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 | 25 | static void _ltt_event_destroy(struct ltt_event *event); |
aa7c23a9 | 26 | static void _ltt_channel_destroy(struct ltt_channel *chan); |
be066e6c | 27 | static int _ltt_event_unregister(struct ltt_event *event); |
c099397a MD |
28 | static |
29 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
30 | struct ltt_channel *chan, | |
31 | struct ltt_event *event); | |
32 | static | |
33 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
34 | ||
35 | ||
36 | static | |
37 | void synchronize_trace(void) | |
abcca994 MD |
38 | { |
39 | synchronize_sched(); | |
40 | #ifdef CONFIG_PREEMPT_RT | |
41 | synchronize_rcu(); | |
42 | #endif | |
43 | } | |
44 | ||
baf20995 | 45 | struct ltt_session *ltt_session_create(void) |
4e3c1b9b MD |
46 | { |
47 | struct ltt_session *session; | |
48 | ||
49 | mutex_lock(&sessions_mutex); | |
f3d01b96 | 50 | session = kzalloc(sizeof(struct ltt_session), GFP_KERNEL); |
4e3c1b9b MD |
51 | if (!session) |
52 | return NULL; | |
4e3c1b9b | 53 | INIT_LIST_HEAD(&session->chan); |
f3d01b96 | 54 | INIT_LIST_HEAD(&session->events); |
d793d5e1 | 55 | uuid_le_gen(&session->uuid); |
4e3c1b9b MD |
56 | list_add(&session->list, &sessions); |
57 | mutex_unlock(&sessions_mutex); | |
58 | return session; | |
4e3c1b9b MD |
59 | } |
60 | ||
11b5a3c2 | 61 | void ltt_session_destroy(struct ltt_session *session) |
4e3c1b9b MD |
62 | { |
63 | struct ltt_channel *chan, *tmpchan; | |
64 | struct ltt_event *event, *tmpevent; | |
dda6a249 | 65 | int ret; |
4e3c1b9b MD |
66 | |
67 | mutex_lock(&sessions_mutex); | |
52fc2e1f | 68 | ACCESS_ONCE(session->active) = 0; |
dda6a249 MD |
69 | list_for_each_entry(event, &session->events, list) { |
70 | ret = _ltt_event_unregister(event); | |
71 | WARN_ON(ret); | |
72 | } | |
abcca994 | 73 | synchronize_trace(); /* Wait for in-flight events to complete */ |
4e3c1b9b MD |
74 | list_for_each_entry_safe(event, tmpevent, &session->events, list) |
75 | _ltt_event_destroy(event); | |
76 | list_for_each_entry_safe(chan, tmpchan, &session->chan, list) | |
77 | _ltt_channel_destroy(chan); | |
78 | list_del(&session->list); | |
79 | mutex_unlock(&sessions_mutex); | |
80 | kfree(session); | |
81 | } | |
82 | ||
c0e31d2e MD |
83 | int ltt_session_start(struct ltt_session *session) |
84 | { | |
85 | int ret = 0; | |
c099397a | 86 | struct ltt_channel *chan; |
c0e31d2e MD |
87 | |
88 | mutex_lock(&sessions_mutex); | |
89 | if (session->active) { | |
90 | ret = -EBUSY; | |
91 | goto end; | |
92 | } | |
c099397a MD |
93 | |
94 | /* | |
95 | * Snapshot the number of events per channel to know the type of header | |
96 | * we need to use. | |
97 | */ | |
98 | list_for_each_entry(chan, &session->chan, list) { | |
99 | if (chan->header_type) | |
100 | continue; /* don't change it if session stop/restart */ | |
101 | if (chan->free_event_id < 31) | |
102 | chan->header_type = 1; /* compact */ | |
103 | else | |
104 | chan->header_type = 2; /* large */ | |
105 | } | |
106 | ||
52fc2e1f | 107 | ACCESS_ONCE(session->active) = 1; |
c0e31d2e | 108 | synchronize_trace(); /* Wait for in-flight events to complete */ |
c099397a MD |
109 | ret = _ltt_session_metadata_statedump(session); |
110 | if (ret) { | |
111 | ACCESS_ONCE(session->active) = 0; | |
112 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
113 | } | |
c0e31d2e MD |
