Commit | Line | Data |
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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 |
b4051ad8 | 23 | #include <stddef.h> |
fb31eb73 | 24 | #include <stdint.h> |
2691221a MD |
25 | #include <sys/types.h> |
26 | #include <sys/socket.h> | |
7fc90dca MD |
27 | #include <sys/mman.h> |
28 | #include <sys/stat.h> | |
58d4b2a2 MD |
29 | #include <sys/types.h> |
30 | #include <sys/wait.h> | |
b2292d85 | 31 | #include <dlfcn.h> |
7fc90dca | 32 | #include <fcntl.h> |
2691221a MD |
33 | #include <unistd.h> |
34 | #include <errno.h> | |
d9e99d10 | 35 | #include <pthread.h> |
11ff9c7d MD |
36 | #include <semaphore.h> |
37 | #include <time.h> | |
1ea11eab | 38 | #include <assert.h> |
e822f505 | 39 | #include <signal.h> |
6f97f9c2 | 40 | #include <limits.h> |
95259bd0 | 41 | #include <urcu/uatomic.h> |
80e2814b | 42 | #include <urcu/futex.h> |
c117fb1b | 43 | #include <urcu/compiler.h> |
1ea11eab | 44 | |
b72687b8 | 45 | #include <lttng/align.h> |
4318ae1b | 46 | #include <lttng/ust-events.h> |
4318ae1b | 47 | #include <lttng/ust-abi.h> |
4318ae1b | 48 | #include <lttng/ust.h> |
7bc53e94 | 49 | #include <lttng/ust-error.h> |
74d81a6c | 50 | #include <lttng/ust-ctl.h> |
8c90a710 | 51 | #include <urcu/tls-compat.h> |
44c72f10 | 52 | #include <ust-comm.h> |
6548fca4 | 53 | #include <ust-fd.h> |
44c72f10 | 54 | #include <usterr-signal-safe.h> |
cd54f6d9 | 55 | #include <helper.h> |
44c72f10 | 56 | #include "tracepoint-internal.h" |
7dd08bec | 57 | #include "lttng-tracer-core.h" |
08114193 | 58 | #include "compat.h" |
6f97f9c2 | 59 | #include "../libringbuffer/rb-init.h" |
cf73e0fe | 60 | #include "lttng-ust-statedump.h" |
f9364363 | 61 | #include "clock.h" |
5e1b7b8b | 62 | #include "../libringbuffer/getcpu.h" |
13efba44 | 63 | #include "getenv.h" |
92495593 | 64 | #include "ust-events-internal.h" |
edaa1431 | 65 | |
b2292d85 | 66 | /* Concatenate lttng ust shared library name with its major version number. */ |
6be9efc1 | 67 | #define LTTNG_UST_LIB_SO_NAME "liblttng-ust.so." __ust_stringify(CONFIG_LTTNG_UST_LIBRARY_VERSION_MAJOR) |
b2292d85 | 68 | |
edaa1431 MD |
69 | /* |
70 | * Has lttng ust comm constructor been called ? | |
71 | */ | |
72 | static int initialized; | |
73 | ||
1ea11eab | 74 | /* |
17dfb34b MD |
75 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
76 | * Held when handling a command, also held by fork() to deal with | |
77 | * removal of threads, and by exit path. | |
3327ac33 MD |
78 | * |
79 | * The UST lock is the centralized mutex across UST tracing control and | |
80 | * probe registration. | |
81 | * | |
82 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 83 | * |
4770bd47 MD |
84 | * ust_fork_mutex must never nest in ust_mutex. |
85 | * | |
d58d1454 MD |
86 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
87 | * counter lazy initialization called by events within the statedump, | |
88 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
89 | * |
90 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
91 | * it is taken within the library constructor. | |
c1be081a MD |
92 | * |
93 | * The ust fd tracker lock nests within the ust_mutex. | |
3327ac33 MD |
94 | */ |
95 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
96 | ||
d58d1454 | 97 | /* Allow nesting the ust_mutex within the same thread. */ |
16adecf1 | 98 | static DEFINE_URCU_TLS(int, ust_mutex_nest); |
d58d1454 | 99 | |
3327ac33 MD |
100 | /* |
101 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
102 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
103 | * internal libc lock, cannot nest within ust_mutex. | |
104 | * | |
105 | * It never nests within a ust_mutex. | |
1ea11eab | 106 | */ |
3327ac33 | 107 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 108 | |
458d678c PW |
109 | /* |
110 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
111 | * prevents the dynamic loader lock to be taken (by base address statedump | |
112 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
113 | * the dynamic loader lock. | |
114 | */ | |
115 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
116 | ||
1ea11eab MD |
117 | /* Should the ust comm thread quit ? */ |
118 | static int lttng_ust_comm_should_quit; | |
119 | ||
07b57e5e MD |
120 | /* |
121 | * This variable can be tested by applications to check whether | |
122 | * lttng-ust is loaded. They simply have to define their own | |
123 | * "lttng_ust_loaded" weak symbol, and test it. It is set to 1 by the | |
124 | * library constructor. | |
125 | */ | |
126 | int lttng_ust_loaded __attribute__((weak)); | |
127 | ||
3327ac33 | 128 | /* |
d58d1454 | 129 | * Return 0 on success, -1 if should quit. |
3327ac33 | 130 | * The lock is taken in both cases. |
d58d1454 | 131 | * Signal-safe. |
3327ac33 MD |
132 | */ |
133 | int ust_lock(void) | |
134 | { | |
d58d1454 | 135 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 136 | int ret, oldstate; |
d58d1454 | 137 | |
e446ad80 MD |
138 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
139 | if (ret) { | |
140 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
141 | } | |
142 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
143 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
144 | } | |
d58d1454 MD |
145 | sigfillset(&sig_all_blocked); |
146 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
147 | if (ret) { | |
148 | ERR("pthread_sigmask: %s", strerror(ret)); | |
149 | } | |
150 | if (!URCU_TLS(ust_mutex_nest)++) | |
151 | pthread_mutex_lock(&ust_mutex); | |
152 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
153 | if (ret) { | |
154 | ERR("pthread_sigmask: %s", strerror(ret)); | |
155 | } | |
3327ac33 MD |
156 | if (lttng_ust_comm_should_quit) { |
157 | return -1; | |
158 | } else { | |
159 | return 0; | |
160 | } | |
161 | } | |
162 | ||
163 | /* | |
164 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
165 | * they are already nested within the dynamic loader lock, and therefore | |
166 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 167 | * Signal-safe. |
3327ac33 MD |
168 | */ |
169 | void ust_lock_nocheck(void) | |
170 | { | |
d58d1454 | 171 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 172 | int ret, oldstate; |
d58d1454 | 173 | |
e446ad80 MD |
174 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
175 | if (ret) { | |
176 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
177 | } | |
178 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
179 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
180 | } | |
d58d1454 MD |
181 | sigfillset(&sig_all_blocked); |
182 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
183 | if (ret) { | |
184 | ERR("pthread_sigmask: %s", strerror(ret)); | |
185 | } | |
186 | if (!URCU_TLS(ust_mutex_nest)++) | |
187 | pthread_mutex_lock(&ust_mutex); | |
188 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
189 | if (ret) { | |
190 | ERR("pthread_sigmask: %s", strerror(ret)); | |
191 | } | |
3327ac33 MD |
192 | } |
193 | ||
d58d1454 MD |
194 | /* |
195 | * Signal-safe. | |
196 | */ | |
3327ac33 MD |
197 | void ust_unlock(void) |
198 | { | |
d58d1454 | 199 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 200 | int ret, oldstate; |
d58d1454 MD |
201 | |
202 | sigfillset(&sig_all_blocked); | |
203 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
204 | if (ret) { | |
205 | ERR("pthread_sigmask: %s", strerror(ret)); | |
206 | } | |
207 | if (!--URCU_TLS(ust_mutex_nest)) | |
208 | pthread_mutex_unlock(&ust_mutex); | |
209 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
210 | if (ret) { | |
211 | ERR("pthread_sigmask: %s", strerror(ret)); | |
212 | } | |
e446ad80 MD |
213 | ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); |
214 | if (ret) { | |
215 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
216 | } | |
217 | if (oldstate != PTHREAD_CANCEL_DISABLE) { | |
218 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
219 | } | |
3327ac33 MD |
220 | } |
221 | ||
11ff9c7d MD |
222 | /* |
223 | * Wait for either of these before continuing to the main | |
224 | * program: | |
225 | * - the register_done message from sessiond daemon | |
226 | * (will let the sessiond daemon enable sessions before main | |
227 | * starts.) | |
228 | * - sessiond daemon is not reachable. | |
229 | * - timeout (ensuring applications are resilient to session | |
230 | * daemon problems). | |
231 | */ | |
232 | static sem_t constructor_wait; | |
950aab0c MD |
233 | /* |
234 | * Doing this for both the global and local sessiond. | |
235 | */ | |
eb0e6022 GAPG |
236 | enum { |
237 | sem_count_initial_value = 4, | |
238 | }; | |
239 | ||
240 | static int sem_count = sem_count_initial_value; | |
11ff9c7d | 241 | |
e8508a49 MD |
242 | /* |
243 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
244 | * from liblttng-ust does not execute the pre/post fork handlers. | |
245 | */ | |
8c90a710 | 246 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 247 | |
1ea11eab MD |
248 | /* |
249 | * Info about socket and associated listener thread. | |
250 | */ | |
251 | struct sock_info { | |
11ff9c7d | 252 | const char *name; |
1ea11eab | 253 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 254 | int root_handle; |
eb0e6022 | 255 | int registration_done; |
8d20bf54 | 256 | int allowed; |
44e073f5 | 257 | int global; |
e33f3265 | 258 | int thread_active; |
7fc90dca MD |
259 | |
260 | char sock_path[PATH_MAX]; | |
261 | int socket; | |
32ce8569 | 262 | int notify_socket; |
7fc90dca MD |
263 | |
264 | char wait_shm_path[PATH_MAX]; | |
265 | char *wait_shm_mmap; | |
37dddb65 MD |
266 | /* Keep track of lazy state dump not performed yet. */ |
267 | int statedump_pending; | |
eb0e6022 | 268 | int initial_statedump_done; |
94be38e8 | 269 | /* Keep procname for statedump */ |
0db3d6ee | 270 | char procname[LTTNG_UST_ABI_PROCNAME_LEN]; |
1ea11eab | 271 | }; |
2691221a MD |
272 | |
273 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 274 | struct sock_info global_apps = { |
11ff9c7d | 275 | .name = "global", |
44e073f5 | 276 | .global = 1, |
7fc90dca | 277 | |
46050b1a | 278 | .root_handle = -1, |
eb0e6022 | 279 | .registration_done = 0, |
060577e3 | 280 | .allowed = 0, |
e33f3265 | 281 | .thread_active = 0, |
7fc90dca | 282 | |
32ce8569 | 283 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 284 | .socket = -1, |
32ce8569 | 285 | .notify_socket = -1, |
7fc90dca | 286 | |
32ce8569 | 287 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 288 | |
