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lttng-abi: Document ioctl numbers reserved by lttng-abi-old.h
[lttng-modules.git] / lttng-abi.c
1 /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
2 *
3 * lttng-abi.c
4 *
5 * LTTng ABI
6 *
7 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 *
9 * Mimic system calls for:
10 * - session creation, returns a file descriptor or failure.
11 * - channel creation, returns a file descriptor or failure.
12 * - Operates on a session file descriptor
13 * - Takes all channel options as parameters.
14 * - stream get, returns a file descriptor or failure.
15 * - Operates on a channel file descriptor.
16 * - stream notifier get, returns a file descriptor or failure.
17 * - Operates on a channel file descriptor.
18 * - event creation, returns a file descriptor or failure.
19 * - Operates on a channel file descriptor
20 * - Takes an event name as parameter
21 * - Takes an instrumentation source as parameter
22 * - e.g. tracepoints, dynamic_probes...
23 * - Takes instrumentation source specific arguments.
24 */
25
26 #include <linux/module.h>
27 #include <linux/proc_fs.h>
28 #include <linux/anon_inodes.h>
29 #include <linux/file.h>
30 #include <linux/uaccess.h>
31 #include <linux/slab.h>
32 #include <linux/err.h>
33 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
34 #include <wrapper/ringbuffer/vfs.h>
35 #include <wrapper/ringbuffer/backend.h>
36 #include <wrapper/ringbuffer/frontend.h>
37 #include <wrapper/poll.h>
38 #include <wrapper/file.h>
39 #include <wrapper/kref.h>
40 #include <lttng-string-utils.h>
41 #include <lttng-abi.h>
42 #include <lttng-abi-old.h>
43 #include <lttng-events.h>
44 #include <lttng-tracer.h>
45 #include <lttng-tp-mempool.h>
46 #include <lib/ringbuffer/frontend_types.h>
47
48 /*
49 * This is LTTng's own personal way to create a system call as an external
50 * module. We use ioctl() on /proc/lttng.
51 */
52
53 static struct proc_dir_entry *lttng_proc_dentry;
54 static const struct file_operations lttng_fops;
55 static const struct file_operations lttng_session_fops;
56 static const struct file_operations lttng_channel_fops;
57 static const struct file_operations lttng_metadata_fops;
58 static const struct file_operations lttng_event_fops;
59 static struct file_operations lttng_stream_ring_buffer_file_operations;
60
61 static int put_u64(uint64_t val, unsigned long arg);
62
63 /*
64 * Teardown management: opened file descriptors keep a refcount on the module,
65 * so it can only exit when all file descriptors are closed.
66 */
67
68 static
69 int lttng_abi_create_session(void)
70 {
71 struct lttng_session *session;
72 struct file *session_file;
73 int session_fd, ret;
74
75 session = lttng_session_create();
76 if (!session)
77 return -ENOMEM;
78 session_fd = lttng_get_unused_fd();
79 if (session_fd < 0) {
80 ret = session_fd;
81 goto fd_error;
82 }
83 session_file = anon_inode_getfile("[lttng_session]",
84 &lttng_session_fops,
85 session, O_RDWR);
86 if (IS_ERR(session_file)) {
87 ret = PTR_ERR(session_file);
88 goto file_error;
89 }
90 session->file = session_file;
91 fd_install(session_fd, session_file);
92 return session_fd;
93
94 file_error:
95 put_unused_fd(session_fd);
96 fd_error:
97 lttng_session_destroy(session);
98 return ret;
99 }
100
101 static
102 int lttng_abi_tracepoint_list(void)
103 {
104 struct file *tracepoint_list_file;
105 int file_fd, ret;
106
107 file_fd = lttng_get_unused_fd();
108 if (file_fd < 0) {
109 ret = file_fd;
110 goto fd_error;
111 }
112
113 tracepoint_list_file = anon_inode_getfile("[lttng_tracepoint_list]",
114 &lttng_tracepoint_list_fops,
115 NULL, O_RDWR);
116 if (IS_ERR(tracepoint_list_file)) {
117 ret = PTR_ERR(tracepoint_list_file);
118 goto file_error;
119 }
120 ret = lttng_tracepoint_list_fops.open(NULL, tracepoint_list_file);
121 if (ret < 0)
122 goto open_error;
123 fd_install(file_fd, tracepoint_list_file);
124 return file_fd;
125
126 open_error:
127 fput(tracepoint_list_file);
128 file_error:
129 put_unused_fd(file_fd);
130 fd_error:
131 return ret;
132 }
133
134 #ifndef CONFIG_HAVE_SYSCALL_TRACEPOINTS
135 static inline
136 int lttng_abi_syscall_list(void)
137 {
138 return -ENOSYS;
139 }
140 #else
141 static
142 int lttng_abi_syscall_list(void)
143 {
144 struct file *syscall_list_file;
145 int file_fd, ret;
146
147 file_fd = lttng_get_unused_fd();
148 if (file_fd < 0) {
149 ret = file_fd;
150 goto fd_error;
151 }
152
153 syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
154 &lttng_syscall_list_fops,
155 NULL, O_RDWR);
156 if (IS_ERR(syscall_list_file)) {
157 ret = PTR_ERR(syscall_list_file);
158 goto file_error;
159 }
160 ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
161 if (ret < 0)
162 goto open_error;
163 fd_install(file_fd, syscall_list_file);
164 return file_fd;
165
166 open_error:
167 fput(syscall_list_file);
168 file_error:
169 put_unused_fd(file_fd);
170 fd_error:
171 return ret;
172 }
173 #endif
174
175 static
176 void lttng_abi_tracer_version(struct lttng_kernel_tracer_version *v)
177 {
178 v->major = LTTNG_MODULES_MAJOR_VERSION;
179 v->minor = LTTNG_MODULES_MINOR_VERSION;
180 v->patchlevel = LTTNG_MODULES_PATCHLEVEL_VERSION;
181 }
182
183 static
184 void lttng_abi_tracer_abi_version(struct lttng_kernel_tracer_abi_version *v)
185 {
186 v->major = LTTNG_MODULES_ABI_MAJOR_VERSION;
187 v->minor = LTTNG_MODULES_ABI_MINOR_VERSION;
188 }
189
190 static
191 long lttng_abi_add_context(struct file *file,
192 struct lttng_kernel_context *context_param,
193 struct lttng_ctx **ctx, struct lttng_session *session)
194 {
195
196 if (session->been_active)
197 return -EPERM;
198
199 switch (context_param->ctx) {
200 case LTTNG_KERNEL_CONTEXT_PID:
201 return lttng_add_pid_to_ctx(ctx);
202 case LTTNG_KERNEL_CONTEXT_PRIO:
203 return lttng_add_prio_to_ctx(ctx);
204 case LTTNG_KERNEL_CONTEXT_NICE:
205 return lttng_add_nice_to_ctx(ctx);
206 case LTTNG_KERNEL_CONTEXT_VPID:
207 return lttng_add_vpid_to_ctx(ctx);
208 case LTTNG_KERNEL_CONTEXT_TID:
209 return lttng_add_tid_to_ctx(ctx);
210 case LTTNG_KERNEL_CONTEXT_VTID:
211 return lttng_add_vtid_to_ctx(ctx);
212 case LTTNG_KERNEL_CONTEXT_PPID:
213 return lttng_add_ppid_to_ctx(ctx);
214 case LTTNG_KERNEL_CONTEXT_VPPID:
215 return lttng_add_vppid_to_ctx(ctx);
216 case LTTNG_KERNEL_CONTEXT_PERF_COUNTER:
217 context_param->u.perf_counter.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
218 return lttng_add_perf_counter_to_ctx(context_param->u.perf_counter.type,
219 context_param->u.perf_counter.config,
220 context_param->u.perf_counter.name,
221 ctx);
222 case LTTNG_KERNEL_CONTEXT_PROCNAME:
223 return lttng_add_procname_to_ctx(ctx);
224 case LTTNG_KERNEL_CONTEXT_HOSTNAME:
225 return lttng_add_hostname_to_ctx(ctx);
226 case LTTNG_KERNEL_CONTEXT_CPU_ID:
