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[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/compiler_attributes.h>
38 #include <wrapper/poll.h>
39 #include <wrapper/file.h>
40 #include <wrapper/kref.h>
41 #include <wrapper/barrier.h>
42 #include <lttng/string-utils.h>
43 #include <lttng/abi.h>
44 #include <lttng/abi-old.h>
45 #include <lttng/events.h>
46 #include <lttng/events-internal.h>
47 #include <lttng/tracer.h>
48 #include <lttng/tp-mempool.h>
49 #include <ringbuffer/frontend_types.h>
50 #include <ringbuffer/iterator.h>
51
52 /*
53 * This is LTTng's own personal way to create a system call as an external
54 * module. We use ioctl() on /proc/lttng.
55 */
56
57 static struct proc_dir_entry *lttng_proc_dentry;
58
59 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
60 static const struct proc_ops lttng_proc_ops;
61 #else
62 static const struct file_operations lttng_proc_ops;
63 #endif
64
65 static const struct file_operations lttng_session_fops;
66 static const struct file_operations lttng_event_notifier_group_fops;
67 static const struct file_operations lttng_channel_fops;
68 static const struct file_operations lttng_metadata_fops;
69 static const struct file_operations lttng_event_recorder_event_fops;
70 static const struct file_operations lttng_event_recorder_enabler_fops;
71 static struct file_operations lttng_stream_ring_buffer_file_operations;
72
73 static int put_u64(uint64_t val, unsigned long arg);
74 static int put_u32(uint32_t val, unsigned long arg);
75
76 static int validate_zeroed_padding(char *p, size_t len)
77 {
78 size_t i;
79
80 for (i = 0; i < len; i++) {
81 if (p[i])
82 return -1;
83 }
84 return 0;
85 }
86
87 /*
88 * Teardown management: opened file descriptors keep a refcount on the module,
89 * so it can only exit when all file descriptors are closed.
90 */
91
92 static
93 int lttng_abi_create_session(void)
94 {
95 struct lttng_kernel_session *session;
96 struct file *session_file;
97 int session_fd, ret;
98
99 session = lttng_session_create();
100 if (!session)
101 return -ENOMEM;
102 session_fd = lttng_get_unused_fd();
103 if (session_fd < 0) {
104 ret = session_fd;
105 goto fd_error;
106 }
107 session_file = anon_inode_getfile("[lttng_session]",
108 &lttng_session_fops,
109 session, O_RDWR);
110 if (IS_ERR(session_file)) {
111 ret = PTR_ERR(session_file);
112 goto file_error;
113 }
114 session->priv->file = session_file;
115 fd_install(session_fd, session_file);
116 return session_fd;
117
118 file_error:
119 put_unused_fd(session_fd);
120 fd_error:
121 lttng_session_destroy(session);
122 return ret;
123 }
124
125 void event_notifier_send_notification_work_wakeup(struct irq_work *entry)
126 {
127 struct lttng_event_notifier_group *event_notifier_group =
128 container_of(entry, struct lttng_event_notifier_group,
129 wakeup_pending);
130 wake_up_interruptible(&event_notifier_group->read_wait);
131 }
132
133 static
134 int lttng_abi_create_event_notifier_group(void)
135 {
136 struct lttng_event_notifier_group *event_notifier_group;
137 struct file *event_notifier_group_file;
138 int event_notifier_group_fd, ret;
139
140 event_notifier_group = lttng_event_notifier_group_create();
141 if (!event_notifier_group)
142 return -ENOMEM;
143
144 event_notifier_group_fd = lttng_get_unused_fd();
145 if (event_notifier_group_fd < 0) {
146 ret = event_notifier_group_fd;
147 goto fd_error;
148 }
149 event_notifier_group_file = anon_inode_getfile("[lttng_event_notifier_group]",
150 &lttng_event_notifier_group_fops,
151 event_notifier_group, O_RDWR);
152 if (IS_ERR(event_notifier_group_file)) {
153 ret = PTR_ERR(event_notifier_group_file);
154 goto file_error;
155 }
156
157 event_notifier_group->file = event_notifier_group_file;
158 init_waitqueue_head(&event_notifier_group->read_wait);
159 init_irq_work(&event_notifier_group->wakeup_pending,
160 event_notifier_send_notification_work_wakeup);
161 fd_install(event_notifier_group_fd, event_notifier_group_file);
162 return event_notifier_group_fd;
163
164 file_error:
165 put_unused_fd(event_notifier_group_fd);
166 fd_error:
167 lttng_event_notifier_group_destroy(event_notifier_group);
168 return ret;
169 }
170
171 static
172 int lttng_abi_tracepoint_list(void)
173 {
174 struct file *tracepoint_list_file;
175 int file_fd, ret;
176
177 file_fd = lttng_get_unused_fd();
178 if (file_fd < 0) {
179 ret = file_fd;
180 goto fd_error;
181 }
182
183 tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
184 &lttng_tracepoint_list_fops,
185 NULL, O_RDWR);
186 if (IS_ERR(tracepoint_list_file)) {
187 ret = PTR_ERR(tracepoint_list_file);
188 goto file_error;
189 }
190 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
191 if (ret < 0)
192 goto open_error;
193 fd_install(file_fd, tracepoint_list_file);
194 return file_fd;
195
196 open_error:
197 fput(tracepoint_list_file);
198 file_error:
199 put_unused_fd(file_fd);
200 fd_error:
201 return ret;
202 }
203
204 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
205 static inline
206 int lttng_abi_syscall_list(void)
207 {
208 return -ENOSYS;
209 }
210 #else
211 static
212 int lttng_abi_syscall_list(void)
213 {
214 struct file *syscall_list_file;
215 int file_fd, ret;
216
217 file_fd = lttng_get_unused_fd();
218 if (file_fd < 0) {
219 ret = file_fd;
220 goto fd_error;
221 }
222
223 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
224 &lttng_syscall_list_fops,
225 NULL, O_RDWR);
226 if (IS_ERR(syscall_list_file)) {
227 ret = PTR_ERR(syscall_list_file);
228 goto file_error;
229 }
230 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
231 if (ret < 0)
232 goto open_error;
233 fd_install(file_fd, syscall_list_file);
234 return file_fd;
235
236 open_error:
237 fput(syscall_list_file);
238 file_error:
239 put_unused_fd(file_fd);
240 fd_error:
241 return ret;
242 }
243 #endif
244
245 static
246 void lttng_abi_tracer_version(struct lttng_kernel_abi_tracer_version *v)
247 {
248 v->major = LTTNG_MODULES_MAJOR_VERSION;
249 v->minor = LTTNG_MODULES_MINOR_VERSION;
250 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
251 }
252
253 static
254 void lttng_abi_tracer_abi_version(struct lttng_kernel_abi_tracer_abi_version *v)
255 {
256 v->major = LTTNG_KERNEL_ABI_MAJOR_VERSION;
257 v->minor = LTTNG_KERNEL_ABI_MINOR_VERSION;
258 }
259
260 static
261 long lttng_abi_add_context(struct file *file,
262 struct lttng_kernel_abi_context *context_param,
263 struct lttng_kernel_ctx **ctx, struct lttng_kernel_session *session)
264 {
265
266 if (session->priv->been_active)
267 return -EPERM;
268
269 switch (context_param->ctx) {
270 case LTTNG_KERNEL_ABI_CONTEXT_PID:
271 return lttng_add_pid_to_ctx(ctx);
272 case LTTNG_KERNEL_ABI_CONTEXT_PRIO:
273 return lttng_add_prio_to_ctx(ctx);
274 case LTTNG_KERNEL_ABI_CONTEXT_NICE:
275 return lttng_add_nice_to_ctx(ctx);
276 case LTTNG_KERNEL_ABI_CONTEXT_VPID:
277 return lttng_add_vpid_to_ctx(ctx);
278 case LTTNG_KERNEL_ABI_CONTEXT_TID:
279 return lttng_add_tid_to_ctx(ctx);
280 case LTTNG_KERNEL_ABI_CONTEXT_VTID:
281 return lttng_add_vtid_to_ctx(ctx);
282 case LTTNG_KERNEL_ABI_CONTEXT_PPID:
283 return lttng_add_ppid_to_ctx(ctx);
284 case LTTNG_KERNEL_ABI_CONTEXT_VPPID:
285 return lttng_add_vppid_to_ctx(ctx);
286 case LTTNG_KERNEL_ABI_CONTEXT_PERF_COUNTER:
287 context_param->u.perf_counter.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
288 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
289 context_param->u.perf_counter.config,
290 context_param->u.perf_counter.name,
291 ctx);
292 case LTTNG_KERNEL_ABI_CONTEXT_PROCNAME:
293 return lttng_add_procname_to_ctx(ctx);
294 case LTTNG_KERNEL_ABI_CONTEXT_HOSTNAME:
295 return lttng_add_hostname_to_ctx(ctx);
296 case LTTNG_KERNEL_ABI_CONTEXT_CPU_ID:
297 return lttng_add_cpu_id_to_ctx(ctx);
298 case LTTNG_KERNEL_ABI_CONTEXT_INTERRUPTIBLE:
299 return lttng_add_interruptible_to_ctx(ctx);
300 case LTTNG_KERNEL_ABI_CONTEXT_NEED_RESCHEDULE:
301 return lttng_add_need_reschedule_to_ctx(ctx);
302 case LTTNG_KERNEL_ABI_CONTEXT_PREEMPTIBLE:
303 return lttng_add_preemptible_to_ctx(ctx);
304 case LTTNG_KERNEL_ABI_CONTEXT_MIGRATABLE:
305 return lttng_add_migratable_to_ctx(ctx);
306 case LTTNG_KERNEL_ABI_CONTEXT_CALLSTACK_KERNEL:
307 case LTTNG_KERNEL_ABI_CONTEXT_CALLSTACK_USER:
308 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
309 case LTTNG_KERNEL_ABI_CONTEXT_CGROUP_NS:
310 return lttng_add_cgroup_ns_to_ctx(ctx);
311 case LTTNG_KERNEL_ABI_CONTEXT_IPC_NS:
312 return lttng_add_ipc_ns_to_ctx(ctx);
313 case LTTNG_KERNEL_ABI_CONTEXT_MNT_NS:
314 return lttng_add_mnt_ns_to_ctx(ctx);
315 case LTTNG_KERNEL_ABI_CONTEXT_NET_NS:
316 return lttng_add_net_ns_to_ctx(ctx);
317 case LTTNG_KERNEL_ABI_CONTEXT_PID_NS:
318 return lttng_add_pid_ns_to_ctx(ctx);
319 case LTTNG_KERNEL_ABI_CONTEXT_USER_NS:
320 return lttng_add_user_ns_to_ctx(ctx);
321 case LTTNG_KERNEL_ABI_CONTEXT_UTS_NS:
322 return lttng_add_uts_ns_to_ctx(ctx);
323 case LTTNG_KERNEL_ABI_CONTEXT_UID:
324 return lttng_add_uid_to_ctx(ctx);
325 case LTTNG_KERNEL_ABI_CONTEXT_EUID:
326 return lttng_add_euid_to_ctx(ctx);
327 case LTTNG_KERNEL_ABI_CONTEXT_SUID:
328 return lttng_add_suid_to_ctx(ctx);
329 case LTTNG_KERNEL_ABI_CONTEXT_GID:
330 return lttng_add_gid_to_ctx(ctx);
331 case LTTNG_KERNEL_ABI_CONTEXT_EGID:
332 return lttng_add_egid_to_ctx(ctx);
333 case LTTNG_KERNEL_ABI_CONTEXT_SGID:
334 return lttng_add_sgid_to_ctx(ctx);
335 case LTTNG_KERNEL_ABI_CONTEXT_VUID:
336 return lttng_add_vuid_to_ctx(ctx);
337 case LTTNG_KERNEL_ABI_CONTEXT_VEUID:
338 return lttng_add_veuid_to_ctx(ctx);
339 case LTTNG_KERNEL_ABI_CONTEXT_VSUID:
340 return lttng_add_vsuid_to_ctx(ctx);
341 case LTTNG_KERNEL_ABI_CONTEXT_VGID:
342 return lttng_add_vgid_to_ctx(ctx);
343 case LTTNG_KERNEL_ABI_CONTEXT_VEGID:
344 return lttng_add_vegid_to_ctx(ctx);
345 case LTTNG_KERNEL_ABI_CONTEXT_VSGID:
346 return lttng_add_vsgid_to_ctx(ctx);
347 case LTTNG_KERNEL_ABI_CONTEXT_TIME_NS:
348 return lttng_add_time_ns_to_ctx(ctx);
349 default:
350 return -EINVAL;
351 }
352 }
353
354 /**
355 * lttng_ioctl - lttng syscall through ioctl
356 *
357 * @file: the file
358 * @cmd: the command
359 * @arg: command arg
360 *
361 * This ioctl implements lttng commands:
362 * LTTNG_KERNEL_ABI_SESSION
363 * Returns a LTTng trace session file descriptor
364 * LTTNG_KERNEL_ABI_TRACER_VERSION
365 * Returns the LTTng kernel tracer version
366 * LTTNG_KERNEL_ABI_TRACEPOINT_LIST
367 * Returns a file descriptor listing available tracepoints
368 * LTTNG_KERNEL_ABI_WAIT_QUIESCENT
369 * Returns after all previously running probes have completed
370 * LTTNG_KERNEL_ABI_TRACER_ABI_VERSION
371 * Returns the LTTng kernel tracer ABI version
372 * LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_CREATE
373 * Returns a LTTng event notifier group file descriptor
374 *
375 * The returned session will be deleted when its file descriptor is closed.
