Commit | Line | Data |
---|---|---|
8020ceb5 MD |
1 | /* |
2 | * ltt-events.c | |
3 | * | |
4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * Holds LTTng per-session event registry. | |
7 | * | |
8 | * Dual LGPL v2.1/GPL v2 license. | |
9 | */ | |
10 | ||
b5234c06 MD |
11 | #define _GNU_SOURCE |
12 | #include <stdio.h> | |
8a98a75d | 13 | #include <endian.h> |
b5234c06 | 14 | #include <urcu/list.h> |
8165c8da | 15 | #include <urcu/hlist.h> |
b5234c06 | 16 | #include <pthread.h> |
b5234c06 | 17 | #include <uuid/uuid.h> |
b5234c06 | 18 | #include <errno.h> |
f4681817 MD |
19 | #include <sys/shm.h> |
20 | #include <sys/ipc.h> | |
44c72f10 MD |
21 | #include <stdint.h> |
22 | #include <stddef.h> | |
23 | ||
24 | #include <urcu-bp.h> | |
25 | #include <urcu/compiler.h> | |
26 | #include <urcu/uatomic.h> | |
27 | #include <urcu/arch.h> | |
28 | ||
29 | #include <lttng/tracepoint.h> | |
4318ae1b | 30 | #include <lttng/ust-events.h> |
44c72f10 MD |
31 | |
32 | #include <usterr-signal-safe.h> | |
33 | #include <helper.h> | |
1f18504e | 34 | #include "error.h" |
44c72f10 | 35 | |
8020ceb5 | 36 | #include "ltt-tracer.h" |
8165c8da | 37 | #include "ltt-tracer-core.h" |
b728d87e | 38 | #include "wait.h" |
8d8a24c8 | 39 | #include "../libringbuffer/shm.h" |
596c4223 | 40 | #include "jhash.h" |
8165c8da MD |
41 | |
42 | /* | |
43 | * The sessions mutex is the centralized mutex across UST tracing | |
17dfb34b MD |
44 | * control and probe registration. All operations within this file are |
45 | * called by the communication thread, under ust_lock protection. | |
8165c8da | 46 | */ |
2b2d6ff7 | 47 | static pthread_mutex_t sessions_mutex = PTHREAD_MUTEX_INITIALIZER; |
8165c8da | 48 | |
17dfb34b | 49 | void ust_lock(void) |
8165c8da MD |
50 | { |
51 | pthread_mutex_lock(&sessions_mutex); | |
52 | } | |
53 | ||
17dfb34b | 54 | void ust_unlock(void) |
8165c8da MD |
55 | { |
56 | pthread_mutex_unlock(&sessions_mutex); | |
57 | } | |
58 | ||
b5234c06 | 59 | static CDS_LIST_HEAD(sessions); |
8165c8da MD |
60 | |
61 | /* | |
62 | * Pending probes hash table, containing the registered ltt events for | |
63 | * which tracepoint probes are still missing. Protected by the sessions | |
64 | * mutex. | |
65 | */ | |
66 | #define PENDING_PROBE_HASH_BITS 6 | |
67 | #define PENDING_PROBE_HASH_SIZE (1 << PENDING_PROBE_HASH_BITS) | |
68 | static struct cds_hlist_head pending_probe_table[PENDING_PROBE_HASH_SIZE]; | |
69 | ||
70 | struct ust_pending_probe { | |
71 | struct ltt_event *event; | |
72 | struct cds_hlist_node node; | |
73 | char name[]; | |
74 | }; | |
8020ceb5 MD |
75 | |
76 | static void _ltt_event_destroy(struct ltt_event *event); | |
574a6217 | 77 | static void _ltt_loglevel_destroy(struct session_loglevel *sl); |
8020ceb5 MD |
78 | static void _ltt_channel_destroy(struct ltt_channel *chan); |
79 | static int _ltt_event_unregister(struct ltt_event *event); | |
80 | static | |
81 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
82 | struct ltt_channel *chan, | |
83 | struct ltt_event *event); | |
84 | static | |
85 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
86 | ||
8165c8da MD |
87 | /* |
88 | * called at event creation if probe is missing. | |
89 | * called with session mutex held. | |
90 | */ | |
91 | static | |
92 | int add_pending_probe(struct ltt_event *event, const char *name) | |
93 | { | |
94 | struct cds_hlist_head *head; | |
8165c8da MD |
95 | struct ust_pending_probe *e; |
96 | size_t name_len = strlen(name) + 1; | |
23c8854a | 97 | uint32_t hash = jhash(name, name_len - 1, 0); |
8165c8da MD |
98 | |
99 | head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)]; | |
100 | e = zmalloc(sizeof(struct ust_pending_probe) + name_len); | |
101 | if (!e) | |
102 | return -ENOMEM; | |
103 | memcpy(&e->name[0], name, name_len); | |
104 | cds_hlist_add_head(&e->node, head); | |
105 | e->event = event; | |
106 | event->pending_probe = e; | |
107 | return 0; | |
108 | } | |
109 | ||
110 | /* | |
111 | * remove a pending probe. called when at event teardown and when an | |
112 | * event is fixed (probe is loaded). | |
113 | * called with session mutex held. | |
114 | */ | |
115 | static | |
116 | void remove_pending_probe(struct ust_pending_probe *e) | |
117 | { | |
118 | if (!e) | |
119 | return; | |
120 | cds_hlist_del(&e->node); | |
121 | free(e); | |
122 | } | |
123 | ||
124 | /* | |
125 | * Called at library load: connect the probe on the events pending on | |
126 | * probe load. | |
127 | * called with session mutex held. | |
128 | */ | |