37dddb65 | 289 | .statedump_pending = 0, |
eb0e6022 | 290 | .initial_statedump_done = 0, |
94be38e8 | 291 | .procname[0] = '\0' |
1ea11eab | 292 | }; |
2691221a MD |
293 | |
294 | /* TODO: allow global_apps_sock_path override */ | |
295 | ||
1ea11eab | 296 | struct sock_info local_apps = { |
11ff9c7d | 297 | .name = "local", |
44e073f5 | 298 | .global = 0, |
46050b1a | 299 | .root_handle = -1, |
eb0e6022 | 300 | .registration_done = 0, |
8d20bf54 | 301 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 302 | .thread_active = 0, |
7fc90dca MD |
303 | |
304 | .socket = -1, | |
32ce8569 | 305 | .notify_socket = -1, |
95c25348 | 306 | |
37dddb65 | 307 | .statedump_pending = 0, |
eb0e6022 | 308 | .initial_statedump_done = 0, |
94be38e8 | 309 | .procname[0] = '\0' |
1ea11eab | 310 | }; |
2691221a | 311 | |
37ed587a MD |
312 | static int wait_poll_fallback; |
313 | ||
74d81a6c MD |
314 | static const char *cmd_name_mapping[] = { |
315 | [ LTTNG_UST_RELEASE ] = "Release", | |
316 | [ LTTNG_UST_SESSION ] = "Create Session", | |
317 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
318 | ||
319 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
320 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
321 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
322 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
323 | ||
d8d2416d FD |
324 | [ LTTNG_UST_EVENT_NOTIFIER_GROUP_CREATE ] = "Create event notifier group", |
325 | ||
74d81a6c MD |
326 | /* Session FD commands */ |
327 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
328 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
329 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
330 | ||
331 | /* Channel FD commands */ | |
332 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
333 | [ LTTNG_UST_EVENT ] = "Create Event", | |
334 | ||
335 | /* Event and Channel FD commands */ | |
336 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
337 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
338 | ||
339 | /* Event, Channel and Session commands */ | |
340 | [ LTTNG_UST_ENABLE ] = "Enable", | |
341 | [ LTTNG_UST_DISABLE ] = "Disable", | |
342 | ||
343 | /* Tracepoint list commands */ | |
344 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
345 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
346 | ||
347 | /* Event FD commands */ | |
348 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 349 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
d8d2416d FD |
350 | |
351 | /* Event notifier group commands */ | |
352 | [ LTTNG_UST_EVENT_NOTIFIER_CREATE ] = "Create event notifier", | |
74d81a6c MD |
353 | }; |
354 | ||
ff517991 MD |
355 | static const char *str_timeout; |
356 | static int got_timeout_env; | |
357 | ||
7dd08bec | 358 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 359 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 360 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 361 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
362 | extern void lttng_ring_buffer_metadata_client_init(void); |
363 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 364 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 365 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 366 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 367 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 368 | |
060577e3 JR |
369 | static char *get_map_shm(struct sock_info *sock_info); |
370 | ||
405be658 MD |
371 | ssize_t lttng_ust_read(int fd, void *buf, size_t len) |
372 | { | |
373 | ssize_t ret; | |
374 | size_t copied = 0, to_copy = len; | |
375 | ||
376 | do { | |
377 | ret = read(fd, buf + copied, to_copy); | |
378 | if (ret > 0) { | |
379 | copied += ret; | |
380 | to_copy -= ret; | |
381 | } | |
382 | } while ((ret > 0 && to_copy > 0) | |
383 | || (ret < 0 && errno == EINTR)); | |
384 | if (ret > 0) { | |
385 | ret = copied; | |
386 | } | |
387 | return ret; | |
388 | } | |
3c6f6263 AM |
389 | /* |
390 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
391 | * pointer. | |
392 | */ | |
393 | static | |
394 | const char *get_lttng_home_dir(void) | |
395 | { | |
396 | const char *val; | |
397 | ||
6f626d28 | 398 | val = (const char *) lttng_getenv("LTTNG_HOME"); |
3c6f6263 AM |
399 | if (val != NULL) { |
400 | return val; | |
401 | } | |
6f626d28 | 402 | return (const char *) lttng_getenv("HOME"); |
3c6f6263 AM |
403 | } |
404 | ||
a903623f MD |
405 | /* |
406 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
407 | */ | |
408 | static | |
409 | void lttng_fixup_nest_count_tls(void) | |
410 | { | |
8c90a710 | 411 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
412 | } |
413 | ||
d58d1454 MD |
414 | static |
415 | void lttng_fixup_ust_mutex_nest_tls(void) | |
416 | { | |
417 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
418 | } | |
419 | ||
1556a549 MD |
420 | /* |
421 | * Fixup urcu bp TLS. | |
422 | */ | |
423 | static | |
424 | void lttng_fixup_urcu_bp_tls(void) | |
425 | { | |
426 | rcu_read_lock(); | |
427 | rcu_read_unlock(); | |
428 | } | |
429 | ||
c362addf MD |
430 | void lttng_ust_fixup_tls(void) |
431 | { | |
432 | lttng_fixup_urcu_bp_tls(); | |
433 | lttng_fixup_ringbuffer_tls(); | |
434 | lttng_fixup_vtid_tls(); | |
435 | lttng_fixup_nest_count_tls(); | |
436 | lttng_fixup_procname_tls(); | |
437 | lttng_fixup_ust_mutex_nest_tls(); | |
20142124 | 438 | lttng_ust_fixup_perf_counter_tls(); |
6548fca4 | 439 | lttng_ust_fixup_fd_tracker_tls(); |
735bef47 MJ |
440 | lttng_fixup_cgroup_ns_tls(); |
441 | lttng_fixup_ipc_ns_tls(); | |
442 | lttng_fixup_net_ns_tls(); | |
cefef7a7 | 443 | lttng_fixup_time_ns_tls(); |
735bef47 | 444 | lttng_fixup_uts_ns_tls(); |
c362addf MD |
445 | } |
446 | ||
32ce8569 MD |
447 | int lttng_get_notify_socket(void *owner) |
448 | { | |
449 | struct sock_info *info = owner; | |
450 | ||
451 | return info->notify_socket; | |
452 | } | |
453 | ||
94be38e8 JR |
454 | |
455 | LTTNG_HIDDEN | |
456 | char* lttng_ust_sockinfo_get_procname(void *owner) | |
457 | { | |
458 | struct sock_info *info = owner; | |
459 | ||
460 | return info->procname; | |
461 | } | |
462 | ||
74d81a6c MD |
463 | static |
464 | void print_cmd(int cmd, int handle) | |
465 | { | |
466 | const char *cmd_name = "Unknown"; | |
467 | ||
fd67a004 MD |
468 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
469 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
470 | cmd_name = cmd_name_mapping[cmd]; |
471 | } | |
fd67a004 MD |
472 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
473 | cmd_name, cmd, | |
74d81a6c MD |
474 | lttng_ust_obj_get_name(handle), handle); |
475 | } | |
476 | ||
060577e3 JR |
477 | static |
478 | int setup_global_apps(void) | |
479 | { | |
480 | int ret = 0; | |
481 | assert(!global_apps.wait_shm_mmap); | |
482 | ||
483 | global_apps.wait_shm_mmap = get_map_shm(&global_apps); | |
484 | if (!global_apps.wait_shm_mmap) { | |
485 | WARN("Unable to get map shm for global apps. Disabling LTTng-UST global tracing."); | |
486 | global_apps.allowed = 0; | |
487 | ret = -EIO; | |
488 | goto error; | |
489 | } | |
490 | ||
491 | global_apps.allowed = 1; | |
0db3d6ee | 492 | lttng_pthread_getname_np(global_apps.procname, LTTNG_UST_ABI_PROCNAME_LEN); |
060577e3 JR |
493 | error: |
494 | return ret; | |
495 | } | |
2691221a | 496 | static |
8d20bf54 | 497 | int setup_local_apps(void) |
2691221a | 498 | { |
060577e3 | 499 | int ret = 0; |
2691221a | 500 | const char *home_dir; |
7fc90dca | 501 | uid_t uid; |
2691221a | 502 | |
060577e3 JR |
503 | assert(!local_apps.wait_shm_mmap); |
504 | ||
7fc90dca | 505 | uid = getuid(); |
8d20bf54 MD |
506 | /* |
507 | * Disallow per-user tracing for setuid binaries. | |
508 | */ | |
7fc90dca | 509 | if (uid != geteuid()) { |
9ec6895c | 510 | assert(local_apps.allowed == 0); |
060577e3 JR |
511 | ret = 0; |
512 | goto end; | |
8d20bf54 | 513 | } |
3c6f6263 | 514 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
515 | if (!home_dir) { |
516 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
517 | assert(local_apps.allowed == 0); | |
060577e3 JR |
518 | ret = -ENOENT; |
519 | goto end; | |
9ec6895c MD |
520 | } |
521 | local_apps.allowed = 1; | |
32ce8569 MD |
522 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
523 | home_dir, | |
524 | LTTNG_DEFAULT_HOME_RUNDIR, | |
525 | LTTNG_UST_SOCK_FILENAME); | |
526 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
527 | LTTNG_UST_WAIT_FILENAME, | |
528 | uid); | |
060577e3 JR |
529 | |
530 | local_apps.wait_shm_mmap = get_map_shm(&local_apps); | |
531 | if (!local_apps.wait_shm_mmap) { | |
532 | WARN("Unable to get map shm for local apps. Disabling LTTng-UST per-user tracing."); | |
533 | local_apps.allowed = 0; | |
534 | ret = -EIO; | |
535 | goto end; | |
536 | } | |
94be38e8 | 537 | |
0db3d6ee | 538 | lttng_pthread_getname_np(local_apps.procname, LTTNG_UST_ABI_PROCNAME_LEN); |
060577e3 JR |
539 | end: |
540 | return ret; | |
2691221a MD |
541 | } |
542 | ||
ff517991 | 543 | /* |
451d66b2 | 544 | * Get socket timeout, in ms. |
28515902 | 545 | * -1: wait forever. 0: don't wait. >0: timeout, in ms. |
ff517991 MD |
546 | */ |
547 | static | |
548 | long get_timeout(void) | |
549 | { | |
550 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
551 | ||
552 | if (!got_timeout_env) { | |
6f626d28 | 553 | str_timeout = lttng_getenv("LTTNG_UST_REGISTER_TIMEOUT"); |
ff517991 MD |
554 | got_timeout_env = 1; |
555 | } | |
556 | if (str_timeout) | |
557 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
5cf81d53 MD |
558 | /* All negative values are considered as "-1". */ |
559 | if (constructor_delay_ms < -1) | |
560 | constructor_delay_ms = -1; | |
ff517991 MD |
561 | return constructor_delay_ms; |
562 | } | |
563 | ||
451d66b2 | 564 | /* Timeout for notify socket send and recv. */ |
ff517991 MD |
565 | static |
566 | long get_notify_sock_timeout(void) | |
567 | { | |
568 | return get_timeout(); | |
569 | } | |
570 | ||
451d66b2 MD |
571 | /* Timeout for connecting to cmd and notify sockets. */ |
572 | static | |
573 | long get_connect_sock_timeout(void) | |
574 | { | |
575 | return get_timeout(); | |
576 | } | |
577 | ||
ff517991 | 578 | /* |
28515902 | 579 | * Return values: -1: wait forever. 0: don't wait. 1: timeout wait. |
ff517991 MD |
580 | */ |
581 | static | |
582 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
583 | { | |
584 | long constructor_delay_ms; | |
585 | int ret; | |
586 | ||
587 | constructor_delay_ms = get_timeout(); | |
