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Add support for kvm x86 specific tracepoints
[lttng-modules.git] / lttng-abi.c
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1/*
2 * lttng-abi.c
3 *
4 * LTTng ABI
5 *
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 *
23 * Mimic system calls for:
24 * - session creation, returns a file descriptor or failure.
25 * - channel creation, returns a file descriptor or failure.
26 * - Operates on a session file descriptor
27 * - Takes all channel options as parameters.
28 * - stream get, returns a file descriptor or failure.
29 * - Operates on a channel file descriptor.
30 * - stream notifier get, returns a file descriptor or failure.
31 * - Operates on a channel file descriptor.
32 * - event creation, returns a file descriptor or failure.
33 * - Operates on a channel file descriptor
34 * - Takes an event name as parameter
35 * - Takes an instrumentation source as parameter
36 * - e.g. tracepoints, dynamic_probes...
37 * - Takes instrumentation source specific arguments.
38 */
39
40#include <linux/module.h>
41#include <linux/proc_fs.h>
42#include <linux/anon_inodes.h>
43#include <linux/file.h>
44#include <linux/uaccess.h>
45#include <linux/slab.h>
46#include "wrapper/vmalloc.h" /* for wrapper_vmalloc_sync_all() */
47#include "wrapper/ringbuffer/vfs.h"
48#include "wrapper/ringbuffer/backend.h"
49#include "wrapper/ringbuffer/frontend.h"
50#include "wrapper/poll.h"
51#include "lttng-abi.h"
52#include "lttng-abi-old.h"
53#include "lttng-events.h"
54#include "lttng-tracer.h"
55
56/*
57 * This is LTTng's own personal way to create a system call as an external
58 * module. We use ioctl() on /proc/lttng.
59 */
60
61static struct proc_dir_entry *lttng_proc_dentry;
62static const struct file_operations lttng_fops;
63static const struct file_operations lttng_session_fops;
64static const struct file_operations lttng_channel_fops;
65static const struct file_operations lttng_metadata_fops;
66static const struct file_operations lttng_event_fops;
67
68/*
69 * Teardown management: opened file descriptors keep a refcount on the module,
70 * so it can only exit when all file descriptors are closed.
71 */
72
73static
74int lttng_abi_create_session(void)
75{
76 struct lttng_session *session;
77 struct file *session_file;
78 int session_fd, ret;
79
80 session = lttng_session_create();
81 if (!session)
82 return -ENOMEM;
83 session_fd = get_unused_fd();
84 if (session_fd < 0) {
85 ret = session_fd;
86 goto fd_error;
87 }
88 session_file = anon_inode_getfile("[lttng_session]",
89 &lttng_session_fops,
90 session, O_RDWR);
91 if (IS_ERR(session_file)) {
92 ret = PTR_ERR(session_file);
93 goto file_error;
94 }
95 session->file = session_file;
96 fd_install(session_fd, session_file);
97 return session_fd;
98
99file_error:
100 put_unused_fd(session_fd);
101fd_error:
102 lttng_session_destroy(session);
103 return ret;
104}
105
106static
107int lttng_abi_tracepoint_list(void)
108{
109 struct file *tracepoint_list_file;
110 int file_fd, ret;
111
112 file_fd = get_unused_fd();
113 if (file_fd < 0) {
114 ret = file_fd;
115 goto fd_error;
116 }
117
118 tracepoint_list_file = anon_inode_getfile("[lttng_session]",
119 &lttng_tracepoint_list_fops,
120 NULL, O_RDWR);
121 if (IS_ERR(tracepoint_list_file)) {
122 ret = PTR_ERR(tracepoint_list_file);
123 goto file_error;
124 }
125 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
126 if (ret < 0)
127 goto open_error;
128 fd_install(file_fd, tracepoint_list_file);
129 if (file_fd < 0) {
130 ret = file_fd;
131 goto fd_error;
132 }
133 return file_fd;
134
135open_error:
136 fput(tracepoint_list_file);
137file_error:
138 put_unused_fd(file_fd);
139fd_error:
140 return ret;
141}
142
143static
144void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
145{
146 v->major = LTTNG_MODULES_MAJOR_VERSION;
147 v->minor = LTTNG_MODULES_MINOR_VERSION;
148 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
149}
150
151static
152long lttng_abi_add_context(struct file *file,
153 struct lttng_kernel_context *context_param,
154 struct lttng_ctx **ctx, struct lttng_session *session)
155{
156
157 if (session->been_active)
158 return -EPERM;
159
160 switch (context_param->ctx) {
161 case LTTNG_KERNEL_CONTEXT_PID:
162 return lttng_add_pid_to_ctx(ctx);
163 case LTTNG_KERNEL_CONTEXT_PRIO:
164 return lttng_add_prio_to_ctx(ctx);
165 case LTTNG_KERNEL_CONTEXT_NICE:
166 return lttng_add_nice_to_ctx(ctx);
167 case LTTNG_KERNEL_CONTEXT_VPID:
168 return lttng_add_vpid_to_ctx(ctx);
169 case LTTNG_KERNEL_CONTEXT_TID:
170 return lttng_add_tid_to_ctx(ctx);
171 case LTTNG_KERNEL_CONTEXT_VTID:
172 return lttng_add_vtid_to_ctx(ctx);
173 case LTTNG_KERNEL_CONTEXT_PPID:
174 return lttng_add_ppid_to_ctx(ctx);
