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> | |
13 | #include <urcu/list.h> | |
8165c8da | 14 | #include <urcu/hlist.h> |
b5234c06 MD |
15 | #include <pthread.h> |
16 | #include <urcu-bp.h> | |
17 | #include <urcu/compiler.h> | |
18 | #include <urcu/uatomic.h> | |
19 | #include <uuid/uuid.h> | |
20 | #include <ust/tracepoint.h> | |
21 | #include <errno.h> | |
f4681817 MD |
22 | #include <sys/shm.h> |
23 | #include <sys/ipc.h> | |
24 | #include <ust/lttng-events.h> | |
1dbfff0c | 25 | #include <ust/usterr-signal-safe.h> |
b5234c06 | 26 | #include "ust/core.h" |
8020ceb5 | 27 | #include "ltt-tracer.h" |
8165c8da | 28 | #include "ltt-tracer-core.h" |
b5234c06 | 29 | #include "ust/wait.h" |
8d8a24c8 | 30 | #include "../libringbuffer/shm.h" |
8020ceb5 | 31 | |
8165c8da MD |
32 | typedef u32 uint32_t; |
33 | #include <ust/kcompat/jhash.h> | |
34 | ||
35 | /* | |
36 | * The sessions mutex is the centralized mutex across UST tracing | |
37 | * control and probe registration. | |
38 | */ | |
39 | static DEFINE_MUTEX(sessions_mutex); | |
40 | ||
41 | void lock_ust(void) | |
42 | { | |
43 | pthread_mutex_lock(&sessions_mutex); | |
44 | } | |
45 | ||
46 | void unlock_ust(void) | |
47 | { | |
48 | pthread_mutex_unlock(&sessions_mutex); | |
49 | } | |
50 | ||
b5234c06 MD |
51 | static CDS_LIST_HEAD(sessions); |
52 | static CDS_LIST_HEAD(ltt_transport_list); | |
8165c8da MD |
53 | |
54 | /* | |
55 | * Pending probes hash table, containing the registered ltt events for | |
56 | * which tracepoint probes are still missing. Protected by the sessions | |
57 | * mutex. | |
58 | */ | |
59 | #define PENDING_PROBE_HASH_BITS 6 | |
60 | #define PENDING_PROBE_HASH_SIZE (1 << PENDING_PROBE_HASH_BITS) | |
61 | static struct cds_hlist_head pending_probe_table[PENDING_PROBE_HASH_SIZE]; | |
62 | ||
63 | struct ust_pending_probe { | |
64 | struct ltt_event *event; | |
65 | struct cds_hlist_node node; | |
66 | char name[]; | |
67 | }; | |
8020ceb5 MD |
68 | |
69 | static void _ltt_event_destroy(struct ltt_event *event); | |
70 | static void _ltt_channel_destroy(struct ltt_channel *chan); | |
71 | static int _ltt_event_unregister(struct ltt_event *event); | |
72 | static | |
73 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
74 | struct ltt_channel *chan, | |
75 | struct ltt_event *event); | |
76 | static | |
77 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
78 | ||
8165c8da MD |
79 | /* |
80 | * called at event creation if probe is missing. | |
81 | * called with session mutex held. | |
82 | */ | |
83 | static | |
84 | int add_pending_probe(struct ltt_event *event, const char *name) | |
85 | { | |
86 | struct cds_hlist_head *head; | |
87 | struct cds_hlist_node *node; | |
88 | struct ust_pending_probe *e; | |
89 | size_t name_len = strlen(name) + 1; | |
90 | u32 hash = jhash(name, name_len - 1, 0); | |
91 | ||
92 | head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)]; | |
93 | e = zmalloc(sizeof(struct ust_pending_probe) + name_len); | |
94 | if (!e) | |
95 | return -ENOMEM; | |
96 | memcpy(&e->name[0], name, name_len); | |
97 | cds_hlist_add_head(&e->node, head); | |
98 | e->event = event; | |
99 | event->pending_probe = e; | |
100 | return 0; | |
101 | } | |
102 | ||
103 | /* | |
104 | * remove a pending probe. called when at event teardown and when an | |
105 | * event is fixed (probe is loaded). | |
106 | * called with session mutex held. | |
107 | */ | |
108 | static | |
109 | void remove_pending_probe(struct ust_pending_probe *e) | |
110 | { | |
111 | if (!e) | |
112 | return; | |
113 | cds_hlist_del(&e->node); | |
114 | free(e); | |
115 | } | |
116 | ||
117 | /* | |
118 | * Called at library load: connect the probe on the events pending on | |
119 | * probe load. | |
120 | * called with session mutex held. | |
121 | */ | |
122 | int pending_probe_fix_events(const struct lttng_event_desc *desc) | |
123 | { | |
124 | struct cds_hlist_head *head; | |
125 | struct cds_hlist_node *node, *p; | |
126 | struct ust_pending_probe *e; | |
127 | const char *name = desc->name; | |
128 | size_t name_len = strlen(name) + 1; | |
129 | u32 hash = jhash(name, name_len - 1, 0); | |
130 | int ret = 0; | |
131 | ||
132 | head = &pending_probe_table[hash & (PENDING_PROBE_HASH_SIZE - 1)]; | |
133 | cds_hlist_for_each_entry_safe(e, node, p, head, node) { | |
