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SoW-2019-0002: Dynamic Snapshot
[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 #include <lib/ringbuffer/iterator.h>
48
49 /*
50 * This is LTTng's own personal way to create a system call as an external
51 * module. We use ioctl() on /proc/lttng.
52 */
53
54 static struct proc_dir_entry *lttng_proc_dentry;
55
56 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
57 static const struct proc_ops lttng_proc_ops;
58 #else
59 static const struct file_operations lttng_proc_ops;
60 #endif
61
62 static const struct file_operations lttng_session_fops;
63 static const struct file_operations lttng_trigger_group_fops;
64 static const struct file_operations lttng_channel_fops;
65 static const struct file_operations lttng_metadata_fops;
66 static const struct file_operations lttng_event_fops;
67 static struct file_operations lttng_stream_ring_buffer_file_operations;
68
69 static int put_u64(uint64_t val, unsigned long arg);
70
71 /*
72 * Teardown management: opened file descriptors keep a refcount on the module,
73 * so it can only exit when all file descriptors are closed.
74 */
75
76 static
77 int lttng_abi_create_session(void)
78 {
79 struct lttng_session *session;
80 struct file *session_file;
81 int session_fd, ret;
82
83 session = lttng_session_create();
84 if (!session)
85 return -ENOMEM;
86 session_fd = lttng_get_unused_fd();
87 if (session_fd < 0) {
88 ret = session_fd;
89 goto fd_error;
90 }
91 session_file = anon_inode_getfile("[lttng_session]",
92 &lttng_session_fops,
93 session, O_RDWR);
94 if (IS_ERR(session_file)) {
95 ret = PTR_ERR(session_file);
96 goto file_error;
97 }
98 session->file = session_file;
99 fd_install(session_fd, session_file);
100 return session_fd;
101
102 file_error:
103 put_unused_fd(session_fd);
104 fd_error:
105 lttng_session_destroy(session);
106 return ret;
107 }
108
109 static
110 void trigger_send_notification_work_wakeup(struct irq_work *entry)
111 {
112 struct lttng_trigger_group *trigger_group = container_of(entry,
113 struct lttng_trigger_group, wakeup_pending);
114 wake_up_interruptible(&trigger_group->read_wait);
115 }
116
117 static
118 int lttng_abi_create_trigger_group(void)
119 {
120 struct lttng_trigger_group *trigger_group;
121 struct file *trigger_group_file;
122 int trigger_group_fd, ret;
123
124 trigger_group = lttng_trigger_group_create();
125 if (!trigger_group)
126 return -ENOMEM;
127
128 trigger_group_fd = lttng_get_unused_fd();
129 if (trigger_group_fd < 0) {
130 ret = trigger_group_fd;
131 goto fd_error;
132 }
133 trigger_group_file = anon_inode_getfile("[lttng_trigger_group]",
134 &lttng_trigger_group_fops,
135 trigger_group, O_RDWR);
136 if (IS_ERR(trigger_group_file)) {
137 ret = PTR_ERR(trigger_group_file);
138 goto file_error;
139 }
140
141 trigger_group->file = trigger_group_file;
142 init_waitqueue_head(&trigger_group->read_wait);
143 init_irq_work(&trigger_group->wakeup_pending,
144 trigger_send_notification_work_wakeup);
145 fd_install(trigger_group_fd, trigger_group_file);
146 return trigger_group_fd;
147
148 file_error:
149 put_unused_fd(trigger_group_fd);
150 fd_error:
151 lttng_trigger_group_destroy(trigger_group);
152 return ret;
153 }
154
155 static
156 int lttng_abi_tracepoint_list(void)
157 {
158 struct file *tracepoint_list_file;
159 int file_fd, ret;
160
161 file_fd = lttng_get_unused_fd();
162 if (file_fd < 0) {
163 ret = file_fd;
164 goto fd_error;
165 }
166
167 tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
168 &lttng_tracepoint_list_fops,
169 NULL, O_RDWR);
170 if (IS_ERR(tracepoint_list_file)) {
171 ret = PTR_ERR(tracepoint_list_file);
172 goto file_error;
173 }
174 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
175 if (ret < 0)
176 goto open_error;
177 fd_install(file_fd, tracepoint_list_file);
178 return file_fd;
179
180 open_error:
181 fput(tracepoint_list_file);
182 file_error:
183 put_unused_fd(file_fd);
184 fd_error:
185 return ret;
186 }
187
188 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
189 static inline
190 int lttng_abi_syscall_list(void)
191 {
192 return -ENOSYS;
193 }
194 #else
195 static
196 int lttng_abi_syscall_list(void)
197 {
198 struct file *syscall_list_file;
199 int file_fd, ret;
200
201 file_fd = lttng_get_unused_fd();
202 if (file_fd < 0) {
203 ret = file_fd;
204 goto fd_error;
205 }
206
207 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
208 &lttng_syscall_list_fops,
209 NULL, O_RDWR);
210 if (IS_ERR(syscall_list_file)) {
211 ret = PTR_ERR(syscall_list_file);
212 goto file_error;
213 }
214 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
215 if (ret < 0)
216 goto open_error;
217 fd_install(file_fd, syscall_list_file);
218 return file_fd;
219
220 open_error:
221 fput(syscall_list_file);
222 file_error:
223 put_unused_fd(file_fd);
224 fd_error:
225 return ret;
226 }
227 #endif
228
229 static
230 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
231 {
232 v->major = LTTNG_MODULES_MAJOR_VERSION;
233 v->minor = LTTNG_MODULES_MINOR_VERSION;
234 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
235 }
236
237 static
238 void lttng_abi_tracer_abi_version(struct lttng_kernel_tracer_abi_version *v)
239 {
240 v->major = LTTNG_MODULES_ABI_MAJOR_VERSION;
241 v->minor = LTTNG_MODULES_ABI_MINOR_VERSION;
242 }
243
244 static
245 long lttng_abi_add_context(struct file *file,
246 struct lttng_kernel_context *context_param,
247 struct lttng_ctx **ctx, struct lttng_session *session)
248 {
249
250 if (session->been_active)
251 return -EPERM;
252
253 switch (context_param->ctx) {
254 case LTTNG_KERNEL_CONTEXT_PID:
255 return lttng_add_pid_to_ctx(ctx);
256 case LTTNG_KERNEL_CONTEXT_PRIO:
257 return lttng_add_prio_to_ctx(ctx);
258 case LTTNG_KERNEL_CONTEXT_NICE:
259 return lttng_add_nice_to_ctx(ctx);
260 case LTTNG_KERNEL_CONTEXT_VPID:
261 return lttng_add_vpid_to_ctx(ctx);
262 case LTTNG_KERNEL_CONTEXT_TID:
263 return lttng_add_tid_to_ctx(ctx);
264 case LTTNG_KERNEL_CONTEXT_VTID:
265 return lttng_add_vtid_to_ctx(ctx);
266 case LTTNG_KERNEL_CONTEXT_PPID:
267 return lttng_add_ppid_to_ctx(ctx);
268 case LTTNG_KERNEL_CONTEXT_VPPID:
269 return lttng_add_vppid_to_ctx(ctx);
270 case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
271 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
272 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
273 context_param->u.perf_counter.config,
274 context_param->u.perf_counter.name,
275 ctx);
276 case LTTNG_KERNEL_CONTEXT_PROCNAME:
277 return lttng_add_procname_to_ctx(ctx);
278 case LTTNG_KERNEL_CONTEXT_HOSTNAME:
279 return lttng_add_hostname_to_ctx(ctx);
280 case LTTNG_KERNEL_CONTEXT_CPU_ID:
281 return lttng_add_cpu_id_to_ctx(ctx);
282 case LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE:
283 return lttng_add_interruptible_to_ctx(ctx);
284 case LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE:
285 return lttng_add_need_reschedule_to_ctx(ctx);
286 case LTTNG_KERNEL_CONTEXT_PREEMPTIBLE:
287 return lttng_add_preemptible_to_ctx(ctx);
288 case LTTNG_KERNEL_CONTEXT_MIGRATABLE:
289 return lttng_add_migratable_to_ctx(ctx);
290 case LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL:
291 case LTTNG_KERNEL_CONTEXT_CALLSTACK_USER:
292 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
293 case LTTNG_KERNEL_CONTEXT_CGROUP_NS:
294 return lttng_add_cgroup_ns_to_ctx(ctx);
295 case LTTNG_KERNEL_CONTEXT_IPC_NS:
296 return lttng_add_ipc_ns_to_ctx(ctx);
297 case LTTNG_KERNEL_CONTEXT_MNT_NS:
298 return lttng_add_mnt_ns_to_ctx(ctx);
299 case LTTNG_KERNEL_CONTEXT_NET_NS:
300 return lttng_add_net_ns_to_ctx(ctx);
301 case LTTNG_KERNEL_CONTEXT_PID_NS:
302 return lttng_add_pid_ns_to_ctx(ctx);
303 case LTTNG_KERNEL_CONTEXT_USER_NS:
304 return lttng_add_user_ns_to_ctx(ctx);
305 case LTTNG_KERNEL_CONTEXT_UTS_NS:
306 return lttng_add_uts_ns_to_ctx(ctx);
307 case LTTNG_KERNEL_CONTEXT_UID:
308 return lttng_add_uid_to_ctx(ctx);
309 case LTTNG_KERNEL_CONTEXT_EUID:
310 return lttng_add_euid_to_ctx(ctx);
311 case LTTNG_KERNEL_CONTEXT_SUID:
312 return lttng_add_suid_to_ctx(ctx);
313 case LTTNG_KERNEL_CONTEXT_GID:
314 return lttng_add_gid_to_ctx(ctx);
315 case LTTNG_KERNEL_CONTEXT_EGID:
316 return lttng_add_egid_to_ctx(ctx);
317 case LTTNG_KERNEL_CONTEXT_SGID:
318 return lttng_add_sgid_to_ctx(ctx);
319 case LTTNG_KERNEL_CONTEXT_VUID:
320 return lttng_add_vuid_to_ctx(ctx);
321 case LTTNG_KERNEL_CONTEXT_VEUID:
322 return lttng_add_veuid_to_ctx(ctx);
323 case LTTNG_KERNEL_CONTEXT_VSUID:
324 return lttng_add_vsuid_to_ctx(ctx);
325 case LTTNG_KERNEL_CONTEXT_VGID:
326 return lttng_add_vgid_to_ctx(ctx);
327 case LTTNG_KERNEL_CONTEXT_VEGID:
328 return lttng_add_vegid_to_ctx(ctx);
329 case LTTNG_KERNEL_CONTEXT_VSGID:
330 return lttng_add_vsgid_to_ctx(ctx);
331 default:
332 return -EINVAL;
333 }
334 }
335
336 /**
337 * lttng_ioctl - lttng syscall through ioctl
338 *
339 * @file: the file
340 * @cmd: the command
341 * @arg: command arg
342 *
343 * This ioctl implements lttng commands:
344 * LTTNG_KERNEL_SESSION
345 * Returns a LTTng trace session file descriptor
346 * LTTNG_KERNEL_TRACER_VERSION
347 * Returns the LTTng kernel tracer version
348 * LTTNG_KERNEL_TRACEPOINT_LIST
349 * Returns a file descriptor listing available tracepoints
350 * LTTNG_KERNEL_WAIT_QUIESCENT
351 * Returns after all previously running probes have completed
352 * LTTNG_KERNEL_TRACER_ABI_VERSION
353 * Returns the LTTng kernel tracer ABI version
354 * LTTNG_KERNEL_TRIGGER_GROUP_CREATE
355 * Returns a LTTng trigger group file descriptor
356 *
357 * The returned session will be deleted when its file descriptor is closed.
