Commit | Line | Data |
---|---|---|
2691221a MD |
1 | /* |
2 | * lttng-ust-comm.c | |
3 | * | |
4 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; only | |
10 | * version 2.1 of the License. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with this library; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
80e2814b | 22 | #define _LGPL_SOURCE |
2691221a MD |
23 | #include <sys/types.h> |
24 | #include <sys/socket.h> | |
7fc90dca MD |
25 | #include <sys/mman.h> |
26 | #include <sys/stat.h> | |
58d4b2a2 MD |
27 | #include <sys/types.h> |
28 | #include <sys/wait.h> | |
7fc90dca | 29 | #include <fcntl.h> |
2691221a MD |
30 | #include <unistd.h> |
31 | #include <errno.h> | |
d9e99d10 | 32 | #include <pthread.h> |
11ff9c7d MD |
33 | #include <semaphore.h> |
34 | #include <time.h> | |
1ea11eab | 35 | #include <assert.h> |
e822f505 | 36 | #include <signal.h> |
95259bd0 | 37 | #include <urcu/uatomic.h> |
80e2814b | 38 | #include <urcu/futex.h> |
c117fb1b | 39 | #include <urcu/compiler.h> |
1ea11eab | 40 | |
4318ae1b | 41 | #include <lttng/ust-events.h> |
4318ae1b | 42 | #include <lttng/ust-abi.h> |
4318ae1b | 43 | #include <lttng/ust.h> |
7bc53e94 | 44 | #include <lttng/ust-error.h> |
74d81a6c | 45 | #include <lttng/ust-ctl.h> |
8c90a710 | 46 | #include <urcu/tls-compat.h> |
44c72f10 MD |
47 | #include <ust-comm.h> |
48 | #include <usterr-signal-safe.h> | |
cd54f6d9 | 49 | #include <helper.h> |
44c72f10 | 50 | #include "tracepoint-internal.h" |
7dd08bec | 51 | #include "lttng-tracer-core.h" |
08114193 | 52 | #include "compat.h" |
f645cfa7 | 53 | #include "../libringbuffer/tlsfixup.h" |
394598c1 | 54 | #include "lttng-ust-baddr.h" |
edaa1431 MD |
55 | |
56 | /* | |
57 | * Has lttng ust comm constructor been called ? | |
58 | */ | |
59 | static int initialized; | |
60 | ||
1ea11eab | 61 | /* |
17dfb34b MD |
62 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
63 | * Held when handling a command, also held by fork() to deal with | |
64 | * removal of threads, and by exit path. | |
3327ac33 MD |
65 | * |
66 | * The UST lock is the centralized mutex across UST tracing control and | |
67 | * probe registration. | |
68 | * | |
69 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 70 | * |
4770bd47 MD |
71 | * ust_fork_mutex must never nest in ust_mutex. |
72 | * | |
d58d1454 MD |
73 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
74 | * counter lazy initialization called by events within the statedump, | |
75 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
76 | * |
77 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
78 | * it is taken within the library constructor. | |
3327ac33 MD |
79 | */ |
80 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
81 | ||
d58d1454 MD |
82 | /* Allow nesting the ust_mutex within the same thread. */ |
83 | static DEFINE_URCU_TLS(int, ust_mutex_nest); | |
84 | ||
3327ac33 MD |
85 | /* |
86 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
87 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
88 | * internal libc lock, cannot nest within ust_mutex. | |
89 | * | |
90 | * It never nests within a ust_mutex. | |
1ea11eab | 91 | */ |
3327ac33 | 92 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 93 | |
458d678c PW |
94 | /* |
95 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
96 | * prevents the dynamic loader lock to be taken (by base address statedump | |
97 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
98 | * the dynamic loader lock. | |
99 | */ | |
100 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
101 | ||
1ea11eab MD |
102 | /* Should the ust comm thread quit ? */ |
103 | static int lttng_ust_comm_should_quit; | |
104 | ||
3327ac33 | 105 | /* |
d58d1454 | 106 | * Return 0 on success, -1 if should quit. |
3327ac33 | 107 | * The lock is taken in both cases. |
d58d1454 | 108 | * Signal-safe. |
3327ac33 MD |
109 | */ |
110 | int ust_lock(void) | |
111 | { | |
d58d1454 MD |
112 | sigset_t sig_all_blocked, orig_mask; |
113 | int ret; | |
114 | ||
115 | sigfillset(&sig_all_blocked); | |
116 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
117 | if (ret) { | |
118 | ERR("pthread_sigmask: %s", strerror(ret)); | |
119 | } | |
120 | if (!URCU_TLS(ust_mutex_nest)++) | |
121 | pthread_mutex_lock(&ust_mutex); | |
122 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
123 | if (ret) { | |
124 | ERR("pthread_sigmask: %s", strerror(ret)); | |
125 | } | |
3327ac33 MD |
126 | if (lttng_ust_comm_should_quit) { |
127 | return -1; | |
128 | } else { | |
129 | return 0; | |
130 | } | |
131 | } | |
132 | ||
133 | /* | |
134 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
135 | * they are already nested within the dynamic loader lock, and therefore | |
136 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 137 | * Signal-safe. |
3327ac33 MD |
138 | */ |
139 | void ust_lock_nocheck(void) | |
140 | { | |
d58d1454 MD |
141 | sigset_t sig_all_blocked, orig_mask; |
142 | int ret; | |
143 | ||
144 | sigfillset(&sig_all_blocked); | |
145 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
146 | if (ret) { | |
147 | ERR("pthread_sigmask: %s", strerror(ret)); | |
148 | } | |
149 | if (!URCU_TLS(ust_mutex_nest)++) | |
150 | pthread_mutex_lock(&ust_mutex); | |
151 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
152 | if (ret) { | |
153 | ERR("pthread_sigmask: %s", strerror(ret)); | |
154 | } | |
3327ac33 MD |
155 | } |
156 | ||
d58d1454 MD |
157 | /* |
158 | * Signal-safe. | |
159 | */ | |
3327ac33 MD |
160 | void ust_unlock(void) |
161 | { | |
d58d1454 MD |
162 | sigset_t sig_all_blocked, orig_mask; |
163 | int ret; | |
164 | ||
165 | sigfillset(&sig_all_blocked); | |
166 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
167 | if (ret) { | |
168 | ERR("pthread_sigmask: %s", strerror(ret)); | |
169 | } | |
170 | if (!--URCU_TLS(ust_mutex_nest)) | |
171 | pthread_mutex_unlock(&ust_mutex); | |
172 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
173 | if (ret) { | |
174 | ERR("pthread_sigmask: %s", strerror(ret)); | |
175 | } | |
3327ac33 MD |
176 | } |
177 | ||
11ff9c7d MD |
178 | /* |
179 | * Wait for either of these before continuing to the main | |
180 | * program: | |
181 | * - the register_done message from sessiond daemon | |
182 | * (will let the sessiond daemon enable sessions before main | |
183 | * starts.) | |
184 | * - sessiond daemon is not reachable. | |
185 | * - timeout (ensuring applications are resilient to session | |
186 | * daemon problems). | |
187 | */ | |
188 | static sem_t constructor_wait; | |
950aab0c MD |
189 | /* |
190 | * Doing this for both the global and local sessiond. | |
191 | */ | |
95259bd0 | 192 | static int sem_count = { 2 }; |
11ff9c7d | 193 | |
e8508a49 MD |
194 | /* |
195 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
196 | * from liblttng-ust does not execute the pre/post fork handlers. | |
197 | */ | |
8c90a710 | 198 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 199 | |
1ea11eab MD |
200 | /* |
201 | * Info about socket and associated listener thread. | |
202 | */ | |
203 | struct sock_info { | |
11ff9c7d | 204 | const char *name; |
1ea11eab | 205 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 206 | int root_handle; |
8d20bf54 MD |
207 | int constructor_sem_posted; |
208 | int allowed; | |
44e073f5 | 209 | int global; |
e33f3265 | 210 | int thread_active; |
7fc90dca MD |
211 | |
212 | char sock_path[PATH_MAX]; | |
213 | int socket; | |
32ce8569 | 214 | int notify_socket; |
7fc90dca MD |
215 | |
216 | char wait_shm_path[PATH_MAX]; | |
217 | char *wait_shm_mmap; | |
37dddb65 MD |
218 | /* Keep track of lazy state dump not performed yet. */ |
219 | int statedump_pending; | |
