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533b5fb4a6083c12e01055a632ff005b1dfefb55
[lttng-modules.git] / src / lttng-abi.c
1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
2 *
3 * lttng-abi.c
4 *
5 * LTTng ABI
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 *
9 * Mimic system calls for:
10 * - session creation, returns a file descriptor or failure.
11 * - channel creation, returns a file descriptor or failure.
12 * - Operates on a session file descriptor
13 * - Takes all channel options as parameters.
14 * - stream get, returns a file descriptor or failure.
15 * - Operates on a channel file descriptor.
16 * - stream notifier get, returns a file descriptor or failure.
17 * - Operates on a channel file descriptor.
18 * - event creation, returns a file descriptor or failure.
19 * - Operates on a channel file descriptor
20 * - Takes an event name as parameter
21 * - Takes an instrumentation source as parameter
22 * - e.g. tracepoints, dynamic_probes...
23 * - Takes instrumentation source specific arguments.
24 */
25
26 #include <linux/module.h>
27 #include <linux/proc_fs.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/file.h>
30 #include <linux/uaccess.h>
31 #include <linux/slab.h>
32 #include <linux/err.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_mappings() */
34 #include <ringbuffer/vfs.h>
35 #include <ringbuffer/backend.h>
36 #include <ringbuffer/frontend.h>
37 #include <wrapper/compiler_attributes.h>
38 #include <wrapper/poll.h>
39 #include <wrapper/file.h>
40 #include <wrapper/kref.h>
41 #include <wrapper/barrier.h>
42 #include <lttng/string-utils.h>
43 #include <lttng/abi.h>
44 #include <lttng/abi-old.h>
45 #include <lttng/events.h>
46 #include <lttng/events-internal.h>
47 #include <lttng/tracer.h>
48 #include <lttng/tp-mempool.h>
49 #include <ringbuffer/frontend_types.h>
50 #include <ringbuffer/iterator.h>
51
52 /*
53 * This is LTTng's own personal way to create a system call as an external
54 * module. We use ioctl() on /proc/lttng.
55 */
56
57 static struct proc_dir_entry *lttng_proc_dentry;
58
59 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
60 static const struct proc_ops lttng_proc_ops;
61 #else
62 static const struct file_operations lttng_proc_ops;
63 #endif
64
65 static const struct file_operations lttng_session_fops;
66 static const struct file_operations lttng_event_notifier_group_fops;
67 static const struct file_operations lttng_channel_fops;
68 static const struct file_operations lttng_metadata_fops;
69 static const struct file_operations lttng_event_recorder_event_fops;
70 static const struct file_operations lttng_event_recorder_enabler_fops;
71 static struct file_operations lttng_stream_ring_buffer_file_operations;
72
73 static int put_u64(uint64_t val, unsigned long arg);
74 static int put_u32(uint32_t val, unsigned long arg);
75
76 static int validate_zeroed_padding(char *p, size_t len)
77 {
78 size_t i;
79
80 for (i = 0; i < len; i++) {
81 if (p[i])
82 return -1;
83 }
84 return 0;
85 }
86
87 /*
88 * Teardown management: opened file descriptors keep a refcount on the module,
89 * so it can only exit when all file descriptors are closed.
90 */
91
92 static
93 int lttng_abi_create_session(void)
94 {
95 struct lttng_kernel_session *session;
96 struct file *session_file;
97 int session_fd, ret;
98
99 session = lttng_session_create();
100 if (!session)
101 return -ENOMEM;
102 session_fd = lttng_get_unused_fd();
103 if (session_fd < 0) {
104 ret = session_fd;
105 goto fd_error;
106 }
107 session_file = anon_inode_getfile("[lttng_session]",
108 &lttng_session_fops,
109 session, O_RDWR);
110 if (IS_ERR(session_file)) {
111 ret = PTR_ERR(session_file);
112 goto file_error;
113 }
114 session->priv->file = session_file;
115 fd_install(session_fd, session_file);
116 return session_fd;
117
118 file_error:
119 put_unused_fd(session_fd);
120 fd_error:
121 lttng_session_destroy(session);
122 return ret;
123 }
124
125 void event_notifier_send_notification_work_wakeup(struct irq_work *entry)
126 {
127 struct lttng_event_notifier_group *event_notifier_group =
128 container_of(entry, struct lttng_event_notifier_group,
129 wakeup_pending);
130 wake_up_interruptible(&event_notifier_group->read_wait);
131 }
132
133 static
134 int lttng_abi_create_event_notifier_group(void)
135 {
136 struct lttng_event_notifier_group *event_notifier_group;
137 struct file *event_notifier_group_file;
138 int event_notifier_group_fd, ret;
139
140 event_notifier_group = lttng_event_notifier_group_create();
141 if (!event_notifier_group)
142 return -ENOMEM;
143
144 event_notifier_group_fd = lttng_get_unused_fd();
145 if (event_notifier_group_fd < 0) {
146 ret = event_notifier_group_fd;
147 goto fd_error;
148 }
149 event_notifier_group_file = anon_inode_getfile("[lttng_event_notifier_group]",
150 &lttng_event_notifier_group_fops,
151 event_notifier_group, O_RDWR);
152 if (IS_ERR(event_notifier_group_file)) {
153 ret = PTR_ERR(event_notifier_group_file);
154 goto file_error;
155 }
156
157 event_notifier_group->file = event_notifier_group_file;
158 init_waitqueue_head(&event_notifier_group->read_wait);
159 init_irq_work(&event_notifier_group->wakeup_pending,
160 event_notifier_send_notification_work_wakeup);
161 fd_install(event_notifier_group_fd, event_notifier_group_file);
162 return event_notifier_group_fd;
163
164 file_error:
165 put_unused_fd(event_notifier_group_fd);
166 fd_error:
167 lttng_event_notifier_group_destroy(event_notifier_group);
168 return ret;
169 }
170
171 static
172 int lttng_abi_tracepoint_list(void)
173 {
174 struct file *tracepoint_list_file;
175 int file_fd, ret;
176
177 file_fd = lttng_get_unused_fd();
178 if (file_fd < 0) {
179 ret = file_fd;
180 goto fd_error;
181 }
182
183 tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
184 &lttng_tracepoint_list_fops,
185 NULL, O_RDWR);
186 if (IS_ERR(tracepoint_list_file)) {
187 ret = PTR_ERR(tracepoint_list_file);
188 goto file_error;
189 }
190 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
191 if (ret < 0)
192 goto open_error;
193 fd_install(file_fd, tracepoint_list_file);
194 return file_fd;
195
196 open_error:
197 fput(tracepoint_list_file);
198 file_error:
199 put_unused_fd(file_fd);
200 fd_error:
201 return ret;
202 }
203
204 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
205 static inline
206 int lttng_abi_syscall_list(void)
207 {
208 return -ENOSYS;
209 }
210 #else
211 static
212 int lttng_abi_syscall_list(void)
213 {
214 struct file *syscall_list_file;
215 int file_fd, ret;
216
217 file_fd = lttng_get_unused_fd();
218 if (file_fd < 0) {
219 ret = file_fd;
220 goto fd_error;
221 }
222
223 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
224 &lttng_syscall_list_fops,
225 NULL, O_RDWR);
226 if (IS_ERR(syscall_list_file)) {
227 ret = PTR_ERR(syscall_list_file);
228 goto file_error;
229 }
230 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
231 if (ret < 0)
232 goto open_error;
233 fd_install(file_fd, syscall_list_file);
234 return file_fd;
235
236 open_error:
237 fput(syscall_list_file);
238 file_error:
239 put_unused_fd(file_fd);
240 fd_error:
241 return ret;
242 }
243 #endif
244
245 static
246 void lttng_abi_tracer_version(struct lttng_kernel_abi_tracer_version *v)
247 {
248 v->major = LTTNG_MODULES_MAJOR_VERSION;
249 v->minor = LTTNG_MODULES_MINOR_VERSION;
250 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
251 }
252
253 static
254 void lttng_abi_tracer_abi_version(struct lttng_kernel_abi_tracer_abi_version *v)
255 {
256 v->major = LTTNG_KERNEL_ABI_MAJOR_VERSION;
257 v->minor = LTTNG_KERNEL_ABI_MINOR_VERSION;
258 }
259
260 static
261 long lttng_abi_add_context(struct file *file,
262 struct lttng_kernel_abi_context *context_param,
263 struct lttng_kernel_ctx **ctx, struct lttng_kernel_session *session)
264 {
265
266 if (session->priv->been_active)
267 return -EPERM;
268
269 switch (context_param->ctx) {
270 case LTTNG_KERNEL_ABI_CONTEXT_PID:
271 return lttng_add_pid_to_ctx(ctx);
272 case LTTNG_KERNEL_ABI_CONTEXT_PRIO:
273 return lttng_add_prio_to_ctx(ctx);
274 case LTTNG_KERNEL_ABI_CONTEXT_NICE:
275 return lttng_add_nice_to_ctx(ctx);
276 case LTTNG_KERNEL_ABI_CONTEXT_VPID:
277 return lttng_add_vpid_to_ctx(ctx);
278 case LTTNG_KERNEL_ABI_CONTEXT_TID:
279 return lttng_add_tid_to_ctx(ctx);
280 case LTTNG_KERNEL_ABI_CONTEXT_VTID:
281 return lttng_add_vtid_to_ctx(ctx);
282 case LTTNG_KERNEL_ABI_CONTEXT_PPID:
283 return lttng_add_ppid_to_ctx(ctx);
284 case LTTNG_KERNEL_ABI_CONTEXT_VPPID:
285 return lttng_add_vppid_to_ctx(ctx);
286 case LTTNG_KERNEL_ABI_CONTEXT_PERF_COUNTER:
287 context_param->u.perf_counter.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
288 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
289 context_param->u.perf_counter.config,
290 context_param->u.perf_counter.name,
291 ctx);
292 case LTTNG_KERNEL_ABI_CONTEXT_PROCNAME:
293 return lttng_add_procname_to_ctx(ctx);
294 case LTTNG_KERNEL_ABI_CONTEXT_HOSTNAME:
295 return lttng_add_hostname_to_ctx(ctx);
296 case LTTNG_KERNEL_ABI_CONTEXT_CPU_ID:
297 return lttng_add_cpu_id_to_ctx(ctx);
298 case LTTNG_KERNEL_ABI_CONTEXT_INTERRUPTIBLE:
299 return lttng_add_interruptible_to_ctx(ctx);
300 case LTTNG_KERNEL_ABI_CONTEXT_NEED_RESCHEDULE:
301 return lttng_add_need_reschedule_to_ctx(ctx);
302 case LTTNG_KERNEL_ABI_CONTEXT_PREEMPTIBLE:
303 return lttng_add_preemptible_to_ctx(ctx);
304 case LTTNG_KERNEL_ABI_CONTEXT_MIGRATABLE:
305 return lttng_add_migratable_to_ctx(ctx);
306 case LTTNG_KERNEL_ABI_CONTEXT_CALLSTACK_KERNEL:
307 case LTTNG_KERNEL_ABI_CONTEXT_CALLSTACK_USER:
308 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
309 case LTTNG_KERNEL_ABI_CONTEXT_CGROUP_NS:
310 return lttng_add_cgroup_ns_to_ctx(ctx);
311 case LTTNG_KERNEL_ABI_CONTEXT_IPC_NS:
312 return lttng_add_ipc_ns_to_ctx(ctx);
313 case LTTNG_KERNEL_ABI_CONTEXT_MNT_NS:
314 return lttng_add_mnt_ns_to_ctx(ctx);
315 case LTTNG_KERNEL_ABI_CONTEXT_NET_NS:
316 return lttng_add_net_ns_to_ctx(ctx);
317 case LTTNG_KERNEL_ABI_CONTEXT_PID_NS:
318 return lttng_add_pid_ns_to_ctx(ctx);
319 case LTTNG_KERNEL_ABI_CONTEXT_USER_NS:
320 return lttng_add_user_ns_to_ctx(ctx);
321 case LTTNG_KERNEL_ABI_CONTEXT_UTS_NS:
322 return lttng_add_uts_ns_to_ctx(ctx);
323 case LTTNG_KERNEL_ABI_CONTEXT_UID:
324 return lttng_add_uid_to_ctx(ctx);
325 case LTTNG_KERNEL_ABI_CONTEXT_EUID:
326 return lttng_add_euid_to_ctx(ctx);
327 case LTTNG_KERNEL_ABI_CONTEXT_SUID:
328 return lttng_add_suid_to_ctx(ctx);
329 case LTTNG_KERNEL_ABI_CONTEXT_GID:
330 return lttng_add_gid_to_ctx(ctx);
331 case LTTNG_KERNEL_ABI_CONTEXT_EGID:
332 return lttng_add_egid_to_ctx(ctx);
333 case LTTNG_KERNEL_ABI_CONTEXT_SGID:
334 return lttng_add_sgid_to_ctx(ctx);
335 case LTTNG_KERNEL_ABI_CONTEXT_VUID:
336 return lttng_add_vuid_to_ctx(ctx);
337 case LTTNG_KERNEL_ABI_CONTEXT_VEUID:
338 return lttng_add_veuid_to_ctx(ctx);
339 case LTTNG_KERNEL_ABI_CONTEXT_VSUID:
340 return lttng_add_vsuid_to_ctx(ctx);
341 case LTTNG_KERNEL_ABI_CONTEXT_VGID:
342 return lttng_add_vgid_to_ctx(ctx);
343 case LTTNG_KERNEL_ABI_CONTEXT_VEGID:
344 return lttng_add_vegid_to_ctx(ctx);
345 case LTTNG_KERNEL_ABI_CONTEXT_VSGID:
346 return lttng_add_vsgid_to_ctx(ctx);
347 case LTTNG_KERNEL_ABI_CONTEXT_TIME_NS:
348 return lttng_add_time_ns_to_ctx(ctx);
349 default:
350 return -EINVAL;
351 }
352 }
353
354 /**
355 * lttng_ioctl - lttng syscall through ioctl
356 *
357 * @file: the file
358 * @cmd: the command
359 * @arg: command arg
360 *
361 * This ioctl implements lttng commands:
362 * LTTNG_KERNEL_ABI_SESSION
363 * Returns a LTTng trace session file descriptor
364 * LTTNG_KERNEL_ABI_TRACER_VERSION
365 * Returns the LTTng kernel tracer version
366 * LTTNG_KERNEL_ABI_TRACEPOINT_LIST
367 * Returns a file descriptor listing available tracepoints
368 * LTTNG_KERNEL_ABI_WAIT_QUIESCENT
369 * Returns after all previously running probes have completed
370 * LTTNG_KERNEL_ABI_TRACER_ABI_VERSION
371 * Returns the LTTng kernel tracer ABI version
372 * LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_CREATE
373 * Returns a LTTng event notifier group file descriptor
374 *
375 * The returned session will be deleted when its file descriptor is closed.
