2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
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.
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.
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.
24 #include <common/common.h>
25 #include <common/defaults.h>
26 #include <common/sessiond-comm/sessiond-comm.h>
29 #include "lttng-sessiond.h"
36 * Return allocated channel attributes.
38 struct lttng_channel
*channel_new_default_attr(int dom
,
39 enum lttng_buffer_type type
)
41 struct lttng_channel
*chan
;
43 chan
= zmalloc(sizeof(struct lttng_channel
));
45 PERROR("zmalloc channel init");
49 if (snprintf(chan
->name
, sizeof(chan
->name
), "%s",
50 DEFAULT_CHANNEL_NAME
) < 0) {
51 PERROR("snprintf default channel name");
55 /* Same for all domains. */
56 chan
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
57 chan
->attr
.tracefile_size
= DEFAULT_CHANNEL_TRACEFILE_SIZE
;
58 chan
->attr
.tracefile_count
= DEFAULT_CHANNEL_TRACEFILE_COUNT
;
61 case LTTNG_DOMAIN_KERNEL
:
62 assert(type
== LTTNG_BUFFER_GLOBAL
);
63 chan
->attr
.subbuf_size
=
64 default_get_kernel_channel_subbuf_size();
65 chan
->attr
.num_subbuf
= DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM
;
66 chan
->attr
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
67 chan
->attr
.switch_timer_interval
= DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER
;
68 chan
->attr
.read_timer_interval
= DEFAULT_KERNEL_CHANNEL_READ_TIMER
;
69 chan
->attr
.live_timer_interval
= DEFAULT_KERNEL_CHANNEL_LIVE_TIMER
;
71 case LTTNG_DOMAIN_UST
:
73 case LTTNG_BUFFER_PER_UID
:
74 chan
->attr
.subbuf_size
= default_get_ust_uid_channel_subbuf_size();
75 chan
->attr
.num_subbuf
= DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM
;
76 chan
->attr
.output
= DEFAULT_UST_UID_CHANNEL_OUTPUT
;
77 chan
->attr
.switch_timer_interval
=
78 DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER
;
79 chan
->attr
.read_timer_interval
=
80 DEFAULT_UST_UID_CHANNEL_READ_TIMER
;
81 chan
->attr
.live_timer_interval
=
82 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER
;
84 case LTTNG_BUFFER_PER_PID
:
86 chan
->attr
.subbuf_size
= default_get_ust_pid_channel_subbuf_size();
87 chan
->attr
.num_subbuf
= DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM
;
88 chan
->attr
.output
= DEFAULT_UST_PID_CHANNEL_OUTPUT
;
89 chan
->attr
.switch_timer_interval
=
90 DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER
;
91 chan
->attr
.read_timer_interval
=
92 DEFAULT_UST_PID_CHANNEL_READ_TIMER
;
93 chan
->attr
.live_timer_interval
=
94 DEFAULT_UST_UID_CHANNEL_LIVE_TIMER
;
99 goto error
; /* Not implemented */
111 * Disable kernel channel of the kernel session.
113 int channel_kernel_disable(struct ltt_kernel_session
*ksession
,
117 struct ltt_kernel_channel
*kchan
;
120 assert(channel_name
);
122 kchan
= trace_kernel_get_channel_by_name(channel_name
, ksession
);
124 ret
= LTTNG_ERR_KERN_CHAN_NOT_FOUND
;
128 /* Only if channel is enabled disable it. */
129 if (kchan
->enabled
== 1) {
130 ret
= kernel_disable_channel(kchan
);
131 if (ret
< 0 && ret
!= -EEXIST
) {
132 ret
= LTTNG_ERR_KERN_CHAN_DISABLE_FAIL
;
144 * Enable kernel channel of the kernel session.
146 int channel_kernel_enable(struct ltt_kernel_session
*ksession
,
147 struct ltt_kernel_channel
*kchan
)
154 if (kchan
->enabled
== 0) {
155 ret
= kernel_enable_channel(kchan
);
157 ret
= LTTNG_ERR_KERN_CHAN_ENABLE_FAIL
;
161 ret
= LTTNG_ERR_KERN_CHAN_EXIST
;
171 static int channel_validate(struct lttng_channel
*attr
)
174 * The ringbuffer (both in user space and kernel) behaves badly
175 * in overwrite mode and with less than 2 subbuffers so block it
176 * right away and send back an invalid attribute error.
