Commit | Line | Data |
---|---|---|
2691221a MD |
1 | /* |
2 | * lttng-ust-comm.c | |
3 | * | |
4 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; only | |
10 | * version 2.1 of the License. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with this library; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
80e2814b | 22 | #define _LGPL_SOURCE |
5e1b7b8b | 23 | #define _GNU_SOURCE |
2691221a MD |
24 | #include <sys/types.h> |
25 | #include <sys/socket.h> | |
7fc90dca MD |
26 | #include <sys/mman.h> |
27 | #include <sys/stat.h> | |
58d4b2a2 MD |
28 | #include <sys/types.h> |
29 | #include <sys/wait.h> | |
7fc90dca | 30 | #include <fcntl.h> |
2691221a MD |
31 | #include <unistd.h> |
32 | #include <errno.h> | |
d9e99d10 | 33 | #include <pthread.h> |
11ff9c7d MD |
34 | #include <semaphore.h> |
35 | #include <time.h> | |
1ea11eab | 36 | #include <assert.h> |
e822f505 | 37 | #include <signal.h> |
6f97f9c2 | 38 | #include <limits.h> |
95259bd0 | 39 | #include <urcu/uatomic.h> |
80e2814b | 40 | #include <urcu/futex.h> |
c117fb1b | 41 | #include <urcu/compiler.h> |
1ea11eab | 42 | |
4318ae1b | 43 | #include <lttng/ust-events.h> |
4318ae1b | 44 | #include <lttng/ust-abi.h> |
4318ae1b | 45 | #include <lttng/ust.h> |
7bc53e94 | 46 | #include <lttng/ust-error.h> |
74d81a6c | 47 | #include <lttng/ust-ctl.h> |
8c90a710 | 48 | #include <urcu/tls-compat.h> |
44c72f10 | 49 | #include <ust-comm.h> |
6548fca4 | 50 | #include <ust-fd.h> |
44c72f10 | 51 | #include <usterr-signal-safe.h> |
cd54f6d9 | 52 | #include <helper.h> |
44c72f10 | 53 | #include "tracepoint-internal.h" |
7dd08bec | 54 | #include "lttng-tracer-core.h" |
08114193 | 55 | #include "compat.h" |
6f97f9c2 | 56 | #include "../libringbuffer/rb-init.h" |
cf73e0fe | 57 | #include "lttng-ust-statedump.h" |
f9364363 | 58 | #include "clock.h" |
5e1b7b8b | 59 | #include "../libringbuffer/getcpu.h" |
13efba44 | 60 | #include "getenv.h" |
edaa1431 MD |
61 | |
62 | /* | |
63 | * Has lttng ust comm constructor been called ? | |
64 | */ | |
65 | static int initialized; | |
66 | ||
1ea11eab | 67 | /* |
17dfb34b MD |
68 | * The ust_lock/ust_unlock lock is used as a communication thread mutex. |
69 | * Held when handling a command, also held by fork() to deal with | |
70 | * removal of threads, and by exit path. | |
3327ac33 MD |
71 | * |
72 | * The UST lock is the centralized mutex across UST tracing control and | |
73 | * probe registration. | |
74 | * | |
75 | * ust_exit_mutex must never nest in ust_mutex. | |
d58d1454 | 76 | * |
4770bd47 MD |
77 | * ust_fork_mutex must never nest in ust_mutex. |
78 | * | |
d58d1454 MD |
79 | * ust_mutex_nest is a per-thread nesting counter, allowing the perf |
80 | * counter lazy initialization called by events within the statedump, | |
81 | * which traces while the ust_mutex is held. | |
4770bd47 MD |
82 | * |
83 | * ust_lock nests within the dynamic loader lock (within glibc) because | |
84 | * it is taken within the library constructor. | |
3327ac33 MD |
85 | */ |
86 | static pthread_mutex_t ust_mutex = PTHREAD_MUTEX_INITIALIZER; | |
87 | ||
d58d1454 MD |
88 | /* Allow nesting the ust_mutex within the same thread. */ |
89 | static DEFINE_URCU_TLS(int, ust_mutex_nest); | |
90 | ||
3327ac33 MD |
91 | /* |
92 | * ust_exit_mutex protects thread_active variable wrt thread exit. It | |
93 | * cannot be done by ust_mutex because pthread_cancel(), which takes an | |
94 | * internal libc lock, cannot nest within ust_mutex. | |
95 | * | |
96 | * It never nests within a ust_mutex. | |
1ea11eab | 97 | */ |
3327ac33 | 98 | static pthread_mutex_t ust_exit_mutex = PTHREAD_MUTEX_INITIALIZER; |
1ea11eab | 99 | |
458d678c PW |
100 | /* |
101 | * ust_fork_mutex protects base address statedump tracing against forks. It | |
102 | * prevents the dynamic loader lock to be taken (by base address statedump | |
103 | * tracing) while a fork is happening, thus preventing deadlock issues with | |
104 | * the dynamic loader lock. | |
105 | */ | |
106 | static pthread_mutex_t ust_fork_mutex = PTHREAD_MUTEX_INITIALIZER; | |
107 | ||
1ea11eab MD |
108 | /* Should the ust comm thread quit ? */ |
109 | static int lttng_ust_comm_should_quit; | |
110 | ||
07b57e5e MD |
111 | /* |
112 | * This variable can be tested by applications to check whether | |
113 | * lttng-ust is loaded. They simply have to define their own | |
114 | * "lttng_ust_loaded" weak symbol, and test it. It is set to 1 by the | |
115 | * library constructor. | |
116 | */ | |
117 | int lttng_ust_loaded __attribute__((weak)); | |
118 | ||
3327ac33 | 119 | /* |
d58d1454 | 120 | * Return 0 on success, -1 if should quit. |
3327ac33 | 121 | * The lock is taken in both cases. |
d58d1454 | 122 | * Signal-safe. |
3327ac33 MD |
123 | */ |
124 | int ust_lock(void) | |
125 | { | |
d58d1454 | 126 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 127 | int ret, oldstate; |
d58d1454 | 128 | |
e446ad80 MD |
129 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
130 | if (ret) { | |
131 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
132 | } | |
133 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
134 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
135 | } | |
d58d1454 MD |
136 | sigfillset(&sig_all_blocked); |
137 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
138 | if (ret) { | |
139 | ERR("pthread_sigmask: %s", strerror(ret)); | |
140 | } | |
141 | if (!URCU_TLS(ust_mutex_nest)++) | |
142 | pthread_mutex_lock(&ust_mutex); | |
143 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
144 | if (ret) { | |
145 | ERR("pthread_sigmask: %s", strerror(ret)); | |
146 | } | |
3327ac33 MD |
147 | if (lttng_ust_comm_should_quit) { |
148 | return -1; | |
149 | } else { | |
150 | return 0; | |
151 | } | |
152 | } | |
153 | ||
154 | /* | |
155 | * ust_lock_nocheck() can be used in constructors/destructors, because | |
156 | * they are already nested within the dynamic loader lock, and therefore | |
157 | * have exclusive access against execution of liblttng-ust destructor. | |
d58d1454 | 158 | * Signal-safe. |
3327ac33 MD |
159 | */ |
160 | void ust_lock_nocheck(void) | |
161 | { | |
d58d1454 | 162 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 163 | int ret, oldstate; |
d58d1454 | 164 | |
e446ad80 MD |
165 | ret = pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &oldstate); |
166 | if (ret) { | |
167 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
168 | } | |
169 | if (oldstate != PTHREAD_CANCEL_ENABLE) { | |
170 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
171 | } | |
d58d1454 MD |
172 | sigfillset(&sig_all_blocked); |
173 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
174 | if (ret) { | |
175 | ERR("pthread_sigmask: %s", strerror(ret)); | |
176 | } | |
177 | if (!URCU_TLS(ust_mutex_nest)++) | |
178 | pthread_mutex_lock(&ust_mutex); | |
179 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
180 | if (ret) { | |
181 | ERR("pthread_sigmask: %s", strerror(ret)); | |
182 | } | |
3327ac33 MD |
183 | } |
184 | ||
d58d1454 MD |
185 | /* |
186 | * Signal-safe. | |
187 | */ | |
3327ac33 MD |
188 | void ust_unlock(void) |
189 | { | |
d58d1454 | 190 | sigset_t sig_all_blocked, orig_mask; |
e446ad80 | 191 | int ret, oldstate; |
d58d1454 MD |
192 | |
193 | sigfillset(&sig_all_blocked); | |
194 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_mask); | |
195 | if (ret) { | |
196 | ERR("pthread_sigmask: %s", strerror(ret)); | |
197 | } | |
198 | if (!--URCU_TLS(ust_mutex_nest)) | |
199 | pthread_mutex_unlock(&ust_mutex); | |
200 | ret = pthread_sigmask(SIG_SETMASK, &orig_mask, NULL); | |
201 | if (ret) { | |
202 | ERR("pthread_sigmask: %s", strerror(ret)); | |
203 | } | |
e446ad80 MD |
204 | ret = pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); |
205 | if (ret) { | |
206 | ERR("pthread_setcancelstate: %s", strerror(ret)); | |
207 | } | |
208 | if (oldstate != PTHREAD_CANCEL_DISABLE) { | |
209 | ERR("pthread_setcancelstate: unexpected oldstate"); | |
210 | } | |
3327ac33 MD |
211 | } |
212 | ||
11ff9c7d MD |
213 | /* |
214 | * Wait for either of these before continuing to the main | |
215 | * program: | |
216 | * - the register_done message from sessiond daemon | |
217 | * (will let the sessiond daemon enable sessions before main | |
218 | * starts.) | |
219 | * - sessiond daemon is not reachable. | |
220 | * - timeout (ensuring applications are resilient to session | |
221 | * daemon problems). | |
222 | */ | |
223 | static sem_t constructor_wait; | |
950aab0c MD |
224 | /* |
225 | * Doing this for both the global and local sessiond. | |
226 | */ | |
95259bd0 | 227 | static int sem_count = { 2 }; |
11ff9c7d | 228 | |
e8508a49 MD |
229 | /* |
230 | * Counting nesting within lttng-ust. Used to ensure that calling fork() | |
231 | * from liblttng-ust does not execute the pre/post fork handlers. | |
232 | */ | |
8c90a710 | 233 | static DEFINE_URCU_TLS(int, lttng_ust_nest_count); |
e8508a49 | 234 | |
1ea11eab MD |
235 | /* |
236 | * Info about socket and associated listener thread. | |
237 | */ | |
238 | struct sock_info { | |
11ff9c7d | 239 | const char *name; |
1ea11eab | 240 | pthread_t ust_listener; /* listener thread */ |
46050b1a | 241 | int root_handle; |
8d20bf54 MD |
242 | int constructor_sem_posted; |
243 | int allowed; | |
44e073f5 | 244 | int global; |
e33f3265 | 245 | int thread_active; |
7fc90dca MD |
246 | |
247 | char sock_path[PATH_MAX]; | |