1ea11eab | 220 | }; |
2691221a MD |
221 | |
222 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 223 | struct sock_info global_apps = { |
11ff9c7d | 224 | .name = "global", |
44e073f5 | 225 | .global = 1, |
7fc90dca | 226 | |
46050b1a | 227 | .root_handle = -1, |
8d20bf54 | 228 | .allowed = 1, |
e33f3265 | 229 | .thread_active = 0, |
7fc90dca | 230 | |
32ce8569 | 231 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 232 | .socket = -1, |
32ce8569 | 233 | .notify_socket = -1, |
7fc90dca | 234 | |
32ce8569 | 235 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 236 | |
37dddb65 | 237 | .statedump_pending = 0, |
1ea11eab | 238 | }; |
2691221a MD |
239 | |
240 | /* TODO: allow global_apps_sock_path override */ | |
241 | ||
1ea11eab | 242 | struct sock_info local_apps = { |
11ff9c7d | 243 | .name = "local", |
44e073f5 | 244 | .global = 0, |
46050b1a | 245 | .root_handle = -1, |
8d20bf54 | 246 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 247 | .thread_active = 0, |
7fc90dca MD |
248 | |
249 | .socket = -1, | |
32ce8569 | 250 | .notify_socket = -1, |
95c25348 | 251 | |
37dddb65 | 252 | .statedump_pending = 0, |
1ea11eab | 253 | }; |
2691221a | 254 | |
37ed587a MD |
255 | static int wait_poll_fallback; |
256 | ||
74d81a6c MD |
257 | static const char *cmd_name_mapping[] = { |
258 | [ LTTNG_UST_RELEASE ] = "Release", | |
259 | [ LTTNG_UST_SESSION ] = "Create Session", | |
260 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
261 | ||
262 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
263 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
264 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
265 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
266 | ||
267 | /* Session FD commands */ | |
268 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
269 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
270 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
271 | ||
272 | /* Channel FD commands */ | |
273 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
274 | [ LTTNG_UST_EVENT ] = "Create Event", | |
275 | ||
276 | /* Event and Channel FD commands */ | |
277 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
278 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
279 | ||
280 | /* Event, Channel and Session commands */ | |
281 | [ LTTNG_UST_ENABLE ] = "Enable", | |
282 | [ LTTNG_UST_DISABLE ] = "Disable", | |
283 | ||
284 | /* Tracepoint list commands */ | |
285 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
286 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
287 | ||
288 | /* Event FD commands */ | |
289 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 290 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
74d81a6c MD |
291 | }; |
292 | ||
ff517991 MD |
293 | static const char *str_timeout; |
294 | static int got_timeout_env; | |
295 | ||
7dd08bec | 296 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 297 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 298 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 299 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
300 | extern void lttng_ring_buffer_metadata_client_init(void); |
301 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 302 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 303 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 304 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 305 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 306 | |
3c6f6263 AM |
307 | /* |
308 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
309 | * pointer. | |
310 | */ | |
311 | static | |
312 | const char *get_lttng_home_dir(void) | |
313 | { | |
314 | const char *val; | |
315 | ||
316 | val = (const char *) getenv("LTTNG_HOME"); | |
317 | if (val != NULL) { | |
318 | return val; | |
319 | } | |
320 | return (const char *) getenv("HOME"); | |
321 | } | |
322 | ||
a903623f MD |
323 | /* |
324 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
325 | */ | |
326 | static | |
327 | void lttng_fixup_nest_count_tls(void) | |
328 | { | |
8c90a710 | 329 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
330 | } |
331 | ||
d58d1454 MD |
332 | static |
333 | void lttng_fixup_ust_mutex_nest_tls(void) | |
334 | { | |
335 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
336 | } | |
337 | ||
3df53fae MD |
338 | /* |
339 | * Fixup urcu bp TLS. | |
340 | */ | |
341 | static | |
342 | void lttng_fixup_urcu_bp_tls(void) | |
343 | { | |
344 | rcu_read_lock(); | |
345 | rcu_read_unlock(); | |
346 | } | |
347 | ||
32ce8569 MD |
348 | int lttng_get_notify_socket(void *owner) |
349 | { | |
350 | struct sock_info *info = owner; | |
351 | ||
352 | return info->notify_socket; | |
353 | } | |
354 | ||
74d81a6c MD |
355 | static |
356 | void print_cmd(int cmd, int handle) | |
357 | { | |
358 | const char *cmd_name = "Unknown"; | |
359 | ||
fd67a004 MD |
360 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
361 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
362 | cmd_name = cmd_name_mapping[cmd]; |
363 | } | |
fd67a004 MD |
364 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
365 | cmd_name, cmd, | |
74d81a6c MD |
366 | lttng_ust_obj_get_name(handle), handle); |
367 | } | |
368 | ||
2691221a | 369 | static |
8d20bf54 | 370 | int setup_local_apps(void) |
2691221a MD |
371 | { |
372 | const char *home_dir; | |
7fc90dca | 373 | uid_t uid; |
2691221a | 374 | |
7fc90dca | 375 | uid = getuid(); |
8d20bf54 MD |
376 | /* |
377 | * Disallow per-user tracing for setuid binaries. | |
378 | */ | |
7fc90dca | 379 | if (uid != geteuid()) { |
9ec6895c | 380 | assert(local_apps.allowed == 0); |
d0a1ae63 | 381 | return 0; |
8d20bf54 | 382 | } |
3c6f6263 | 383 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
384 | if (!home_dir) { |
385 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
386 | assert(local_apps.allowed == 0); | |
2691221a | 387 | return -ENOENT; |
9ec6895c MD |
388 | } |
389 | local_apps.allowed = 1; | |
32ce8569 MD |
390 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
391 | home_dir, | |
392 | LTTNG_DEFAULT_HOME_RUNDIR, | |
393 | LTTNG_UST_SOCK_FILENAME); | |
394 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
395 | LTTNG_UST_WAIT_FILENAME, | |
396 | uid); | |
2691221a MD |
397 | return 0; |
398 | } | |
399 | ||
ff517991 MD |
400 | /* |
401 | * Get notify_sock timeout, in ms. | |
6612d11a | 402 | * -1: wait forever. 0: don't wait. >0: timeout, in ms. |
ff517991 MD |
403 | */ |
404 | static | |
405 | long get_timeout(void) | |
406 | { | |
407 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
408 | ||
409 | if (!got_timeout_env) { | |
410 | str_timeout = getenv("LTTNG_UST_REGISTER_TIMEOUT"); | |
411 | got_timeout_env = 1; | |
412 | } | |
413 | if (str_timeout) | |
414 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
415 | return constructor_delay_ms; | |
416 | } | |
417 | ||
418 | static | |
419 | long get_notify_sock_timeout(void) | |
420 | { | |
421 | return get_timeout(); | |
422 | } | |
423 | ||
424 | /* | |
6612d11a | 425 | * Return values: -1: wait forever. 0: don't wait. 1: timeout wait. |
ff517991 MD |
426 | */ |
427 | static | |
428 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
429 | { | |
430 | long constructor_delay_ms; | |
431 | int ret; | |
432 | ||
433 | constructor_delay_ms = get_timeout(); | |
434 | ||
435 | switch (constructor_delay_ms) { | |
436 | case -1:/* fall-through */ | |
437 | case 0: | |
438 | return constructor_delay_ms; | |
439 | default: | |
440 | break; | |
441 | } | |
442 | ||
443 | /* | |
444 | * If we are unable to find the current time, don't wait. | |
445 | */ | |
446 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