114 | end: |
115 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 116 | return ret; |
c0e31d2e MD |
117 | } |
118 | ||
119 | int ltt_session_stop(struct ltt_session *session) | |
120 | { | |
121 | int ret = 0; | |
122 | ||
123 | mutex_lock(&sessions_mutex); | |
124 | if (!session->active) { | |
125 | ret = -EBUSY; | |
126 | goto end; | |
127 | } | |
52fc2e1f | 128 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
129 | synchronize_trace(); /* Wait for in-flight events to complete */ |
130 | end: | |
131 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 132 | return ret; |
c0e31d2e MD |
133 | } |
134 | ||
c535175e | 135 | static struct ltt_transport *ltt_transport_find(const char *name) |
f3d01b96 MD |
136 | { |
137 | struct ltt_transport *transport; | |
138 | ||
139 | list_for_each_entry(transport, <t_transport_list, node) { | |
140 | if (!strcmp(transport->name, name)) | |
141 | return transport; | |
142 | } | |
143 | return NULL; | |
144 | } | |
145 | ||
baf20995 | 146 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, |
5dbbdb43 MD |
147 | const char *transport_name, |
148 | void *buf_addr, | |
4e3c1b9b MD |
149 | size_t subbuf_size, size_t num_subbuf, |
150 | unsigned int switch_timer_interval, | |
151 | unsigned int read_timer_interval) | |
152 | { | |
153 | struct ltt_channel *chan; | |
f3d01b96 | 154 | struct ltt_transport *transport; |
4e3c1b9b MD |
155 | |
156 | mutex_lock(&sessions_mutex); | |
f3d01b96 MD |
157 | if (session->active) { |
158 | printk(KERN_WARNING "LTTng refusing to add channel to active session\n"); | |
e5382b6d | 159 | goto active; /* Refuse to add channel to active session */ |
c0e31d2e | 160 | } |
f3d01b96 MD |
161 | transport = ltt_transport_find(transport_name); |
162 | if (!transport) { | |
163 | printk(KERN_WARNING "LTTng transport %s not found\n", | |
164 | transport_name); | |
c0e31d2e | 165 | goto notransport; |
f3d01b96 | 166 | } |
f3d01b96 | 167 | chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL); |
4e3c1b9b | 168 | if (!chan) |
c0e31d2e | 169 | goto nomem; |
4e3c1b9b | 170 | chan->session = session; |
653fe716 | 171 | init_waitqueue_head(&chan->notify_wait); |
9115fbdc | 172 | chan->chan = transport->ops.channel_create("[lttng]", chan, buf_addr, |
11b5a3c2 MD |
173 | subbuf_size, num_subbuf, switch_timer_interval, |
174 | read_timer_interval); | |
f3d01b96 MD |
175 | if (!chan->chan) |
176 | goto create_error; | |
c099397a | 177 | chan->id = session->free_chan_id++; |
11b5a3c2 | 178 | chan->ops = &transport->ops; |
4e3c1b9b MD |
179 | list_add(&chan->list, &session->chan); |
180 | mutex_unlock(&sessions_mutex); | |
181 | return chan; | |
182 | ||
f3d01b96 MD |
183 | create_error: |
184 | kfree(chan); | |
c0e31d2e MD |
185 | nomem: |
186 | notransport: | |
e5382b6d | 187 | active: |
4e3c1b9b MD |
188 | mutex_unlock(&sessions_mutex); |
189 | return NULL; | |
190 | } | |
191 | ||
192 | /* | |
193 | * Only used internally at session destruction. | |
194 | */ | |
aa7c23a9 | 195 | static |
11b5a3c2 | 196 | void _ltt_channel_destroy(struct ltt_channel *chan) |
4e3c1b9b | 197 | { |
11b5a3c2 | 198 | chan->ops->channel_destroy(chan->chan); |
4e3c1b9b MD |
199 | list_del(&chan->list); |
200 | kfree(chan); | |
201 | } | |
202 | ||
e5382b6d MD |
203 | /* |
204 | * Supports event creation while tracing session is active. | |
205 | */ | |