227 return lttng_add_cpu_id_to_ctx(ctx);
228 case LTTNG_KERNEL_CONTEXT_INTERRUPTIBLE:
229 return lttng_add_interruptible_to_ctx(ctx);
230 case LTTNG_KERNEL_CONTEXT_NEED_RESCHEDULE:
231 return lttng_add_need_reschedule_to_ctx(ctx);
232 case LTTNG_KERNEL_CONTEXT_PREEMPTIBLE:
233 return lttng_add_preemptible_to_ctx(ctx);
234 case LTTNG_KERNEL_CONTEXT_MIGRATABLE:
235 return lttng_add_migratable_to_ctx(ctx);
236 case LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL:
237 case LTTNG_KERNEL_CONTEXT_CALLSTACK_USER:
238 return lttng_add_callstack_to_ctx(ctx, context_param->ctx);
239 case LTTNG_KERNEL_CONTEXT_CGROUP_NS:
240 return lttng_add_cgroup_ns_to_ctx(ctx);
241 case LTTNG_KERNEL_CONTEXT_IPC_NS:
242 return lttng_add_ipc_ns_to_ctx(ctx);
243 case LTTNG_KERNEL_CONTEXT_MNT_NS:
244 return lttng_add_mnt_ns_to_ctx(ctx);
245 case LTTNG_KERNEL_CONTEXT_NET_NS:
246 return lttng_add_net_ns_to_ctx(ctx);
247 case LTTNG_KERNEL_CONTEXT_PID_NS:
248 return lttng_add_pid_ns_to_ctx(ctx);
249 case LTTNG_KERNEL_CONTEXT_USER_NS:
250 return lttng_add_user_ns_to_ctx(ctx);
251 case LTTNG_KERNEL_CONTEXT_UTS_NS:
252 return lttng_add_uts_ns_to_ctx(ctx);
253 case LTTNG_KERNEL_CONTEXT_UID:
254 return lttng_add_uid_to_ctx(ctx);
255 case LTTNG_KERNEL_CONTEXT_EUID:
256 return lttng_add_euid_to_ctx(ctx);
257 case LTTNG_KERNEL_CONTEXT_SUID:
258 return lttng_add_suid_to_ctx(ctx);
259 case LTTNG_KERNEL_CONTEXT_GID:
260 return lttng_add_gid_to_ctx(ctx);
261 case LTTNG_KERNEL_CONTEXT_EGID:
262 return lttng_add_egid_to_ctx(ctx);
263 case LTTNG_KERNEL_CONTEXT_SGID:
264 return lttng_add_sgid_to_ctx(ctx);
265 case LTTNG_KERNEL_CONTEXT_VUID:
266 return lttng_add_vuid_to_ctx(ctx);
267 case LTTNG_KERNEL_CONTEXT_VEUID:
268 return lttng_add_veuid_to_ctx(ctx);
269 case LTTNG_KERNEL_CONTEXT_VSUID:
270 return lttng_add_vsuid_to_ctx(ctx);
271 case LTTNG_KERNEL_CONTEXT_VGID:
272 return lttng_add_vgid_to_ctx(ctx);
273 case LTTNG_KERNEL_CONTEXT_VEGID:
274 return lttng_add_vegid_to_ctx(ctx);
275 case LTTNG_KERNEL_CONTEXT_VSGID:
276 return lttng_add_vsgid_to_ctx(ctx);
277 default:
278 return -EINVAL;
279 }
280 }
281
282 /**
283 * lttng_ioctl - lttng syscall through ioctl
284 *
285 * @file: the file
286 * @cmd: the command
287 * @arg: command arg
288 *
289 * This ioctl implements lttng commands:
290 * LTTNG_KERNEL_SESSION
291 * Returns a LTTng trace session file descriptor
292 * LTTNG_KERNEL_TRACER_VERSION
293 * Returns the LTTng kernel tracer version
294 * LTTNG_KERNEL_TRACEPOINT_LIST
295 * Returns a file descriptor listing available tracepoints
296 * LTTNG_KERNEL_WAIT_QUIESCENT
297 * Returns after all previously running probes have completed
298 * LTTNG_KERNEL_TRACER_ABI_VERSION
299 * Returns the LTTng kernel tracer ABI version
300 *
301 * The returned session will be deleted when its file descriptor is closed.
302 */
303 static
304 long lttng_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
305 {
306 switch (cmd) {
307 case LTTNG_KERNEL_OLD_SESSION:
308 case LTTNG_KERNEL_SESSION:
309 return lttng_abi_create_session();
310 case LTTNG_KERNEL_OLD_TRACER_VERSION:
311 {
312 struct lttng_kernel_tracer_version v;
313 struct lttng_kernel_old_tracer_version oldv;
314 struct lttng_kernel_old_tracer_version *uversion =
315 (struct lttng_kernel_old_tracer_version __user *) arg;
316
317 lttng_abi_tracer_version(&v);
318 oldv.major = v.major;
319 oldv.minor = v.minor;
320 oldv.patchlevel = v.patchlevel;
321
322 if (copy_to_user(uversion, &oldv, sizeof(oldv)))
323 return -EFAULT;
324 return 0;
325 }
326 case LTTNG_KERNEL_TRACER_VERSION:
327 {
328 struct lttng_kernel_tracer_version version;
329 struct lttng_kernel_tracer_version *uversion =
330 (struct lttng_kernel_tracer_version __user *) arg;
331
332 lttng_abi_tracer_version(&version);
333
334 if (copy_to_user(uversion, &version, sizeof(version)))
335 return -EFAULT;
336 return 0;
337 }
338 case LTTNG_KERNEL_TRACER_ABI_VERSION:
339 {
340 struct lttng_kernel_tracer_abi_version version;
341 struct lttng_kernel_tracer_abi_version *uversion =
342 (struct lttng_kernel_tracer_abi_version __user *) arg;
343
344 lttng_abi_tracer_abi_version(&version);
345
346 if (copy_to_user(uversion, &version, sizeof(version)))
347 return -EFAULT;
348 return 0;
349 }
350 case LTTNG_KERNEL_OLD_TRACEPOINT_LIST:
351 case LTTNG_KERNEL_TRACEPOINT_LIST:
352 return lttng_abi_tracepoint_list();
353 case LTTNG_KERNEL_SYSCALL_LIST:
354 return lttng_abi_syscall_list();
355 case LTTNG_KERNEL_OLD_WAIT_QUIESCENT:
356 case LTTNG_KERNEL_WAIT_QUIESCENT:
357 synchronize_trace();
358 return 0;
359 case LTTNG_KERNEL_OLD_CALIBRATE:
360 {
361 struct lttng_kernel_old_calibrate __user *ucalibrate =
362 (struct lttng_kernel_old_calibrate __user *) arg;
363 struct lttng_kernel_old_calibrate old_calibrate;
364 struct lttng_kernel_calibrate calibrate;
365 int ret;
366
367 if (copy_from_user(&old_calibrate, ucalibrate, sizeof(old_calibrate)))
368 return -EFAULT;
369 calibrate.type = old_calibrate.type;
370 ret = lttng_calibrate(&calibrate);
371 if (copy_to_user(ucalibrate, &old_calibrate, sizeof(old_calibrate)))
372 return -EFAULT;
373 return ret;
374 }
375 case LTTNG_KERNEL_CALIBRATE:
376 {
377 struct lttng_kernel_calibrate __user *ucalibrate =
378 (struct lttng_kernel_calibrate __user *) arg;
379 struct lttng_kernel_calibrate calibrate;
380 int ret;
381
382 if (copy_from_user(&calibrate, ucalibrate, sizeof(calibrate)))
383 return -EFAULT;
384 ret = lttng_calibrate(&calibrate);
385 if (copy_to_user(ucalibrate, &calibrate, sizeof(calibrate)))
386 return -EFAULT;
387 return ret;
388 }
389 default:
390 return -ENOIOCTLCMD;
391 }
392 }
393
394 static const struct file_operations lttng_fops = {
395 .owner = THIS_MODULE,
396 .unlocked_ioctl = lttng_ioctl,
397 #ifdef CONFIG_COMPAT
398 .compat_ioctl = lttng_ioctl,
399 #endif
400 };
401
402 static
403 int lttng_abi_create_channel(struct file *session_file,
404 struct lttng_kernel_channel *chan_param,
405 enum channel_type channel_type)
406 {
407 struct lttng_session *session = session_file->private_data;
408 const struct file_operations *fops = NULL;
409 const char *transport_name;
410 struct lttng_channel *chan;
411 struct file *chan_file;
412 int chan_fd;
413 int ret = 0;
414
415 chan_fd = lttng_get_unused_fd();
416 if (chan_fd < 0) {
417 ret = chan_fd;
418 goto fd_error;
419 }
420 switch (channel_type) {
421 case PER_CPU_CHANNEL:
422 fops = &lttng_channel_fops;
423 break;
424 case METADATA_CHANNEL:
425 fops = &lttng_metadata_fops;
426 break;
427 }
428
429 chan_file = anon_inode_getfile("[lttng_channel]",
430 fops,
431 NULL, O_RDWR);
432 if (IS_ERR(chan_file)) {
433 ret = PTR_ERR(chan_file);
434 goto file_error;
435 }
436 switch (channel_type) {
437 case PER_CPU_CHANNEL:
438 if (chan_param->output == LTTNG_KERNEL_SPLICE) {
439 transport_name = chan_param->overwrite ?