248 | int socket; | |
32ce8569 | 249 | int notify_socket; |
7fc90dca MD |
250 | |
251 | char wait_shm_path[PATH_MAX]; | |
252 | char *wait_shm_mmap; | |
37dddb65 MD |
253 | /* Keep track of lazy state dump not performed yet. */ |
254 | int statedump_pending; | |
1ea11eab | 255 | }; |
2691221a MD |
256 | |
257 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab | 258 | struct sock_info global_apps = { |
11ff9c7d | 259 | .name = "global", |
44e073f5 | 260 | .global = 1, |
7fc90dca | 261 | |
46050b1a | 262 | .root_handle = -1, |
ef4a06d9 | 263 | .allowed = 0, |
e33f3265 | 264 | .thread_active = 0, |
7fc90dca | 265 | |
32ce8569 | 266 | .sock_path = LTTNG_DEFAULT_RUNDIR "/" LTTNG_UST_SOCK_FILENAME, |
7fc90dca | 267 | .socket = -1, |
32ce8569 | 268 | .notify_socket = -1, |
7fc90dca | 269 | |
32ce8569 | 270 | .wait_shm_path = "/" LTTNG_UST_WAIT_FILENAME, |
95c25348 | 271 | |
37dddb65 | 272 | .statedump_pending = 0, |
1ea11eab | 273 | }; |
2691221a MD |
274 | |
275 | /* TODO: allow global_apps_sock_path override */ | |
276 | ||
1ea11eab | 277 | struct sock_info local_apps = { |
11ff9c7d | 278 | .name = "local", |
44e073f5 | 279 | .global = 0, |
46050b1a | 280 | .root_handle = -1, |
8d20bf54 | 281 | .allowed = 0, /* Check setuid bit first */ |
e33f3265 | 282 | .thread_active = 0, |
7fc90dca MD |
283 | |
284 | .socket = -1, | |
32ce8569 | 285 | .notify_socket = -1, |
95c25348 | 286 | |
37dddb65 | 287 | .statedump_pending = 0, |
1ea11eab | 288 | }; |
2691221a | 289 | |
37ed587a MD |
290 | static int wait_poll_fallback; |
291 | ||
74d81a6c MD |
292 | static const char *cmd_name_mapping[] = { |
293 | [ LTTNG_UST_RELEASE ] = "Release", | |
294 | [ LTTNG_UST_SESSION ] = "Create Session", | |
295 | [ LTTNG_UST_TRACER_VERSION ] = "Get Tracer Version", | |
296 | ||
297 | [ LTTNG_UST_TRACEPOINT_LIST ] = "Create Tracepoint List", | |
298 | [ LTTNG_UST_WAIT_QUIESCENT ] = "Wait for Quiescent State", | |
299 | [ LTTNG_UST_REGISTER_DONE ] = "Registration Done", | |
300 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST ] = "Create Tracepoint Field List", | |
301 | ||
302 | /* Session FD commands */ | |
303 | [ LTTNG_UST_CHANNEL ] = "Create Channel", | |
304 | [ LTTNG_UST_SESSION_START ] = "Start Session", | |
305 | [ LTTNG_UST_SESSION_STOP ] = "Stop Session", | |
306 | ||
307 | /* Channel FD commands */ | |
308 | [ LTTNG_UST_STREAM ] = "Create Stream", | |
309 | [ LTTNG_UST_EVENT ] = "Create Event", | |
310 | ||
311 | /* Event and Channel FD commands */ | |
312 | [ LTTNG_UST_CONTEXT ] = "Create Context", | |
313 | [ LTTNG_UST_FLUSH_BUFFER ] = "Flush Buffer", | |
314 | ||
315 | /* Event, Channel and Session commands */ | |
316 | [ LTTNG_UST_ENABLE ] = "Enable", | |
317 | [ LTTNG_UST_DISABLE ] = "Disable", | |
318 | ||
319 | /* Tracepoint list commands */ | |
320 | [ LTTNG_UST_TRACEPOINT_LIST_GET ] = "List Next Tracepoint", | |
321 | [ LTTNG_UST_TRACEPOINT_FIELD_LIST_GET ] = "List Next Tracepoint Field", | |
322 | ||
323 | /* Event FD commands */ | |
324 | [ LTTNG_UST_FILTER ] = "Create Filter", | |
75582b3a | 325 | [ LTTNG_UST_EXCLUSION ] = "Add exclusions to event", |
74d81a6c MD |
326 | }; |
327 | ||
ff517991 MD |
328 | static const char *str_timeout; |
329 | static int got_timeout_env; | |
330 | ||
7dd08bec | 331 | extern void lttng_ring_buffer_client_overwrite_init(void); |
34a91bdb | 332 | extern void lttng_ring_buffer_client_overwrite_rt_init(void); |
7dd08bec | 333 | extern void lttng_ring_buffer_client_discard_init(void); |
34a91bdb | 334 | extern void lttng_ring_buffer_client_discard_rt_init(void); |
7dd08bec MD |
335 | extern void lttng_ring_buffer_metadata_client_init(void); |
336 | extern void lttng_ring_buffer_client_overwrite_exit(void); | |
34a91bdb | 337 | extern void lttng_ring_buffer_client_overwrite_rt_exit(void); |
7dd08bec | 338 | extern void lttng_ring_buffer_client_discard_exit(void); |
34a91bdb | 339 | extern void lttng_ring_buffer_client_discard_rt_exit(void); |
7dd08bec | 340 | extern void lttng_ring_buffer_metadata_client_exit(void); |
edaa1431 | 341 | |
ef4a06d9 JR |
342 | static char *get_map_shm(struct sock_info *sock_info); |
343 | ||
405be658 MD |
344 | ssize_t lttng_ust_read(int fd, void *buf, size_t len) |
345 | { | |
346 | ssize_t ret; | |
347 | size_t copied = 0, to_copy = len; | |
348 | ||
349 | do { | |
350 | ret = read(fd, buf + copied, to_copy); | |
351 | if (ret > 0) { | |
352 | copied += ret; | |
353 | to_copy -= ret; | |
354 | } | |
355 | } while ((ret > 0 && to_copy > 0) | |
356 | || (ret < 0 && errno == EINTR)); | |
357 | if (ret > 0) { | |
358 | ret = copied; | |
359 | } | |
360 | return ret; | |
361 | } | |
3c6f6263 AM |
362 | /* |
363 | * Returns the HOME directory path. Caller MUST NOT free(3) the returned | |
364 | * pointer. | |
365 | */ | |
366 | static | |
367 | const char *get_lttng_home_dir(void) | |
368 | { | |
369 | const char *val; | |
370 | ||
6f626d28 | 371 | val = (const char *) lttng_getenv("LTTNG_HOME"); |
3c6f6263 AM |
372 | if (val != NULL) { |
373 | return val; | |
374 | } | |
6f626d28 | 375 | return (const char *) lttng_getenv("HOME"); |
3c6f6263 AM |
376 | } |
377 | ||
a903623f MD |
378 | /* |
379 | * Force a read (imply TLS fixup for dlopen) of TLS variables. | |
380 | */ | |
381 | static | |
382 | void lttng_fixup_nest_count_tls(void) | |
383 | { | |
8c90a710 | 384 | asm volatile ("" : : "m" (URCU_TLS(lttng_ust_nest_count))); |
a903623f MD |
385 | } |
386 | ||
d58d1454 MD |
387 | static |
388 | void lttng_fixup_ust_mutex_nest_tls(void) | |
389 | { | |
390 | asm volatile ("" : : "m" (URCU_TLS(ust_mutex_nest))); | |
391 | } | |
392 | ||
1556a549 MD |
393 | /* |
394 | * Fixup urcu bp TLS. | |
395 | */ | |
396 | static | |
397 | void lttng_fixup_urcu_bp_tls(void) | |
398 | { | |
399 | rcu_read_lock(); | |
400 | rcu_read_unlock(); | |
401 | } | |
402 | ||
c362addf MD |
403 | void lttng_ust_fixup_tls(void) |
404 | { | |
405 | lttng_fixup_urcu_bp_tls(); | |
406 | lttng_fixup_ringbuffer_tls(); | |
407 | lttng_fixup_vtid_tls(); | |
408 | lttng_fixup_nest_count_tls(); | |
409 | lttng_fixup_procname_tls(); | |
410 | lttng_fixup_ust_mutex_nest_tls(); | |
6548fca4 | 411 | lttng_ust_fixup_fd_tracker_tls(); |
c362addf MD |
412 | } |
413 | ||
32ce8569 MD |
414 | int lttng_get_notify_socket(void *owner) |
415 | { | |
416 | struct sock_info *info = owner; | |
417 | ||
418 | return info->notify_socket; | |
419 | } | |
420 | ||
74d81a6c MD |
421 | static |
422 | void print_cmd(int cmd, int handle) | |
423 | { | |
424 | const char *cmd_name = "Unknown"; | |
425 | ||
fd67a004 MD |
426 | if (cmd >= 0 && cmd < LTTNG_ARRAY_SIZE(cmd_name_mapping) |
427 | && cmd_name_mapping[cmd]) { | |
74d81a6c MD |
428 | cmd_name = cmd_name_mapping[cmd]; |
429 | } | |
fd67a004 MD |
430 | DBG("Message Received \"%s\" (%d), Handle \"%s\" (%d)", |
431 | cmd_name, cmd, | |
74d81a6c MD |
432 | lttng_ust_obj_get_name(handle), handle); |
433 | } | |
434 | ||
ef4a06d9 JR |
435 | static |
436 | int setup_global_apps(void) | |
437 | { | |
438 | int ret = 0; | |
439 | assert(!global_apps.wait_shm_mmap); | |
440 | ||
441 | global_apps.wait_shm_mmap = get_map_shm(&global_apps); | |
442 | if (!global_apps.wait_shm_mmap) { | |
443 | WARN("Unable to get map shm for global apps. Disabling LTTng-UST global tracing."); | |
444 | global_apps.allowed = 0; | |
445 | ret = -EIO; | |
446 | goto error; | |
447 | } | |
448 | ||
449 | global_apps.allowed = 1; | |
450 | error: | |
451 | return ret; | |
452 | } | |
2691221a | 453 | static |
8d20bf54 | 454 | int setup_local_apps(void) |
2691221a | 455 | { |
ef4a06d9 | 456 | int ret = 0; |
2691221a | 457 | const char *home_dir; |
7fc90dca | 458 | uid_t uid; |
2691221a | 459 | |
ef4a06d9 JR |
460 | assert(!local_apps.wait_shm_mmap); |
461 | ||
7fc90dca | 462 | uid = getuid(); |
8d20bf54 MD |
463 | /* |
464 | * Disallow per-user tracing for setuid binaries. | |
465 | */ | |
7fc90dca | 466 | if (uid != geteuid()) { |
9ec6895c | 467 | assert(local_apps.allowed == 0); |
ef4a06d9 JR |
468 | ret = 0; |
469 | goto end; | |
8d20bf54 | 470 | } |
3c6f6263 | 471 | home_dir = get_lttng_home_dir(); |
9ec6895c MD |
472 | if (!home_dir) { |
473 | WARN("HOME environment variable not set. Disabling LTTng-UST per-user tracing."); | |
474 | assert(local_apps.allowed == 0); | |
ef4a06d9 JR |
475 | ret = -ENOENT; |
476 | goto end; | |
9ec6895c MD |
477 | } |
478 | local_apps.allowed = 1; | |
32ce8569 MD |
479 | snprintf(local_apps.sock_path, PATH_MAX, "%s/%s/%s", |
480 | home_dir, | |
481 | LTTNG_DEFAULT_HOME_RUNDIR, | |
482 | LTTNG_UST_SOCK_FILENAME); | |
483 | snprintf(local_apps.wait_shm_path, PATH_MAX, "/%s-%u", | |
484 | LTTNG_UST_WAIT_FILENAME, | |
485 | uid); | |
ef4a06d9 JR |
486 | |
487 | local_apps.wait_shm_mmap = get_map_shm(&local_apps); | |
488 | if (!local_apps.wait_shm_mmap) { | |
489 | WARN("Unable to get map shm for local apps. Disabling LTTng-UST per-user tracing."); | |
490 | local_apps.allowed = 0; | |
491 | ret = -EIO; | |
492 | goto end; | |
493 | } | |
494 | end: | |
495 | return ret; | |
2691221a MD |
496 | } |
497 | ||
ff517991 | 498 | /* |
451d66b2 | 499 | * Get socket timeout, in ms. |
28515902 | 500 | * -1: wait forever. 0: don't wait. >0: timeout, in ms. |
ff517991 MD |
501 | */ |
502 | static | |
503 | long get_timeout(void) | |
504 | { | |
505 | long constructor_delay_ms = LTTNG_UST_DEFAULT_CONSTRUCTOR_TIMEOUT_MS; | |
506 | ||
507 | if (!got_timeout_env) { | |
