Add auto start UST trace support
[lttng-tools.git] / lttng-sessiond / trace-ust.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; only version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307, USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include <lttngerr.h>
25 #include <lttng-share.h>
26
27 #include "hashtable.h"
28 #include "trace-ust.h"
29
30 /*
31 * Find the channel in the hashtable.
32 */
33 struct ltt_ust_channel *trace_ust_find_channel_by_name(struct cds_lfht *ht,
34 char *name)
35 {
36 struct cds_lfht_node *node;
37 struct cds_lfht_iter iter;
38
39 rcu_read_lock();
40 node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
41 if (node == NULL) {
42 rcu_read_unlock();
43 goto error;
44 }
45 rcu_read_unlock();
46
47 DBG2("Trace UST channel %s found by name", name);
48
49 return caa_container_of(node, struct ltt_ust_channel, node);
50
51 error:
52 DBG2("Trace UST channel %s not found by name", name);
53 return NULL;
54 }
55
56 /*
57 * Find the event in the hashtable.
58 */
59 struct ltt_ust_event *trace_ust_find_event_by_name(struct cds_lfht *ht,
60 char *name)
61 {
62 struct cds_lfht_node *node;
63 struct cds_lfht_iter iter;
64
65 rcu_read_lock();
66 node = hashtable_lookup(ht, (void *) name, strlen(name), &iter);
67 if (node == NULL) {
68 rcu_read_unlock();
69 goto error;
70 }
71 rcu_read_unlock();
72
73 DBG2("Found UST event by name %s", name);
74
75 return caa_container_of(node, struct ltt_ust_event, node);
76
77 error:
78 return NULL;
79 }
80
81 /*
82 * Allocate and initialize a ust session data structure.
83 *
84 * Return pointer to structure or NULL.
85 */
86 struct ltt_ust_session *trace_ust_create_session(char *path, unsigned int uid,
87 struct lttng_domain *domain)
88 {
89 int ret;
90 struct ltt_ust_session *lus;
91
92 /* Allocate a new ltt ust session */
93 lus = malloc(sizeof(struct ltt_ust_session));
94 if (lus == NULL) {
95 PERROR("create ust session malloc");
96 goto error;
97 }
98
99 /* Init data structure */
100 lus->consumer_fds_sent = 0;
101 lus->uid = uid;
102 lus->start_trace = 0;
103
104 /* Alloc UST domain hash tables */
105 lus->domain_pid = hashtable_new(0);
106 lus->domain_exec = hashtable_new_str(0);
107
108 /* Alloc UST global domain channels' HT */
109 lus->domain_global.channels = hashtable_new_str(0);
110
111 /* Set session path */
112 ret = snprintf(lus->pathname, PATH_MAX, "%s/ust", path);
113 if (ret < 0) {
114 PERROR("snprintf kernel traces path");
115 goto error;
116 }
117
118 DBG2("UST trace session create successful");
119
120 return lus;
121
122 error:
123 return NULL;
124 }
125
126 /*
127 * Allocate and initialize a ust channel data structure.
128 *
129 * Return pointer to structure or NULL.
130 */
131 struct ltt_ust_channel *trace_ust_create_channel(struct lttng_channel *chan,
132 char *path)
133 {
134 int ret;
135 struct ltt_ust_channel *luc;
136
137 luc = malloc(sizeof(struct ltt_ust_channel));
138 if (luc == NULL) {
139 perror("ltt_ust_channel malloc");
140 goto error;
141 }
142
143 /* Copy UST channel attributes */
144 luc->attr.overwrite = chan->attr.overwrite;
145 luc->attr.subbuf_size = chan->attr.subbuf_size;
146 luc->attr.num_subbuf = chan->attr.num_subbuf;
147 luc->attr.switch_timer_interval = chan->attr.switch_timer_interval;
148 luc->attr.read_timer_interval = chan->attr.read_timer_interval;
149 luc->attr.output = chan->attr.output;
150
151 /* Translate to UST output enum */
152 switch (luc->attr.output) {
153 default:
154 luc->attr.output = LTTNG_UST_MMAP;
155 break;
156 }
157
158 /* Copy channel name */
159 strncpy(luc->name, chan->name, sizeof(&luc->name));
160 luc->name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
161
162 /* Init node */
163 hashtable_node_init(&luc->node, (void *) luc->name, strlen(luc->name));
164 /* Alloc hash tables */
165 luc->events = hashtable_new_str(0);
166 luc->ctx = hashtable_new_str(0);
167
168 /* Set trace output path */
169 ret = snprintf(luc->pathname, PATH_MAX, "%s", path);
170 if (ret < 0) {
171 perror("asprintf ust create channel");
172 goto error;
173 }
174
175 DBG2("Trace UST channel %s created", luc->name);
176
177 return luc;
178
179 error:
180 return NULL;
181 }
182
183 /*
184 * Allocate and initialize a ust event. Set name and event type.
