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 | ||
be066e6c MD |
25 | static void _ltt_event_destroy(struct ltt_event *event); |
26 | static int _ltt_event_unregister(struct ltt_event *event); | |
c099397a MD |
27 | static |
28 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
29 | struct ltt_channel *chan, | |
30 | struct ltt_event *event); | |
31 | static | |
32 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
33 | ||
34 | ||
35 | static | |
36 | void synchronize_trace(void) | |
abcca994 MD |
37 | { |
38 | synchronize_sched(); | |
39 | #ifdef CONFIG_PREEMPT_RT | |
40 | synchronize_rcu(); | |
41 | #endif | |
42 | } | |
43 | ||
baf20995 | 44 | struct ltt_session *ltt_session_create(void) |
4e3c1b9b MD |
45 | { |
46 | struct ltt_session *session; | |
47 | ||
48 | mutex_lock(&sessions_mutex); | |
f3d01b96 | 49 | session = kzalloc(sizeof(struct ltt_session), GFP_KERNEL); |
4e3c1b9b MD |
50 | if (!session) |
51 | return NULL; | |
4e3c1b9b | 52 | INIT_LIST_HEAD(&session->chan); |
f3d01b96 | 53 | INIT_LIST_HEAD(&session->events); |
d793d5e1 | 54 | uuid_le_gen(&session->uuid); |
4e3c1b9b MD |
55 | list_add(&session->list, &sessions); |
56 | mutex_unlock(&sessions_mutex); | |
57 | return session; | |
4e3c1b9b MD |
58 | } |
59 | ||
11b5a3c2 | 60 | void ltt_session_destroy(struct ltt_session *session) |
4e3c1b9b MD |
61 | { |
62 | struct ltt_channel *chan, *tmpchan; | |
63 | struct ltt_event *event, *tmpevent; | |
dda6a249 | 64 | int ret; |
4e3c1b9b MD |
65 | |
66 | mutex_lock(&sessions_mutex); | |
52fc2e1f | 67 | ACCESS_ONCE(session->active) = 0; |
dda6a249 MD |
68 | list_for_each_entry(event, &session->events, list) { |
69 | ret = _ltt_event_unregister(event); | |
70 | WARN_ON(ret); | |
71 | } | |
abcca994 | 72 | synchronize_trace(); /* Wait for in-flight events to complete */ |
4e3c1b9b MD |
73 | list_for_each_entry_safe(event, tmpevent, &session->events, list) |
74 | _ltt_event_destroy(event); | |
75 | list_for_each_entry_safe(chan, tmpchan, &session->chan, list) | |
76 | _ltt_channel_destroy(chan); | |
77 | list_del(&session->list); | |
78 | mutex_unlock(&sessions_mutex); | |
79 | kfree(session); | |
80 | } | |
81 | ||
c0e31d2e MD |
82 | int ltt_session_start(struct ltt_session *session) |
83 | { | |
84 | int ret = 0; | |
c099397a | 85 | struct ltt_channel *chan; |
c0e31d2e MD |
86 | |
87 | mutex_lock(&sessions_mutex); | |
88 | if (session->active) { | |
89 | ret = -EBUSY; | |
90 | goto end; | |
91 | } | |
c099397a MD |
92 | |
93 | /* | |
94 | * Snapshot the number of events per channel to know the type of header | |
95 | * we need to use. | |
96 | */ | |
97 | list_for_each_entry(chan, &session->chan, list) { | |
98 | if (chan->header_type) | |
99 | continue; /* don't change it if session stop/restart */ | |
100 | if (chan->free_event_id < 31) | |
101 | chan->header_type = 1; /* compact */ | |
102 | else | |
103 | chan->header_type = 2; /* large */ | |
104 | } | |
105 | ||
52fc2e1f | 106 | ACCESS_ONCE(session->active) = 1; |
c0e31d2e | 107 | synchronize_trace(); /* Wait for in-flight events to complete */ |
c099397a MD |
108 | ret = _ltt_session_metadata_statedump(session); |
109 | if (ret) { | |
110 | ACCESS_ONCE(session->active) = 0; | |
111 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
112 | } | |
c0e31d2e MD |
113 | end: |
114 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 115 | return ret; |
c0e31d2e MD |
116 | } |
117 | ||
118 | int ltt_session_stop(struct ltt_session *session) | |
119 | { | |
120 | int ret = 0; | |
121 | ||
122 | mutex_lock(&sessions_mutex); | |
123 | if (!session->active) { | |
124 | ret = -EBUSY; | |
125 | goto end; | |
126 | } | |
52fc2e1f | 127 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