4e3c1b9b | 206 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, char *name, |
d6d808f3 | 207 | struct lttng_kernel_event *event_param, |
85a9ca7f | 208 | void *filter) |
4e3c1b9b MD |
209 | { |
210 | struct ltt_event *event; | |
3d084699 | 211 | int ret; |
4e3c1b9b MD |
212 | |
213 | mutex_lock(&sessions_mutex); | |
e5382b6d MD |
214 | if (chan->free_event_id == -1UL) |
215 | goto full; | |
4e3c1b9b | 216 | /* |
dda6a249 MD |
217 | * This is O(n^2) (for each event, the loop is called at event |
218 | * creation). Might require a hash if we have lots of events. | |
4e3c1b9b MD |
219 | */ |
220 | list_for_each_entry(event, &chan->session->events, list) | |
85a9ca7f | 221 | if (!strcmp(event->desc->name, name)) |
4e3c1b9b | 222 | goto exist; |
11b5a3c2 | 223 | event = kmem_cache_zalloc(event_cache, GFP_KERNEL); |
4e3c1b9b MD |
224 | if (!event) |
225 | goto cache_error; | |
4e3c1b9b MD |
226 | event->chan = chan; |
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: |
d3dbe23c MD |
234 | event->desc = ltt_event_get(name); |
235 | if (!event->desc) | |
236 | goto register_error; | |
237 | ret = tracepoint_probe_register(name, | |
238 | event->desc->probe_callback, | |
239 | event); | |
11b5a3c2 MD |
240 | if (ret) |
241 | goto register_error; | |
baf20995 | 242 | break; |
d6d808f3 | 243 | case LTTNG_KERNEL_KPROBES: |
f17701fb MD |
244 | ret = lttng_kprobes_register(name, |
245 | event_param->u.kprobe.symbol_name, | |
246 | event_param->u.kprobe.offset, | |
247 | event_param->u.kprobe.addr, | |
248 | event); | |
249 | if (ret) | |
d6d808f3 | 250 | goto register_error; |
d6d808f3 | 251 | break; |
e0a7a7c4 MD |
252 | case LTTNG_KERNEL_FUNCTION_TRACER: |
253 | ret = lttng_ftrace_register(name, | |
254 | event_param->u.ftrace.symbol_name, | |
255 | event); | |
256 | if (ret) | |
257 | goto register_error; | |
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 | 269 | statedump_error: |
d3dbe23c MD |
270 | WARN_ON_ONCE(tracepoint_probe_unregister(name, |
271 | event->desc->probe_callback, | |
272 | event)); | |
273 | ltt_event_put(event->desc); | |
11b5a3c2 | 274 | register_error: |
11b5a3c2 | 275 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
276 | cache_error: |
277 | exist: | |
e5382b6d | 278 | full: |
4e3c1b9b MD |
279 | mutex_unlock(&sessions_mutex); |
280 | return NULL; | |
281 | } | |
282 | ||
283 | /* | |
284 | * Only used internally at session destruction. | |
285 | */ | |
dda6a249 | 286 | int _ltt_event_unregister(struct ltt_event *event) |
4e3c1b9b | 287 | { |
11b5a3c2 MD |
288 | int ret = -EINVAL; |
289 | ||
38d024ae MD |
290 | switch (event->instrumentation) { |
291 | case LTTNG_KERNEL_TRACEPOINTS: | |
85a9ca7f MD |
292 | ret = tracepoint_probe_unregister(event->desc->name, |
293 | event->desc->probe_callback, | |
11b5a3c2 MD |
294 | event); |
295 | if (ret) | |
296 | return ret; | |
d3dbe23c | 297 | ltt_event_put(event->desc); |
baf20995 | 298 | break; |
d6d808f3 | 299 | case LTTNG_KERNEL_KPROBES: |
f17701fb | 300 | lttng_kprobes_unregister(event); |
d6d808f3 MD |
301 | ret = 0; |
302 | break; | |
e0a7a7c4 MD |
303 | case LTTNG_KERNEL_FUNCTION_TRACER: |
304 | lttng_ftrace_unregister(event); | |
305 | ret = 0; | |
306 | break; | |
baf20995 MD |
307 | default: |
308 | WARN_ON_ONCE(1); | |
309 | } | |
dda6a249 MD |
310 | return ret; |
311 | } | |
312 | ||
313 | /* | |
314 | * Only used internally at session destruction. | |