376 */
377 static
378 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
379 {
380 switch (cmd) {
381 case LTTNG_KERNEL_ABI_OLD_SESSION:
382 case LTTNG_KERNEL_ABI_SESSION:
383 return lttng_abi_create_session();
384 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_CREATE:
385 return lttng_abi_create_event_notifier_group();
386 case LTTNG_KERNEL_ABI_OLD_TRACER_VERSION:
387 {
388 struct lttng_kernel_abi_tracer_version v;
389 struct lttng_kernel_abi_old_tracer_version oldv;
390 struct lttng_kernel_abi_old_tracer_version *uversion =
391 (struct lttng_kernel_abi_old_tracer_version __user *) arg;
392
393 lttng_abi_tracer_version(&v);
394 oldv.major = v.major;
395 oldv.minor = v.minor;
396 oldv.patchlevel = v.patchlevel;
397
398 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
399 return -EFAULT;
400 return 0;
401 }
402 case LTTNG_KERNEL_ABI_TRACER_VERSION:
403 {
404 struct lttng_kernel_abi_tracer_version version;
405 struct lttng_kernel_abi_tracer_version *uversion =
406 (struct lttng_kernel_abi_tracer_version __user *) arg;
407
408 lttng_abi_tracer_version(&version);
409
410 if (copy_to_user(uversion, &version, sizeof(version)))
411 return -EFAULT;
412 return 0;
413 }
414 case LTTNG_KERNEL_ABI_TRACER_ABI_VERSION:
415 {
416 struct lttng_kernel_abi_tracer_abi_version version;
417 struct lttng_kernel_abi_tracer_abi_version *uversion =
418 (struct lttng_kernel_abi_tracer_abi_version __user *) arg;
419
420 lttng_abi_tracer_abi_version(&version);
421
422 if (copy_to_user(uversion, &version, sizeof(version)))
423 return -EFAULT;
424 return 0;
425 }
426 case LTTNG_KERNEL_ABI_OLD_TRACEPOINT_LIST:
427 case LTTNG_KERNEL_ABI_TRACEPOINT_LIST:
428 return lttng_abi_tracepoint_list();
429 case LTTNG_KERNEL_ABI_SYSCALL_LIST:
430 return lttng_abi_syscall_list();
431 case LTTNG_KERNEL_ABI_OLD_WAIT_QUIESCENT:
432 case LTTNG_KERNEL_ABI_WAIT_QUIESCENT:
433 synchronize_trace();
434 return 0;
435 case LTTNG_KERNEL_ABI_OLD_CALIBRATE:
436 {
437 struct lttng_kernel_abi_old_calibrate __user *ucalibrate =
438 (struct lttng_kernel_abi_old_calibrate __user *) arg;
439 struct lttng_kernel_abi_old_calibrate old_calibrate;
440 struct lttng_kernel_abi_calibrate calibrate;
441 int ret;
442
443 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
444 return -EFAULT;
445 calibrate.type = old_calibrate.type;
446 ret = lttng_calibrate(&calibrate);
447 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
448 return -EFAULT;
449 return ret;
450 }
451 case LTTNG_KERNEL_ABI_CALIBRATE:
452 {
453 struct lttng_kernel_abi_calibrate __user *ucalibrate =
454 (struct lttng_kernel_abi_calibrate __user *) arg;
455 struct lttng_kernel_abi_calibrate calibrate;
456 int ret;
457
458 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
459 return -EFAULT;
460 ret = lttng_calibrate(&calibrate);
461 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
462 return -EFAULT;
463 return ret;
464 }
465 default:
466 return -ENOIOCTLCMD;
467 }
468 }
469
470 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
471 static const struct proc_ops lttng_proc_ops = {
472 .proc_ioctl = lttng_ioctl,
473 #ifdef CONFIG_COMPAT
474 .proc_compat_ioctl = lttng_ioctl,
475 #endif /* CONFIG_COMPAT */
476 };
477 #else
478 static const struct file_operations lttng_proc_ops = {
479 .owner = THIS_MODULE,
480 .unlocked_ioctl = lttng_ioctl,
481 #ifdef CONFIG_COMPAT
482 .compat_ioctl = lttng_ioctl,
483 #endif /* CONFIG_COMPAT */
484 };
485 #endif
486
487 static
488 int lttng_abi_create_channel(struct file *session_file,
489 struct lttng_kernel_abi_channel *chan_param,
490 enum channel_type channel_type)
491 {
492 struct lttng_kernel_session *session = session_file->private_data;
493 const struct file_operations *fops = NULL;
494 const char *transport_name;
495 struct lttng_kernel_channel_buffer *chan;
496 struct file *chan_file;
497 int chan_fd;
498 int ret = 0;
499
500 chan_fd = lttng_get_unused_fd();
501 if (chan_fd < 0) {
502 ret = chan_fd;
503 goto fd_error;
504 }
505 switch (channel_type) {
506 case PER_CPU_CHANNEL:
507 fops = &lttng_channel_fops;
508 break;
509 case METADATA_CHANNEL:
510 fops = &lttng_metadata_fops;
511 break;
512 }
513
514 chan_file = anon_inode_getfile("[lttng_channel]",
515 fops,
516 NULL, O_RDWR);
517 if (IS_ERR(chan_file)) {
518 ret = PTR_ERR(chan_file);
519 goto file_error;
520 }
521 switch (channel_type) {
522 case PER_CPU_CHANNEL:
523 if (chan_param->output == LTTNG_KERNEL_ABI_SPLICE) {
524 transport_name = chan_param->overwrite ?
525 "relay-overwrite" : "relay-discard";
526 } else if (chan_param->output == LTTNG_KERNEL_ABI_MMAP) {
527 transport_name = chan_param->overwrite ?
528 "relay-overwrite-mmap" : "relay-discard-mmap";
529 } else {
530 return -EINVAL;
531 }
532 break;
533 case METADATA_CHANNEL:
534 if (chan_param->output == LTTNG_KERNEL_ABI_SPLICE)
535 transport_name = "relay-metadata";
536 else if (chan_param->output == LTTNG_KERNEL_ABI_MMAP)
537 transport_name = "relay-metadata-mmap";
538 else
539 return -EINVAL;
540 break;
541 default:
542 transport_name = "<unknown>";
543 break;
544 }
545 if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
546 ret = -EOVERFLOW;
547 goto refcount_error;
548 }
549 /*
550 * We tolerate no failure path after channel creation. It will stay
551 * invariant for the rest of the session.
552 */
553 chan = lttng_channel_buffer_create(session, transport_name, NULL,
554 chan_param->subbuf_size,
555 chan_param->num_subbuf,
556 chan_param->switch_timer_interval,
557 chan_param->read_timer_interval,
558 channel_type);
559 if (!chan) {
560 ret = -EINVAL;
561 goto chan_error;
562 }
563 chan->priv->parent.file = chan_file;
564 chan_file->private_data = chan;
565 fd_install(chan_fd, chan_file);
566
567 return chan_fd;
568
569 chan_error:
570 atomic_long_dec(&session_file->f_count);
571 refcount_error:
572 fput(chan_file);
573 file_error:
574 put_unused_fd(chan_fd);
575 fd_error:
576 return ret;
577 }
578
579 static
580 int lttng_abi_session_set_name(struct lttng_kernel_session *session,
581 struct lttng_kernel_abi_session_name *name)
582 {
583 size_t len;
584
585 len = strnlen(name->name, LTTNG_KERNEL_ABI_SESSION_NAME_LEN);
586
587 if (len == LTTNG_KERNEL_ABI_SESSION_NAME_LEN) {
588 /* Name is too long/malformed */
589 return -EINVAL;
590 }
591
592 strcpy(session->priv->name, name->name);
593 return 0;
594 }
595
596 static
597 int lttng_abi_session_set_creation_time(struct lttng_kernel_session *session,
598 struct lttng_kernel_abi_session_creation_time *time)
599 {
600 size_t len;
601
602 len = strnlen(time->iso8601, LTTNG_KERNEL_ABI_SESSION_CREATION_TIME_ISO8601_LEN);
603
604 if (len == LTTNG_KERNEL_ABI_SESSION_CREATION_TIME_ISO8601_LEN) {
605 /* Time is too long/malformed */
606 return -EINVAL;
607 }
608
609 strcpy(session->priv->creation_time, time->iso8601);
610 return 0;
611 }
612
613 static
614 int lttng_counter_release(struct inode *inode, struct file *file)
615 {
616 struct lttng_counter *counter = file->private_data;
617
618 if (counter) {
619 /*
620 * Do not destroy the counter itself. Wait of the owner
621 * (event_notifier group) to be destroyed.
622 */
623 fput(counter->owner);
624 }
625
626 return 0;
627 }
628
629 static
630 long lttng_counter_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
631 {
632 struct lttng_counter *counter = file->private_data;
633 size_t indexes[LTTNG_KERNEL_ABI_COUNTER_DIMENSION_MAX] = { 0 };
634 int i;
635
636 switch (cmd) {
637 case LTTNG_KERNEL_ABI_COUNTER_READ:
638 {
639 struct lttng_kernel_abi_counter_read local_counter_read;
640 struct lttng_kernel_abi_counter_read __user *ucounter_read =
641 (struct lttng_kernel_abi_counter_read __user *) arg;
642 bool overflow, underflow;
643 int64_t value;
644 int32_t cpu;
645 int ret;
646
647 if (copy_from_user(&local_counter_read, ucounter_read,
648 sizeof(local_counter_read)))
649 return -EFAULT;
650 if (validate_zeroed_padding(local_counter_read.padding,
651 sizeof(local_counter_read.padding)))
652 return -EINVAL;
653
654 /* Cast all indexes into size_t. */
655 for (i = 0; i < local_counter_read.index.number_dimensions; i++)
656 indexes[i] = (size_t) local_counter_read.index.dimension_indexes[i];
657 cpu = local_counter_read.cpu;
658
659 ret = lttng_kernel_counter_read(counter, indexes, cpu, &value,
660 &overflow, &underflow);
661 if (ret)
662 return ret;
663 local_counter_read.value.value = value;
664 local_counter_read.value.overflow = overflow;
665 local_counter_read.value.underflow = underflow;
666
667 if (copy_to_user(&ucounter_read->value, &local_counter_read.value,
668 sizeof(local_counter_read.value)))
669 return -EFAULT;
670
671 return 0;
672 }
673 case LTTNG_KERNEL_ABI_COUNTER_AGGREGATE:
674 {
675 struct lttng_kernel_abi_counter_aggregate local_counter_aggregate;
676 struct lttng_kernel_abi_counter_aggregate __user *ucounter_aggregate =
677 (struct lttng_kernel_abi_counter_aggregate __user *) arg;
678 bool overflow, underflow;
679 int64_t value;
680 int ret;
681
682 if (copy_from_user(&local_counter_aggregate, ucounter_aggregate,
683 sizeof(local_counter_aggregate)))
684 return -EFAULT;
685 if (validate_zeroed_padding(local_counter_aggregate.padding,
686 sizeof(local_counter_aggregate.padding)))
687 return -EINVAL;
688
689 /* Cast all indexes into size_t. */
690 for (i = 0; i < local_counter_aggregate.index.number_dimensions; i++)
691 indexes[i] = (size_t) local_counter_aggregate.index.dimension_indexes[i];
692
693 ret = lttng_kernel_counter_aggregate(counter, indexes, &value,
694 &overflow, &underflow);
695 if (ret)
696 return ret;
697 local_counter_aggregate.value.value = value;
698 local_counter_aggregate.value.overflow = overflow;
699 local_counter_aggregate.value.underflow = underflow;
700
701 if (copy_to_user(&ucounter_aggregate->value, &local_counter_aggregate.value,
702 sizeof(local_counter_aggregate.value)))
703 return -EFAULT;
704
705 return 0;
706 }
707 case LTTNG_KERNEL_ABI_COUNTER_CLEAR:
708 {
709 struct lttng_kernel_abi_counter_clear local_counter_clear;
710 struct lttng_kernel_abi_counter_clear __user *ucounter_clear =
711 (struct lttng_kernel_abi_counter_clear __user *) arg;
712
713 if (copy_from_user(&local_counter_clear, ucounter_clear,
714 sizeof(local_counter_clear)))
715 return -EFAULT;
716 if (validate_zeroed_padding(local_counter_clear.padding,
717 sizeof(local_counter_clear.padding)))
718 return -EINVAL;
719
720 /* Cast all indexes into size_t. */
721 for (i = 0; i < local_counter_clear.index.number_dimensions; i++)
722 indexes[i] = (size_t) local_counter_clear.index.dimension_indexes[i];
723
724 return lttng_kernel_counter_clear(counter, indexes);
725 }
726 default:
727 WARN_ON_ONCE(1);
728 return -ENOSYS;
729 }
730 }
731
732 static const struct file_operations lttng_counter_fops = {
733 .owner = THIS_MODULE,
734 .release = lttng_counter_release,
735 .unlocked_ioctl = lttng_counter_ioctl,
736 #ifdef CONFIG_COMPAT
737 .compat_ioctl = lttng_counter_ioctl,
738 #endif
739 };
740
741
742 static
743 enum tracker_type get_tracker_type(struct lttng_kernel_abi_tracker_args *tracker)
744 {
745 switch (tracker->type) {
746 case LTTNG_KERNEL_ABI_TRACKER_PID:
747 return TRACKER_PID;
748 case LTTNG_KERNEL_ABI_TRACKER_VPID:
749 return TRACKER_VPID;
750 case LTTNG_KERNEL_ABI_TRACKER_UID:
751 return TRACKER_UID;
752 case LTTNG_KERNEL_ABI_TRACKER_VUID:
753 return TRACKER_VUID;
754 case LTTNG_KERNEL_ABI_TRACKER_GID:
755 return TRACKER_GID;
756 case LTTNG_KERNEL_ABI_TRACKER_VGID:
757 return TRACKER_VGID;
758 default:
759 return TRACKER_UNKNOWN;
760 }
761 }
762
763 /**
764 * lttng_session_ioctl - lttng session fd ioctl
765 *
766 * @file: the file
767 * @cmd: the command
768 * @arg: command arg
769 *
770 * This ioctl implements lttng commands:
771 * LTTNG_KERNEL_ABI_CHANNEL
772 * Returns a LTTng channel file descriptor
773 * LTTNG_KERNEL_ABI_ENABLE
774 * Enables tracing for a session (weak enable)
775 * LTTNG_KERNEL_ABI_DISABLE
776 * Disables tracing for a session (strong disable)
777 * LTTNG_KERNEL_ABI_METADATA
778 * Returns a LTTng metadata file descriptor
779 * LTTNG_KERNEL_ABI_SESSION_TRACK_PID
780 * Add PID to session PID tracker
781 * LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID
782 * Remove PID from session PID tracker
783 * LTTNG_KERNEL_ABI_SESSION_TRACK_ID
784 * Add ID to tracker
785 * LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID
786 * Remove ID from tracker
787 *
788 * The returned channel will be deleted when its file descriptor is closed.
