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doc: event notifier on kretprobe is not supported
[lttng-modules.git] / src / lttng-abi.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
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_mappings() */
34 #include <ringbuffer/vfs.h>
35 #include <ringbuffer/backend.h>
36 #include <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 <ringbuffer/frontend_types.h>
47 #include <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_event_notifier_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 static int put_u32(uint32_t val, unsigned long arg);
71
72 /*
73 * Teardown management: opened file descriptors keep a refcount on the module,
74 * so it can only exit when all file descriptors are closed.
75 */
76
77 static
78 int lttng_abi_create_session(void)
79 {
80 struct lttng_session *session;
81 struct file *session_file;
82 int session_fd, ret;
83
84 session = lttng_session_create();
85 if (!session)
86 return -ENOMEM;
87 session_fd = lttng_get_unused_fd();
88 if (session_fd < 0) {
89 ret = session_fd;
90 goto fd_error;
91 }
92 session_file = anon_inode_getfile("[lttng_session]",
93 &lttng_session_fops,
94 session, O_RDWR);
95 if (IS_ERR(session_file)) {
96 ret = PTR_ERR(session_file);
97 goto file_error;
98 }
99 session->file = session_file;
100 fd_install(session_fd, session_file);
101 return session_fd;
102
103 file_error:
104 put_unused_fd(session_fd);
105 fd_error:
106 lttng_session_destroy(session);
107 return ret;
108 }
109
110 void event_notifier_send_notification_work_wakeup(struct irq_work *entry)
111 {
112 struct lttng_event_notifier_group *event_notifier_group =
113 container_of(entry, struct lttng_event_notifier_group,
114 wakeup_pending);
115 wake_up_interruptible(&event_notifier_group->read_wait);
116 }
117
118 static
119 int lttng_abi_create_event_notifier_group(void)
120 {
121 struct lttng_event_notifier_group *event_notifier_group;
122 struct file *event_notifier_group_file;
123 int event_notifier_group_fd, ret;
124
125 event_notifier_group = lttng_event_notifier_group_create();
126 if (!event_notifier_group)
127 return -ENOMEM;
128
129 event_notifier_group_fd = lttng_get_unused_fd();
130 if (event_notifier_group_fd < 0) {
131 ret = event_notifier_group_fd;
132 goto fd_error;
133 }
134 event_notifier_group_file = anon_inode_getfile("[lttng_event_notifier_group]",
135 &lttng_event_notifier_group_fops,
136 event_notifier_group, O_RDWR);
137 if (IS_ERR(event_notifier_group_file)) {
138 ret = PTR_ERR(event_notifier_group_file);
139 goto file_error;
140 }
141
142 event_notifier_group->file = event_notifier_group_file;
143 init_waitqueue_head(&event_notifier_group->read_wait);
144 init_irq_work(&event_notifier_group->wakeup_pending,
145 event_notifier_send_notification_work_wakeup);
146 fd_install(event_notifier_group_fd, event_notifier_group_file);
147 return event_notifier_group_fd;
148
149 file_error:
150 put_unused_fd(event_notifier_group_fd);
151 fd_error:
152 lttng_event_notifier_group_destroy(event_notifier_group);
153 return ret;
154 }
155
156 static
157 int lttng_abi_tracepoint_list(void)
158 {
159 struct file *tracepoint_list_file;
160 int file_fd, ret;
161
162 file_fd = lttng_get_unused_fd();
163 if (file_fd < 0) {
164 ret = file_fd;
165 goto fd_error;
166 }
167
168 tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
169 &lttng_tracepoint_list_fops,
170 NULL, O_RDWR);
171 if (IS_ERR(tracepoint_list_file)) {
172 ret = PTR_ERR(tracepoint_list_file);
173 goto file_error;
174 }
175 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
176 if (ret < 0)
177 goto open_error;
178 fd_install(file_fd, tracepoint_list_file);
179 return file_fd;
180
181 open_error:
182 fput(tracepoint_list_file);
183 file_error:
184 put_unused_fd(file_fd);
185 fd_error:
186 return ret;
187 }
188
189 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
190 static inline
191 int lttng_abi_syscall_list(void)
192 {
193 return -ENOSYS;
194 }
195 #else
196 static
197 int lttng_abi_syscall_list(void)
198 {
199 struct file *syscall_list_file;
200 int file_fd, ret;
201
202 file_fd = lttng_get_unused_fd();
203 if (file_fd < 0) {
204 ret = file_fd;
205 goto fd_error;
206 }
207
208 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
209 &lttng_syscall_list_fops,
210 NULL, O_RDWR);
211 if (IS_ERR(syscall_list_file)) {
212 ret = PTR_ERR(syscall_list_file);
213 goto file_error;
214 }
215 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
216 if (ret < 0)
217 goto open_error;
218 fd_install(file_fd, syscall_list_file);
219 return file_fd;
220
221 open_error:
222 fput(syscall_list_file);
223 file_error:
224 put_unused_fd(file_fd);
225 fd_error:
226 return ret;
227 }
228 #endif
229
230 static
231 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
232 {
233 v->major = LTTNG_MODULES_MAJOR_VERSION;
234 v->minor = LTTNG_MODULES_MINOR_VERSION;
235 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
236 }
237
238 static
239 void lttng_abi_tracer_abi_version(struct lttng_kernel_tracer_abi_version *v)
240 {
241 v->major = LTTNG_MODULES_ABI_MAJOR_VERSION;
242 v->minor = LTTNG_MODULES_ABI_MINOR_VERSION;
243 }
244
245 static
246 long lttng_abi_add_context(struct file *file,
247 struct lttng_kernel_context *context_param,
248 struct lttng_ctx **ctx, struct lttng_session *session)
249 {
250
251 if (session->been_active)
252 return -EPERM;
253
254 switch (context_param->ctx) {
255 case LTTNG_KERNEL_CONTEXT_PID:
256 return lttng_add_pid_to_ctx(ctx);
257 case LTTNG_KERNEL_CONTEXT_PRIO:
258 return lttng_add_prio_to_ctx(ctx);
259 case LTTNG_KERNEL_CONTEXT_NICE:
260 return lttng_add_nice_to_ctx(ctx);
261 case LTTNG_KERNEL_CONTEXT_VPID:
262 return lttng_add_vpid_to_ctx(ctx);
263 case LTTNG_KERNEL_CONTEXT_TID:
264 return lttng_add_tid_to_ctx(ctx);
265 case LTTNG_KERNEL_CONTEXT_VTID:
266 return lttng_add_vtid_to_ctx(ctx);
267 case LTTNG_KERNEL_CONTEXT_PPID:
268 return lttng_add_ppid_to_ctx(ctx);
269 case LTTNG_KERNEL_CONTEXT_VPPID:
270 return lttng_add_vppid_to_ctx(ctx);
271 case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
272 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
273 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
274 context_param->u.perf_counter.config,
275 context_param->u.perf_counter.name,
276 ctx);
277 case LTTNG_KERNEL_CONTEXT_PROCNAME:
278 return lttng_add_procname_to_ctx(ctx);
279 case LTTNG_KERNEL_CONTEXT_HOSTNAME:
280 return lttng_add_hostname_to_ctx(ctx);
281 case LTTNG_KERNEL_CONTEXT_CPU_ID:
282 return lttng_add_cpu_id_to_ctx(ctx);
283 case LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE:
284 return lttng_add_interruptible_to_ctx(ctx);
285 case LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE:
286 return lttng_add_need_reschedule_to_ctx(ctx);
287 case LTTNG_KERNEL_CONTEXT_PREEMPTIBLE:
288 return lttng_add_preemptible_to_ctx(ctx);
289 case LTTNG_KERNEL_CONTEXT_MIGRATABLE:
290 return lttng_add_migratable_to_ctx(ctx);
291 case LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL:
292 case LTTNG_KERNEL_CONTEXT_CALLSTACK_USER:
293 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
294 case LTTNG_KERNEL_CONTEXT_CGROUP_NS:
295 return lttng_add_cgroup_ns_to_ctx(ctx);
296 case LTTNG_KERNEL_CONTEXT_IPC_NS:
297 return lttng_add_ipc_ns_to_ctx(ctx);
298 case LTTNG_KERNEL_CONTEXT_MNT_NS:
299 return lttng_add_mnt_ns_to_ctx(ctx);
300 case LTTNG_KERNEL_CONTEXT_NET_NS:
301 return lttng_add_net_ns_to_ctx(ctx);
302 case LTTNG_KERNEL_CONTEXT_PID_NS:
303 return lttng_add_pid_ns_to_ctx(ctx);
304 case LTTNG_KERNEL_CONTEXT_USER_NS:
305 return lttng_add_user_ns_to_ctx(ctx);
306 case LTTNG_KERNEL_CONTEXT_UTS_NS:
307 return lttng_add_uts_ns_to_ctx(ctx);
308 case LTTNG_KERNEL_CONTEXT_UID:
309 return lttng_add_uid_to_ctx(ctx);
310 case LTTNG_KERNEL_CONTEXT_EUID:
311 return lttng_add_euid_to_ctx(ctx);
312 case LTTNG_KERNEL_CONTEXT_SUID:
313 return lttng_add_suid_to_ctx(ctx);
314 case LTTNG_KERNEL_CONTEXT_GID:
315 return lttng_add_gid_to_ctx(ctx);
316 case LTTNG_KERNEL_CONTEXT_EGID:
317 return lttng_add_egid_to_ctx(ctx);
318 case LTTNG_KERNEL_CONTEXT_SGID:
319 return lttng_add_sgid_to_ctx(ctx);
320 case LTTNG_KERNEL_CONTEXT_VUID:
321 return lttng_add_vuid_to_ctx(ctx);
322 case LTTNG_KERNEL_CONTEXT_VEUID:
323 return lttng_add_veuid_to_ctx(ctx);
324 case LTTNG_KERNEL_CONTEXT_VSUID:
325 return lttng_add_vsuid_to_ctx(ctx);
326 case LTTNG_KERNEL_CONTEXT_VGID:
327 return lttng_add_vgid_to_ctx(ctx);
328 case LTTNG_KERNEL_CONTEXT_VEGID:
329 return lttng_add_vegid_to_ctx(ctx);
330 case LTTNG_KERNEL_CONTEXT_VSGID:
331 return lttng_add_vsgid_to_ctx(ctx);
332 case LTTNG_KERNEL_CONTEXT_TIME_NS:
333 return lttng_add_time_ns_to_ctx(ctx);
334 default:
335 return -EINVAL;
336 }
337 }
338
339 /**
340 * lttng_ioctl - lttng syscall through ioctl
341 *
342 * @file: the file
343 * @cmd: the command
344 * @arg: command arg
345 *
346 * This ioctl implements lttng commands:
347 * LTTNG_KERNEL_SESSION
348 * Returns a LTTng trace session file descriptor
349 * LTTNG_KERNEL_TRACER_VERSION
350 * Returns the LTTng kernel tracer version
351 * LTTNG_KERNEL_TRACEPOINT_LIST
352 * Returns a file descriptor listing available tracepoints
353 * LTTNG_KERNEL_WAIT_QUIESCENT
354 * Returns after all previously running probes have completed
355 * LTTNG_KERNEL_TRACER_ABI_VERSION
356 * Returns the LTTng kernel tracer ABI version
357 * LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_CREATE
358 * Returns a LTTng event notifier group file descriptor
359 *
360 * The returned session will be deleted when its file descriptor is closed.