129 | int pending_probe_fix_events(const struct lttng_event_desc *desc) | |
130 | { | |
131 | struct cds_hlist_head *head; | |
132 | struct cds_hlist_node *node, *p; | |
133 | struct ust_pending_probe *e; | |
134 | const char *name = desc->name; | |
135 | size_t name_len = strlen(name) + 1; | |
23c8854a | 136 | uint32_t hash = jhash(name, name_len - 1, 0); |
8165c8da | 137 | int ret = 0; |
7ee3cc56 | 138 | struct lttng_ust_event event_param; |
8165c8da | 139 | |
574a6217 | 140 | /* |
1f18504e MD |
141 | * For this event, we need to lookup the loglevel. If active (in |
142 | * the active loglevels hash table), we must create the event. | |
143 | */ | |
574a6217 MD |
144 | if (desc->loglevel) { |
145 | const struct tracepoint_loglevel_entry *ev_ll; | |
146 | struct loglevel_entry *loglevel; | |
147 | ||
148 | ev_ll = *desc->loglevel; | |
149 | loglevel = get_loglevel(ev_ll->identifier); | |
150 | if (loglevel) { | |
151 | struct session_loglevel *sl; | |
152 | ||
153 | cds_list_for_each_entry(sl, &loglevel->session_list, | |
154 | session_list) { | |
155 | struct ltt_event *ev; | |
156 | int ret; | |
157 | ||
7ee3cc56 MD |
158 | memcpy(&event_param, &sl->event_param, |
159 | sizeof(event_param)); | |
160 | memcpy(event_param.name, | |
161 | desc->name, | |
162 | sizeof(event_param.name)); | |
574a6217 MD |
163 | /* create event */ |
164 | ret = ltt_event_create(sl->chan, | |
7ee3cc56 | 165 | &event_param, NULL, |
574a6217 | 166 | &ev); |
7ee3cc56 MD |
167 | if (ret) { |
168 | DBG("Error creating event"); | |
574a6217 | 169 | continue; |
7ee3cc56 | 170 | } |
574a6217 MD |
171 | cds_list_add(&ev->loglevel_list, |
172 | &sl->events); | |
173 | } | |
174 | } | |
175 | } | |
1f18504e | 176 | |
8165c8da MD |
177 | head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)]; |
178 | cds_hlist_for_each_entry_safe(e, node, p, head, node) { | |
179 | struct ltt_event *event; | |
180 | struct ltt_channel *chan; | |
181 | ||
182 | if (strcmp(name, e->name)) | |
183 | continue; | |
184 | event = e->event; | |
185 | chan = event->chan; | |
186 | assert(!event->desc); | |
187 | event->desc = desc; | |
188 | event->pending_probe = NULL; | |
189 | remove_pending_probe(e); | |
190 | ret |= __tracepoint_probe_register(name, | |
191 | event->desc->probe_callback, | |
192 | event); | |
636c5aa4 MD |
193 | if (ret) |
194 | continue; | |
195 | event->id = chan->free_event_id++; | |
8165c8da MD |
196 | ret |= _ltt_event_metadata_statedump(chan->session, chan, |
197 | event); | |
198 | } | |
199 | return ret; | |
200 | } | |
201 | ||
8020ceb5 MD |
202 | void synchronize_trace(void) |
203 | { | |
8020ceb5 | 204 | synchronize_rcu(); |
8020ceb5 MD |
205 | } |
206 | ||
207 | struct ltt_session *ltt_session_create(void) | |
208 | { | |
209 | struct ltt_session *session; | |
210 | ||
b5234c06 | 211 | session = zmalloc(sizeof(struct ltt_session)); |
8020ceb5 MD |
212 | if (!session) |
213 | return NULL; | |
b5234c06 MD |
214 | CDS_INIT_LIST_HEAD(&session->chan); |
215 | CDS_INIT_LIST_HEAD(&session->events); | |
1f18504e | 216 | CDS_INIT_LIST_HEAD(&session->loglevels); |
b5234c06 MD |
217 | uuid_generate(session->uuid); |
218 | cds_list_add(&session->list, &sessions); | |
8020ceb5 MD |
219 | return session; |
220 | } | |
221 | ||
222 | void ltt_session_destroy(struct ltt_session *session) | |
223 | { | |
224 | struct ltt_channel *chan, *tmpchan; | |
225 | struct ltt_event *event, *tmpevent; | |
574a6217 | 226 | struct session_loglevel *loglevel, *tmploglevel; |
8020ceb5 MD |
227 | int ret; |
228 | ||
b5234c06 MD |
229 | CMM_ACCESS_ONCE(session->active) = 0; |
230 | cds_list_for_each_entry(event, &session->events, list) { | |
8020ceb5 MD |
231 | ret = _ltt_event_unregister(event); |
232 | WARN_ON(ret); | |
233 | } | |
234 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
1f18504e MD |
235 | cds_list_for_each_entry_safe(loglevel, tmploglevel, &session->loglevels, list) |
236 | _ltt_loglevel_destroy(loglevel); | |
b5234c06 | 237 | cds_list_for_each_entry_safe(event, tmpevent, &session->events, list) |
8020ceb5 | 238 | _ltt_event_destroy(event); |
b5234c06 | 239 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list) |
8020ceb5 | 240 | _ltt_channel_destroy(chan); |
b5234c06 | 241 | cds_list_del(&session->list); |
b5234c06 | 242 | free(session); |
8020ceb5 MD |
243 | } |
244 | ||
976fe9ea | 245 | int ltt_session_enable(struct ltt_session *session) |
8020ceb5 MD |
246 | { |
247 | int ret = 0; | |
248 | struct ltt_channel *chan; | |
249 | ||
8020ceb5 MD |
250 | if (session->active) { |
