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); | |
48740cab MD |
150 | if (!loglevel) |
151 | loglevel = get_loglevel_value(ev_ll->value); | |
574a6217 MD |
152 | if (loglevel) { |
153 | struct session_loglevel *sl; | |
154 | ||
155 | cds_list_for_each_entry(sl, &loglevel->session_list, | |
156 | session_list) { | |
157 | struct ltt_event *ev; | |
158 | int ret; | |
159 | ||
7ee3cc56 MD |
160 | memcpy(&event_param, &sl->event_param, |
161 | sizeof(event_param)); | |
162 | memcpy(event_param.name, | |
163 | desc->name, | |
164 | sizeof(event_param.name)); | |
574a6217 MD |
165 | /* create event */ |
166 | ret = ltt_event_create(sl->chan, | |
7ee3cc56 | 167 | &event_param, NULL, |
574a6217 | 168 | &ev); |
7ee3cc56 MD |
169 | if (ret) { |
170 | DBG("Error creating event"); | |
574a6217 | 171 | continue; |
7ee3cc56 | 172 | } |
574a6217 MD |
173 | cds_list_add(&ev->loglevel_list, |
174 | &sl->events); | |
175 | } | |
176 | } | |
177 | } | |
1f18504e | 178 | |
8165c8da MD |
179 | head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)]; |
180 | cds_hlist_for_each_entry_safe(e, node, p, head, node) { | |
181 | struct ltt_event *event; | |
182 | struct ltt_channel *chan; | |
183 | ||
184 | if (strcmp(name, e->name)) | |
185 | continue; | |
186 | event = e->event; | |
187 | chan = event->chan; | |
188 | assert(!event->desc); | |
189 | event->desc = desc; | |
190 | event->pending_probe = NULL; | |
191 | remove_pending_probe(e); | |
192 | ret |= __tracepoint_probe_register(name, | |
193 | event->desc->probe_callback, | |
194 | event); | |
636c5aa4 MD |
195 | if (ret) |
196 | continue; | |
197 | event->id = chan->free_event_id++; | |
8165c8da MD |
198 | ret |= _ltt_event_metadata_statedump(chan->session, chan, |
199 | event); | |
200 | } | |
201 | return ret; | |
202 | } | |
203 | ||
8020ceb5 MD |
204 | void synchronize_trace(void) |
205 | { | |
8020ceb5 | 206 | synchronize_rcu(); |
8020ceb5 MD |
207 | } |
208 | ||
209 | struct ltt_session *ltt_session_create(void) | |
210 | { | |
211 | struct ltt_session *session; | |
212 | ||
b5234c06 | 213 | session = zmalloc(sizeof(struct ltt_session)); |
8020ceb5 MD |
214 | if (!session) |
215 | return NULL; | |
b5234c06 MD |
216 | CDS_INIT_LIST_HEAD(&session->chan); |
217 | CDS_INIT_LIST_HEAD(&session->events); | |
1f18504e | 218 | CDS_INIT_LIST_HEAD(&session->loglevels); |
b5234c06 MD |
219 | uuid_generate(session->uuid); |
220 | cds_list_add(&session->list, &sessions); | |
8020ceb5 MD |
221 | return session; |
222 | } | |
223 | ||
224 | void ltt_session_destroy(struct ltt_session *session) | |
225 | { | |
226 | struct ltt_channel *chan, *tmpchan; | |
227 | struct ltt_event *event, *tmpevent; | |
574a6217 | 228 | struct session_loglevel *loglevel, *tmploglevel; |
8020ceb5 MD |
229 | int ret; |
230 | ||
b5234c06 MD |
231 | CMM_ACCESS_ONCE(session->active) = 0; |
232 | cds_list_for_each_entry(event, &session->events, list) { | |
8020ceb5 MD |
233 | ret = _ltt_event_unregister(event); |
234 | WARN_ON(ret); | |
235 | } | |
236 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
1f18504e MD |
237 | cds_list_for_each_entry_safe(loglevel, tmploglevel, &session->loglevels, list) |
238 | _ltt_loglevel_destroy(loglevel); | |
b5234c06 | 239 | cds_list_for_each_entry_safe(event, tmpevent, &session->events, list) |
8020ceb5 | 240 | _ltt_event_destroy(event); |
b5234c06 | 241 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list) |
8020ceb5 | 242 | _ltt_channel_destroy(chan); |
b5234c06 | 243 | cds_list_del(&session->list); |
b5234c06 | 244 | free(session); |
8020ceb5 MD |
245 | } |
246 | ||
976fe9ea | 247 | int ltt_session_enable(struct ltt_session *session) |
8020ceb5 MD |
248 | { |
249 | int ret = 0; | |
250 | struct ltt_channel *chan; | |
251 | ||
8020ceb5 MD |
252 | if (session->active) { |
253 | ret = -EBUSY; | |