175 case LTTNG_KERNEL_CONTEXT_VPPID:
176 return lttng_add_vppid_to_ctx(ctx);
177 case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
178 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
179 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
180 context_param->u.perf_counter.config,
181 context_param->u.perf_counter.name,
182 ctx);
183 case LTTNG_KERNEL_CONTEXT_PROCNAME:
184 return lttng_add_procname_to_ctx(ctx);
185 case LTTNG_KERNEL_CONTEXT_HOSTNAME:
186 return lttng_add_hostname_to_ctx(ctx);
187 default:
188 return -EINVAL;
189 }
190}
191
192/**
193 * lttng_ioctl - lttng syscall through ioctl
194 *
195 * @file: the file
196 * @cmd: the command
197 * @arg: command arg
198 *
199 * This ioctl implements lttng commands:
200 * LTTNG_KERNEL_SESSION
201 * Returns a LTTng trace session file descriptor
202 * LTTNG_KERNEL_TRACER_VERSION
203 * Returns the LTTng kernel tracer version
204 * LTTNG_KERNEL_TRACEPOINT_LIST
205 * Returns a file descriptor listing available tracepoints
206 * LTTNG_KERNEL_WAIT_QUIESCENT
207 * Returns after all previously running probes have completed
208 *
209 * The returned session will be deleted when its file descriptor is closed.
210 */
211static
212long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
213{
214 switch (cmd) {
215 case LTTNG_KERNEL_OLD_SESSION:
216 case LTTNG_KERNEL_SESSION:
217 return lttng_abi_create_session();
218 case LTTNG_KERNEL_OLD_TRACER_VERSION:
219 {
220 struct lttng_kernel_tracer_version v;
221 struct lttng_kernel_old_tracer_version oldv;
222 struct lttng_kernel_old_tracer_version *uversion =
223 (struct lttng_kernel_old_tracer_version __user *) arg;
224
225 lttng_abi_tracer_version(&v);
226 oldv.major = v.major;
227 oldv.minor = v.minor;
228 oldv.patchlevel = v.patchlevel;
229
230 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
231 return -EFAULT;
232 return 0;
233 }
234 case LTTNG_KERNEL_TRACER_VERSION:
235 {
236 struct lttng_kernel_tracer_version version;
237 struct lttng_kernel_tracer_version *uversion =
238 (struct lttng_kernel_tracer_version __user *) arg;
239
240 lttng_abi_tracer_version(&version);
241
242 if (copy_to_user(uversion, &version, sizeof(version)))
243 return -EFAULT;
244 return 0;
245 }
246 case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
247 case LTTNG_KERNEL_TRACEPOINT_LIST:
248 return lttng_abi_tracepoint_list();
249 case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
250 case LTTNG_KERNEL_WAIT_QUIESCENT:
251 synchronize_trace();
252 return 0;
253 case LTTNG_KERNEL_OLD_CALIBRATE:
254 {
255 struct lttng_kernel_old_calibrate __user *ucalibrate =
256 (struct lttng_kernel_old_calibrate __user *) arg;
257 struct lttng_kernel_old_calibrate old_calibrate;
258 struct lttng_kernel_calibrate calibrate;
259 int ret;
260
261 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
262 return -EFAULT;
263 calibrate.type = old_calibrate.type;
264 ret = lttng_calibrate(&calibrate);
265 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
266 return -EFAULT;
267 return ret;
268 }
269 case LTTNG_KERNEL_CALIBRATE:
270 {
271 struct lttng_kernel_calibrate __user *ucalibrate =
272 (struct lttng_kernel_calibrate __user *) arg;
273 struct lttng_kernel_calibrate calibrate;
274 int ret;
275
276 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
277 return -EFAULT;
278 ret = lttng_calibrate(&calibrate);
279 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
280 return -EFAULT;
281 return ret;
282 }
283 default:
284 return -ENOIOCTLCMD;
285 }
286}
287
288static const struct file_operations lttng_fops = {
289 .owner = THIS_MODULE,
290 .unlocked_ioctl = lttng_ioctl,
291#ifdef CONFIG_COMPAT
292 .compat_ioctl = lttng_ioctl,
293#endif
294};
295
296static
297int lttng_abi_create_channel(struct file *session_file,
298 struct lttng_kernel_channel *chan_param,
299 enum channel_type channel_type)
300{
301 struct lttng_session *session = session_file->private_data;
302 const struct file_operations *fops = NULL;
303 const char *transport_name;
304 struct lttng_channel *chan;
305 struct file *chan_file;
306 int chan_fd;
307 int ret = 0;
308
309 chan_fd = get_unused_fd();
310 if (chan_fd < 0) {
311 ret = chan_fd;
312 goto fd_error;
313 }
314 switch (channel_type) {
315 case PER_CPU_CHANNEL:
316 fops = &lttng_channel_fops;
317 break;
318 case METADATA_CHANNEL:
319 fops = &lttng_metadata_fops;
320 break;
321 }
322
323 chan_file = anon_inode_getfile("[lttng_channel]",
324 fops,
325 NULL, O_RDWR);
326 if (IS_ERR(chan_file)) {
327 ret = PTR_ERR(chan_file);
328 goto file_error;
329 }
330 switch (channel_type) {
331 case PER_CPU_CHANNEL:
332 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
333 transport_name = chan_param->overwrite ?