178 if (attr
->attr
.overwrite
&& attr
->attr
.num_subbuf
< 2) {
185 * Create kernel channel of the kernel session and notify kernel thread.
187 int channel_kernel_create(struct ltt_kernel_session
*ksession
,
188 struct lttng_channel
*attr
, int kernel_pipe
)
191 struct lttng_channel
*defattr
= NULL
;
195 /* Creating channel attributes if needed */
197 defattr
= channel_new_default_attr(LTTNG_DOMAIN_KERNEL
,
198 LTTNG_BUFFER_GLOBAL
);
199 if (defattr
== NULL
) {
200 ret
= LTTNG_ERR_FATAL
;
206 if (ksession
->snapshot_mode
) {
207 /* Force channel attribute for snapshot mode. */
208 attr
->attr
.overwrite
= 1;
209 attr
->attr
.output
= LTTNG_EVENT_MMAP
;
212 /* Validate common channel properties. */
213 if (channel_validate(attr
) < 0) {
214 ret
= LTTNG_ERR_INVALID
;
218 /* Channel not found, creating it */
219 ret
= kernel_create_channel(ksession
, attr
);
221 ret
= LTTNG_ERR_KERN_CHAN_FAIL
;
225 /* Notify kernel thread that there is a new channel */
226 ret
= notify_thread_pipe(kernel_pipe
);
228 ret
= LTTNG_ERR_FATAL
;
239 * Enable UST channel for session and domain.
241 int channel_ust_enable(struct ltt_ust_session
*usess
,
242 struct ltt_ust_channel
*uchan
)
249 /* If already enabled, everything is OK */
250 if (uchan
->enabled
) {
251 DBG3("Channel %s already enabled. Skipping", uchan
->name
);
252 ret
= LTTNG_ERR_UST_CHAN_EXIST
;
256 DBG2("Channel %s being enabled in UST domain", uchan
->name
);
259 * Enable channel for UST global domain on all applications. Ignore return
260 * value here since whatever error we got, it means that the channel was
261 * not created on one or many registered applications and we can not report
262 * this to the user yet. However, at this stage, the channel was
263 * successfully created on the session daemon side so the enable-channel
264 * command is a success.
266 (void) ust_app_enable_channel_glb(usess
, uchan
);
269 DBG2("Channel %s enabled successfully", uchan
->name
);
276 * Create UST channel for session and domain.
278 int channel_ust_create(struct ltt_ust_session
*usess
,
279 struct lttng_channel
*attr
, enum lttng_buffer_type type
)
282 struct ltt_ust_channel
*uchan
= NULL
;
283 struct lttng_channel
*defattr
= NULL
;
287 /* Creating channel attributes if needed */
289 defattr
= channel_new_default_attr(LTTNG_DOMAIN_UST
, type
);
290 if (defattr
== NULL
) {
291 ret
= LTTNG_ERR_FATAL
;
297 if (usess
->snapshot_mode
) {
298 /* Force channel attribute for snapshot mode. */
299 attr
->attr
.overwrite
= 1;
300 attr
->attr
.output
= LTTNG_EVENT_MMAP
;
303 /* Validate common channel properties. */
304 if (channel_validate(attr
) < 0) {
305 ret
= LTTNG_ERR_INVALID
;
310 * Validate UST buffer size and number of buffers: must both be power of 2
311 * and nonzero. We validate right here for UST, because applications will
312 * not report the error to the user (unlike kernel tracing).
314 if (!attr
->attr
.subbuf_size
||
315 (attr
->attr
.subbuf_size
& (attr
->attr
.subbuf_size
- 1))) {
316 ret
= LTTNG_ERR_INVALID
;
321 * Invalid subbuffer size if it's lower then the page size.