254 | goto end; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Snapshot the number of events per channel to know the type of header | |
259 | * we need to use. | |
260 | */ | |
b5234c06 | 261 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
262 | if (chan->header_type) |
263 | continue; /* don't change it if session stop/restart */ | |
264 | if (chan->free_event_id < 31) | |
265 | chan->header_type = 1; /* compact */ | |
266 | else | |
267 | chan->header_type = 2; /* large */ | |
268 | } | |
269 | ||
b5234c06 MD |
270 | CMM_ACCESS_ONCE(session->active) = 1; |
271 | CMM_ACCESS_ONCE(session->been_active) = 1; | |
8020ceb5 | 272 | ret = _ltt_session_metadata_statedump(session); |
4b4de73e | 273 | if (ret) |
b5234c06 | 274 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 275 | end: |
8020ceb5 MD |
276 | return ret; |
277 | } | |
278 | ||
976fe9ea | 279 | int ltt_session_disable(struct ltt_session *session) |
8020ceb5 MD |
280 | { |
281 | int ret = 0; | |
282 | ||
8020ceb5 MD |
283 | if (!session->active) { |
284 | ret = -EBUSY; | |
285 | goto end; | |
286 | } | |
b5234c06 | 287 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 288 | end: |
8020ceb5 MD |
289 | return ret; |
290 | } | |
291 | ||
976fe9ea MD |
292 | int ltt_channel_enable(struct ltt_channel *channel) |
293 | { | |
294 | int old; | |
295 | ||
9beb36ba MD |
296 | if (channel == channel->session->metadata) |
297 | return -EPERM; | |
b5234c06 | 298 | old = uatomic_xchg(&channel->enabled, 1); |
976fe9ea MD |
299 | if (old) |
300 | return -EEXIST; | |
301 | return 0; | |
302 | } | |
303 | ||
304 | int ltt_channel_disable(struct ltt_channel *channel) | |
305 | { | |
306 | int old; | |
307 | ||
9beb36ba MD |
308 | if (channel == channel->session->metadata) |
309 | return -EPERM; | |
b5234c06 | 310 | old = uatomic_xchg(&channel->enabled, 0); |
976fe9ea MD |
311 | if (!old) |
312 | return -EEXIST; | |
313 | return 0; | |
314 | } | |
315 | ||
316 | int ltt_event_enable(struct ltt_event *event) | |
317 | { | |
318 | int old; | |
319 | ||
9beb36ba MD |
320 | if (event->chan == event->chan->session->metadata) |
321 | return -EPERM; | |
b5234c06 | 322 | old = uatomic_xchg(&event->enabled, 1); |
976fe9ea MD |
323 | if (old) |
324 | return -EEXIST; | |
325 | return 0; | |
326 | } | |
327 | ||
328 | int ltt_event_disable(struct ltt_event *event) | |
329 | { | |
330 | int old; | |
331 | ||
9beb36ba MD |
332 | if (event->chan == event->chan->session->metadata) |
333 | return -EPERM; | |
b5234c06 | 334 | old = uatomic_xchg(&event->enabled, 0); |
976fe9ea MD |
335 | if (!old) |
336 | return -EEXIST; | |
337 | return 0; | |
338 | } | |
339 | ||
8020ceb5 MD |
340 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, |
341 | const char *transport_name, | |
342 | void *buf_addr, | |
343 | size_t subbuf_size, size_t num_subbuf, | |
344 | unsigned int switch_timer_interval, | |
193183fb MD |
345 | unsigned int read_timer_interval, |
346 | int *shm_fd, int *wait_fd, | |
d028eddb MD |
347 | uint64_t *memory_map_size, |
348 | struct ltt_channel *chan_priv_init) | |
8020ceb5 | 349 | { |
a3f61e7f | 350 | struct ltt_channel *chan = NULL; |
8020ceb5 MD |
351 | struct ltt_transport *transport; |
352 | ||
8020ceb5 MD |
353 | if (session->been_active) |
354 | goto active; /* Refuse to add channel to active session */ | |
355 | transport = ltt_transport_find(transport_name); | |
356 | if (!transport) { | |
b5234c06 | 357 | DBG("LTTng transport %s not found\n", |
8020ceb5 MD |
358 | transport_name); |
359 | goto notransport; | |
360 | } | |
d028eddb MD |
361 | chan_priv_init->id = session->free_chan_id++; |
362 | chan_priv_init->session = session; | |
8020ceb5 MD |
363 | /* |
364 | * Note: the channel creation op already writes into the packet | |
365 | * headers. Therefore the "chan" information used as input | |
366 | * should be already accessible. | |
367 | */ | |
