Commit | Line | Data |
---|---|---|
4e3c1b9b MD |
1 | /* |
2 | * ltt-events.c | |
3 | * | |
4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * Holds LTTng per-session event registry. | |
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> |
d793d5e1 | 17 | #include <linux/uuid.h> |
b13f3ebe | 18 | #include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */ |
4e3c1b9b | 19 | #include "ltt-events.h" |
c099397a | 20 | #include "ltt-tracer.h" |
4e3c1b9b MD |
21 | |
22 | static LIST_HEAD(sessions); | |
c0e31d2e | 23 | static LIST_HEAD(ltt_transport_list); |
4e3c1b9b MD |
24 | static DEFINE_MUTEX(sessions_mutex); |
25 | static struct kmem_cache *event_cache; | |
26 | ||
be066e6c | 27 | static void _ltt_event_destroy(struct ltt_event *event); |
aa7c23a9 | 28 | static void _ltt_channel_destroy(struct ltt_channel *chan); |
be066e6c | 29 | static int _ltt_event_unregister(struct ltt_event *event); |
c099397a MD |
30 | static |
31 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
32 | struct ltt_channel *chan, | |
33 | struct ltt_event *event); | |
34 | static | |
35 | int _ltt_session_metadata_statedump(struct ltt_session *session); | |
36 | ||
37 | ||
38 | static | |
39 | void synchronize_trace(void) | |
abcca994 MD |
40 | { |
41 | synchronize_sched(); | |
42 | #ifdef CONFIG_PREEMPT_RT | |
43 | synchronize_rcu(); | |
44 | #endif | |
45 | } | |
46 | ||
baf20995 | 47 | struct ltt_session *ltt_session_create(void) |
4e3c1b9b MD |
48 | { |
49 | struct ltt_session *session; | |
50 | ||
51 | mutex_lock(&sessions_mutex); | |
f3d01b96 | 52 | session = kzalloc(sizeof(struct ltt_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 | ||
11b5a3c2 | 63 | void ltt_session_destroy(struct ltt_session *session) |
4e3c1b9b MD |
64 | { |
65 | struct ltt_channel *chan, *tmpchan; | |
66 | struct ltt_event *event, *tmpevent; | |
dda6a249 | 67 | int ret; |
4e3c1b9b MD |
68 | |
69 | mutex_lock(&sessions_mutex); | |
52fc2e1f | 70 | ACCESS_ONCE(session->active) = 0; |
dda6a249 MD |
71 | list_for_each_entry(event, &session->events, list) { |
72 | ret = _ltt_event_unregister(event); | |
73 | WARN_ON(ret); | |
74 | } | |
abcca994 | 75 | synchronize_trace(); /* Wait for in-flight events to complete */ |
4e3c1b9b MD |
76 | list_for_each_entry_safe(event, tmpevent, &session->events, list) |
77 | _ltt_event_destroy(event); | |
78 | list_for_each_entry_safe(chan, tmpchan, &session->chan, list) | |
79 | _ltt_channel_destroy(chan); | |
80 | list_del(&session->list); | |
81 | mutex_unlock(&sessions_mutex); | |
82 | kfree(session); | |
83 | } | |
84 | ||
e64957da | 85 | int ltt_session_enable(struct ltt_session *session) |
c0e31d2e MD |
86 | { |
87 | int ret = 0; | |
c099397a | 88 | struct ltt_channel *chan; |
c0e31d2e MD |
89 | |
90 | mutex_lock(&sessions_mutex); | |
91 | if (session->active) { | |
92 | ret = -EBUSY; | |
93 | goto end; | |
94 | } | |
c099397a MD |
95 | |
96 | /* | |
97 | * Snapshot the number of events per channel to know the type of header | |
98 | * we need to use. | |
99 | */ | |
100 | list_for_each_entry(chan, &session->chan, list) { | |
101 | if (chan->header_type) | |
102 | continue; /* don't change it if session stop/restart */ | |
103 | if (chan->free_event_id < 31) | |
104 | chan->header_type = 1; /* compact */ | |
105 | else | |
106 | chan->header_type = 2; /* large */ | |
107 | } | |
108 | ||
52fc2e1f | 109 | ACCESS_ONCE(session->active) = 1; |
8070f5c0 | 110 | ACCESS_ONCE(session->been_active) = 1; |
c0e31d2e | 111 | synchronize_trace(); /* Wait for in-flight events to complete */ |
c099397a MD |
112 | ret = _ltt_session_metadata_statedump(session); |
113 | if (ret) { | |
114 | ACCESS_ONCE(session->active) = 0; | |
115 | synchronize_trace(); /* Wait for in-flight events to complete */ | |
116 | } | |
c0e31d2e MD |
117 | end: |
118 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 119 | return ret; |
c0e31d2e MD |
120 | } |
121 | ||
e64957da | 122 | int ltt_session_disable(struct ltt_session *session) |
c0e31d2e MD |
123 | { |
124 | int ret = 0; | |
125 | ||
126 | mutex_lock(&sessions_mutex); | |
127 | if (!session->active) { | |
128 | ret = -EBUSY; | |
129 | goto end; | |