440 "relay-overwrite" : "relay-discard";
441 } else if (chan_param->output == LTTNG_KERNEL_MMAP) {
442 transport_name = chan_param->overwrite ?
443 "relay-overwrite-mmap" : "relay-discard-mmap";
444 } else {
445 return -EINVAL;
446 }
447 break;
448 case METADATA_CHANNEL:
449 if (chan_param->output == LTTNG_KERNEL_SPLICE)
450 transport_name = "relay-metadata";
451 else if (chan_param->output == LTTNG_KERNEL_MMAP)
452 transport_name = "relay-metadata-mmap";
453 else
454 return -EINVAL;
455 break;
456 default:
457 transport_name = "<unknown>";
458 break;
459 }
460 if (!atomic_long_add_unless(&session_file->f_count, 1, LONG_MAX)) {
461 ret = -EOVERFLOW;
462 goto refcount_error;
463 }
464 /*
465 * We tolerate no failure path after channel creation. It will stay
466 * invariant for the rest of the session.
467 */
468 chan = lttng_channel_create(session, transport_name, NULL,
469 chan_param->subbuf_size,
470 chan_param->num_subbuf,
471 chan_param->switch_timer_interval,
472 chan_param->read_timer_interval,
473 channel_type);
474 if (!chan) {
475 ret = -EINVAL;
476 goto chan_error;
477 }
478 chan->file = chan_file;
479 chan_file->private_data = chan;
480 fd_install(chan_fd, chan_file);
481
482 return chan_fd;
483
484 chan_error:
485 atomic_long_dec(&session_file->f_count);
486 refcount_error:
487 fput(chan_file);
488 file_error:
489 put_unused_fd(chan_fd);
490 fd_error:
491 return ret;
492 }
493
494 static
495 int lttng_abi_session_set_name(struct lttng_session *session,
496 struct lttng_kernel_session_name *name)
497 {
498 size_t len;
499
500 len = strnlen(name->name, LTTNG_KERNEL_SESSION_NAME_LEN);
501
502 if (len == LTTNG_KERNEL_SESSION_NAME_LEN) {
503 /* Name is too long/malformed */
504 return -EINVAL;
505 }
506
507 strcpy(session->name, name->name);
508 return 0;
509 }
510
511 static
512 int lttng_abi_session_set_creation_time(struct lttng_session *session,
513 struct lttng_kernel_session_creation_time *time)
514 {
515 size_t len;
516
517 len = strnlen(time->iso8601, LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN);
518
519 if (len == LTTNG_KERNEL_SESSION_CREATION_TIME_ISO8601_LEN) {
520 /* Time is too long/malformed */
521 return -EINVAL;
522 }
523
524 strcpy(session->creation_time, time->iso8601);
525 return 0;
526 }
527
528 /**
529 * lttng_session_ioctl - lttng session fd ioctl
530 *
531 * @file: the file
532 * @cmd: the command
533 * @arg: command arg
534 *
535 * This ioctl implements lttng commands:
536 * LTTNG_KERNEL_CHANNEL
537 * Returns a LTTng channel file descriptor
538 * LTTNG_KERNEL_ENABLE
539 * Enables tracing for a session (weak enable)
540 * LTTNG_KERNEL_DISABLE
541 * Disables tracing for a session (strong disable)
542 * LTTNG_KERNEL_METADATA
543 * Returns a LTTng metadata file descriptor
544 * LTTNG_KERNEL_SESSION_TRACK_PID
545 * Add PID to session tracker
546 * LTTNG_KERNEL_SESSION_UNTRACK_PID
547 * Remove PID from session tracker
548 *
549 * The returned channel will be deleted when its file descriptor is closed.
550 */
551 static
552 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
553 {
554 struct lttng_session *session = file->private_data;
555 struct lttng_kernel_channel chan_param;
556 struct lttng_kernel_old_channel old_chan_param;
557
558 switch (cmd) {
559 case LTTNG_KERNEL_OLD_CHANNEL:
560 {
561 if (copy_from_user(&old_chan_param,
562 (struct lttng_kernel_old_channel __user *) arg,
563 sizeof(struct lttng_kernel_old_channel)))
564 return -EFAULT;
565 chan_param.overwrite = old_chan_param.overwrite;
566 chan_param.subbuf_size = old_chan_param.subbuf_size;
567 chan_param.num_subbuf = old_chan_param.num_subbuf;
568 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
569 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
570 chan_param.output = old_chan_param.output;
571
572 return lttng_abi_create_channel(file, &chan_param,
573 PER_CPU_CHANNEL);
574 }
575 case LTTNG_KERNEL_CHANNEL:
576 {
577 if (copy_from_user(&chan_param,
578 (struct lttng_kernel_channel __user *) arg,
579 sizeof(struct lttng_kernel_channel)))
580 return -EFAULT;
581 return lttng_abi_create_channel(file, &chan_param,
582 PER_CPU_CHANNEL);
583 }
584 case LTTNG_KERNEL_OLD_SESSION_START:
585 case LTTNG_KERNEL_OLD_ENABLE:
586 case LTTNG_KERNEL_SESSION_START:
587 case LTTNG_KERNEL_ENABLE:
588 return lttng_session_enable(session);
589 case LTTNG_KERNEL_OLD_SESSION_STOP:
590 case LTTNG_KERNEL_OLD_DISABLE:
591 case LTTNG_KERNEL_SESSION_STOP:
592 case LTTNG_KERNEL_DISABLE:
593 return lttng_session_disable(session);
594 case LTTNG_KERNEL_OLD_METADATA:
595 {
596 if (copy_from_user(&old_chan_param,
597 (struct lttng_kernel_old_channel __user *) arg,
598 sizeof(struct lttng_kernel_old_channel)))
599 return -EFAULT;
600 chan_param.overwrite = old_chan_param.overwrite;
601 chan_param.subbuf_size = old_chan_param.subbuf_size;
602 chan_param.num_subbuf = old_chan_param.num_subbuf;
603 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
604 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
605 chan_param.output = old_chan_param.output;
606
607 return lttng_abi_create_channel(file, &chan_param,
608 METADATA_CHANNEL);
609 }
610 case LTTNG_KERNEL_METADATA:
611 {
612 if (copy_from_user(&chan_param,
613 (struct lttng_kernel_channel __user *) arg,
614 sizeof(struct lttng_kernel_channel)))
615 return -EFAULT;
616 return lttng_abi_create_channel(file, &chan_param,
617 METADATA_CHANNEL);
618 }
619 case LTTNG_KERNEL_SESSION_TRACK_PID:
620 return lttng_session_track_pid(session, (int) arg);
621 case LTTNG_KERNEL_SESSION_UNTRACK_PID:
622 return lttng_session_untrack_pid(session, (int) arg);
623 case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
624 return lttng_session_list_tracker_pids(session);
625 case LTTNG_KERNEL_SESSION_METADATA_REGEN:
626 return lttng_session_metadata_regenerate(session);
627 case LTTNG_KERNEL_SESSION_STATEDUMP:
628 return lttng_session_statedump(session);
629 case LTTNG_KERNEL_SESSION_SET_NAME:
630 {
631 struct lttng_kernel_session_name name;
632
633 if (copy_from_user(&name,
634 (struct lttng_kernel_session_name __user *) arg,
635 sizeof(struct lttng_kernel_session_name)))
636 return -EFAULT;
637 return lttng_abi_session_set_name(session, &name);
638 }
639 case LTTNG_KERNEL_SESSION_SET_CREATION_TIME:
640 {
641 struct lttng_kernel_session_creation_time time;
642
643 if (copy_from_user(&time,
644 (struct lttng_kernel_session_creation_time __user *) arg,
645 sizeof(struct lttng_kernel_session_creation_time)))
646 return -EFAULT;
647 return lttng_abi_session_set_creation_time(session, &time);
648 }
649 default:
650 return -ENOIOCTLCMD;
651 }
652 }
653
654 /*
655 * Called when the last file reference is dropped.