a3f61e7f | 368 | chan = transport->ops.channel_create("[lttng]", buf_addr, |
8020ceb5 | 369 | subbuf_size, num_subbuf, switch_timer_interval, |
193183fb | 370 | read_timer_interval, shm_fd, wait_fd, |
d028eddb | 371 | memory_map_size, chan_priv_init); |
a3f61e7f | 372 | if (!chan) |
8020ceb5 | 373 | goto create_error; |
976fe9ea | 374 | chan->enabled = 1; |
8020ceb5 | 375 | chan->ops = &transport->ops; |
b5234c06 | 376 | cds_list_add(&chan->list, &session->chan); |
8020ceb5 MD |
377 | return chan; |
378 | ||
379 | create_error: | |
8020ceb5 MD |
380 | notransport: |
381 | active: | |
8020ceb5 MD |
382 | return NULL; |
383 | } | |
384 | ||
385 | /* | |
386 | * Only used internally at session destruction. | |
387 | */ | |
388 | static | |
389 | void _ltt_channel_destroy(struct ltt_channel *chan) | |
390 | { | |
b5234c06 | 391 | cds_list_del(&chan->list); |
8020ceb5 | 392 | lttng_destroy_context(chan->ctx); |
a3f61e7f | 393 | chan->ops->channel_destroy(chan); |
8020ceb5 MD |
394 | } |
395 | ||
1f18504e MD |
396 | int ltt_loglevel_create(struct ltt_channel *chan, |
397 | struct lttng_ust_event *event_param, | |
574a6217 | 398 | struct session_loglevel **_sl) |
1f18504e | 399 | { |
574a6217 | 400 | struct session_loglevel *sl; |
1f18504e | 401 | |
574a6217 MD |
402 | sl = add_loglevel(event_param->name, chan, event_param); |
403 | if (!sl || IS_ERR(sl)) { | |
404 | return PTR_ERR(sl); | |
1f18504e | 405 | } |
574a6217 | 406 | *_sl = sl; |
1f18504e MD |
407 | return 0; |
408 | } | |
409 | ||
410 | static | |
574a6217 | 411 | void _ltt_loglevel_destroy(struct session_loglevel *sl) |
1f18504e | 412 | { |
574a6217 | 413 | _remove_loglevel(sl); |
1f18504e MD |
414 | } |
415 | ||
8020ceb5 MD |
416 | /* |
417 | * Supports event creation while tracing session is active. | |
418 | */ | |
576599a0 MD |
419 | int ltt_event_create(struct ltt_channel *chan, |
420 | struct lttng_ust_event *event_param, | |
421 | void *filter, | |
422 | struct ltt_event **_event) | |
8020ceb5 MD |
423 | { |
424 | struct ltt_event *event; | |
576599a0 | 425 | int ret = 0; |
8020ceb5 | 426 | |
576599a0 MD |
427 | if (chan->used_event_id == -1UL) { |
428 | ret = -ENOMEM; | |
8020ceb5 | 429 | goto full; |
576599a0 | 430 | } |
8020ceb5 MD |
431 | /* |
432 | * This is O(n^2) (for each event, the loop is called at event | |
433 | * creation). Might require a hash if we have lots of events. | |
434 | */ | |
576599a0 MD |
435 | cds_list_for_each_entry(event, &chan->session->events, list) { |
436 | if (event->desc && !strcmp(event->desc->name, event_param->name)) { | |
437 | ret = -EEXIST; | |
8020ceb5 | 438 | goto exist; |
576599a0 MD |
439 | } |
440 | } | |
b5234c06 | 441 | event = zmalloc(sizeof(struct ltt_event)); |
576599a0 MD |
442 | if (!event) { |
443 | ret = -ENOMEM; | |
8020ceb5 | 444 | goto cache_error; |
576599a0 | 445 | } |
8020ceb5 MD |
446 | event->chan = chan; |
447 | event->filter = filter; | |
8165c8da MD |
448 | /* |
449 | * used_event_id counts the maximum number of event IDs that can | |
450 | * register if all probes register. | |
451 | */ | |
452 | chan->used_event_id++; | |
976fe9ea | 453 | event->enabled = 1; |
8020ceb5 MD |
454 | event->instrumentation = event_param->instrumentation; |
455 | /* Populate ltt_event structure before tracepoint registration. */ | |
b5234c06 | 456 | cmm_smp_wmb(); |
8020ceb5 | 457 | switch (event_param->instrumentation) { |
b5234c06 | 458 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 | 459 | event->desc = ltt_event_get(event_param->name); |
8165c8da MD |
460 | if (event->desc) { |
461 | ret = __tracepoint_probe_register(event_param->name, | |
462 | event->desc->probe_callback, | |
463 | event); | |
464 | if (ret) | |
465 | goto register_error; | |
466 | event->id = chan->free_event_id++; | |
467 | } else { | |
468 | /* | |
469 | * If the probe is not present, event->desc stays NULL, | |