361 */
362 static
363 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
364 {
365 switch (cmd) {
366 case LTTNG_KERNEL_OLD_SESSION:
367 case LTTNG_KERNEL_SESSION:
368 return lttng_abi_create_session();
369 case LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_CREATE:
370 return lttng_abi_create_event_notifier_group();
371 case LTTNG_KERNEL_OLD_TRACER_VERSION:
372 {
373 struct lttng_kernel_tracer_version v;
374 struct lttng_kernel_old_tracer_version oldv;
375 struct lttng_kernel_old_tracer_version *uversion =
376 (struct lttng_kernel_old_tracer_version __user *) arg;
377
378 lttng_abi_tracer_version(&v);
379 oldv.major = v.major;
380 oldv.minor = v.minor;
381 oldv.patchlevel = v.patchlevel;
382
383 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
384 return -EFAULT;
385 return 0;
386 }
387 case LTTNG_KERNEL_TRACER_VERSION:
388 {
389 struct lttng_kernel_tracer_version version;
390 struct lttng_kernel_tracer_version *uversion =
391 (struct lttng_kernel_tracer_version __user *) arg;
392
393 lttng_abi_tracer_version(&version);
394
395 if (copy_to_user(uversion, &version, sizeof(version)))
396 return -EFAULT;
397 return 0;
398 }
399 case LTTNG_KERNEL_TRACER_ABI_VERSION:
400 {
401 struct lttng_kernel_tracer_abi_version version;
402 struct lttng_kernel_tracer_abi_version *uversion =
403 (struct lttng_kernel_tracer_abi_version __user *) arg;
404
405 lttng_abi_tracer_abi_version(&version);
406
407 if (copy_to_user(uversion, &version, sizeof(version)))
408 return -EFAULT;
409 return 0;
410 }
411 case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
412 case LTTNG_KERNEL_TRACEPOINT_LIST:
413 return lttng_abi_tracepoint_list();
414 case LTTNG_KERNEL_SYSCALL_LIST:
415 return lttng_abi_syscall_list();
416 case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
417 case LTTNG_KERNEL_WAIT_QUIESCENT:
418 synchronize_trace();
419 return 0;
420 case LTTNG_KERNEL_OLD_CALIBRATE:
421 {
422 struct lttng_kernel_old_calibrate __user *ucalibrate =
423 (struct lttng_kernel_old_calibrate __user *) arg;
424 struct lttng_kernel_old_calibrate old_calibrate;
425 struct lttng_kernel_calibrate calibrate;
426 int ret;
427
428 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
429 return -EFAULT;
430 calibrate.type = old_calibrate.type;
431 ret = lttng_calibrate(&calibrate);
432 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
433 return -EFAULT;
434 return ret;
435 }
436 case LTTNG_KERNEL_CALIBRATE:
437 {
438 struct lttng_kernel_calibrate __user *ucalibrate =
439 (struct lttng_kernel_calibrate __user *) arg;
440 struct lttng_kernel_calibrate calibrate;
441 int ret;
442
443 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
444 return -EFAULT;
445 ret = lttng_calibrate(&calibrate);
446 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
447 return -EFAULT;
448 return ret;
449 }
450 default:
451 return -ENOIOCTLCMD;
452 }
453 }
454
455 #if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,6,0))
456 static const struct proc_ops lttng_proc_ops = {
457 .proc_ioctl = lttng_ioctl,
458 #ifdef CONFIG_COMPAT
459 .proc_compat_ioctl = lttng_ioctl,
460 #endif /* CONFIG_COMPAT */
461 };
462 #else
463 static const struct file_operations lttng_proc_ops = {
464 .owner = THIS_MODULE,
465 .unlocked_ioctl = lttng_ioctl,
466 #ifdef CONFIG_COMPAT
467 .compat_ioctl = lttng_ioctl,
468 #endif /* CONFIG_COMPAT */
469 };
470 #endif
471
472 static
473 int lttng_abi_create_channel(struct file *session_file,
474 struct lttng_kernel_channel *chan_param,
475 enum channel_type channel_type)
476 {
477 struct lttng_session *session = session_file->private_data;
478 const struct file_operations *fops = NULL;
479 const char *transport_name;
480 struct lttng_channel *chan;
481 struct file *chan_file;
482 int chan_fd;
483 int ret = 0;
484
485 chan_fd = lttng_get_unused_fd();
486 if (chan_fd < 0) {
487 ret = chan_fd;
488 goto fd_error;
489 }
490 switch (channel_type) {
491 case PER_CPU_CHANNEL:
492 fops = &lttng_channel_fops;
493 break;
494 case METADATA_CHANNEL:
495 fops = &lttng_metadata_fops;
496 break;
497 }
498
499 chan_file = anon_inode_getfile("[lttng_channel]",
500 fops,
501 NULL, O_RDWR);
502 if (IS_ERR(chan_file)) {
503 ret = PTR_ERR(chan_file);
504 goto file_error;
505 }
506 switch (channel_type) {
507 case PER_CPU_CHANNEL:
508 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
509 transport_name = chan_param->overwrite ?
510 "relay-overwrite" : "relay-discard";
511 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
512 transport_name = chan_param->overwrite ?
513 "relay-overwrite-mmap" : "relay-discard-mmap";
514 } else {
515 return -EINVAL;
516 }
517 break;
518 case METADATA_CHANNEL:
519 if (chan_param->output == LTTNG_KERNEL_SPLICE)
520 transport_name = "relay-metadata";
521 else if (chan_param->output == LTTNG_KERNEL_MMAP)
522 transport_name = "relay-metadata-mmap";
523 else
524 return -EINVAL;
525 break;
526 default:
527 transport_name = "<unknown>";
528 break;
529 }
530 if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
531 ret = -EOVERFLOW;
532 goto refcount_error;
533 }
534 /*
535 * We tolerate no failure path after channel creation. It will stay
536 * invariant for the rest of the session.
537 */
538 chan = lttng_channel_create(session, transport_name, NULL,
539 chan_param->subbuf_size,
540 chan_param->num_subbuf,
541 chan_param->switch_timer_interval,
542 chan_param->read_timer_interval,
543 channel_type);
544 if (!chan) {
545 ret = -EINVAL;
546 goto chan_error;
547 }
548 chan->file = chan_file;
549 chan_file->private_data = chan;
550 fd_install(chan_fd, chan_file);
551
552 return chan_fd;
553
554 chan_error:
555 atomic_long_dec(&session_file->f_count);
556 refcount_error:
557 fput(chan_file);
558 file_error:
559 put_unused_fd(chan_fd);
560 fd_error:
561 return ret;
562 }
563
564 static
565 int lttng_abi_session_set_name(struct lttng_session *session,
566 struct lttng_kernel_session_name *name)
567 {
568 size_t len;
569
570 len = strnlen(name->name, LTTNG_KERNEL_SESSION_NAME_LEN);
571
572 if (len == LTTNG_KERNEL_SESSION_NAME_LEN) {
573 /* Name is too long/malformed */
574 return -EINVAL;
575 }
576
577 strcpy(session->name, name->name);
578 return 0;
579 }
580
581 static
582 int lttng_abi_session_set_creation_time(struct lttng_session *session,
583 struct lttng_kernel_session_creation_time *time)
584 {
585 size_t len;
586
587 len = strnlen(time->iso8601, LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN);
588
589 if (len == LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN) {
590 /* Time is too long/malformed */
591 return -EINVAL;
592 }
593
594 strcpy(session->creation_time, time->iso8601);
595 return 0;
596 }
597
598 static
599 enum tracker_type get_tracker_type(struct lttng_kernel_tracker_args *tracker)
600 {
601 switch (tracker->type) {
602 case LTTNG_KERNEL_TRACKER_PID:
603 return TRACKER_PID;
604 case LTTNG_KERNEL_TRACKER_VPID:
605 return TRACKER_VPID;
606 case LTTNG_KERNEL_TRACKER_UID:
607 return TRACKER_UID;
608 case LTTNG_KERNEL_TRACKER_VUID:
609 return TRACKER_VUID;
610 case LTTNG_KERNEL_TRACKER_GID:
611 return TRACKER_GID;
612 case LTTNG_KERNEL_TRACKER_VGID:
613 return TRACKER_VGID;
614 default:
615 return TRACKER_UNKNOWN;
616 }
617 }
618
619 /**
620 * lttng_session_ioctl - lttng session fd ioctl
621 *
622 * @file: the file
623 * @cmd: the command
624 * @arg: command arg
625 *
626 * This ioctl implements lttng commands:
627 * LTTNG_KERNEL_CHANNEL
628 * Returns a LTTng channel file descriptor
629 * LTTNG_KERNEL_ENABLE
630 * Enables tracing for a session (weak enable)
631 * LTTNG_KERNEL_DISABLE
632 * Disables tracing for a session (strong disable)
633 * LTTNG_KERNEL_METADATA
634 * Returns a LTTng metadata file descriptor
635 * LTTNG_KERNEL_SESSION_TRACK_PID
636 * Add PID to session PID tracker
637 * LTTNG_KERNEL_SESSION_UNTRACK_PID
638 * Remove PID from session PID tracker
639 * LTTNG_KERNEL_SESSION_TRACK_ID
640 * Add ID to tracker
641 * LTTNG_KERNEL_SESSION_UNTRACK_ID
642 * Remove ID from tracker
643 *
644 * The returned channel will be deleted when its file descriptor is closed.
