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 MD |
239 | case LTTNG_KERNEL_KPROBES: |
240 | event->u.kprobe.kp.pre_handler = lttng_kprobes_handler_pre; | |
241 | event->u.kprobe.symbol_name = | |
242 | kzalloc(LTTNG_KPROBE_SYM_NAME_LEN * sizeof(char), | |
243 | GFP_KERNEL); | |
244 | if (!event->u.kprobe.symbol_name) | |
245 | goto register_error; | |
246 | memcpy(event->u.kprobe.symbol_name, | |
247 | event_param->u.kprobe.symbol_name, | |
248 | LTTNG_KPROBE_SYM_NAME_LEN * sizeof(char)); | |
249 | event->u.kprobe.kp.symbol_name = | |
250 | event->u.kprobe.symbol_name; | |
251 | event->u.kprobe.kp.offset = event_param->u.kprobe.offset; | |
252 | event->u.kprobe.kp.addr = (void *) event_param->u.kprobe.addr; | |
253 | ret = register_kprobe(&event->u.kprobe.kp); | |
254 | if (ret) { | |
255 | kfree(event->u.kprobe.symbol_name); | |
256 | goto register_error; | |
257 | } | |
258 | break; | |
baf20995 MD |
259 | default: |
260 | WARN_ON_ONCE(1); | |
261 | } | |
c099397a MD |
262 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); |
263 | if (ret) | |
264 | goto statedump_error; | |
dda6a249 | 265 | list_add(&event->list, &chan->session->events); |
11b5a3c2 | 266 | mutex_unlock(&sessions_mutex); |
4e3c1b9b MD |
267 | return event; |
268 | ||
c099397a MD |
269 | statedump_error: |
270 | WARN_ON_ONCE(tracepoint_probe_unregister(name, event_desc->probe_callback, | |
271 | event)); | |
11b5a3c2 | 272 | register_error: |
11b5a3c2 | 273 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
274 | cache_error: |
275 | exist: | |
e5382b6d | 276 | full: |
4e3c1b9b MD |
277 | mutex_unlock(&sessions_mutex); |
278 | return NULL; | |
279 | } | |
280 | ||
281 | /* | |
282 | * Only used internally at session destruction. | |
283 | */ | |
dda6a249 | 284 | int _ltt_event_unregister(struct ltt_event *event) |
4e3c1b9b | 285 | { |
11b5a3c2 MD |
286 | int ret = -EINVAL; |
287 | ||
38d024ae MD |
288 | switch (event->instrumentation) { |
289 | case LTTNG_KERNEL_TRACEPOINTS: | |
85a9ca7f MD |
290 | ret = tracepoint_probe_unregister(event->desc->name, |
291 | event->desc->probe_callback, | |
11b5a3c2 MD |
292 | event); |
293 | if (ret) | |
294 | return ret; | |
baf20995 | 295 | break; |
d6d808f3 MD |
296 | case LTTNG_KERNEL_KPROBES: |
297 | unregister_kprobe(&event->u.kprobe.kp); | |
298 | kfree(event->u.kprobe.symbol_name); | |
299 | ret = 0; | |
300 | break; | |
baf20995 MD |
301 | default: |
302 | WARN_ON_ONCE(1); | |
303 | } | |
dda6a249 MD |
304 | return ret; |
305 | } | |
306 | ||
be066e6c MD |
307 | /* |
308 | * Used when an event FD is released. | |
309 | */ | |
310 | int ltt_event_unregister(struct ltt_event *event) | |
311 | { | |
312 | int ret; | |
313 | ||
314 | mutex_lock(&sessions_mutex); | |
315 | ret = ltt_event_unregister(event); | |
316 | mutex_unlock(&sessions_mutex); | |
317 | return ret; | |
318 | } | |
319 | ||
dda6a249 MD |
320 | /* |
321 | * Only used internally at session destruction. | |
322 | */ | |
be066e6c | 323 | static |
dda6a249 MD |
324 | void _ltt_event_destroy(struct ltt_event *event) |
325 | { | |
85a9ca7f | 326 | ltt_event_put(event->desc); |
dda6a249 | 327 | list_del(&event->list); |
11b5a3c2 | 328 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
329 | } |
330 | ||
1ec3f75a MD |
331 | /* |
332 | * We have exclusive access to our metadata buffer (protected by the | |
333 | * sessions_mutex), so we can do racy operations such as looking for | |
334 | * remaining space left in packet and write, since mutual exclusion | |
335 | * protects us from concurrent writes. | |
336 | */ | |
c099397a MD |
337 | int lttng_metadata_printf(struct ltt_session *session, |
338 | const char *fmt, ...) | |
339 | { | |
