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Fix: event notifier: racy use of last subbuffer record
[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_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 if (local_counter_read.index.number_dimensions > LTTNG_KERNEL_ABI_COUNTER_DIMENSION_MAX)
654 return -EINVAL;
655
656 /* Cast all indexes into size_t. */
657 for (i = 0; i < local_counter_read.index.number_dimensions; i++)
658 indexes[i] = (size_t) local_counter_read.index.dimension_indexes[i];
659 cpu = local_counter_read.cpu;
660
661 ret = lttng_kernel_counter_read(counter, indexes, cpu, &value,
662 &overflow, &underflow);
663 if (ret)
664 return ret;
665 local_counter_read.value.value = value;
666 local_counter_read.value.overflow = overflow;
667 local_counter_read.value.underflow = underflow;
668
669 if (copy_to_user(&ucounter_read->value, &local_counter_read.value,
670 sizeof(local_counter_read.value)))
671 return -EFAULT;
672
673 return 0;
674 }
675 case LTTNG_KERNEL_ABI_COUNTER_AGGREGATE:
676 {
677 struct lttng_kernel_abi_counter_aggregate local_counter_aggregate;
678 struct lttng_kernel_abi_counter_aggregate __user *ucounter_aggregate =
679 (struct lttng_kernel_abi_counter_aggregate __user *) arg;
680 bool overflow, underflow;
681 int64_t value;
682 int ret;
683
684 if (copy_from_user(&local_counter_aggregate, ucounter_aggregate,
685 sizeof(local_counter_aggregate)))
686 return -EFAULT;
687 if (validate_zeroed_padding(local_counter_aggregate.padding,
688 sizeof(local_counter_aggregate.padding)))
689 return -EINVAL;
690 if (local_counter_aggregate.index.number_dimensions > LTTNG_KERNEL_ABI_COUNTER_DIMENSION_MAX)
691 return -EINVAL;
692
693 /* Cast all indexes into size_t. */
694 for (i = 0; i < local_counter_aggregate.index.number_dimensions; i++)
695 indexes[i] = (size_t) local_counter_aggregate.index.dimension_indexes[i];
696
697 ret = lttng_kernel_counter_aggregate(counter, indexes, &value,
698 &overflow, &underflow);
699 if (ret)
700 return ret;
701 local_counter_aggregate.value.value = value;
702 local_counter_aggregate.value.overflow = overflow;
703 local_counter_aggregate.value.underflow = underflow;
704
705 if (copy_to_user(&ucounter_aggregate->value, &local_counter_aggregate.value,
706 sizeof(local_counter_aggregate.value)))
707 return -EFAULT;
708
709 return 0;
710 }
711 case LTTNG_KERNEL_ABI_COUNTER_CLEAR:
712 {
713 struct lttng_kernel_abi_counter_clear local_counter_clear;
714 struct lttng_kernel_abi_counter_clear __user *ucounter_clear =
715 (struct lttng_kernel_abi_counter_clear __user *) arg;
716
717 if (copy_from_user(&local_counter_clear, ucounter_clear,
718 sizeof(local_counter_clear)))
719 return -EFAULT;
720 if (validate_zeroed_padding(local_counter_clear.padding,
721 sizeof(local_counter_clear.padding)))
722 return -EINVAL;
723 if (local_counter_clear.index.number_dimensions > LTTNG_KERNEL_ABI_COUNTER_DIMENSION_MAX)
724 return -EINVAL;
725
726 /* Cast all indexes into size_t. */
727 for (i = 0; i < local_counter_clear.index.number_dimensions; i++)
728 indexes[i] = (size_t) local_counter_clear.index.dimension_indexes[i];
729
730 return lttng_kernel_counter_clear(counter, indexes);
731 }
732 default:
733 return -ENOSYS;
734 }
735 }
736
737 static const struct file_operations lttng_counter_fops = {
738 .owner = THIS_MODULE,
739 .release = lttng_counter_release,
740 .unlocked_ioctl = lttng_counter_ioctl,
741 #ifdef CONFIG_COMPAT
742 .compat_ioctl = lttng_counter_ioctl,
743 #endif
744 };
745
746
747 static
748 enum tracker_type get_tracker_type(struct lttng_kernel_abi_tracker_args *tracker)
749 {
750 switch (tracker->type) {
751 case LTTNG_KERNEL_ABI_TRACKER_PID:
752 return TRACKER_PID;
753 case LTTNG_KERNEL_ABI_TRACKER_VPID:
754 return TRACKER_VPID;
755 case LTTNG_KERNEL_ABI_TRACKER_UID:
756 return TRACKER_UID;
757 case LTTNG_KERNEL_ABI_TRACKER_VUID:
758 return TRACKER_VUID;
759 case LTTNG_KERNEL_ABI_TRACKER_GID:
760 return TRACKER_GID;
761 case LTTNG_KERNEL_ABI_TRACKER_VGID:
762 return TRACKER_VGID;
763 default:
764 return TRACKER_UNKNOWN;
765 }
766 }
767
768 /**
769 * lttng_session_ioctl - lttng session fd ioctl
770 *
771 * @file: the file
772 * @cmd: the command
773 * @arg: command arg
774 *
775 * This ioctl implements lttng commands:
776 * LTTNG_KERNEL_ABI_CHANNEL
777 * Returns a LTTng channel file descriptor
778 * LTTNG_KERNEL_ABI_ENABLE
779 * Enables tracing for a session (weak enable)
780 * LTTNG_KERNEL_ABI_DISABLE
781 * Disables tracing for a session (strong disable)
782 * LTTNG_KERNEL_ABI_METADATA
783 * Returns a LTTng metadata file descriptor
784 * LTTNG_KERNEL_ABI_SESSION_TRACK_PID
785 * Add PID to session PID tracker
786 * LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID
787 * Remove PID from session PID tracker
788 * LTTNG_KERNEL_ABI_SESSION_TRACK_ID
789 * Add ID to tracker
790 * LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID
791 * Remove ID from tracker
792 *
793 * The returned channel will be deleted when its file descriptor is closed.
794 */
795 static
796 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
797 {
798 struct lttng_kernel_session *session = file->private_data;
799 struct lttng_kernel_abi_channel chan_param;
800 struct lttng_kernel_abi_old_channel old_chan_param;
801
802 /*
803 * Handle backward compatibility. OLD commands have wrong
804 * directions, replace them by the correct direction.
805 */
806 switch (cmd) {
807 case LTTNG_KERNEL_ABI_OLD_SESSION_TRACK_PID:
808 cmd = LTTNG_KERNEL_ABI_SESSION_TRACK_PID;
809 break;
810 case LTTNG_KERNEL_ABI_OLD_SESSION_UNTRACK_PID:
811 cmd = LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID;
812 break;
813 case LTTNG_KERNEL_ABI_OLD_SESSION_TRACK_ID:
814 cmd = LTTNG_KERNEL_ABI_SESSION_TRACK_ID;
815 break;
816 case LTTNG_KERNEL_ABI_OLD_SESSION_UNTRACK_ID:
817 cmd = LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID;
818 break;
819 case LTTNG_KERNEL_ABI_OLD_SESSION_LIST_TRACKER_IDS:
820 cmd = LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_IDS;
821 break;
822 case LTTNG_KERNEL_ABI_OLD_SESSION_SET_NAME:
823 cmd = LTTNG_KERNEL_ABI_SESSION_SET_NAME;
824 break;
825 case LTTNG_KERNEL_ABI_OLD_SESSION_SET_CREATION_TIME:
826 cmd = LTTNG_KERNEL_ABI_SESSION_SET_CREATION_TIME;
827 break;
828 default:
829 /* Nothing to do. */
830 break;
831 }
832
833 switch (cmd) {
834 case LTTNG_KERNEL_ABI_OLD_CHANNEL:
835 {
836 if (copy_from_user(&old_chan_param,
837 (struct lttng_kernel_abi_old_channel __user *) arg,
838 sizeof(struct lttng_kernel_abi_old_channel)))
839 return -EFAULT;
840 chan_param.overwrite = old_chan_param.overwrite;
841 chan_param.subbuf_size = old_chan_param.subbuf_size;
842 chan_param.num_subbuf = old_chan_param.num_subbuf;
843 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
844 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
845 chan_param.output = old_chan_param.output;
846
847 return lttng_abi_create_channel(file, &chan_param,
848 PER_CPU_CHANNEL);
849 }
850 case LTTNG_KERNEL_ABI_CHANNEL:
851 {
852 if (copy_from_user(&chan_param,
853 (struct lttng_kernel_abi_channel __user *) arg,
854 sizeof(struct lttng_kernel_abi_channel)))
855 return -EFAULT;
856 return lttng_abi_create_channel(file, &chan_param,
857 PER_CPU_CHANNEL);
858 }
859 case LTTNG_KERNEL_ABI_OLD_SESSION_START:
860 case LTTNG_KERNEL_ABI_OLD_ENABLE:
861 case LTTNG_KERNEL_ABI_SESSION_START:
862 case LTTNG_KERNEL_ABI_ENABLE:
863 return lttng_session_enable(session);
864 case LTTNG_KERNEL_ABI_OLD_SESSION_STOP:
865 case LTTNG_KERNEL_ABI_OLD_DISABLE:
866 case LTTNG_KERNEL_ABI_SESSION_STOP:
867 case LTTNG_KERNEL_ABI_DISABLE:
868 return lttng_session_disable(session);
869 case LTTNG_KERNEL_ABI_OLD_METADATA:
870 {
871 if (copy_from_user(&old_chan_param,
872 (struct lttng_kernel_abi_old_channel __user *) arg,
873 sizeof(struct lttng_kernel_abi_old_channel)))
874 return -EFAULT;
875 chan_param.overwrite = old_chan_param.overwrite;
876 chan_param.subbuf_size = old_chan_param.subbuf_size;
877 chan_param.num_subbuf = old_chan_param.num_subbuf;
878 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
879 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
880 chan_param.output = old_chan_param.output;
881
882 return lttng_abi_create_channel(file, &chan_param,
883 METADATA_CHANNEL);
884 }
885 case LTTNG_KERNEL_ABI_METADATA:
886 {
887 if (copy_from_user(&chan_param,
888 (struct lttng_kernel_abi_channel __user *) arg,
889 sizeof(struct lttng_kernel_abi_channel)))
890 return -EFAULT;
891 return lttng_abi_create_channel(file, &chan_param,
892 METADATA_CHANNEL);
893 }
894 case LTTNG_KERNEL_ABI_SESSION_TRACK_PID:
895 return lttng_session_track_id(session, TRACKER_PID, (int) arg);
896 case LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID:
897 return lttng_session_untrack_id(session, TRACKER_PID, (int) arg);
898 case LTTNG_KERNEL_ABI_SESSION_TRACK_ID:
899 {
900 struct lttng_kernel_abi_tracker_args tracker;
901 enum tracker_type tracker_type;
902
903 if (copy_from_user(&tracker,
904 (struct lttng_kernel_abi_tracker_args __user *) arg,
