Commit | Line | Data |
---|---|---|
4e3c1b9b | 1 | /* |
a90917c3 | 2 | * lttng-events.c |
4e3c1b9b | 3 | * |
a90917c3 | 4 | * Copyright 2010-2011 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
4e3c1b9b MD |
5 | * |
6 | * Holds LTTng per-session event registry. | |
17baffe2 MD |
7 | * |
8 | * Dual LGPL v2.1/GPL v2 license. | |
4e3c1b9b MD |
9 | */ |
10 | ||
11 | #include <linux/module.h> | |
c0e31d2e MD |
12 | #include <linux/list.h> |
13 | #include <linux/mutex.h> | |
14 | #include <linux/sched.h> | |
11b5a3c2 | 15 | #include <linux/slab.h> |
c099397a | 16 | #include <linux/jiffies.h> |
99dc9597 | 17 | #include <linux/utsname.h> |
a864fb02 | 18 | #include "wrapper/uuid.h" |
b13f3ebe | 19 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
a82c63f1 | 20 | #include "wrapper/random.h" |
a90917c3 MD |
21 | #include "lttng-events.h" |
22 | #include "lttng-tracer.h" | |
4e3c1b9b MD |
23 | |
24 | static LIST_HEAD(sessions); | |
a90917c3 | 25 | static LIST_HEAD(lttng_transport_list); |
4e3c1b9b MD |
26 | static DEFINE_MUTEX(sessions_mutex); |
27 | static struct kmem_cache *event_cache; | |
28 | ||
a90917c3 MD |
29 | static void _lttng_event_destroy(struct lttng_event *event); |
30 | static void _lttng_channel_destroy(struct lttng_channel *chan); | |
31 | static int _lttng_event_unregister(struct lttng_event *event); | |
c099397a | 32 | static |
a90917c3 MD |
33 | int _lttng_event_metadata_statedump(struct lttng_session *session, |
34 | struct lttng_channel *chan, | |
35 | struct lttng_event *event); | |
c099397a | 36 | static |
a90917c3 | 37 | int _lttng_session_metadata_statedump(struct lttng_session *session); |
c099397a | 38 | |
c099397a | 39 | void synchronize_trace(void) |
abcca994 MD |
40 | { |
41 | synchronize_sched(); | |
42 | #ifdef CONFIG_PREEMPT_RT | |
43 | synchronize_rcu(); | |
44 | #endif | |
45 | } | |
46 | ||
a90917c3 | 47 | struct lttng_session *lttng_session_create(void) |
4e3c1b9b | 48 | { |
a90917c3 | 49 | struct lttng_session *session; |
4e3c1b9b MD |
50 | |
51 | mutex_lock(&sessions_mutex); | |
a90917c3 | 52 | session = kzalloc(sizeof(struct lttng_session), GFP_KERNEL); |
4e3c1b9b MD |
53 | if (!session) |
54 | return NULL; | |
4e3c1b9b | 55 | INIT_LIST_HEAD(&session->chan); |
f3d01b96 | 56 | INIT_LIST_HEAD(&session->events); |
d793d5e1 | 57 | uuid_le_gen(&session->uuid); |
4e3c1b9b MD |
58 | list_add(&session->list, &sessions); |
59 | mutex_unlock(&sessions_mutex); | |
60 | return session; | |
4e3c1b9b MD |
61 | } |
62 | ||
a90917c3 | 63 | void lttng_session_destroy(struct lttng_session *session) |
4e3c1b9b | 64 | { |
a90917c3 MD |
65 | struct lttng_channel *chan, *tmpchan; |
66 | struct lttng_event *event, *tmpevent; | |
dda6a249 | 67 | int ret; |
4e3c1b9b MD |
68 | |
69 | mutex_lock(&sessions_mutex); | |
52fc2e1f | 70 | ACCESS_ONCE(session->active) = 0; |
1ec65de1 MD |
71 | list_for_each_entry(chan, &session->chan, list) { |
72 | ret = lttng_syscalls_unregister(chan); | |
73 | WARN_ON(ret); | |
74 | } | |
dda6a249 | 75 | list_for_each_entry(event, &session->events, list) { |
a90917c3 | 76 | ret = _lttng_event_unregister(event); |
dda6a249 MD |
77 | WARN_ON(ret); |
78 | } | |
abcca994 | 79 | synchronize_trace(); /* Wait for in-flight events to complete */ |
4e3c1b9b | 80 | list_for_each_entry_safe(event, tmpevent, &session->events, list) |
a90917c3 | 81 | _lttng_event_destroy(event); |
4e3c1b9b | 82 | list_for_each_entry_safe(chan, tmpchan, &session->chan, list) |
a90917c3 | 83 | _lttng_channel_destroy(chan); |
4e3c1b9b MD |
84 | list_del(&session->list); |
85 | mutex_unlock(&sessions_mutex); | |
86 | kfree(session); | |
87 | } | |
88 | ||
a90917c3 | 89 | int lttng_session_enable(struct lttng_session *session) |
c0e31d2e MD |
90 | { |
91 | int ret = 0; | |
a90917c3 | 92 | struct lttng_channel *chan; |
c0e31d2e MD |
93 | |
94 | mutex_lock(&sessions_mutex); | |
95 | if (session->active) { | |
96 | ret = -EBUSY; | |
97 | goto end; | |
98 | } | |
c099397a MD |
99 | |
100 | /* | |
101 | * Snapshot the number of events per channel to know the type of header | |
102 | * we need to use. | |
103 | */ | |
104 | list_for_each_entry(chan, &session->chan, list) { | |
105 | if (chan->header_type) | |
106 | continue; /* don't change it if session stop/restart */ | |
107 | if (chan->free_event_id < 31) | |
108 | chan->header_type = 1; /* compact */ | |
109 | else | |
110 | chan->header_type = 2; /* large */ | |
111 | } | |
112 | ||
52fc2e1f | 113 | ACCESS_ONCE(session->active) = 1; |
8070f5c0 | 114 | ACCESS_ONCE(session->been_active) = 1; |
a90917c3 | 115 | ret = _lttng_session_metadata_statedump(session); |
c337ddc2 MD |
116 | if (ret) { |
117 | ACCESS_ONCE(session->active) = 0; | |
118 | goto end; | |
119 | } | |
120 | ret = lttng_statedump_start(session); | |
360f38ea | 121 | if (ret) |
c099397a | 122 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
123 | end: |
124 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 125 | return ret; |
c0e31d2e MD |
126 | } |
127 | ||
a90917c3 | 128 | int lttng_session_disable(struct lttng_session *session) |
c0e31d2e MD |
129 | { |
130 | int ret = 0; | |
131 | ||
