Commit | Line | Data |
---|---|---|
4e3c1b9b 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 | ||
9 | #include <linux/module.h> | |
c0e31d2e MD |
10 | #include <linux/list.h> |
11 | #include <linux/mutex.h> | |
12 | #include <linux/sched.h> | |
11b5a3c2 | 13 | #include <linux/slab.h> |
c099397a | 14 | #include <linux/jiffies.h> |
d793d5e1 | 15 | #include <linux/uuid.h> |
b13f3ebe | 16 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
4e3c1b9b | 17 | #include "ltt-events.h" |
c099397a | 18 | #include "ltt-tracer.h" |
4e3c1b9b MD |
19 | |
20 | static LIST_HEAD(sessions); | |
c0e31d2e | 21 | static LIST_HEAD(ltt_transport_list); |
4e3c1b9b MD |
22 | static DEFINE_MUTEX(sessions_mutex); |
23 | static struct kmem_cache *event_cache; | |
24 | ||
c099397a MD |
25 | static |
26 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
27 | struct ltt_channel *chan, | |
28 | struct ltt_event *event); | |
29 | static | |
30 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
31 | ||
32 | ||
33 | static | |
34 | void synchronize_trace(void) | |
abcca994 MD |
35 | { |
36 | synchronize_sched(); | |
37 | #ifdef CONFIG_PREEMPT_RT | |
38 | synchronize_rcu(); | |
39 | #endif | |
40 | } | |
41 | ||
baf20995 | 42 | struct ltt_session *ltt_session_create(void) |
4e3c1b9b MD |
43 | { |
44 | struct ltt_session *session; | |
45 | ||
46 | mutex_lock(&sessions_mutex); | |
f3d01b96 | 47 | session = kzalloc(sizeof(struct ltt_session), GFP_KERNEL); |
4e3c1b9b MD |
48 | if (!session) |
49 | return NULL; | |
4e3c1b9b | 50 | INIT_LIST_HEAD(&session->chan); |
f3d01b96 | 51 | INIT_LIST_HEAD(&session->events); |
d793d5e1 | 52 | uuid_le_gen(&session->uuid); |
4e3c1b9b MD |
53 | list_add(&session->list, &sessions); |
54 | mutex_unlock(&sessions_mutex); | |
55 | return session; | |
4e3c1b9b MD |
56 | } |
57 | ||
11b5a3c2 | 58 | void ltt_session_destroy(struct ltt_session *session) |
4e3c1b9b MD |
59 | { |
60 | struct ltt_channel *chan, *tmpchan; | |
61 | struct ltt_event *event, *tmpevent; | |
dda6a249 | 62 | int ret; |
4e3c1b9b MD |
63 | |
64 | mutex_lock(&sessions_mutex); | |
52fc2e1f | 65 | ACCESS_ONCE(session->active) = 0; |
dda6a249 MD |
66 | list_for_each_entry(event, &session->events, list) { |
67 | ret = _ltt_event_unregister(event); | |
68 | WARN_ON(ret); | |
69 | } | |
abcca994 | 70 | synchronize_trace(); /* Wait for in-flight events to complete */ |
4e3c1b9b MD |
71 | list_for_each_entry_safe(event, tmpevent, &session->events, list) |
72 | _ltt_event_destroy(event); | |
73 | list_for_each_entry_safe(chan, tmpchan, &session->chan, list) | |
74 | _ltt_channel_destroy(chan); | |
75 | list_del(&session->list); | |
76 | mutex_unlock(&sessions_mutex); | |
77 | kfree(session); | |
78 | } | |
79 | ||
c0e31d2e MD |
80 | int ltt_session_start(struct ltt_session *session) |
81 | { | |
82 | int ret = 0; | |
c099397a | 83 | struct ltt_channel *chan; |
c0e31d2e MD |
84 | |
85 | mutex_lock(&sessions_mutex); | |
86 | if (session->active) { | |
87 | ret = -EBUSY; | |
88 | goto end; | |
89 | } | |
c099397a MD |
90 | |
91 | /* | |
92 | * Snapshot the number of events per channel to know the type of header | |
93 | * we need to use. | |
94 | */ | |
95 | list_for_each_entry(chan, &session->chan, list) { | |
96 | if (chan->header_type) | |
97 | continue; /* don't change it if session stop/restart */ | |