334 "relay-overwrite" : "relay-discard";
335 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
336 transport_name = chan_param->overwrite ?
337 "relay-overwrite-mmap" : "relay-discard-mmap";
338 } else {
339 return -EINVAL;
340 }
341 break;
342 case METADATA_CHANNEL:
343 if (chan_param->output == LTTNG_KERNEL_SPLICE)
344 transport_name = "relay-metadata";
345 else if (chan_param->output == LTTNG_KERNEL_MMAP)
346 transport_name = "relay-metadata-mmap";
347 else
348 return -EINVAL;
349 break;
350 default:
351 transport_name = "<unknown>";
352 break;
353 }
354 /*
355 * We tolerate no failure path after channel creation. It will stay
356 * invariant for the rest of the session.
357 */
358 chan = lttng_channel_create(session, transport_name, NULL,
359 chan_param->subbuf_size,
360 chan_param->num_subbuf,
361 chan_param->switch_timer_interval,
362 chan_param->read_timer_interval,
363 channel_type);
364 if (!chan) {
365 ret = -EINVAL;
366 goto chan_error;
367 }
368 chan->file = chan_file;
369 chan_file->private_data = chan;
370 fd_install(chan_fd, chan_file);
371 atomic_long_inc(&session_file->f_count);
372
373 return chan_fd;
374
375chan_error:
376 fput(chan_file);
377file_error:
378 put_unused_fd(chan_fd);
379fd_error:
380 return ret;
381}
382
383/**
384 * lttng_session_ioctl - lttng session fd ioctl
385 *
386 * @file: the file
387 * @cmd: the command
388 * @arg: command arg
389 *
390 * This ioctl implements lttng commands:
391 * LTTNG_KERNEL_CHANNEL
392 * Returns a LTTng channel file descriptor
393 * LTTNG_KERNEL_ENABLE
394 * Enables tracing for a session (weak enable)
395 * LTTNG_KERNEL_DISABLE
396 * Disables tracing for a session (strong disable)
397 * LTTNG_KERNEL_METADATA
398 * Returns a LTTng metadata file descriptor
399 *
400 * The returned channel will be deleted when its file descriptor is closed.
401 */
402static
403long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
404{
405 struct lttng_session *session = file->private_data;
406
407 switch (cmd) {
408 case LTTNG_KERNEL_OLD_CHANNEL:
409 {
410 struct lttng_kernel_channel chan_param;
411 struct lttng_kernel_old_channel old_chan_param;
412
413 if (copy_from_user(&old_chan_param,
414 (struct lttng_kernel_old_channel __user *) arg,
415 sizeof(struct lttng_kernel_old_channel)))
416 return -EFAULT;
417 chan_param.overwrite = old_chan_param.overwrite;
418 chan_param.subbuf_size = old_chan_param.subbuf_size;
419 chan_param.num_subbuf = old_chan_param.num_subbuf;
420 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
421 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
422 chan_param.output = old_chan_param.output;
423
424 return lttng_abi_create_channel(file, &chan_param,
425 PER_CPU_CHANNEL);
426 }
427 case LTTNG_KERNEL_CHANNEL:
428 {
429 struct lttng_kernel_channel chan_param;
430
431 if (copy_from_user(&chan_param,
432 (struct lttng_kernel_channel __user *) arg,
433 sizeof(struct lttng_kernel_channel)))
434 return -EFAULT;
435 return lttng_abi_create_channel(file, &chan_param,
436 PER_CPU_CHANNEL);
437 }
438 case LTTNG_KERNEL_OLD_SESSION_START:
439 case LTTNG_KERNEL_OLD_ENABLE:
440 case LTTNG_KERNEL_SESSION_START:
441 case LTTNG_KERNEL_ENABLE:
442 return lttng_session_enable(session);
443 case LTTNG_KERNEL_OLD_SESSION_STOP:
444 case LTTNG_KERNEL_OLD_DISABLE:
445 case LTTNG_KERNEL_SESSION_STOP:
446 case LTTNG_KERNEL_DISABLE:
447 return lttng_session_disable(session);
448 case LTTNG_KERNEL_OLD_METADATA:
449 {
450 struct lttng_kernel_channel chan_param;
451 struct lttng_kernel_old_channel old_chan_param;
452
453 if (copy_from_user(&old_chan_param,
454 (struct lttng_kernel_old_channel __user *) arg,
455 sizeof(struct lttng_kernel_old_channel)))
456 return -EFAULT;
457 chan_param.overwrite = old_chan_param.overwrite;
458 chan_param.subbuf_size = old_chan_param.subbuf_size;
459 chan_param.num_subbuf = old_chan_param.num_subbuf;
460 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
461 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
462 chan_param.output = old_chan_param.output;
463
464 return lttng_abi_create_channel(file, &chan_param,
465 METADATA_CHANNEL);
466 }
467 case LTTNG_KERNEL_METADATA:
468 {
469 struct lttng_kernel_channel chan_param;
470
471 if (copy_from_user(&chan_param,
472 (struct lttng_kernel_channel __user *) arg,
473 sizeof(struct lttng_kernel_channel)))
474 return -EFAULT;
475 return lttng_abi_create_channel(file, &chan_param,
476 METADATA_CHANNEL);
477 }
478 default:
479 return -ENOIOCTLCMD;
480 }
481}
482
483/*
484 * Called when the last file reference is dropped.