447 | if (ret) { | |
6612d11a JG |
448 | /* Don't wait. */ |
449 | return 0; | |
ff517991 MD |
450 | } |
451 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
452 | constructor_timeout->tv_nsec += | |
453 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
454 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
455 | constructor_timeout->tv_sec++; | |
456 | constructor_timeout->tv_nsec -= 1000000000UL; | |
457 | } | |
6612d11a | 458 | /* Timeout wait (constructor_delay_ms). */ |
ff517991 MD |
459 | return 1; |
460 | } | |
461 | ||
2691221a | 462 | static |
32ce8569 | 463 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 464 | { |
32ce8569 MD |
465 | return ustcomm_send_reg_msg(socket, |
466 | type, | |
467 | CAA_BITS_PER_LONG, | |
468 | lttng_alignof(uint8_t) * CHAR_BIT, | |
469 | lttng_alignof(uint16_t) * CHAR_BIT, | |
470 | lttng_alignof(uint32_t) * CHAR_BIT, | |
471 | lttng_alignof(uint64_t) * CHAR_BIT, | |
472 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
473 | } |
474 | ||
d9e99d10 | 475 | static |
57773204 | 476 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 477 | { |
9eb62b9c | 478 | ssize_t len; |
d3a492d1 | 479 | |
57773204 | 480 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 481 | switch (len) { |
a4be8962 | 482 | case sizeof(*lur): |
d3a492d1 MD |
483 | DBG("message successfully sent"); |
484 | return 0; | |
7bc53e94 MD |
485 | default: |
486 | if (len == -ECONNRESET) { | |
487 | DBG("remote end closed connection"); | |
d3a492d1 MD |
488 | return 0; |
489 | } | |
7bc53e94 MD |
490 | if (len < 0) |
491 | return len; | |
492 | DBG("incorrect message size: %zd", len); | |
493 | return -EINVAL; | |
d3a492d1 MD |
494 | } |
495 | } | |
496 | ||
497 | static | |
edaa1431 | 498 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
499 | { |
500 | int ret; | |
501 | ||
edaa1431 MD |
502 | if (sock_info->constructor_sem_posted) |
503 | return 0; | |
504 | sock_info->constructor_sem_posted = 1; | |
56cd7e2f MD |
505 | if (uatomic_read(&sem_count) <= 0) { |
506 | return 0; | |
507 | } | |
95259bd0 MD |
508 | ret = uatomic_add_return(&sem_count, -1); |
509 | if (ret == 0) { | |
510 | ret = sem_post(&constructor_wait); | |
511 | assert(!ret); | |
512 | } | |
11ff9c7d MD |
513 | return 0; |
514 | } | |
515 | ||
37dddb65 MD |
516 | /* |
517 | * Only execute pending statedump after the constructor semaphore has | |
518 | * been posted by each listener thread. This means statedump will only | |
519 | * be performed after the "registration done" command is received from | |
520 | * each session daemon the application is connected to. | |
521 | * | |
522 | * This ensures we don't run into deadlock issues with the dynamic | |
523 | * loader mutex, which is held while the constructor is called and | |
524 | * waiting on the constructor semaphore. All operations requiring this | |
525 | * dynamic loader lock need to be postponed using this mechanism. | |
526 | */ | |
527 | static | |
528 | void handle_pending_statedump(struct sock_info *sock_info) | |
529 | { | |
530 | int ctor_passed = sock_info->constructor_sem_posted; | |
531 | ||
532 | if (ctor_passed && sock_info->statedump_pending) { | |
533 | sock_info->statedump_pending = 0; | |
2932a87f | 534 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 535 | lttng_handle_pending_statedump(sock_info); |
458d678c | 536 | pthread_mutex_unlock(&ust_fork_mutex); |
37dddb65 MD |
537 | } |
538 | } | |
539 | ||
11ff9c7d MD |
540 | static |
541 | int handle_message(struct sock_info *sock_info, | |
57773204 | 542 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 543 | { |
1ea11eab | 544 | int ret = 0; |
b61ce3b2 | 545 | const struct lttng_ust_objd_ops *ops; |
57773204 | 546 | struct ustcomm_ust_reply lur; |
ef9ff354 | 547 | union ust_args args; |
40003310 | 548 | ssize_t len; |
1ea11eab | 549 | |
46050b1a MD |
550 | memset(&lur, 0, sizeof(lur)); |
551 | ||
3327ac33 | 552 | if (ust_lock()) { |
74d81a6c | 553 | ret = -LTTNG_UST_ERR_EXITING; |
1ea11eab MD |
554 | goto end; |
555 | } | |
9eb62b9c | 556 | |
46050b1a MD |
557 | ops = objd_ops(lum->handle); |
558 | if (!ops) { | |
559 | ret = -ENOENT; | |
560 | goto end; | |
1ea11eab | 561 | } |
46050b1a MD |
562 | |
563 | switch (lum->cmd) { | |
11ff9c7d MD |
564 | case LTTNG_UST_REGISTER_DONE: |
565 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 566 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
567 | else |
568 | ret = -EINVAL; | |
569 | break; | |
46050b1a MD |
570 | case LTTNG_UST_RELEASE: |
571 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
572 | ret = -EPERM; | |
573 | else | |
1849ef7c | 574 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 575 | break; |
2d78951a MD |
576 | case LTTNG_UST_FILTER: |
577 | { | |
578 | /* Receive filter data */ | |
f488575f | 579 | struct lttng_ust_filter_bytecode_node *bytecode; |
2d78951a | 580 | |
cd54f6d9 | 581 | if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) { |
7bc53e94 | 582 | ERR("Filter data size is too large: %u bytes", |
2d78951a MD |
583 | lum->u.filter.data_size); |
584 | ret = -EINVAL; | |
585 | goto error; | |
586 | } | |
2734ca65 | 587 | |
885b1dfd | 588 | if (lum->u.filter.reloc_offset > lum->u.filter.data_size) { |
7bc53e94 | 589 | ERR("Filter reloc offset %u is not within data", |
2734ca65 CB |
590 | lum->u.filter.reloc_offset); |
591 | ret = -EINVAL; | |
592 | goto error; | |
593 | } | |
594 | ||
cd54f6d9 MD |
595 | bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size); |
596 | if (!bytecode) { | |
597 | ret = -ENOMEM; | |
598 | goto error; | |
599 | } | |
f488575f | 600 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, |
2d78951a MD |
601 | lum->u.filter.data_size); |
602 | switch (len) { | |
603 | case 0: /* orderly shutdown */ | |
604 | ret = 0; | |
cd54f6d9 | 605 | free(bytecode); |
2d78951a | 606 | goto error; |
2d78951a MD |
607 | default: |
608 | if (len == lum->u.filter.data_size) { | |
7bc53e94 | 609 | DBG("filter data received"); |
2d78951a | 610 | break; |
7bc53e94 MD |
611 | } else if (len < 0) { |
612 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
613 | if (len == -ECONNRESET) { | |
614 | ERR("%s remote end closed connection", sock_info->name); | |
615 | ret = len; | |
616 | free(bytecode); | |
617 | goto error; | |
618 | } | |
619 | ret = len; | |
eb8bf361 | 620 | free(bytecode); |
7bc53e94 | 621 | goto end; |
2d78951a | 622 | } else { |
7bc53e94 | 623 | DBG("incorrect filter data message size: %zd", len); |
2d78951a | 624 | ret = -EINVAL; |
cd54f6d9 | 625 | free(bytecode); |
2d78951a MD |
626 | goto end; |
627 | } | |
628 | } | |
f488575f MD |
629 | bytecode->bc.len = lum->u.filter.data_size; |
630 | bytecode->bc.reloc_offset = lum->u.filter.reloc_offset; | |
3f6fd224 | 631 | bytecode->bc.seqnum = lum->u.filter.seqnum; |
cd54f6d9 | 632 | if (ops->cmd) { |
2d78951a | 633 | ret = ops->cmd(lum->handle, lum->cmd, |
cd54f6d9 | 634 | (unsigned long) bytecode, |
f59ed768 | 635 | &args, sock_info); |
cd54f6d9 MD |
636 | if (ret) { |
637 | free(bytecode); | |
638 | } | |
639 | /* don't free bytecode if everything went fine. */ | |
640 | } else { | |
2d78951a | 641 | ret = -ENOSYS; |
cd54f6d9 MD |
642 | free(bytecode); |
643 | } | |
2d78951a MD |
644 | break; |
645 | } | |
86e36163 JI |
646 | case LTTNG_UST_EXCLUSION: |
647 | { | |
648 | /* Receive exclusion names */ | |
649 | struct lttng_ust_excluder_node *node; | |
650 | unsigned int count; | |
651 | ||
652 | count = lum->u.exclusion.count; | |
653 | if (count == 0) { | |
654 | /* There are no names to read */ | |
655 | ret = 0; | |
656 | goto error; | |
657 | } | |
658 | node = zmalloc(sizeof(*node) + | |
659 | count * LTTNG_UST_SYM_NAME_LEN); | |
