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[deliverable/lttng-modules.git] / lttng-abi.c
1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
2 *
3 * lttng-abi.c
4 *
5 * LTTng ABI
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 *
9 * Mimic system calls for:
10 * - session creation, returns a file descriptor or failure.
11 * - channel creation, returns a file descriptor or failure.
12 * - Operates on a session file descriptor
13 * - Takes all channel options as parameters.
14 * - stream get, returns a file descriptor or failure.
15 * - Operates on a channel file descriptor.
16 * - stream notifier get, returns a file descriptor or failure.
17 * - Operates on a channel file descriptor.
18 * - event creation, returns a file descriptor or failure.
19 * - Operates on a channel file descriptor
20 * - Takes an event name as parameter
21 * - Takes an instrumentation source as parameter
22 * - e.g. tracepoints, dynamic_probes...
23 * - Takes instrumentation source specific arguments.
24 */
25
26 #include <linux/module.h>
27 #include <linux/proc_fs.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/file.h>
30 #include <linux/uaccess.h>
31 #include <linux/slab.h>
32 #include <linux/err.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
34 #include <wrapper/ringbuffer/vfs.h>
35 #include <wrapper/ringbuffer/backend.h>
36 #include <wrapper/ringbuffer/frontend.h>
37 #include <wrapper/poll.h>
38 #include <wrapper/file.h>
39 #include <wrapper/kref.h>
40 #include <lttng-string-utils.h>
41 #include <lttng-abi.h>
42 #include <lttng-abi-old.h>
43 #include <lttng-events.h>
44 #include <lttng-tracer.h>
45 #include <lttng-tp-mempool.h>
46 #include <lib/ringbuffer/frontend_types.h>
47
48 /*
49 * This is LTTng's own personal way to create a system call as an external
50 * module. We use ioctl() on /proc/lttng.
51 */
52
53 static struct proc_dir_entry *lttng_proc_dentry;
54 static const struct file_operations lttng_fops;
55 static const struct file_operations lttng_session_fops;
56 static const struct file_operations lttng_channel_fops;
57 static const struct file_operations lttng_metadata_fops;
58 static const struct file_operations lttng_event_fops;
59 static struct file_operations lttng_stream_ring_buffer_file_operations;
60
61 static int put_u64(uint64_t val, unsigned long arg);
62
63 /*
64 * Teardown management: opened file descriptors keep a refcount on the module,
65 * so it can only exit when all file descriptors are closed.
66 */
67
68 static
69 int lttng_abi_create_session(void)
70 {
71 struct lttng_session *session;
72 struct file *session_file;
73 int session_fd, ret;
74
75 session = lttng_session_create();
76 if (!session)
77 return -ENOMEM;
78 session_fd = lttng_get_unused_fd();
79 if (session_fd < 0) {
80 ret = session_fd;
81 goto fd_error;
82 }
83 session_file = anon_inode_getfile("[lttng_session]",
84 &lttng_session_fops,
85 session, O_RDWR);
86 if (IS_ERR(session_file)) {
87 ret = PTR_ERR(session_file);
88 goto file_error;
89 }
90 session->file = session_file;
91 fd_install(session_fd, session_file);
92 return session_fd;
93
94 file_error:
95 put_unused_fd(session_fd);
96 fd_error:
97 lttng_session_destroy(session);
98 return ret;
99 }
100
101 static
102 int lttng_abi_tracepoint_list(void)
103 {
104 struct file *tracepoint_list_file;
105 int file_fd, ret;
106
107 file_fd = lttng_get_unused_fd();
108 if (file_fd < 0) {
109 ret = file_fd;
110 goto fd_error;
111 }
112
113 tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
114 &lttng_tracepoint_list_fops,
115 NULL, O_RDWR);
116 if (IS_ERR(tracepoint_list_file)) {
117 ret = PTR_ERR(tracepoint_list_file);
118 goto file_error;
119 }
120 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
121 if (ret < 0)
122 goto open_error;
123 fd_install(file_fd, tracepoint_list_file);
124 return file_fd;
125
126 open_error:
127 fput(tracepoint_list_file);
128 file_error:
129 put_unused_fd(file_fd);
130 fd_error:
131 return ret;
132 }
133
134 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
135 static inline
136 int lttng_abi_syscall_list(void)
137 {
138 return -ENOSYS;
139 }
140 #else
141 static
142 int lttng_abi_syscall_list(void)
143 {
144 struct file *syscall_list_file;
145 int file_fd, ret;
146
147 file_fd = lttng_get_unused_fd();
148 if (file_fd < 0) {
149 ret = file_fd;
150 goto fd_error;
151 }
152
153 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
154 &lttng_syscall_list_fops,
155 NULL, O_RDWR);
156 if (IS_ERR(syscall_list_file)) {
157 ret = PTR_ERR(syscall_list_file);
158 goto file_error;
159 }
160 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
161 if (ret < 0)
162 goto open_error;
163 fd_install(file_fd, syscall_list_file);
164 return file_fd;
165
166 open_error:
167 fput(syscall_list_file);
168 file_error:
169 put_unused_fd(file_fd);
170 fd_error:
171 return ret;
172 }
173 #endif
174
175 static
176 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
177 {
178 v->major = LTTNG_MODULES_MAJOR_VERSION;
179 v->minor = LTTNG_MODULES_MINOR_VERSION;
180 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
181 }
182
183 static
184 void lttng_abi_tracer_abi_version(struct lttng_kernel_tracer_abi_version *v)
185 {
186 v->major = LTTNG_MODULES_ABI_MAJOR_VERSION;
187 v->minor = LTTNG_MODULES_ABI_MINOR_VERSION;
188 }
189
190 static
191 long lttng_abi_add_context(struct file *file,
192 struct lttng_kernel_context *context_param,
193 struct lttng_ctx **ctx, struct lttng_session *session)
194 {
195
196 if (session->been_active)
197 return -EPERM;
198
199 switch (context_param->ctx) {
200 case LTTNG_KERNEL_CONTEXT_PID:
201 return lttng_add_pid_to_ctx(ctx);
202 case LTTNG_KERNEL_CONTEXT_PRIO:
203 return lttng_add_prio_to_ctx(ctx);
204 case LTTNG_KERNEL_CONTEXT_NICE:
205 return lttng_add_nice_to_ctx(ctx);
206 case LTTNG_KERNEL_CONTEXT_VPID:
207 return lttng_add_vpid_to_ctx(ctx);
208 case LTTNG_KERNEL_CONTEXT_TID:
209 return lttng_add_tid_to_ctx(ctx);
210 case LTTNG_KERNEL_CONTEXT_VTID:
211 return lttng_add_vtid_to_ctx(ctx);
212 case LTTNG_KERNEL_CONTEXT_PPID:
213 return lttng_add_ppid_to_ctx(ctx);
214 case LTTNG_KERNEL_CONTEXT_VPPID:
215 return lttng_add_vppid_to_ctx(ctx);
216 case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
217 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
218 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