905 sizeof(struct lttng_kernel_abi_tracker_args)))
906 return -EFAULT;
907 tracker_type = get_tracker_type(&tracker);
908 if (tracker_type == TRACKER_UNKNOWN)
909 return -EINVAL;
910 return lttng_session_track_id(session, tracker_type, tracker.id);
911 }
912 case LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID:
913 {
914 struct lttng_kernel_abi_tracker_args tracker;
915 enum tracker_type tracker_type;
916
917 if (copy_from_user(&tracker,
918 (struct lttng_kernel_abi_tracker_args __user *) arg,
919 sizeof(struct lttng_kernel_abi_tracker_args)))
920 return -EFAULT;
921 tracker_type = get_tracker_type(&tracker);
922 if (tracker_type == TRACKER_UNKNOWN)
923 return -EINVAL;
924 return lttng_session_untrack_id(session, tracker_type,
925 tracker.id);
926 }
927 case LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_PIDS:
928 return lttng_session_list_tracker_ids(session, TRACKER_PID);
929 case LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_IDS:
930 {
931 struct lttng_kernel_abi_tracker_args tracker;
932 enum tracker_type tracker_type;
933
934 if (copy_from_user(&tracker,
935 (struct lttng_kernel_abi_tracker_args __user *) arg,
936 sizeof(struct lttng_kernel_abi_tracker_args)))
937 return -EFAULT;
938 tracker_type = get_tracker_type(&tracker);
939 if (tracker_type == TRACKER_UNKNOWN)
940 return -EINVAL;
941 return lttng_session_list_tracker_ids(session, tracker_type);
942 }
943 case LTTNG_KERNEL_ABI_SESSION_METADATA_REGEN:
944 return lttng_session_metadata_regenerate(session);
945 case LTTNG_KERNEL_ABI_SESSION_STATEDUMP:
946 return lttng_session_statedump(session);
947 case LTTNG_KERNEL_ABI_SESSION_SET_NAME:
948 {
949 struct lttng_kernel_abi_session_name name;
950
951 if (copy_from_user(&name,
952 (struct lttng_kernel_abi_session_name __user *) arg,
953 sizeof(struct lttng_kernel_abi_session_name)))
954 return -EFAULT;
955 return lttng_abi_session_set_name(session, &name);
956 }
957 case LTTNG_KERNEL_ABI_SESSION_SET_CREATION_TIME:
958 {
959 struct lttng_kernel_abi_session_creation_time time;
960
961 if (copy_from_user(&time,
962 (struct lttng_kernel_abi_session_creation_time __user *) arg,
963 sizeof(struct lttng_kernel_abi_session_creation_time)))
964 return -EFAULT;
965 return lttng_abi_session_set_creation_time(session, &time);
966 }
967 default:
968 return -ENOIOCTLCMD;
969 }
970 }
971
972 /*
973 * Called when the last file reference is dropped.
974 *
975 * Big fat note: channels and events are invariant for the whole session after
976 * their creation. So this session destruction also destroys all channel and
977 * event structures specific to this session (they are not destroyed when their
978 * individual file is released).
979 */
980 static
981 int lttng_session_release(struct inode *inode, struct file *file)
982 {
983 struct lttng_kernel_session *session = file->private_data;
984
985 if (session)
986 lttng_session_destroy(session);
987 return 0;
988 }
989
990 static const struct file_operations lttng_session_fops = {
991 .owner = THIS_MODULE,
992 .release = lttng_session_release,
993 .unlocked_ioctl = lttng_session_ioctl,
994 #ifdef CONFIG_COMPAT
995 .compat_ioctl = lttng_session_ioctl,
996 #endif
997 };
998
999 /*
1000 * When encountering empty buffer, flush current sub-buffer if non-empty
1001 * and retry (if new data available to read after flush).
1002 */
1003 static
1004 ssize_t lttng_event_notifier_group_notif_read(struct file *filp, char __user *user_buf,
1005 size_t count, loff_t *ppos)
1006 {
1007 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
1008 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1009 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1010 ssize_t read_count = 0, len;
1011 size_t read_offset;
1012
1013 might_sleep();
1014 if (!lttng_access_ok(VERIFY_WRITE, user_buf, count))
1015 return -EFAULT;
1016
1017 /* Finish copy of previous record */
1018 if (*ppos != 0) {
1019 if (count != 0) {
1020 len = chan->iter.len_left;
1021 read_offset = *ppos;
1022 goto skip_get_next;
1023 }
1024 }
1025
1026 while (read_count < count) {
1027 size_t copy_len, space_left;
1028
1029 len = lib_ring_buffer_get_next_record(chan, buf);
1030 len_test:
1031 if (len < 0) {
1032 /*
1033 * Check if buffer is finalized (end of file).
1034 */
1035 if (len == -ENODATA) {
1036 /* A 0 read_count will tell about end of file */
1037 goto nodata;
1038 }
1039 if (filp->f_flags & O_NONBLOCK) {
1040 if (!read_count)
1041 read_count = -EAGAIN;
1042 goto nodata;
1043 } else {
1044 int error;
1045
1046 /*
1047 * No data available at the moment, return what
1048 * we got.
1049 */
1050 if (read_count)
1051 goto nodata;
1052
1053 /*
1054 * Wait for returned len to be >= 0 or -ENODATA.
1055 */
1056 error = wait_event_interruptible(
1057 event_notifier_group->read_wait,
1058 ((len = lib_ring_buffer_get_next_record(
1059 chan, buf)), len != -EAGAIN));
1060 CHAN_WARN_ON(chan, len == -EBUSY);
1061 if (error) {
1062 read_count = error;
1063 goto nodata;
1064 }
1065 CHAN_WARN_ON(chan, len < 0 && len != -ENODATA);
1066 goto len_test;
1067 }
1068 }
1069 read_offset = buf->iter.read_offset;
1070 skip_get_next:
1071 space_left = count - read_count;
1072 if (len <= space_left) {
1073 copy_len = len;
1074 chan->iter.len_left = 0;
1075 *ppos = 0;
1076 } else {
1077 copy_len = space_left;
1078 chan->iter.len_left = len - copy_len;
1079 *ppos = read_offset + copy_len;
1080 }
1081 if (__lib_ring_buffer_copy_to_user(&buf->backend, read_offset,
1082 &user_buf[read_count],
1083 copy_len)) {
1084 /*
1085 * Leave the len_left and ppos values at their current
1086 * state, as we currently have a valid event to read.
1087 */
1088 return -EFAULT;
1089 }
1090 read_count += copy_len;
1091 }
1092 goto put_record;
1093
1094 nodata:
1095 *ppos = 0;
1096 chan->iter.len_left = 0;
1097
1098 put_record:
1099 if (*ppos == 0)
1100 lib_ring_buffer_put_current_record(buf);
1101 return read_count;
1102 }
1103
1104 /*
1105 * If the ring buffer is non empty (even just a partial subbuffer), return that
1106 * there is data available. Perform a ring buffer flush if we encounter a
1107 * non-empty ring buffer which does not have any consumeable subbuffer available.
1108 */
1109 static
1110 unsigned int lttng_event_notifier_group_notif_poll(struct file *filp,
1111 poll_table *wait)
1112 {
1113 unsigned int mask = 0;
1114 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
1115 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1116 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1117 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
1118 int finalized, disabled;
1119 unsigned long consumed, offset;
1120 size_t subbuffer_header_size = config->cb.subbuffer_header_size();
1121
1122 if (filp->f_mode & FMODE_READ) {
1123 poll_wait_set_exclusive(wait);
1124 poll_wait(filp, &event_notifier_group->read_wait, wait);
1125
1126 finalized = lib_ring_buffer_is_finalized(config, buf);
1127 disabled = lib_ring_buffer_channel_is_disabled(chan);
1128
1129 /*
1130 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
1131 * finalized load before offsets loads.
1132 */
1133 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1134 retry:
1135 if (disabled)
1136 return POLLERR;
1137
1138 offset = lib_ring_buffer_get_offset(config, buf);
1139 consumed = lib_ring_buffer_get_consumed(config, buf);
1140
1141 /*
1142 * If there is no buffer available to consume.
1143 */
1144 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) == 0) {
1145 /*
1146 * If there is a non-empty subbuffer, flush and try again.
1147 */
1148 if (subbuf_offset(offset, chan) > subbuffer_header_size) {
1149 lib_ring_buffer_switch_remote(buf);
1150 goto retry;
1151 }
1152
1153 if (finalized)
1154 return POLLHUP;
1155 else {
1156 /*
1157 * The memory barriers
1158 * __wait_event()/wake_up_interruptible() take
1159 * care of "raw_spin_is_locked" memory ordering.
1160 */
1161 if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
1162 goto retry;
1163 else
1164 return 0;
1165 }
1166 } else {
1167 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan)
1168 >= chan->backend.buf_size)
1169 return POLLPRI | POLLRDBAND;
1170 else
1171 return POLLIN | POLLRDNORM;
1172 }
1173 }
1174
1175 return mask;
1176 }
1177
1178 /**
1179 * lttng_event_notifier_group_notif_open - event_notifier ring buffer open file operation
1180 * @inode: opened inode
1181 * @file: opened file
1182 *
1183 * Open implementation. Makes sure only one open instance of a buffer is
1184 * done at a given moment.
1185 */
1186 static int lttng_event_notifier_group_notif_open(struct inode *inode, struct file *file)
1187 {
1188 struct lttng_event_notifier_group *event_notifier_group = inode->i_private;
1189 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1190
1191 file->private_data = event_notifier_group;
1192 return lib_ring_buffer_open(inode, file, buf);
1193 }
1194
1195 /**
1196 * lttng_event_notifier_group_notif_release - event_notifier ring buffer release file operation
1197 * @inode: opened inode
1198 * @file: opened file
1199 *
1200 * Release implementation.