789 */
790 static
791 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
792 {
793 struct lttng_kernel_session *session = file->private_data;
794 struct lttng_kernel_abi_channel chan_param;
795 struct lttng_kernel_abi_old_channel old_chan_param;
796
797 /*
798 * Handle backward compatibility. OLD commands have wrong
799 * directions, replace them by the correct direction.
800 */
801 switch (cmd) {
802 case LTTNG_KERNEL_ABI_OLD_SESSION_TRACK_PID:
803 cmd = LTTNG_KERNEL_ABI_SESSION_TRACK_PID;
804 break;
805 case LTTNG_KERNEL_ABI_OLD_SESSION_UNTRACK_PID:
806 cmd = LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID;
807 break;
808 case LTTNG_KERNEL_ABI_OLD_SESSION_TRACK_ID:
809 cmd = LTTNG_KERNEL_ABI_SESSION_TRACK_ID;
810 break;
811 case LTTNG_KERNEL_ABI_OLD_SESSION_UNTRACK_ID:
812 cmd = LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID;
813 break;
814 case LTTNG_KERNEL_ABI_OLD_SESSION_LIST_TRACKER_IDS:
815 cmd = LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_IDS;
816 break;
817 case LTTNG_KERNEL_ABI_OLD_SESSION_SET_NAME:
818 cmd = LTTNG_KERNEL_ABI_SESSION_SET_NAME;
819 break;
820 case LTTNG_KERNEL_ABI_OLD_SESSION_SET_CREATION_TIME:
821 cmd = LTTNG_KERNEL_ABI_SESSION_SET_CREATION_TIME;
822 break;
823 default:
824 /* Nothing to do. */
825 break;
826 }
827
828 switch (cmd) {
829 case LTTNG_KERNEL_ABI_OLD_CHANNEL:
830 {
831 if (copy_from_user(&old_chan_param,
832 (struct lttng_kernel_abi_old_channel __user *) arg,
833 sizeof(struct lttng_kernel_abi_old_channel)))
834 return -EFAULT;
835 chan_param.overwrite = old_chan_param.overwrite;
836 chan_param.subbuf_size = old_chan_param.subbuf_size;
837 chan_param.num_subbuf = old_chan_param.num_subbuf;
838 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
839 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
840 chan_param.output = old_chan_param.output;
841
842 return lttng_abi_create_channel(file, &chan_param,
843 PER_CPU_CHANNEL);
844 }
845 case LTTNG_KERNEL_ABI_CHANNEL:
846 {
847 if (copy_from_user(&chan_param,
848 (struct lttng_kernel_abi_channel __user *) arg,
849 sizeof(struct lttng_kernel_abi_channel)))
850 return -EFAULT;
851 return lttng_abi_create_channel(file, &chan_param,
852 PER_CPU_CHANNEL);
853 }
854 case LTTNG_KERNEL_ABI_OLD_SESSION_START:
855 case LTTNG_KERNEL_ABI_OLD_ENABLE:
856 case LTTNG_KERNEL_ABI_SESSION_START:
857 case LTTNG_KERNEL_ABI_ENABLE:
858 return lttng_session_enable(session);
859 case LTTNG_KERNEL_ABI_OLD_SESSION_STOP:
860 case LTTNG_KERNEL_ABI_OLD_DISABLE:
861 case LTTNG_KERNEL_ABI_SESSION_STOP:
862 case LTTNG_KERNEL_ABI_DISABLE:
863 return lttng_session_disable(session);
864 case LTTNG_KERNEL_ABI_OLD_METADATA:
865 {
866 if (copy_from_user(&old_chan_param,
867 (struct lttng_kernel_abi_old_channel __user *) arg,
868 sizeof(struct lttng_kernel_abi_old_channel)))
869 return -EFAULT;
870 chan_param.overwrite = old_chan_param.overwrite;
871 chan_param.subbuf_size = old_chan_param.subbuf_size;
872 chan_param.num_subbuf = old_chan_param.num_subbuf;
873 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
874 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
875 chan_param.output = old_chan_param.output;
876
877 return lttng_abi_create_channel(file, &chan_param,
878 METADATA_CHANNEL);
879 }
880 case LTTNG_KERNEL_ABI_METADATA:
881 {
882 if (copy_from_user(&chan_param,
883 (struct lttng_kernel_abi_channel __user *) arg,
884 sizeof(struct lttng_kernel_abi_channel)))
885 return -EFAULT;
886 return lttng_abi_create_channel(file, &chan_param,
887 METADATA_CHANNEL);
888 }
889 case LTTNG_KERNEL_ABI_SESSION_TRACK_PID:
890 return lttng_session_track_id(session, TRACKER_PID, (int) arg);
891 case LTTNG_KERNEL_ABI_SESSION_UNTRACK_PID:
892 return lttng_session_untrack_id(session, TRACKER_PID, (int) arg);
893 case LTTNG_KERNEL_ABI_SESSION_TRACK_ID:
894 {
895 struct lttng_kernel_abi_tracker_args tracker;
896 enum tracker_type tracker_type;
897
898 if (copy_from_user(&tracker,
899 (struct lttng_kernel_abi_tracker_args __user *) arg,
900 sizeof(struct lttng_kernel_abi_tracker_args)))
901 return -EFAULT;
902 tracker_type = get_tracker_type(&tracker);
903 if (tracker_type == TRACKER_UNKNOWN)
904 return -EINVAL;
905 return lttng_session_track_id(session, tracker_type, tracker.id);
906 }
907 case LTTNG_KERNEL_ABI_SESSION_UNTRACK_ID:
908 {
909 struct lttng_kernel_abi_tracker_args tracker;
910 enum tracker_type tracker_type;
911
912 if (copy_from_user(&tracker,
913 (struct lttng_kernel_abi_tracker_args __user *) arg,
914 sizeof(struct lttng_kernel_abi_tracker_args)))
915 return -EFAULT;
916 tracker_type = get_tracker_type(&tracker);
917 if (tracker_type == TRACKER_UNKNOWN)
918 return -EINVAL;
919 return lttng_session_untrack_id(session, tracker_type,
920 tracker.id);
921 }
922 case LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_PIDS:
923 return lttng_session_list_tracker_ids(session, TRACKER_PID);
924 case LTTNG_KERNEL_ABI_SESSION_LIST_TRACKER_IDS:
925 {
926 struct lttng_kernel_abi_tracker_args tracker;
927 enum tracker_type tracker_type;
928
929 if (copy_from_user(&tracker,
930 (struct lttng_kernel_abi_tracker_args __user *) arg,
931 sizeof(struct lttng_kernel_abi_tracker_args)))
932 return -EFAULT;
933 tracker_type = get_tracker_type(&tracker);
934 if (tracker_type == TRACKER_UNKNOWN)
935 return -EINVAL;
936 return lttng_session_list_tracker_ids(session, tracker_type);
937 }
938 case LTTNG_KERNEL_ABI_SESSION_METADATA_REGEN:
939 return lttng_session_metadata_regenerate(session);
940 case LTTNG_KERNEL_ABI_SESSION_STATEDUMP:
941 return lttng_session_statedump(session);
942 case LTTNG_KERNEL_ABI_SESSION_SET_NAME:
943 {
944 struct lttng_kernel_abi_session_name name;
945
946 if (copy_from_user(&name,
947 (struct lttng_kernel_abi_session_name __user *) arg,
948 sizeof(struct lttng_kernel_abi_session_name)))
949 return -EFAULT;
950 return lttng_abi_session_set_name(session, &name);
951 }
952 case LTTNG_KERNEL_ABI_SESSION_SET_CREATION_TIME:
953 {
954 struct lttng_kernel_abi_session_creation_time time;
955
956 if (copy_from_user(&time,
957 (struct lttng_kernel_abi_session_creation_time __user *) arg,
958 sizeof(struct lttng_kernel_abi_session_creation_time)))
959 return -EFAULT;
960 return lttng_abi_session_set_creation_time(session, &time);
961 }
962 default:
963 return -ENOIOCTLCMD;
964 }
965 }
966
967 /*
968 * Called when the last file reference is dropped.
969 *
970 * Big fat note: channels and events are invariant for the whole session after
971 * their creation. So this session destruction also destroys all channel and
972 * event structures specific to this session (they are not destroyed when their
973 * individual file is released).
974 */
975 static
976 int lttng_session_release(struct inode *inode, struct file *file)
977 {
978 struct lttng_kernel_session *session = file->private_data;
979
980 if (session)
981 lttng_session_destroy(session);
982 return 0;
983 }
984
985 static const struct file_operations lttng_session_fops = {
986 .owner = THIS_MODULE,
987 .release = lttng_session_release,
988 .unlocked_ioctl = lttng_session_ioctl,
989 #ifdef CONFIG_COMPAT
990 .compat_ioctl = lttng_session_ioctl,
991 #endif
992 };
993
994 /*
995 * When encountering empty buffer, flush current sub-buffer if non-empty
996 * and retry (if new data available to read after flush).
997 */
998 static
999 ssize_t lttng_event_notifier_group_notif_read(struct file *filp, char __user *user_buf,
1000 size_t count, loff_t *ppos)
1001 {
1002 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
1003 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1004 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1005 ssize_t read_count = 0, len;
1006 size_t read_offset;
1007
1008 might_sleep();
1009 if (!lttng_access_ok(VERIFY_WRITE, user_buf, count))
1010 return -EFAULT;
1011
1012 /* Finish copy of previous record */
1013 if (*ppos != 0) {
1014 if (read_count < count) {
1015 len = chan->iter.len_left;
1016 read_offset = *ppos;
1017 goto skip_get_next;
1018 }
1019 }
1020
1021 while (read_count < count) {
1022 size_t copy_len, space_left;
1023
1024 len = lib_ring_buffer_get_next_record(chan, buf);
1025 len_test:
1026 if (len < 0) {
1027 /*
1028 * Check if buffer is finalized (end of file).
1029 */
1030 if (len == -ENODATA) {
1031 /* A 0 read_count will tell about end of file */
1032 goto nodata;
1033 }
1034 if (filp->f_flags & O_NONBLOCK) {
1035 if (!read_count)
1036 read_count = -EAGAIN;
1037 goto nodata;
1038 } else {
1039 int error;
1040
1041 /*
1042 * No data available at the moment, return what
1043 * we got.
1044 */
1045 if (read_count)
1046 goto nodata;
1047
1048 /*
1049 * Wait for returned len to be >= 0 or -ENODATA.