645 */
646 static
647 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
648 {
649 struct lttng_session *session = file->private_data;
650 struct lttng_kernel_channel chan_param;
651 struct lttng_kernel_old_channel old_chan_param;
652
653 switch (cmd) {
654 case LTTNG_KERNEL_OLD_CHANNEL:
655 {
656 if (copy_from_user(&old_chan_param,
657 (struct lttng_kernel_old_channel __user *) arg,
658 sizeof(struct lttng_kernel_old_channel)))
659 return -EFAULT;
660 chan_param.overwrite = old_chan_param.overwrite;
661 chan_param.subbuf_size = old_chan_param.subbuf_size;
662 chan_param.num_subbuf = old_chan_param.num_subbuf;
663 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
664 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
665 chan_param.output = old_chan_param.output;
666
667 return lttng_abi_create_channel(file, &chan_param,
668 PER_CPU_CHANNEL);
669 }
670 case LTTNG_KERNEL_CHANNEL:
671 {
672 if (copy_from_user(&chan_param,
673 (struct lttng_kernel_channel __user *) arg,
674 sizeof(struct lttng_kernel_channel)))
675 return -EFAULT;
676 return lttng_abi_create_channel(file, &chan_param,
677 PER_CPU_CHANNEL);
678 }
679 case LTTNG_KERNEL_OLD_SESSION_START:
680 case LTTNG_KERNEL_OLD_ENABLE:
681 case LTTNG_KERNEL_SESSION_START:
682 case LTTNG_KERNEL_ENABLE:
683 return lttng_session_enable(session);
684 case LTTNG_KERNEL_OLD_SESSION_STOP:
685 case LTTNG_KERNEL_OLD_DISABLE:
686 case LTTNG_KERNEL_SESSION_STOP:
687 case LTTNG_KERNEL_DISABLE:
688 return lttng_session_disable(session);
689 case LTTNG_KERNEL_OLD_METADATA:
690 {
691 if (copy_from_user(&old_chan_param,
692 (struct lttng_kernel_old_channel __user *) arg,
693 sizeof(struct lttng_kernel_old_channel)))
694 return -EFAULT;
695 chan_param.overwrite = old_chan_param.overwrite;
696 chan_param.subbuf_size = old_chan_param.subbuf_size;
697 chan_param.num_subbuf = old_chan_param.num_subbuf;
698 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
699 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
700 chan_param.output = old_chan_param.output;
701
702 return lttng_abi_create_channel(file, &chan_param,
703 METADATA_CHANNEL);
704 }
705 case LTTNG_KERNEL_METADATA:
706 {
707 if (copy_from_user(&chan_param,
708 (struct lttng_kernel_channel __user *) arg,
709 sizeof(struct lttng_kernel_channel)))
710 return -EFAULT;
711 return lttng_abi_create_channel(file, &chan_param,
712 METADATA_CHANNEL);
713 }
714 case LTTNG_KERNEL_SESSION_TRACK_PID:
715 return lttng_session_track_id(session, TRACKER_PID, (int) arg);
716 case LTTNG_KERNEL_SESSION_UNTRACK_PID:
717 return lttng_session_untrack_id(session, TRACKER_PID, (int) arg);
718 case LTTNG_KERNEL_SESSION_TRACK_ID:
719 {
720 struct lttng_kernel_tracker_args tracker;
721 enum tracker_type tracker_type;
722
723 if (copy_from_user(&tracker,
724 (struct lttng_kernel_tracker_args __user *) arg,
725 sizeof(struct lttng_kernel_tracker_args)))
726 return -EFAULT;
727 tracker_type = get_tracker_type(&tracker);
728 if (tracker_type == TRACKER_UNKNOWN)
729 return -EINVAL;
730 return lttng_session_track_id(session, tracker_type, tracker.id);
731 }
732 case LTTNG_KERNEL_SESSION_UNTRACK_ID:
733 {
734 struct lttng_kernel_tracker_args tracker;
735 enum tracker_type tracker_type;
736
737 if (copy_from_user(&tracker,
738 (struct lttng_kernel_tracker_args __user *) arg,
739 sizeof(struct lttng_kernel_tracker_args)))
740 return -EFAULT;
741 tracker_type = get_tracker_type(&tracker);
742 if (tracker_type == TRACKER_UNKNOWN)
743 return -EINVAL;
744 return lttng_session_untrack_id(session, tracker_type,
745 tracker.id);
746 }
747 case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
748 return lttng_session_list_tracker_ids(session, TRACKER_PID);
749 case LTTNG_KERNEL_SESSION_LIST_TRACKER_IDS:
750 {
751 struct lttng_kernel_tracker_args tracker;
752 enum tracker_type tracker_type;
753
754 if (copy_from_user(&tracker,
755 (struct lttng_kernel_tracker_args __user *) arg,
756 sizeof(struct lttng_kernel_tracker_args)))
757 return -EFAULT;
758 tracker_type = get_tracker_type(&tracker);
759 if (tracker_type == TRACKER_UNKNOWN)
760 return -EINVAL;
761 return lttng_session_list_tracker_ids(session, tracker_type);
762 }
763 case LTTNG_KERNEL_SESSION_METADATA_REGEN:
764 return lttng_session_metadata_regenerate(session);
765 case LTTNG_KERNEL_SESSION_STATEDUMP:
766 return lttng_session_statedump(session);
767 case LTTNG_KERNEL_SESSION_SET_NAME:
768 {
769 struct lttng_kernel_session_name name;
770
771 if (copy_from_user(&name,
772 (struct lttng_kernel_session_name __user *) arg,
773 sizeof(struct lttng_kernel_session_name)))
774 return -EFAULT;
775 return lttng_abi_session_set_name(session, &name);
776 }
777 case LTTNG_KERNEL_SESSION_SET_CREATION_TIME:
778 {
779 struct lttng_kernel_session_creation_time time;
780
781 if (copy_from_user(&time,
782 (struct lttng_kernel_session_creation_time __user *) arg,
783 sizeof(struct lttng_kernel_session_creation_time)))
784 return -EFAULT;
785 return lttng_abi_session_set_creation_time(session, &time);
786 }
787 default:
788 return -ENOIOCTLCMD;
789 }
790 }
791
792 /*
793 * Called when the last file reference is dropped.
794 *
795 * Big fat note: channels and events are invariant for the whole session after
796 * their creation. So this session destruction also destroys all channel and
797 * event structures specific to this session (they are not destroyed when their
798 * individual file is released).
799 */
800 static
801 int lttng_session_release(struct inode *inode, struct file *file)
802 {
803 struct lttng_session *session = file->private_data;
804
805 if (session)
806 lttng_session_destroy(session);
807 return 0;
808 }
809
810 static const struct file_operations lttng_session_fops = {
811 .owner = THIS_MODULE,
812 .release = lttng_session_release,
813 .unlocked_ioctl = lttng_session_ioctl,
814 #ifdef CONFIG_COMPAT
815 .compat_ioctl = lttng_session_ioctl,
816 #endif
817 };
818
819 /*
820 * When encountering empty buffer, flush current sub-buffer if non-empty
821 * and retry (if new data available to read after flush).
822 */
823 static
824 ssize_t lttng_event_notifier_group_notif_read(struct file *filp, char __user *user_buf,
825 size_t count, loff_t *ppos)
826 {
827 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
828 struct channel *chan = event_notifier_group->chan;
829 struct lib_ring_buffer *buf = event_notifier_group->buf;
830 ssize_t read_count = 0, len;
831 size_t read_offset;
832
833 might_sleep();
834 if (!lttng_access_ok(VERIFY_WRITE, user_buf, count))
835 return -EFAULT;
836
837 /* Finish copy of previous record */
838 if (*ppos != 0) {
839 if (read_count < count) {
840 len = chan->iter.len_left;
841 read_offset = *ppos;
842 goto skip_get_next;
843 }
844 }
845
846 while (read_count < count) {
847 size_t copy_len, space_left;
848
849 len = lib_ring_buffer_get_next_record(chan, buf);
850 len_test:
851 if (len < 0) {
852 /*
853 * Check if buffer is finalized (end of file).
854 */
855 if (len == -ENODATA) {
856 /* A 0 read_count will tell about end of file */
857 goto nodata;
858 }
859 if (filp->f_flags & O_NONBLOCK) {
860 if (!read_count)
861 read_count = -EAGAIN;
862 goto nodata;
863 } else {
864 int error;
865
866 /*
867 * No data available at the moment, return what
868 * we got.
869 */
870 if (read_count)
871 goto nodata;
872
873 /*
874 * Wait for returned len to be >= 0 or -ENODATA.
875 */
876 error = wait_event_interruptible(
877 event_notifier_group->read_wait,
878 ((len = lib_ring_buffer_get_next_record(
879 chan, buf)), len != -EAGAIN));
880 CHAN_WARN_ON(chan, len == -EBUSY);
881 if (error) {
882 read_count = error;
883 goto nodata;
884 }
885 CHAN_WARN_ON(chan, len < 0 && len != -ENODATA);
886 goto len_test;
887 }
888 }
889 read_offset = buf->iter.read_offset;
890 skip_get_next:
891 space_left = count - read_count;
892 if (len <= space_left) {
893 copy_len = len;
894 chan->iter.len_left = 0;
895 *ppos = 0;
896 } else {
897 copy_len = space_left;
898 chan->iter.len_left = len - copy_len;
899 *ppos = read_offset + copy_len;
900 }
901 if (__lib_ring_buffer_copy_to_user(&buf->backend, read_offset,
902 &user_buf[read_count],
903 copy_len)) {
904 /*
905 * Leave the len_left and ppos values at their current
906 * state, as we currently have a valid event to read.
907 */
908 return -EFAULT;
909 }
910 read_count += copy_len;
911 }
912 goto put_record;
913
914 nodata:
915 *ppos = 0;
916 chan->iter.len_left = 0;
917
918 put_record:
919 lib_ring_buffer_put_current_record(buf);
920 return read_count;
921 }
922
923 /*
924 * If the ring buffer is non empty (even just a partial subbuffer), return that
925 * there is data available. Perform a ring buffer flush if we encounter a
926 * non-empty ring buffer which does not have any consumeable subbuffer available.
927 */
928 static
929 unsigned int lttng_event_notifier_group_notif_poll(struct file *filp,
930 poll_table *wait)
931 {
932 unsigned int mask = 0;
933 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
934 struct channel *chan = event_notifier_group->chan;
935 struct lib_ring_buffer *buf = event_notifier_group->buf;
936 const struct lib_ring_buffer_config *config = &chan->backend.config;
937 int finalized, disabled;
938 unsigned long consumed, offset;
939 size_t subbuffer_header_size = config->cb.subbuffer_header_size();
940
941 if (filp->f_mode & FMODE_READ) {
942 poll_wait_set_exclusive(wait);
943 poll_wait(filp, &event_notifier_group->read_wait, wait);
944
945 finalized = lib_ring_buffer_is_finalized(config, buf);
946 disabled = lib_ring_buffer_channel_is_disabled(chan);
947
948 /*
949 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
950 * finalized load before offsets loads.
951 */
952 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
953 retry:
954 if (disabled)
955 return POLLERR;
956
957 offset = lib_ring_buffer_get_offset(config, buf);
958 consumed = lib_ring_buffer_get_consumed(config, buf);
959
960 /*
961 * If there is no buffer available to consume.
962 */
963 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) == 0) {
964 /*
965 * If there is a non-empty subbuffer, flush and try again.
966 */
967 if (subbuf_offset(offset, chan) > subbuffer_header_size) {
968 lib_ring_buffer_switch_remote(buf);
969 goto retry;
970 }
971
972 if (finalized)
973 return POLLHUP;
974 else {
975 /*
976 * The memory barriers
977 * __wait_event()/wake_up_interruptible() take
978 * care of "raw_spin_is_locked" memory ordering.