470 | * waiting for the probe to register, and the event->id | |
471 | * stays unallocated. | |
472 | */ | |
473 | ret = add_pending_probe(event, event_param->name); | |
474 | if (ret) | |
475 | goto add_pending_error; | |
476 | } | |
8020ceb5 | 477 | break; |
df854e41 | 478 | case LTTNG_UST_TRACEPOINT_LOGLEVEL: |
1f18504e | 479 | assert(0); |
df854e41 | 480 | break; |
8020ceb5 MD |
481 | default: |
482 | WARN_ON_ONCE(1); | |
483 | } | |
8165c8da MD |
484 | if (event->desc) { |
485 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); | |
486 | if (ret) | |
487 | goto statedump_error; | |
488 | } | |
b5234c06 | 489 | cds_list_add(&event->list, &chan->session->events); |
576599a0 MD |
490 | *_event = event; |
491 | return 0; | |
8020ceb5 MD |
492 | |
493 | statedump_error: | |
8165c8da MD |
494 | if (event->desc) { |
495 | WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name, | |
496 | event->desc->probe_callback, | |
497 | event)); | |
498 | ltt_event_put(event->desc); | |
499 | } | |
500 | add_pending_error: | |
8020ceb5 | 501 | register_error: |
b5234c06 | 502 | free(event); |
8020ceb5 MD |
503 | cache_error: |
504 | exist: | |
505 | full: | |
576599a0 | 506 | return ret; |
8020ceb5 MD |
507 | } |
508 | ||
509 | /* | |
510 | * Only used internally at session destruction. | |
511 | */ | |
512 | int _ltt_event_unregister(struct ltt_event *event) | |
513 | { | |
514 | int ret = -EINVAL; | |
515 | ||
516 | switch (event->instrumentation) { | |
b5234c06 | 517 | case LTTNG_UST_TRACEPOINT: |
8165c8da MD |
518 | if (event->desc) { |
519 | ret = __tracepoint_probe_unregister(event->desc->name, | |
520 | event->desc->probe_callback, | |
521 | event); | |
522 | if (ret) | |
523 | return ret; | |
524 | } else { | |
525 | remove_pending_probe(event->pending_probe); | |
526 | ret = 0; | |
527 | } | |
8020ceb5 | 528 | break; |
8020ceb5 MD |
529 | default: |
530 | WARN_ON_ONCE(1); | |
531 | } | |
532 | return ret; | |
533 | } | |
534 | ||
535 | /* | |
536 | * Only used internally at session destruction. | |
537 | */ | |
538 | static | |
539 | void _ltt_event_destroy(struct ltt_event *event) | |
540 | { | |
541 | switch (event->instrumentation) { | |
b5234c06 | 542 | case LTTNG_UST_TRACEPOINT: |
8165c8da MD |
543 | if (event->desc) { |
544 | ltt_event_put(event->desc); | |
545 | } | |
8020ceb5 | 546 | break; |
8020ceb5 MD |
547 | default: |
548 | WARN_ON_ONCE(1); | |
549 | } | |
b5234c06 | 550 | cds_list_del(&event->list); |
8020ceb5 | 551 | lttng_destroy_context(event->ctx); |
b5234c06 | 552 | free(event); |
8020ceb5 MD |
553 | } |
554 | ||
555 | /* | |
556 | * We have exclusive access to our metadata buffer (protected by the | |
17dfb34b | 557 | * ust_lock), so we can do racy operations such as looking for |
8020ceb5 MD |
558 | * remaining space left in packet and write, since mutual exclusion |
559 | * protects us from concurrent writes. | |
560 | */ | |
561 | int lttng_metadata_printf(struct ltt_session *session, | |
562 | const char *fmt, ...) | |
563 | { | |
4cfec15c | 564 | struct lttng_ust_lib_ring_buffer_ctx ctx; |
8020ceb5 | 565 | struct ltt_channel *chan = session->metadata; |
b5234c06 | 566 | char *str = NULL; |
8020ceb5 MD |
567 | int ret = 0, waitret; |
568 | size_t len, reserve_len, pos; | |
569 | va_list ap; | |
570 | ||
b5234c06 | 571 | WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active)); |
8020ceb5 MD |
572 | |
573 | va_start(ap, fmt); | |
b5234c06 | 574 | ret = vasprintf(&str, fmt, ap); |
8020ceb5 | 575 | va_end(ap); |
b5234c06 | 576 | if (ret < 0) |
8020ceb5 MD |
577 | return -ENOMEM; |
578 | ||
579 | len = strlen(str); | |
580 | pos = 0; | |
581 | ||
582 | for (pos = 0; pos < len; pos += reserve_len) { | |
583 | reserve_len = min_t(size_t, | |
1d498196 | 584 | chan->ops->packet_avail_size(chan->chan, chan->handle), |
8020ceb5 MD |
585 | len - pos); |
586 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