485 *
486 * Big fat note: channels and events are invariant for the whole session after
487 * their creation. So this session destruction also destroys all channel and
488 * event structures specific to this session (they are not destroyed when their
489 * individual file is released).
490 */
491static
492int lttng_session_release(struct inode *inode, struct file *file)
493{
494 struct lttng_session *session = file->private_data;
495
496 if (session)
497 lttng_session_destroy(session);
498 return 0;
499}
500
501static const struct file_operations lttng_session_fops = {
502 .owner = THIS_MODULE,
503 .release = lttng_session_release,
504 .unlocked_ioctl = lttng_session_ioctl,
505#ifdef CONFIG_COMPAT
506 .compat_ioctl = lttng_session_ioctl,
507#endif
508};
509
510/**
511 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
512 * @filp: the file
513 * @wait: poll table
514 *
515 * Handles the poll operations for the metadata channels.
516 */
517static
518unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
519 poll_table *wait)
520{
521 struct lttng_metadata_stream *stream = filp->private_data;
522 struct lib_ring_buffer *buf = stream->priv;
523 int finalized;
524 unsigned int mask = 0;
525
526 if (filp->f_mode & FMODE_READ) {
527 poll_wait_set_exclusive(wait);
528 poll_wait(filp, &stream->read_wait, wait);
529
530 finalized = stream->finalized;
531
532 /*
533 * lib_ring_buffer_is_finalized() contains a smp_rmb()
534 * ordering finalized load before offsets loads.
535 */
536 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
537
538 if (finalized)
539 mask |= POLLHUP;
540
541 if (stream->metadata_cache->metadata_written >
542 stream->metadata_cache_read)
543 mask |= POLLIN;
544 }
545
546 return mask;
547}
548
549static
550int lttng_metadata_ring_buffer_ioctl_get_subbuf(struct file *filp,
551 unsigned int cmd, unsigned long arg)
552{
553 struct lttng_metadata_stream *stream = filp->private_data;
554 struct lib_ring_buffer *buf = stream->priv;
555 struct channel *chan = buf->backend.chan;
556 struct lttng_channel *lttng_chan = channel_get_private(chan);
557 int ret;
558
559 ret = lttng_metadata_output_channel(lttng_chan, stream);
560 if (ret > 0) {
561 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
562 ret = 0;
563 }
564 return ret;
565}
566
567static
568long lttng_metadata_ring_buffer_ioctl(struct file *filp,
569 unsigned int cmd, unsigned long arg)
570{
571 int ret;
572 struct lttng_metadata_stream *stream = filp->private_data;
573 struct lib_ring_buffer *buf = stream->priv;
574
575 switch (cmd) {
576 case RING_BUFFER_GET_SUBBUF:
577 case RING_BUFFER_GET_NEXT_SUBBUF:
578 {
579 ret = lttng_metadata_ring_buffer_ioctl_get_subbuf(filp,
580 cmd, arg);
581 if (ret < 0)
582 goto err;
583 break;
584 }
585 default:
586 break;
587 }
588 /* Performing lib ring buffer ioctl after our own. */
589 return lib_ring_buffer_ioctl(filp, cmd, arg, buf);
590
591err:
592 return ret;
593}
594
595#ifdef CONFIG_COMPAT
596static
597long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
598 unsigned int cmd, unsigned long arg)
599{
600 int ret;
601 struct lttng_metadata_stream *stream = filp->private_data;
602 struct lib_ring_buffer *buf = stream->priv;
603
604 switch (cmd) {
605 case RING_BUFFER_GET_SUBBUF:
606 case RING_BUFFER_GET_NEXT_SUBBUF:
607 {
608 ret = lttng_metadata_ring_buffer_ioctl_get_subbuf(filp,
609 cmd, arg);
610 if (ret < 0)
611 goto err;
612 break;
613 }
614 default:
615 break;
616 }
617 /* Performing lib ring buffer ioctl after our own. */
618 return lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
619
620err:
621 return ret;
622}
623#endif
624
625static
626int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
627{
628 struct lttng_metadata_stream *stream = inode->i_private;
629 struct lib_ring_buffer *buf = stream->priv;
630
631 file->private_data = buf;
632 return lib_ring_buffer_open(inode, file, buf);
633}
634
635static
636int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
637{
638 struct lttng_metadata_stream *stream = file->private_data;
639 struct lib_ring_buffer *buf = stream->priv;
640
641 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
642
643 return lib_ring_buffer_release(inode, file, buf);
644}
645
646static
647ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
648 struct pipe_inode_info *pipe, size_t len,
649 unsigned int flags)
650{
651 struct lttng_metadata_stream *stream = in->private_data;
652 struct lib_ring_buffer *buf = stream->priv;
653
654 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
655 flags, buf);
656}
657
658static
659int lttng_metadata_ring_buffer_mmap(struct file *filp,