98 | if (chan->free_event_id < 31) | |
99 | chan->header_type = 1; /* compact */ | |
100 | else | |
101 | chan->header_type = 2; /* large */ | |
102 | } | |
103 | ||
52fc2e1f | 104 | ACCESS_ONCE(session->active) = 1; |
c0e31d2e | 105 | synchronize_trace(); /* Wait for in-flight events to complete */ |
c099397a MD |
106 | ret = _ltt_session_metadata_statedump(session); |
107 | if (ret) { | |
108 | ACCESS_ONCE(session->active) = 0; | |
109 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
110 | } | |
c0e31d2e MD |
111 | end: |
112 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 113 | return ret; |
c0e31d2e MD |
114 | } |
115 | ||
116 | int ltt_session_stop(struct ltt_session *session) | |
117 | { | |
118 | int ret = 0; | |
119 | ||
120 | mutex_lock(&sessions_mutex); | |
121 | if (!session->active) { | |
122 | ret = -EBUSY; | |
123 | goto end; | |
124 | } | |
52fc2e1f | 125 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
126 | synchronize_trace(); /* Wait for in-flight events to complete */ |
127 | end: | |
128 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 129 | return ret; |
c0e31d2e MD |
130 | } |
131 | ||
c535175e | 132 | static struct ltt_transport *ltt_transport_find(const char *name) |
f3d01b96 MD |
133 | { |
134 | struct ltt_transport *transport; | |
135 | ||
136 | list_for_each_entry(transport, <t_transport_list, node) { | |
137 | if (!strcmp(transport->name, name)) | |
138 | return transport; | |
139 | } | |
140 | return NULL; | |
141 | } | |
142 | ||
baf20995 | 143 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, |
5dbbdb43 MD |
144 | const char *transport_name, |
145 | void *buf_addr, | |
4e3c1b9b MD |
146 | size_t subbuf_size, size_t num_subbuf, |
147 | unsigned int switch_timer_interval, | |
148 | unsigned int read_timer_interval) | |
149 | { | |
150 | struct ltt_channel *chan; | |
f3d01b96 | 151 | struct ltt_transport *transport; |
4e3c1b9b MD |
152 | |
153 | mutex_lock(&sessions_mutex); | |
f3d01b96 MD |
154 | if (session->active) { |
155 | printk(KERN_WARNING "LTTng refusing to add channel to active session\n"); | |
e5382b6d | 156 | goto active; /* Refuse to add channel to active session */ |
c0e31d2e | 157 | } |
f3d01b96 MD |
158 | transport = ltt_transport_find(transport_name); |
159 | if (!transport) { | |
160 | printk(KERN_WARNING "LTTng transport %s not found\n", | |
161 | transport_name); | |
c0e31d2e | 162 | goto notransport; |
f3d01b96 | 163 | } |
f3d01b96 | 164 | chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL); |
4e3c1b9b | 165 | if (!chan) |
c0e31d2e | 166 | goto nomem; |
4e3c1b9b | 167 | chan->session = session; |
653fe716 | 168 | init_waitqueue_head(&chan->notify_wait); |
11b5a3c2 MD |
169 | chan->chan = transport->ops.channel_create("[lttng]", session, buf_addr, |
170 | subbuf_size, num_subbuf, switch_timer_interval, | |
171 | read_timer_interval); | |
f3d01b96 MD |
172 | if (!chan->chan) |
173 | goto create_error; | |
c099397a | 174 | chan->id = session->free_chan_id++; |
11b5a3c2 | 175 | chan->ops = &transport->ops; |
4e3c1b9b MD |
176 | list_add(&chan->list, &session->chan); |
177 | mutex_unlock(&sessions_mutex); | |
178 | return chan; | |
179 | ||
f3d01b96 MD |
180 | create_error: |
181 | kfree(chan); | |
c0e31d2e MD |
182 | nomem: |
183 | notransport: | |