134 | struct ltt_event *event; | |
135 | struct ltt_channel *chan; | |
136 | ||
137 | if (strcmp(name, e->name)) | |
138 | continue; | |
139 | event = e->event; | |
140 | chan = event->chan; | |
141 | assert(!event->desc); | |
142 | event->desc = desc; | |
143 | event->pending_probe = NULL; | |
144 | remove_pending_probe(e); | |
145 | ret |= __tracepoint_probe_register(name, | |
146 | event->desc->probe_callback, | |
147 | event); | |
148 | ret |= _ltt_event_metadata_statedump(chan->session, chan, | |
149 | event); | |
150 | } | |
151 | return ret; | |
152 | } | |
153 | ||
8020ceb5 MD |
154 | void synchronize_trace(void) |
155 | { | |
8020ceb5 | 156 | synchronize_rcu(); |
8020ceb5 MD |
157 | } |
158 | ||
159 | struct ltt_session *ltt_session_create(void) | |
160 | { | |
161 | struct ltt_session *session; | |
162 | ||
b5234c06 | 163 | session = zmalloc(sizeof(struct ltt_session)); |
8020ceb5 MD |
164 | if (!session) |
165 | return NULL; | |
1ea11eab | 166 | pthread_mutex_lock(&sessions_mutex); |
b5234c06 MD |
167 | CDS_INIT_LIST_HEAD(&session->chan); |
168 | CDS_INIT_LIST_HEAD(&session->events); | |
169 | uuid_generate(session->uuid); | |
170 | cds_list_add(&session->list, &sessions); | |
171 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
172 | return session; |
173 | } | |
174 | ||
175 | void ltt_session_destroy(struct ltt_session *session) | |
176 | { | |
177 | struct ltt_channel *chan, *tmpchan; | |
178 | struct ltt_event *event, *tmpevent; | |
179 | int ret; | |
180 | ||
b5234c06 MD |
181 | pthread_mutex_lock(&sessions_mutex); |
182 | CMM_ACCESS_ONCE(session->active) = 0; | |
183 | cds_list_for_each_entry(event, &session->events, list) { | |
8020ceb5 MD |
184 | ret = _ltt_event_unregister(event); |
185 | WARN_ON(ret); | |
186 | } | |
187 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
b5234c06 | 188 | cds_list_for_each_entry_safe(event, tmpevent, &session->events, list) |
8020ceb5 | 189 | _ltt_event_destroy(event); |
b5234c06 | 190 | cds_list_for_each_entry_safe(chan, tmpchan, &session->chan, list) |
8020ceb5 | 191 | _ltt_channel_destroy(chan); |
b5234c06 MD |
192 | cds_list_del(&session->list); |
193 | pthread_mutex_unlock(&sessions_mutex); | |
194 | free(session); | |
8020ceb5 MD |
195 | } |
196 | ||
976fe9ea | 197 | int ltt_session_enable(struct ltt_session *session) |
8020ceb5 MD |
198 | { |
199 | int ret = 0; | |
200 | struct ltt_channel *chan; | |
201 | ||
b5234c06 | 202 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
203 | if (session->active) { |
204 | ret = -EBUSY; | |
205 | goto end; | |
206 | } | |
207 | ||
208 | /* | |
209 | * Snapshot the number of events per channel to know the type of header | |
210 | * we need to use. | |
211 | */ | |
b5234c06 | 212 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
213 | if (chan->header_type) |
214 | continue; /* don't change it if session stop/restart */ | |
215 | if (chan->free_event_id < 31) | |
216 | chan->header_type = 1; /* compact */ | |
217 | else | |
218 | chan->header_type = 2; /* large */ | |
219 | } | |
220 | ||
b5234c06 MD |
221 | CMM_ACCESS_ONCE(session->active) = 1; |
222 | CMM_ACCESS_ONCE(session->been_active) = 1; | |
8020ceb5 | 223 | ret = _ltt_session_metadata_statedump(session); |
4b4de73e | 224 | if (ret) |
b5234c06 | 225 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 226 | end: |
b5234c06 | 227 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
228 | return ret; |
229 | } | |
230 | ||
976fe9ea | 231 | int ltt_session_disable(struct ltt_session *session) |
8020ceb5 MD |
232 | { |
233 | int ret = 0; | |
234 | ||
b5234c06 | 235 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
236 | if (!session->active) { |
237 | ret = -EBUSY; | |
238 | goto end; | |
239 | } | |
b5234c06 | 240 | CMM_ACCESS_ONCE(session->active) = 0; |
8020ceb5 | 241 | end: |
b5234c06 | 242 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
243 | return ret; |
244 | } | |
245 | ||
976fe9ea MD |
246 | int ltt_channel_enable(struct ltt_channel *channel) |
247 | { | |
248 | int old; | |
249 | ||
9beb36ba MD |
250 | if (channel == channel->session->metadata) |
251 | return -EPERM; | |
b5234c06 | 252 | old = uatomic_xchg(&channel->enabled, 1); |
976fe9ea MD |
253 | if (old) |
254 | return -EEXIST; | |
255 | return 0; | |