1d498196 | 587 | sizeof(char), -1, chan->handle); |
8020ceb5 MD |
588 | /* |
589 | * We don't care about metadata buffer's records lost | |
590 | * count, because we always retry here. Report error if | |
591 | * we need to bail out after timeout or being | |
592 | * interrupted. | |
593 | */ | |
b5234c06 | 594 | waitret = wait_cond_interruptible_timeout( |
8020ceb5 MD |
595 | ({ |
596 | ret = chan->ops->event_reserve(&ctx, 0); | |
597 | ret != -ENOBUFS || !ret; | |
598 | }), | |
b5234c06 | 599 | LTTNG_METADATA_TIMEOUT_MSEC); |
b472cfc0 | 600 | if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) { |
b5234c06 MD |
601 | DBG("LTTng: Failure to write metadata to buffers (%s)\n", |
602 | waitret == -EINTR ? "interrupted" : | |
8020ceb5 | 603 | (ret == -ENOBUFS ? "timeout" : "I/O error")); |
b5234c06 | 604 | if (waitret == -EINTR) |
8020ceb5 MD |
605 | ret = waitret; |
606 | goto end; | |
607 | } | |
608 | chan->ops->event_write(&ctx, &str[pos], reserve_len); | |
609 | chan->ops->event_commit(&ctx); | |
610 | } | |
611 | end: | |
b5234c06 | 612 | free(str); |
8020ceb5 MD |
613 | return ret; |
614 | } | |
615 | ||
616 | static | |
617 | int _ltt_field_statedump(struct ltt_session *session, | |
618 | const struct lttng_event_field *field) | |
619 | { | |
620 | int ret = 0; | |
621 | ||
622 | switch (field->type.atype) { | |
623 | case atype_integer: | |
624 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 625 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n", |
8020ceb5 MD |
626 | field->type.u.basic.integer.size, |
627 | field->type.u.basic.integer.alignment, | |
628 | field->type.u.basic.integer.signedness, | |
629 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
630 | ? "none" | |
631 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
632 | ? "UTF8" | |
633 | : "ASCII", | |
634 | field->type.u.basic.integer.base, | |
8a98a75d | 635 | #if (BYTE_ORDER == BIG_ENDIAN) |
403c40b4 MD |
636 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
637 | #else | |
638 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
639 | #endif | |
640 | field->name); | |
641 | break; | |
642 | case atype_float: | |
643 | ret = lttng_metadata_printf(session, | |
8a98a75d | 644 | " floating_point { exp_dig = %u; mant_dig = %u; align = %u;%s } _%s;\n", |
403c40b4 MD |
645 | field->type.u.basic._float.exp_dig, |
646 | field->type.u.basic._float.mant_dig, | |
647 | field->type.u.basic._float.alignment, | |
8a98a75d | 648 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
649 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
650 | #else | |
651 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
652 | #endif | |
653 | field->name); | |
654 | break; | |
655 | case atype_enum: | |
656 | ret = lttng_metadata_printf(session, | |
657 | " %s %s;\n", | |
658 | field->type.u.basic.enumeration.name, | |
659 | field->name); | |
660 | break; | |
661 | case atype_array: | |
662 | { | |
663 | const struct lttng_basic_type *elem_type; | |
664 | ||
665 | elem_type = &field->type.u.array.elem_type; | |
666 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 667 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n", |
8020ceb5 MD |
668 | elem_type->u.basic.integer.size, |
669 | elem_type->u.basic.integer.alignment, | |
670 | elem_type->u.basic.integer.signedness, | |
671 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
672 | ? "none" | |
673 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
674 | ? "UTF8" | |
675 | : "ASCII", | |
676 | elem_type->u.basic.integer.base, | |
8a98a75d | 677 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
678 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
679 | #else | |
680 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
681 | #endif | |
682 | field->name, field->type.u.array.length); | |
683 | break; | |
684 | } | |
685 | case atype_sequence: | |