6f626d28 | 508 | str_timeout = lttng_getenv("LTTNG_UST_REGISTER_TIMEOUT"); |
ff517991 MD |
509 | got_timeout_env = 1; |
510 | } | |
511 | if (str_timeout) | |
512 | constructor_delay_ms = strtol(str_timeout, NULL, 10); | |
5cf81d53 MD |
513 | /* All negative values are considered as "-1". */ |
514 | if (constructor_delay_ms < -1) | |
515 | constructor_delay_ms = -1; | |
ff517991 MD |
516 | return constructor_delay_ms; |
517 | } | |
518 | ||
451d66b2 | 519 | /* Timeout for notify socket send and recv. */ |
ff517991 MD |
520 | static |
521 | long get_notify_sock_timeout(void) | |
522 | { | |
523 | return get_timeout(); | |
524 | } | |
525 | ||
451d66b2 MD |
526 | /* Timeout for connecting to cmd and notify sockets. */ |
527 | static | |
528 | long get_connect_sock_timeout(void) | |
529 | { | |
530 | return get_timeout(); | |
531 | } | |
532 | ||
ff517991 | 533 | /* |
28515902 | 534 | * Return values: -1: wait forever. 0: don't wait. 1: timeout wait. |
ff517991 MD |
535 | */ |
536 | static | |
537 | int get_constructor_timeout(struct timespec *constructor_timeout) | |
538 | { | |
539 | long constructor_delay_ms; | |
540 | int ret; | |
541 | ||
542 | constructor_delay_ms = get_timeout(); | |
543 | ||
544 | switch (constructor_delay_ms) { | |
545 | case -1:/* fall-through */ | |
546 | case 0: | |
547 | return constructor_delay_ms; | |
548 | default: | |
549 | break; | |
550 | } | |
551 | ||
552 | /* | |
553 | * If we are unable to find the current time, don't wait. | |
554 | */ | |
555 | ret = clock_gettime(CLOCK_REALTIME, constructor_timeout); | |
556 | if (ret) { | |
28515902 JG |
557 | /* Don't wait. */ |
558 | return 0; | |
ff517991 MD |
559 | } |
560 | constructor_timeout->tv_sec += constructor_delay_ms / 1000UL; | |
561 | constructor_timeout->tv_nsec += | |
562 | (constructor_delay_ms % 1000UL) * 1000000UL; | |
563 | if (constructor_timeout->tv_nsec >= 1000000000UL) { | |
564 | constructor_timeout->tv_sec++; | |
565 | constructor_timeout->tv_nsec -= 1000000000UL; | |
566 | } | |
28515902 | 567 | /* Timeout wait (constructor_delay_ms). */ |
ff517991 MD |
568 | return 1; |
569 | } | |
570 | ||
6f97f9c2 | 571 | static |
9050321d | 572 | void get_allow_blocking(void) |
6f97f9c2 | 573 | { |
9050321d MD |
574 | const char *str_allow_blocking = |
575 | lttng_getenv("LTTNG_UST_ALLOW_BLOCKING"); | |
576 | ||
577 | if (str_allow_blocking) { | |
578 | DBG("%s environment variable is set", | |
579 | "LTTNG_UST_ALLOW_BLOCKING"); | |
580 | lttng_ust_ringbuffer_set_allow_blocking(); | |
6f97f9c2 MD |
581 | } |
582 | } | |
583 | ||
2691221a | 584 | static |
32ce8569 | 585 | int register_to_sessiond(int socket, enum ustctl_socket_type type) |
2691221a | 586 | { |
32ce8569 MD |
587 | return ustcomm_send_reg_msg(socket, |
588 | type, | |
589 | CAA_BITS_PER_LONG, | |
590 | lttng_alignof(uint8_t) * CHAR_BIT, | |
591 | lttng_alignof(uint16_t) * CHAR_BIT, | |
592 | lttng_alignof(uint32_t) * CHAR_BIT, | |
593 | lttng_alignof(uint64_t) * CHAR_BIT, | |
594 | lttng_alignof(unsigned long) * CHAR_BIT); | |
2691221a MD |
595 | } |
596 | ||
d9e99d10 | 597 | static |
57773204 | 598 | int send_reply(int sock, struct ustcomm_ust_reply *lur) |
d9e99d10 | 599 | { |
9eb62b9c | 600 | ssize_t len; |
d3a492d1 | 601 | |
57773204 | 602 | len = ustcomm_send_unix_sock(sock, lur, sizeof(*lur)); |
d3a492d1 | 603 | switch (len) { |
a4be8962 | 604 | case sizeof(*lur): |
d3a492d1 MD |
605 | DBG("message successfully sent"); |
606 | return 0; | |
7bc53e94 MD |
607 | default: |
608 | if (len == -ECONNRESET) { | |
609 | DBG("remote end closed connection"); | |
d3a492d1 MD |
610 | return 0; |
611 | } | |
7bc53e94 MD |
612 | if (len < 0) |
613 | return len; | |
614 | DBG("incorrect message size: %zd", len); | |
615 | return -EINVAL; | |
d3a492d1 MD |
616 | } |
617 | } | |
618 | ||
619 | static | |
edaa1431 | 620 | int handle_register_done(struct sock_info *sock_info) |
11ff9c7d MD |
621 | { |
622 | int ret; | |
623 | ||
edaa1431 MD |
624 | if (sock_info->constructor_sem_posted) |
625 | return 0; | |
626 | sock_info->constructor_sem_posted = 1; | |
56cd7e2f MD |
627 | if (uatomic_read(&sem_count) <= 0) { |
628 | return 0; | |
629 | } | |
95259bd0 MD |
630 | ret = uatomic_add_return(&sem_count, -1); |
631 | if (ret == 0) { | |
632 | ret = sem_post(&constructor_wait); | |
633 | assert(!ret); | |
634 | } | |
11ff9c7d MD |
635 | return 0; |
636 | } | |
637 | ||
37dddb65 MD |
638 | /* |
639 | * Only execute pending statedump after the constructor semaphore has | |
640 | * been posted by each listener thread. This means statedump will only | |
641 | * be performed after the "registration done" command is received from | |
642 | * each session daemon the application is connected to. | |
643 | * | |
644 | * This ensures we don't run into deadlock issues with the dynamic | |
645 | * loader mutex, which is held while the constructor is called and | |
646 | * waiting on the constructor semaphore. All operations requiring this | |
647 | * dynamic loader lock need to be postponed using this mechanism. | |
648 | */ | |
649 | static | |
650 | void handle_pending_statedump(struct sock_info *sock_info) | |
651 | { | |
652 | int ctor_passed = sock_info->constructor_sem_posted; | |
653 | ||
654 | if (ctor_passed && sock_info->statedump_pending) { | |
655 | sock_info->statedump_pending = 0; | |
2932a87f | 656 | pthread_mutex_lock(&ust_fork_mutex); |
37dddb65 | 657 | lttng_handle_pending_statedump(sock_info); |
458d678c | 658 | pthread_mutex_unlock(&ust_fork_mutex); |
37dddb65 MD |
659 | } |
660 | } | |
661 | ||
11ff9c7d MD |
662 | static |
663 | int handle_message(struct sock_info *sock_info, | |
57773204 | 664 | int sock, struct ustcomm_ust_msg *lum) |
d3a492d1 | 665 | { |
1ea11eab | 666 | int ret = 0; |
b61ce3b2 | 667 | const struct lttng_ust_objd_ops *ops; |
57773204 | 668 | struct ustcomm_ust_reply lur; |
ef9ff354 | 669 | union ust_args args; |
8e696cfa | 670 | char ctxstr[LTTNG_UST_SYM_NAME_LEN]; /* App context string. */ |
40003310 | 671 | ssize_t len; |
1ea11eab | 672 | |
46050b1a MD |
673 | memset(&lur, 0, sizeof(lur)); |
674 | ||
3327ac33 | 675 | if (ust_lock()) { |
74d81a6c | 676 | ret = -LTTNG_UST_ERR_EXITING; |
0dafcd63 | 677 | goto error; |
1ea11eab | 678 | } |
9eb62b9c | 679 | |
46050b1a MD |
680 | ops = objd_ops(lum->handle); |
681 | if (!ops) { | |
682 | ret = -ENOENT; | |
0dafcd63 | 683 | goto error; |
1ea11eab | 684 | } |
46050b1a MD |
685 | |
686 | switch (lum->cmd) { | |
11ff9c7d MD |
687 | case LTTNG_UST_REGISTER_DONE: |
688 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
edaa1431 | 689 | ret = handle_register_done(sock_info); |
11ff9c7d MD |
690 | else |
691 | ret = -EINVAL; | |
692 | break; | |
46050b1a MD |
693 | case LTTNG_UST_RELEASE: |
694 | if (lum->handle == LTTNG_UST_ROOT_HANDLE) | |
695 | ret = -EPERM; | |
696 | else | |
1849ef7c | 697 | ret = lttng_ust_objd_unref(lum->handle, 1); |
d9e99d10 | 698 | break; |
2d78951a MD |
699 | case LTTNG_UST_FILTER: |
700 | { | |
701 | /* Receive filter data */ | |
f488575f | 702 | struct lttng_ust_filter_bytecode_node *bytecode; |
2d78951a | 703 | |
cd54f6d9 | 704 | if (lum->u.filter.data_size > FILTER_BYTECODE_MAX_LEN) { |
7bc53e94 | 705 | ERR("Filter data size is too large: %u bytes", |
2d78951a MD |
706 | lum->u.filter.data_size); |
707 | ret = -EINVAL; | |
708 | goto error; | |
709 | } | |
2734ca65 | 710 | |
885b1dfd | 711 | if (lum->u.filter.reloc_offset > lum->u.filter.data_size) { |
7bc53e94 | 712 | ERR("Filter reloc offset %u is not within data", |
2734ca65 CB |
713 | lum->u.filter.reloc_offset); |
714 | ret = -EINVAL; | |
715 | goto error; | |
716 | } | |
717 | ||
cd54f6d9 MD |
718 | bytecode = zmalloc(sizeof(*bytecode) + lum->u.filter.data_size); |
719 | if (!bytecode) { | |
720 | ret = -ENOMEM; | |
721 | goto error; | |
722 | } | |
f488575f | 723 | len = ustcomm_recv_unix_sock(sock, bytecode->bc.data, |
2d78951a MD |
724 | lum->u.filter.data_size); |
725 | switch (len) { | |
726 | case 0: /* orderly shutdown */ | |
727 | ret = 0; | |
cd54f6d9 | 728 | free(bytecode); |
2d78951a | 729 | goto error; |
2d78951a MD |
730 | default: |
731 | if (len == lum->u.filter.data_size) { | |
7bc53e94 | 732 | DBG("filter data received"); |
2d78951a | 733 | break; |
7bc53e94 MD |
734 | } else if (len < 0) { |
735 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
736 | if (len == -ECONNRESET) { | |
737 | ERR("%s remote end closed connection", sock_info->name); | |
738 | ret = len; | |
739 | free(bytecode); | |
740 | goto error; | |
741 | } | |
742 | ret = len; | |
eb8bf361 | 743 | free(bytecode); |
0dafcd63 | 744 | goto error; |
2d78951a | 745 | } else { |
7bc53e94 | 746 | DBG("incorrect filter data message size: %zd", len); |
2d78951a | 747 | ret = -EINVAL; |
cd54f6d9 | 748 | free(bytecode); |
0dafcd63 | 749 | goto error; |
2d78951a MD |
750 | } |
751 | } | |
f488575f MD |
752 | bytecode->bc.len = lum->u.filter.data_size; |
753 | bytecode->bc.reloc_offset = lum->u.filter.reloc_offset; | |
3f6fd224 | 754 | bytecode->bc.seqnum = lum->u.filter.seqnum; |
cd54f6d9 | 755 | if (ops->cmd) { |
2d78951a | 756 | ret = ops->cmd(lum->handle, lum->cmd, |
cd54f6d9 | 757 | (unsigned long) bytecode, |
f59ed768 | 758 | &args, sock_info); |
cd54f6d9 MD |
759 | if (ret) { |
760 | free(bytecode); | |
761 | } | |
762 | /* don't free bytecode if everything went fine. */ | |
763 | } else { | |
2d78951a | 764 | ret = -ENOSYS; |
