Commit | Line | Data |
---|---|---|
baf20995 MD |
1 | /* |
2 | * ltt-debugfs-abi.c | |
3 | * | |
4 | * Copyright 2010 (c) - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
6 | * LTTng debugfs ABI | |
7 | * | |
8 | * Mimic system calls for: | |
9 | * - session creation, returns a file descriptor or failure. | |
ad1c05e1 MD |
10 | * - channel creation, returns a file descriptor or failure. |
11 | * - Operates on a session file descriptor | |
12 | * - Takes all channel options as parameters. | |
13 | * - stream get, returns a file descriptor or failure. | |
14 | * - Operates on a channel file descriptor. | |
15 | * - stream notifier get, returns a file descriptor or failure. | |
16 | * - Operates on a channel file descriptor. | |
17 | * - event creation, returns a file descriptor or failure. | |
18 | * - Operates on a channel file descriptor | |
19 | * - Takes an event name as parameter | |
20 | * - Takes an instrumentation source as parameter | |
21 | * - e.g. tracepoints, dynamic_probes... | |
22 | * - Takes instrumentation source specific arguments. | |
baf20995 MD |
23 | */ |
24 | ||
11b5a3c2 | 25 | #include <linux/module.h> |
baf20995 | 26 | #include <linux/debugfs.h> |
11b5a3c2 MD |
27 | #include <linux/anon_inodes.h> |
28 | #include <linux/file.h> | |
29 | #include <linux/uaccess.h> | |
30 | #include <linux/slab.h> | |
f3bc08c5 | 31 | #include "wrapper/ringbuffer/vfs.h" |
11b5a3c2 | 32 | #include "ltt-debugfs-abi.h" |
ad1c05e1 | 33 | #include "ltt-events.h" |
baf20995 MD |
34 | |
35 | /* | |
36 | * This is LTTng's own personal way to create a system call as an external | |
37 | * module. We use ioctl() on /sys/kernel/debug/lttng. | |
38 | */ | |
39 | ||
40 | static struct dentry *lttng_dentry; | |
ad1c05e1 MD |
41 | static const struct file_operations lttng_fops; |
42 | static const struct file_operations lttng_session_fops; | |
43 | static const struct file_operations lttng_channel_fops; | |
5dbbdb43 | 44 | static const struct file_operations lttng_metadata_fops; |
305d3e42 | 45 | static const struct file_operations lttng_event_fops; |
baf20995 | 46 | |
5dbbdb43 MD |
47 | enum channel_type { |
48 | PER_CPU_CHANNEL, | |
49 | GLOBAL_CHANNEL, | |
50 | METADATA_CHANNEL, | |
51 | }; | |
52 | ||
ad1c05e1 | 53 | static |
baf20995 MD |
54 | int lttng_abi_create_session(void) |
55 | { | |
56 | struct ltt_session *session; | |
c0e31d2e | 57 | struct file *session_file; |
11b5a3c2 | 58 | int session_fd, ret; |
baf20995 | 59 | |
653fe716 | 60 | session = ltt_session_create(); |
baf20995 MD |
61 | if (!session) |
62 | return -ENOMEM; | |
1c25284c | 63 | session_fd = get_unused_fd(); |
baf20995 MD |
64 | if (session_fd < 0) { |
65 | ret = session_fd; | |
66 | goto fd_error; | |
67 | } | |
c0e31d2e | 68 | session_file = anon_inode_getfile("[lttng_session]", |
ad1c05e1 | 69 | <tng_session_fops, |
baf20995 | 70 | session, O_RDWR); |
c0e31d2e MD |
71 | if (IS_ERR(session_file)) { |
72 | ret = PTR_ERR(session_file); | |
baf20995 MD |
73 | goto file_error; |
74 | } | |
c0e31d2e MD |
75 | session->file = session_file; |
76 | fd_install(session_fd, session_file); | |
baf20995 MD |
77 | return session_fd; |
78 | ||
79 | file_error: | |
80 | put_unused_fd(session_fd); | |
81 | fd_error: | |
82 | ltt_session_destroy(session); | |
83 | return ret; | |
84 | } | |
85 | ||
ad1c05e1 MD |
86 | /** |
87 | * lttng_ioctl - lttng syscall through ioctl | |
