Commit | Line | Data |
---|---|---|
4e3c1b9b | 1 | /* |
a90917c3 | 2 | * lttng-events.c |
4e3c1b9b | 3 | * |
4e3c1b9b | 4 | * Holds LTTng per-session event registry. |
17baffe2 | 5 | * |
886d51a3 MD |
6 | * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
7 | * | |
8 | * This library is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License as published by the Free Software Foundation; only | |
11 | * version 2.1 of the License. | |
12 | * | |
13 | * This library is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | * Lesser General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU Lesser General Public | |
19 | * License along with this library; if not, write to the Free Software | |
20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
4e3c1b9b MD |
21 | */ |
22 | ||
165eee70 MD |
23 | /* |
24 | * This page_alloc.h wrapper needs to be included before gfpflags.h because it | |
25 | * overrides a function with a define. | |
26 | */ | |
27 | #include "wrapper/page_alloc.h" | |
28 | ||
4e3c1b9b | 29 | #include <linux/module.h> |
c0e31d2e MD |
30 | #include <linux/list.h> |
31 | #include <linux/mutex.h> | |
32 | #include <linux/sched.h> | |
11b5a3c2 | 33 | #include <linux/slab.h> |
c099397a | 34 | #include <linux/jiffies.h> |
99dc9597 | 35 | #include <linux/utsname.h> |
abc0446a | 36 | #include <linux/err.h> |
30913c47 ML |
37 | #include <linux/vmalloc.h> |
38 | ||
a864fb02 | 39 | #include "wrapper/uuid.h" |
b13f3ebe | 40 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
a82c63f1 | 41 | #include "wrapper/random.h" |
3a523f5b | 42 | #include "wrapper/tracepoint.h" |
b8590f40 | 43 | #include "lttng-kernel-version.h" |
a90917c3 MD |
44 | #include "lttng-events.h" |
45 | #include "lttng-tracer.h" | |
6dccd6c1 | 46 | #include "lttng-abi-old.h" |
dd8227fa | 47 | #include "wrapper/vzalloc.h" |
b63af41c MD |
48 | #include "wrapper/ringbuffer/backend.h" |
49 | #include "wrapper/ringbuffer/frontend.h" | |
4e3c1b9b | 50 | |
d83004aa JD |
51 | #define METADATA_CACHE_DEFAULT_SIZE 4096 |
52 | ||
4e3c1b9b | 53 | static LIST_HEAD(sessions); |
a90917c3 | 54 | static LIST_HEAD(lttng_transport_list); |
d83004aa JD |
55 | /* |
56 | * Protect the sessions and metadata caches. | |
57 | */ | |
4e3c1b9b MD |
58 | static DEFINE_MUTEX(sessions_mutex); |
59 | static struct kmem_cache *event_cache; | |
60 | ||
a90917c3 MD |
61 | static void _lttng_event_destroy(struct lttng_event *event); |
62 | static void _lttng_channel_destroy(struct lttng_channel *chan); | |
63 | static int _lttng_event_unregister(struct lttng_event *event); | |
c099397a | 64 | static |
a90917c3 MD |
65 | int _lttng_event_metadata_statedump(struct lttng_session *session, |
66 | struct lttng_channel *chan, | |
67 | struct lttng_event *event); | |
c099397a | 68 | static |
a90917c3 | 69 | int _lttng_session_metadata_statedump(struct lttng_session *session); |
d83004aa JD |
70 | static |
71 | void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream); | |
c099397a | 72 | |
c099397a | 73 | void synchronize_trace(void) |
abcca994 MD |
74 | { |
75 | synchronize_sched(); | |
b8590f40 MD |
76 | #if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) |
77 | #ifdef CONFIG_PREEMPT_RT_FULL | |
78 | synchronize_rcu(); | |
79 | #endif | |
80 | #else /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */ | |
abcca994 MD |
81 | #ifdef CONFIG_PREEMPT_RT |
82 | synchronize_rcu(); | |
83 | #endif | |
b8590f40 | 84 | #endif /* (LINUX_VERSION_CODE >= KERNEL_VERSION(3,4,0)) */ |
abcca994 MD |
85 | } |
86 | ||
a90917c3 | 87 | struct lttng_session *lttng_session_create(void) |
4e3c1b9b | 88 | { |
a90917c3 | 89 | struct lttng_session *session; |
d83004aa | 90 | struct lttng_metadata_cache *metadata_cache; |
4e3c1b9b MD |
91 | |
92 | mutex_lock(&sessions_mutex); | |
a90917c3 | 93 | session = kzalloc(sizeof(struct lttng_session), GFP_KERNEL); |
4e3c1b9b | 94 | if (!session) |
d83004aa | 95 | goto err; |
4e3c1b9b | 96 | INIT_LIST_HEAD(&session->chan); |
f3d01b96 | 97 | INIT_LIST_HEAD(&session->events); |
d793d5e1 | 98 | uuid_le_gen(&session->uuid); |
d83004aa JD |
99 | |
100 | metadata_cache = kzalloc(sizeof(struct lttng_metadata_cache), | |
101 | GFP_KERNEL); | |
102 | if (!metadata_cache) | |
103 | goto err_free_session; | |
dd8227fa | 104 | metadata_cache->data = lttng_vzalloc(METADATA_CACHE_DEFAULT_SIZE); |
d83004aa JD |
105 | if (!metadata_cache->data) |
106 | goto err_free_cache; | |
107 | metadata_cache->cache_alloc = METADATA_CACHE_DEFAULT_SIZE; | |
108 | kref_init(&metadata_cache->refcount); | |
9a0aa3b1 | 109 | mutex_init(&metadata_cache->lock); |
d83004aa JD |
110 | session->metadata_cache = metadata_cache; |
111 | INIT_LIST_HEAD(&metadata_cache->metadata_stream); | |
a36580d5 MD |
112 | memcpy(&metadata_cache->uuid, &session->uuid, |
113 | sizeof(metadata_cache->uuid)); | |
4e3c1b9b MD |
114 | list_add(&session->list, &sessions); |
115 | mutex_unlock(&sessions_mutex); | |
116 | return session; | |
d83004aa JD |
117 | |
118 | err_free_cache: | |
119 | kfree(metadata_cache); | |
120 | err_free_session: | |
121 | kfree(session); | |
122 | err: | |
123 | mutex_unlock(&sessions_mutex); | |
124 | return NULL; | |
125 | } | |
126 | ||
127 | void metadata_cache_destroy(struct kref *kref) | |
128 | { | |
129 | struct lttng_metadata_cache *cache = | |
130 | container_of(kref, struct lttng_metadata_cache, refcount); | |
30913c47 | 131 | vfree(cache->data); |
d83004aa | 132 | kfree(cache); |
4e3c1b9b MD |
133 | } |
134 | ||
a90917c3 | 135 | void lttng_session_destroy(struct lttng_session *session) |
4e3c1b9b | 136 | { |
a90917c3 MD |
137 | struct lttng_channel *chan, *tmpchan; |
138 | struct lttng_event *event, *tmpevent; | |
d83004aa | 139 | struct lttng_metadata_stream *metadata_stream; |
dda6a249 | 140 | int ret; |
4e3c1b9b MD |
141 | |
142 | mutex_lock(&sessions_mutex); | |
52fc2e1f | 143 | ACCESS_ONCE(session->active) = 0; |
1ec65de1 MD |
144 | list_for_each_entry(chan, &session->chan, list) { |
145 | ret = lttng_syscalls_unregister(chan); | |
146 | WARN_ON(ret); | |
147 | } | |
dda6a249 | 148 | list_for_each_entry(event, &session->events, list) { |
a90917c3 | 149 | ret = _lttng_event_unregister(event); |
dda6a249 MD |
150 | WARN_ON(ret); |
151 | } | |
abcca994 | 152 | synchronize_trace(); /* Wait for in-flight events to complete */ |
4e3c1b9b | 153 | list_for_each_entry_safe(event, tmpevent, &session->events, list) |
a90917c3 | 154 | _lttng_event_destroy(event); |
d83004aa JD |
155 | list_for_each_entry_safe(chan, tmpchan, &session->chan, list) { |
156 | BUG_ON(chan->channel_type == METADATA_CHANNEL); | |