128 | synchronize_trace(); /* Wait for in-flight events to complete */ |
129 | end: | |
130 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 131 | return ret; |
c0e31d2e MD |
132 | } |
133 | ||
c535175e | 134 | static struct ltt_transport *ltt_transport_find(const char *name) |
f3d01b96 MD |
135 | { |
136 | struct ltt_transport *transport; | |
137 | ||
138 | list_for_each_entry(transport, <t_transport_list, node) { | |
139 | if (!strcmp(transport->name, name)) | |
140 | return transport; | |
141 | } | |
142 | return NULL; | |
143 | } | |
144 | ||
baf20995 | 145 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, |
5dbbdb43 MD |
146 | const char *transport_name, |
147 | void *buf_addr, | |
4e3c1b9b MD |
148 | size_t subbuf_size, size_t num_subbuf, |
149 | unsigned int switch_timer_interval, | |
150 | unsigned int read_timer_interval) | |
151 | { | |
152 | struct ltt_channel *chan; | |
f3d01b96 | 153 | struct ltt_transport *transport; |
4e3c1b9b MD |
154 | |
155 | mutex_lock(&sessions_mutex); | |
f3d01b96 MD |
156 | if (session->active) { |
157 | printk(KERN_WARNING "LTTng refusing to add channel to active session\n"); | |
e5382b6d | 158 | goto active; /* Refuse to add channel to active session */ |
c0e31d2e | 159 | } |
f3d01b96 MD |
160 | transport = ltt_transport_find(transport_name); |
161 | if (!transport) { | |
162 | printk(KERN_WARNING "LTTng transport %s not found\n", | |
163 | transport_name); | |
c0e31d2e | 164 | goto notransport; |
f3d01b96 | 165 | } |
f3d01b96 | 166 | chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL); |
4e3c1b9b | 167 | if (!chan) |
c0e31d2e | 168 | goto nomem; |
4e3c1b9b | 169 | chan->session = session; |
653fe716 | 170 | init_waitqueue_head(&chan->notify_wait); |
9115fbdc | 171 | chan->chan = transport->ops.channel_create("[lttng]", chan, buf_addr, |
11b5a3c2 MD |
172 | subbuf_size, num_subbuf, switch_timer_interval, |
173 | read_timer_interval); | |
f3d01b96 MD |
174 | if (!chan->chan) |
175 | goto create_error; | |
c099397a | 176 | chan->id = session->free_chan_id++; |
11b5a3c2 | 177 | chan->ops = &transport->ops; |
4e3c1b9b MD |
178 | list_add(&chan->list, &session->chan); |
179 | mutex_unlock(&sessions_mutex); | |
180 | return chan; | |
181 | ||
f3d01b96 MD |
182 | create_error: |
183 | kfree(chan); | |
c0e31d2e MD |
184 | nomem: |
185 | notransport: | |
e5382b6d | 186 | active: |
4e3c1b9b MD |
187 | mutex_unlock(&sessions_mutex); |
188 | return NULL; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Only used internally at session destruction. | |
193 | */ | |
11b5a3c2 | 194 | void _ltt_channel_destroy(struct ltt_channel *chan) |
4e3c1b9b | 195 | { |
11b5a3c2 | 196 | chan->ops->channel_destroy(chan->chan); |
4e3c1b9b MD |
197 | list_del(&chan->list); |
198 | kfree(chan); | |
199 | } | |
200 | ||
e5382b6d MD |
201 | /* |
202 | * Supports event creation while tracing session is active. | |
203 | */ | |
4e3c1b9b | 204 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name, |
d6d808f3 | 205 | struct lttng_kernel_event *event_param, |
85a9ca7f MD |
206 | const struct lttng_event_desc *event_desc, |
207 | void *filter) | |
4e3c1b9b MD |
208 | { |
209 | struct ltt_event *event; | |
3d084699 | 210 | int ret; |
4e3c1b9b MD |
211 | |
212 | mutex_lock(&sessions_mutex); | |
e5382b6d MD |
213 | if (chan->free_event_id == -1UL) |
214 | goto full; | |
4e3c1b9b | 215 | /* |
dda6a249 MD |
216 | * This is O(n^2) (for each event, the loop is called at event |
217 | * creation). Might require a hash if we have lots of events. | |
4e3c1b9b MD |
218 | */ |
219 | list_for_each_entry(event, &chan->session->events, list) | |
85a9ca7f | 220 | if (!strcmp(event->desc->name, name)) |
4e3c1b9b | 221 | goto exist; |
11b5a3c2 | 222 | event = kmem_cache_zalloc(event_cache, GFP_KERNEL); |