323 if (attr
->attr
.subbuf_size
< page_size
) {
324 ret
= LTTNG_ERR_INVALID
;
328 if (!attr
->attr
.num_subbuf
||
329 (attr
->attr
.num_subbuf
& (attr
->attr
.num_subbuf
- 1))) {
330 ret
= LTTNG_ERR_INVALID
;
334 if (attr
->attr
.output
!= LTTNG_EVENT_MMAP
) {
335 ret
= LTTNG_ERR_NOT_SUPPORTED
;
340 * The tracefile_size should not be < to the subbuf_size, otherwise
341 * we won't be able to write the packets on disk
343 if ((attr
->attr
.tracefile_size
> 0) &&
344 (attr
->attr
.tracefile_size
< attr
->attr
.subbuf_size
)) {
345 ret
= LTTNG_ERR_INVALID
;
349 /* Validate buffer type. */
351 case LTTNG_BUFFER_PER_PID
:
353 case LTTNG_BUFFER_PER_UID
:
356 ret
= LTTNG_ERR_BUFFER_NOT_SUPPORTED
;
360 /* Create UST channel */
361 uchan
= trace_ust_create_channel(attr
, LTTNG_DOMAIN_UST
);
363 ret
= LTTNG_ERR_FATAL
;
368 * HACK: Set the channel's subdomain (JUL, Log4j, Python, etc.)
369 * based on the default name.
371 if (!strcmp(uchan
->name
, DEFAULT_JUL_CHANNEL_NAME
)) {
372 uchan
->domain
= LTTNG_DOMAIN_JUL
;
373 } else if (!strcmp(uchan
->name
, DEFAULT_LOG4J_CHANNEL_NAME
)) {
374 uchan
->domain
= LTTNG_DOMAIN_LOG4J
;
375 } else if (!strcmp(uchan
->name
, DEFAULT_PYTHON_CHANNEL_NAME
)) {
376 uchan
->domain
= LTTNG_DOMAIN_PYTHON
;
380 if (trace_ust_is_max_id(usess
->used_channel_id
)) {
381 ret
= LTTNG_ERR_UST_CHAN_FAIL
;
384 uchan
->id
= trace_ust_get_next_chan_id(usess
);
386 DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64
,
387 uchan
->name
, type
, uchan
->id
);
389 /* Flag session buffer type. */
390 if (!usess
->buffer_type_changed
) {
391 usess
->buffer_type
= type
;
392 usess
->buffer_type_changed
= 1;
393 } else if (usess
->buffer_type
!= type
) {
394 /* Buffer type was already set. Refuse to create channel. */
395 ret
= LTTNG_ERR_BUFFER_TYPE_MISMATCH
;
396 goto error_free_chan
;
399 /* Enable channel for global domain */
400 ret
= ust_app_create_channel_glb(usess
, uchan
);
401 if (ret
< 0 && ret
!= -LTTNG_UST_ERR_EXIST
) {
402 ret
= LTTNG_ERR_UST_CHAN_FAIL
;
403 goto error_free_chan
;
406 /* Adding the channel to the channel hash table. */
408 if (strncmp(uchan
->name
, DEFAULT_METADATA_NAME
,
409 sizeof(uchan
->name
))) {
410 lttng_ht_add_unique_str(usess
->domain_global
.channels
, &uchan
->node
);
413 * Copy channel attribute to session if this is metadata so if NO
414 * application exists we can access that data in the shadow copy during
415 * the global update of newly registered application.
417 memcpy(&usess
->metadata_attr
, &uchan
->attr
,
418 sizeof(usess
->metadata_attr
));
422 DBG2("Channel %s created successfully", uchan
->name
);
429 * No need to remove the channel from the hash table because at this point
430 * it was not added hence the direct call and no call_rcu().
432 trace_ust_destroy_channel(uchan
);
439 * Disable UST channel for session and domain.
441 int channel_ust_disable(struct ltt_ust_session
*usess
,
442 struct ltt_ust_channel
*uchan
)
449 /* Already disabled */
450 if (uchan
->enabled
== 0) {
451 DBG2("Channel UST %s already disabled", uchan
->name
);
455 DBG2("Channel %s being disabled in UST global domain", uchan
->name
);
456 /* Disable channel for global domain */
457 ret
= ust_app_disable_channel_glb(usess
, uchan
);
458 if (ret
< 0 && ret
!= -LTTNG_UST_ERR_EXIST
) {
459 ret
= LTTNG_ERR_UST_CHAN_DISABLE_FAIL
;
465 DBG2("Channel %s disabled successfully", uchan
->name
);