Fix RCU-related hangs: incorrect lttng_ht_destroy use
[lttng-tools.git] / src / bin / lttng-sessiond / trace-kernel.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
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 <common/common.h>
25 #include <common/defaults.h>
26
27 #include "consumer.h"
28 #include "trace-kernel.h"
29
30 /*
31 * Find the channel name for the given kernel session.
32 */
33 struct ltt_kernel_channel *trace_kernel_get_channel_by_name(
34 char *name, struct ltt_kernel_session *session)
35 {
36 struct ltt_kernel_channel *chan;
37
38 assert(session);
39 assert(name);
40
41 DBG("Trying to find channel %s", name);
42
43 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
44 if (strcmp(name, chan->channel->name) == 0) {
45 DBG("Found channel by name %s", name);
46 return chan;
47 }
48 }
49
50 return NULL;
51 }
52
53 /*
54 * Find the event name for the given channel.
55 */
56 struct ltt_kernel_event *trace_kernel_get_event_by_name(
57 char *name, struct ltt_kernel_channel *channel)
58 {
59 struct ltt_kernel_event *ev;
60
61 assert(name);
62 assert(channel);
63
64 cds_list_for_each_entry(ev, &channel->events_list.head, list) {
65 if (strcmp(name, ev->event->name) == 0) {
66 DBG("Found event by name %s for channel %s", name,
67 channel->channel->name);
68 return ev;
69 }
70 }
71
72 return NULL;
73 }
74
75 /*
76 * Allocate and initialize a kernel session data structure.
77 *
78 * Return pointer to structure or NULL.
79 */
80 struct ltt_kernel_session *trace_kernel_create_session(void)
81 {
82 struct ltt_kernel_session *lks = NULL;
83
84 /* Allocate a new ltt kernel session */
85 lks = zmalloc(sizeof(struct ltt_kernel_session));
86 if (lks == NULL) {
87 PERROR("create kernel session zmalloc");
88 goto alloc_error;
89 }
90
91 /* Init data structure */
92 lks->fd = -1;
93 lks->metadata_stream_fd = -1;
94 lks->channel_count = 0;
95 lks->stream_count_global = 0;
96 lks->metadata = NULL;
97 CDS_INIT_LIST_HEAD(&lks->channel_list.head);
98
99 lks->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
100 if (lks->consumer == NULL) {
101 goto error;
102 }
103
104 /*
105 * The tmp_consumer stays NULL until a set_consumer_uri command is
106 * executed. At this point, the consumer should be nullify until an
107 * enable_consumer command. This assignment is symbolic since we've zmalloc
108 * the struct.
109 */
110 lks->tmp_consumer = NULL;
111
112 return lks;
113
114 error:
115 free(lks);
116
117 alloc_error:
118 return NULL;
119 }
120
121 /*
122 * Allocate and initialize a kernel channel data structure.
123 *
124 * Return pointer to structure or NULL.
125 */
126 struct ltt_kernel_channel *trace_kernel_create_channel(
127 struct lttng_channel *chan)
128 {
129 struct ltt_kernel_channel *lkc;
130
131 assert(chan);
132
133 lkc = zmalloc(sizeof(struct ltt_kernel_channel));
134 if (lkc == NULL) {
135 PERROR("ltt_kernel_channel zmalloc");
136 goto error;
137 }
138
139 lkc->channel = zmalloc(sizeof(struct lttng_channel));
140 if (lkc->channel == NULL) {
141 PERROR("lttng_channel zmalloc");
142 free(lkc);
143 goto error;
144 }
145 memcpy(lkc->channel, chan, sizeof(struct lttng_channel));
146
147 lkc->fd = -1;
148 lkc->stream_count = 0;
149 lkc->event_count = 0;
150 lkc->enabled = 1;
151 lkc->ctx = NULL;
152 /* Init linked list */
153 CDS_INIT_LIST_HEAD(&lkc->events_list.head);
154 CDS_INIT_LIST_HEAD(&lkc->stream_list.head);
155
156 return lkc;
157
158 error:
159 return NULL;
160 }
161
162 /*
163 * Allocate and initialize a kernel event. Set name and event type.
164 *
165 * Return pointer to structure or NULL.