660 | if (!node) { | |
661 | ret = -ENOMEM; | |
662 | goto error; | |
663 | } | |
664 | node->excluder.count = count; | |
665 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
666 | count * LTTNG_UST_SYM_NAME_LEN); | |
667 | switch (len) { | |
668 | case 0: /* orderly shutdown */ | |
669 | ret = 0; | |
670 | free(node); | |
671 | goto error; | |
672 | default: | |
673 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
674 | DBG("Exclusion data received"); | |
675 | break; | |
676 | } else if (len < 0) { | |
677 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
678 | if (len == -ECONNRESET) { | |
679 | ERR("%s remote end closed connection", sock_info->name); | |
680 | ret = len; | |
681 | free(node); | |
682 | goto error; | |
683 | } | |
684 | ret = len; | |
685 | free(node); | |
686 | goto end; | |
687 | } else { | |
688 | DBG("Incorrect exclusion data message size: %zd", len); | |
689 | ret = -EINVAL; | |
690 | free(node); | |
691 | goto end; | |
692 | } | |
693 | } | |
694 | if (ops->cmd) { | |
695 | ret = ops->cmd(lum->handle, lum->cmd, | |
696 | (unsigned long) node, | |
697 | &args, sock_info); | |
698 | if (ret) { | |
699 | free(node); | |
700 | } | |
701 | /* Don't free exclusion data if everything went fine. */ | |
702 | } else { | |
703 | ret = -ENOSYS; | |
704 | free(node); | |
705 | } | |
706 | break; | |
707 | } | |
74d81a6c MD |
708 | case LTTNG_UST_CHANNEL: |
709 | { | |
710 | void *chan_data; | |
ff0f5728 | 711 | int wakeup_fd; |
74d81a6c MD |
712 | |
713 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
714 | &chan_data, lum->u.channel.len, |
715 | &wakeup_fd); | |
74d81a6c MD |
716 | switch (len) { |
717 | case 0: /* orderly shutdown */ | |
718 | ret = 0; | |
719 | goto error; | |
720 | default: | |
721 | if (len == lum->u.channel.len) { | |
722 | DBG("channel data received"); | |
723 | break; | |
724 | } else if (len < 0) { | |
725 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
726 | if (len == -ECONNRESET) { | |
727 | ERR("%s remote end closed connection", sock_info->name); | |
728 | ret = len; | |
729 | goto error; | |
730 | } | |
731 | ret = len; | |
732 | goto end; | |
733 | } else { | |
734 | DBG("incorrect channel data message size: %zd", len); | |
735 | ret = -EINVAL; | |
736 | goto end; | |
737 | } | |
738 | } | |
739 | args.channel.chan_data = chan_data; | |
ff0f5728 | 740 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
741 | if (ops->cmd) |
742 | ret = ops->cmd(lum->handle, lum->cmd, | |
743 | (unsigned long) &lum->u, | |
744 | &args, sock_info); | |
745 | else | |
746 | ret = -ENOSYS; | |
747 | break; | |
748 | } | |
749 | case LTTNG_UST_STREAM: | |
750 | { | |
751 | /* Receive shm_fd, wakeup_fd */ | |
752 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
753 | &lum->u.stream.len, | |
754 | &args.stream.shm_fd, | |
755 | &args.stream.wakeup_fd); | |
756 | if (ret) { | |
757 | goto end; | |
758 | } | |
759 | if (ops->cmd) | |
760 | ret = ops->cmd(lum->handle, lum->cmd, | |
761 | (unsigned long) &lum->u, | |
762 | &args, sock_info); | |
763 | else | |
764 | ret = -ENOSYS; | |
765 | break; | |
766 | } | |
d9e99d10 | 767 | default: |
46050b1a MD |
768 | if (ops->cmd) |
769 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 770 | (unsigned long) &lum->u, |
f59ed768 | 771 | &args, sock_info); |
46050b1a MD |
772 | else |
773 | ret = -ENOSYS; | |
774 | break; | |
d9e99d10 | 775 | } |
46050b1a | 776 | |
1ea11eab | 777 | end: |
46050b1a MD |
778 | lur.handle = lum->handle; |
779 | lur.cmd = lum->cmd; | |
780 | lur.ret_val = ret; | |
781 | if (ret >= 0) { | |
7bc53e94 | 782 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 783 | } else { |
7bc53e94 MD |
784 | /* |
785 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
786 | * error that are not caused by the transport, except if | |
787 | * we already have a more precise error message to | |
788 | * report. | |
789 | */ | |
64b2564e DG |
790 | if (ret > -LTTNG_UST_ERR) { |
791 | /* Translate code to UST error. */ | |
792 | switch (ret) { | |
793 | case -EEXIST: | |
794 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
795 | break; | |
796 | case -EINVAL: | |
797 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
798 | break; | |
799 | case -ENOENT: | |
800 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
801 | break; | |
802 | case -EPERM: | |
803 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
804 | break; | |
805 | case -ENOSYS: | |
806 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
807 | break; | |
808 | default: | |
809 | lur.ret_code = -LTTNG_UST_ERR; | |
810 | break; | |
811 | } | |
812 | } else { | |
7bc53e94 | 813 | lur.ret_code = ret; |
64b2564e | 814 | } |
46050b1a | 815 | } |
e6ea14c5 MD |
816 | if (ret >= 0) { |
817 | switch (lum->cmd) { | |
e6ea14c5 MD |
818 | case LTTNG_UST_TRACER_VERSION: |
819 | lur.u.version = lum->u.version; | |
820 | break; | |
821 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
822 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
823 | break; | |
824 | } | |
381c0f1e | 825 | } |
74d81a6c | 826 | DBG("Return value: %d", lur.ret_val); |
46050b1a | 827 | ret = send_reply(sock, &lur); |
193183fb | 828 | if (ret < 0) { |
7bc53e94 | 829 | DBG("error sending reply"); |
193183fb MD |
830 | goto error; |
831 | } | |
46050b1a | 832 | |
40003310 MD |
833 | /* |
834 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
835 | * after the reply. | |
836 | */ | |
7bc53e94 | 837 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
838 | switch (lum->cmd) { |
839 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
840 | len = ustcomm_send_unix_sock(sock, | |
841 | &args.field_list.entry, | |
842 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
843 | if (len < 0) { |
844 | ret = len; | |
845 | goto error; | |
846 | } | |
40003310 | 847 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 848 | ret = -EINVAL; |
40003310 MD |
849 | goto error; |
850 | } | |
851 | } | |
852 | } | |
ef9ff354 | 853 | |
381c0f1e | 854 | error: |
17dfb34b | 855 | ust_unlock(); |
d9e99d10 | 856 | |
37dddb65 MD |
857 | /* |
858 | * Performed delayed statedump operations outside of the UST | |
859 | * lock. We need to take the dynamic loader lock before we take | |
860 | * the UST lock internally within handle_pending_statedump(). | |
861 | */ | |
862 | handle_pending_statedump(sock_info); | |
246be17e | 863 | |
37dddb65 | 864 | return ret; |
246be17e PW |
865 | } |
866 | ||
46050b1a | 867 | static |
efe0de09 | 868 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
869 | { |
870 | int ret; | |
871 | ||
5b14aab3 MD |
872 | if (sock_info->root_handle != -1) { |
873 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
874 | if (ret) { | |
875 | ERR("Error unref root handle"); | |
876 | } | |
877 | sock_info->root_handle = -1; | |
878 | } | |
879 | sock_info->constructor_sem_posted = 0; | |
880 | ||
881 | /* | |
882 | * wait_shm_mmap, socket and notify socket are used by listener | |
883 | * threads outside of the ust lock, so we cannot tear them down | |
884 | * ourselves, because we cannot join on these threads. Leave | |
885 | * responsibility of cleaning up these resources to the OS | |
886 | * process exit. | |
887 | */ | |
888 | if (exiting) | |
889 | return; | |
890 | ||
46050b1a | 891 | if (sock_info->socket != -1) { |
e6973a89 | 892 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 893 | if (ret) { |
32ce8569 | 894 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
895 | } |
896 | sock_info->socket = -1; | |
897 | } | |
32ce8569 MD |
898 | if (sock_info->notify_socket != -1) { |
899 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