219 context_param->u.perf_counter.config,
220 context_param->u.perf_counter.name,
221 ctx);
222 case LTTNG_KERNEL_CONTEXT_PROCNAME:
223 return lttng_add_procname_to_ctx(ctx);
224 case LTTNG_KERNEL_CONTEXT_HOSTNAME:
225 return lttng_add_hostname_to_ctx(ctx);
226 case LTTNG_KERNEL_CONTEXT_CPU_ID:
227 return lttng_add_cpu_id_to_ctx(ctx);
228 case LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE:
229 return lttng_add_interruptible_to_ctx(ctx);
230 case LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE:
231 return lttng_add_need_reschedule_to_ctx(ctx);
232 case LTTNG_KERNEL_CONTEXT_PREEMPTIBLE:
233 return lttng_add_preemptible_to_ctx(ctx);
234 case LTTNG_KERNEL_CONTEXT_MIGRATABLE:
235 return lttng_add_migratable_to_ctx(ctx);
236 case LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL:
237 case LTTNG_KERNEL_CONTEXT_CALLSTACK_USER:
238 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
239 case LTTNG_KERNEL_CONTEXT_CGROUP_NS:
240 return lttng_add_cgroup_ns_to_ctx(ctx);
241 case LTTNG_KERNEL_CONTEXT_IPC_NS:
242 return lttng_add_ipc_ns_to_ctx(ctx);
243 case LTTNG_KERNEL_CONTEXT_MNT_NS:
244 return lttng_add_mnt_ns_to_ctx(ctx);
245 case LTTNG_KERNEL_CONTEXT_NET_NS:
246 return lttng_add_net_ns_to_ctx(ctx);
247 case LTTNG_KERNEL_CONTEXT_PID_NS:
248 return lttng_add_pid_ns_to_ctx(ctx);
249 case LTTNG_KERNEL_CONTEXT_USER_NS:
250 return lttng_add_user_ns_to_ctx(ctx);
251 case LTTNG_KERNEL_CONTEXT_UTS_NS:
252 return lttng_add_uts_ns_to_ctx(ctx);
253 default:
254 return -EINVAL;
255 }
256 }
257
258 /**
259 * lttng_ioctl - lttng syscall through ioctl
260 *
261 * @file: the file
262 * @cmd: the command
263 * @arg: command arg
264 *
265 * This ioctl implements lttng commands:
266 * LTTNG_KERNEL_SESSION
267 * Returns a LTTng trace session file descriptor
268 * LTTNG_KERNEL_TRACER_VERSION
269 * Returns the LTTng kernel tracer version
270 * LTTNG_KERNEL_TRACEPOINT_LIST
271 * Returns a file descriptor listing available tracepoints
272 * LTTNG_KERNEL_WAIT_QUIESCENT
273 * Returns after all previously running probes have completed
274 * LTTNG_KERNEL_TRACER_ABI_VERSION
275 * Returns the LTTng kernel tracer ABI version
276 *
277 * The returned session will be deleted when its file descriptor is closed.
278 */
279 static
280 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
281 {
282 switch (cmd) {
283 case LTTNG_KERNEL_OLD_SESSION:
284 case LTTNG_KERNEL_SESSION:
285 return lttng_abi_create_session();
286 case LTTNG_KERNEL_OLD_TRACER_VERSION:
287 {
288 struct lttng_kernel_tracer_version v;
289 struct lttng_kernel_old_tracer_version oldv;
290 struct lttng_kernel_old_tracer_version *uversion =
291 (struct lttng_kernel_old_tracer_version __user *) arg;
292
293 lttng_abi_tracer_version(&v);
294 oldv.major = v.major;
295 oldv.minor = v.minor;
296 oldv.patchlevel = v.patchlevel;
297
298 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
299 return -EFAULT;
300 return 0;
301 }
302 case LTTNG_KERNEL_TRACER_VERSION:
303 {
304 struct lttng_kernel_tracer_version version;
305 struct lttng_kernel_tracer_version *uversion =
306 (struct lttng_kernel_tracer_version __user *) arg;
307
308 lttng_abi_tracer_version(&version);
309
310 if (copy_to_user(uversion, &version, sizeof(version)))
311 return -EFAULT;
312 return 0;
313 }
314 case LTTNG_KERNEL_TRACER_ABI_VERSION:
315 {
316 struct lttng_kernel_tracer_abi_version version;
317 struct lttng_kernel_tracer_abi_version *uversion =
318 (struct lttng_kernel_tracer_abi_version __user *) arg;
319
320 lttng_abi_tracer_abi_version(&version);
321
322 if (copy_to_user(uversion, &version, sizeof(version)))
323 return -EFAULT;
324 return 0;
325 }
326 case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
327 case LTTNG_KERNEL_TRACEPOINT_LIST:
328 return lttng_abi_tracepoint_list();
329 case LTTNG_KERNEL_SYSCALL_LIST:
330 return lttng_abi_syscall_list();
331 case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
332 case LTTNG_KERNEL_WAIT_QUIESCENT:
333 synchronize_trace();
334 return 0;
335 case LTTNG_KERNEL_OLD_CALIBRATE:
336 {
337 struct lttng_kernel_old_calibrate __user *ucalibrate =
338 (struct lttng_kernel_old_calibrate __user *) arg;
339 struct lttng_kernel_old_calibrate old_calibrate;
340 struct lttng_kernel_calibrate calibrate;
341 int ret;
342
343 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
344 return -EFAULT;
345 calibrate.type = old_calibrate.type;
346 ret = lttng_calibrate(&calibrate);
347 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
348 return -EFAULT;
349 return ret;
350 }
351 case LTTNG_KERNEL_CALIBRATE:
352 {
353 struct lttng_kernel_calibrate __user *ucalibrate =
354 (struct lttng_kernel_calibrate __user *) arg;
355 struct lttng_kernel_calibrate calibrate;
356 int ret;
357
358 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
359 return -EFAULT;
360 ret = lttng_calibrate(&calibrate);
361 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
362 return -EFAULT;
363 return ret;
364 }
365 default:
366 return -ENOIOCTLCMD;
367 }
368 }
369
370 static const struct file_operations lttng_fops = {
371 .owner = THIS_MODULE,
372 .unlocked_ioctl = lttng_ioctl,
373 #ifdef CONFIG_COMPAT
374 .compat_ioctl = lttng_ioctl,
375 #endif
376 };
377
378 static
379 int lttng_abi_create_channel(struct file *session_file,
380 struct lttng_kernel_channel *chan_param,
381 enum channel_type channel_type)
382 {
383 struct lttng_session *session = session_file->private_data;
384 const struct file_operations *fops = NULL;
385 const char *transport_name;
386 struct lttng_channel *chan;
387 struct file *chan_file;
388 int chan_fd;
389 int ret = 0;
390
391 chan_fd = lttng_get_unused_fd();
392 if (chan_fd < 0) {
393 ret = chan_fd;
394 goto fd_error;
395 }
396 switch (channel_type) {
397 case PER_CPU_CHANNEL:
398 fops = &lttng_channel_fops;
399 break;
400 case METADATA_CHANNEL:
401 fops = &lttng_metadata_fops;
402 break;
403 }
404
405 chan_file = anon_inode_getfile("[lttng_channel]",
406 fops,
407 NULL, O_RDWR);
408 if (IS_ERR(chan_file)) {
409 ret = PTR_ERR(chan_file);
410 goto file_error;
411 }
412 switch (channel_type) {
413 case PER_CPU_CHANNEL:
414 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
415 transport_name = chan_param->overwrite ?
416 "relay-overwrite" : "relay-discard";
417 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
418 transport_name = chan_param->overwrite ?