88 | * | |
c0e31d2e | 89 | * @file: the file |
ad1c05e1 MD |
90 | * @cmd: the command |
91 | * @arg: command arg | |
92 | * | |
93 | * This ioctl implements lttng commands: | |
94 | * LTTNG_SESSION | |
95 | * Returns a LTTng trace session file descriptor | |
96 | * | |
97 | * The returned session will be deleted when its file descriptor is closed. | |
98 | */ | |
99 | static | |
c0e31d2e | 100 | long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
ad1c05e1 MD |
101 | { |
102 | switch (cmd) { | |
103 | case LTTNG_SESSION: | |
104 | return lttng_abi_create_session(); | |
105 | default: | |
106 | return -ENOIOCTLCMD; | |
107 | } | |
108 | } | |
109 | ||
ad1c05e1 MD |
110 | static const struct file_operations lttng_fops = { |
111 | .unlocked_ioctl = lttng_ioctl, | |
112 | #ifdef CONFIG_COMPAT | |
03037b98 | 113 | .compat_ioctl = lttng_ioctl, |
ad1c05e1 | 114 | #endif |
11b5a3c2 | 115 | }; |
ad1c05e1 | 116 | |
5dbbdb43 MD |
117 | /* |
118 | * We tolerate no failure in this function (if one happens, we print a dmesg | |
119 | * error, but cannot return any error, because the channel information is | |
120 | * invariant. | |
121 | */ | |
122 | static | |
123 | void lttng_metadata_create_events(struct file *channel_file) | |
124 | { | |
125 | struct ltt_channel *channel = channel_file->private_data; | |
126 | char *event_name = "lttng-metadata"; | |
127 | struct ltt_event *event; | |
128 | int ret; | |
129 | void *probe; | |
130 | ||
131 | probe = ltt_probe_get(event_name); | |
132 | if (!probe) { | |
133 | ret = -ENOENT; | |
134 | goto probe_error; | |
135 | } | |
136 | /* | |
137 | * We tolerate no failure path after event creation. It will stay | |
138 | * invariant for the rest of the session. | |
139 | */ | |
140 | event = ltt_event_create(channel, event_name, INSTRUM_TRACEPOINTS, | |
141 | probe, NULL); | |
142 | if (!event) { | |
143 | goto event_error; | |
144 | ret = -EEXIST; | |
145 | } | |
146 | return; | |
147 | ||
148 | event_error: | |
149 | ltt_probe_put(probe); | |
150 | probe_error: | |
151 | WARN_ON(1); | |
152 | return; /* not allowed to return error */ | |
153 | } | |
154 | ||
155 | static | |
c0e31d2e | 156 | int lttng_abi_create_channel(struct file *session_file, |
5dbbdb43 MD |
157 | struct lttng_channel __user *uchan_param, |
158 | enum channel_type channel_type) | |
baf20995 | 159 | { |
c0e31d2e | 160 | struct ltt_session *session = session_file->private_data; |
5dbbdb43 MD |
161 | const struct file_operations *fops; |
162 | const char *transport_name; | |
baf20995 | 163 | struct ltt_channel *chan; |
c0e31d2e | 164 | struct file *chan_file; |
baf20995 MD |
165 | struct lttng_channel chan_param; |
166 | int chan_fd; | |
ad1c05e1 | 167 | int ret = 0; |
baf20995 | 168 | |
653fe716 | 169 | if (copy_from_user(&chan_param, uchan_param, sizeof(chan_param))) |
baf20995 | 170 | return -EFAULT; |
1c25284c | 171 | chan_fd = get_unused_fd(); |
baf20995 MD |
172 | if (chan_fd < 0) { |
173 | ret = chan_fd; | |
174 | goto fd_error; | |
175 | } | |
c0e31d2e | 176 | chan_file = anon_inode_getfile("[lttng_channel]", |
ad1c05e1 | 177 | <tng_channel_fops, |
03037b98 | 178 | NULL, O_RDWR); |
c0e31d2e MD |
179 | if (IS_ERR(chan_file)) { |
180 | ret = PTR_ERR(chan_file); | |
baf20995 MD |
181 | goto file_error; |
182 | } | |
5dbbdb43 MD |
183 | switch (channel_type) { |
184 | case PER_CPU_CHANNEL: | |