588 | ||
589 | switch (constructor_delay_ms) { | |
590 | case -1:/* fall-through */ | |
591 | case 0: | |
592 | return constructor_delay_ms; | |
593 | default: | |
594 | break; | |
595 | } | |
596 | ||
597 | /* | |
598 | * If we are unable to find the current time, don't wait. | |
599 | */ | |
600 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
601 | if (ret) { | |
28515902 JG |
602 | /* Don't wait. */ |
603 | return 0; | |
ff517991 MD |
604 | } |
605 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
606 | constructor_timeout->tv_nsec += | |
607 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
608 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
609 | constructor_timeout->tv_sec++; | |
610 | constructor_timeout->tv_nsec -= 1000000000UL; | |
611 | } | |
28515902 | 612 | /* Timeout wait (constructor_delay_ms). */ |
ff517991 MD |
613 | return 1; |
614 | } | |
615 | ||
6f97f9c2 | 616 | static |
b2c5f61a | 617 | void get_allow_blocking(void) |
6f97f9c2 | 618 | { |
b2c5f61a MD |
619 | const char *str_allow_blocking = |
620 | lttng_getenv("LTTNG_UST_ALLOW_BLOCKING"); | |
621 | ||
622 | if (str_allow_blocking) { | |
623 | DBG("%s environment variable is set", | |
624 | "LTTNG_UST_ALLOW_BLOCKING"); | |
625 | lttng_ust_ringbuffer_set_allow_blocking(); | |
6f97f9c2 MD |
626 | } |
627 | } | |
628 | ||
2691221a | 629 | static |
32ce8569 | 630 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 631 | { |
32ce8569 MD |
632 | return ustcomm_send_reg_msg(socket, |
633 | type, | |
634 | CAA_BITS_PER_LONG, | |
635 | lttng_alignof(uint8_t) * CHAR_BIT, | |
636 | lttng_alignof(uint16_t) * CHAR_BIT, | |
637 | lttng_alignof(uint32_t) * CHAR_BIT, | |
638 | lttng_alignof(uint64_t) * CHAR_BIT, | |
639 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
640 | } |
641 | ||
d9e99d10 | 642 | static |
57773204 | 643 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 644 | { |
9eb62b9c | 645 | ssize_t len; |
d3a492d1 | 646 | |
57773204 | 647 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 648 | switch (len) { |
a4be8962 | 649 | case sizeof(*lur): |
d3a492d1 MD |
650 | DBG("message successfully sent"); |
651 | return 0; | |
7bc53e94 MD |
652 | default: |
653 | if (len == -ECONNRESET) { | |
654 | DBG("remote end closed connection"); | |
d3a492d1 MD |
655 | return 0; |
656 | } | |
7bc53e94 MD |
657 | if (len < 0) |
658 | return len; | |
659 | DBG("incorrect message size: %zd", len); | |
660 | return -EINVAL; | |
d3a492d1 MD |
661 | } |
662 | } | |
663 | ||
664 | static | |
eb0e6022 | 665 | void decrement_sem_count(unsigned int count) |
11ff9c7d MD |
666 | { |
667 | int ret; | |
668 | ||
eb0e6022 GAPG |
669 | assert(uatomic_read(&sem_count) >= count); |
670 | ||
56cd7e2f | 671 | if (uatomic_read(&sem_count) <= 0) { |
eb0e6022 | 672 | return; |
56cd7e2f | 673 | } |
eb0e6022 GAPG |
674 | |
675 | ret = uatomic_add_return(&sem_count, -count); | |
95259bd0 MD |
676 | if (ret == 0) { |
677 | ret = sem_post(&constructor_wait); | |
678 | assert(!ret); | |
679 | } | |
eb0e6022 GAPG |
680 | } |
681 | ||
682 | static | |
683 | int handle_register_done(struct sock_info *sock_info) | |
684 | { | |
685 | if (sock_info->registration_done) | |
686 | return 0; | |
687 | sock_info->registration_done = 1; | |
688 | ||
689 | decrement_sem_count(1); | |
04682184 MD |
690 | if (!sock_info->statedump_pending) { |
691 | sock_info->initial_statedump_done = 1; | |
692 | decrement_sem_count(1); | |
693 | } | |
eb0e6022 GAPG |
694 | |
695 | return 0; | |
696 | } | |
697 | ||
698 | static | |
699 | int handle_register_failed(struct sock_info *sock_info) | |
700 | { | |
701 | if (sock_info->registration_done) | |
702 | return 0; | |
703 | sock_info->registration_done = 1; | |
704 | sock_info->initial_statedump_done = 1; | |
705 | ||
706 | decrement_sem_count(2); | |
707 | ||
11ff9c7d MD |
708 | return 0; |
709 | } | |
710 | ||
37dddb65 MD |
711 | /* |
712 | * Only execute pending statedump after the constructor semaphore has | |
eb0e6022 GAPG |
713 | * been posted by the current listener thread. This means statedump will |
714 | * only be performed after the "registration done" command is received | |
715 | * from this thread's session daemon. | |
37dddb65 MD |
716 | * |
717 | * This ensures we don't run into deadlock issues with the dynamic | |
718 | * loader mutex, which is held while the constructor is called and | |
719 | * waiting on the constructor semaphore. All operations requiring this | |
720 | * dynamic loader lock need to be postponed using this mechanism. | |
eb0e6022 GAPG |
721 | * |
722 | * In a scenario with two session daemons connected to the application, | |
723 | * it is possible that the first listener thread which receives the | |
724 | * registration done command issues its statedump while the dynamic | |
725 | * loader lock is still held by the application constructor waiting on | |
726 | * the semaphore. It will however be allowed to proceed when the | |
727 | * second session daemon sends the registration done command to the | |
728 | * second listener thread. This situation therefore does not produce | |
729 | * a deadlock. | |
37dddb65 MD |
730 | */ |
731 | static | |
732 | void handle_pending_statedump(struct sock_info *sock_info) | |
733 | { | |
eb0e6022 | 734 | if (sock_info->registration_done && sock_info->statedump_pending) { |
37dddb65 | 735 | sock_info->statedump_pending = 0; |
2932a87f | 736 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 737 | lttng_handle_pending_statedump(sock_info); |
458d678c | 738 | pthread_mutex_unlock(&ust_fork_mutex); |
eb0e6022 GAPG |
739 | |
740 | if (!sock_info->initial_statedump_done) { | |
741 | sock_info->initial_statedump_done = 1; | |
742 | decrement_sem_count(1); | |
743 | } | |
37dddb65 MD |
744 | } |
745 | } | |
746 | ||
6a6ef048 FD |
747 | static inline |
748 | const char *bytecode_type_str(uint32_t cmd) | |
749 | { | |
750 | switch (cmd) { | |
d37ecb3f FD |
751 | case LTTNG_UST_CAPTURE: |
752 | return "capture"; | |
6a6ef048 FD |
753 | case LTTNG_UST_FILTER: |
754 | return "filter"; | |
755 | default: | |
756 | abort(); | |
757 | } | |
758 | } | |
759 | ||
760 | static | |
761 | int handle_bytecode_recv(struct sock_info *sock_info, | |
762 | int sock, struct ustcomm_ust_msg *lum) | |
763 | { | |
764 | struct lttng_ust_bytecode_node *bytecode; | |
765 | enum lttng_ust_bytecode_node_type type; | |
766 | const struct lttng_ust_objd_ops *ops; | |
767 | uint32_t data_size, data_size_max, reloc_offset; | |
768 | uint64_t seqnum; | |
769 | ssize_t len; | |
770 | int ret = 0; | |
771 | ||
772 | switch (lum->cmd) { | |
773 | case LTTNG_UST_FILTER: | |
774 | type = LTTNG_UST_BYTECODE_NODE_TYPE_FILTER; | |
775 | data_size = lum->u.filter.data_size; | |
776 | data_size_max = FILTER_BYTECODE_MAX_LEN; | |
777 | reloc_offset = lum->u.filter.reloc_offset; | |
778 | seqnum = lum->u.filter.seqnum; | |
779 | break; | |
d37ecb3f FD |
780 | case LTTNG_UST_CAPTURE: |
781 | type = LTTNG_UST_BYTECODE_NODE_TYPE_CAPTURE; | |
782 | data_size = lum->u.capture.data_size; | |
783 | data_size_max = CAPTURE_BYTECODE_MAX_LEN; | |
784 | reloc_offset = lum->u.capture.reloc_offset; | |
785 | seqnum = lum->u.capture.seqnum; | |
786 | break; | |
6a6ef048 FD |
787 | default: |
788 | abort(); | |
789 | } | |
790 | ||
791 | if (data_size > data_size_max) { | |
792 | ERR("Bytecode %s data size is too large: %u bytes", | |
793 | bytecode_type_str(lum->cmd), data_size); | |
794 | ret = -EINVAL; | |
795 | goto end; | |
796 | } | |
797 | ||
798 | if (reloc_offset > data_size) { | |
799 | ERR("Bytecode %s reloc offset %u is not within data", | |
800 | bytecode_type_str(lum->cmd), reloc_offset); | |
801 | ret = -EINVAL; | |
802 | goto end; | |
803 | } | |
804 | ||
805 | /* Allocate the structure AND the `data[]` field. */ | |
806 | bytecode = zmalloc(sizeof(*bytecode) + data_size); | |
807 | if (!bytecode) { | |
808 | ret = -ENOMEM; | |
809 | goto end; | |
810 | } | |
811 | ||
812 | bytecode->bc.len = data_size; | |
813 | bytecode->bc.reloc_offset = reloc_offset; | |
814 | bytecode->bc.seqnum = seqnum; | |
815 | bytecode->type = type; | |
816 | ||
817 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, bytecode->bc.len); | |
818 | switch (len) { | |
819 | case 0: /* orderly shutdown */ | |
820 | ret = 0; | |
821 | goto error_free_bytecode; | |
822 | default: | |
823 | if (len == bytecode->bc.len) { | |
824 | DBG("Bytecode %s data received", | |
825 | bytecode_type_str(lum->cmd)); | |
826 | break; | |
827 | } else if (len < 0) { | |
828 | DBG("Receive failed from lttng-sessiond with errno %d", | |
829 | (int) -len); | |
830 | if (len == -ECONNRESET) { | |
831 | ERR("%s remote end closed connection", | |
832 | sock_info->name); | |
833 | ret = len; | |
834 | goto error_free_bytecode; | |
835 | } | |
836 | ret = len; | |
837 | goto error_free_bytecode; | |
838 | } else { | |
839 | DBG("Incorrect %s bytecode data message size: %zd", | |
840 | bytecode_type_str(lum->cmd), len); | |
841 | ret = -EINVAL; | |
842 | goto error_free_bytecode; | |
843 | } | |
844 | } | |
845 | ||
846 | ops = objd_ops(lum->handle); | |
847 | if (!ops) { | |
848 | ret = -ENOENT; | |
849 | goto error_free_bytecode; | |
850 | } | |
851 | ||
852 | if (ops->cmd) { | |
853 | ret = ops->cmd(lum->handle, lum->cmd, | |
854 | (unsigned long) bytecode, | |
855 | NULL, sock_info); | |
856 | if (ret) | |
857 | goto error_free_bytecode; | |
858 | /* don't free bytecode if everything went fine. */ | |
859 | } else { | |
860 | ret = -ENOSYS; | |
861 | goto error_free_bytecode; | |
862 | } | |
863 | ||
864 | goto end; | |
865 | ||
866 | error_free_bytecode: | |
867 | free(bytecode); | |
868 | end: | |
869 | return ret; | |
870 | } | |
871 | ||
11ff9c7d MD |
872 | static |
873 | int handle_message(struct sock_info *sock_info, | |
57773204 | 874 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 875 | { |
1ea11eab | 876 | int ret = 0; |
b61ce3b2 | 877 | const struct lttng_ust_objd_ops *ops; |
57773204 | 878 | struct ustcomm_ust_reply lur; |
ef9ff354 | 879 | union ust_args args; |
8e696cfa | 880 | char ctxstr[LTTNG_UST_SYM_NAME_LEN]; /* App context string. */ |
40003310 | 881 | ssize_t len; |
1ea11eab | 882 | |
46050b1a MD |
883 | memset(&lur, 0, sizeof(lur)); |
884 | ||
3327ac33 | 885 | if (ust_lock()) { |
74d81a6c | 886 | ret = -LTTNG_UST_ERR_EXITING; |
0dafcd63 | 887 | goto error; |
1ea11eab | 888 | } |
9eb62b9c | 889 | |
46050b1a MD |
890 | ops = objd_ops(lum->handle); |