132 | mutex_lock(&sessions_mutex); | |
133 | if (!session->active) { | |
134 | ret = -EBUSY; | |
135 | goto end; | |
136 | } | |
52fc2e1f | 137 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
138 | end: |
139 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 140 | return ret; |
c0e31d2e MD |
141 | } |
142 | ||
a90917c3 | 143 | int lttng_channel_enable(struct lttng_channel *channel) |
e64957da MD |
144 | { |
145 | int old; | |
146 | ||
c6485006 MD |
147 | if (channel == channel->session->metadata) |
148 | return -EPERM; | |
e64957da MD |
149 | old = xchg(&channel->enabled, 1); |
150 | if (old) | |
151 | return -EEXIST; | |
152 | return 0; | |
153 | } | |
154 | ||
a90917c3 | 155 | int lttng_channel_disable(struct lttng_channel *channel) |
e64957da MD |
156 | { |
157 | int old; | |
158 | ||
c6485006 MD |
159 | if (channel == channel->session->metadata) |
160 | return -EPERM; | |
e64957da MD |
161 | old = xchg(&channel->enabled, 0); |
162 | if (!old) | |
163 | return -EEXIST; | |
164 | return 0; | |
165 | } | |
166 | ||
a90917c3 | 167 | int lttng_event_enable(struct lttng_event *event) |
e64957da MD |
168 | { |
169 | int old; | |
170 | ||
c6485006 MD |
171 | if (event->chan == event->chan->session->metadata) |
172 | return -EPERM; | |
e64957da MD |
173 | old = xchg(&event->enabled, 1); |
174 | if (old) | |
175 | return -EEXIST; | |
176 | return 0; | |
177 | } | |
178 | ||
a90917c3 | 179 | int lttng_event_disable(struct lttng_event *event) |
e64957da MD |
180 | { |
181 | int old; | |
182 | ||
c6485006 MD |
183 | if (event->chan == event->chan->session->metadata) |
184 | return -EPERM; | |
e64957da MD |
185 | old = xchg(&event->enabled, 0); |
186 | if (!old) | |
187 | return -EEXIST; | |
188 | return 0; | |
189 | } | |
190 | ||
a90917c3 | 191 | static struct lttng_transport *lttng_transport_find(const char *name) |
f3d01b96 | 192 | { |
a90917c3 | 193 | struct lttng_transport *transport; |
f3d01b96 | 194 | |
a90917c3 | 195 | list_for_each_entry(transport, <tng_transport_list, node) { |
f3d01b96 MD |
196 | if (!strcmp(transport->name, name)) |
197 | return transport; | |
198 | } | |
199 | return NULL; | |
200 | } | |
201 | ||
a90917c3 | 202 | struct lttng_channel *lttng_channel_create(struct lttng_session *session, |
5dbbdb43 MD |
203 | const char *transport_name, |
204 | void *buf_addr, | |
4e3c1b9b MD |
205 | size_t subbuf_size, size_t num_subbuf, |
206 | unsigned int switch_timer_interval, | |
207 | unsigned int read_timer_interval) | |
208 | { | |
a90917c3 MD |
209 | struct lttng_channel *chan; |
210 | struct lttng_transport *transport = NULL; | |
4e3c1b9b MD |
211 | |
212 | mutex_lock(&sessions_mutex); | |
8070f5c0 | 213 | if (session->been_active) |
e5382b6d | 214 | goto active; /* Refuse to add channel to active session */ |
a90917c3 | 215 | transport = lttng_transport_find(transport_name); |
f3d01b96 MD |
216 | if (!transport) { |
217 | printk(KERN_WARNING "LTTng transport %s not found\n", | |
218 | transport_name); | |
c0e31d2e | 219 | goto notransport; |
f3d01b96 | 220 | } |
a33c9927 MD |
221 | if (!try_module_get(transport->owner)) { |
222 | printk(KERN_WARNING "LTT : Can't lock transport module.\n"); | |
223 | goto notransport; | |
224 | } | |
a90917c3 | 225 | chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL); |
4e3c1b9b | 226 | if (!chan) |
c0e31d2e | 227 | goto nomem; |
4e3c1b9b | 228 | chan->session = session; |
05d32c64 | 229 | chan->id = session->free_chan_id++; |
125b4df4 MD |
230 | /* |
231 | * Note: the channel creation op already writes into the packet | |
232 | * headers. Therefore the "chan" information used as input | |
233 | * should be already accessible. | |
234 | */ | |
9115fbdc | 235 | chan->chan = transport->ops.channel_create("[lttng]", chan, buf_addr, |
11b5a3c2 MD |
236 | subbuf_size, num_subbuf, switch_timer_interval, |
237 | read_timer_interval); | |
f3d01b96 MD |
238 | if (!chan->chan) |
239 | goto create_error; | |
e64957da | 240 | chan->enabled = 1; |
11b5a3c2 | 241 | chan->ops = &transport->ops; |
a33c9927 | 242 | chan->transport = transport; |
4e3c1b9b MD |
243 | list_add(&chan->list, &session->chan); |
244 | mutex_unlock(&sessions_mutex); | |
245 | return chan; | |
246 | ||
f3d01b96 MD |
247 | create_error: |
248 | kfree(chan); | |
c0e31d2e | 249 | nomem: |
a33c9927 MD |
250 | if (transport) |
251 | module_put(transport->owner); | |
c0e31d2e | 252 | notransport: |
e5382b6d | 253 | active: |
4e3c1b9b MD |
254 | mutex_unlock(&sessions_mutex); |
255 | return NULL; | |
256 | } | |
257 | ||
258 | /* | |
259 | * Only used internally at session destruction. | |
260 | */ | |
aa7c23a9 | 261 | static |
a90917c3 | 262 | void _lttng_channel_destroy(struct lttng_channel *chan) |
4e3c1b9b | 263 | { |
11b5a3c2 | 264 | chan->ops->channel_destroy(chan->chan); |
a33c9927 | 265 | module_put(chan->transport->owner); |
4e3c1b9b | 266 | list_del(&chan->list); |
8070f5c0 | 267 | lttng_destroy_context(chan->ctx); |
4e3c1b9b MD |
268 | kfree(chan); |
269 | } | |
270 | ||
e5382b6d MD |
271 | /* |
272 | * Supports event creation while tracing session is active. | |
273 | */ | |
a90917c3 | 274 | struct lttng_event *lttng_event_create(struct lttng_channel *chan, |