340 | struct lib_ring_buffer_ctx ctx; | |
341 | struct ltt_channel *chan = session->metadata; | |
342 | char *str; | |
343 | int ret = 0, waitret; | |
1ec3f75a | 344 | size_t len, reserve_len, pos; |
c099397a MD |
345 | va_list ap; |
346 | ||
347 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
348 | ||
349 | va_start(ap, fmt); | |
350 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
351 | va_end(ap); | |
352 | if (!str) | |
353 | return -ENOMEM; | |
354 | ||
1ec3f75a MD |
355 | len = strlen(str); |
356 | pos = 0; | |
357 | ||
358 | for (pos = 0; pos < len; pos += reserve_len) { | |
359 | reserve_len = min_t(size_t, | |
360 | chan->ops->packet_avail_size(chan->chan), | |
361 | len - pos); | |
362 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
363 | sizeof(char), -1); | |
364 | /* | |
365 | * We don't care about metadata buffer's records lost | |
366 | * count, because we always retry here. Report error if | |
367 | * we need to bail out after timeout or being | |
368 | * interrupted. | |
369 | */ | |
370 | waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan), | |
371 | ({ | |
372 | ret = chan->ops->event_reserve(&ctx); | |
373 | ret != -ENOBUFS || !ret; | |
374 | }), | |
375 | msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); | |
376 | if (!waitret || waitret == -ERESTARTSYS || ret) { | |
377 | printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n", | |
378 | waitret == -ERESTARTSYS ? "interrupted" : | |
379 | (ret == -ENOBUFS ? "timeout" : "I/O error")); | |
380 | if (waitret == -ERESTARTSYS) | |
381 | ret = waitret; | |
382 | goto end; | |
383 | } | |
384 | chan->ops->event_write(&ctx, &str[pos], len); | |
385 | chan->ops->event_commit(&ctx); | |
c099397a | 386 | } |
c099397a MD |
387 | end: |
388 | kfree(str); | |
389 | return ret; | |
390 | } | |
391 | ||
392 | static | |
393 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
394 | struct ltt_event *event) | |
395 | { | |
396 | const struct lttng_event_desc *desc = event->desc; | |
397 | int ret = 0; | |
398 | int i; | |
399 | ||
400 | for (i = 0; i < desc->nr_fields; i++) { | |
401 | const struct lttng_event_field *field = &desc->fields[i]; | |
402 | ||
403 | switch (field->type.atype) { | |
404 | case atype_integer: | |
405 | ret = lttng_metadata_printf(session, | |
406 | " integer { size = %u; align = %u; signed = %u;%s } %s;\n", | |
407 | field->type.u.basic.integer.size, | |
408 | field->type.u.basic.integer.alignment, | |
409 | field->type.u.basic.integer.signedness, | |
410 | #ifdef __BIG_ENDIAN | |
411 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
412 | #else | |
413 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
414 | #endif | |
415 | field->name); | |
416 | break; | |
417 | case atype_enum: | |
418 | ret = lttng_metadata_printf(session, | |
419 | " %s %s;\n", | |
420 | field->type.u.basic.enumeration.name, | |
421 | field->name); | |
422 | break; | |
423 | case atype_array: | |
8fa75f34 MD |
424 | { |
425 | const struct lttng_basic_type *elem_type; | |
426 | ||
427 | elem_type = &field->type.u.array.elem_type; | |
428 | ret = lttng_metadata_printf(session, | |
429 | " integer { size = %u; align = %u; signed = %u;%s } %s[%u];\n", | |
430 | elem_type->u.basic.integer.size, | |
431 | elem_type->u.basic.integer.alignment, | |
432 | elem_type->u.basic.integer.signedness, | |
433 | #ifdef __BIG_ENDIAN | |
434 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
435 | #else | |
436 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
437 | #endif | |
438 | field->name, field->type.u.array.length); | |
c099397a | 439 | break; |
8fa75f34 | 440 | } |
c099397a | 441 | case atype_sequence: |
8fa75f34 MD |
442 | { |
