Fix bad return value on enable syscalls making it freeze
[lttng-tools.git] / lttng-sessiond / event.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 #include <errno.h>
19 #include <urcu/list.h>
20 #include <string.h>
21
22 #include <lttng/lttng.h>
23 #include <lttng-sessiond-comm.h>
24 #include <lttngerr.h>
25
26 #include "channel.h"
27 #include "event.h"
28 #include "hashtable.h"
29 #include "kernel.h"
30 #include "ust-ctl.h"
31 #include "ust-app.h"
32 #include "trace-kernel.h"
33 #include "trace-ust.h"
34
35 /*
36 * Setup a lttng_event used to enable *all* syscall tracing.
37 */
38 static void init_syscalls_kernel_event(struct lttng_event *event)
39 {
40 event->name[0] = '\0';
41 /*
42 * We use LTTNG_EVENT* here since the trace kernel creation will make the
43 * right changes for the kernel.
44 */
45 event->type = LTTNG_EVENT_SYSCALL;
46 }
47
48 /*
49 * Disable kernel tracepoint event for a channel from the kernel session.
50 */
51 int event_kernel_disable_tracepoint(struct ltt_kernel_session *ksession,
52 struct ltt_kernel_channel *kchan, char *event_name)
53 {
54 int ret;
55 struct ltt_kernel_event *kevent;
56
57 kevent = trace_kernel_get_event_by_name(event_name, kchan);
58 if (kevent == NULL) {
59 ret = LTTCOMM_NO_EVENT;
60 goto error;
61 }
62
63 ret = kernel_disable_event(kevent);
64 if (ret < 0) {
65 ret = LTTCOMM_KERN_DISABLE_FAIL;
66 goto error;
67 }
68
69 DBG("Kernel event %s disable for channel %s.",
70 kevent->event->name, kchan->channel->name);
71
72 ret = LTTCOMM_OK;
73
74 error:
75 return ret;
76 }
77
78 /*
79 * Disable kernel tracepoint events for a channel from the kernel session.
80 */
81 int event_kernel_disable_all_tracepoints(struct ltt_kernel_session *ksession,
82 struct ltt_kernel_channel *kchan)
83 {
84 int ret;
85 struct ltt_kernel_event *kevent;
86
87 /* For each event in the kernel session */
88 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
89 ret = kernel_disable_event(kevent);
90 if (ret < 0) {
91 /* We continue disabling the rest */
92 continue;
93 }
94 }
95 ret = LTTCOMM_OK;
96 return ret;
97 }
98
99 /*
100 * Disable kernel syscall events for a channel from the kernel session.
101 */
102 int event_kernel_disable_all_syscalls(struct ltt_kernel_session *ksession,
103 struct ltt_kernel_channel *kchan)
104 {
105 ERR("Cannot disable syscall tracing for existing session. Please destroy session instead.");
106 return LTTCOMM_OK; /* Return OK so disable all succeeds */
107 }
108
109 /*
110 * Disable all kernel event for a channel from the kernel session.
111 */
112 int event_kernel_disable_all(struct ltt_kernel_session *ksession,
113 struct ltt_kernel_channel *kchan)
114 {
115 int ret;
116
117 ret = event_kernel_disable_all_tracepoints(ksession, kchan);
118 if (ret != LTTCOMM_OK)
119 return ret;
120 ret = event_kernel_disable_all_syscalls(ksession, kchan);
121 return ret;
122 }
123
124 /*
125 * Enable kernel tracepoint event for a channel from the kernel session.
126 */
127 int event_kernel_enable_tracepoint(struct ltt_kernel_session *ksession,
128 struct ltt_kernel_channel *kchan, struct lttng_event *event)
129 {
130 int ret;
131 struct ltt_kernel_event *kevent;
132
133 kevent = trace_kernel_get_event_by_name(event->name, kchan);
134 if (kevent == NULL) {
135 ret = kernel_create_event(event, kchan);
136 if (ret < 0) {
137 if (ret == -EEXIST) {
138 ret = LTTCOMM_KERN_EVENT_EXIST;
139 } else {
140 ret = LTTCOMM_KERN_ENABLE_FAIL;
141 }
142 goto end;
143 }
144 } else if (kevent->enabled == 0) {
145 ret = kernel_enable_event(kevent);
146 if (ret < 0) {
147 ret = LTTCOMM_KERN_ENABLE_FAIL;
148 goto end;
149 }
150 }
151 ret = LTTCOMM_OK;
152 end:
153 return ret;
154 }
155
156 /*
157 * Enable all kernel tracepoint events of a channel of the kernel session.
