MD |
1232 | * If we cannot find the sessiond daemon, don't delay |
1233 | * constructor execution. | |
e3426ddc | 1234 | */ |
321f2351 MD |
1235 | ret = handle_register_done(sock_info); |
1236 | assert(!ret); | |
1237 | ust_unlock(); | |
1238 | goto restart; | |
27fe9f21 | 1239 | } |
321f2351 | 1240 | sock_info->socket = ret; |
27fe9f21 | 1241 | |
3327ac33 | 1242 | if (ust_lock()) { |
5b14aab3 MD |
1243 | goto quit; |
1244 | } | |
1245 | ||
46050b1a MD |
1246 | /* |
1247 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1248 | * process lifetime, so we ensure we get ID which is statically |
1249 | * assigned to the root handle. | |
46050b1a MD |
1250 | */ |
1251 | if (sock_info->root_handle == -1) { | |
1252 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1253 | if (ret < 0) { |
46050b1a | 1254 | ERR("Error creating root handle"); |
46050b1a MD |
1255 | goto quit; |
1256 | } | |
1257 | sock_info->root_handle = ret; | |
9eb62b9c | 1258 | } |
1ea11eab | 1259 | |
32ce8569 | 1260 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1261 | if (ret < 0) { |
32ce8569 MD |
1262 | ERR("Error registering to %s ust cmd socket", |
1263 | sock_info->name); | |
c0eedf81 | 1264 | prev_connect_failed = 1; |
11ff9c7d MD |
1265 | /* |
1266 | * If we cannot register to the sessiond daemon, don't | |
1267 | * delay constructor execution. | |
1268 | */ | |
edaa1431 | 1269 | ret = handle_register_done(sock_info); |
11ff9c7d | 1270 | assert(!ret); |
17dfb34b | 1271 | ust_unlock(); |
9eb62b9c MD |
1272 | goto restart; |
1273 | } | |
321f2351 MD |
1274 | |
1275 | ust_unlock(); | |
1276 | ||
1277 | /* Connect notify socket */ | |
1278 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1279 | if (ret < 0) { | |
1280 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1281 | prev_connect_failed = 1; | |
1282 | ||
3327ac33 | 1283 | if (ust_lock()) { |
321f2351 MD |
1284 | goto quit; |
1285 | } | |
1286 | ||
1287 | /* | |
1288 | * If we cannot find the sessiond daemon, don't delay | |
1289 | * constructor execution. | |
1290 | */ | |
1291 | ret = handle_register_done(sock_info); | |
1292 | assert(!ret); | |
1293 | ust_unlock(); | |
1294 | goto restart; | |
1295 | } | |
1296 | sock_info->notify_socket = ret; | |
1297 | ||
1298 | timeout = get_notify_sock_timeout(); | |
1299 | if (timeout >= 0) { | |
1300 | /* | |
1301 | * Give at least 10ms to sessiond to reply to | |
1302 | * notifications. | |
1303 | */ | |
1304 | if (timeout < 10) | |
1305 | timeout = 10; | |
1306 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1307 | timeout); | |
1308 | if (ret < 0) { | |
1309 | WARN("Error setting socket receive timeout"); | |
1310 | } | |
1311 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1312 | timeout); | |
1313 | if (ret < 0) { | |
1314 | WARN("Error setting socket send timeout"); | |
1315 | } | |
1316 | } else if (timeout < -1) { | |
1317 | WARN("Unsupported timeout value %ld", timeout); | |
1318 | } | |
1319 | ||
3327ac33 | 1320 | if (ust_lock()) { |
321f2351 MD |
1321 | goto quit; |
1322 | } | |
1323 | ||
32ce8569 MD |
1324 | ret = register_to_sessiond(sock_info->notify_socket, |
1325 | USTCTL_SOCKET_NOTIFY); | |
1326 | if (ret < 0) { | |
1327 | ERR("Error registering to %s ust notify socket", | |
1328 | sock_info->name); | |
1329 | prev_connect_failed = 1; | |
1330 | /* | |
1331 | * If we cannot register to the sessiond daemon, don't | |
1332 | * delay constructor execution. | |
1333 | */ | |
1334 | ret = handle_register_done(sock_info); | |
1335 | assert(!ret); | |
1336 | ust_unlock(); | |
1337 | goto restart; | |
1338 | } | |
1339 | sock = sock_info->socket; | |
1340 | ||
17dfb34b | 1341 | ust_unlock(); |
46050b1a | 1342 | |
d9e99d10 MD |
1343 | for (;;) { |
1344 | ssize_t len; | |