a90917c3 | 157 | _lttng_channel_destroy(chan); |
d83004aa JD |
158 | } |
159 | list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list) | |
160 | _lttng_metadata_channel_hangup(metadata_stream); | |
161 | kref_put(&session->metadata_cache->refcount, metadata_cache_destroy); | |
4e3c1b9b MD |
162 | list_del(&session->list); |
163 | mutex_unlock(&sessions_mutex); | |
164 | kfree(session); | |
165 | } | |
166 | ||
a90917c3 | 167 | int lttng_session_enable(struct lttng_session *session) |
c0e31d2e MD |
168 | { |
169 | int ret = 0; | |
a90917c3 | 170 | struct lttng_channel *chan; |
c0e31d2e MD |
171 | |
172 | mutex_lock(&sessions_mutex); | |
173 | if (session->active) { | |
174 | ret = -EBUSY; | |
175 | goto end; | |
176 | } | |
c099397a MD |
177 | |
178 | /* | |
179 | * Snapshot the number of events per channel to know the type of header | |
180 | * we need to use. | |
181 | */ | |
182 | list_for_each_entry(chan, &session->chan, list) { | |
183 | if (chan->header_type) | |
184 | continue; /* don't change it if session stop/restart */ | |
185 | if (chan->free_event_id < 31) | |
186 | chan->header_type = 1; /* compact */ | |
187 | else | |
188 | chan->header_type = 2; /* large */ | |
189 | } | |
190 | ||
b63af41c | 191 | /* Clear each stream's quiescent state. */ |
d36743ab MD |
192 | list_for_each_entry(chan, &session->chan, list) { |
193 | if (chan->channel_type != METADATA_CHANNEL) | |
194 | lib_ring_buffer_clear_quiescent_channel(chan->chan); | |
195 | } | |
b63af41c | 196 | |
52fc2e1f | 197 | ACCESS_ONCE(session->active) = 1; |
8070f5c0 | 198 | ACCESS_ONCE(session->been_active) = 1; |
a90917c3 | 199 | ret = _lttng_session_metadata_statedump(session); |
c337ddc2 MD |
200 | if (ret) { |
201 | ACCESS_ONCE(session->active) = 0; | |
202 | goto end; | |
203 | } | |
204 | ret = lttng_statedump_start(session); | |
360f38ea | 205 | if (ret) |
c099397a | 206 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
207 | end: |
208 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 209 | return ret; |
c0e31d2e MD |
210 | } |
211 | ||
a90917c3 | 212 | int lttng_session_disable(struct lttng_session *session) |
c0e31d2e MD |
213 | { |
214 | int ret = 0; | |
b63af41c | 215 | struct lttng_channel *chan; |
c0e31d2e MD |
216 | |
217 | mutex_lock(&sessions_mutex); | |
218 | if (!session->active) { | |
219 | ret = -EBUSY; | |
220 | goto end; | |
221 | } | |
52fc2e1f | 222 | ACCESS_ONCE(session->active) = 0; |
b63af41c MD |
223 | |
224 | /* Set each stream's quiescent state. */ | |
d36743ab MD |
225 | list_for_each_entry(chan, &session->chan, list) { |
226 | if (chan->channel_type != METADATA_CHANNEL) | |
227 | lib_ring_buffer_set_quiescent_channel(chan->chan); | |
228 | } | |
b63af41c | 229 | |
c0e31d2e MD |
230 | end: |
231 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 232 | return ret; |
c0e31d2e MD |
233 | } |
234 | ||
a90917c3 | 235 | int lttng_channel_enable(struct lttng_channel *channel) |
e64957da MD |
236 | { |
237 | int old; | |
238 | ||
d83004aa | 239 | if (channel->channel_type == METADATA_CHANNEL) |
c6485006 | 240 | return -EPERM; |
e64957da MD |
241 | old = xchg(&channel->enabled, 1); |
242 | if (old) | |
243 | return -EEXIST; | |
244 | return 0; | |
245 | } | |
246 | ||
a90917c3 | 247 | int lttng_channel_disable(struct lttng_channel *channel) |
e64957da MD |
248 | { |
249 | int old; | |
250 | ||
d83004aa | 251 | if (channel->channel_type == METADATA_CHANNEL) |
c6485006 | 252 | return -EPERM; |
e64957da MD |
253 | old = xchg(&channel->enabled, 0); |
254 | if (!old) | |
255 | return -EEXIST; | |
256 | return 0; | |
257 | } | |
258 | ||
a90917c3 | 259 | int lttng_event_enable(struct lttng_event *event) |
e64957da MD |
260 | { |
261 | int old; | |
262 | ||
d83004aa | 263 | if (event->chan->channel_type == METADATA_CHANNEL) |
c6485006 | 264 | return -EPERM; |
e64957da MD |
265 | old = xchg(&event->enabled, 1); |
266 | if (old) | |
267 | return -EEXIST; | |
268 | return 0; | |
269 | } | |
270 | ||
a90917c3 | 271 | int lttng_event_disable(struct lttng_event *event) |
e64957da MD |
272 | { |
273 | int old; | |
274 | ||
d83004aa | 275 | if (event->chan->channel_type == METADATA_CHANNEL) |
c6485006 | 276 | return -EPERM; |
e64957da MD |
277 | old = xchg(&event->enabled, 0); |
278 | if (!old) | |
279 | return -EEXIST; | |
280 | return 0; | |
281 | } | |
282 | ||
a90917c3 | 283 | static struct lttng_transport *lttng_transport_find(const char *name) |
f3d01b96 | 284 | { |
a90917c3 | 285 | struct lttng_transport *transport; |
f3d01b96 | 286 | |
a90917c3 | 287 | list_for_each_entry(transport, <tng_transport_list, node) { |
f3d01b96 MD |
288 | if (!strcmp(transport->name, name)) |
289 | return transport; | |
290 | } | |
291 | return NULL; | |
292 | } | |
293 | ||
a90917c3 | 294 | struct lttng_channel *lttng_channel_create(struct lttng_session *session, |
5dbbdb43 MD |
295 | const char *transport_name, |
296 | void *buf_addr, | |
4e3c1b9b MD |
297 | size_t subbuf_size, size_t num_subbuf, |
298 | unsigned int switch_timer_interval, | |
d83004aa JD |
299 | unsigned int read_timer_interval, |
300 | enum channel_type channel_type) | |
4e3c1b9b | 301 | { |
a90917c3 MD |
302 | struct lttng_channel *chan; |
303 | struct lttng_transport *transport = NULL; | |
4e3c1b9b MD |
304 | |
305 | mutex_lock(&sessions_mutex); | |
d83004aa | 306 | if (session->been_active && channel_type != METADATA_CHANNEL) |
e5382b6d | 307 | goto active; /* Refuse to add channel to active session */ |
a90917c3 | 308 | transport = lttng_transport_find(transport_name); |
f3d01b96 MD |
309 | if (!transport) { |
310 | printk(KERN_WARNING "LTTng transport %s not found\n", | |
311 | transport_name); | |
c0e31d2e | 312 | goto notransport; |
f3d01b96 | 313 | } |
a33c9927 MD |
314 | if (!try_module_get(transport->owner)) { |
315 | printk(KERN_WARNING "LTT : Can't lock transport module.\n"); | |
316 | goto notransport; | |
317 | } | |
a90917c3 | 318 | chan = kzalloc(sizeof(struct lttng_channel), GFP_KERNEL); |
4e3c1b9b | 319 | if (!chan) |
c0e31d2e | 320 | goto nomem; |
4e3c1b9b | 321 | chan->session = session; |
05d32c64 | 322 | chan->id = session->free_chan_id++; |
3b731ab1 | 323 | chan->ops = &transport->ops; |
125b4df4 MD |
324 | /* |
325 | * Note: the channel creation op already writes into the packet | |
326 | * headers. Therefore the "chan" information used as input | |
327 | * should be already accessible. | |
328 | */ | |
5f5ddf01 MD |
329 | chan->chan = transport->ops.channel_create(transport_name, |
330 | chan, buf_addr, subbuf_size, num_subbuf, | |
331 | switch_timer_interval, read_timer_interval); | |
f3d01b96 MD |