315 | */ | |
be066e6c | 316 | static |
dda6a249 MD |
317 | void _ltt_event_destroy(struct ltt_event *event) |
318 | { | |
85a9ca7f | 319 | ltt_event_put(event->desc); |
dda6a249 | 320 | list_del(&event->list); |
11b5a3c2 | 321 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
322 | } |
323 | ||
1ec3f75a MD |
324 | /* |
325 | * We have exclusive access to our metadata buffer (protected by the | |
326 | * sessions_mutex), so we can do racy operations such as looking for | |
327 | * remaining space left in packet and write, since mutual exclusion | |
328 | * protects us from concurrent writes. | |
329 | */ | |
c099397a MD |
330 | int lttng_metadata_printf(struct ltt_session *session, |
331 | const char *fmt, ...) | |
332 | { | |
333 | struct lib_ring_buffer_ctx ctx; | |
334 | struct ltt_channel *chan = session->metadata; | |
335 | char *str; | |
336 | int ret = 0, waitret; | |
1ec3f75a | 337 | size_t len, reserve_len, pos; |
c099397a MD |
338 | va_list ap; |
339 | ||
340 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
341 | ||
342 | va_start(ap, fmt); | |
343 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
344 | va_end(ap); | |
345 | if (!str) | |
346 | return -ENOMEM; | |
347 | ||
1ec3f75a MD |
348 | len = strlen(str); |
349 | pos = 0; | |
350 | ||
351 | for (pos = 0; pos < len; pos += reserve_len) { | |
352 | reserve_len = min_t(size_t, | |
353 | chan->ops->packet_avail_size(chan->chan), | |
354 | len - pos); | |
355 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
356 | sizeof(char), -1); | |
357 | /* | |
358 | * We don't care about metadata buffer's records lost | |
359 | * count, because we always retry here. Report error if | |
360 | * we need to bail out after timeout or being | |
361 | * interrupted. | |
362 | */ | |
363 | waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan), | |
364 | ({ | |
365 | ret = chan->ops->event_reserve(&ctx); | |
366 | ret != -ENOBUFS || !ret; | |
367 | }), | |
368 | msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); | |
369 | if (!waitret || waitret == -ERESTARTSYS || ret) { | |
370 | printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n", | |
371 | waitret == -ERESTARTSYS ? "interrupted" : | |
372 | (ret == -ENOBUFS ? "timeout" : "I/O error")); | |
373 | if (waitret == -ERESTARTSYS) | |
374 | ret = waitret; | |
375 | goto end; | |
376 | } | |
377 | chan->ops->event_write(&ctx, &str[pos], len); | |
378 | chan->ops->event_commit(&ctx); | |
c099397a | 379 | } |
c099397a MD |
380 | end: |
381 | kfree(str); | |
382 | return ret; | |
383 | } | |
384 | ||
385 | static | |
386 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
387 | struct ltt_event *event) | |
388 | { | |
389 | const struct lttng_event_desc *desc = event->desc; | |
390 | int ret = 0; | |
391 | int i; | |
392 | ||
393 | for (i = 0; i < desc->nr_fields; i++) { | |
394 | const struct lttng_event_field *field = &desc->fields[i]; | |
395 | ||
396 | switch (field->type.atype) { | |
397 | case atype_integer: | |
398 | ret = lttng_metadata_printf(session, | |
e0a7a7c4 | 399 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n", |
c099397a MD |
400 | field->type.u.basic.integer.size, |
401 | field->type.u.basic.integer.alignment, | |
402 | field->type.u.basic.integer.signedness, | |
e0a7a7c4 MD |
403 | (field->type.u.basic.integer.encoding == lttng_encode_none) |