891 | if (!ops) { | |
892 | ret = -ENOENT; | |
0dafcd63 | 893 | goto error; |
1ea11eab | 894 | } |
46050b1a MD |
895 | |
896 | switch (lum->cmd) { | |
11ff9c7d MD |
897 | case LTTNG_UST_REGISTER_DONE: |
898 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 899 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
900 | else |
901 | ret = -EINVAL; | |
902 | break; | |
46050b1a MD |
903 | case LTTNG_UST_RELEASE: |
904 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
905 | ret = -EPERM; | |
906 | else | |
1849ef7c | 907 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 908 | break; |
d37ecb3f | 909 | case LTTNG_UST_CAPTURE: |
2d78951a | 910 | case LTTNG_UST_FILTER: |
6a6ef048 FD |
911 | ret = handle_bytecode_recv(sock_info, sock, lum); |
912 | if (ret) | |
2734ca65 | 913 | goto error; |
2d78951a | 914 | break; |
86e36163 JI |
915 | case LTTNG_UST_EXCLUSION: |
916 | { | |
917 | /* Receive exclusion names */ | |
918 | struct lttng_ust_excluder_node *node; | |
919 | unsigned int count; | |
920 | ||
921 | count = lum->u.exclusion.count; | |
922 | if (count == 0) { | |
923 | /* There are no names to read */ | |
924 | ret = 0; | |
925 | goto error; | |
926 | } | |
927 | node = zmalloc(sizeof(*node) + | |
928 | count * LTTNG_UST_SYM_NAME_LEN); | |
929 | if (!node) { | |
930 | ret = -ENOMEM; | |
931 | goto error; | |
932 | } | |
933 | node->excluder.count = count; | |
934 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
935 | count * LTTNG_UST_SYM_NAME_LEN); | |
936 | switch (len) { | |
937 | case 0: /* orderly shutdown */ | |
938 | ret = 0; | |
939 | free(node); | |
940 | goto error; | |
941 | default: | |
942 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
943 | DBG("Exclusion data received"); | |
944 | break; | |
945 | } else if (len < 0) { | |
946 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
947 | if (len == -ECONNRESET) { | |
948 | ERR("%s remote end closed connection", sock_info->name); | |
949 | ret = len; | |
950 | free(node); | |
951 | goto error; | |
952 | } | |
953 | ret = len; | |
954 | free(node); | |
0dafcd63 | 955 | goto error; |
86e36163 JI |
956 | } else { |
957 | DBG("Incorrect exclusion data message size: %zd", len); | |
958 | ret = -EINVAL; | |
959 | free(node); | |
0dafcd63 | 960 | goto error; |
86e36163 JI |
961 | } |
962 | } | |
963 | if (ops->cmd) { | |
964 | ret = ops->cmd(lum->handle, lum->cmd, | |
965 | (unsigned long) node, | |
966 | &args, sock_info); | |
967 | if (ret) { | |
968 | free(node); | |
969 | } | |
970 | /* Don't free exclusion data if everything went fine. */ | |
971 | } else { | |
972 | ret = -ENOSYS; | |
973 | free(node); | |
974 | } | |
975 | break; | |
976 | } | |
d8d2416d FD |
977 | case LTTNG_UST_EVENT_NOTIFIER_GROUP_CREATE: |
978 | { | |
979 | int event_notifier_notif_fd; | |
980 | ||
981 | len = ustcomm_recv_event_notifier_notif_fd_from_sessiond(sock, | |
982 | &event_notifier_notif_fd); | |
983 | switch (len) { | |
984 | case 0: /* orderly shutdown */ | |
985 | ret = 0; | |
986 | goto error; | |
987 | case 1: | |
988 | break; | |
989 | default: | |
990 | if (len < 0) { | |
991 | DBG("Receive failed from lttng-sessiond with errno %d", | |
992 | (int) -len); | |
993 | if (len == -ECONNRESET) { | |
994 | ERR("%s remote end closed connection", | |
995 | sock_info->name); | |
996 | ret = len; | |
997 | goto error; | |
998 | } | |
999 | ret = len; | |
1000 | goto error; | |
1001 | } else { | |
1002 | DBG("Incorrect event notifier fd message size: %zd", | |
1003 | len); | |
1004 | ret = -EINVAL; | |
1005 | goto error; | |
1006 | } | |
1007 | } | |
1008 | args.event_notifier_handle.event_notifier_notif_fd = | |
1009 | event_notifier_notif_fd; | |
1010 | if (ops->cmd) | |
1011 | ret = ops->cmd(lum->handle, lum->cmd, | |
1012 | (unsigned long) &lum->u, | |
1013 | &args, sock_info); | |
1014 | else | |
1015 | ret = -ENOSYS; | |
1016 | break; | |
1017 | } | |
74d81a6c MD |
1018 | case LTTNG_UST_CHANNEL: |
1019 | { | |
1020 | void *chan_data; | |
ff0f5728 | 1021 | int wakeup_fd; |
74d81a6c MD |
1022 | |
1023 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
1024 | &chan_data, lum->u.channel.len, |
1025 | &wakeup_fd); | |
74d81a6c MD |
1026 | switch (len) { |
1027 | case 0: /* orderly shutdown */ | |
1028 | ret = 0; | |
1029 | goto error; | |
1030 | default: | |
1031 | if (len == lum->u.channel.len) { | |
1032 | DBG("channel data received"); | |
1033 | break; | |
1034 | } else if (len < 0) { | |
1035 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1036 | if (len == -ECONNRESET) { | |
1037 | ERR("%s remote end closed connection", sock_info->name); | |
1038 | ret = len; | |
1039 | goto error; | |
1040 | } | |
1041 | ret = len; | |
0dafcd63 | 1042 | goto error; |
74d81a6c MD |
1043 | } else { |
1044 | DBG("incorrect channel data message size: %zd", len); | |
1045 | ret = -EINVAL; | |
0dafcd63 | 1046 | goto error; |
74d81a6c MD |
1047 | } |
1048 | } | |
1049 | args.channel.chan_data = chan_data; | |
ff0f5728 | 1050 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
1051 | if (ops->cmd) |
1052 | ret = ops->cmd(lum->handle, lum->cmd, | |
1053 | (unsigned long) &lum->u, | |
1054 | &args, sock_info); | |
1055 | else | |
1056 | ret = -ENOSYS; | |
1057 | break; | |
1058 | } | |
1059 | case LTTNG_UST_STREAM: | |
1060 | { | |
1061 | /* Receive shm_fd, wakeup_fd */ | |
1062 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
61e520fb | 1063 | NULL, |
74d81a6c MD |
1064 | &args.stream.shm_fd, |
1065 | &args.stream.wakeup_fd); | |
1066 | if (ret) { | |
0dafcd63 | 1067 | goto error; |
74d81a6c | 1068 | } |
973eac63 | 1069 | |
74d81a6c MD |
1070 | if (ops->cmd) |
1071 | ret = ops->cmd(lum->handle, lum->cmd, | |
1072 | (unsigned long) &lum->u, | |
1073 | &args, sock_info); | |
1074 | else | |
1075 | ret = -ENOSYS; | |
1076 | break; | |
1077 | } | |
8e696cfa MD |
1078 | case LTTNG_UST_CONTEXT: |
1079 | switch (lum->u.context.ctx) { | |
1080 | case LTTNG_UST_CONTEXT_APP_CONTEXT: | |
1081 | { | |
1082 | char *p; | |
1083 | size_t ctxlen, recvlen; | |
1084 | ||
1085 | ctxlen = strlen("$app.") + lum->u.context.u.app_ctx.provider_name_len - 1 | |
1086 | + strlen(":") + lum->u.context.u.app_ctx.ctx_name_len; | |
1087 | if (ctxlen >= LTTNG_UST_SYM_NAME_LEN) { | |
1088 | ERR("Application context string length size is too large: %zu bytes", | |
1089 | ctxlen); | |
1090 | ret = -EINVAL; | |
1091 | goto error; | |
1092 | } | |
1093 | strcpy(ctxstr, "$app."); | |
1094 | p = &ctxstr[strlen("$app.")]; | |
1095 | recvlen = ctxlen - strlen("$app."); | |
1096 | len = ustcomm_recv_unix_sock(sock, p, recvlen); | |
1097 | switch (len) { | |
1098 | case 0: /* orderly shutdown */ | |
1099 | ret = 0; | |
1100 | goto error; | |
1101 | default: | |
1102 | if (len == recvlen) { | |
1103 | DBG("app context data received"); | |
1104 | break; | |
1105 | } else if (len < 0) { | |
1106 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1107 | if (len == -ECONNRESET) { | |
1108 | ERR("%s remote end closed connection", sock_info->name); | |
1109 | ret = len; | |
1110 | goto error; | |
1111 | } | |
1112 | ret = len; | |
1113 | goto error; | |
1114 | } else { | |
1115 | DBG("incorrect app context data message size: %zd", len); | |
1116 | ret = -EINVAL; | |
1117 | goto error; | |
1118 | } | |
1119 | } | |
1120 | /* Put : between provider and ctxname. */ | |
1121 | p[lum->u.context.u.app_ctx.provider_name_len - 1] = ':'; | |
1122 | args.app_context.ctxname = ctxstr; | |
1123 | break; | |
1124 | } | |
1125 | default: | |
1126 | break; | |
1127 | } | |
1128 | if (ops->cmd) { | |
1129 | ret = ops->cmd(lum->handle, lum->cmd, | |
1130 | (unsigned long) &lum->u, | |
1131 | &args, sock_info); | |
1132 | } else { | |
1133 | ret = -ENOSYS; | |
1134 | } | |
1135 | break; | |
d9e99d10 | 1136 | default: |
46050b1a MD |
1137 | if (ops->cmd) |
1138 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 1139 | (unsigned long) &lum->u, |
f59ed768 | 1140 | &args, sock_info); |
46050b1a MD |
1141 | else |
1142 | ret = -ENOSYS; | |
1143 | break; | |
d9e99d10 | 1144 | } |
46050b1a | 1145 | |
46050b1a MD |
1146 | lur.handle = lum->handle; |
1147 | lur.cmd = lum->cmd; | |
1148 | lur.ret_val = ret; | |
1149 | if (ret >= 0) { | |
7bc53e94 | 1150 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 1151 | } else { |
7bc53e94 MD |
1152 | /* |
1153 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
1154 | * error that are not caused by the transport, except if | |
1155 | * we already have a more precise error message to | |
1156 | * report. | |
1157 | */ | |
64b2564e DG |
1158 | if (ret > -LTTNG_UST_ERR) { |
1159 | /* Translate code to UST error. */ | |
1160 | switch (ret) { | |
1161 | case -EEXIST: | |
1162 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
1163 | break; | |
1164 | case -EINVAL: | |
1165 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
1166 | break; | |
1167 | case -ENOENT: | |
1168 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
1169 | break; | |
1170 | case -EPERM: | |
1171 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
1172 | break; | |
1173 | case -ENOSYS: | |
1174 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
1175 | break; | |
1176 | default: | |
1177 | lur.ret_code = -LTTNG_UST_ERR; | |
1178 | break; | |
1179 | } | |
1180 | } else { | |
7bc53e94 | 1181 | lur.ret_code = ret; |
64b2564e | 1182 | } |
46050b1a | 1183 | } |
e6ea14c5 MD |
1184 | if (ret >= 0) { |
1185 | switch (lum->cmd) { | |
e6ea14c5 MD |
1186 | case LTTNG_UST_TRACER_VERSION: |
1187 | lur.u.version = lum->u.version; | |
1188 | break; | |
1189 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
1190 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
1191 | break; | |
1192 | } | |
381c0f1e | 1193 | } |
74d81a6c | 1194 | DBG("Return value: %d", lur.ret_val); |
4c62d8d1 MD |
1195 | |
1196 | ust_unlock(); | |
1197 | ||
1198 | /* | |
1199 | * Performed delayed statedump operations outside of the UST | |
1200 | * lock. We need to take the dynamic loader lock before we take | |
1201 | * the UST lock internally within handle_pending_statedump(). | |
1202 | */ | |
1203 | handle_pending_statedump(sock_info); | |
1204 | ||
1205 | if (ust_lock()) { | |
1206 | ret = -LTTNG_UST_ERR_EXITING; | |
1207 | goto error; | |
1208 | } | |
1209 | ||
46050b1a | 1210 | ret = send_reply(sock, &lur); |
193183fb | 1211 | if (ret < 0) { |
7bc53e94 | 1212 | DBG("error sending reply"); |
193183fb MD |
1213 | goto error; |
1214 | } | |
46050b1a | 1215 | |