376 */
377 static
378 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
379 {
380 switch (cmd) {
381 case LTTNG_KERNEL_ABI_OLD_SESSION:
382 case LTTNG_KERNEL_ABI_SESSION:
383 return lttng_abi_create_session();
384 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_CREATE:
385 return lttng_abi_create_event_notifier_group();
386 case LTTNG_KERNEL_ABI_OLD_TRACER_VERSION:
387 {
388 struct lttng_kernel_abi_tracer_version v;
389 struct lttng_kernel_abi_old_tracer_version oldv;
390 struct lttng_kernel_abi_old_tracer_version *uversion =
391 (struct lttng_kernel_abi_old_tracer_version __user *) arg;
392
393 lttng_abi_tracer_version(&v);
394 oldv.major = v.major;
395 oldv.minor = v.minor;
396 oldv.patchlevel = v.patchlevel;
397
398 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
399 return -EFAULT;
400 return 0;
401 }
402 case LTTNG_KERNEL_ABI_TRACER_VERSION:
403 {
404 struct lttng_kernel_abi_tracer_version version;
405 struct lttng_kernel_abi_tracer_version *uversion =
406 (struct lttng_kernel_abi_tracer_version __user *) arg;
407
408 lttng_abi_tracer_version(&version);
409
410 if (copy_to_user(uversion, &version, sizeof(version)))
411 return -EFAULT;
412 return 0;
413 }
414 case LTTNG_KERNEL_ABI_TRACER_ABI_VERSION:
415 {
416 struct lttng_kernel_abi_tracer_abi_version version;
417 struct lttng_kernel_abi_tracer_abi_version *uversion =
418 (struct lttng_kernel_abi_tracer_abi_version __user *) arg;
419
420 lttng_abi_tracer_abi_version(&version);
421
422 if (copy_to_user(uversion, &version, sizeof(version)))
423 return -EFAULT;
424 return 0;
425 }
426 case LTTNG_KERNEL_ABI_OLD_TRACEPOINT_LIST:
427 case LTTNG_KERNEL_ABI_TRACEPOINT_LIST:
428 return lttng_abi_tracepoint_list();
429 case LTTNG_KERNEL_ABI_SYSCALL_LIST:
430 return lttng_abi_syscall_list();
431 case LTTNG_KERNEL_ABI_OLD_WAIT_QUIESCENT:
432 case LTTNG_KERNEL_ABI_WAIT_QUIESCENT:
433 synchronize_trace();
434 return 0;
435 case LTTNG_KERNEL_ABI_OLD_CALIBRATE:
436 {
437 struct lttng_kernel_abi_old_calibrate __user *ucalibrate =
438 (struct lttng_kernel_abi_old_calibrate __user *) arg;
439 struct lttng_kernel_abi_old_calibrate old_calibrate;
440 struct lttng_kernel_abi_calibrate calibrate;
441 int ret;
442
443 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
444 return -EFAULT;
445 calibrate.type = old_calibrate.type;
446 ret = lttng_calibrate(&calibrate);
447 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
448 return -EFAULT;
449 return ret;
450 }
451 case LTTNG_KERNEL_ABI_CALIBRATE:
452 {
453 struct lttng_kernel_abi_calibrate __user *ucalibrate =
454 (struct lttng_kernel_abi_calibrate __user *) arg;
455 struct lttng_kernel_abi_calibrate calibrate;
456 int ret;
457
458 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
459 return -EFAULT;
460 ret = lttng_calibrate(&calibrate);
461 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
462 return -EFAULT;
463 return ret;
464 }
465 default:
466 return -ENOIOCTLCMD;
467 }
468 }
469
470 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
471 static const struct proc_ops lttng_proc_ops = {
472 .proc_ioctl = lttng_ioctl,
473 #ifdef CONFIG_COMPAT
474 .proc_compat_ioctl = lttng_ioctl,
475 #endif /* CONFIG_COMPAT */
476 };
477 #else
478 static const struct file_operations lttng_proc_ops = {
479 .owner = THIS_MODULE,
480 .unlocked_ioctl = lttng_ioctl,
481 #ifdef CONFIG_COMPAT
482 .compat_ioctl = lttng_ioctl,
483 #endif /* CONFIG_COMPAT */
484 };
485 #endif
486
487 static
488 int lttng_abi_create_channel(struct file *session_file,
489 struct lttng_kernel_abi_channel *chan_param,
490 enum channel_type channel_type)
491 {
492 struct lttng_kernel_session *session = session_file->private_data;
493 const struct file_operations *fops = NULL;
494 const char *transport_name;
495 struct lttng_kernel_channel_buffer *chan;
496 struct file *chan_file;
497 int chan_fd;
498 int ret = 0;
499
500 chan_fd = lttng_get_unused_fd();
501 if (chan_fd < 0) {
502 ret = chan_fd;
503 goto fd_error;
504 }
505 switch (channel_type) {
506 case PER_CPU_CHANNEL:
507 fops = &lttng_channel_fops;
508 break;
509 case METADATA_CHANNEL:
510 fops = &lttng_metadata_fops;
511 break;
512 }
513
514 chan_file = anon_inode_getfile("[lttng_channel]",
515 fops,
516 NULL, O_RDWR);
517 if (IS_ERR(chan_file)) {
518 ret = PTR_ERR(chan_file);
519 goto file_error;
520 }
521 switch (channel_type) {
522 case PER_CPU_CHANNEL:
523 if (chan_param->output == LTTNG_KERNEL_ABI_SPLICE) {
524 transport_name = chan_param->overwrite ?
525 "relay-overwrite" : "relay-discard";
526 } else if (chan_param->output == LTTNG_KERNEL_ABI_MMAP) {
527 transport_name = chan_param->overwrite ?
528 "relay-overwrite-mmap" : "relay-discard-mmap";
529 } else {
530 return -EINVAL;
531 }
532 break;
533 case METADATA_CHANNEL:
534 if (chan_param->output == LTTNG_KERNEL_ABI_SPLICE)
535 transport_name = "relay-metadata";
536 else if (chan_param->output == LTTNG_KERNEL_ABI_MMAP)
537 transport_name = "relay-metadata-mmap";
538 else
539 return -EINVAL;
540 break;
541 default:
542 transport_name = "<unknown>";
543 break;
544 }
545 if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
546 ret = -EOVERFLOW;
547 goto refcount_error;
548 }
549 /*
550 * We tolerate no failure path after channel creation. It will stay
551 * invariant for the rest of the session.
552 */
553 chan = lttng_channel_buffer_create(session, transport_name, NULL,
554 chan_param->subbuf_size,
555 chan_param->num_subbuf,
556 chan_param->switch_timer_interval,
557 chan_param->read_timer_interval,
558 channel_type);
559 if (!chan) {
560 ret = -EINVAL;
561 goto chan_error;
562 }
563 chan->priv->parent.file = chan_file;
564 chan_file->private_data = chan;
565 fd_install(chan_fd, chan_file);
566
567 return chan_fd;
568
569 chan_error:
570 atomic_long_dec(&session_file->f_count);
571 refcount_error:
572 fput(chan_file);
573 file_error:
574 put_unused_fd(chan_fd);
575 fd_error:
576 return ret;
577 }
578
579 static
580 int lttng_abi_session_set_name(struct lttng_kernel_session *session,
581 struct lttng_kernel_abi_session_name *name)
582 {
583 size_t len;
584
585 len = strnlen(name->name, LTTNG_KERNEL_ABI_SESSION_NAME_LEN);
586
587 if (len == LTTNG_KERNEL_ABI_SESSION_NAME_LEN) {
588 /* Name is too long/malformed */
589 return -EINVAL;
590 }
591
592 strcpy(session->priv->name, name->name);
593 return 0;
594 }
595
596 static
597 int lttng_abi_session_set_creation_time(struct lttng_kernel_session *session,
598 struct lttng_kernel_abi_session_creation_time *time)
599 {
600 size_t len;
601
602 len = strnlen(time->iso8601, LTTNG_KERNEL_ABI_SESSION_CREATION_TIME_ISO8601_LEN);
603
604 if (len == LTTNG_KERNEL_ABI_SESSION_CREATION_TIME_ISO8601_LEN) {
605 /* Time is too long/malformed */
606 return -EINVAL;
607 }
608
609 strcpy(session->priv->creation_time, time->iso8601);
610 return 0;
611 }
612
613 static
614 int lttng_counter_release(struct inode *inode, struct file *file)
615 {
616 struct lttng_counter *counter = file->private_data;
617
618 if (counter) {
619 /*
620 * Do not destroy the counter itself. Wait of the owner
621 * (event_notifier group) to be destroyed.
622 */
623 fput(counter->owner);
624 }
625
626 return 0;
627 }
628
629 static
630 long lttng_counter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
631 {
632 struct lttng_counter *counter = file->private_data;
633 size_t indexes[LTTNG_KERNEL_ABI_COUNTER_DIMENSION_MAX] = { 0 };
634 int i;
635
636 switch (cmd) {
637 case LTTNG_KERNEL_ABI_COUNTER_READ:
638 {
639 struct lttng_kernel_abi_counter_read local_counter_read;
640 struct lttng_kernel_abi_counter_read __user *ucounter_read =
641 (struct lttng_kernel_abi_counter_read __user *) arg;
642 bool overflow, underflow;
643 int64_t value;
644 int32_t cpu;
645 int ret;
646
647 if (copy_from_user(&local_counter_read, ucounter_read,
648 sizeof(local_counter_read)))
649 return -EFAULT;
650 if (validate_zeroed_padding(local_counter_read.padding,
651 sizeof(local_counter_read.padding)))
652 return -EINVAL;
653
654 /* Cast all indexes into size_t. */
655 for (i = 0; i < local_counter_read.index.number_dimensions; i++)
656 indexes[i] = (size_t) local_counter_read.index.dimension_indexes[i];
657 cpu = local_counter_read.cpu;
658
659 ret = lttng_kernel_counter_read(counter, indexes, cpu, &value,
660 &overflow, &underflow);
661 if (ret)
662 return ret;
663 local_counter_read.value.value = value;
664 local_counter_read.value.overflow = overflow;
665 local_counter_read.value.underflow = underflow;
666
667 if (copy_to_user(&ucounter_read->value, &local_counter_read.value,
668 sizeof(local_counter_read.value)))
669 return -EFAULT;
670
671 return 0;
672 }
673 case LTTNG_KERNEL_ABI_COUNTER_AGGREGATE:
674 {
675 struct lttng_kernel_abi_counter_aggregate local_counter_aggregate;
676 struct lttng_kernel_abi_counter_aggregate __user *ucounter_aggregate =
677 (struct lttng_kernel_abi_counter_aggregate __user *) arg;
678 bool overflow, underflow;
679 int64_t value;
680 int ret;
681
682 if (copy_from_user(&local_counter_aggregate, ucounter_aggregate,
683 sizeof(local_counter_aggregate)))
684 return -EFAULT;
685 if (validate_zeroed_padding(local_counter_aggregate.padding,
686 sizeof(local_counter_aggregate.padding)))
687 return -EINVAL;
688
689 /* Cast all indexes into size_t. */
690 for (i = 0; i < local_counter_aggregate.index.number_dimensions; i++)
691 indexes[i] = (size_t) local_counter_aggregate.index.dimension_indexes[i];
692
693 ret = lttng_kernel_counter_aggregate(counter, indexes, &value,
694 &overflow, &underflow);
695 if (ret)
696 return ret;
697 local_counter_aggregate.value.value = value;
698 local_counter_aggregate.value.overflow = overflow;
699 local_counter_aggregate.value.underflow = underflow;
700
701 if (copy_to_user(&ucounter_aggregate->value, &local_counter_aggregate.value,
702 sizeof(local_counter_aggregate.value)))
703 return -EFAULT;
704
705 return 0;
706 }
707 case LTTNG_KERNEL_ABI_COUNTER_CLEAR:
708 {
709 struct lttng_kernel_abi_counter_clear local_counter_clear;
710 struct lttng_kernel_abi_counter_clear __user *ucounter_clear =
711 (struct lttng_kernel_abi_counter_clear __user *) arg;
712
713 if (copy_from_user(&local_counter_clear, ucounter_clear,
714 sizeof(local_counter_clear)))
715 return -EFAULT;
716 if (validate_zeroed_padding(local_counter_clear.padding,
717 sizeof(local_counter_clear.padding)))
718 return -EINVAL;
719
720 /* Cast all indexes into size_t. */
721 for (i = 0; i < local_counter_clear.index.number_dimensions; i++)
722 indexes[i] = (size_t) local_counter_clear.index.dimension_indexes[i];
723
724 return lttng_kernel_counter_clear(counter, indexes);
725 }
726 default:
727 WARN_ON_ONCE(1);
728 return -ENOSYS;
729 }
730 }
731
732 static const struct file_operations lttng_counter_fops = {
733 .owner = THIS_MODULE,
734 .release = lttng_counter_release,
735 .unlocked_ioctl = lttng_counter_ioctl,
736 #ifdef CONFIG_COMPAT
737 .compat_ioctl = lttng_counter_ioctl,
738 #endif
739 };
740
741
742 static
743 enum tracker_type get_tracker_type(struct lttng_kernel_abi_tracker_args *tracker)
744 {
745 switch (tracker->type) {
746 case LTTNG_KERNEL_ABI_TRACKER_PID:
747 return TRACKER_PID;
748 case LTTNG_KERNEL_ABI_TRACKER_VPID:
749 return TRACKER_VPID;
750 case LTTNG_KERNEL_ABI_TRACKER_UID:
751 return TRACKER_UID;
752 case LTTNG_KERNEL_ABI_TRACKER_VUID:
753 return TRACKER_VUID;
754 case LTTNG_KERNEL_ABI_TRACKER_GID:
755 return TRACKER_GID;
756 case LTTNG_KERNEL_ABI_TRACKER_VGID:
757 return TRACKER_VGID;
758 default:
759 return TRACKER_UNKNOWN;
760 }
761 }
762
763 /**
764 * lttng_session_ioctl - lttng session fd ioctl
765 *
766 * @file: the file
767 * @cmd: the command
768 * @arg: command arg
769 *
770 * This ioctl implements lttng commands:
771 * LTTNG_KERNEL_ABI_CHANNEL
772 * Returns a LTTng channel file descriptor
773 * LTTNG_KERNEL_ABI_ENABLE
774 * Enables tracing for a session (weak enable)
775 * LTTNG_KERNEL_ABI_DISABLE
776 * Disables tracing for a session (strong disable)
777 * LTTNG_KERNEL_ABI_METADATA
778 * Returns a LTTng metadata file descriptor
779 * LTTNG_KERNEL_ABI_SESSION_TRACK_PID
780 * Add PID to session PID tracker
781 * LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID
782 * Remove PID from session PID tracker
783 * LTTNG_KERNEL_ABI_SESSION_TRACK_ID
784 * Add ID to tracker
785 * LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID
786 * Remove ID from tracker
787 *
788 * The returned channel will be deleted when its file descriptor is closed.