251 | ret = -EBUSY; | |
252 | goto end; | |
253 | } | |
254 | ||
255 | /* | |
256 | * Snapshot the number of events per channel to know the type of header | |
257 | * we need to use. | |
258 | */ | |
b5234c06 | 259 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
260 | if (chan->header_type) |
261 | continue; /* don't change it if session stop/restart */ | |
262 | if (chan->free_event_id < 31) | |
263 | chan->header_type = 1; /* compact */ | |
264 | else | |
265 | chan->header_type = 2; /* large */ | |
266 | } | |
267 | ||
b5234c06 MD |
268 | CMM_ACCESS_ONCE(session->active) = 1; |
269 | CMM_ACCESS_ONCE(session->been_active) = 1; | |
8020ceb5 | 270 | ret = _ltt_session_metadata_statedump(session); |
4b4de73e | 271 | if (ret) |
b5234c06 | 272 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 273 | end: |
8020ceb5 MD |
274 | return ret; |
275 | } | |
276 | ||
976fe9ea | 277 | int ltt_session_disable(struct ltt_session *session) |
8020ceb5 MD |
278 | { |
279 | int ret = 0; | |
280 | ||
8020ceb5 MD |
281 | if (!session->active) { |
282 | ret = -EBUSY; | |
283 | goto end; | |
284 | } | |
b5234c06 | 285 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 286 | end: |
8020ceb5 MD |
287 | return ret; |
288 | } | |
289 | ||
976fe9ea MD |
290 | int ltt_channel_enable(struct ltt_channel *channel) |
291 | { | |
292 | int old; | |
293 | ||
9beb36ba MD |
294 | if (channel == channel->session->metadata) |
295 | return -EPERM; | |
b5234c06 | 296 | old = uatomic_xchg(&channel->enabled, 1); |
976fe9ea MD |
297 | if (old) |
298 | return -EEXIST; | |
299 | return 0; | |
300 | } | |
301 | ||
302 | int ltt_channel_disable(struct ltt_channel *channel) | |
303 | { | |
304 | int old; | |
305 | ||
9beb36ba MD |
306 | if (channel == channel->session->metadata) |
307 | return -EPERM; | |
b5234c06 | 308 | old = uatomic_xchg(&channel->enabled, 0); |
976fe9ea MD |
309 | if (!old) |
310 | return -EEXIST; | |
311 | return 0; | |
312 | } | |
313 | ||
314 | int ltt_event_enable(struct ltt_event *event) | |
315 | { | |
316 | int old; | |
317 | ||
9beb36ba MD |
318 | if (event->chan == event->chan->session->metadata) |
319 | return -EPERM; | |
b5234c06 | 320 | old = uatomic_xchg(&event->enabled, 1); |
976fe9ea MD |
321 | if (old) |
322 | return -EEXIST; | |
323 | return 0; | |
324 | } | |
325 | ||
326 | int ltt_event_disable(struct ltt_event *event) | |
327 | { | |
328 | int old; | |
329 | ||
9beb36ba MD |
330 | if (event->chan == event->chan->session->metadata) |
331 | return -EPERM; | |
b5234c06 | 332 | old = uatomic_xchg(&event->enabled, 0); |
976fe9ea MD |
333 | if (!old) |
334 | return -EEXIST; | |
335 | return 0; | |
336 | } | |
337 | ||
8020ceb5 MD |
338 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, |
339 | const char *transport_name, | |
340 | void *buf_addr, | |
341 | size_t subbuf_size, size_t num_subbuf, | |
342 | unsigned int switch_timer_interval, | |
193183fb MD |
343 | unsigned int read_timer_interval, |
344 | int *shm_fd, int *wait_fd, | |
d028eddb MD |
345 | uint64_t *memory_map_size, |
346 | struct ltt_channel *chan_priv_init) | |
8020ceb5 | 347 | { |
a3f61e7f | 348 | struct ltt_channel *chan = NULL; |
8020ceb5 MD |
349 | struct ltt_transport *transport; |
350 | ||
8020ceb5 MD |
351 | if (session->been_active) |
352 | goto active; /* Refuse to add channel to active session */ | |
353 | transport = ltt_transport_find(transport_name); | |
354 | if (!transport) { | |
b5234c06 | 355 | DBG("LTTng transport %s not found\n", |
8020ceb5 MD |
356 | transport_name); |
357 | goto notransport; | |
358 | } | |
d028eddb MD |
359 | chan_priv_init->id = session->free_chan_id++; |
360 | chan_priv_init->session = session; | |
8020ceb5 MD |
361 | /* |
362 | * Note: the channel creation op already writes into the packet | |
363 | * headers. Therefore the "chan" information used as input | |
364 | * should be already accessible. | |
365 | */ | |
a3f61e7f | 366 | chan = transport->ops.channel_create("[lttng]", buf_addr, |
8020ceb5 | 367 | subbuf_size, num_subbuf, switch_timer_interval, |
193183fb | 368 | read_timer_interval, shm_fd, wait_fd, |
d028eddb | 369 | memory_map_size, chan_priv_init); |
a3f61e7f | 370 | if (!chan) |
8020ceb5 | 371 | goto create_error; |
976fe9ea | 372 | chan->enabled = 1; |
8020ceb5 | 373 | chan->ops = &transport->ops; |
b5234c06 | 374 | cds_list_add(&chan->list, &session->chan); |
8020ceb5 MD |
375 | return chan; |
376 | ||
377 | create_error: | |
8020ceb5 MD |
378 | notransport: |
379 | active: | |
8020ceb5 MD |