d6d808f3 | 275 | struct lttng_kernel_event *event_param, |
259b6cb3 MD |
276 | void *filter, |
277 | const struct lttng_event_desc *internal_desc) | |
4e3c1b9b | 278 | { |
a90917c3 | 279 | struct lttng_event *event; |
3d084699 | 280 | int ret; |
4e3c1b9b MD |
281 | |
282 | mutex_lock(&sessions_mutex); | |
e5382b6d MD |
283 | if (chan->free_event_id == -1UL) |
284 | goto full; | |
4e3c1b9b | 285 | /* |
dda6a249 MD |
286 | * This is O(n^2) (for each event, the loop is called at event |
287 | * creation). Might require a hash if we have lots of events. | |
4e3c1b9b MD |
288 | */ |
289 | list_for_each_entry(event, &chan->session->events, list) | |
30bdb6e4 | 290 | if (!strcmp(event->desc->name, event_param->name)) |
4e3c1b9b | 291 | goto exist; |
11b5a3c2 | 292 | event = kmem_cache_zalloc(event_cache, GFP_KERNEL); |
4e3c1b9b MD |
293 | if (!event) |
294 | goto cache_error; | |
4e3c1b9b MD |
295 | event->chan = chan; |
296 | event->filter = filter; | |
e5382b6d | 297 | event->id = chan->free_event_id++; |
e64957da | 298 | event->enabled = 1; |
d6d808f3 | 299 | event->instrumentation = event_param->instrumentation; |
a90917c3 | 300 | /* Populate lttng_event structure before tracepoint registration. */ |
e5382b6d | 301 | smp_wmb(); |
d6d808f3 | 302 | switch (event_param->instrumentation) { |
ab2277d6 | 303 | case LTTNG_KERNEL_TRACEPOINT: |
a90917c3 | 304 | event->desc = lttng_event_get(event_param->name); |
d3dbe23c MD |
305 | if (!event->desc) |
306 | goto register_error; | |
30bdb6e4 | 307 | ret = tracepoint_probe_register(event_param->name, |
d3dbe23c MD |
308 | event->desc->probe_callback, |
309 | event); | |
11b5a3c2 MD |
310 | if (ret) |
311 | goto register_error; | |
baf20995 | 312 | break; |
ab2277d6 | 313 | case LTTNG_KERNEL_KPROBE: |
30bdb6e4 | 314 | ret = lttng_kprobes_register(event_param->name, |
f17701fb MD |
315 | event_param->u.kprobe.symbol_name, |
316 | event_param->u.kprobe.offset, | |
317 | event_param->u.kprobe.addr, | |
318 | event); | |
319 | if (ret) | |
d6d808f3 | 320 | goto register_error; |
edeb3137 MD |
321 | ret = try_module_get(event->desc->owner); |
322 | WARN_ON_ONCE(!ret); | |
d6d808f3 | 323 | break; |
7371f44c MD |
324 | case LTTNG_KERNEL_KRETPROBE: |
325 | { | |
a90917c3 | 326 | struct lttng_event *event_return; |
7371f44c MD |
327 | |
328 | /* kretprobe defines 2 events */ | |
329 | event_return = | |
330 | kmem_cache_zalloc(event_cache, GFP_KERNEL); | |
331 | if (!event_return) | |
332 | goto register_error; | |
333 | event_return->chan = chan; | |
334 | event_return->filter = filter; | |
335 | event_return->id = chan->free_event_id++; | |
336 | event_return->enabled = 1; | |
337 | event_return->instrumentation = event_param->instrumentation; | |
338 | /* | |
a90917c3 | 339 | * Populate lttng_event structure before kretprobe registration. |
7371f44c MD |
340 | */ |
341 | smp_wmb(); | |
342 | ret = lttng_kretprobes_register(event_param->name, | |
343 | event_param->u.kretprobe.symbol_name, | |
344 | event_param->u.kretprobe.offset, | |
345 | event_param->u.kretprobe.addr, | |
346 | event, event_return); | |
347 | if (ret) { | |
348 | kmem_cache_free(event_cache, event_return); | |
349 | goto register_error; | |
350 | } | |
351 | /* Take 2 refs on the module: one per event. */ | |
352 | ret = try_module_get(event->desc->owner); | |
353 | WARN_ON_ONCE(!ret); | |
354 | ret = try_module_get(event->desc->owner); | |
355 | WARN_ON_ONCE(!ret); | |
a90917c3 | 356 | ret = _lttng_event_metadata_statedump(chan->session, chan, |
7371f44c MD |
357 | event_return); |
358 | if (ret) { | |
359 | kmem_cache_free(event_cache, event_return); | |
360 | module_put(event->desc->owner); | |
361 | module_put(event->desc->owner); | |
362 | goto statedump_error; | |
363 | } | |
364 | list_add(&event_return->list, &chan->session->events); | |
365 | break; | |
366 | } | |
ab2277d6 | 367 | case LTTNG_KERNEL_FUNCTION: |
30bdb6e4 | 368 | ret = lttng_ftrace_register(event_param->name, |
e0a7a7c4 MD |
369 | event_param->u.ftrace.symbol_name, |
370 | event); | |
371 | if (ret) | |
372 | goto register_error; | |
edeb3137 MD |
373 | ret = try_module_get(event->desc->owner); |
374 | WARN_ON_ONCE(!ret); | |
e0a7a7c4 | 375 | break; |
1ec65de1 | 376 | case LTTNG_KERNEL_NOOP: |
259b6cb3 MD |
377 | event->desc = internal_desc; |
378 | if (!event->desc) | |
379 | goto register_error; | |
1ec65de1 | 380 | break; |
baf20995 MD |
381 | default: |
382 | WARN_ON_ONCE(1); | |
383 | } | |
a90917c3 | 384 | ret = _lttng_event_metadata_statedump(chan->session, chan, event); |
c099397a MD |
385 | if (ret) |
386 | goto statedump_error; | |
dda6a249 | 387 | list_add(&event->list, &chan->session->events); |
11b5a3c2 | 388 | mutex_unlock(&sessions_mutex); |
4e3c1b9b MD |
389 | return event; |
390 | ||
c099397a | 391 | statedump_error: |
259b6cb3 | 392 | /* If a statedump error occurs, events will not be readable. */ |
11b5a3c2 | 393 | register_error: |
11b5a3c2 | 394 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
395 | cache_error: |
396 | exist: | |
e5382b6d | 397 | full: |
4e3c1b9b MD |
398 | mutex_unlock(&sessions_mutex); |