57773204 | 1345 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1346 | |
57773204 | 1347 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1348 | switch (len) { |
1349 | case 0: /* orderly shutdown */ | |
7dd08bec | 1350 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1351 | if (ust_lock()) { |
d5e1fea6 MD |
1352 | goto quit; |
1353 | } | |
8236ba10 MD |
1354 | /* |
1355 | * Either sessiond has shutdown or refused us by closing the socket. | |
1356 | * In either case, we don't want to delay construction execution, | |
1357 | * and we need to wait before retry. | |
1358 | */ | |
1359 | prev_connect_failed = 1; | |
1360 | /* | |
1361 | * If we cannot register to the sessiond daemon, don't | |
1362 | * delay constructor execution. | |
1363 | */ | |
1364 | ret = handle_register_done(sock_info); | |
1365 | assert(!ret); | |
1366 | ust_unlock(); | |
d9e99d10 | 1367 | goto end; |
e7723462 | 1368 | case sizeof(lum): |
74d81a6c | 1369 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1370 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1371 | if (ret) { |
11ff9c7d | 1372 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
1373 | } |
1374 | continue; | |
7bc53e94 MD |
1375 | default: |
1376 | if (len < 0) { | |
1377 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1378 | } else { | |
1379 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1380 | } | |
1381 | if (len == -ECONNRESET) { | |
1382 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1383 | goto end; |
1384 | } | |
1385 | goto end; | |
d9e99d10 MD |
1386 | } |
1387 | ||
1388 | } | |
1389 | end: | |
3327ac33 | 1390 | if (ust_lock()) { |
d5e1fea6 MD |
1391 | goto quit; |
1392 | } | |
f59ed768 MD |
1393 | /* Cleanup socket handles before trying to reconnect */ |
1394 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1395 | ust_unlock(); | |
9eb62b9c | 1396 | goto restart; /* try to reconnect */ |
e33f3265 | 1397 | |
1ea11eab | 1398 | quit: |
e33f3265 | 1399 | ust_unlock(); |
3327ac33 MD |
1400 | |
1401 | pthread_mutex_lock(&ust_exit_mutex); | |
1402 | sock_info->thread_active = 0; | |
1403 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1404 | return NULL; |
1405 | } | |
1406 | ||
2594a5b4 MD |
1407 | /* |
1408 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1409 | */ | |
1410 | __attribute__((weak)) | |
1411 | void lttng_ust_malloc_wrapper_init(void) | |
1412 | { | |
1413 | } | |
1414 | ||
2691221a MD |
1415 | /* |
1416 | * sessiond monitoring thread: monitor presence of global and per-user | |
1417 | * sessiond by polling the application common named pipe. | |
1418 | */ | |
edaa1431 | 1419 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1420 | { |
11ff9c7d | 1421 | struct timespec constructor_timeout; |
ae6a58bf | 1422 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1423 | pthread_attr_t thread_attr; |
cf12a773 | 1424 | int timeout_mode; |
2691221a MD |
1425 | int ret; |
1426 | ||
edaa1431 MD |
1427 | if (uatomic_xchg(&initialized, 1) == 1) |
1428 | return; | |
1429 | ||
eddd8d5d MD |
1430 | /* |
1431 | * Fixup interdependency between TLS fixup mutex (which happens | |
1432 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1433 | * the ust lock. | |
1434 | */ | |
1556a549 | 1435 | lttng_fixup_urcu_bp_tls(); |
f645cfa7 | 1436 | lttng_fixup_ringbuffer_tls(); |
4158a15a | 1437 | lttng_fixup_vtid_tls(); |
a903623f | 1438 | lttng_fixup_nest_count_tls(); |
009745db | 1439 | lttng_fixup_procname_tls(); |
d58d1454 | 1440 | lttng_fixup_ust_mutex_nest_tls(); |
eddd8d5d | 1441 | |
edaa1431 MD |
1442 | /* |
1443 | * We want precise control over the order in which we construct | |
1444 | * our sub-libraries vs starting to receive commands from | |
1445 | * sessiond (otherwise leading to errors when trying to create | |