130 | } | |
52fc2e1f | 131 | ACCESS_ONCE(session->active) = 0; |
c0e31d2e MD |
132 | synchronize_trace(); /* Wait for in-flight events to complete */ |
133 | end: | |
134 | mutex_unlock(&sessions_mutex); | |
11b5a3c2 | 135 | return ret; |
c0e31d2e MD |
136 | } |
137 | ||
e64957da MD |
138 | int ltt_channel_enable(struct ltt_channel *channel) |
139 | { | |
140 | int old; | |
141 | ||
142 | old = xchg(&channel->enabled, 1); | |
143 | if (old) | |
144 | return -EEXIST; | |
145 | return 0; | |
146 | } | |
147 | ||
148 | int ltt_channel_disable(struct ltt_channel *channel) | |
149 | { | |
150 | int old; | |
151 | ||
152 | old = xchg(&channel->enabled, 0); | |
153 | if (!old) | |
154 | return -EEXIST; | |
155 | return 0; | |
156 | } | |
157 | ||
158 | int ltt_event_enable(struct ltt_event *event) | |
159 | { | |
160 | int old; | |
161 | ||
162 | old = xchg(&event->enabled, 1); | |
163 | if (old) | |
164 | return -EEXIST; | |
165 | return 0; | |
166 | } | |
167 | ||
168 | int ltt_event_disable(struct ltt_event *event) | |
169 | { | |
170 | int old; | |
171 | ||
172 | old = xchg(&event->enabled, 0); | |
173 | if (!old) | |
174 | return -EEXIST; | |
175 | return 0; | |
176 | } | |
177 | ||
c535175e | 178 | static struct ltt_transport *ltt_transport_find(const char *name) |
f3d01b96 MD |
179 | { |
180 | struct ltt_transport *transport; | |
181 | ||
182 | list_for_each_entry(transport, <t_transport_list, node) { | |
183 | if (!strcmp(transport->name, name)) | |
184 | return transport; | |
185 | } | |
186 | return NULL; | |
187 | } | |
188 | ||
baf20995 | 189 | struct ltt_channel *ltt_channel_create(struct ltt_session *session, |
5dbbdb43 MD |
190 | const char *transport_name, |
191 | void *buf_addr, | |
4e3c1b9b MD |
192 | size_t subbuf_size, size_t num_subbuf, |
193 | unsigned int switch_timer_interval, | |
194 | unsigned int read_timer_interval) | |
195 | { | |
196 | struct ltt_channel *chan; | |
f3d01b96 | 197 | struct ltt_transport *transport; |
4e3c1b9b MD |
198 | |
199 | mutex_lock(&sessions_mutex); | |
8070f5c0 | 200 | if (session->been_active) |
e5382b6d | 201 | goto active; /* Refuse to add channel to active session */ |
f3d01b96 MD |
202 | transport = ltt_transport_find(transport_name); |
203 | if (!transport) { | |
204 | printk(KERN_WARNING "LTTng transport %s not found\n", | |
205 | transport_name); | |
c0e31d2e | 206 | goto notransport; |
f3d01b96 | 207 | } |
f3d01b96 | 208 | chan = kzalloc(sizeof(struct ltt_channel), GFP_KERNEL); |
4e3c1b9b | 209 | if (!chan) |
c0e31d2e | 210 | goto nomem; |
4e3c1b9b | 211 | chan->session = session; |
05d32c64 | 212 | chan->id = session->free_chan_id++; |
125b4df4 MD |
213 | /* |
214 | * Note: the channel creation op already writes into the packet | |
215 | * headers. Therefore the "chan" information used as input | |
216 | * should be already accessible. | |
217 | */ | |
9115fbdc | 218 | chan->chan = transport->ops.channel_create("[lttng]", chan, buf_addr, |
11b5a3c2 MD |
219 | subbuf_size, num_subbuf, switch_timer_interval, |
220 | read_timer_interval); | |
f3d01b96 MD |
221 | if (!chan->chan) |
222 | goto create_error; | |
e64957da | 223 | chan->enabled = 1; |
11b5a3c2 | 224 | chan->ops = &transport->ops; |
4e3c1b9b MD |
225 | list_add(&chan->list, &session->chan); |
226 | mutex_unlock(&sessions_mutex); | |
227 | return chan; | |
228 | ||
f3d01b96 MD |
229 | create_error: |
230 | kfree(chan); | |
c0e31d2e MD |
231 | nomem: |
232 | notransport: | |
e5382b6d | 233 | active: |
4e3c1b9b MD |
234 | mutex_unlock(&sessions_mutex); |
235 | return NULL; | |
236 | } | |
237 | ||
238 | /* | |
239 | * Only used internally at session destruction. | |
240 | */ | |
aa7c23a9 | 241 | static |
11b5a3c2 | 242 | void _ltt_channel_destroy(struct ltt_channel *chan) |
4e3c1b9b | 243 | { |
11b5a3c2 | 244 | chan->ops->channel_destroy(chan->chan); |
4e3c1b9b | 245 | list_del(&chan->list); |
8070f5c0 | 246 | lttng_destroy_context(chan->ctx); |
4e3c1b9b MD |
247 | kfree(chan); |
248 | } | |
249 | ||
e5382b6d MD |
250 | /* |
251 | * Supports event creation while tracing session is active. | |
252 | */ | |
30bdb6e4 | 253 | struct ltt_event *ltt_event_create(struct ltt_channel *chan, |