789 */
790 static
791 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
792 {
793 struct lttng_kernel_session *session = file->private_data;
794 struct lttng_kernel_abi_channel chan_param;
795 struct lttng_kernel_abi_old_channel old_chan_param;
796
797 /*
798 * Handle backward compatibility. OLD commands have wrong
799 * directions, replace them by the correct direction.
800 */
801 switch (cmd) {
802 case LTTNG_KERNEL_ABI_OLD_SESSION_TRACK_PID:
803 cmd = LTTNG_KERNEL_ABI_SESSION_TRACK_PID;
804 break;
805 case LTTNG_KERNEL_ABI_OLD_SESSION_UNTRACK_PID:
806 cmd = LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID;
807 break;
808 case LTTNG_KERNEL_ABI_OLD_SESSION_TRACK_ID:
809 cmd = LTTNG_KERNEL_ABI_SESSION_TRACK_ID;
810 break;
811 case LTTNG_KERNEL_ABI_OLD_SESSION_UNTRACK_ID:
812 cmd = LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID;
813 break;
814 case LTTNG_KERNEL_ABI_OLD_SESSION_LIST_TRACKER_IDS:
815 cmd = LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_IDS;
816 break;
817 case LTTNG_KERNEL_ABI_OLD_SESSION_SET_NAME:
818 cmd = LTTNG_KERNEL_ABI_SESSION_SET_NAME;
819 break;
820 case LTTNG_KERNEL_ABI_OLD_SESSION_SET_CREATION_TIME:
821 cmd = LTTNG_KERNEL_ABI_SESSION_SET_CREATION_TIME;
822 break;
823 default:
824 /* Nothing to do. */
825 break;
826 }
827
828 switch (cmd) {
829 case LTTNG_KERNEL_ABI_OLD_CHANNEL:
830 {
831 if (copy_from_user(&old_chan_param,
832 (struct lttng_kernel_abi_old_channel __user *) arg,
833 sizeof(struct lttng_kernel_abi_old_channel)))
834 return -EFAULT;
835 chan_param.overwrite = old_chan_param.overwrite;
836 chan_param.subbuf_size = old_chan_param.subbuf_size;
837 chan_param.num_subbuf = old_chan_param.num_subbuf;
838 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
839 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
840 chan_param.output = old_chan_param.output;
841
842 return lttng_abi_create_channel(file, &chan_param,
843 PER_CPU_CHANNEL);
844 }
845 case LTTNG_KERNEL_ABI_CHANNEL:
846 {
847 if (copy_from_user(&chan_param,
848 (struct lttng_kernel_abi_channel __user *) arg,
849 sizeof(struct lttng_kernel_abi_channel)))
850 return -EFAULT;
851 return lttng_abi_create_channel(file, &chan_param,
852 PER_CPU_CHANNEL);
853 }
854 case LTTNG_KERNEL_ABI_OLD_SESSION_START:
855 case LTTNG_KERNEL_ABI_OLD_ENABLE:
856 case LTTNG_KERNEL_ABI_SESSION_START:
857 case LTTNG_KERNEL_ABI_ENABLE:
858 return lttng_session_enable(session);
859 case LTTNG_KERNEL_ABI_OLD_SESSION_STOP:
860 case LTTNG_KERNEL_ABI_OLD_DISABLE:
861 case LTTNG_KERNEL_ABI_SESSION_STOP:
862 case LTTNG_KERNEL_ABI_DISABLE:
863 return lttng_session_disable(session);
864 case LTTNG_KERNEL_ABI_OLD_METADATA:
865 {
866 if (copy_from_user(&old_chan_param,
867 (struct lttng_kernel_abi_old_channel __user *) arg,
868 sizeof(struct lttng_kernel_abi_old_channel)))
869 return -EFAULT;
870 chan_param.overwrite = old_chan_param.overwrite;
871 chan_param.subbuf_size = old_chan_param.subbuf_size;
872 chan_param.num_subbuf = old_chan_param.num_subbuf;
873 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
874 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
875 chan_param.output = old_chan_param.output;
876
877 return lttng_abi_create_channel(file, &chan_param,
878 METADATA_CHANNEL);
879 }
880 case LTTNG_KERNEL_ABI_METADATA:
881 {
882 if (copy_from_user(&chan_param,
883 (struct lttng_kernel_abi_channel __user *) arg,
884 sizeof(struct lttng_kernel_abi_channel)))
885 return -EFAULT;
886 return lttng_abi_create_channel(file, &chan_param,
887 METADATA_CHANNEL);
888 }
889 case LTTNG_KERNEL_ABI_SESSION_TRACK_PID:
890 return lttng_session_track_id(session, TRACKER_PID, (int) arg);
891 case LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID:
892 return lttng_session_untrack_id(session, TRACKER_PID, (int) arg);
893 case LTTNG_KERNEL_ABI_SESSION_TRACK_ID:
894 {
895 struct lttng_kernel_abi_tracker_args tracker;
896 enum tracker_type tracker_type;
897
898 if (copy_from_user(&tracker,
899 (struct lttng_kernel_abi_tracker_args __user *) arg,
900 sizeof(struct lttng_kernel_abi_tracker_args)))
901 return -EFAULT;
902 tracker_type = get_tracker_type(&tracker);
903 if (tracker_type == TRACKER_UNKNOWN)
904 return -EINVAL;
905 return lttng_session_track_id(session, tracker_type, tracker.id);
906 }
907 case LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID:
908 {
909 struct lttng_kernel_abi_tracker_args tracker;
910 enum tracker_type tracker_type;
911
912 if (copy_from_user(&tracker,
913 (struct lttng_kernel_abi_tracker_args __user *) arg,
914 sizeof(struct lttng_kernel_abi_tracker_args)))
915 return -EFAULT;
916 tracker_type = get_tracker_type(&tracker);
917 if (tracker_type == TRACKER_UNKNOWN)
918 return -EINVAL;
919 return lttng_session_untrack_id(session, tracker_type,
920 tracker.id);
921 }
922 case LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_PIDS:
923 return lttng_session_list_tracker_ids(session, TRACKER_PID);
924 case LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_IDS:
925 {
926 struct lttng_kernel_abi_tracker_args tracker;
927 enum tracker_type tracker_type;
928
929 if (copy_from_user(&tracker,
930 (struct lttng_kernel_abi_tracker_args __user *) arg,
931 sizeof(struct lttng_kernel_abi_tracker_args)))
932 return -EFAULT;
933 tracker_type = get_tracker_type(&tracker);
934 if (tracker_type == TRACKER_UNKNOWN)
935 return -EINVAL;
936 return lttng_session_list_tracker_ids(session, tracker_type);
937 }
938 case LTTNG_KERNEL_ABI_SESSION_METADATA_REGEN:
939 return lttng_session_metadata_regenerate(session);
940 case LTTNG_KERNEL_ABI_SESSION_STATEDUMP:
941 return lttng_session_statedump(session);
942 case LTTNG_KERNEL_ABI_SESSION_SET_NAME:
943 {
944 struct lttng_kernel_abi_session_name name;
945
946 if (copy_from_user(&name,
947 (struct lttng_kernel_abi_session_name __user *) arg,
948 sizeof(struct lttng_kernel_abi_session_name)))
949 return -EFAULT;
950 return lttng_abi_session_set_name(session, &name);
951 }
952 case LTTNG_KERNEL_ABI_SESSION_SET_CREATION_TIME:
953 {
954 struct lttng_kernel_abi_session_creation_time time;
955
956 if (copy_from_user(&time,
957 (struct lttng_kernel_abi_session_creation_time __user *) arg,
958 sizeof(struct lttng_kernel_abi_session_creation_time)))
959 return -EFAULT;
960 return lttng_abi_session_set_creation_time(session, &time);
961 }
962 default:
963 return -ENOIOCTLCMD;
964 }
965 }
966
967 /*
968 * Called when the last file reference is dropped.
969 *
970 * Big fat note: channels and events are invariant for the whole session after
971 * their creation. So this session destruction also destroys all channel and
972 * event structures specific to this session (they are not destroyed when their
973 * individual file is released).
974 */
975 static
976 int lttng_session_release(struct inode *inode, struct file *file)
977 {
978 struct lttng_kernel_session *session = file->private_data;
979
980 if (session)
981 lttng_session_destroy(session);
982 return 0;
983 }
984
985 static const struct file_operations lttng_session_fops = {
986 .owner = THIS_MODULE,
987 .release = lttng_session_release,
988 .unlocked_ioctl = lttng_session_ioctl,
989 #ifdef CONFIG_COMPAT
990 .compat_ioctl = lttng_session_ioctl,
991 #endif
992 };
993
994 /*
995 * When encountering empty buffer, flush current sub-buffer if non-empty
996 * and retry (if new data available to read after flush).
997 */
998 static
999 ssize_t lttng_event_notifier_group_notif_read(struct file *filp, char __user *user_buf,
1000 size_t count, loff_t *ppos)
1001 {
1002 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
1003 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1004 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1005 ssize_t read_count = 0, len;
1006 size_t read_offset;
1007
1008 might_sleep();
1009 if (!lttng_access_ok(VERIFY_WRITE, user_buf, count))
1010 return -EFAULT;
1011
1012 /* Finish copy of previous record */
1013 if (*ppos != 0) {
1014 if (read_count < count) {
1015 len = chan->iter.len_left;
1016 read_offset = *ppos;
1017 goto skip_get_next;
1018 }
1019 }
1020
1021 while (read_count < count) {
1022 size_t copy_len, space_left;
1023
1024 len = lib_ring_buffer_get_next_record(chan, buf);
1025 len_test:
1026 if (len < 0) {
1027 /*
1028 * Check if buffer is finalized (end of file).
1029 */
1030 if (len == -ENODATA) {
1031 /* A 0 read_count will tell about end of file */
1032 goto nodata;
1033 }
1034 if (filp->f_flags & O_NONBLOCK) {
1035 if (!read_count)
1036 read_count = -EAGAIN;
1037 goto nodata;
1038 } else {
1039 int error;
1040
1041 /*
1042 * No data available at the moment, return what
1043 * we got.
1044 */
1045 if (read_count)
1046 goto nodata;
1047
1048 /*
1049 * Wait for returned len to be >= 0 or -ENODATA.
1050 */
1051 error = wait_event_interruptible(
1052 event_notifier_group->read_wait,
1053 ((len = lib_ring_buffer_get_next_record(
1054 chan, buf)), len != -EAGAIN));
1055 CHAN_WARN_ON(chan, len == -EBUSY);
1056 if (error) {
1057 read_count = error;
1058 goto nodata;
1059 }
1060 CHAN_WARN_ON(chan, len < 0 && len != -ENODATA);
1061 goto len_test;
1062 }
1063 }
1064 read_offset = buf->iter.read_offset;
1065 skip_get_next:
1066 space_left = count - read_count;
1067 if (len <= space_left) {
1068 copy_len = len;
1069 chan->iter.len_left = 0;
1070 *ppos = 0;
1071 } else {
1072 copy_len = space_left;
1073 chan->iter.len_left = len - copy_len;
1074 *ppos = read_offset + copy_len;
1075 }
1076 if (__lib_ring_buffer_copy_to_user(&buf->backend, read_offset,
1077 &user_buf[read_count],
1078 copy_len)) {
1079 /*
1080 * Leave the len_left and ppos values at their current
1081 * state, as we currently have a valid event to read.