380 | return NULL; |
381 | } | |
382 | ||
383 | /* | |
384 | * Only used internally at session destruction. | |
385 | */ | |
386 | static | |
387 | void _ltt_channel_destroy(struct ltt_channel *chan) | |
388 | { | |
b5234c06 | 389 | cds_list_del(&chan->list); |
8020ceb5 | 390 | lttng_destroy_context(chan->ctx); |
a3f61e7f | 391 | chan->ops->channel_destroy(chan); |
8020ceb5 MD |
392 | } |
393 | ||
1f18504e MD |
394 | int ltt_loglevel_create(struct ltt_channel *chan, |
395 | struct lttng_ust_event *event_param, | |
574a6217 | 396 | struct session_loglevel **_sl) |
1f18504e | 397 | { |
574a6217 | 398 | struct session_loglevel *sl; |
1f18504e | 399 | |
574a6217 MD |
400 | sl = add_loglevel(event_param->name, chan, event_param); |
401 | if (!sl || IS_ERR(sl)) { | |
402 | return PTR_ERR(sl); | |
1f18504e | 403 | } |
574a6217 | 404 | *_sl = sl; |
1f18504e MD |
405 | return 0; |
406 | } | |
407 | ||
408 | static | |
574a6217 | 409 | void _ltt_loglevel_destroy(struct session_loglevel *sl) |
1f18504e | 410 | { |
574a6217 | 411 | _remove_loglevel(sl); |
1f18504e MD |
412 | } |
413 | ||
8020ceb5 MD |
414 | /* |
415 | * Supports event creation while tracing session is active. | |
416 | */ | |
576599a0 MD |
417 | int ltt_event_create(struct ltt_channel *chan, |
418 | struct lttng_ust_event *event_param, | |
419 | void *filter, | |
420 | struct ltt_event **_event) | |
8020ceb5 MD |
421 | { |
422 | struct ltt_event *event; | |
576599a0 | 423 | int ret = 0; |
8020ceb5 | 424 | |
576599a0 MD |
425 | if (chan->used_event_id == -1UL) { |
426 | ret = -ENOMEM; | |
8020ceb5 | 427 | goto full; |
576599a0 | 428 | } |
8020ceb5 MD |
429 | /* |
430 | * This is O(n^2) (for each event, the loop is called at event | |
431 | * creation). Might require a hash if we have lots of events. | |
432 | */ | |
576599a0 MD |
433 | cds_list_for_each_entry(event, &chan->session->events, list) { |
434 | if (event->desc && !strcmp(event->desc->name, event_param->name)) { | |
435 | ret = -EEXIST; | |
8020ceb5 | 436 | goto exist; |
576599a0 MD |
437 | } |
438 | } | |
b5234c06 | 439 | event = zmalloc(sizeof(struct ltt_event)); |
576599a0 MD |
440 | if (!event) { |
441 | ret = -ENOMEM; | |
8020ceb5 | 442 | goto cache_error; |
576599a0 | 443 | } |
8020ceb5 MD |
444 | event->chan = chan; |
445 | event->filter = filter; | |
8165c8da MD |
446 | /* |
447 | * used_event_id counts the maximum number of event IDs that can | |
448 | * register if all probes register. | |
449 | */ | |
450 | chan->used_event_id++; | |
976fe9ea | 451 | event->enabled = 1; |
8020ceb5 MD |
452 | event->instrumentation = event_param->instrumentation; |
453 | /* Populate ltt_event structure before tracepoint registration. */ | |
b5234c06 | 454 | cmm_smp_wmb(); |
8020ceb5 | 455 | switch (event_param->instrumentation) { |
b5234c06 | 456 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 | 457 | event->desc = ltt_event_get(event_param->name); |
8165c8da MD |
458 | if (event->desc) { |
459 | ret = __tracepoint_probe_register(event_param->name, | |
460 | event->desc->probe_callback, | |
461 | event); | |
462 | if (ret) | |
463 | goto register_error; | |
464 | event->id = chan->free_event_id++; | |
465 | } else { | |
466 | /* | |
467 | * If the probe is not present, event->desc stays NULL, | |
468 | * waiting for the probe to register, and the event->id | |
469 | * stays unallocated. | |
470 | */ | |
471 | ret = add_pending_probe(event, event_param->name); | |
472 | if (ret) | |
473 | goto add_pending_error; | |
474 | } | |
8020ceb5 | 475 | break; |
df854e41 | 476 | case LTTNG_UST_TRACEPOINT_LOGLEVEL: |
1f18504e | 477 | assert(0); |
df854e41 | 478 | break; |
8020ceb5 MD |
479 | default: |
480 | WARN_ON_ONCE(1); | |
481 | } | |
8165c8da MD |
482 | if (event->desc) { |
483 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); | |
484 | if (ret) | |
485 | goto statedump_error; | |
486 | } | |
b5234c06 | 487 | cds_list_add(&event->list, &chan->session->events); |
576599a0 MD |
488 | *_event = event; |
489 | return 0; | |
8020ceb5 MD |
490 | |
491 | statedump_error: | |
8165c8da MD |
492 | if (event->desc) { |
493 | WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name, | |
494 | event->desc->probe_callback, | |
495 | event)); | |
496 | ltt_event_put(event->desc); | |
497 | } | |
498 | add_pending_error: | |
8020ceb5 | 499 | register_error: |
b5234c06 | 500 | free(event); |
8020ceb5 MD |
501 | cache_error: |
502 | exist: | |
503 | full: | |
576599a0 | 504 | return ret; |
8020ceb5 MD |
505 | } |
506 | ||
507 | /* | |