1201 */
1202 static int lttng_event_notifier_group_notif_release(struct inode *inode, struct file *file)
1203 {
1204 struct lttng_event_notifier_group *event_notifier_group = file->private_data;
1205 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1206 int ret;
1207
1208 ret = lib_ring_buffer_release(inode, file, buf);
1209 if (ret)
1210 return ret;
1211 fput(event_notifier_group->file);
1212 return 0;
1213 }
1214
1215 static const struct file_operations lttng_event_notifier_group_notif_fops = {
1216 .owner = THIS_MODULE,
1217 .open = lttng_event_notifier_group_notif_open,
1218 .release = lttng_event_notifier_group_notif_release,
1219 .read = lttng_event_notifier_group_notif_read,
1220 .poll = lttng_event_notifier_group_notif_poll,
1221 };
1222
1223 /**
1224 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
1225 * @filp: the file
1226 * @wait: poll table
1227 *
1228 * Handles the poll operations for the metadata channels.
1229 */
1230 static
1231 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
1232 poll_table *wait)
1233 {
1234 struct lttng_metadata_stream *stream = filp->private_data;
1235 struct lttng_kernel_ring_buffer *buf = stream->priv;
1236 int finalized;
1237 unsigned int mask = 0;
1238
1239 if (filp->f_mode & FMODE_READ) {
1240 poll_wait_set_exclusive(wait);
1241 poll_wait(filp, &stream->read_wait, wait);
1242
1243 finalized = stream->finalized;
1244
1245 /*
1246 * lib_ring_buffer_is_finalized() contains a smp_rmb()
1247 * ordering finalized load before offsets loads.
1248 */
1249 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1250
1251 if (finalized)
1252 mask |= POLLHUP;
1253
1254 mutex_lock(&stream->metadata_cache->lock);
1255 if (stream->metadata_cache->metadata_written >
1256 stream->metadata_out)
1257 mask |= POLLIN;
1258 mutex_unlock(&stream->metadata_cache->lock);
1259 }
1260
1261 return mask;
1262 }
1263
1264 static
1265 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
1266 unsigned int cmd, unsigned long arg)
1267 {
1268 struct lttng_metadata_stream *stream = filp->private_data;
1269
1270 stream->metadata_out = stream->metadata_in;
1271 }
1272
1273 /*
1274 * Reset the counter of how much metadata has been consumed to 0. That way,
1275 * the consumer receives the content of the metadata cache unchanged. This is
1276 * different from the metadata_regenerate where the offset from epoch is
1277 * resampled, here we want the exact same content as the last time the metadata
1278 * was generated. This command is only possible if all the metadata written
1279 * in the cache has been output to the metadata stream to avoid corrupting the
1280 * metadata file.
1281 *
1282 * Return 0 on success, a negative value on error.
1283 */
1284 static
1285 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
1286 {
1287 int ret;
1288 struct lttng_metadata_cache *cache = stream->metadata_cache;
1289
1290 mutex_lock(&cache->lock);
1291 if (stream->metadata_out != cache->metadata_written) {
1292 ret = -EBUSY;
1293 goto end;
1294 }
1295 stream->metadata_out = 0;
1296 stream->metadata_in = 0;
1297 wake_up_interruptible(&stream->read_wait);
1298 ret = 0;
1299
1300 end:
1301 mutex_unlock(&cache->lock);
1302 return ret;
1303 }
1304
1305 static
1306 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
1307 unsigned int cmd, unsigned long arg)
1308 {
1309 int ret;
1310 struct lttng_metadata_stream *stream = filp->private_data;
1311 struct lttng_kernel_ring_buffer *buf = stream->priv;
1312 unsigned int rb_cmd;
1313 bool coherent;
1314
1315 if (cmd == LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1316 rb_cmd = LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF;
1317 else
1318 rb_cmd = cmd;
1319
1320 switch (cmd) {
1321 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF:
1322 {
1323 struct lttng_metadata_stream *stream = filp->private_data;
1324 struct lttng_kernel_ring_buffer *buf = stream->priv;
1325 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1326
1327 ret = lttng_metadata_output_channel(stream, chan, NULL);
1328 if (ret > 0) {
1329 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1330 ret = 0;
1331 } else if (ret < 0)
1332 goto err;
1333 break;
1334 }
1335 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF:
1336 {
1337 /*
1338 * Random access is not allowed for metadata channel.
1339 */
1340 return -ENOSYS;
1341 }
1342 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY:
1343 lttng_fallthrough;
1344 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH:
1345 {
1346 struct lttng_metadata_stream *stream = filp->private_data;
1347 struct lttng_kernel_ring_buffer *buf = stream->priv;
1348 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1349
1350 /*
1351 * Before doing the actual ring buffer flush, write up to one
1352 * packet of metadata in the ring buffer.
1353 */
1354 ret = lttng_metadata_output_channel(stream, chan, NULL);
1355 if (ret < 0)
1356 goto err;
1357 break;
1358 }
1359 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION:
1360 {
1361 struct lttng_metadata_stream *stream = filp->private_data;
1362
1363 return put_u64(stream->version, arg);
1364 }
1365 case LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP:
1366 {
1367 struct lttng_metadata_stream *stream = filp->private_data;
1368
1369 return lttng_metadata_cache_dump(stream);
1370 }
1371 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1372 {
1373 struct lttng_metadata_stream *stream = filp->private_data;
1374 struct lttng_kernel_ring_buffer *buf = stream->priv;
1375 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1376
1377 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1378 if (ret > 0) {
1379 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1380 ret = 0;
1381 } else if (ret < 0) {
1382 goto err;
1383 }
1384 break;
1385 }
1386 default:
1387 break;
1388 }
1389 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1390
1391 /* Performing lib ring buffer ioctl after our own. */
1392 ret = lib_ring_buffer_ioctl(filp, rb_cmd, arg, buf);
1393 if (ret < 0)
1394 goto err;
1395
1396 switch (cmd) {
1397 case LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF:
1398 {
1399 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1400 cmd, arg);
1401 break;
1402 }
1403 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1404 {
1405 return put_u32(coherent, arg);
1406 }
1407 default:
1408 break;
1409 }
1410 err:
1411 return ret;
1412 }
1413
1414 #ifdef CONFIG_COMPAT
1415 static
1416 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
1417 unsigned int cmd, unsigned long arg)
1418 {
1419 int ret;
1420 struct lttng_metadata_stream *stream = filp->private_data;
1421 struct lttng_kernel_ring_buffer *buf = stream->priv;
1422 unsigned int rb_cmd;
1423 bool coherent;
1424
1425 if (cmd == LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1426 rb_cmd = LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF;
1427 else
1428 rb_cmd = cmd;
1429
1430 switch (cmd) {
1431 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF:
1432 {
1433 struct lttng_metadata_stream *stream = filp->private_data;
1434 struct lttng_kernel_ring_buffer *buf = stream->priv;
1435 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1436
1437 ret = lttng_metadata_output_channel(stream, chan, NULL);
1438 if (ret > 0) {
1439 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1440 ret = 0;
1441 } else if (ret < 0)
1442 goto err;
1443 break;
1444 }
1445 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF:
1446 {
1447 /*
1448 * Random access is not allowed for metadata channel.
1449 */
1450 return -ENOSYS;
1451 }
1452 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY:
1453 lttng_fallthrough;
1454 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH:
1455 {
1456 struct lttng_metadata_stream *stream = filp->private_data;
1457 struct lttng_kernel_ring_buffer *buf = stream->priv;
1458 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1459
1460 /*
1461 * Before doing the actual ring buffer flush, write up to one
1462 * packet of metadata in the ring buffer.
1463 */
1464 ret = lttng_metadata_output_channel(stream, chan, NULL);
1465 if (ret < 0)
1466 goto err;
1467 break;
1468 }
1469 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION:
1470 {
1471 struct lttng_metadata_stream *stream = filp->private_data;
1472
1473 return put_u64(stream->version, arg);
1474 }
1475 case LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP:
1476 {
1477 struct lttng_metadata_stream *stream = filp->private_data;
1478
1479 return lttng_metadata_cache_dump(stream);
1480 }
1481 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1482 {
1483 struct lttng_metadata_stream *stream = filp->private_data;
1484 struct lttng_kernel_ring_buffer *buf = stream->priv;
1485 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1486
1487 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1488 if (ret > 0) {
1489 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1490 ret = 0;
1491 } else if (ret < 0) {
1492 goto err;
1493 }
1494 break;
1495 }
1496 default:
1497 break;
1498 }
1499 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1500
1501 /* Performing lib ring buffer ioctl after our own. */
1502 ret = lib_ring_buffer_compat_ioctl(filp, rb_cmd, arg, buf);
1503 if (ret < 0)
1504 goto err;
1505
1506 switch (cmd) {
1507 case LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF:
1508 {
1509 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1510 cmd, arg);
1511 break;
1512 }
1513 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1514 {
1515 return put_u32(coherent, arg);
1516 }
1517 default:
1518 break;
1519 }
1520 err:
1521 return ret;
1522 }
1523 #endif
1524
1525 /*
1526 * This is not used by anonymous file descriptors. This code is left
1527 * there if we ever want to implement an inode with open() operation.
1528 */
1529 static
1530 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
1531 {
1532 struct lttng_metadata_stream *stream = inode->i_private;
1533 struct lttng_kernel_ring_buffer *buf = stream->priv;
1534
1535 file->private_data = buf;
1536 /*
1537 * Since life-time of metadata cache differs from that of
1538 * session, we need to keep our own reference on the transport.