1050 */
1051 error = wait_event_interruptible(
1052 event_notifier_group->read_wait,
1053 ((len = lib_ring_buffer_get_next_record(
1054 chan, buf)), len != -EAGAIN));
1055 CHAN_WARN_ON(chan, len == -EBUSY);
1056 if (error) {
1057 read_count = error;
1058 goto nodata;
1059 }
1060 CHAN_WARN_ON(chan, len < 0 && len != -ENODATA);
1061 goto len_test;
1062 }
1063 }
1064 read_offset = buf->iter.read_offset;
1065 skip_get_next:
1066 space_left = count - read_count;
1067 if (len <= space_left) {
1068 copy_len = len;
1069 chan->iter.len_left = 0;
1070 *ppos = 0;
1071 } else {
1072 copy_len = space_left;
1073 chan->iter.len_left = len - copy_len;
1074 *ppos = read_offset + copy_len;
1075 }
1076 if (__lib_ring_buffer_copy_to_user(&buf->backend, read_offset,
1077 &user_buf[read_count],
1078 copy_len)) {
1079 /*
1080 * Leave the len_left and ppos values at their current
1081 * state, as we currently have a valid event to read.
1082 */
1083 return -EFAULT;
1084 }
1085 read_count += copy_len;
1086 }
1087 goto put_record;
1088
1089 nodata:
1090 *ppos = 0;
1091 chan->iter.len_left = 0;
1092
1093 put_record:
1094 lib_ring_buffer_put_current_record(buf);
1095 return read_count;
1096 }
1097
1098 /*
1099 * If the ring buffer is non empty (even just a partial subbuffer), return that
1100 * there is data available. Perform a ring buffer flush if we encounter a
1101 * non-empty ring buffer which does not have any consumeable subbuffer available.
1102 */
1103 static
1104 unsigned int lttng_event_notifier_group_notif_poll(struct file *filp,
1105 poll_table *wait)
1106 {
1107 unsigned int mask = 0;
1108 struct lttng_event_notifier_group *event_notifier_group = filp->private_data;
1109 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1110 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1111 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
1112 int finalized, disabled;
1113 unsigned long consumed, offset;
1114 size_t subbuffer_header_size = config->cb.subbuffer_header_size();
1115
1116 if (filp->f_mode & FMODE_READ) {
1117 poll_wait_set_exclusive(wait);
1118 poll_wait(filp, &event_notifier_group->read_wait, wait);
1119
1120 finalized = lib_ring_buffer_is_finalized(config, buf);
1121 disabled = lib_ring_buffer_channel_is_disabled(chan);
1122
1123 /*
1124 * lib_ring_buffer_is_finalized() contains a smp_rmb() ordering
1125 * finalized load before offsets loads.
1126 */
1127 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1128 retry:
1129 if (disabled)
1130 return POLLERR;
1131
1132 offset = lib_ring_buffer_get_offset(config, buf);
1133 consumed = lib_ring_buffer_get_consumed(config, buf);
1134
1135 /*
1136 * If there is no buffer available to consume.
1137 */
1138 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan) == 0) {
1139 /*
1140 * If there is a non-empty subbuffer, flush and try again.
1141 */
1142 if (subbuf_offset(offset, chan) > subbuffer_header_size) {
1143 lib_ring_buffer_switch_remote(buf);
1144 goto retry;
1145 }
1146
1147 if (finalized)
1148 return POLLHUP;
1149 else {
1150 /*
1151 * The memory barriers
1152 * __wait_event()/wake_up_interruptible() take
1153 * care of "raw_spin_is_locked" memory ordering.
1154 */
1155 if (raw_spin_is_locked(&buf->raw_tick_nohz_spinlock))
1156 goto retry;
1157 else
1158 return 0;
1159 }
1160 } else {
1161 if (subbuf_trunc(offset, chan) - subbuf_trunc(consumed, chan)
1162 >= chan->backend.buf_size)
1163 return POLLPRI | POLLRDBAND;
1164 else
1165 return POLLIN | POLLRDNORM;
1166 }
1167 }
1168
1169 return mask;
1170 }
1171
1172 /**
1173 * lttng_event_notifier_group_notif_open - event_notifier ring buffer open file operation
1174 * @inode: opened inode
1175 * @file: opened file
1176 *
1177 * Open implementation. Makes sure only one open instance of a buffer is
1178 * done at a given moment.
1179 */
1180 static int lttng_event_notifier_group_notif_open(struct inode *inode, struct file *file)
1181 {
1182 struct lttng_event_notifier_group *event_notifier_group = inode->i_private;
1183 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1184
1185 file->private_data = event_notifier_group;
1186 return lib_ring_buffer_open(inode, file, buf);
1187 }
1188
1189 /**
1190 * lttng_event_notifier_group_notif_release - event_notifier ring buffer release file operation
1191 * @inode: opened inode
1192 * @file: opened file
1193 *
1194 * Release implementation.
1195 */
1196 static int lttng_event_notifier_group_notif_release(struct inode *inode, struct file *file)
1197 {
1198 struct lttng_event_notifier_group *event_notifier_group = file->private_data;
1199 struct lttng_kernel_ring_buffer *buf = event_notifier_group->buf;
1200 int ret;
1201
1202 ret = lib_ring_buffer_release(inode, file, buf);
1203 if (ret)
1204 return ret;
1205 fput(event_notifier_group->file);
1206 return 0;
1207 }
1208
1209 static const struct file_operations lttng_event_notifier_group_notif_fops = {
1210 .owner = THIS_MODULE,
1211 .open = lttng_event_notifier_group_notif_open,
1212 .release = lttng_event_notifier_group_notif_release,
1213 .read = lttng_event_notifier_group_notif_read,
1214 .poll = lttng_event_notifier_group_notif_poll,
1215 };
1216
1217 /**
1218 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
1219 * @filp: the file
1220 * @wait: poll table
1221 *
1222 * Handles the poll operations for the metadata channels.
1223 */
1224 static
1225 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
1226 poll_table *wait)
1227 {
1228 struct lttng_metadata_stream *stream = filp->private_data;
1229 struct lttng_kernel_ring_buffer *buf = stream->priv;
1230 int finalized;
1231 unsigned int mask = 0;
1232
1233 if (filp->f_mode & FMODE_READ) {
1234 poll_wait_set_exclusive(wait);
1235 poll_wait(filp, &stream->read_wait, wait);
1236
1237 finalized = stream->finalized;
1238
1239 /*
1240 * lib_ring_buffer_is_finalized() contains a smp_rmb()
1241 * ordering finalized load before offsets loads.
1242 */
1243 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
1244
1245 if (finalized)
1246 mask |= POLLHUP;
1247
1248 mutex_lock(&stream->metadata_cache->lock);
1249 if (stream->metadata_cache->metadata_written >
1250 stream->metadata_out)
1251 mask |= POLLIN;
1252 mutex_unlock(&stream->metadata_cache->lock);
1253 }
1254
1255 return mask;
1256 }
1257
1258 static
1259 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
1260 unsigned int cmd, unsigned long arg)
1261 {
1262 struct lttng_metadata_stream *stream = filp->private_data;
1263
1264 stream->metadata_out = stream->metadata_in;
1265 }
1266
1267 /*
1268 * Reset the counter of how much metadata has been consumed to 0. That way,
1269 * the consumer receives the content of the metadata cache unchanged. This is
1270 * different from the metadata_regenerate where the offset from epoch is
1271 * resampled, here we want the exact same content as the last time the metadata
1272 * was generated. This command is only possible if all the metadata written
1273 * in the cache has been output to the metadata stream to avoid corrupting the
1274 * metadata file.
1275 *
1276 * Return 0 on success, a negative value on error.
1277 */
1278 static
1279 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
1280 {
1281 int ret;
1282 struct lttng_metadata_cache *cache = stream->metadata_cache;
1283
1284 mutex_lock(&cache->lock);
1285 if (stream->metadata_out != cache->metadata_written) {
1286 ret = -EBUSY;
1287 goto end;
1288 }
1289 stream->metadata_out = 0;
1290 stream->metadata_in = 0;
1291 wake_up_interruptible(&stream->read_wait);
1292 ret = 0;
1293
1294 end:
1295 mutex_unlock(&cache->lock);
1296 return ret;
1297 }
1298
1299 static
1300 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
1301 unsigned int cmd, unsigned long arg)
1302 {
1303 int ret;
1304 struct lttng_metadata_stream *stream = filp->private_data;
1305 struct lttng_kernel_ring_buffer *buf = stream->priv;
1306 unsigned int rb_cmd;
1307 bool coherent;
1308
1309 if (cmd == LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1310 rb_cmd = LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF;
1311 else
1312 rb_cmd = cmd;
1313
1314 switch (cmd) {
1315 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF:
1316 {
1317 struct lttng_metadata_stream *stream = filp->private_data;
1318 struct lttng_kernel_ring_buffer *buf = stream->priv;
1319 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1320
1321 ret = lttng_metadata_output_channel(stream, chan, NULL);
1322 if (ret > 0) {
1323 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1324 ret = 0;
1325 } else if (ret < 0)
1326 goto err;
1327 break;
1328 }
1329 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF:
1330 {
1331 /*
1332 * Random access is not allowed for metadata channel.
1333 */
1334 return -ENOSYS;
1335 }
1336 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY:
1337 lttng_fallthrough;
1338 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH:
1339 {
1340 struct lttng_metadata_stream *stream = filp->private_data;
1341 struct lttng_kernel_ring_buffer *buf = stream->priv;
1342 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1343
1344 /*
1345 * Before doing the actual ring buffer flush, write up to one
1346 * packet of metadata in the ring buffer.
1347 */
1348 ret = lttng_metadata_output_channel(stream, chan, NULL);
1349 if (ret < 0)
1350 goto err;
1351 break;
1352 }
1353 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION:
1354 {
1355 struct lttng_metadata_stream *stream = filp->private_data;
1356
1357 return put_u64(stream->version, arg);
1358 }
1359 case LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP:
1360 {
1361 struct lttng_metadata_stream *stream = filp->private_data;
1362
1363 return lttng_metadata_cache_dump(stream);
1364 }
1365 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1366 {
1367 struct lttng_metadata_stream *stream = filp->private_data;
1368 struct lttng_kernel_ring_buffer *buf = stream->priv;
1369 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1370
1371 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1372 if (ret > 0) {
1373 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1374 ret = 0;
1375 } else if (ret < 0) {
1376 goto err;
1377 }
1378 break;
1379 }
1380 default:
1381 break;
1382 }
1383 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1384
1385 /* Performing lib ring buffer ioctl after our own. */
1386 ret = lib_ring_buffer_ioctl(filp, rb_cmd, arg, buf);
1387 if (ret < 0)
1388 goto err;
1389
1390 switch (cmd) {
1391 case LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF:
1392 {
1393 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1394 cmd, arg);
1395 break;
1396 }
1397 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1398 {
1399 return put_u32(coherent, arg);
1400 }
1401 default:
1402 break;
1403 }
1404 err:
1405 return ret;
1406 }
1407
1408 #ifdef CONFIG_COMPAT
1409 static
1410 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
1411 unsigned int cmd, unsigned long arg)
1412 {
1413 int ret;
1414 struct lttng_metadata_stream *stream = filp->private_data;
1415 struct lttng_kernel_ring_buffer *buf = stream->priv;
1416 unsigned int rb_cmd;
1417 bool coherent;
1418
1419 if (cmd == LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK)
1420 rb_cmd = LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF;
1421 else
1422 rb_cmd = cmd;
1423
1424 switch (cmd) {
1425 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF:
1426 {
1427 struct lttng_metadata_stream *stream = filp->private_data;
1428 struct lttng_kernel_ring_buffer *buf = stream->priv;
1429 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1430
1431 ret = lttng_metadata_output_channel(stream, chan, NULL);
1432 if (ret > 0) {
1433 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1434 ret = 0;
1435 } else if (ret < 0)
1436 goto err;
1437 break;
1438 }
1439 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SUBBUF:
1440 {
1441 /*
1442 * Random access is not allowed for metadata channel.
1443 */
1444 return -ENOSYS;
1445 }
1446 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH_EMPTY:
1447 lttng_fallthrough;
1448 case LTTNG_KERNEL_ABI_RING_BUFFER_FLUSH:
1449 {
1450 struct lttng_metadata_stream *stream = filp->private_data;
1451 struct lttng_kernel_ring_buffer *buf = stream->priv;
1452 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1453
1454 /*
1455 * Before doing the actual ring buffer flush, write up to one
1456 * packet of metadata in the ring buffer.
1457 */
1458 ret = lttng_metadata_output_channel(stream, chan, NULL);
1459 if (ret < 0)
1460 goto err;
1461 break;
1462 }
1463 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_METADATA_VERSION:
1464 {
1465 struct lttng_metadata_stream *stream = filp->private_data;
1466
1467 return put_u64(stream->version, arg);
1468 }
1469 case LTTNG_KERNEL_ABI_RING_BUFFER_METADATA_CACHE_DUMP:
1470 {
1471 struct lttng_metadata_stream *stream = filp->private_data;
1472
1473 return lttng_metadata_cache_dump(stream);
1474 }
1475 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1476 {
1477 struct lttng_metadata_stream *stream = filp->private_data;
1478 struct lttng_kernel_ring_buffer *buf = stream->priv;
1479 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
1480
1481 ret = lttng_metadata_output_channel(stream, chan, &coherent);
1482 if (ret > 0) {
1483 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
1484 ret = 0;
1485 } else if (ret < 0) {
1486 goto err;
1487 }
1488 break;
1489 }
1490 default:
1491 break;
1492 }
1493 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
1494
1495 /* Performing lib ring buffer ioctl after our own. */
1496 ret = lib_ring_buffer_compat_ioctl(filp, rb_cmd, arg, buf);
1497 if (ret < 0)
1498 goto err;
1499
1500 switch (cmd) {
1501 case LTTNG_KERNEL_ABI_RING_BUFFER_PUT_NEXT_SUBBUF:
1502 {
1503 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
1504 cmd, arg);
1505 break;
1506 }
1507 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_NEXT_SUBBUF_METADATA_CHECK:
1508 {
1509 return put_u32(coherent, arg);
1510 }
1511 default:
1512 break;
1513 }
1514 err:
1515 return ret;
1516 }
1517 #endif
1518
1519 /*
1520 * This is not used by anonymous file descriptors. This code is left
1521 * there if we ever want to implement an inode with open() operation.