443 | const struct lttng_basic_type *elem_type; | |
444 | const struct lttng_basic_type *length_type; | |
445 | ||
446 | elem_type = &field->type.u.sequence.elem_type; | |
447 | length_type = &field->type.u.sequence.length_type; | |
448 | ret = lttng_metadata_printf(session, | |
449 | " integer { size = %u; align = %u; signed = %u;%s } %s[ integer { size = %u; align = %u; signed = %u;%s } ];\n", | |
450 | elem_type->u.basic.integer.size, | |
451 | elem_type->u.basic.integer.alignment, | |
452 | elem_type->u.basic.integer.signedness, | |
453 | #ifdef __BIG_ENDIAN | |
454 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
455 | #else | |
456 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
457 | #endif | |
458 | field->name, | |
459 | length_type->u.basic.integer.size, | |
460 | length_type->u.basic.integer.alignment, | |
461 | length_type->u.basic.integer.signedness, | |
462 | #ifdef __BIG_ENDIAN | |
463 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
464 | #else | |
465 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "" | |
466 | #endif | |
467 | ); | |
c099397a | 468 | break; |
8fa75f34 | 469 | } |
c099397a MD |
470 | |
471 | case atype_string: | |
472 | ret = lttng_metadata_printf(session, | |
473 | " string%s %s;\n", | |
474 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
475 | " { encoding = ASCII; }" : "", | |
476 | field->name); | |
477 | break; | |
478 | default: | |
479 | WARN_ON_ONCE(1); | |
480 | return -EINVAL; | |
481 | } | |
482 | } | |
483 | return ret; | |
484 | } | |
485 | ||
486 | static | |
487 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
488 | struct ltt_channel *chan, | |
489 | struct ltt_event *event) | |
490 | { | |
491 | int ret = 0; | |
492 | ||
493 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
494 | return 0; | |
495 | if (chan == session->metadata) | |
496 | return 0; | |
497 | ||
498 | ret = lttng_metadata_printf(session, | |
499 | "event {\n" | |
500 | " name = %s;\n" | |
501 | " id = %u;\n" | |
502 | " stream_id = %u;\n" | |
503 | " event.fields := struct {\n", | |
504 | event->desc->name, | |
505 | event->id, | |
506 | event->chan->id); | |
507 | if (ret) | |
508 | goto end; | |
509 | ||
510 | ret = _ltt_fields_metadata_statedump(session, event); | |
511 | if (ret) | |
512 | goto end; | |
513 | ||
514 | /* | |
515 | * LTTng space reservation can only reserve multiples of the | |
516 | * byte size. | |
517 | */ | |
518 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
519 | " };\n" |
520 | "};\n\n"); | |
c099397a MD |
521 | if (ret) |
522 | goto end; | |
523 | ||
524 | ||
525 | ||
526 | ||
527 | event->metadata_dumped = 1; | |
528 | end: | |
529 | return ret; | |
530 | ||
531 | } | |
532 | ||
533 | static | |
534 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
535 | struct ltt_channel *chan) | |
536 | { | |
537 | int ret = 0; | |
538 | ||
539 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
540 | return 0; | |
541 | if (chan == session->metadata) | |
542 | return 0; | |
543 | ||
544 | WARN_ON_ONCE(!chan->header_type); | |
545 | ret = lttng_metadata_printf(session, | |
546 | "stream {\n" | |
547 | " id = %u;\n" | |
9115fbdc MD |
548 | " event.header := %s;\n" |
549 | " packet.context := struct packet_context;\n" | |
d793d5e1 | 550 | "};\n\n", |
c099397a MD |
551 | chan->id, |
552 | chan->header_type == 1 ? "struct event_header_compact" : | |
553 | "struct event_header_large"); | |
554 | if (ret) | |
555 | goto end; | |
556 | ||
557 | chan->metadata_dumped = 1; | |
558 | end: | |
559 | return ret; | |
560 | } | |
561 | ||
9115fbdc MD |
562 | static |
563 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
564 | { | |
565 | return lttng_metadata_printf(session, | |