256 | } | |
257 | ||
258 | int ltt_channel_disable(struct ltt_channel *channel) | |
259 | { | |
260 | int old; | |
261 | ||
9beb36ba MD |
262 | if (channel == channel->session->metadata) |
263 | return -EPERM; | |
b5234c06 | 264 | old = uatomic_xchg(&channel->enabled, 0); |
976fe9ea MD |
265 | if (!old) |
266 | return -EEXIST; | |
267 | return 0; | |
268 | } | |
269 | ||
270 | int ltt_event_enable(struct ltt_event *event) | |
271 | { | |
272 | int old; | |
273 | ||
9beb36ba MD |
274 | if (event->chan == event->chan->session->metadata) |
275 | return -EPERM; | |
b5234c06 | 276 | old = uatomic_xchg(&event->enabled, 1); |
976fe9ea MD |
277 | if (old) |
278 | return -EEXIST; | |
279 | return 0; | |
280 | } | |
281 | ||
282 | int ltt_event_disable(struct ltt_event *event) | |
283 | { | |
284 | int old; | |
285 | ||
9beb36ba MD |
286 | if (event->chan == event->chan->session->metadata) |
287 | return -EPERM; | |
b5234c06 | 288 | old = uatomic_xchg(&event->enabled, 0); |
976fe9ea MD |
289 | if (!old) |
290 | return -EEXIST; | |
291 | return 0; | |
292 | } | |
293 | ||
8020ceb5 MD |
294 | static struct ltt_transport *ltt_transport_find(const char *name) |
295 | { | |
296 | struct ltt_transport *transport; | |
297 | ||
b5234c06 | 298 | cds_list_for_each_entry(transport, <t_transport_list, node) { |
8020ceb5 MD |
299 | if (!strcmp(transport->name, name)) |
300 | return transport; | |
301 | } | |
302 | return NULL; | |
303 | } | |
304 | ||
305 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, | |
306 | const char *transport_name, | |
307 | void *buf_addr, | |
308 | size_t subbuf_size, size_t num_subbuf, | |
309 | unsigned int switch_timer_interval, | |
f4681817 | 310 | unsigned int read_timer_interval) |
8020ceb5 MD |
311 | { |
312 | struct ltt_channel *chan; | |
313 | struct ltt_transport *transport; | |
314 | ||
b5234c06 | 315 | pthread_mutex_lock(&sessions_mutex); |
8020ceb5 MD |
316 | if (session->been_active) |
317 | goto active; /* Refuse to add channel to active session */ | |
318 | transport = ltt_transport_find(transport_name); | |
319 | if (!transport) { | |
b5234c06 | 320 | DBG("LTTng transport %s not found\n", |
8020ceb5 MD |
321 | transport_name); |
322 | goto notransport; | |
323 | } | |
b5234c06 | 324 | chan = zmalloc(sizeof(struct ltt_channel)); |
8020ceb5 MD |
325 | if (!chan) |
326 | goto nomem; | |
327 | chan->session = session; | |
328 | chan->id = session->free_chan_id++; | |
329 | /* | |
330 | * Note: the channel creation op already writes into the packet | |
331 | * headers. Therefore the "chan" information used as input | |
332 | * should be already accessible. | |
333 | */ | |
1d498196 | 334 | transport->ops.channel_create("[lttng]", chan, buf_addr, |
8020ceb5 | 335 | subbuf_size, num_subbuf, switch_timer_interval, |
8d8a24c8 | 336 | read_timer_interval); |
8020ceb5 MD |
337 | if (!chan->chan) |
338 | goto create_error; | |
976fe9ea | 339 | chan->enabled = 1; |
8020ceb5 | 340 | chan->ops = &transport->ops; |
b5234c06 MD |
341 | cds_list_add(&chan->list, &session->chan); |
342 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
343 | return chan; |
344 | ||
345 | create_error: | |
b5234c06 | 346 | free(chan); |
8020ceb5 MD |
347 | nomem: |
348 | notransport: | |
349 | active: | |
b5234c06 | 350 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
351 | return NULL; |
352 | } | |
353 | ||
354 | /* | |
355 | * Only used internally at session destruction. | |
356 | */ | |
357 | static | |
358 | void _ltt_channel_destroy(struct ltt_channel *chan) | |
359 | { | |
1d498196 | 360 | chan->ops->channel_destroy(chan); |
b5234c06 | 361 | cds_list_del(&chan->list); |
8020ceb5 | 362 | lttng_destroy_context(chan->ctx); |
b5234c06 | 363 | free(chan); |
8020ceb5 MD |
364 | } |
365 | ||
366 | /* | |
367 | * Supports event creation while tracing session is active. | |
368 | */ | |
369 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, | |
b5234c06 | 370 | struct lttng_ust_event *event_param, |
8020ceb5 MD |
371 | void *filter) |
372 | { | |
373 | struct ltt_event *event; | |
374 | int ret; | |
375 | ||
b5234c06 | 376 | pthread_mutex_lock(&sessions_mutex); |
8165c8da | 377 | if (chan->used_event_id == -1UL) |
8020ceb5 MD |
378 | goto full; |
379 | /* | |
380 | * This is O(n^2) (for each event, the loop is called at event | |