419 "relay-overwrite-mmap" : "relay-discard-mmap";
420 } else {
421 return -EINVAL;
422 }
423 break;
424 case METADATA_CHANNEL:
425 if (chan_param->output == LTTNG_KERNEL_SPLICE)
426 transport_name = "relay-metadata";
427 else if (chan_param->output == LTTNG_KERNEL_MMAP)
428 transport_name = "relay-metadata-mmap";
429 else
430 return -EINVAL;
431 break;
432 default:
433 transport_name = "<unknown>";
434 break;
435 }
436 if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
437 ret = -EOVERFLOW;
438 goto refcount_error;
439 }
440 /*
441 * We tolerate no failure path after channel creation. It will stay
442 * invariant for the rest of the session.
443 */
444 chan = lttng_channel_create(session, transport_name, NULL,
445 chan_param->subbuf_size,
446 chan_param->num_subbuf,
447 chan_param->switch_timer_interval,
448 chan_param->read_timer_interval,
449 channel_type);
450 if (!chan) {
451 ret = -EINVAL;
452 goto chan_error;
453 }
454 chan->file = chan_file;
455 chan_file->private_data = chan;
456 fd_install(chan_fd, chan_file);
457
458 return chan_fd;
459
460 chan_error:
461 atomic_long_dec(&session_file->f_count);
462 refcount_error:
463 fput(chan_file);
464 file_error:
465 put_unused_fd(chan_fd);
466 fd_error:
467 return ret;
468 }
469
470 /**
471 * lttng_session_ioctl - lttng session fd ioctl
472 *
473 * @file: the file
474 * @cmd: the command
475 * @arg: command arg
476 *
477 * This ioctl implements lttng commands:
478 * LTTNG_KERNEL_CHANNEL
479 * Returns a LTTng channel file descriptor
480 * LTTNG_KERNEL_ENABLE
481 * Enables tracing for a session (weak enable)
482 * LTTNG_KERNEL_DISABLE
483 * Disables tracing for a session (strong disable)
484 * LTTNG_KERNEL_METADATA
485 * Returns a LTTng metadata file descriptor
486 * LTTNG_KERNEL_SESSION_TRACK_PID
487 * Add PID to session tracker
488 * LTTNG_KERNEL_SESSION_UNTRACK_PID
489 * Remove PID from session tracker
490 *
491 * The returned channel will be deleted when its file descriptor is closed.
492 */
493 static
494 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
495 {
496 struct lttng_session *session = file->private_data;
497
498 switch (cmd) {
499 case LTTNG_KERNEL_OLD_CHANNEL:
500 {
501 struct lttng_kernel_channel chan_param;
502 struct lttng_kernel_old_channel old_chan_param;
503
504 if (copy_from_user(&old_chan_param,
505 (struct lttng_kernel_old_channel __user *) arg,
506 sizeof(struct lttng_kernel_old_channel)))
507 return -EFAULT;
508 chan_param.overwrite = old_chan_param.overwrite;
509 chan_param.subbuf_size = old_chan_param.subbuf_size;
510 chan_param.num_subbuf = old_chan_param.num_subbuf;
511 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
512 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
513 chan_param.output = old_chan_param.output;
514
515 return lttng_abi_create_channel(file, &chan_param,
516 PER_CPU_CHANNEL);
517 }
518 case LTTNG_KERNEL_CHANNEL:
519 {
520 struct lttng_kernel_channel chan_param;
521
522 if (copy_from_user(&chan_param,
523 (struct lttng_kernel_channel __user *) arg,
524 sizeof(struct lttng_kernel_channel)))
525 return -EFAULT;
526 return lttng_abi_create_channel(file, &chan_param,
527 PER_CPU_CHANNEL);
528 }
529 case LTTNG_KERNEL_OLD_SESSION_START:
530 case LTTNG_KERNEL_OLD_ENABLE:
531 case LTTNG_KERNEL_SESSION_START:
532 case LTTNG_KERNEL_ENABLE:
533 return lttng_session_enable(session);
534 case LTTNG_KERNEL_OLD_SESSION_STOP:
535 case LTTNG_KERNEL_OLD_DISABLE:
536 case LTTNG_KERNEL_SESSION_STOP:
537 case LTTNG_KERNEL_DISABLE:
538 return lttng_session_disable(session);
539 case LTTNG_KERNEL_OLD_METADATA:
540 {
541 struct lttng_kernel_channel chan_param;
542 struct lttng_kernel_old_channel old_chan_param;
543
544 if (copy_from_user(&old_chan_param,
545 (struct lttng_kernel_old_channel __user *) arg,
546 sizeof(struct lttng_kernel_old_channel)))
547 return -EFAULT;
548 chan_param.overwrite = old_chan_param.overwrite;
549 chan_param.subbuf_size = old_chan_param.subbuf_size;
550 chan_param.num_subbuf = old_chan_param.num_subbuf;
551 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
552 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
553 chan_param.output = old_chan_param.output;
554
555 return lttng_abi_create_channel(file, &chan_param,
556 METADATA_CHANNEL);
557 }
558 case LTTNG_KERNEL_METADATA:
559 {
560 struct lttng_kernel_channel chan_param;
561
562 if (copy_from_user(&chan_param,
563 (struct lttng_kernel_channel __user *) arg,
564 sizeof(struct lttng_kernel_channel)))
565 return -EFAULT;
566 return lttng_abi_create_channel(file, &chan_param,
567 METADATA_CHANNEL);
568 }
569 case LTTNG_KERNEL_SESSION_TRACK_PID:
570 return lttng_session_track_pid(session, (int) arg);
571 case LTTNG_KERNEL_SESSION_UNTRACK_PID:
572 return lttng_session_untrack_pid(session, (int) arg);
573 case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
574 return lttng_session_list_tracker_pids(session);
575 case LTTNG_KERNEL_SESSION_METADATA_REGEN:
576 return lttng_session_metadata_regenerate(session);
577 case LTTNG_KERNEL_SESSION_STATEDUMP:
578 return lttng_session_statedump(session);
579 default:
580 return -ENOIOCTLCMD;
581 }
582 }
583
584 /*
585 * Called when the last file reference is dropped.
586 *
587 * Big fat note: channels and events are invariant for the whole session after
588 * their creation. So this session destruction also destroys all channel and
589 * event structures specific to this session (they are not destroyed when their
590 * individual file is released).
591 */
592 static
593 int lttng_session_release(struct inode *inode, struct file *file)
594 {
595 struct lttng_session *session = file->private_data;
596
597 if (session)
598 lttng_session_destroy(session);
599 return 0;
600 }
601
602 static const struct file_operations lttng_session_fops = {
603 .owner = THIS_MODULE,
604 .release = lttng_session_release,
605 .unlocked_ioctl = lttng_session_ioctl,
606 #ifdef CONFIG_COMPAT
607 .compat_ioctl = lttng_session_ioctl,
608 #endif
609 };
610
611 /**
612 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
613 * @filp: the file
614 * @wait: poll table
615 *
616 * Handles the poll operations for the metadata channels.
617 */
618 static
619 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
620 poll_table *wait)
621 {
622 struct lttng_metadata_stream *stream = filp->private_data;
623 struct lib_ring_buffer *buf = stream->priv;
624 int finalized;
625 unsigned int mask = 0;
626
627 if (filp->f_mode & FMODE_READ) {
628 poll_wait_set_exclusive(wait);
629 poll_wait(filp, &stream->read_wait, wait);
630
631 finalized = stream->finalized;
632
633 /*
634 * lib_ring_buffer_is_finalized() contains a smp_rmb()
635 * ordering finalized load before offsets loads.