1446 | * sessiond before the init functions are completed). | |
1447 | */ | |
2691221a | 1448 | init_usterr(); |
edaa1431 | 1449 | init_tracepoint(); |
f9364363 | 1450 | lttng_ust_clock_init(); |
5e1b7b8b | 1451 | lttng_ust_getcpu_init(); |
bd703713 | 1452 | lttng_ust_baddr_statedump_init(); |
7dd08bec MD |
1453 | lttng_ring_buffer_metadata_client_init(); |
1454 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1455 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1456 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1457 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1458 | lttng_perf_counter_init(); |
a0a3bef9 | 1459 | lttng_context_init(); |
2594a5b4 MD |
1460 | /* |
1461 | * Invoke ust malloc wrapper init before starting other threads. | |
1462 | */ | |
1463 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1464 | |
ff517991 | 1465 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1466 | |
95259bd0 | 1467 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
1468 | assert(!ret); |
1469 | ||
8d20bf54 | 1470 | ret = setup_local_apps(); |
2691221a | 1471 | if (ret) { |
9ec6895c | 1472 | DBG("local apps setup returned %d", ret); |
2691221a | 1473 | } |
ae6a58bf WP |
1474 | |
1475 | /* A new thread created by pthread_create inherits the signal mask | |
1476 | * from the parent. To avoid any signal being received by the | |
1477 | * listener thread, we block all signals temporarily in the parent, | |
1478 | * while we create the listener thread. | |
1479 | */ | |
1480 | sigfillset(&sig_all_blocked); | |
1481 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1482 | if (ret) { | |
d94d802c | 1483 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1484 | } |
1485 | ||
1879f67f MG |
1486 | ret = pthread_attr_init(&thread_attr); |
1487 | if (ret) { | |
1488 | ERR("pthread_attr_init: %s", strerror(ret)); | |
1489 | } | |
1490 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
1491 | if (ret) { | |
1492 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
1493 | } | |
1494 | ||
c0bbbd5a | 1495 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1496 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, |
dde70ea0 | 1497 | ust_listener_thread, &global_apps); |
d94d802c MD |
1498 | if (ret) { |
1499 | ERR("pthread_create global: %s", strerror(ret)); | |
1500 | } | |
e33f3265 | 1501 | global_apps.thread_active = 1; |
c0bbbd5a | 1502 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1503 | |
8d20bf54 | 1504 | if (local_apps.allowed) { |
c0bbbd5a | 1505 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1506 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 1507 | ust_listener_thread, &local_apps); |
d94d802c MD |
1508 | if (ret) { |
1509 | ERR("pthread_create local: %s", strerror(ret)); | |
1510 | } | |
e33f3265 | 1511 | local_apps.thread_active = 1; |
c0bbbd5a | 1512 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
1513 | } else { |
1514 | handle_register_done(&local_apps); | |
1515 | } | |
1879f67f MG |
1516 | ret = pthread_attr_destroy(&thread_attr); |
1517 | if (ret) { | |
1518 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
1519 | } | |
8d20bf54 | 1520 | |
ae6a58bf WP |
1521 | /* Restore original signal mask in parent */ |
1522 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
1523 | if (ret) { | |
d94d802c | 1524 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1525 | } |
1526 | ||
cf12a773 MD |
1527 | switch (timeout_mode) { |
1528 | case 1: /* timeout wait */ | |
95259bd0 MD |
1529 | do { |
1530 | ret = sem_timedwait(&constructor_wait, | |
1531 | &constructor_timeout); | |
1532 | } while (ret < 0 && errno == EINTR); | |
cf12a773 | 1533 | if (ret < 0 && errno == ETIMEDOUT) { |
7dd08bec | 1534 | ERR("Timed out waiting for lttng-sessiond"); |