1082 */
1083 return -EFAULT;
1084 }
1085 read_count += copy_len;
1086 }
1087 goto put_record;
1088
1089 nodata:
1090 *ppos = 0;
1091 chan->iter.len_left = 0;
1092
1093 put_record:
1094 lib_ring_buffer_put_current_record(buf);
1095 return read_count;
1096 }
1097
1098 /*
1099 * If the ring buffer is non empty (even just a partial subbuffer), return that
1100 * there is data available. Perform a ring buffer flush if we encounter a
1101 * non-empty ring buffer which does not have any consumeable subbuffer available.
1102 */
1103 static
1104 unsigned int lttng_event_notifier_group_notif_poll(struct file *filp,
1105 poll_table *wait)
1106 {
1107 unsigned int mask = 0;
1108 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
1109 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1110 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1111 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
1112 int finalized, disabled;
1113 unsigned long consumed, offset;
1114 size_t subbuffer_header_size = config->cb.subbuffer_header_size();
1115
1116 if (filp->f_mode & FMODE_READ) {
1117 poll_wait_set_exclusive(wait);
1118 poll_wait(filp, &event_notifier_group->read_wait, wait);
1119
1120 finalized = lib_ring_buffer_is_finalized(config, buf);
1121 disabled = lib_ring_buffer_channel_is_disabled(chan);
1122
1123 /*
1124 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
1125 * finalized load before offsets loads.
1126 */
1127 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1128 retry:
1129 if (disabled)
1130 return POLLERR;
1131
1132 offset = lib_ring_buffer_get_offset(config, buf);
1133 consumed = lib_ring_buffer_get_consumed(config, buf);
1134
1135 /*
1136 * If there is no buffer available to consume.
1137 */
1138 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) == 0) {
1139 /*
1140 * If there is a non-empty subbuffer, flush and try again.
1141 */
1142 if (subbuf_offset(offset, chan) > subbuffer_header_size) {
1143 lib_ring_buffer_switch_remote(buf);
1144 goto retry;
1145 }
1146
1147 if (finalized)
1148 return POLLHUP;
1149 else {
1150 /*
1151 * The memory barriers
1152 * __wait_event()/wake_up_interruptible() take
1153 * care of "raw_spin_is_locked" memory ordering.
1154 */
1155 if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
1156 goto retry;
1157 else
1158 return 0;
1159 }
1160 } else {
1161 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan)
1162 >= chan->backend.buf_size)
1163 return POLLPRI | POLLRDBAND;
1164 else
1165 return POLLIN | POLLRDNORM;
1166 }
1167 }
1168
1169 return mask;
1170 }
1171
1172 /**
1173 * lttng_event_notifier_group_notif_open - event_notifier ring buffer open file operation
1174 * @inode: opened inode
1175 * @file: opened file
1176 *
1177 * Open implementation. Makes sure only one open instance of a buffer is
1178 * done at a given moment.
1179 */
1180 static int lttng_event_notifier_group_notif_open(struct inode *inode, struct file *file)
1181 {
1182 struct lttng_event_notifier_group *event_notifier_group = inode->i_private;
1183 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1184
1185 file->private_data = event_notifier_group;
1186 return lib_ring_buffer_open(inode, file, buf);
1187 }
1188
1189 /**
1190 * lttng_event_notifier_group_notif_release - event_notifier ring buffer release file operation
1191 * @inode: opened inode
1192 * @file: opened file
1193 *
1194 * Release implementation.
1195 */
1196 static int lttng_event_notifier_group_notif_release(struct inode *inode, struct file *file)
1197 {
1198 struct lttng_event_notifier_group *event_notifier_group = file->private_data;
1199 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1200 int ret;
1201
1202 ret = lib_ring_buffer_release(inode, file, buf);
1203 if (ret)
1204 return ret;
1205 fput(event_notifier_group->file);
1206 return 0;
1207 }
1208
1209 static const struct file_operations lttng_event_notifier_group_notif_fops = {
1210 .owner = THIS_MODULE,
1211 .open = lttng_event_notifier_group_notif_open,
1212 .release = lttng_event_notifier_group_notif_release,
1213 .read = lttng_event_notifier_group_notif_read,
1214 .poll = lttng_event_notifier_group_notif_poll,
1215 };
1216
1217 /**
1218 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
1219 * @filp: the file
1220 * @wait: poll table
1221 *
1222 * Handles the poll operations for the metadata channels.
1223 */
1224 static
1225 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
1226 poll_table *wait)
1227 {
1228 struct lttng_metadata_stream *stream = filp->private_data;
1229 struct lttng_kernel_ring_buffer *buf = stream->priv;
1230 int finalized;
1231 unsigned int mask = 0;
1232
1233 if (filp->f_mode & FMODE_READ) {
1234 poll_wait_set_exclusive(wait);
1235 poll_wait(filp, &stream->read_wait, wait);
1236
1237 finalized = stream->finalized;
1238
1239 /*
1240 * lib_ring_buffer_is_finalized() contains a smp_rmb()
1241 * ordering finalized load before offsets loads.
1242 */
1243 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1244
1245 if (finalized)
1246 mask |= POLLHUP;
1247
1248 mutex_lock(&stream->metadata_cache->lock);
1249 if (stream->metadata_cache->metadata_written >
1250 stream->metadata_out)
1251 mask |= POLLIN;
1252 mutex_unlock(&stream->metadata_cache->lock);
1253 }
1254
1255 return mask;
1256 }
1257
1258 static
1259 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
1260 unsigned int cmd, unsigned long arg)
1261 {
1262 struct lttng_metadata_stream *stream = filp->private_data;
1263
1264 stream->metadata_out = stream->metadata_in;
1265 }
1266
1267 /*
1268 * Reset the counter of how much metadata has been consumed to 0. That way,
1269 * the consumer receives the content of the metadata cache unchanged. This is
1270 * different from the metadata_regenerate where the offset from epoch is
1271 * resampled, here we want the exact same content as the last time the metadata
1272 * was generated. This command is only possible if all the metadata written
1273 * in the cache has been output to the metadata stream to avoid corrupting the
1274 * metadata file.
1275 *
1276 * Return 0 on success, a negative value on error.
1277 */
1278 static
1279 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
1280 {
1281 int ret;
1282 struct lttng_metadata_cache *cache = stream->metadata_cache;
1283
1284 mutex_lock(&cache->lock);
1285 if (stream->metadata_out != cache->metadata_written) {
1286 ret = -EBUSY;
1287 goto end;
1288 }
1289 stream->metadata_out = 0;
1290 stream->metadata_in = 0;
1291 wake_up_interruptible(&stream->read_wait);
1292 ret = 0;
1293
1294 end:
1295 mutex_unlock(&cache->lock);
1296 return ret;
1297 }
1298
1299 static
1300 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
1301 unsigned int cmd, unsigned long arg)
1302 {
1303 int ret;
1304 struct lttng_metadata_stream *stream = filp->private_data;
1305 struct lttng_kernel_ring_buffer *buf = stream->priv;
1306 unsigned int rb_cmd;
1307 bool coherent;
1308
1309 if (cmd == LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1310 rb_cmd = LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF;
1311 else
1312 rb_cmd = cmd;
1313
1314 switch (cmd) {
1315 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF:
1316 {
1317 struct lttng_metadata_stream *stream = filp->private_data;
1318 struct lttng_kernel_ring_buffer *buf = stream->priv;
1319 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1320
1321 ret = lttng_metadata_output_channel(stream, chan, NULL);
1322 if (ret > 0) {
1323 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1324 ret = 0;
1325 } else if (ret < 0)
1326 goto err;
1327 break;
1328 }
1329 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF:
1330 {
1331 /*
1332 * Random access is not allowed for metadata channel.
1333 */
1334 return -ENOSYS;
1335 }
1336 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY:
1337 lttng_fallthrough;
1338 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH:
1339 {
1340 struct lttng_metadata_stream *stream = filp->private_data;
1341 struct lttng_kernel_ring_buffer *buf = stream->priv;
1342 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1343
1344 /*
1345 * Before doing the actual ring buffer flush, write up to one
1346 * packet of metadata in the ring buffer.
1347 */
1348 ret = lttng_metadata_output_channel(stream, chan, NULL);
1349 if (ret < 0)
1350 goto err;
1351 break;
1352 }
1353 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION:
1354 {
1355 struct lttng_metadata_stream *stream = filp->private_data;
1356
1357 return put_u64(stream->version, arg);
1358 }
1359 case LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP:
1360 {
1361 struct lttng_metadata_stream *stream = filp->private_data;
1362
1363 return lttng_metadata_cache_dump(stream);
1364 }
1365 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1366 {
1367 struct lttng_metadata_stream *stream = filp->private_data;
1368 struct lttng_kernel_ring_buffer *buf = stream->priv;
1369 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1370
1371 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1372 if (ret > 0) {
1373 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1374 ret = 0;
1375 } else if (ret < 0) {
1376 goto err;
1377 }
1378 break;
1379 }
1380 default:
1381 break;
1382 }
1383 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1384
1385 /* Performing lib ring buffer ioctl after our own. */
1386 ret = lib_ring_buffer_ioctl(filp, rb_cmd, arg, buf);
1387 if (ret < 0)
1388 goto err;
1389
1390 switch (cmd) {
1391 case LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF:
1392 {
1393 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1394 cmd, arg);
1395 break;
1396 }
1397 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1398 {
1399 return put_u32(coherent, arg);
1400 }
1401 default:
1402 break;
1403 }
1404 err:
1405 return ret;
1406 }
1407
1408 #ifdef CONFIG_COMPAT
1409 static
1410 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
1411 unsigned int cmd, unsigned long arg)
1412 {
1413 int ret;
1414 struct lttng_metadata_stream *stream = filp->private_data;
1415 struct lttng_kernel_ring_buffer *buf = stream->priv;
1416 unsigned int rb_cmd;
1417 bool coherent;
1418
1419 if (cmd == LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1420 rb_cmd = LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF;
1421 else
1422 rb_cmd = cmd;
1423
1424 switch (cmd) {
1425 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF:
1426 {
1427 struct lttng_metadata_stream *stream = filp->private_data;
1428 struct lttng_kernel_ring_buffer *buf = stream->priv;
1429 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1430
1431 ret = lttng_metadata_output_channel(stream, chan, NULL);
1432 if (ret > 0) {
1433 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1434 ret = 0;
1435 } else if (ret < 0)
1436 goto err;
1437 break;
1438 }
1439 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF:
1440 {
1441 /*
1442 * Random access is not allowed for metadata channel.
1443 */
1444 return -ENOSYS;
1445 }
1446 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY:
1447 lttng_fallthrough;
1448 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH:
1449 {
1450 struct lttng_metadata_stream *stream = filp->private_data;
1451 struct lttng_kernel_ring_buffer *buf = stream->priv;
1452 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1453
1454 /*
1455 * Before doing the actual ring buffer flush, write up to one
1456 * packet of metadata in the ring buffer.
1457 */
1458 ret = lttng_metadata_output_channel(stream, chan, NULL);
1459 if (ret < 0)
1460 goto err;
1461 break;
1462 }
1463 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION:
1464 {
1465 struct lttng_metadata_stream *stream = filp->private_data;
1466
1467 return put_u64(stream->version, arg);
1468 }
1469 case LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP:
1470 {
1471 struct lttng_metadata_stream *stream = filp->private_data;
1472
1473 return lttng_metadata_cache_dump(stream);
1474 }
1475 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1476 {
1477 struct lttng_metadata_stream *stream = filp->private_data;
1478 struct lttng_kernel_ring_buffer *buf = stream->priv;
1479 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1480
1481 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1482 if (ret > 0) {
1483 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1484 ret = 0;
1485 } else if (ret < 0) {
1486 goto err;
1487 }
1488 break;
1489 }
1490 default:
1491 break;
1492 }
1493 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1494
1495 /* Performing lib ring buffer ioctl after our own. */
1496 ret = lib_ring_buffer_compat_ioctl(filp, rb_cmd, arg, buf);
1497 if (ret < 0)
1498 goto err;
1499
1500 switch (cmd) {
1501 case LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF:
1502 {
1503 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1504 cmd, arg);
1505 break;
1506 }
1507 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1508 {
1509 return put_u32(coherent, arg);
1510 }
1511 default:
1512 break;
1513 }
1514 err:
1515 return ret;
1516 }
1517 #endif
1518
1519 /*
1520 * This is not used by anonymous file descriptors. This code is left
1521 * there if we ever want to implement an inode with open() operation.
1522 */
1523 static
1524 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
1525 {
1526 struct lttng_metadata_stream *stream = inode->i_private;
1527 struct lttng_kernel_ring_buffer *buf = stream->priv;
1528
1529 file->private_data = buf;
1530 /*
1531 * Since life-time of metadata cache differs from that of
1532 * session, we need to keep our own reference on the transport.