404 | ? "none" | |
405 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
406 | ? "UTF8" | |
407 | : "ASCII", | |
408 | field->type.u.basic.integer.base, | |
c099397a MD |
409 | #ifdef __BIG_ENDIAN |
410 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
411 | #else | |
412 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
413 | #endif | |
414 | field->name); | |
415 | break; | |
416 | case atype_enum: | |
417 | ret = lttng_metadata_printf(session, | |
418 | " %s %s;\n", | |
419 | field->type.u.basic.enumeration.name, | |
420 | field->name); | |
421 | break; | |
422 | case atype_array: | |
8fa75f34 MD |
423 | { |
424 | const struct lttng_basic_type *elem_type; | |
425 | ||
426 | elem_type = &field->type.u.array.elem_type; | |
427 | ret = lttng_metadata_printf(session, | |
e0a7a7c4 | 428 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n", |
8fa75f34 MD |
429 | elem_type->u.basic.integer.size, |
430 | elem_type->u.basic.integer.alignment, | |
431 | elem_type->u.basic.integer.signedness, | |
e0a7a7c4 MD |
432 | (elem_type->u.basic.integer.encoding == lttng_encode_none) |
433 | ? "none" | |
434 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
435 | ? "UTF8" | |
436 | : "ASCII", | |
437 | elem_type->u.basic.integer.base, | |
8fa75f34 MD |
438 | #ifdef __BIG_ENDIAN |
439 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
440 | #else | |
441 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
442 | #endif | |
443 | field->name, field->type.u.array.length); | |
c099397a | 444 | break; |
8fa75f34 | 445 | } |
c099397a | 446 | case atype_sequence: |
8fa75f34 MD |
447 | { |
448 | const struct lttng_basic_type *elem_type; | |
449 | const struct lttng_basic_type *length_type; | |
450 | ||
451 | elem_type = &field->type.u.sequence.elem_type; | |
452 | length_type = &field->type.u.sequence.length_type; | |
453 | ret = lttng_metadata_printf(session, | |
e0a7a7c4 MD |
454 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", |
455 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n", | |
456 | length_type->u.basic.integer.size, | |
457 | length_type->u.basic.integer.alignment, | |
458 | length_type->u.basic.integer.signedness, | |
459 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
460 | ? "none" | |
461 | : (length_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
462 | ? "UTF8" | |
463 | : "ASCII", | |
464 | length_type->u.basic.integer.base, | |
465 | #ifdef __BIG_ENDIAN | |
466 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
467 | #else | |
468 | length_type->u.basic.integer.reverse_byte_order | |
469 | ? " byte_order = be;" : "", | |
470 | #endif | |
471 | field->name, | |
8fa75f34 MD |
472 | elem_type->u.basic.integer.size, |
473 | elem_type->u.basic.integer.alignment, | |
474 | elem_type->u.basic.integer.signedness, | |
e0a7a7c4 MD |
475 | (elem_type->u.basic.integer.encoding == lttng_encode_none) |
476 | ? "none" | |
477 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
478 | ? "UTF8" | |
479 | : "ASCII", | |
480 | elem_type->u.basic.integer.base, | |
8fa75f34 MD |
481 | #ifdef __BIG_ENDIAN |
482 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", | |
483 | #else | |
484 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", | |
485 | #endif | |
486 | field->name, | |
e0a7a7c4 | 487 | field->name |
8fa75f34 | 488 | ); |
c099397a | 489 | break; |
8fa75f34 | 490 | } |