cf12a773 MD |
1535 | } else { |
1536 | assert(!ret); | |
1537 | } | |
1538 | break; | |
7b766b16 | 1539 | case -1:/* wait forever */ |
95259bd0 MD |
1540 | do { |
1541 | ret = sem_wait(&constructor_wait); | |
1542 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 1543 | assert(!ret); |
cf12a773 | 1544 | break; |
7b766b16 | 1545 | case 0: /* no timeout */ |
cf12a773 | 1546 | break; |
11ff9c7d | 1547 | } |
2691221a MD |
1548 | } |
1549 | ||
17dfb34b MD |
1550 | static |
1551 | void lttng_ust_cleanup(int exiting) | |
1552 | { | |
efe0de09 | 1553 | cleanup_sock_info(&global_apps, exiting); |
17dfb34b | 1554 | if (local_apps.allowed) { |
efe0de09 | 1555 | cleanup_sock_info(&local_apps, exiting); |
17dfb34b | 1556 | } |
efe0de09 MD |
1557 | /* |
1558 | * The teardown in this function all affect data structures | |
1559 | * accessed under the UST lock by the listener thread. This | |
1560 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
1561 | * that none of these threads are accessing this data at this | |
1562 | * point. | |
1563 | */ | |
17dfb34b | 1564 | lttng_ust_abi_exit(); |
003fedf4 | 1565 | lttng_ust_events_exit(); |
a0a3bef9 | 1566 | lttng_context_exit(); |
d58d1454 | 1567 | lttng_perf_counter_exit(); |
34a91bdb | 1568 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 1569 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 1570 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
1571 | lttng_ring_buffer_client_overwrite_exit(); |
1572 | lttng_ring_buffer_metadata_client_exit(); | |
bd703713 | 1573 | lttng_ust_baddr_statedump_destroy(); |
17dfb34b MD |
1574 | exit_tracepoint(); |
1575 | if (!exiting) { | |
1576 | /* Reinitialize values for fork */ | |
1577 | sem_count = 2; | |
1578 | lttng_ust_comm_should_quit = 0; | |
1579 | initialized = 0; | |
1580 | } | |
1581 | } | |
1582 | ||
edaa1431 | 1583 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
1584 | { |
1585 | int ret; | |
1586 | ||
9eb62b9c MD |
1587 | /* |
1588 | * Using pthread_cancel here because: | |
1589 | * A) we don't want to hang application teardown. | |
1590 | * B) the thread is not allocating any resource. | |
1591 | */ | |
1ea11eab MD |
1592 | |
1593 | /* | |
1594 | * Require the communication thread to quit. Synchronize with | |
1595 | * mutexes to ensure it is not in a mutex critical section when | |
1596 | * pthread_cancel is later called. | |
1597 | */ | |
3327ac33 | 1598 | ust_lock_nocheck(); |
1ea11eab | 1599 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 1600 | ust_unlock(); |
1ea11eab | 1601 | |
3327ac33 | 1602 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 1603 | /* cancel threads */ |
e33f3265 MD |
1604 | if (global_apps.thread_active) { |
1605 | ret = pthread_cancel(global_apps.ust_listener); | |
1606 | if (ret) { | |
1607 | ERR("Error cancelling global ust listener thread: %s", | |
1608 | strerror(ret)); | |
1609 | } else { | |
1610 | global_apps.thread_active = 0; | |
1611 | } | |
2691221a | 1612 | } |
e33f3265 | 1613 | if (local_apps.thread_active) { |
8d20bf54 MD |
1614 | ret = pthread_cancel(local_apps.ust_listener); |
1615 | if (ret) { | |
d94d802c MD |
1616 | ERR("Error cancelling local ust listener thread: %s", |
1617 | strerror(ret)); | |
e33f3265 MD |
1618 | } else { |
1619 | local_apps.thread_active = 0; | |
8d20bf54 | 1620 | } |
8d20bf54 | 1621 | } |
3327ac33 | 1622 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1623 | |
efe0de09 MD |
1624 | /* |
1625 | * Do NOT join threads: use of sys_futex makes it impossible to | |
1626 | * join the threads without using async-cancel, but async-cancel | |
1627 | * is delivered by a signal, which could hit the target thread | |
1628 | * anywhere in its code path, including while the ust_lock() is | |