e5382b6d | 184 | active: |
4e3c1b9b MD |
185 | mutex_unlock(&sessions_mutex); |
186 | return NULL; | |
187 | } | |
188 | ||
189 | /* | |
190 | * Only used internally at session destruction. | |
191 | */ | |
11b5a3c2 | 192 | void _ltt_channel_destroy(struct ltt_channel *chan) |
4e3c1b9b | 193 | { |
11b5a3c2 | 194 | chan->ops->channel_destroy(chan->chan); |
4e3c1b9b MD |
195 | list_del(&chan->list); |
196 | kfree(chan); | |
197 | } | |
198 | ||
e5382b6d MD |
199 | /* |
200 | * Supports event creation while tracing session is active. | |
201 | */ | |
4e3c1b9b | 202 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name, |
baf20995 | 203 | enum instrum_type itype, |
85a9ca7f MD |
204 | const struct lttng_event_desc *event_desc, |
205 | void *filter) | |
4e3c1b9b MD |
206 | { |
207 | struct ltt_event *event; | |
3d084699 | 208 | int ret; |
4e3c1b9b MD |
209 | |
210 | mutex_lock(&sessions_mutex); | |
e5382b6d MD |
211 | if (chan->free_event_id == -1UL) |
212 | goto full; | |
4e3c1b9b | 213 | /* |
dda6a249 MD |
214 | * This is O(n^2) (for each event, the loop is called at event |
215 | * creation). Might require a hash if we have lots of events. | |
4e3c1b9b MD |
216 | */ |
217 | list_for_each_entry(event, &chan->session->events, list) | |
85a9ca7f | 218 | if (!strcmp(event->desc->name, name)) |
4e3c1b9b | 219 | goto exist; |
11b5a3c2 | 220 | event = kmem_cache_zalloc(event_cache, GFP_KERNEL); |
4e3c1b9b MD |
221 | if (!event) |
222 | goto cache_error; | |
4e3c1b9b | 223 | event->chan = chan; |
85a9ca7f | 224 | event->desc = event_desc; |
4e3c1b9b | 225 | event->filter = filter; |
e5382b6d | 226 | event->id = chan->free_event_id++; |
baf20995 | 227 | event->itype = itype; |
e5382b6d MD |
228 | /* Populate ltt_event structure before tracepoint registration. */ |
229 | smp_wmb(); | |
baf20995 MD |
230 | switch (itype) { |
231 | case INSTRUM_TRACEPOINTS: | |
85a9ca7f MD |
232 | ret = tracepoint_probe_register(name, event_desc->probe_callback, |
233 | event); | |
11b5a3c2 MD |
234 | if (ret) |
235 | goto register_error; | |
baf20995 MD |
236 | break; |
237 | default: | |
238 | WARN_ON_ONCE(1); | |
239 | } | |
c099397a MD |
240 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); |
241 | if (ret) | |
242 | goto statedump_error; | |
dda6a249 | 243 | list_add(&event->list, &chan->session->events); |
11b5a3c2 | 244 | mutex_unlock(&sessions_mutex); |
4e3c1b9b MD |
245 | return event; |
246 | ||
c099397a MD |
247 | statedump_error: |
248 | WARN_ON_ONCE(tracepoint_probe_unregister(name, event_desc->probe_callback, | |
249 | event)); | |
11b5a3c2 | 250 | register_error: |
11b5a3c2 | 251 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
252 | cache_error: |
253 | exist: | |
e5382b6d | 254 | full: |
4e3c1b9b MD |
255 | mutex_unlock(&sessions_mutex); |
256 | return NULL; | |
257 | } | |
258 | ||
259 | /* | |
260 | * Only used internally at session destruction. | |
261 | */ | |
dda6a249 | 262 | int _ltt_event_unregister(struct ltt_event *event) |
4e3c1b9b | 263 | { |
11b5a3c2 MD |
264 | int ret = -EINVAL; |
265 | ||
baf20995 MD |
266 | switch (event->itype) { |
267 | case INSTRUM_TRACEPOINTS: | |
85a9ca7f MD |
268 | ret = tracepoint_probe_unregister(event->desc->name, |
269 | event->desc->probe_callback, | |
11b5a3c2 MD |
270 | event); |
271 | if (ret) | |
272 | return ret; | |