979 */
980 if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
981 goto retry;
982 else
983 return 0;
984 }
985 } else {
986 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan)
987 >= chan->backend.buf_size)
988 return POLLPRI | POLLRDBAND;
989 else
990 return POLLIN | POLLRDNORM;
991 }
992 }
993
994 return mask;
995 }
996
997 /**
998 * lttng_event_notifier_group_notif_open - event_notifier ring buffer open file operation
999 * @inode: opened inode
1000 * @file: opened file
1001 *
1002 * Open implementation. Makes sure only one open instance of a buffer is
1003 * done at a given moment.
1004 */
1005 static int lttng_event_notifier_group_notif_open(struct inode *inode, struct file *file)
1006 {
1007 struct lttng_event_notifier_group *event_notifier_group = inode->i_private;
1008 struct lib_ring_buffer *buf = event_notifier_group->buf;
1009
1010 file->private_data = event_notifier_group;
1011 return lib_ring_buffer_open(inode, file, buf);
1012 }
1013
1014 /**
1015 * lttng_event_notifier_group_notif_release - event_notifier ring buffer release file operation
1016 * @inode: opened inode
1017 * @file: opened file
1018 *
1019 * Release implementation.
1020 */
1021 static int lttng_event_notifier_group_notif_release(struct inode *inode, struct file *file)
1022 {
1023 struct lttng_event_notifier_group *event_notifier_group = file->private_data;
1024 struct lib_ring_buffer *buf = event_notifier_group->buf;
1025 int ret;
1026
1027 ret = lib_ring_buffer_release(inode, file, buf);
1028 if (ret)
1029 return ret;
1030 fput(event_notifier_group->file);
1031 return 0;
1032 }
1033
1034 static const struct file_operations lttng_event_notifier_group_notif_fops = {
1035 .owner = THIS_MODULE,
1036 .open = lttng_event_notifier_group_notif_open,
1037 .release = lttng_event_notifier_group_notif_release,
1038 .read = lttng_event_notifier_group_notif_read,
1039 .poll = lttng_event_notifier_group_notif_poll,
1040 };
1041
1042 /**
1043 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
1044 * @filp: the file
1045 * @wait: poll table
1046 *
1047 * Handles the poll operations for the metadata channels.
1048 */
1049 static
1050 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
1051 poll_table *wait)
1052 {
1053 struct lttng_metadata_stream *stream = filp->private_data;
1054 struct lib_ring_buffer *buf = stream->priv;
1055 int finalized;
1056 unsigned int mask = 0;
1057
1058 if (filp->f_mode & FMODE_READ) {
1059 poll_wait_set_exclusive(wait);
1060 poll_wait(filp, &stream->read_wait, wait);
1061
1062 finalized = stream->finalized;
1063
1064 /*
1065 * lib_ring_buffer_is_finalized() contains a smp_rmb()
1066 * ordering finalized load before offsets loads.
1067 */
1068 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1069
1070 if (finalized)
1071 mask |= POLLHUP;
1072
1073 mutex_lock(&stream->metadata_cache->lock);
1074 if (stream->metadata_cache->metadata_written >
1075 stream->metadata_out)
1076 mask |= POLLIN;
1077 mutex_unlock(&stream->metadata_cache->lock);
1078 }
1079
1080 return mask;
1081 }
1082
1083 static
1084 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
1085 unsigned int cmd, unsigned long arg)
1086 {
1087 struct lttng_metadata_stream *stream = filp->private_data;
1088
1089 stream->metadata_out = stream->metadata_in;
1090 }
1091
1092 /*
1093 * Reset the counter of how much metadata has been consumed to 0. That way,
1094 * the consumer receives the content of the metadata cache unchanged. This is
1095 * different from the metadata_regenerate where the offset from epoch is
1096 * resampled, here we want the exact same content as the last time the metadata
1097 * was generated. This command is only possible if all the metadata written
1098 * in the cache has been output to the metadata stream to avoid corrupting the
1099 * metadata file.
1100 *
1101 * Return 0 on success, a negative value on error.
1102 */
1103 static
1104 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
1105 {
1106 int ret;
1107 struct lttng_metadata_cache *cache = stream->metadata_cache;
1108
1109 mutex_lock(&cache->lock);
1110 if (stream->metadata_out != cache->metadata_written) {
1111 ret = -EBUSY;
1112 goto end;
1113 }
1114 stream->metadata_out = 0;
1115 stream->metadata_in = 0;
1116 wake_up_interruptible(&stream->read_wait);
1117 ret = 0;
1118
1119 end:
1120 mutex_unlock(&cache->lock);
1121 return ret;
1122 }
1123
1124 static
1125 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
1126 unsigned int cmd, unsigned long arg)
1127 {
1128 int ret;
1129 struct lttng_metadata_stream *stream = filp->private_data;
1130 struct lib_ring_buffer *buf = stream->priv;
1131 unsigned int rb_cmd;
1132 bool coherent;
1133
1134 if (cmd == RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1135 rb_cmd = RING_BUFFER_GET_NEXT_SUBBUF;
1136 else
1137 rb_cmd = cmd;
1138
1139 switch (cmd) {
1140 case RING_BUFFER_GET_NEXT_SUBBUF:
1141 {
1142 struct lttng_metadata_stream *stream = filp->private_data;
1143 struct lib_ring_buffer *buf = stream->priv;
1144 struct channel *chan = buf->backend.chan;
1145
1146 ret = lttng_metadata_output_channel(stream, chan, NULL);
1147 if (ret > 0) {
1148 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1149 ret = 0;
1150 } else if (ret < 0)
1151 goto err;
1152 break;
1153 }
1154 case RING_BUFFER_GET_SUBBUF:
1155 {
1156 /*
1157 * Random access is not allowed for metadata channel.
1158 */
1159 return -ENOSYS;
1160 }
1161 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
1162 case RING_BUFFER_FLUSH:
1163 {
1164 struct lttng_metadata_stream *stream = filp->private_data;
1165 struct lib_ring_buffer *buf = stream->priv;
1166 struct channel *chan = buf->backend.chan;
1167
1168 /*
1169 * Before doing the actual ring buffer flush, write up to one
1170 * packet of metadata in the ring buffer.
1171 */
1172 ret = lttng_metadata_output_channel(stream, chan, NULL);
1173 if (ret < 0)
1174 goto err;
1175 break;
1176 }
1177 case RING_BUFFER_GET_METADATA_VERSION:
1178 {
1179 struct lttng_metadata_stream *stream = filp->private_data;
1180
1181 return put_u64(stream->version, arg);
1182 }
1183 case RING_BUFFER_METADATA_CACHE_DUMP:
1184 {
1185 struct lttng_metadata_stream *stream = filp->private_data;
1186
1187 return lttng_metadata_cache_dump(stream);
1188 }
1189 case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1190 {
1191 struct lttng_metadata_stream *stream = filp->private_data;
1192 struct lib_ring_buffer *buf = stream->priv;
1193 struct channel *chan = buf->backend.chan;
1194
1195 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1196 if (ret > 0) {
1197 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1198 ret = 0;
1199 } else if (ret < 0) {
1200 goto err;
1201 }
1202 break;
1203 }
1204 default:
1205 break;
1206 }
1207 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1208
1209 /* Performing lib ring buffer ioctl after our own. */
1210 ret = lib_ring_buffer_ioctl(filp, rb_cmd, arg, buf);
1211 if (ret < 0)
1212 goto err;
1213
1214 switch (cmd) {
1215 case RING_BUFFER_PUT_NEXT_SUBBUF:
1216 {
1217 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1218 cmd, arg);
1219 break;
1220 }
1221 case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1222 {
1223 return put_u32(coherent, arg);
1224 }
1225 default:
1226 break;
1227 }
1228 err:
1229 return ret;
1230 }
1231
1232 #ifdef CONFIG_COMPAT
1233 static
1234 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
1235 unsigned int cmd, unsigned long arg)
1236 {
1237 int ret;
1238 struct lttng_metadata_stream *stream = filp->private_data;
1239 struct lib_ring_buffer *buf = stream->priv;
1240 unsigned int rb_cmd;
1241 bool coherent;
1242
1243 if (cmd == RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1244 rb_cmd = RING_BUFFER_GET_NEXT_SUBBUF;
1245 else
1246 rb_cmd = cmd;
1247
1248 switch (cmd) {
1249 case RING_BUFFER_GET_NEXT_SUBBUF:
1250 {
1251 struct lttng_metadata_stream *stream = filp->private_data;
1252 struct lib_ring_buffer *buf = stream->priv;
1253 struct channel *chan = buf->backend.chan;
1254
1255 ret = lttng_metadata_output_channel(stream, chan, NULL);
1256 if (ret > 0) {
1257 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1258 ret = 0;
1259 } else if (ret < 0)
1260 goto err;
1261 break;
1262 }
1263 case RING_BUFFER_GET_SUBBUF:
1264 {
1265 /*
1266 * Random access is not allowed for metadata channel.
1267 */
1268 return -ENOSYS;
1269 }
1270 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
1271 case RING_BUFFER_FLUSH:
1272 {
1273 struct lttng_metadata_stream *stream = filp->private_data;
1274 struct lib_ring_buffer *buf = stream->priv;
1275 struct channel *chan = buf->backend.chan;
1276
1277 /*
1278 * Before doing the actual ring buffer flush, write up to one
1279 * packet of metadata in the ring buffer.
1280 */
1281 ret = lttng_metadata_output_channel(stream, chan, NULL);
1282 if (ret < 0)
1283 goto err;
1284 break;
1285 }
1286 case RING_BUFFER_GET_METADATA_VERSION:
1287 {
1288 struct lttng_metadata_stream *stream = filp->private_data;
1289
1290 return put_u64(stream->version, arg);
1291 }
1292 case RING_BUFFER_METADATA_CACHE_DUMP:
1293 {
1294 struct lttng_metadata_stream *stream = filp->private_data;
1295
1296 return lttng_metadata_cache_dump(stream);
1297 }
1298 case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1299 {
1300 struct lttng_metadata_stream *stream = filp->private_data;
1301 struct lib_ring_buffer *buf = stream->priv;
1302 struct channel *chan = buf->backend.chan;
1303
1304 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1305 if (ret > 0) {
1306 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1307 ret = 0;
1308 } else if (ret < 0) {
1309 goto err;
1310 }
1311 break;
1312 }
1313 default:
1314 break;
1315 }
1316 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1317
1318 /* Performing lib ring buffer ioctl after our own. */
1319 ret = lib_ring_buffer_compat_ioctl(filp, rb_cmd, arg, buf);
1320 if (ret < 0)
1321 goto err;
1322
1323 switch (cmd) {
1324 case RING_BUFFER_PUT_NEXT_SUBBUF:
1325 {
1326 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1327 cmd, arg);
1328 break;
1329 }
1330 case RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1331 {
1332 return put_u32(coherent, arg);
1333 }
1334 default:
1335 break;
1336 }
1337 err:
1338 return ret;
1339 }
1340 #endif
1341
1342 /*
1343 * This is not used by anonymous file descriptors. This code is left
1344 * there if we ever want to implement an inode with open() operation.