185 *
186 * Return pointer to structure or NULL.
187 */
188 struct ltt_ust_event *trace_ust_create_event(struct lttng_event *ev)
189 {
190 struct ltt_ust_event *lue;
191
192 lue = malloc(sizeof(struct ltt_ust_event));
193 if (lue == NULL) {
194 PERROR("ust event malloc");
195 goto error;
196 }
197
198 switch (ev->type) {
199 case LTTNG_EVENT_PROBE:
200 lue->attr.instrumentation = LTTNG_UST_PROBE;
201 break;
202 case LTTNG_EVENT_FUNCTION:
203 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
204 break;
205 case LTTNG_EVENT_FUNCTION_ENTRY:
206 lue->attr.instrumentation = LTTNG_UST_FUNCTION;
207 break;
208 case LTTNG_EVENT_TRACEPOINT:
209 lue->attr.instrumentation = LTTNG_UST_TRACEPOINT;
210 break;
211 default:
212 ERR("Unknown ust instrumentation type (%d)", ev->type);
213 goto error;
214 }
215
216 /* Copy event name */
217 strncpy(lue->attr.name, ev->name, LTTNG_UST_SYM_NAME_LEN);
218 lue->attr.name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
219
220 /* Init node */
221 hashtable_node_init(&lue->node, (void *) lue->attr.name,
222 strlen(lue->attr.name));
223 /* Alloc context hash tables */
224 lue->ctx = hashtable_new_str(5);
225
226 return lue;
227
228 error:
229 return NULL;
230 }
231
232 /*
233 * Allocate and initialize a ust metadata.
234 *
235 * Return pointer to structure or NULL.
236 */
237 struct ltt_ust_metadata *trace_ust_create_metadata(char *path)
238 {
239 int ret;
240 struct ltt_ust_metadata *lum;
241
242 lum = malloc(sizeof(struct ltt_ust_metadata));
243 if (lum == NULL) {
244 perror("ust metadata malloc");
245 goto error;
246 }
247
248 /* Set default attributes */
249 lum->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
250 lum->attr.subbuf_size = DEFAULT_METADATA_SUBBUF_SIZE;
251 lum->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
252 lum->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
253 lum->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
254 lum->attr.output = LTTNG_UST_MMAP;
255
256 lum->handle = -1;
257 /* Set metadata trace path */
258 ret = snprintf(lum->pathname, PATH_MAX, "%s/metadata", path);
259 if (ret < 0) {
260 perror("asprintf ust metadata");
261 goto error;
262 }
263
264 return lum;
265
266 error:
267 return NULL;
268 }
269
270 /*
271 * RCU safe free context structure.
272 */
273 static void destroy_context_rcu(struct rcu_head *head)
274 {
275 struct cds_lfht_node *node =
276 caa_container_of(head, struct cds_lfht_node, head);
277 struct ltt_ust_context *ctx =
278 caa_container_of(node, struct ltt_ust_context, node);
279
280 free(ctx);
281 }
282
283 /*
284 * Cleanup UST context hash table.
285 */
286 static void destroy_context(struct cds_lfht *ht)
287 {
288 int ret;
289 struct cds_lfht_node *node;
290 struct cds_lfht_iter iter;
291
292 hashtable_get_first(ht, &iter);
293 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
294 ret = hashtable_del(ht, &iter);
295 if (!ret) {
296 call_rcu(&node->head, destroy_context_rcu);
297 }
298 hashtable_get_next(ht, &iter);
299 }
300 }
301
302 /*
303 * Cleanup ust event structure.
304 */
305 void trace_ust_destroy_event(struct ltt_ust_event *event)
306 {
307 DBG2("Trace destroy UST event %s", event->attr.name);
308 destroy_context(event->ctx);
309 free(event);
310 }
311
312 /*
313 * URCU intermediate call to complete destroy event.