1533 */
1534 if (!try_module_get(stream->transport->owner)) {
1535 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1536 return -EBUSY;
1537 }
1538 return lib_ring_buffer_open(inode, file, buf);
1539 }
1540
1541 static
1542 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
1543 {
1544 struct lttng_metadata_stream *stream = file->private_data;
1545 struct lttng_kernel_ring_buffer *buf = stream->priv;
1546
1547 mutex_lock(&stream->metadata_cache->lock);
1548 list_del(&stream->list);
1549 mutex_unlock(&stream->metadata_cache->lock);
1550 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
1551 module_put(stream->transport->owner);
1552 kfree(stream);
1553 return lib_ring_buffer_release(inode, file, buf);
1554 }
1555
1556 static
1557 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
1558 struct pipe_inode_info *pipe, size_t len,
1559 unsigned int flags)
1560 {
1561 struct lttng_metadata_stream *stream = in->private_data;
1562 struct lttng_kernel_ring_buffer *buf = stream->priv;
1563
1564 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
1565 flags, buf);
1566 }
1567
1568 static
1569 int lttng_metadata_ring_buffer_mmap(struct file *filp,
1570 struct vm_area_struct *vma)
1571 {
1572 struct lttng_metadata_stream *stream = filp->private_data;
1573 struct lttng_kernel_ring_buffer *buf = stream->priv;
1574
1575 return lib_ring_buffer_mmap(filp, vma, buf);
1576 }
1577
1578 static
1579 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
1580 .owner = THIS_MODULE,
1581 .open = lttng_metadata_ring_buffer_open,
1582 .release = lttng_metadata_ring_buffer_release,
1583 .poll = lttng_metadata_ring_buffer_poll,
1584 .splice_read = lttng_metadata_ring_buffer_splice_read,
1585 .mmap = lttng_metadata_ring_buffer_mmap,
1586 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
1587 .llseek = vfs_lib_ring_buffer_no_llseek,
1588 #ifdef CONFIG_COMPAT
1589 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
1590 #endif
1591 };
1592
1593 static
1594 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1595 const struct file_operations *fops, const char *name)
1596 {
1597 int stream_fd, ret;
1598 struct file *stream_file;
1599
1600 stream_fd = lttng_get_unused_fd();
1601 if (stream_fd < 0) {
1602 ret = stream_fd;
1603 goto fd_error;
1604 }
1605 stream_file = anon_inode_getfile(name, fops, stream_priv, O_RDWR);
1606 if (IS_ERR(stream_file)) {
1607 ret = PTR_ERR(stream_file);
1608 goto file_error;
1609 }
1610 /*
1611 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1612 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1613 * file descriptor, so we set FMODE_PREAD here.
1614 */
1615 stream_file->f_mode |= FMODE_PREAD;
1616 fd_install(stream_fd, stream_file);
1617 /*
1618 * The stream holds a reference to the channel within the generic ring
1619 * buffer library, so no need to hold a refcount on the channel and
1620 * session files here.
1621 */
1622 return stream_fd;
1623
1624 file_error:
1625 put_unused_fd(stream_fd);
1626 fd_error:
1627 return ret;
1628 }
1629
1630 static
1631 int lttng_abi_open_stream(struct file *channel_file)
1632 {
1633 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1634 struct lttng_kernel_ring_buffer *buf;
1635 int ret;
1636 void *stream_priv;
1637
1638 buf = channel->ops->priv->buffer_read_open(channel->priv->rb_chan);
1639 if (!buf)
1640 return -ENOENT;
1641
1642 stream_priv = buf;
1643 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1644 &lttng_stream_ring_buffer_file_operations,
1645 "[lttng_stream]");
1646 if (ret < 0)
1647 goto fd_error;
1648
1649 return ret;
1650
1651 fd_error:
1652 channel->ops->priv->buffer_read_close(buf);
1653 return ret;
1654 }
1655
1656 static
1657 int lttng_abi_open_metadata_stream(struct file *channel_file)
1658 {
1659 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1660 struct lttng_kernel_session *session = channel->parent.session;
1661 struct lttng_kernel_ring_buffer *buf;
1662 int ret;
1663 struct lttng_metadata_stream *metadata_stream;
1664 void *stream_priv;
1665
1666 buf = channel->ops->priv->buffer_read_open(channel->priv->rb_chan);
1667 if (!buf)
1668 return -ENOENT;
1669
1670 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1671 GFP_KERNEL);
1672 if (!metadata_stream) {
1673 ret = -ENOMEM;
1674 goto nomem;
1675 }
1676 metadata_stream->metadata_cache = session->priv->metadata_cache;
1677 init_waitqueue_head(&metadata_stream->read_wait);
1678 metadata_stream->priv = buf;
1679 stream_priv = metadata_stream;
1680 metadata_stream->transport = channel->priv->transport;
1681 /* Initial state is an empty metadata, considered as incoherent. */
1682 metadata_stream->coherent = false;
1683
1684 /*
1685 * Since life-time of metadata cache differs from that of
1686 * session, we need to keep our own reference on the transport.
1687 */
1688 if (!try_module_get(metadata_stream->transport->owner)) {
1689 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1690 ret = -EINVAL;
1691 goto notransport;
1692 }
1693
1694 if (!lttng_kref_get(&session->priv->metadata_cache->refcount)) {
1695 ret = -EOVERFLOW;
1696 goto kref_error;
1697 }
1698
1699 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1700 &lttng_metadata_ring_buffer_file_operations,
1701 "[lttng_metadata_stream]");
1702 if (ret < 0)
1703 goto fd_error;
1704
1705 mutex_lock(&session->priv->metadata_cache->lock);
1706 list_add(&metadata_stream->list,
1707 &session->priv->metadata_cache->metadata_stream);
1708 mutex_unlock(&session->priv->metadata_cache->lock);
1709 return ret;
1710
1711 fd_error:
1712 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
1713 kref_error:
1714 module_put(metadata_stream->transport->owner);
1715 notransport:
1716 kfree(metadata_stream);
1717 nomem:
1718 channel->ops->priv->buffer_read_close(buf);
1719 return ret;
1720 }
1721
1722 static
1723 int lttng_abi_open_event_notifier_group_stream(struct file *notif_file)
1724 {
1725 struct lttng_event_notifier_group *event_notifier_group = notif_file->private_data;
1726 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1727 struct lttng_kernel_ring_buffer *buf;
1728 int ret;
1729 void *stream_priv;
1730
1731 buf = event_notifier_group->ops->priv->buffer_read_open(chan);
1732 if (!buf)
1733 return -ENOENT;
1734
1735 /* The event_notifier notification fd holds a reference on the event_notifier group */
1736 if (!atomic_long_add_unless(&notif_file->f_count, 1, LONG_MAX)) {
1737 ret = -EOVERFLOW;
1738 goto refcount_error;
1739 }
1740 event_notifier_group->buf = buf;
1741 stream_priv = event_notifier_group;
1742 ret = lttng_abi_create_stream_fd(notif_file, stream_priv,
1743 &lttng_event_notifier_group_notif_fops,
1744 "[lttng_event_notifier_stream]");
1745 if (ret < 0)
1746 goto fd_error;
1747
1748 return ret;
1749
1750 fd_error:
1751 atomic_long_dec(&notif_file->f_count);
1752 refcount_error:
1753 event_notifier_group->ops->priv->buffer_read_close(buf);
1754 return ret;
1755 }
1756
1757 static
1758 int lttng_abi_validate_event_param(struct lttng_kernel_abi_event *event_param)
1759 {
1760 /* Limit ABI to implemented features. */
1761 switch (event_param->instrumentation) {
1762 case LTTNG_KERNEL_ABI_SYSCALL:
1763 switch (event_param->u.syscall.entryexit) {
1764 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1765 lttng_fallthrough;
1766 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1767 lttng_fallthrough;
1768 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1769 break;
1770 default:
1771 return -EINVAL;
1772 }
1773 switch (event_param->u.syscall.abi) {
1774 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1775 break;
1776 default:
1777 return -EINVAL;
1778 }
1779 switch (event_param->u.syscall.match) {
1780 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1781 break;
1782 default:
1783 return -EINVAL;
1784 }
1785 break;
1786
1787 case LTTNG_KERNEL_ABI_KRETPROBE:
1788 switch (event_param->u.kretprobe.entryexit) {
1789 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1790 break;
1791 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1792 lttng_fallthrough;
1793 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1794 lttng_fallthrough;
1795 default:
1796 return -EINVAL;
1797 }
1798 break;
1799
1800 case LTTNG_KERNEL_ABI_TRACEPOINT:
1801 lttng_fallthrough;
1802 case LTTNG_KERNEL_ABI_KPROBE:
1803 lttng_fallthrough;
1804 case LTTNG_KERNEL_ABI_UPROBE:
1805 break;
1806
1807 case LTTNG_KERNEL_ABI_FUNCTION:
1808 lttng_fallthrough;
1809 case LTTNG_KERNEL_ABI_NOOP:
1810 lttng_fallthrough;
1811 default:
1812 return -EINVAL;
1813 }
1814 return 0;
1815 }
1816
1817 static
1818 int lttng_abi_create_event(struct file *channel_file,
1819 struct lttng_kernel_abi_event *event_param)
1820 {
1821 const struct file_operations *fops;
1822 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1823 int event_fd, ret;
1824 struct file *event_file;
1825 void *priv;
1826
1827 event_param->name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1828 switch (event_param->instrumentation) {
1829 case LTTNG_KERNEL_ABI_KRETPROBE:
1830 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1831 break;
1832 case LTTNG_KERNEL_ABI_KPROBE:
1833 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1834 break;
1835 case LTTNG_KERNEL_ABI_FUNCTION:
1836 WARN_ON_ONCE(1);
1837 /* Not implemented. */
1838 break;
1839 default:
1840 break;
1841 }
1842
1843 switch (event_param->instrumentation) {
1844 case LTTNG_KERNEL_ABI_TRACEPOINT:
1845 lttng_fallthrough;
1846 case LTTNG_KERNEL_ABI_SYSCALL:
1847 fops = &lttng_event_recorder_enabler_fops;
1848 break;
1849 case LTTNG_KERNEL_ABI_KPROBE:
1850 lttng_fallthrough;
1851 case LTTNG_KERNEL_ABI_KRETPROBE:
1852 lttng_fallthrough;
1853 case LTTNG_KERNEL_ABI_UPROBE:
1854 fops = &lttng_event_recorder_event_fops;
1855 break;
1856
1857 case LTTNG_KERNEL_ABI_FUNCTION:
1858 lttng_fallthrough;
1859 case LTTNG_KERNEL_ABI_NOOP:
1860 lttng_fallthrough;
1861 default:
1862 return -EINVAL;
1863 }
1864
1865 event_fd = lttng_get_unused_fd();
1866 if (event_fd < 0) {
1867 ret = event_fd;
1868 goto fd_error;
1869 }
1870 event_file = anon_inode_getfile("[lttng_event]",
1871 fops, NULL, O_RDWR);
1872 if (IS_ERR(event_file)) {
1873 ret = PTR_ERR(event_file);
1874 goto file_error;
1875 }
1876 /* The event holds a reference on the channel */
1877 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1878 ret = -EOVERFLOW;
1879 goto refcount_error;
1880 }
1881 ret = lttng_abi_validate_event_param(event_param);
1882 if (ret)
1883 goto event_error;
1884
1885 switch (event_param->instrumentation) {
1886 case LTTNG_KERNEL_ABI_TRACEPOINT:
1887 lttng_fallthrough;
1888 case LTTNG_KERNEL_ABI_SYSCALL:
1889 {
1890 struct lttng_event_recorder_enabler *event_enabler;
1891
1892 if (strutils_is_star_glob_pattern(event_param->name)) {
1893 /*
1894 * If the event name is a star globbing pattern,
1895 * we create the special star globbing enabler.
1896 */
1897 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_STAR_GLOB,
1898 event_param, channel);
1899 } else {
1900 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1901 event_param, channel);
1902 }
1903 if (event_enabler)
1904 lttng_event_enabler_session_add(channel->parent.session, event_enabler);
1905 priv = event_enabler;
1906 break;
1907 }
1908
1909 case LTTNG_KERNEL_ABI_KPROBE:
1910 lttng_fallthrough;
1911 case LTTNG_KERNEL_ABI_KRETPROBE:
1912 lttng_fallthrough;
1913 case LTTNG_KERNEL_ABI_UPROBE:
1914 {
1915 struct lttng_kernel_event_common *event;
1916 struct lttng_event_recorder_enabler *event_enabler;
1917
1918 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1919 event_param, channel);
1920 if (!event_enabler) {
1921 ret = -ENOMEM;
1922 goto event_error;
1923 }
1924 /*
1925 * We tolerate no failure path after event creation. It
1926 * will stay invariant for the rest of the session.