900 | if (ret) { | |
901 | ERR("Error closing ust notify socket"); | |
902 | } | |
903 | sock_info->notify_socket = -1; | |
904 | } | |
5b14aab3 | 905 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
906 | long page_size; |
907 | ||
908 | page_size = sysconf(_SC_PAGE_SIZE); | |
909 | if (page_size > 0) { | |
910 | ret = munmap(sock_info->wait_shm_mmap, page_size); | |
911 | if (ret) { | |
912 | ERR("Error unmapping wait shm"); | |
913 | } | |
7fc90dca MD |
914 | } |
915 | sock_info->wait_shm_mmap = NULL; | |
916 | } | |
917 | } | |
918 | ||
58d4b2a2 | 919 | /* |
33bbeb90 MD |
920 | * Using fork to set umask in the child process (not multi-thread safe). |
921 | * We deal with the shm_open vs ftruncate race (happening when the | |
922 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
923 | * safety against shm_unlink) by simply letting the mmap fail and | |
924 | * retrying after a few seconds. | |
925 | * For global shm, everybody has rw access to it until the sessiond | |
926 | * starts. | |
58d4b2a2 | 927 | */ |
7fc90dca | 928 | static |
58d4b2a2 | 929 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 930 | { |
7fc90dca | 931 | int wait_shm_fd, ret; |
58d4b2a2 | 932 | pid_t pid; |
44e073f5 | 933 | |
58d4b2a2 | 934 | /* |
33bbeb90 | 935 | * Try to open read-only. |
58d4b2a2 | 936 | */ |
33bbeb90 | 937 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 938 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
939 | int32_t tmp_read; |
940 | ssize_t len; | |
941 | size_t bytes_read = 0; | |
942 | ||
943 | /* | |
944 | * Try to read the fd. If unable to do so, try opening | |
945 | * it in write mode. | |
946 | */ | |
947 | do { | |
948 | len = read(wait_shm_fd, | |
949 | &((char *) &tmp_read)[bytes_read], | |
950 | sizeof(tmp_read) - bytes_read); | |
951 | if (len > 0) { | |
952 | bytes_read += len; | |
953 | } | |
954 | } while ((len < 0 && errno == EINTR) | |
955 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
956 | if (bytes_read != sizeof(tmp_read)) { | |
957 | ret = close(wait_shm_fd); | |
958 | if (ret) { | |
959 | ERR("close wait_shm_fd"); | |
960 | } | |
961 | goto open_write; | |
962 | } | |
58d4b2a2 MD |
963 | goto end; |
964 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
965 | /* | |
33bbeb90 MD |
966 | * Real-only open did not work, and it's not because the |
967 | * entry was not present. It's a failure that prohibits | |
968 | * using shm. | |
58d4b2a2 | 969 | */ |
7fc90dca | 970 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 971 | goto end; |
7fc90dca | 972 | } |
7aa76730 MD |
973 | |
974 | open_write: | |
7fc90dca | 975 | /* |
7aa76730 MD |
976 | * If the open failed because the file did not exist, or because |
977 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 978 | */ |
8c90a710 | 979 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 980 | pid = fork(); |
8c90a710 | 981 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
982 | if (pid > 0) { |
983 | int status; | |
984 | ||
985 | /* | |
986 | * Parent: wait for child to return, in which case the | |
987 | * shared memory map will have been created. | |
988 | */ | |
989 | pid = wait(&status); | |
b7d3cb32 | 990 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
991 | wait_shm_fd = -1; |
992 | goto end; | |
7fc90dca | 993 | } |
58d4b2a2 MD |
994 | /* |
995 | * Try to open read-only again after creation. | |
996 | */ | |
33bbeb90 | 997 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
998 | if (wait_shm_fd < 0) { |
999 | /* | |
1000 | * Real-only open did not work. It's a failure | |
1001 | * that prohibits using shm. | |
1002 | */ | |
1003 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1004 | goto end; | |
1005 | } | |
1006 | goto end; | |
1007 | } else if (pid == 0) { | |
1008 | int create_mode; | |
1009 | ||
1010 | /* Child */ | |
33bbeb90 | 1011 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1012 | if (sock_info->global) |
33bbeb90 | 1013 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1014 | /* |
1015 | * We're alone in a child process, so we can modify the | |
1016 | * process-wide umask. | |
1017 | */ | |
33bbeb90 | 1018 | umask(~create_mode); |
58d4b2a2 | 1019 | /* |
33bbeb90 MD |
1020 | * Try creating shm (or get rw access). |
1021 | * We don't do an exclusive open, because we allow other | |
1022 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1023 | */ |
1024 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1025 | O_RDWR | O_CREAT, create_mode); | |
1026 | if (wait_shm_fd >= 0) { | |
1027 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1028 | if (ret) { | |
1029 | PERROR("ftruncate"); | |
b0c1425d | 1030 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1031 | } |
b0c1425d | 1032 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1033 | } |
33bbeb90 MD |
1034 | /* |
1035 | * For local shm, we need to have rw access to accept | |
1036 | * opening it: this means the local sessiond will be | |
1037 | * able to wake us up. For global shm, we open it even | |
1038 | * if rw access is not granted, because the root.root | |
1039 | * sessiond will be able to override all rights and wake | |
1040 | * us up. | |
1041 | */ | |
1042 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1043 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1044 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1045 | } |
1046 | /* | |
33bbeb90 MD |
1047 | * The shm exists, but we cannot open it RW. Report |
1048 | * success. | |
58d4b2a2 | 1049 | */ |
5d3bc5ed | 1050 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1051 | } else { |
1052 | return -1; | |
7fc90dca | 1053 | } |
58d4b2a2 | 1054 | end: |
33bbeb90 MD |
1055 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1056 | struct stat statbuf; | |
1057 | ||
1058 | /* | |
1059 | * Ensure that our user is the owner of the shm file for | |
1060 | * local shm. If we do not own the file, it means our | |
1061 | * sessiond will not have access to wake us up (there is | |
1062 | * probably a rogue process trying to fake our | |
1063 | * sessiond). Fallback to polling method in this case. | |
1064 | */ | |
1065 | ret = fstat(wait_shm_fd, &statbuf); | |
1066 | if (ret) { | |
1067 | PERROR("fstat"); | |
1068 | goto error_close; | |
1069 | } | |
1070 | if (statbuf.st_uid != getuid()) | |
1071 | goto error_close; | |
1072 | } | |
58d4b2a2 | 1073 | return wait_shm_fd; |
33bbeb90 MD |
1074 | |
1075 | error_close: | |
1076 | ret = close(wait_shm_fd); | |
1077 | if (ret) { | |
1078 | PERROR("Error closing fd"); | |
1079 | } | |
1080 | return -1; | |
58d4b2a2 MD |
1081 | } |
1082 | ||
1083 | static | |
1084 | char *get_map_shm(struct sock_info *sock_info) | |
1085 | { | |
172d6b68 | 1086 | long page_size; |
58d4b2a2 MD |
1087 | int wait_shm_fd, ret; |
1088 | char *wait_shm_mmap; | |
1089 | ||
172d6b68 MD |
1090 | page_size = sysconf(_SC_PAGE_SIZE); |
1091 | if (page_size < 0) { | |
1092 | goto error; | |
1093 | } | |
1094 | ||
1095 | wait_shm_fd = get_wait_shm(sock_info, page_size); | |
58d4b2a2 MD |
1096 | if (wait_shm_fd < 0) { |
1097 | goto error; | |
44e073f5 | 1098 | } |
172d6b68 | 1099 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1100 | MAP_SHARED, wait_shm_fd, 0); |
7fc90dca MD |
1101 | /* close shm fd immediately after taking the mmap reference */ |
1102 | ret = close(wait_shm_fd); | |
1103 | if (ret) { | |
33bbeb90 MD |
1104 | PERROR("Error closing fd"); |
1105 | } | |
1106 | if (wait_shm_mmap == MAP_FAILED) { | |
1107 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1108 | goto error; | |
7fc90dca MD |
1109 | } |
1110 | return wait_shm_mmap; | |
1111 | ||
1112 | error: | |
1113 | return NULL; | |
1114 | } | |
1115 | ||