40003310 MD |
1216 | /* |
1217 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
1218 | * after the reply. | |
1219 | */ | |
7bc53e94 | 1220 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
1221 | switch (lum->cmd) { |
1222 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
1223 | len = ustcomm_send_unix_sock(sock, | |
1224 | &args.field_list.entry, | |
1225 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
1226 | if (len < 0) { |
1227 | ret = len; | |
1228 | goto error; | |
1229 | } | |
40003310 | 1230 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 1231 | ret = -EINVAL; |
40003310 MD |
1232 | goto error; |
1233 | } | |
1234 | } | |
1235 | } | |
ef9ff354 | 1236 | |
381c0f1e | 1237 | error: |
17dfb34b | 1238 | ust_unlock(); |
d9e99d10 | 1239 | |
37dddb65 | 1240 | return ret; |
246be17e PW |
1241 | } |
1242 | ||
46050b1a | 1243 | static |
efe0de09 | 1244 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
1245 | { |
1246 | int ret; | |
1247 | ||
5b14aab3 MD |
1248 | if (sock_info->root_handle != -1) { |
1249 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
1250 | if (ret) { | |
1251 | ERR("Error unref root handle"); | |
1252 | } | |
1253 | sock_info->root_handle = -1; | |
1254 | } | |
eb0e6022 GAPG |
1255 | sock_info->registration_done = 0; |
1256 | sock_info->initial_statedump_done = 0; | |
5b14aab3 MD |
1257 | |
1258 | /* | |
1259 | * wait_shm_mmap, socket and notify socket are used by listener | |
1260 | * threads outside of the ust lock, so we cannot tear them down | |
1261 | * ourselves, because we cannot join on these threads. Leave | |
1262 | * responsibility of cleaning up these resources to the OS | |
1263 | * process exit. | |
1264 | */ | |
1265 | if (exiting) | |
1266 | return; | |
1267 | ||
46050b1a | 1268 | if (sock_info->socket != -1) { |
e6973a89 | 1269 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 1270 | if (ret) { |
32ce8569 | 1271 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
1272 | } |
1273 | sock_info->socket = -1; | |
1274 | } | |
32ce8569 MD |
1275 | if (sock_info->notify_socket != -1) { |
1276 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1277 | if (ret) { | |
1278 | ERR("Error closing ust notify socket"); | |
1279 | } | |
1280 | sock_info->notify_socket = -1; | |
1281 | } | |
5b14aab3 | 1282 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
1283 | long page_size; |
1284 | ||
b72687b8 | 1285 | page_size = LTTNG_UST_PAGE_SIZE; |
2657d1ba MD |
1286 | if (page_size <= 0) { |
1287 | if (!page_size) { | |
1288 | errno = EINVAL; | |
1289 | } | |
1290 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
1291 | } else { | |
172d6b68 MD |
1292 | ret = munmap(sock_info->wait_shm_mmap, page_size); |
1293 | if (ret) { | |
1294 | ERR("Error unmapping wait shm"); | |
1295 | } | |
7fc90dca MD |
1296 | } |
1297 | sock_info->wait_shm_mmap = NULL; | |
1298 | } | |
1299 | } | |
1300 | ||
58d4b2a2 | 1301 | /* |
33bbeb90 MD |
1302 | * Using fork to set umask in the child process (not multi-thread safe). |
1303 | * We deal with the shm_open vs ftruncate race (happening when the | |
1304 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
1305 | * safety against shm_unlink) by simply letting the mmap fail and | |
1306 | * retrying after a few seconds. | |
1307 | * For global shm, everybody has rw access to it until the sessiond | |
1308 | * starts. | |
58d4b2a2 | 1309 | */ |
7fc90dca | 1310 | static |
58d4b2a2 | 1311 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 1312 | { |
7fc90dca | 1313 | int wait_shm_fd, ret; |
58d4b2a2 | 1314 | pid_t pid; |
44e073f5 | 1315 | |
58d4b2a2 | 1316 | /* |
33bbeb90 | 1317 | * Try to open read-only. |
58d4b2a2 | 1318 | */ |
33bbeb90 | 1319 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 1320 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
1321 | int32_t tmp_read; |
1322 | ssize_t len; | |
1323 | size_t bytes_read = 0; | |
1324 | ||
1325 | /* | |
1326 | * Try to read the fd. If unable to do so, try opening | |
1327 | * it in write mode. | |
1328 | */ | |
1329 | do { | |
1330 | len = read(wait_shm_fd, | |
1331 | &((char *) &tmp_read)[bytes_read], | |
1332 | sizeof(tmp_read) - bytes_read); | |
1333 | if (len > 0) { | |
1334 | bytes_read += len; | |
1335 | } | |
1336 | } while ((len < 0 && errno == EINTR) | |
1337 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
1338 | if (bytes_read != sizeof(tmp_read)) { | |
1339 | ret = close(wait_shm_fd); | |
1340 | if (ret) { | |
1341 | ERR("close wait_shm_fd"); | |
1342 | } | |
1343 | goto open_write; | |
1344 | } | |
58d4b2a2 MD |
1345 | goto end; |
1346 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
1347 | /* | |
33bbeb90 MD |
1348 | * Real-only open did not work, and it's not because the |
1349 | * entry was not present. It's a failure that prohibits | |
1350 | * using shm. | |
58d4b2a2 | 1351 | */ |
7fc90dca | 1352 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 1353 | goto end; |
7fc90dca | 1354 | } |
7aa76730 MD |
1355 | |
1356 | open_write: | |
7fc90dca | 1357 | /* |
7aa76730 MD |
1358 | * If the open failed because the file did not exist, or because |
1359 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 1360 | */ |
8c90a710 | 1361 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 1362 | pid = fork(); |
8c90a710 | 1363 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
1364 | if (pid > 0) { |
1365 | int status; | |
1366 | ||
1367 | /* | |
1368 | * Parent: wait for child to return, in which case the | |
1369 | * shared memory map will have been created. | |
1370 | */ | |
1371 | pid = wait(&status); | |
b7d3cb32 | 1372 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
1373 | wait_shm_fd = -1; |
1374 | goto end; | |
7fc90dca | 1375 | } |
58d4b2a2 MD |
1376 | /* |
1377 | * Try to open read-only again after creation. | |
1378 | */ | |
33bbeb90 | 1379 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
1380 | if (wait_shm_fd < 0) { |
1381 | /* | |
1382 | * Real-only open did not work. It's a failure | |
1383 | * that prohibits using shm. | |
1384 | */ | |
1385 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1386 | goto end; | |
1387 | } | |
1388 | goto end; | |
1389 | } else if (pid == 0) { | |
1390 | int create_mode; | |
1391 | ||
1392 | /* Child */ | |
33bbeb90 | 1393 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1394 | if (sock_info->global) |
33bbeb90 | 1395 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1396 | /* |
1397 | * We're alone in a child process, so we can modify the | |
1398 | * process-wide umask. | |
1399 | */ | |
33bbeb90 | 1400 | umask(~create_mode); |
58d4b2a2 | 1401 | /* |
33bbeb90 MD |
1402 | * Try creating shm (or get rw access). |
1403 | * We don't do an exclusive open, because we allow other | |
1404 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1405 | */ |
1406 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1407 | O_RDWR | O_CREAT, create_mode); | |
1408 | if (wait_shm_fd >= 0) { | |
1409 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1410 | if (ret) { | |
1411 | PERROR("ftruncate"); | |
b0c1425d | 1412 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1413 | } |
b0c1425d | 1414 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1415 | } |
33bbeb90 MD |
1416 | /* |
1417 | * For local shm, we need to have rw access to accept | |
1418 | * opening it: this means the local sessiond will be | |
1419 | * able to wake us up. For global shm, we open it even | |
1420 | * if rw access is not granted, because the root.root | |
1421 | * sessiond will be able to override all rights and wake | |
1422 | * us up. | |
1423 | */ | |
1424 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1425 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1426 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1427 | } |
1428 | /* | |
33bbeb90 MD |
1429 | * The shm exists, but we cannot open it RW. Report |
1430 | * success. | |
58d4b2a2 | 1431 | */ |
5d3bc5ed | 1432 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1433 | } else { |
1434 | return -1; | |
7fc90dca | 1435 | } |
58d4b2a2 | 1436 | end: |
33bbeb90 MD |
1437 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1438 | struct stat statbuf; | |
1439 | ||
1440 | /* | |
1441 | * Ensure that our user is the owner of the shm file for | |
1442 | * local shm. If we do not own the file, it means our | |
1443 | * sessiond will not have access to wake us up (there is | |
1444 | * probably a rogue process trying to fake our | |
1445 | * sessiond). Fallback to polling method in this case. | |
1446 | */ | |
1447 | ret = fstat(wait_shm_fd, &statbuf); | |
1448 | if (ret) { | |
1449 | PERROR("fstat"); | |
1450 | goto error_close; | |
1451 | } | |
1452 | if (statbuf.st_uid != getuid()) | |
1453 | goto error_close; | |
1454 | } | |
58d4b2a2 | 1455 | return wait_shm_fd; |
33bbeb90 MD |
1456 | |
1457 | error_close: | |
1458 | ret = close(wait_shm_fd); | |
1459 | if (ret) { | |
1460 | PERROR("Error closing fd"); | |
1461 | } | |
1462 | return -1; | |
58d4b2a2 MD |
1463 | } |
1464 | ||
1465 | static | |
1466 | char *get_map_shm(struct sock_info *sock_info) | |
1467 | { | |
172d6b68 | 1468 | long page_size; |
58d4b2a2 MD |
1469 | int wait_shm_fd, ret; |
1470 | char *wait_shm_mmap; | |
1471 | ||
172d6b68 | 1472 | page_size = sysconf(_SC_PAGE_SIZE); |
2657d1ba MD |
1473 | if (page_size <= 0) { |
1474 | if (!page_size) { | |
1475 | errno = EINVAL; | |
1476 | } | |
1477 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
172d6b68 MD |
1478 | goto error; |
1479 | } | |
1480 | ||
6548fca4 | 1481 | lttng_ust_lock_fd_tracker(); |
172d6b68 | 1482 | wait_shm_fd = get_wait_shm(sock_info, page_size); |
58d4b2a2 | 1483 | if (wait_shm_fd < 0) { |
6548fca4 | 1484 | lttng_ust_unlock_fd_tracker(); |
58d4b2a2 | 1485 | goto error; |
44e073f5 | 1486 | } |
f5c453e9 JR |
1487 | |
1488 | ret = lttng_ust_add_fd_to_tracker(wait_shm_fd); | |
1489 | if (ret < 0) { | |
1490 | ret = close(wait_shm_fd); | |
1491 | if (!ret) { | |
1492 | PERROR("Error closing fd"); | |
1493 | } | |
1494 | lttng_ust_unlock_fd_tracker(); | |
1495 | goto error; | |
1496 | } | |
1497 | ||
1498 | wait_shm_fd = ret; | |
6548fca4 MD |
1499 | lttng_ust_unlock_fd_tracker(); |
1500 | ||
172d6b68 | 1501 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1502 | MAP_SHARED, wait_shm_fd, 0); |
6548fca4 | 1503 | |
7fc90dca | 1504 | /* close shm fd immediately after taking the mmap reference */ |
6548fca4 | 1505 | lttng_ust_lock_fd_tracker(); |