636 */
637 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
638
639 if (finalized)
640 mask |= POLLHUP;
641
642 mutex_lock(&stream->metadata_cache->lock);
643 if (stream->metadata_cache->metadata_written >
644 stream->metadata_out)
645 mask |= POLLIN;
646 mutex_unlock(&stream->metadata_cache->lock);
647 }
648
649 return mask;
650 }
651
652 static
653 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
654 unsigned int cmd, unsigned long arg)
655 {
656 struct lttng_metadata_stream *stream = filp->private_data;
657
658 stream->metadata_out = stream->metadata_in;
659 }
660
661 /*
662 * Reset the counter of how much metadata has been consumed to 0. That way,
663 * the consumer receives the content of the metadata cache unchanged. This is
664 * different from the metadata_regenerate where the offset from epoch is
665 * resampled, here we want the exact same content as the last time the metadata
666 * was generated. This command is only possible if all the metadata written
667 * in the cache has been output to the metadata stream to avoid corrupting the
668 * metadata file.
669 *
670 * Return 0 on success, a negative value on error.
671 */
672 static
673 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
674 {
675 int ret;
676 struct lttng_metadata_cache *cache = stream->metadata_cache;
677
678 mutex_lock(&cache->lock);
679 if (stream->metadata_out != cache->metadata_written) {
680 ret = -EBUSY;
681 goto end;
682 }
683 stream->metadata_out = 0;
684 stream->metadata_in = 0;
685 wake_up_interruptible(&stream->read_wait);
686 ret = 0;
687
688 end:
689 mutex_unlock(&cache->lock);
690 return ret;
691 }
692
693 static
694 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
695 unsigned int cmd, unsigned long arg)
696 {
697 int ret;
698 struct lttng_metadata_stream *stream = filp->private_data;
699 struct lib_ring_buffer *buf = stream->priv;
700
701 switch (cmd) {
702 case RING_BUFFER_GET_NEXT_SUBBUF:
703 {
704 struct lttng_metadata_stream *stream = filp->private_data;
705 struct lib_ring_buffer *buf = stream->priv;
706 struct channel *chan = buf->backend.chan;
707
708 ret = lttng_metadata_output_channel(stream, chan);
709 if (ret > 0) {
710 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
711 ret = 0;
712 } else if (ret < 0)
713 goto err;
714 break;
715 }
716 case RING_BUFFER_GET_SUBBUF:
717 {
718 /*
719 * Random access is not allowed for metadata channel.
720 */
721 return -ENOSYS;
722 }
723 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
724 case RING_BUFFER_FLUSH:
725 {
726 struct lttng_metadata_stream *stream = filp->private_data;
727 struct lib_ring_buffer *buf = stream->priv;
728 struct channel *chan = buf->backend.chan;
729
730 /*
731 * Before doing the actual ring buffer flush, write up to one
732 * packet of metadata in the ring buffer.
733 */
734 ret = lttng_metadata_output_channel(stream, chan);
735 if (ret < 0)
736 goto err;
737 break;
738 }
739 case RING_BUFFER_GET_METADATA_VERSION:
740 {
741 struct lttng_metadata_stream *stream = filp->private_data;
742
743 return put_u64(stream->version, arg);
744 }
745 case RING_BUFFER_METADATA_CACHE_DUMP:
746 {
747 struct lttng_metadata_stream *stream = filp->private_data;
748
749 return lttng_metadata_cache_dump(stream);
750 }
751 default:
752 break;
753 }
754 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
755
756 /* Performing lib ring buffer ioctl after our own. */
757 ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
758 if (ret < 0)
759 goto err;
760
761 switch (cmd) {
762 case RING_BUFFER_PUT_NEXT_SUBBUF:
763 {
764 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
765 cmd, arg);
766 break;
767 }
768 default:
769 break;
770 }
771 err:
772 return ret;
773 }
774
775 #ifdef CONFIG_COMPAT
776 static
777 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
778 unsigned int cmd, unsigned long arg)
779 {
780 int ret;
781 struct lttng_metadata_stream *stream = filp->private_data;
782 struct lib_ring_buffer *buf = stream->priv;
783
784 switch (cmd) {
785 case RING_BUFFER_GET_NEXT_SUBBUF:
786 {
787 struct lttng_metadata_stream *stream = filp->private_data;
788 struct lib_ring_buffer *buf = stream->priv;
789 struct channel *chan = buf->backend.chan;
790
791 ret = lttng_metadata_output_channel(stream, chan);
792 if (ret > 0) {
793 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
794 ret = 0;
795 } else if (ret < 0)
796 goto err;
797 break;
798 }
799 case RING_BUFFER_GET_SUBBUF:
800 {
801 /*
802 * Random access is not allowed for metadata channel.
803 */
804 return -ENOSYS;
805 }
806 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
807 case RING_BUFFER_FLUSH:
808 {
809 struct lttng_metadata_stream *stream = filp->private_data;
810 struct lib_ring_buffer *buf = stream->priv;
811 struct channel *chan = buf->backend.chan;
812
813 /*
814 * Before doing the actual ring buffer flush, write up to one
815 * packet of metadata in the ring buffer.
816 */
817 ret = lttng_metadata_output_channel(stream, chan);
818 if (ret < 0)
819 goto err;
820 break;
821 }
822 case RING_BUFFER_GET_METADATA_VERSION:
823 {
824 struct lttng_metadata_stream *stream = filp->private_data;
825
826 return put_u64(stream->version, arg);
827 }
828 case RING_BUFFER_METADATA_CACHE_DUMP:
829 {
830 struct lttng_metadata_stream *stream = filp->private_data;
831
832 return lttng_metadata_cache_dump(stream);
833 }
834 default:
835 break;
836 }
837 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
838
839 /* Performing lib ring buffer ioctl after our own. */
840 ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
841 if (ret < 0)
842 goto err;
843
844 switch (cmd) {
845 case RING_BUFFER_PUT_NEXT_SUBBUF:
846 {
847 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
848 cmd, arg);
849 break;
850 }
851 default:
852 break;
853 }
854 err:
855 return ret;
856 }
857 #endif
858
859 /*
860 * This is not used by anonymous file descriptors. This code is left
861 * there if we ever want to implement an inode with open() operation.
862 */
863 static
864 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
865 {
866 struct lttng_metadata_stream *stream = inode->i_private;
867 struct lib_ring_buffer *buf = stream->priv;
868
869 file->private_data = buf;
870 /*
871 * Since life-time of metadata cache differs from that of
872 * session, we need to keep our own reference on the transport.