660 struct vm_area_struct *vma)
661{
662 struct lttng_metadata_stream *stream = filp->private_data;
663 struct lib_ring_buffer *buf = stream->priv;
664
665 return lib_ring_buffer_mmap(filp, vma, buf);
666}
667
668static
669const struct file_operations lttng_metadata_ring_buffer_file_operations = {
670 .owner = THIS_MODULE,
671 .open = lttng_metadata_ring_buffer_open,
672 .release = lttng_metadata_ring_buffer_release,
673 .poll = lttng_metadata_ring_buffer_poll,
674 .splice_read = lttng_metadata_ring_buffer_splice_read,
675 .mmap = lttng_metadata_ring_buffer_mmap,
676 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
677 .llseek = vfs_lib_ring_buffer_no_llseek,
678#ifdef CONFIG_COMPAT
679 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
680#endif
681};
682
683static
684int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
685 const struct file_operations *fops)
686{
687 int stream_fd, ret;
688 struct file *stream_file;
689
690 stream_fd = get_unused_fd();
691 if (stream_fd < 0) {
692 ret = stream_fd;
693 goto fd_error;
694 }
695 stream_file = anon_inode_getfile("[lttng_stream]", fops,
696 stream_priv, O_RDWR);
697 if (IS_ERR(stream_file)) {
698 ret = PTR_ERR(stream_file);
699 goto file_error;
700 }
701 /*
702 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
703 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
704 * file descriptor, so we set FMODE_PREAD here.
705 */
706 stream_file->f_mode |= FMODE_PREAD;
707 fd_install(stream_fd, stream_file);
708 /*
709 * The stream holds a reference to the channel within the generic ring
710 * buffer library, so no need to hold a refcount on the channel and
711 * session files here.
712 */
713 return stream_fd;
714
715file_error:
716 put_unused_fd(stream_fd);
717fd_error:
718 return ret;
719}
720
721static
722int lttng_abi_open_stream(struct file *channel_file)
723{
724 struct lttng_channel *channel = channel_file->private_data;
725 struct lib_ring_buffer *buf;
726 int ret;
727 void *stream_priv;
728
729 buf = channel->ops->buffer_read_open(channel->chan);
730 if (!buf)
731 return -ENOENT;
732
733 stream_priv = buf;
734 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
735 &lib_ring_buffer_file_operations);
736 if (ret < 0)
737 goto fd_error;
738
739 return ret;
740
741fd_error:
742 channel->ops->buffer_read_close(buf);
743 return ret;
744}
745
746static
747int lttng_abi_open_metadata_stream(struct file *channel_file)
748{
749 struct lttng_channel *channel = channel_file->private_data;
750 struct lttng_session *session = channel->session;
751 struct lib_ring_buffer *buf;
752 int ret;
753 struct lttng_metadata_stream *metadata_stream;
754 void *stream_priv;
755
756 buf = channel->ops->buffer_read_open(channel->chan);
757 if (!buf)
758 return -ENOENT;
759
760 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
761 GFP_KERNEL);
762 if (!metadata_stream)
763 return -ENOMEM;
764 metadata_stream->metadata_cache = session->metadata_cache;
765 init_waitqueue_head(&metadata_stream->read_wait);
766 metadata_stream->priv = buf;
767 stream_priv = metadata_stream;
768 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
769 &lttng_metadata_ring_buffer_file_operations);
770 if (ret < 0)
771 goto fd_error;
772
773 kref_get(&session->metadata_cache->refcount);
774 list_add(&metadata_stream->list,
775 &session->metadata_cache->metadata_stream);
776 return ret;
777
778fd_error:
779 channel->ops->buffer_read_close(buf);
780 return ret;
781}
782
783static
784int lttng_abi_create_event(struct file *channel_file,
785 struct lttng_kernel_event *event_param)
786{
787 struct lttng_channel *channel = channel_file->private_data;
788 struct lttng_event *event;
789 int event_fd, ret;
790 struct file *event_file;
791
792 event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
793 switch (event_param->instrumentation) {
794 case LTTNG_KERNEL_KRETPROBE:
795 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
796 break;
797 case LTTNG_KERNEL_KPROBE:
798 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
799 break;
800 case LTTNG_KERNEL_FUNCTION:
801 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
802 break;
803 default:
804 break;
805 }
806 switch (event_param->instrumentation) {
807 default:
808 event_fd = get_unused_fd();
809 if (event_fd < 0) {
810 ret = event_fd;
811 goto fd_error;
812 }
813 event_file = anon_inode_getfile("[lttng_event]",
814 &lttng_event_fops,
815 NULL, O_RDWR);
816 if (IS_ERR(event_file)) {
817 ret = PTR_ERR(event_file);
818 goto file_error;
819 }
820 /*
821 * We tolerate no failure path after event creation. It
822 * will stay invariant for the rest of the session.