1116 | static | |
1117 | void wait_for_sessiond(struct sock_info *sock_info) | |
1118 | { | |
efe0de09 | 1119 | int ret; |
80e2814b | 1120 | |
3327ac33 | 1121 | if (ust_lock()) { |
7fc90dca MD |
1122 | goto quit; |
1123 | } | |
37ed587a MD |
1124 | if (wait_poll_fallback) { |
1125 | goto error; | |
1126 | } | |
7fc90dca MD |
1127 | if (!sock_info->wait_shm_mmap) { |
1128 | sock_info->wait_shm_mmap = get_map_shm(sock_info); | |
1129 | if (!sock_info->wait_shm_mmap) | |
1130 | goto error; | |
1131 | } | |
1132 | ust_unlock(); | |
1133 | ||
1134 | DBG("Waiting for %s apps sessiond", sock_info->name); | |
80e2814b MD |
1135 | /* Wait for futex wakeup */ |
1136 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap) == 0) { | |
1137 | ret = futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1138 | FUTEX_WAIT, 0, NULL, NULL, 0); | |
80e2814b | 1139 | if (ret < 0) { |
37ed587a MD |
1140 | if (errno == EFAULT) { |
1141 | wait_poll_fallback = 1; | |
a8b870ad | 1142 | DBG( |
37ed587a MD |
1143 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1144 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1145 | "Please upgrade your kernel " | |
1146 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1147 | "mainline). LTTng-UST will use polling mode fallback."); | |
cd27263b MD |
1148 | if (ust_debug()) |
1149 | PERROR("futex"); | |
37ed587a | 1150 | } |
80e2814b MD |
1151 | } |
1152 | } | |
7fc90dca MD |
1153 | return; |
1154 | ||
1155 | quit: | |
1156 | ust_unlock(); | |
1157 | return; | |
1158 | ||
1159 | error: | |
1160 | ust_unlock(); | |
7fc90dca | 1161 | return; |
46050b1a MD |
1162 | } |
1163 | ||
1ea11eab MD |
1164 | /* |
1165 | * This thread does not allocate any resource, except within | |
1166 | * handle_message, within mutex protection. This mutex protects against | |
1167 | * fork and exit. | |
98bf993f | 1168 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1169 | * is also protected by the mutex. |
1170 | */ | |
d9e99d10 MD |
1171 | static |
1172 | void *ust_listener_thread(void *arg) | |
1173 | { | |
1ea11eab | 1174 | struct sock_info *sock_info = arg; |
c0eedf81 | 1175 | int sock, ret, prev_connect_failed = 0, has_waited = 0; |
ff517991 | 1176 | long timeout; |
d9e99d10 | 1177 | |
9eb62b9c MD |
1178 | /* Restart trying to connect to the session daemon */ |
1179 | restart: | |
c0eedf81 MD |
1180 | if (prev_connect_failed) { |
1181 | /* Wait for sessiond availability with pipe */ | |
1182 | wait_for_sessiond(sock_info); | |
1183 | if (has_waited) { | |
1184 | has_waited = 0; | |
1185 | /* | |
1186 | * Sleep for 5 seconds before retrying after a | |
1187 | * sequence of failure / wait / failure. This | |
1188 | * deals with a killed or broken session daemon. | |
1189 | */ | |
1190 | sleep(5); | |
1191 | } | |
1192 | has_waited = 1; | |
1193 | prev_connect_failed = 0; | |
1194 | } | |
9eb62b9c | 1195 | |
1ea11eab | 1196 | if (sock_info->socket != -1) { |
e6973a89 | 1197 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1198 | if (ret) { |
32ce8569 MD |
1199 | ERR("Error closing %s ust cmd socket", |
1200 | sock_info->name); | |
1ea11eab MD |
1201 | } |
1202 | sock_info->socket = -1; | |
1203 | } | |
32ce8569 MD |
1204 | if (sock_info->notify_socket != -1) { |
1205 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1206 | if (ret) { | |
1207 | ERR("Error closing %s ust notify socket", | |
1208 | sock_info->name); | |
1209 | } | |
1210 | sock_info->notify_socket = -1; | |
1211 | } | |
46050b1a | 1212 | |
321f2351 MD |
1213 | /* |
1214 | * Register. We need to perform both connect and sending | |
1215 | * registration message before doing the next connect otherwise | |
1216 | * we may reach unix socket connect queue max limits and block | |
1217 | * on the 2nd connect while the session daemon is awaiting the | |
1218 | * first connect registration message. | |
1219 | */ | |
1220 | /* Connect cmd socket */ | |
1221 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1222 | if (ret < 0) { | |
1223 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1224 | prev_connect_failed = 1; | |
5b14aab3 | 1225 | |
3327ac33 | 1226 | if (ust_lock()) { |
321f2351 | 1227 | goto quit; |
32ce8569 | 1228 | } |
46050b1a | 1229 | |
e3426ddc | 1230 | /* |
321f2351 MD |
1231 | * If we cannot find the sessiond daemon, don't delay |
1232 | * constructor execution. | |
e3426ddc | 1233 | */ |
321f2351 MD |
1234 | ret = handle_register_done(sock_info); |
1235 | assert(!ret); | |
1236 | ust_unlock(); | |
1237 | goto restart; | |
27fe9f21 | 1238 | } |
321f2351 | 1239 | sock_info->socket = ret; |
27fe9f21 | 1240 | |
3327ac33 | 1241 | if (ust_lock()) { |
5b14aab3 MD |
1242 | goto quit; |
1243 | } | |
1244 | ||
46050b1a MD |
1245 | /* |
1246 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1247 | * process lifetime, so we ensure we get ID which is statically |
1248 | * assigned to the root handle. | |
46050b1a MD |
1249 | */ |
1250 | if (sock_info->root_handle == -1) { | |
1251 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1252 | if (ret < 0) { |
46050b1a | 1253 | ERR("Error creating root handle"); |
46050b1a MD |
1254 | goto quit; |
1255 | } | |
1256 | sock_info->root_handle = ret; | |
9eb62b9c | 1257 | } |
1ea11eab | 1258 | |
32ce8569 | 1259 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1260 | if (ret < 0) { |
32ce8569 MD |
1261 | ERR("Error registering to %s ust cmd socket", |
1262 | sock_info->name); | |
c0eedf81 | 1263 | prev_connect_failed = 1; |
11ff9c7d MD |
1264 | /* |
1265 | * If we cannot register to the sessiond daemon, don't | |
1266 | * delay constructor execution. | |
1267 | */ | |
edaa1431 | 1268 | ret = handle_register_done(sock_info); |
11ff9c7d | 1269 | assert(!ret); |
17dfb34b | 1270 | ust_unlock(); |
9eb62b9c MD |
1271 | goto restart; |
1272 | } | |
321f2351 MD |
1273 | |
1274 | ust_unlock(); | |
1275 | ||
1276 | /* Connect notify socket */ | |
1277 | ret = ustcomm_connect_unix_sock(sock_info->sock_path); | |
1278 | if (ret < 0) { | |
1279 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); | |
1280 | prev_connect_failed = 1; | |
1281 | ||
3327ac33 | 1282 | if (ust_lock()) { |
321f2351 MD |
1283 | goto quit; |
1284 | } | |
1285 | ||
1286 | /* | |
1287 | * If we cannot find the sessiond daemon, don't delay | |
1288 | * constructor execution. | |
1289 | */ | |
1290 | ret = handle_register_done(sock_info); | |
1291 | assert(!ret); | |
1292 | ust_unlock(); | |
1293 | goto restart; | |
1294 | } | |
1295 | sock_info->notify_socket = ret; | |
1296 | ||
1297 | timeout = get_notify_sock_timeout(); | |
1298 | if (timeout >= 0) { | |
1299 | /* | |
1300 | * Give at least 10ms to sessiond to reply to | |
1301 | * notifications. | |
1302 | */ | |
1303 | if (timeout < 10) | |
1304 | timeout = 10; | |
1305 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1306 | timeout); | |
1307 | if (ret < 0) { | |
1308 | WARN("Error setting socket receive timeout"); | |
1309 | } | |
1310 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1311 | timeout); | |
1312 | if (ret < 0) { | |
1313 | WARN("Error setting socket send timeout"); | |
1314 | } | |
1315 | } else if (timeout < -1) { | |
1316 | WARN("Unsupported timeout value %ld", timeout); | |
1317 | } | |
1318 | ||
3327ac33 | 1319 | if (ust_lock()) { |
321f2351 MD |
1320 | goto quit; |
1321 | } | |
1322 | ||
32ce8569 MD |
1323 | ret = register_to_sessiond(sock_info->notify_socket, |
1324 | USTCTL_SOCKET_NOTIFY); | |
1325 | if (ret < 0) { | |
1326 | ERR("Error registering to %s ust notify socket", | |
1327 | sock_info->name); | |
1328 | prev_connect_failed = 1; | |
1329 | /* | |
1330 | * If we cannot register to the sessiond daemon, don't | |
1331 | * delay constructor execution. | |