508 | * Only used internally at session destruction. | |
509 | */ | |
510 | int _ltt_event_unregister(struct ltt_event *event) | |
511 | { | |
512 | int ret = -EINVAL; | |
513 | ||
514 | switch (event->instrumentation) { | |
b5234c06 | 515 | case LTTNG_UST_TRACEPOINT: |
8165c8da MD |
516 | if (event->desc) { |
517 | ret = __tracepoint_probe_unregister(event->desc->name, | |
518 | event->desc->probe_callback, | |
519 | event); | |
520 | if (ret) | |
521 | return ret; | |
522 | } else { | |
523 | remove_pending_probe(event->pending_probe); | |
524 | ret = 0; | |
525 | } | |
8020ceb5 | 526 | break; |
8020ceb5 MD |
527 | default: |
528 | WARN_ON_ONCE(1); | |
529 | } | |
530 | return ret; | |
531 | } | |
532 | ||
533 | /* | |
534 | * Only used internally at session destruction. | |
535 | */ | |
536 | static | |
537 | void _ltt_event_destroy(struct ltt_event *event) | |
538 | { | |
539 | switch (event->instrumentation) { | |
b5234c06 | 540 | case LTTNG_UST_TRACEPOINT: |
8165c8da MD |
541 | if (event->desc) { |
542 | ltt_event_put(event->desc); | |
543 | } | |
8020ceb5 | 544 | break; |
8020ceb5 MD |
545 | default: |
546 | WARN_ON_ONCE(1); | |
547 | } | |
b5234c06 | 548 | cds_list_del(&event->list); |
8020ceb5 | 549 | lttng_destroy_context(event->ctx); |
b5234c06 | 550 | free(event); |
8020ceb5 MD |
551 | } |
552 | ||
553 | /* | |
554 | * We have exclusive access to our metadata buffer (protected by the | |
17dfb34b | 555 | * ust_lock), so we can do racy operations such as looking for |
8020ceb5 MD |
556 | * remaining space left in packet and write, since mutual exclusion |
557 | * protects us from concurrent writes. | |
558 | */ | |
559 | int lttng_metadata_printf(struct ltt_session *session, | |
560 | const char *fmt, ...) | |
561 | { | |
4cfec15c | 562 | struct lttng_ust_lib_ring_buffer_ctx ctx; |
8020ceb5 | 563 | struct ltt_channel *chan = session->metadata; |
b5234c06 | 564 | char *str = NULL; |
8020ceb5 MD |
565 | int ret = 0, waitret; |
566 | size_t len, reserve_len, pos; | |
567 | va_list ap; | |
568 | ||
b5234c06 | 569 | WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active)); |
8020ceb5 MD |
570 | |
571 | va_start(ap, fmt); | |
b5234c06 | 572 | ret = vasprintf(&str, fmt, ap); |
8020ceb5 | 573 | va_end(ap); |
b5234c06 | 574 | if (ret < 0) |
8020ceb5 MD |
575 | return -ENOMEM; |
576 | ||
577 | len = strlen(str); | |
578 | pos = 0; | |
579 | ||
580 | for (pos = 0; pos < len; pos += reserve_len) { | |
581 | reserve_len = min_t(size_t, | |
1d498196 | 582 | chan->ops->packet_avail_size(chan->chan, chan->handle), |
8020ceb5 MD |
583 | len - pos); |
584 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
1d498196 | 585 | sizeof(char), -1, chan->handle); |
8020ceb5 MD |
586 | /* |
587 | * We don't care about metadata buffer's records lost | |
588 | * count, because we always retry here. Report error if | |
589 | * we need to bail out after timeout or being | |
590 | * interrupted. | |
591 | */ | |
b5234c06 | 592 | waitret = wait_cond_interruptible_timeout( |
8020ceb5 MD |
593 | ({ |
594 | ret = chan->ops->event_reserve(&ctx, 0); | |
595 | ret != -ENOBUFS || !ret; | |
596 | }), | |
b5234c06 | 597 | LTTNG_METADATA_TIMEOUT_MSEC); |
b472cfc0 | 598 | if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) { |
b5234c06 MD |
599 | DBG("LTTng: Failure to write metadata to buffers (%s)\n", |
600 | waitret == -EINTR ? "interrupted" : | |
8020ceb5 | 601 | (ret == -ENOBUFS ? "timeout" : "I/O error")); |
b5234c06 | 602 | if (waitret == -EINTR) |
8020ceb5 MD |
603 | ret = waitret; |
604 | goto end; | |
605 | } | |
606 | chan->ops->event_write(&ctx, &str[pos], reserve_len); | |
607 | chan->ops->event_commit(&ctx); | |
608 | } | |
609 | end: | |
b5234c06 | 610 | free(str); |
8020ceb5 MD |
611 | return ret; |
612 | } | |
613 | ||
614 | static | |
615 | int _ltt_field_statedump(struct ltt_session *session, | |
616 | const struct lttng_event_field *field) | |
617 | { | |
618 | int ret = 0; | |
619 | ||
620 | switch (field->type.atype) { | |
621 | case atype_integer: | |
622 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 623 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n", |
8020ceb5 MD |
624 | field->type.u.basic.integer.size, |
625 | field->type.u.basic.integer.alignment, | |
626 | field->type.u.basic.integer.signedness, | |
627 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
628 | ? "none" | |
629 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
630 | ? "UTF8" | |
631 | : "ASCII", | |
632 | field->type.u.basic.integer.base, | |