823 */
824 event = lttng_event_create(channel, event_param, NULL, NULL);
825 if (!event) {
826 ret = -EINVAL;
827 goto event_error;
828 }
829 event_file->private_data = event;
830 fd_install(event_fd, event_file);
831 /* The event holds a reference on the channel */
832 atomic_long_inc(&channel_file->f_count);
833 break;
834 case LTTNG_KERNEL_SYSCALL:
835 /*
836 * Only all-syscall tracing supported for now.
837 */
838 if (event_param->name[0] != '\0')
839 return -EINVAL;
840 ret = lttng_syscalls_register(channel, NULL);
841 if (ret)
842 goto fd_error;
843 event_fd = 0;
844 break;
845 }
846 return event_fd;
847
848event_error:
849 fput(event_file);
850file_error:
851 put_unused_fd(event_fd);
852fd_error:
853 return ret;
854}
855
856/**
857 * lttng_channel_ioctl - lttng syscall through ioctl
858 *
859 * @file: the file
860 * @cmd: the command
861 * @arg: command arg
862 *
863 * This ioctl implements lttng commands:
864 * LTTNG_KERNEL_STREAM
865 * Returns an event stream file descriptor or failure.
866 * (typically, one event stream records events from one CPU)
867 * LTTNG_KERNEL_EVENT
868 * Returns an event file descriptor or failure.
869 * LTTNG_KERNEL_CONTEXT
870 * Prepend a context field to each event in the channel
871 * LTTNG_KERNEL_ENABLE
872 * Enable recording for events in this channel (weak enable)
873 * LTTNG_KERNEL_DISABLE
874 * Disable recording for events in this channel (strong disable)
875 *
876 * Channel and event file descriptors also hold a reference on the session.
877 */
878static
879long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
880{
881 struct lttng_channel *channel = file->private_data;
882
883 switch (cmd) {
884 case LTTNG_KERNEL_OLD_STREAM:
885 case LTTNG_KERNEL_STREAM:
886 return lttng_abi_open_stream(file);
887 case LTTNG_KERNEL_OLD_EVENT:
888 {
889 struct lttng_kernel_event *uevent_param;
890 struct lttng_kernel_old_event *old_uevent_param;
891 int ret;
892
893 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
894 GFP_KERNEL);
895 if (!uevent_param) {
896 ret = -ENOMEM;
897 goto old_event_end;
898 }
899 old_uevent_param = kmalloc(
900 sizeof(struct lttng_kernel_old_event),
901 GFP_KERNEL);
902 if (!old_uevent_param) {
903 ret = -ENOMEM;
904 goto old_event_error_free_param;
905 }
906 if (copy_from_user(old_uevent_param,
907 (struct lttng_kernel_old_event __user *) arg,
908 sizeof(struct lttng_kernel_old_event))) {
909 ret = -EFAULT;
910 goto old_event_error_free_old_param;
911 }
912
913 memcpy(uevent_param->name, old_uevent_param->name,
914 sizeof(uevent_param->name));
915 uevent_param->instrumentation =
916 old_uevent_param->instrumentation;
917
918 switch (old_uevent_param->instrumentation) {
919 case LTTNG_KERNEL_KPROBE:
920 uevent_param->u.kprobe.addr =
921 old_uevent_param->u.kprobe.addr;
922 uevent_param->u.kprobe.offset =
923 old_uevent_param->u.kprobe.offset;
924 memcpy(uevent_param->u.kprobe.symbol_name,
925 old_uevent_param->u.kprobe.symbol_name,
926 sizeof(uevent_param->u.kprobe.symbol_name));
927 break;
928 case LTTNG_KERNEL_KRETPROBE:
929 uevent_param->u.kretprobe.addr =
930 old_uevent_param->u.kretprobe.addr;
931 uevent_param->u.kretprobe.offset =
932 old_uevent_param->u.kretprobe.offset;
933 memcpy(uevent_param->u.kretprobe.symbol_name,
934 old_uevent_param->u.kretprobe.symbol_name,
935 sizeof(uevent_param->u.kretprobe.symbol_name));
936 break;
937 case LTTNG_KERNEL_FUNCTION:
938 memcpy(uevent_param->u.ftrace.symbol_name,
939 old_uevent_param->u.ftrace.symbol_name,
940 sizeof(uevent_param->u.ftrace.symbol_name));
941 break;
942 default:
943 break;
944 }
945 ret = lttng_abi_create_event(file, uevent_param);
946
947old_event_error_free_old_param:
948 kfree(old_uevent_param);
949old_event_error_free_param:
950 kfree(uevent_param);
951old_event_end:
952 return ret;
953 }
954 case LTTNG_KERNEL_EVENT:
955 {
956 struct lttng_kernel_event uevent_param;
957
958 if (copy_from_user(&uevent_param,
959 (struct lttng_kernel_event __user *) arg,
960 sizeof(uevent_param)))
961 return -EFAULT;
962 return lttng_abi_create_event(file, &uevent_param);
963 }
964 case LTTNG_KERNEL_OLD_CONTEXT:
965 {
966 struct lttng_kernel_context *ucontext_param;
967 struct lttng_kernel_old_context *old_ucontext_param;