d6d808f3 | 254 | struct lttng_kernel_event *event_param, |
85a9ca7f | 255 | void *filter) |
4e3c1b9b MD |
256 | { |
257 | struct ltt_event *event; | |
3d084699 | 258 | int ret; |
4e3c1b9b MD |
259 | |
260 | mutex_lock(&sessions_mutex); | |
e5382b6d MD |
261 | if (chan->free_event_id == -1UL) |
262 | goto full; | |
4e3c1b9b | 263 | /* |
dda6a249 MD |
264 | * This is O(n^2) (for each event, the loop is called at event |
265 | * creation). Might require a hash if we have lots of events. | |
4e3c1b9b MD |
266 | */ |
267 | list_for_each_entry(event, &chan->session->events, list) | |
30bdb6e4 | 268 | if (!strcmp(event->desc->name, event_param->name)) |
4e3c1b9b | 269 | goto exist; |
11b5a3c2 | 270 | event = kmem_cache_zalloc(event_cache, GFP_KERNEL); |
4e3c1b9b MD |
271 | if (!event) |
272 | goto cache_error; | |
4e3c1b9b MD |
273 | event->chan = chan; |
274 | event->filter = filter; | |
e5382b6d | 275 | event->id = chan->free_event_id++; |
e64957da | 276 | event->enabled = 1; |
d6d808f3 | 277 | event->instrumentation = event_param->instrumentation; |
e5382b6d MD |
278 | /* Populate ltt_event structure before tracepoint registration. */ |
279 | smp_wmb(); | |
d6d808f3 | 280 | switch (event_param->instrumentation) { |
ab2277d6 | 281 | case LTTNG_KERNEL_TRACEPOINT: |
30bdb6e4 | 282 | event->desc = ltt_event_get(event_param->name); |
d3dbe23c MD |
283 | if (!event->desc) |
284 | goto register_error; | |
30bdb6e4 | 285 | ret = tracepoint_probe_register(event_param->name, |
d3dbe23c MD |
286 | event->desc->probe_callback, |
287 | event); | |
11b5a3c2 MD |
288 | if (ret) |
289 | goto register_error; | |
baf20995 | 290 | break; |
ab2277d6 | 291 | case LTTNG_KERNEL_KPROBE: |
30bdb6e4 | 292 | ret = lttng_kprobes_register(event_param->name, |
f17701fb MD |
293 | event_param->u.kprobe.symbol_name, |
294 | event_param->u.kprobe.offset, | |
295 | event_param->u.kprobe.addr, | |
296 | event); | |
297 | if (ret) | |
d6d808f3 | 298 | goto register_error; |
edeb3137 MD |
299 | ret = try_module_get(event->desc->owner); |
300 | WARN_ON_ONCE(!ret); | |
d6d808f3 | 301 | break; |
ab2277d6 | 302 | case LTTNG_KERNEL_FUNCTION: |
30bdb6e4 | 303 | ret = lttng_ftrace_register(event_param->name, |
e0a7a7c4 MD |
304 | event_param->u.ftrace.symbol_name, |
305 | event); | |
306 | if (ret) | |
307 | goto register_error; | |
edeb3137 MD |
308 | ret = try_module_get(event->desc->owner); |
309 | WARN_ON_ONCE(!ret); | |
e0a7a7c4 | 310 | break; |
baf20995 MD |
311 | default: |
312 | WARN_ON_ONCE(1); | |
313 | } | |
c099397a MD |
314 | ret = _ltt_event_metadata_statedump(chan->session, chan, event); |
315 | if (ret) | |
316 | goto statedump_error; | |
dda6a249 | 317 | list_add(&event->list, &chan->session->events); |
11b5a3c2 | 318 | mutex_unlock(&sessions_mutex); |
4e3c1b9b MD |
319 | return event; |
320 | ||
c099397a | 321 | statedump_error: |
30bdb6e4 | 322 | WARN_ON_ONCE(tracepoint_probe_unregister(event_param->name, |
d3dbe23c MD |
323 | event->desc->probe_callback, |
324 | event)); | |
325 | ltt_event_put(event->desc); | |
11b5a3c2 | 326 | register_error: |
11b5a3c2 | 327 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
328 | cache_error: |
329 | exist: | |
e5382b6d | 330 | full: |
4e3c1b9b MD |
331 | mutex_unlock(&sessions_mutex); |
332 | return NULL; | |
333 | } | |
334 | ||
335 | /* | |
336 | * Only used internally at session destruction. | |
337 | */ | |
dda6a249 | 338 | int _ltt_event_unregister(struct ltt_event *event) |
4e3c1b9b | 339 | { |
11b5a3c2 MD |
340 | int ret = -EINVAL; |
341 | ||
38d024ae | 342 | switch (event->instrumentation) { |
ab2277d6 | 343 | case LTTNG_KERNEL_TRACEPOINT: |
85a9ca7f MD |
344 | ret = tracepoint_probe_unregister(event->desc->name, |
345 | event->desc->probe_callback, | |
11b5a3c2 MD |
346 | event); |
347 | if (ret) | |
348 | return ret; | |
baf20995 | 349 | break; |
ab2277d6 | 350 | case LTTNG_KERNEL_KPROBE: |
f17701fb | 351 | lttng_kprobes_unregister(event); |
d6d808f3 MD |
352 | ret = 0; |
353 | break; | |
ab2277d6 | 354 | case LTTNG_KERNEL_FUNCTION: |
e0a7a7c4 MD |
355 | lttng_ftrace_unregister(event); |
356 | ret = 0; | |
357 | break; | |