381 | * creation). Might require a hash if we have lots of events. | |
382 | */ | |
b5234c06 | 383 | cds_list_for_each_entry(event, &chan->session->events, list) |
8165c8da | 384 | if (event->desc && !strcmp(event->desc->name, event_param->name)) |
8020ceb5 | 385 | goto exist; |
b5234c06 | 386 | event = zmalloc(sizeof(struct ltt_event)); |
8020ceb5 MD |
387 | if (!event) |
388 | goto cache_error; | |
389 | event->chan = chan; | |
390 | event->filter = filter; | |
8165c8da MD |
391 | /* |
392 | * used_event_id counts the maximum number of event IDs that can | |
393 | * register if all probes register. | |
394 | */ | |
395 | chan->used_event_id++; | |
976fe9ea | 396 | event->enabled = 1; |
8020ceb5 MD |
397 | event->instrumentation = event_param->instrumentation; |
398 | /* Populate ltt_event structure before tracepoint registration. */ | |
b5234c06 | 399 | cmm_smp_wmb(); |
8020ceb5 | 400 | switch (event_param->instrumentation) { |
b5234c06 | 401 | case LTTNG_UST_TRACEPOINT: |
8020ceb5 | 402 | event->desc = ltt_event_get(event_param->name); |
8165c8da MD |
403 | if (event->desc) { |
404 | ret = __tracepoint_probe_register(event_param->name, | |
405 | event->desc->probe_callback, | |
406 | event); | |
407 | if (ret) | |
408 | goto register_error; | |
409 | event->id = chan->free_event_id++; | |
410 | } else { | |
411 | /* | |
412 | * If the probe is not present, event->desc stays NULL, | |
413 | * waiting for the probe to register, and the event->id | |
414 | * stays unallocated. | |
415 | */ | |
416 | ret = add_pending_probe(event, event_param->name); | |
417 | if (ret) | |
418 | goto add_pending_error; | |
419 | } | |
8020ceb5 | 420 | break; |
8020ceb5 MD |
421 | default: |
422 | WARN_ON_ONCE(1); | |
423 | } | |
8165c8da MD |
424 | if (event->desc) { |
425 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); | |
426 | if (ret) | |
427 | goto statedump_error; | |
428 | } | |
b5234c06 MD |
429 | cds_list_add(&event->list, &chan->session->events); |
430 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
431 | return event; |
432 | ||
433 | statedump_error: | |
8165c8da MD |
434 | if (event->desc) { |
435 | WARN_ON_ONCE(__tracepoint_probe_unregister(event_param->name, | |
436 | event->desc->probe_callback, | |
437 | event)); | |
438 | ltt_event_put(event->desc); | |
439 | } | |
440 | add_pending_error: | |
8020ceb5 | 441 | register_error: |
b5234c06 | 442 | free(event); |
8020ceb5 MD |
443 | cache_error: |
444 | exist: | |
445 | full: | |
b5234c06 | 446 | pthread_mutex_unlock(&sessions_mutex); |
8020ceb5 MD |
447 | return NULL; |
448 | } | |
449 | ||
450 | /* | |
451 | * Only used internally at session destruction. | |
452 | */ | |
453 | int _ltt_event_unregister(struct ltt_event *event) | |
454 | { | |
455 | int ret = -EINVAL; | |
456 | ||
457 | switch (event->instrumentation) { | |
b5234c06 | 458 | case LTTNG_UST_TRACEPOINT: |
8165c8da MD |
459 | if (event->desc) { |
460 | ret = __tracepoint_probe_unregister(event->desc->name, | |
461 | event->desc->probe_callback, | |
462 | event); | |
463 | if (ret) | |
464 | return ret; | |
465 | } else { | |
466 | remove_pending_probe(event->pending_probe); | |
467 | ret = 0; | |
468 | } | |
8020ceb5 | 469 | break; |
8020ceb5 MD |
470 | default: |
471 | WARN_ON_ONCE(1); | |
472 | } | |
473 | return ret; | |
474 | } | |
475 | ||
476 | /* | |
477 | * Only used internally at session destruction. | |
478 | */ | |
479 | static | |
480 | void _ltt_event_destroy(struct ltt_event *event) | |
481 | { | |
482 | switch (event->instrumentation) { | |
b5234c06 | 483 | case LTTNG_UST_TRACEPOINT: |
8165c8da MD |
484 | if (event->desc) { |
485 | ltt_event_put(event->desc); | |
486 | } | |
8020ceb5 | 487 | break; |
8020ceb5 MD |
488 | default: |
489 | WARN_ON_ONCE(1); | |
490 | } | |
b5234c06 | 491 | cds_list_del(&event->list); |
8020ceb5 | 492 | lttng_destroy_context(event->ctx); |
b5234c06 | 493 | free(event); |
8020ceb5 MD |
494 | } |
495 | ||
496 | /* | |
497 | * We have exclusive access to our metadata buffer (protected by the | |
498 | * sessions_mutex), so we can do racy operations such as looking for | |
499 | * remaining space left in packet and write, since mutual exclusion | |
500 | * protects us from concurrent writes. | |
501 | */ | |
502 | int lttng_metadata_printf(struct ltt_session *session, | |