7fc90dca | 1506 | ret = close(wait_shm_fd); |
6548fca4 MD |
1507 | if (!ret) { |
1508 | lttng_ust_delete_fd_from_tracker(wait_shm_fd); | |
1509 | } else { | |
33bbeb90 MD |
1510 | PERROR("Error closing fd"); |
1511 | } | |
6548fca4 MD |
1512 | lttng_ust_unlock_fd_tracker(); |
1513 | ||
33bbeb90 MD |
1514 | if (wait_shm_mmap == MAP_FAILED) { |
1515 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1516 | goto error; | |
7fc90dca MD |
1517 | } |
1518 | return wait_shm_mmap; | |
1519 | ||
1520 | error: | |
1521 | return NULL; | |
1522 | } | |
1523 | ||
1524 | static | |
1525 | void wait_for_sessiond(struct sock_info *sock_info) | |
1526 | { | |
060577e3 | 1527 | /* Use ust_lock to check if we should quit. */ |
3327ac33 | 1528 | if (ust_lock()) { |
7fc90dca MD |
1529 | goto quit; |
1530 | } | |
37ed587a MD |
1531 | if (wait_poll_fallback) { |
1532 | goto error; | |
1533 | } | |
7fc90dca MD |
1534 | ust_unlock(); |
1535 | ||
060577e3 JR |
1536 | assert(sock_info->wait_shm_mmap); |
1537 | ||
7fc90dca | 1538 | DBG("Waiting for %s apps sessiond", sock_info->name); |
80e2814b | 1539 | /* Wait for futex wakeup */ |
ee7fcec8 MD |
1540 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) |
1541 | goto end_wait; | |
1542 | ||
1543 | while (futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1544 | FUTEX_WAIT, 0, NULL, NULL, 0)) { | |
1545 | switch (errno) { | |
1546 | case EWOULDBLOCK: | |
1547 | /* Value already changed. */ | |
1548 | goto end_wait; | |
1549 | case EINTR: | |
1550 | /* Retry if interrupted by signal. */ | |
1551 | break; /* Get out of switch. */ | |
1552 | case EFAULT: | |
1553 | wait_poll_fallback = 1; | |
1554 | DBG( | |
37ed587a MD |
1555 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1556 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1557 | "Please upgrade your kernel " | |
1558 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1559 | "mainline). LTTng-UST will use polling mode fallback."); | |
ee7fcec8 MD |
1560 | if (ust_debug()) |
1561 | PERROR("futex"); | |
1562 | goto end_wait; | |
80e2814b MD |
1563 | } |
1564 | } | |
ee7fcec8 | 1565 | end_wait: |
7fc90dca MD |
1566 | return; |
1567 | ||
1568 | quit: | |
1569 | ust_unlock(); | |
1570 | return; | |
1571 | ||
1572 | error: | |
1573 | ust_unlock(); | |
7fc90dca | 1574 | return; |
46050b1a MD |
1575 | } |
1576 | ||
1ea11eab MD |
1577 | /* |
1578 | * This thread does not allocate any resource, except within | |
1579 | * handle_message, within mutex protection. This mutex protects against | |
1580 | * fork and exit. | |
98bf993f | 1581 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1582 | * is also protected by the mutex. |
1583 | */ | |
d9e99d10 MD |
1584 | static |
1585 | void *ust_listener_thread(void *arg) | |
1586 | { | |
1ea11eab | 1587 | struct sock_info *sock_info = arg; |
f5c453e9 | 1588 | int sock, ret, prev_connect_failed = 0, has_waited = 0, fd; |
ff517991 | 1589 | long timeout; |
d9e99d10 | 1590 | |
c362addf | 1591 | lttng_ust_fixup_tls(); |
01f0e40c RB |
1592 | /* |
1593 | * If available, add '-ust' to the end of this thread's | |
1594 | * process name | |
1595 | */ | |
1596 | ret = lttng_ust_setustprocname(); | |
1597 | if (ret) { | |
1598 | ERR("Unable to set UST process name"); | |
1599 | } | |
1600 | ||
9eb62b9c MD |
1601 | /* Restart trying to connect to the session daemon */ |
1602 | restart: | |
c0eedf81 MD |
1603 | if (prev_connect_failed) { |
1604 | /* Wait for sessiond availability with pipe */ | |
1605 | wait_for_sessiond(sock_info); | |
1606 | if (has_waited) { | |
1607 | has_waited = 0; | |
1608 | /* | |
1609 | * Sleep for 5 seconds before retrying after a | |
1610 | * sequence of failure / wait / failure. This | |
1611 | * deals with a killed or broken session daemon. | |
1612 | */ | |
1613 | sleep(5); | |
eacc4aa4 MD |
1614 | } else { |
1615 | has_waited = 1; | |
c0eedf81 | 1616 | } |
c0eedf81 MD |
1617 | prev_connect_failed = 0; |
1618 | } | |
9eb62b9c | 1619 | |
101dace0 JR |
1620 | if (ust_lock()) { |
1621 | goto quit; | |
1622 | } | |
1623 | ||
1ea11eab | 1624 | if (sock_info->socket != -1) { |
6548fca4 | 1625 | /* FD tracker is updated by ustcomm_close_unix_sock() */ |
e6973a89 | 1626 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1627 | if (ret) { |
32ce8569 MD |
1628 | ERR("Error closing %s ust cmd socket", |
1629 | sock_info->name); | |
1ea11eab MD |
1630 | } |
1631 | sock_info->socket = -1; | |
1632 | } | |
32ce8569 | 1633 | if (sock_info->notify_socket != -1) { |
6548fca4 | 1634 | /* FD tracker is updated by ustcomm_close_unix_sock() */ |
32ce8569 MD |
1635 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); |
1636 | if (ret) { | |
1637 | ERR("Error closing %s ust notify socket", | |
1638 | sock_info->name); | |
1639 | } | |
1640 | sock_info->notify_socket = -1; | |
1641 | } | |
46050b1a | 1642 | |
6548fca4 | 1643 | |
321f2351 MD |
1644 | /* |
1645 | * Register. We need to perform both connect and sending | |
1646 | * registration message before doing the next connect otherwise | |
1647 | * we may reach unix socket connect queue max limits and block | |
1648 | * on the 2nd connect while the session daemon is awaiting the | |
1649 | * first connect registration message. | |
1650 | */ | |
1651 | /* Connect cmd socket */ | |
6548fca4 | 1652 | lttng_ust_lock_fd_tracker(); |
451d66b2 MD |
1653 | ret = ustcomm_connect_unix_sock(sock_info->sock_path, |
1654 | get_connect_sock_timeout()); | |
321f2351 | 1655 | if (ret < 0) { |
6548fca4 | 1656 | lttng_ust_unlock_fd_tracker(); |
321f2351 MD |
1657 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); |
1658 | prev_connect_failed = 1; | |
5b14aab3 | 1659 | |
e3426ddc | 1660 | /* |
321f2351 MD |
1661 | * If we cannot find the sessiond daemon, don't delay |
1662 | * constructor execution. | |
e3426ddc | 1663 | */ |
eb0e6022 | 1664 | ret = handle_register_failed(sock_info); |
321f2351 MD |
1665 | assert(!ret); |
1666 | ust_unlock(); | |
1667 | goto restart; | |
27fe9f21 | 1668 | } |
f5c453e9 JR |
1669 | fd = ret; |
1670 | ret = lttng_ust_add_fd_to_tracker(fd); | |
1671 | if (ret < 0) { | |
1672 | ret = close(fd); | |
1673 | if (ret) { | |
1674 | PERROR("close on sock_info->socket"); | |
1675 | } | |
1676 | ret = -1; | |
1677 | lttng_ust_unlock_fd_tracker(); | |
1678 | ust_unlock(); | |
1679 | goto quit; | |
1680 | } | |
1681 | ||
321f2351 | 1682 | sock_info->socket = ret; |
f5c453e9 | 1683 | lttng_ust_unlock_fd_tracker(); |
27fe9f21 | 1684 | |
6548fca4 MD |
1685 | ust_unlock(); |
1686 | /* | |
1687 | * Unlock/relock ust lock because connect is blocking (with | |
1688 | * timeout). Don't delay constructors on the ust lock for too | |
1689 | * long. | |
1690 | */ | |
3327ac33 | 1691 | if (ust_lock()) { |
5b14aab3 MD |
1692 | goto quit; |
1693 | } | |
1694 | ||
46050b1a MD |
1695 | /* |
1696 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1697 | * process lifetime, so we ensure we get ID which is statically |
1698 | * assigned to the root handle. | |
46050b1a MD |
1699 | */ |
1700 | if (sock_info->root_handle == -1) { | |
1701 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1702 | if (ret < 0) { |
46050b1a | 1703 | ERR("Error creating root handle"); |
46050b1a MD |
1704 | goto quit; |
1705 | } | |
1706 | sock_info->root_handle = ret; | |
9eb62b9c | 1707 | } |
1ea11eab | 1708 | |
32ce8569 | 1709 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1710 | if (ret < 0) { |
32ce8569 MD |
1711 | ERR("Error registering to %s ust cmd socket", |
1712 | sock_info->name); | |
c0eedf81 | 1713 | prev_connect_failed = 1; |
11ff9c7d MD |
1714 | /* |
1715 | * If we cannot register to the sessiond daemon, don't | |
1716 | * delay constructor execution. | |
1717 | */ | |
eb0e6022 | 1718 | ret = handle_register_failed(sock_info); |
11ff9c7d | 1719 | assert(!ret); |
17dfb34b | 1720 | ust_unlock(); |
9eb62b9c MD |
1721 | goto restart; |
1722 | } | |
321f2351 MD |
1723 | |
1724 | ust_unlock(); | |
6548fca4 MD |
1725 | /* |
1726 | * Unlock/relock ust lock because connect is blocking (with | |
1727 | * timeout). Don't delay constructors on the ust lock for too | |
1728 | * long. | |
1729 | */ | |
1730 | if (ust_lock()) { | |
1731 | goto quit; | |
1732 | } | |
321f2351 MD |
1733 | |
1734 | /* Connect notify socket */ | |
6548fca4 | 1735 | lttng_ust_lock_fd_tracker(); |
451d66b2 MD |
1736 | ret = ustcomm_connect_unix_sock(sock_info->sock_path, |
1737 | get_connect_sock_timeout()); | |
321f2351 | 1738 | if (ret < 0) { |
6548fca4 | 1739 | lttng_ust_unlock_fd_tracker(); |
321f2351 MD |
1740 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); |
1741 | prev_connect_failed = 1; | |
1742 | ||
321f2351 MD |
1743 | /* |
1744 | * If we cannot find the sessiond daemon, don't delay | |
1745 | * constructor execution. | |
1746 | */ | |
eb0e6022 | 1747 | ret = handle_register_failed(sock_info); |
321f2351 MD |
1748 | assert(!ret); |
1749 | ust_unlock(); | |
1750 | goto restart; | |
1751 | } | |
f5c453e9 JR |
1752 | |
1753 | fd = ret; | |
1754 | ret = lttng_ust_add_fd_to_tracker(fd); | |
1755 | if (ret < 0) { | |
1756 | ret = close(fd); | |
1757 | if (ret) { | |
1758 | PERROR("close on sock_info->notify_socket"); | |
1759 | } | |
1760 | ret = -1; | |
1761 | lttng_ust_unlock_fd_tracker(); | |
1762 | ust_unlock(); | |
1763 | goto quit; | |
1764 | } | |
1765 | ||
321f2351 | 1766 | sock_info->notify_socket = ret; |
f5c453e9 | 1767 | lttng_ust_unlock_fd_tracker(); |
321f2351 | 1768 | |
6548fca4 MD |
1769 | ust_unlock(); |
1770 | /* | |
1771 | * Unlock/relock ust lock because connect is blocking (with | |
1772 | * timeout). Don't delay constructors on the ust lock for too | |
1773 | * long. | |
1774 | */ | |
1775 | if (ust_lock()) { | |
1776 | goto quit; | |
1777 | } | |
1778 | ||
321f2351 MD |
1779 | timeout = get_notify_sock_timeout(); |
1780 | if (timeout >= 0) { | |
1781 | /* | |
1782 | * Give at least 10ms to sessiond to reply to | |
1783 | * notifications. | |
1784 | */ | |
1785 | if (timeout < 10) | |
1786 | timeout = 10; | |
1787 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1788 | timeout); | |
1789 | if (ret < 0) { | |
1790 | WARN("Error setting socket receive timeout"); | |
1791 | } | |
1792 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1793 | timeout); | |
1794 | if (ret < 0) { | |
1795 | WARN("Error setting socket send timeout"); | |
1796 | } | |
1797 | } else if (timeout < -1) { | |
1798 | WARN("Unsupported timeout value %ld", timeout); | |
1799 | } | |
1800 | ||
32ce8569 MD |