1927 */
1928 event = lttng_kernel_event_create(&event_enabler->parent, NULL);
1929 WARN_ON_ONCE(!event);
1930 lttng_event_enabler_destroy(&event_enabler->parent);
1931 if (IS_ERR(event)) {
1932 ret = PTR_ERR(event);
1933 goto event_error;
1934 }
1935 priv = container_of(event, struct lttng_kernel_event_recorder, parent);
1936 break;
1937 }
1938
1939 case LTTNG_KERNEL_ABI_FUNCTION:
1940 lttng_fallthrough;
1941 case LTTNG_KERNEL_ABI_NOOP:
1942 lttng_fallthrough;
1943 default:
1944 ret = -EINVAL;
1945 goto event_error;
1946 }
1947 event_file->private_data = priv;
1948 fd_install(event_fd, event_file);
1949 return event_fd;
1950
1951 event_error:
1952 atomic_long_dec(&channel_file->f_count);
1953 refcount_error:
1954 fput(event_file);
1955 file_error:
1956 put_unused_fd(event_fd);
1957 fd_error:
1958 return ret;
1959 }
1960
1961 static
1962 long lttng_event_notifier_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1963 {
1964 struct lttng_kernel_event_notifier *event_notifier = file->private_data;
1965
1966 switch (cmd) {
1967 case LTTNG_KERNEL_ABI_ENABLE:
1968 return lttng_event_enable(&event_notifier->parent);
1969 case LTTNG_KERNEL_ABI_DISABLE:
1970 return lttng_event_disable(&event_notifier->parent);
1971 case LTTNG_KERNEL_ABI_FILTER:
1972 return -EINVAL;
1973 case LTTNG_KERNEL_ABI_CAPTURE:
1974 return -EINVAL;
1975 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
1976 return lttng_event_add_callsite(&event_notifier->parent,
1977 (struct lttng_kernel_abi_event_callsite __user *) arg);
1978 default:
1979 return -ENOIOCTLCMD;
1980 }
1981 }
1982
1983 static
1984 long lttng_event_notifier_enabler_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1985 {
1986 struct lttng_event_notifier_enabler *event_notifier_enabler = file->private_data;
1987
1988 switch (cmd) {
1989 case LTTNG_KERNEL_ABI_ENABLE:
1990 return lttng_event_enabler_enable(&event_notifier_enabler->parent);
1991 case LTTNG_KERNEL_ABI_DISABLE:
1992 return lttng_event_enabler_disable(&event_notifier_enabler->parent);
1993 case LTTNG_KERNEL_ABI_FILTER:
1994 return lttng_event_enabler_attach_filter_bytecode(&event_notifier_enabler->parent,
1995 (struct lttng_kernel_abi_filter_bytecode __user *) arg);
1996 case LTTNG_KERNEL_ABI_CAPTURE:
1997 return lttng_event_notifier_enabler_attach_capture_bytecode(
1998 event_notifier_enabler,
1999 (struct lttng_kernel_abi_capture_bytecode __user *) arg);
2000 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2001 return -EINVAL;
2002 default:
2003 return -ENOIOCTLCMD;
2004 }
2005 }
2006
2007 static
2008 int lttng_event_notifier_event_release(struct inode *inode, struct file *file)
2009 {
2010 struct lttng_kernel_event_notifier *event_notifier = file->private_data;
2011
2012 if (event_notifier)
2013 fput(event_notifier->priv->group->file);
2014 return 0;
2015 }
2016
2017 static
2018 int lttng_event_notifier_enabler_release(struct inode *inode, struct file *file)
2019 {
2020 struct lttng_event_notifier_enabler *event_notifier_enabler = file->private_data;
2021
2022 if (event_notifier_enabler)
2023 fput(event_notifier_enabler->group->file);
2024 return 0;
2025 }
2026
2027 static const struct file_operations lttng_event_notifier_event_fops = {
2028 .owner = THIS_MODULE,
2029 .release = lttng_event_notifier_event_release,
2030 .unlocked_ioctl = lttng_event_notifier_event_ioctl,
2031 #ifdef CONFIG_COMPAT
2032 .compat_ioctl = lttng_event_notifier_event_ioctl,
2033 #endif
2034 };
2035
2036 static const struct file_operations lttng_event_notifier_enabler_fops = {
2037 .owner = THIS_MODULE,
2038 .release = lttng_event_notifier_enabler_release,
2039 .unlocked_ioctl = lttng_event_notifier_enabler_ioctl,
2040 #ifdef CONFIG_COMPAT
2041 .compat_ioctl = lttng_event_notifier_enabler_ioctl,
2042 #endif
2043 };
2044
2045 static
2046 int lttng_abi_create_event_notifier(struct file *event_notifier_group_file,
2047 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2048 {
2049 struct lttng_event_notifier_group *event_notifier_group =
2050 event_notifier_group_file->private_data;
2051 const struct file_operations *fops;
2052 int event_notifier_fd, ret;
2053 struct file *event_notifier_file;
2054 void *priv;
2055
2056 switch (event_notifier_param->event.instrumentation) {
2057 case LTTNG_KERNEL_ABI_TRACEPOINT:
2058 case LTTNG_KERNEL_ABI_UPROBE:
2059 break;
2060 case LTTNG_KERNEL_ABI_KPROBE:
2061 event_notifier_param->event.u.kprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
2062 break;
2063 case LTTNG_KERNEL_ABI_SYSCALL:
2064 break;
2065 case LTTNG_KERNEL_ABI_KRETPROBE:
2066 /* Placing an event notifier on kretprobe is not supported. */
2067 case LTTNG_KERNEL_ABI_FUNCTION:
2068 case LTTNG_KERNEL_ABI_NOOP:
2069 default:
2070 ret = -EINVAL;
2071 goto inval_instr;
2072 }
2073
2074 switch (event_notifier_param->event.instrumentation) {
2075 case LTTNG_KERNEL_ABI_TRACEPOINT:
2076 lttng_fallthrough;
2077 case LTTNG_KERNEL_ABI_SYSCALL:
2078 fops = &lttng_event_notifier_enabler_fops;
2079 break;
2080 case LTTNG_KERNEL_ABI_KPROBE:
2081 lttng_fallthrough;
2082 case LTTNG_KERNEL_ABI_KRETPROBE:
2083 lttng_fallthrough;
2084 case LTTNG_KERNEL_ABI_UPROBE:
2085 fops = &lttng_event_notifier_event_fops;
2086 break;
2087
2088 case LTTNG_KERNEL_ABI_FUNCTION:
2089 lttng_fallthrough;
2090 case LTTNG_KERNEL_ABI_NOOP:
2091 lttng_fallthrough;
2092 default:
2093 ret = -EINVAL;
2094 goto inval_instr;
2095 }
2096
2097 event_notifier_param->event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
2098
2099 event_notifier_fd = lttng_get_unused_fd();
2100 if (event_notifier_fd < 0) {
2101 ret = event_notifier_fd;
2102 goto fd_error;
2103 }
2104
2105 event_notifier_file = anon_inode_getfile("[lttng_event_notifier]",
2106 fops, NULL, O_RDWR);
2107 if (IS_ERR(event_notifier_file)) {
2108 ret = PTR_ERR(event_notifier_file);
2109 goto file_error;
2110 }
2111
2112 /* The event notifier holds a reference on the event notifier group. */
2113 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
2114 ret = -EOVERFLOW;
2115 goto refcount_error;
2116 }
2117
2118 ret = lttng_abi_validate_event_param(&event_notifier_param->event);
2119 if (ret)
2120 goto event_notifier_error;
2121
2122 switch (event_notifier_param->event.instrumentation) {
2123 case LTTNG_KERNEL_ABI_TRACEPOINT:
2124 lttng_fallthrough;
2125 case LTTNG_KERNEL_ABI_SYSCALL:
2126 {
2127 struct lttng_event_notifier_enabler *enabler;
2128
2129 if (strutils_is_star_glob_pattern(event_notifier_param->event.name)) {
2130 /*
2131 * If the event name is a star globbing pattern,
2132 * we create the special star globbing enabler.
2133 */
2134 enabler = lttng_event_notifier_enabler_create(
2135 LTTNG_ENABLER_FORMAT_STAR_GLOB,
2136 event_notifier_param,
2137 event_notifier_group);
2138 } else {
2139 enabler = lttng_event_notifier_enabler_create(
2140 LTTNG_ENABLER_FORMAT_NAME,
2141 event_notifier_param,
2142 event_notifier_group);
2143 }
2144 if (enabler)
2145 lttng_event_notifier_enabler_group_add(event_notifier_group, enabler);
2146 priv = enabler;
2147 break;
2148 }
2149
2150 case LTTNG_KERNEL_ABI_KPROBE:
2151 lttng_fallthrough;
2152 case LTTNG_KERNEL_ABI_KRETPROBE:
2153 lttng_fallthrough;
2154 case LTTNG_KERNEL_ABI_UPROBE:
2155 {
2156 struct lttng_kernel_event_common *event;
2157 struct lttng_event_notifier_enabler *event_notifier_enabler;
2158
2159 event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
2160 event_notifier_param, event_notifier_group);
2161 if (!event_notifier_enabler) {
2162 ret = -ENOMEM;
2163 goto event_notifier_error;
2164 }
2165 event = lttng_kernel_event_create(&event_notifier_enabler->parent, NULL);
2166 WARN_ON_ONCE(!event);
2167 lttng_event_enabler_destroy(&event_notifier_enabler->parent);
2168 if (IS_ERR(event)) {
2169 ret = PTR_ERR(event);
2170 goto event_notifier_error;
2171 }
2172 priv = container_of(event, struct lttng_kernel_event_notifier, parent);
2173 break;
2174 }
2175
2176 case LTTNG_KERNEL_ABI_FUNCTION:
2177 lttng_fallthrough;
2178 case LTTNG_KERNEL_ABI_NOOP:
2179 lttng_fallthrough;
2180 default:
2181 ret = -EINVAL;
2182 goto event_notifier_error;
2183 }
2184 event_notifier_file->private_data = priv;
2185 fd_install(event_notifier_fd, event_notifier_file);
2186 return event_notifier_fd;
2187
2188 event_notifier_error:
2189 atomic_long_dec(&event_notifier_group_file->f_count);
2190 refcount_error:
2191 fput(event_notifier_file);
2192 file_error:
2193 put_unused_fd(event_notifier_fd);
2194 fd_error:
2195 inval_instr:
2196 return ret;
2197 }
2198
2199 static
2200 long lttng_abi_event_notifier_group_create_error_counter(
2201 struct file *event_notifier_group_file,
2202 const struct lttng_kernel_abi_counter_conf *error_counter_conf)
2203 {
2204 int counter_fd, ret;
2205 char *counter_transport_name;
2206 size_t counter_len;
2207 struct lttng_counter *counter = NULL;
2208 struct file *counter_file;
2209 struct lttng_event_notifier_group *event_notifier_group =
2210 (struct lttng_event_notifier_group *) event_notifier_group_file->private_data;
2211
2212 if (error_counter_conf->arithmetic != LTTNG_KERNEL_ABI_COUNTER_ARITHMETIC_MODULAR) {
2213 printk(KERN_ERR "LTTng: event_notifier: Error counter of the wrong arithmetic type.\n");
2214 return -EINVAL;
2215 }
2216
2217 if (error_counter_conf->number_dimensions != 1) {
2218 printk(KERN_ERR "LTTng: event_notifier: Error counter has more than one dimension.\n");
2219 return -EINVAL;
2220 }
2221
2222 switch (error_counter_conf->bitness) {
2223 case LTTNG_KERNEL_ABI_COUNTER_BITNESS_64:
2224 counter_transport_name = "counter-per-cpu-64-modular";
2225 break;
2226 case LTTNG_KERNEL_ABI_COUNTER_BITNESS_32:
2227 counter_transport_name = "counter-per-cpu-32-modular";
2228 break;
2229 default:
2230 return -EINVAL;
2231 }
2232
2233 /*
2234 * Lock sessions to provide mutual exclusion against concurrent
2235 * modification of event_notifier group, which would result in
2236 * overwriting the error counter if set concurrently.
2237 */
2238 lttng_lock_sessions();
2239
2240 if (event_notifier_group->error_counter) {
2241 printk(KERN_ERR "Error counter already created in event_notifier group\n");
2242 ret = -EBUSY;
2243 goto fd_error;
2244 }
2245
2246 counter_fd = lttng_get_unused_fd();
2247 if (counter_fd < 0) {
2248 ret = counter_fd;
2249 goto fd_error;
2250 }
2251
2252 counter_file = anon_inode_getfile("[lttng_counter]",
2253 &lttng_counter_fops,
2254 NULL, O_RDONLY);
2255 if (IS_ERR(counter_file)) {
2256 ret = PTR_ERR(counter_file);
2257 goto file_error;
2258 }
2259
2260 counter_len = error_counter_conf->dimensions[0].size;
2261
2262 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
2263 ret = -EOVERFLOW;
2264 goto refcount_error;
2265 }
2266
2267 counter = lttng_kernel_counter_create(counter_transport_name,
2268 1, &counter_len);
2269 if (!counter) {
2270 ret = -EINVAL;
2271 goto counter_error;
2272 }
2273
2274 event_notifier_group->error_counter_len = counter_len;
2275 /*
2276 * store-release to publish error counter matches load-acquire
2277 * in record_error. Ensures the counter is created and the
2278 * error_counter_len is set before they are used.