656 *
657 * Big fat note: channels and events are invariant for the whole session after
658 * their creation. So this session destruction also destroys all channel and
659 * event structures specific to this session (they are not destroyed when their
660 * individual file is released).
661 */
662 static
663 int lttng_session_release(struct inode *inode, struct file *file)
664 {
665 struct lttng_session *session = file->private_data;
666
667 if (session)
668 lttng_session_destroy(session);
669 return 0;
670 }
671
672 static const struct file_operations lttng_session_fops = {
673 .owner = THIS_MODULE,
674 .release = lttng_session_release,
675 .unlocked_ioctl = lttng_session_ioctl,
676 #ifdef CONFIG_COMPAT
677 .compat_ioctl = lttng_session_ioctl,
678 #endif
679 };
680
681 /**
682 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
683 * @filp: the file
684 * @wait: poll table
685 *
686 * Handles the poll operations for the metadata channels.
687 */
688 static
689 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
690 poll_table *wait)
691 {
692 struct lttng_metadata_stream *stream = filp->private_data;
693 struct lib_ring_buffer *buf = stream->priv;
694 int finalized;
695 unsigned int mask = 0;
696
697 if (filp->f_mode & FMODE_READ) {
698 poll_wait_set_exclusive(wait);
699 poll_wait(filp, &stream->read_wait, wait);
700
701 finalized = stream->finalized;
702
703 /*
704 * lib_ring_buffer_is_finalized() contains a smp_rmb()
705 * ordering finalized load before offsets loads.
706 */
707 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
708
709 if (finalized)
710 mask |= POLLHUP;
711
712 mutex_lock(&stream->metadata_cache->lock);
713 if (stream->metadata_cache->metadata_written >
714 stream->metadata_out)
715 mask |= POLLIN;
716 mutex_unlock(&stream->metadata_cache->lock);
717 }
718
719 return mask;
720 }
721
722 static
723 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
724 unsigned int cmd, unsigned long arg)
725 {
726 struct lttng_metadata_stream *stream = filp->private_data;
727
728 stream->metadata_out = stream->metadata_in;
729 }
730
731 /*
732 * Reset the counter of how much metadata has been consumed to 0. That way,
733 * the consumer receives the content of the metadata cache unchanged. This is
734 * different from the metadata_regenerate where the offset from epoch is
735 * resampled, here we want the exact same content as the last time the metadata
736 * was generated. This command is only possible if all the metadata written
737 * in the cache has been output to the metadata stream to avoid corrupting the
738 * metadata file.
739 *
740 * Return 0 on success, a negative value on error.
741 */
742 static
743 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
744 {
745 int ret;
746 struct lttng_metadata_cache *cache = stream->metadata_cache;
747
748 mutex_lock(&cache->lock);
749 if (stream->metadata_out != cache->metadata_written) {
750 ret = -EBUSY;
751 goto end;
752 }
753 stream->metadata_out = 0;
754 stream->metadata_in = 0;
755 wake_up_interruptible(&stream->read_wait);
756 ret = 0;
757
758 end:
759 mutex_unlock(&cache->lock);
760 return ret;
761 }
762
763 static
764 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
765 unsigned int cmd, unsigned long arg)
766 {
767 int ret;
768 struct lttng_metadata_stream *stream = filp->private_data;
769 struct lib_ring_buffer *buf = stream->priv;
770
771 switch (cmd) {
772 case RING_BUFFER_GET_NEXT_SUBBUF:
773 {
774 struct lttng_metadata_stream *stream = filp->private_data;
775 struct lib_ring_buffer *buf = stream->priv;
776 struct channel *chan = buf->backend.chan;
777
778 ret = lttng_metadata_output_channel(stream, chan);
779 if (ret > 0) {
780 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
781 ret = 0;
782 } else if (ret < 0)
783 goto err;
784 break;
785 }
786 case RING_BUFFER_GET_SUBBUF:
787 {
788 /*
789 * Random access is not allowed for metadata channel.
790 */
791 return -ENOSYS;
792 }
793 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
794 case RING_BUFFER_FLUSH:
795 {
796 struct lttng_metadata_stream *stream = filp->private_data;
797 struct lib_ring_buffer *buf = stream->priv;
798 struct channel *chan = buf->backend.chan;
799
800 /*
801 * Before doing the actual ring buffer flush, write up to one
802 * packet of metadata in the ring buffer.
803 */
804 ret = lttng_metadata_output_channel(stream, chan);
805 if (ret < 0)
806 goto err;
807 break;
808 }
809 case RING_BUFFER_GET_METADATA_VERSION:
810 {
811 struct lttng_metadata_stream *stream = filp->private_data;
812
813 return put_u64(stream->version, arg);
814 }
815 case RING_BUFFER_METADATA_CACHE_DUMP:
816 {
817 struct lttng_metadata_stream *stream = filp->private_data;
818
819 return lttng_metadata_cache_dump(stream);
820 }
821 default:
822 break;
823 }
824 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
825
826 /* Performing lib ring buffer ioctl after our own. */
827 ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
828 if (ret < 0)
829 goto err;
830
831 switch (cmd) {
832 case RING_BUFFER_PUT_NEXT_SUBBUF:
833 {
834 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
835 cmd, arg);
836 break;
837 }
838 default:
839 break;
840 }
841 err:
842 return ret;
843 }
844
845 #ifdef CONFIG_COMPAT
846 static
847 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
848 unsigned int cmd, unsigned long arg)
849 {
850 int ret;
851 struct lttng_metadata_stream *stream = filp->private_data;
852 struct lib_ring_buffer *buf = stream->priv;
853
854 switch (cmd) {
855 case RING_BUFFER_GET_NEXT_SUBBUF:
856 {
857 struct lttng_metadata_stream *stream = filp->private_data;
858 struct lib_ring_buffer *buf = stream->priv;
859 struct channel *chan = buf->backend.chan;
860
861 ret = lttng_metadata_output_channel(stream, chan);
862 if (ret > 0) {
863 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
864 ret = 0;
865 } else if (ret < 0)
866 goto err;
867 break;
868 }
869 case RING_BUFFER_GET_SUBBUF:
870 {
871 /*
872 * Random access is not allowed for metadata channel.