1539 */
1540 if (!try_module_get(stream->transport->owner)) {
1541 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1542 return -EBUSY;
1543 }
1544 return lib_ring_buffer_open(inode, file, buf);
1545 }
1546
1547 static
1548 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
1549 {
1550 struct lttng_metadata_stream *stream = file->private_data;
1551 struct lttng_kernel_ring_buffer *buf = stream->priv;
1552
1553 mutex_lock(&stream->metadata_cache->lock);
1554 list_del(&stream->list);
1555 mutex_unlock(&stream->metadata_cache->lock);
1556 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
1557 module_put(stream->transport->owner);
1558 kfree(stream);
1559 return lib_ring_buffer_release(inode, file, buf);
1560 }
1561
1562 static
1563 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
1564 struct pipe_inode_info *pipe, size_t len,
1565 unsigned int flags)
1566 {
1567 struct lttng_metadata_stream *stream = in->private_data;
1568 struct lttng_kernel_ring_buffer *buf = stream->priv;
1569
1570 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
1571 flags, buf);
1572 }
1573
1574 static
1575 int lttng_metadata_ring_buffer_mmap(struct file *filp,
1576 struct vm_area_struct *vma)
1577 {
1578 struct lttng_metadata_stream *stream = filp->private_data;
1579 struct lttng_kernel_ring_buffer *buf = stream->priv;
1580
1581 return lib_ring_buffer_mmap(filp, vma, buf);
1582 }
1583
1584 static
1585 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
1586 .owner = THIS_MODULE,
1587 .open = lttng_metadata_ring_buffer_open,
1588 .release = lttng_metadata_ring_buffer_release,
1589 .poll = lttng_metadata_ring_buffer_poll,
1590 .splice_read = lttng_metadata_ring_buffer_splice_read,
1591 .mmap = lttng_metadata_ring_buffer_mmap,
1592 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
1593 .llseek = vfs_lib_ring_buffer_no_llseek,
1594 #ifdef CONFIG_COMPAT
1595 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
1596 #endif
1597 };
1598
1599 static
1600 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1601 const struct file_operations *fops, const char *name)
1602 {
1603 int stream_fd, ret;
1604 struct file *stream_file;
1605
1606 stream_fd = lttng_get_unused_fd();
1607 if (stream_fd < 0) {
1608 ret = stream_fd;
1609 goto fd_error;
1610 }
1611 stream_file = anon_inode_getfile(name, fops, stream_priv, O_RDWR);
1612 if (IS_ERR(stream_file)) {
1613 ret = PTR_ERR(stream_file);
1614 goto file_error;
1615 }
1616 /*
1617 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1618 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1619 * file descriptor, so we set FMODE_PREAD here.
1620 */
1621 stream_file->f_mode |= FMODE_PREAD;
1622 fd_install(stream_fd, stream_file);
1623 /*
1624 * The stream holds a reference to the channel within the generic ring
1625 * buffer library, so no need to hold a refcount on the channel and
1626 * session files here.
1627 */
1628 return stream_fd;
1629
1630 file_error:
1631 put_unused_fd(stream_fd);
1632 fd_error:
1633 return ret;
1634 }
1635
1636 static
1637 int lttng_abi_open_stream(struct file *channel_file)
1638 {
1639 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1640 struct lttng_kernel_ring_buffer *buf;
1641 int ret;
1642 void *stream_priv;
1643
1644 buf = channel->ops->priv->buffer_read_open(channel->priv->rb_chan);
1645 if (!buf)
1646 return -ENOENT;
1647
1648 stream_priv = buf;
1649 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1650 &lttng_stream_ring_buffer_file_operations,
1651 "[lttng_stream]");
1652 if (ret < 0)
1653 goto fd_error;
1654
1655 return ret;
1656
1657 fd_error:
1658 channel->ops->priv->buffer_read_close(buf);
1659 return ret;
1660 }
1661
1662 static
1663 int lttng_abi_open_metadata_stream(struct file *channel_file)
1664 {
1665 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1666 struct lttng_kernel_session *session = channel->parent.session;
1667 struct lttng_kernel_ring_buffer *buf;
1668 int ret;
1669 struct lttng_metadata_stream *metadata_stream;
1670 void *stream_priv;
1671
1672 buf = channel->ops->priv->buffer_read_open(channel->priv->rb_chan);
1673 if (!buf)
1674 return -ENOENT;
1675
1676 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1677 GFP_KERNEL);
1678 if (!metadata_stream) {
1679 ret = -ENOMEM;
1680 goto nomem;
1681 }
1682 metadata_stream->metadata_cache = session->priv->metadata_cache;
1683 init_waitqueue_head(&metadata_stream->read_wait);
1684 metadata_stream->priv = buf;
1685 stream_priv = metadata_stream;
1686 metadata_stream->transport = channel->priv->transport;
1687 /* Initial state is an empty metadata, considered as incoherent. */
1688 metadata_stream->coherent = false;
1689
1690 /*
1691 * Since life-time of metadata cache differs from that of
1692 * session, we need to keep our own reference on the transport.
1693 */
1694 if (!try_module_get(metadata_stream->transport->owner)) {
1695 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1696 ret = -EINVAL;
1697 goto notransport;
1698 }
1699
1700 if (!lttng_kref_get(&session->priv->metadata_cache->refcount)) {
1701 ret = -EOVERFLOW;
1702 goto kref_error;
1703 }
1704
1705 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1706 &lttng_metadata_ring_buffer_file_operations,
1707 "[lttng_metadata_stream]");
1708 if (ret < 0)
1709 goto fd_error;
1710
1711 mutex_lock(&session->priv->metadata_cache->lock);
1712 list_add(&metadata_stream->list,
1713 &session->priv->metadata_cache->metadata_stream);
1714 mutex_unlock(&session->priv->metadata_cache->lock);
1715 return ret;
1716
1717 fd_error:
1718 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
1719 kref_error:
1720 module_put(metadata_stream->transport->owner);
1721 notransport:
1722 kfree(metadata_stream);
1723 nomem:
1724 channel->ops->priv->buffer_read_close(buf);
1725 return ret;
1726 }
1727
1728 static
1729 int lttng_abi_open_event_notifier_group_stream(struct file *notif_file)
1730 {
1731 struct lttng_event_notifier_group *event_notifier_group = notif_file->private_data;
1732 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1733 struct lttng_kernel_ring_buffer *buf;
1734 int ret;
1735 void *stream_priv;
1736
1737 buf = event_notifier_group->ops->priv->buffer_read_open(chan);
1738 if (!buf)
1739 return -ENOENT;
1740
1741 /* The event_notifier notification fd holds a reference on the event_notifier group */
1742 if (!atomic_long_add_unless(&notif_file->f_count, 1, LONG_MAX)) {
1743 ret = -EOVERFLOW;
1744 goto refcount_error;
1745 }
1746 event_notifier_group->buf = buf;
1747 stream_priv = event_notifier_group;
1748 ret = lttng_abi_create_stream_fd(notif_file, stream_priv,
1749 &lttng_event_notifier_group_notif_fops,
1750 "[lttng_event_notifier_stream]");
1751 if (ret < 0)
1752 goto fd_error;
1753
1754 return ret;
1755
1756 fd_error:
1757 atomic_long_dec(&notif_file->f_count);
1758 refcount_error:
1759 event_notifier_group->ops->priv->buffer_read_close(buf);
1760 return ret;
1761 }
1762
1763 static
1764 int lttng_abi_validate_event_param(struct lttng_kernel_abi_event *event_param)
1765 {
1766 /* Limit ABI to implemented features. */
1767 switch (event_param->instrumentation) {
1768 case LTTNG_KERNEL_ABI_SYSCALL:
1769 switch (event_param->u.syscall.entryexit) {
1770 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1771 lttng_fallthrough;
1772 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1773 lttng_fallthrough;
1774 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1775 break;
1776 default:
1777 return -EINVAL;
1778 }
1779 switch (event_param->u.syscall.abi) {
1780 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1781 break;
1782 default:
1783 return -EINVAL;
1784 }
1785 switch (event_param->u.syscall.match) {
1786 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1787 break;
1788 default:
1789 return -EINVAL;
1790 }
1791 break;
1792
1793 case LTTNG_KERNEL_ABI_KRETPROBE:
1794 switch (event_param->u.kretprobe.entryexit) {
1795 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1796 break;
1797 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1798 lttng_fallthrough;
1799 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1800 lttng_fallthrough;
1801 default:
1802 return -EINVAL;
1803 }
1804 break;
1805
1806 case LTTNG_KERNEL_ABI_TRACEPOINT:
1807 lttng_fallthrough;
1808 case LTTNG_KERNEL_ABI_KPROBE:
1809 lttng_fallthrough;
1810 case LTTNG_KERNEL_ABI_UPROBE:
1811 break;
1812
1813 case LTTNG_KERNEL_ABI_FUNCTION:
1814 lttng_fallthrough;
1815 case LTTNG_KERNEL_ABI_NOOP:
1816 lttng_fallthrough;
1817 default:
1818 return -EINVAL;
1819 }
1820 return 0;
1821 }
1822
1823 static
1824 int lttng_abi_create_event(struct file *channel_file,
1825 struct lttng_kernel_abi_event *event_param)
1826 {
1827 const struct file_operations *fops;
1828 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1829 int event_fd, ret;
1830 struct file *event_file;
1831 void *priv;
1832
1833 event_param->name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1834 switch (event_param->instrumentation) {
1835 case LTTNG_KERNEL_ABI_KRETPROBE:
1836 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1837 break;
1838 case LTTNG_KERNEL_ABI_KPROBE:
1839 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1840 break;
1841 case LTTNG_KERNEL_ABI_FUNCTION:
1842 WARN_ON_ONCE(1);
1843 /* Not implemented. */
1844 break;
1845 default:
1846 break;
1847 }
1848
1849 switch (event_param->instrumentation) {
1850 case LTTNG_KERNEL_ABI_TRACEPOINT:
1851 lttng_fallthrough;
1852 case LTTNG_KERNEL_ABI_SYSCALL:
1853 fops = &lttng_event_recorder_enabler_fops;
1854 break;
1855 case LTTNG_KERNEL_ABI_KPROBE:
1856 lttng_fallthrough;
1857 case LTTNG_KERNEL_ABI_KRETPROBE:
1858 lttng_fallthrough;
1859 case LTTNG_KERNEL_ABI_UPROBE:
1860 fops = &lttng_event_recorder_event_fops;
1861 break;
1862
1863 case LTTNG_KERNEL_ABI_FUNCTION:
1864 lttng_fallthrough;
1865 case LTTNG_KERNEL_ABI_NOOP:
1866 lttng_fallthrough;
1867 default:
1868 return -EINVAL;
1869 }
1870
1871 event_fd = lttng_get_unused_fd();
1872 if (event_fd < 0) {
1873 ret = event_fd;
1874 goto fd_error;
1875 }
1876 event_file = anon_inode_getfile("[lttng_event]",
1877 fops, NULL, O_RDWR);
1878 if (IS_ERR(event_file)) {
1879 ret = PTR_ERR(event_file);
1880 goto file_error;
1881 }
1882 /* The event holds a reference on the channel */
1883 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1884 ret = -EOVERFLOW;
1885 goto refcount_error;
1886 }
1887 ret = lttng_abi_validate_event_param(event_param);
1888 if (ret)
1889 goto event_error;
1890
1891 switch (event_param->instrumentation) {
1892 case LTTNG_KERNEL_ABI_TRACEPOINT:
1893 lttng_fallthrough;
1894 case LTTNG_KERNEL_ABI_SYSCALL:
1895 {
1896 struct lttng_event_enabler *event_enabler;
1897
1898 if (strutils_is_star_glob_pattern(event_param->name)) {
1899 /*
1900 * If the event name is a star globbing pattern,
1901 * we create the special star globbing enabler.