332 | if (!chan->chan) |
333 | goto create_error; | |
e64957da | 334 | chan->enabled = 1; |
a33c9927 | 335 | chan->transport = transport; |
d83004aa | 336 | chan->channel_type = channel_type; |
4e3c1b9b MD |
337 | list_add(&chan->list, &session->chan); |
338 | mutex_unlock(&sessions_mutex); | |
339 | return chan; | |
340 | ||
f3d01b96 MD |
341 | create_error: |
342 | kfree(chan); | |
c0e31d2e | 343 | nomem: |
a33c9927 MD |
344 | if (transport) |
345 | module_put(transport->owner); | |
c0e31d2e | 346 | notransport: |
e5382b6d | 347 | active: |
4e3c1b9b MD |
348 | mutex_unlock(&sessions_mutex); |
349 | return NULL; | |
350 | } | |
351 | ||
352 | /* | |
d83004aa JD |
353 | * Only used internally at session destruction for per-cpu channels, and |
354 | * when metadata channel is released. | |
355 | * Needs to be called with sessions mutex held. | |
4e3c1b9b | 356 | */ |
aa7c23a9 | 357 | static |
a90917c3 | 358 | void _lttng_channel_destroy(struct lttng_channel *chan) |
4e3c1b9b | 359 | { |
11b5a3c2 | 360 | chan->ops->channel_destroy(chan->chan); |
a33c9927 | 361 | module_put(chan->transport->owner); |
4e3c1b9b | 362 | list_del(&chan->list); |
8070f5c0 | 363 | lttng_destroy_context(chan->ctx); |
4e3c1b9b MD |
364 | kfree(chan); |
365 | } | |
366 | ||
d83004aa JD |
367 | void lttng_metadata_channel_destroy(struct lttng_channel *chan) |
368 | { | |
369 | BUG_ON(chan->channel_type != METADATA_CHANNEL); | |
370 | ||
371 | /* Protect the metadata cache with the sessions_mutex. */ | |
372 | mutex_lock(&sessions_mutex); | |
373 | _lttng_channel_destroy(chan); | |
374 | mutex_unlock(&sessions_mutex); | |
375 | } | |
376 | EXPORT_SYMBOL_GPL(lttng_metadata_channel_destroy); | |
377 | ||
378 | static | |
379 | void _lttng_metadata_channel_hangup(struct lttng_metadata_stream *stream) | |
380 | { | |
381 | stream->finalized = 1; | |
382 | wake_up_interruptible(&stream->read_wait); | |
383 | } | |
384 | ||
e5382b6d MD |
385 | /* |
386 | * Supports event creation while tracing session is active. | |
387 | */ | |
a90917c3 | 388 | struct lttng_event *lttng_event_create(struct lttng_channel *chan, |
d6d808f3 | 389 | struct lttng_kernel_event *event_param, |
259b6cb3 MD |
390 | void *filter, |
391 | const struct lttng_event_desc *internal_desc) | |
4e3c1b9b | 392 | { |
a90917c3 | 393 | struct lttng_event *event; |
3d084699 | 394 | int ret; |
4e3c1b9b MD |
395 | |
396 | mutex_lock(&sessions_mutex); | |
abc0446a | 397 | if (chan->free_event_id == -1U) { |
4cf0bf51 | 398 | ret = -EMFILE; |
e5382b6d | 399 | goto full; |
abc0446a | 400 | } |
4e3c1b9b | 401 | /* |
dda6a249 MD |
402 | * This is O(n^2) (for each event, the loop is called at event |
403 | * creation). Might require a hash if we have lots of events. | |
4e3c1b9b | 404 | */ |
abc0446a MD |
405 | list_for_each_entry(event, &chan->session->events, list) { |
406 | if (!strcmp(event->desc->name, event_param->name)) { | |
f046a95d MD |
407 | /* |
408 | * Allow events with the same name to appear in | |
409 | * different channels. | |
410 | */ | |
411 | if (event->chan == chan) { | |
412 | ret = -EEXIST; | |
413 | goto exist; | |
414 | } | |
abc0446a MD |
415 | } |
416 | } | |
11b5a3c2 | 417 | event = kmem_cache_zalloc(event_cache, GFP_KERNEL); |
abc0446a | 418 | if (!event) { |
4cf0bf51 | 419 | ret = -ENOMEM; |
4e3c1b9b | 420 | goto cache_error; |
abc0446a | 421 | } |
4e3c1b9b MD |
422 | event->chan = chan; |
423 | event->filter = filter; | |
e5382b6d | 424 | event->id = chan->free_event_id++; |
e64957da | 425 | event->enabled = 1; |
d6d808f3 | 426 | event->instrumentation = event_param->instrumentation; |
a90917c3 | 427 | /* Populate lttng_event structure before tracepoint registration. */ |
e5382b6d | 428 | smp_wmb(); |
d6d808f3 | 429 | switch (event_param->instrumentation) { |
ab2277d6 | 430 | case LTTNG_KERNEL_TRACEPOINT: |
a90917c3 | 431 | event->desc = lttng_event_get(event_param->name); |
abc0446a | 432 | if (!event->desc) { |
4cf0bf51 | 433 | ret = -ENOENT; |
d3dbe23c | 434 | goto register_error; |
abc0446a | 435 | } |
20591cf7 | 436 | ret = lttng_wrapper_tracepoint_probe_register(event->desc->kname, |
d3dbe23c MD |
437 | event->desc->probe_callback, |
438 | event); | |
abc0446a | 439 | if (ret) { |
4cf0bf51 | 440 | ret = -EINVAL; |
11b5a3c2 | 441 | goto register_error; |
abc0446a | 442 | } |
baf20995 | 443 | break; |
ab2277d6 | 444 | case LTTNG_KERNEL_KPROBE: |
30bdb6e4 | 445 | ret = lttng_kprobes_register(event_param->name, |
f17701fb MD |
446 | event_param->u.kprobe.symbol_name, |
447 | event_param->u.kprobe.offset, | |
448 | event_param->u.kprobe.addr, | |
449 | event); | |
abc0446a | 450 | if (ret) { |
4cf0bf51 | 451 | ret = -EINVAL; |
d6d808f3 | 452 | goto register_error; |
abc0446a | 453 | } |
edeb3137 MD |
454 | ret = try_module_get(event->desc->owner); |
455 | WARN_ON_ONCE(!ret); | |
d6d808f3 | 456 | break; |
7371f44c MD |
457 | case LTTNG_KERNEL_KRETPROBE: |
458 | { | |
a90917c3 | 459 | struct lttng_event *event_return; |
7371f44c MD |
460 | |
461 | /* kretprobe defines 2 events */ | |
462 | event_return = | |
463 | kmem_cache_zalloc(event_cache, GFP_KERNEL); | |
abc0446a | 464 | if (!event_return) { |
4cf0bf51 | 465 | ret = -ENOMEM; |
7371f44c | 466 | goto register_error; |
abc0446a | 467 | } |
7371f44c MD |
468 | event_return->chan = chan; |
469 | event_return->filter = filter; | |
470 | event_return->id = chan->free_event_id++; | |
471 | event_return->enabled = 1; | |
472 | event_return->instrumentation = event_param->instrumentation; | |
473 | /* | |
a90917c3 | 474 | * Populate lttng_event structure before kretprobe registration. |
7371f44c MD |
475 | */ |
476 | smp_wmb(); | |
477 | ret = lttng_kretprobes_register(event_param->name, | |
478 | event_param->u.kretprobe.symbol_name, | |
479 | event_param->u.kretprobe.offset, | |
480 | event_param->u.kretprobe.addr, | |
481 | event, event_return); | |
482 | if (ret) { | |
483 | kmem_cache_free(event_cache, event_return); | |
4cf0bf51 | 484 | ret = -EINVAL; |
7371f44c MD |
485 | goto register_error; |
486 | } | |
487 | /* Take 2 refs on the module: one per event. */ | |
488 | ret = try_module_get(event->desc->owner); | |
489 | WARN_ON_ONCE(!ret); | |
490 | ret = try_module_get(event->desc->owner); | |
491 | WARN_ON_ONCE(!ret); | |
a90917c3 | 492 | ret = _lttng_event_metadata_statedump(chan->session, chan, |
7371f44c | 493 | event_return); |
abc0446a | 494 | WARN_ON_ONCE(ret > 0); |
7371f44c MD |
495 | if (ret) { |
496 | kmem_cache_free(event_cache, event_return); | |
497 | module_put(event->desc->owner); | |
498 | module_put(event->desc->owner); | |
499 | goto statedump_error; | |