399 | return NULL; | |
400 | } | |
401 | ||
402 | /* | |
403 | * Only used internally at session destruction. | |
404 | */ | |
a90917c3 | 405 | int _lttng_event_unregister(struct lttng_event *event) |
4e3c1b9b | 406 | { |
11b5a3c2 MD |
407 | int ret = -EINVAL; |
408 | ||
38d024ae | 409 | switch (event->instrumentation) { |
ab2277d6 | 410 | case LTTNG_KERNEL_TRACEPOINT: |
85a9ca7f MD |
411 | ret = tracepoint_probe_unregister(event->desc->name, |
412 | event->desc->probe_callback, | |
11b5a3c2 MD |
413 | event); |
414 | if (ret) | |
415 | return ret; | |
baf20995 | 416 | break; |
ab2277d6 | 417 | case LTTNG_KERNEL_KPROBE: |
f17701fb | 418 | lttng_kprobes_unregister(event); |
d6d808f3 MD |
419 | ret = 0; |
420 | break; | |
7371f44c MD |
421 | case LTTNG_KERNEL_KRETPROBE: |
422 | lttng_kretprobes_unregister(event); | |
423 | ret = 0; | |
424 | break; | |
ab2277d6 | 425 | case LTTNG_KERNEL_FUNCTION: |
e0a7a7c4 MD |
426 | lttng_ftrace_unregister(event); |
427 | ret = 0; | |
428 | break; | |
259b6cb3 MD |
429 | case LTTNG_KERNEL_NOOP: |
430 | ret = 0; | |
431 | break; | |
baf20995 MD |
432 | default: |
433 | WARN_ON_ONCE(1); | |
434 | } | |
dda6a249 MD |
435 | return ret; |
436 | } | |
437 | ||
438 | /* | |
439 | * Only used internally at session destruction. | |
440 | */ | |
be066e6c | 441 | static |
a90917c3 | 442 | void _lttng_event_destroy(struct lttng_event *event) |
dda6a249 | 443 | { |
edeb3137 MD |
444 | switch (event->instrumentation) { |
445 | case LTTNG_KERNEL_TRACEPOINT: | |
a90917c3 | 446 | lttng_event_put(event->desc); |
edeb3137 MD |
447 | break; |
448 | case LTTNG_KERNEL_KPROBE: | |
449 | module_put(event->desc->owner); | |
450 | lttng_kprobes_destroy_private(event); | |
451 | break; | |
7371f44c MD |
452 | case LTTNG_KERNEL_KRETPROBE: |
453 | module_put(event->desc->owner); | |
454 | lttng_kretprobes_destroy_private(event); | |
455 | break; | |
edeb3137 MD |
456 | case LTTNG_KERNEL_FUNCTION: |
457 | module_put(event->desc->owner); | |
458 | lttng_ftrace_destroy_private(event); | |
459 | break; | |
259b6cb3 MD |
460 | case LTTNG_KERNEL_NOOP: |
461 | break; | |
edeb3137 MD |
462 | default: |
463 | WARN_ON_ONCE(1); | |
464 | } | |
dda6a249 | 465 | list_del(&event->list); |
8070f5c0 | 466 | lttng_destroy_context(event->ctx); |
11b5a3c2 | 467 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
468 | } |
469 | ||
1ec3f75a MD |
470 | /* |
471 | * We have exclusive access to our metadata buffer (protected by the | |
472 | * sessions_mutex), so we can do racy operations such as looking for | |
473 | * remaining space left in packet and write, since mutual exclusion | |
474 | * protects us from concurrent writes. | |
475 | */ | |
a90917c3 | 476 | int lttng_metadata_printf(struct lttng_session *session, |
c099397a MD |
477 | const char *fmt, ...) |
478 | { | |
479 | struct lib_ring_buffer_ctx ctx; | |
a90917c3 | 480 | struct lttng_channel *chan = session->metadata; |
c099397a MD |
481 | char *str; |
482 | int ret = 0, waitret; | |
1ec3f75a | 483 | size_t len, reserve_len, pos; |
c099397a MD |
484 | va_list ap; |
485 | ||
486 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
487 | ||
488 | va_start(ap, fmt); | |
489 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
490 | va_end(ap); | |
491 | if (!str) | |
492 | return -ENOMEM; | |
493 | ||
1ec3f75a MD |
494 | len = strlen(str); |
495 | pos = 0; | |
496 | ||
497 | for (pos = 0; pos < len; pos += reserve_len) { | |
498 | reserve_len = min_t(size_t, | |
499 | chan->ops->packet_avail_size(chan->chan), | |
500 | len - pos); | |
501 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
502 | sizeof(char), -1); | |
503 | /* | |
504 | * We don't care about metadata buffer's records lost | |
505 | * count, because we always retry here. Report error if | |
506 | * we need to bail out after timeout or being | |
507 | * interrupted. | |
508 | */ | |
71c1d843 | 509 | waitret = wait_event_interruptible_timeout(*chan->ops->get_writer_buf_wait_queue(chan->chan, -1), |
1ec3f75a | 510 | ({ |
4e1f08f4 | 511 | ret = chan->ops->event_reserve(&ctx, 0); |
1ec3f75a MD |
512 | ret != -ENOBUFS || !ret; |
513 | }), | |
514 | msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); | |
515 | if (!waitret || waitret == -ERESTARTSYS || ret) { | |
516 | printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n", | |
517 | waitret == -ERESTARTSYS ? "interrupted" : | |
518 | (ret == -ENOBUFS ? "timeout" : "I/O error")); | |
519 | if (waitret == -ERESTARTSYS) | |
520 | ret = waitret; | |
521 | goto end; | |
522 | } | |
f5cf8eff | 523 | chan->ops->event_write(&ctx, &str[pos], reserve_len); |
1ec3f75a | 524 | chan->ops->event_commit(&ctx); |
c099397a | 525 | } |
c099397a MD |
526 | end: |
527 | kfree(str); | |
528 | return ret; | |
529 | } | |
530 | ||
531 | static | |
a90917c3 | 532 | int _lttng_field_statedump(struct lttng_session *session, |
8070f5c0 | 533 | const struct lttng_event_field *field) |
c099397a | 534 | { |
c099397a | 535 | int ret = 0; |
c099397a | 536 | |
8070f5c0 MD |
537 | switch (field->type.atype) { |
538 | case atype_integer: | |
539 | ret = lttng_metadata_printf(session, | |