4e3c1b9b MD |
223 | if (!event) |
224 | goto cache_error; | |
4e3c1b9b | 225 | event->chan = chan; |
85a9ca7f | 226 | event->desc = event_desc; |
4e3c1b9b | 227 | event->filter = filter; |
e5382b6d | 228 | event->id = chan->free_event_id++; |
d6d808f3 | 229 | event->instrumentation = event_param->instrumentation; |
e5382b6d MD |
230 | /* Populate ltt_event structure before tracepoint registration. */ |
231 | smp_wmb(); | |
d6d808f3 | 232 | switch (event_param->instrumentation) { |
38d024ae | 233 | case LTTNG_KERNEL_TRACEPOINTS: |
85a9ca7f MD |
234 | ret = tracepoint_probe_register(name, event_desc->probe_callback, |
235 | event); | |
11b5a3c2 MD |
236 | if (ret) |
237 | goto register_error; | |
baf20995 | 238 | break; |
d6d808f3 | 239 | case LTTNG_KERNEL_KPROBES: |
f17701fb MD |
240 | ret = lttng_kprobes_register(name, |
241 | event_param->u.kprobe.symbol_name, | |
242 | event_param->u.kprobe.offset, | |
243 | event_param->u.kprobe.addr, | |
244 | event); | |
245 | if (ret) | |
d6d808f3 | 246 | goto register_error; |
d6d808f3 | 247 | break; |
baf20995 MD |
248 | default: |
249 | WARN_ON_ONCE(1); | |
250 | } | |
c099397a MD |
251 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); |
252 | if (ret) | |
253 | goto statedump_error; | |
dda6a249 | 254 | list_add(&event->list, &chan->session->events); |
11b5a3c2 | 255 | mutex_unlock(&sessions_mutex); |
4e3c1b9b MD |
256 | return event; |
257 | ||
c099397a MD |
258 | statedump_error: |
259 | WARN_ON_ONCE(tracepoint_probe_unregister(name, event_desc->probe_callback, | |
260 | event)); | |
11b5a3c2 | 261 | register_error: |
11b5a3c2 | 262 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
263 | cache_error: |
264 | exist: | |
e5382b6d | 265 | full: |
4e3c1b9b MD |
266 | mutex_unlock(&sessions_mutex); |
267 | return NULL; | |
268 | } | |
269 | ||
270 | /* | |
271 | * Only used internally at session destruction. | |
272 | */ | |
dda6a249 | 273 | int _ltt_event_unregister(struct ltt_event *event) |
4e3c1b9b | 274 | { |
11b5a3c2 MD |
275 | int ret = -EINVAL; |
276 | ||
38d024ae MD |
277 | switch (event->instrumentation) { |
278 | case LTTNG_KERNEL_TRACEPOINTS: | |
85a9ca7f MD |
279 | ret = tracepoint_probe_unregister(event->desc->name, |
280 | event->desc->probe_callback, | |
11b5a3c2 MD |
281 | event); |
282 | if (ret) | |
283 | return ret; | |
baf20995 | 284 | break; |
d6d808f3 | 285 | case LTTNG_KERNEL_KPROBES: |
f17701fb | 286 | lttng_kprobes_unregister(event); |
d6d808f3 MD |
287 | ret = 0; |
288 | break; | |
baf20995 MD |
289 | default: |
290 | WARN_ON_ONCE(1); | |
291 | } | |
dda6a249 MD |
292 | return ret; |
293 | } | |
294 | ||
be066e6c MD |
295 | /* |
296 | * Used when an event FD is released. | |
297 | */ | |
298 | int ltt_event_unregister(struct ltt_event *event) | |
299 | { | |
300 | int ret; | |
301 | ||
302 | mutex_lock(&sessions_mutex); | |
303 | ret = ltt_event_unregister(event); | |
304 | mutex_unlock(&sessions_mutex); | |
305 | return ret; | |
306 | } | |
307 | ||
dda6a249 MD |
308 | /* |
309 | * Only used internally at session destruction. | |
310 | */ | |
be066e6c | 311 | static |
dda6a249 MD |
312 | void _ltt_event_destroy(struct ltt_event *event) |
313 | { | |
85a9ca7f | 314 | ltt_event_put(event->desc); |
dda6a249 | 315 | list_del(&event->list); |
11b5a3c2 | 316 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
317 | } |
318 | ||
1ec3f75a MD |
319 | /* |
320 | * We have exclusive access to our metadata buffer (protected by the | |
321 | * sessions_mutex), so we can do racy operations such as looking for | |
322 | * remaining space left in packet and write, since mutual exclusion | |
323 | * protects us from concurrent writes. | |
324 | */ | |
c099397a MD |