1522 */
1523 static
1524 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
1525 {
1526 struct lttng_metadata_stream *stream = inode->i_private;
1527 struct lttng_kernel_ring_buffer *buf = stream->priv;
1528
1529 file->private_data = buf;
1530 /*
1531 * Since life-time of metadata cache differs from that of
1532 * session, we need to keep our own reference on the transport.
1533 */
1534 if (!try_module_get(stream->transport->owner)) {
1535 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1536 return -EBUSY;
1537 }
1538 return lib_ring_buffer_open(inode, file, buf);
1539 }
1540
1541 static
1542 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
1543 {
1544 struct lttng_metadata_stream *stream = file->private_data;
1545 struct lttng_kernel_ring_buffer *buf = stream->priv;
1546
1547 mutex_lock(&stream->metadata_cache->lock);
1548 list_del(&stream->list);
1549 mutex_unlock(&stream->metadata_cache->lock);
1550 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
1551 module_put(stream->transport->owner);
1552 kfree(stream);
1553 return lib_ring_buffer_release(inode, file, buf);
1554 }
1555
1556 static
1557 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
1558 struct pipe_inode_info *pipe, size_t len,
1559 unsigned int flags)
1560 {
1561 struct lttng_metadata_stream *stream = in->private_data;
1562 struct lttng_kernel_ring_buffer *buf = stream->priv;
1563
1564 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
1565 flags, buf);
1566 }
1567
1568 static
1569 int lttng_metadata_ring_buffer_mmap(struct file *filp,
1570 struct vm_area_struct *vma)
1571 {
1572 struct lttng_metadata_stream *stream = filp->private_data;
1573 struct lttng_kernel_ring_buffer *buf = stream->priv;
1574
1575 return lib_ring_buffer_mmap(filp, vma, buf);
1576 }
1577
1578 static
1579 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
1580 .owner = THIS_MODULE,
1581 .open = lttng_metadata_ring_buffer_open,
1582 .release = lttng_metadata_ring_buffer_release,
1583 .poll = lttng_metadata_ring_buffer_poll,
1584 .splice_read = lttng_metadata_ring_buffer_splice_read,
1585 .mmap = lttng_metadata_ring_buffer_mmap,
1586 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
1587 .llseek = vfs_lib_ring_buffer_no_llseek,
1588 #ifdef CONFIG_COMPAT
1589 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
1590 #endif
1591 };
1592
1593 static
1594 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1595 const struct file_operations *fops, const char *name)
1596 {
1597 int stream_fd, ret;
1598 struct file *stream_file;
1599
1600 stream_fd = lttng_get_unused_fd();
1601 if (stream_fd < 0) {
1602 ret = stream_fd;
1603 goto fd_error;
1604 }
1605 stream_file = anon_inode_getfile(name, fops, stream_priv, O_RDWR);
1606 if (IS_ERR(stream_file)) {
1607 ret = PTR_ERR(stream_file);
1608 goto file_error;
1609 }
1610 /*
1611 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1612 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1613 * file descriptor, so we set FMODE_PREAD here.
1614 */
1615 stream_file->f_mode |= FMODE_PREAD;
1616 fd_install(stream_fd, stream_file);
1617 /*
1618 * The stream holds a reference to the channel within the generic ring
1619 * buffer library, so no need to hold a refcount on the channel and
1620 * session files here.
1621 */
1622 return stream_fd;
1623
1624 file_error:
1625 put_unused_fd(stream_fd);
1626 fd_error:
1627 return ret;
1628 }
1629
1630 static
1631 int lttng_abi_open_stream(struct file *channel_file)
1632 {
1633 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1634 struct lttng_kernel_ring_buffer *buf;
1635 int ret;
1636 void *stream_priv;
1637
1638 buf = channel->ops->priv->buffer_read_open(channel->priv->rb_chan);
1639 if (!buf)
1640 return -ENOENT;
1641
1642 stream_priv = buf;
1643 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1644 &lttng_stream_ring_buffer_file_operations,
1645 "[lttng_stream]");
1646 if (ret < 0)
1647 goto fd_error;
1648
1649 return ret;
1650
1651 fd_error:
1652 channel->ops->priv->buffer_read_close(buf);
1653 return ret;
1654 }
1655
1656 static
1657 int lttng_abi_open_metadata_stream(struct file *channel_file)
1658 {
1659 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1660 struct lttng_kernel_session *session = channel->parent.session;
1661 struct lttng_kernel_ring_buffer *buf;
1662 int ret;
1663 struct lttng_metadata_stream *metadata_stream;
1664 void *stream_priv;
1665
1666 buf = channel->ops->priv->buffer_read_open(channel->priv->rb_chan);
1667 if (!buf)
1668 return -ENOENT;
1669
1670 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1671 GFP_KERNEL);
1672 if (!metadata_stream) {
1673 ret = -ENOMEM;
1674 goto nomem;
1675 }
1676 metadata_stream->metadata_cache = session->priv->metadata_cache;
1677 init_waitqueue_head(&metadata_stream->read_wait);
1678 metadata_stream->priv = buf;
1679 stream_priv = metadata_stream;
1680 metadata_stream->transport = channel->priv->transport;
1681 /* Initial state is an empty metadata, considered as incoherent. */
1682 metadata_stream->coherent = false;
1683
1684 /*
1685 * Since life-time of metadata cache differs from that of
1686 * session, we need to keep our own reference on the transport.
1687 */
1688 if (!try_module_get(metadata_stream->transport->owner)) {
1689 printk(KERN_WARNING "LTTng: Can't lock transport module.\n");
1690 ret = -EINVAL;
1691 goto notransport;
1692 }
1693
1694 if (!lttng_kref_get(&session->priv->metadata_cache->refcount)) {
1695 ret = -EOVERFLOW;
1696 goto kref_error;
1697 }
1698
1699 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1700 &lttng_metadata_ring_buffer_file_operations,
1701 "[lttng_metadata_stream]");
1702 if (ret < 0)
1703 goto fd_error;
1704
1705 mutex_lock(&session->priv->metadata_cache->lock);
1706 list_add(&metadata_stream->list,
1707 &session->priv->metadata_cache->metadata_stream);
1708 mutex_unlock(&session->priv->metadata_cache->lock);
1709 return ret;
1710
1711 fd_error:
1712 kref_put(&session->priv->metadata_cache->refcount, metadata_cache_destroy);
1713 kref_error:
1714 module_put(metadata_stream->transport->owner);
1715 notransport:
1716 kfree(metadata_stream);
1717 nomem:
1718 channel->ops->priv->buffer_read_close(buf);
1719 return ret;
1720 }
1721
1722 static
1723 int lttng_abi_open_event_notifier_group_stream(struct file *notif_file)
1724 {
1725 struct lttng_event_notifier_group *event_notifier_group = notif_file->private_data;
1726 struct lttng_kernel_ring_buffer_channel *chan = event_notifier_group->chan;
1727 struct lttng_kernel_ring_buffer *buf;
1728 int ret;
1729 void *stream_priv;
1730
1731 buf = event_notifier_group->ops->priv->buffer_read_open(chan);
1732 if (!buf)
1733 return -ENOENT;
1734
1735 /* The event_notifier notification fd holds a reference on the event_notifier group */
1736 if (!atomic_long_add_unless(&notif_file->f_count, 1, LONG_MAX)) {
1737 ret = -EOVERFLOW;
1738 goto refcount_error;
1739 }
1740 event_notifier_group->buf = buf;
1741 stream_priv = event_notifier_group;
1742 ret = lttng_abi_create_stream_fd(notif_file, stream_priv,
1743 &lttng_event_notifier_group_notif_fops,
1744 "[lttng_event_notifier_stream]");
1745 if (ret < 0)
1746 goto fd_error;
1747
1748 return ret;
1749
1750 fd_error:
1751 atomic_long_dec(&notif_file->f_count);
1752 refcount_error:
1753 event_notifier_group->ops->priv->buffer_read_close(buf);
1754 return ret;
1755 }
1756
1757 static
1758 int lttng_abi_validate_event_param(struct lttng_kernel_abi_event *event_param)
1759 {
1760 /* Limit ABI to implemented features. */
1761 switch (event_param->instrumentation) {
1762 case LTTNG_KERNEL_ABI_SYSCALL:
1763 switch (event_param->u.syscall.entryexit) {
1764 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1765 lttng_fallthrough;
1766 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1767 lttng_fallthrough;
1768 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1769 break;
1770 default:
1771 return -EINVAL;
1772 }
1773 switch (event_param->u.syscall.abi) {
1774 case LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL:
1775 break;
1776 default:
1777 return -EINVAL;
1778 }
1779 switch (event_param->u.syscall.match) {
1780 case LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME:
1781 break;
1782 default:
1783 return -EINVAL;
1784 }
1785 break;
1786
1787 case LTTNG_KERNEL_ABI_KRETPROBE:
1788 switch (event_param->u.kretprobe.entryexit) {
1789 case LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT:
1790 break;
1791 case LTTNG_KERNEL_ABI_SYSCALL_ENTRY:
1792 lttng_fallthrough;
1793 case LTTNG_KERNEL_ABI_SYSCALL_EXIT:
1794 lttng_fallthrough;
1795 default:
1796 return -EINVAL;
1797 }
1798 break;
1799
1800 case LTTNG_KERNEL_ABI_TRACEPOINT:
1801 lttng_fallthrough;
1802 case LTTNG_KERNEL_ABI_KPROBE:
1803 lttng_fallthrough;
1804 case LTTNG_KERNEL_ABI_UPROBE:
1805 break;
1806
1807 case LTTNG_KERNEL_ABI_FUNCTION:
1808 lttng_fallthrough;
1809 case LTTNG_KERNEL_ABI_NOOP:
1810 lttng_fallthrough;
1811 default:
1812 return -EINVAL;
1813 }
1814 return 0;
1815 }
1816
1817 static
1818 int lttng_abi_create_event(struct file *channel_file,
1819 struct lttng_kernel_abi_event *event_param)
1820 {
1821 const struct file_operations *fops;
1822 struct lttng_kernel_channel_buffer *channel = channel_file->private_data;
1823 int event_fd, ret;
1824 struct file *event_file;
1825 void *priv;
1826
1827 event_param->name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1828 switch (event_param->instrumentation) {
1829 case LTTNG_KERNEL_ABI_KRETPROBE:
1830 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1831 break;
1832 case LTTNG_KERNEL_ABI_KPROBE:
1833 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
1834 break;
1835 case LTTNG_KERNEL_ABI_FUNCTION:
1836 WARN_ON_ONCE(1);
1837 /* Not implemented. */
1838 break;
1839 default:
1840 break;
1841 }
1842
1843 switch (event_param->instrumentation) {
1844 case LTTNG_KERNEL_ABI_TRACEPOINT:
1845 lttng_fallthrough;
1846 case LTTNG_KERNEL_ABI_SYSCALL:
1847 fops = &lttng_event_recorder_enabler_fops;
1848 break;
1849 case LTTNG_KERNEL_ABI_KPROBE:
1850 lttng_fallthrough;
1851 case LTTNG_KERNEL_ABI_KRETPROBE:
1852 lttng_fallthrough;
1853 case LTTNG_KERNEL_ABI_UPROBE:
1854 fops = &lttng_event_recorder_event_fops;
1855 break;
1856
1857 case LTTNG_KERNEL_ABI_FUNCTION:
1858 lttng_fallthrough;
1859 case LTTNG_KERNEL_ABI_NOOP:
1860 lttng_fallthrough;
1861 default:
1862 return -EINVAL;
1863 }
1864
1865 event_fd = lttng_get_unused_fd();
1866 if (event_fd < 0) {
1867 ret = event_fd;
1868 goto fd_error;
1869 }
1870 event_file = anon_inode_getfile("[lttng_event]",
1871 fops, NULL, O_RDWR);
1872 if (IS_ERR(event_file)) {
1873 ret = PTR_ERR(event_file);
1874 goto file_error;
1875 }
1876 /* The event holds a reference on the channel */
1877 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1878 ret = -EOVERFLOW;
1879 goto refcount_error;
1880 }
1881 ret = lttng_abi_validate_event_param(event_param);
1882 if (ret)
1883 goto event_error;
1884
1885 switch (event_param->instrumentation) {
1886 case LTTNG_KERNEL_ABI_TRACEPOINT:
1887 lttng_fallthrough;
1888 case LTTNG_KERNEL_ABI_SYSCALL:
1889 {
1890 struct lttng_event_recorder_enabler *event_enabler;
1891
1892 if (strutils_is_star_glob_pattern(event_param->name)) {
1893 /*
1894 * If the event name is a star globbing pattern,
1895 * we create the special star globbing enabler.
1896 */
1897 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_STAR_GLOB,
1898 event_param, channel);
1899 } else {
1900 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1901 event_param, channel);
1902 }
1903 if (event_enabler)
1904 lttng_event_enabler_session_add(channel->parent.session, event_enabler);
1905 priv = event_enabler;
1906 break;
1907 }
1908
1909 case LTTNG_KERNEL_ABI_KPROBE:
1910 lttng_fallthrough;
1911 case LTTNG_KERNEL_ABI_KRETPROBE:
1912 lttng_fallthrough;
1913 case LTTNG_KERNEL_ABI_UPROBE:
1914 {
1915 struct lttng_kernel_event_recorder *event;
1916 struct lttng_event_recorder_enabler *event_enabler;
1917
1918 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
1919 event_param, channel);
1920 if (!event_enabler) {
1921 ret = -ENOMEM;
1922 goto event_error;
1923 }
1924 /*
1925 * We tolerate no failure path after event creation. It
1926 * will stay invariant for the rest of the session.