baf20995 MD |
358 | default: |
359 | WARN_ON_ONCE(1); | |
360 | } | |
dda6a249 MD |
361 | return ret; |
362 | } | |
363 | ||
364 | /* | |
365 | * Only used internally at session destruction. | |
366 | */ | |
be066e6c | 367 | static |
dda6a249 MD |
368 | void _ltt_event_destroy(struct ltt_event *event) |
369 | { | |
edeb3137 MD |
370 | switch (event->instrumentation) { |
371 | case LTTNG_KERNEL_TRACEPOINT: | |
372 | ltt_event_put(event->desc); | |
373 | break; | |
374 | case LTTNG_KERNEL_KPROBE: | |
375 | module_put(event->desc->owner); | |
376 | lttng_kprobes_destroy_private(event); | |
377 | break; | |
378 | case LTTNG_KERNEL_FUNCTION: | |
379 | module_put(event->desc->owner); | |
380 | lttng_ftrace_destroy_private(event); | |
381 | break; | |
382 | default: | |
383 | WARN_ON_ONCE(1); | |
384 | } | |
dda6a249 | 385 | list_del(&event->list); |
8070f5c0 | 386 | lttng_destroy_context(event->ctx); |
11b5a3c2 | 387 | kmem_cache_free(event_cache, event); |
4e3c1b9b MD |
388 | } |
389 | ||
1ec3f75a MD |
390 | /* |
391 | * We have exclusive access to our metadata buffer (protected by the | |
392 | * sessions_mutex), so we can do racy operations such as looking for | |
393 | * remaining space left in packet and write, since mutual exclusion | |
394 | * protects us from concurrent writes. | |
395 | */ | |
c099397a MD |
396 | int lttng_metadata_printf(struct ltt_session *session, |
397 | const char *fmt, ...) | |
398 | { | |
399 | struct lib_ring_buffer_ctx ctx; | |
400 | struct ltt_channel *chan = session->metadata; | |
401 | char *str; | |
402 | int ret = 0, waitret; | |
1ec3f75a | 403 | size_t len, reserve_len, pos; |
c099397a MD |
404 | va_list ap; |
405 | ||
406 | WARN_ON_ONCE(!ACCESS_ONCE(session->active)); | |
407 | ||
408 | va_start(ap, fmt); | |
409 | str = kvasprintf(GFP_KERNEL, fmt, ap); | |
410 | va_end(ap); | |
411 | if (!str) | |
412 | return -ENOMEM; | |
413 | ||
1ec3f75a MD |
414 | len = strlen(str); |
415 | pos = 0; | |
416 | ||
417 | for (pos = 0; pos < len; pos += reserve_len) { | |
418 | reserve_len = min_t(size_t, | |
419 | chan->ops->packet_avail_size(chan->chan), | |
420 | len - pos); | |
421 | lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len, | |
422 | sizeof(char), -1); | |
423 | /* | |
424 | * We don't care about metadata buffer's records lost | |
425 | * count, because we always retry here. Report error if | |
426 | * we need to bail out after timeout or being | |
427 | * interrupted. | |
428 | */ | |
24cedcfe | 429 | waitret = wait_event_interruptible_timeout(*chan->ops->get_reader_wait_queue(chan->chan), |
1ec3f75a | 430 | ({ |
4e1f08f4 | 431 | ret = chan->ops->event_reserve(&ctx, 0); |
1ec3f75a MD |
432 | ret != -ENOBUFS || !ret; |
433 | }), | |
434 | msecs_to_jiffies(LTTNG_METADATA_TIMEOUT_MSEC)); | |
435 | if (!waitret || waitret == -ERESTARTSYS || ret) { | |
436 | printk(KERN_WARNING "LTTng: Failure to write metadata to buffers (%s)\n", | |
437 | waitret == -ERESTARTSYS ? "interrupted" : | |
438 | (ret == -ENOBUFS ? "timeout" : "I/O error")); | |
439 | if (waitret == -ERESTARTSYS) | |
440 | ret = waitret; | |
441 | goto end; | |
442 | } | |
f5cf8eff | 443 | chan->ops->event_write(&ctx, &str[pos], reserve_len); |
1ec3f75a | 444 | chan->ops->event_commit(&ctx); |
c099397a | 445 | } |
c099397a MD |
446 | end: |
447 | kfree(str); | |
448 | return ret; | |
449 | } | |
450 | ||
451 | static | |
8070f5c0 MD |
452 | int _ltt_field_statedump(struct ltt_session *session, |
453 | const struct lttng_event_field *field) | |
c099397a | 454 | { |
c099397a | 455 | int ret = 0; |
c099397a | 456 | |
8070f5c0 MD |
457 | switch (field->type.atype) { |
458 | case atype_integer: | |
459 | ret = lttng_metadata_printf(session, | |
460 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s;\n", | |
461 | field->type.u.basic.integer.size, | |
462 | field->type.u.basic.integer.alignment, | |
463 | field->type.u.basic.integer.signedness, | |
464 | (field->type.u.basic.integer.encoding == lttng_encode_none) | |
465 | ? "none" | |
466 | : (field->type.u.basic.integer.encoding == lttng_encode_UTF8) | |
467 | ? "UTF8" | |
468 | : "ASCII", | |
469 | field->type.u.basic.integer.base, | |