325 | int lttng_metadata_printf(struct ltt_session *session, |
326 | const char *fmt, ...) | |
327 | { | |
328 | struct lib_ring_buffer_ctx ctx; | |
329 | struct ltt_channel *chan = session->metadata; | |
330 | char *str; | |
331 | int ret = 0, waitret; | |
1ec3f75a | 332 | size_t len, reserve_len, pos; |
c099397a MD |
333 | va_list ap; |
334 | ||
335 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
336 | ||
337 | va_start(ap, fmt); | |
338 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
339 | va_end(ap); | |
340 | if (!str) | |
341 | return -ENOMEM; | |
342 | ||
1ec3f75a MD |
343 | len = strlen(str); |
344 | pos = 0; | |
345 | ||
346 | for (pos = 0; pos < len; pos += reserve_len) { | |
347 | reserve_len = min_t(size_t, | |
348 | chan->ops->packet_avail_size(chan->chan), | |
349 | len - pos); | |
350 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
351 | sizeof(char), -1); | |
352 | /* | |
353 | * We don't care about metadata buffer's records lost | |
354 | * count, because we always retry here. Report error if | |
355 | * we need to bail out after timeout or being | |
356 | * interrupted. | |
357 | */ | |
358 | waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan), | |
359 | ({ | |
360 | ret = chan->ops->event_reserve(&ctx); | |
361 | ret != -ENOBUFS || !ret; | |
362 | }), | |
363 | msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); | |
364 | if (!waitret || waitret == -ERESTARTSYS || ret) { | |
365 | printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n", | |
366 | waitret == -ERESTARTSYS ? "interrupted" : | |
367 | (ret == -ENOBUFS ? "timeout" : "I/O error")); | |
368 | if (waitret == -ERESTARTSYS) | |
369 | ret = waitret; | |
370 | goto end; | |
371 | } | |
372 | chan->ops->event_write(&ctx, &str[pos], len); | |
373 | chan->ops->event_commit(&ctx); | |
c099397a | 374 | } |
c099397a MD |
375 | end: |
376 | kfree(str); | |
377 | return ret; | |
378 | } | |
379 | ||
380 | static | |
381 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
382 | struct ltt_event *event) | |
383 | { | |
384 | const struct lttng_event_desc *desc = event->desc; | |
385 | int ret = 0; | |
386 | int i; | |
387 | ||
388 | for (i = 0; i < desc->nr_fields; i++) { | |
389 | const struct lttng_event_field *field = &desc->fields[i]; | |
390 | ||
391 | switch (field->type.atype) { | |
392 | case atype_integer: | |
393 | ret = lttng_metadata_printf(session, | |
394 | " integer { size = %u; align = %u; signed = %u;%s } %s;\n", | |
395 | field->type.u.basic.integer.size, | |
396 | field->type.u.basic.integer.alignment, | |
397 | field->type.u.basic.integer.signedness, | |
398 | #ifdef __BIG_ENDIAN | |
399 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
400 | #else | |
401 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
402 | #endif | |
403 | field->name); | |
404 | break; | |
405 | case atype_enum: | |
406 | ret = lttng_metadata_printf(session, | |
407 | " %s %s;\n", | |
408 | field->type.u.basic.enumeration.name, | |
409 | field->name); | |
410 | break; | |
411 | case atype_array: | |
8fa75f34 MD |
412 | { |
413 | const struct lttng_basic_type *elem_type; | |
414 | ||
415 | elem_type = &field->type.u.array.elem_type; | |
416 | ret = lttng_metadata_printf(session, | |
417 | " integer { size = %u; align = %u; signed = %u;%s } %s[%u];\n", | |
418 | elem_type->u.basic.integer.size, | |
419 | elem_type->u.basic.integer.alignment, | |
420 | elem_type->u.basic.integer.signedness, | |
421 | #ifdef __BIG_ENDIAN | |
422 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
423 | #else | |
424 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
425 | #endif | |
426 | field->name, field->type.u.array.length); | |
c099397a | 427 | break; |
8fa75f34 | 428 | } |