503 | const char *fmt, ...) | |
504 | { | |
505 | struct lib_ring_buffer_ctx ctx; | |
506 | struct ltt_channel *chan = session->metadata; | |
b5234c06 | 507 | char *str = NULL; |
8020ceb5 MD |
508 | int ret = 0, waitret; |
509 | size_t len, reserve_len, pos; | |
510 | va_list ap; | |
511 | ||
b5234c06 | 512 | WARN_ON_ONCE(!CMM_ACCESS_ONCE(session->active)); |
8020ceb5 MD |
513 | |
514 | va_start(ap, fmt); | |
b5234c06 | 515 | ret = vasprintf(&str, fmt, ap); |
8020ceb5 | 516 | va_end(ap); |
b5234c06 | 517 | if (ret < 0) |
8020ceb5 MD |
518 | return -ENOMEM; |
519 | ||
520 | len = strlen(str); | |
521 | pos = 0; | |
522 | ||
523 | for (pos = 0; pos < len; pos += reserve_len) { | |
524 | reserve_len = min_t(size_t, | |
1d498196 | 525 | chan->ops->packet_avail_size(chan->chan, chan->handle), |
8020ceb5 MD |
526 | len - pos); |
527 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
1d498196 | 528 | sizeof(char), -1, chan->handle); |
8020ceb5 MD |
529 | /* |
530 | * We don't care about metadata buffer's records lost | |
531 | * count, because we always retry here. Report error if | |
532 | * we need to bail out after timeout or being | |
533 | * interrupted. | |
534 | */ | |
b5234c06 | 535 | waitret = wait_cond_interruptible_timeout( |
8020ceb5 MD |
536 | ({ |
537 | ret = chan->ops->event_reserve(&ctx, 0); | |
538 | ret != -ENOBUFS || !ret; | |
539 | }), | |
b5234c06 | 540 | LTTNG_METADATA_TIMEOUT_MSEC); |
b472cfc0 | 541 | if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) { |
b5234c06 MD |
542 | DBG("LTTng: Failure to write metadata to buffers (%s)\n", |
543 | waitret == -EINTR ? "interrupted" : | |
8020ceb5 | 544 | (ret == -ENOBUFS ? "timeout" : "I/O error")); |
b5234c06 | 545 | if (waitret == -EINTR) |
8020ceb5 MD |
546 | ret = waitret; |
547 | goto end; | |
548 | } | |
549 | chan->ops->event_write(&ctx, &str[pos], reserve_len); | |
550 | chan->ops->event_commit(&ctx); | |
551 | } | |
552 | end: | |
b5234c06 | 553 | free(str); |
8020ceb5 MD |
554 | return ret; |
555 | } | |
556 | ||
557 | static | |
558 | int _ltt_field_statedump(struct ltt_session *session, | |
559 | const struct lttng_event_field *field) | |
560 | { | |
561 | int ret = 0; | |
562 | ||
563 | switch (field->type.atype) { | |
564 | case atype_integer: | |
565 | ret = lttng_metadata_printf(session, | |
566 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n", | |
567 | field->type.u.basic.integer.size, | |
568 | field->type.u.basic.integer.alignment, | |
569 | field->type.u.basic.integer.signedness, | |
570 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
571 | ? "none" | |
572 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
573 | ? "UTF8" | |
574 | : "ASCII", | |
575 | field->type.u.basic.integer.base, | |
403c40b4 MD |
576 | #ifdef __BIG_ENDIAN |
577 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
578 | #else | |
579 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
580 | #endif | |
581 | field->name); | |
582 | break; | |
583 | case atype_float: | |
584 | ret = lttng_metadata_printf(session, | |
585 | " floating_point { exp_dig = %u; mant_dig = %u; align = %u; } %s;\n", | |
586 | field->type.u.basic._float.exp_dig, | |
587 | field->type.u.basic._float.mant_dig, | |
588 | field->type.u.basic._float.alignment, | |
589 | #ifdef __BIG_ENDIAN | |
8020ceb5 MD |
590 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
591 | #else | |
592 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
593 | #endif | |
594 | field->name); | |
595 | break; | |
596 | case atype_enum: | |
597 | ret = lttng_metadata_printf(session, | |
598 | " %s %s;\n", | |
599 | field->type.u.basic.enumeration.name, | |
600 | field->name); | |
601 | break; | |
602 | case atype_array: | |
603 | { | |
604 | const struct lttng_basic_type *elem_type; | |
605 | ||
606 | elem_type = &field->type.u.array.elem_type; | |
607 | ret = lttng_metadata_printf(session, | |
608 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n", | |
609 | elem_type->u.basic.integer.size, | |
610 | elem_type->u.basic.integer.alignment, | |
611 | elem_type->u.basic.integer.signedness, | |
612 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
613 | ? "none" | |
614 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
615 | ? "UTF8" | |
616 | : "ASCII", | |