166 */
167 struct ltt_kernel_event *trace_kernel_create_event(struct lttng_event *ev)
168 {
169 struct ltt_kernel_event *lke;
170 struct lttng_kernel_event *attr;
171
172 assert(ev);
173
174 lke = zmalloc(sizeof(struct ltt_kernel_event));
175 attr = zmalloc(sizeof(struct lttng_kernel_event));
176 if (lke == NULL || attr == NULL) {
177 PERROR("kernel event zmalloc");
178 goto error;
179 }
180
181 switch (ev->type) {
182 case LTTNG_EVENT_PROBE:
183 attr->instrumentation = LTTNG_KERNEL_KPROBE;
184 attr->u.kprobe.addr = ev->attr.probe.addr;
185 attr->u.kprobe.offset = ev->attr.probe.offset;
186 strncpy(attr->u.kprobe.symbol_name,
187 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
188 attr->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
189 break;
190 case LTTNG_EVENT_FUNCTION:
191 attr->instrumentation = LTTNG_KERNEL_KRETPROBE;
192 attr->u.kretprobe.addr = ev->attr.probe.addr;
193 attr->u.kretprobe.offset = ev->attr.probe.offset;
194 attr->u.kretprobe.offset = ev->attr.probe.offset;
195 strncpy(attr->u.kretprobe.symbol_name,
196 ev->attr.probe.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
197 attr->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
198 break;
199 case LTTNG_EVENT_FUNCTION_ENTRY:
200 attr->instrumentation = LTTNG_KERNEL_FUNCTION;
201 strncpy(attr->u.ftrace.symbol_name,
202 ev->attr.ftrace.symbol_name, LTTNG_KERNEL_SYM_NAME_LEN);
203 attr->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
204 break;
205 case LTTNG_EVENT_TRACEPOINT:
206 attr->instrumentation = LTTNG_KERNEL_TRACEPOINT;
207 break;
208 case LTTNG_EVENT_SYSCALL:
209 attr->instrumentation = LTTNG_KERNEL_SYSCALL;
210 break;
211 case LTTNG_EVENT_ALL:
212 attr->instrumentation = LTTNG_KERNEL_ALL;
213 break;
214 default:
215 ERR("Unknown kernel instrumentation type (%d)", ev->type);
216 goto error;
217 }
218
219 /* Copy event name */
220 strncpy(attr->name, ev->name, LTTNG_KERNEL_SYM_NAME_LEN);
221 attr->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
222
223 /* Setting up a kernel event */
224 lke->fd = -1;
225 lke->event = attr;
226 lke->enabled = 1;
227
228 return lke;
229
230 error:
231 free(lke);
232 free(attr);
233 return NULL;
234 }
235
236 /*
237 * Allocate and initialize a kernel metadata.
238 *
239 * Return pointer to structure or NULL.
240 */
241 struct ltt_kernel_metadata *trace_kernel_create_metadata(void)
242 {
243 struct ltt_kernel_metadata *lkm;
244 struct lttng_channel *chan;
245
246 lkm = zmalloc(sizeof(struct ltt_kernel_metadata));
247 chan = zmalloc(sizeof(struct lttng_channel));
248 if (lkm == NULL || chan == NULL) {
249 PERROR("kernel metadata zmalloc");
250 goto error;
251 }
252
253 /* Set default attributes */
254 chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
255 chan->attr.subbuf_size = default_get_metadata_subbuf_size();
256 chan->attr.num_subbuf = DEFAULT_METADATA_SUBBUF_NUM;
257 chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER;
258 chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER;
259 chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
260
261 /* Init metadata */
262 lkm->fd = -1;
263 lkm->conf = chan;
264
265 return lkm;
266
267 error:
268 free(lkm);
269 free(chan);
270 return NULL;
271 }
272
273 /*
274 * Allocate and initialize a kernel stream. The stream is set to ACTIVE_FD by
275 * default.
276 *
277 * Return pointer to structure or NULL.
278 */
279 struct ltt_kernel_stream *trace_kernel_create_stream(const char *name,
280 unsigned int count)
281 {
282 int ret;
283 struct ltt_kernel_stream *lks;
284
285 assert(name);
286
287 lks = zmalloc(sizeof(struct ltt_kernel_stream));
288 if (lks == NULL) {
289 PERROR("kernel stream zmalloc");
290 goto error;
291 }
292
293 /* Set name */
294 ret = snprintf(lks->name, sizeof(lks->name), "%s_%d", name, count);
295 if (ret < 0) {
296 PERROR("snprintf stream name");
297 goto error;
298 }
299 lks->name[sizeof(lks->name) - 1] = '\0';
300
301 /* Init stream */
302 lks->fd = -1;
303 lks->state = 0;
304 lks->cpu = count;
305
306 return lks;
307
308 error:
309 return NULL;
310 }
311
312 /*
313 * Cleanup kernel stream structure.