314 */
315 static void destroy_event_rcu(struct rcu_head *head)
316 {
317 struct cds_lfht_node *node =
318 caa_container_of(head, struct cds_lfht_node, head);
319 struct ltt_ust_event *event =
320 caa_container_of(node, struct ltt_ust_event, node);
321
322 trace_ust_destroy_event(event);
323 }
324
325 /*
326 * Cleanup ust channel structure.
327 */
328 void trace_ust_destroy_channel(struct ltt_ust_channel *channel)
329 {
330 int ret;
331 struct cds_lfht_node *node;
332 struct cds_lfht_iter iter;
333
334 DBG2("Trace destroy UST channel %s", channel->name);
335
336 rcu_read_lock();
337
338 hashtable_get_first(channel->events, &iter);
339 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
340 ret = hashtable_del(channel->events, &iter);
341 if (!ret) {
342 call_rcu(&node->head, destroy_event_rcu);
343 }
344 hashtable_get_next(channel->events, &iter);
345 }
346
347 free(channel->events);
348 destroy_context(channel->ctx);
349 free(channel);
350
351 rcu_read_unlock();
352 }
353
354 /*
355 * URCU intermediate call to complete destroy channel.
356 */
357 static void destroy_channel_rcu(struct rcu_head *head)
358 {
359 struct cds_lfht_node *node =
360 caa_container_of(head, struct cds_lfht_node, head);
361 struct ltt_ust_channel *channel =
362 caa_container_of(node, struct ltt_ust_channel, node);
363
364 trace_ust_destroy_channel(channel);
365 }
366
367 /*
368 * Cleanup ust metadata structure.
369 */
370 void trace_ust_destroy_metadata(struct ltt_ust_metadata *metadata)
371 {
372 DBG2("Trace UST destroy metadata %d", metadata->handle);
373
374 free(metadata);
375 }
376
377 /*
378 * Iterate over a hash table containing channels and cleanup safely.
379 */
380 static void destroy_channels(struct cds_lfht *channels)
381 {
382 int ret;
383 struct cds_lfht_node *node;
384 struct cds_lfht_iter iter;
385
386 hashtable_get_first(channels, &iter);
387 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
388 ret = hashtable_del(channels, &iter);
389 if (!ret) {
390 call_rcu(&node->head, destroy_channel_rcu);
391 }
392 hashtable_get_next(channels, &iter);
393 }
394 }
395
396 /*
397 * Cleanup UST pid domain.
398 */
399 static void destroy_domain_pid(struct cds_lfht *ht)
400 {
401 int ret;
402 struct cds_lfht_node *node;
403 struct cds_lfht_iter iter;
404 struct ltt_ust_domain_pid *d;
405
406 hashtable_get_first(ht, &iter);
407 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
408 ret = hashtable_del(ht , &iter);
409 if (!ret) {
410 d = caa_container_of(node, struct ltt_ust_domain_pid, node);
411 destroy_channels(d->channels);
412 }
413 hashtable_get_next(ht, &iter);
414 }
415 }
416
417 /*
418 * Cleanup UST exec name domain.
419 */
420 static void destroy_domain_exec(struct cds_lfht *ht)
421 {
422 int ret;
423 struct cds_lfht_node *node;
424 struct cds_lfht_iter iter;
425 struct ltt_ust_domain_exec *d;
426
427 hashtable_get_first(ht, &iter);
428 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
429 ret = hashtable_del(ht , &iter);
430 if (!ret) {
431 d = caa_container_of(node, struct ltt_ust_domain_exec, node);
432 destroy_channels(d->channels);
433 }
434 hashtable_get_next(ht, &iter);
435 }
436 }
437
438 /*
439 * Cleanup UST global domain.
440 */
441 static void destroy_domain_global(struct ltt_ust_domain_global *dom)
442 {
443 destroy_channels(dom->channels);
444 }
445
446 /*
447 * Cleanup ust session structure
448 */
449 void trace_ust_destroy_session(struct ltt_ust_session *session)
450 {
451 /* Extra safety */
452 if (session == NULL) {
453 return;
454 }
455
456 rcu_read_lock();
457
458 DBG2("Trace UST destroy session %d", session->uid);
459
460 //if (session->metadata != NULL) {
461 // trace_ust_destroy_metadata(session->metadata);
462 //}
463
464 /* Cleaning up UST domain */
465 destroy_domain_global(&session->domain_global);
466 destroy_domain_pid(session->domain_pid);
467 destroy_domain_exec(session->domain_exec);
468
469 free(session);
470
471 rcu_read_unlock();
472 }
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