358 */
359 static
360 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
361 {
362 switch (cmd) {
363 case LTTNG_KERNEL_OLD_SESSION:
364 case LTTNG_KERNEL_SESSION:
365 return lttng_abi_create_session();
366 case LTTNG_KERNEL_TRIGGER_GROUP_CREATE:
367 return lttng_abi_create_trigger_group();
368 case LTTNG_KERNEL_OLD_TRACER_VERSION:
369 {
370 struct lttng_kernel_tracer_version v;
371 struct lttng_kernel_old_tracer_version oldv;
372 struct lttng_kernel_old_tracer_version *uversion =
373 (struct lttng_kernel_old_tracer_version __user *) arg;
374
375 lttng_abi_tracer_version(&v);
376 oldv.major = v.major;
377 oldv.minor = v.minor;
378 oldv.patchlevel = v.patchlevel;
379
380 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
381 return -EFAULT;
382 return 0;
383 }
384 case LTTNG_KERNEL_TRACER_VERSION:
385 {
386 struct lttng_kernel_tracer_version version;
387 struct lttng_kernel_tracer_version *uversion =
388 (struct lttng_kernel_tracer_version __user *) arg;
389
390 lttng_abi_tracer_version(&version);
391
392 if (copy_to_user(uversion, &version, sizeof(version)))
393 return -EFAULT;
394 return 0;
395 }
396 case LTTNG_KERNEL_TRACER_ABI_VERSION:
397 {
398 struct lttng_kernel_tracer_abi_version version;
399 struct lttng_kernel_tracer_abi_version *uversion =
400 (struct lttng_kernel_tracer_abi_version __user *) arg;
401
402 lttng_abi_tracer_abi_version(&version);
403
404 if (copy_to_user(uversion, &version, sizeof(version)))
405 return -EFAULT;
406 return 0;
407 }
408 case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
409 case LTTNG_KERNEL_TRACEPOINT_LIST:
410 return lttng_abi_tracepoint_list();
411 case LTTNG_KERNEL_SYSCALL_LIST:
412 return lttng_abi_syscall_list();
413 case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
414 case LTTNG_KERNEL_WAIT_QUIESCENT:
415 synchronize_trace();
416 return 0;
417 case LTTNG_KERNEL_OLD_CALIBRATE:
418 {
419 struct lttng_kernel_old_calibrate __user *ucalibrate =
420 (struct lttng_kernel_old_calibrate __user *) arg;
421 struct lttng_kernel_old_calibrate old_calibrate;
422 struct lttng_kernel_calibrate calibrate;
423 int ret;
424
425 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
426 return -EFAULT;
427 calibrate.type = old_calibrate.type;
428 ret = lttng_calibrate(&calibrate);
429 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
430 return -EFAULT;
431 return ret;
432 }
433 case LTTNG_KERNEL_CALIBRATE:
434 {
435 struct lttng_kernel_calibrate __user *ucalibrate =
436 (struct lttng_kernel_calibrate __user *) arg;
437 struct lttng_kernel_calibrate calibrate;
438 int ret;
439
440 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
441 return -EFAULT;
442 ret = lttng_calibrate(&calibrate);
443 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
444 return -EFAULT;
445 return ret;
446 }
447 default:
448 return -ENOIOCTLCMD;
449 }
450 }
451
452 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
453 static const struct proc_ops lttng_proc_ops = {
454 .proc_ioctl = lttng_ioctl,
455 #ifdef CONFIG_COMPAT
456 .proc_compat_ioctl = lttng_ioctl,
457 #endif /* CONFIG_COMPAT */
458 };
459 #else
460 static const struct file_operations lttng_proc_ops = {
461 .owner = THIS_MODULE,
462 .unlocked_ioctl = lttng_ioctl,
463 #ifdef CONFIG_COMPAT
464 .compat_ioctl = lttng_ioctl,
465 #endif /* CONFIG_COMPAT */
466 };
467 #endif
468
469 static
470 int lttng_abi_create_channel(struct file *session_file,
471 struct lttng_kernel_channel *chan_param,
472 enum channel_type channel_type)
473 {
474 struct lttng_session *session = session_file->private_data;
475 const struct file_operations *fops = NULL;
476 const char *transport_name;
477 struct lttng_channel *chan;
478 struct file *chan_file;
479 int chan_fd;
480 int ret = 0;
481
482 chan_fd = lttng_get_unused_fd();
483 if (chan_fd < 0) {
484 ret = chan_fd;
485 goto fd_error;
486 }
487 switch (channel_type) {
488 case PER_CPU_CHANNEL:
489 fops = &lttng_channel_fops;
490 break;
491 case METADATA_CHANNEL:
492 fops = &lttng_metadata_fops;
493 break;
494 }
495
496 chan_file = anon_inode_getfile("[lttng_channel]",
497 fops,
498 NULL, O_RDWR);
499 if (IS_ERR(chan_file)) {
500 ret = PTR_ERR(chan_file);
501 goto file_error;
502 }
503 switch (channel_type) {
504 case PER_CPU_CHANNEL:
505 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
506 transport_name = chan_param->overwrite ?
507 "relay-overwrite" : "relay-discard";
508 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
509 transport_name = chan_param->overwrite ?
510 "relay-overwrite-mmap" : "relay-discard-mmap";
511 } else {
512 return -EINVAL;
513 }
514 break;
515 case METADATA_CHANNEL:
516 if (chan_param->output == LTTNG_KERNEL_SPLICE)
517 transport_name = "relay-metadata";
518 else if (chan_param->output == LTTNG_KERNEL_MMAP)
519 transport_name = "relay-metadata-mmap";
520 else
521 return -EINVAL;
522 break;
523 default:
524 transport_name = "<unknown>";
525 break;
526 }
527 if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
528 ret = -EOVERFLOW;
529 goto refcount_error;
530 }
531 /*
532 * We tolerate no failure path after channel creation. It will stay
533 * invariant for the rest of the session.
534 */
535 chan = lttng_channel_create(session, transport_name, NULL,
536 chan_param->subbuf_size,
537 chan_param->num_subbuf,
538 chan_param->switch_timer_interval,
539 chan_param->read_timer_interval,
540 channel_type);
541 if (!chan) {
542 ret = -EINVAL;
543 goto chan_error;
544 }
545 chan->file = chan_file;
546 chan_file->private_data = chan;
547 fd_install(chan_fd, chan_file);
548
549 return chan_fd;
550
551 chan_error:
552 atomic_long_dec(&session_file->f_count);
553 refcount_error:
554 fput(chan_file);
555 file_error:
556 put_unused_fd(chan_fd);
557 fd_error:
558 return ret;
559 }
560
561 static
562 int lttng_abi_session_set_name(struct lttng_session *session,
563 struct lttng_kernel_session_name *name)
564 {
565 size_t len;
566
567 len = strnlen(name->name, LTTNG_KERNEL_SESSION_NAME_LEN);
568
569 if (len == LTTNG_KERNEL_SESSION_NAME_LEN) {
570 /* Name is too long/malformed */
571 return -EINVAL;
572 }
573
574 strcpy(session->name, name->name);
575 return 0;
576 }
577
578 static
579 int lttng_abi_session_set_creation_time(struct lttng_session *session,
580 struct lttng_kernel_session_creation_time *time)
581 {
582 size_t len;
583
584 len = strnlen(time->iso8601, LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN);
585
586 if (len == LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN) {
587 /* Time is too long/malformed */
588 return -EINVAL;
589 }
590
591 strcpy(session->creation_time, time->iso8601);
592 return 0;
593 }
594
595 static
596 enum tracker_type get_tracker_type(struct lttng_kernel_tracker_args *tracker)
597 {
598 switch (tracker->type) {
599 case LTTNG_KERNEL_TRACKER_PID:
600 return TRACKER_PID;
601 case LTTNG_KERNEL_TRACKER_VPID:
602 return TRACKER_VPID;
603 case LTTNG_KERNEL_TRACKER_UID:
604 return TRACKER_UID;
605 case LTTNG_KERNEL_TRACKER_VUID:
606 return TRACKER_VUID;
607 case LTTNG_KERNEL_TRACKER_GID:
608 return TRACKER_GID;
609 case LTTNG_KERNEL_TRACKER_VGID:
610 return TRACKER_VGID;
611 default:
612 return TRACKER_UNKNOWN;
613 }
614 }
615
616 /**
617 * lttng_session_ioctl - lttng session fd ioctl
618 *
619 * @file: the file
620 * @cmd: the command
621 * @arg: command arg
622 *
623 * This ioctl implements lttng commands:
624 * LTTNG_KERNEL_CHANNEL
625 * Returns a LTTng channel file descriptor
626 * LTTNG_KERNEL_ENABLE
627 * Enables tracing for a session (weak enable)
628 * LTTNG_KERNEL_DISABLE
629 * Disables tracing for a session (strong disable)
630 * LTTNG_KERNEL_METADATA
631 * Returns a LTTng metadata file descriptor
632 * LTTNG_KERNEL_SESSION_TRACK_PID
633 * Add PID to session PID tracker
634 * LTTNG_KERNEL_SESSION_UNTRACK_PID
635 * Remove PID from session PID tracker
636 * LTTNG_KERNEL_SESSION_TRACK_ID
637 * Add ID to tracker
638 * LTTNG_KERNEL_SESSION_UNTRACK_ID
639 * Remove ID from tracker
640 *
641 * The returned channel will be deleted when its file descriptor is closed.