baf20995 MD |
273 | break; |
274 | default: | |
275 | WARN_ON_ONCE(1); | |
276 | } | |
dda6a249 MD |
277 | return ret; |
278 | } | |
279 | ||
280 | /* | |
281 | * Only used internally at session destruction. | |
282 | */ | |
283 | void _ltt_event_destroy(struct ltt_event *event) | |
284 | { | |
85a9ca7f | 285 | ltt_event_put(event->desc); |
dda6a249 | 286 | list_del(&event->list); |
11b5a3c2 | 287 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
288 | } |
289 | ||
c099397a MD |
290 | int lttng_metadata_printf(struct ltt_session *session, |
291 | const char *fmt, ...) | |
292 | { | |
293 | struct lib_ring_buffer_ctx ctx; | |
294 | struct ltt_channel *chan = session->metadata; | |
295 | char *str; | |
296 | int ret = 0, waitret; | |
297 | size_t len; | |
298 | va_list ap; | |
299 | ||
300 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
301 | ||
302 | va_start(ap, fmt); | |
303 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
304 | va_end(ap); | |
305 | if (!str) | |
306 | return -ENOMEM; | |
307 | ||
308 | len = strlen(str) + 1; | |
309 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, len, sizeof(char), -1); | |
310 | /* | |
311 | * We don't care about metadata buffer's records lost count, because we | |
312 | * always retry here. Report error if we need to bail out after timeout | |
313 | * or being interrupted. | |
314 | */ | |
315 | waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan), | |
316 | ({ | |
317 | ret = chan->ops->event_reserve(&ctx); | |
318 | ret != -ENOBUFS || !ret; | |
319 | }), | |
320 | msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); | |
d793d5e1 | 321 | if (!waitret || waitret == -ERESTARTSYS || ret) { |
c099397a MD |
322 | printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n", |
323 | waitret == -ERESTARTSYS ? "interrupted" : | |
324 | (ret == -ENOBUFS ? "timeout" : "I/O error")); | |
d793d5e1 | 325 | printk("waitret %d retval %d\n", waitret, ret); |
c099397a MD |
326 | if (waitret == -ERESTARTSYS) |
327 | ret = waitret; | |
328 | goto end; | |
329 | } | |
330 | chan->ops->event_write(&ctx, str, len); | |
331 | chan->ops->event_commit(&ctx); | |
332 | end: | |
333 | kfree(str); | |
334 | return ret; | |
335 | } | |
336 | ||
337 | static | |
338 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
339 | struct ltt_event *event) | |
340 | { | |
341 | const struct lttng_event_desc *desc = event->desc; | |
342 | int ret = 0; | |
343 | int i; | |
344 | ||
345 | for (i = 0; i < desc->nr_fields; i++) { | |
346 | const struct lttng_event_field *field = &desc->fields[i]; | |
347 | ||
348 | switch (field->type.atype) { | |
349 | case atype_integer: | |
350 | ret = lttng_metadata_printf(session, | |
351 | " integer { size = %u; align = %u; signed = %u;%s } %s;\n", | |
352 | field->type.u.basic.integer.size, | |
353 | field->type.u.basic.integer.alignment, | |
354 | field->type.u.basic.integer.signedness, | |
355 | #ifdef __BIG_ENDIAN | |
356 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
357 | #else | |
358 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
359 | #endif | |
360 | field->name); | |
361 | break; | |
362 | case atype_enum: | |
363 | ret = lttng_metadata_printf(session, | |
364 | " %s %s;\n", | |
365 | field->type.u.basic.enumeration.name, | |
366 | field->name); | |