500 | } | |
501 | list_add(&event_return->list, &chan->session->events); | |
502 | break; | |
503 | } | |
ab2277d6 | 504 | case LTTNG_KERNEL_FUNCTION: |
30bdb6e4 | 505 | ret = lttng_ftrace_register(event_param->name, |
e0a7a7c4 MD |
506 | event_param->u.ftrace.symbol_name, |
507 | event); | |
abc0446a | 508 | if (ret) { |
e0a7a7c4 | 509 | goto register_error; |
abc0446a | 510 | } |
edeb3137 MD |
511 | ret = try_module_get(event->desc->owner); |
512 | WARN_ON_ONCE(!ret); | |
e0a7a7c4 | 513 | break; |
1ec65de1 | 514 | case LTTNG_KERNEL_NOOP: |
259b6cb3 | 515 | event->desc = internal_desc; |
abc0446a | 516 | if (!event->desc) { |
4cf0bf51 | 517 | ret = -EINVAL; |
259b6cb3 | 518 | goto register_error; |
abc0446a | 519 | } |
1ec65de1 | 520 | break; |
baf20995 MD |
521 | default: |
522 | WARN_ON_ONCE(1); | |
4cf0bf51 | 523 | ret = -EINVAL; |
df07930b | 524 | goto register_error; |
baf20995 | 525 | } |
a90917c3 | 526 | ret = _lttng_event_metadata_statedump(chan->session, chan, event); |
abc0446a MD |
527 | WARN_ON_ONCE(ret > 0); |
528 | if (ret) { | |
c099397a | 529 | goto statedump_error; |
abc0446a | 530 | } |
dda6a249 | 531 | list_add(&event->list, &chan->session->events); |
11b5a3c2 | 532 | mutex_unlock(&sessions_mutex); |
4e3c1b9b MD |
533 | return event; |
534 | ||
c099397a | 535 | statedump_error: |
259b6cb3 | 536 | /* If a statedump error occurs, events will not be readable. */ |
11b5a3c2 | 537 | register_error: |
11b5a3c2 | 538 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
539 | cache_error: |
540 | exist: | |
e5382b6d | 541 | full: |
4e3c1b9b | 542 | mutex_unlock(&sessions_mutex); |
4cf0bf51 | 543 | return ERR_PTR(ret); |
4e3c1b9b MD |
544 | } |
545 | ||
546 | /* | |
547 | * Only used internally at session destruction. | |
548 | */ | |
a90917c3 | 549 | int _lttng_event_unregister(struct lttng_event *event) |
4e3c1b9b | 550 | { |
11b5a3c2 MD |
551 | int ret = -EINVAL; |
552 | ||
38d024ae | 553 | switch (event->instrumentation) { |
ab2277d6 | 554 | case LTTNG_KERNEL_TRACEPOINT: |
20591cf7 | 555 | ret = lttng_wrapper_tracepoint_probe_unregister(event->desc->kname, |
85a9ca7f | 556 | event->desc->probe_callback, |
11b5a3c2 MD |
557 | event); |
558 | if (ret) | |
559 | return ret; | |
baf20995 | 560 | break; |
ab2277d6 | 561 | case LTTNG_KERNEL_KPROBE: |
f17701fb | 562 | lttng_kprobes_unregister(event); |
d6d808f3 MD |
563 | ret = 0; |
564 | break; | |
7371f44c MD |
565 | case LTTNG_KERNEL_KRETPROBE: |
566 | lttng_kretprobes_unregister(event); | |
567 | ret = 0; | |
568 | break; | |
ab2277d6 | 569 | case LTTNG_KERNEL_FUNCTION: |
e0a7a7c4 MD |
570 | lttng_ftrace_unregister(event); |
571 | ret = 0; | |
572 | break; | |
259b6cb3 MD |
573 | case LTTNG_KERNEL_NOOP: |
574 | ret = 0; | |
575 | break; | |
baf20995 MD |
576 | default: |
577 | WARN_ON_ONCE(1); | |
578 | } | |
dda6a249 MD |
579 | return ret; |
580 | } | |
581 | ||
582 | /* | |
583 | * Only used internally at session destruction. | |
584 | */ | |
be066e6c | 585 | static |
a90917c3 | 586 | void _lttng_event_destroy(struct lttng_event *event) |
dda6a249 | 587 | { |
edeb3137 MD |
588 | switch (event->instrumentation) { |
589 | case LTTNG_KERNEL_TRACEPOINT: | |
a90917c3 | 590 | lttng_event_put(event->desc); |
edeb3137 MD |
591 | break; |
592 | case LTTNG_KERNEL_KPROBE: | |
593 | module_put(event->desc->owner); | |
594 | lttng_kprobes_destroy_private(event); | |
595 | break; | |
7371f44c MD |
596 | case LTTNG_KERNEL_KRETPROBE: |
597 | module_put(event->desc->owner); | |
598 | lttng_kretprobes_destroy_private(event); | |
599 | break; | |
edeb3137 MD |
600 | case LTTNG_KERNEL_FUNCTION: |
601 | module_put(event->desc->owner); | |
602 | lttng_ftrace_destroy_private(event); | |
603 | break; | |
259b6cb3 MD |
604 | case LTTNG_KERNEL_NOOP: |
605 | break; | |
edeb3137 MD |
606 | default: |
607 | WARN_ON_ONCE(1); | |
608 | } | |
dda6a249 | 609 | list_del(&event->list); |
8070f5c0 | 610 | lttng_destroy_context(event->ctx); |
11b5a3c2 | 611 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
612 | } |
613 | ||
1ec3f75a | 614 | /* |
d83004aa JD |
615 | * Serialize at most one packet worth of metadata into a metadata |
616 | * channel. | |
9a0aa3b1 MD |
617 | * We grab the metadata cache mutex to get exclusive access to our metadata |
618 | * buffer and to the metadata cache. Exclusive access to the metadata buffer | |
619 | * allows us to do racy operations such as looking for remaining space left in | |
620 | * packet and write, since mutual exclusion protects us from concurrent writes. | |
621 | * Mutual exclusion on the metadata cache allow us to read the cache content | |
622 | * without racing against reallocation of the cache by updates. | |
35097f36 JD |
623 | * Returns the number of bytes written in the channel, 0 if no data |
624 | * was written and a negative value on error. | |
1ec3f75a | 625 | */ |
b3b8072b MD |
626 | int lttng_metadata_output_channel(struct lttng_metadata_stream *stream, |
627 | struct channel *chan) | |
d83004aa JD |
628 | { |
629 | struct lib_ring_buffer_ctx ctx; | |
630 | int ret = 0; | |
631 | size_t len, reserve_len; | |
632 | ||
f613e3e6 | 633 | /* |
9a0aa3b1 MD |
634 | * Ensure we support mutiple get_next / put sequences followed by |
635 | * put_next. The metadata cache lock protects reading the metadata | |
636 | * cache. It can indeed be read concurrently by "get_next_subbuf" and | |
637 | * "flush" operations on the buffer invoked by different processes. | |
638 | * Moreover, since the metadata cache memory can be reallocated, we | |
639 | * need to have exclusive access against updates even though we only | |
640 | * read it. | |
f613e3e6 | 641 | */ |
9a0aa3b1 | 642 | mutex_lock(&stream->metadata_cache->lock); |
f613e3e6 MD |
643 | WARN_ON(stream->metadata_in < stream->metadata_out); |
644 | if (stream->metadata_in != stream->metadata_out) | |
de23d59d | 645 | goto end; |
f613e3e6 | 646 | |
d83004aa | 647 | len = stream->metadata_cache->metadata_written - |
f613e3e6 | 648 | stream->metadata_in; |
9de2c215 | 649 | if (!len) |
de23d59d | 650 | goto end; |
d83004aa | 651 | reserve_len = min_t(size_t, |
b3b8072b | 652 | stream->transport->ops.packet_avail_size(chan), |
d83004aa | 653 | len); |
b3b8072b | 654 | lib_ring_buffer_ctx_init(&ctx, chan, NULL, reserve_len, |
d83004aa JD |
655 | sizeof(char), -1); |
656 | /* | |
657 | * If reservation failed, return an error to the caller. | |
658 | */ | |
b3b8072b | 659 | ret = stream->transport->ops.event_reserve(&ctx, 0); |
d83004aa JD |
660 | if (ret != 0) { |
661 | printk(KERN_WARNING "LTTng: Metadata event reservation failed\n"); | |