1801 | ret = register_to_sessiond(sock_info->notify_socket, |
1802 | USTCTL_SOCKET_NOTIFY); | |
1803 | if (ret < 0) { | |
1804 | ERR("Error registering to %s ust notify socket", | |
1805 | sock_info->name); | |
1806 | prev_connect_failed = 1; | |
1807 | /* | |
1808 | * If we cannot register to the sessiond daemon, don't | |
1809 | * delay constructor execution. | |
1810 | */ | |
eb0e6022 | 1811 | ret = handle_register_failed(sock_info); |
32ce8569 MD |
1812 | assert(!ret); |
1813 | ust_unlock(); | |
1814 | goto restart; | |
1815 | } | |
1816 | sock = sock_info->socket; | |
1817 | ||
17dfb34b | 1818 | ust_unlock(); |
46050b1a | 1819 | |
d9e99d10 MD |
1820 | for (;;) { |
1821 | ssize_t len; | |
57773204 | 1822 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1823 | |
57773204 | 1824 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1825 | switch (len) { |
1826 | case 0: /* orderly shutdown */ | |
7dd08bec | 1827 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1828 | if (ust_lock()) { |
d5e1fea6 MD |
1829 | goto quit; |
1830 | } | |
8236ba10 MD |
1831 | /* |
1832 | * Either sessiond has shutdown or refused us by closing the socket. | |
1833 | * In either case, we don't want to delay construction execution, | |
1834 | * and we need to wait before retry. | |
1835 | */ | |
1836 | prev_connect_failed = 1; | |
1837 | /* | |
1838 | * If we cannot register to the sessiond daemon, don't | |
1839 | * delay constructor execution. | |
1840 | */ | |
eb0e6022 | 1841 | ret = handle_register_failed(sock_info); |
8236ba10 MD |
1842 | assert(!ret); |
1843 | ust_unlock(); | |
d9e99d10 | 1844 | goto end; |
e7723462 | 1845 | case sizeof(lum): |
74d81a6c | 1846 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1847 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1848 | if (ret) { |
0dafcd63 MD |
1849 | ERR("Error handling message for %s socket", |
1850 | sock_info->name); | |
1851 | /* | |
1852 | * Close socket if protocol error is | |
1853 | * detected. | |
1854 | */ | |
1855 | goto end; | |
d9e99d10 MD |
1856 | } |
1857 | continue; | |
7bc53e94 MD |
1858 | default: |
1859 | if (len < 0) { | |
1860 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1861 | } else { | |
1862 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1863 | } | |
1864 | if (len == -ECONNRESET) { | |
1865 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1866 | goto end; |
1867 | } | |
1868 | goto end; | |
d9e99d10 MD |
1869 | } |
1870 | ||
1871 | } | |
1872 | end: | |
3327ac33 | 1873 | if (ust_lock()) { |
d5e1fea6 MD |
1874 | goto quit; |
1875 | } | |
f59ed768 MD |
1876 | /* Cleanup socket handles before trying to reconnect */ |
1877 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1878 | ust_unlock(); | |
9eb62b9c | 1879 | goto restart; /* try to reconnect */ |
e33f3265 | 1880 | |
1ea11eab | 1881 | quit: |
e33f3265 | 1882 | ust_unlock(); |
3327ac33 MD |
1883 | |
1884 | pthread_mutex_lock(&ust_exit_mutex); | |
1885 | sock_info->thread_active = 0; | |
1886 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1887 | return NULL; |
1888 | } | |
1889 | ||
2594a5b4 MD |
1890 | /* |
1891 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1892 | */ | |
1893 | __attribute__((weak)) | |
1894 | void lttng_ust_malloc_wrapper_init(void) | |
1895 | { | |
1896 | } | |
1897 | ||
2691221a MD |
1898 | /* |
1899 | * sessiond monitoring thread: monitor presence of global and per-user | |
1900 | * sessiond by polling the application common named pipe. | |
1901 | */ | |
edaa1431 | 1902 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1903 | { |
11ff9c7d | 1904 | struct timespec constructor_timeout; |
ae6a58bf | 1905 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1906 | pthread_attr_t thread_attr; |
cf12a773 | 1907 | int timeout_mode; |
2691221a | 1908 | int ret; |
b2292d85 | 1909 | void *handle; |
2691221a | 1910 | |
edaa1431 MD |
1911 | if (uatomic_xchg(&initialized, 1) == 1) |
1912 | return; | |
1913 | ||
eddd8d5d MD |
1914 | /* |
1915 | * Fixup interdependency between TLS fixup mutex (which happens | |
1916 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1917 | * the ust lock. | |
1918 | */ | |
c362addf | 1919 | lttng_ust_fixup_tls(); |
eddd8d5d | 1920 | |
07b57e5e MD |
1921 | lttng_ust_loaded = 1; |
1922 | ||
b2292d85 FD |
1923 | /* |
1924 | * We need to ensure that the liblttng-ust library is not unloaded to avoid | |
1925 | * the unloading of code used by the ust_listener_threads as we can not | |
1926 | * reliably know when they exited. To do that, manually load | |
1927 | * liblttng-ust.so to increment the dynamic loader's internal refcount for | |
1928 | * this library so it never becomes zero, thus never gets unloaded from the | |
1929 | * address space of the process. Since we are already running in the | |
1930 | * constructor of the LTTNG_UST_LIB_SO_NAME library, calling dlopen will | |
1931 | * simply increment the refcount and no additionnal work is needed by the | |
1932 | * dynamic loader as the shared library is already loaded in the address | |
1933 | * space. As a safe guard, we use the RTLD_NODELETE flag to prevent | |
1934 | * unloading of the UST library if its refcount becomes zero (which should | |
1935 | * never happen). Do the return value check but discard the handle at the | |
1936 | * end of the function as it's not needed. | |
1937 | */ | |
1938 | handle = dlopen(LTTNG_UST_LIB_SO_NAME, RTLD_LAZY | RTLD_NODELETE); | |
1939 | if (!handle) { | |
1940 | ERR("dlopen of liblttng-ust shared library (%s).", LTTNG_UST_LIB_SO_NAME); | |
1941 | } | |
1942 | ||
edaa1431 MD |
1943 | /* |
1944 | * We want precise control over the order in which we construct | |
1945 | * our sub-libraries vs starting to receive commands from | |
1946 | * sessiond (otherwise leading to errors when trying to create | |
1947 | * sessiond before the init functions are completed). | |
1948 | */ | |
2691221a | 1949 | init_usterr(); |
6f626d28 | 1950 | lttng_ust_getenv_init(); /* Needs init_usterr() to be completed. */ |
edaa1431 | 1951 | init_tracepoint(); |
6548fca4 | 1952 | lttng_ust_init_fd_tracker(); |
f9364363 | 1953 | lttng_ust_clock_init(); |
5e1b7b8b | 1954 | lttng_ust_getcpu_init(); |
cf73e0fe | 1955 | lttng_ust_statedump_init(); |
7dd08bec MD |
1956 | lttng_ring_buffer_metadata_client_init(); |
1957 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1958 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1959 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1960 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1961 | lttng_perf_counter_init(); |
2594a5b4 MD |
1962 | /* |
1963 | * Invoke ust malloc wrapper init before starting other threads. | |
1964 | */ | |
1965 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1966 | |
ff517991 | 1967 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1968 | |
b2c5f61a | 1969 | get_allow_blocking(); |
6f97f9c2 | 1970 | |
95259bd0 | 1971 | ret = sem_init(&constructor_wait, 0, 0); |
8aadb54a MD |
1972 | if (ret) { |
1973 | PERROR("sem_init"); | |
1974 | } | |
11ff9c7d | 1975 | |
060577e3 JR |
1976 | ret = setup_global_apps(); |
1977 | if (ret) { | |
1978 | assert(global_apps.allowed == 0); | |
1979 | DBG("global apps setup returned %d", ret); | |
1980 | } | |
1981 | ||
8d20bf54 | 1982 | ret = setup_local_apps(); |
2691221a | 1983 | if (ret) { |
060577e3 | 1984 | assert(local_apps.allowed == 0); |
9ec6895c | 1985 | DBG("local apps setup returned %d", ret); |
2691221a | 1986 | } |
ae6a58bf WP |
1987 | |
1988 | /* A new thread created by pthread_create inherits the signal mask | |
1989 | * from the parent. To avoid any signal being received by the | |
1990 | * listener thread, we block all signals temporarily in the parent, | |
1991 | * while we create the listener thread. | |
1992 | */ | |
1993 | sigfillset(&sig_all_blocked); | |
1994 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1995 | if (ret) { | |
d94d802c | 1996 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1997 | } |
1998 | ||
1879f67f MG |
1999 | ret = pthread_attr_init(&thread_attr); |
2000 | if (ret) { | |
2001 | ERR("pthread_attr_init: %s", strerror(ret)); | |
2002 | } | |
2003 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
2004 | if (ret) { | |
2005 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
2006 | } | |
2007 | ||
060577e3 JR |
2008 | if (global_apps.allowed) { |
2009 | pthread_mutex_lock(&ust_exit_mutex); | |
2010 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, | |
2011 | ust_listener_thread, &global_apps); | |
2012 | if (ret) { | |
2013 | ERR("pthread_create global: %s", strerror(ret)); | |
2014 | } | |
2015 | global_apps.thread_active = 1; | |
2016 | pthread_mutex_unlock(&ust_exit_mutex); | |
2017 | } else { | |
2018 | handle_register_done(&global_apps); | |
d94d802c | 2019 | } |
e33f3265 | 2020 | |
8d20bf54 | 2021 | if (local_apps.allowed) { |
c0bbbd5a | 2022 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 2023 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 2024 | ust_listener_thread, &local_apps); |
d94d802c MD |
2025 | if (ret) { |
2026 | ERR("pthread_create local: %s", strerror(ret)); | |
2027 | } | |
e33f3265 | 2028 | local_apps.thread_active = 1; |
c0bbbd5a | 2029 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
2030 | } else { |
2031 | handle_register_done(&local_apps); | |
2032 | } | |
1879f67f MG |
2033 | ret = pthread_attr_destroy(&thread_attr); |
2034 | if (ret) { | |
2035 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
2036 | } | |
8d20bf54 | 2037 | |
ae6a58bf WP |
2038 | /* Restore original signal mask in parent */ |
2039 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
2040 | if (ret) { | |
d94d802c | 2041 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
2042 | } |
2043 | ||
cf12a773 MD |
2044 | switch (timeout_mode) { |
2045 | case 1: /* timeout wait */ | |
95259bd0 MD |
2046 | do { |
2047 | ret = sem_timedwait(&constructor_wait, | |
2048 | &constructor_timeout); | |
2049 | } while (ret < 0 && errno == EINTR); | |
8aadb54a MD |
2050 | if (ret < 0) { |
2051 | switch (errno) { | |
2052 | case ETIMEDOUT: | |
2053 | ERR("Timed out waiting for lttng-sessiond"); | |
2054 | break; | |
2055 | case EINVAL: | |
2056 | PERROR("sem_timedwait"); | |
2057 | break; | |
2058 | default: | |
2059 | ERR("Unexpected error \"%s\" returned by sem_timedwait", | |
2060 | strerror(errno)); | |
2061 | } | |
cf12a773 MD |
2062 | } |
2063 | break; | |
7b766b16 | 2064 | case -1:/* wait forever */ |
95259bd0 MD |