367 | break; | |
368 | case atype_array: | |
8fa75f34 MD |
369 | { |
370 | const struct lttng_basic_type *elem_type; | |
371 | ||
372 | elem_type = &field->type.u.array.elem_type; | |
373 | ret = lttng_metadata_printf(session, | |
374 | " integer { size = %u; align = %u; signed = %u;%s } %s[%u];\n", | |
375 | elem_type->u.basic.integer.size, | |
376 | elem_type->u.basic.integer.alignment, | |
377 | elem_type->u.basic.integer.signedness, | |
378 | #ifdef __BIG_ENDIAN | |
379 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
380 | #else | |
381 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
382 | #endif | |
383 | field->name, field->type.u.array.length); | |
c099397a | 384 | break; |
8fa75f34 | 385 | } |
c099397a | 386 | case atype_sequence: |
8fa75f34 MD |
387 | { |
388 | const struct lttng_basic_type *elem_type; | |
389 | const struct lttng_basic_type *length_type; | |
390 | ||
391 | elem_type = &field->type.u.sequence.elem_type; | |
392 | length_type = &field->type.u.sequence.length_type; | |
393 | ret = lttng_metadata_printf(session, | |
394 | " integer { size = %u; align = %u; signed = %u;%s } %s[ integer { size = %u; align = %u; signed = %u;%s } ];\n", | |
395 | elem_type->u.basic.integer.size, | |
396 | elem_type->u.basic.integer.alignment, | |
397 | elem_type->u.basic.integer.signedness, | |
398 | #ifdef __BIG_ENDIAN | |
399 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
400 | #else | |
401 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
402 | #endif | |
403 | field->name, | |
404 | length_type->u.basic.integer.size, | |
405 | length_type->u.basic.integer.alignment, | |
406 | length_type->u.basic.integer.signedness, | |
407 | #ifdef __BIG_ENDIAN | |
408 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
409 | #else | |
410 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "" | |
411 | #endif | |
412 | ); | |
c099397a | 413 | break; |
8fa75f34 | 414 | } |
c099397a MD |
415 | |
416 | case atype_string: | |
417 | ret = lttng_metadata_printf(session, | |
418 | " string%s %s;\n", | |
419 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
420 | " { encoding = ASCII; }" : "", | |
421 | field->name); | |
422 | break; | |
423 | default: | |
424 | WARN_ON_ONCE(1); | |
425 | return -EINVAL; | |
426 | } | |
427 | } | |
428 | return ret; | |
429 | } | |
430 | ||
431 | static | |
432 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
433 | struct ltt_channel *chan, | |
434 | struct ltt_event *event) | |
435 | { | |
436 | int ret = 0; | |
437 | ||
438 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
439 | return 0; | |
440 | if (chan == session->metadata) | |
441 | return 0; | |
442 | ||
443 | ret = lttng_metadata_printf(session, | |
444 | "event {\n" | |
445 | " name = %s;\n" | |
446 | " id = %u;\n" | |
447 | " stream_id = %u;\n" | |
448 | " event.fields := struct {\n", | |
449 | event->desc->name, | |
450 | event->id, | |
451 | event->chan->id); | |
452 | if (ret) | |
453 | goto end; | |
454 | ||
455 | ret = _ltt_fields_metadata_statedump(session, event); | |
456 | if (ret) | |
457 | goto end; | |
458 | ||
459 | /* | |
460 | * LTTng space reservation can only reserve multiples of the | |
461 | * byte size. | |
462 | */ | |
463 | ret = lttng_metadata_printf(session, | |
464 | " } aligned(%u);\n" | |