c099397a MD |
491 | |
492 | case atype_string: | |
e0a7a7c4 | 493 | /* Default encoding is UTF8 */ |
c099397a MD |
494 | ret = lttng_metadata_printf(session, |
495 | " string%s %s;\n", | |
496 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
497 | " { encoding = ASCII; }" : "", | |
498 | field->name); | |
499 | break; | |
500 | default: | |
501 | WARN_ON_ONCE(1); | |
502 | return -EINVAL; | |
503 | } | |
504 | } | |
505 | return ret; | |
506 | } | |
507 | ||
508 | static | |
509 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
510 | struct ltt_channel *chan, | |
511 | struct ltt_event *event) | |
512 | { | |
513 | int ret = 0; | |
514 | ||
515 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
516 | return 0; | |
517 | if (chan == session->metadata) | |
518 | return 0; | |
519 | ||
520 | ret = lttng_metadata_printf(session, | |
521 | "event {\n" | |
522 | " name = %s;\n" | |
523 | " id = %u;\n" | |
524 | " stream_id = %u;\n" | |
525 | " event.fields := struct {\n", | |
526 | event->desc->name, | |
527 | event->id, | |
528 | event->chan->id); | |
529 | if (ret) | |
530 | goto end; | |
531 | ||
532 | ret = _ltt_fields_metadata_statedump(session, event); | |
533 | if (ret) | |
534 | goto end; | |
535 | ||
536 | /* | |
537 | * LTTng space reservation can only reserve multiples of the | |
538 | * byte size. | |
539 | */ | |
540 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
541 | " };\n" |
542 | "};\n\n"); | |
c099397a MD |
543 | if (ret) |
544 | goto end; | |
545 | ||
c099397a MD |
546 | event->metadata_dumped = 1; |
547 | end: | |
548 | return ret; | |
549 | ||
550 | } | |
551 | ||
552 | static | |
553 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
554 | struct ltt_channel *chan) | |
555 | { | |
556 | int ret = 0; | |
557 | ||
558 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
559 | return 0; | |
560 | if (chan == session->metadata) | |
561 | return 0; | |
562 | ||
563 | WARN_ON_ONCE(!chan->header_type); | |
564 | ret = lttng_metadata_printf(session, | |
565 | "stream {\n" | |
566 | " id = %u;\n" | |
9115fbdc MD |
567 | " event.header := %s;\n" |
568 | " packet.context := struct packet_context;\n" | |
d793d5e1 | 569 | "};\n\n", |
c099397a MD |
570 | chan->id, |
571 | chan->header_type == 1 ? "struct event_header_compact" : | |
572 | "struct event_header_large"); | |
573 | if (ret) | |
574 | goto end; | |
575 | ||
576 | chan->metadata_dumped = 1; | |
577 | end: | |
578 | return ret; | |
579 | } | |
580 | ||
9115fbdc MD |
581 | static |
582 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
583 | { | |
584 | return lttng_metadata_printf(session, | |
585 | "struct packet_context {\n" | |
586 | " uint64_t timestamp_begin;\n" | |
587 | " uint64_t timestamp_end;\n" | |
588 | " uint32_t events_discarded;\n" | |
589 | " uint32_t content_size;\n" | |
590 | " uint32_t packet_size;\n" | |
591 | " uint32_t cpu_id;\n" | |
592 | "};\n" | |
593 | ); | |
594 | } | |
595 | ||
596 | /* | |
597 | * Compact header: | |
598 | * id: range: 0 - 30. | |
599 | * id 31 is reserved to indicate an extended header. | |
600 | * | |
601 | * Large header: | |
602 | * id: range: 0 - 65534. | |
603 | * id 65535 is reserved to indicate an extended header. | |
604 | */ | |
605 | static | |
606 | int _ltt_event_header_declare(struct ltt_session *session) | |
607 | { | |
608 | return lttng_metadata_printf(session, | |