617 | elem_type->u.basic.integer.base, | |
403c40b4 | 618 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
619 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
620 | #else | |
621 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
622 | #endif | |
623 | field->name, field->type.u.array.length); | |
624 | break; | |
625 | } | |
626 | case atype_sequence: | |
627 | { | |
628 | const struct lttng_basic_type *elem_type; | |
629 | const struct lttng_basic_type *length_type; | |
630 | ||
631 | elem_type = &field->type.u.sequence.elem_type; | |
632 | length_type = &field->type.u.sequence.length_type; | |
633 | ret = lttng_metadata_printf(session, | |
634 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
635 | length_type->u.basic.integer.size, | |
636 | (unsigned int) length_type->u.basic.integer.alignment, | |
637 | length_type->u.basic.integer.signedness, | |
638 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
639 | ? "none" | |
640 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
641 | ? "UTF8" | |
642 | : "ASCII"), | |
643 | length_type->u.basic.integer.base, | |
403c40b4 | 644 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
645 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
646 | #else | |
647 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
648 | #endif | |
649 | field->name); | |
650 | if (ret) | |
651 | return ret; | |
652 | ||
653 | ret = lttng_metadata_printf(session, | |
654 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n", | |
655 | elem_type->u.basic.integer.size, | |
656 | (unsigned int) elem_type->u.basic.integer.alignment, | |
657 | elem_type->u.basic.integer.signedness, | |
658 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
659 | ? "none" | |
660 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
661 | ? "UTF8" | |
662 | : "ASCII"), | |
663 | elem_type->u.basic.integer.base, | |
403c40b4 | 664 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
665 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
666 | #else | |
667 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
668 | #endif | |
669 | field->name, | |
670 | field->name); | |
671 | break; | |
672 | } | |
673 | ||
674 | case atype_string: | |
675 | /* Default encoding is UTF8 */ | |
676 | ret = lttng_metadata_printf(session, | |
677 | " string%s %s;\n", | |
678 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
679 | " { encoding = ASCII; }" : "", | |
680 | field->name); | |
681 | break; | |
682 | default: | |
683 | WARN_ON_ONCE(1); | |
684 | return -EINVAL; | |
685 | } | |
686 | return ret; | |
687 | } | |
688 | ||
689 | static | |
690 | int _ltt_context_metadata_statedump(struct ltt_session *session, | |
691 | struct lttng_ctx *ctx) | |
692 | { | |
693 | int ret = 0; | |
694 | int i; | |
695 | ||
696 | if (!ctx) | |
697 | return 0; | |
698 | for (i = 0; i < ctx->nr_fields; i++) { | |
699 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
700 | ||
701 | ret = _ltt_field_statedump(session, &field->event_field); | |
702 | if (ret) | |
703 | return ret; | |
704 | } | |
705 | return ret; | |
706 | } | |
707 | ||
708 | static | |
709 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
710 | struct ltt_event *event) | |
711 | { | |
712 | const struct lttng_event_desc *desc = event->desc; | |
713 | int ret = 0; | |
714 | int i; | |
715 | ||
716 | for (i = 0; i < desc->nr_fields; i++) { | |
717 | const struct lttng_event_field *field = &desc->fields[i]; | |
718 | ||
719 | ret = _ltt_field_statedump(session, field); | |
720 | if (ret) | |
721 | return ret; | |
722 | } | |
723 | return ret; | |
724 | } | |
725 | ||
726 | static | |
727 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
728 | struct ltt_channel *chan, | |
729 | struct ltt_event *event) | |
730 | { | |
731 | int ret = 0; | |
732 | ||
b5234c06 | 733 | if (event->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
734 | return 0; |
735 | if (chan == session->metadata) | |
736 | return 0; | |
8165c8da MD |
737 | /* |
738 | * Don't print events for which probe load is pending. | |
739 | */ | |
740 | if (!event->desc) | |
741 | return 0; | |
8020ceb5 MD |
742 | |
743 | ret = lttng_metadata_printf(session, | |
744 | "event {\n" | |
745 | " name = %s;\n" | |
746 | " id = %u;\n" | |
747 | " stream_id = %u;\n", | |
748 | event->desc->name, | |