873 */
874 if (!try_module_get(stream->transport->owner)) {
875 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
876 return -EBUSY;
877 }
878 return lib_ring_buffer_open(inode, file, buf);
879 }
880
881 static
882 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
883 {
884 struct lttng_metadata_stream *stream = file->private_data;
885 struct lib_ring_buffer *buf = stream->priv;
886
887 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
888 module_put(stream->transport->owner);
889 return lib_ring_buffer_release(inode, file, buf);
890 }
891
892 static
893 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
894 struct pipe_inode_info *pipe, size_t len,
895 unsigned int flags)
896 {
897 struct lttng_metadata_stream *stream = in->private_data;
898 struct lib_ring_buffer *buf = stream->priv;
899
900 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
901 flags, buf);
902 }
903
904 static
905 int lttng_metadata_ring_buffer_mmap(struct file *filp,
906 struct vm_area_struct *vma)
907 {
908 struct lttng_metadata_stream *stream = filp->private_data;
909 struct lib_ring_buffer *buf = stream->priv;
910
911 return lib_ring_buffer_mmap(filp, vma, buf);
912 }
913
914 static
915 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
916 .owner = THIS_MODULE,
917 .open = lttng_metadata_ring_buffer_open,
918 .release = lttng_metadata_ring_buffer_release,
919 .poll = lttng_metadata_ring_buffer_poll,
920 .splice_read = lttng_metadata_ring_buffer_splice_read,
921 .mmap = lttng_metadata_ring_buffer_mmap,
922 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
923 .llseek = vfs_lib_ring_buffer_no_llseek,
924 #ifdef CONFIG_COMPAT
925 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
926 #endif
927 };
928
929 static
930 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
931 const struct file_operations *fops)
932 {
933 int stream_fd, ret;
934 struct file *stream_file;
935
936 stream_fd = lttng_get_unused_fd();
937 if (stream_fd < 0) {
938 ret = stream_fd;
939 goto fd_error;
940 }
941 stream_file = anon_inode_getfile("[lttng_stream]", fops,
942 stream_priv, O_RDWR);
943 if (IS_ERR(stream_file)) {
944 ret = PTR_ERR(stream_file);
945 goto file_error;
946 }
947 /*
948 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
949 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
950 * file descriptor, so we set FMODE_PREAD here.
951 */
952 stream_file->f_mode |= FMODE_PREAD;
953 fd_install(stream_fd, stream_file);
954 /*
955 * The stream holds a reference to the channel within the generic ring
956 * buffer library, so no need to hold a refcount on the channel and
957 * session files here.
958 */
959 return stream_fd;
960
961 file_error:
962 put_unused_fd(stream_fd);
963 fd_error:
964 return ret;
965 }
966
967 static
968 int lttng_abi_open_stream(struct file *channel_file)
969 {
970 struct lttng_channel *channel = channel_file->private_data;
971 struct lib_ring_buffer *buf;
972 int ret;
973 void *stream_priv;
974
975 buf = channel->ops->buffer_read_open(channel->chan);
976 if (!buf)
977 return -ENOENT;
978
979 stream_priv = buf;
980 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
981 &lttng_stream_ring_buffer_file_operations);
982 if (ret < 0)
983 goto fd_error;
984
985 return ret;
986
987 fd_error:
988 channel->ops->buffer_read_close(buf);
989 return ret;
990 }
991
992 static
993 int lttng_abi_open_metadata_stream(struct file *channel_file)
994 {
995 struct lttng_channel *channel = channel_file->private_data;
996 struct lttng_session *session = channel->session;
997 struct lib_ring_buffer *buf;
998 int ret;
999 struct lttng_metadata_stream *metadata_stream;
1000 void *stream_priv;
1001
1002 buf = channel->ops->buffer_read_open(channel->chan);
1003 if (!buf)
1004 return -ENOENT;
1005
1006 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1007 GFP_KERNEL);
1008 if (!metadata_stream) {
1009 ret = -ENOMEM;
1010 goto nomem;
1011 }
1012 metadata_stream->metadata_cache = session->metadata_cache;
1013 init_waitqueue_head(&metadata_stream->read_wait);
1014 metadata_stream->priv = buf;
1015 stream_priv = metadata_stream;
1016 metadata_stream->transport = channel->transport;
1017
1018 /*
1019 * Since life-time of metadata cache differs from that of
1020 * session, we need to keep our own reference on the transport.
1021 */
1022 if (!try_module_get(metadata_stream->transport->owner)) {
1023 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1024 ret = -EINVAL;
1025 goto notransport;
1026 }
1027
1028 if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1029 ret = -EOVERFLOW;
1030 goto kref_error;
1031 }
1032
1033 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1034 &lttng_metadata_ring_buffer_file_operations);
1035 if (ret < 0)
1036 goto fd_error;
1037
1038 list_add(&metadata_stream->list,
1039 &session->metadata_cache->metadata_stream);
1040 return ret;
1041
1042 fd_error:
1043 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1044 kref_error:
1045 module_put(metadata_stream->transport->owner);
1046 notransport:
1047 kfree(metadata_stream);
1048 nomem:
1049 channel->ops->buffer_read_close(buf);
1050 return ret;
1051 }
1052
1053 static
1054 int lttng_abi_create_event(struct file *channel_file,
1055 struct lttng_kernel_event *event_param)
1056 {
1057 struct lttng_channel *channel = channel_file->private_data;
1058 int event_fd, ret;
1059 struct file *event_file;
1060 void *priv;
1061
1062 event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1063 switch (event_param->instrumentation) {
1064 case LTTNG_KERNEL_KRETPROBE:
1065 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1066 break;
1067 case LTTNG_KERNEL_KPROBE:
1068 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1069 break;
1070 case LTTNG_KERNEL_FUNCTION:
1071 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1072 break;
1073 default:
1074 break;
1075 }
1076 event_fd = lttng_get_unused_fd();
1077 if (event_fd < 0) {
1078 ret = event_fd;
1079 goto fd_error;
1080 }
1081 event_file = anon_inode_getfile("[lttng_event]",
1082 &lttng_event_fops,
1083 NULL, O_RDWR);
1084 if (IS_ERR(event_file)) {
1085 ret = PTR_ERR(event_file);
1086 goto file_error;
1087 }
1088 /* The event holds a reference on the channel */
1089 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1090 ret = -EOVERFLOW;
1091 goto refcount_error;
1092 }
1093 if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1094 || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1095 struct lttng_enabler *enabler;
1096
1097 if (strutils_is_star_glob_pattern(event_param->name)) {
1098 /*
1099 * If the event name is a star globbing pattern,
1100 * we create the special star globbing enabler.
1101 */
1102 enabler = lttng_enabler_create(LTTNG_ENABLER_STAR_GLOB,
1103 event_param, channel);
1104 } else {
1105 enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
1106 event_param, channel);
1107 }
1108 priv = enabler;
1109 } else {
1110 struct lttng_event *event;
1111
1112 /*
1113 * We tolerate no failure path after event creation. It
1114 * will stay invariant for the rest of the session.
1115 */
1116 event = lttng_event_create(channel, event_param,
1117 NULL, NULL,
1118 event_param->instrumentation);
1119 WARN_ON_ONCE(!event);
1120 if (IS_ERR(event)) {
1121 ret = PTR_ERR(event);
1122 goto event_error;
1123 }
1124 priv = event;
1125 }
1126 event_file->private_data = priv;
1127 fd_install(event_fd, event_file);
1128 return event_fd;
1129
1130 event_error:
1131 atomic_long_dec(&channel_file->f_count);
1132 refcount_error:
1133 fput(event_file);
1134 file_error:
1135 put_unused_fd(event_fd);
1136 fd_error:
1137 return ret;
1138 }
1139
1140 /**
1141 * lttng_channel_ioctl - lttng syscall through ioctl
1142 *
1143 * @file: the file
1144 * @cmd: the command
1145 * @arg: command arg
1146 *
1147 * This ioctl implements lttng commands:
1148 * LTTNG_KERNEL_STREAM
1149 * Returns an event stream file descriptor or failure.