968 int ret;
969
970 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
971 GFP_KERNEL);
972 if (!ucontext_param) {
973 ret = -ENOMEM;
974 goto old_ctx_end;
975 }
976 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
977 GFP_KERNEL);
978 if (!old_ucontext_param) {
979 ret = -ENOMEM;
980 goto old_ctx_error_free_param;
981 }
982
983 if (copy_from_user(old_ucontext_param,
984 (struct lttng_kernel_old_context __user *) arg,
985 sizeof(struct lttng_kernel_old_context))) {
986 ret = -EFAULT;
987 goto old_ctx_error_free_old_param;
988 }
989 ucontext_param->ctx = old_ucontext_param->ctx;
990 memcpy(ucontext_param->padding, old_ucontext_param->padding,
991 sizeof(ucontext_param->padding));
992 /* only type that uses the union */
993 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
994 ucontext_param->u.perf_counter.type =
995 old_ucontext_param->u.perf_counter.type;
996 ucontext_param->u.perf_counter.config =
997 old_ucontext_param->u.perf_counter.config;
998 memcpy(ucontext_param->u.perf_counter.name,
999 old_ucontext_param->u.perf_counter.name,
1000 sizeof(ucontext_param->u.perf_counter.name));
1001 }
1002
1003 ret = lttng_abi_add_context(file,
1004 ucontext_param,
1005 &channel->ctx, channel->session);
1006
1007old_ctx_error_free_old_param:
1008 kfree(old_ucontext_param);
1009old_ctx_error_free_param:
1010 kfree(ucontext_param);
1011old_ctx_end:
1012 return ret;
1013 }
1014 case LTTNG_KERNEL_CONTEXT:
1015 {
1016 struct lttng_kernel_context ucontext_param;
1017
1018 if (copy_from_user(&ucontext_param,
1019 (struct lttng_kernel_context __user *) arg,
1020 sizeof(ucontext_param)))
1021 return -EFAULT;
1022 return lttng_abi_add_context(file,
1023 &ucontext_param,
1024 &channel->ctx, channel->session);
1025 }
1026 case LTTNG_KERNEL_OLD_ENABLE:
1027 case LTTNG_KERNEL_ENABLE:
1028 return lttng_channel_enable(channel);
1029 case LTTNG_KERNEL_OLD_DISABLE:
1030 case LTTNG_KERNEL_DISABLE:
1031 return lttng_channel_disable(channel);
1032 default:
1033 return -ENOIOCTLCMD;
1034 }
1035
1036}
1037
1038/**
1039 * lttng_metadata_ioctl - lttng syscall through ioctl
1040 *
1041 * @file: the file
1042 * @cmd: the command
1043 * @arg: command arg
1044 *
1045 * This ioctl implements lttng commands:
1046 * LTTNG_KERNEL_STREAM
1047 * Returns an event stream file descriptor or failure.
1048 *
1049 * Channel and event file descriptors also hold a reference on the session.
1050 */
1051static
1052long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1053{
1054 switch (cmd) {
1055 case LTTNG_KERNEL_OLD_STREAM:
1056 case LTTNG_KERNEL_STREAM:
1057 return lttng_abi_open_metadata_stream(file);
1058 default:
1059 return -ENOIOCTLCMD;
1060 }
1061}
1062
1063/**
1064 * lttng_channel_poll - lttng stream addition/removal monitoring
1065 *
1066 * @file: the file
1067 * @wait: poll table
1068 */
1069unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1070{
1071 struct lttng_channel *channel = file->private_data;
1072 unsigned int mask = 0;
1073
1074 if (file->f_mode & FMODE_READ) {
1075 poll_wait_set_exclusive(wait);
1076 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1077 wait);
1078
1079 if (channel->ops->is_disabled(channel->chan))
1080 return POLLERR;
1081 if (channel->ops->is_finalized(channel->chan))
1082 return POLLHUP;
1083 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1084 return POLLIN | POLLRDNORM;
1085 return 0;
1086 }
1087 return mask;
1088
1089}
1090
1091static
1092int lttng_channel_release(struct inode *inode, struct file *file)
1093{
1094 struct lttng_channel *channel = file->private_data;
1095
1096 if (channel)
1097 fput(channel->session->file);
1098 return 0;
1099}
1100
1101static
1102int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1103{
1104 struct lttng_channel *channel = file->private_data;
1105
1106 if (channel) {
1107 lttng_metadata_channel_destroy(channel);
1108 fput(channel->session->file);
1109 }
1110
1111 return 0;
1112}
1113
1114static const struct file_operations lttng_channel_fops = {
1115 .owner = THIS_MODULE,
1116 .release = lttng_channel_release,
1117 .poll = lttng_channel_poll,
1118 .unlocked_ioctl = lttng_channel_ioctl,
1119#ifdef CONFIG_COMPAT