642 */
643 static
644 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
645 {
646 struct lttng_session *session = file->private_data;
647 struct lttng_kernel_channel chan_param;
648 struct lttng_kernel_old_channel old_chan_param;
649
650 switch (cmd) {
651 case LTTNG_KERNEL_OLD_CHANNEL:
652 {
653 if (copy_from_user(&old_chan_param,
654 (struct lttng_kernel_old_channel __user *) arg,
655 sizeof(struct lttng_kernel_old_channel)))
656 return -EFAULT;
657 chan_param.overwrite = old_chan_param.overwrite;
658 chan_param.subbuf_size = old_chan_param.subbuf_size;
659 chan_param.num_subbuf = old_chan_param.num_subbuf;
660 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
661 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
662 chan_param.output = old_chan_param.output;
663
664 return lttng_abi_create_channel(file, &chan_param,
665 PER_CPU_CHANNEL);
666 }
667 case LTTNG_KERNEL_CHANNEL:
668 {
669 if (copy_from_user(&chan_param,
670 (struct lttng_kernel_channel __user *) arg,
671 sizeof(struct lttng_kernel_channel)))
672 return -EFAULT;
673 return lttng_abi_create_channel(file, &chan_param,
674 PER_CPU_CHANNEL);
675 }
676 case LTTNG_KERNEL_OLD_SESSION_START:
677 case LTTNG_KERNEL_OLD_ENABLE:
678 case LTTNG_KERNEL_SESSION_START:
679 case LTTNG_KERNEL_ENABLE:
680 return lttng_session_enable(session);
681 case LTTNG_KERNEL_OLD_SESSION_STOP:
682 case LTTNG_KERNEL_OLD_DISABLE:
683 case LTTNG_KERNEL_SESSION_STOP:
684 case LTTNG_KERNEL_DISABLE:
685 return lttng_session_disable(session);
686 case LTTNG_KERNEL_OLD_METADATA:
687 {
688 if (copy_from_user(&old_chan_param,
689 (struct lttng_kernel_old_channel __user *) arg,
690 sizeof(struct lttng_kernel_old_channel)))
691 return -EFAULT;
692 chan_param.overwrite = old_chan_param.overwrite;
693 chan_param.subbuf_size = old_chan_param.subbuf_size;
694 chan_param.num_subbuf = old_chan_param.num_subbuf;
695 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
696 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
697 chan_param.output = old_chan_param.output;
698
699 return lttng_abi_create_channel(file, &chan_param,
700 METADATA_CHANNEL);
701 }
702 case LTTNG_KERNEL_METADATA:
703 {
704 if (copy_from_user(&chan_param,
705 (struct lttng_kernel_channel __user *) arg,
706 sizeof(struct lttng_kernel_channel)))
707 return -EFAULT;
708 return lttng_abi_create_channel(file, &chan_param,
709 METADATA_CHANNEL);
710 }
711 case LTTNG_KERNEL_SESSION_TRACK_PID:
712 return lttng_session_track_id(session, TRACKER_PID, (int) arg);
713 case LTTNG_KERNEL_SESSION_UNTRACK_PID:
714 return lttng_session_untrack_id(session, TRACKER_PID, (int) arg);
715 case LTTNG_KERNEL_SESSION_TRACK_ID:
716 {
717 struct lttng_kernel_tracker_args tracker;
718 enum tracker_type tracker_type;
719
720 if (copy_from_user(&tracker,
721 (struct lttng_kernel_tracker_args __user *) arg,
722 sizeof(struct lttng_kernel_tracker_args)))
723 return -EFAULT;
724 tracker_type = get_tracker_type(&tracker);
725 if (tracker_type == TRACKER_UNKNOWN)
726 return -EINVAL;
727 return lttng_session_track_id(session, tracker_type, tracker.id);
728 }
729 case LTTNG_KERNEL_SESSION_UNTRACK_ID:
730 {
731 struct lttng_kernel_tracker_args tracker;
732 enum tracker_type tracker_type;
733
734 if (copy_from_user(&tracker,
735 (struct lttng_kernel_tracker_args __user *) arg,
736 sizeof(struct lttng_kernel_tracker_args)))
737 return -EFAULT;
738 tracker_type = get_tracker_type(&tracker);
739 if (tracker_type == TRACKER_UNKNOWN)
740 return -EINVAL;
741 return lttng_session_untrack_id(session, tracker_type,
742 tracker.id);
743 }
744 case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
745 return lttng_session_list_tracker_ids(session, TRACKER_PID);
746 case LTTNG_KERNEL_SESSION_LIST_TRACKER_IDS:
747 {
748 struct lttng_kernel_tracker_args tracker;
749 enum tracker_type tracker_type;
750
751 if (copy_from_user(&tracker,
752 (struct lttng_kernel_tracker_args __user *) arg,
753 sizeof(struct lttng_kernel_tracker_args)))
754 return -EFAULT;
755 tracker_type = get_tracker_type(&tracker);
756 if (tracker_type == TRACKER_UNKNOWN)
757 return -EINVAL;
758 return lttng_session_list_tracker_ids(session, tracker_type);
759 }
760 case LTTNG_KERNEL_SESSION_METADATA_REGEN:
761 return lttng_session_metadata_regenerate(session);
762 case LTTNG_KERNEL_SESSION_STATEDUMP:
763 return lttng_session_statedump(session);
764 case LTTNG_KERNEL_SESSION_SET_NAME:
765 {
766 struct lttng_kernel_session_name name;
767
768 if (copy_from_user(&name,
769 (struct lttng_kernel_session_name __user *) arg,
770 sizeof(struct lttng_kernel_session_name)))
771 return -EFAULT;
772 return lttng_abi_session_set_name(session, &name);
773 }
774 case LTTNG_KERNEL_SESSION_SET_CREATION_TIME:
775 {
776 struct lttng_kernel_session_creation_time time;
777
778 if (copy_from_user(&time,
779 (struct lttng_kernel_session_creation_time __user *) arg,
780 sizeof(struct lttng_kernel_session_creation_time)))
781 return -EFAULT;
782 return lttng_abi_session_set_creation_time(session, &time);
783 }
784 default:
785 return -ENOIOCTLCMD;
786 }
787 }
788
789 /*
790 * Called when the last file reference is dropped.
791 *
792 * Big fat note: channels and events are invariant for the whole session after
793 * their creation. So this session destruction also destroys all channel and
794 * event structures specific to this session (they are not destroyed when their
795 * individual file is released).
796 */
797 static
798 int lttng_session_release(struct inode *inode, struct file *file)
799 {
800 struct lttng_session *session = file->private_data;
801
802 if (session)
803 lttng_session_destroy(session);
804 return 0;
805 }
806
807 static const struct file_operations lttng_session_fops = {
808 .owner = THIS_MODULE,
809 .release = lttng_session_release,
810 .unlocked_ioctl = lttng_session_ioctl,
811 #ifdef CONFIG_COMPAT
812 .compat_ioctl = lttng_session_ioctl,
813 #endif
814 };
815
816 /*
817 * When encountering empty buffer, flush current sub-buffer if non-empty
818 * and retry (if new data available to read after flush).
819 */
820 static
821 ssize_t lttng_trigger_group_notif_read(struct file *filp, char __user *user_buf,
822 size_t count, loff_t *ppos)
823 {
824 struct lttng_trigger_group *trigger_group = filp->private_data;
825 struct channel *chan = trigger_group->chan;
826 struct lib_ring_buffer *buf = trigger_group->buf;
827 ssize_t read_count = 0, len;
828 size_t read_offset;
829
830 might_sleep();
831 if (!lttng_access_ok(VERIFY_WRITE, user_buf, count))
832 return -EFAULT;
833
834 /* Finish copy of previous record */
835 if (*ppos != 0) {
836 if (read_count < count) {
837 len = chan->iter.len_left;
838 read_offset = *ppos;
839 goto skip_get_next;
840 }
841 }
842
843 while (read_count < count) {
844 size_t copy_len, space_left;
845
846 len = lib_ring_buffer_get_next_record(chan, buf);
847 len_test:
848 if (len < 0) {
849 /*
850 * Check if buffer is finalized (end of file).
851 */
852 if (len == -ENODATA) {
853 /* A 0 read_count will tell about end of file */
854 goto nodata;
855 }
856 if (filp->f_flags & O_NONBLOCK) {
857 if (!read_count)
858 read_count = -EAGAIN;
859 goto nodata;
860 } else {
861 int error;
862
863 /*
864 * No data available at the moment, return what
865 * we got.
866 */
867 if (read_count)
868 goto nodata;
869
870 /*
871 * Wait for returned len to be >= 0 or -ENODATA.
872 */
873 error = wait_event_interruptible(
874 trigger_group->read_wait,
875 ((len = lib_ring_buffer_get_next_record(
876 chan, buf)), len != -EAGAIN));
877 CHAN_WARN_ON(chan, len == -EBUSY);
878 if (error) {
879 read_count = error;
880 goto nodata;
881 }
882 CHAN_WARN_ON(chan, len < 0 && len != -ENODATA);
883 goto len_test;
884 }
885 }
886 read_offset = buf->iter.read_offset;
887 skip_get_next:
888 space_left = count - read_count;
889 if (len <= space_left) {
890 copy_len = len;
891 chan->iter.len_left = 0;
892 *ppos = 0;
893 } else {
894 copy_len = space_left;
895 chan->iter.len_left = len - copy_len;
896 *ppos = read_offset + copy_len;
897 }
898 if (__lib_ring_buffer_copy_to_user(&buf->backend, read_offset,
899 &user_buf[read_count],
900 copy_len)) {
901 /*
902 * Leave the len_left and ppos values at their current
903 * state, as we currently have a valid event to read.
904 */
905 return -EFAULT;
906 }
907 read_count += copy_len;
908 }
909 goto put_record;
910
911 nodata:
912 *ppos = 0;
913 chan->iter.len_left = 0;
914
915 put_record:
916 lib_ring_buffer_put_current_record(buf);
917 return read_count;
918 }
919
920 /*
921 * If the ring buffer is non empty (even just a partial subbuffer), return that
922 * there is data available. Perform a ring buffer flush if we encounter a
923 * non-empty ring buffer which does not have any consumeable subbuffer available.