1332 | */ | |
1333 | ret = handle_register_done(sock_info); | |
1334 | assert(!ret); | |
1335 | ust_unlock(); | |
1336 | goto restart; | |
1337 | } | |
1338 | sock = sock_info->socket; | |
1339 | ||
17dfb34b | 1340 | ust_unlock(); |
46050b1a | 1341 | |
d9e99d10 MD |
1342 | for (;;) { |
1343 | ssize_t len; | |
57773204 | 1344 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1345 | |
57773204 | 1346 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1347 | switch (len) { |
1348 | case 0: /* orderly shutdown */ | |
7dd08bec | 1349 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1350 | if (ust_lock()) { |
d5e1fea6 MD |
1351 | goto quit; |
1352 | } | |
8236ba10 MD |
1353 | /* |
1354 | * Either sessiond has shutdown or refused us by closing the socket. | |
1355 | * In either case, we don't want to delay construction execution, | |
1356 | * and we need to wait before retry. | |
1357 | */ | |
1358 | prev_connect_failed = 1; | |
1359 | /* | |
1360 | * If we cannot register to the sessiond daemon, don't | |
1361 | * delay constructor execution. | |
1362 | */ | |
1363 | ret = handle_register_done(sock_info); | |
1364 | assert(!ret); | |
1365 | ust_unlock(); | |
d9e99d10 | 1366 | goto end; |
e7723462 | 1367 | case sizeof(lum): |
74d81a6c | 1368 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1369 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1370 | if (ret) { |
11ff9c7d | 1371 | ERR("Error handling message for %s socket", sock_info->name); |
d9e99d10 MD |
1372 | } |
1373 | continue; | |
7bc53e94 MD |
1374 | default: |
1375 | if (len < 0) { | |
1376 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1377 | } else { | |
1378 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1379 | } | |
1380 | if (len == -ECONNRESET) { | |
1381 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1382 | goto end; |
1383 | } | |
1384 | goto end; | |
d9e99d10 MD |
1385 | } |
1386 | ||
1387 | } | |
1388 | end: | |
3327ac33 | 1389 | if (ust_lock()) { |
d5e1fea6 MD |
1390 | goto quit; |
1391 | } | |
f59ed768 MD |
1392 | /* Cleanup socket handles before trying to reconnect */ |
1393 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1394 | ust_unlock(); | |
9eb62b9c | 1395 | goto restart; /* try to reconnect */ |
e33f3265 | 1396 | |
1ea11eab | 1397 | quit: |
e33f3265 | 1398 | ust_unlock(); |
3327ac33 MD |
1399 | |
1400 | pthread_mutex_lock(&ust_exit_mutex); | |
1401 | sock_info->thread_active = 0; | |
1402 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1403 | return NULL; |
1404 | } | |
1405 | ||
2594a5b4 MD |
1406 | /* |
1407 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1408 | */ | |
1409 | __attribute__((weak)) | |
1410 | void lttng_ust_malloc_wrapper_init(void) | |
1411 | { | |
1412 | } | |
1413 | ||
2691221a MD |
1414 | /* |
1415 | * sessiond monitoring thread: monitor presence of global and per-user | |
1416 | * sessiond by polling the application common named pipe. | |
1417 | */ | |
edaa1431 | 1418 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1419 | { |
11ff9c7d | 1420 | struct timespec constructor_timeout; |
ae6a58bf | 1421 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1422 | pthread_attr_t thread_attr; |
cf12a773 | 1423 | int timeout_mode; |
2691221a MD |
1424 | int ret; |
1425 | ||
edaa1431 MD |
1426 | if (uatomic_xchg(&initialized, 1) == 1) |
1427 | return; | |
1428 | ||
eddd8d5d MD |
1429 | /* |
1430 | * Fixup interdependency between TLS fixup mutex (which happens | |
1431 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1432 | * the ust lock. | |
1433 | */ | |
3df53fae | 1434 | lttng_fixup_urcu_bp_tls(); |
f645cfa7 | 1435 | lttng_fixup_ringbuffer_tls(); |
4158a15a | 1436 | lttng_fixup_vtid_tls(); |
a903623f | 1437 | lttng_fixup_nest_count_tls(); |
009745db | 1438 | lttng_fixup_procname_tls(); |
d58d1454 | 1439 | lttng_fixup_ust_mutex_nest_tls(); |
eddd8d5d | 1440 | |
edaa1431 MD |
1441 | /* |
1442 | * We want precise control over the order in which we construct | |
1443 | * our sub-libraries vs starting to receive commands from | |
1444 | * sessiond (otherwise leading to errors when trying to create | |
1445 | * sessiond before the init functions are completed). | |
1446 | */ | |
2691221a | 1447 | init_usterr(); |
edaa1431 | 1448 | init_tracepoint(); |
bd703713 | 1449 | lttng_ust_baddr_statedump_init(); |
7dd08bec MD |
1450 | lttng_ring_buffer_metadata_client_init(); |
1451 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1452 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1453 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1454 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1455 | lttng_perf_counter_init(); |
a0a3bef9 | 1456 | lttng_context_init(); |
2594a5b4 MD |
1457 | /* |
1458 | * Invoke ust malloc wrapper init before starting other threads. | |
1459 | */ | |
1460 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1461 | |
ff517991 | 1462 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1463 | |
95259bd0 | 1464 | ret = sem_init(&constructor_wait, 0, 0); |
11ff9c7d MD |
1465 | assert(!ret); |
1466 | ||
8d20bf54 | 1467 | ret = setup_local_apps(); |
2691221a | 1468 | if (ret) { |
9ec6895c | 1469 | DBG("local apps setup returned %d", ret); |
2691221a | 1470 | } |
ae6a58bf WP |
1471 | |
1472 | /* A new thread created by pthread_create inherits the signal mask | |
1473 | * from the parent. To avoid any signal being received by the | |
1474 | * listener thread, we block all signals temporarily in the parent, | |
1475 | * while we create the listener thread. | |
1476 | */ | |
1477 | sigfillset(&sig_all_blocked); | |
1478 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1479 | if (ret) { | |
d94d802c | 1480 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1481 | } |
1482 | ||
1879f67f MG |
1483 | ret = pthread_attr_init(&thread_attr); |
1484 | if (ret) { | |
1485 | ERR("pthread_attr_init: %s", strerror(ret)); | |
1486 | } | |
1487 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
1488 | if (ret) { | |
1489 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
1490 | } | |
1491 | ||
c0bbbd5a | 1492 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1493 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, |
dde70ea0 | 1494 | ust_listener_thread, &global_apps); |
d94d802c MD |
1495 | if (ret) { |
1496 | ERR("pthread_create global: %s", strerror(ret)); | |
1497 | } | |
e33f3265 | 1498 | global_apps.thread_active = 1; |
c0bbbd5a | 1499 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1500 | |
8d20bf54 | 1501 | if (local_apps.allowed) { |
c0bbbd5a | 1502 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1503 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 1504 | ust_listener_thread, &local_apps); |
d94d802c MD |
1505 | if (ret) { |
1506 | ERR("pthread_create local: %s", strerror(ret)); | |
1507 | } | |
e33f3265 | 1508 | local_apps.thread_active = 1; |
c0bbbd5a | 1509 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
1510 | } else { |
1511 | handle_register_done(&local_apps); | |
1512 | } | |
1879f67f MG |
1513 | ret = pthread_attr_destroy(&thread_attr); |
1514 | if (ret) { | |
1515 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
1516 | } | |
8d20bf54 | 1517 | |
ae6a58bf WP |
1518 | /* Restore original signal mask in parent */ |
1519 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
1520 | if (ret) { | |
d94d802c | 1521 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1522 | } |
1523 | ||
cf12a773 MD |
1524 | switch (timeout_mode) { |
1525 | case 1: /* timeout wait */ | |
95259bd0 MD |
1526 | do { |
1527 | ret = sem_timedwait(&constructor_wait, | |
1528 | &constructor_timeout); | |
1529 | } while (ret < 0 && errno == EINTR); | |