8a98a75d | 633 | #if (BYTE_ORDER == BIG_ENDIAN) |
403c40b4 MD |
634 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
635 | #else | |
636 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
637 | #endif | |
638 | field->name); | |
639 | break; | |
640 | case atype_float: | |
641 | ret = lttng_metadata_printf(session, | |
8a98a75d | 642 | " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n", |
403c40b4 MD |
643 | field->type.u.basic._float.exp_dig, |
644 | field->type.u.basic._float.mant_dig, | |
645 | field->type.u.basic._float.alignment, | |
8a98a75d | 646 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
647 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
648 | #else | |
649 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
650 | #endif | |
651 | field->name); | |
652 | break; | |
653 | case atype_enum: | |
654 | ret = lttng_metadata_printf(session, | |
655 | " %s %s;\n", | |
656 | field->type.u.basic.enumeration.name, | |
657 | field->name); | |
658 | break; | |
659 | case atype_array: | |
660 | { | |
661 | const struct lttng_basic_type *elem_type; | |
662 | ||
663 | elem_type = &field->type.u.array.elem_type; | |
664 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 665 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n", |
8020ceb5 MD |
666 | elem_type->u.basic.integer.size, |
667 | elem_type->u.basic.integer.alignment, | |
668 | elem_type->u.basic.integer.signedness, | |
669 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
670 | ? "none" | |
671 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
672 | ? "UTF8" | |
673 | : "ASCII", | |
674 | elem_type->u.basic.integer.base, | |
8a98a75d | 675 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
676 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
677 | #else | |
678 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
679 | #endif | |
680 | field->name, field->type.u.array.length); | |
681 | break; | |
682 | } | |
683 | case atype_sequence: | |
684 | { | |
685 | const struct lttng_basic_type *elem_type; | |
686 | const struct lttng_basic_type *length_type; | |
687 | ||
688 | elem_type = &field->type.u.sequence.elem_type; | |
689 | length_type = &field->type.u.sequence.length_type; | |
690 | ret = lttng_metadata_printf(session, | |
691 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
692 | length_type->u.basic.integer.size, | |
693 | (unsigned int) length_type->u.basic.integer.alignment, | |
694 | length_type->u.basic.integer.signedness, | |
695 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
696 | ? "none" | |
697 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
698 | ? "UTF8" | |
699 | : "ASCII"), | |
700 | length_type->u.basic.integer.base, | |
8a98a75d | 701 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
702 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
703 | #else | |
704 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
705 | #endif | |
706 | field->name); | |
707 | if (ret) | |
708 | return ret; | |
709 | ||
710 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 711 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n", |
8020ceb5 MD |
712 | elem_type->u.basic.integer.size, |
713 | (unsigned int) elem_type->u.basic.integer.alignment, | |
714 | elem_type->u.basic.integer.signedness, | |
715 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
716 | ? "none" | |
717 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
718 | ? "UTF8" | |
719 | : "ASCII"), | |
720 | elem_type->u.basic.integer.base, | |
8a98a75d | 721 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
722 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
723 | #else | |
724 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
725 | #endif | |
726 | field->name, | |
727 | field->name); | |
728 | break; | |
729 | } | |
730 | ||
731 | case atype_string: | |
732 | /* Default encoding is UTF8 */ | |
733 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 734 | " string%s _%s;\n", |
8020ceb5 MD |
735 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? |
736 | " { encoding = ASCII; }" : "", | |
737 | field->name); | |
738 | break; | |
739 | default: | |
740 | WARN_ON_ONCE(1); | |
741 | return -EINVAL; | |
742 | } | |
743 | return ret; | |
744 | } | |
745 | ||
746 | static | |
747 | int _ltt_context_metadata_statedump(struct ltt_session *session, | |
748 | struct lttng_ctx *ctx) | |
749 | { | |
750 | int ret = 0; | |
751 | int i; | |
752 | ||
753 | if (!ctx) | |
754 | return 0; | |
755 | for (i = 0; i < ctx->nr_fields; i++) { | |