1345 */
1346 static
1347 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
1348 {
1349 struct lttng_metadata_stream *stream = inode->i_private;
1350 struct lib_ring_buffer *buf = stream->priv;
1351
1352 file->private_data = buf;
1353 /*
1354 * Since life-time of metadata cache differs from that of
1355 * session, we need to keep our own reference on the transport.
1356 */
1357 if (!try_module_get(stream->transport->owner)) {
1358 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1359 return -EBUSY;
1360 }
1361 return lib_ring_buffer_open(inode, file, buf);
1362 }
1363
1364 static
1365 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
1366 {
1367 struct lttng_metadata_stream *stream = file->private_data;
1368 struct lib_ring_buffer *buf = stream->priv;
1369
1370 mutex_lock(&stream->metadata_cache->lock);
1371 list_del(&stream->list);
1372 mutex_unlock(&stream->metadata_cache->lock);
1373 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
1374 module_put(stream->transport->owner);
1375 kfree(stream);
1376 return lib_ring_buffer_release(inode, file, buf);
1377 }
1378
1379 static
1380 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
1381 struct pipe_inode_info *pipe, size_t len,
1382 unsigned int flags)
1383 {
1384 struct lttng_metadata_stream *stream = in->private_data;
1385 struct lib_ring_buffer *buf = stream->priv;
1386
1387 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
1388 flags, buf);
1389 }
1390
1391 static
1392 int lttng_metadata_ring_buffer_mmap(struct file *filp,
1393 struct vm_area_struct *vma)
1394 {
1395 struct lttng_metadata_stream *stream = filp->private_data;
1396 struct lib_ring_buffer *buf = stream->priv;
1397
1398 return lib_ring_buffer_mmap(filp, vma, buf);
1399 }
1400
1401 static
1402 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
1403 .owner = THIS_MODULE,
1404 .open = lttng_metadata_ring_buffer_open,
1405 .release = lttng_metadata_ring_buffer_release,
1406 .poll = lttng_metadata_ring_buffer_poll,
1407 .splice_read = lttng_metadata_ring_buffer_splice_read,
1408 .mmap = lttng_metadata_ring_buffer_mmap,
1409 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
1410 .llseek = vfs_lib_ring_buffer_no_llseek,
1411 #ifdef CONFIG_COMPAT
1412 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
1413 #endif
1414 };
1415
1416 static
1417 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1418 const struct file_operations *fops, const char *name)
1419 {
1420 int stream_fd, ret;
1421 struct file *stream_file;
1422
1423 stream_fd = lttng_get_unused_fd();
1424 if (stream_fd < 0) {
1425 ret = stream_fd;
1426 goto fd_error;
1427 }
1428 stream_file = anon_inode_getfile(name, fops, stream_priv, O_RDWR);
1429 if (IS_ERR(stream_file)) {
1430 ret = PTR_ERR(stream_file);
1431 goto file_error;
1432 }
1433 /*
1434 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1435 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1436 * file descriptor, so we set FMODE_PREAD here.
1437 */
1438 stream_file->f_mode |= FMODE_PREAD;
1439 fd_install(stream_fd, stream_file);
1440 /*
1441 * The stream holds a reference to the channel within the generic ring
1442 * buffer library, so no need to hold a refcount on the channel and
1443 * session files here.
1444 */
1445 return stream_fd;
1446
1447 file_error:
1448 put_unused_fd(stream_fd);
1449 fd_error:
1450 return ret;
1451 }
1452
1453 static
1454 int lttng_abi_open_stream(struct file *channel_file)
1455 {
1456 struct lttng_channel *channel = channel_file->private_data;
1457 struct lib_ring_buffer *buf;
1458 int ret;
1459 void *stream_priv;
1460
1461 buf = channel->ops->buffer_read_open(channel->chan);
1462 if (!buf)
1463 return -ENOENT;
1464
1465 stream_priv = buf;
1466 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1467 &lttng_stream_ring_buffer_file_operations,
1468 "[lttng_stream]");
1469 if (ret < 0)
1470 goto fd_error;
1471
1472 return ret;
1473
1474 fd_error:
1475 channel->ops->buffer_read_close(buf);
1476 return ret;
1477 }
1478
1479 static
1480 int lttng_abi_open_metadata_stream(struct file *channel_file)
1481 {
1482 struct lttng_channel *channel = channel_file->private_data;
1483 struct lttng_session *session = channel->session;
1484 struct lib_ring_buffer *buf;
1485 int ret;
1486 struct lttng_metadata_stream *metadata_stream;
1487 void *stream_priv;
1488
1489 buf = channel->ops->buffer_read_open(channel->chan);
1490 if (!buf)
1491 return -ENOENT;
1492
1493 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1494 GFP_KERNEL);
1495 if (!metadata_stream) {
1496 ret = -ENOMEM;
1497 goto nomem;
1498 }
1499 metadata_stream->metadata_cache = session->metadata_cache;
1500 init_waitqueue_head(&metadata_stream->read_wait);
1501 metadata_stream->priv = buf;
1502 stream_priv = metadata_stream;
1503 metadata_stream->transport = channel->transport;
1504 /* Initial state is an empty metadata, considered as incoherent. */
1505 metadata_stream->coherent = false;
1506
1507 /*
1508 * Since life-time of metadata cache differs from that of
1509 * session, we need to keep our own reference on the transport.
1510 */
1511 if (!try_module_get(metadata_stream->transport->owner)) {
1512 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1513 ret = -EINVAL;
1514 goto notransport;
1515 }
1516
1517 if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1518 ret = -EOVERFLOW;
1519 goto kref_error;
1520 }
1521
1522 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1523 &lttng_metadata_ring_buffer_file_operations,
1524 "[lttng_metadata_stream]");
1525 if (ret < 0)
1526 goto fd_error;
1527
1528 mutex_lock(&session->metadata_cache->lock);
1529 list_add(&metadata_stream->list,
1530 &session->metadata_cache->metadata_stream);
1531 mutex_unlock(&session->metadata_cache->lock);
1532 return ret;
1533
1534 fd_error:
1535 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1536 kref_error:
1537 module_put(metadata_stream->transport->owner);
1538 notransport:
1539 kfree(metadata_stream);
1540 nomem:
1541 channel->ops->buffer_read_close(buf);
1542 return ret;
1543 }
1544
1545 static
1546 int lttng_abi_open_event_notifier_group_stream(struct file *notif_file)
1547 {
1548 struct lttng_event_notifier_group *event_notifier_group = notif_file->private_data;
1549 struct channel *chan = event_notifier_group->chan;
1550 struct lib_ring_buffer *buf;
1551 int ret;
1552 void *stream_priv;
1553
1554 buf = event_notifier_group->ops->buffer_read_open(chan);
1555 if (!buf)
1556 return -ENOENT;
1557
1558 /* The event_notifier notification fd holds a reference on the event_notifier group */
1559 if (!atomic_long_add_unless(&notif_file->f_count, 1, LONG_MAX)) {
1560 ret = -EOVERFLOW;
1561 goto refcount_error;
1562 }
1563 event_notifier_group->buf = buf;
1564 stream_priv = event_notifier_group;
1565 ret = lttng_abi_create_stream_fd(notif_file, stream_priv,
1566 &lttng_event_notifier_group_notif_fops,
1567 "[lttng_event_notifier_stream]");
1568 if (ret < 0)
1569 goto fd_error;
1570
1571 return ret;
1572
1573 fd_error:
1574 atomic_long_dec(&notif_file->f_count);
1575 refcount_error:
1576 event_notifier_group->ops->buffer_read_close(buf);
1577 return ret;
1578 }
1579
1580 static
1581 int lttng_abi_validate_event_param(struct lttng_kernel_event *event_param)
1582 {
1583 /* Limit ABI to implemented features. */
1584 switch (event_param->instrumentation) {
1585 case LTTNG_KERNEL_SYSCALL:
1586 switch (event_param->u.syscall.entryexit) {
1587 case LTTNG_KERNEL_SYSCALL_ENTRYEXIT:
1588 break;
1589 default:
1590 return -EINVAL;
1591 }
1592 switch (event_param->u.syscall.abi) {
1593 case LTTNG_KERNEL_SYSCALL_ABI_ALL:
1594 break;
1595 default:
1596 return -EINVAL;
1597 }
1598 switch (event_param->u.syscall.match) {
1599 case LTTNG_SYSCALL_MATCH_NAME:
1600 break;
1601 default:
1602 return -EINVAL;
1603 }
1604 break;
1605
1606 case LTTNG_KERNEL_TRACEPOINT: /* Fallthrough */
1607 case LTTNG_KERNEL_KPROBE: /* Fallthrough */
1608 case LTTNG_KERNEL_KRETPROBE: /* Fallthrough */
1609 case LTTNG_KERNEL_NOOP: /* Fallthrough */
1610 case LTTNG_KERNEL_UPROBE:
1611 break;
1612
1613 case LTTNG_KERNEL_FUNCTION: /* Fallthrough */
1614 default:
1615 return -EINVAL;
1616 }
1617 return 0;
1618 }
1619
1620 static
1621 int lttng_abi_create_event(struct file *channel_file,
1622 struct lttng_kernel_event *event_param)
1623 {
1624 struct lttng_channel *channel = channel_file->private_data;
1625 int event_fd, ret;
1626 struct file *event_file;
1627 void *priv;
1628
1629 event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1630 switch (event_param->instrumentation) {
1631 case LTTNG_KERNEL_KRETPROBE:
1632 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1633 break;
1634 case LTTNG_KERNEL_KPROBE:
1635 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1636 break;
1637 case LTTNG_KERNEL_FUNCTION:
1638 WARN_ON_ONCE(1);
1639 /* Not implemented. */
1640 break;
1641 default:
1642 break;
1643 }
1644 event_fd = lttng_get_unused_fd();
1645 if (event_fd < 0) {
1646 ret = event_fd;
1647 goto fd_error;
1648 }
1649 event_file = anon_inode_getfile("[lttng_event]",
1650 &lttng_event_fops,
1651 NULL, O_RDWR);
1652 if (IS_ERR(event_file)) {
1653 ret = PTR_ERR(event_file);
1654 goto file_error;
1655 }
1656 /* The event holds a reference on the channel */
1657 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1658 ret = -EOVERFLOW;
1659 goto refcount_error;
1660 }
1661 ret = lttng_abi_validate_event_param(event_param);
1662 if (ret)
1663 goto event_error;
1664 if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1665 || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1666 struct lttng_event_enabler *event_enabler;
1667
1668 if (strutils_is_star_glob_pattern(event_param->name)) {
1669 /*
1670 * If the event name is a star globbing pattern,
1671 * we create the special star globbing enabler.