1902 */
1903 event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_STAR_GLOB,
1904 event_param, channel);
1905 } else {
1906 event_enabler = lttng_event_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1907 event_param, channel);
1908 }
1909 priv = event_enabler;
1910 break;
1911 }
1912
1913 case LTTNG_KERNEL_ABI_KPROBE:
1914 lttng_fallthrough;
1915 case LTTNG_KERNEL_ABI_KRETPROBE:
1916 lttng_fallthrough;
1917 case LTTNG_KERNEL_ABI_UPROBE:
1918 {
1919 struct lttng_kernel_event_recorder *event;
1920
1921 /*
1922 * We tolerate no failure path after event creation. It
1923 * will stay invariant for the rest of the session.
1924 */
1925 event = lttng_kernel_event_recorder_create(channel, event_param,
1926 NULL, event_param->instrumentation);
1927 WARN_ON_ONCE(!event);
1928 if (IS_ERR(event)) {
1929 ret = PTR_ERR(event);
1930 goto event_error;
1931 }
1932 priv = event;
1933 break;
1934 }
1935
1936 case LTTNG_KERNEL_ABI_FUNCTION:
1937 lttng_fallthrough;
1938 case LTTNG_KERNEL_ABI_NOOP:
1939 lttng_fallthrough;
1940 default:
1941 ret = -EINVAL;
1942 goto event_error;
1943 }
1944 event_file->private_data = priv;
1945 fd_install(event_fd, event_file);
1946 return event_fd;
1947
1948 event_error:
1949 atomic_long_dec(&channel_file->f_count);
1950 refcount_error:
1951 fput(event_file);
1952 file_error:
1953 put_unused_fd(event_fd);
1954 fd_error:
1955 return ret;
1956 }
1957
1958 static
1959 long lttng_event_notifier_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1960 {
1961 struct lttng_kernel_event_notifier *event_notifier = file->private_data;
1962
1963 switch (cmd) {
1964 case LTTNG_KERNEL_ABI_ENABLE:
1965 return lttng_event_enable(&event_notifier->parent);
1966 case LTTNG_KERNEL_ABI_DISABLE:
1967 return lttng_event_disable(&event_notifier->parent);
1968 case LTTNG_KERNEL_ABI_FILTER:
1969 return -EINVAL;
1970 case LTTNG_KERNEL_ABI_CAPTURE:
1971 return -EINVAL;
1972 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
1973 return lttng_event_add_callsite(&event_notifier->parent,
1974 (struct lttng_kernel_abi_event_callsite __user *) arg);
1975 default:
1976 return -ENOIOCTLCMD;
1977 }
1978 }
1979
1980 static
1981 long lttng_event_notifier_enabler_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1982 {
1983 struct lttng_event_notifier_enabler *event_notifier_enabler = file->private_data;
1984
1985 switch (cmd) {
1986 case LTTNG_KERNEL_ABI_ENABLE:
1987 return lttng_event_notifier_enabler_enable(event_notifier_enabler);
1988 case LTTNG_KERNEL_ABI_DISABLE:
1989 return lttng_event_notifier_enabler_disable(event_notifier_enabler);
1990 case LTTNG_KERNEL_ABI_FILTER:
1991 return lttng_event_notifier_enabler_attach_filter_bytecode(
1992 event_notifier_enabler,
1993 (struct lttng_kernel_abi_filter_bytecode __user *) arg);
1994 case LTTNG_KERNEL_ABI_CAPTURE:
1995 return lttng_event_notifier_enabler_attach_capture_bytecode(
1996 event_notifier_enabler,
1997 (struct lttng_kernel_abi_capture_bytecode __user *) arg);
1998 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
1999 return -EINVAL;
2000 default:
2001 return -ENOIOCTLCMD;
2002 }
2003 }
2004
2005 static
2006 int lttng_event_notifier_event_release(struct inode *inode, struct file *file)
2007 {
2008 struct lttng_kernel_event_notifier *event_notifier = file->private_data;
2009
2010 if (event_notifier)
2011 fput(event_notifier->priv->group->file);
2012 return 0;
2013 }
2014
2015 static
2016 int lttng_event_notifier_enabler_release(struct inode *inode, struct file *file)
2017 {
2018 struct lttng_event_notifier_enabler *event_notifier_enabler = file->private_data;
2019
2020 if (event_notifier_enabler)
2021 fput(event_notifier_enabler->group->file);
2022 return 0;
2023 }
2024
2025 static const struct file_operations lttng_event_notifier_event_fops = {
2026 .owner = THIS_MODULE,
2027 .release = lttng_event_notifier_event_release,
2028 .unlocked_ioctl = lttng_event_notifier_event_ioctl,
2029 #ifdef CONFIG_COMPAT
2030 .compat_ioctl = lttng_event_notifier_event_ioctl,
2031 #endif
2032 };
2033
2034 static const struct file_operations lttng_event_notifier_enabler_fops = {
2035 .owner = THIS_MODULE,
2036 .release = lttng_event_notifier_enabler_release,
2037 .unlocked_ioctl = lttng_event_notifier_enabler_ioctl,
2038 #ifdef CONFIG_COMPAT
2039 .compat_ioctl = lttng_event_notifier_enabler_ioctl,
2040 #endif
2041 };
2042
2043 static
2044 int lttng_abi_create_event_notifier(struct file *event_notifier_group_file,
2045 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2046 {
2047 struct lttng_event_notifier_group *event_notifier_group =
2048 event_notifier_group_file->private_data;
2049 const struct file_operations *fops;
2050 int event_notifier_fd, ret;
2051 struct file *event_notifier_file;
2052 void *priv;
2053
2054 switch (event_notifier_param->event.instrumentation) {
2055 case LTTNG_KERNEL_ABI_TRACEPOINT:
2056 case LTTNG_KERNEL_ABI_UPROBE:
2057 break;
2058 case LTTNG_KERNEL_ABI_KPROBE:
2059 event_notifier_param->event.u.kprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
2060 break;
2061 case LTTNG_KERNEL_ABI_SYSCALL:
2062 break;
2063 case LTTNG_KERNEL_ABI_KRETPROBE:
2064 /* Placing an event notifier on kretprobe is not supported. */
2065 case LTTNG_KERNEL_ABI_FUNCTION:
2066 case LTTNG_KERNEL_ABI_NOOP:
2067 default:
2068 ret = -EINVAL;
2069 goto inval_instr;
2070 }
2071
2072 switch (event_notifier_param->event.instrumentation) {
2073 case LTTNG_KERNEL_ABI_TRACEPOINT:
2074 lttng_fallthrough;
2075 case LTTNG_KERNEL_ABI_SYSCALL:
2076 fops = &lttng_event_notifier_enabler_fops;
2077 break;
2078 case LTTNG_KERNEL_ABI_KPROBE:
2079 lttng_fallthrough;
2080 case LTTNG_KERNEL_ABI_KRETPROBE:
2081 lttng_fallthrough;
2082 case LTTNG_KERNEL_ABI_UPROBE:
2083 fops = &lttng_event_notifier_event_fops;
2084 break;
2085
2086 case LTTNG_KERNEL_ABI_FUNCTION:
2087 lttng_fallthrough;
2088 case LTTNG_KERNEL_ABI_NOOP:
2089 lttng_fallthrough;
2090 default:
2091 ret = -EINVAL;
2092 goto inval_instr;
2093 }
2094
2095 event_notifier_param->event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
2096
2097 event_notifier_fd = lttng_get_unused_fd();
2098 if (event_notifier_fd < 0) {
2099 ret = event_notifier_fd;
2100 goto fd_error;
2101 }
2102
2103 event_notifier_file = anon_inode_getfile("[lttng_event_notifier]",
2104 fops, NULL, O_RDWR);
2105 if (IS_ERR(event_notifier_file)) {
2106 ret = PTR_ERR(event_notifier_file);
2107 goto file_error;
2108 }
2109
2110 /* The event notifier holds a reference on the event notifier group. */
2111 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
2112 ret = -EOVERFLOW;
2113 goto refcount_error;
2114 }
2115
2116 ret = lttng_abi_validate_event_param(&event_notifier_param->event);
2117 if (ret)
2118 goto event_notifier_error;
2119
2120 switch (event_notifier_param->event.instrumentation) {
2121 case LTTNG_KERNEL_ABI_TRACEPOINT:
2122 lttng_fallthrough;
2123 case LTTNG_KERNEL_ABI_SYSCALL:
2124 {
2125 struct lttng_event_notifier_enabler *enabler;
2126
2127 if (strutils_is_star_glob_pattern(event_notifier_param->event.name)) {
2128 /*
2129 * If the event name is a star globbing pattern,
2130 * we create the special star globbing enabler.
2131 */
2132 enabler = lttng_event_notifier_enabler_create(
2133 event_notifier_group,
2134 LTTNG_ENABLER_FORMAT_STAR_GLOB,
2135 event_notifier_param);
2136 } else {
2137 enabler = lttng_event_notifier_enabler_create(
2138 event_notifier_group,
2139 LTTNG_ENABLER_FORMAT_NAME,
2140 event_notifier_param);
2141 }
2142 priv = enabler;
2143 break;
2144 }
2145
2146 case LTTNG_KERNEL_ABI_KPROBE:
2147 lttng_fallthrough;
2148 case LTTNG_KERNEL_ABI_KRETPROBE:
2149 lttng_fallthrough;
2150 case LTTNG_KERNEL_ABI_UPROBE:
2151 {
2152 struct lttng_kernel_event_notifier *event_notifier;
2153
2154 /*
2155 * We tolerate no failure path after event notifier creation.