756 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
757 | ||
758 | ret = _ltt_field_statedump(session, &field->event_field); | |
759 | if (ret) | |
760 | return ret; | |
761 | } | |
762 | return ret; | |
763 | } | |
764 | ||
765 | static | |
766 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
767 | struct ltt_event *event) | |
768 | { | |
769 | const struct lttng_event_desc *desc = event->desc; | |
770 | int ret = 0; | |
771 | int i; | |
772 | ||
773 | for (i = 0; i < desc->nr_fields; i++) { | |
774 | const struct lttng_event_field *field = &desc->fields[i]; | |
775 | ||
776 | ret = _ltt_field_statedump(session, field); | |
777 | if (ret) | |
778 | return ret; | |
779 | } | |
780 | return ret; | |
781 | } | |
782 | ||
783 | static | |
784 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
785 | struct ltt_channel *chan, | |
786 | struct ltt_event *event) | |
787 | { | |
788 | int ret = 0; | |
789 | ||
b5234c06 | 790 | if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
791 | return 0; |
792 | if (chan == session->metadata) | |
793 | return 0; | |
8165c8da MD |
794 | /* |
795 | * Don't print events for which probe load is pending. | |
796 | */ | |
797 | if (!event->desc) | |
798 | return 0; | |
8020ceb5 MD |
799 | |
800 | ret = lttng_metadata_printf(session, | |
801 | "event {\n" | |
7083f0fe | 802 | " name = \"%s\";\n" |
8020ceb5 MD |
803 | " id = %u;\n" |
804 | " stream_id = %u;\n", | |
805 | event->desc->name, | |
806 | event->id, | |
807 | event->chan->id); | |
808 | if (ret) | |
809 | goto end; | |
810 | ||
811 | if (event->ctx) { | |
812 | ret = lttng_metadata_printf(session, | |
813 | " context := struct {\n"); | |
814 | if (ret) | |
815 | goto end; | |
816 | } | |
817 | ret = _ltt_context_metadata_statedump(session, event->ctx); | |
818 | if (ret) | |
819 | goto end; | |
820 | if (event->ctx) { | |
821 | ret = lttng_metadata_printf(session, | |
822 | " };\n"); | |
823 | if (ret) | |
824 | goto end; | |
825 | } | |
826 | ||
827 | ret = lttng_metadata_printf(session, | |
828 | " fields := struct {\n" | |
829 | ); | |
830 | if (ret) | |
831 | goto end; | |
832 | ||
833 | ret = _ltt_fields_metadata_statedump(session, event); | |
834 | if (ret) | |
835 | goto end; | |
836 | ||
837 | /* | |
838 | * LTTng space reservation can only reserve multiples of the | |
839 | * byte size. | |
840 | */ | |
841 | ret = lttng_metadata_printf(session, | |
842 | " };\n" | |
843 | "};\n\n"); | |
844 | if (ret) | |
845 | goto end; | |
846 | ||
847 | event->metadata_dumped = 1; | |
848 | end: | |
849 | return ret; | |
850 | ||
851 | } | |
852 | ||
853 | static | |
854 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
855 | struct ltt_channel *chan) | |
856 | { | |
857 | int ret = 0; | |
858 | ||
b5234c06 | 859 | if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
860 | return 0; |
861 | if (chan == session->metadata) | |
862 | return 0; | |
863 | ||
864 | WARN_ON_ONCE(!chan->header_type); | |
865 | ret = lttng_metadata_printf(session, | |
866 | "stream {\n" | |
867 | " id = %u;\n" | |
868 | " event.header := %s;\n" | |
869 | " packet.context := struct packet_context;\n", | |
870 | chan->id, | |
871 | chan->header_type == 1 ? "struct event_header_compact" : | |
872 | "struct event_header_large"); | |
873 | if (ret) | |
874 | goto end; | |
875 | ||
876 | if (chan->ctx) { | |
877 | ret = lttng_metadata_printf(session, | |
878 | " event.context := struct {\n"); | |
879 | if (ret) | |
880 | goto end; | |
881 | } | |
882 | ret = _ltt_context_metadata_statedump(session, chan->ctx); | |
883 | if (ret) | |
884 | goto end; | |
885 | if (chan->ctx) { | |
886 | ret = lttng_metadata_printf(session, | |
887 | " };\n"); | |
888 | if (ret) | |
889 | goto end; | |
890 | } | |
891 | ||
892 | ret = lttng_metadata_printf(session, | |
893 | "};\n\n"); | |
894 | ||
895 | chan->metadata_dumped = 1; | |
896 | end: | |
897 | return ret; | |
898 | } | |
899 | ||
900 | static | |
901 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
902 | { | |
903 | return lttng_metadata_printf(session, | |
904 | "struct packet_context {\n" | |
905 | " uint64_t timestamp_begin;\n" | |
906 | " uint64_t timestamp_end;\n" | |
907 | " uint32_t events_discarded;\n" | |
908 | " uint32_t content_size;\n" | |
909 | " uint32_t packet_size;\n" | |
910 | " uint32_t cpu_id;\n" | |
911 | "};\n\n" | |
912 | ); | |
913 | } | |
914 | ||
915 | /* | |
916 | * Compact header: | |
917 | * id: range: 0 - 30. | |
918 | * id 31 is reserved to indicate an extended header. | |
919 | * | |
920 | * Large header: | |