c099397a | 429 | case atype_sequence: |
8fa75f34 MD |
430 | { |
431 | const struct lttng_basic_type *elem_type; | |
432 | const struct lttng_basic_type *length_type; | |
433 | ||
434 | elem_type = &field->type.u.sequence.elem_type; | |
435 | length_type = &field->type.u.sequence.length_type; | |
436 | ret = lttng_metadata_printf(session, | |
437 | " integer { size = %u; align = %u; signed = %u;%s } %s[ integer { size = %u; align = %u; signed = %u;%s } ];\n", | |
438 | elem_type->u.basic.integer.size, | |
439 | elem_type->u.basic.integer.alignment, | |
440 | elem_type->u.basic.integer.signedness, | |
441 | #ifdef __BIG_ENDIAN | |
442 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
443 | #else | |
444 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
445 | #endif | |
446 | field->name, | |
447 | length_type->u.basic.integer.size, | |
448 | length_type->u.basic.integer.alignment, | |
449 | length_type->u.basic.integer.signedness, | |
450 | #ifdef __BIG_ENDIAN | |
451 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
452 | #else | |
453 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "" | |
454 | #endif | |
455 | ); | |
c099397a | 456 | break; |
8fa75f34 | 457 | } |
c099397a MD |
458 | |
459 | case atype_string: | |
460 | ret = lttng_metadata_printf(session, | |
461 | " string%s %s;\n", | |
462 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
463 | " { encoding = ASCII; }" : "", | |
464 | field->name); | |
465 | break; | |
466 | default: | |
467 | WARN_ON_ONCE(1); | |
468 | return -EINVAL; | |
469 | } | |
470 | } | |
471 | return ret; | |
472 | } | |
473 | ||
474 | static | |
475 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
476 | struct ltt_channel *chan, | |
477 | struct ltt_event *event) | |
478 | { | |
479 | int ret = 0; | |
480 | ||
481 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
482 | return 0; | |
483 | if (chan == session->metadata) | |
484 | return 0; | |
485 | ||
486 | ret = lttng_metadata_printf(session, | |
487 | "event {\n" | |
488 | " name = %s;\n" | |
489 | " id = %u;\n" | |
490 | " stream_id = %u;\n" | |
491 | " event.fields := struct {\n", | |
492 | event->desc->name, | |
493 | event->id, | |
494 | event->chan->id); | |
495 | if (ret) | |
496 | goto end; | |
497 | ||
498 | ret = _ltt_fields_metadata_statedump(session, event); | |
499 | if (ret) | |
500 | goto end; | |
501 | ||
502 | /* | |
503 | * LTTng space reservation can only reserve multiples of the | |
504 | * byte size. | |
505 | */ | |
506 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
507 | " };\n" |
508 | "};\n\n"); | |
c099397a MD |
509 | if (ret) |
510 | goto end; | |
511 | ||
512 | ||
513 | ||
514 | ||
515 | event->metadata_dumped = 1; | |
516 | end: | |
517 | return ret; | |
518 | ||
519 | } | |
520 | ||
521 | static | |
522 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
523 | struct ltt_channel *chan) | |
524 | { | |
525 | int ret = 0; | |
526 | ||
527 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
528 | return 0; | |
529 | if (chan == session->metadata) | |
530 | return 0; | |
531 | ||
532 | WARN_ON_ONCE(!chan->header_type); | |
533 | ret = lttng_metadata_printf(session, | |
534 | "stream {\n" | |
535 | " id = %u;\n" | |
9115fbdc MD |
536 | " event.header := %s;\n" |
537 | " packet.context := struct packet_context;\n" | |
d793d5e1 | 538 | "};\n\n", |
c099397a MD |
539 | chan->id, |
540 | chan->header_type == 1 ? "struct event_header_compact" : | |
541 | "struct event_header_large"); | |
542 | if (ret) | |
543 | goto end; | |
544 | ||
545 | chan->metadata_dumped = 1; | |
546 | end: | |
547 | return ret; | |
548 | } | |
549 | ||
9115fbdc MD |
550 | static |
551 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
552 | { | |