185 | transport_name = chan_param.overwrite ? | |
186 | "relay-overwrite" : "relay-discard"; | |
187 | fops = <tng_channel_fops; | |
188 | break; | |
189 | case GLOBAL_CHANNEL: | |
190 | transport_name = chan_param.overwrite ? | |
191 | "global-relay-overwrite" : "global-relay-discard"; | |
192 | fops = <tng_channel_fops; | |
193 | break; | |
194 | case METADATA_CHANNEL: | |
195 | transport_name = "global-relay-discard"; | |
196 | fops = <tng_metadata_fops; | |
197 | break; | |
198 | default: | |
199 | transport_name = "<unknown>"; | |
200 | break; | |
201 | } | |
03037b98 MD |
202 | /* |
203 | * We tolerate no failure path after channel creation. It will stay | |
204 | * invariant for the rest of the session. | |
205 | */ | |
5dbbdb43 | 206 | chan = ltt_channel_create(session, transport_name, NULL, |
11b5a3c2 MD |
207 | chan_param.subbuf_size, |
208 | chan_param.num_subbuf, | |
209 | chan_param.switch_timer_interval, | |
210 | chan_param.read_timer_interval); | |
03037b98 | 211 | if (!chan) { |
f3d01b96 | 212 | ret = -EINVAL; |
03037b98 MD |
213 | goto chan_error; |
214 | } | |
11b5a3c2 | 215 | chan->file = chan_file; |
c0e31d2e MD |
216 | chan_file->private_data = chan; |
217 | fd_install(chan_fd, chan_file); | |
5dbbdb43 MD |
218 | if (channel_type == METADATA_CHANNEL) |
219 | lttng_metadata_create_events(chan_file); | |
220 | ||
ad1c05e1 | 221 | /* The channel created holds a reference on the session */ |
b0caa15a | 222 | atomic_long_inc(&session_file->f_count); |
ad1c05e1 | 223 | |
baf20995 MD |
224 | return chan_fd; |
225 | ||
03037b98 | 226 | chan_error: |
c0e31d2e | 227 | fput(chan_file); |
baf20995 MD |
228 | file_error: |
229 | put_unused_fd(chan_fd); | |
230 | fd_error: | |
baf20995 MD |
231 | return ret; |
232 | } | |
233 | ||
234 | /** | |
ad1c05e1 | 235 | * lttng_session_ioctl - lttng session fd ioctl |
baf20995 | 236 | * |
c0e31d2e | 237 | * @file: the file |
baf20995 MD |
238 | * @cmd: the command |
239 | * @arg: command arg | |
240 | * | |
241 | * This ioctl implements lttng commands: | |
baf20995 MD |
242 | * LTTNG_CHANNEL |
243 | * Returns a LTTng channel file descriptor | |
ad1c05e1 MD |
244 | * |
245 | * The returned channel will be deleted when its file descriptor is closed. | |
246 | */ | |
247 | static | |
c0e31d2e | 248 | long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
ad1c05e1 | 249 | { |
c0e31d2e MD |
250 | struct ltt_session *session = file->private_data; |
251 | ||
ad1c05e1 MD |
252 | switch (cmd) { |
253 | case LTTNG_CHANNEL: | |
5dbbdb43 MD |
254 | return lttng_abi_create_channel(file, |
255 | (struct lttng_channel __user *)arg, | |
256 | PER_CPU_CHANNEL); | |
c0e31d2e MD |
257 | case LTTNG_SESSION_START: |
258 | return ltt_session_start(session); | |
259 | case LTTNG_SESSION_STOP: | |
260 | return ltt_session_stop(session); | |
5dbbdb43 MD |
261 | case LTTNG_METADATA: |
262 | return lttng_abi_create_channel(file, | |
263 | (struct lttng_channel __user *)arg, | |
264 | METADATA_CHANNEL); | |
ad1c05e1 MD |
265 | default: |
266 | return -ENOIOCTLCMD; | |
267 | } | |
268 | } | |
269 | ||
03037b98 MD |
270 | /* |
271 | * Called when the last file reference is dropped. | |
272 | * | |
273 | * Big fat note: channels and events are invariant for the whole session after | |
274 | * their creation. So this session destruction also destroys all channel and | |