686 | { | |
687 | const struct lttng_basic_type *elem_type; | |
688 | const struct lttng_basic_type *length_type; | |
689 | ||
690 | elem_type = &field->type.u.sequence.elem_type; | |
691 | length_type = &field->type.u.sequence.length_type; | |
692 | ret = lttng_metadata_printf(session, | |
693 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
694 | length_type->u.basic.integer.size, | |
695 | (unsigned int) length_type->u.basic.integer.alignment, | |
696 | length_type->u.basic.integer.signedness, | |
697 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
698 | ? "none" | |
699 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
700 | ? "UTF8" | |
701 | : "ASCII"), | |
702 | length_type->u.basic.integer.base, | |
8a98a75d | 703 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
704 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
705 | #else | |
706 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
707 | #endif | |
708 | field->name); | |
709 | if (ret) | |
710 | return ret; | |
711 | ||
712 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 713 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n", |
8020ceb5 MD |
714 | elem_type->u.basic.integer.size, |
715 | (unsigned int) elem_type->u.basic.integer.alignment, | |
716 | elem_type->u.basic.integer.signedness, | |
717 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
718 | ? "none" | |
719 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
720 | ? "UTF8" | |
721 | : "ASCII"), | |
722 | elem_type->u.basic.integer.base, | |
8a98a75d | 723 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
724 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
725 | #else | |
726 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
727 | #endif | |
728 | field->name, | |
729 | field->name); | |
730 | break; | |
731 | } | |
732 | ||
733 | case atype_string: | |
734 | /* Default encoding is UTF8 */ | |
735 | ret = lttng_metadata_printf(session, | |
4e2ee1f5 | 736 | " string%s _%s;\n", |
8020ceb5 MD |
737 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? |
738 | " { encoding = ASCII; }" : "", | |
739 | field->name); | |
740 | break; | |
741 | default: | |
742 | WARN_ON_ONCE(1); | |
743 | return -EINVAL; | |
744 | } | |
745 | return ret; | |
746 | } | |
747 | ||
748 | static | |
749 | int _ltt_context_metadata_statedump(struct ltt_session *session, | |
750 | struct lttng_ctx *ctx) | |
751 | { | |
752 | int ret = 0; | |
753 | int i; | |
754 | ||
755 | if (!ctx) | |
756 | return 0; | |
757 | for (i = 0; i < ctx->nr_fields; i++) { | |
758 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
759 | ||
760 | ret = _ltt_field_statedump(session, &field->event_field); | |
761 | if (ret) | |
762 | return ret; | |
763 | } | |
764 | return ret; | |
765 | } | |
766 | ||
767 | static | |
768 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
769 | struct ltt_event *event) | |
770 | { | |
771 | const struct lttng_event_desc *desc = event->desc; | |
772 | int ret = 0; | |
773 | int i; | |
774 | ||
775 | for (i = 0; i < desc->nr_fields; i++) { | |
776 | const struct lttng_event_field *field = &desc->fields[i]; | |
777 | ||
778 | ret = _ltt_field_statedump(session, field); | |
779 | if (ret) | |
780 | return ret; | |
781 | } | |
782 | return ret; | |
783 | } | |
784 | ||
785 | static | |
786 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
787 | struct ltt_channel *chan, | |
788 | struct ltt_event *event) | |
789 | { | |
790 | int ret = 0; | |
791 | ||
b5234c06 | 792 | if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
793 | return 0; |
794 | if (chan == session->metadata) | |
795 | return 0; | |
8165c8da MD |
796 | /* |
797 | * Don't print events for which probe load is pending. | |
798 | */ | |
799 | if (!event->desc) | |
800 | return 0; | |
8020ceb5 MD |
801 | |
802 | ret = lttng_metadata_printf(session, | |
803 | "event {\n" | |