d793d5e1 | 465 | "};\n\n", ltt_get_header_alignment()); |
c099397a MD |
466 | if (ret) |
467 | goto end; | |
468 | ||
469 | ||
470 | ||
471 | ||
472 | event->metadata_dumped = 1; | |
473 | end: | |
474 | return ret; | |
475 | ||
476 | } | |
477 | ||
478 | static | |
479 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
480 | struct ltt_channel *chan) | |
481 | { | |
482 | int ret = 0; | |
483 | ||
484 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
485 | return 0; | |
486 | if (chan == session->metadata) | |
487 | return 0; | |
488 | ||
489 | WARN_ON_ONCE(!chan->header_type); | |
490 | ret = lttng_metadata_printf(session, | |
491 | "stream {\n" | |
492 | " id = %u;\n" | |
493 | " event.header := %s;\n", | |
d793d5e1 | 494 | "};\n\n", |
c099397a MD |
495 | chan->id, |
496 | chan->header_type == 1 ? "struct event_header_compact" : | |
497 | "struct event_header_large"); | |
498 | if (ret) | |
499 | goto end; | |
500 | ||
501 | chan->metadata_dumped = 1; | |
502 | end: | |
503 | return ret; | |
504 | } | |
505 | ||
506 | /* | |
507 | * Output metadata into this session's metadata buffers. | |
508 | */ | |
509 | static | |
510 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
511 | { | |
d793d5e1 | 512 | char uuid_s[37]; |
c099397a MD |
513 | struct ltt_channel *chan; |
514 | struct ltt_event *event; | |
515 | int ret = 0; | |
516 | ||
517 | if (!ACCESS_ONCE(session->active)) | |
518 | return 0; | |
519 | if (session->metadata_dumped) | |
520 | goto skip_session; | |
f40270ad | 521 | if (!session->metadata) { |
cd4bd11f | 522 | printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
f40270ad MD |
523 | return -EPERM; |
524 | } | |
c099397a | 525 | |
d793d5e1 MD |
526 | snprintf(uuid_s, sizeof(uuid_s), |
527 | "%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x", | |
528 | uuid_s[0], uuid_s[1], uuid_s[2], uuid_s[3], | |
529 | uuid_s[4], uuid_s[5], uuid_s[6], uuid_s[7], | |
530 | uuid_s[8], uuid_s[9], uuid_s[10], uuid_s[11], | |
531 | uuid_s[12], uuid_s[13], uuid_s[14], uuid_s[15]); | |
532 | ||
533 | ret = lttng_metadata_printf(session, | |
534 | "typealias integer {size = 8; align = %u; signed = false; } := uint8_t;\n" | |
535 | "typealias integer {size = 32; align = %u; signed = false; } := uint32_t;\n" | |
536 | "typealias integer {size = 64; align = %u; signed = false; } := uint64_t;\n" | |
537 | "\n" | |
538 | "trace {\n" | |
539 | " major = %u;\n" | |
540 | " minor = %u;\n" | |
541 | " uuid = %s;\n" | |
542 | " byte_order = %s;\n" | |
543 | " packet.header := struct {\n" | |
544 | " uint32_t magic;\n" | |
545 | " uint8_t trace_uuid[16];\n" | |
546 | " uint32_t stream_id;\n" | |
547 | " uint64_t timestamp_begin;\n" | |
548 | " uint64_t timestamp_end;\n" | |
549 | " uint32_t content_size;\n" | |
550 | " uint32_t packet_size;\n" | |
551 | " uint32_t events_lost;\n" | |
552 | " };\n", | |
553 | "};\n\n", | |
554 | ltt_alignof(uint8_t) * CHAR_BIT, | |
555 | ltt_alignof(uint32_t) * CHAR_BIT, | |
556 | ltt_alignof(uint64_t) * CHAR_BIT, | |
557 | CTF_VERSION_MAJOR, | |
558 | CTF_VERSION_MINOR, | |
559 | uuid_s, | |
560 | #ifdef __BIG_ENDIAN | |
561 | "be" | |
562 | #else | |
563 | "le" | |
564 | #endif | |
565 | ); | |
566 | if (ret) | |
567 | goto end; | |
568 | ||
c099397a MD |
569 | skip_session: |
570 | list_for_each_entry(chan, &session->chan, list) { | |