2279 */
2280 lttng_smp_store_release(&event_notifier_group->error_counter, counter);
2281
2282 counter->file = counter_file;
2283 counter->owner = event_notifier_group->file;
2284 counter_file->private_data = counter;
2285 /* Ownership transferred. */
2286 counter = NULL;
2287
2288 fd_install(counter_fd, counter_file);
2289 lttng_unlock_sessions();
2290
2291 return counter_fd;
2292
2293 counter_error:
2294 atomic_long_dec(&event_notifier_group_file->f_count);
2295 refcount_error:
2296 fput(counter_file);
2297 file_error:
2298 put_unused_fd(counter_fd);
2299 fd_error:
2300 lttng_unlock_sessions();
2301 return ret;
2302 }
2303
2304 static
2305 long lttng_event_notifier_group_ioctl(struct file *file, unsigned int cmd,
2306 unsigned long arg)
2307 {
2308 switch (cmd) {
2309 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD:
2310 {
2311 return lttng_abi_open_event_notifier_group_stream(file);
2312 }
2313 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_CREATE:
2314 {
2315 struct lttng_kernel_abi_event_notifier uevent_notifier_param;
2316
2317 if (copy_from_user(&uevent_notifier_param,
2318 (struct lttng_kernel_abi_event_notifier __user *) arg,
2319 sizeof(uevent_notifier_param)))
2320 return -EFAULT;
2321 return lttng_abi_create_event_notifier(file, &uevent_notifier_param);
2322 }
2323 case LTTNG_KERNEL_ABI_COUNTER:
2324 {
2325 struct lttng_kernel_abi_counter_conf uerror_counter_conf;
2326
2327 if (copy_from_user(&uerror_counter_conf,
2328 (struct lttng_kernel_abi_counter_conf __user *) arg,
2329 sizeof(uerror_counter_conf)))
2330 return -EFAULT;
2331 return lttng_abi_event_notifier_group_create_error_counter(file,
2332 &uerror_counter_conf);
2333 }
2334 default:
2335 return -ENOIOCTLCMD;
2336 }
2337 return 0;
2338 }
2339
2340 static
2341 int lttng_event_notifier_group_release(struct inode *inode, struct file *file)
2342 {
2343 struct lttng_event_notifier_group *event_notifier_group =
2344 file->private_data;
2345
2346 if (event_notifier_group)
2347 lttng_event_notifier_group_destroy(event_notifier_group);
2348 return 0;
2349 }
2350
2351 static const struct file_operations lttng_event_notifier_group_fops = {
2352 .owner = THIS_MODULE,
2353 .release = lttng_event_notifier_group_release,
2354 .unlocked_ioctl = lttng_event_notifier_group_ioctl,
2355 #ifdef CONFIG_COMPAT
2356 .compat_ioctl = lttng_event_notifier_group_ioctl,
2357 #endif
2358 };
2359
2360 /**
2361 * lttng_channel_ioctl - lttng syscall through ioctl
2362 *
2363 * @file: the file
2364 * @cmd: the command
2365 * @arg: command arg
2366 *
2367 * This ioctl implements lttng commands:
2368 * LTTNG_KERNEL_ABI_STREAM
2369 * Returns an event stream file descriptor or failure.
2370 * (typically, one event stream records events from one CPU)
2371 * LTTNG_KERNEL_ABI_EVENT
2372 * Returns an event file descriptor or failure.
2373 * LTTNG_KERNEL_ABI_CONTEXT
2374 * Prepend a context field to each event in the channel
2375 * LTTNG_KERNEL_ABI_ENABLE
2376 * Enable recording for events in this channel (weak enable)
2377 * LTTNG_KERNEL_ABI_DISABLE
2378 * Disable recording for events in this channel (strong disable)
2379 *
2380 * Channel and event file descriptors also hold a reference on the session.
2381 */
2382 static
2383 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2384 {
2385 struct lttng_kernel_channel_buffer *channel = file->private_data;
2386
2387 switch (cmd) {
2388 case LTTNG_KERNEL_ABI_OLD_STREAM:
2389 case LTTNG_KERNEL_ABI_STREAM:
2390 return lttng_abi_open_stream(file);
2391 case LTTNG_KERNEL_ABI_OLD_EVENT:
2392 {
2393 struct lttng_kernel_abi_event *uevent_param;
2394 struct lttng_kernel_abi_old_event *old_uevent_param;
2395 int ret;
2396
2397 uevent_param = kmalloc(sizeof(struct lttng_kernel_abi_event),
2398 GFP_KERNEL);
2399 if (!uevent_param) {
2400 ret = -ENOMEM;
2401 goto old_event_end;
2402 }
2403 old_uevent_param = kmalloc(
2404 sizeof(struct lttng_kernel_abi_old_event),
2405 GFP_KERNEL);
2406 if (!old_uevent_param) {
2407 ret = -ENOMEM;
2408 goto old_event_error_free_param;
2409 }
2410 if (copy_from_user(old_uevent_param,
2411 (struct lttng_kernel_abi_old_event __user *) arg,
2412 sizeof(struct lttng_kernel_abi_old_event))) {
2413 ret = -EFAULT;
2414 goto old_event_error_free_old_param;
2415 }
2416
2417 memcpy(uevent_param->name, old_uevent_param->name,
2418 sizeof(uevent_param->name));
2419 uevent_param->instrumentation =
2420 old_uevent_param->instrumentation;
2421
2422 switch (old_uevent_param->instrumentation) {
2423 case LTTNG_KERNEL_ABI_KPROBE:
2424 uevent_param->u.kprobe.addr =
2425 old_uevent_param->u.kprobe.addr;
2426 uevent_param->u.kprobe.offset =
2427 old_uevent_param->u.kprobe.offset;
2428 memcpy(uevent_param->u.kprobe.symbol_name,
2429 old_uevent_param->u.kprobe.symbol_name,
2430 sizeof(uevent_param->u.kprobe.symbol_name));
2431 break;
2432 case LTTNG_KERNEL_ABI_KRETPROBE:
2433 uevent_param->u.kretprobe.addr =
2434 old_uevent_param->u.kretprobe.addr;
2435 uevent_param->u.kretprobe.offset =
2436 old_uevent_param->u.kretprobe.offset;
2437 memcpy(uevent_param->u.kretprobe.symbol_name,
2438 old_uevent_param->u.kretprobe.symbol_name,
2439 sizeof(uevent_param->u.kretprobe.symbol_name));
2440 break;
2441 case LTTNG_KERNEL_ABI_FUNCTION:
2442 WARN_ON_ONCE(1);
2443 /* Not implemented. */
2444 break;
2445 default:
2446 break;
2447 }
2448 ret = lttng_abi_create_event(file, uevent_param);
2449
2450 old_event_error_free_old_param:
2451 kfree(old_uevent_param);
2452 old_event_error_free_param:
2453 kfree(uevent_param);
2454 old_event_end:
2455 return ret;
2456 }
2457 case LTTNG_KERNEL_ABI_EVENT:
2458 {
2459 struct lttng_kernel_abi_event uevent_param;
2460
2461 if (copy_from_user(&uevent_param,
2462 (struct lttng_kernel_abi_event __user *) arg,
2463 sizeof(uevent_param)))
2464 return -EFAULT;
2465 return lttng_abi_create_event(file, &uevent_param);
2466 }
2467 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2468 {
2469 struct lttng_kernel_abi_context *ucontext_param;
2470 struct lttng_kernel_abi_old_context *old_ucontext_param;
2471 int ret;
2472
2473 ucontext_param = kmalloc(sizeof(struct lttng_kernel_abi_context),
2474 GFP_KERNEL);
2475 if (!ucontext_param) {
2476 ret = -ENOMEM;
2477 goto old_ctx_end;
2478 }
2479 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_abi_old_context),
2480 GFP_KERNEL);
2481 if (!old_ucontext_param) {
2482 ret = -ENOMEM;
2483 goto old_ctx_error_free_param;
2484 }
2485
2486 if (copy_from_user(old_ucontext_param,
2487 (struct lttng_kernel_abi_old_context __user *) arg,
2488 sizeof(struct lttng_kernel_abi_old_context))) {
2489 ret = -EFAULT;
2490 goto old_ctx_error_free_old_param;
2491 }
2492 ucontext_param->ctx = old_ucontext_param->ctx;
2493 memcpy(ucontext_param->padding, old_ucontext_param->padding,
2494 sizeof(ucontext_param->padding));
2495 /* only type that uses the union */
2496 if (old_ucontext_param->ctx == LTTNG_KERNEL_ABI_CONTEXT_PERF_COUNTER) {
2497 ucontext_param->u.perf_counter.type =
2498 old_ucontext_param->u.perf_counter.type;
2499 ucontext_param->u.perf_counter.config =
2500 old_ucontext_param->u.perf_counter.config;
2501 memcpy(ucontext_param->u.perf_counter.name,
2502 old_ucontext_param->u.perf_counter.name,
2503 sizeof(ucontext_param->u.perf_counter.name));
2504 }
2505
2506 ret = lttng_abi_add_context(file,
2507 ucontext_param,
2508 &channel->priv->ctx, channel->parent.session);
2509
2510 old_ctx_error_free_old_param:
2511 kfree(old_ucontext_param);
2512 old_ctx_error_free_param:
2513 kfree(ucontext_param);
2514 old_ctx_end:
2515 return ret;
2516 }
2517 case LTTNG_KERNEL_ABI_CONTEXT:
2518 {
2519 struct lttng_kernel_abi_context ucontext_param;
2520
2521 if (copy_from_user(&ucontext_param,
2522 (struct lttng_kernel_abi_context __user *) arg,
2523 sizeof(ucontext_param)))
2524 return -EFAULT;
2525 return lttng_abi_add_context(file,
2526 &ucontext_param,
2527 &channel->priv->ctx, channel->parent.session);
2528 }
2529 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2530 case LTTNG_KERNEL_ABI_ENABLE:
2531 return lttng_channel_enable(&channel->parent);
2532 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2533 case LTTNG_KERNEL_ABI_DISABLE:
2534 return lttng_channel_disable(&channel->parent);
2535 case LTTNG_KERNEL_ABI_SYSCALL_MASK:
2536 return lttng_syscall_table_get_active_mask(&channel->priv->parent.syscall_table,
2537 (struct lttng_kernel_abi_syscall_mask __user *) arg);
2538 default:
2539 return -ENOIOCTLCMD;
2540 }
2541 }
2542
2543 /**
2544 * lttng_metadata_ioctl - lttng syscall through ioctl
2545 *
2546 * @file: the file
2547 * @cmd: the command
2548 * @arg: command arg
2549 *
2550 * This ioctl implements lttng commands:
2551 * LTTNG_KERNEL_ABI_STREAM
2552 * Returns an event stream file descriptor or failure.
2553 *
2554 * Channel and event file descriptors also hold a reference on the session.