7083f0fe | 804 | " name = \"%s\";\n" |
8020ceb5 MD |
805 | " id = %u;\n" |
806 | " stream_id = %u;\n", | |
807 | event->desc->name, | |
808 | event->id, | |
809 | event->chan->id); | |
810 | if (ret) | |
811 | goto end; | |
812 | ||
813 | if (event->ctx) { | |
814 | ret = lttng_metadata_printf(session, | |
815 | " context := struct {\n"); | |
816 | if (ret) | |
817 | goto end; | |
818 | } | |
819 | ret = _ltt_context_metadata_statedump(session, event->ctx); | |
820 | if (ret) | |
821 | goto end; | |
822 | if (event->ctx) { | |
823 | ret = lttng_metadata_printf(session, | |
824 | " };\n"); | |
825 | if (ret) | |
826 | goto end; | |
827 | } | |
828 | ||
829 | ret = lttng_metadata_printf(session, | |
830 | " fields := struct {\n" | |
831 | ); | |
832 | if (ret) | |
833 | goto end; | |
834 | ||
835 | ret = _ltt_fields_metadata_statedump(session, event); | |
836 | if (ret) | |
837 | goto end; | |
838 | ||
839 | /* | |
840 | * LTTng space reservation can only reserve multiples of the | |
841 | * byte size. | |
842 | */ | |
843 | ret = lttng_metadata_printf(session, | |
844 | " };\n" | |
845 | "};\n\n"); | |
846 | if (ret) | |
847 | goto end; | |
848 | ||
849 | event->metadata_dumped = 1; | |
850 | end: | |
851 | return ret; | |
852 | ||
853 | } | |
854 | ||
855 | static | |
856 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
857 | struct ltt_channel *chan) | |
858 | { | |
859 | int ret = 0; | |
860 | ||
b5234c06 | 861 | if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
862 | return 0; |
863 | if (chan == session->metadata) | |
864 | return 0; | |
865 | ||
866 | WARN_ON_ONCE(!chan->header_type); | |
867 | ret = lttng_metadata_printf(session, | |
868 | "stream {\n" | |
869 | " id = %u;\n" | |
870 | " event.header := %s;\n" | |
871 | " packet.context := struct packet_context;\n", | |
872 | chan->id, | |
873 | chan->header_type == 1 ? "struct event_header_compact" : | |
874 | "struct event_header_large"); | |
875 | if (ret) | |
876 | goto end; | |
877 | ||
878 | if (chan->ctx) { | |
879 | ret = lttng_metadata_printf(session, | |
880 | " event.context := struct {\n"); | |
881 | if (ret) | |
882 | goto end; | |
883 | } | |
884 | ret = _ltt_context_metadata_statedump(session, chan->ctx); | |
885 | if (ret) | |
886 | goto end; | |
887 | if (chan->ctx) { | |
888 | ret = lttng_metadata_printf(session, | |
889 | " };\n"); | |
890 | if (ret) | |
891 | goto end; | |
892 | } | |
893 | ||
894 | ret = lttng_metadata_printf(session, | |
895 | "};\n\n"); | |
896 | ||
897 | chan->metadata_dumped = 1; | |
898 | end: | |
899 | return ret; | |
900 | } | |
901 | ||
902 | static | |
903 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
904 | { | |
905 | return lttng_metadata_printf(session, | |
906 | "struct packet_context {\n" | |
907 | " uint64_t timestamp_begin;\n" | |
908 | " uint64_t timestamp_end;\n" | |
909 | " uint32_t events_discarded;\n" | |
910 | " uint32_t content_size;\n" | |
911 | " uint32_t packet_size;\n" | |
912 | " uint32_t cpu_id;\n" | |
913 | "};\n\n" | |
914 | ); | |
915 | } | |
916 | ||
917 | /* | |
918 | * Compact header: | |
919 | * id: range: 0 - 30. | |
920 | * id 31 is reserved to indicate an extended header. | |
921 | * | |
922 | * Large header: | |
923 | * id: range: 0 - 65534. | |
924 | * id 65535 is reserved to indicate an extended header. | |
925 | */ | |
926 | static | |
927 | int _ltt_event_header_declare(struct ltt_session *session) | |
928 | { | |
929 | return lttng_metadata_printf(session, | |
930 | "struct event_header_compact {\n" | |
931 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
932 | " variant <id> {\n" | |
933 | " struct {\n" | |
934 | " uint27_t timestamp;\n" | |
935 | " } compact;\n" | |
936 | " struct {\n" | |
937 | " uint32_t id;\n" | |
938 | " uint64_t timestamp;\n" | |
939 | " } extended;\n" | |
940 | " } v;\n" | |
941 | "} align(%u);\n" | |
942 | "\n" | |