1672 */
1673 event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_STAR_GLOB,
1674 event_param, channel);
1675 } else {
1676 event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1677 event_param, channel);
1678 }
1679 priv = event_enabler;
1680 } else {
1681 struct lttng_event *event;
1682
1683 /*
1684 * We tolerate no failure path after event creation. It
1685 * will stay invariant for the rest of the session.
1686 */
1687 event = lttng_event_create(channel, event_param,
1688 NULL, NULL,
1689 event_param->instrumentation);
1690 WARN_ON_ONCE(!event);
1691 if (IS_ERR(event)) {
1692 ret = PTR_ERR(event);
1693 goto event_error;
1694 }
1695 priv = event;
1696 }
1697 event_file->private_data = priv;
1698 fd_install(event_fd, event_file);
1699 return event_fd;
1700
1701 event_error:
1702 atomic_long_dec(&channel_file->f_count);
1703 refcount_error:
1704 fput(event_file);
1705 file_error:
1706 put_unused_fd(event_fd);
1707 fd_error:
1708 return ret;
1709 }
1710
1711 static
1712 long lttng_event_notifier_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1713 {
1714 struct lttng_event_notifier *event_notifier;
1715 struct lttng_event_notifier_enabler *event_notifier_enabler;
1716 enum lttng_event_type *evtype = file->private_data;
1717
1718 switch (cmd) {
1719 case LTTNG_KERNEL_ENABLE:
1720 switch (*evtype) {
1721 case LTTNG_TYPE_EVENT:
1722 event_notifier = file->private_data;
1723 return lttng_event_notifier_enable(event_notifier);
1724 case LTTNG_TYPE_ENABLER:
1725 event_notifier_enabler = file->private_data;
1726 return lttng_event_notifier_enabler_enable(event_notifier_enabler);
1727 default:
1728 WARN_ON_ONCE(1);
1729 return -ENOSYS;
1730 }
1731 case LTTNG_KERNEL_DISABLE:
1732 switch (*evtype) {
1733 case LTTNG_TYPE_EVENT:
1734 event_notifier = file->private_data;
1735 return lttng_event_notifier_disable(event_notifier);
1736 case LTTNG_TYPE_ENABLER:
1737 event_notifier_enabler = file->private_data;
1738 return lttng_event_notifier_enabler_disable(event_notifier_enabler);
1739 default:
1740 WARN_ON_ONCE(1);
1741 return -ENOSYS;
1742 }
1743 case LTTNG_KERNEL_FILTER:
1744 switch (*evtype) {
1745 case LTTNG_TYPE_EVENT:
1746 return -EINVAL;
1747 case LTTNG_TYPE_ENABLER:
1748 event_notifier_enabler = file->private_data;
1749 return lttng_event_notifier_enabler_attach_bytecode(event_notifier_enabler,
1750 (struct lttng_kernel_filter_bytecode __user *) arg);
1751 default:
1752 WARN_ON_ONCE(1);
1753 return -ENOSYS;
1754 }
1755 default:
1756 return -ENOIOCTLCMD;
1757 }
1758 }
1759
1760 static
1761 int lttng_event_notifier_release(struct inode *inode, struct file *file)
1762 {
1763 struct lttng_event_notifier *event_notifier;
1764 struct lttng_event_notifier_enabler *event_notifier_enabler;
1765 enum lttng_event_type *evtype = file->private_data;
1766
1767 if (!evtype)
1768 return 0;
1769
1770 switch (*evtype) {
1771 case LTTNG_TYPE_EVENT:
1772 event_notifier = file->private_data;
1773 if (event_notifier)
1774 fput(event_notifier->group->file);
1775 break;
1776 case LTTNG_TYPE_ENABLER:
1777 event_notifier_enabler = file->private_data;
1778 if (event_notifier_enabler)
1779 fput(event_notifier_enabler->group->file);
1780 break;
1781 default:
1782 WARN_ON_ONCE(1);
1783 break;
1784 }
1785
1786 return 0;
1787 }
1788
1789 static const struct file_operations lttng_event_notifier_fops = {
1790 .owner = THIS_MODULE,
1791 .release = lttng_event_notifier_release,
1792 .unlocked_ioctl = lttng_event_notifier_ioctl,
1793 #ifdef CONFIG_COMPAT
1794 .compat_ioctl = lttng_event_notifier_ioctl,
1795 #endif
1796 };
1797
1798 static
1799 int lttng_abi_create_event_notifier(struct file *event_notifier_group_file,
1800 struct lttng_kernel_event_notifier *event_notifier_param)
1801 {
1802 struct lttng_event_notifier_group *event_notifier_group =
1803 event_notifier_group_file->private_data;
1804 int event_notifier_fd, ret;
1805 struct file *event_notifier_file;
1806 void *priv;
1807
1808 switch (event_notifier_param->event.instrumentation) {
1809 case LTTNG_KERNEL_TRACEPOINT:
1810 break;
1811 case LTTNG_KERNEL_KPROBE:
1812 event_notifier_param->event.u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1813 break;
1814 case LTTNG_KERNEL_KRETPROBE:
1815 /* Placing a trigger on kretprobe is not supported. */
1816 case LTTNG_KERNEL_UPROBE:
1817 case LTTNG_KERNEL_FUNCTION:
1818 case LTTNG_KERNEL_NOOP:
1819 case LTTNG_KERNEL_SYSCALL:
1820 default:
1821 ret = -EINVAL;
1822 goto inval_instr;
1823 }
1824
1825 event_notifier_param->event.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1826
1827 event_notifier_fd = lttng_get_unused_fd();
1828 if (event_notifier_fd < 0) {
1829 ret = event_notifier_fd;
1830 goto fd_error;
1831 }
1832
1833 event_notifier_file = anon_inode_getfile("[lttng_event_notifier]",
1834 &lttng_event_notifier_fops,
1835 NULL, O_RDWR);
1836 if (IS_ERR(event_notifier_file)) {
1837 ret = PTR_ERR(event_notifier_file);
1838 goto file_error;
1839 }
1840
1841 /* The event notifier holds a reference on the event notifier group. */
1842 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
1843 ret = -EOVERFLOW;
1844 goto refcount_error;
1845 }
1846
1847 if (event_notifier_param->event.instrumentation == LTTNG_KERNEL_TRACEPOINT
1848 || event_notifier_param->event.instrumentation == LTTNG_KERNEL_SYSCALL) {
1849 struct lttng_event_notifier_enabler *enabler;
1850
1851 if (strutils_is_star_glob_pattern(event_notifier_param->event.name)) {
1852 /*
1853 * If the event name is a star globbing pattern,
1854 * we create the special star globbing enabler.
1855 */
1856 enabler = lttng_event_notifier_enabler_create(
1857 event_notifier_group,
1858 LTTNG_ENABLER_FORMAT_STAR_GLOB,
1859 event_notifier_param);
1860 } else {
1861 enabler = lttng_event_notifier_enabler_create(
1862 event_notifier_group,
1863 LTTNG_ENABLER_FORMAT_NAME,
1864 event_notifier_param);
1865 }
1866 priv = enabler;
1867 } else {
1868 struct lttng_event_notifier *event_notifier;
1869
1870 /*
1871 * We tolerate no failure path after event notifier creation.
1872 * It will stay invariant for the rest of the session.
1873 */
1874 event_notifier = lttng_event_notifier_create(NULL,
1875 event_notifier_param->event.token, event_notifier_group,
1876 event_notifier_param, NULL,
1877 event_notifier_param->event.instrumentation);
1878 WARN_ON_ONCE(!event_notifier);
1879 if (IS_ERR(event_notifier)) {
1880 ret = PTR_ERR(event_notifier);
1881 goto event_notifier_error;
1882 }
1883 priv = event_notifier;
1884 }
1885 event_notifier_file->private_data = priv;
1886 fd_install(event_notifier_fd, event_notifier_file);
1887 return event_notifier_fd;
1888
1889 event_notifier_error:
1890 atomic_long_dec(&event_notifier_group_file->f_count);
1891 refcount_error:
1892 fput(event_notifier_file);
1893 file_error:
1894 put_unused_fd(event_notifier_fd);
1895 fd_error:
1896 inval_instr:
1897 return ret;
1898 }
1899
1900 static
1901 long lttng_event_notifier_group_ioctl(struct file *file, unsigned int cmd,
1902 unsigned long arg)
1903 {
1904 switch (cmd) {
1905 case LTTNG_KERNEL_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD:
1906 {
1907 return lttng_abi_open_event_notifier_group_stream(file);
1908 }
1909 case LTTNG_KERNEL_EVENT_NOTIFIER_CREATE:
1910 {
1911 struct lttng_kernel_event_notifier uevent_notifier_param;
1912
1913 if (copy_from_user(&uevent_notifier_param,
1914 (struct lttng_kernel_event_notifier __user *) arg,
1915 sizeof(uevent_notifier_param)))
1916 return -EFAULT;
1917 return lttng_abi_create_event_notifier(file, &uevent_notifier_param);
1918 }
1919 default:
1920 return -ENOIOCTLCMD;
1921 }
1922 return 0;
1923 }
1924
1925 static
1926 int lttng_event_notifier_group_release(struct inode *inode, struct file *file)
1927 {
1928 struct lttng_event_notifier_group *event_notifier_group =
1929 file->private_data;
1930
1931 if (event_notifier_group)
1932 lttng_event_notifier_group_destroy(event_notifier_group);
1933 return 0;
1934 }
1935
1936 static const struct file_operations lttng_event_notifier_group_fops = {
1937 .owner = THIS_MODULE,
1938 .release = lttng_event_notifier_group_release,
1939 .unlocked_ioctl = lttng_event_notifier_group_ioctl,
1940 #ifdef CONFIG_COMPAT
1941 .compat_ioctl = lttng_event_notifier_group_ioctl,
1942 #endif
1943 };
1944
1945 /**
1946 * lttng_channel_ioctl - lttng syscall through ioctl
1947 *
1948 * @file: the file
1949 * @cmd: the command
1950 * @arg: command arg
1951 *
1952 * This ioctl implements lttng commands:
1953 * LTTNG_KERNEL_STREAM
1954 * Returns an event stream file descriptor or failure.
1955 * (typically, one event stream records events from one CPU)
1956 * LTTNG_KERNEL_EVENT
1957 * Returns an event file descriptor or failure.
1958 * LTTNG_KERNEL_CONTEXT
1959 * Prepend a context field to each event in the channel
1960 * LTTNG_KERNEL_ENABLE
1961 * Enable recording for events in this channel (weak enable)
1962 * LTTNG_KERNEL_DISABLE
1963 * Disable recording for events in this channel (strong disable)
1964 *
1965 * Channel and event file descriptors also hold a reference on the session.