275 | * event structures specific to this session (they are not destroyed when their | |
276 | * individual file is released). | |
277 | */ | |
ad1c05e1 | 278 | static |
03037b98 | 279 | int lttng_session_release(struct inode *inode, struct file *file) |
ad1c05e1 | 280 | { |
03037b98 | 281 | struct ltt_session *session = file->private_data; |
c269fff4 MD |
282 | |
283 | if (session) | |
284 | ltt_session_destroy(session); | |
11b5a3c2 | 285 | return 0; |
ad1c05e1 | 286 | } |
ad1c05e1 MD |
287 | |
288 | static const struct file_operations lttng_session_fops = { | |
03037b98 | 289 | .release = lttng_session_release, |
ad1c05e1 MD |
290 | .unlocked_ioctl = lttng_session_ioctl, |
291 | #ifdef CONFIG_COMPAT | |
03037b98 | 292 | .compat_ioctl = lttng_session_ioctl, |
ad1c05e1 | 293 | #endif |
11b5a3c2 | 294 | }; |
ad1c05e1 MD |
295 | |
296 | static | |
c0e31d2e | 297 | int lttng_abi_open_stream(struct file *channel_file) |
ad1c05e1 | 298 | { |
c0e31d2e | 299 | struct ltt_channel *channel = channel_file->private_data; |
ad1c05e1 MD |
300 | struct lib_ring_buffer *buf; |
301 | int stream_fd, ret; | |
11b5a3c2 | 302 | struct file *stream_file; |
ad1c05e1 | 303 | |
11b5a3c2 | 304 | buf = channel->ops->buffer_read_open(channel->chan); |
ad1c05e1 MD |
305 | if (!buf) |
306 | return -ENOENT; | |
307 | ||
1c25284c | 308 | stream_fd = get_unused_fd(); |
ad1c05e1 MD |
309 | if (stream_fd < 0) { |
310 | ret = stream_fd; | |
311 | goto fd_error; | |
312 | } | |
c0e31d2e | 313 | stream_file = anon_inode_getfile("[lttng_stream]", |
7f57c73c | 314 | &lib_ring_buffer_file_operations, |
ad1c05e1 | 315 | buf, O_RDWR); |
c0e31d2e MD |
316 | if (IS_ERR(stream_file)) { |
317 | ret = PTR_ERR(stream_file); | |
ad1c05e1 MD |
318 | goto file_error; |
319 | } | |
409453cb MD |
320 | /* |
321 | * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor | |
322 | * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this | |
323 | * file descriptor, so we set FMODE_PREAD here. | |
324 | */ | |
d7b6f197 | 325 | stream_file->f_mode |= FMODE_PREAD; |
c0e31d2e | 326 | fd_install(stream_fd, stream_file); |
dda6a249 MD |
327 | /* |
328 | * The stream holds a reference to the channel within the generic ring | |
329 | * buffer library, so no need to hold a refcount on the channel and | |
330 | * session files here. | |
331 | */ | |
ad1c05e1 MD |
332 | return stream_fd; |
333 | ||
334 | file_error: | |
335 | put_unused_fd(stream_fd); | |
336 | fd_error: | |
11b5a3c2 | 337 | channel->ops->buffer_read_close(buf); |
ad1c05e1 MD |
338 | return ret; |
339 | } | |
340 | ||
653fe716 | 341 | static |
c0e31d2e | 342 | int lttng_abi_create_event(struct file *channel_file, |
653fe716 MD |
343 | struct lttng_event __user *uevent_param) |
344 | { | |
c0e31d2e | 345 | struct ltt_channel *channel = channel_file->private_data; |
653fe716 MD |
346 | struct ltt_event *event; |
347 | char *event_name; | |
348 | struct lttng_event event_param; | |
349 | int event_fd, ret; | |
11b5a3c2 | 350 | struct file *event_file; |
dda6a249 | 351 | void *probe; |
653fe716 MD |
352 | |
353 | if (copy_from_user(&event_param, uevent_param, sizeof(event_param))) | |
354 | return -EFAULT; | |
355 | event_name = kmalloc(PATH_MAX, GFP_KERNEL); | |
356 | if (!event_name) | |
357 | return -ENOMEM; | |
981616e8 | 358 | if (strncpy_from_user(event_name, uevent_param->name, PATH_MAX) < 0) { |
653fe716 MD |
359 | ret = -EFAULT; |