cf12a773 | 1530 | if (ret < 0 && errno == ETIMEDOUT) { |
7dd08bec | 1531 | ERR("Timed out waiting for lttng-sessiond"); |
cf12a773 MD |
1532 | } else { |
1533 | assert(!ret); | |
1534 | } | |
1535 | break; | |
7b766b16 | 1536 | case -1:/* wait forever */ |
95259bd0 MD |
1537 | do { |
1538 | ret = sem_wait(&constructor_wait); | |
1539 | } while (ret < 0 && errno == EINTR); | |
11ff9c7d | 1540 | assert(!ret); |
cf12a773 | 1541 | break; |
7b766b16 | 1542 | case 0: /* no timeout */ |
cf12a773 | 1543 | break; |
11ff9c7d | 1544 | } |
2691221a MD |
1545 | } |
1546 | ||
17dfb34b MD |
1547 | static |
1548 | void lttng_ust_cleanup(int exiting) | |
1549 | { | |
efe0de09 | 1550 | cleanup_sock_info(&global_apps, exiting); |
17dfb34b | 1551 | if (local_apps.allowed) { |
efe0de09 | 1552 | cleanup_sock_info(&local_apps, exiting); |
17dfb34b | 1553 | } |
efe0de09 MD |
1554 | /* |
1555 | * The teardown in this function all affect data structures | |
1556 | * accessed under the UST lock by the listener thread. This | |
1557 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
1558 | * that none of these threads are accessing this data at this | |
1559 | * point. | |
1560 | */ | |
17dfb34b | 1561 | lttng_ust_abi_exit(); |
003fedf4 | 1562 | lttng_ust_events_exit(); |
a0a3bef9 | 1563 | lttng_context_exit(); |
d58d1454 | 1564 | lttng_perf_counter_exit(); |
34a91bdb | 1565 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 1566 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 1567 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
1568 | lttng_ring_buffer_client_overwrite_exit(); |
1569 | lttng_ring_buffer_metadata_client_exit(); | |
bd703713 | 1570 | lttng_ust_baddr_statedump_destroy(); |
17dfb34b MD |
1571 | exit_tracepoint(); |
1572 | if (!exiting) { | |
1573 | /* Reinitialize values for fork */ | |
1574 | sem_count = 2; | |
1575 | lttng_ust_comm_should_quit = 0; | |
1576 | initialized = 0; | |
1577 | } | |
1578 | } | |
1579 | ||
edaa1431 | 1580 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
1581 | { |
1582 | int ret; | |
1583 | ||
9eb62b9c MD |
1584 | /* |
1585 | * Using pthread_cancel here because: | |
1586 | * A) we don't want to hang application teardown. | |
1587 | * B) the thread is not allocating any resource. | |
1588 | */ | |
1ea11eab MD |
1589 | |
1590 | /* | |
1591 | * Require the communication thread to quit. Synchronize with | |
1592 | * mutexes to ensure it is not in a mutex critical section when | |
1593 | * pthread_cancel is later called. | |
1594 | */ | |
3327ac33 | 1595 | ust_lock_nocheck(); |
1ea11eab | 1596 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 1597 | ust_unlock(); |
1ea11eab | 1598 | |
3327ac33 | 1599 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 1600 | /* cancel threads */ |
e33f3265 MD |
1601 | if (global_apps.thread_active) { |
1602 | ret = pthread_cancel(global_apps.ust_listener); | |
1603 | if (ret) { | |
1604 | ERR("Error cancelling global ust listener thread: %s", | |
1605 | strerror(ret)); | |
1606 | } else { | |
1607 | global_apps.thread_active = 0; | |
1608 | } | |
2691221a | 1609 | } |
e33f3265 | 1610 | if (local_apps.thread_active) { |
8d20bf54 MD |
1611 | ret = pthread_cancel(local_apps.ust_listener); |
1612 | if (ret) { | |
d94d802c MD |
1613 | ERR("Error cancelling local ust listener thread: %s", |
1614 | strerror(ret)); | |
e33f3265 MD |
1615 | } else { |
1616 | local_apps.thread_active = 0; | |
8d20bf54 | 1617 | } |
8d20bf54 | 1618 | } |
3327ac33 | 1619 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1620 | |
efe0de09 MD |
1621 | /* |
1622 | * Do NOT join threads: use of sys_futex makes it impossible to | |
1623 | * join the threads without using async-cancel, but async-cancel | |
1624 | * is delivered by a signal, which could hit the target thread | |
1625 | * anywhere in its code path, including while the ust_lock() is | |
1626 | * held, causing a deadlock for the other thread. Let the OS | |
1627 | * cleanup the threads if there are stalled in a syscall. | |
1628 | */ | |
17dfb34b | 1629 | lttng_ust_cleanup(1); |
2691221a | 1630 | } |
e822f505 MD |
1631 | |
1632 | /* | |
1633 | * We exclude the worker threads across fork and clone (except | |
1634 | * CLONE_VM), because these system calls only keep the forking thread | |
1635 | * running in the child. Therefore, we don't want to call fork or clone | |
1636 | * in the middle of an tracepoint or ust tracing state modification. | |
1637 | * Holding this mutex protects these structures across fork and clone. | |
1638 | */ | |
b728d87e | 1639 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
1640 | { |
1641 | /* | |
1642 | * Disable signals. This is to avoid that the child intervenes | |
1643 | * before it is properly setup for tracing. It is safer to | |
1644 | * disable all signals, because then we know we are not breaking | |
1645 | * anything by restoring the original mask. | |
1646 | */ | |
1647 | sigset_t all_sigs; | |
1648 | int ret; | |
1649 | ||
8c90a710 | 1650 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1651 | return; |
e822f505 MD |
1652 | /* Disable signals */ |
1653 | sigfillset(&all_sigs); | |
b728d87e | 1654 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
1655 | if (ret == -1) { |
1656 | PERROR("sigprocmask"); | |
1657 | } | |
458d678c PW |
1658 | |
1659 | pthread_mutex_lock(&ust_fork_mutex); | |
1660 | ||
3327ac33 | 1661 | ust_lock_nocheck(); |
e822f505 MD |
1662 | rcu_bp_before_fork(); |
1663 | } | |
1664 | ||
b728d87e | 1665 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
1666 | { |
1667 | int ret; | |
1668 | ||
17dfb34b MD |
1669 | DBG("process %d", getpid()); |
1670 | ust_unlock(); | |
458d678c PW |
1671 | |
1672 | pthread_mutex_unlock(&ust_fork_mutex); | |
1673 | ||
e822f505 | 1674 | /* Restore signals */ |
23c8854a | 1675 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
1676 | if (ret == -1) { |
1677 | PERROR("sigprocmask"); | |
1678 | } | |
1679 | } | |
1680 | ||
b728d87e | 1681 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 1682 | { |
8c90a710 | 1683 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1684 | return; |
17dfb34b | 1685 | DBG("process %d", getpid()); |
e822f505 MD |
1686 | rcu_bp_after_fork_parent(); |
1687 | /* Release mutexes and reenable signals */ | |
b728d87e | 1688 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
1689 | } |
1690 | ||
17dfb34b MD |
1691 | /* |
1692 | * After fork, in the child, we need to cleanup all the leftover state, | |
1693 | * except the worker thread which already magically disappeared thanks | |
1694 | * to the weird Linux fork semantics. After tyding up, we call | |
1695 | * lttng_ust_init() again to start over as a new PID. | |
1696 | * | |
1697 | * This is meant for forks() that have tracing in the child between the | |
1698 | * fork and following exec call (if there is any). | |
1699 | */ | |
b728d87e | 1700 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 1701 | { |
8c90a710 | 1702 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1703 | return; |
17dfb34b | 1704 | DBG("process %d", getpid()); |
e822f505 MD |
1705 | /* Release urcu mutexes */ |
1706 | rcu_bp_after_fork_child(); | |
17dfb34b | 1707 | lttng_ust_cleanup(0); |
a93bfc45 | 1708 | lttng_context_vtid_reset(); |
e822f505 | 1709 | /* Release mutexes and reenable signals */ |
b728d87e | 1710 | ust_after_fork_common(restore_sigset); |
318dfea9 | 1711 | lttng_ust_init(); |
e822f505 | 1712 | } |
95c25348 | 1713 | |
246be17e | 1714 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
1715 | { |
1716 | struct sock_info *sock_info = owner; | |
37dddb65 | 1717 | sock_info->statedump_pending = 1; |
95c25348 | 1718 | } |