2156 * It will stay invariant for the rest of the session.
2157 */
2158 event_notifier = lttng_event_notifier_create(NULL,
2159 event_notifier_param->event.token,
2160 event_notifier_param->error_counter_index,
2161 event_notifier_group,
2162 event_notifier_param,
2163 event_notifier_param->event.instrumentation);
2164 WARN_ON_ONCE(!event_notifier);
2165 if (IS_ERR(event_notifier)) {
2166 ret = PTR_ERR(event_notifier);
2167 goto event_notifier_error;
2168 }
2169 priv = event_notifier;
2170 break;
2171 }
2172
2173 case LTTNG_KERNEL_ABI_FUNCTION:
2174 lttng_fallthrough;
2175 case LTTNG_KERNEL_ABI_NOOP:
2176 lttng_fallthrough;
2177 default:
2178 ret = -EINVAL;
2179 goto event_notifier_error;
2180 }
2181 event_notifier_file->private_data = priv;
2182 fd_install(event_notifier_fd, event_notifier_file);
2183 return event_notifier_fd;
2184
2185 event_notifier_error:
2186 atomic_long_dec(&event_notifier_group_file->f_count);
2187 refcount_error:
2188 fput(event_notifier_file);
2189 file_error:
2190 put_unused_fd(event_notifier_fd);
2191 fd_error:
2192 inval_instr:
2193 return ret;
2194 }
2195
2196 static
2197 long lttng_abi_event_notifier_group_create_error_counter(
2198 struct file *event_notifier_group_file,
2199 const struct lttng_kernel_abi_counter_conf *error_counter_conf)
2200 {
2201 int counter_fd, ret;
2202 char *counter_transport_name;
2203 size_t counter_len;
2204 struct lttng_counter *counter = NULL;
2205 struct file *counter_file;
2206 struct lttng_event_notifier_group *event_notifier_group =
2207 (struct lttng_event_notifier_group *) event_notifier_group_file->private_data;
2208
2209 if (error_counter_conf->arithmetic != LTTNG_KERNEL_ABI_COUNTER_ARITHMETIC_MODULAR) {
2210 printk(KERN_ERR "LTTng: event_notifier: Error counter of the wrong arithmetic type.\n");
2211 return -EINVAL;
2212 }
2213
2214 if (error_counter_conf->number_dimensions != 1) {
2215 printk(KERN_ERR "LTTng: event_notifier: Error counter has more than one dimension.\n");
2216 return -EINVAL;
2217 }
2218
2219 switch (error_counter_conf->bitness) {
2220 case LTTNG_KERNEL_ABI_COUNTER_BITNESS_64:
2221 counter_transport_name = "counter-per-cpu-64-modular";
2222 break;
2223 case LTTNG_KERNEL_ABI_COUNTER_BITNESS_32:
2224 counter_transport_name = "counter-per-cpu-32-modular";
2225 break;
2226 default:
2227 return -EINVAL;
2228 }
2229
2230 /*
2231 * Lock sessions to provide mutual exclusion against concurrent
2232 * modification of event_notifier group, which would result in
2233 * overwriting the error counter if set concurrently.
2234 */
2235 lttng_lock_sessions();
2236
2237 if (event_notifier_group->error_counter) {
2238 printk(KERN_ERR "Error counter already created in event_notifier group\n");
2239 ret = -EBUSY;
2240 goto fd_error;
2241 }
2242
2243 counter_fd = lttng_get_unused_fd();
2244 if (counter_fd < 0) {
2245 ret = counter_fd;
2246 goto fd_error;
2247 }
2248
2249 counter_file = anon_inode_getfile("[lttng_counter]",
2250 &lttng_counter_fops,
2251 NULL, O_RDONLY);
2252 if (IS_ERR(counter_file)) {
2253 ret = PTR_ERR(counter_file);
2254 goto file_error;
2255 }
2256
2257 counter_len = error_counter_conf->dimensions[0].size;
2258
2259 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
2260 ret = -EOVERFLOW;
2261 goto refcount_error;
2262 }
2263
2264 counter = lttng_kernel_counter_create(counter_transport_name,
2265 1, &counter_len);
2266 if (!counter) {
2267 ret = -EINVAL;
2268 goto counter_error;
2269 }
2270
2271 event_notifier_group->error_counter_len = counter_len;
2272 /*
2273 * store-release to publish error counter matches load-acquire
2274 * in record_error. Ensures the counter is created and the
2275 * error_counter_len is set before they are used.
2276 */
2277 lttng_smp_store_release(&event_notifier_group->error_counter, counter);
2278
2279 counter->file = counter_file;
2280 counter->owner = event_notifier_group->file;
2281 counter_file->private_data = counter;
2282 /* Ownership transferred. */
2283 counter = NULL;
2284
2285 fd_install(counter_fd, counter_file);
2286 lttng_unlock_sessions();
2287
2288 return counter_fd;
2289
2290 counter_error:
2291 atomic_long_dec(&event_notifier_group_file->f_count);
2292 refcount_error:
2293 fput(counter_file);
2294 file_error:
2295 put_unused_fd(counter_fd);
2296 fd_error:
2297 lttng_unlock_sessions();
2298 return ret;
2299 }
2300
2301 static
2302 long lttng_event_notifier_group_ioctl(struct file *file, unsigned int cmd,
2303 unsigned long arg)
2304 {
2305 switch (cmd) {
2306 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD:
2307 {
2308 return lttng_abi_open_event_notifier_group_stream(file);
2309 }
2310 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_CREATE:
2311 {
2312 struct lttng_kernel_abi_event_notifier uevent_notifier_param;
2313
2314 if (copy_from_user(&uevent_notifier_param,
2315 (struct lttng_kernel_abi_event_notifier __user *) arg,
2316 sizeof(uevent_notifier_param)))
2317 return -EFAULT;
2318 return lttng_abi_create_event_notifier(file, &uevent_notifier_param);
2319 }
2320 case LTTNG_KERNEL_ABI_COUNTER:
2321 {
2322 struct lttng_kernel_abi_counter_conf uerror_counter_conf;
2323
2324 if (copy_from_user(&uerror_counter_conf,
2325 (struct lttng_kernel_abi_counter_conf __user *) arg,
2326 sizeof(uerror_counter_conf)))
2327 return -EFAULT;
2328 return lttng_abi_event_notifier_group_create_error_counter(file,
2329 &uerror_counter_conf);
2330 }
2331 default:
2332 return -ENOIOCTLCMD;
2333 }
2334 return 0;
2335 }
2336
2337 static
2338 int lttng_event_notifier_group_release(struct inode *inode, struct file *file)
2339 {
2340 struct lttng_event_notifier_group *event_notifier_group =
2341 file->private_data;
2342
2343 if (event_notifier_group)
2344 lttng_event_notifier_group_destroy(event_notifier_group);
2345 return 0;
2346 }
2347
2348 static const struct file_operations lttng_event_notifier_group_fops = {
2349 .owner = THIS_MODULE,
2350 .release = lttng_event_notifier_group_release,
2351 .unlocked_ioctl = lttng_event_notifier_group_ioctl,
2352 #ifdef CONFIG_COMPAT
2353 .compat_ioctl = lttng_event_notifier_group_ioctl,
2354 #endif
2355 };
2356
2357 /**
2358 * lttng_channel_ioctl - lttng syscall through ioctl
2359 *
2360 * @file: the file
2361 * @cmd: the command
2362 * @arg: command arg
2363 *
2364 * This ioctl implements lttng commands:
2365 * LTTNG_KERNEL_ABI_STREAM
2366 * Returns an event stream file descriptor or failure.
2367 * (typically, one event stream records events from one CPU)
2368 * LTTNG_KERNEL_ABI_EVENT
2369 * Returns an event file descriptor or failure.
2370 * LTTNG_KERNEL_ABI_CONTEXT
2371 * Prepend a context field to each event in the channel
2372 * LTTNG_KERNEL_ABI_ENABLE
2373 * Enable recording for events in this channel (weak enable)
2374 * LTTNG_KERNEL_ABI_DISABLE
2375 * Disable recording for events in this channel (strong disable)
2376 *
2377 * Channel and event file descriptors also hold a reference on the session.