244465ab | 540 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n", |
8070f5c0 MD |
541 | field->type.u.basic.integer.size, |
542 | field->type.u.basic.integer.alignment, | |
543 | field->type.u.basic.integer.signedness, | |
544 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
545 | ? "none" | |
546 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
547 | ? "UTF8" | |
548 | : "ASCII", | |
549 | field->type.u.basic.integer.base, | |
c099397a | 550 | #ifdef __BIG_ENDIAN |
8070f5c0 | 551 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
c099397a | 552 | #else |
8070f5c0 | 553 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
c099397a | 554 | #endif |
8070f5c0 MD |
555 | field->name); |
556 | break; | |
557 | case atype_enum: | |
558 | ret = lttng_metadata_printf(session, | |
244465ab | 559 | " %s _%s;\n", |
8070f5c0 MD |
560 | field->type.u.basic.enumeration.name, |
561 | field->name); | |
562 | break; | |
563 | case atype_array: | |
564 | { | |
565 | const struct lttng_basic_type *elem_type; | |
566 | ||
567 | elem_type = &field->type.u.array.elem_type; | |
568 | ret = lttng_metadata_printf(session, | |
244465ab | 569 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n", |
8070f5c0 MD |
570 | elem_type->u.basic.integer.size, |
571 | elem_type->u.basic.integer.alignment, | |
572 | elem_type->u.basic.integer.signedness, | |
573 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
574 | ? "none" | |
575 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
576 | ? "UTF8" | |
577 | : "ASCII", | |
578 | elem_type->u.basic.integer.base, | |
8fa75f34 | 579 | #ifdef __BIG_ENDIAN |
8070f5c0 | 580 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
8fa75f34 | 581 | #else |
8070f5c0 | 582 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
8fa75f34 | 583 | #endif |
8070f5c0 MD |
584 | field->name, field->type.u.array.length); |
585 | break; | |
586 | } | |
587 | case atype_sequence: | |
588 | { | |
589 | const struct lttng_basic_type *elem_type; | |
590 | const struct lttng_basic_type *length_type; | |
591 | ||
592 | elem_type = &field->type.u.sequence.elem_type; | |
593 | length_type = &field->type.u.sequence.length_type; | |
594 | ret = lttng_metadata_printf(session, | |
595 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
8070f5c0 | 596 | length_type->u.basic.integer.size, |
32257272 | 597 | (unsigned int) length_type->u.basic.integer.alignment, |
8070f5c0 MD |
598 | length_type->u.basic.integer.signedness, |
599 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
600 | ? "none" | |
0635cdd4 | 601 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) |
8070f5c0 | 602 | ? "UTF8" |
0635cdd4 | 603 | : "ASCII"), |
8070f5c0 | 604 | length_type->u.basic.integer.base, |
e0a7a7c4 | 605 | #ifdef __BIG_ENDIAN |
8070f5c0 | 606 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
e0a7a7c4 | 607 | #else |
0635cdd4 | 608 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
e0a7a7c4 | 609 | #endif |
27d2368e MD |
610 | field->name); |
611 | if (ret) | |
612 | return ret; | |
613 | ||
614 | ret = lttng_metadata_printf(session, | |
244465ab | 615 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n", |
8070f5c0 | 616 | elem_type->u.basic.integer.size, |
32257272 | 617 | (unsigned int) elem_type->u.basic.integer.alignment, |
8070f5c0 MD |
618 | elem_type->u.basic.integer.signedness, |
619 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
620 | ? "none" | |
0635cdd4 | 621 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) |
8070f5c0 | 622 | ? "UTF8" |
0635cdd4 | 623 | : "ASCII"), |
8070f5c0 | 624 | elem_type->u.basic.integer.base, |
8fa75f34 | 625 | #ifdef __BIG_ENDIAN |
8070f5c0 | 626 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
8fa75f34 | 627 | #else |
8070f5c0 | 628 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
8fa75f34 | 629 | #endif |
8070f5c0 | 630 | field->name, |
27d2368e | 631 | field->name); |
8070f5c0 MD |
632 | break; |
633 | } | |
c099397a | 634 | |
8070f5c0 MD |
635 | case atype_string: |
636 | /* Default encoding is UTF8 */ | |
637 | ret = lttng_metadata_printf(session, | |
244465ab | 638 | " string%s _%s;\n", |
8070f5c0 MD |
639 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? |
640 | " { encoding = ASCII; }" : "", | |
641 | field->name); | |
642 | break; | |
643 | default: | |
644 | WARN_ON_ONCE(1); | |
645 | return -EINVAL; | |
646 | } | |
647 | return ret; | |
648 | } | |
649 | ||
650 | static | |
a90917c3 | 651 | int _lttng_context_metadata_statedump(struct lttng_session *session, |
8070f5c0 MD |
652 | struct lttng_ctx *ctx) |
653 | { | |
654 | int ret = 0; | |
655 | int i; | |
656 | ||
657 | if (!ctx) | |
658 | return 0; | |
659 | for (i = 0; i < ctx->nr_fields; i++) { | |
660 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
661 | ||
a90917c3 | 662 | ret = _lttng_field_statedump(session, &field->event_field); |
8070f5c0 MD |
663 | if (ret) |
664 | return ret; | |
665 | } | |
666 | return ret; | |
667 | } | |
668 | ||
669 | static | |
a90917c3 MD |
670 | int _lttng_fields_metadata_statedump(struct lttng_session *session, |
671 | struct lttng_event *event) | |
8070f5c0 MD |
672 | { |