553 | return lttng_metadata_printf(session, | |
554 | "struct packet_context {\n" | |
555 | " uint64_t timestamp_begin;\n" | |
556 | " uint64_t timestamp_end;\n" | |
557 | " uint32_t events_discarded;\n" | |
558 | " uint32_t content_size;\n" | |
559 | " uint32_t packet_size;\n" | |
560 | " uint32_t cpu_id;\n" | |
561 | "};\n" | |
562 | ); | |
563 | } | |
564 | ||
565 | /* | |
566 | * Compact header: | |
567 | * id: range: 0 - 30. | |
568 | * id 31 is reserved to indicate an extended header. | |
569 | * | |
570 | * Large header: | |
571 | * id: range: 0 - 65534. | |
572 | * id 65535 is reserved to indicate an extended header. | |
573 | */ | |
574 | static | |
575 | int _ltt_event_header_declare(struct ltt_session *session) | |
576 | { | |
577 | return lttng_metadata_printf(session, | |
578 | "struct event_header_compact {\n" | |
579 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
580 | " variant <id> {\n" | |
581 | " struct {\n" | |
582 | " uint27_t timestamp;\n" | |
583 | " } compact;\n" | |
584 | " struct {\n" | |
585 | " uint32_t id;\n" | |
586 | " uint64_t timestamp;\n" | |
587 | " } extended;\n" | |
588 | " } v;\n" | |
589 | "} align(%u);\n" | |
590 | "\n" | |
591 | "struct event_header_large {\n" | |
592 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
593 | " variant <id> {\n" | |
594 | " struct {\n" | |
595 | " uint32_t timestamp;\n" | |
596 | " } compact;\n" | |
597 | " struct {\n" | |
598 | " uint32_t id;\n" | |
599 | " uint64_t timestamp;\n" | |
600 | " } extended;\n" | |
601 | " } v;\n" | |
602 | "} align(%u);\n\n", | |
603 | ltt_alignof(uint32_t) * CHAR_BIT, | |
604 | ltt_alignof(uint16_t) * CHAR_BIT | |
605 | ); | |
606 | } | |
607 | ||
c099397a MD |
608 | /* |
609 | * Output metadata into this session's metadata buffers. | |
610 | */ | |
611 | static | |
612 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
613 | { | |
d793d5e1 | 614 | char uuid_s[37]; |
c099397a MD |
615 | struct ltt_channel *chan; |
616 | struct ltt_event *event; | |
617 | int ret = 0; | |
618 | ||
619 | if (!ACCESS_ONCE(session->active)) | |
620 | return 0; | |
621 | if (session->metadata_dumped) | |
622 | goto skip_session; | |
f40270ad | 623 | if (!session->metadata) { |
cd4bd11f | 624 | printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
f40270ad MD |
625 | return -EPERM; |
626 | } | |
c099397a | 627 | |
d793d5e1 MD |
628 | snprintf(uuid_s, sizeof(uuid_s), |
629 | "%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x", | |
630 | uuid_s[0], uuid_s[1], uuid_s[2], uuid_s[3], | |
631 | uuid_s[4], uuid_s[5], uuid_s[6], uuid_s[7], | |
632 | uuid_s[8], uuid_s[9], uuid_s[10], uuid_s[11], | |
633 | uuid_s[12], uuid_s[13], uuid_s[14], uuid_s[15]); | |
634 | ||
635 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
636 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
637 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
638 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
639 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
640 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
641 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
d793d5e1 MD |
642 | "\n" |
643 | "trace {\n" | |
644 | " major = %u;\n" | |
645 | " minor = %u;\n" | |
646 | " uuid = %s;\n" | |
647 | " byte_order = %s;\n" | |
648 | " packet.header := struct {\n" | |
649 | " uint32_t magic;\n" | |
1ec3f75a | 650 | " uint8_t uuid[16];\n" |
d793d5e1 | 651 | " uint32_t stream_id;\n" |
d793d5e1 MD |
652 | " };\n", |
653 | "};\n\n", | |
654 | ltt_alignof(uint8_t) * CHAR_BIT, | |
655 | ltt_alignof(uint32_t) * CHAR_BIT, | |
656 | ltt_alignof(uint64_t) * CHAR_BIT, | |
657 | CTF_VERSION_MAJOR, | |
658 | CTF_VERSION_MINOR, | |
659 | uuid_s, | |
660 | #ifdef __BIG_ENDIAN | |