921 | * id: range: 0 - 65534. | |
922 | * id 65535 is reserved to indicate an extended header. | |
923 | */ | |
924 | static | |
925 | int _ltt_event_header_declare(struct ltt_session *session) | |
926 | { | |
927 | return lttng_metadata_printf(session, | |
928 | "struct event_header_compact {\n" | |
929 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
930 | " variant <id> {\n" | |
931 | " struct {\n" | |
932 | " uint27_t timestamp;\n" | |
933 | " } compact;\n" | |
934 | " struct {\n" | |
935 | " uint32_t id;\n" | |
936 | " uint64_t timestamp;\n" | |
937 | " } extended;\n" | |
938 | " } v;\n" | |
939 | "} align(%u);\n" | |
940 | "\n" | |
941 | "struct event_header_large {\n" | |
942 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
943 | " variant <id> {\n" | |
944 | " struct {\n" | |
945 | " uint32_t timestamp;\n" | |
946 | " } compact;\n" | |
947 | " struct {\n" | |
948 | " uint32_t id;\n" | |
949 | " uint64_t timestamp;\n" | |
950 | " } extended;\n" | |
951 | " } v;\n" | |
952 | "} align(%u);\n\n", | |
1dbfff0c MD |
953 | lttng_alignof(uint32_t) * CHAR_BIT, |
954 | lttng_alignof(uint16_t) * CHAR_BIT | |
8020ceb5 MD |
955 | ); |
956 | } | |
957 | ||
958 | /* | |
959 | * Output metadata into this session's metadata buffers. | |
960 | */ | |
961 | static | |
962 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
963 | { | |
b5234c06 MD |
964 | unsigned char *uuid_c = session->uuid; |
965 | char uuid_s[37]; | |
8020ceb5 MD |
966 | struct ltt_channel *chan; |
967 | struct ltt_event *event; | |
968 | int ret = 0; | |
969 | ||
b5234c06 | 970 | if (!CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
971 | return 0; |
972 | if (session->metadata_dumped) | |
973 | goto skip_session; | |
974 | if (!session->metadata) { | |
b5234c06 | 975 | DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
8020ceb5 MD |
976 | return -EPERM; |
977 | } | |
978 | ||
979 | snprintf(uuid_s, sizeof(uuid_s), | |
980 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", | |
981 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
982 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
983 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
984 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
985 | ||
986 | ret = lttng_metadata_printf(session, | |
987 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" | |
988 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
989 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
990 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
991 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
992 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
993 | "\n" | |
994 | "trace {\n" | |
995 | " major = %u;\n" | |
996 | " minor = %u;\n" | |
997 | " uuid = \"%s\";\n" | |
998 | " byte_order = %s;\n" | |
999 | " packet.header := struct {\n" | |
1000 | " uint32_t magic;\n" | |
1001 | " uint8_t uuid[16];\n" | |
1002 | " uint32_t stream_id;\n" | |
1003 | " };\n" | |
1004 | "};\n\n", | |
1dbfff0c MD |
1005 | lttng_alignof(uint8_t) * CHAR_BIT, |
1006 | lttng_alignof(uint16_t) * CHAR_BIT, | |
1007 | lttng_alignof(uint32_t) * CHAR_BIT, | |
1008 | lttng_alignof(uint64_t) * CHAR_BIT, | |
8020ceb5 MD |
1009 | CTF_VERSION_MAJOR, |
1010 | CTF_VERSION_MINOR, | |
1011 | uuid_s, | |
8a98a75d | 1012 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
1013 | "be" |
1014 | #else | |
1015 | "le" | |
1016 | #endif | |
1017 | ); | |
1018 | if (ret) | |
1019 | goto end; | |
1020 | ||
1021 | ret = _ltt_stream_packet_context_declare(session); | |
1022 | if (ret) | |
1023 | goto end; | |
1024 | ||
1025 | ret = _ltt_event_header_declare(session); | |
1026 | if (ret) | |
1027 | goto end; | |
1028 | ||
1029 | skip_session: | |
b5234c06 | 1030 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
1031 | ret = _ltt_channel_metadata_statedump(session, chan); |
1032 | if (ret) | |
1033 | goto end; | |
1034 | } | |
1035 | ||
b5234c06 | 1036 | cds_list_for_each_entry(event, &session->events, list) { |
8020ceb5 MD |
1037 | ret = _ltt_event_metadata_statedump(session, event->chan, event); |
1038 | if (ret) | |
1039 | goto end; | |
1040 | } | |
1041 | session->metadata_dumped = 1; | |
1042 | end: | |
1043 | return ret; | |
1044 | } | |
1045 | ||
003fedf4 | 1046 | void lttng_ust_events_exit(void) |
8020ceb5 MD |
1047 | { |
1048 | struct ltt_session *session, *tmpsession; | |
1049 | ||
b5234c06 | 1050 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, list) |
8020ceb5 | 1051 | ltt_session_destroy(session); |
8020ceb5 | 1052 | } |