cd54f6d9 MD |
765 | free(bytecode); |
766 | } | |
2d78951a MD |
767 | break; |
768 | } | |
86e36163 JI |
769 | case LTTNG_UST_EXCLUSION: |
770 | { | |
771 | /* Receive exclusion names */ | |
772 | struct lttng_ust_excluder_node *node; | |
773 | unsigned int count; | |
774 | ||
775 | count = lum->u.exclusion.count; | |
776 | if (count == 0) { | |
777 | /* There are no names to read */ | |
778 | ret = 0; | |
779 | goto error; | |
780 | } | |
781 | node = zmalloc(sizeof(*node) + | |
782 | count * LTTNG_UST_SYM_NAME_LEN); | |
783 | if (!node) { | |
784 | ret = -ENOMEM; | |
785 | goto error; | |
786 | } | |
787 | node->excluder.count = count; | |
788 | len = ustcomm_recv_unix_sock(sock, node->excluder.names, | |
789 | count * LTTNG_UST_SYM_NAME_LEN); | |
790 | switch (len) { | |
791 | case 0: /* orderly shutdown */ | |
792 | ret = 0; | |
793 | free(node); | |
794 | goto error; | |
795 | default: | |
796 | if (len == count * LTTNG_UST_SYM_NAME_LEN) { | |
797 | DBG("Exclusion data received"); | |
798 | break; | |
799 | } else if (len < 0) { | |
800 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
801 | if (len == -ECONNRESET) { | |
802 | ERR("%s remote end closed connection", sock_info->name); | |
803 | ret = len; | |
804 | free(node); | |
805 | goto error; | |
806 | } | |
807 | ret = len; | |
808 | free(node); | |
0dafcd63 | 809 | goto error; |
86e36163 JI |
810 | } else { |
811 | DBG("Incorrect exclusion data message size: %zd", len); | |
812 | ret = -EINVAL; | |
813 | free(node); | |
0dafcd63 | 814 | goto error; |
86e36163 JI |
815 | } |
816 | } | |
817 | if (ops->cmd) { | |
818 | ret = ops->cmd(lum->handle, lum->cmd, | |
819 | (unsigned long) node, | |
820 | &args, sock_info); | |
821 | if (ret) { | |
822 | free(node); | |
823 | } | |
824 | /* Don't free exclusion data if everything went fine. */ | |
825 | } else { | |
826 | ret = -ENOSYS; | |
827 | free(node); | |
828 | } | |
829 | break; | |
830 | } | |
74d81a6c MD |
831 | case LTTNG_UST_CHANNEL: |
832 | { | |
833 | void *chan_data; | |
ff0f5728 | 834 | int wakeup_fd; |
74d81a6c MD |
835 | |
836 | len = ustcomm_recv_channel_from_sessiond(sock, | |
ff0f5728 MD |
837 | &chan_data, lum->u.channel.len, |
838 | &wakeup_fd); | |
74d81a6c MD |
839 | switch (len) { |
840 | case 0: /* orderly shutdown */ | |
841 | ret = 0; | |
842 | goto error; | |
843 | default: | |
844 | if (len == lum->u.channel.len) { | |
845 | DBG("channel data received"); | |
846 | break; | |
847 | } else if (len < 0) { | |
848 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
849 | if (len == -ECONNRESET) { | |
850 | ERR("%s remote end closed connection", sock_info->name); | |
851 | ret = len; | |
852 | goto error; | |
853 | } | |
854 | ret = len; | |
0dafcd63 | 855 | goto error; |
74d81a6c MD |
856 | } else { |
857 | DBG("incorrect channel data message size: %zd", len); | |
858 | ret = -EINVAL; | |
0dafcd63 | 859 | goto error; |
74d81a6c MD |
860 | } |
861 | } | |
862 | args.channel.chan_data = chan_data; | |
ff0f5728 | 863 | args.channel.wakeup_fd = wakeup_fd; |
74d81a6c MD |
864 | if (ops->cmd) |
865 | ret = ops->cmd(lum->handle, lum->cmd, | |
866 | (unsigned long) &lum->u, | |
867 | &args, sock_info); | |
868 | else | |
869 | ret = -ENOSYS; | |
870 | break; | |
871 | } | |
872 | case LTTNG_UST_STREAM: | |
873 | { | |
874 | /* Receive shm_fd, wakeup_fd */ | |
875 | ret = ustcomm_recv_stream_from_sessiond(sock, | |
729df81e | 876 | NULL, |
74d81a6c MD |
877 | &args.stream.shm_fd, |
878 | &args.stream.wakeup_fd); | |
879 | if (ret) { | |
0dafcd63 | 880 | goto error; |
74d81a6c | 881 | } |
cf4dd19d | 882 | |
74d81a6c MD |
883 | if (ops->cmd) |
884 | ret = ops->cmd(lum->handle, lum->cmd, | |
885 | (unsigned long) &lum->u, | |
886 | &args, sock_info); | |
887 | else | |
888 | ret = -ENOSYS; | |
889 | break; | |
890 | } | |
8e696cfa MD |
891 | case LTTNG_UST_CONTEXT: |
892 | switch (lum->u.context.ctx) { | |
893 | case LTTNG_UST_CONTEXT_APP_CONTEXT: | |
894 | { | |
895 | char *p; | |
896 | size_t ctxlen, recvlen; | |
897 | ||
898 | ctxlen = strlen("$app.") + lum->u.context.u.app_ctx.provider_name_len - 1 | |
899 | + strlen(":") + lum->u.context.u.app_ctx.ctx_name_len; | |
900 | if (ctxlen >= LTTNG_UST_SYM_NAME_LEN) { | |
901 | ERR("Application context string length size is too large: %zu bytes", | |
902 | ctxlen); | |
903 | ret = -EINVAL; | |
904 | goto error; | |
905 | } | |
906 | strcpy(ctxstr, "$app."); | |
907 | p = &ctxstr[strlen("$app.")]; | |
908 | recvlen = ctxlen - strlen("$app."); | |
909 | len = ustcomm_recv_unix_sock(sock, p, recvlen); | |
910 | switch (len) { | |
911 | case 0: /* orderly shutdown */ | |
912 | ret = 0; | |
913 | goto error; | |
914 | default: | |
915 | if (len == recvlen) { | |
916 | DBG("app context data received"); | |
917 | break; | |
918 | } else if (len < 0) { | |
919 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
920 | if (len == -ECONNRESET) { | |
921 | ERR("%s remote end closed connection", sock_info->name); | |
922 | ret = len; | |
923 | goto error; | |
924 | } | |
925 | ret = len; | |
926 | goto error; | |
927 | } else { | |
928 | DBG("incorrect app context data message size: %zd", len); | |
929 | ret = -EINVAL; | |
930 | goto error; | |
931 | } | |
932 | } | |
933 | /* Put : between provider and ctxname. */ | |
934 | p[lum->u.context.u.app_ctx.provider_name_len - 1] = ':'; | |
935 | args.app_context.ctxname = ctxstr; | |
936 | break; | |
937 | } | |
938 | default: | |
939 | break; | |
940 | } | |
941 | if (ops->cmd) { | |
942 | ret = ops->cmd(lum->handle, lum->cmd, | |
943 | (unsigned long) &lum->u, | |
944 | &args, sock_info); | |
945 | } else { | |
946 | ret = -ENOSYS; | |
947 | } | |
948 | break; | |
d9e99d10 | 949 | default: |
46050b1a MD |
950 | if (ops->cmd) |
951 | ret = ops->cmd(lum->handle, lum->cmd, | |
ef9ff354 | 952 | (unsigned long) &lum->u, |
f59ed768 | 953 | &args, sock_info); |
46050b1a MD |
954 | else |
955 | ret = -ENOSYS; | |
956 | break; | |
d9e99d10 | 957 | } |
46050b1a | 958 | |
46050b1a MD |
959 | lur.handle = lum->handle; |
960 | lur.cmd = lum->cmd; | |
961 | lur.ret_val = ret; | |
962 | if (ret >= 0) { | |
7bc53e94 | 963 | lur.ret_code = LTTNG_UST_OK; |
46050b1a | 964 | } else { |
7bc53e94 MD |
965 | /* |
966 | * Use -LTTNG_UST_ERR as wildcard for UST internal | |
967 | * error that are not caused by the transport, except if | |
968 | * we already have a more precise error message to | |
969 | * report. | |
970 | */ | |
64b2564e DG |
971 | if (ret > -LTTNG_UST_ERR) { |
972 | /* Translate code to UST error. */ | |
973 | switch (ret) { | |
974 | case -EEXIST: | |
975 | lur.ret_code = -LTTNG_UST_ERR_EXIST; | |
976 | break; | |
977 | case -EINVAL: | |
978 | lur.ret_code = -LTTNG_UST_ERR_INVAL; | |
979 | break; | |
980 | case -ENOENT: | |
981 | lur.ret_code = -LTTNG_UST_ERR_NOENT; | |
982 | break; | |
983 | case -EPERM: | |
984 | lur.ret_code = -LTTNG_UST_ERR_PERM; | |
985 | break; | |
986 | case -ENOSYS: | |
987 | lur.ret_code = -LTTNG_UST_ERR_NOSYS; | |
988 | break; | |
989 | default: | |
990 | lur.ret_code = -LTTNG_UST_ERR; | |
991 | break; | |
992 | } | |
993 | } else { | |
7bc53e94 | 994 | lur.ret_code = ret; |
64b2564e | 995 | } |
46050b1a | 996 | } |
e6ea14c5 MD |
997 | if (ret >= 0) { |
998 | switch (lum->cmd) { | |
e6ea14c5 MD |
999 | case LTTNG_UST_TRACER_VERSION: |
1000 | lur.u.version = lum->u.version; | |
1001 | break; | |
1002 | case LTTNG_UST_TRACEPOINT_LIST_GET: | |
1003 | memcpy(&lur.u.tracepoint, &lum->u.tracepoint, sizeof(lur.u.tracepoint)); | |
1004 | break; | |
1005 | } | |
381c0f1e | 1006 | } |
74d81a6c | 1007 | DBG("Return value: %d", lur.ret_val); |
4c62d8d1 MD |
1008 | |
1009 | ust_unlock(); | |
1010 | ||
1011 | /* | |
1012 | * Performed delayed statedump operations outside of the UST | |
1013 | * lock. We need to take the dynamic loader lock before we take | |
1014 | * the UST lock internally within handle_pending_statedump(). | |
1015 | */ | |
1016 | handle_pending_statedump(sock_info); | |
1017 | ||
1018 | if (ust_lock()) { | |
1019 | ret = -LTTNG_UST_ERR_EXITING; | |
1020 | goto error; | |
1021 | } | |
1022 | ||
46050b1a | 1023 | ret = send_reply(sock, &lur); |
193183fb | 1024 | if (ret < 0) { |
7bc53e94 | 1025 | DBG("error sending reply"); |
193183fb MD |
1026 | goto error; |
1027 | } | |
46050b1a | 1028 | |
40003310 MD |
1029 | /* |
1030 | * LTTNG_UST_TRACEPOINT_FIELD_LIST_GET needs to send the field | |
1031 | * after the reply. | |
1032 | */ | |
7bc53e94 | 1033 | if (lur.ret_code == LTTNG_UST_OK) { |
40003310 MD |
1034 | switch (lum->cmd) { |
1035 | case LTTNG_UST_TRACEPOINT_FIELD_LIST_GET: | |
1036 | len = ustcomm_send_unix_sock(sock, | |
1037 | &args.field_list.entry, | |
1038 | sizeof(args.field_list.entry)); | |
7bc53e94 MD |
1039 | if (len < 0) { |
1040 | ret = len; | |
1041 | goto error; | |
1042 | } | |
40003310 | 1043 | if (len != sizeof(args.field_list.entry)) { |
7bc53e94 | 1044 | ret = -EINVAL; |
40003310 MD |
1045 | goto error; |
1046 | } | |
1047 | } | |
1048 | } | |
ef9ff354 | 1049 | |
381c0f1e | 1050 | error: |
17dfb34b | 1051 | ust_unlock(); |
d9e99d10 | 1052 | |
37dddb65 | 1053 | return ret; |
246be17e PW |
1054 | } |
1055 | ||
46050b1a | 1056 | static |
efe0de09 | 1057 | void cleanup_sock_info(struct sock_info *sock_info, int exiting) |
46050b1a MD |
1058 | { |
1059 | int ret; | |
1060 | ||
5b14aab3 MD |
1061 | if (sock_info->root_handle != -1) { |