314 */
315 void trace_kernel_destroy_stream(struct ltt_kernel_stream *stream)
316 {
317 assert(stream);
318
319 DBG("[trace] Closing stream fd %d", stream->fd);
320 /* Close kernel fd */
321 if (stream->fd >= 0) {
322 int ret;
323
324 ret = close(stream->fd);
325 if (ret) {
326 PERROR("close");
327 }
328 }
329 /* Remove from stream list */
330 cds_list_del(&stream->list);
331
332 free(stream);
333 }
334
335 /*
336 * Cleanup kernel event structure.
337 */
338 void trace_kernel_destroy_event(struct ltt_kernel_event *event)
339 {
340 assert(event);
341
342 if (event->fd >= 0) {
343 int ret;
344
345 DBG("[trace] Closing event fd %d", event->fd);
346 /* Close kernel fd */
347 ret = close(event->fd);
348 if (ret) {
349 PERROR("close");
350 }
351 } else {
352 DBG("[trace] Tearing down event (no associated fd)");
353 }
354
355 /* Remove from event list */
356 cds_list_del(&event->list);
357
358 free(event->event);
359 free(event);
360 }
361
362 /*
363 * Cleanup kernel channel structure.
364 */
365 void trace_kernel_destroy_channel(struct ltt_kernel_channel *channel)
366 {
367 struct ltt_kernel_stream *stream, *stmp;
368 struct ltt_kernel_event *event, *etmp;
369 int ret;
370
371 assert(channel);
372
373 DBG("[trace] Closing channel fd %d", channel->fd);
374 /* Close kernel fd */
375 if (channel->fd >= 0) {
376 ret = close(channel->fd);
377 if (ret) {
378 PERROR("close");
379 }
380 }
381
382 /* For each stream in the channel list */
383 cds_list_for_each_entry_safe(stream, stmp, &channel->stream_list.head, list) {
384 trace_kernel_destroy_stream(stream);
385 }
386
387 /* For each event in the channel list */
388 cds_list_for_each_entry_safe(event, etmp, &channel->events_list.head, list) {
389 trace_kernel_destroy_event(event);
390 }
391
392 /* Remove from channel list */
393 cds_list_del(&channel->list);
394
395 free(channel->channel);
396 free(channel->ctx);
397 free(channel);
398 }
399
400 /*
401 * Cleanup kernel metadata structure.
402 */
403 void trace_kernel_destroy_metadata(struct ltt_kernel_metadata *metadata)
404 {
405 assert(metadata);
406
407 DBG("[trace] Closing metadata fd %d", metadata->fd);
408 /* Close kernel fd */
409 if (metadata->fd >= 0) {
410 int ret;
411
412 ret = close(metadata->fd);
413 if (ret) {
414 PERROR("close");
415 }
416 }
417
418 free(metadata->conf);
419 free(metadata);
420 }
421
422 /*
423 * Cleanup kernel session structure
424 *
425 * Should *NOT* be called with RCU read-side lock held.
426 */
427 void trace_kernel_destroy_session(struct ltt_kernel_session *session)
428 {
429 struct ltt_kernel_channel *channel, *ctmp;
430 int ret;
431
432 assert(session);
433
434 DBG("[trace] Closing session fd %d", session->fd);
435 /* Close kernel fds */
436 if (session->fd >= 0) {
437 ret = close(session->fd);
438 if (ret) {
439 PERROR("close");
440 }
441 }
442
443 if (session->metadata_stream_fd >= 0) {
444 DBG("[trace] Closing metadata stream fd %d", session->metadata_stream_fd);
445 ret = close(session->metadata_stream_fd);
446 if (ret) {
447 PERROR("close");
448 }
449 }
450
451 if (session->metadata != NULL) {
452 trace_kernel_destroy_metadata(session->metadata);
453 }
454
455 cds_list_for_each_entry_safe(channel, ctmp, &session->channel_list.head, list) {
456 trace_kernel_destroy_channel(channel);
457 }
458
459 /* Wipe consumer output object */
460 consumer_destroy_output(session->consumer);
461 consumer_destroy_output(session->tmp_consumer);
462
463 free(session);
464 }
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