749 | event->id, | |
750 | event->chan->id); | |
751 | if (ret) | |
752 | goto end; | |
753 | ||
754 | if (event->ctx) { | |
755 | ret = lttng_metadata_printf(session, | |
756 | " context := struct {\n"); | |
757 | if (ret) | |
758 | goto end; | |
759 | } | |
760 | ret = _ltt_context_metadata_statedump(session, event->ctx); | |
761 | if (ret) | |
762 | goto end; | |
763 | if (event->ctx) { | |
764 | ret = lttng_metadata_printf(session, | |
765 | " };\n"); | |
766 | if (ret) | |
767 | goto end; | |
768 | } | |
769 | ||
770 | ret = lttng_metadata_printf(session, | |
771 | " fields := struct {\n" | |
772 | ); | |
773 | if (ret) | |
774 | goto end; | |
775 | ||
776 | ret = _ltt_fields_metadata_statedump(session, event); | |
777 | if (ret) | |
778 | goto end; | |
779 | ||
780 | /* | |
781 | * LTTng space reservation can only reserve multiples of the | |
782 | * byte size. | |
783 | */ | |
784 | ret = lttng_metadata_printf(session, | |
785 | " };\n" | |
786 | "};\n\n"); | |
787 | if (ret) | |
788 | goto end; | |
789 | ||
790 | event->metadata_dumped = 1; | |
791 | end: | |
792 | return ret; | |
793 | ||
794 | } | |
795 | ||
796 | static | |
797 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
798 | struct ltt_channel *chan) | |
799 | { | |
800 | int ret = 0; | |
801 | ||
b5234c06 | 802 | if (chan->metadata_dumped || !CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
803 | return 0; |
804 | if (chan == session->metadata) | |
805 | return 0; | |
806 | ||
807 | WARN_ON_ONCE(!chan->header_type); | |
808 | ret = lttng_metadata_printf(session, | |
809 | "stream {\n" | |
810 | " id = %u;\n" | |
811 | " event.header := %s;\n" | |
812 | " packet.context := struct packet_context;\n", | |
813 | chan->id, | |
814 | chan->header_type == 1 ? "struct event_header_compact" : | |
815 | "struct event_header_large"); | |
816 | if (ret) | |
817 | goto end; | |
818 | ||
819 | if (chan->ctx) { | |
820 | ret = lttng_metadata_printf(session, | |
821 | " event.context := struct {\n"); | |
822 | if (ret) | |
823 | goto end; | |
824 | } | |
825 | ret = _ltt_context_metadata_statedump(session, chan->ctx); | |
826 | if (ret) | |
827 | goto end; | |
828 | if (chan->ctx) { | |
829 | ret = lttng_metadata_printf(session, | |
830 | " };\n"); | |
831 | if (ret) | |
832 | goto end; | |
833 | } | |
834 | ||
835 | ret = lttng_metadata_printf(session, | |
836 | "};\n\n"); | |
837 | ||
838 | chan->metadata_dumped = 1; | |
839 | end: | |
840 | return ret; | |
841 | } | |
842 | ||
843 | static | |
844 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
845 | { | |
846 | return lttng_metadata_printf(session, | |
847 | "struct packet_context {\n" | |
848 | " uint64_t timestamp_begin;\n" | |
849 | " uint64_t timestamp_end;\n" | |
850 | " uint32_t events_discarded;\n" | |
851 | " uint32_t content_size;\n" | |
852 | " uint32_t packet_size;\n" | |
853 | " uint32_t cpu_id;\n" | |
854 | "};\n\n" | |
855 | ); | |
856 | } | |
857 | ||
858 | /* | |
859 | * Compact header: | |
860 | * id: range: 0 - 30. | |
861 | * id 31 is reserved to indicate an extended header. | |
862 | * | |
863 | * Large header: | |
864 | * id: range: 0 - 65534. | |
865 | * id 65535 is reserved to indicate an extended header. | |
866 | */ | |
867 | static | |
868 | int _ltt_event_header_declare(struct ltt_session *session) | |
869 | { | |
870 | return lttng_metadata_printf(session, | |
871 | "struct event_header_compact {\n" | |
872 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
873 | " variant <id> {\n" | |
874 | " struct {\n" | |
875 | " uint27_t timestamp;\n" | |
876 | " } compact;\n" | |
877 | " struct {\n" | |
878 | " uint32_t id;\n" | |
879 | " uint64_t timestamp;\n" | |
880 | " } extended;\n" | |
881 | " } v;\n" | |
882 | "} align(%u);\n" | |
883 | "\n" | |
884 | "struct event_header_large {\n" | |
885 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
886 | " variant <id> {\n" | |
887 | " struct {\n" | |
888 | " uint32_t timestamp;\n" | |
889 | " } compact;\n" | |
890 | " struct {\n" | |
891 | " uint32_t id;\n" | |
892 | " uint64_t timestamp;\n" | |
893 | " } extended;\n" | |
894 | " } v;\n" | |
895 | "} align(%u);\n\n", | |
1dbfff0c MD |
896 | lttng_alignof(uint32_t) * CHAR_BIT, |
897 | lttng_alignof(uint16_t) * CHAR_BIT | |
8020ceb5 MD |
898 | ); |
899 | } | |