360 | goto name_error; | |
361 | } | |
362 | event_name[PATH_MAX - 1] = '\0'; | |
dda6a249 MD |
363 | |
364 | probe = ltt_probe_get(event_name); | |
365 | if (!probe) { | |
366 | ret = -ENOENT; | |
367 | goto probe_error; | |
368 | } | |
1c25284c | 369 | event_fd = get_unused_fd(); |
653fe716 MD |
370 | if (event_fd < 0) { |
371 | ret = event_fd; | |
372 | goto fd_error; | |
373 | } | |
c0e31d2e | 374 | event_file = anon_inode_getfile("[lttng_event]", |
3b923e5b | 375 | <tng_event_fops, |
03037b98 | 376 | NULL, O_RDWR); |
c0e31d2e MD |
377 | if (IS_ERR(event_file)) { |
378 | ret = PTR_ERR(event_file); | |
653fe716 MD |
379 | goto file_error; |
380 | } | |
03037b98 MD |
381 | /* |
382 | * We tolerate no failure path after event creation. It will stay | |
383 | * invariant for the rest of the session. | |
384 | */ | |
11b5a3c2 | 385 | event = ltt_event_create(channel, event_name, event_param.itype, |
dda6a249 | 386 | probe, NULL); |
03037b98 MD |
387 | if (!event) { |
388 | goto event_error; | |
389 | ret = -EEXIST; | |
390 | } | |
c0e31d2e MD |
391 | event_file->private_data = event; |
392 | fd_install(event_fd, event_file); | |
653fe716 | 393 | /* The event holds a reference on the channel */ |
b0caa15a | 394 | atomic_long_inc(&channel_file->f_count); |
03037b98 | 395 | kfree(event_name); |
653fe716 MD |
396 | return event_fd; |
397 | ||
03037b98 | 398 | event_error: |
c0e31d2e | 399 | fput(event_file); |
653fe716 MD |
400 | file_error: |
401 | put_unused_fd(event_fd); | |
402 | fd_error: | |
dda6a249 MD |
403 | ltt_probe_put(probe); |
404 | probe_error: | |
653fe716 MD |
405 | name_error: |
406 | kfree(event_name); | |
407 | return ret; | |
408 | } | |
ad1c05e1 MD |
409 | |
410 | /** | |
411 | * lttng_channel_ioctl - lttng syscall through ioctl | |
412 | * | |
c0e31d2e | 413 | * @file: the file |
ad1c05e1 MD |
414 | * @cmd: the command |
415 | * @arg: command arg | |
416 | * | |
417 | * This ioctl implements lttng commands: | |
418 | * LTTNG_STREAM | |
419 | * Returns an event stream file descriptor or failure. | |
420 | * (typically, one event stream records events from one CPU) | |
baf20995 | 421 | * LTTNG_EVENT |
ad1c05e1 | 422 | * Returns an event file descriptor or failure. |
baf20995 | 423 | * |
baf20995 MD |
424 | * Channel and event file descriptors also hold a reference on the session. |
425 | */ | |
ad1c05e1 | 426 | static |
c0e31d2e | 427 | long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
baf20995 | 428 | { |
baf20995 | 429 | switch (cmd) { |
ad1c05e1 | 430 | case LTTNG_STREAM: |
c0e31d2e | 431 | return lttng_abi_open_stream(file); |
baf20995 | 432 | case LTTNG_EVENT: |
c0e31d2e | 433 | return lttng_abi_create_event(file, (struct lttng_event __user *)arg); |
baf20995 MD |
434 | default: |
435 | return -ENOIOCTLCMD; | |
436 | } | |
437 | } | |
438 | ||
5dbbdb43 MD |
439 | /** |
440 | * lttng_metadata_ioctl - lttng syscall through ioctl | |
441 | * | |
442 | * @file: the file | |
443 | * @cmd: the command | |
444 | * @arg: command arg | |
445 | * | |
446 | * This ioctl implements lttng commands: | |
447 | * LTTNG_STREAM | |
448 | * Returns an event stream file descriptor or failure. | |
449 | * | |
450 | * Channel and event file descriptors also hold a reference on the session. | |
451 | */ | |
452 | static | |
453 | long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
454 | { | |