1062 | ret = lttng_ust_objd_unref(sock_info->root_handle, 1); | |
1063 | if (ret) { | |
1064 | ERR("Error unref root handle"); | |
1065 | } | |
1066 | sock_info->root_handle = -1; | |
1067 | } | |
1068 | sock_info->constructor_sem_posted = 0; | |
1069 | ||
1070 | /* | |
1071 | * wait_shm_mmap, socket and notify socket are used by listener | |
1072 | * threads outside of the ust lock, so we cannot tear them down | |
1073 | * ourselves, because we cannot join on these threads. Leave | |
1074 | * responsibility of cleaning up these resources to the OS | |
1075 | * process exit. | |
1076 | */ | |
1077 | if (exiting) | |
1078 | return; | |
1079 | ||
46050b1a | 1080 | if (sock_info->socket != -1) { |
e6973a89 | 1081 | ret = ustcomm_close_unix_sock(sock_info->socket); |
46050b1a | 1082 | if (ret) { |
32ce8569 | 1083 | ERR("Error closing ust cmd socket"); |
46050b1a MD |
1084 | } |
1085 | sock_info->socket = -1; | |
1086 | } | |
32ce8569 MD |
1087 | if (sock_info->notify_socket != -1) { |
1088 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); | |
1089 | if (ret) { | |
1090 | ERR("Error closing ust notify socket"); | |
1091 | } | |
1092 | sock_info->notify_socket = -1; | |
1093 | } | |
5b14aab3 | 1094 | if (sock_info->wait_shm_mmap) { |
172d6b68 MD |
1095 | long page_size; |
1096 | ||
1097 | page_size = sysconf(_SC_PAGE_SIZE); | |
2657d1ba MD |
1098 | if (page_size <= 0) { |
1099 | if (!page_size) { | |
1100 | errno = EINVAL; | |
1101 | } | |
1102 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
1103 | } else { | |
172d6b68 MD |
1104 | ret = munmap(sock_info->wait_shm_mmap, page_size); |
1105 | if (ret) { | |
1106 | ERR("Error unmapping wait shm"); | |
1107 | } | |
7fc90dca MD |
1108 | } |
1109 | sock_info->wait_shm_mmap = NULL; | |
1110 | } | |
1111 | } | |
1112 | ||
58d4b2a2 | 1113 | /* |
33bbeb90 MD |
1114 | * Using fork to set umask in the child process (not multi-thread safe). |
1115 | * We deal with the shm_open vs ftruncate race (happening when the | |
1116 | * sessiond owns the shm and does not let everybody modify it, to ensure | |
1117 | * safety against shm_unlink) by simply letting the mmap fail and | |
1118 | * retrying after a few seconds. | |
1119 | * For global shm, everybody has rw access to it until the sessiond | |
1120 | * starts. | |
58d4b2a2 | 1121 | */ |
7fc90dca | 1122 | static |
58d4b2a2 | 1123 | int get_wait_shm(struct sock_info *sock_info, size_t mmap_size) |
7fc90dca | 1124 | { |
7fc90dca | 1125 | int wait_shm_fd, ret; |
58d4b2a2 | 1126 | pid_t pid; |
44e073f5 | 1127 | |
58d4b2a2 | 1128 | /* |
33bbeb90 | 1129 | * Try to open read-only. |
58d4b2a2 | 1130 | */ |
33bbeb90 | 1131 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 | 1132 | if (wait_shm_fd >= 0) { |
7aa76730 MD |
1133 | int32_t tmp_read; |
1134 | ssize_t len; | |
1135 | size_t bytes_read = 0; | |
1136 | ||
1137 | /* | |
1138 | * Try to read the fd. If unable to do so, try opening | |
1139 | * it in write mode. | |
1140 | */ | |
1141 | do { | |
1142 | len = read(wait_shm_fd, | |
1143 | &((char *) &tmp_read)[bytes_read], | |
1144 | sizeof(tmp_read) - bytes_read); | |
1145 | if (len > 0) { | |
1146 | bytes_read += len; | |
1147 | } | |
1148 | } while ((len < 0 && errno == EINTR) | |
1149 | || (len > 0 && bytes_read < sizeof(tmp_read))); | |
1150 | if (bytes_read != sizeof(tmp_read)) { | |
1151 | ret = close(wait_shm_fd); | |
1152 | if (ret) { | |
1153 | ERR("close wait_shm_fd"); | |
1154 | } | |
1155 | goto open_write; | |
1156 | } | |
58d4b2a2 MD |
1157 | goto end; |
1158 | } else if (wait_shm_fd < 0 && errno != ENOENT) { | |
1159 | /* | |
33bbeb90 MD |
1160 | * Real-only open did not work, and it's not because the |
1161 | * entry was not present. It's a failure that prohibits | |
1162 | * using shm. | |
58d4b2a2 | 1163 | */ |
7fc90dca | 1164 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
58d4b2a2 | 1165 | goto end; |
7fc90dca | 1166 | } |
7aa76730 MD |
1167 | |
1168 | open_write: | |
7fc90dca | 1169 | /* |
7aa76730 MD |
1170 | * If the open failed because the file did not exist, or because |
1171 | * the file was not truncated yet, try creating it ourself. | |
7fc90dca | 1172 | */ |
8c90a710 | 1173 | URCU_TLS(lttng_ust_nest_count)++; |
58d4b2a2 | 1174 | pid = fork(); |
8c90a710 | 1175 | URCU_TLS(lttng_ust_nest_count)--; |
58d4b2a2 MD |
1176 | if (pid > 0) { |
1177 | int status; | |
1178 | ||
1179 | /* | |
1180 | * Parent: wait for child to return, in which case the | |
1181 | * shared memory map will have been created. | |
1182 | */ | |
1183 | pid = wait(&status); | |
b7d3cb32 | 1184 | if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
58d4b2a2 MD |
1185 | wait_shm_fd = -1; |
1186 | goto end; | |
7fc90dca | 1187 | } |
58d4b2a2 MD |
1188 | /* |
1189 | * Try to open read-only again after creation. | |
1190 | */ | |
33bbeb90 | 1191 | wait_shm_fd = shm_open(sock_info->wait_shm_path, O_RDONLY, 0); |
58d4b2a2 MD |
1192 | if (wait_shm_fd < 0) { |
1193 | /* | |
1194 | * Real-only open did not work. It's a failure | |
1195 | * that prohibits using shm. | |
1196 | */ | |
1197 | ERR("Error opening shm %s", sock_info->wait_shm_path); | |
1198 | goto end; | |
1199 | } | |
1200 | goto end; | |
1201 | } else if (pid == 0) { | |
1202 | int create_mode; | |
1203 | ||
1204 | /* Child */ | |
33bbeb90 | 1205 | create_mode = S_IRUSR | S_IWUSR | S_IRGRP; |
58d4b2a2 | 1206 | if (sock_info->global) |
33bbeb90 | 1207 | create_mode |= S_IROTH | S_IWGRP | S_IWOTH; |
58d4b2a2 MD |
1208 | /* |
1209 | * We're alone in a child process, so we can modify the | |
1210 | * process-wide umask. | |
1211 | */ | |
33bbeb90 | 1212 | umask(~create_mode); |
58d4b2a2 | 1213 | /* |
33bbeb90 MD |
1214 | * Try creating shm (or get rw access). |
1215 | * We don't do an exclusive open, because we allow other | |
1216 | * processes to create+ftruncate it concurrently. | |
58d4b2a2 MD |
1217 | */ |
1218 | wait_shm_fd = shm_open(sock_info->wait_shm_path, | |
1219 | O_RDWR | O_CREAT, create_mode); | |
1220 | if (wait_shm_fd >= 0) { | |
1221 | ret = ftruncate(wait_shm_fd, mmap_size); | |
1222 | if (ret) { | |
1223 | PERROR("ftruncate"); | |
b0c1425d | 1224 | _exit(EXIT_FAILURE); |
58d4b2a2 | 1225 | } |
b0c1425d | 1226 | _exit(EXIT_SUCCESS); |
58d4b2a2 | 1227 | } |
33bbeb90 MD |
1228 | /* |
1229 | * For local shm, we need to have rw access to accept | |
1230 | * opening it: this means the local sessiond will be | |
1231 | * able to wake us up. For global shm, we open it even | |
1232 | * if rw access is not granted, because the root.root | |
1233 | * sessiond will be able to override all rights and wake | |
1234 | * us up. | |
1235 | */ | |
1236 | if (!sock_info->global && errno != EACCES) { | |
58d4b2a2 | 1237 | ERR("Error opening shm %s", sock_info->wait_shm_path); |
5d3bc5ed | 1238 | _exit(EXIT_FAILURE); |
58d4b2a2 MD |
1239 | } |
1240 | /* | |
33bbeb90 MD |
1241 | * The shm exists, but we cannot open it RW. Report |
1242 | * success. | |
58d4b2a2 | 1243 | */ |
5d3bc5ed | 1244 | _exit(EXIT_SUCCESS); |
58d4b2a2 MD |
1245 | } else { |
1246 | return -1; | |
7fc90dca | 1247 | } |
58d4b2a2 | 1248 | end: |
33bbeb90 MD |
1249 | if (wait_shm_fd >= 0 && !sock_info->global) { |
1250 | struct stat statbuf; | |
1251 | ||
1252 | /* | |
1253 | * Ensure that our user is the owner of the shm file for | |
1254 | * local shm. If we do not own the file, it means our | |
1255 | * sessiond will not have access to wake us up (there is | |
1256 | * probably a rogue process trying to fake our | |
1257 | * sessiond). Fallback to polling method in this case. | |
1258 | */ | |
1259 | ret = fstat(wait_shm_fd, &statbuf); | |
1260 | if (ret) { | |
1261 | PERROR("fstat"); | |
1262 | goto error_close; | |
1263 | } | |
1264 | if (statbuf.st_uid != getuid()) | |
1265 | goto error_close; | |
1266 | } | |
58d4b2a2 | 1267 | return wait_shm_fd; |
33bbeb90 MD |
1268 | |
1269 | error_close: | |
1270 | ret = close(wait_shm_fd); | |
1271 | if (ret) { | |
1272 | PERROR("Error closing fd"); | |
1273 | } | |
1274 | return -1; | |
58d4b2a2 MD |
1275 | } |
1276 | ||
1277 | static | |
1278 | char *get_map_shm(struct sock_info *sock_info) | |
1279 | { | |
172d6b68 | 1280 | long page_size; |
58d4b2a2 MD |
1281 | int wait_shm_fd, ret; |
1282 | char *wait_shm_mmap; | |
1283 | ||
172d6b68 | 1284 | page_size = sysconf(_SC_PAGE_SIZE); |
2657d1ba MD |
1285 | if (page_size <= 0) { |
1286 | if (!page_size) { | |
1287 | errno = EINVAL; | |
1288 | } | |
1289 | PERROR("Error in sysconf(_SC_PAGE_SIZE)"); | |
172d6b68 MD |
1290 | goto error; |
1291 | } | |
1292 | ||
6548fca4 | 1293 | lttng_ust_lock_fd_tracker(); |
172d6b68 | 1294 | wait_shm_fd = get_wait_shm(sock_info, page_size); |
58d4b2a2 | 1295 | if (wait_shm_fd < 0) { |
6548fca4 | 1296 | lttng_ust_unlock_fd_tracker(); |
58d4b2a2 | 1297 | goto error; |
44e073f5 | 1298 | } |
0dd6b494 JR |
1299 | |
1300 | ret = lttng_ust_add_fd_to_tracker(wait_shm_fd); | |
1301 | if (ret < 0) { | |
1302 | ret = close(wait_shm_fd); | |
1303 | if (!ret) { | |
1304 | PERROR("Error closing fd"); | |
1305 | } | |
1306 | lttng_ust_unlock_fd_tracker(); | |
1307 | goto error; | |
1308 | } | |
1309 | ||
1310 | wait_shm_fd = ret; | |
6548fca4 MD |
1311 | lttng_ust_unlock_fd_tracker(); |
1312 | ||
172d6b68 | 1313 | wait_shm_mmap = mmap(NULL, page_size, PROT_READ, |
7fc90dca | 1314 | MAP_SHARED, wait_shm_fd, 0); |
6548fca4 | 1315 | |
7fc90dca | 1316 | /* close shm fd immediately after taking the mmap reference */ |