571 | ret = _ltt_channel_metadata_statedump(session, chan); | |
572 | if (ret) | |
573 | goto end; | |
574 | } | |
575 | ||
576 | list_for_each_entry(event, &session->events, list) { | |
577 | ret = _ltt_event_metadata_statedump(session, chan, event); | |
578 | if (ret) | |
579 | goto end; | |
580 | } | |
581 | session->metadata_dumped = 1; | |
582 | end: | |
583 | return ret; | |
584 | } | |
585 | ||
c0e31d2e MD |
586 | /** |
587 | * ltt_transport_register - LTT transport registration | |
588 | * @transport: transport structure | |
589 | * | |
590 | * Registers a transport which can be used as output to extract the data out of | |
591 | * LTTng. The module calling this registration function must ensure that no | |
592 | * trap-inducing code will be executed by the transport functions. E.g. | |
593 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
594 | * is made visible to the transport function. This registration acts as a | |
595 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
596 | * after its registration must it synchronize the TLBs. | |
597 | */ | |
598 | void ltt_transport_register(struct ltt_transport *transport) | |
599 | { | |
600 | /* | |
601 | * Make sure no page fault can be triggered by the module about to be | |
602 | * registered. We deal with this here so we don't have to call | |
603 | * vmalloc_sync_all() in each module's init. | |
604 | */ | |
6d2a620c | 605 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
606 | |
607 | mutex_lock(&sessions_mutex); | |
608 | list_add_tail(&transport->node, <t_transport_list); | |
609 | mutex_unlock(&sessions_mutex); | |
610 | } | |
611 | EXPORT_SYMBOL_GPL(ltt_transport_register); | |
612 | ||
613 | /** | |
614 | * ltt_transport_unregister - LTT transport unregistration | |
615 | * @transport: transport structure | |
616 | */ | |
617 | void ltt_transport_unregister(struct ltt_transport *transport) | |
618 | { | |
619 | mutex_lock(&sessions_mutex); | |
620 | list_del(&transport->node); | |
621 | mutex_unlock(&sessions_mutex); | |
622 | } | |
623 | EXPORT_SYMBOL_GPL(ltt_transport_unregister); | |
624 | ||
4e3c1b9b MD |
625 | static int __init ltt_events_init(void) |
626 | { | |
1c25284c MD |
627 | int ret; |
628 | ||
11b5a3c2 MD |
629 | event_cache = KMEM_CACHE(ltt_event, 0); |
630 | if (!event_cache) | |
4e3c1b9b | 631 | return -ENOMEM; |
02119ee5 MD |
632 | ret = ltt_debugfs_abi_init(); |
633 | if (ret) | |
634 | goto error_abi; | |
4e3c1b9b | 635 | return 0; |
02119ee5 | 636 | error_abi: |
1c25284c MD |
637 | kmem_cache_destroy(event_cache); |
638 | return ret; | |
4e3c1b9b MD |
639 | } |
640 | ||
11b5a3c2 MD |
641 | module_init(ltt_events_init); |
642 | ||
4e3c1b9b MD |
643 | static void __exit ltt_events_exit(void) |
644 | { | |
92e94819 MD |
645 | struct ltt_session *session, *tmpsession; |
646 | ||
1c25284c | 647 | ltt_debugfs_abi_exit(); |
92e94819 MD |
648 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
649 | ltt_session_destroy(session); | |
11b5a3c2 | 650 | kmem_cache_destroy(event_cache); |
4e3c1b9b | 651 | } |
92e94819 | 652 | |
11b5a3c2 MD |
653 | module_exit(ltt_events_exit); |
654 | ||
92e94819 MD |
655 | MODULE_LICENSE("GPL and additional rights"); |
656 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
657 | MODULE_DESCRIPTION("LTTng Events"); |