1927 */
1928 event = lttng_kernel_event_recorder_create(event_enabler, NULL);
1929 WARN_ON_ONCE(!event);
1930 lttng_event_enabler_destroy(&event_enabler->parent);
1931 if (IS_ERR(event)) {
1932 ret = PTR_ERR(event);
1933 goto event_error;
1934 }
1935 priv = event;
1936 break;
1937 }
1938
1939 case LTTNG_KERNEL_ABI_FUNCTION:
1940 lttng_fallthrough;
1941 case LTTNG_KERNEL_ABI_NOOP:
1942 lttng_fallthrough;
1943 default:
1944 ret = -EINVAL;
1945 goto event_error;
1946 }
1947 event_file->private_data = priv;
1948 fd_install(event_fd, event_file);
1949 return event_fd;
1950
1951 event_error:
1952 atomic_long_dec(&channel_file->f_count);
1953 refcount_error:
1954 fput(event_file);
1955 file_error:
1956 put_unused_fd(event_fd);
1957 fd_error:
1958 return ret;
1959 }
1960
1961 static
1962 long lttng_event_notifier_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1963 {
1964 struct lttng_kernel_event_notifier *event_notifier = file->private_data;
1965
1966 switch (cmd) {
1967 case LTTNG_KERNEL_ABI_ENABLE:
1968 return lttng_event_enable(&event_notifier->parent);
1969 case LTTNG_KERNEL_ABI_DISABLE:
1970 return lttng_event_disable(&event_notifier->parent);
1971 case LTTNG_KERNEL_ABI_FILTER:
1972 return -EINVAL;
1973 case LTTNG_KERNEL_ABI_CAPTURE:
1974 return -EINVAL;
1975 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
1976 return lttng_event_add_callsite(&event_notifier->parent,
1977 (struct lttng_kernel_abi_event_callsite __user *) arg);
1978 default:
1979 return -ENOIOCTLCMD;
1980 }
1981 }
1982
1983 static
1984 long lttng_event_notifier_enabler_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1985 {
1986 struct lttng_event_notifier_enabler *event_notifier_enabler = file->private_data;
1987
1988 switch (cmd) {
1989 case LTTNG_KERNEL_ABI_ENABLE:
1990 return lttng_event_enabler_enable(&event_notifier_enabler->parent);
1991 case LTTNG_KERNEL_ABI_DISABLE:
1992 return lttng_event_enabler_disable(&event_notifier_enabler->parent);
1993 case LTTNG_KERNEL_ABI_FILTER:
1994 return lttng_event_enabler_attach_filter_bytecode(&event_notifier_enabler->parent,
1995 (struct lttng_kernel_abi_filter_bytecode __user *) arg);
1996 case LTTNG_KERNEL_ABI_CAPTURE:
1997 return lttng_event_notifier_enabler_attach_capture_bytecode(
1998 event_notifier_enabler,
1999 (struct lttng_kernel_abi_capture_bytecode __user *) arg);
2000 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2001 return -EINVAL;
2002 default:
2003 return -ENOIOCTLCMD;
2004 }
2005 }
2006
2007 static
2008 int lttng_event_notifier_event_release(struct inode *inode, struct file *file)
2009 {
2010 struct lttng_kernel_event_notifier *event_notifier = file->private_data;
2011
2012 if (event_notifier)
2013 fput(event_notifier->priv->group->file);
2014 return 0;
2015 }
2016
2017 static
2018 int lttng_event_notifier_enabler_release(struct inode *inode, struct file *file)
2019 {
2020 struct lttng_event_notifier_enabler *event_notifier_enabler = file->private_data;
2021
2022 if (event_notifier_enabler)
2023 fput(event_notifier_enabler->group->file);
2024 return 0;
2025 }
2026
2027 static const struct file_operations lttng_event_notifier_event_fops = {
2028 .owner = THIS_MODULE,
2029 .release = lttng_event_notifier_event_release,
2030 .unlocked_ioctl = lttng_event_notifier_event_ioctl,
2031 #ifdef CONFIG_COMPAT
2032 .compat_ioctl = lttng_event_notifier_event_ioctl,
2033 #endif
2034 };
2035
2036 static const struct file_operations lttng_event_notifier_enabler_fops = {
2037 .owner = THIS_MODULE,
2038 .release = lttng_event_notifier_enabler_release,
2039 .unlocked_ioctl = lttng_event_notifier_enabler_ioctl,
2040 #ifdef CONFIG_COMPAT
2041 .compat_ioctl = lttng_event_notifier_enabler_ioctl,
2042 #endif
2043 };
2044
2045 static
2046 int lttng_abi_create_event_notifier(struct file *event_notifier_group_file,
2047 struct lttng_kernel_abi_event_notifier *event_notifier_param)
2048 {
2049 struct lttng_event_notifier_group *event_notifier_group =
2050 event_notifier_group_file->private_data;
2051 const struct file_operations *fops;
2052 int event_notifier_fd, ret;
2053 struct file *event_notifier_file;
2054 void *priv;
2055
2056 switch (event_notifier_param->event.instrumentation) {
2057 case LTTNG_KERNEL_ABI_TRACEPOINT:
2058 case LTTNG_KERNEL_ABI_UPROBE:
2059 break;
2060 case LTTNG_KERNEL_ABI_KPROBE:
2061 event_notifier_param->event.u.kprobe.symbol_name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
2062 break;
2063 case LTTNG_KERNEL_ABI_SYSCALL:
2064 break;
2065 case LTTNG_KERNEL_ABI_KRETPROBE:
2066 /* Placing an event notifier on kretprobe is not supported. */
2067 case LTTNG_KERNEL_ABI_FUNCTION:
2068 case LTTNG_KERNEL_ABI_NOOP:
2069 default:
2070 ret = -EINVAL;
2071 goto inval_instr;
2072 }
2073
2074 switch (event_notifier_param->event.instrumentation) {
2075 case LTTNG_KERNEL_ABI_TRACEPOINT:
2076 lttng_fallthrough;
2077 case LTTNG_KERNEL_ABI_SYSCALL:
2078 fops = &lttng_event_notifier_enabler_fops;
2079 break;
2080 case LTTNG_KERNEL_ABI_KPROBE:
2081 lttng_fallthrough;
2082 case LTTNG_KERNEL_ABI_KRETPROBE:
2083 lttng_fallthrough;
2084 case LTTNG_KERNEL_ABI_UPROBE:
2085 fops = &lttng_event_notifier_event_fops;
2086 break;
2087
2088 case LTTNG_KERNEL_ABI_FUNCTION:
2089 lttng_fallthrough;
2090 case LTTNG_KERNEL_ABI_NOOP:
2091 lttng_fallthrough;
2092 default:
2093 ret = -EINVAL;
2094 goto inval_instr;
2095 }
2096
2097 event_notifier_param->event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
2098
2099 event_notifier_fd = lttng_get_unused_fd();
2100 if (event_notifier_fd < 0) {
2101 ret = event_notifier_fd;
2102 goto fd_error;
2103 }
2104
2105 event_notifier_file = anon_inode_getfile("[lttng_event_notifier]",
2106 fops, NULL, O_RDWR);
2107 if (IS_ERR(event_notifier_file)) {
2108 ret = PTR_ERR(event_notifier_file);
2109 goto file_error;
2110 }
2111
2112 /* The event notifier holds a reference on the event notifier group. */
2113 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
2114 ret = -EOVERFLOW;
2115 goto refcount_error;
2116 }
2117
2118 ret = lttng_abi_validate_event_param(&event_notifier_param->event);
2119 if (ret)
2120 goto event_notifier_error;
2121
2122 switch (event_notifier_param->event.instrumentation) {
2123 case LTTNG_KERNEL_ABI_TRACEPOINT:
2124 lttng_fallthrough;
2125 case LTTNG_KERNEL_ABI_SYSCALL:
2126 {
2127 struct lttng_event_notifier_enabler *enabler;
2128
2129 if (strutils_is_star_glob_pattern(event_notifier_param->event.name)) {
2130 /*
2131 * If the event name is a star globbing pattern,
2132 * we create the special star globbing enabler.
2133 */
2134 enabler = lttng_event_notifier_enabler_create(
2135 event_notifier_group,
2136 LTTNG_ENABLER_FORMAT_STAR_GLOB,
2137 event_notifier_param);
2138 } else {
2139 enabler = lttng_event_notifier_enabler_create(
2140 event_notifier_group,
2141 LTTNG_ENABLER_FORMAT_NAME,
2142 event_notifier_param);
2143 }
2144 priv = enabler;
2145 break;
2146 }
2147
2148 case LTTNG_KERNEL_ABI_KPROBE:
2149 lttng_fallthrough;
2150 case LTTNG_KERNEL_ABI_KRETPROBE:
2151 lttng_fallthrough;
2152 case LTTNG_KERNEL_ABI_UPROBE:
2153 {
2154 struct lttng_kernel_event_notifier *event_notifier;
2155
2156 /*
2157 * We tolerate no failure path after event notifier creation.
2158 * It will stay invariant for the rest of the session.
2159 */
2160 event_notifier = lttng_event_notifier_create(NULL,
2161 event_notifier_param->event.token,
2162 event_notifier_param->error_counter_index,
2163 event_notifier_group,
2164 event_notifier_param,
2165 event_notifier_param->event.instrumentation);
2166 WARN_ON_ONCE(!event_notifier);
2167 if (IS_ERR(event_notifier)) {
2168 ret = PTR_ERR(event_notifier);
2169 goto event_notifier_error;
2170 }
2171 priv = event_notifier;
2172 break;
2173 }
2174
2175 case LTTNG_KERNEL_ABI_FUNCTION:
2176 lttng_fallthrough;
2177 case LTTNG_KERNEL_ABI_NOOP:
2178 lttng_fallthrough;
2179 default:
2180 ret = -EINVAL;
2181 goto event_notifier_error;
2182 }
2183 event_notifier_file->private_data = priv;
2184 fd_install(event_notifier_fd, event_notifier_file);
2185 return event_notifier_fd;
2186
2187 event_notifier_error:
2188 atomic_long_dec(&event_notifier_group_file->f_count);
2189 refcount_error:
2190 fput(event_notifier_file);
2191 file_error:
2192 put_unused_fd(event_notifier_fd);
2193 fd_error:
2194 inval_instr:
2195 return ret;
2196 }
2197
2198 static
2199 long lttng_abi_event_notifier_group_create_error_counter(
2200 struct file *event_notifier_group_file,
2201 const struct lttng_kernel_abi_counter_conf *error_counter_conf)
2202 {
2203 int counter_fd, ret;
2204 char *counter_transport_name;
2205 size_t counter_len;
2206 struct lttng_counter *counter = NULL;
2207 struct file *counter_file;
2208 struct lttng_event_notifier_group *event_notifier_group =
2209 (struct lttng_event_notifier_group *) event_notifier_group_file->private_data;
2210
2211 if (error_counter_conf->arithmetic != LTTNG_KERNEL_ABI_COUNTER_ARITHMETIC_MODULAR) {
2212 printk(KERN_ERR "LTTng: event_notifier: Error counter of the wrong arithmetic type.\n");
2213 return -EINVAL;
2214 }
2215
2216 if (error_counter_conf->number_dimensions != 1) {
2217 printk(KERN_ERR "LTTng: event_notifier: Error counter has more than one dimension.\n");
2218 return -EINVAL;
2219 }
2220
2221 switch (error_counter_conf->bitness) {
2222 case LTTNG_KERNEL_ABI_COUNTER_BITNESS_64:
2223 counter_transport_name = "counter-per-cpu-64-modular";
2224 break;
2225 case LTTNG_KERNEL_ABI_COUNTER_BITNESS_32:
2226 counter_transport_name = "counter-per-cpu-32-modular";
2227 break;
2228 default:
2229 return -EINVAL;
2230 }
2231
2232 /*
2233 * Lock sessions to provide mutual exclusion against concurrent
2234 * modification of event_notifier group, which would result in
2235 * overwriting the error counter if set concurrently.
2236 */
2237 lttng_lock_sessions();
2238
2239 if (event_notifier_group->error_counter) {
2240 printk(KERN_ERR "Error counter already created in event_notifier group\n");
2241 ret = -EBUSY;
2242 goto fd_error;
2243 }
2244
2245 counter_fd = lttng_get_unused_fd();
2246 if (counter_fd < 0) {
2247 ret = counter_fd;
2248 goto fd_error;
2249 }
2250
2251 counter_file = anon_inode_getfile("[lttng_counter]",
2252 &lttng_counter_fops,
2253 NULL, O_RDONLY);
2254 if (IS_ERR(counter_file)) {
2255 ret = PTR_ERR(counter_file);
2256 goto file_error;
2257 }
2258
2259 counter_len = error_counter_conf->dimensions[0].size;
2260
2261 if (!atomic_long_add_unless(&event_notifier_group_file->f_count, 1, LONG_MAX)) {
2262 ret = -EOVERFLOW;
2263 goto refcount_error;
2264 }
2265
2266 counter = lttng_kernel_counter_create(counter_transport_name,
2267 1, &counter_len);
2268 if (!counter) {
2269 ret = -EINVAL;
2270 goto counter_error;
2271 }
2272
2273 event_notifier_group->error_counter_len = counter_len;
2274 /*
2275 * store-release to publish error counter matches load-acquire
2276 * in record_error. Ensures the counter is created and the
2277 * error_counter_len is set before they are used.