1150 * (typically, one event stream records events from one CPU)
1151 * LTTNG_KERNEL_EVENT
1152 * Returns an event file descriptor or failure.
1153 * LTTNG_KERNEL_CONTEXT
1154 * Prepend a context field to each event in the channel
1155 * LTTNG_KERNEL_ENABLE
1156 * Enable recording for events in this channel (weak enable)
1157 * LTTNG_KERNEL_DISABLE
1158 * Disable recording for events in this channel (strong disable)
1159 *
1160 * Channel and event file descriptors also hold a reference on the session.
1161 */
1162 static
1163 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1164 {
1165 struct lttng_channel *channel = file->private_data;
1166
1167 switch (cmd) {
1168 case LTTNG_KERNEL_OLD_STREAM:
1169 case LTTNG_KERNEL_STREAM:
1170 return lttng_abi_open_stream(file);
1171 case LTTNG_KERNEL_OLD_EVENT:
1172 {
1173 struct lttng_kernel_event *uevent_param;
1174 struct lttng_kernel_old_event *old_uevent_param;
1175 int ret;
1176
1177 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1178 GFP_KERNEL);
1179 if (!uevent_param) {
1180 ret = -ENOMEM;
1181 goto old_event_end;
1182 }
1183 old_uevent_param = kmalloc(
1184 sizeof(struct lttng_kernel_old_event),
1185 GFP_KERNEL);
1186 if (!old_uevent_param) {
1187 ret = -ENOMEM;
1188 goto old_event_error_free_param;
1189 }
1190 if (copy_from_user(old_uevent_param,
1191 (struct lttng_kernel_old_event __user *) arg,
1192 sizeof(struct lttng_kernel_old_event))) {
1193 ret = -EFAULT;
1194 goto old_event_error_free_old_param;
1195 }
1196
1197 memcpy(uevent_param->name, old_uevent_param->name,
1198 sizeof(uevent_param->name));
1199 uevent_param->instrumentation =
1200 old_uevent_param->instrumentation;
1201
1202 switch (old_uevent_param->instrumentation) {
1203 case LTTNG_KERNEL_KPROBE:
1204 uevent_param->u.kprobe.addr =
1205 old_uevent_param->u.kprobe.addr;
1206 uevent_param->u.kprobe.offset =
1207 old_uevent_param->u.kprobe.offset;
1208 memcpy(uevent_param->u.kprobe.symbol_name,
1209 old_uevent_param->u.kprobe.symbol_name,
1210 sizeof(uevent_param->u.kprobe.symbol_name));
1211 break;
1212 case LTTNG_KERNEL_KRETPROBE:
1213 uevent_param->u.kretprobe.addr =
1214 old_uevent_param->u.kretprobe.addr;
1215 uevent_param->u.kretprobe.offset =
1216 old_uevent_param->u.kretprobe.offset;
1217 memcpy(uevent_param->u.kretprobe.symbol_name,
1218 old_uevent_param->u.kretprobe.symbol_name,
1219 sizeof(uevent_param->u.kretprobe.symbol_name));
1220 break;
1221 case LTTNG_KERNEL_FUNCTION:
1222 memcpy(uevent_param->u.ftrace.symbol_name,
1223 old_uevent_param->u.ftrace.symbol_name,
1224 sizeof(uevent_param->u.ftrace.symbol_name));
1225 break;
1226 default:
1227 break;
1228 }
1229 ret = lttng_abi_create_event(file, uevent_param);
1230
1231 old_event_error_free_old_param:
1232 kfree(old_uevent_param);
1233 old_event_error_free_param:
1234 kfree(uevent_param);
1235 old_event_end:
1236 return ret;
1237 }
1238 case LTTNG_KERNEL_EVENT:
1239 {
1240 struct lttng_kernel_event uevent_param;
1241
1242 if (copy_from_user(&uevent_param,
1243 (struct lttng_kernel_event __user *) arg,
1244 sizeof(uevent_param)))
1245 return -EFAULT;
1246 return lttng_abi_create_event(file, &uevent_param);
1247 }
1248 case LTTNG_KERNEL_OLD_CONTEXT:
1249 {
1250 struct lttng_kernel_context *ucontext_param;
1251 struct lttng_kernel_old_context *old_ucontext_param;
1252 int ret;
1253
1254 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1255 GFP_KERNEL);
1256 if (!ucontext_param) {
1257 ret = -ENOMEM;
1258 goto old_ctx_end;
1259 }
1260 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1261 GFP_KERNEL);
1262 if (!old_ucontext_param) {
1263 ret = -ENOMEM;
1264 goto old_ctx_error_free_param;
1265 }
1266
1267 if (copy_from_user(old_ucontext_param,
1268 (struct lttng_kernel_old_context __user *) arg,
1269 sizeof(struct lttng_kernel_old_context))) {
1270 ret = -EFAULT;
1271 goto old_ctx_error_free_old_param;
1272 }
1273 ucontext_param->ctx = old_ucontext_param->ctx;
1274 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1275 sizeof(ucontext_param->padding));
1276 /* only type that uses the union */
1277 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1278 ucontext_param->u.perf_counter.type =
1279 old_ucontext_param->u.perf_counter.type;
1280 ucontext_param->u.perf_counter.config =
1281 old_ucontext_param->u.perf_counter.config;
1282 memcpy(ucontext_param->u.perf_counter.name,
1283 old_ucontext_param->u.perf_counter.name,
1284 sizeof(ucontext_param->u.perf_counter.name));
1285 }
1286
1287 ret = lttng_abi_add_context(file,
1288 ucontext_param,
1289 &channel->ctx, channel->session);
1290
1291 old_ctx_error_free_old_param:
1292 kfree(old_ucontext_param);
1293 old_ctx_error_free_param:
1294 kfree(ucontext_param);
1295 old_ctx_end:
1296 return ret;
1297 }
1298 case LTTNG_KERNEL_CONTEXT:
1299 {
1300 struct lttng_kernel_context ucontext_param;
1301
1302 if (copy_from_user(&ucontext_param,
1303 (struct lttng_kernel_context __user *) arg,
1304 sizeof(ucontext_param)))
1305 return -EFAULT;
1306 return lttng_abi_add_context(file,
1307 &ucontext_param,
1308 &channel->ctx, channel->session);
1309 }
1310 case LTTNG_KERNEL_OLD_ENABLE:
1311 case LTTNG_KERNEL_ENABLE:
1312 return lttng_channel_enable(channel);
1313 case LTTNG_KERNEL_OLD_DISABLE:
1314 case LTTNG_KERNEL_DISABLE:
1315 return lttng_channel_disable(channel);
1316 case LTTNG_KERNEL_SYSCALL_MASK:
1317 return lttng_channel_syscall_mask(channel,
1318 (struct lttng_kernel_syscall_mask __user *) arg);
1319 default:
1320 return -ENOIOCTLCMD;
1321 }
1322 }
1323
1324 /**
1325 * lttng_metadata_ioctl - lttng syscall through ioctl
1326 *
1327 * @file: the file
1328 * @cmd: the command
1329 * @arg: command arg
1330 *
1331 * This ioctl implements lttng commands:
1332 * LTTNG_KERNEL_STREAM
1333 * Returns an event stream file descriptor or failure.