943 | "struct event_header_large {\n" | |
944 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
945 | " variant <id> {\n" | |
946 | " struct {\n" | |
947 | " uint32_t timestamp;\n" | |
948 | " } compact;\n" | |
949 | " struct {\n" | |
950 | " uint32_t id;\n" | |
951 | " uint64_t timestamp;\n" | |
952 | " } extended;\n" | |
953 | " } v;\n" | |
954 | "} align(%u);\n\n", | |
1dbfff0c MD |
955 | lttng_alignof(uint32_t) * CHAR_BIT, |
956 | lttng_alignof(uint16_t) * CHAR_BIT | |
8020ceb5 MD |
957 | ); |
958 | } | |
959 | ||
960 | /* | |
961 | * Output metadata into this session's metadata buffers. | |
962 | */ | |
963 | static | |
964 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
965 | { | |
b5234c06 MD |
966 | unsigned char *uuid_c = session->uuid; |
967 | char uuid_s[37]; | |
8020ceb5 MD |
968 | struct ltt_channel *chan; |
969 | struct ltt_event *event; | |
970 | int ret = 0; | |
971 | ||
b5234c06 | 972 | if (!CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
973 | return 0; |
974 | if (session->metadata_dumped) | |
975 | goto skip_session; | |
976 | if (!session->metadata) { | |
b5234c06 | 977 | DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
8020ceb5 MD |
978 | return -EPERM; |
979 | } | |
980 | ||
981 | snprintf(uuid_s, sizeof(uuid_s), | |
982 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", | |
983 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
984 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
985 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
986 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
987 | ||
988 | ret = lttng_metadata_printf(session, | |
989 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" | |
990 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
991 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
992 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
993 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
994 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
995 | "\n" | |
996 | "trace {\n" | |
997 | " major = %u;\n" | |
998 | " minor = %u;\n" | |
999 | " uuid = \"%s\";\n" | |
1000 | " byte_order = %s;\n" | |
1001 | " packet.header := struct {\n" | |
1002 | " uint32_t magic;\n" | |
1003 | " uint8_t uuid[16];\n" | |
1004 | " uint32_t stream_id;\n" | |
1005 | " };\n" | |
1006 | "};\n\n", | |
1dbfff0c MD |
1007 | lttng_alignof(uint8_t) * CHAR_BIT, |
1008 | lttng_alignof(uint16_t) * CHAR_BIT, | |
1009 | lttng_alignof(uint32_t) * CHAR_BIT, | |
1010 | lttng_alignof(uint64_t) * CHAR_BIT, | |
8020ceb5 MD |
1011 | CTF_VERSION_MAJOR, |
1012 | CTF_VERSION_MINOR, | |
1013 | uuid_s, | |
8a98a75d | 1014 | #if (BYTE_ORDER == BIG_ENDIAN) |
8020ceb5 MD |
1015 | "be" |
1016 | #else | |
1017 | "le" | |
1018 | #endif | |
1019 | ); | |
1020 | if (ret) | |
1021 | goto end; | |
1022 | ||
1023 | ret = _ltt_stream_packet_context_declare(session); | |
1024 | if (ret) | |
1025 | goto end; | |
1026 | ||
1027 | ret = _ltt_event_header_declare(session); | |
1028 | if (ret) | |
1029 | goto end; | |
1030 | ||
1031 | skip_session: | |
b5234c06 | 1032 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
1033 | ret = _ltt_channel_metadata_statedump(session, chan); |
1034 | if (ret) | |
1035 | goto end; | |
1036 | } | |
1037 | ||
b5234c06 | 1038 | cds_list_for_each_entry(event, &session->events, list) { |
8020ceb5 MD |
1039 | ret = _ltt_event_metadata_statedump(session, event->chan, event); |
1040 | if (ret) | |
1041 | goto end; | |
1042 | } | |
1043 | session->metadata_dumped = 1; | |
1044 | end: | |
1045 | return ret; | |
1046 | } | |
1047 | ||
003fedf4 | 1048 | void lttng_ust_events_exit(void) |
8020ceb5 MD |
1049 | { |
1050 | struct ltt_session *session, *tmpsession; | |
1051 | ||
b5234c06 | 1052 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, list) |
8020ceb5 | 1053 | ltt_session_destroy(session); |
8020ceb5 | 1054 | } |