c099397a | 470 | #ifdef __BIG_ENDIAN |
8070f5c0 | 471 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
c099397a | 472 | #else |
8070f5c0 | 473 | field->type.u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
c099397a | 474 | #endif |
8070f5c0 MD |
475 | field->name); |
476 | break; | |
477 | case atype_enum: | |
478 | ret = lttng_metadata_printf(session, | |
479 | " %s %s;\n", | |
480 | field->type.u.basic.enumeration.name, | |
481 | field->name); | |
482 | break; | |
483 | case atype_array: | |
484 | { | |
485 | const struct lttng_basic_type *elem_type; | |
486 | ||
487 | elem_type = &field->type.u.array.elem_type; | |
488 | ret = lttng_metadata_printf(session, | |
489 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[%u];\n", | |
490 | elem_type->u.basic.integer.size, | |
491 | elem_type->u.basic.integer.alignment, | |
492 | elem_type->u.basic.integer.signedness, | |
493 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
494 | ? "none" | |
495 | : (elem_type->u.basic.integer.encoding == lttng_encode_UTF8) | |
496 | ? "UTF8" | |
497 | : "ASCII", | |
498 | elem_type->u.basic.integer.base, | |
8fa75f34 | 499 | #ifdef __BIG_ENDIAN |
8070f5c0 | 500 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
8fa75f34 | 501 | #else |
8070f5c0 | 502 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
8fa75f34 | 503 | #endif |
8070f5c0 MD |
504 | field->name, field->type.u.array.length); |
505 | break; | |
506 | } | |
507 | case atype_sequence: | |
508 | { | |
509 | const struct lttng_basic_type *elem_type; | |
510 | const struct lttng_basic_type *length_type; | |
511 | ||
512 | elem_type = &field->type.u.sequence.elem_type; | |
513 | length_type = &field->type.u.sequence.length_type; | |
514 | ret = lttng_metadata_printf(session, | |
515 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } __%s_length;\n", | |
8070f5c0 | 516 | length_type->u.basic.integer.size, |
32257272 | 517 | (unsigned int) length_type->u.basic.integer.alignment, |
8070f5c0 MD |
518 | length_type->u.basic.integer.signedness, |
519 | (length_type->u.basic.integer.encoding == lttng_encode_none) | |
520 | ? "none" | |
0635cdd4 | 521 | : ((length_type->u.basic.integer.encoding == lttng_encode_UTF8) |
8070f5c0 | 522 | ? "UTF8" |
0635cdd4 | 523 | : "ASCII"), |
8070f5c0 | 524 | length_type->u.basic.integer.base, |
e0a7a7c4 | 525 | #ifdef __BIG_ENDIAN |
8070f5c0 | 526 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
e0a7a7c4 | 527 | #else |
0635cdd4 | 528 | length_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
e0a7a7c4 | 529 | #endif |
27d2368e MD |
530 | field->name); |
531 | if (ret) | |
532 | return ret; | |
533 | ||
534 | ret = lttng_metadata_printf(session, | |
535 | " integer { size = %u; align = %u; signed = %u; encoding = %s; base = %u;%s } %s[ __%s_length ];\n", | |
8070f5c0 | 536 | elem_type->u.basic.integer.size, |
32257272 | 537 | (unsigned int) elem_type->u.basic.integer.alignment, |
8070f5c0 MD |
538 | elem_type->u.basic.integer.signedness, |
539 | (elem_type->u.basic.integer.encoding == lttng_encode_none) | |
540 | ? "none" | |
0635cdd4 | 541 | : ((elem_type->u.basic.integer.encoding == lttng_encode_UTF8) |
8070f5c0 | 542 | ? "UTF8" |
0635cdd4 | 543 | : "ASCII"), |
8070f5c0 | 544 | elem_type->u.basic.integer.base, |
8fa75f34 | 545 | #ifdef __BIG_ENDIAN |
8070f5c0 | 546 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = le;" : "", |
8fa75f34 | 547 | #else |
8070f5c0 | 548 | elem_type->u.basic.integer.reverse_byte_order ? " byte_order = be;" : "", |
8fa75f34 | 549 | #endif |
8070f5c0 | 550 | field->name, |
27d2368e | 551 | field->name); |
8070f5c0 MD |
552 | break; |
553 | } | |
c099397a | 554 | |
8070f5c0 MD |
555 | case atype_string: |
556 | /* Default encoding is UTF8 */ | |
557 | ret = lttng_metadata_printf(session, | |
558 | " string%s %s;\n", | |
559 | field->type.u.basic.string.encoding == lttng_encode_ASCII ? | |
560 | " { encoding = ASCII; }" : "", | |
561 | field->name); | |
562 | break; | |
563 | default: | |
564 | WARN_ON_ONCE(1); | |
565 | return -EINVAL; | |
566 | } | |
567 | return ret; | |
568 | } | |
569 | ||
570 | static | |