924 */
925 static
926 unsigned int lttng_trigger_group_notif_poll(struct file *filp,
927 poll_table *wait)
928 {
929 unsigned int mask = 0;
930 struct lttng_trigger_group *trigger_group = filp->private_data;
931 struct channel *chan = trigger_group->chan;
932 struct lib_ring_buffer *buf = trigger_group->buf;
933 const struct lib_ring_buffer_config *config = &chan->backend.config;
934 int finalized, disabled;
935 unsigned long consumed, offset;
936 size_t subbuffer_header_size = config->cb.subbuffer_header_size();
937
938 if (filp->f_mode & FMODE_READ) {
939 poll_wait_set_exclusive(wait);
940 poll_wait(filp, &trigger_group->read_wait, wait);
941
942 finalized = lib_ring_buffer_is_finalized(config, buf);
943 disabled = lib_ring_buffer_channel_is_disabled(chan);
944
945 /*
946 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
947 * finalized load before offsets loads.
948 */
949 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
950 retry:
951 if (disabled)
952 return POLLERR;
953
954 offset = lib_ring_buffer_get_offset(config, buf);
955 consumed = lib_ring_buffer_get_consumed(config, buf);
956
957 /*
958 * If there is no buffer available to consume.
959 */
960 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) == 0) {
961 /*
962 * If there is a non-empty subbuffer, flush and try again.
963 */
964 if (subbuf_offset(offset, chan) > subbuffer_header_size) {
965 lib_ring_buffer_switch_remote(buf);
966 goto retry;
967 }
968
969 if (finalized)
970 return POLLHUP;
971 else {
972 /*
973 * The memory barriers
974 * __wait_event()/wake_up_interruptible() take
975 * care of "raw_spin_is_locked" memory ordering.
976 */
977 if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
978 goto retry;
979 else
980 return 0;
981 }
982 } else {
983 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan)
984 >= chan->backend.buf_size)
985 return POLLPRI | POLLRDBAND;
986 else
987 return POLLIN | POLLRDNORM;
988 }
989 }
990
991 return mask;
992 }
993
994 /**
995 * lttng_trigger_group_notif_open - trigger ring buffer open file operation
996 * @inode: opened inode
997 * @file: opened file
998 *
999 * Open implementation. Makes sure only one open instance of a buffer is
1000 * done at a given moment.
1001 */
1002 static int lttng_trigger_group_notif_open(struct inode *inode, struct file *file)
1003 {
1004 struct lttng_trigger_group *trigger_group = inode->i_private;
1005 struct lib_ring_buffer *buf = trigger_group->buf;
1006
1007 file->private_data = trigger_group;
1008 return lib_ring_buffer_open(inode, file, buf);
1009 }
1010
1011 /**
1012 * lttng_trigger_group_notif_release - trigger ring buffer release file operation
1013 * @inode: opened inode
1014 * @file: opened file
1015 *
1016 * Release implementation.
1017 */
1018 static int lttng_trigger_group_notif_release(struct inode *inode, struct file *file)
1019 {
1020 struct lttng_trigger_group *trigger_group = file->private_data;
1021 struct lib_ring_buffer *buf = trigger_group->buf;
1022 int ret;
1023
1024 ret = lib_ring_buffer_release(inode, file, buf);
1025 if (ret)
1026 return ret;
1027 fput(trigger_group->file);
1028 return 0;
1029 }
1030
1031 static const struct file_operations lttng_trigger_group_notif_fops = {
1032 .owner = THIS_MODULE,
1033 .open = lttng_trigger_group_notif_open,
1034 .release = lttng_trigger_group_notif_release,
1035 .read = lttng_trigger_group_notif_read,
1036 .poll = lttng_trigger_group_notif_poll,
1037 };
1038
1039 /**
1040 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
1041 * @filp: the file
1042 * @wait: poll table
1043 *
1044 * Handles the poll operations for the metadata channels.
1045 */
1046 static
1047 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
1048 poll_table *wait)
1049 {
1050 struct lttng_metadata_stream *stream = filp->private_data;
1051 struct lib_ring_buffer *buf = stream->priv;
1052 int finalized;
1053 unsigned int mask = 0;
1054
1055 if (filp->f_mode & FMODE_READ) {
1056 poll_wait_set_exclusive(wait);
1057 poll_wait(filp, &stream->read_wait, wait);
1058
1059 finalized = stream->finalized;
1060
1061 /*
1062 * lib_ring_buffer_is_finalized() contains a smp_rmb()
1063 * ordering finalized load before offsets loads.
1064 */
1065 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1066
1067 if (finalized)
1068 mask |= POLLHUP;
1069
1070 mutex_lock(&stream->metadata_cache->lock);
1071 if (stream->metadata_cache->metadata_written >
1072 stream->metadata_out)
1073 mask |= POLLIN;
1074 mutex_unlock(&stream->metadata_cache->lock);
1075 }
1076
1077 return mask;
1078 }
1079
1080 static
1081 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
1082 unsigned int cmd, unsigned long arg)
1083 {
1084 struct lttng_metadata_stream *stream = filp->private_data;
1085
1086 stream->metadata_out = stream->metadata_in;
1087 }
1088
1089 /*
1090 * Reset the counter of how much metadata has been consumed to 0. That way,
1091 * the consumer receives the content of the metadata cache unchanged. This is
1092 * different from the metadata_regenerate where the offset from epoch is
1093 * resampled, here we want the exact same content as the last time the metadata
1094 * was generated. This command is only possible if all the metadata written
1095 * in the cache has been output to the metadata stream to avoid corrupting the
1096 * metadata file.
1097 *
1098 * Return 0 on success, a negative value on error.
1099 */
1100 static
1101 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
1102 {
1103 int ret;
1104 struct lttng_metadata_cache *cache = stream->metadata_cache;
1105
1106 mutex_lock(&cache->lock);
1107 if (stream->metadata_out != cache->metadata_written) {
1108 ret = -EBUSY;
1109 goto end;
1110 }
1111 stream->metadata_out = 0;
1112 stream->metadata_in = 0;
1113 wake_up_interruptible(&stream->read_wait);
1114 ret = 0;
1115
1116 end:
1117 mutex_unlock(&cache->lock);
1118 return ret;
1119 }
1120
1121 static
1122 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
1123 unsigned int cmd, unsigned long arg)
1124 {
1125 int ret;
1126 struct lttng_metadata_stream *stream = filp->private_data;
1127 struct lib_ring_buffer *buf = stream->priv;
1128
1129 switch (cmd) {
1130 case RING_BUFFER_GET_NEXT_SUBBUF:
1131 {
1132 struct lttng_metadata_stream *stream = filp->private_data;
1133 struct lib_ring_buffer *buf = stream->priv;
1134 struct channel *chan = buf->backend.chan;
1135
1136 ret = lttng_metadata_output_channel(stream, chan);
1137 if (ret > 0) {
1138 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1139 ret = 0;
1140 } else if (ret < 0)
1141 goto err;
1142 break;
1143 }
1144 case RING_BUFFER_GET_SUBBUF:
1145 {
1146 /*
1147 * Random access is not allowed for metadata channel.
1148 */
1149 return -ENOSYS;
1150 }
1151 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
1152 case RING_BUFFER_FLUSH:
1153 {
1154 struct lttng_metadata_stream *stream = filp->private_data;
1155 struct lib_ring_buffer *buf = stream->priv;
1156 struct channel *chan = buf->backend.chan;
1157
1158 /*
1159 * Before doing the actual ring buffer flush, write up to one
1160 * packet of metadata in the ring buffer.
1161 */
1162 ret = lttng_metadata_output_channel(stream, chan);
1163 if (ret < 0)
1164 goto err;
1165 break;
1166 }
1167 case RING_BUFFER_GET_METADATA_VERSION:
1168 {
1169 struct lttng_metadata_stream *stream = filp->private_data;
1170
1171 return put_u64(stream->version, arg);
1172 }
1173 case RING_BUFFER_METADATA_CACHE_DUMP:
1174 {
1175 struct lttng_metadata_stream *stream = filp->private_data;
1176
1177 return lttng_metadata_cache_dump(stream);
1178 }
1179 default:
1180 break;
1181 }
1182 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1183
1184 /* Performing lib ring buffer ioctl after our own. */
1185 ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
1186 if (ret < 0)
1187 goto err;
1188
1189 switch (cmd) {
1190 case RING_BUFFER_PUT_NEXT_SUBBUF:
1191 {
1192 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1193 cmd, arg);
1194 break;
1195 }
1196 default:
1197 break;
1198 }
1199 err:
1200 return ret;
1201 }
1202
1203 #ifdef CONFIG_COMPAT
1204 static
1205 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
1206 unsigned int cmd, unsigned long arg)
1207 {
1208 int ret;
1209 struct lttng_metadata_stream *stream = filp->private_data;
1210 struct lib_ring_buffer *buf = stream->priv;
1211
1212 switch (cmd) {
1213 case RING_BUFFER_GET_NEXT_SUBBUF:
1214 {
1215 struct lttng_metadata_stream *stream = filp->private_data;
1216 struct lib_ring_buffer *buf = stream->priv;
1217 struct channel *chan = buf->backend.chan;
1218
1219 ret = lttng_metadata_output_channel(stream, chan);
1220 if (ret > 0) {
1221 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1222 ret = 0;
1223 } else if (ret < 0)
1224 goto err;
1225 break;
1226 }
1227 case RING_BUFFER_GET_SUBBUF:
1228 {
1229 /*
1230 * Random access is not allowed for metadata channel.
1231 */
1232 return -ENOSYS;
1233 }
1234 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
1235 case RING_BUFFER_FLUSH:
1236 {
1237 struct lttng_metadata_stream *stream = filp->private_data;
1238 struct lib_ring_buffer *buf = stream->priv;
1239 struct channel *chan = buf->backend.chan;
1240
1241 /*
1242 * Before doing the actual ring buffer flush, write up to one
1243 * packet of metadata in the ring buffer.
