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