571 | int _ltt_context_metadata_statedump(struct ltt_session *session, | |
572 | struct lttng_ctx *ctx) | |
573 | { | |
574 | int ret = 0; | |
575 | int i; | |
576 | ||
577 | if (!ctx) | |
578 | return 0; | |
579 | for (i = 0; i < ctx->nr_fields; i++) { | |
580 | const struct lttng_ctx_field *field = &ctx->fields[i]; | |
581 | ||
582 | ret = _ltt_field_statedump(session, &field->event_field); | |
583 | if (ret) | |
584 | return ret; | |
585 | } | |
586 | return ret; | |
587 | } | |
588 | ||
589 | static | |
590 | int _ltt_fields_metadata_statedump(struct ltt_session *session, | |
591 | struct ltt_event *event) | |
592 | { | |
593 | const struct lttng_event_desc *desc = event->desc; | |
594 | int ret = 0; | |
595 | int i; | |
596 | ||
597 | for (i = 0; i < desc->nr_fields; i++) { | |
598 | const struct lttng_event_field *field = &desc->fields[i]; | |
599 | ||
600 | ret = _ltt_field_statedump(session, field); | |
601 | if (ret) | |
602 | return ret; | |
c099397a MD |
603 | } |
604 | return ret; | |
605 | } | |
606 | ||
607 | static | |
608 | int _ltt_event_metadata_statedump(struct ltt_session *session, | |
609 | struct ltt_channel *chan, | |
610 | struct ltt_event *event) | |
611 | { | |
612 | int ret = 0; | |
613 | ||
614 | if (event->metadata_dumped || !ACCESS_ONCE(session->active)) | |
615 | return 0; | |
616 | if (chan == session->metadata) | |
617 | return 0; | |
618 | ||
619 | ret = lttng_metadata_printf(session, | |
620 | "event {\n" | |
621 | " name = %s;\n" | |
622 | " id = %u;\n" | |
b9074a1b | 623 | " stream_id = %u;\n", |
c099397a MD |
624 | event->desc->name, |
625 | event->id, | |
626 | event->chan->id); | |
627 | if (ret) | |
628 | goto end; | |
629 | ||
b9074a1b MD |
630 | if (event->ctx) { |
631 | ret = lttng_metadata_printf(session, | |
632 | " context := struct {\n"); | |
633 | if (ret) | |
634 | goto end; | |
635 | } | |
8070f5c0 MD |
636 | ret = _ltt_context_metadata_statedump(session, event->ctx); |
637 | if (ret) | |
638 | goto end; | |
b9074a1b MD |
639 | if (event->ctx) { |
640 | ret = lttng_metadata_printf(session, | |
641 | " };\n"); | |
642 | if (ret) | |
643 | goto end; | |
644 | } | |
8070f5c0 MD |
645 | |
646 | ret = lttng_metadata_printf(session, | |
8070f5c0 MD |
647 | " fields := struct {\n" |
648 | ); | |
649 | if (ret) | |
650 | goto end; | |
651 | ||
c099397a MD |
652 | ret = _ltt_fields_metadata_statedump(session, event); |
653 | if (ret) | |
654 | goto end; | |
655 | ||
656 | /* | |
657 | * LTTng space reservation can only reserve multiples of the | |
658 | * byte size. | |
659 | */ | |
660 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
661 | " };\n" |
662 | "};\n\n"); | |
c099397a MD |
663 | if (ret) |
664 | goto end; | |
665 | ||
c099397a MD |
666 | event->metadata_dumped = 1; |
667 | end: | |
668 | return ret; | |
669 | ||
670 | } | |
671 | ||
672 | static | |
673 | int _ltt_channel_metadata_statedump(struct ltt_session *session, | |
674 | struct ltt_channel *chan) | |
675 | { | |
676 | int ret = 0; | |
677 | ||
678 | if (chan->metadata_dumped || !ACCESS_ONCE(session->active)) | |
679 | return 0; | |
680 | if (chan == session->metadata) | |
681 | return 0; | |
682 | ||
683 | WARN_ON_ONCE(!chan->header_type); | |
684 | ret = lttng_metadata_printf(session, | |
685 | "stream {\n" | |
686 | " id = %u;\n" | |
9115fbdc | 687 | " event.header := %s;\n" |
b9074a1b | 688 | " packet.context := struct packet_context;\n", |
c099397a MD |
689 | chan->id, |
690 | chan->header_type == 1 ? "struct event_header_compact" : | |
691 | "struct event_header_large"); | |
692 | if (ret) | |
693 | goto end; | |
694 | ||
b9074a1b MD |
695 | if (chan->ctx) { |
696 | ret = lttng_metadata_printf(session, | |
697 | " event.context := struct {\n"); | |
698 | if (ret) | |
699 | goto end; | |
700 | } | |
8070f5c0 MD |
701 | ret = _ltt_context_metadata_statedump(session, chan->ctx); |
702 | if (ret) | |
703 | goto end; | |
b9074a1b MD |
704 | if (chan->ctx) { |
705 | ret = lttng_metadata_printf(session, | |
706 | " };\n"); | |
707 | if (ret) | |
708 | goto end; | |
709 | } | |
8070f5c0 MD |
710 | |
711 | ret = lttng_metadata_printf(session, | |
b9074a1b | 712 | "};\n\n"); |