1334 *
1335 * Channel and event file descriptors also hold a reference on the session.
1336 */
1337 static
1338 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1339 {
1340 switch (cmd) {
1341 case LTTNG_KERNEL_OLD_STREAM:
1342 case LTTNG_KERNEL_STREAM:
1343 return lttng_abi_open_metadata_stream(file);
1344 default:
1345 return -ENOIOCTLCMD;
1346 }
1347 }
1348
1349 /**
1350 * lttng_channel_poll - lttng stream addition/removal monitoring
1351 *
1352 * @file: the file
1353 * @wait: poll table
1354 */
1355 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1356 {
1357 struct lttng_channel *channel = file->private_data;
1358 unsigned int mask = 0;
1359
1360 if (file->f_mode & FMODE_READ) {
1361 poll_wait_set_exclusive(wait);
1362 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1363 wait);
1364
1365 if (channel->ops->is_disabled(channel->chan))
1366 return POLLERR;
1367 if (channel->ops->is_finalized(channel->chan))
1368 return POLLHUP;
1369 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1370 return POLLIN | POLLRDNORM;
1371 return 0;
1372 }
1373 return mask;
1374
1375 }
1376
1377 static
1378 int lttng_channel_release(struct inode *inode, struct file *file)
1379 {
1380 struct lttng_channel *channel = file->private_data;
1381
1382 if (channel)
1383 fput(channel->session->file);
1384 return 0;
1385 }
1386
1387 static
1388 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1389 {
1390 struct lttng_channel *channel = file->private_data;
1391
1392 if (channel) {
1393 fput(channel->session->file);
1394 lttng_metadata_channel_destroy(channel);
1395 }
1396
1397 return 0;
1398 }
1399
1400 static const struct file_operations lttng_channel_fops = {
1401 .owner = THIS_MODULE,
1402 .release = lttng_channel_release,
1403 .poll = lttng_channel_poll,
1404 .unlocked_ioctl = lttng_channel_ioctl,
1405 #ifdef CONFIG_COMPAT
1406 .compat_ioctl = lttng_channel_ioctl,
1407 #endif
1408 };
1409
1410 static const struct file_operations lttng_metadata_fops = {
1411 .owner = THIS_MODULE,
1412 .release = lttng_metadata_channel_release,
1413 .unlocked_ioctl = lttng_metadata_ioctl,
1414 #ifdef CONFIG_COMPAT
1415 .compat_ioctl = lttng_metadata_ioctl,
1416 #endif
1417 };
1418
1419 /**
1420 * lttng_event_ioctl - lttng syscall through ioctl
1421 *
1422 * @file: the file
1423 * @cmd: the command
1424 * @arg: command arg
1425 *
1426 * This ioctl implements lttng commands:
1427 * LTTNG_KERNEL_CONTEXT
1428 * Prepend a context field to each record of this event
1429 * LTTNG_KERNEL_ENABLE
1430 * Enable recording for this event (weak enable)
1431 * LTTNG_KERNEL_DISABLE
1432 * Disable recording for this event (strong disable)
1433 */
1434 static
1435 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1436 {
1437 struct lttng_event *event;
1438 struct lttng_enabler *enabler;
1439 enum lttng_event_type *evtype = file->private_data;
1440
1441 switch (cmd) {
1442 case LTTNG_KERNEL_OLD_CONTEXT:
1443 {
1444 /* Not implemented */
1445 return -ENOSYS;
1446 }
1447 case LTTNG_KERNEL_CONTEXT:
1448 {
1449 /* Not implemented */
1450 return -ENOSYS;
1451 }
1452 case LTTNG_KERNEL_OLD_ENABLE:
1453 case LTTNG_KERNEL_ENABLE:
1454 switch (*evtype) {
1455 case LTTNG_TYPE_EVENT:
1456 event = file->private_data;
1457 return lttng_event_enable(event);
1458 case LTTNG_TYPE_ENABLER:
1459 enabler = file->private_data;
1460 return lttng_enabler_enable(enabler);
1461 default:
1462 WARN_ON_ONCE(1);
1463 return -ENOSYS;
1464 }
1465 case LTTNG_KERNEL_OLD_DISABLE:
1466 case LTTNG_KERNEL_DISABLE:
1467 switch (*evtype) {
1468 case LTTNG_TYPE_EVENT:
1469 event = file->private_data;
1470 return lttng_event_disable(event);
1471 case LTTNG_TYPE_ENABLER:
1472 enabler = file->private_data;
1473 return lttng_enabler_disable(enabler);
1474 default:
1475 WARN_ON_ONCE(1);
1476 return -ENOSYS;
1477 }
1478 case LTTNG_KERNEL_FILTER:
1479 switch (*evtype) {
1480 case LTTNG_TYPE_EVENT:
1481 return -EINVAL;
1482 case LTTNG_TYPE_ENABLER:
1483 {
1484 enabler = file->private_data;
1485 return lttng_enabler_attach_bytecode(enabler,
1486 (struct lttng_kernel_filter_bytecode __user *) arg);
1487 }
1488 default:
1489 WARN_ON_ONCE(1);
1490 return -ENOSYS;
1491 }
1492 case LTTNG_KERNEL_ADD_CALLSITE:
1493 switch (*evtype) {
1494 case LTTNG_TYPE_EVENT:
1495 event = file->private_data;
1496 return lttng_event_add_callsite(event,
1497 (struct lttng_kernel_event_callsite __user *) arg);
1498 case LTTNG_TYPE_ENABLER:
1499 return -EINVAL;
1500 }
1501 default:
1502 return -ENOIOCTLCMD;
1503 }
1504 }
1505
1506 static
1507 int lttng_event_release(struct inode *inode, struct file *file)
1508 {
1509 struct lttng_event *event;
1510 struct lttng_enabler *enabler;
1511 enum lttng_event_type *evtype = file->private_data;
1512
1513 if (!evtype)
1514 return 0;
1515
1516 switch (*evtype) {
1517 case LTTNG_TYPE_EVENT:
1518 event = file->private_data;
1519 if (event)
1520 fput(event->chan->file);
1521 break;
1522 case LTTNG_TYPE_ENABLER:
1523 enabler = file->private_data;
1524 if (enabler)
1525 fput(enabler->chan->file);
1526 break;
1527 default:
1528 WARN_ON_ONCE(1);
1529 break;
1530 }
1531
1532 return 0;
1533 }
1534
1535 /* TODO: filter control ioctl */
1536 static const struct file_operations lttng_event_fops = {
1537 .owner = THIS_MODULE,
1538 .release = lttng_event_release,
1539 .unlocked_ioctl = lttng_event_ioctl,
1540 #ifdef CONFIG_COMPAT
1541 .compat_ioctl = lttng_event_ioctl,
1542 #endif
1543 };
1544
1545 static int put_u64(uint64_t val, unsigned long arg)
1546 {
1547 return put_user(val, (uint64_t __user *) arg);
1548 }
1549
1550 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1551 unsigned int cmd, unsigned long arg)
1552 {
1553 struct lib_ring_buffer *buf = filp->private_data;
1554 struct channel *chan = buf->backend.chan;
1555 const struct lib_ring_buffer_config *config = &chan->backend.config;
1556 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1557 int ret;
1558
1559 if (atomic_read(&chan->record_disabled))
1560 return -EIO;
1561
1562 switch (cmd) {
1563 case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1564 {
1565 uint64_t ts;
1566
1567 ret = ops->timestamp_begin(config, buf, &ts);
1568 if (ret < 0)
1569 goto error;
1570 return put_u64(ts, arg);
1571 }