873 */
874 return -ENOSYS;
875 }
876 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
877 case RING_BUFFER_FLUSH:
878 {
879 struct lttng_metadata_stream *stream = filp->private_data;
880 struct lib_ring_buffer *buf = stream->priv;
881 struct channel *chan = buf->backend.chan;
882
883 /*
884 * Before doing the actual ring buffer flush, write up to one
885 * packet of metadata in the ring buffer.
886 */
887 ret = lttng_metadata_output_channel(stream, chan);
888 if (ret < 0)
889 goto err;
890 break;
891 }
892 case RING_BUFFER_GET_METADATA_VERSION:
893 {
894 struct lttng_metadata_stream *stream = filp->private_data;
895
896 return put_u64(stream->version, arg);
897 }
898 case RING_BUFFER_METADATA_CACHE_DUMP:
899 {
900 struct lttng_metadata_stream *stream = filp->private_data;
901
902 return lttng_metadata_cache_dump(stream);
903 }
904 default:
905 break;
906 }
907 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
908
909 /* Performing lib ring buffer ioctl after our own. */
910 ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
911 if (ret < 0)
912 goto err;
913
914 switch (cmd) {
915 case RING_BUFFER_PUT_NEXT_SUBBUF:
916 {
917 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
918 cmd, arg);
919 break;
920 }
921 default:
922 break;
923 }
924 err:
925 return ret;
926 }
927 #endif
928
929 /*
930 * This is not used by anonymous file descriptors. This code is left
931 * there if we ever want to implement an inode with open() operation.
932 */
933 static
934 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
935 {
936 struct lttng_metadata_stream *stream = inode->i_private;
937 struct lib_ring_buffer *buf = stream->priv;
938
939 file->private_data = buf;
940 /*
941 * Since life-time of metadata cache differs from that of
942 * session, we need to keep our own reference on the transport.
943 */
944 if (!try_module_get(stream->transport->owner)) {
945 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
946 return -EBUSY;
947 }
948 return lib_ring_buffer_open(inode, file, buf);
949 }
950
951 static
952 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
953 {
954 struct lttng_metadata_stream *stream = file->private_data;
955 struct lib_ring_buffer *buf = stream->priv;
956
957 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
958 module_put(stream->transport->owner);
959 return lib_ring_buffer_release(inode, file, buf);
960 }
961
962 static
963 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
964 struct pipe_inode_info *pipe, size_t len,
965 unsigned int flags)
966 {
967 struct lttng_metadata_stream *stream = in->private_data;
968 struct lib_ring_buffer *buf = stream->priv;
969
970 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
971 flags, buf);
972 }
973
974 static
975 int lttng_metadata_ring_buffer_mmap(struct file *filp,
976 struct vm_area_struct *vma)
977 {
978 struct lttng_metadata_stream *stream = filp->private_data;
979 struct lib_ring_buffer *buf = stream->priv;
980
981 return lib_ring_buffer_mmap(filp, vma, buf);
982 }
983
984 static
985 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
986 .owner = THIS_MODULE,
987 .open = lttng_metadata_ring_buffer_open,
988 .release = lttng_metadata_ring_buffer_release,
989 .poll = lttng_metadata_ring_buffer_poll,
990 .splice_read = lttng_metadata_ring_buffer_splice_read,
991 .mmap = lttng_metadata_ring_buffer_mmap,
992 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
993 .llseek = vfs_lib_ring_buffer_no_llseek,
994 #ifdef CONFIG_COMPAT
995 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
996 #endif
997 };
998
999 static
1000 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
1001 const struct file_operations *fops)
1002 {
1003 int stream_fd, ret;
1004 struct file *stream_file;
1005
1006 stream_fd = lttng_get_unused_fd();
1007 if (stream_fd < 0) {
1008 ret = stream_fd;
1009 goto fd_error;
1010 }
1011 stream_file = anon_inode_getfile("[lttng_stream]", fops,
1012 stream_priv, O_RDWR);
1013 if (IS_ERR(stream_file)) {
1014 ret = PTR_ERR(stream_file);
1015 goto file_error;
1016 }
1017 /*
1018 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
1019 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
1020 * file descriptor, so we set FMODE_PREAD here.
1021 */
1022 stream_file->f_mode |= FMODE_PREAD;
1023 fd_install(stream_fd, stream_file);
1024 /*
1025 * The stream holds a reference to the channel within the generic ring
1026 * buffer library, so no need to hold a refcount on the channel and
1027 * session files here.
1028 */
1029 return stream_fd;
1030
1031 file_error:
1032 put_unused_fd(stream_fd);
1033 fd_error:
1034 return ret;
1035 }
1036
1037 static
1038 int lttng_abi_open_stream(struct file *channel_file)
1039 {
1040 struct lttng_channel *channel = channel_file->private_data;
1041 struct lib_ring_buffer *buf;
1042 int ret;
1043 void *stream_priv;
1044
1045 buf = channel->ops->buffer_read_open(channel->chan);
1046 if (!buf)
1047 return -ENOENT;
1048
1049 stream_priv = buf;
1050 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1051 &lttng_stream_ring_buffer_file_operations);
1052 if (ret < 0)
1053 goto fd_error;
1054
1055 return ret;
1056
1057 fd_error:
1058 channel->ops->buffer_read_close(buf);
1059 return ret;
1060 }
1061
1062 static
1063 int lttng_abi_open_metadata_stream(struct file *channel_file)
1064 {
1065 struct lttng_channel *channel = channel_file->private_data;
1066 struct lttng_session *session = channel->session;
1067 struct lib_ring_buffer *buf;
1068 int ret;
1069 struct lttng_metadata_stream *metadata_stream;
1070 void *stream_priv;
1071
1072 buf = channel->ops->buffer_read_open(channel->chan);
1073 if (!buf)
1074 return -ENOENT;
1075
1076 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1077 GFP_KERNEL);
1078 if (!metadata_stream) {
1079 ret = -ENOMEM;
1080 goto nomem;
1081 }
1082 metadata_stream->metadata_cache = session->metadata_cache;
1083 init_waitqueue_head(&metadata_stream->read_wait);
1084 metadata_stream->priv = buf;
1085 stream_priv = metadata_stream;
1086 metadata_stream->transport = channel->transport;
1087
1088 /*
1089 * Since life-time of metadata cache differs from that of
1090 * session, we need to keep our own reference on the transport.
1091 */
1092 if (!try_module_get(metadata_stream->transport->owner)) {
1093 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1094 ret = -EINVAL;
1095 goto notransport;
1096 }
1097
1098 if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1099 ret = -EOVERFLOW;
1100 goto kref_error;
1101 }
1102
1103 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1104 &lttng_metadata_ring_buffer_file_operations);
1105 if (ret < 0)
1106 goto fd_error;
1107
1108 list_add(&metadata_stream->list,
1109 &session->metadata_cache->metadata_stream);
1110 return ret;
1111
1112 fd_error:
1113 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1114 kref_error:
1115 module_put(metadata_stream->transport->owner);
1116 notransport:
1117 kfree(metadata_stream);
1118 nomem:
1119 channel->ops->buffer_read_close(buf);
1120 return ret;
1121 }
1122
1123 static
1124 int lttng_abi_create_event(struct file *channel_file,
1125 struct lttng_kernel_event *event_param)
1126 {
1127 struct lttng_channel *channel = channel_file->private_data;
1128 int event_fd, ret;
1129 struct file *event_file;
1130 void *priv;
1131
1132 event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1133 switch (event_param->instrumentation) {
1134 case LTTNG_KERNEL_KRETPROBE:
1135 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1136 break;
1137 case LTTNG_KERNEL_KPROBE:
1138 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1139 break;
1140 case LTTNG_KERNEL_FUNCTION:
1141 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1142 break;
1143 default:
1144 break;
1145 }
1146 event_fd = lttng_get_unused_fd();
1147 if (event_fd < 0) {
1148 ret = event_fd;
1149 goto fd_error;
1150 }
1151 event_file = anon_inode_getfile("[lttng_event]",
1152 &lttng_event_fops,
1153 NULL, O_RDWR);
1154 if (IS_ERR(event_file)) {
1155 ret = PTR_ERR(event_file);
1156 goto file_error;
1157 }
1158 /* The event holds a reference on the channel */
1159 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1160 ret = -EOVERFLOW;
1161 goto refcount_error;
1162 }
1163 if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1164 || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1165 struct lttng_enabler *enabler;
1166
1167 if (strutils_is_star_glob_pattern(event_param->name)) {
1168 /*
1169 * If the event name is a star globbing pattern,
1170 * we create the special star globbing enabler.