6548fca4 | 1317 | lttng_ust_lock_fd_tracker(); |
7fc90dca | 1318 | ret = close(wait_shm_fd); |
6548fca4 MD |
1319 | if (!ret) { |
1320 | lttng_ust_delete_fd_from_tracker(wait_shm_fd); | |
1321 | } else { | |
33bbeb90 MD |
1322 | PERROR("Error closing fd"); |
1323 | } | |
6548fca4 MD |
1324 | lttng_ust_unlock_fd_tracker(); |
1325 | ||
33bbeb90 MD |
1326 | if (wait_shm_mmap == MAP_FAILED) { |
1327 | DBG("mmap error (can be caused by race with sessiond). Fallback to poll mode."); | |
1328 | goto error; | |
7fc90dca MD |
1329 | } |
1330 | return wait_shm_mmap; | |
1331 | ||
1332 | error: | |
1333 | return NULL; | |
1334 | } | |
1335 | ||
1336 | static | |
1337 | void wait_for_sessiond(struct sock_info *sock_info) | |
1338 | { | |
ef4a06d9 | 1339 | /* Use ust_lock to check if we should quit. */ |
3327ac33 | 1340 | if (ust_lock()) { |
7fc90dca MD |
1341 | goto quit; |
1342 | } | |
37ed587a MD |
1343 | if (wait_poll_fallback) { |
1344 | goto error; | |
1345 | } | |
7fc90dca MD |
1346 | ust_unlock(); |
1347 | ||
ef4a06d9 JR |
1348 | assert(sock_info->wait_shm_mmap); |
1349 | ||
7fc90dca | 1350 | DBG("Waiting for %s apps sessiond", sock_info->name); |
80e2814b | 1351 | /* Wait for futex wakeup */ |
ee7fcec8 MD |
1352 | if (uatomic_read((int32_t *) sock_info->wait_shm_mmap)) |
1353 | goto end_wait; | |
1354 | ||
1355 | while (futex_async((int32_t *) sock_info->wait_shm_mmap, | |
1356 | FUTEX_WAIT, 0, NULL, NULL, 0)) { | |
1357 | switch (errno) { | |
1358 | case EWOULDBLOCK: | |
1359 | /* Value already changed. */ | |
1360 | goto end_wait; | |
1361 | case EINTR: | |
1362 | /* Retry if interrupted by signal. */ | |
1363 | break; /* Get out of switch. */ | |
1364 | case EFAULT: | |
1365 | wait_poll_fallback = 1; | |
1366 | DBG( | |
37ed587a MD |
1367 | "Linux kernels 2.6.33 to 3.0 (with the exception of stable versions) " |
1368 | "do not support FUTEX_WAKE on read-only memory mappings correctly. " | |
1369 | "Please upgrade your kernel " | |
1370 | "(fix is commit 9ea71503a8ed9184d2d0b8ccc4d269d05f7940ae in Linux kernel " | |
1371 | "mainline). LTTng-UST will use polling mode fallback."); | |
ee7fcec8 MD |
1372 | if (ust_debug()) |
1373 | PERROR("futex"); | |
1374 | goto end_wait; | |
80e2814b MD |
1375 | } |
1376 | } | |
ee7fcec8 | 1377 | end_wait: |
7fc90dca MD |
1378 | return; |
1379 | ||
1380 | quit: | |
1381 | ust_unlock(); | |
1382 | return; | |
1383 | ||
1384 | error: | |
1385 | ust_unlock(); | |
7fc90dca | 1386 | return; |
46050b1a MD |
1387 | } |
1388 | ||
1ea11eab MD |
1389 | /* |
1390 | * This thread does not allocate any resource, except within | |
1391 | * handle_message, within mutex protection. This mutex protects against | |
1392 | * fork and exit. | |
98bf993f | 1393 | * The other moment it allocates resources is at socket connection, which |
1ea11eab MD |
1394 | * is also protected by the mutex. |
1395 | */ | |
d9e99d10 MD |
1396 | static |
1397 | void *ust_listener_thread(void *arg) | |
1398 | { | |
1ea11eab | 1399 | struct sock_info *sock_info = arg; |
0dd6b494 | 1400 | int sock, ret, prev_connect_failed = 0, has_waited = 0, fd; |
ff517991 | 1401 | long timeout; |
d9e99d10 | 1402 | |
c362addf | 1403 | lttng_ust_fixup_tls(); |
01f0e40c RB |
1404 | /* |
1405 | * If available, add '-ust' to the end of this thread's | |
1406 | * process name | |
1407 | */ | |
1408 | ret = lttng_ust_setustprocname(); | |
1409 | if (ret) { | |
1410 | ERR("Unable to set UST process name"); | |
1411 | } | |
1412 | ||
9eb62b9c MD |
1413 | /* Restart trying to connect to the session daemon */ |
1414 | restart: | |
c0eedf81 MD |
1415 | if (prev_connect_failed) { |
1416 | /* Wait for sessiond availability with pipe */ | |
1417 | wait_for_sessiond(sock_info); | |
1418 | if (has_waited) { | |
1419 | has_waited = 0; | |
1420 | /* | |
1421 | * Sleep for 5 seconds before retrying after a | |
1422 | * sequence of failure / wait / failure. This | |
1423 | * deals with a killed or broken session daemon. | |
1424 | */ | |
1425 | sleep(5); | |
eacc4aa4 MD |
1426 | } else { |
1427 | has_waited = 1; | |
c0eedf81 | 1428 | } |
c0eedf81 MD |
1429 | prev_connect_failed = 0; |
1430 | } | |
9eb62b9c | 1431 | |
0818d379 JR |
1432 | if (ust_lock()) { |
1433 | goto quit; | |
1434 | } | |
1435 | ||
1ea11eab | 1436 | if (sock_info->socket != -1) { |
6548fca4 | 1437 | /* FD tracker is updated by ustcomm_close_unix_sock() */ |
e6973a89 | 1438 | ret = ustcomm_close_unix_sock(sock_info->socket); |
1ea11eab | 1439 | if (ret) { |
32ce8569 MD |
1440 | ERR("Error closing %s ust cmd socket", |
1441 | sock_info->name); | |
1ea11eab MD |
1442 | } |
1443 | sock_info->socket = -1; | |
1444 | } | |
32ce8569 | 1445 | if (sock_info->notify_socket != -1) { |
6548fca4 | 1446 | /* FD tracker is updated by ustcomm_close_unix_sock() */ |
32ce8569 MD |
1447 | ret = ustcomm_close_unix_sock(sock_info->notify_socket); |
1448 | if (ret) { | |
1449 | ERR("Error closing %s ust notify socket", | |
1450 | sock_info->name); | |
1451 | } | |
1452 | sock_info->notify_socket = -1; | |
1453 | } | |
46050b1a | 1454 | |
6548fca4 | 1455 | |
321f2351 MD |
1456 | /* |
1457 | * Register. We need to perform both connect and sending | |
1458 | * registration message before doing the next connect otherwise | |
1459 | * we may reach unix socket connect queue max limits and block | |
1460 | * on the 2nd connect while the session daemon is awaiting the | |
1461 | * first connect registration message. | |
1462 | */ | |
1463 | /* Connect cmd socket */ | |
6548fca4 | 1464 | lttng_ust_lock_fd_tracker(); |
451d66b2 MD |
1465 | ret = ustcomm_connect_unix_sock(sock_info->sock_path, |
1466 | get_connect_sock_timeout()); | |
321f2351 | 1467 | if (ret < 0) { |
6548fca4 | 1468 | lttng_ust_unlock_fd_tracker(); |
321f2351 MD |
1469 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); |
1470 | prev_connect_failed = 1; | |
5b14aab3 | 1471 | |
e3426ddc | 1472 | /* |
321f2351 MD |
1473 | * If we cannot find the sessiond daemon, don't delay |
1474 | * constructor execution. | |
e3426ddc | 1475 | */ |
321f2351 MD |
1476 | ret = handle_register_done(sock_info); |
1477 | assert(!ret); | |
1478 | ust_unlock(); | |
1479 | goto restart; | |
27fe9f21 | 1480 | } |
0dd6b494 JR |
1481 | fd = ret; |
1482 | ret = lttng_ust_add_fd_to_tracker(fd); | |
1483 | if (ret < 0) { | |
1484 | ret = close(fd); | |
1485 | if (ret) { | |
1486 | PERROR("close on sock_info->socket"); | |
1487 | } | |
1488 | ret = -1; | |
1489 | lttng_ust_unlock_fd_tracker(); | |
1490 | ust_unlock(); | |
1491 | goto quit; | |
1492 | } | |
1493 | ||
321f2351 | 1494 | sock_info->socket = ret; |
0dd6b494 | 1495 | lttng_ust_unlock_fd_tracker(); |
27fe9f21 | 1496 | |
6548fca4 MD |
1497 | ust_unlock(); |
1498 | /* | |
1499 | * Unlock/relock ust lock because connect is blocking (with | |
1500 | * timeout). Don't delay constructors on the ust lock for too | |
1501 | * long. | |
1502 | */ | |
3327ac33 | 1503 | if (ust_lock()) { |
5b14aab3 MD |
1504 | goto quit; |
1505 | } | |
1506 | ||
46050b1a MD |
1507 | /* |
1508 | * Create only one root handle per listener thread for the whole | |
f59ed768 MD |
1509 | * process lifetime, so we ensure we get ID which is statically |
1510 | * assigned to the root handle. | |
46050b1a MD |
1511 | */ |
1512 | if (sock_info->root_handle == -1) { | |
1513 | ret = lttng_abi_create_root_handle(); | |
a51070bb | 1514 | if (ret < 0) { |
46050b1a | 1515 | ERR("Error creating root handle"); |
46050b1a MD |
1516 | goto quit; |
1517 | } | |
1518 | sock_info->root_handle = ret; | |
9eb62b9c | 1519 | } |
1ea11eab | 1520 | |
32ce8569 | 1521 | ret = register_to_sessiond(sock_info->socket, USTCTL_SOCKET_CMD); |
9eb62b9c | 1522 | if (ret < 0) { |
32ce8569 MD |
1523 | ERR("Error registering to %s ust cmd socket", |
1524 | sock_info->name); | |
c0eedf81 | 1525 | prev_connect_failed = 1; |
11ff9c7d MD |
1526 | /* |
1527 | * If we cannot register to the sessiond daemon, don't | |
1528 | * delay constructor execution. | |
1529 | */ | |
edaa1431 | 1530 | ret = handle_register_done(sock_info); |
11ff9c7d | 1531 | assert(!ret); |
17dfb34b | 1532 | ust_unlock(); |
9eb62b9c MD |
1533 | goto restart; |
1534 | } | |
321f2351 MD |
1535 | |
1536 | ust_unlock(); | |
6548fca4 MD |
1537 | /* |
1538 | * Unlock/relock ust lock because connect is blocking (with | |
1539 | * timeout). Don't delay constructors on the ust lock for too | |
1540 | * long. | |
1541 | */ | |
1542 | if (ust_lock()) { | |
1543 | goto quit; | |
1544 | } | |
321f2351 MD |
1545 | |
1546 | /* Connect notify socket */ | |
6548fca4 | 1547 | lttng_ust_lock_fd_tracker(); |
451d66b2 MD |
1548 | ret = ustcomm_connect_unix_sock(sock_info->sock_path, |
1549 | get_connect_sock_timeout()); | |
321f2351 | 1550 | if (ret < 0) { |
6548fca4 | 1551 | lttng_ust_unlock_fd_tracker(); |
321f2351 MD |
1552 | DBG("Info: sessiond not accepting connections to %s apps socket", sock_info->name); |
1553 | prev_connect_failed = 1; | |
1554 | ||
321f2351 MD |
1555 | /* |
1556 | * If we cannot find the sessiond daemon, don't delay | |
1557 | * constructor execution. | |
1558 | */ | |
1559 | ret = handle_register_done(sock_info); | |
1560 | assert(!ret); | |
1561 | ust_unlock(); | |
1562 | goto restart; | |
1563 | } | |
0dd6b494 JR |
1564 | |
1565 | fd = ret; | |
1566 | ret = lttng_ust_add_fd_to_tracker(fd); | |
1567 | if (ret < 0) { | |
1568 | ret = close(fd); | |
