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