1966 */
1967 static
1968 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1969 {
1970 struct lttng_channel *channel = file->private_data;
1971
1972 switch (cmd) {
1973 case LTTNG_KERNEL_OLD_STREAM:
1974 case LTTNG_KERNEL_STREAM:
1975 return lttng_abi_open_stream(file);
1976 case LTTNG_KERNEL_OLD_EVENT:
1977 {
1978 struct lttng_kernel_event *uevent_param;
1979 struct lttng_kernel_old_event *old_uevent_param;
1980 int ret;
1981
1982 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1983 GFP_KERNEL);
1984 if (!uevent_param) {
1985 ret = -ENOMEM;
1986 goto old_event_end;
1987 }
1988 old_uevent_param = kmalloc(
1989 sizeof(struct lttng_kernel_old_event),
1990 GFP_KERNEL);
1991 if (!old_uevent_param) {
1992 ret = -ENOMEM;
1993 goto old_event_error_free_param;
1994 }
1995 if (copy_from_user(old_uevent_param,
1996 (struct lttng_kernel_old_event __user *) arg,
1997 sizeof(struct lttng_kernel_old_event))) {
1998 ret = -EFAULT;
1999 goto old_event_error_free_old_param;
2000 }
2001
2002 memcpy(uevent_param->name, old_uevent_param->name,
2003 sizeof(uevent_param->name));
2004 uevent_param->instrumentation =
2005 old_uevent_param->instrumentation;
2006
2007 switch (old_uevent_param->instrumentation) {
2008 case LTTNG_KERNEL_KPROBE:
2009 uevent_param->u.kprobe.addr =
2010 old_uevent_param->u.kprobe.addr;
2011 uevent_param->u.kprobe.offset =
2012 old_uevent_param->u.kprobe.offset;
2013 memcpy(uevent_param->u.kprobe.symbol_name,
2014 old_uevent_param->u.kprobe.symbol_name,
2015 sizeof(uevent_param->u.kprobe.symbol_name));
2016 break;
2017 case LTTNG_KERNEL_KRETPROBE:
2018 uevent_param->u.kretprobe.addr =
2019 old_uevent_param->u.kretprobe.addr;
2020 uevent_param->u.kretprobe.offset =
2021 old_uevent_param->u.kretprobe.offset;
2022 memcpy(uevent_param->u.kretprobe.symbol_name,
2023 old_uevent_param->u.kretprobe.symbol_name,
2024 sizeof(uevent_param->u.kretprobe.symbol_name));
2025 break;
2026 case LTTNG_KERNEL_FUNCTION:
2027 WARN_ON_ONCE(1);
2028 /* Not implemented. */
2029 break;
2030 default:
2031 break;
2032 }
2033 ret = lttng_abi_create_event(file, uevent_param);
2034
2035 old_event_error_free_old_param:
2036 kfree(old_uevent_param);
2037 old_event_error_free_param:
2038 kfree(uevent_param);
2039 old_event_end:
2040 return ret;
2041 }
2042 case LTTNG_KERNEL_EVENT:
2043 {
2044 struct lttng_kernel_event uevent_param;
2045
2046 if (copy_from_user(&uevent_param,
2047 (struct lttng_kernel_event __user *) arg,
2048 sizeof(uevent_param)))
2049 return -EFAULT;
2050 return lttng_abi_create_event(file, &uevent_param);
2051 }
2052 case LTTNG_KERNEL_OLD_CONTEXT:
2053 {
2054 struct lttng_kernel_context *ucontext_param;
2055 struct lttng_kernel_old_context *old_ucontext_param;
2056 int ret;
2057
2058 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
2059 GFP_KERNEL);
2060 if (!ucontext_param) {
2061 ret = -ENOMEM;
2062 goto old_ctx_end;
2063 }
2064 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
2065 GFP_KERNEL);
2066 if (!old_ucontext_param) {
2067 ret = -ENOMEM;
2068 goto old_ctx_error_free_param;
2069 }
2070
2071 if (copy_from_user(old_ucontext_param,
2072 (struct lttng_kernel_old_context __user *) arg,
2073 sizeof(struct lttng_kernel_old_context))) {
2074 ret = -EFAULT;
2075 goto old_ctx_error_free_old_param;
2076 }
2077 ucontext_param->ctx = old_ucontext_param->ctx;
2078 memcpy(ucontext_param->padding, old_ucontext_param->padding,
2079 sizeof(ucontext_param->padding));
2080 /* only type that uses the union */
2081 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
2082 ucontext_param->u.perf_counter.type =
2083 old_ucontext_param->u.perf_counter.type;
2084 ucontext_param->u.perf_counter.config =
2085 old_ucontext_param->u.perf_counter.config;
2086 memcpy(ucontext_param->u.perf_counter.name,
2087 old_ucontext_param->u.perf_counter.name,
2088 sizeof(ucontext_param->u.perf_counter.name));
2089 }
2090
2091 ret = lttng_abi_add_context(file,
2092 ucontext_param,
2093 &channel->ctx, channel->session);
2094
2095 old_ctx_error_free_old_param:
2096 kfree(old_ucontext_param);
2097 old_ctx_error_free_param:
2098 kfree(ucontext_param);
2099 old_ctx_end:
2100 return ret;
2101 }
2102 case LTTNG_KERNEL_CONTEXT:
2103 {
2104 struct lttng_kernel_context ucontext_param;
2105
2106 if (copy_from_user(&ucontext_param,
2107 (struct lttng_kernel_context __user *) arg,
2108 sizeof(ucontext_param)))
2109 return -EFAULT;
2110 return lttng_abi_add_context(file,
2111 &ucontext_param,
2112 &channel->ctx, channel->session);
2113 }
2114 case LTTNG_KERNEL_OLD_ENABLE:
2115 case LTTNG_KERNEL_ENABLE:
2116 return lttng_channel_enable(channel);
2117 case LTTNG_KERNEL_OLD_DISABLE:
2118 case LTTNG_KERNEL_DISABLE:
2119 return lttng_channel_disable(channel);
2120 case LTTNG_KERNEL_SYSCALL_MASK:
2121 return lttng_channel_syscall_mask(channel,
2122 (struct lttng_kernel_syscall_mask __user *) arg);
2123 default:
2124 return -ENOIOCTLCMD;
2125 }
2126 }
2127
2128 /**
2129 * lttng_metadata_ioctl - lttng syscall through ioctl
2130 *
2131 * @file: the file
2132 * @cmd: the command
2133 * @arg: command arg
2134 *
2135 * This ioctl implements lttng commands:
2136 * LTTNG_KERNEL_STREAM
2137 * Returns an event stream file descriptor or failure.
2138 *
2139 * Channel and event file descriptors also hold a reference on the session.
2140 */
2141 static
2142 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2143 {
2144 switch (cmd) {
2145 case LTTNG_KERNEL_OLD_STREAM:
2146 case LTTNG_KERNEL_STREAM:
2147 return lttng_abi_open_metadata_stream(file);
2148 default:
2149 return -ENOIOCTLCMD;
2150 }
2151 }
2152
2153 /**
2154 * lttng_channel_poll - lttng stream addition/removal monitoring
2155 *
2156 * @file: the file
2157 * @wait: poll table
2158 */
2159 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
2160 {
2161 struct lttng_channel *channel = file->private_data;
2162 unsigned int mask = 0;
2163
2164 if (file->f_mode & FMODE_READ) {
2165 poll_wait_set_exclusive(wait);
2166 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
2167 wait);
2168
2169 if (channel->ops->is_disabled(channel->chan))
2170 return POLLERR;
2171 if (channel->ops->is_finalized(channel->chan))
2172 return POLLHUP;
2173 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
2174 return POLLIN | POLLRDNORM;
2175 return 0;
2176 }
2177 return mask;
2178
2179 }
2180
2181 static
2182 int lttng_channel_release(struct inode *inode, struct file *file)
2183 {
2184 struct lttng_channel *channel = file->private_data;
2185
2186 if (channel)
2187 fput(channel->session->file);
2188 return 0;
2189 }
2190
2191 static
2192 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
2193 {
2194 struct lttng_channel *channel = file->private_data;
2195
2196 if (channel) {
2197 fput(channel->session->file);
2198 lttng_metadata_channel_destroy(channel);
2199 }
2200
2201 return 0;
2202 }
2203
2204 static const struct file_operations lttng_channel_fops = {
2205 .owner = THIS_MODULE,
2206 .release = lttng_channel_release,
2207 .poll = lttng_channel_poll,
2208 .unlocked_ioctl = lttng_channel_ioctl,
2209 #ifdef CONFIG_COMPAT
2210 .compat_ioctl = lttng_channel_ioctl,
2211 #endif
2212 };
2213
2214 static const struct file_operations lttng_metadata_fops = {
2215 .owner = THIS_MODULE,
2216 .release = lttng_metadata_channel_release,
2217 .unlocked_ioctl = lttng_metadata_ioctl,
2218 #ifdef CONFIG_COMPAT
2219 .compat_ioctl = lttng_metadata_ioctl,
2220 #endif
2221 };
2222
2223 /**
2224 * lttng_event_ioctl - lttng syscall through ioctl
2225 *
2226 * @file: the file
2227 * @cmd: the command
2228 * @arg: command arg
2229 *
2230 * This ioctl implements lttng commands:
2231 * LTTNG_KERNEL_CONTEXT
2232 * Prepend a context field to each record of this event
2233 * LTTNG_KERNEL_ENABLE
2234 * Enable recording for this event (weak enable)
2235 * LTTNG_KERNEL_DISABLE
2236 * Disable recording for this event (strong disable)
2237 */
2238 static
2239 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2240 {
2241 struct lttng_event *event;
2242 struct lttng_event_enabler *event_enabler;
2243 enum lttng_event_type *evtype = file->private_data;
2244
2245 switch (cmd) {
2246 case LTTNG_KERNEL_OLD_CONTEXT:
2247 {
2248 /* Not implemented */
2249 return -ENOSYS;
2250 }
2251 case LTTNG_KERNEL_CONTEXT:
2252 {
2253 /* Not implemented */
2254 return -ENOSYS;
2255 }
2256 case LTTNG_KERNEL_OLD_ENABLE:
2257 case LTTNG_KERNEL_ENABLE:
2258 switch (*evtype) {
2259 case LTTNG_TYPE_EVENT:
2260 event = file->private_data;
2261 return lttng_event_enable(event);
2262 case LTTNG_TYPE_ENABLER:
2263 event_enabler = file->private_data;
2264 return lttng_event_enabler_enable(event_enabler);
2265 default:
2266 WARN_ON_ONCE(1);
2267 return -ENOSYS;
2268 }
2269 case LTTNG_KERNEL_OLD_DISABLE:
2270 case LTTNG_KERNEL_DISABLE:
2271 switch (*evtype) {
2272 case LTTNG_TYPE_EVENT:
2273 event = file->private_data;
2274 return lttng_event_disable(event);
2275 case LTTNG_TYPE_ENABLER:
2276 event_enabler = file->private_data;
2277 return lttng_event_enabler_disable(event_enabler);