455 | switch (cmd) { | |
456 | case LTTNG_STREAM: | |
457 | return lttng_abi_open_stream(file); | |
458 | default: | |
459 | return -ENOIOCTLCMD; | |
460 | } | |
461 | } | |
462 | ||
3b923e5b MD |
463 | /* TODO: poll */ |
464 | #if 0 | |
653fe716 MD |
465 | /** |
466 | * lttng_channel_poll - lttng stream addition/removal monitoring | |
467 | * | |
c0e31d2e | 468 | * @file: the file |
653fe716 MD |
469 | * @wait: poll table |
470 | */ | |
c0e31d2e | 471 | unsigned int lttng_channel_poll(struct file *file, poll_table *wait) |
653fe716 | 472 | { |
c0e31d2e | 473 | struct ltt_channel *channel = file->private_data; |
653fe716 MD |
474 | unsigned int mask = 0; |
475 | ||
c0e31d2e | 476 | if (file->f_mode & FMODE_READ) { |
653fe716 | 477 | poll_wait_set_exclusive(wait); |
c0e31d2e | 478 | poll_wait(file, &channel->notify_wait, wait); |
653fe716 MD |
479 | |
480 | /* TODO: identify when the channel is being finalized. */ | |
481 | if (finalized) | |
482 | return POLLHUP; | |
483 | else | |
484 | return POLLIN | POLLRDNORM; | |
485 | } | |
486 | return mask; | |
487 | ||
488 | } | |
3b923e5b | 489 | #endif //0 |
653fe716 | 490 | |
0a84a57f MD |
491 | static |
492 | int lttng_channel_release(struct inode *inode, struct file *file) | |
493 | { | |
494 | struct ltt_channel *channel = file->private_data; | |
c269fff4 MD |
495 | |
496 | if (channel) | |
497 | fput(channel->session->file); | |
0a84a57f MD |
498 | return 0; |
499 | } | |
500 | ||
ad1c05e1 | 501 | static const struct file_operations lttng_channel_fops = { |
03037b98 | 502 | .release = lttng_channel_release, |
3b923e5b MD |
503 | /* TODO */ |
504 | #if 0 | |
653fe716 | 505 | .poll = lttng_channel_poll, |
3b923e5b | 506 | #endif //0 |
ad1c05e1 | 507 | .unlocked_ioctl = lttng_channel_ioctl, |
baf20995 | 508 | #ifdef CONFIG_COMPAT |
03037b98 | 509 | .compat_ioctl = lttng_channel_ioctl, |
baf20995 | 510 | #endif |
11b5a3c2 | 511 | }; |
baf20995 | 512 | |
5dbbdb43 MD |
513 | static const struct file_operations lttng_metadata_fops = { |
514 | .release = lttng_channel_release, | |
515 | .unlocked_ioctl = lttng_metadata_ioctl, | |
516 | #ifdef CONFIG_COMPAT | |
517 | .compat_ioctl = lttng_metadata_ioctl, | |
518 | #endif | |
519 | }; | |
520 | ||
0a84a57f MD |
521 | static |
522 | int lttng_event_release(struct inode *inode, struct file *file) | |
523 | { | |
524 | struct ltt_event *event = file->private_data; | |
c269fff4 MD |
525 | |
526 | if (event) | |
527 | fput(event->chan->file); | |
0a84a57f MD |
528 | return 0; |
529 | } | |
530 | ||
3b923e5b | 531 | /* TODO: filter control ioctl */ |
0a84a57f MD |
532 | static const struct file_operations lttng_event_fops = { |
533 | .release = lttng_event_release, | |
11b5a3c2 | 534 | }; |
0a84a57f | 535 | |
1c25284c | 536 | int __init ltt_debugfs_abi_init(void) |
baf20995 MD |
537 | { |
538 | int ret = 0; | |
539 | ||
11b5a3c2 | 540 | lttng_dentry = debugfs_create_file("lttng", S_IWUSR, NULL, NULL, |
f3d01b96 | 541 | <tng_fops); |
11b5a3c2 | 542 | if (IS_ERR(lttng_dentry) || !lttng_dentry) { |
baf20995 MD |
543 | printk(KERN_ERR "Error creating LTTng control file\n"); |
544 | ret = -ENOMEM; | |
545 | goto error; | |
546 | } | |
547 | error: | |
548 | return ret; | |
549 | } | |
550 | ||
1c25284c | 551 | void __exit ltt_debugfs_abi_exit(void) |
baf20995 | 552 | { |
11b5a3c2 | 553 | debugfs_remove(lttng_dentry); |
baf20995 | 554 | } |