2278 */
2279 lttng_smp_store_release(&event_notifier_group->error_counter, counter);
2280
2281 counter->file = counter_file;
2282 counter->owner = event_notifier_group->file;
2283 counter_file->private_data = counter;
2284 /* Ownership transferred. */
2285 counter = NULL;
2286
2287 fd_install(counter_fd, counter_file);
2288 lttng_unlock_sessions();
2289
2290 return counter_fd;
2291
2292 counter_error:
2293 atomic_long_dec(&event_notifier_group_file->f_count);
2294 refcount_error:
2295 fput(counter_file);
2296 file_error:
2297 put_unused_fd(counter_fd);
2298 fd_error:
2299 lttng_unlock_sessions();
2300 return ret;
2301 }
2302
2303 static
2304 long lttng_event_notifier_group_ioctl(struct file *file, unsigned int cmd,
2305 unsigned long arg)
2306 {
2307 switch (cmd) {
2308 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_GROUP_NOTIFICATION_FD:
2309 {
2310 return lttng_abi_open_event_notifier_group_stream(file);
2311 }
2312 case LTTNG_KERNEL_ABI_EVENT_NOTIFIER_CREATE:
2313 {
2314 struct lttng_kernel_abi_event_notifier uevent_notifier_param;
2315
2316 if (copy_from_user(&uevent_notifier_param,
2317 (struct lttng_kernel_abi_event_notifier __user *) arg,
2318 sizeof(uevent_notifier_param)))
2319 return -EFAULT;
2320 return lttng_abi_create_event_notifier(file, &uevent_notifier_param);
2321 }
2322 case LTTNG_KERNEL_ABI_COUNTER:
2323 {
2324 struct lttng_kernel_abi_counter_conf uerror_counter_conf;
2325
2326 if (copy_from_user(&uerror_counter_conf,
2327 (struct lttng_kernel_abi_counter_conf __user *) arg,
2328 sizeof(uerror_counter_conf)))
2329 return -EFAULT;
2330 return lttng_abi_event_notifier_group_create_error_counter(file,
2331 &uerror_counter_conf);
2332 }
2333 default:
2334 return -ENOIOCTLCMD;
2335 }
2336 return 0;
2337 }
2338
2339 static
2340 int lttng_event_notifier_group_release(struct inode *inode, struct file *file)
2341 {
2342 struct lttng_event_notifier_group *event_notifier_group =
2343 file->private_data;
2344
2345 if (event_notifier_group)
2346 lttng_event_notifier_group_destroy(event_notifier_group);
2347 return 0;
2348 }
2349
2350 static const struct file_operations lttng_event_notifier_group_fops = {
2351 .owner = THIS_MODULE,
2352 .release = lttng_event_notifier_group_release,
2353 .unlocked_ioctl = lttng_event_notifier_group_ioctl,
2354 #ifdef CONFIG_COMPAT
2355 .compat_ioctl = lttng_event_notifier_group_ioctl,
2356 #endif
2357 };
2358
2359 /**
2360 * lttng_channel_ioctl - lttng syscall through ioctl
2361 *
2362 * @file: the file
2363 * @cmd: the command
2364 * @arg: command arg
2365 *
2366 * This ioctl implements lttng commands:
2367 * LTTNG_KERNEL_ABI_STREAM
2368 * Returns an event stream file descriptor or failure.
2369 * (typically, one event stream records events from one CPU)
2370 * LTTNG_KERNEL_ABI_EVENT
2371 * Returns an event file descriptor or failure.
2372 * LTTNG_KERNEL_ABI_CONTEXT
2373 * Prepend a context field to each event in the channel
2374 * LTTNG_KERNEL_ABI_ENABLE
2375 * Enable recording for events in this channel (weak enable)
2376 * LTTNG_KERNEL_ABI_DISABLE
2377 * Disable recording for events in this channel (strong disable)
2378 *
2379 * Channel and event file descriptors also hold a reference on the session.
2380 */
2381 static
2382 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2383 {
2384 struct lttng_kernel_channel_buffer *channel = file->private_data;
2385
2386 switch (cmd) {
2387 case LTTNG_KERNEL_ABI_OLD_STREAM:
2388 case LTTNG_KERNEL_ABI_STREAM:
2389 return lttng_abi_open_stream(file);
2390 case LTTNG_KERNEL_ABI_OLD_EVENT:
2391 {
2392 struct lttng_kernel_abi_event *uevent_param;
2393 struct lttng_kernel_abi_old_event *old_uevent_param;
2394 int ret;
2395
2396 uevent_param = kmalloc(sizeof(struct lttng_kernel_abi_event),
2397 GFP_KERNEL);
2398 if (!uevent_param) {
2399 ret = -ENOMEM;
2400 goto old_event_end;
2401 }
2402 old_uevent_param = kmalloc(
2403 sizeof(struct lttng_kernel_abi_old_event),
2404 GFP_KERNEL);
2405 if (!old_uevent_param) {
2406 ret = -ENOMEM;
2407 goto old_event_error_free_param;
2408 }
2409 if (copy_from_user(old_uevent_param,
2410 (struct lttng_kernel_abi_old_event __user *) arg,
2411 sizeof(struct lttng_kernel_abi_old_event))) {
2412 ret = -EFAULT;
2413 goto old_event_error_free_old_param;
2414 }
2415
2416 memcpy(uevent_param->name, old_uevent_param->name,
2417 sizeof(uevent_param->name));
2418 uevent_param->instrumentation =
2419 old_uevent_param->instrumentation;
2420
2421 switch (old_uevent_param->instrumentation) {
2422 case LTTNG_KERNEL_ABI_KPROBE:
2423 uevent_param->u.kprobe.addr =
2424 old_uevent_param->u.kprobe.addr;
2425 uevent_param->u.kprobe.offset =
2426 old_uevent_param->u.kprobe.offset;
2427 memcpy(uevent_param->u.kprobe.symbol_name,
2428 old_uevent_param->u.kprobe.symbol_name,
2429 sizeof(uevent_param->u.kprobe.symbol_name));
2430 break;
2431 case LTTNG_KERNEL_ABI_KRETPROBE:
2432 uevent_param->u.kretprobe.addr =
2433 old_uevent_param->u.kretprobe.addr;
2434 uevent_param->u.kretprobe.offset =
2435 old_uevent_param->u.kretprobe.offset;
2436 memcpy(uevent_param->u.kretprobe.symbol_name,
2437 old_uevent_param->u.kretprobe.symbol_name,
2438 sizeof(uevent_param->u.kretprobe.symbol_name));
2439 break;
2440 case LTTNG_KERNEL_ABI_FUNCTION:
2441 WARN_ON_ONCE(1);
2442 /* Not implemented. */
2443 break;
2444 default:
2445 break;
2446 }
2447 ret = lttng_abi_create_event(file, uevent_param);
2448
2449 old_event_error_free_old_param:
2450 kfree(old_uevent_param);
2451 old_event_error_free_param:
2452 kfree(uevent_param);
2453 old_event_end:
2454 return ret;
2455 }
2456 case LTTNG_KERNEL_ABI_EVENT:
2457 {
2458 struct lttng_kernel_abi_event uevent_param;
2459
2460 if (copy_from_user(&uevent_param,
2461 (struct lttng_kernel_abi_event __user *) arg,
2462 sizeof(uevent_param)))
2463 return -EFAULT;
2464 return lttng_abi_create_event(file, &uevent_param);
2465 }
2466 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2467 {
2468 struct lttng_kernel_abi_context *ucontext_param;
2469 struct lttng_kernel_abi_old_context *old_ucontext_param;
2470 int ret;
2471
2472 ucontext_param = kmalloc(sizeof(struct lttng_kernel_abi_context),
2473 GFP_KERNEL);
2474 if (!ucontext_param) {
2475 ret = -ENOMEM;
2476 goto old_ctx_end;
2477 }
2478 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_abi_old_context),
2479 GFP_KERNEL);
2480 if (!old_ucontext_param) {
2481 ret = -ENOMEM;
2482 goto old_ctx_error_free_param;
2483 }
2484
2485 if (copy_from_user(old_ucontext_param,
2486 (struct lttng_kernel_abi_old_context __user *) arg,
2487 sizeof(struct lttng_kernel_abi_old_context))) {
2488 ret = -EFAULT;
2489 goto old_ctx_error_free_old_param;
2490 }
2491 ucontext_param->ctx = old_ucontext_param->ctx;
2492 memcpy(ucontext_param->padding, old_ucontext_param->padding,
2493 sizeof(ucontext_param->padding));
2494 /* only type that uses the union */
2495 if (old_ucontext_param->ctx == LTTNG_KERNEL_ABI_CONTEXT_PERF_COUNTER) {
2496 ucontext_param->u.perf_counter.type =
2497 old_ucontext_param->u.perf_counter.type;
2498 ucontext_param->u.perf_counter.config =
2499 old_ucontext_param->u.perf_counter.config;
2500 memcpy(ucontext_param->u.perf_counter.name,
2501 old_ucontext_param->u.perf_counter.name,
2502 sizeof(ucontext_param->u.perf_counter.name));
2503 }
2504
2505 ret = lttng_abi_add_context(file,
2506 ucontext_param,
2507 &channel->priv->ctx, channel->parent.session);
2508
2509 old_ctx_error_free_old_param:
2510 kfree(old_ucontext_param);
2511 old_ctx_error_free_param:
2512 kfree(ucontext_param);
2513 old_ctx_end:
2514 return ret;
2515 }
2516 case LTTNG_KERNEL_ABI_CONTEXT:
2517 {
2518 struct lttng_kernel_abi_context ucontext_param;
2519
2520 if (copy_from_user(&ucontext_param,
2521 (struct lttng_kernel_abi_context __user *) arg,
2522 sizeof(ucontext_param)))
2523 return -EFAULT;
2524 return lttng_abi_add_context(file,
2525 &ucontext_param,
2526 &channel->priv->ctx, channel->parent.session);
2527 }
2528 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2529 case LTTNG_KERNEL_ABI_ENABLE:
2530 return lttng_channel_enable(&channel->parent);
2531 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2532 case LTTNG_KERNEL_ABI_DISABLE:
2533 return lttng_channel_disable(&channel->parent);
2534 case LTTNG_KERNEL_ABI_SYSCALL_MASK:
2535 return lttng_channel_syscall_mask(channel,
2536 (struct lttng_kernel_abi_syscall_mask __user *) arg);
2537 default:
2538 return -ENOIOCTLCMD;
2539 }
2540 }
2541
2542 /**
2543 * lttng_metadata_ioctl - lttng syscall through ioctl
2544 *
2545 * @file: the file
2546 * @cmd: the command
2547 * @arg: command arg
2548 *
2549 * This ioctl implements lttng commands:
2550 * LTTNG_KERNEL_ABI_STREAM
2551 * Returns an event stream file descriptor or failure.
2552 *
2553 * Channel and event file descriptors also hold a reference on the session.