662 | goto end; | |
663 | } | |
b3b8072b | 664 | stream->transport->ops.event_write(&ctx, |
f613e3e6 | 665 | stream->metadata_cache->data + stream->metadata_in, |
d83004aa | 666 | reserve_len); |
b3b8072b | 667 | stream->transport->ops.event_commit(&ctx); |
f613e3e6 | 668 | stream->metadata_in += reserve_len; |
d83004aa JD |
669 | ret = reserve_len; |
670 | ||
671 | end: | |
9a0aa3b1 | 672 | mutex_unlock(&stream->metadata_cache->lock); |
d83004aa JD |
673 | return ret; |
674 | } | |
675 | ||
676 | /* | |
677 | * Write the metadata to the metadata cache. | |
678 | * Must be called with sessions_mutex held. | |
9a0aa3b1 MD |
679 | * The metadata cache lock protects us from concurrent read access from |
680 | * thread outputting metadata content to ring buffer. | |
d83004aa | 681 | */ |
a90917c3 | 682 | int lttng_metadata_printf(struct lttng_session *session, |
c099397a MD |
683 | const char *fmt, ...) |
684 | { | |
c099397a | 685 | char *str; |
d83004aa | 686 | size_t len; |
c099397a | 687 | va_list ap; |
d83004aa | 688 | struct lttng_metadata_stream *stream; |
c099397a MD |
689 | |
690 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
691 | ||
692 | va_start(ap, fmt); | |
693 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
694 | va_end(ap); | |
695 | if (!str) | |
696 | return -ENOMEM; | |
697 | ||
1ec3f75a | 698 | len = strlen(str); |
9a0aa3b1 | 699 | mutex_lock(&session->metadata_cache->lock); |
d83004aa JD |
700 | if (session->metadata_cache->metadata_written + len > |
701 | session->metadata_cache->cache_alloc) { | |
702 | char *tmp_cache_realloc; | |
703 | unsigned int tmp_cache_alloc_size; | |
704 | ||
705 | tmp_cache_alloc_size = max_t(unsigned int, | |
706 | session->metadata_cache->cache_alloc + len, | |
707 | session->metadata_cache->cache_alloc << 1); | |
dd8227fa | 708 | tmp_cache_realloc = lttng_vzalloc(tmp_cache_alloc_size); |
d83004aa JD |
709 | if (!tmp_cache_realloc) |
710 | goto err; | |
30913c47 ML |
711 | if (session->metadata_cache->data) { |
712 | memcpy(tmp_cache_realloc, | |
713 | session->metadata_cache->data, | |
714 | session->metadata_cache->cache_alloc); | |
715 | vfree(session->metadata_cache->data); | |
716 | } | |
717 | ||
d83004aa JD |
718 | session->metadata_cache->cache_alloc = tmp_cache_alloc_size; |
719 | session->metadata_cache->data = tmp_cache_realloc; | |
c099397a | 720 | } |
d83004aa JD |
721 | memcpy(session->metadata_cache->data + |
722 | session->metadata_cache->metadata_written, | |
723 | str, len); | |
724 | session->metadata_cache->metadata_written += len; | |
9a0aa3b1 | 725 | mutex_unlock(&session->metadata_cache->lock); |
c099397a | 726 | kfree(str); |
d83004aa JD |
727 | |
728 | list_for_each_entry(stream, &session->metadata_cache->metadata_stream, list) | |
729 | wake_up_interruptible(&stream->read_wait); | |
730 | ||
731 | return 0; | |
732 | ||
733 | err: | |
9a0aa3b1 | 734 | mutex_unlock(&session->metadata_cache->lock); |
d83004aa JD |
735 | kfree(str); |
736 | return -ENOMEM; | |
c099397a MD |
737 | } |
738 | ||
d83004aa JD |
739 | /* |
740 | * Must be called with sessions_mutex held. | |
741 | */ | |
c099397a | 742 | static |
a90917c3 | 743 | int _lttng_field_statedump(struct lttng_session *session, |
8070f5c0 | 744 | const struct lttng_event_field *field) |
c099397a | 745 | { |
c099397a | 746 | int ret = 0; |
c099397a | 747 | |
8070f5c0 MD |
748 | switch (field->type.atype) { |
749 | case atype_integer: | |
750 | ret = lttng_metadata_printf(session, | |
244465ab | 751 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s;\n", |
8070f5c0 MD |
752 | field->type.u.basic.integer.size, |
753 | field->type.u.basic.integer.alignment, | |
754 | field->type.u.basic.integer.signedness, | |
755 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
756 | ? "none" | |
757 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
758 | ? "UTF8" | |
759 | : "ASCII", | |
760 | field->type.u.basic.integer.base, | |
c099397a | 761 | #ifdef __BIG_ENDIAN |
8070f5c0 | 762 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
c099397a | 763 | #else |
8070f5c0 | 764 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
c099397a | 765 | #endif |
8070f5c0 MD |
766 | field->name); |
767 | break; | |
768 | case atype_enum: | |
769 | ret = lttng_metadata_printf(session, | |
244465ab | 770 | " %s _%s;\n", |
8070f5c0 MD |
771 | field->type.u.basic.enumeration.name, |
772 | field->name); | |
773 | break; | |
774 | case atype_array: | |
775 | { | |
776 | const struct lttng_basic_type *elem_type; | |
777 | ||
778 | elem_type = &field->type.u.array.elem_type; | |
779 | ret = lttng_metadata_printf(session, | |
244465ab | 780 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[%u];\n", |
8070f5c0 MD |
781 | elem_type->u.basic.integer.size, |
782 | elem_type->u.basic.integer.alignment, | |
783 | elem_type->u.basic.integer.signedness, | |
784 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
785 | ? "none" | |
786 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
787 | ? "UTF8" | |
788 | : "ASCII", | |
789 | elem_type->u.basic.integer.base, | |
8fa75f34 | 790 | #ifdef __BIG_ENDIAN |
8070f5c0 | 791 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
8fa75f34 | 792 | #else |
8070f5c0 | 793 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
8fa75f34 | 794 | #endif |
8070f5c0 MD |
795 | field->name, field->type.u.array.length); |
796 | break; | |
797 | } | |
798 | case atype_sequence: | |
799 | { | |
800 | const struct lttng_basic_type *elem_type; | |
801 | const struct lttng_basic_type *length_type; | |
802 | ||
803 | elem_type = &field->type.u.sequence.elem_type; | |
804 | length_type = &field->type.u.sequence.length_type; | |
805 | ret = lttng_metadata_printf(session, | |
806 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
8070f5c0 | 807 | length_type->u.basic.integer.size, |
32257272 | 808 | (unsigned int) length_type->u.basic.integer.alignment, |
8070f5c0 MD |
809 | length_type->u.basic.integer.signedness, |
810 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
811 | ? "none" | |
0635cdd4 | 812 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) |
8070f5c0 | 813 | ? "UTF8" |
0635cdd4 | 814 | : "ASCII"), |
8070f5c0 | 815 | length_type->u.basic.integer.base, |
e0a7a7c4 | 816 | #ifdef __BIG_ENDIAN |
8070f5c0 | 817 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
e0a7a7c4 | 818 | #else |
0635cdd4 | 819 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
e0a7a7c4 | 820 | #endif |
27d2368e MD |
821 | field->name); |
822 | if (ret) | |
823 | return ret; | |
824 | ||
825 | ret = lttng_metadata_printf(session, | |