8070f5c0 | 713 | |
c099397a MD |
714 | chan->metadata_dumped = 1; |
715 | end: | |
716 | return ret; | |
717 | } | |
718 | ||
9115fbdc MD |
719 | static |
720 | int _ltt_stream_packet_context_declare(struct ltt_session *session) | |
721 | { | |
722 | return lttng_metadata_printf(session, | |
723 | "struct packet_context {\n" | |
724 | " uint64_t timestamp_begin;\n" | |
725 | " uint64_t timestamp_end;\n" | |
726 | " uint32_t events_discarded;\n" | |
727 | " uint32_t content_size;\n" | |
728 | " uint32_t packet_size;\n" | |
729 | " uint32_t cpu_id;\n" | |
c6dfdf6f | 730 | "};\n\n" |
9115fbdc MD |
731 | ); |
732 | } | |
733 | ||
734 | /* | |
735 | * Compact header: | |
736 | * id: range: 0 - 30. | |
737 | * id 31 is reserved to indicate an extended header. | |
738 | * | |
739 | * Large header: | |
740 | * id: range: 0 - 65534. | |
741 | * id 65535 is reserved to indicate an extended header. | |
742 | */ | |
743 | static | |
744 | int _ltt_event_header_declare(struct ltt_session *session) | |
745 | { | |
746 | return lttng_metadata_printf(session, | |
747 | "struct event_header_compact {\n" | |
748 | " enum : uint5_t { compact = 0 ... 30, extended = 31 } id;\n" | |
749 | " variant <id> {\n" | |
750 | " struct {\n" | |
751 | " uint27_t timestamp;\n" | |
752 | " } compact;\n" | |
753 | " struct {\n" | |
754 | " uint32_t id;\n" | |
755 | " uint64_t timestamp;\n" | |
756 | " } extended;\n" | |
757 | " } v;\n" | |
758 | "} align(%u);\n" | |
759 | "\n" | |
760 | "struct event_header_large {\n" | |
761 | " enum : uint16_t { compact = 0 ... 65534, extended = 65535 } id;\n" | |
762 | " variant <id> {\n" | |
763 | " struct {\n" | |
764 | " uint32_t timestamp;\n" | |
765 | " } compact;\n" | |
766 | " struct {\n" | |
767 | " uint32_t id;\n" | |
768 | " uint64_t timestamp;\n" | |
769 | " } extended;\n" | |
770 | " } v;\n" | |
771 | "} align(%u);\n\n", | |
772 | ltt_alignof(uint32_t) * CHAR_BIT, | |
773 | ltt_alignof(uint16_t) * CHAR_BIT | |
774 | ); | |
775 | } | |
776 | ||
c099397a MD |
777 | /* |
778 | * Output metadata into this session's metadata buffers. | |
779 | */ | |
780 | static | |
781 | int _ltt_session_metadata_statedump(struct ltt_session *session) | |
782 | { | |
30bdb6e4 MD |
783 | unsigned char *uuid_c = session->uuid.b; |
784 | unsigned char uuid_s[37]; | |
c099397a MD |
785 | struct ltt_channel *chan; |
786 | struct ltt_event *event; | |
787 | int ret = 0; | |
788 | ||
789 | if (!ACCESS_ONCE(session->active)) | |
790 | return 0; | |
791 | if (session->metadata_dumped) | |
792 | goto skip_session; | |
f40270ad | 793 | if (!session->metadata) { |
cd4bd11f | 794 | printk(KERN_WARNING "LTTng: attempt to start tracing, but metadata channel is not found. Operation abort.\n"); |
f40270ad MD |
795 | return -EPERM; |
796 | } | |
c099397a | 797 | |
d793d5e1 | 798 | snprintf(uuid_s, sizeof(uuid_s), |
30bdb6e4 MD |
799 | "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", |
800 | uuid_c[0], uuid_c[1], uuid_c[2], uuid_c[3], | |
801 | uuid_c[4], uuid_c[5], uuid_c[6], uuid_c[7], | |
802 | uuid_c[8], uuid_c[9], uuid_c[10], uuid_c[11], | |
803 | uuid_c[12], uuid_c[13], uuid_c[14], uuid_c[15]); | |
d793d5e1 MD |
804 | |
805 | ret = lttng_metadata_printf(session, | |
9115fbdc MD |
806 | "typealias integer { size = 8; align = %u; signed = false; } := uint8_t;\n" |
807 | "typealias integer { size = 16; align = %u; signed = false; } := uint16_t;\n" | |
808 | "typealias integer { size = 32; align = %u; signed = false; } := uint32_t;\n" | |
809 | "typealias integer { size = 64; align = %u; signed = false; } := uint64_t;\n" | |
810 | "typealias integer { size = 5; align = 1; signed = false; } := uint5_t;\n" | |
811 | "typealias integer { size = 27; align = 1; signed = false; } := uint27_t;\n" | |
d793d5e1 MD |
812 | "\n" |
813 | "trace {\n" | |
814 | " major = %u;\n" | |
815 | " minor = %u;\n" | |
30bdb6e4 | 816 | " uuid = \"%s\";\n" |
d793d5e1 MD |
817 | " byte_order = %s;\n" |
818 | " packet.header := struct {\n" | |
819 | " uint32_t magic;\n" | |
1ec3f75a | 820 | " uint8_t uuid[16];\n" |
d793d5e1 | 821 | " uint32_t stream_id;\n" |
0eb25f58 | 822 | " };\n" |
d793d5e1 MD |
823 | "};\n\n", |