673 | const struct lttng_event_desc *desc = event->desc; | |
674 | int ret = 0; | |
675 | int i; | |
676 | ||
677 | for (i = 0; i < desc->nr_fields; i++) { | |
678 | const struct lttng_event_field *field = &desc->fields[i]; | |
679 | ||
a90917c3 | 680 | ret = _lttng_field_statedump(session, field); |
8070f5c0 MD |
681 | if (ret) |
682 | return ret; | |
c099397a MD |
683 | } |
684 | return ret; | |
685 | } | |
686 | ||
687 | static | |
a90917c3 MD |
688 | int _lttng_event_metadata_statedump(struct lttng_session *session, |
689 | struct lttng_channel *chan, | |
690 | struct lttng_event *event) | |
c099397a MD |
691 | { |
692 | int ret = 0; | |
693 | ||
694 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
695 | return 0; | |
696 | if (chan == session->metadata) | |
697 | return 0; | |
698 | ||
699 | ret = lttng_metadata_printf(session, | |
700 | "event {\n" | |
701 | " name = %s;\n" | |
702 | " id = %u;\n" | |
b9074a1b | 703 | " stream_id = %u;\n", |
c099397a MD |
704 | event->desc->name, |
705 | event->id, | |
706 | event->chan->id); | |
707 | if (ret) | |
708 | goto end; | |
709 | ||
b9074a1b MD |
710 | if (event->ctx) { |
711 | ret = lttng_metadata_printf(session, | |
712 | " context := struct {\n"); | |
713 | if (ret) | |
714 | goto end; | |
715 | } | |
a90917c3 | 716 | ret = _lttng_context_metadata_statedump(session, event->ctx); |
8070f5c0 MD |
717 | if (ret) |
718 | goto end; | |
b9074a1b MD |
719 | if (event->ctx) { |
720 | ret = lttng_metadata_printf(session, | |
721 | " };\n"); | |
722 | if (ret) | |
723 | goto end; | |
724 | } | |
8070f5c0 MD |
725 | |
726 | ret = lttng_metadata_printf(session, | |
8070f5c0 MD |
727 | " fields := struct {\n" |
728 | ); | |
729 | if (ret) | |
730 | goto end; | |
731 | ||
a90917c3 | 732 | ret = _lttng_fields_metadata_statedump(session, event); |
c099397a MD |
733 | if (ret) |
734 | goto end; | |
735 | ||
736 | /* | |
737 | * LTTng space reservation can only reserve multiples of the | |
738 | * byte size. | |
739 | */ | |
740 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
741 | " };\n" |
742 | "};\n\n"); | |
c099397a MD |
743 | if (ret) |
744 | goto end; | |
745 | ||
c099397a MD |
746 | event->metadata_dumped = 1; |
747 | end: | |
748 | return ret; | |
749 | ||
750 | } | |
751 | ||
752 | static | |
a90917c3 MD |
753 | int _lttng_channel_metadata_statedump(struct lttng_session *session, |
754 | struct lttng_channel *chan) | |
c099397a MD |
755 | { |
756 | int ret = 0; | |
757 | ||
758 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
759 | return 0; | |
760 | if (chan == session->metadata) | |
761 | return 0; | |
762 | ||
763 | WARN_ON_ONCE(!chan->header_type); | |
764 | ret = lttng_metadata_printf(session, | |
765 | "stream {\n" | |
766 | " id = %u;\n" | |
9115fbdc | 767 | " event.header := %s;\n" |
b9074a1b | 768 | " packet.context := struct packet_context;\n", |
c099397a MD |
769 | chan->id, |
770 | chan->header_type == 1 ? "struct event_header_compact" : | |
771 | "struct event_header_large"); | |
772 | if (ret) | |
773 | goto end; | |
774 | ||
b9074a1b MD |
775 | if (chan->ctx) { |
776 | ret = lttng_metadata_printf(session, | |
777 | " event.context := struct {\n"); | |
778 | if (ret) | |
779 | goto end; | |
780 | } | |
a90917c3 | 781 | ret = _lttng_context_metadata_statedump(session, chan->ctx); |
8070f5c0 MD |
782 | if (ret) |
783 | goto end; | |
b9074a1b MD |
784 | if (chan->ctx) { |
785 | ret = lttng_metadata_printf(session, | |
786 | " };\n"); | |
787 | if (ret) | |
788 | goto end; | |
789 | } | |
8070f5c0 MD |
790 | |
791 | ret = lttng_metadata_printf(session, | |
b9074a1b | 792 | "};\n\n"); |
8070f5c0 | 793 | |
c099397a MD |
794 | chan->metadata_dumped = 1; |
795 | end: | |
796 | return ret; | |
797 | } | |
798 | ||
9115fbdc | 799 | static |
a90917c3 | 800 | int _lttng_stream_packet_context_declare(struct lttng_session *session) |
9115fbdc MD |
801 | { |
802 | return lttng_metadata_printf(session, | |
803 | "struct packet_context {\n" | |
a3ccff4f MD |
804 | " uint64_clock_monotonic_t timestamp_begin;\n" |
805 | " uint64_clock_monotonic_t timestamp_end;\n" | |
9115fbdc MD |
806 | " uint32_t events_discarded;\n" |
807 | " uint32_t content_size;\n" | |
808 | " uint32_t packet_size;\n" | |
809 | " uint32_t cpu_id;\n" | |
c6dfdf6f | 810 | "};\n\n" |
9115fbdc MD |
811 | ); |
812 | } | |
813 | ||
814 | /* | |
815 | * Compact header: | |
816 | * id: range: 0 - 30. | |
817 | * id 31 is reserved to indicate an extended header. | |
818 | * | |
819 | * Large header: | |
820 | * id: range: 0 - 65534. | |
821 | * id 65535 is reserved to indicate an extended header. | |
822 | */ | |
823 | static | |
a90917c3 | 824 | int _lttng_event_header_declare(struct lttng_session *session) |
9115fbdc MD |
825 | { |
826 | return lttng_metadata_printf(session, | |
827 | "struct event_header_compact {\n" | |
828 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
829 | " variant <id> {\n" | |
830 | " struct {\n" | |
a3ccff4f | 831 | " uint27_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
832 | " } compact;\n" |
833 | " struct {\n" | |
834 | " uint32_t id;\n" | |