2554 */
2555 static
2556 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2557 {
2558 switch (cmd) {
2559 case LTTNG_KERNEL_ABI_OLD_STREAM:
2560 case LTTNG_KERNEL_ABI_STREAM:
2561 return lttng_abi_open_metadata_stream(file);
2562 default:
2563 return -ENOIOCTLCMD;
2564 }
2565 }
2566
2567 /**
2568 * lttng_channel_poll - lttng stream addition/removal monitoring
2569 *
2570 * @file: the file
2571 * @wait: poll table
2572 */
2573 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
2574 {
2575 struct lttng_kernel_channel_buffer *channel = file->private_data;
2576 unsigned int mask = 0;
2577
2578 if (file->f_mode & FMODE_READ) {
2579 poll_wait_set_exclusive(wait);
2580 poll_wait(file, channel->ops->priv->get_hp_wait_queue(channel->priv->rb_chan),
2581 wait);
2582
2583 if (channel->ops->priv->is_disabled(channel->priv->rb_chan))
2584 return POLLERR;
2585 if (channel->ops->priv->is_finalized(channel->priv->rb_chan))
2586 return POLLHUP;
2587 if (channel->ops->priv->buffer_has_read_closed_stream(channel->priv->rb_chan))
2588 return POLLIN | POLLRDNORM;
2589 return 0;
2590 }
2591 return mask;
2592
2593 }
2594
2595 static
2596 int lttng_channel_release(struct inode *inode, struct file *file)
2597 {
2598 struct lttng_kernel_channel_buffer *channel = file->private_data;
2599
2600 if (channel)
2601 fput(channel->parent.session->priv->file);
2602 return 0;
2603 }
2604
2605 static
2606 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
2607 {
2608 struct lttng_kernel_channel_buffer *channel = file->private_data;
2609
2610 if (channel) {
2611 fput(channel->parent.session->priv->file);
2612 lttng_metadata_channel_destroy(channel);
2613 }
2614
2615 return 0;
2616 }
2617
2618 static const struct file_operations lttng_channel_fops = {
2619 .owner = THIS_MODULE,
2620 .release = lttng_channel_release,
2621 .poll = lttng_channel_poll,
2622 .unlocked_ioctl = lttng_channel_ioctl,
2623 #ifdef CONFIG_COMPAT
2624 .compat_ioctl = lttng_channel_ioctl,
2625 #endif
2626 };
2627
2628 static const struct file_operations lttng_metadata_fops = {
2629 .owner = THIS_MODULE,
2630 .release = lttng_metadata_channel_release,
2631 .unlocked_ioctl = lttng_metadata_ioctl,
2632 #ifdef CONFIG_COMPAT
2633 .compat_ioctl = lttng_metadata_ioctl,
2634 #endif
2635 };
2636
2637 /**
2638 * lttng_event_recorder_event_ioctl - lttng syscall through ioctl
2639 *
2640 * @file: the file
2641 * @cmd: the command
2642 * @arg: command arg
2643 *
2644 * This ioctl implements lttng commands:
2645 * LTTNG_KERNEL_ABI_CONTEXT
2646 * Prepend a context field to each record of this event
2647 * LTTNG_KERNEL_ABI_ENABLE
2648 * Enable recording for this event (weak enable)
2649 * LTTNG_KERNEL_ABI_DISABLE
2650 * Disable recording for this event (strong disable)
2651 */
2652 static
2653 long lttng_event_recorder_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2654 {
2655 struct lttng_kernel_event_recorder *event_recorder = file->private_data;
2656
2657 switch (cmd) {
2658 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2659 {
2660 /* Not implemented */
2661 return -ENOSYS;
2662 }
2663 case LTTNG_KERNEL_ABI_CONTEXT:
2664 {
2665 /* Not implemented */
2666 return -ENOSYS;
2667 }
2668 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2669 case LTTNG_KERNEL_ABI_ENABLE:
2670 return lttng_event_enable(&event_recorder->parent);
2671 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2672 case LTTNG_KERNEL_ABI_DISABLE:
2673 return lttng_event_disable(&event_recorder->parent);
2674 case LTTNG_KERNEL_ABI_FILTER:
2675 return -EINVAL;
2676 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2677 return lttng_event_add_callsite(&event_recorder->parent,
2678 (struct lttng_kernel_abi_event_callsite __user *) arg);
2679 default:
2680 return -ENOIOCTLCMD;
2681 }
2682 }
2683
2684 /**
2685 * lttng_event_recorder_enabler_ioctl - lttng syscall through ioctl
2686 *
2687 * @file: the file
2688 * @cmd: the command
2689 * @arg: command arg
2690 *
2691 * This ioctl implements lttng commands:
2692 * LTTNG_KERNEL_ABI_CONTEXT
2693 * Prepend a context field to each record of this event
2694 * LTTNG_KERNEL_ABI_ENABLE
2695 * Enable recording for this event (weak enable)
2696 * LTTNG_KERNEL_ABI_DISABLE
2697 * Disable recording for this event (strong disable)
2698 */
2699 static
2700 long lttng_event_recorder_enabler_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2701 {
2702 struct lttng_event_recorder_enabler *event_enabler = file->private_data;
2703
2704 switch (cmd) {
2705 case LTTNG_KERNEL_ABI_OLD_CONTEXT:
2706 {
2707 /* Not implemented */
2708 return -ENOSYS;
2709 }
2710 case LTTNG_KERNEL_ABI_CONTEXT:
2711 {
2712 /* Not implemented */
2713 return -ENOSYS;
2714 }
2715 case LTTNG_KERNEL_ABI_OLD_ENABLE:
2716 case LTTNG_KERNEL_ABI_ENABLE:
2717 return lttng_event_enabler_enable(&event_enabler->parent);
2718 case LTTNG_KERNEL_ABI_OLD_DISABLE:
2719 case LTTNG_KERNEL_ABI_DISABLE:
2720 return lttng_event_enabler_disable(&event_enabler->parent);
2721 case LTTNG_KERNEL_ABI_FILTER:
2722 return lttng_event_enabler_attach_filter_bytecode(&event_enabler->parent,
2723 (struct lttng_kernel_abi_filter_bytecode __user *) arg);
2724 case LTTNG_KERNEL_ABI_ADD_CALLSITE:
2725 return -EINVAL;
2726 default:
2727 return -ENOIOCTLCMD;
2728 }
2729 }
2730
2731 static
2732 int lttng_event_recorder_event_release(struct inode *inode, struct file *file)
2733 {
2734 struct lttng_kernel_event_recorder *event = file->private_data;
2735
2736 if (event)
2737 fput(event->chan->priv->parent.file);
2738 return 0;
2739 }
2740
2741 static
2742 int lttng_event_recorder_enabler_release(struct inode *inode, struct file *file)
2743 {
2744 struct lttng_event_recorder_enabler *event_enabler = file->private_data;
2745
2746 if (event_enabler)
2747 fput(event_enabler->chan->priv->parent.file);
2748 return 0;
2749 }
2750
2751 static const struct file_operations lttng_event_recorder_event_fops = {
2752 .owner = THIS_MODULE,
2753 .release = lttng_event_recorder_event_release,
2754 .unlocked_ioctl = lttng_event_recorder_event_ioctl,
2755 #ifdef CONFIG_COMPAT
2756 .compat_ioctl = lttng_event_recorder_event_ioctl,
2757 #endif
2758 };
2759
2760 static const struct file_operations lttng_event_recorder_enabler_fops = {
2761 .owner = THIS_MODULE,
2762 .release = lttng_event_recorder_enabler_release,
2763 .unlocked_ioctl = lttng_event_recorder_enabler_ioctl,
2764 #ifdef CONFIG_COMPAT
2765 .compat_ioctl = lttng_event_recorder_enabler_ioctl,
2766 #endif
2767 };
2768
2769 static int put_u64(uint64_t val, unsigned long arg)
2770 {
2771 return put_user(val, (uint64_t __user *) arg);
2772 }
2773
2774 static int put_u32(uint32_t val, unsigned long arg)
2775 {
2776 return put_user(val, (uint32_t __user *) arg);
2777 }
2778
2779 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
2780 unsigned int cmd, unsigned long arg)
2781 {
2782 struct lttng_kernel_ring_buffer *buf = filp->private_data;
2783 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
2784 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
2785 const struct lttng_kernel_channel_buffer_ops *ops = chan->backend.priv_ops;
2786 int ret;
2787
2788 if (atomic_read(&chan->record_disabled))
2789 return -EIO;
2790
2791 switch (cmd) {
2792 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_TIMESTAMP_BEGIN:
2793 {
2794 uint64_t ts;
2795
2796 ret = ops->priv->timestamp_begin(config, buf, &ts);
2797 if (ret < 0)
2798 goto error;
2799 return put_u64(ts, arg);
2800 }
2801 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_TIMESTAMP_END:
2802 {
2803 uint64_t ts;
2804
2805 ret = ops->priv->timestamp_end(config, buf, &ts);
2806 if (ret < 0)
2807 goto error;
2808 return put_u64(ts, arg);
2809 }
2810 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_EVENTS_DISCARDED:
2811 {
2812 uint64_t ed;
2813
2814 ret = ops->priv->events_discarded(config, buf, &ed);
2815 if (ret < 0)
2816 goto error;
2817 return put_u64(ed, arg);
2818 }
2819 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CONTENT_SIZE:
2820 {
2821 uint64_t cs;
2822
2823 ret = ops->priv->content_size(config, buf, &cs);
2824 if (ret < 0)
2825 goto error;
2826 return put_u64(cs, arg);
2827 }
2828 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_PACKET_SIZE:
2829 {
2830 uint64_t ps;
2831
2832 ret = ops->priv->packet_size(config, buf, &ps);
2833 if (ret < 0)
2834 goto error;
2835 return put_u64(ps, arg);
2836 }
2837 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_STREAM_ID:
2838 {
2839 uint64_t si;
2840
2841 ret = ops->priv->stream_id(config, buf, &si);
2842 if (ret < 0)
2843 goto error;
2844 return put_u64(si, arg);
2845 }
2846 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2847 {
2848 uint64_t ts;
2849
2850 ret = ops->priv->current_timestamp(config, buf, &ts);
2851 if (ret < 0)
2852 goto error;
2853 return put_u64(ts, arg);
2854 }
2855 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_SEQ_NUM:
2856 {
2857 uint64_t seq;
2858
2859 ret = ops->priv->sequence_number(config, buf, &seq);
2860 if (ret < 0)
2861 goto error;
2862 return put_u64(seq, arg);
2863 }
2864 case LTTNG_KERNEL_ABI_RING_BUFFER_INSTANCE_ID:
2865 {
2866 uint64_t id;
2867
2868 ret = ops->priv->instance_id(config, buf, &id);
2869 if (ret < 0)
2870 goto error;
2871 return put_u64(id, arg);
2872 }
2873 default:
2874 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
2875 cmd, arg);
2876 }
2877
2878 error:
2879 return -ENOSYS;
2880 }
2881
2882 #ifdef CONFIG_COMPAT
2883 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
2884 unsigned int cmd, unsigned long arg)
2885 {
2886 struct lttng_kernel_ring_buffer *buf = filp->private_data;
2887 struct lttng_kernel_ring_buffer_channel *chan = buf->backend.chan;
2888 const struct lttng_kernel_ring_buffer_config *config = &chan->backend.config;
2889 const struct lttng_kernel_channel_buffer_ops *ops = chan->backend.priv_ops;
2890 int ret;
2891
2892 if (atomic_read(&chan->record_disabled))
2893 return -EIO;
2894
2895 switch (cmd) {
2896 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
2897 {
2898 uint64_t ts;
2899
2900 ret = ops->priv->timestamp_begin(config, buf, &ts);
2901 if (ret < 0)
2902 goto error;
2903 return put_u64(ts, arg);
2904 }
2905 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
2906 {
2907 uint64_t ts;
2908
2909 ret = ops->priv->timestamp_end(config, buf, &ts);
2910 if (ret < 0)
2911 goto error;
2912 return put_u64(ts, arg);
2913 }
2914 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
2915 {
2916 uint64_t ed;
2917
2918 ret = ops->priv->events_discarded(config, buf, &ed);
2919 if (ret < 0)
2920 goto error;
2921 return put_u64(ed, arg);
2922 }
2923 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
2924 {
2925 uint64_t cs;
2926
2927 ret = ops->priv->content_size(config, buf, &cs);
2928 if (ret < 0)
2929 goto error;
2930 return put_u64(cs, arg);
2931 }
2932 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
2933 {
2934 uint64_t ps;
2935
2936 ret = ops->priv->packet_size(config, buf, &ps);
2937 if (ret < 0)
2938 goto error;
2939 return put_u64(ps, arg);
2940 }
2941 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_STREAM_ID:
2942 {
2943 uint64_t si;
2944
2945 ret = ops->priv->stream_id(config, buf, &si);
2946 if (ret < 0)
2947 goto error;
2948 return put_u64(si, arg);
2949 }
2950 case LTTNG_KERNEL_ABI_RING_BUFFER_GET_CURRENT_TIMESTAMP:
2951 {
2952 uint64_t ts;
2953
2954 ret = ops->priv->current_timestamp(config, buf, &ts);
2955 if (ret < 0)
2956 goto error;
2957 return put_u64(ts, arg);
2958 }
2959 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_GET_SEQ_NUM:
2960 {
2961 uint64_t seq;
2962
2963 ret = ops->priv->sequence_number(config, buf, &seq);
2964 if (ret < 0)
2965 goto error;
2966 return put_u64(seq, arg);
2967 }
2968 case LTTNG_KERNEL_ABI_RING_BUFFER_COMPAT_INSTANCE_ID:
2969 {
2970 uint64_t id;
2971
2972 ret = ops->priv->instance_id(config, buf, &id);
2973 if (ret < 0)
2974 goto error;
2975 return put_u64(id, arg);
2976 }
2977 default:
2978 return lib_ring_buffer_file_operations.compat_ioctl(filp,
2979 cmd, arg);
2980 }
2981
2982 error:
2983 return -ENOSYS;
2984 }
2985 #endif /* CONFIG_COMPAT */
2986
2987 static void lttng_stream_override_ring_buffer_fops(void)
2988 {
2989 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
2990 lttng_stream_ring_buffer_file_operations.open =
2991 lib_ring_buffer_file_operations.open;
2992 lttng_stream_ring_buffer_file_operations.release =
2993 lib_ring_buffer_file_operations.release;
2994 lttng_stream_ring_buffer_file_operations.poll =
2995 lib_ring_buffer_file_operations.poll;
2996 lttng_stream_ring_buffer_file_operations.splice_read =
2997 lib_ring_buffer_file_operations.splice_read;
2998 lttng_stream_ring_buffer_file_operations.mmap =
2999 lib_ring_buffer_file_operations.mmap;
3000 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
3001 lttng_stream_ring_buffer_ioctl;
3002 lttng_stream_ring_buffer_file_operations.llseek =
3003 lib_ring_buffer_file_operations.llseek;
3004 #ifdef CONFIG_COMPAT
3005 lttng_stream_ring_buffer_file_operations.compat_ioctl =
3006 lttng_stream_ring_buffer_compat_ioctl;
3007 #endif
3008 }
3009
3010 int __init lttng_abi_init(void)
3011 {
3012 int ret = 0;
3013
3014 wrapper_vmalloc_sync_mappings();
3015 lttng_clock_ref();
3016
3017 ret = lttng_tp_mempool_init();
3018 if (ret) {
3019 goto error;
3020 }
3021
3022 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
3023 &lttng_proc_ops, NULL);
3024
3025 if (!lttng_proc_dentry) {
3026 printk(KERN_ERR "LTTng: Error creating control file\n");
3027 ret = -ENOMEM;
3028 goto error;
3029 }
3030 lttng_stream_override_ring_buffer_fops();
3031 return 0;
3032
3033 error:
3034 lttng_tp_mempool_destroy();
3035 lttng_clock_unref();
3036 return ret;
3037 }
3038
3039 /* No __exit annotation because used by init error path too. */
3040 void lttng_abi_exit(void)
3041 {
3042 lttng_tp_mempool_destroy();
3043 lttng_clock_unref();
3044 if (lttng_proc_dentry)
3045 remove_proc_entry("lttng", NULL);
3046 }
LTTng 2.0/0.x modules
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