244465ab | 826 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } _%s[ __%s_length ];\n", |
8070f5c0 | 827 | elem_type->u.basic.integer.size, |
32257272 | 828 | (unsigned int) elem_type->u.basic.integer.alignment, |
8070f5c0 MD |
829 | elem_type->u.basic.integer.signedness, |
830 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
831 | ? "none" | |
0635cdd4 | 832 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) |
8070f5c0 | 833 | ? "UTF8" |
0635cdd4 | 834 | : "ASCII"), |
8070f5c0 | 835 | elem_type->u.basic.integer.base, |
8fa75f34 | 836 | #ifdef __BIG_ENDIAN |
8070f5c0 | 837 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
8fa75f34 | 838 | #else |
8070f5c0 | 839 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
8fa75f34 | 840 | #endif |
8070f5c0 | 841 | field->name, |
27d2368e | 842 | field->name); |
8070f5c0 MD |
843 | break; |
844 | } | |
c099397a | 845 | |
8070f5c0 MD |
846 | case atype_string: |
847 | /* Default encoding is UTF8 */ | |
848 | ret = lttng_metadata_printf(session, | |
244465ab | 849 | " string%s _%s;\n", |
8070f5c0 MD |
850 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? |
851 | " { encoding = ASCII; }" : "", | |
852 | field->name); | |
853 | break; | |
854 | default: | |
855 | WARN_ON_ONCE(1); | |
856 | return -EINVAL; | |
857 | } | |
858 | return ret; | |
859 | } | |
860 | ||
861 | static | |
a90917c3 | 862 | int _lttng_context_metadata_statedump(struct lttng_session *session, |
8070f5c0 MD |
863 | struct lttng_ctx *ctx) |
864 | { | |
865 | int ret = 0; | |
866 | int i; | |
867 | ||
868 | if (!ctx) | |
869 | return 0; | |
870 | for (i = 0; i < ctx->nr_fields; i++) { | |
871 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
872 | ||
a90917c3 | 873 | ret = _lttng_field_statedump(session, &field->event_field); |
8070f5c0 MD |
874 | if (ret) |
875 | return ret; | |
876 | } | |
877 | return ret; | |
878 | } | |
879 | ||
880 | static | |
a90917c3 MD |
881 | int _lttng_fields_metadata_statedump(struct lttng_session *session, |
882 | struct lttng_event *event) | |
8070f5c0 MD |
883 | { |
884 | const struct lttng_event_desc *desc = event->desc; | |
885 | int ret = 0; | |
886 | int i; | |
887 | ||
888 | for (i = 0; i < desc->nr_fields; i++) { | |
889 | const struct lttng_event_field *field = &desc->fields[i]; | |
890 | ||
a90917c3 | 891 | ret = _lttng_field_statedump(session, field); |
8070f5c0 MD |
892 | if (ret) |
893 | return ret; | |
c099397a MD |
894 | } |
895 | return ret; | |
896 | } | |
897 | ||
d83004aa JD |
898 | /* |
899 | * Must be called with sessions_mutex held. | |
900 | */ | |
c099397a | 901 | static |
a90917c3 MD |
902 | int _lttng_event_metadata_statedump(struct lttng_session *session, |
903 | struct lttng_channel *chan, | |
904 | struct lttng_event *event) | |
c099397a MD |
905 | { |
906 | int ret = 0; | |
907 | ||
908 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
909 | return 0; | |
d83004aa | 910 | if (chan->channel_type == METADATA_CHANNEL) |
c099397a MD |
911 | return 0; |
912 | ||
913 | ret = lttng_metadata_printf(session, | |
914 | "event {\n" | |
ae734547 | 915 | " name = \"%s\";\n" |
c099397a | 916 | " id = %u;\n" |
b9074a1b | 917 | " stream_id = %u;\n", |
c099397a MD |
918 | event->desc->name, |
919 | event->id, | |
920 | event->chan->id); | |
921 | if (ret) | |
922 | goto end; | |
923 | ||
b9074a1b MD |
924 | if (event->ctx) { |
925 | ret = lttng_metadata_printf(session, | |
926 | " context := struct {\n"); | |
927 | if (ret) | |
928 | goto end; | |
929 | } | |
a90917c3 | 930 | ret = _lttng_context_metadata_statedump(session, event->ctx); |
8070f5c0 MD |
931 | if (ret) |
932 | goto end; | |
b9074a1b MD |
933 | if (event->ctx) { |
934 | ret = lttng_metadata_printf(session, | |
935 | " };\n"); | |
936 | if (ret) | |
937 | goto end; | |
938 | } | |
8070f5c0 MD |
939 | |
940 | ret = lttng_metadata_printf(session, | |
8070f5c0 MD |
941 | " fields := struct {\n" |
942 | ); | |
943 | if (ret) | |
944 | goto end; | |
945 | ||
a90917c3 | 946 | ret = _lttng_fields_metadata_statedump(session, event); |
c099397a MD |
947 | if (ret) |
948 | goto end; | |
949 | ||
950 | /* | |
951 | * LTTng space reservation can only reserve multiples of the | |
952 | * byte size. | |
953 | */ | |
954 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
955 | " };\n" |
956 | "};\n\n"); | |
c099397a MD |
957 | if (ret) |
958 | goto end; | |
959 | ||
c099397a MD |
960 | event->metadata_dumped = 1; |
961 | end: | |
962 | return ret; | |
963 | ||
964 | } | |
965 | ||
d83004aa JD |
966 | /* |
967 | * Must be called with sessions_mutex held. | |
968 | */ | |
c099397a | 969 | static |
a90917c3 MD |
970 | int _lttng_channel_metadata_statedump(struct lttng_session *session, |
971 | struct lttng_channel *chan) | |
c099397a MD |
972 | { |
973 | int ret = 0; | |
974 | ||
975 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
976 | return 0; | |
d83004aa JD |
977 | |
978 | if (chan->channel_type == METADATA_CHANNEL) | |
c099397a MD |
979 | return 0; |
980 | ||
981 | WARN_ON_ONCE(!chan->header_type); | |
982 | ret = lttng_metadata_printf(session, | |
983 | "stream {\n" | |
984 | " id = %u;\n" | |
9115fbdc | 985 | " event.header := %s;\n" |
b9074a1b | 986 | " packet.context := struct packet_context;\n", |
c099397a MD |
987 | chan->id, |
988 | chan->header_type == 1 ? "struct event_header_compact" : | |
989 | "struct event_header_large"); | |
990 | if (ret) | |
991 | goto end; | |
992 | ||
b9074a1b MD |
993 | if (chan->ctx) { |
994 | ret = lttng_metadata_printf(session, | |
995 | " event.context := struct {\n"); | |
996 | if (ret) | |
997 | goto end; | |
998 | } | |
a90917c3 | 999 | ret = _lttng_context_metadata_statedump(session, chan->ctx); |
8070f5c0 MD |
1000 | if (ret) |
1001 | goto end; | |
b9074a1b MD |
1002 | if (chan->ctx) { |
1003 | ret = lttng_metadata_printf(session, | |
1004 | " };\n"); | |
1005 | if (ret) | |
1006 | goto end; | |
1007 | } | |
8070f5c0 MD |
1008 | |
1009 | ret = lttng_metadata_printf(session, | |
b9074a1b | 1010 | "};\n\n"); |
8070f5c0 | 1011 | |
c099397a MD |
1012 | chan->metadata_dumped = 1; |
1013 | end: | |
1014 | return ret; | |
1015 | } | |
1016 | ||
d83004aa JD |
1017 | /* |
1018 | * Must be called with sessions_mutex held. | |
1019 | */ | |
9115fbdc | 1020 | static |
a90917c3 | 1021 | int _lttng_stream_packet_context_declare(struct lttng_session *session) |
9115fbdc MD |
1022 | { |
1023 | return lttng_metadata_printf(session, | |
1024 | "struct packet_context {\n" | |
a3ccff4f MD |
1025 | " uint64_clock_monotonic_t timestamp_begin;\n" |
1026 | " uint64_clock_monotonic_t timestamp_end;\n" | |