1171 */
1172 enabler = lttng_enabler_create(LTTNG_ENABLER_STAR_GLOB,
1173 event_param, channel);
1174 } else {
1175 enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
1176 event_param, channel);
1177 }
1178 priv = enabler;
1179 } else {
1180 struct lttng_event *event;
1181
1182 /*
1183 * We tolerate no failure path after event creation. It
1184 * will stay invariant for the rest of the session.
1185 */
1186 event = lttng_event_create(channel, event_param,
1187 NULL, NULL,
1188 event_param->instrumentation);
1189 WARN_ON_ONCE(!event);
1190 if (IS_ERR(event)) {
1191 ret = PTR_ERR(event);
1192 goto event_error;
1193 }
1194 priv = event;
1195 }
1196 event_file->private_data = priv;
1197 fd_install(event_fd, event_file);
1198 return event_fd;
1199
1200 event_error:
1201 atomic_long_dec(&channel_file->f_count);
1202 refcount_error:
1203 fput(event_file);
1204 file_error:
1205 put_unused_fd(event_fd);
1206 fd_error:
1207 return ret;
1208 }
1209
1210 /**
1211 * lttng_channel_ioctl - lttng syscall through ioctl
1212 *
1213 * @file: the file
1214 * @cmd: the command
1215 * @arg: command arg
1216 *
1217 * This ioctl implements lttng commands:
1218 * LTTNG_KERNEL_STREAM
1219 * Returns an event stream file descriptor or failure.
1220 * (typically, one event stream records events from one CPU)
1221 * LTTNG_KERNEL_EVENT
1222 * Returns an event file descriptor or failure.
1223 * LTTNG_KERNEL_CONTEXT
1224 * Prepend a context field to each event in the channel
1225 * LTTNG_KERNEL_ENABLE
1226 * Enable recording for events in this channel (weak enable)
1227 * LTTNG_KERNEL_DISABLE
1228 * Disable recording for events in this channel (strong disable)
1229 *
1230 * Channel and event file descriptors also hold a reference on the session.
1231 */
1232 static
1233 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1234 {
1235 struct lttng_channel *channel = file->private_data;
1236
1237 switch (cmd) {
1238 case LTTNG_KERNEL_OLD_STREAM:
1239 case LTTNG_KERNEL_STREAM:
1240 return lttng_abi_open_stream(file);
1241 case LTTNG_KERNEL_OLD_EVENT:
1242 {
1243 struct lttng_kernel_event *uevent_param;
1244 struct lttng_kernel_old_event *old_uevent_param;
1245 int ret;
1246
1247 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1248 GFP_KERNEL);
1249 if (!uevent_param) {
1250 ret = -ENOMEM;
1251 goto old_event_end;
1252 }
1253 old_uevent_param = kmalloc(
1254 sizeof(struct lttng_kernel_old_event),
1255 GFP_KERNEL);
1256 if (!old_uevent_param) {
1257 ret = -ENOMEM;
1258 goto old_event_error_free_param;
1259 }
1260 if (copy_from_user(old_uevent_param,
1261 (struct lttng_kernel_old_event __user *) arg,
1262 sizeof(struct lttng_kernel_old_event))) {
1263 ret = -EFAULT;
1264 goto old_event_error_free_old_param;
1265 }
1266
1267 memcpy(uevent_param->name, old_uevent_param->name,
1268 sizeof(uevent_param->name));
1269 uevent_param->instrumentation =
1270 old_uevent_param->instrumentation;
1271
1272 switch (old_uevent_param->instrumentation) {
1273 case LTTNG_KERNEL_KPROBE:
1274 uevent_param->u.kprobe.addr =
1275 old_uevent_param->u.kprobe.addr;
1276 uevent_param->u.kprobe.offset =
1277 old_uevent_param->u.kprobe.offset;
1278 memcpy(uevent_param->u.kprobe.symbol_name,
1279 old_uevent_param->u.kprobe.symbol_name,
1280 sizeof(uevent_param->u.kprobe.symbol_name));
1281 break;
1282 case LTTNG_KERNEL_KRETPROBE:
1283 uevent_param->u.kretprobe.addr =
1284 old_uevent_param->u.kretprobe.addr;
1285 uevent_param->u.kretprobe.offset =
1286 old_uevent_param->u.kretprobe.offset;
1287 memcpy(uevent_param->u.kretprobe.symbol_name,
1288 old_uevent_param->u.kretprobe.symbol_name,
1289 sizeof(uevent_param->u.kretprobe.symbol_name));
1290 break;
1291 case LTTNG_KERNEL_FUNCTION:
1292 memcpy(uevent_param->u.ftrace.symbol_name,
1293 old_uevent_param->u.ftrace.symbol_name,
1294 sizeof(uevent_param->u.ftrace.symbol_name));
1295 break;
1296 default:
1297 break;
1298 }
1299 ret = lttng_abi_create_event(file, uevent_param);
1300
1301 old_event_error_free_old_param:
1302 kfree(old_uevent_param);
1303 old_event_error_free_param:
1304 kfree(uevent_param);
1305 old_event_end:
1306 return ret;
1307 }
1308 case LTTNG_KERNEL_EVENT:
1309 {
1310 struct lttng_kernel_event uevent_param;
1311
1312 if (copy_from_user(&uevent_param,
1313 (struct lttng_kernel_event __user *) arg,
1314 sizeof(uevent_param)))
1315 return -EFAULT;
1316 return lttng_abi_create_event(file, &uevent_param);
1317 }
1318 case LTTNG_KERNEL_OLD_CONTEXT:
1319 {
1320 struct lttng_kernel_context *ucontext_param;
1321 struct lttng_kernel_old_context *old_ucontext_param;
1322 int ret;
1323
1324 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1325 GFP_KERNEL);
1326 if (!ucontext_param) {
1327 ret = -ENOMEM;
1328 goto old_ctx_end;
1329 }
1330 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1331 GFP_KERNEL);
1332 if (!old_ucontext_param) {
1333 ret = -ENOMEM;
1334 goto old_ctx_error_free_param;
1335 }
1336
1337 if (copy_from_user(old_ucontext_param,
1338 (struct lttng_kernel_old_context __user *) arg,
1339 sizeof(struct lttng_kernel_old_context))) {
1340 ret = -EFAULT;
1341 goto old_ctx_error_free_old_param;
1342 }
1343 ucontext_param->ctx = old_ucontext_param->ctx;
1344 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1345 sizeof(ucontext_param->padding));
1346 /* only type that uses the union */
1347 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1348 ucontext_param->u.perf_counter.type =
1349 old_ucontext_param->u.perf_counter.type;
1350 ucontext_param->u.perf_counter.config =
1351 old_ucontext_param->u.perf_counter.config;
1352 memcpy(ucontext_param->u.perf_counter.name,
1353 old_ucontext_param->u.perf_counter.name,
1354 sizeof(ucontext_param->u.perf_counter.name));
1355 }
1356
1357 ret = lttng_abi_add_context(file,
1358 ucontext_param,
1359 &channel->ctx, channel->session);
1360
1361 old_ctx_error_free_old_param:
1362 kfree(old_ucontext_param);
1363 old_ctx_error_free_param:
1364 kfree(ucontext_param);
1365 old_ctx_end:
1366 return ret;
1367 }
1368 case LTTNG_KERNEL_CONTEXT:
1369 {
1370 struct lttng_kernel_context ucontext_param;
1371
1372 if (copy_from_user(&ucontext_param,
1373 (struct lttng_kernel_context __user *) arg,
1374 sizeof(ucontext_param)))
1375 return -EFAULT;
1376 return lttng_abi_add_context(file,
1377 &ucontext_param,
1378 &channel->ctx, channel->session);
1379 }
1380 case LTTNG_KERNEL_OLD_ENABLE:
1381 case LTTNG_KERNEL_ENABLE:
1382 return lttng_channel_enable(channel);
1383 case LTTNG_KERNEL_OLD_DISABLE:
1384 case LTTNG_KERNEL_DISABLE:
1385 return lttng_channel_disable(channel);
1386 case LTTNG_KERNEL_SYSCALL_MASK:
1387 return lttng_channel_syscall_mask(channel,
1388 (struct lttng_kernel_syscall_mask __user *) arg);
1389 default:
1390 return -ENOIOCTLCMD;
1391 }
1392 }
1393
1394 /**
1395 * lttng_metadata_ioctl - lttng syscall through ioctl
1396 *
1397 * @file: the file
1398 * @cmd: the command
1399 * @arg: command arg
1400 *
1401 * This ioctl implements lttng commands:
1402 * LTTNG_KERNEL_STREAM
1403 * Returns an event stream file descriptor or failure.