661 | "be" | |
662 | #else | |
663 | "le" | |
664 | #endif | |
665 | ); | |
666 | if (ret) | |
667 | goto end; | |
668 | ||
9115fbdc MD |
669 | ret = _ltt_stream_packet_context_declare(session); |
670 | if (ret) | |
671 | goto end; | |
672 | ||
673 | ret = _ltt_event_header_declare(session); | |
674 | if (ret) | |
675 | goto end; | |
676 | ||
c099397a MD |
677 | skip_session: |
678 | list_for_each_entry(chan, &session->chan, list) { | |
679 | ret = _ltt_channel_metadata_statedump(session, chan); | |
680 | if (ret) | |
681 | goto end; | |
682 | } | |
683 | ||
684 | list_for_each_entry(event, &session->events, list) { | |
685 | ret = _ltt_event_metadata_statedump(session, chan, event); | |
686 | if (ret) | |
687 | goto end; | |
688 | } | |
689 | session->metadata_dumped = 1; | |
690 | end: | |
691 | return ret; | |
692 | } | |
693 | ||
c0e31d2e MD |
694 | /** |
695 | * ltt_transport_register - LTT transport registration | |
696 | * @transport: transport structure | |
697 | * | |
698 | * Registers a transport which can be used as output to extract the data out of | |
699 | * LTTng. The module calling this registration function must ensure that no | |
700 | * trap-inducing code will be executed by the transport functions. E.g. | |
701 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
702 | * is made visible to the transport function. This registration acts as a | |
703 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
704 | * after its registration must it synchronize the TLBs. | |
705 | */ | |
706 | void ltt_transport_register(struct ltt_transport *transport) | |
707 | { | |
708 | /* | |
709 | * Make sure no page fault can be triggered by the module about to be | |
710 | * registered. We deal with this here so we don't have to call | |
711 | * vmalloc_sync_all() in each module's init. | |
712 | */ | |
6d2a620c | 713 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
714 | |
715 | mutex_lock(&sessions_mutex); | |
716 | list_add_tail(&transport->node, <t_transport_list); | |
717 | mutex_unlock(&sessions_mutex); | |
718 | } | |
719 | EXPORT_SYMBOL_GPL(ltt_transport_register); | |
720 | ||
721 | /** | |
722 | * ltt_transport_unregister - LTT transport unregistration | |
723 | * @transport: transport structure | |
724 | */ | |
725 | void ltt_transport_unregister(struct ltt_transport *transport) | |
726 | { | |
727 | mutex_lock(&sessions_mutex); | |
728 | list_del(&transport->node); | |
729 | mutex_unlock(&sessions_mutex); | |
730 | } | |
731 | EXPORT_SYMBOL_GPL(ltt_transport_unregister); | |
732 | ||
4e3c1b9b MD |
733 | static int __init ltt_events_init(void) |
734 | { | |
1c25284c MD |
735 | int ret; |
736 | ||
11b5a3c2 MD |
737 | event_cache = KMEM_CACHE(ltt_event, 0); |
738 | if (!event_cache) | |
4e3c1b9b | 739 | return -ENOMEM; |
02119ee5 MD |
740 | ret = ltt_debugfs_abi_init(); |
741 | if (ret) | |
742 | goto error_abi; | |
4e3c1b9b | 743 | return 0; |
02119ee5 | 744 | error_abi: |
1c25284c MD |
745 | kmem_cache_destroy(event_cache); |
746 | return ret; | |
4e3c1b9b MD |
747 | } |
748 | ||
11b5a3c2 MD |
749 | module_init(ltt_events_init); |
750 | ||
4e3c1b9b MD |
751 | static void __exit ltt_events_exit(void) |
752 | { | |
92e94819 MD |
753 | struct ltt_session *session, *tmpsession; |
754 | ||
1c25284c | 755 | ltt_debugfs_abi_exit(); |
92e94819 MD |
756 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
757 | ltt_session_destroy(session); | |
11b5a3c2 | 758 | kmem_cache_destroy(event_cache); |
4e3c1b9b | 759 | } |
92e94819 | 760 | |
11b5a3c2 MD |
761 | module_exit(ltt_events_exit); |
762 | ||
92e94819 MD |
763 | MODULE_LICENSE("GPL and additional rights"); |
764 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
765 | MODULE_DESCRIPTION("LTTng Events"); |