1244 */
1245 ret = lttng_metadata_output_channel(stream, chan);
1246 if (ret < 0)
1247 goto err;
1248 break;
1249 }
1250 case RING_BUFFER_GET_METADATA_VERSION:
1251 {
1252 struct lttng_metadata_stream *stream = filp->private_data;
1253
1254 return put_u64(stream->version, arg);
1255 }
1256 case RING_BUFFER_METADATA_CACHE_DUMP:
1257 {
1258 struct lttng_metadata_stream *stream = filp->private_data;
1259
1260 return lttng_metadata_cache_dump(stream);
1261 }
1262 default:
1263 break;
1264 }
1265 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1266
1267 /* Performing lib ring buffer ioctl after our own. */
1268 ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
1269 if (ret < 0)
1270 goto err;
1271
1272 switch (cmd) {
1273 case RING_BUFFER_PUT_NEXT_SUBBUF:
1274 {
1275 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1276 cmd, arg);
1277 break;
1278 }
1279 default:
1280 break;
1281 }
1282 err:
1283 return ret;
1284 }
1285 #endif
1286
1287 /*
1288 * This is not used by anonymous file descriptors. This code is left
1289 * there if we ever want to implement an inode with open() operation.
1290 */
1291 static
1292 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
1293 {
1294 struct lttng_metadata_stream *stream = inode->i_private;
1295 struct lib_ring_buffer *buf = stream->priv;
1296
1297 file->private_data = buf;
1298 /*
1299 * Since life-time of metadata cache differs from that of
1300 * session, we need to keep our own reference on the transport.
1301 */
1302 if (!try_module_get(stream->transport->owner)) {
1303 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1304 return -EBUSY;
1305 }
1306 return lib_ring_buffer_open(inode, file, buf);
1307 }
1308
1309 static
1310 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
1311 {
1312 struct lttng_metadata_stream *stream = file->private_data;
1313 struct lib_ring_buffer *buf = stream->priv;
1314
1315 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
1316 module_put(stream->transport->owner);
1317 return lib_ring_buffer_release(inode, file, buf);
1318 }
1319
1320 static
1321 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
1322 struct pipe_inode_info *pipe, size_t len,
1323 unsigned int flags)
1324 {
1325 struct lttng_metadata_stream *stream = in->private_data;
1326 struct lib_ring_buffer *buf = stream->priv;
1327
1328 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
1329 flags, buf);
1330 }
1331
1332 static
1333 int lttng_metadata_ring_buffer_mmap(struct file *filp,
1334 struct vm_area_struct *vma)
1335 {
1336 struct lttng_metadata_stream *stream = filp->private_data;
1337 struct lib_ring_buffer *buf = stream->priv;
1338
1339 return lib_ring_buffer_mmap(filp, vma, buf);
1340 }
1341
1342 static
1343 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
1344 .owner = THIS_MODULE,
1345 .open = lttng_metadata_ring_buffer_open,
1346 .release = lttng_metadata_ring_buffer_release,
1347 .poll = lttng_metadata_ring_buffer_poll,
1348 .splice_read = lttng_metadata_ring_buffer_splice_read,
1349 .mmap = lttng_metadata_ring_buffer_mmap,
1350 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
1351 .llseek = vfs_lib_ring_buffer_no_llseek,
1352 #ifdef CONFIG_COMPAT
1353 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
1354 #endif
1355 };
1356
1357 static
1358 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1359 const struct file_operations *fops, const char *name)
1360 {
1361 int stream_fd, ret;
1362 struct file *stream_file;
1363
1364 stream_fd = lttng_get_unused_fd();
1365 if (stream_fd < 0) {
1366 ret = stream_fd;
1367 goto fd_error;
1368 }
1369 stream_file = anon_inode_getfile(name, fops, stream_priv, O_RDWR);
1370 if (IS_ERR(stream_file)) {
1371 ret = PTR_ERR(stream_file);
1372 goto file_error;
1373 }
1374 /*
1375 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1376 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1377 * file descriptor, so we set FMODE_PREAD here.
1378 */
1379 stream_file->f_mode |= FMODE_PREAD;
1380 fd_install(stream_fd, stream_file);
1381 /*
1382 * The stream holds a reference to the channel within the generic ring
1383 * buffer library, so no need to hold a refcount on the channel and
1384 * session files here.
1385 */
1386 return stream_fd;
1387
1388 file_error:
1389 put_unused_fd(stream_fd);
1390 fd_error:
1391 return ret;
1392 }
1393
1394 static
1395 int lttng_abi_open_stream(struct file *channel_file)
1396 {
1397 struct lttng_channel *channel = channel_file->private_data;
1398 struct lib_ring_buffer *buf;
1399 int ret;
1400 void *stream_priv;
1401
1402 buf = channel->ops->buffer_read_open(channel->chan);
1403 if (!buf)
1404 return -ENOENT;
1405
1406 stream_priv = buf;
1407 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1408 &lttng_stream_ring_buffer_file_operations,
1409 "[lttng_stream]");
1410 if (ret < 0)
1411 goto fd_error;
1412
1413 return ret;
1414
1415 fd_error:
1416 channel->ops->buffer_read_close(buf);
1417 return ret;
1418 }
1419
1420 static
1421 int lttng_abi_open_metadata_stream(struct file *channel_file)
1422 {
1423 struct lttng_channel *channel = channel_file->private_data;
1424 struct lttng_session *session = channel->session;
1425 struct lib_ring_buffer *buf;
1426 int ret;
1427 struct lttng_metadata_stream *metadata_stream;
1428 void *stream_priv;
1429
1430 buf = channel->ops->buffer_read_open(channel->chan);
1431 if (!buf)
1432 return -ENOENT;
1433
1434 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1435 GFP_KERNEL);
1436 if (!metadata_stream) {
1437 ret = -ENOMEM;
1438 goto nomem;
1439 }
1440 metadata_stream->metadata_cache = session->metadata_cache;
1441 init_waitqueue_head(&metadata_stream->read_wait);
1442 metadata_stream->priv = buf;
1443 stream_priv = metadata_stream;
1444 metadata_stream->transport = channel->transport;
1445
1446 /*
1447 * Since life-time of metadata cache differs from that of
1448 * session, we need to keep our own reference on the transport.
1449 */
1450 if (!try_module_get(metadata_stream->transport->owner)) {
1451 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1452 ret = -EINVAL;
1453 goto notransport;
1454 }
1455
1456 if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1457 ret = -EOVERFLOW;
1458 goto kref_error;
1459 }
1460
1461 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1462 &lttng_metadata_ring_buffer_file_operations,
1463 "[lttng_metadata_stream]");
1464 if (ret < 0)
1465 goto fd_error;
1466
1467 list_add(&metadata_stream->list,
1468 &session->metadata_cache->metadata_stream);
1469 return ret;
1470
1471 fd_error:
1472 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1473 kref_error:
1474 module_put(metadata_stream->transport->owner);
1475 notransport:
1476 kfree(metadata_stream);
1477 nomem:
1478 channel->ops->buffer_read_close(buf);
1479 return ret;
1480 }
1481
1482 static
1483 int lttng_abi_open_trigger_group_stream(struct file *notif_file)
1484 {
1485 struct lttng_trigger_group *trigger_group = notif_file->private_data;
1486 struct channel *chan = trigger_group->chan;
1487 struct lib_ring_buffer *buf;
1488 int ret;
1489 void *stream_priv;
1490
1491 buf = trigger_group->ops->buffer_read_open(chan);
1492 if (!buf)
1493 return -ENOENT;
1494
1495 /* The trigger notification fd holds a reference on the trigger group */
1496 if (!atomic_long_add_unless(&notif_file->f_count, 1, LONG_MAX)) {
1497 ret = -EOVERFLOW;
1498 goto refcount_error;
1499 }
1500 trigger_group->buf = buf;
1501 stream_priv = trigger_group;
1502 ret = lttng_abi_create_stream_fd(notif_file, stream_priv,
1503 &lttng_trigger_group_notif_fops,
1504 "[lttng_trigger_stream]");
1505 if (ret < 0)
1506 goto fd_error;
1507
1508 return ret;
1509
1510 fd_error:
1511 atomic_long_dec(&notif_file->f_count);
1512 refcount_error:
1513 trigger_group->ops->buffer_read_close(buf);
1514 return ret;
1515 }
1516
1517 static
1518 int lttng_abi_create_event(struct file *channel_file,
1519 struct lttng_kernel_event *event_param)
1520 {
1521 struct lttng_channel *channel = channel_file->private_data;
1522 int event_fd, ret;
1523 struct file *event_file;
1524 void *priv;
1525
1526 event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1527 switch (event_param->instrumentation) {
1528 case LTTNG_KERNEL_KRETPROBE:
1529 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1530 break;
1531 case LTTNG_KERNEL_KPROBE:
1532 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1533 break;
1534 case LTTNG_KERNEL_FUNCTION:
1535 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1536 break;
1537 default:
1538 break;
1539 }
1540 event_fd = lttng_get_unused_fd();
1541 if (event_fd < 0) {
1542 ret = event_fd;
1543 goto fd_error;
1544 }
1545 event_file = anon_inode_getfile("[lttng_event]",
1546 &lttng_event_fops,
1547 NULL, O_RDWR);
1548 if (IS_ERR(event_file)) {
1549 ret = PTR_ERR(event_file);
1550 goto file_error;
1551 }
1552 /* The event holds a reference on the channel */
1553 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1554 ret = -EOVERFLOW;
1555 goto refcount_error;
1556 }
1557 if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1558 || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1559 struct lttng_event_enabler *event_enabler;
1560
1561 if (strutils_is_star_glob_pattern(event_param->name)) {
1562 /*
1563 * If the event name is a star globbing pattern,
1564 * we create the special star globbing enabler.
1565 */
1566 event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_STAR_GLOB,
1567 event_param, channel);
1568 } else {
1569 event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1570 event_param, channel);
1571 }
1572 priv = event_enabler;
1573 } else {
1574 struct lttng_event *event;
1575
1576 /*
1577 * We tolerate no failure path after event creation. It
1578 * will stay invariant for the rest of the session.