1404 *
1405 * Channel and event file descriptors also hold a reference on the session.
1406 */
1407 static
1408 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1409 {
1410 switch (cmd) {
1411 case LTTNG_KERNEL_OLD_STREAM:
1412 case LTTNG_KERNEL_STREAM:
1413 return lttng_abi_open_metadata_stream(file);
1414 default:
1415 return -ENOIOCTLCMD;
1416 }
1417 }
1418
1419 /**
1420 * lttng_channel_poll - lttng stream addition/removal monitoring
1421 *
1422 * @file: the file
1423 * @wait: poll table
1424 */
1425 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1426 {
1427 struct lttng_channel *channel = file->private_data;
1428 unsigned int mask = 0;
1429
1430 if (file->f_mode & FMODE_READ) {
1431 poll_wait_set_exclusive(wait);
1432 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1433 wait);
1434
1435 if (channel->ops->is_disabled(channel->chan))
1436 return POLLERR;
1437 if (channel->ops->is_finalized(channel->chan))
1438 return POLLHUP;
1439 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1440 return POLLIN | POLLRDNORM;
1441 return 0;
1442 }
1443 return mask;
1444
1445 }
1446
1447 static
1448 int lttng_channel_release(struct inode *inode, struct file *file)
1449 {
1450 struct lttng_channel *channel = file->private_data;
1451
1452 if (channel)
1453 fput(channel->session->file);
1454 return 0;
1455 }
1456
1457 static
1458 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1459 {
1460 struct lttng_channel *channel = file->private_data;
1461
1462 if (channel) {
1463 fput(channel->session->file);
1464 lttng_metadata_channel_destroy(channel);
1465 }
1466
1467 return 0;
1468 }
1469
1470 static const struct file_operations lttng_channel_fops = {
1471 .owner = THIS_MODULE,
1472 .release = lttng_channel_release,
1473 .poll = lttng_channel_poll,
1474 .unlocked_ioctl = lttng_channel_ioctl,
1475 #ifdef CONFIG_COMPAT
1476 .compat_ioctl = lttng_channel_ioctl,
1477 #endif
1478 };
1479
1480 static const struct file_operations lttng_metadata_fops = {
1481 .owner = THIS_MODULE,
1482 .release = lttng_metadata_channel_release,
1483 .unlocked_ioctl = lttng_metadata_ioctl,
1484 #ifdef CONFIG_COMPAT
1485 .compat_ioctl = lttng_metadata_ioctl,
1486 #endif
1487 };
1488
1489 /**
1490 * lttng_event_ioctl - lttng syscall through ioctl
1491 *
1492 * @file: the file
1493 * @cmd: the command
1494 * @arg: command arg
1495 *
1496 * This ioctl implements lttng commands:
1497 * LTTNG_KERNEL_CONTEXT
1498 * Prepend a context field to each record of this event
1499 * LTTNG_KERNEL_ENABLE
1500 * Enable recording for this event (weak enable)
1501 * LTTNG_KERNEL_DISABLE
1502 * Disable recording for this event (strong disable)
1503 */
1504 static
1505 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1506 {
1507 struct lttng_event *event;
1508 struct lttng_enabler *enabler;
1509 enum lttng_event_type *evtype = file->private_data;
1510
1511 switch (cmd) {
1512 case LTTNG_KERNEL_OLD_CONTEXT:
1513 {
1514 /* Not implemented */
1515 return -ENOSYS;
1516 }
1517 case LTTNG_KERNEL_CONTEXT:
1518 {
1519 /* Not implemented */
1520 return -ENOSYS;
1521 }
1522 case LTTNG_KERNEL_OLD_ENABLE:
1523 case LTTNG_KERNEL_ENABLE:
1524 switch (*evtype) {
1525 case LTTNG_TYPE_EVENT:
1526 event = file->private_data;
1527 return lttng_event_enable(event);
1528 case LTTNG_TYPE_ENABLER:
1529 enabler = file->private_data;
1530 return lttng_enabler_enable(enabler);
1531 default:
1532 WARN_ON_ONCE(1);
1533 return -ENOSYS;
1534 }
1535 case LTTNG_KERNEL_OLD_DISABLE:
1536 case LTTNG_KERNEL_DISABLE:
1537 switch (*evtype) {
1538 case LTTNG_TYPE_EVENT:
1539 event = file->private_data;
1540 return lttng_event_disable(event);
1541 case LTTNG_TYPE_ENABLER:
1542 enabler = file->private_data;
1543 return lttng_enabler_disable(enabler);
1544 default:
1545 WARN_ON_ONCE(1);
1546 return -ENOSYS;
1547 }
1548 case LTTNG_KERNEL_FILTER:
1549 switch (*evtype) {
1550 case LTTNG_TYPE_EVENT:
1551 return -EINVAL;
1552 case LTTNG_TYPE_ENABLER:
1553 {
1554 enabler = file->private_data;
1555 return lttng_enabler_attach_bytecode(enabler,
1556 (struct lttng_kernel_filter_bytecode __user *) arg);
1557 }
1558 default:
1559 WARN_ON_ONCE(1);
1560 return -ENOSYS;
1561 }
1562 case LTTNG_KERNEL_ADD_CALLSITE:
1563 switch (*evtype) {
1564 case LTTNG_TYPE_EVENT:
1565 event = file->private_data;
1566 return lttng_event_add_callsite(event,
1567 (struct lttng_kernel_event_callsite __user *) arg);
1568 case LTTNG_TYPE_ENABLER:
1569 return -EINVAL;
1570 default:
1571 WARN_ON_ONCE(1);
1572 return -ENOSYS;
1573 }
1574 default:
1575 return -ENOIOCTLCMD;
1576 }
1577 }
1578
1579 static
1580 int lttng_event_release(struct inode *inode, struct file *file)
1581 {
1582 struct lttng_event *event;
1583 struct lttng_enabler *enabler;
1584 enum lttng_event_type *evtype = file->private_data;
1585
1586 if (!evtype)
1587 return 0;
1588
1589 switch (*evtype) {
1590 case LTTNG_TYPE_EVENT:
1591 event = file->private_data;
1592 if (event)
1593 fput(event->chan->file);
1594 break;
1595 case LTTNG_TYPE_ENABLER:
1596 enabler = file->private_data;
1597 if (enabler)
1598 fput(enabler->chan->file);
1599 break;
1600 default:
1601 WARN_ON_ONCE(1);
1602 break;
1603 }
1604
1605 return 0;
1606 }
1607
1608 /* TODO: filter control ioctl */
1609 static const struct file_operations lttng_event_fops = {
1610 .owner = THIS_MODULE,
1611 .release = lttng_event_release,
1612 .unlocked_ioctl = lttng_event_ioctl,
1613 #ifdef CONFIG_COMPAT
1614 .compat_ioctl = lttng_event_ioctl,
1615 #endif
1616 };
1617
1618 static int put_u64(uint64_t val, unsigned long arg)
1619 {
1620 return put_user(val, (uint64_t __user *) arg);
1621 }
1622
1623 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1624 unsigned int cmd, unsigned long arg)
1625 {
1626 struct lib_ring_buffer *buf = filp->private_data;
1627 struct channel *chan = buf->backend.chan;
1628 const struct lib_ring_buffer_config *config = &chan->backend.config;
1629 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1630 int ret;
1631
1632 if (atomic_read(&chan->record_disabled))
1633 return -EIO;
1634
1635 switch (cmd) {
1636 case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1637 {
1638 uint64_t ts;
1639
1640 ret = ops->timestamp_begin(config, buf, &ts);
1641 if (ret < 0)
1642 goto error;
1643 return put_u64(ts, arg);
