Fix message argument type
[lttng-tools.git] / ltt-sessiond / kernel-ctl.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
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <errno.h>
21 #include <stdlib.h>
22 #include <stdio.h>
23 #include <string.h>
24 #include <unistd.h>
25
26 #include "lttngerr.h"
27 #include "ltt-sessiond.h"
28 #include "libkernelctl.h"
29 #include "kernel-ctl.h"
30
31 /*
32 * kernel_create_session
33 *
34 * Create a new kernel session, register it to the kernel tracer and add it to
35 * the session daemon session.
36 */
37 int kernel_create_session(struct ltt_session *session, int tracer_fd)
38 {
39 int ret;
40 struct ltt_kernel_session *lks;
41
42 /* Allocate data structure */
43 lks = trace_create_kernel_session();
44 if (lks == NULL) {
45 ret = -1;
46 goto error;
47 }
48
49 /* Kernel tracer session creation */
50 ret = kernctl_create_session(tracer_fd);
51 if (ret < 0) {
52 perror("ioctl kernel create session");
53 goto error;
54 }
55
56 lks->fd = ret;
57 session->kernel_session = lks;
58 session->kern_session_count++;
59
60 DBG("Kernel session created (fd: %d)", lks->fd);
61
62 return 0;
63
64 error:
65 return ret;
66 }
67
68 /*
69 * kernel_create_channel
70 *
71 * Create a kernel channel, register it to the kernel tracer and add it to the
72 * kernel session.
73 */
74 int kernel_create_channel(struct ltt_kernel_session *session)
75 {
76 int ret;
77 struct ltt_kernel_channel *lkc;
78
79 /* Allocate kernel channel */
80 lkc = trace_create_kernel_channel();
81 if (lkc == NULL) {
82 goto error;
83 }
84
85 /* Kernel tracer channel creation */
86 ret = kernctl_create_channel(session->fd, lkc->channel);
87 if (ret < 0) {
88 perror("ioctl kernel create channel");
89 goto error;
90 }
91
92 /* Setup the channel fd */
93 lkc->fd = ret;
94 /* Add channel to session */
95 cds_list_add(&lkc->list, &session->channel_list.head);
96 session->channel_count++;
97
98 DBG("Kernel channel created (fd: %d and path: %s)", lkc->fd, lkc->pathname);
99
100 return 0;
101
102 error:
103 return -1;
104 }
105
106 /*
107 * kernel_enable_event
108 *
109 * Create a kernel event, enable it to the kernel tracer and add it to the
110 * channel event list of the kernel session.
111 */
112 int kernel_enable_event(struct ltt_kernel_session *session, char *name)
113 {
114 int ret;
115 struct ltt_kernel_channel *chan;
116 struct ltt_kernel_event *event;
117
118 event = trace_create_kernel_event(name, LTTNG_KERNEL_TRACEPOINTS);
119 if (event == NULL) {
120 goto error;
121 }
122
123 cds_list_for_each_entry(chan, &session->channel_list.head, list) {
124 ret = kernctl_create_event(chan->fd, event->event);
125 if (ret < 0) {
126 ERR("Unable to enable event %s", name);
127 goto error;
128 }
129
130 event->fd = ret;
131 /* Add event to event list */
132 cds_list_add(&event->list, &chan->events_list.head);
133 DBG("Event %s enabled (fd: %d)", name, event->fd);
134 }
135
136 return 0;
137
138 error:
139 return -1;
140 }
141
142 /*
143 * kernel_open_metadata
144 *
145 * Create kernel metadata, open from the kernel tracer and add it to the
146 * kernel session.
147 */
148 int kernel_open_metadata(struct ltt_kernel_session *session)
149 {
150 int ret;
151 struct ltt_kernel_metadata *lkm;
152
153 /* Allocate kernel metadata */
154 lkm = trace_create_kernel_metadata();
155 if (lkm == NULL) {
156 goto error;
157 }
158
159 /* Kernel tracer metadata creation */
160 ret = kernctl_open_metadata(session->fd, lkm->conf);
161 if (ret < 0) {
162 goto error;
163 }
164
165 lkm->fd = ret;
166 session->metadata = lkm;
167
168 DBG("Kernel metadata opened (fd: %d and path: %s)", lkm->fd, lkm->pathname);
169
170 return 0;
171
172 error:
173 return -1;
174 }
175
176 /*
177 * kernel_start_session
178 *
179 * Start tracing session.