1120 .compat_ioctl = lttng_channel_ioctl,
1121#endif
1122};
1123
1124static const struct file_operations lttng_metadata_fops = {
1125 .owner = THIS_MODULE,
1126 .release = lttng_metadata_channel_release,
1127 .unlocked_ioctl = lttng_metadata_ioctl,
1128#ifdef CONFIG_COMPAT
1129 .compat_ioctl = lttng_metadata_ioctl,
1130#endif
1131};
1132
1133/**
1134 * lttng_event_ioctl - lttng syscall through ioctl
1135 *
1136 * @file: the file
1137 * @cmd: the command
1138 * @arg: command arg
1139 *
1140 * This ioctl implements lttng commands:
1141 * LTTNG_KERNEL_CONTEXT
1142 * Prepend a context field to each record of this event
1143 * LTTNG_KERNEL_ENABLE
1144 * Enable recording for this event (weak enable)
1145 * LTTNG_KERNEL_DISABLE
1146 * Disable recording for this event (strong disable)
1147 */
1148static
1149long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1150{
1151 struct lttng_event *event = file->private_data;
1152
1153 switch (cmd) {
1154 case LTTNG_KERNEL_OLD_CONTEXT:
1155 {
1156 struct lttng_kernel_context *ucontext_param;
1157 struct lttng_kernel_old_context *old_ucontext_param;
1158 int ret;
1159
1160 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1161 GFP_KERNEL);
1162 if (!ucontext_param) {
1163 ret = -ENOMEM;
1164 goto old_ctx_end;
1165 }
1166 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1167 GFP_KERNEL);
1168 if (!old_ucontext_param) {
1169 ret = -ENOMEM;
1170 goto old_ctx_error_free_param;
1171 }
1172
1173 if (copy_from_user(old_ucontext_param,
1174 (struct lttng_kernel_old_context __user *) arg,
1175 sizeof(struct lttng_kernel_old_context))) {
1176 ret = -EFAULT;
1177 goto old_ctx_error_free_old_param;
1178 }
1179 ucontext_param->ctx = old_ucontext_param->ctx;
1180 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1181 sizeof(ucontext_param->padding));
1182 /* only type that uses the union */
1183 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1184 ucontext_param->u.perf_counter.type =
1185 old_ucontext_param->u.perf_counter.type;
1186 ucontext_param->u.perf_counter.config =
1187 old_ucontext_param->u.perf_counter.config;
1188 memcpy(ucontext_param->u.perf_counter.name,
1189 old_ucontext_param->u.perf_counter.name,
1190 sizeof(ucontext_param->u.perf_counter.name));
1191 }
1192
1193 ret = lttng_abi_add_context(file,
1194 ucontext_param,
1195 &event->ctx, event->chan->session);
1196
1197old_ctx_error_free_old_param:
1198 kfree(old_ucontext_param);
1199old_ctx_error_free_param:
1200 kfree(ucontext_param);
1201old_ctx_end:
1202 return ret;
1203 }
1204 case LTTNG_KERNEL_CONTEXT:
1205 {
1206 struct lttng_kernel_context ucontext_param;
1207
1208 if (copy_from_user(&ucontext_param,
1209 (struct lttng_kernel_context __user *) arg,
1210 sizeof(ucontext_param)))
1211 return -EFAULT;
1212 return lttng_abi_add_context(file,
1213 &ucontext_param,
1214 &event->ctx, event->chan->session);
1215 }
1216 case LTTNG_KERNEL_OLD_ENABLE:
1217 case LTTNG_KERNEL_ENABLE:
1218 return lttng_event_enable(event);
1219 case LTTNG_KERNEL_OLD_DISABLE:
1220 case LTTNG_KERNEL_DISABLE:
1221 return lttng_event_disable(event);
1222 default:
1223 return -ENOIOCTLCMD;
1224 }
1225}
1226
1227static
1228int lttng_event_release(struct inode *inode, struct file *file)
1229{
1230 struct lttng_event *event = file->private_data;
1231
1232 if (event)
1233 fput(event->chan->file);
1234 return 0;
1235}
1236
1237/* TODO: filter control ioctl */
1238static const struct file_operations lttng_event_fops = {
1239 .owner = THIS_MODULE,
1240 .release = lttng_event_release,
1241 .unlocked_ioctl = lttng_event_ioctl,
1242#ifdef CONFIG_COMPAT
1243 .compat_ioctl = lttng_event_ioctl,
1244#endif
1245};
1246
1247int __init lttng_abi_init(void)
1248{
1249 int ret = 0;
1250
1251 wrapper_vmalloc_sync_all();
1252 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1253 &lttng_fops, NULL);
1254
1255 if (!lttng_proc_dentry) {
1256 printk(KERN_ERR "Error creating LTTng control file\n");
1257 ret = -ENOMEM;
1258 goto error;
1259 }
1260error:
1261 return ret;
1262}
1263
1264void __exit lttng_abi_exit(void)
1265{
1266 if (lttng_proc_dentry)
1267 remove_proc_entry("lttng", NULL);
1268}
LTTng 2.0/0.x modules
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