1579 */
1580 event = lttng_event_create(channel, event_param,
1581 NULL, NULL,
1582 event_param->instrumentation);
1583 WARN_ON_ONCE(!event);
1584 if (IS_ERR(event)) {
1585 ret = PTR_ERR(event);
1586 goto event_error;
1587 }
1588 priv = event;
1589 }
1590 event_file->private_data = priv;
1591 fd_install(event_fd, event_file);
1592 return event_fd;
1593
1594 event_error:
1595 atomic_long_dec(&channel_file->f_count);
1596 refcount_error:
1597 fput(event_file);
1598 file_error:
1599 put_unused_fd(event_fd);
1600 fd_error:
1601 return ret;
1602 }
1603
1604 static
1605 long lttng_trigger_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1606 {
1607 struct lttng_trigger *trigger;
1608 struct lttng_trigger_enabler *trigger_enabler;
1609 enum lttng_event_type *evtype = file->private_data;
1610
1611 switch (cmd) {
1612 case LTTNG_KERNEL_ENABLE:
1613 switch (*evtype) {
1614 case LTTNG_TYPE_EVENT:
1615 trigger = file->private_data;
1616 return lttng_trigger_enable(trigger);
1617 case LTTNG_TYPE_ENABLER:
1618 trigger_enabler = file->private_data;
1619 return lttng_trigger_enabler_enable(trigger_enabler);
1620 default:
1621 WARN_ON_ONCE(1);
1622 return -ENOSYS;
1623 }
1624 case LTTNG_KERNEL_DISABLE:
1625 switch (*evtype) {
1626 case LTTNG_TYPE_EVENT:
1627 trigger = file->private_data;
1628 return lttng_trigger_disable(trigger);
1629 case LTTNG_TYPE_ENABLER:
1630 trigger_enabler = file->private_data;
1631 return lttng_trigger_enabler_disable(trigger_enabler);
1632 default:
1633 WARN_ON_ONCE(1);
1634 return -ENOSYS;
1635 }
1636 case LTTNG_KERNEL_FILTER:
1637 switch (*evtype) {
1638 case LTTNG_TYPE_EVENT:
1639 return -EINVAL;
1640 case LTTNG_TYPE_ENABLER:
1641 trigger_enabler = file->private_data;
1642 return lttng_trigger_enabler_attach_bytecode(trigger_enabler,
1643 (struct lttng_kernel_filter_bytecode __user *) arg);
1644 default:
1645 WARN_ON_ONCE(1);
1646 return -ENOSYS;
1647 }
1648 case LTTNG_KERNEL_ADD_CALLSITE:
1649 switch (*evtype) {
1650 case LTTNG_TYPE_EVENT:
1651 trigger = file->private_data;
1652 return lttng_trigger_add_callsite(trigger,
1653 (struct lttng_kernel_event_callsite __user *) arg);
1654 case LTTNG_TYPE_ENABLER:
1655 return -EINVAL;
1656 default:
1657 WARN_ON_ONCE(1);
1658 return -ENOSYS;
1659 }
1660 default:
1661 return -ENOIOCTLCMD;
1662 }
1663 }
1664
1665 static
1666 int lttng_trigger_release(struct inode *inode, struct file *file)
1667 {
1668 struct lttng_trigger *trigger;
1669 struct lttng_trigger_enabler *trigger_enabler;
1670 enum lttng_event_type *evtype = file->private_data;
1671
1672 if (!evtype)
1673 return 0;
1674
1675 switch (*evtype) {
1676 case LTTNG_TYPE_EVENT:
1677 trigger = file->private_data;
1678 if (trigger)
1679 fput(trigger->group->file);
1680 break;
1681 case LTTNG_TYPE_ENABLER:
1682 trigger_enabler = file->private_data;
1683 if (trigger_enabler)
1684 fput(trigger_enabler->group->file);
1685 break;
1686 default:
1687 WARN_ON_ONCE(1);
1688 break;
1689 }
1690
1691 return 0;
1692 }
1693
1694 static const struct file_operations lttng_trigger_fops = {
1695 .owner = THIS_MODULE,
1696 .release = lttng_trigger_release,
1697 .unlocked_ioctl = lttng_trigger_ioctl,
1698 #ifdef CONFIG_COMPAT
1699 .compat_ioctl = lttng_trigger_ioctl,
1700 #endif
1701 };
1702
1703 static
1704 int lttng_abi_create_trigger(struct file *trigger_group_file,
1705 struct lttng_kernel_trigger *trigger_param)
1706 {
1707 struct lttng_trigger_group *trigger_group = trigger_group_file->private_data;
1708 int trigger_fd, ret;
1709 struct file *trigger_file;
1710 void *priv;
1711
1712 switch (trigger_param->instrumentation) {
1713 case LTTNG_KERNEL_TRACEPOINT:
1714 case LTTNG_KERNEL_UPROBE:
1715 break;
1716 case LTTNG_KERNEL_KPROBE:
1717 trigger_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1718 break;
1719 case LTTNG_KERNEL_SYSCALL:
1720 break;
1721 case LTTNG_KERNEL_KRETPROBE:
1722 /* Placing a trigger on kretprobe is not supported. */
1723 case LTTNG_KERNEL_FUNCTION:
1724 case LTTNG_KERNEL_NOOP:
1725 default:
1726 ret = -EINVAL;
1727 goto inval_instr;
1728 }
1729
1730 trigger_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1731
1732 trigger_fd = lttng_get_unused_fd();
1733 if (trigger_fd < 0) {
1734 ret = trigger_fd;
1735 goto fd_error;
1736 }
1737
1738 trigger_file = anon_inode_getfile("[lttng_trigger]",
1739 &lttng_trigger_fops,
1740 NULL, O_RDWR);
1741 if (IS_ERR(trigger_file)) {
1742 ret = PTR_ERR(trigger_file);
1743 goto file_error;
1744 }
1745
1746 /* The trigger holds a reference on the trigger group. */
1747 if (!atomic_long_add_unless(&trigger_group_file->f_count, 1, LONG_MAX)) {
1748 ret = -EOVERFLOW;
1749 goto refcount_error;
1750 }
1751
1752 if (trigger_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1753 || trigger_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1754 struct lttng_trigger_enabler *enabler;
1755
1756 if (strutils_is_star_glob_pattern(trigger_param->name)) {
1757 /*
1758 * If the event name is a star globbing pattern,
1759 * we create the special star globbing enabler.
1760 */
1761 enabler = lttng_trigger_enabler_create(trigger_group,
1762 LTTNG_ENABLER_FORMAT_STAR_GLOB, trigger_param);
1763 } else {
1764 enabler = lttng_trigger_enabler_create(trigger_group,
1765 LTTNG_ENABLER_FORMAT_NAME, trigger_param);
1766 }
1767 priv = enabler;
1768 } else {
1769 struct lttng_trigger *trigger;
1770
1771 /*
1772 * We tolerate no failure path after trigger creation. It
1773 * will stay invariant for the rest of the session.
1774 */
1775 trigger = lttng_trigger_create(NULL, trigger_param->id,
1776 trigger_group, trigger_param, NULL,
1777 trigger_param->instrumentation);
1778 WARN_ON_ONCE(!trigger);
1779 if (IS_ERR(trigger)) {
1780 ret = PTR_ERR(trigger);
1781 goto trigger_error;
1782 }
1783 priv = trigger;
1784 }
1785 trigger_file->private_data = priv;
1786 fd_install(trigger_fd, trigger_file);
1787 return trigger_fd;
1788
1789 trigger_error:
1790 atomic_long_dec(&trigger_group_file->f_count);
1791 refcount_error:
1792 fput(trigger_file);
1793 file_error:
1794 put_unused_fd(trigger_fd);
1795 fd_error:
1796 inval_instr:
1797 return ret;
1798 }
1799
1800 static
1801 long lttng_trigger_group_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1802 {
1803 switch (cmd) {
1804 case LTTNG_KERNEL_TRIGGER_GROUP_NOTIFICATION_FD:
1805 {
1806 return lttng_abi_open_trigger_group_stream(file);
1807 }
1808 case LTTNG_KERNEL_TRIGGER_CREATE:
1809 {
1810 struct lttng_kernel_trigger utrigger_param;
1811
1812 if (copy_from_user(&utrigger_param,
1813 (struct lttng_kernel_trigger __user *) arg,
1814 sizeof(utrigger_param)))
1815 return -EFAULT;
1816 return lttng_abi_create_trigger(file, &utrigger_param);
1817 }
1818 default:
1819 return -ENOIOCTLCMD;
1820 }
1821 return 0;
1822 }
1823
1824 static
1825 int lttng_trigger_group_release(struct inode *inode, struct file *file)
1826 {
1827 struct lttng_trigger_group *trigger_group = file->private_data;
1828
1829 if (trigger_group)
1830 lttng_trigger_group_destroy(trigger_group);
1831 return 0;
1832 }
1833
1834 static const struct file_operations lttng_trigger_group_fops = {
1835 .owner = THIS_MODULE,
1836 .release = lttng_trigger_group_release,
1837 .unlocked_ioctl = lttng_trigger_group_ioctl,
1838 #ifdef CONFIG_COMPAT
1839 .compat_ioctl = lttng_trigger_group_ioctl,
1840 #endif
1841 };
1842
1843 /**
1844 * lttng_channel_ioctl - lttng syscall through ioctl
1845 *
1846 * @file: the file
1847 * @cmd: the command
1848 * @arg: command arg
1849 *
1850 * This ioctl implements lttng commands:
1851 * LTTNG_KERNEL_STREAM
1852 * Returns an event stream file descriptor or failure.
1853 * (typically, one event stream records events from one CPU)
1854 * LTTNG_KERNEL_EVENT
1855 * Returns an event file descriptor or failure.
1856 * LTTNG_KERNEL_CONTEXT
1857 * Prepend a context field to each event in the channel
1858 * LTTNG_KERNEL_ENABLE
1859 * Enable recording for events in this channel (weak enable)
1860 * LTTNG_KERNEL_DISABLE
1861 * Disable recording for events in this channel (strong disable)
1862 *
1863 * Channel and event file descriptors also hold a reference on the session.