1569 | if (ret) { | |
1570 | PERROR("close on sock_info->notify_socket"); | |
1571 | } | |
1572 | ret = -1; | |
1573 | lttng_ust_unlock_fd_tracker(); | |
1574 | ust_unlock(); | |
1575 | goto quit; | |
1576 | } | |
1577 | ||
321f2351 | 1578 | sock_info->notify_socket = ret; |
0dd6b494 | 1579 | lttng_ust_unlock_fd_tracker(); |
321f2351 | 1580 | |
6548fca4 MD |
1581 | ust_unlock(); |
1582 | /* | |
1583 | * Unlock/relock ust lock because connect is blocking (with | |
1584 | * timeout). Don't delay constructors on the ust lock for too | |
1585 | * long. | |
1586 | */ | |
1587 | if (ust_lock()) { | |
1588 | goto quit; | |
1589 | } | |
1590 | ||
321f2351 MD |
1591 | timeout = get_notify_sock_timeout(); |
1592 | if (timeout >= 0) { | |
1593 | /* | |
1594 | * Give at least 10ms to sessiond to reply to | |
1595 | * notifications. | |
1596 | */ | |
1597 | if (timeout < 10) | |
1598 | timeout = 10; | |
1599 | ret = ustcomm_setsockopt_rcv_timeout(sock_info->notify_socket, | |
1600 | timeout); | |
1601 | if (ret < 0) { | |
1602 | WARN("Error setting socket receive timeout"); | |
1603 | } | |
1604 | ret = ustcomm_setsockopt_snd_timeout(sock_info->notify_socket, | |
1605 | timeout); | |
1606 | if (ret < 0) { | |
1607 | WARN("Error setting socket send timeout"); | |
1608 | } | |
1609 | } else if (timeout < -1) { | |
1610 | WARN("Unsupported timeout value %ld", timeout); | |
1611 | } | |
1612 | ||
32ce8569 MD |
1613 | ret = register_to_sessiond(sock_info->notify_socket, |
1614 | USTCTL_SOCKET_NOTIFY); | |
1615 | if (ret < 0) { | |
1616 | ERR("Error registering to %s ust notify socket", | |
1617 | sock_info->name); | |
1618 | prev_connect_failed = 1; | |
1619 | /* | |
1620 | * If we cannot register to the sessiond daemon, don't | |
1621 | * delay constructor execution. | |
1622 | */ | |
1623 | ret = handle_register_done(sock_info); | |
1624 | assert(!ret); | |
1625 | ust_unlock(); | |
1626 | goto restart; | |
1627 | } | |
1628 | sock = sock_info->socket; | |
1629 | ||
17dfb34b | 1630 | ust_unlock(); |
46050b1a | 1631 | |
d9e99d10 MD |
1632 | for (;;) { |
1633 | ssize_t len; | |
57773204 | 1634 | struct ustcomm_ust_msg lum; |
d9e99d10 | 1635 | |
57773204 | 1636 | len = ustcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
1637 | switch (len) { |
1638 | case 0: /* orderly shutdown */ | |
7dd08bec | 1639 | DBG("%s lttng-sessiond has performed an orderly shutdown", sock_info->name); |
3327ac33 | 1640 | if (ust_lock()) { |
d5e1fea6 MD |
1641 | goto quit; |
1642 | } | |
8236ba10 MD |
1643 | /* |
1644 | * Either sessiond has shutdown or refused us by closing the socket. | |
1645 | * In either case, we don't want to delay construction execution, | |
1646 | * and we need to wait before retry. | |
1647 | */ | |
1648 | prev_connect_failed = 1; | |
1649 | /* | |
1650 | * If we cannot register to the sessiond daemon, don't | |
1651 | * delay constructor execution. | |
1652 | */ | |
1653 | ret = handle_register_done(sock_info); | |
1654 | assert(!ret); | |
1655 | ust_unlock(); | |
d9e99d10 | 1656 | goto end; |
e7723462 | 1657 | case sizeof(lum): |
74d81a6c | 1658 | print_cmd(lum.cmd, lum.handle); |
11ff9c7d | 1659 | ret = handle_message(sock_info, sock, &lum); |
7bc53e94 | 1660 | if (ret) { |
0dafcd63 MD |
1661 | ERR("Error handling message for %s socket", |
1662 | sock_info->name); | |
1663 | /* | |
1664 | * Close socket if protocol error is | |
1665 | * detected. | |
1666 | */ | |
1667 | goto end; | |
d9e99d10 MD |
1668 | } |
1669 | continue; | |
7bc53e94 MD |
1670 | default: |
1671 | if (len < 0) { | |
1672 | DBG("Receive failed from lttng-sessiond with errno %d", (int) -len); | |
1673 | } else { | |
1674 | DBG("incorrect message size (%s socket): %zd", sock_info->name, len); | |
1675 | } | |
1676 | if (len == -ECONNRESET) { | |
1677 | DBG("%s remote end closed connection", sock_info->name); | |
d9e99d10 MD |
1678 | goto end; |
1679 | } | |
1680 | goto end; | |
d9e99d10 MD |
1681 | } |
1682 | ||
1683 | } | |
1684 | end: | |
3327ac33 | 1685 | if (ust_lock()) { |
d5e1fea6 MD |
1686 | goto quit; |
1687 | } | |
f59ed768 MD |
1688 | /* Cleanup socket handles before trying to reconnect */ |
1689 | lttng_ust_objd_table_owner_cleanup(sock_info); | |
1690 | ust_unlock(); | |
9eb62b9c | 1691 | goto restart; /* try to reconnect */ |
e33f3265 | 1692 | |
1ea11eab | 1693 | quit: |
e33f3265 | 1694 | ust_unlock(); |
3327ac33 MD |
1695 | |
1696 | pthread_mutex_lock(&ust_exit_mutex); | |
1697 | sock_info->thread_active = 0; | |
1698 | pthread_mutex_unlock(&ust_exit_mutex); | |
d9e99d10 MD |
1699 | return NULL; |
1700 | } | |
1701 | ||
2594a5b4 MD |
1702 | /* |
1703 | * Weak symbol to call when the ust malloc wrapper is not loaded. | |
1704 | */ | |
1705 | __attribute__((weak)) | |
1706 | void lttng_ust_malloc_wrapper_init(void) | |
1707 | { | |
1708 | } | |
1709 | ||
2691221a MD |
1710 | /* |
1711 | * sessiond monitoring thread: monitor presence of global and per-user | |
1712 | * sessiond by polling the application common named pipe. | |
1713 | */ | |
edaa1431 | 1714 | void __attribute__((constructor)) lttng_ust_init(void) |
2691221a | 1715 | { |
11ff9c7d | 1716 | struct timespec constructor_timeout; |
ae6a58bf | 1717 | sigset_t sig_all_blocked, orig_parent_mask; |
1879f67f | 1718 | pthread_attr_t thread_attr; |
cf12a773 | 1719 | int timeout_mode; |
2691221a MD |
1720 | int ret; |
1721 | ||
edaa1431 MD |
1722 | if (uatomic_xchg(&initialized, 1) == 1) |
1723 | return; | |
1724 | ||
eddd8d5d MD |
1725 | /* |
1726 | * Fixup interdependency between TLS fixup mutex (which happens | |
1727 | * to be the dynamic linker mutex) and ust_lock, taken within | |
1728 | * the ust lock. | |
1729 | */ | |
c362addf | 1730 | lttng_ust_fixup_tls(); |
eddd8d5d | 1731 | |
07b57e5e MD |
1732 | lttng_ust_loaded = 1; |
1733 | ||
edaa1431 MD |
1734 | /* |
1735 | * We want precise control over the order in which we construct | |
1736 | * our sub-libraries vs starting to receive commands from | |
1737 | * sessiond (otherwise leading to errors when trying to create | |
1738 | * sessiond before the init functions are completed). | |
1739 | */ | |
2691221a | 1740 | init_usterr(); |
6f626d28 | 1741 | lttng_ust_getenv_init(); /* Needs init_usterr() to be completed. */ |
edaa1431 | 1742 | init_tracepoint(); |
6548fca4 | 1743 | lttng_ust_init_fd_tracker(); |
f9364363 | 1744 | lttng_ust_clock_init(); |
5e1b7b8b | 1745 | lttng_ust_getcpu_init(); |
cf73e0fe | 1746 | lttng_ust_statedump_init(); |
7dd08bec MD |
1747 | lttng_ring_buffer_metadata_client_init(); |
1748 | lttng_ring_buffer_client_overwrite_init(); | |
34a91bdb | 1749 | lttng_ring_buffer_client_overwrite_rt_init(); |
7dd08bec | 1750 | lttng_ring_buffer_client_discard_init(); |
34a91bdb | 1751 | lttng_ring_buffer_client_discard_rt_init(); |
d58d1454 | 1752 | lttng_perf_counter_init(); |
2594a5b4 MD |
1753 | /* |
1754 | * Invoke ust malloc wrapper init before starting other threads. | |
1755 | */ | |
1756 | lttng_ust_malloc_wrapper_init(); | |
2691221a | 1757 | |
ff517991 | 1758 | timeout_mode = get_constructor_timeout(&constructor_timeout); |
11ff9c7d | 1759 | |
9050321d | 1760 | get_allow_blocking(); |
6f97f9c2 | 1761 | |
95259bd0 | 1762 | ret = sem_init(&constructor_wait, 0, 0); |
8aadb54a MD |
1763 | if (ret) { |
1764 | PERROR("sem_init"); | |
1765 | } | |
11ff9c7d | 1766 | |
ef4a06d9 JR |
1767 | ret = setup_global_apps(); |
1768 | if (ret) { | |
1769 | assert(global_apps.allowed == 0); | |
1770 | DBG("global apps setup returned %d", ret); | |
1771 | } | |
1772 | ||
8d20bf54 | 1773 | ret = setup_local_apps(); |
2691221a | 1774 | if (ret) { |
ef4a06d9 | 1775 | assert(local_apps.allowed == 0); |
9ec6895c | 1776 | DBG("local apps setup returned %d", ret); |
2691221a | 1777 | } |
ae6a58bf WP |
1778 | |
1779 | /* A new thread created by pthread_create inherits the signal mask | |
1780 | * from the parent. To avoid any signal being received by the | |
1781 | * listener thread, we block all signals temporarily in the parent, | |
1782 | * while we create the listener thread. | |
1783 | */ | |
1784 | sigfillset(&sig_all_blocked); | |
1785 | ret = pthread_sigmask(SIG_SETMASK, &sig_all_blocked, &orig_parent_mask); | |
1786 | if (ret) { | |
d94d802c | 1787 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1788 | } |
1789 | ||
1879f67f MG |
1790 | ret = pthread_attr_init(&thread_attr); |
1791 | if (ret) { | |
1792 | ERR("pthread_attr_init: %s", strerror(ret)); | |
1793 | } | |
1794 | ret = pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED); | |
1795 | if (ret) { | |
1796 | ERR("pthread_attr_setdetachstate: %s", strerror(ret)); | |
1797 | } | |
1798 | ||
ef4a06d9 JR |
1799 | if (global_apps.allowed) { |
1800 | pthread_mutex_lock(&ust_exit_mutex); | |
1801 | ret = pthread_create(&global_apps.ust_listener, &thread_attr, | |
1802 | ust_listener_thread, &global_apps); | |
1803 | if (ret) { | |
1804 | ERR("pthread_create global: %s", strerror(ret)); | |
1805 | } | |
1806 | global_apps.thread_active = 1; | |
1807 | pthread_mutex_unlock(&ust_exit_mutex); | |
1808 | } else { | |
1809 | handle_register_done(&global_apps); | |
d94d802c | 1810 | } |
e33f3265 | 1811 | |
8d20bf54 | 1812 | if (local_apps.allowed) { |
c0bbbd5a | 1813 | pthread_mutex_lock(&ust_exit_mutex); |
1879f67f | 1814 | ret = pthread_create(&local_apps.ust_listener, &thread_attr, |
dde70ea0 | 1815 | ust_listener_thread, &local_apps); |
d94d802c MD |
1816 | if (ret) { |