576ca06a MD |
1027 | " uint64_t content_size;\n" |
1028 | " uint64_t packet_size;\n" | |
a9afe705 | 1029 | " unsigned long events_discarded;\n" |
9115fbdc | 1030 | " uint32_t cpu_id;\n" |
c6dfdf6f | 1031 | "};\n\n" |
9115fbdc MD |
1032 | ); |
1033 | } | |
1034 | ||
1035 | /* | |
1036 | * Compact header: | |
1037 | * id: range: 0 - 30. | |
1038 | * id 31 is reserved to indicate an extended header. | |
1039 | * | |
1040 | * Large header: | |
1041 | * id: range: 0 - 65534. | |
1042 | * id 65535 is reserved to indicate an extended header. | |
d83004aa JD |
1043 | * |
1044 | * Must be called with sessions_mutex held. | |
9115fbdc MD |
1045 | */ |
1046 | static | |
a90917c3 | 1047 | int _lttng_event_header_declare(struct lttng_session *session) |
9115fbdc MD |
1048 | { |
1049 | return lttng_metadata_printf(session, | |
1050 | "struct event_header_compact {\n" | |
1051 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
1052 | " variant <id> {\n" | |
1053 | " struct {\n" | |
a3ccff4f | 1054 | " uint27_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
1055 | " } compact;\n" |
1056 | " struct {\n" | |
1057 | " uint32_t id;\n" | |
a3ccff4f | 1058 | " uint64_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
1059 | " } extended;\n" |
1060 | " } v;\n" | |
1061 | "} align(%u);\n" | |
1062 | "\n" | |
1063 | "struct event_header_large {\n" | |
1064 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
1065 | " variant <id> {\n" | |
1066 | " struct {\n" | |
a3ccff4f | 1067 | " uint32_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
1068 | " } compact;\n" |
1069 | " struct {\n" | |
1070 | " uint32_t id;\n" | |
a3ccff4f | 1071 | " uint64_clock_monotonic_t timestamp;\n" |
9115fbdc MD |
1072 | " } extended;\n" |
1073 | " } v;\n" | |
1074 | "} align(%u);\n\n", | |
a90917c3 MD |
1075 | lttng_alignof(uint32_t) * CHAR_BIT, |
1076 | lttng_alignof(uint16_t) * CHAR_BIT | |
9115fbdc MD |
1077 | ); |
1078 | } | |
1079 | ||
a3ccff4f MD |
1080 | /* |
1081 | * Approximation of NTP time of day to clock monotonic correlation, | |
1082 | * taken at start of trace. | |
1083 | * Yes, this is only an approximation. Yes, we can (and will) do better | |
1084 | * in future versions. | |
1085 | */ | |
1086 | static | |
1087 | uint64_t measure_clock_offset(void) | |
1088 | { | |
1089 | uint64_t offset, monotonic[2], realtime; | |
1090 | struct timespec rts = { 0, 0 }; | |
1091 | unsigned long flags; | |
1092 | ||
1093 | /* Disable interrupts to increase correlation precision. */ | |
1094 | local_irq_save(flags); | |
1095 | monotonic[0] = trace_clock_read64(); | |
1096 | getnstimeofday(&rts); | |
1097 | monotonic[1] = trace_clock_read64(); | |
1098 | local_irq_restore(flags); | |
1099 | ||
1100 | offset = (monotonic[0] + monotonic[1]) >> 1; | |
57be518d | 1101 | realtime = (uint64_t) rts.tv_sec * NSEC_PER_SEC; |
a3ccff4f MD |
1102 | realtime += rts.tv_nsec; |
1103 | offset = realtime - offset; | |
1104 | return offset; | |
1105 | } | |
1106 | ||
c099397a MD |
1107 | /* |
1108 | * Output metadata into this session's metadata buffers. | |
d83004aa | 1109 | * Must be called with sessions_mutex held. |
c099397a MD |
1110 | */ |
1111 | static | |
a90917c3 | 1112 | int _lttng_session_metadata_statedump(struct lttng_session *session) |
c099397a | 1113 | { |
30bdb6e4 | 1114 | unsigned char *uuid_c = session->uuid.b; |
a82c63f1 | 1115 | unsigned char uuid_s[37], clock_uuid_s[BOOT_ID_LEN]; |
a90917c3 MD |
1116 | struct lttng_channel *chan; |
1117 | struct lttng_event *event; | |
c099397a MD |
1118 | int ret = 0; |
1119 | ||
1120 | if (!ACCESS_ONCE(session->active)) | |
1121 | return 0; | |
1122 | if (session->metadata_dumped) | |
1123 | goto skip_session; | |
c099397a | 1124 | |
d793d5e1 | 1125 | snprintf(uuid_s, sizeof(uuid_s), |
30bdb6e4 MD |
1126 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", |
1127 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
1128 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
1129 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
1130 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
d793d5e1 MD |
1131 | |
1132 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
1133 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
1134 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
1135 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
1136 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
a9afe705 | 1137 | "typealias integer { size = %u; align = %u; signed = false; } := unsigned long;\n" |
9115fbdc MD |
1138 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" |
1139 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
d793d5e1 MD |
1140 | "\n" |
1141 | "trace {\n" | |
1142 | " major = %u;\n" | |
1143 | " minor = %u;\n" | |
30bdb6e4 | 1144 | " uuid = \"%s\";\n" |
d793d5e1 MD |
1145 | " byte_order = %s;\n" |
1146 | " packet.header := struct {\n" | |
1147 | " uint32_t magic;\n" | |
1ec3f75a | 1148 | " uint8_t uuid[16];\n" |
d793d5e1 | 1149 | " uint32_t stream_id;\n" |
0eb25f58 | 1150 | " };\n" |
d793d5e1 | 1151 | "};\n\n", |
a90917c3 MD |
1152 | lttng_alignof(uint8_t) * CHAR_BIT, |
1153 | lttng_alignof(uint16_t) * CHAR_BIT, | |
1154 | lttng_alignof(uint32_t) * CHAR_BIT, | |
1155 | lttng_alignof(uint64_t) * CHAR_BIT, | |
a9afe705 MD |
1156 | sizeof(unsigned long) * CHAR_BIT, |
1157 | lttng_alignof(unsigned long) * CHAR_BIT, | |
c6c9e10f MD |
1158 | CTF_SPEC_MAJOR, |
1159 | CTF_SPEC_MINOR, | |
d793d5e1 MD |
1160 | uuid_s, |
1161 | #ifdef __BIG_ENDIAN | |
1162 | "be" | |
1163 | #else | |
1164 | "le" | |
1165 | #endif | |
1166 | ); | |
1167 | if (ret) | |
1168 | goto end; | |
1169 | ||
99dc9597 MD |
1170 | ret = lttng_metadata_printf(session, |
1171 | "env {\n" | |
a6058143 | 1172 | " hostname = \"%s\";\n" |
c6c9e10f | 1173 | " domain = \"kernel\";\n" |
99dc9597 | 1174 | " sysname = \"%s\";\n" |
c6c9e10f MD |
1175 | " kernel_release = \"%s\";\n" |
1176 | " kernel_version = \"%s\";\n" | |
1177 | " tracer_name = \"lttng-modules\";\n" | |
1178 | " tracer_major = %d;\n" | |
1179 | " tracer_minor = %d;\n" | |
1180 | " tracer_patchlevel = %d;\n" | |
99dc9597 | 1181 | "};\n\n", |
3d0d43db | 1182 | current->nsproxy->uts_ns->name.nodename, |
99dc9597 MD |
1183 | utsname()->sysname, |
1184 | utsname()->release, | |
c6c9e10f MD |
1185 | utsname()->version, |
1186 | LTTNG_MODULES_MAJOR_VERSION, | |
1187 | LTTNG_MODULES_MINOR_VERSION, | |
1188 | LTTNG_MODULES_PATCHLEVEL_VERSION | |
99dc9597 MD |
1189 | ); |
1190 | if (ret) | |
1191 | goto end; | |
1192 | ||
a3ccff4f MD |
1193 | ret = lttng_metadata_printf(session, |
1194 | "clock {\n" | |
a82c63f1 MD |