900 | ||
901 | /* | |
902 | * Output metadata into this session's metadata buffers. | |
903 | */ | |
904 | static | |
905 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
906 | { | |
b5234c06 MD |
907 | unsigned char *uuid_c = session->uuid; |
908 | char uuid_s[37]; | |
8020ceb5 MD |
909 | struct ltt_channel *chan; |
910 | struct ltt_event *event; | |
911 | int ret = 0; | |
912 | ||
b5234c06 | 913 | if (!CMM_ACCESS_ONCE(session->active)) |
8020ceb5 MD |
914 | return 0; |
915 | if (session->metadata_dumped) | |
916 | goto skip_session; | |
917 | if (!session->metadata) { | |
b5234c06 | 918 | DBG("LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
8020ceb5 MD |
919 | return -EPERM; |
920 | } | |
921 | ||
922 | snprintf(uuid_s, sizeof(uuid_s), | |
923 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", | |
924 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
925 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
926 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
927 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
928 | ||
929 | ret = lttng_metadata_printf(session, | |
930 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" | |
931 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
932 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
933 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
934 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
935 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
936 | "\n" | |
937 | "trace {\n" | |
938 | " major = %u;\n" | |
939 | " minor = %u;\n" | |
940 | " uuid = \"%s\";\n" | |
941 | " byte_order = %s;\n" | |
942 | " packet.header := struct {\n" | |
943 | " uint32_t magic;\n" | |
944 | " uint8_t uuid[16];\n" | |
945 | " uint32_t stream_id;\n" | |
946 | " };\n" | |
947 | "};\n\n", | |
1dbfff0c MD |
948 | lttng_alignof(uint8_t) * CHAR_BIT, |
949 | lttng_alignof(uint16_t) * CHAR_BIT, | |
950 | lttng_alignof(uint32_t) * CHAR_BIT, | |
951 | lttng_alignof(uint64_t) * CHAR_BIT, | |
8020ceb5 MD |
952 | CTF_VERSION_MAJOR, |
953 | CTF_VERSION_MINOR, | |
954 | uuid_s, | |
403c40b4 | 955 | #ifdef __BIG_ENDIAN |
8020ceb5 MD |
956 | "be" |
957 | #else | |
958 | "le" | |
959 | #endif | |
960 | ); | |
961 | if (ret) | |
962 | goto end; | |
963 | ||
964 | ret = _ltt_stream_packet_context_declare(session); | |
965 | if (ret) | |
966 | goto end; | |
967 | ||
968 | ret = _ltt_event_header_declare(session); | |
969 | if (ret) | |
970 | goto end; | |
971 | ||
972 | skip_session: | |
b5234c06 | 973 | cds_list_for_each_entry(chan, &session->chan, list) { |
8020ceb5 MD |
974 | ret = _ltt_channel_metadata_statedump(session, chan); |
975 | if (ret) | |
976 | goto end; | |
977 | } | |
978 | ||
b5234c06 | 979 | cds_list_for_each_entry(event, &session->events, list) { |
8020ceb5 MD |
980 | ret = _ltt_event_metadata_statedump(session, event->chan, event); |
981 | if (ret) | |
982 | goto end; | |
983 | } | |
984 | session->metadata_dumped = 1; | |
985 | end: | |
986 | return ret; | |
987 | } | |
988 | ||
989 | /** | |
990 | * ltt_transport_register - LTT transport registration | |
991 | * @transport: transport structure | |
992 | * | |
993 | * Registers a transport which can be used as output to extract the data out of | |
b5234c06 | 994 | * LTTng. |
8020ceb5 MD |
995 | */ |
996 | void ltt_transport_register(struct ltt_transport *transport) | |
997 | { | |
b5234c06 MD |
998 | pthread_mutex_lock(&sessions_mutex); |
999 | cds_list_add_tail(&transport->node, <t_transport_list); | |
1000 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 | 1001 | } |
8020ceb5 MD |
1002 | |
1003 | /** | |
1004 | * ltt_transport_unregister - LTT transport unregistration | |
1005 | * @transport: transport structure | |
1006 | */ | |
1007 | void ltt_transport_unregister(struct ltt_transport *transport) | |
1008 | { | |
b5234c06 MD |
1009 | pthread_mutex_lock(&sessions_mutex); |
1010 | cds_list_del(&transport->node); | |
1011 | pthread_mutex_unlock(&sessions_mutex); | |
8020ceb5 MD |
1012 | } |
1013 | ||
1ea11eab | 1014 | void ltt_events_exit(void) |
8020ceb5 MD |
1015 | { |
1016 | struct ltt_session *session, *tmpsession; | |
1017 | ||
b5234c06 | 1018 | cds_list_for_each_entry_safe(session, tmpsession, &sessions, list) |
8020ceb5 | 1019 | ltt_session_destroy(session); |
8020ceb5 | 1020 | } |