1629 | * held, causing a deadlock for the other thread. Let the OS | |
1630 | * cleanup the threads if there are stalled in a syscall. | |
1631 | */ | |
17dfb34b | 1632 | lttng_ust_cleanup(1); |
2691221a | 1633 | } |
e822f505 MD |
1634 | |
1635 | /* | |
1636 | * We exclude the worker threads across fork and clone (except | |
1637 | * CLONE_VM), because these system calls only keep the forking thread | |
1638 | * running in the child. Therefore, we don't want to call fork or clone | |
1639 | * in the middle of an tracepoint or ust tracing state modification. | |
1640 | * Holding this mutex protects these structures across fork and clone. | |
1641 | */ | |
b728d87e | 1642 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
1643 | { |
1644 | /* | |
1645 | * Disable signals. This is to avoid that the child intervenes | |
1646 | * before it is properly setup for tracing. It is safer to | |
1647 | * disable all signals, because then we know we are not breaking | |
1648 | * anything by restoring the original mask. | |
1649 | */ | |
1650 | sigset_t all_sigs; | |
1651 | int ret; | |
1652 | ||
8c90a710 | 1653 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1654 | return; |
e822f505 MD |
1655 | /* Disable signals */ |
1656 | sigfillset(&all_sigs); | |
b728d87e | 1657 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
1658 | if (ret == -1) { |
1659 | PERROR("sigprocmask"); | |
1660 | } | |
458d678c PW |
1661 | |
1662 | pthread_mutex_lock(&ust_fork_mutex); | |
1663 | ||
3327ac33 | 1664 | ust_lock_nocheck(); |
e822f505 MD |
1665 | rcu_bp_before_fork(); |
1666 | } | |
1667 | ||
b728d87e | 1668 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
1669 | { |
1670 | int ret; | |
1671 | ||
17dfb34b MD |
1672 | DBG("process %d", getpid()); |
1673 | ust_unlock(); | |
458d678c PW |
1674 | |
1675 | pthread_mutex_unlock(&ust_fork_mutex); | |
1676 | ||
e822f505 | 1677 | /* Restore signals */ |
23c8854a | 1678 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
1679 | if (ret == -1) { |
1680 | PERROR("sigprocmask"); | |
1681 | } | |
1682 | } | |
1683 | ||
b728d87e | 1684 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 1685 | { |
8c90a710 | 1686 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1687 | return; |
17dfb34b | 1688 | DBG("process %d", getpid()); |
e822f505 MD |
1689 | rcu_bp_after_fork_parent(); |
1690 | /* Release mutexes and reenable signals */ | |
b728d87e | 1691 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
1692 | } |
1693 | ||
17dfb34b MD |
1694 | /* |
1695 | * After fork, in the child, we need to cleanup all the leftover state, | |
1696 | * except the worker thread which already magically disappeared thanks | |
1697 | * to the weird Linux fork semantics. After tyding up, we call | |
1698 | * lttng_ust_init() again to start over as a new PID. | |
1699 | * | |
1700 | * This is meant for forks() that have tracing in the child between the | |
1701 | * fork and following exec call (if there is any). | |
1702 | */ | |
b728d87e | 1703 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 1704 | { |
8c90a710 | 1705 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1706 | return; |
17dfb34b | 1707 | DBG("process %d", getpid()); |
e822f505 MD |
1708 | /* Release urcu mutexes */ |
1709 | rcu_bp_after_fork_child(); | |
17dfb34b | 1710 | lttng_ust_cleanup(0); |
a93bfc45 | 1711 | lttng_context_vtid_reset(); |
e822f505 | 1712 | /* Release mutexes and reenable signals */ |
b728d87e | 1713 | ust_after_fork_common(restore_sigset); |
318dfea9 | 1714 | lttng_ust_init(); |
e822f505 | 1715 | } |
95c25348 | 1716 | |
246be17e | 1717 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
1718 | { |
1719 | struct sock_info *sock_info = owner; | |
37dddb65 | 1720 | sock_info->statedump_pending = 1; |
95c25348 | 1721 | } |