1864 */
1865 static
1866 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1867 {
1868 struct lttng_channel *channel = file->private_data;
1869
1870 switch (cmd) {
1871 case LTTNG_KERNEL_OLD_STREAM:
1872 case LTTNG_KERNEL_STREAM:
1873 return lttng_abi_open_stream(file);
1874 case LTTNG_KERNEL_OLD_EVENT:
1875 {
1876 struct lttng_kernel_event *uevent_param;
1877 struct lttng_kernel_old_event *old_uevent_param;
1878 int ret;
1879
1880 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1881 GFP_KERNEL);
1882 if (!uevent_param) {
1883 ret = -ENOMEM;
1884 goto old_event_end;
1885 }
1886 old_uevent_param = kmalloc(
1887 sizeof(struct lttng_kernel_old_event),
1888 GFP_KERNEL);
1889 if (!old_uevent_param) {
1890 ret = -ENOMEM;
1891 goto old_event_error_free_param;
1892 }
1893 if (copy_from_user(old_uevent_param,
1894 (struct lttng_kernel_old_event __user *) arg,
1895 sizeof(struct lttng_kernel_old_event))) {
1896 ret = -EFAULT;
1897 goto old_event_error_free_old_param;
1898 }
1899
1900 memcpy(uevent_param->name, old_uevent_param->name,
1901 sizeof(uevent_param->name));
1902 uevent_param->instrumentation =
1903 old_uevent_param->instrumentation;
1904
1905 switch (old_uevent_param->instrumentation) {
1906 case LTTNG_KERNEL_KPROBE:
1907 uevent_param->u.kprobe.addr =
1908 old_uevent_param->u.kprobe.addr;
1909 uevent_param->u.kprobe.offset =
1910 old_uevent_param->u.kprobe.offset;
1911 memcpy(uevent_param->u.kprobe.symbol_name,
1912 old_uevent_param->u.kprobe.symbol_name,
1913 sizeof(uevent_param->u.kprobe.symbol_name));
1914 break;
1915 case LTTNG_KERNEL_KRETPROBE:
1916 uevent_param->u.kretprobe.addr =
1917 old_uevent_param->u.kretprobe.addr;
1918 uevent_param->u.kretprobe.offset =
1919 old_uevent_param->u.kretprobe.offset;
1920 memcpy(uevent_param->u.kretprobe.symbol_name,
1921 old_uevent_param->u.kretprobe.symbol_name,
1922 sizeof(uevent_param->u.kretprobe.symbol_name));
1923 break;
1924 case LTTNG_KERNEL_FUNCTION:
1925 memcpy(uevent_param->u.ftrace.symbol_name,
1926 old_uevent_param->u.ftrace.symbol_name,
1927 sizeof(uevent_param->u.ftrace.symbol_name));
1928 break;
1929 default:
1930 break;
1931 }
1932 ret = lttng_abi_create_event(file, uevent_param);
1933
1934 old_event_error_free_old_param:
1935 kfree(old_uevent_param);
1936 old_event_error_free_param:
1937 kfree(uevent_param);
1938 old_event_end:
1939 return ret;
1940 }
1941 case LTTNG_KERNEL_EVENT:
1942 {
1943 struct lttng_kernel_event uevent_param;
1944
1945 if (copy_from_user(&uevent_param,
1946 (struct lttng_kernel_event __user *) arg,
1947 sizeof(uevent_param)))
1948 return -EFAULT;
1949 return lttng_abi_create_event(file, &uevent_param);
1950 }
1951 case LTTNG_KERNEL_OLD_CONTEXT:
1952 {
1953 struct lttng_kernel_context *ucontext_param;
1954 struct lttng_kernel_old_context *old_ucontext_param;
1955 int ret;
1956
1957 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1958 GFP_KERNEL);
1959 if (!ucontext_param) {
1960 ret = -ENOMEM;
1961 goto old_ctx_end;
1962 }
1963 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1964 GFP_KERNEL);
1965 if (!old_ucontext_param) {
1966 ret = -ENOMEM;
1967 goto old_ctx_error_free_param;
1968 }
1969
1970 if (copy_from_user(old_ucontext_param,
1971 (struct lttng_kernel_old_context __user *) arg,
1972 sizeof(struct lttng_kernel_old_context))) {
1973 ret = -EFAULT;
1974 goto old_ctx_error_free_old_param;
1975 }
1976 ucontext_param->ctx = old_ucontext_param->ctx;
1977 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1978 sizeof(ucontext_param->padding));
1979 /* only type that uses the union */
1980 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1981 ucontext_param->u.perf_counter.type =
1982 old_ucontext_param->u.perf_counter.type;
1983 ucontext_param->u.perf_counter.config =
1984 old_ucontext_param->u.perf_counter.config;
1985 memcpy(ucontext_param->u.perf_counter.name,
1986 old_ucontext_param->u.perf_counter.name,
1987 sizeof(ucontext_param->u.perf_counter.name));
1988 }
1989
1990 ret = lttng_abi_add_context(file,
1991 ucontext_param,
1992 &channel->ctx, channel->session);
1993
1994 old_ctx_error_free_old_param:
1995 kfree(old_ucontext_param);
1996 old_ctx_error_free_param:
1997 kfree(ucontext_param);
1998 old_ctx_end:
1999 return ret;
2000 }
2001 case LTTNG_KERNEL_CONTEXT:
2002 {
2003 struct lttng_kernel_context ucontext_param;
2004
2005 if (copy_from_user(&ucontext_param,
2006 (struct lttng_kernel_context __user *) arg,
2007 sizeof(ucontext_param)))
2008 return -EFAULT;
2009 return lttng_abi_add_context(file,
2010 &ucontext_param,
2011 &channel->ctx, channel->session);
2012 }
2013 case LTTNG_KERNEL_OLD_ENABLE:
2014 case LTTNG_KERNEL_ENABLE:
2015 return lttng_channel_enable(channel);
2016 case LTTNG_KERNEL_OLD_DISABLE:
2017 case LTTNG_KERNEL_DISABLE:
2018 return lttng_channel_disable(channel);
2019 case LTTNG_KERNEL_SYSCALL_MASK:
2020 return lttng_channel_syscall_mask(channel,
2021 (struct lttng_kernel_syscall_mask __user *) arg);
2022 default:
2023 return -ENOIOCTLCMD;
2024 }
2025 }
2026
2027 /**
2028 * lttng_metadata_ioctl - lttng syscall through ioctl
2029 *
2030 * @file: the file
2031 * @cmd: the command
2032 * @arg: command arg
2033 *
2034 * This ioctl implements lttng commands:
2035 * LTTNG_KERNEL_STREAM
2036 * Returns an event stream file descriptor or failure.
2037 *
2038 * Channel and event file descriptors also hold a reference on the session.
2039 */
2040 static
2041 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2042 {
2043 switch (cmd) {
2044 case LTTNG_KERNEL_OLD_STREAM:
2045 case LTTNG_KERNEL_STREAM:
2046 return lttng_abi_open_metadata_stream(file);
2047 default:
2048 return -ENOIOCTLCMD;
2049 }
2050 }
2051
2052 /**
2053 * lttng_channel_poll - lttng stream addition/removal monitoring
2054 *
2055 * @file: the file
2056 * @wait: poll table
2057 */
2058 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
2059 {
2060 struct lttng_channel *channel = file->private_data;
2061 unsigned int mask = 0;
2062
2063 if (file->f_mode & FMODE_READ) {
2064 poll_wait_set_exclusive(wait);
2065 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
2066 wait);
2067
2068 if (channel->ops->is_disabled(channel->chan))
2069 return POLLERR;
2070 if (channel->ops->is_finalized(channel->chan))
2071 return POLLHUP;
2072 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
2073 return POLLIN | POLLRDNORM;
2074 return 0;
2075 }
2076 return mask;
2077
2078 }
2079
2080 static
2081 int lttng_channel_release(struct inode *inode, struct file *file)
2082 {
2083 struct lttng_channel *channel = file->private_data;
2084
2085 if (channel)
2086 fput(channel->session->file);
2087 return 0;
2088 }
2089
2090 static
2091 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
2092 {
2093 struct lttng_channel *channel = file->private_data;
2094
2095 if (channel) {
2096 fput(channel->session->file);
2097 lttng_metadata_channel_destroy(channel);
2098 }
2099
2100 return 0;
2101 }
2102
2103 static const struct file_operations lttng_channel_fops = {
2104 .owner = THIS_MODULE,
2105 .release = lttng_channel_release,
2106 .poll = lttng_channel_poll,
2107 .unlocked_ioctl = lttng_channel_ioctl,
2108 #ifdef CONFIG_COMPAT
2109 .compat_ioctl = lttng_channel_ioctl,
2110 #endif
2111 };
2112
2113 static const struct file_operations lttng_metadata_fops = {
2114 .owner = THIS_MODULE,
2115 .release = lttng_metadata_channel_release,
2116 .unlocked_ioctl = lttng_metadata_ioctl,
2117 #ifdef CONFIG_COMPAT
2118 .compat_ioctl = lttng_metadata_ioctl,
2119 #endif
2120 };
2121
2122 /**
2123 * lttng_event_ioctl - lttng syscall through ioctl
2124 *
2125 * @file: the file
2126 * @cmd: the command
2127 * @arg: command arg
2128 *
2129 * This ioctl implements lttng commands:
2130 * LTTNG_KERNEL_CONTEXT
2131 * Prepend a context field to each record of this event
2132 * LTTNG_KERNEL_ENABLE
2133 * Enable recording for this event (weak enable)
2134 * LTTNG_KERNEL_DISABLE
2135 * Disable recording for this event (strong disable)
2136 */
2137 static
2138 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2139 {
2140 struct lttng_event *event;
2141 struct lttng_event_enabler *event_enabler;
2142 enum lttng_event_type *evtype = file->private_data;
2143
2144 switch (cmd) {
2145 case LTTNG_KERNEL_OLD_CONTEXT:
2146 {
2147 /* Not implemented */
2148 return -ENOSYS;
2149 }
2150 case LTTNG_KERNEL_CONTEXT:
2151 {
2152 /* Not implemented */
2153 return -ENOSYS;
2154 }
2155 case LTTNG_KERNEL_OLD_ENABLE:
2156 case LTTNG_KERNEL_ENABLE:
2157 switch (*evtype) {
2158 case LTTNG_TYPE_EVENT:
2159 event = file->private_data;
2160 return lttng_event_enable(event);
2161 case LTTNG_TYPE_ENABLER:
2162 event_enabler = file->private_data;
2163 return lttng_event_enabler_enable(event_enabler);
2164 default:
2165 WARN_ON_ONCE(1);
2166 return -ENOSYS;
2167 }
2168 case LTTNG_KERNEL_OLD_DISABLE:
2169 case LTTNG_KERNEL_DISABLE:
2170 switch (*evtype) {
2171 case LTTNG_TYPE_EVENT:
2172 event = file->private_data;
2173 return lttng_event_disable(event);
2174 case LTTNG_TYPE_ENABLER:
2175 event_enabler = file->private_data;
2176 return lttng_event_enabler_disable(event_enabler);
2177 default:
2178 WARN_ON_ONCE(1);
2179 return -ENOSYS;
2180 }
2181 case LTTNG_KERNEL_FILTER:
2182 switch (*evtype) {
2183 case LTTNG_TYPE_EVENT:
2184 return -EINVAL;
2185 case LTTNG_TYPE_ENABLER:
2186 {
2187 event_enabler = file->private_data;
2188 return lttng_event_enabler_attach_bytecode(event_enabler,
2189 (struct lttng_kernel_filter_bytecode __user *) arg);
2190 }
2191 default:
2192 WARN_ON_ONCE(1);
2193 return -ENOSYS;
2194 }
2195 case LTTNG_KERNEL_ADD_CALLSITE:
2196 switch (*evtype) {
2197 case LTTNG_TYPE_EVENT:
2198 event = file->private_data;
2199 return lttng_event_add_callsite(event,
2200 (struct lttng_kernel_event_callsite __user *) arg);
2201 case LTTNG_TYPE_ENABLER:
2202 return -EINVAL;
2203 default:
2204 WARN_ON_ONCE(1);
2205 return -ENOSYS;
2206 }
2207 default:
2208 return -ENOIOCTLCMD;
2209 }
2210 }
2211
2212 static
2213 int lttng_event_release(struct inode *inode, struct file *file)
2214 {
2215 struct lttng_event *event;
2216 struct lttng_event_enabler *event_enabler;
2217 enum lttng_event_type *evtype = file->private_data;
2218
2219 if (!evtype)
2220 return 0;
2221
2222 switch (*evtype) {
2223 case LTTNG_TYPE_EVENT:
2224 event = file->private_data;
2225 if (event)
2226 fput(event->chan->file);
2227 break;
2228 case LTTNG_TYPE_ENABLER:
2229 event_enabler = file->private_data;
2230 if (event_enabler)
2231 fput(event_enabler->chan->file);
2232 break;
2233 default:
2234 WARN_ON_ONCE(1);
2235 break;
2236 }
2237
2238 return 0;
2239 }
2240
2241 /* TODO: filter control ioctl */
2242 static const struct file_operations lttng_event_fops = {
2243 .owner = THIS_MODULE,
2244 .release = lttng_event_release,
2245 .unlocked_ioctl = lttng_event_ioctl,
2246 #ifdef CONFIG_COMPAT
2247 .compat_ioctl = lttng_event_ioctl,
2248 #endif
2249 };
2250
2251 static int put_u64(uint64_t val, unsigned long arg)
2252 {
2253 return put_user(val, (uint64_t __user *) arg);
2254 }
2255
2256 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
2257 unsigned int cmd, unsigned long arg)
2258 {
2259 struct lib_ring_buffer *buf = filp->private_data;
2260 struct channel *chan = buf->backend.chan;
2261 const struct lib_ring_buffer_config *config = &chan->backend.config;
2262 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
2263 int ret;
2264
2265 if (atomic_read(&chan->record_disabled))
2266 return -EIO;
2267
2268 switch (cmd) {
2269 case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
2270 {
2271 uint64_t ts;
2272
2273 ret = ops->timestamp_begin(config, buf, &ts);
2274 if (ret < 0)
2275 goto error;
2276 return put_u64(ts, arg);
2277 }
2278 case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
2279 {
2280 uint64_t ts;
2281
2282 ret = ops->timestamp_end(config, buf, &ts);
2283 if (ret < 0)
2284 goto error;
2285 return put_u64(ts, arg);
2286 }
2287 case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
2288 {
2289 uint64_t ed;
2290
2291 ret = ops->events_discarded(config, buf, &ed);
2292 if (ret < 0)
2293 goto error;
2294 return put_u64(ed, arg);
2295 }
2296 case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
2297 {
2298 uint64_t cs;
2299
2300 ret = ops->content_size(config, buf, &cs);
2301 if (ret < 0)
2302 goto error;
2303 return put_u64(cs, arg);
2304 }
2305 case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
2306 {
2307 uint64_t ps;
2308
2309 ret = ops->packet_size(config, buf, &ps);
2310 if (ret < 0)
2311 goto error;
2312 return put_u64(ps, arg);
2313 }
2314 case LTTNG_RING_BUFFER_GET_STREAM_ID:
2315 {
2316 uint64_t si;
2317
2318 ret = ops->stream_id(config, buf, &si);
2319 if (ret < 0)
2320 goto error;
2321 return put_u64(si, arg);
2322 }
2323 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2324 {
2325 uint64_t ts;
2326
2327 ret = ops->current_timestamp(config, buf, &ts);
2328 if (ret < 0)
2329 goto error;
2330 return put_u64(ts, arg);
2331 }
2332 case LTTNG_RING_BUFFER_GET_SEQ_NUM:
2333 {
2334 uint64_t seq;
2335
2336 ret = ops->sequence_number(config, buf, &seq);
2337 if (ret < 0)
2338 goto error;
2339 return put_u64(seq, arg);
2340 }
2341 case LTTNG_RING_BUFFER_INSTANCE_ID:
2342 {
2343 uint64_t id;
2344
2345 ret = ops->instance_id(config, buf, &id);
2346 if (ret < 0)
2347 goto error;
2348 return put_u64(id, arg);
2349 }
2350 default:
2351 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
2352 cmd, arg);
2353 }
2354
2355 error:
2356 return -ENOSYS;
2357 }
2358
2359 #ifdef CONFIG_COMPAT
2360 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
2361 unsigned int cmd, unsigned long arg)
2362 {
2363 struct lib_ring_buffer *buf = filp->private_data;
2364 struct channel *chan = buf->backend.chan;
2365 const struct lib_ring_buffer_config *config = &chan->backend.config;
2366 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
2367 int ret;
2368
2369 if (atomic_read(&chan->record_disabled))
2370 return -EIO;
2371
2372 switch (cmd) {
2373 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
2374 {
2375 uint64_t ts;
2376
2377 ret = ops->timestamp_begin(config, buf, &ts);
2378 if (ret < 0)
2379 goto error;
2380 return put_u64(ts, arg);
2381 }
2382 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
2383 {
2384 uint64_t ts;
2385
2386 ret = ops->timestamp_end(config, buf, &ts);
2387 if (ret < 0)
2388 goto error;
2389 return put_u64(ts, arg);
2390 }
2391 case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
2392 {
2393 uint64_t ed;
2394
2395 ret = ops->events_discarded(config, buf, &ed);
2396 if (ret < 0)
2397 goto error;
2398 return put_u64(ed, arg);
2399 }
2400 case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
2401 {
2402 uint64_t cs;
2403
2404 ret = ops->content_size(config, buf, &cs);
2405 if (ret < 0)
2406 goto error;
2407 return put_u64(cs, arg);
2408 }
2409 case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
2410 {
2411 uint64_t ps;
2412
2413 ret = ops->packet_size(config, buf, &ps);
2414 if (ret < 0)
2415 goto error;
2416 return put_u64(ps, arg);
2417 }
2418 case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
2419 {
2420 uint64_t si;
2421
2422 ret = ops->stream_id(config, buf, &si);
2423 if (ret < 0)
2424 goto error;
2425 return put_u64(si, arg);
2426 }
2427 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2428 {
2429 uint64_t ts;
2430
2431 ret = ops->current_timestamp(config, buf, &ts);
2432 if (ret < 0)
2433 goto error;
2434 return put_u64(ts, arg);
2435 }
2436 case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
2437 {
2438 uint64_t seq;
2439
2440 ret = ops->sequence_number(config, buf, &seq);
2441 if (ret < 0)
2442 goto error;
2443 return put_u64(seq, arg);
2444 }
2445 case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
2446 {
2447 uint64_t id;
2448
2449 ret = ops->instance_id(config, buf, &id);
2450 if (ret < 0)
2451 goto error;
2452 return put_u64(id, arg);
2453 }
2454 default:
2455 return lib_ring_buffer_file_operations.compat_ioctl(filp,
2456 cmd, arg);
2457 }
2458
2459 error:
2460 return -ENOSYS;
2461 }
2462 #endif /* CONFIG_COMPAT */
2463
2464 static void lttng_stream_override_ring_buffer_fops(void)
2465 {
2466 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
2467 lttng_stream_ring_buffer_file_operations.open =
2468 lib_ring_buffer_file_operations.open;
2469 lttng_stream_ring_buffer_file_operations.release =
2470 lib_ring_buffer_file_operations.release;
2471 lttng_stream_ring_buffer_file_operations.poll =
2472 lib_ring_buffer_file_operations.poll;
2473 lttng_stream_ring_buffer_file_operations.splice_read =
2474 lib_ring_buffer_file_operations.splice_read;
2475 lttng_stream_ring_buffer_file_operations.mmap =
2476 lib_ring_buffer_file_operations.mmap;
2477 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
2478 lttng_stream_ring_buffer_ioctl;
2479 lttng_stream_ring_buffer_file_operations.llseek =
2480 lib_ring_buffer_file_operations.llseek;
2481 #ifdef CONFIG_COMPAT
2482 lttng_stream_ring_buffer_file_operations.compat_ioctl =
2483 lttng_stream_ring_buffer_compat_ioctl;
2484 #endif
2485 }
2486
2487 int __init lttng_abi_init(void)
2488 {
2489 int ret = 0;
2490
2491 wrapper_vmalloc_sync_all();
2492 lttng_clock_ref();
2493
2494 ret = lttng_tp_mempool_init();
2495 if (ret) {
2496 goto error;
2497 }
2498
2499 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
2500 &lttng_proc_ops, NULL);
2501
2502 if (!lttng_proc_dentry) {
2503 printk(KERN_ERR "Error creating LTTng control file\n");
2504 ret = -ENOMEM;
2505 goto error;
2506 }
2507 lttng_stream_override_ring_buffer_fops();
2508 return 0;
2509
2510 error:
2511 lttng_tp_mempool_destroy();
2512 lttng_clock_unref();
2513 return ret;
2514 }
2515
2516 /* No __exit annotation because used by init error path too. */
2517 void lttng_abi_exit(void)
2518 {
2519 lttng_tp_mempool_destroy();
2520 lttng_clock_unref();
2521 if (lttng_proc_dentry)
2522 remove_proc_entry("lttng", NULL);
2523 }
LTTng modules - Deliverables
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