2278 default:
2279 WARN_ON_ONCE(1);
2280 return -ENOSYS;
2281 }
2282 case LTTNG_KERNEL_FILTER:
2283 switch (*evtype) {
2284 case LTTNG_TYPE_EVENT:
2285 return -EINVAL;
2286 case LTTNG_TYPE_ENABLER:
2287 {
2288 event_enabler = file->private_data;
2289 return lttng_event_enabler_attach_bytecode(event_enabler,
2290 (struct lttng_kernel_filter_bytecode __user *) arg);
2291 }
2292 default:
2293 WARN_ON_ONCE(1);
2294 return -ENOSYS;
2295 }
2296 case LTTNG_KERNEL_ADD_CALLSITE:
2297 switch (*evtype) {
2298 case LTTNG_TYPE_EVENT:
2299 event = file->private_data;
2300 return lttng_event_add_callsite(event,
2301 (struct lttng_kernel_event_callsite __user *) arg);
2302 case LTTNG_TYPE_ENABLER:
2303 return -EINVAL;
2304 default:
2305 WARN_ON_ONCE(1);
2306 return -ENOSYS;
2307 }
2308 default:
2309 return -ENOIOCTLCMD;
2310 }
2311 }
2312
2313 static
2314 int lttng_event_release(struct inode *inode, struct file *file)
2315 {
2316 struct lttng_event *event;
2317 struct lttng_event_enabler *event_enabler;
2318 enum lttng_event_type *evtype = file->private_data;
2319
2320 if (!evtype)
2321 return 0;
2322
2323 switch (*evtype) {
2324 case LTTNG_TYPE_EVENT:
2325 event = file->private_data;
2326 if (event)
2327 fput(event->chan->file);
2328 break;
2329 case LTTNG_TYPE_ENABLER:
2330 event_enabler = file->private_data;
2331 if (event_enabler)
2332 fput(event_enabler->chan->file);
2333 break;
2334 default:
2335 WARN_ON_ONCE(1);
2336 break;
2337 }
2338
2339 return 0;
2340 }
2341
2342 /* TODO: filter control ioctl */
2343 static const struct file_operations lttng_event_fops = {
2344 .owner = THIS_MODULE,
2345 .release = lttng_event_release,
2346 .unlocked_ioctl = lttng_event_ioctl,
2347 #ifdef CONFIG_COMPAT
2348 .compat_ioctl = lttng_event_ioctl,
2349 #endif
2350 };
2351
2352 static int put_u64(uint64_t val, unsigned long arg)
2353 {
2354 return put_user(val, (uint64_t __user *) arg);
2355 }
2356
2357 static int put_u32(uint32_t val, unsigned long arg)
2358 {
2359 return put_user(val, (uint32_t __user *) arg);
2360 }
2361
2362 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
2363 unsigned int cmd, unsigned long arg)
2364 {
2365 struct lib_ring_buffer *buf = filp->private_data;
2366 struct channel *chan = buf->backend.chan;
2367 const struct lib_ring_buffer_config *config = &chan->backend.config;
2368 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
2369 int ret;
2370
2371 if (atomic_read(&chan->record_disabled))
2372 return -EIO;
2373
2374 switch (cmd) {
2375 case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
2376 {
2377 uint64_t ts;
2378
2379 ret = ops->timestamp_begin(config, buf, &ts);
2380 if (ret < 0)
2381 goto error;
2382 return put_u64(ts, arg);
2383 }
2384 case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
2385 {
2386 uint64_t ts;
2387
2388 ret = ops->timestamp_end(config, buf, &ts);
2389 if (ret < 0)
2390 goto error;
2391 return put_u64(ts, arg);
2392 }
2393 case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
2394 {
2395 uint64_t ed;
2396
2397 ret = ops->events_discarded(config, buf, &ed);
2398 if (ret < 0)
2399 goto error;
2400 return put_u64(ed, arg);
2401 }
2402 case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
2403 {
2404 uint64_t cs;
2405
2406 ret = ops->content_size(config, buf, &cs);
2407 if (ret < 0)
2408 goto error;
2409 return put_u64(cs, arg);
2410 }
2411 case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
2412 {
2413 uint64_t ps;
2414
2415 ret = ops->packet_size(config, buf, &ps);
2416 if (ret < 0)
2417 goto error;
2418 return put_u64(ps, arg);
2419 }
2420 case LTTNG_RING_BUFFER_GET_STREAM_ID:
2421 {
2422 uint64_t si;
2423
2424 ret = ops->stream_id(config, buf, &si);
2425 if (ret < 0)
2426 goto error;
2427 return put_u64(si, arg);
2428 }
2429 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2430 {
2431 uint64_t ts;
2432
2433 ret = ops->current_timestamp(config, buf, &ts);
2434 if (ret < 0)
2435 goto error;
2436 return put_u64(ts, arg);
2437 }
2438 case LTTNG_RING_BUFFER_GET_SEQ_NUM:
2439 {
2440 uint64_t seq;
2441
2442 ret = ops->sequence_number(config, buf, &seq);
2443 if (ret < 0)
2444 goto error;
2445 return put_u64(seq, arg);
2446 }
2447 case LTTNG_RING_BUFFER_INSTANCE_ID:
2448 {
2449 uint64_t id;
2450
2451 ret = ops->instance_id(config, buf, &id);
2452 if (ret < 0)
2453 goto error;
2454 return put_u64(id, arg);
2455 }
2456 default:
2457 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
2458 cmd, arg);
2459 }
2460
2461 error:
2462 return -ENOSYS;
2463 }
2464
2465 #ifdef CONFIG_COMPAT
2466 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
2467 unsigned int cmd, unsigned long arg)
2468 {
2469 struct lib_ring_buffer *buf = filp->private_data;
2470 struct channel *chan = buf->backend.chan;
2471 const struct lib_ring_buffer_config *config = &chan->backend.config;
2472 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
2473 int ret;
2474
2475 if (atomic_read(&chan->record_disabled))
2476 return -EIO;
2477
2478 switch (cmd) {
2479 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
2480 {
2481 uint64_t ts;
2482
2483 ret = ops->timestamp_begin(config, buf, &ts);
2484 if (ret < 0)
2485 goto error;
2486 return put_u64(ts, arg);
2487 }
2488 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
2489 {
2490 uint64_t ts;
2491
2492 ret = ops->timestamp_end(config, buf, &ts);
2493 if (ret < 0)
2494 goto error;
2495 return put_u64(ts, arg);
2496 }
2497 case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
2498 {
2499 uint64_t ed;
2500
2501 ret = ops->events_discarded(config, buf, &ed);
2502 if (ret < 0)
2503 goto error;
2504 return put_u64(ed, arg);
2505 }
2506 case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
2507 {
2508 uint64_t cs;
2509
2510 ret = ops->content_size(config, buf, &cs);
2511 if (ret < 0)
2512 goto error;
2513 return put_u64(cs, arg);
2514 }
2515 case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
2516 {
2517 uint64_t ps;
2518
2519 ret = ops->packet_size(config, buf, &ps);
2520 if (ret < 0)
2521 goto error;
2522 return put_u64(ps, arg);
2523 }
2524 case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
2525 {
2526 uint64_t si;
2527
2528 ret = ops->stream_id(config, buf, &si);
2529 if (ret < 0)
2530 goto error;
2531 return put_u64(si, arg);
2532 }
2533 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2534 {
2535 uint64_t ts;
2536
2537 ret = ops->current_timestamp(config, buf, &ts);
2538 if (ret < 0)
2539 goto error;
2540 return put_u64(ts, arg);
2541 }
2542 case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
2543 {
2544 uint64_t seq;
2545
2546 ret = ops->sequence_number(config, buf, &seq);
2547 if (ret < 0)
2548 goto error;
2549 return put_u64(seq, arg);
2550 }
2551 case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
2552 {
2553 uint64_t id;
2554
2555 ret = ops->instance_id(config, buf, &id);
2556 if (ret < 0)
2557 goto error;
2558 return put_u64(id, arg);
2559 }
2560 default:
2561 return lib_ring_buffer_file_operations.compat_ioctl(filp,
2562 cmd, arg);
2563 }
2564
2565 error:
2566 return -ENOSYS;
2567 }
2568 #endif /* CONFIG_COMPAT */
2569
2570 static void lttng_stream_override_ring_buffer_fops(void)
2571 {
2572 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
2573 lttng_stream_ring_buffer_file_operations.open =
2574 lib_ring_buffer_file_operations.open;
2575 lttng_stream_ring_buffer_file_operations.release =
2576 lib_ring_buffer_file_operations.release;
2577 lttng_stream_ring_buffer_file_operations.poll =
2578 lib_ring_buffer_file_operations.poll;
2579 lttng_stream_ring_buffer_file_operations.splice_read =
2580 lib_ring_buffer_file_operations.splice_read;
2581 lttng_stream_ring_buffer_file_operations.mmap =
2582 lib_ring_buffer_file_operations.mmap;
2583 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
2584 lttng_stream_ring_buffer_ioctl;
2585 lttng_stream_ring_buffer_file_operations.llseek =
2586 lib_ring_buffer_file_operations.llseek;
2587 #ifdef CONFIG_COMPAT
2588 lttng_stream_ring_buffer_file_operations.compat_ioctl =
2589 lttng_stream_ring_buffer_compat_ioctl;
2590 #endif
2591 }
2592
2593 int __init lttng_abi_init(void)
2594 {
2595 int ret = 0;
2596
2597 wrapper_vmalloc_sync_mappings();
2598 lttng_clock_ref();
2599
2600 ret = lttng_tp_mempool_init();
2601 if (ret) {
2602 goto error;
2603 }
2604
2605 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
2606 &lttng_proc_ops, NULL);
2607
2608 if (!lttng_proc_dentry) {
2609 printk(KERN_ERR "LTTng: Error creating control file\n");
2610 ret = -ENOMEM;
2611 goto error;
2612 }
2613 lttng_stream_override_ring_buffer_fops();
2614 return 0;
2615
2616 error:
2617 lttng_tp_mempool_destroy();
2618 lttng_clock_unref();
2619 return ret;
2620 }
2621
2622 /* No __exit annotation because used by init error path too. */
2623 void lttng_abi_exit(void)
2624 {
2625 lttng_tp_mempool_destroy();
2626 lttng_clock_unref();
2627 if (lttng_proc_dentry)
2628 remove_proc_entry("lttng", NULL);
2629 }
LTTng 2.0/0.x modules
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