a3ccff4f | 835 | " uint64_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
836 | " } extended;\n" |
837 | " } v;\n" | |
838 | "} align(%u);\n" | |
839 | "\n" | |
840 | "struct event_header_large {\n" | |
841 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
842 | " variant <id> {\n" | |
843 | " struct {\n" | |
a3ccff4f | 844 | " uint32_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
845 | " } compact;\n" |
846 | " struct {\n" | |
847 | " uint32_t id;\n" | |
a3ccff4f | 848 | " uint64_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
849 | " } extended;\n" |
850 | " } v;\n" | |
851 | "} align(%u);\n\n", | |
a90917c3 MD |
852 | lttng_alignof(uint32_t) * CHAR_BIT, |
853 | lttng_alignof(uint16_t) * CHAR_BIT | |
9115fbdc MD |
854 | ); |
855 | } | |
856 | ||
a3ccff4f MD |
857 | /* |
858 | * Approximation of NTP time of day to clock monotonic correlation, | |
859 | * taken at start of trace. | |
860 | * Yes, this is only an approximation. Yes, we can (and will) do better | |
861 | * in future versions. | |
862 | */ | |
863 | static | |
864 | uint64_t measure_clock_offset(void) | |
865 | { | |
866 | uint64_t offset, monotonic[2], realtime; | |
867 | struct timespec rts = { 0, 0 }; | |
868 | unsigned long flags; | |
869 | ||
870 | /* Disable interrupts to increase correlation precision. */ | |
871 | local_irq_save(flags); | |
872 | monotonic[0] = trace_clock_read64(); | |
873 | getnstimeofday(&rts); | |
874 | monotonic[1] = trace_clock_read64(); | |
875 | local_irq_restore(flags); | |
876 | ||
877 | offset = (monotonic[0] + monotonic[1]) >> 1; | |
878 | realtime = rts.tv_sec * NSEC_PER_SEC; | |
879 | realtime += rts.tv_nsec; | |
880 | offset = realtime - offset; | |
881 | return offset; | |
882 | } | |
883 | ||
c099397a MD |
884 | /* |
885 | * Output metadata into this session's metadata buffers. | |
886 | */ | |
887 | static | |
a90917c3 | 888 | int _lttng_session_metadata_statedump(struct lttng_session *session) |
c099397a | 889 | { |
30bdb6e4 | 890 | unsigned char *uuid_c = session->uuid.b; |
a82c63f1 | 891 | unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN]; |
a90917c3 MD |
892 | struct lttng_channel *chan; |
893 | struct lttng_event *event; | |
c099397a MD |
894 | int ret = 0; |
895 | ||
896 | if (!ACCESS_ONCE(session->active)) | |
897 | return 0; | |
898 | if (session->metadata_dumped) | |
899 | goto skip_session; | |
f40270ad | 900 | if (!session->metadata) { |
cd4bd11f | 901 | printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
f40270ad MD |
902 | return -EPERM; |
903 | } | |
c099397a | 904 | |
d793d5e1 | 905 | snprintf(uuid_s, sizeof(uuid_s), |
30bdb6e4 MD |
906 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", |
907 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
908 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
909 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
910 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
d793d5e1 MD |
911 | |
912 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
913 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
914 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
915 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
916 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
917 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
918 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
d793d5e1 MD |
919 | "\n" |
920 | "trace {\n" | |
921 | " major = %u;\n" | |
922 | " minor = %u;\n" | |
30bdb6e4 | 923 | " uuid = \"%s\";\n" |
d793d5e1 MD |
924 | " byte_order = %s;\n" |
925 | " packet.header := struct {\n" | |
926 | " uint32_t magic;\n" | |
1ec3f75a | 927 | " uint8_t uuid[16];\n" |
d793d5e1 | 928 | " uint32_t stream_id;\n" |
0eb25f58 | 929 | " };\n" |
d793d5e1 | 930 | "};\n\n", |
a90917c3 MD |
931 | lttng_alignof(uint8_t) * CHAR_BIT, |
932 | lttng_alignof(uint16_t) * CHAR_BIT, | |
933 | lttng_alignof(uint32_t) * CHAR_BIT, | |
934 | lttng_alignof(uint64_t) * CHAR_BIT, | |
d793d5e1 MD |
935 | CTF_VERSION_MAJOR, |
936 | CTF_VERSION_MINOR, | |
937 | uuid_s, | |
938 | #ifdef __BIG_ENDIAN | |
939 | "be" | |
940 | #else | |
941 | "le" | |
942 | #endif | |
943 | ); | |
944 | if (ret) | |
945 | goto end; | |
946 | ||
99dc9597 MD |
947 | ret = lttng_metadata_printf(session, |
948 | "env {\n" | |
949 | " domain = \"%s\";\n" | |
950 | " sysname = \"%s\";\n" | |
951 | " release = \"%s\";\n" | |
952 | " version = \"%s\";\n" | |
953 | "};\n\n", | |
954 | "kernel", | |
955 | utsname()->sysname, | |
956 | utsname()->release, | |
957 | utsname()->version | |
958 | ); | |
959 | if (ret) | |
960 | goto end; | |
961 | ||
a3ccff4f MD |
962 | ret = lttng_metadata_printf(session, |
963 | "clock {\n" | |
a82c63f1 MD |
964 | " name = %s;\n", |
965 | "monotonic" | |
966 | ); | |
967 | if (ret) | |
968 | goto end; | |
969 | ||
970 | if (!trace_clock_uuid(clock_uuid_s)) { | |
971 | ret = lttng_metadata_printf(session, | |
7c27cb17 | 972 | " uuid = \"%s\";\n", |
a82c63f1 MD |
973 | clock_uuid_s |
974 | ); | |
975 | if (ret) | |
976 | goto end; | |
977 | } | |
978 | ||
979 | ret = lttng_metadata_printf(session, | |
a3ccff4f MD |
980 | " description = \"Monotonic Clock\";\n" |