609 | "struct event_header_compact {\n" | |
610 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
611 | " variant <id> {\n" | |
612 | " struct {\n" | |
613 | " uint27_t timestamp;\n" | |
614 | " } compact;\n" | |
615 | " struct {\n" | |
616 | " uint32_t id;\n" | |
617 | " uint64_t timestamp;\n" | |
618 | " } extended;\n" | |
619 | " } v;\n" | |
620 | "} align(%u);\n" | |
621 | "\n" | |
622 | "struct event_header_large {\n" | |
623 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
624 | " variant <id> {\n" | |
625 | " struct {\n" | |
626 | " uint32_t timestamp;\n" | |
627 | " } compact;\n" | |
628 | " struct {\n" | |
629 | " uint32_t id;\n" | |
630 | " uint64_t timestamp;\n" | |
631 | " } extended;\n" | |
632 | " } v;\n" | |
633 | "} align(%u);\n\n", | |
634 | ltt_alignof(uint32_t) * CHAR_BIT, | |
635 | ltt_alignof(uint16_t) * CHAR_BIT | |
636 | ); | |
637 | } | |
638 | ||
c099397a MD |
639 | /* |
640 | * Output metadata into this session's metadata buffers. | |
641 | */ | |
642 | static | |
643 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
644 | { | |
d793d5e1 | 645 | char uuid_s[37]; |
c099397a MD |
646 | struct ltt_channel *chan; |
647 | struct ltt_event *event; | |
648 | int ret = 0; | |
649 | ||
650 | if (!ACCESS_ONCE(session->active)) | |
651 | return 0; | |
652 | if (session->metadata_dumped) | |
653 | goto skip_session; | |
f40270ad | 654 | if (!session->metadata) { |
cd4bd11f | 655 | printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
f40270ad MD |
656 | return -EPERM; |
657 | } | |
c099397a | 658 | |
d793d5e1 MD |
659 | snprintf(uuid_s, sizeof(uuid_s), |
660 | "%x%x%x%x-%x%x-%x%x-%x%x-%x%x%x%x%x%x", | |
661 | uuid_s[0], uuid_s[1], uuid_s[2], uuid_s[3], | |
662 | uuid_s[4], uuid_s[5], uuid_s[6], uuid_s[7], | |
663 | uuid_s[8], uuid_s[9], uuid_s[10], uuid_s[11], | |
664 | uuid_s[12], uuid_s[13], uuid_s[14], uuid_s[15]); | |
665 | ||
666 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
667 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
668 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
669 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
670 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
671 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
672 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
d793d5e1 MD |
673 | "\n" |
674 | "trace {\n" | |
675 | " major = %u;\n" | |
676 | " minor = %u;\n" | |
677 | " uuid = %s;\n" | |
678 | " byte_order = %s;\n" | |
679 | " packet.header := struct {\n" | |
680 | " uint32_t magic;\n" | |
1ec3f75a | 681 | " uint8_t uuid[16];\n" |
d793d5e1 | 682 | " uint32_t stream_id;\n" |
0eb25f58 | 683 | " };\n" |
d793d5e1 MD |
684 | "};\n\n", |
685 | ltt_alignof(uint8_t) * CHAR_BIT, | |
0eb25f58 | 686 | ltt_alignof(uint16_t) * CHAR_BIT, |
d793d5e1 MD |
687 | ltt_alignof(uint32_t) * CHAR_BIT, |
688 | ltt_alignof(uint64_t) * CHAR_BIT, | |
689 | CTF_VERSION_MAJOR, | |
690 | CTF_VERSION_MINOR, | |
691 | uuid_s, | |
692 | #ifdef __BIG_ENDIAN | |
693 | "be" | |
694 | #else | |
695 | "le" | |
696 | #endif | |
697 | ); | |
698 | if (ret) | |
699 | goto end; | |
700 | ||
9115fbdc MD |
701 | ret = _ltt_stream_packet_context_declare(session); |
702 | if (ret) | |
703 | goto end; | |
704 | ||
705 | ret = _ltt_event_header_declare(session); | |
706 | if (ret) | |
707 | goto end; | |
708 | ||
c099397a MD |
709 | skip_session: |