2378 */
2379 static
2380 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2381 {
2382 struct lttng_kernel_channel_buffer *channel = file->private_data;
2383
2384 switch (cmd) {
2385 case LTTNG_KERNEL_ABI_OLD_STREAM:
2386 case LTTNG_KERNEL_ABI_STREAM:
2387 return lttng_abi_open_stream(file);
2388 case LTTNG_KERNEL_ABI_OLD_EVENT:
2389 {
2390 struct lttng_kernel_abi_event *uevent_param;
2391 struct lttng_kernel_abi_old_event *old_uevent_param;
2392 int ret;
2393
2394 uevent_param = kmalloc(sizeof(struct lttng_kernel_abi_event),
2395 GFP_KERNEL);
2396 if (!uevent_param) {
2397 ret = -ENOMEM;
2398 goto old_event_end;
2399 }
2400 old_uevent_param = kmalloc(
2401 sizeof(struct lttng_kernel_abi_old_event),
2402 GFP_KERNEL);
2403 if (!old_uevent_param) {
2404 ret = -ENOMEM;
2405 goto old_event_error_free_param;
2406 }
2407 if (copy_from_user(old_uevent_param,
2408 (struct lttng_kernel_abi_old_event __user *) arg,
2409 sizeof(struct lttng_kernel_abi_old_event))) {
2410 ret = -EFAULT;
2411 goto old_event_error_free_old_param;
2412 }
2413
2414 memcpy(uevent_param->name, old_uevent_param->name,
2415 sizeof(uevent_param->name));
2416 uevent_param->instrumentation =
2417 old_uevent_param->instrumentation;
2418
2419 switch (old_uevent_param->instrumentation) {
2420 case LTTNG_KERNEL_ABI_KPROBE:
2421 uevent_param->u.kprobe.addr =
2422 old_uevent_param->u.kprobe.addr;
2423 uevent_param->u.kprobe.offset =
2424 old_uevent_param->u.kprobe.offset;
2425 memcpy(uevent_param->u.kprobe.symbol_name,
2426 old_uevent_param->u.kprobe.symbol_name,
2427 sizeof(uevent_param->u.kprobe.symbol_name));
2428 break;
2429 case LTTNG_KERNEL_ABI_KRETPROBE:
2430 uevent_param->u.kretprobe.addr =
2431 old_uevent_param->u.kretprobe.addr;
2432 uevent_param->u.kretprobe.offset =
2433 old_uevent_param->u.kretprobe.offset;
2434 memcpy(uevent_param->u.kretprobe.symbol_name,
2435 old_uevent_param->u.kretprobe.symbol_name,
2436 sizeof(uevent_param->u.kretprobe.symbol_name));
2437 break;
2438 case LTTNG_KERNEL_ABI_FUNCTION:
2439 WARN_ON_ONCE(1);
2440 /* Not implemented. */
2441 break;
2442 default:
2443 break;
2444 }
2445 ret = lttng_abi_create_event(file, uevent_param);
2446
2447 old_event_error_free_old_param:
2448 kfree(old_uevent_param);
2449 old_event_error_free_param:
2450 kfree(uevent_param);
2451 old_event_end:
2452 return ret;
2453 }
2454 case LTTNG_KERNEL_ABI_EVENT:
2455 {
2456 struct lttng_kernel_abi_event uevent_param;
2457
2458 if (copy_from_user(&uevent_param,
2459 (struct lttng_kernel_abi_event __user *) arg,
2460 sizeof(uevent_param)))
2461 return -EFAULT;
2462 return lttng_abi_create_event(file, &uevent_param);
2463 }
2464 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2465 {
2466 struct lttng_kernel_abi_context *ucontext_param;
2467 struct lttng_kernel_abi_old_context *old_ucontext_param;
2468 int ret;
2469
2470 ucontext_param = kmalloc(sizeof(struct lttng_kernel_abi_context),
2471 GFP_KERNEL);
2472 if (!ucontext_param) {
2473 ret = -ENOMEM;
2474 goto old_ctx_end;
2475 }
2476 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_abi_old_context),
2477 GFP_KERNEL);
2478 if (!old_ucontext_param) {
2479 ret = -ENOMEM;
2480 goto old_ctx_error_free_param;
2481 }
2482
2483 if (copy_from_user(old_ucontext_param,
2484 (struct lttng_kernel_abi_old_context __user *) arg,
2485 sizeof(struct lttng_kernel_abi_old_context))) {
2486 ret = -EFAULT;
2487 goto old_ctx_error_free_old_param;
2488 }
2489 ucontext_param->ctx = old_ucontext_param->ctx;
2490 memcpy(ucontext_param->padding, old_ucontext_param->padding,
2491 sizeof(ucontext_param->padding));
2492 /* only type that uses the union */
2493 if (old_ucontext_param->ctx == LTTNG_KERNEL_ABI_CONTEXT_PERF_COUNTER) {
2494 ucontext_param->u.perf_counter.type =
2495 old_ucontext_param->u.perf_counter.type;
2496 ucontext_param->u.perf_counter.config =
2497 old_ucontext_param->u.perf_counter.config;
2498 memcpy(ucontext_param->u.perf_counter.name,
2499 old_ucontext_param->u.perf_counter.name,
2500 sizeof(ucontext_param->u.perf_counter.name));
2501 }
2502
2503 ret = lttng_abi_add_context(file,
2504 ucontext_param,
2505 &channel->priv->ctx, channel->parent.session);
2506
2507 old_ctx_error_free_old_param:
2508 kfree(old_ucontext_param);
2509 old_ctx_error_free_param:
2510 kfree(ucontext_param);
2511 old_ctx_end:
2512 return ret;
2513 }
2514 case LTTNG_KERNEL_ABI_CONTEXT:
2515 {
2516 struct lttng_kernel_abi_context ucontext_param;
2517
2518 if (copy_from_user(&ucontext_param,
2519 (struct lttng_kernel_abi_context __user *) arg,
2520 sizeof(ucontext_param)))
2521 return -EFAULT;
2522 return lttng_abi_add_context(file,
2523 &ucontext_param,
2524 &channel->priv->ctx, channel->parent.session);
2525 }
2526 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2527 case LTTNG_KERNEL_ABI_ENABLE:
2528 return lttng_channel_enable(channel);
2529 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2530 case LTTNG_KERNEL_ABI_DISABLE:
2531 return lttng_channel_disable(channel);
2532 case LTTNG_KERNEL_ABI_SYSCALL_MASK:
2533 return lttng_channel_syscall_mask(channel,
2534 (struct lttng_kernel_abi_syscall_mask __user *) arg);
2535 default:
2536 return -ENOIOCTLCMD;
2537 }
2538 }
2539
2540 /**
2541 * lttng_metadata_ioctl - lttng syscall through ioctl
2542 *
2543 * @file: the file
2544 * @cmd: the command
2545 * @arg: command arg
2546 *
2547 * This ioctl implements lttng commands:
2548 * LTTNG_KERNEL_ABI_STREAM
2549 * Returns an event stream file descriptor or failure.
2550 *
2551 * Channel and event file descriptors also hold a reference on the session.
2552 */
2553 static
2554 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2555 {
2556 switch (cmd) {
2557 case LTTNG_KERNEL_ABI_OLD_STREAM:
2558 case LTTNG_KERNEL_ABI_STREAM:
2559 return lttng_abi_open_metadata_stream(file);
2560 default:
2561 return -ENOIOCTLCMD;
2562 }
2563 }
2564
2565 /**
2566 * lttng_channel_poll - lttng stream addition/removal monitoring
2567 *
2568 * @file: the file
2569 * @wait: poll table
2570 */
2571 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
2572 {
2573 struct lttng_kernel_channel_buffer *channel = file->private_data;
2574 unsigned int mask = 0;
2575
2576 if (file->f_mode & FMODE_READ) {
2577 poll_wait_set_exclusive(wait);
2578 poll_wait(file, channel->ops->priv->get_hp_wait_queue(channel->priv->rb_chan),
2579 wait);
2580
2581 if (channel->ops->priv->is_disabled(channel->priv->rb_chan))
2582 return POLLERR;
2583 if (channel->ops->priv->is_finalized(channel->priv->rb_chan))
2584 return POLLHUP;
2585 if (channel->ops->priv->buffer_has_read_closed_stream(channel->priv->rb_chan))
2586 return POLLIN | POLLRDNORM;
2587 return 0;
2588 }
2589 return mask;
2590
2591 }
2592
2593 static
2594 int lttng_channel_release(struct inode *inode, struct file *file)
2595 {
2596 struct lttng_kernel_channel_buffer *channel = file->private_data;
2597
2598 if (channel)
2599 fput(channel->parent.session->priv->file);
2600 return 0;
2601 }
2602
2603 static
2604 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
2605 {
2606 struct lttng_kernel_channel_buffer *channel = file->private_data;
2607
2608 if (channel) {
2609 fput(channel->parent.session->priv->file);
2610 lttng_metadata_channel_destroy(channel);
2611 }
2612
2613 return 0;
2614 }
2615
2616 static const struct file_operations lttng_channel_fops = {
2617 .owner = THIS_MODULE,
2618 .release = lttng_channel_release,
2619 .poll = lttng_channel_poll,
2620 .unlocked_ioctl = lttng_channel_ioctl,
2621 #ifdef CONFIG_COMPAT
2622 .compat_ioctl = lttng_channel_ioctl,
2623 #endif
2624 };
2625
2626 static const struct file_operations lttng_metadata_fops = {
2627 .owner = THIS_MODULE,
2628 .release = lttng_metadata_channel_release,
2629 .unlocked_ioctl = lttng_metadata_ioctl,
2630 #ifdef CONFIG_COMPAT
2631 .compat_ioctl = lttng_metadata_ioctl,
2632 #endif
2633 };
2634
2635 /**
2636 * lttng_event_recorder_event_ioctl - lttng syscall through ioctl
2637 *
2638 * @file: the file
2639 * @cmd: the command
2640 * @arg: command arg
2641 *
2642 * This ioctl implements lttng commands:
2643 * LTTNG_KERNEL_ABI_CONTEXT
2644 * Prepend a context field to each record of this event
2645 * LTTNG_KERNEL_ABI_ENABLE
2646 * Enable recording for this event (weak enable)
2647 * LTTNG_KERNEL_ABI_DISABLE
2648 * Disable recording for this event (strong disable)
2649 */
2650 static
2651 long lttng_event_recorder_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2652 {
2653 struct lttng_kernel_event_recorder *event_recorder = file->private_data;
2654
2655 switch (cmd) {
2656 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2657 {
2658 /* Not implemented */
2659 return -ENOSYS;
2660 }
2661 case LTTNG_KERNEL_ABI_CONTEXT:
2662 {
2663 /* Not implemented */
2664 return -ENOSYS;
2665 }
2666 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2667 case LTTNG_KERNEL_ABI_ENABLE:
2668 return lttng_event_enable(&event_recorder->parent);
2669 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2670 case LTTNG_KERNEL_ABI_DISABLE:
2671 return lttng_event_disable(&event_recorder->parent);
2672 case LTTNG_KERNEL_ABI_FILTER:
2673 return -EINVAL;
2674 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2675 return lttng_event_add_callsite(&event_recorder->parent,
2676 (struct lttng_kernel_abi_event_callsite __user *) arg);
2677 default:
2678 return -ENOIOCTLCMD;
2679 }
2680 }
2681
2682 /**
2683 * lttng_event_recorder_enabler_ioctl - lttng syscall through ioctl
2684 *
2685 * @file: the file
2686 * @cmd: the command
2687 * @arg: command arg
2688 *
2689 * This ioctl implements lttng commands:
2690 * LTTNG_KERNEL_ABI_CONTEXT
2691 * Prepend a context field to each record of this event
2692 * LTTNG_KERNEL_ABI_ENABLE
2693 * Enable recording for this event (weak enable)
2694 * LTTNG_KERNEL_ABI_DISABLE