1195 | " name = %s;\n", |
1196 | "monotonic" | |
1197 | ); | |
1198 | if (ret) | |
1199 | goto end; | |
1200 | ||
1201 | if (!trace_clock_uuid(clock_uuid_s)) { | |
1202 | ret = lttng_metadata_printf(session, | |
7c27cb17 | 1203 | " uuid = \"%s\";\n", |
a82c63f1 MD |
1204 | clock_uuid_s |
1205 | ); | |
1206 | if (ret) | |
1207 | goto end; | |
1208 | } | |
1209 | ||
1210 | ret = lttng_metadata_printf(session, | |
a3ccff4f MD |
1211 | " description = \"Monotonic Clock\";\n" |
1212 | " freq = %llu; /* Frequency, in Hz */\n" | |
1213 | " /* clock value offset from Epoch is: offset * (1/freq) */\n" | |
1214 | " offset = %llu;\n" | |
1215 | "};\n\n", | |
a3ccff4f MD |
1216 | (unsigned long long) trace_clock_freq(), |
1217 | (unsigned long long) measure_clock_offset() | |
1218 | ); | |
1219 | if (ret) | |
1220 | goto end; | |
1221 | ||
1222 | ret = lttng_metadata_printf(session, | |
1223 | "typealias integer {\n" | |
1224 | " size = 27; align = 1; signed = false;\n" | |
1225 | " map = clock.monotonic.value;\n" | |
1226 | "} := uint27_clock_monotonic_t;\n" | |
1227 | "\n" | |
1228 | "typealias integer {\n" | |
1229 | " size = 32; align = %u; signed = false;\n" | |
1230 | " map = clock.monotonic.value;\n" | |
1231 | "} := uint32_clock_monotonic_t;\n" | |
1232 | "\n" | |
1233 | "typealias integer {\n" | |
1234 | " size = 64; align = %u; signed = false;\n" | |
1235 | " map = clock.monotonic.value;\n" | |
1236 | "} := uint64_clock_monotonic_t;\n\n", | |
1237 | lttng_alignof(uint32_t) * CHAR_BIT, | |
1238 | lttng_alignof(uint64_t) * CHAR_BIT | |
1239 | ); | |
1240 | if (ret) | |
1241 | goto end; | |
1242 | ||
a90917c3 | 1243 | ret = _lttng_stream_packet_context_declare(session); |
9115fbdc MD |
1244 | if (ret) |
1245 | goto end; | |
1246 | ||
a90917c3 | 1247 | ret = _lttng_event_header_declare(session); |
9115fbdc MD |
1248 | if (ret) |
1249 | goto end; | |
1250 | ||
c099397a MD |
1251 | skip_session: |
1252 | list_for_each_entry(chan, &session->chan, list) { | |
a90917c3 | 1253 | ret = _lttng_channel_metadata_statedump(session, chan); |
c099397a MD |
1254 | if (ret) |
1255 | goto end; | |
1256 | } | |
1257 | ||
1258 | list_for_each_entry(event, &session->events, list) { | |
a90917c3 | 1259 | ret = _lttng_event_metadata_statedump(session, event->chan, event); |
c099397a MD |
1260 | if (ret) |
1261 | goto end; | |
1262 | } | |
1263 | session->metadata_dumped = 1; | |
1264 | end: | |
1265 | return ret; | |
1266 | } | |
1267 | ||
c0e31d2e | 1268 | /** |
a90917c3 | 1269 | * lttng_transport_register - LTT transport registration |
c0e31d2e MD |
1270 | * @transport: transport structure |
1271 | * | |
1272 | * Registers a transport which can be used as output to extract the data out of | |
1273 | * LTTng. The module calling this registration function must ensure that no | |
1274 | * trap-inducing code will be executed by the transport functions. E.g. | |
1275 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
1276 | * is made visible to the transport function. This registration acts as a | |
1277 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
1278 | * after its registration must it synchronize the TLBs. | |
1279 | */ | |
a90917c3 | 1280 | void lttng_transport_register(struct lttng_transport *transport) |
c0e31d2e MD |
1281 | { |
1282 | /* | |
1283 | * Make sure no page fault can be triggered by the module about to be | |
1284 | * registered. We deal with this here so we don't have to call | |
1285 | * vmalloc_sync_all() in each module's init. | |
1286 | */ | |
6d2a620c | 1287 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
1288 | |
1289 | mutex_lock(&sessions_mutex); | |
a90917c3 | 1290 | list_add_tail(&transport->node, <tng_transport_list); |
c0e31d2e MD |
1291 | mutex_unlock(&sessions_mutex); |
1292 | } | |
a90917c3 | 1293 | EXPORT_SYMBOL_GPL(lttng_transport_register); |
c0e31d2e MD |
1294 | |
1295 | /** | |
a90917c3 | 1296 | * lttng_transport_unregister - LTT transport unregistration |
c0e31d2e MD |
1297 | * @transport: transport structure |
1298 | */ | |
a90917c3 | 1299 | void lttng_transport_unregister(struct lttng_transport *transport) |
c0e31d2e MD |
1300 | { |
1301 | mutex_lock(&sessions_mutex); | |
1302 | list_del(&transport->node); | |
1303 | mutex_unlock(&sessions_mutex); | |
1304 | } | |
a90917c3 | 1305 | EXPORT_SYMBOL_GPL(lttng_transport_unregister); |
c0e31d2e | 1306 | |
a90917c3 | 1307 | static int __init lttng_events_init(void) |
4e3c1b9b | 1308 | { |
1c25284c MD |
1309 | int ret; |
1310 | ||
453b2495 JD |
1311 | ret = wrapper_lttng_fixup_sig(THIS_MODULE); |
1312 | if (ret) | |
1313 | return ret; | |
165eee70 MD |
1314 | ret = wrapper_get_pfnblock_flags_mask_init(); |
1315 | if (ret) | |
1316 | return ret; | |
20591cf7 MD |
1317 | ret = lttng_tracepoint_init(); |
1318 | if (ret) | |
1319 | return ret; | |
a90917c3 | 1320 | event_cache = KMEM_CACHE(lttng_event, 0); |
20591cf7 MD |
1321 | if (!event_cache) { |
1322 | ret = -ENOMEM; | |
1323 | goto error_kmem; | |
1324 | } | |
80996790 | 1325 | ret = lttng_abi_init(); |
02119ee5 MD |
1326 | if (ret) |
1327 | goto error_abi; | |
0c956676 MD |
1328 | ret = lttng_logger_init(); |
1329 | if (ret) | |
1330 | goto error_logger; | |
4e3c1b9b | 1331 | return 0; |
0c956676 MD |
1332 | |
1333 | error_logger: | |
1334 | lttng_abi_exit(); | |
02119ee5 | 1335 | error_abi: |
1c25284c | 1336 | kmem_cache_destroy(event_cache); |
20591cf7 MD |
1337 | error_kmem: |
1338 | lttng_tracepoint_exit(); | |
1c25284c | 1339 | return ret; |
4e3c1b9b MD |
1340 | } |
1341 | ||
a90917c3 | 1342 | module_init(lttng_events_init); |
11b5a3c2 | 1343 | |
a90917c3 | 1344 | static void __exit lttng_events_exit(void) |
4e3c1b9b | 1345 | { |
a90917c3 | 1346 | struct lttng_session *session, *tmpsession; |
92e94819 | 1347 | |
0c956676 | 1348 | lttng_logger_exit(); |
80996790 | 1349 | lttng_abi_exit(); |
92e94819 | 1350 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
a90917c3 | 1351 | lttng_session_destroy(session); |
11b5a3c2 | 1352 | kmem_cache_destroy(event_cache); |
20591cf7 | 1353 | lttng_tracepoint_exit(); |
4e3c1b9b | 1354 | } |
92e94819 | 1355 | |
a90917c3 | 1356 | module_exit(lttng_events_exit); |
11b5a3c2 | 1357 | |
92e94819 MD |
1358 | MODULE_LICENSE("GPL and additional rights"); |
1359 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
1360 | MODULE_DESCRIPTION("LTTng Events"); | |
9a9973ef MD |
1361 | MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "." |
1362 | __stringify(LTTNG_MODULES_MINOR_VERSION) "." | |
309370e2 MD |
1363 | __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION) |
1364 | LTTNG_MODULES_EXTRAVERSION); |