180 */
181 int kernel_start_session(struct ltt_kernel_session *session)
182 {
183 int ret;
184
185 ret = kernctl_start_session(session->fd);
186 if (ret < 0) {
187 goto error;
188 }
189
190 DBG("Kernel session started");
191
192 return 0;
193
194 error:
195 return ret;
196 }
197
198 /*
199 * kernel_stop_session
200 *
201 * Stop tracing session.
202 */
203 int kernel_stop_session(struct ltt_kernel_session *session)
204 {
205 int ret;
206
207 ret = kernctl_stop_session(session->fd);
208 if (ret < 0) {
209 goto error;
210 }
211
212 DBG("Kernel session stopped");
213
214 return 0;
215
216 error:
217 return ret;
218 }
219
220 /*
221 * kernel_create_channel_stream
222 *
223 * Create a stream for a channel, register it to the kernel tracer and add it
224 * to the stream list of the channel.
225 *
226 * Return the number of created stream. Else, a negative value.
227 */
228 int kernel_create_channel_stream(struct ltt_kernel_channel *channel)
229 {
230 int ret;
231 struct ltt_kernel_stream *lks;
232
233 while ((ret = kernctl_create_stream(channel->fd)) > 0) {
234 lks = trace_create_kernel_stream();
235 if (lks == NULL) {
236 close(ret);
237 goto error;
238 }
239
240 lks->fd = ret;
241 ret = asprintf(&lks->pathname, "%s/trace_%d",
242 channel->pathname, channel->stream_count);
243 if (ret < 0) {
244 perror("asprintf kernel create stream");
245 goto error;
246 }
247
248 /* Add stream to channe stream list */
249 cds_list_add(&lks->list, &channel->stream_list.head);
250 channel->stream_count++;
251
252 DBG("Kernel stream %d created (fd: %d, state: %d, path: %s)",
253 channel->stream_count, lks->fd, lks->state, lks->pathname);
254 }
255
256 return channel->stream_count;
257
258 error:
259 return -1;
260 }
261
262 /*
263 * kernel_create_metadata_stream
264 *
265 * Create the metadata stream and set it to the kernel session.
266 */
267 int kernel_create_metadata_stream(struct ltt_kernel_session *session)
268 {
269 int ret;
270
271 ret = kernctl_create_stream(session->metadata->fd);
272 if (ret < 0) {
273 perror("kernel create metadata stream");
274 goto error;
275 }
276
277 DBG("Kernel metadata stream created (fd: %d)", ret);
278 session->metadata_stream_fd = ret;
279
280 return 0;
281
282 error:
283 return -1;
284 }
285
286 /*
287 * kernel_list_events
288 *
289 * Get the event list from the kernel tracer and return that list in the CTF
290 * format.
291 */
292 ssize_t kernel_list_events(int tracer_fd, char **list)
293 {
294 int fd;
295 char *buf, *line = NULL;
296 size_t nb, nbmem, total = 0;
297 ssize_t size;
298 FILE *fp;
299
300 fd = kernctl_tracepoint_list(tracer_fd);
301 if (fd < 0) {
302 perror("kernel tracepoint list");
303 goto error;
304 }
305
306 fp = fdopen(fd, "r");
307 if (fp == NULL) {
308 perror("kernel tracepoint list fdopen");
309 goto error;
310 }
311
312 /*
313 * Init memory size counter
314 * See kernel-ctl.h for explanation of this value
315 */
316 nbmem = KERNEL_EVENT_LIST_SIZE;
317 buf = malloc(nbmem);
318
319 while ((size = getline(&line, &nb, fp)) != -1) {
320 if (total + size > nbmem) {
321 DBG("Reallocating event list from %zd to %zd bytes", nbmem,
322 total + size + KERNEL_EVENT_LIST_SIZE);
323 /* Adding the default size again */
324 nbmem = total + size + KERNEL_EVENT_LIST_SIZE;
325 buf = realloc(buf, nbmem);
326 if (buf == NULL) {
327 perror("realloc list events");
328 goto error;
329 }
330 }
331 memcpy(buf + total, line, size);
332 total += size;
333 }
334
335 *list = buf;
336
337 DBG("Kernel list events done");
338
339 return total;
340
341 error:
342 return -1;
343 }
344
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