2065 | do { |
2066 | ret = sem_wait(&constructor_wait); | |
2067 | } while (ret < 0 && errno == EINTR); | |
8aadb54a MD |
2068 | if (ret < 0) { |
2069 | switch (errno) { | |
2070 | case EINVAL: | |
2071 | PERROR("sem_wait"); | |
2072 | break; | |
2073 | default: | |
2074 | ERR("Unexpected error \"%s\" returned by sem_wait", | |
2075 | strerror(errno)); | |
2076 | } | |
2077 | } | |
cf12a773 | 2078 | break; |
7b766b16 | 2079 | case 0: /* no timeout */ |
cf12a773 | 2080 | break; |
11ff9c7d | 2081 | } |
2691221a MD |
2082 | } |
2083 | ||
17dfb34b MD |
2084 | static |
2085 | void lttng_ust_cleanup(int exiting) | |
2086 | { | |
efe0de09 | 2087 | cleanup_sock_info(&global_apps, exiting); |
932cfadb | 2088 | cleanup_sock_info(&local_apps, exiting); |
74f98bc9 | 2089 | local_apps.allowed = 0; |
060577e3 | 2090 | global_apps.allowed = 0; |
efe0de09 MD |
2091 | /* |
2092 | * The teardown in this function all affect data structures | |
2093 | * accessed under the UST lock by the listener thread. This | |
2094 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
2095 | * that none of these threads are accessing this data at this | |
2096 | * point. | |
2097 | */ | |
17dfb34b | 2098 | lttng_ust_abi_exit(); |
003fedf4 | 2099 | lttng_ust_events_exit(); |
d58d1454 | 2100 | lttng_perf_counter_exit(); |
34a91bdb | 2101 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 2102 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 2103 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
2104 | lttng_ring_buffer_client_overwrite_exit(); |
2105 | lttng_ring_buffer_metadata_client_exit(); | |
cf73e0fe | 2106 | lttng_ust_statedump_destroy(); |
17dfb34b MD |
2107 | exit_tracepoint(); |
2108 | if (!exiting) { | |
2109 | /* Reinitialize values for fork */ | |
eb0e6022 | 2110 | sem_count = sem_count_initial_value; |
17dfb34b MD |
2111 | lttng_ust_comm_should_quit = 0; |
2112 | initialized = 0; | |
2113 | } | |
2114 | } | |
2115 | ||
edaa1431 | 2116 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
2117 | { |
2118 | int ret; | |
2119 | ||
9eb62b9c MD |
2120 | /* |
2121 | * Using pthread_cancel here because: | |
2122 | * A) we don't want to hang application teardown. | |
2123 | * B) the thread is not allocating any resource. | |
2124 | */ | |
1ea11eab MD |
2125 | |
2126 | /* | |
2127 | * Require the communication thread to quit. Synchronize with | |
2128 | * mutexes to ensure it is not in a mutex critical section when | |
2129 | * pthread_cancel is later called. | |
2130 | */ | |
3327ac33 | 2131 | ust_lock_nocheck(); |
1ea11eab | 2132 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 2133 | ust_unlock(); |
1ea11eab | 2134 | |
3327ac33 | 2135 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 2136 | /* cancel threads */ |
e33f3265 MD |
2137 | if (global_apps.thread_active) { |
2138 | ret = pthread_cancel(global_apps.ust_listener); | |
2139 | if (ret) { | |
2140 | ERR("Error cancelling global ust listener thread: %s", | |
2141 | strerror(ret)); | |
2142 | } else { | |
2143 | global_apps.thread_active = 0; | |
2144 | } | |
2691221a | 2145 | } |
e33f3265 | 2146 | if (local_apps.thread_active) { |
8d20bf54 MD |
2147 | ret = pthread_cancel(local_apps.ust_listener); |
2148 | if (ret) { | |
d94d802c MD |
2149 | ERR("Error cancelling local ust listener thread: %s", |
2150 | strerror(ret)); | |
e33f3265 MD |
2151 | } else { |
2152 | local_apps.thread_active = 0; | |
8d20bf54 | 2153 | } |
8d20bf54 | 2154 | } |
3327ac33 | 2155 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 2156 | |
efe0de09 MD |
2157 | /* |
2158 | * Do NOT join threads: use of sys_futex makes it impossible to | |
2159 | * join the threads without using async-cancel, but async-cancel | |
2160 | * is delivered by a signal, which could hit the target thread | |
2161 | * anywhere in its code path, including while the ust_lock() is | |
2162 | * held, causing a deadlock for the other thread. Let the OS | |
2163 | * cleanup the threads if there are stalled in a syscall. | |
2164 | */ | |
17dfb34b | 2165 | lttng_ust_cleanup(1); |
2691221a | 2166 | } |
e822f505 | 2167 | |
735bef47 MJ |
2168 | static |
2169 | void ust_context_ns_reset(void) | |
2170 | { | |
2171 | lttng_context_pid_ns_reset(); | |
2172 | lttng_context_cgroup_ns_reset(); | |
2173 | lttng_context_ipc_ns_reset(); | |
2174 | lttng_context_mnt_ns_reset(); | |
2175 | lttng_context_net_ns_reset(); | |
2176 | lttng_context_user_ns_reset(); | |
cefef7a7 | 2177 | lttng_context_time_ns_reset(); |
735bef47 MJ |
2178 | lttng_context_uts_ns_reset(); |
2179 | } | |
2180 | ||
fca2f191 MJ |
2181 | static |
2182 | void ust_context_vuids_reset(void) | |
2183 | { | |
2184 | lttng_context_vuid_reset(); | |
2185 | lttng_context_veuid_reset(); | |
2186 | lttng_context_vsuid_reset(); | |
2187 | } | |
2188 | ||
2189 | static | |
2190 | void ust_context_vgids_reset(void) | |
2191 | { | |
2192 | lttng_context_vgid_reset(); | |
2193 | lttng_context_vegid_reset(); | |
2194 | lttng_context_vsgid_reset(); | |
2195 | } | |
2196 | ||
e822f505 MD |
2197 | /* |
2198 | * We exclude the worker threads across fork and clone (except | |
2199 | * CLONE_VM), because these system calls only keep the forking thread | |
2200 | * running in the child. Therefore, we don't want to call fork or clone | |
2201 | * in the middle of an tracepoint or ust tracing state modification. | |
2202 | * Holding this mutex protects these structures across fork and clone. | |
2203 | */ | |
b728d87e | 2204 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
2205 | { |
2206 | /* | |
2207 | * Disable signals. This is to avoid that the child intervenes | |
2208 | * before it is properly setup for tracing. It is safer to | |
2209 | * disable all signals, because then we know we are not breaking | |
2210 | * anything by restoring the original mask. | |
2211 | */ | |
2212 | sigset_t all_sigs; | |
2213 | int ret; | |
2214 | ||
c362addf MD |
2215 | /* Fixup lttng-ust TLS. */ |
2216 | lttng_ust_fixup_tls(); | |
2217 | ||
8c90a710 | 2218 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2219 | return; |
e822f505 MD |
2220 | /* Disable signals */ |
2221 | sigfillset(&all_sigs); | |
b728d87e | 2222 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
2223 | if (ret == -1) { |
2224 | PERROR("sigprocmask"); | |
2225 | } | |
458d678c PW |
2226 | |
2227 | pthread_mutex_lock(&ust_fork_mutex); | |
2228 | ||
3327ac33 | 2229 | ust_lock_nocheck(); |
d6ddec3f | 2230 | urcu_bp_before_fork(); |
c1be081a | 2231 | lttng_ust_lock_fd_tracker(); |
20142124 | 2232 | lttng_perf_lock(); |
e822f505 MD |
2233 | } |
2234 | ||
b728d87e | 2235 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
2236 | { |
2237 | int ret; | |
2238 | ||
17dfb34b | 2239 | DBG("process %d", getpid()); |
20142124 | 2240 | lttng_perf_unlock(); |
c1be081a | 2241 | lttng_ust_unlock_fd_tracker(); |
17dfb34b | 2242 | ust_unlock(); |
458d678c PW |
2243 | |
2244 | pthread_mutex_unlock(&ust_fork_mutex); | |
2245 | ||
e822f505 | 2246 | /* Restore signals */ |
23c8854a | 2247 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
2248 | if (ret == -1) { |
2249 | PERROR("sigprocmask"); | |
2250 | } | |
2251 | } | |
2252 | ||
b728d87e | 2253 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 2254 | { |
8c90a710 | 2255 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2256 | return; |
17dfb34b | 2257 | DBG("process %d", getpid()); |
d6ddec3f | 2258 | urcu_bp_after_fork_parent(); |
e822f505 | 2259 | /* Release mutexes and reenable signals */ |
b728d87e | 2260 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
2261 | } |
2262 | ||
17dfb34b MD |
2263 | /* |
2264 | * After fork, in the child, we need to cleanup all the leftover state, | |
2265 | * except the worker thread which already magically disappeared thanks | |
2266 | * to the weird Linux fork semantics. After tyding up, we call | |
2267 | * lttng_ust_init() again to start over as a new PID. | |
2268 | * | |
2269 | * This is meant for forks() that have tracing in the child between the | |
2270 | * fork and following exec call (if there is any). | |
2271 | */ | |
b728d87e | 2272 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 2273 | { |
8c90a710 | 2274 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2275 | return; |
06b16a0b | 2276 | lttng_context_vpid_reset(); |
8478887d | 2277 | lttng_context_vtid_reset(); |
46228a6f | 2278 | lttng_context_procname_reset(); |
735bef47 | 2279 | ust_context_ns_reset(); |
fca2f191 MJ |
2280 | ust_context_vuids_reset(); |
2281 | ust_context_vgids_reset(); | |
17dfb34b | 2282 | DBG("process %d", getpid()); |
e822f505 | 2283 | /* Release urcu mutexes */ |
d6ddec3f | 2284 | urcu_bp_after_fork_child(); |
17dfb34b | 2285 | lttng_ust_cleanup(0); |
e822f505 | 2286 | /* Release mutexes and reenable signals */ |
b728d87e | 2287 | ust_after_fork_common(restore_sigset); |
318dfea9 | 2288 | lttng_ust_init(); |
e822f505 | 2289 | } |
95c25348 | 2290 | |
735bef47 MJ |
2291 | void ust_after_setns(void) |
2292 | { | |
2293 | ust_context_ns_reset(); | |
fca2f191 MJ |
2294 | ust_context_vuids_reset(); |
2295 | ust_context_vgids_reset(); | |
735bef47 MJ |
2296 | } |
2297 | ||
2298 | void ust_after_unshare(void) | |
2299 | { | |
2300 | ust_context_ns_reset(); | |
fca2f191 MJ |
2301 | ust_context_vuids_reset(); |
2302 | ust_context_vgids_reset(); | |
2303 | } | |
2304 | ||
2305 | void ust_after_setuid(void) | |
2306 | { | |
2307 | ust_context_vuids_reset(); | |
2308 | } | |
2309 | ||
2310 | void ust_after_seteuid(void) | |
2311 | { | |
2312 | ust_context_vuids_reset(); | |
2313 | } | |
2314 | ||
2315 | void ust_after_setreuid(void) | |
2316 | { | |
2317 | ust_context_vuids_reset(); | |
2318 | } | |
2319 | ||
2320 | void ust_after_setresuid(void) | |
2321 | { | |
2322 | ust_context_vuids_reset(); | |
2323 | } | |
2324 | ||
2325 | void ust_after_setgid(void) | |
2326 | { | |
2327 | ust_context_vgids_reset(); | |
2328 | } | |
2329 | ||
2330 | void ust_after_setegid(void) | |
2331 | { | |
2332 | ust_context_vgids_reset(); | |
2333 | } | |
2334 | ||
2335 | void ust_after_setregid(void) | |
2336 | { | |
2337 | ust_context_vgids_reset(); | |
2338 | } | |
2339 | ||
2340 | void ust_after_setresgid(void) | |
2341 | { | |
2342 | ust_context_vgids_reset(); | |
735bef47 MJ |
2343 | } |
2344 | ||
246be17e | 2345 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
2346 | { |
2347 | struct sock_info *sock_info = owner; | |
37dddb65 | 2348 | sock_info->statedump_pending = 1; |
95c25348 | 2349 | } |