566 | "struct packet_context {\n" | |
567 | " uint64_t timestamp_begin;\n" | |
568 | " uint64_t timestamp_end;\n" | |
569 | " uint32_t events_discarded;\n" | |
570 | " uint32_t content_size;\n" | |
571 | " uint32_t packet_size;\n" | |
572 | " uint32_t cpu_id;\n" | |
573 | "};\n" | |
574 | ); | |
575 | } | |
576 | ||
577 | /* | |
578 | * Compact header: | |
579 | * id: range: 0 - 30. | |
580 | * id 31 is reserved to indicate an extended header. | |
581 | * | |
582 | * Large header: | |
583 | * id: range: 0 - 65534. | |
584 | * id 65535 is reserved to indicate an extended header. | |
585 | */ | |
586 | static | |
587 | int _ltt_event_header_declare(struct ltt_session *session) | |
588 | { | |
589 | return lttng_metadata_printf(session, | |
590 | "struct event_header_compact {\n" | |
591 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
592 | " variant <id> {\n" | |
593 | " struct {\n" | |
594 | " uint27_t timestamp;\n" | |
595 | " } compact;\n" | |
596 | " struct {\n" | |
597 | " uint32_t id;\n" | |
598 | " uint64_t timestamp;\n" | |
599 | " } extended;\n" | |
600 | " } v;\n" | |
601 | "} align(%u);\n" | |
602 | "\n" | |
603 | "struct event_header_large {\n" | |
604 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
605 | " variant <id> {\n" | |
606 | " struct {\n" | |
607 | " uint32_t timestamp;\n" | |
608 | " } compact;\n" | |
609 | " struct {\n" | |
610 | " uint32_t id;\n" | |
611 | " uint64_t timestamp;\n" | |
612 | " } extended;\n" | |
613 | " } v;\n" | |
614 | "} align(%u);\n\n", | |
615 | ltt_alignof(uint32_t) * CHAR_BIT, | |
616 | ltt_alignof(uint16_t) * CHAR_BIT | |
617 | ); | |
618 | } | |
619 | ||
c099397a MD |
620 | /* |
621 | * Output metadata into this session's metadata buffers. | |
622 | */ | |
623 | static | |
624 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
625 | { | |
d793d5e1 | 626 | char uuid_s[37]; |
c099397a MD |
627 | struct ltt_channel *chan; |
628 | struct ltt_event *event; | |
629 | int ret = 0; | |
630 | ||
631 | if (!ACCESS_ONCE(session->active)) | |
632 | return 0; | |
633 | if (session->metadata_dumped) | |
634 | goto skip_session; | |
f40270ad | 635 | if (!session->metadata) { |
cd4bd11f | 636 | printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
f40270ad MD |
637 | return -EPERM; |
638 | } | |
c099397a | 639 | |
d793d5e1 MD |
640 | snprintf(uuid_s, sizeof(uuid_s), |
641 | "%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x", | |
642 | uuid_s[0], uuid_s[1], uuid_s[2], uuid_s[3], | |
643 | uuid_s[4], uuid_s[5], uuid_s[6], uuid_s[7], | |
644 | uuid_s[8], uuid_s[9], uuid_s[10], uuid_s[11], | |
645 | uuid_s[12], uuid_s[13], uuid_s[14], uuid_s[15]); | |
646 | ||
647 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
648 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
649 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
650 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
651 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
652 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
653 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
d793d5e1 MD |
654 | "\n" |
655 | "trace {\n" | |
656 | " major = %u;\n" | |
657 | " minor = %u;\n" | |
658 | " uuid = %s;\n" | |
659 | " byte_order = %s;\n" | |
660 | " packet.header := struct {\n" | |
661 | " uint32_t magic;\n" | |
1ec3f75a | 662 | " uint8_t uuid[16];\n" |
d793d5e1 | 663 | " uint32_t stream_id;\n" |
d793d5e1 MD |
664 | " };\n", |
665 | "};\n\n", | |
666 | ltt_alignof(uint8_t) * CHAR_BIT, | |
667 | ltt_alignof(uint32_t) * CHAR_BIT, | |
668 | ltt_alignof(uint64_t) * CHAR_BIT, | |
669 | CTF_VERSION_MAJOR, | |
670 | CTF_VERSION_MINOR, | |
671 | uuid_s, | |
672 | #ifdef __BIG_ENDIAN | |
673 | "be" | |
674 | #else | |