710 | list_for_each_entry(chan, &session->chan, list) { | |
711 | ret = _ltt_channel_metadata_statedump(session, chan); | |
712 | if (ret) | |
713 | goto end; | |
714 | } | |
715 | ||
716 | list_for_each_entry(event, &session->events, list) { | |
717 | ret = _ltt_event_metadata_statedump(session, chan, event); | |
718 | if (ret) | |
719 | goto end; | |
720 | } | |
721 | session->metadata_dumped = 1; | |
722 | end: | |
723 | return ret; | |
724 | } | |
725 | ||
c0e31d2e MD |
726 | /** |
727 | * ltt_transport_register - LTT transport registration | |
728 | * @transport: transport structure | |
729 | * | |
730 | * Registers a transport which can be used as output to extract the data out of | |
731 | * LTTng. The module calling this registration function must ensure that no | |
732 | * trap-inducing code will be executed by the transport functions. E.g. | |
733 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
734 | * is made visible to the transport function. This registration acts as a | |
735 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
736 | * after its registration must it synchronize the TLBs. | |
737 | */ | |
738 | void ltt_transport_register(struct ltt_transport *transport) | |
739 | { | |
740 | /* | |
741 | * Make sure no page fault can be triggered by the module about to be | |
742 | * registered. We deal with this here so we don't have to call | |
743 | * vmalloc_sync_all() in each module's init. | |
744 | */ | |
6d2a620c | 745 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
746 | |
747 | mutex_lock(&sessions_mutex); | |
748 | list_add_tail(&transport->node, <t_transport_list); | |
749 | mutex_unlock(&sessions_mutex); | |
750 | } | |
751 | EXPORT_SYMBOL_GPL(ltt_transport_register); | |
752 | ||
753 | /** | |
754 | * ltt_transport_unregister - LTT transport unregistration | |
755 | * @transport: transport structure | |
756 | */ | |
757 | void ltt_transport_unregister(struct ltt_transport *transport) | |
758 | { | |
759 | mutex_lock(&sessions_mutex); | |
760 | list_del(&transport->node); | |
761 | mutex_unlock(&sessions_mutex); | |
762 | } | |
763 | EXPORT_SYMBOL_GPL(ltt_transport_unregister); | |
764 | ||
4e3c1b9b MD |
765 | static int __init ltt_events_init(void) |
766 | { | |
1c25284c MD |
767 | int ret; |
768 | ||
11b5a3c2 MD |
769 | event_cache = KMEM_CACHE(ltt_event, 0); |
770 | if (!event_cache) | |
4e3c1b9b | 771 | return -ENOMEM; |
02119ee5 MD |
772 | ret = ltt_debugfs_abi_init(); |
773 | if (ret) | |
774 | goto error_abi; | |
4e3c1b9b | 775 | return 0; |
02119ee5 | 776 | error_abi: |
1c25284c MD |
777 | kmem_cache_destroy(event_cache); |
778 | return ret; | |
4e3c1b9b MD |
779 | } |
780 | ||
11b5a3c2 MD |
781 | module_init(ltt_events_init); |
782 | ||
4e3c1b9b MD |
783 | static void __exit ltt_events_exit(void) |
784 | { | |
92e94819 MD |
785 | struct ltt_session *session, *tmpsession; |
786 | ||
1c25284c | 787 | ltt_debugfs_abi_exit(); |
92e94819 MD |
788 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
789 | ltt_session_destroy(session); | |
11b5a3c2 | 790 | kmem_cache_destroy(event_cache); |
4e3c1b9b | 791 | } |
92e94819 | 792 | |
11b5a3c2 MD |
793 | module_exit(ltt_events_exit); |
794 | ||
92e94819 MD |
795 | MODULE_LICENSE("GPL and additional rights"); |
796 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
797 | MODULE_DESCRIPTION("LTTng Events"); |