1572 case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1573 {
1574 uint64_t ts;
1575
1576 ret = ops->timestamp_end(config, buf, &ts);
1577 if (ret < 0)
1578 goto error;
1579 return put_u64(ts, arg);
1580 }
1581 case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1582 {
1583 uint64_t ed;
1584
1585 ret = ops->events_discarded(config, buf, &ed);
1586 if (ret < 0)
1587 goto error;
1588 return put_u64(ed, arg);
1589 }
1590 case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1591 {
1592 uint64_t cs;
1593
1594 ret = ops->content_size(config, buf, &cs);
1595 if (ret < 0)
1596 goto error;
1597 return put_u64(cs, arg);
1598 }
1599 case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1600 {
1601 uint64_t ps;
1602
1603 ret = ops->packet_size(config, buf, &ps);
1604 if (ret < 0)
1605 goto error;
1606 return put_u64(ps, arg);
1607 }
1608 case LTTNG_RING_BUFFER_GET_STREAM_ID:
1609 {
1610 uint64_t si;
1611
1612 ret = ops->stream_id(config, buf, &si);
1613 if (ret < 0)
1614 goto error;
1615 return put_u64(si, arg);
1616 }
1617 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1618 {
1619 uint64_t ts;
1620
1621 ret = ops->current_timestamp(config, buf, &ts);
1622 if (ret < 0)
1623 goto error;
1624 return put_u64(ts, arg);
1625 }
1626 case LTTNG_RING_BUFFER_GET_SEQ_NUM:
1627 {
1628 uint64_t seq;
1629
1630 ret = ops->sequence_number(config, buf, &seq);
1631 if (ret < 0)
1632 goto error;
1633 return put_u64(seq, arg);
1634 }
1635 case LTTNG_RING_BUFFER_INSTANCE_ID:
1636 {
1637 uint64_t id;
1638
1639 ret = ops->instance_id(config, buf, &id);
1640 if (ret < 0)
1641 goto error;
1642 return put_u64(id, arg);
1643 }
1644 default:
1645 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1646 cmd, arg);
1647 }
1648
1649 error:
1650 return -ENOSYS;
1651 }
1652
1653 #ifdef CONFIG_COMPAT
1654 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1655 unsigned int cmd, unsigned long arg)
1656 {
1657 struct lib_ring_buffer *buf = filp->private_data;
1658 struct channel *chan = buf->backend.chan;
1659 const struct lib_ring_buffer_config *config = &chan->backend.config;
1660 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1661 int ret;
1662
1663 if (atomic_read(&chan->record_disabled))
1664 return -EIO;
1665
1666 switch (cmd) {
1667 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1668 {
1669 uint64_t ts;
1670
1671 ret = ops->timestamp_begin(config, buf, &ts);
1672 if (ret < 0)
1673 goto error;
1674 return put_u64(ts, arg);
1675 }
1676 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1677 {
1678 uint64_t ts;
1679
1680 ret = ops->timestamp_end(config, buf, &ts);
1681 if (ret < 0)
1682 goto error;
1683 return put_u64(ts, arg);
1684 }
1685 case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1686 {
1687 uint64_t ed;
1688
1689 ret = ops->events_discarded(config, buf, &ed);
1690 if (ret < 0)
1691 goto error;
1692 return put_u64(ed, arg);
1693 }
1694 case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1695 {
1696 uint64_t cs;
1697
1698 ret = ops->content_size(config, buf, &cs);
1699 if (ret < 0)
1700 goto error;
1701 return put_u64(cs, arg);
1702 }
1703 case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1704 {
1705 uint64_t ps;
1706
1707 ret = ops->packet_size(config, buf, &ps);
1708 if (ret < 0)
1709 goto error;
1710 return put_u64(ps, arg);
1711 }
1712 case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1713 {
1714 uint64_t si;
1715
1716 ret = ops->stream_id(config, buf, &si);
1717 if (ret < 0)
1718 goto error;
1719 return put_u64(si, arg);
1720 }
1721 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1722 {
1723 uint64_t ts;
1724
1725 ret = ops->current_timestamp(config, buf, &ts);
1726 if (ret < 0)
1727 goto error;
1728 return put_u64(ts, arg);
1729 }
1730 case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
1731 {
1732 uint64_t seq;
1733
1734 ret = ops->sequence_number(config, buf, &seq);
1735 if (ret < 0)
1736 goto error;
1737 return put_u64(seq, arg);
1738 }
1739 case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
1740 {
1741 uint64_t id;
1742
1743 ret = ops->instance_id(config, buf, &id);
1744 if (ret < 0)
1745 goto error;
1746 return put_u64(id, arg);
1747 }
1748 default:
1749 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1750 cmd, arg);
1751 }
1752
1753 error:
1754 return -ENOSYS;
1755 }
1756 #endif /* CONFIG_COMPAT */
1757
1758 static void lttng_stream_override_ring_buffer_fops(void)
1759 {
1760 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1761 lttng_stream_ring_buffer_file_operations.open =
1762 lib_ring_buffer_file_operations.open;
1763 lttng_stream_ring_buffer_file_operations.release =
1764 lib_ring_buffer_file_operations.release;
1765 lttng_stream_ring_buffer_file_operations.poll =
1766 lib_ring_buffer_file_operations.poll;
1767 lttng_stream_ring_buffer_file_operations.splice_read =
1768 lib_ring_buffer_file_operations.splice_read;
1769 lttng_stream_ring_buffer_file_operations.mmap =
1770 lib_ring_buffer_file_operations.mmap;
1771 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1772 lttng_stream_ring_buffer_ioctl;
1773 lttng_stream_ring_buffer_file_operations.llseek =
1774 lib_ring_buffer_file_operations.llseek;
1775 #ifdef CONFIG_COMPAT
1776 lttng_stream_ring_buffer_file_operations.compat_ioctl =
1777 lttng_stream_ring_buffer_compat_ioctl;
1778 #endif
1779 }
1780
1781 int __init lttng_abi_init(void)
1782 {
1783 int ret = 0;
1784
1785 wrapper_vmalloc_sync_all();
1786 lttng_clock_ref();
1787
1788 ret = lttng_tp_mempool_init();
1789 if (ret) {
1790 goto error;
1791 }
1792
1793 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1794 &lttng_fops, NULL);
1795
1796 if (!lttng_proc_dentry) {
1797 printk(KERN_ERR "Error creating LTTng control file\n");
1798 ret = -ENOMEM;
1799 goto error;
1800 }
1801 lttng_stream_override_ring_buffer_fops();
1802 return 0;
1803
1804 error:
1805 lttng_tp_mempool_destroy();
1806 lttng_clock_unref();
1807 return ret;
1808 }
1809
1810 /* No __exit annotation because used by init error path too. */
1811 void lttng_abi_exit(void)
1812 {
1813 lttng_tp_mempool_destroy();
1814 lttng_clock_unref();
1815 if (lttng_proc_dentry)
1816 remove_proc_entry("lttng", NULL);
1817 }
LTTng modules - Deliverables
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