675 | "le" | |
676 | #endif | |
677 | ); | |
678 | if (ret) | |
679 | goto end; | |
680 | ||
9115fbdc MD |
681 | ret = _ltt_stream_packet_context_declare(session); |
682 | if (ret) | |
683 | goto end; | |
684 | ||
685 | ret = _ltt_event_header_declare(session); | |
686 | if (ret) | |
687 | goto end; | |
688 | ||
c099397a MD |
689 | skip_session: |
690 | list_for_each_entry(chan, &session->chan, list) { | |
691 | ret = _ltt_channel_metadata_statedump(session, chan); | |
692 | if (ret) | |
693 | goto end; | |
694 | } | |
695 | ||
696 | list_for_each_entry(event, &session->events, list) { | |
697 | ret = _ltt_event_metadata_statedump(session, chan, event); | |
698 | if (ret) | |
699 | goto end; | |
700 | } | |
701 | session->metadata_dumped = 1; | |
702 | end: | |
703 | return ret; | |
704 | } | |
705 | ||
c0e31d2e MD |
706 | /** |
707 | * ltt_transport_register - LTT transport registration | |
708 | * @transport: transport structure | |
709 | * | |
710 | * Registers a transport which can be used as output to extract the data out of | |
711 | * LTTng. The module calling this registration function must ensure that no | |
712 | * trap-inducing code will be executed by the transport functions. E.g. | |
713 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
714 | * is made visible to the transport function. This registration acts as a | |
715 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
716 | * after its registration must it synchronize the TLBs. | |
717 | */ | |
718 | void ltt_transport_register(struct ltt_transport *transport) | |
719 | { | |
720 | /* | |
721 | * Make sure no page fault can be triggered by the module about to be | |
722 | * registered. We deal with this here so we don't have to call | |
723 | * vmalloc_sync_all() in each module's init. | |
724 | */ | |
6d2a620c | 725 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
726 | |
727 | mutex_lock(&sessions_mutex); | |
728 | list_add_tail(&transport->node, <t_transport_list); | |
729 | mutex_unlock(&sessions_mutex); | |
730 | } | |
731 | EXPORT_SYMBOL_GPL(ltt_transport_register); | |
732 | ||
733 | /** | |
734 | * ltt_transport_unregister - LTT transport unregistration | |
735 | * @transport: transport structure | |
736 | */ | |
737 | void ltt_transport_unregister(struct ltt_transport *transport) | |
738 | { | |
739 | mutex_lock(&sessions_mutex); | |
740 | list_del(&transport->node); | |
741 | mutex_unlock(&sessions_mutex); | |
742 | } | |
743 | EXPORT_SYMBOL_GPL(ltt_transport_unregister); | |
744 | ||
4e3c1b9b MD |
745 | static int __init ltt_events_init(void) |
746 | { | |
1c25284c MD |
747 | int ret; |
748 | ||
11b5a3c2 MD |
749 | event_cache = KMEM_CACHE(ltt_event, 0); |
750 | if (!event_cache) | |
4e3c1b9b | 751 | return -ENOMEM; |
02119ee5 MD |
752 | ret = ltt_debugfs_abi_init(); |
753 | if (ret) | |
754 | goto error_abi; | |
4e3c1b9b | 755 | return 0; |
02119ee5 | 756 | error_abi: |
1c25284c MD |
757 | kmem_cache_destroy(event_cache); |
758 | return ret; | |
4e3c1b9b MD |
759 | } |
760 | ||
11b5a3c2 MD |
761 | module_init(ltt_events_init); |
762 | ||
4e3c1b9b MD |
763 | static void __exit ltt_events_exit(void) |
764 | { | |
92e94819 MD |
765 | struct ltt_session *session, *tmpsession; |
766 | ||
1c25284c | 767 | ltt_debugfs_abi_exit(); |
92e94819 MD |
768 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
769 | ltt_session_destroy(session); | |
11b5a3c2 | 770 | kmem_cache_destroy(event_cache); |
4e3c1b9b | 771 | } |
92e94819 | 772 | |
11b5a3c2 MD |
773 | module_exit(ltt_events_exit); |
774 | ||
92e94819 MD |
775 | MODULE_LICENSE("GPL and additional rights"); |
776 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
777 | MODULE_DESCRIPTION("LTTng Events"); |