158 */
159 int event_kernel_enable_all_tracepoints(struct ltt_kernel_session *ksession,
160 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
161 {
162 int size, i, ret;
163 struct ltt_kernel_event *kevent;
164 struct lttng_event *event_list = NULL;
165
166 /* For each event in the kernel session */
167 cds_list_for_each_entry(kevent, &kchan->events_list.head, list) {
168 if (kevent->enabled == 0) {
169 ret = kernel_enable_event(kevent);
170 if (ret < 0) {
171 /* Enable failed but still continue */
172 continue;
173 }
174 }
175 }
176
177 size = kernel_list_events(kernel_tracer_fd, &event_list);
178 if (size < 0) {
179 ret = LTTCOMM_KERN_LIST_FAIL;
180 goto end;
181 }
182
183 for (i = 0; i < size; i++) {
184 kevent = trace_kernel_get_event_by_name(event_list[i].name, kchan);
185 if (kevent == NULL) {
186 /* Default event type for enable all */
187 event_list[i].type = LTTNG_EVENT_TRACEPOINT;
188 /* Enable each single tracepoint event */
189 ret = kernel_create_event(&event_list[i], kchan);
190 if (ret < 0) {
191 /* Ignore error here and continue */
192 }
193 }
194 }
195 free(event_list);
196
197 ret = LTTCOMM_OK;
198 end:
199 return ret;
200
201 }
202
203 /*
204 * Enable all kernel tracepoint events of a channel of the kernel session.
205 */
206 int event_kernel_enable_all_syscalls(struct ltt_kernel_session *ksession,
207 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
208 {
209 int ret;
210 struct lttng_event event;
211
212 init_syscalls_kernel_event(&event);
213
214 DBG("Enabling all syscall tracing");
215
216 ret = kernel_create_event(&event, kchan);
217 if (ret < 0) {
218 if (ret == -EEXIST) {
219 ret = LTTCOMM_KERN_EVENT_EXIST;
220 } else {
221 ret = LTTCOMM_KERN_ENABLE_FAIL;
222 }
223 goto end;
224 }
225
226 ret = LTTCOMM_OK;
227 end:
228 return ret;
229 }
230
231 /*
232 * Enable all kernel events of a channel of the kernel session.
233 */
234 int event_kernel_enable_all(struct ltt_kernel_session *ksession,
235 struct ltt_kernel_channel *kchan, int kernel_tracer_fd)
236 {
237 int ret;
238
239 ret = event_kernel_enable_all_tracepoints(ksession, kchan, kernel_tracer_fd);
240 if (ret != LTTCOMM_OK) {
241 goto end;
242 }
243 ret = event_kernel_enable_all_syscalls(ksession, kchan, kernel_tracer_fd);
244 end:
245 return ret;
246 }
247
248 /*
249 * Enable UST tracepoint event for a channel from a UST session.
250 */
251 int event_ust_enable_tracepoint(struct ltt_ust_session *usess, int domain,
252 struct ltt_ust_channel *uchan, struct lttng_event *event)
253 {
254 int ret, to_create = 0;
255 struct ltt_ust_event *uevent;
256
257 uevent = trace_ust_find_event_by_name(uchan->events, event->name);
258 if (uevent == NULL) {
259 uevent = trace_ust_create_event(event);
260 if (uevent == NULL) {
261 ret = LTTCOMM_FATAL;
262 goto error;
263 }
264 to_create = 1;
265 }
266
267 switch (domain) {
268 case LTTNG_DOMAIN_UST:
269 {
270 if (to_create) {
271 /* Create event on all UST registered apps for session */
272 ret = ust_app_create_event_glb(usess, uchan, uevent);
273 } else {
274 /* Enable event on all UST registered apps for session */
275 ret = ust_app_enable_event_glb(usess, uchan, uevent);
276 }
277
278 if (ret < 0) {
279 if (ret == -EEXIST) {
280 ret = LTTCOMM_UST_EVENT_EXIST;
281 } else {
282 ret = LTTCOMM_UST_ENABLE_FAIL;
283 }
284 goto error;
285 }
286
287 DBG("Event UST %s added to channel %s", uevent->attr.name,
288 uchan->name);
289 break;
290 }
291 case LTTNG_DOMAIN_UST_EXEC_NAME:
292 case LTTNG_DOMAIN_UST_PID:
293 case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
294 default:
295 ret = LTTCOMM_NOT_IMPLEMENTED;
296 goto error;
297 }
298
299 uevent->enabled = 1;
300 /* Add ltt ust event to channel */
301 rcu_read_lock();
302 hashtable_add_unique(uchan->events, &uevent->node);
303 rcu_read_unlock();
304
305 return LTTCOMM_OK;
306
307 error:
308 trace_ust_destroy_event(uevent);
309 return ret;
310 }
311
312 #ifdef DISABLE
313 int event_ust_disable_tracepoint(struct ltt_ust_session *ustsession,
314 struct ltt_ust_channel *ustchan, char *event_name)
315 {
316 int ret;
317 struct ltt_ust_event *ustevent;
318
319 ustevent = trace_ust_find_event_by_name(ustchan->events, event_name);
320 if (ustevent == NULL) {
321 ret = LTTCOMM_NO_EVENT;
322 goto end;
323 }
324 //ret = ustctl_disable(ustsession->sock, ustevent->obj);
325 if (ret < 0) {
326 ret = LTTCOMM_UST_ENABLE_FAIL;
327 goto end;
328 }
329 ustevent->enabled = 0;
330 ret = LTTCOMM_OK;
331 end:
332 return ret;
333 }
334 #endif
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