2555 */
2556 static
2557 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2558 {
2559 switch (cmd) {
2560 case LTTNG_KERNEL_ABI_OLD_STREAM:
2561 case LTTNG_KERNEL_ABI_STREAM:
2562 return lttng_abi_open_metadata_stream(file);
2563 default:
2564 return -ENOIOCTLCMD;
2565 }
2566 }
2567
2568 /**
2569 * lttng_channel_poll - lttng stream addition/removal monitoring
2570 *
2571 * @file: the file
2572 * @wait: poll table
2573 */
2574 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
2575 {
2576 struct lttng_kernel_channel_buffer *channel = file->private_data;
2577 unsigned int mask = 0;
2578
2579 if (file->f_mode & FMODE_READ) {
2580 poll_wait_set_exclusive(wait);
2581 poll_wait(file, channel->ops->priv->get_hp_wait_queue(channel->priv->rb_chan),
2582 wait);
2583
2584 if (channel->ops->priv->is_disabled(channel->priv->rb_chan))
2585 return POLLERR;
2586 if (channel->ops->priv->is_finalized(channel->priv->rb_chan))
2587 return POLLHUP;
2588 if (channel->ops->priv->buffer_has_read_closed_stream(channel->priv->rb_chan))
2589 return POLLIN | POLLRDNORM;
2590 return 0;
2591 }
2592 return mask;
2593
2594 }
2595
2596 static
2597 int lttng_channel_release(struct inode *inode, struct file *file)
2598 {
2599 struct lttng_kernel_channel_buffer *channel = file->private_data;
2600
2601 if (channel)
2602 fput(channel->parent.session->priv->file);
2603 return 0;
2604 }
2605
2606 static
2607 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
2608 {
2609 struct lttng_kernel_channel_buffer *channel = file->private_data;
2610
2611 if (channel) {
2612 fput(channel->parent.session->priv->file);
2613 lttng_metadata_channel_destroy(channel);
2614 }
2615
2616 return 0;
2617 }
2618
2619 static const struct file_operations lttng_channel_fops = {
2620 .owner = THIS_MODULE,
2621 .release = lttng_channel_release,
2622 .poll = lttng_channel_poll,
2623 .unlocked_ioctl = lttng_channel_ioctl,
2624 #ifdef CONFIG_COMPAT
2625 .compat_ioctl = lttng_channel_ioctl,
2626 #endif
2627 };
2628
2629 static const struct file_operations lttng_metadata_fops = {
2630 .owner = THIS_MODULE,
2631 .release = lttng_metadata_channel_release,
2632 .unlocked_ioctl = lttng_metadata_ioctl,
2633 #ifdef CONFIG_COMPAT
2634 .compat_ioctl = lttng_metadata_ioctl,
2635 #endif
2636 };
2637
2638 /**
2639 * lttng_event_recorder_event_ioctl - lttng syscall through ioctl
2640 *
2641 * @file: the file
2642 * @cmd: the command
2643 * @arg: command arg
2644 *
2645 * This ioctl implements lttng commands:
2646 * LTTNG_KERNEL_ABI_CONTEXT
2647 * Prepend a context field to each record of this event
2648 * LTTNG_KERNEL_ABI_ENABLE
2649 * Enable recording for this event (weak enable)
2650 * LTTNG_KERNEL_ABI_DISABLE
2651 * Disable recording for this event (strong disable)
2652 */
2653 static
2654 long lttng_event_recorder_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2655 {
2656 struct lttng_kernel_event_recorder *event_recorder = file->private_data;
2657
2658 switch (cmd) {
2659 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2660 {
2661 /* Not implemented */
2662 return -ENOSYS;
2663 }
2664 case LTTNG_KERNEL_ABI_CONTEXT:
2665 {
2666 /* Not implemented */
2667 return -ENOSYS;
2668 }
2669 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2670 case LTTNG_KERNEL_ABI_ENABLE:
2671 return lttng_event_enable(&event_recorder->parent);
2672 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2673 case LTTNG_KERNEL_ABI_DISABLE:
2674 return lttng_event_disable(&event_recorder->parent);
2675 case LTTNG_KERNEL_ABI_FILTER:
2676 return -EINVAL;
2677 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2678 return lttng_event_add_callsite(&event_recorder->parent,
2679 (struct lttng_kernel_abi_event_callsite __user *) arg);
2680 default:
2681 return -ENOIOCTLCMD;
2682 }
2683 }
2684
2685 /**
2686 * lttng_event_recorder_enabler_ioctl - lttng syscall through ioctl
2687 *
2688 * @file: the file
2689 * @cmd: the command
2690 * @arg: command arg
2691 *
2692 * This ioctl implements lttng commands:
2693 * LTTNG_KERNEL_ABI_CONTEXT
2694 * Prepend a context field to each record of this event
2695 * LTTNG_KERNEL_ABI_ENABLE
2696 * Enable recording for this event (weak enable)
2697 * LTTNG_KERNEL_ABI_DISABLE
2698 * Disable recording for this event (strong disable)
2699 */
2700 static
2701 long lttng_event_recorder_enabler_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2702 {
2703 struct lttng_event_recorder_enabler *event_enabler = file->private_data;
2704
2705 switch (cmd) {
2706 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2707 {
2708 /* Not implemented */
2709 return -ENOSYS;
2710 }
2711 case LTTNG_KERNEL_ABI_CONTEXT:
2712 {
2713 /* Not implemented */
2714 return -ENOSYS;
2715 }
2716 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2717 case LTTNG_KERNEL_ABI_ENABLE:
2718 return lttng_event_enabler_enable(&event_enabler->parent);
2719 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2720 case LTTNG_KERNEL_ABI_DISABLE:
2721 return lttng_event_enabler_disable(&event_enabler->parent);
2722 case LTTNG_KERNEL_ABI_FILTER:
2723 return lttng_event_enabler_attach_filter_bytecode(&event_enabler->parent,
2724 (struct lttng_kernel_abi_filter_bytecode __user *) arg);
2725 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2726 return -EINVAL;
2727 default:
2728 return -ENOIOCTLCMD;
2729 }
2730 }
2731
2732 static
2733 int lttng_event_recorder_event_release(struct inode *inode, struct file *file)
2734 {
2735 struct lttng_kernel_event_recorder *event = file->private_data;
2736
2737 if (event)
2738 fput(event->chan->priv->parent.file);
2739 return 0;
2740 }
2741
2742 static
2743 int lttng_event_recorder_enabler_release(struct inode *inode, struct file *file)
2744 {
2745 struct lttng_event_recorder_enabler *event_enabler = file->private_data;
2746
2747 if (event_enabler)
2748 fput(event_enabler->chan->priv->parent.file);
2749 return 0;
2750 }
2751
2752 static const struct file_operations lttng_event_recorder_event_fops = {
2753 .owner = THIS_MODULE,
2754 .release = lttng_event_recorder_event_release,
2755 .unlocked_ioctl = lttng_event_recorder_event_ioctl,
2756 #ifdef CONFIG_COMPAT
2757 .compat_ioctl = lttng_event_recorder_event_ioctl,
2758 #endif
2759 };
2760
2761 static const struct file_operations lttng_event_recorder_enabler_fops = {
2762 .owner = THIS_MODULE,
2763 .release = lttng_event_recorder_enabler_release,
2764 .unlocked_ioctl = lttng_event_recorder_enabler_ioctl,
2765 #ifdef CONFIG_COMPAT
2766 .compat_ioctl = lttng_event_recorder_enabler_ioctl,
2767 #endif
2768 };
2769
2770 static int put_u64(uint64_t val, unsigned long arg)
2771 {
2772 return put_user(val, (uint64_t __user *) arg);
2773 }
2774
2775 static int put_u32(uint32_t val, unsigned long arg)
2776 {
2777 return put_user(val, (uint32_t __user *) arg);
2778 }
2779
2780 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
2781 unsigned int cmd, unsigned long arg)
2782 {
2783 struct lttng_kernel_ring_buffer *buf = filp->private_data;
2784 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
2785 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
2786 const struct lttng_kernel_channel_buffer_ops *ops = chan->backend.priv_ops;
2787 int ret;
2788
2789 if (atomic_read(&chan->record_disabled))
2790 return -EIO;
2791
2792 switch (cmd) {
2793 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_TIMESTAMP_BEGIN:
2794 {
2795 uint64_t ts;
2796
2797 ret = ops->priv->timestamp_begin(config, buf, &ts);
2798 if (ret < 0)
2799 goto error;
2800 return put_u64(ts, arg);
2801 }
2802 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_TIMESTAMP_END:
2803 {
2804 uint64_t ts;
2805
2806 ret = ops->priv->timestamp_end(config, buf, &ts);
2807 if (ret < 0)
2808 goto error;
2809 return put_u64(ts, arg);
2810 }
2811 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_EVENTS_DISCARDED:
2812 {
2813 uint64_t ed;
2814
2815 ret = ops->priv->events_discarded(config, buf, &ed);
2816 if (ret < 0)
2817 goto error;
2818 return put_u64(ed, arg);
2819 }
2820 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CONTENT_SIZE:
2821 {
2822 uint64_t cs;
2823
2824 ret = ops->priv->content_size(config, buf, &cs);
2825 if (ret < 0)
2826 goto error;
2827 return put_u64(cs, arg);
2828 }
2829 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_PACKET_SIZE:
2830 {
2831 uint64_t ps;
2832
2833 ret = ops->priv->packet_size(config, buf, &ps);
2834 if (ret < 0)
2835 goto error;
2836 return put_u64(ps, arg);
2837 }
2838 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_STREAM_ID:
2839 {
2840 uint64_t si;
2841
2842 ret = ops->priv->stream_id(config, buf, &si);
2843 if (ret < 0)
2844 goto error;
2845 return put_u64(si, arg);
2846 }
2847 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2848 {
2849 uint64_t ts;
2850
2851 ret = ops->priv->current_timestamp(config, buf, &ts);
2852 if (ret < 0)
2853 goto error;
2854 return put_u64(ts, arg);
2855 }
2856 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SEQ_NUM:
2857 {
2858 uint64_t seq;
2859
2860 ret = ops->priv->sequence_number(config, buf, &seq);
2861 if (ret < 0)
2862 goto error;
2863 return put_u64(seq, arg);
2864 }
2865 case LTTNG_KERNEL_ABI_RING_BUFFER_INSTANCE_ID:
2866 {
2867 uint64_t id;
2868
2869 ret = ops->priv->instance_id(config, buf, &id);
2870 if (ret < 0)
2871 goto error;
2872 return put_u64(id, arg);
2873 }
2874 default:
2875 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
2876 cmd, arg);
2877 }
2878
2879 error:
2880 return -ENOSYS;
2881 }
2882
2883 #ifdef CONFIG_COMPAT
2884 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
2885 unsigned int cmd, unsigned long arg)
2886 {
2887 struct lttng_kernel_ring_buffer *buf = filp->private_data;
2888 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
2889 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
2890 const struct lttng_kernel_channel_buffer_ops *ops = chan->backend.priv_ops;
2891 int ret;
2892
2893 if (atomic_read(&chan->record_disabled))
2894 return -EIO;
2895
2896 switch (cmd) {
2897 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
2898 {
2899 uint64_t ts;
2900
2901 ret = ops->priv->timestamp_begin(config, buf, &ts);
2902 if (ret < 0)
2903 goto error;
2904 return put_u64(ts, arg);
2905 }
2906 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
2907 {
2908 uint64_t ts;
2909
2910 ret = ops->priv->timestamp_end(config, buf, &ts);
2911 if (ret < 0)
2912 goto error;
2913 return put_u64(ts, arg);
2914 }
2915 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
2916 {
2917 uint64_t ed;
2918
2919 ret = ops->priv->events_discarded(config, buf, &ed);
2920 if (ret < 0)
2921 goto error;
2922 return put_u64(ed, arg);
2923 }
2924 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
2925 {
2926 uint64_t cs;
2927
2928 ret = ops->priv->content_size(config, buf, &cs);
2929 if (ret < 0)
2930 goto error;
2931 return put_u64(cs, arg);
2932 }
2933 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
2934 {
2935 uint64_t ps;
2936
2937 ret = ops->priv->packet_size(config, buf, &ps);
2938 if (ret < 0)
2939 goto error;
2940 return put_u64(ps, arg);
2941 }
2942 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_STREAM_ID:
2943 {
2944 uint64_t si;
2945
2946 ret = ops->priv->stream_id(config, buf, &si);
2947 if (ret < 0)
2948 goto error;
2949 return put_u64(si, arg);
2950 }
2951 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2952 {
2953 uint64_t ts;
2954
2955 ret = ops->priv->current_timestamp(config, buf, &ts);
2956 if (ret < 0)
2957 goto error;
2958 return put_u64(ts, arg);
2959 }
2960 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_SEQ_NUM:
2961 {
2962 uint64_t seq;
2963
2964 ret = ops->priv->sequence_number(config, buf, &seq);
2965 if (ret < 0)
2966 goto error;
2967 return put_u64(seq, arg);
2968 }
2969 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_INSTANCE_ID:
2970 {
2971 uint64_t id;
2972
2973 ret = ops->priv->instance_id(config, buf, &id);
2974 if (ret < 0)
2975 goto error;
2976 return put_u64(id, arg);
2977 }
2978 default:
2979 return lib_ring_buffer_file_operations.compat_ioctl(filp,
2980 cmd, arg);
2981 }
2982
2983 error:
2984 return -ENOSYS;
2985 }
2986 #endif /* CONFIG_COMPAT */
2987
2988 static void lttng_stream_override_ring_buffer_fops(void)
2989 {
2990 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
2991 lttng_stream_ring_buffer_file_operations.open =
2992 lib_ring_buffer_file_operations.open;
2993 lttng_stream_ring_buffer_file_operations.release =
2994 lib_ring_buffer_file_operations.release;
2995 lttng_stream_ring_buffer_file_operations.poll =
2996 lib_ring_buffer_file_operations.poll;
2997 lttng_stream_ring_buffer_file_operations.splice_read =
2998 lib_ring_buffer_file_operations.splice_read;
2999 lttng_stream_ring_buffer_file_operations.mmap =
3000 lib_ring_buffer_file_operations.mmap;
3001 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
3002 lttng_stream_ring_buffer_ioctl;
3003 lttng_stream_ring_buffer_file_operations.llseek =
3004 lib_ring_buffer_file_operations.llseek;
3005 #ifdef CONFIG_COMPAT
3006 lttng_stream_ring_buffer_file_operations.compat_ioctl =
3007 lttng_stream_ring_buffer_compat_ioctl;
3008 #endif
3009 }
3010
3011 int __init lttng_abi_init(void)
3012 {
3013 int ret = 0;
3014
3015 wrapper_vmalloc_sync_mappings();
3016 lttng_clock_ref();
3017
3018 ret = lttng_tp_mempool_init();
3019 if (ret) {
3020 goto error;
3021 }
3022
3023 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
3024 &lttng_proc_ops, NULL);
3025
3026 if (!lttng_proc_dentry) {
3027 printk(KERN_ERR "LTTng: Error creating control file\n");
3028 ret = -ENOMEM;
3029 goto error;
3030 }
3031 lttng_stream_override_ring_buffer_fops();
3032 return 0;
3033
3034 error:
3035 lttng_tp_mempool_destroy();
3036 lttng_clock_unref();
3037 return ret;
3038 }
3039
3040 /* No __exit annotation because used by init error path too. */
3041 void lttng_abi_exit(void)
3042 {
3043 lttng_tp_mempool_destroy();
3044 lttng_clock_unref();
3045 if (lttng_proc_dentry)
3046 remove_proc_entry("lttng", NULL);
3047 }
LTTng 2.0/0.x modules
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