1817 | ERR("pthread_create local: %s", strerror(ret)); | |
1818 | } | |
e33f3265 | 1819 | local_apps.thread_active = 1; |
c0bbbd5a | 1820 | pthread_mutex_unlock(&ust_exit_mutex); |
8d20bf54 MD |
1821 | } else { |
1822 | handle_register_done(&local_apps); | |
1823 | } | |
1879f67f MG |
1824 | ret = pthread_attr_destroy(&thread_attr); |
1825 | if (ret) { | |
1826 | ERR("pthread_attr_destroy: %s", strerror(ret)); | |
1827 | } | |
8d20bf54 | 1828 | |
ae6a58bf WP |
1829 | /* Restore original signal mask in parent */ |
1830 | ret = pthread_sigmask(SIG_SETMASK, &orig_parent_mask, NULL); | |
1831 | if (ret) { | |
d94d802c | 1832 | ERR("pthread_sigmask: %s", strerror(ret)); |
ae6a58bf WP |
1833 | } |
1834 | ||
cf12a773 MD |
1835 | switch (timeout_mode) { |
1836 | case 1: /* timeout wait */ | |
95259bd0 MD |
1837 | do { |
1838 | ret = sem_timedwait(&constructor_wait, | |
1839 | &constructor_timeout); | |
1840 | } while (ret < 0 && errno == EINTR); | |
8aadb54a MD |
1841 | if (ret < 0) { |
1842 | switch (errno) { | |
1843 | case ETIMEDOUT: | |
1844 | ERR("Timed out waiting for lttng-sessiond"); | |
1845 | break; | |
1846 | case EINVAL: | |
1847 | PERROR("sem_timedwait"); | |
1848 | break; | |
1849 | default: | |
1850 | ERR("Unexpected error \"%s\" returned by sem_timedwait", | |
1851 | strerror(errno)); | |
1852 | } | |
cf12a773 MD |
1853 | } |
1854 | break; | |
7b766b16 | 1855 | case -1:/* wait forever */ |
95259bd0 MD |
1856 | do { |
1857 | ret = sem_wait(&constructor_wait); | |
1858 | } while (ret < 0 && errno == EINTR); | |
8aadb54a MD |
1859 | if (ret < 0) { |
1860 | switch (errno) { | |
1861 | case EINVAL: | |
1862 | PERROR("sem_wait"); | |
1863 | break; | |
1864 | default: | |
1865 | ERR("Unexpected error \"%s\" returned by sem_wait", | |
1866 | strerror(errno)); | |
1867 | } | |
1868 | } | |
cf12a773 | 1869 | break; |
7b766b16 | 1870 | case 0: /* no timeout */ |
cf12a773 | 1871 | break; |
11ff9c7d | 1872 | } |
2691221a MD |
1873 | } |
1874 | ||
17dfb34b MD |
1875 | static |
1876 | void lttng_ust_cleanup(int exiting) | |
1877 | { | |
efe0de09 | 1878 | cleanup_sock_info(&global_apps, exiting); |
932cfadb | 1879 | cleanup_sock_info(&local_apps, exiting); |
74f98bc9 | 1880 | local_apps.allowed = 0; |
ef4a06d9 | 1881 | global_apps.allowed = 0; |
efe0de09 MD |
1882 | /* |
1883 | * The teardown in this function all affect data structures | |
1884 | * accessed under the UST lock by the listener thread. This | |
1885 | * lock, along with the lttng_ust_comm_should_quit flag, ensure | |
1886 | * that none of these threads are accessing this data at this | |
1887 | * point. | |
1888 | */ | |
17dfb34b | 1889 | lttng_ust_abi_exit(); |
003fedf4 | 1890 | lttng_ust_events_exit(); |
d58d1454 | 1891 | lttng_perf_counter_exit(); |
34a91bdb | 1892 | lttng_ring_buffer_client_discard_rt_exit(); |
7dd08bec | 1893 | lttng_ring_buffer_client_discard_exit(); |
34a91bdb | 1894 | lttng_ring_buffer_client_overwrite_rt_exit(); |
7dd08bec MD |
1895 | lttng_ring_buffer_client_overwrite_exit(); |
1896 | lttng_ring_buffer_metadata_client_exit(); | |
cf73e0fe | 1897 | lttng_ust_statedump_destroy(); |
17dfb34b MD |
1898 | exit_tracepoint(); |
1899 | if (!exiting) { | |
1900 | /* Reinitialize values for fork */ | |
1901 | sem_count = 2; | |
1902 | lttng_ust_comm_should_quit = 0; | |
1903 | initialized = 0; | |
1904 | } | |
1905 | } | |
1906 | ||
edaa1431 | 1907 | void __attribute__((destructor)) lttng_ust_exit(void) |
2691221a MD |
1908 | { |
1909 | int ret; | |
1910 | ||
9eb62b9c MD |
1911 | /* |
1912 | * Using pthread_cancel here because: | |
1913 | * A) we don't want to hang application teardown. | |
1914 | * B) the thread is not allocating any resource. | |
1915 | */ | |
1ea11eab MD |
1916 | |
1917 | /* | |
1918 | * Require the communication thread to quit. Synchronize with | |
1919 | * mutexes to ensure it is not in a mutex critical section when | |
1920 | * pthread_cancel is later called. | |
1921 | */ | |
3327ac33 | 1922 | ust_lock_nocheck(); |
1ea11eab | 1923 | lttng_ust_comm_should_quit = 1; |
3327ac33 | 1924 | ust_unlock(); |
1ea11eab | 1925 | |
3327ac33 | 1926 | pthread_mutex_lock(&ust_exit_mutex); |
f5f94532 | 1927 | /* cancel threads */ |
e33f3265 MD |
1928 | if (global_apps.thread_active) { |
1929 | ret = pthread_cancel(global_apps.ust_listener); | |
1930 | if (ret) { | |
1931 | ERR("Error cancelling global ust listener thread: %s", | |
1932 | strerror(ret)); | |
1933 | } else { | |
1934 | global_apps.thread_active = 0; | |
1935 | } | |
2691221a | 1936 | } |
e33f3265 | 1937 | if (local_apps.thread_active) { |
8d20bf54 MD |
1938 | ret = pthread_cancel(local_apps.ust_listener); |
1939 | if (ret) { | |
d94d802c MD |
1940 | ERR("Error cancelling local ust listener thread: %s", |
1941 | strerror(ret)); | |
e33f3265 MD |
1942 | } else { |
1943 | local_apps.thread_active = 0; | |
8d20bf54 | 1944 | } |
8d20bf54 | 1945 | } |
3327ac33 | 1946 | pthread_mutex_unlock(&ust_exit_mutex); |
e33f3265 | 1947 | |
efe0de09 MD |
1948 | /* |
1949 | * Do NOT join threads: use of sys_futex makes it impossible to | |
1950 | * join the threads without using async-cancel, but async-cancel | |
1951 | * is delivered by a signal, which could hit the target thread | |
1952 | * anywhere in its code path, including while the ust_lock() is | |
1953 | * held, causing a deadlock for the other thread. Let the OS | |
1954 | * cleanup the threads if there are stalled in a syscall. | |
1955 | */ | |
17dfb34b | 1956 | lttng_ust_cleanup(1); |
2691221a | 1957 | } |
e822f505 MD |
1958 | |
1959 | /* | |
1960 | * We exclude the worker threads across fork and clone (except | |
1961 | * CLONE_VM), because these system calls only keep the forking thread | |
1962 | * running in the child. Therefore, we don't want to call fork or clone | |
1963 | * in the middle of an tracepoint or ust tracing state modification. | |
1964 | * Holding this mutex protects these structures across fork and clone. | |
1965 | */ | |
b728d87e | 1966 | void ust_before_fork(sigset_t *save_sigset) |
e822f505 MD |
1967 | { |
1968 | /* | |
1969 | * Disable signals. This is to avoid that the child intervenes | |
1970 | * before it is properly setup for tracing. It is safer to | |
1971 | * disable all signals, because then we know we are not breaking | |
1972 | * anything by restoring the original mask. | |
1973 | */ | |
1974 | sigset_t all_sigs; | |
1975 | int ret; | |
1976 | ||
c362addf MD |
1977 | /* Fixup lttng-ust TLS. */ |
1978 | lttng_ust_fixup_tls(); | |
1979 | ||
8c90a710 | 1980 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 1981 | return; |
e822f505 MD |
1982 | /* Disable signals */ |
1983 | sigfillset(&all_sigs); | |
b728d87e | 1984 | ret = sigprocmask(SIG_BLOCK, &all_sigs, save_sigset); |
e822f505 MD |
1985 | if (ret == -1) { |
1986 | PERROR("sigprocmask"); | |
1987 | } | |
458d678c PW |
1988 | |
1989 | pthread_mutex_lock(&ust_fork_mutex); | |
1990 | ||
3327ac33 | 1991 | ust_lock_nocheck(); |
e822f505 MD |
1992 | rcu_bp_before_fork(); |
1993 | } | |
1994 | ||
b728d87e | 1995 | static void ust_after_fork_common(sigset_t *restore_sigset) |
e822f505 MD |
1996 | { |
1997 | int ret; | |
1998 | ||
17dfb34b MD |
1999 | DBG("process %d", getpid()); |
2000 | ust_unlock(); | |
458d678c PW |
2001 | |
2002 | pthread_mutex_unlock(&ust_fork_mutex); | |
2003 | ||
e822f505 | 2004 | /* Restore signals */ |
23c8854a | 2005 | ret = sigprocmask(SIG_SETMASK, restore_sigset, NULL); |
e822f505 MD |
2006 | if (ret == -1) { |
2007 | PERROR("sigprocmask"); | |
2008 | } | |
2009 | } | |
2010 | ||
b728d87e | 2011 | void ust_after_fork_parent(sigset_t *restore_sigset) |
e822f505 | 2012 | { |
8c90a710 | 2013 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2014 | return; |
17dfb34b | 2015 | DBG("process %d", getpid()); |
e822f505 MD |
2016 | rcu_bp_after_fork_parent(); |
2017 | /* Release mutexes and reenable signals */ | |
b728d87e | 2018 | ust_after_fork_common(restore_sigset); |
e822f505 MD |
2019 | } |
2020 | ||
17dfb34b MD |
2021 | /* |
2022 | * After fork, in the child, we need to cleanup all the leftover state, | |
2023 | * except the worker thread which already magically disappeared thanks | |
2024 | * to the weird Linux fork semantics. After tyding up, we call | |
2025 | * lttng_ust_init() again to start over as a new PID. | |
2026 | * | |
2027 | * This is meant for forks() that have tracing in the child between the | |
2028 | * fork and following exec call (if there is any). | |
2029 | */ | |
b728d87e | 2030 | void ust_after_fork_child(sigset_t *restore_sigset) |
e822f505 | 2031 | { |
8c90a710 | 2032 | if (URCU_TLS(lttng_ust_nest_count)) |
e8508a49 | 2033 | return; |
f575e049 | 2034 | lttng_context_vpid_reset(); |
8478887d | 2035 | lttng_context_vtid_reset(); |
5fe0ab0b | 2036 | lttng_context_procname_reset(); |
17dfb34b | 2037 | DBG("process %d", getpid()); |
e822f505 MD |
2038 | /* Release urcu mutexes */ |
2039 | rcu_bp_after_fork_child(); | |
17dfb34b | 2040 | lttng_ust_cleanup(0); |
e822f505 | 2041 | /* Release mutexes and reenable signals */ |
b728d87e | 2042 | ust_after_fork_common(restore_sigset); |
318dfea9 | 2043 | lttng_ust_init(); |
e822f505 | 2044 | } |
95c25348 | 2045 | |
246be17e | 2046 | void lttng_ust_sockinfo_session_enabled(void *owner) |
95c25348 PW |
2047 | { |
2048 | struct sock_info *sock_info = owner; | |
37dddb65 | 2049 | sock_info->statedump_pending = 1; |
95c25348 | 2050 | } |