981 | " freq = %llu; /* Frequency, in Hz */\n" | |
982 | " /* clock value offset from Epoch is: offset * (1/freq) */\n" | |
983 | " offset = %llu;\n" | |
984 | "};\n\n", | |
a3ccff4f MD |
985 | (unsigned long long) trace_clock_freq(), |
986 | (unsigned long long) measure_clock_offset() | |
987 | ); | |
988 | if (ret) | |
989 | goto end; | |
990 | ||
991 | ret = lttng_metadata_printf(session, | |
992 | "typealias integer {\n" | |
993 | " size = 27; align = 1; signed = false;\n" | |
994 | " map = clock.monotonic.value;\n" | |
995 | "} := uint27_clock_monotonic_t;\n" | |
996 | "\n" | |
997 | "typealias integer {\n" | |
998 | " size = 32; align = %u; signed = false;\n" | |
999 | " map = clock.monotonic.value;\n" | |
1000 | "} := uint32_clock_monotonic_t;\n" | |
1001 | "\n" | |
1002 | "typealias integer {\n" | |
1003 | " size = 64; align = %u; signed = false;\n" | |
1004 | " map = clock.monotonic.value;\n" | |
1005 | "} := uint64_clock_monotonic_t;\n\n", | |
1006 | lttng_alignof(uint32_t) * CHAR_BIT, | |
1007 | lttng_alignof(uint64_t) * CHAR_BIT | |
1008 | ); | |
1009 | if (ret) | |
1010 | goto end; | |
1011 | ||
a90917c3 | 1012 | ret = _lttng_stream_packet_context_declare(session); |
9115fbdc MD |
1013 | if (ret) |
1014 | goto end; | |
1015 | ||
a90917c3 | 1016 | ret = _lttng_event_header_declare(session); |
9115fbdc MD |
1017 | if (ret) |
1018 | goto end; | |
1019 | ||
c099397a MD |
1020 | skip_session: |
1021 | list_for_each_entry(chan, &session->chan, list) { | |
a90917c3 | 1022 | ret = _lttng_channel_metadata_statedump(session, chan); |
c099397a MD |
1023 | if (ret) |
1024 | goto end; | |
1025 | } | |
1026 | ||
1027 | list_for_each_entry(event, &session->events, list) { | |
a90917c3 | 1028 | ret = _lttng_event_metadata_statedump(session, event->chan, event); |
c099397a MD |
1029 | if (ret) |
1030 | goto end; | |
1031 | } | |
1032 | session->metadata_dumped = 1; | |
1033 | end: | |
1034 | return ret; | |
1035 | } | |
1036 | ||
c0e31d2e | 1037 | /** |
a90917c3 | 1038 | * lttng_transport_register - LTT transport registration |
c0e31d2e MD |
1039 | * @transport: transport structure |
1040 | * | |
1041 | * Registers a transport which can be used as output to extract the data out of | |
1042 | * LTTng. The module calling this registration function must ensure that no | |
1043 | * trap-inducing code will be executed by the transport functions. E.g. | |
1044 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
1045 | * is made visible to the transport function. This registration acts as a | |
1046 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
1047 | * after its registration must it synchronize the TLBs. | |
1048 | */ | |
a90917c3 | 1049 | void lttng_transport_register(struct lttng_transport *transport) |
c0e31d2e MD |
1050 | { |
1051 | /* | |
1052 | * Make sure no page fault can be triggered by the module about to be | |
1053 | * registered. We deal with this here so we don't have to call | |
1054 | * vmalloc_sync_all() in each module's init. | |
1055 | */ | |
6d2a620c | 1056 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
1057 | |
1058 | mutex_lock(&sessions_mutex); | |
a90917c3 | 1059 | list_add_tail(&transport->node, <tng_transport_list); |
c0e31d2e MD |
1060 | mutex_unlock(&sessions_mutex); |
1061 | } | |
a90917c3 | 1062 | EXPORT_SYMBOL_GPL(lttng_transport_register); |
c0e31d2e MD |
1063 | |
1064 | /** | |
a90917c3 | 1065 | * lttng_transport_unregister - LTT transport unregistration |
c0e31d2e MD |
1066 | * @transport: transport structure |
1067 | */ | |
a90917c3 | 1068 | void lttng_transport_unregister(struct lttng_transport *transport) |
c0e31d2e MD |
1069 | { |
1070 | mutex_lock(&sessions_mutex); | |
1071 | list_del(&transport->node); | |
1072 | mutex_unlock(&sessions_mutex); | |
1073 | } | |
a90917c3 | 1074 | EXPORT_SYMBOL_GPL(lttng_transport_unregister); |
c0e31d2e | 1075 | |
a90917c3 | 1076 | static int __init lttng_events_init(void) |
4e3c1b9b | 1077 | { |
1c25284c MD |
1078 | int ret; |
1079 | ||
a90917c3 | 1080 | event_cache = KMEM_CACHE(lttng_event, 0); |
11b5a3c2 | 1081 | if (!event_cache) |
4e3c1b9b | 1082 | return -ENOMEM; |
80996790 | 1083 | ret = lttng_abi_init(); |
02119ee5 MD |
1084 | if (ret) |
1085 | goto error_abi; | |
4e3c1b9b | 1086 | return 0; |
02119ee5 | 1087 | error_abi: |
1c25284c MD |
1088 | kmem_cache_destroy(event_cache); |
1089 | return ret; | |
4e3c1b9b MD |
1090 | } |
1091 | ||
a90917c3 | 1092 | module_init(lttng_events_init); |
11b5a3c2 | 1093 | |
a90917c3 | 1094 | static void __exit lttng_events_exit(void) |
4e3c1b9b | 1095 | { |
a90917c3 | 1096 | struct lttng_session *session, *tmpsession; |
92e94819 | 1097 | |
80996790 | 1098 | lttng_abi_exit(); |
92e94819 | 1099 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
a90917c3 | 1100 | lttng_session_destroy(session); |
11b5a3c2 | 1101 | kmem_cache_destroy(event_cache); |
4e3c1b9b | 1102 | } |
92e94819 | 1103 | |
a90917c3 | 1104 | module_exit(lttng_events_exit); |
11b5a3c2 | 1105 | |
92e94819 MD |
1106 | MODULE_LICENSE("GPL and additional rights"); |
1107 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
1108 | MODULE_DESCRIPTION("LTTng Events"); |