2695 * Disable recording for this event (strong disable)
2696 */
2697 static
2698 long lttng_event_recorder_enabler_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2699 {
2700 struct lttng_event_enabler *event_enabler = file->private_data;
2701
2702 switch (cmd) {
2703 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2704 {
2705 /* Not implemented */
2706 return -ENOSYS;
2707 }
2708 case LTTNG_KERNEL_ABI_CONTEXT:
2709 {
2710 /* Not implemented */
2711 return -ENOSYS;
2712 }
2713 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2714 case LTTNG_KERNEL_ABI_ENABLE:
2715 return lttng_event_enabler_enable(event_enabler);
2716 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2717 case LTTNG_KERNEL_ABI_DISABLE:
2718 return lttng_event_enabler_disable(event_enabler);
2719 case LTTNG_KERNEL_ABI_FILTER:
2720 return lttng_event_enabler_attach_filter_bytecode(
2721 event_enabler,
2722 (struct lttng_kernel_abi_filter_bytecode __user *) arg);
2723 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2724 return -EINVAL;
2725 default:
2726 return -ENOIOCTLCMD;
2727 }
2728 }
2729
2730 static
2731 int lttng_event_recorder_event_release(struct inode *inode, struct file *file)
2732 {
2733 struct lttng_kernel_event_recorder *event = file->private_data;
2734
2735 if (event)
2736 fput(event->chan->priv->parent.file);
2737 return 0;
2738 }
2739
2740 static
2741 int lttng_event_recorder_enabler_release(struct inode *inode, struct file *file)
2742 {
2743 struct lttng_event_enabler *event_enabler = file->private_data;
2744
2745 if (event_enabler)
2746 fput(event_enabler->chan->priv->parent.file);
2747 return 0;
2748 }
2749
2750 static const struct file_operations lttng_event_recorder_event_fops = {
2751 .owner = THIS_MODULE,
2752 .release = lttng_event_recorder_event_release,
2753 .unlocked_ioctl = lttng_event_recorder_event_ioctl,
2754 #ifdef CONFIG_COMPAT
2755 .compat_ioctl = lttng_event_recorder_event_ioctl,
2756 #endif
2757 };
2758
2759 static const struct file_operations lttng_event_recorder_enabler_fops = {
2760 .owner = THIS_MODULE,
2761 .release = lttng_event_recorder_enabler_release,
2762 .unlocked_ioctl = lttng_event_recorder_enabler_ioctl,
2763 #ifdef CONFIG_COMPAT
2764 .compat_ioctl = lttng_event_recorder_enabler_ioctl,
2765 #endif
2766 };
2767
2768 static int put_u64(uint64_t val, unsigned long arg)
2769 {
2770 return put_user(val, (uint64_t __user *) arg);
2771 }
2772
2773 static int put_u32(uint32_t val, unsigned long arg)
2774 {
2775 return put_user(val, (uint32_t __user *) arg);
2776 }
2777
2778 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
2779 unsigned int cmd, unsigned long arg)
2780 {
2781 struct lttng_kernel_ring_buffer *buf = filp->private_data;
2782 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
2783 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
2784 const struct lttng_kernel_channel_buffer_ops *ops = chan->backend.priv_ops;
2785 int ret;
2786
2787 if (atomic_read(&chan->record_disabled))
2788 return -EIO;
2789
2790 switch (cmd) {
2791 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_TIMESTAMP_BEGIN:
2792 {
2793 uint64_t ts;
2794
2795 ret = ops->priv->timestamp_begin(config, buf, &ts);
2796 if (ret < 0)
2797 goto error;
2798 return put_u64(ts, arg);
2799 }
2800 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_TIMESTAMP_END:
2801 {
2802 uint64_t ts;
2803
2804 ret = ops->priv->timestamp_end(config, buf, &ts);
2805 if (ret < 0)
2806 goto error;
2807 return put_u64(ts, arg);
2808 }
2809 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_EVENTS_DISCARDED:
2810 {
2811 uint64_t ed;
2812
2813 ret = ops->priv->events_discarded(config, buf, &ed);
2814 if (ret < 0)
2815 goto error;
2816 return put_u64(ed, arg);
2817 }
2818 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CONTENT_SIZE:
2819 {
2820 uint64_t cs;
2821
2822 ret = ops->priv->content_size(config, buf, &cs);
2823 if (ret < 0)
2824 goto error;
2825 return put_u64(cs, arg);
2826 }
2827 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_PACKET_SIZE:
2828 {
2829 uint64_t ps;
2830
2831 ret = ops->priv->packet_size(config, buf, &ps);
2832 if (ret < 0)
2833 goto error;
2834 return put_u64(ps, arg);
2835 }
2836 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_STREAM_ID:
2837 {
2838 uint64_t si;
2839
2840 ret = ops->priv->stream_id(config, buf, &si);
2841 if (ret < 0)
2842 goto error;
2843 return put_u64(si, arg);
2844 }
2845 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2846 {
2847 uint64_t ts;
2848
2849 ret = ops->priv->current_timestamp(config, buf, &ts);
2850 if (ret < 0)
2851 goto error;
2852 return put_u64(ts, arg);
2853 }
2854 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SEQ_NUM:
2855 {
2856 uint64_t seq;
2857
2858 ret = ops->priv->sequence_number(config, buf, &seq);
2859 if (ret < 0)
2860 goto error;
2861 return put_u64(seq, arg);
2862 }
2863 case LTTNG_KERNEL_ABI_RING_BUFFER_INSTANCE_ID:
2864 {
2865 uint64_t id;
2866
2867 ret = ops->priv->instance_id(config, buf, &id);
2868 if (ret < 0)
2869 goto error;
2870 return put_u64(id, arg);
2871 }
2872 default:
2873 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
2874 cmd, arg);
2875 }
2876
2877 error:
2878 return -ENOSYS;
2879 }
2880
2881 #ifdef CONFIG_COMPAT
2882 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
2883 unsigned int cmd, unsigned long arg)
2884 {
2885 struct lttng_kernel_ring_buffer *buf = filp->private_data;
2886 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
2887 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
2888 const struct lttng_kernel_channel_buffer_ops *ops = chan->backend.priv_ops;
2889 int ret;
2890
2891 if (atomic_read(&chan->record_disabled))
2892 return -EIO;
2893
2894 switch (cmd) {
2895 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
2896 {
2897 uint64_t ts;
2898
2899 ret = ops->priv->timestamp_begin(config, buf, &ts);
2900 if (ret < 0)
2901 goto error;
2902 return put_u64(ts, arg);
2903 }
2904 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
2905 {
2906 uint64_t ts;
2907
2908 ret = ops->priv->timestamp_end(config, buf, &ts);
2909 if (ret < 0)
2910 goto error;
2911 return put_u64(ts, arg);
2912 }
2913 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
2914 {
2915 uint64_t ed;
2916
2917 ret = ops->priv->events_discarded(config, buf, &ed);
2918 if (ret < 0)
2919 goto error;
2920 return put_u64(ed, arg);
2921 }
2922 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
2923 {
2924 uint64_t cs;
2925
2926 ret = ops->priv->content_size(config, buf, &cs);
2927 if (ret < 0)
2928 goto error;
2929 return put_u64(cs, arg);
2930 }
2931 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
2932 {
2933 uint64_t ps;
2934
2935 ret = ops->priv->packet_size(config, buf, &ps);
2936 if (ret < 0)
2937 goto error;
2938 return put_u64(ps, arg);
2939 }
2940 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_STREAM_ID:
2941 {
2942 uint64_t si;
2943
2944 ret = ops->priv->stream_id(config, buf, &si);
2945 if (ret < 0)
2946 goto error;
2947 return put_u64(si, arg);
2948 }
2949 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2950 {
2951 uint64_t ts;
2952
2953 ret = ops->priv->current_timestamp(config, buf, &ts);
2954 if (ret < 0)
2955 goto error;
2956 return put_u64(ts, arg);
2957 }
2958 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_SEQ_NUM:
2959 {
2960 uint64_t seq;
2961
2962 ret = ops->priv->sequence_number(config, buf, &seq);
2963 if (ret < 0)
2964 goto error;
2965 return put_u64(seq, arg);
2966 }
2967 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_INSTANCE_ID:
2968 {
2969 uint64_t id;
2970
2971 ret = ops->priv->instance_id(config, buf, &id);
2972 if (ret < 0)
2973 goto error;
2974 return put_u64(id, arg);
2975 }
2976 default:
2977 return lib_ring_buffer_file_operations.compat_ioctl(filp,
2978 cmd, arg);
2979 }
2980
2981 error:
2982 return -ENOSYS;
2983 }
2984 #endif /* CONFIG_COMPAT */
2985
2986 static void lttng_stream_override_ring_buffer_fops(void)
2987 {
2988 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
2989 lttng_stream_ring_buffer_file_operations.open =
2990 lib_ring_buffer_file_operations.open;
2991 lttng_stream_ring_buffer_file_operations.release =
2992 lib_ring_buffer_file_operations.release;
2993 lttng_stream_ring_buffer_file_operations.poll =
2994 lib_ring_buffer_file_operations.poll;
2995 lttng_stream_ring_buffer_file_operations.splice_read =
2996 lib_ring_buffer_file_operations.splice_read;
2997 lttng_stream_ring_buffer_file_operations.mmap =
2998 lib_ring_buffer_file_operations.mmap;
2999 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
3000 lttng_stream_ring_buffer_ioctl;
3001 lttng_stream_ring_buffer_file_operations.llseek =
3002 lib_ring_buffer_file_operations.llseek;
3003 #ifdef CONFIG_COMPAT
3004 lttng_stream_ring_buffer_file_operations.compat_ioctl =
3005 lttng_stream_ring_buffer_compat_ioctl;
3006 #endif
3007 }
3008
3009 int __init lttng_abi_init(void)
3010 {
3011 int ret = 0;
3012
3013 wrapper_vmalloc_sync_mappings();
3014 lttng_clock_ref();
3015
3016 ret = lttng_tp_mempool_init();
3017 if (ret) {
3018 goto error;
3019 }
3020
3021 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
3022 &lttng_proc_ops, NULL);
3023
3024 if (!lttng_proc_dentry) {
3025 printk(KERN_ERR "LTTng: Error creating control file\n");
3026 ret = -ENOMEM;
3027 goto error;
3028 }
3029 lttng_stream_override_ring_buffer_fops();
3030 return 0;
3031
3032 error:
3033 lttng_tp_mempool_destroy();
3034 lttng_clock_unref();
3035 return ret;
3036 }
3037
3038 /* No __exit annotation because used by init error path too. */
3039 void lttng_abi_exit(void)
3040 {
3041 lttng_tp_mempool_destroy();
3042 lttng_clock_unref();
3043 if (lttng_proc_dentry)
3044 remove_proc_entry("lttng", NULL);
3045 }
LTTng 2.0/0.x modules
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