824 | ltt_alignof(uint8_t) * CHAR_BIT, | |
0eb25f58 | 825 | ltt_alignof(uint16_t) * CHAR_BIT, |
d793d5e1 MD |
826 | ltt_alignof(uint32_t) * CHAR_BIT, |
827 | ltt_alignof(uint64_t) * CHAR_BIT, | |
828 | CTF_VERSION_MAJOR, | |
829 | CTF_VERSION_MINOR, | |
830 | uuid_s, | |
831 | #ifdef __BIG_ENDIAN | |
832 | "be" | |
833 | #else | |
834 | "le" | |
835 | #endif | |
836 | ); | |
837 | if (ret) | |
838 | goto end; | |
839 | ||
9115fbdc MD |
840 | ret = _ltt_stream_packet_context_declare(session); |
841 | if (ret) | |
842 | goto end; | |
843 | ||
844 | ret = _ltt_event_header_declare(session); | |
845 | if (ret) | |
846 | goto end; | |
847 | ||
c099397a MD |
848 | skip_session: |
849 | list_for_each_entry(chan, &session->chan, list) { | |
850 | ret = _ltt_channel_metadata_statedump(session, chan); | |
851 | if (ret) | |
852 | goto end; | |
853 | } | |
854 | ||
855 | list_for_each_entry(event, &session->events, list) { | |
91e0dcaa | 856 | ret = _ltt_event_metadata_statedump(session, event->chan, event); |
c099397a MD |
857 | if (ret) |
858 | goto end; | |
859 | } | |
860 | session->metadata_dumped = 1; | |
861 | end: | |
862 | return ret; | |
863 | } | |
864 | ||
c0e31d2e MD |
865 | /** |
866 | * ltt_transport_register - LTT transport registration | |
867 | * @transport: transport structure | |
868 | * | |
869 | * Registers a transport which can be used as output to extract the data out of | |
870 | * LTTng. The module calling this registration function must ensure that no | |
871 | * trap-inducing code will be executed by the transport functions. E.g. | |
872 | * vmalloc_sync_all() must be called between a vmalloc and the moment the memory | |
873 | * is made visible to the transport function. This registration acts as a | |
874 | * vmalloc_sync_all. Therefore, only if the module allocates virtual memory | |
875 | * after its registration must it synchronize the TLBs. | |
876 | */ | |
877 | void ltt_transport_register(struct ltt_transport *transport) | |
878 | { | |
879 | /* | |
880 | * Make sure no page fault can be triggered by the module about to be | |
881 | * registered. We deal with this here so we don't have to call | |
882 | * vmalloc_sync_all() in each module's init. | |
883 | */ | |
6d2a620c | 884 | wrapper_vmalloc_sync_all(); |
c0e31d2e MD |
885 | |
886 | mutex_lock(&sessions_mutex); | |
887 | list_add_tail(&transport->node, <t_transport_list); | |
888 | mutex_unlock(&sessions_mutex); | |
889 | } | |
890 | EXPORT_SYMBOL_GPL(ltt_transport_register); | |
891 | ||
892 | /** | |
893 | * ltt_transport_unregister - LTT transport unregistration | |
894 | * @transport: transport structure | |
895 | */ | |
896 | void ltt_transport_unregister(struct ltt_transport *transport) | |
897 | { | |
898 | mutex_lock(&sessions_mutex); | |
899 | list_del(&transport->node); | |
900 | mutex_unlock(&sessions_mutex); | |
901 | } | |
902 | EXPORT_SYMBOL_GPL(ltt_transport_unregister); | |
903 | ||
4e3c1b9b MD |
904 | static int __init ltt_events_init(void) |
905 | { | |
1c25284c MD |
906 | int ret; |
907 | ||
11b5a3c2 MD |
908 | event_cache = KMEM_CACHE(ltt_event, 0); |
909 | if (!event_cache) | |
4e3c1b9b | 910 | return -ENOMEM; |
02119ee5 MD |
911 | ret = ltt_debugfs_abi_init(); |
912 | if (ret) | |
913 | goto error_abi; | |
4e3c1b9b | 914 | return 0; |
02119ee5 | 915 | error_abi: |
1c25284c MD |
916 | kmem_cache_destroy(event_cache); |
917 | return ret; | |
4e3c1b9b MD |
918 | } |
919 | ||
11b5a3c2 MD |
920 | module_init(ltt_events_init); |
921 | ||
4e3c1b9b MD |
922 | static void __exit ltt_events_exit(void) |
923 | { | |
92e94819 MD |
924 | struct ltt_session *session, *tmpsession; |
925 | ||
1c25284c | 926 | ltt_debugfs_abi_exit(); |
92e94819 MD |
927 | list_for_each_entry_safe(session, tmpsession, &sessions, list) |
928 | ltt_session_destroy(session); | |
11b5a3c2 | 929 | kmem_cache_destroy(event_cache); |
4e3c1b9b | 930 | } |
92e94819 | 931 | |
11b5a3c2 MD |
932 | module_exit(ltt_events_exit); |
933 | ||
92e94819 MD |
934 | MODULE_LICENSE("GPL and additional rights"); |
935 | MODULE_AUTHOR("Mathieu Desnoyers <mathieu.desnoyers@efficios.com>"); | |
936 | MODULE_DESCRIPTION("LTTng Events"); |