1644 }
1645 case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1646 {
1647 uint64_t ts;
1648
1649 ret = ops->timestamp_end(config, buf, &ts);
1650 if (ret < 0)
1651 goto error;
1652 return put_u64(ts, arg);
1653 }
1654 case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1655 {
1656 uint64_t ed;
1657
1658 ret = ops->events_discarded(config, buf, &ed);
1659 if (ret < 0)
1660 goto error;
1661 return put_u64(ed, arg);
1662 }
1663 case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1664 {
1665 uint64_t cs;
1666
1667 ret = ops->content_size(config, buf, &cs);
1668 if (ret < 0)
1669 goto error;
1670 return put_u64(cs, arg);
1671 }
1672 case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1673 {
1674 uint64_t ps;
1675
1676 ret = ops->packet_size(config, buf, &ps);
1677 if (ret < 0)
1678 goto error;
1679 return put_u64(ps, arg);
1680 }
1681 case LTTNG_RING_BUFFER_GET_STREAM_ID:
1682 {
1683 uint64_t si;
1684
1685 ret = ops->stream_id(config, buf, &si);
1686 if (ret < 0)
1687 goto error;
1688 return put_u64(si, arg);
1689 }
1690 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1691 {
1692 uint64_t ts;
1693
1694 ret = ops->current_timestamp(config, buf, &ts);
1695 if (ret < 0)
1696 goto error;
1697 return put_u64(ts, arg);
1698 }
1699 case LTTNG_RING_BUFFER_GET_SEQ_NUM:
1700 {
1701 uint64_t seq;
1702
1703 ret = ops->sequence_number(config, buf, &seq);
1704 if (ret < 0)
1705 goto error;
1706 return put_u64(seq, arg);
1707 }
1708 case LTTNG_RING_BUFFER_INSTANCE_ID:
1709 {
1710 uint64_t id;
1711
1712 ret = ops->instance_id(config, buf, &id);
1713 if (ret < 0)
1714 goto error;
1715 return put_u64(id, arg);
1716 }
1717 default:
1718 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1719 cmd, arg);
1720 }
1721
1722 error:
1723 return -ENOSYS;
1724 }
1725
1726 #ifdef CONFIG_COMPAT
1727 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1728 unsigned int cmd, unsigned long arg)
1729 {
1730 struct lib_ring_buffer *buf = filp->private_data;
1731 struct channel *chan = buf->backend.chan;
1732 const struct lib_ring_buffer_config *config = &chan->backend.config;
1733 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1734 int ret;
1735
1736 if (atomic_read(&chan->record_disabled))
1737 return -EIO;
1738
1739 switch (cmd) {
1740 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1741 {
1742 uint64_t ts;
1743
1744 ret = ops->timestamp_begin(config, buf, &ts);
1745 if (ret < 0)
1746 goto error;
1747 return put_u64(ts, arg);
1748 }
1749 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1750 {
1751 uint64_t ts;
1752
1753 ret = ops->timestamp_end(config, buf, &ts);
1754 if (ret < 0)
1755 goto error;
1756 return put_u64(ts, arg);
1757 }
1758 case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1759 {
1760 uint64_t ed;
1761
1762 ret = ops->events_discarded(config, buf, &ed);
1763 if (ret < 0)
1764 goto error;
1765 return put_u64(ed, arg);
1766 }
1767 case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1768 {
1769 uint64_t cs;
1770
1771 ret = ops->content_size(config, buf, &cs);
1772 if (ret < 0)
1773 goto error;
1774 return put_u64(cs, arg);
1775 }
1776 case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1777 {
1778 uint64_t ps;
1779
1780 ret = ops->packet_size(config, buf, &ps);
1781 if (ret < 0)
1782 goto error;
1783 return put_u64(ps, arg);
1784 }
1785 case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1786 {
1787 uint64_t si;
1788
1789 ret = ops->stream_id(config, buf, &si);
1790 if (ret < 0)
1791 goto error;
1792 return put_u64(si, arg);
1793 }
1794 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1795 {
1796 uint64_t ts;
1797
1798 ret = ops->current_timestamp(config, buf, &ts);
1799 if (ret < 0)
1800 goto error;
1801 return put_u64(ts, arg);
1802 }
1803 case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
1804 {
1805 uint64_t seq;
1806
1807 ret = ops->sequence_number(config, buf, &seq);
1808 if (ret < 0)
1809 goto error;
1810 return put_u64(seq, arg);
1811 }
1812 case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
1813 {
1814 uint64_t id;
1815
1816 ret = ops->instance_id(config, buf, &id);
1817 if (ret < 0)
1818 goto error;
1819 return put_u64(id, arg);
1820 }
1821 default:
1822 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1823 cmd, arg);
1824 }
1825
1826 error:
1827 return -ENOSYS;
1828 }
1829 #endif /* CONFIG_COMPAT */
1830
1831 static void lttng_stream_override_ring_buffer_fops(void)
1832 {
1833 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1834 lttng_stream_ring_buffer_file_operations.open =
1835 lib_ring_buffer_file_operations.open;
1836 lttng_stream_ring_buffer_file_operations.release =
1837 lib_ring_buffer_file_operations.release;
1838 lttng_stream_ring_buffer_file_operations.poll =
1839 lib_ring_buffer_file_operations.poll;
1840 lttng_stream_ring_buffer_file_operations.splice_read =
1841 lib_ring_buffer_file_operations.splice_read;
1842 lttng_stream_ring_buffer_file_operations.mmap =
1843 lib_ring_buffer_file_operations.mmap;
1844 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1845 lttng_stream_ring_buffer_ioctl;
1846 lttng_stream_ring_buffer_file_operations.llseek =
1847 lib_ring_buffer_file_operations.llseek;
1848 #ifdef CONFIG_COMPAT
1849 lttng_stream_ring_buffer_file_operations.compat_ioctl =
1850 lttng_stream_ring_buffer_compat_ioctl;
1851 #endif
1852 }
1853
1854 int __init lttng_abi_init(void)
1855 {
1856 int ret = 0;
1857
1858 wrapper_vmalloc_sync_all();
1859 lttng_clock_ref();
1860
1861 ret = lttng_tp_mempool_init();
1862 if (ret) {
1863 goto error;
1864 }
1865
1866 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1867 &lttng_fops, NULL);
1868
1869 if (!lttng_proc_dentry) {
1870 printk(KERN_ERR "Error creating LTTng control file\n");
1871 ret = -ENOMEM;
1872 goto error;
1873 }
1874 lttng_stream_override_ring_buffer_fops();
1875 return 0;
1876
1877 error:
1878 lttng_tp_mempool_destroy();
1879 lttng_clock_unref();
1880 return ret;
1881 }
1882
1883 /* No __exit annotation because used by init error path too. */
1884 void lttng_abi_exit(void)
1885 {
1886 lttng_tp_mempool_destroy();
1887 lttng_clock_unref();
1888 if (lttng_proc_dentry)
1889 remove_proc_entry("lttng", NULL);
1890 }
LTTng 2.0/0.x modules
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