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Cleanup: statedump process state event pid namespace fields
[deliverable/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 /**
495 * lttng_session_ioctl - lttng session fd ioctl
496 *
497 * @file: the file
498 * @cmd: the command
499 * @arg: command arg
500 *
501 * This ioctl implements lttng commands:
502 * LTTNG_KERNEL_CHANNEL
503 * Returns a LTTng channel file descriptor
504 * LTTNG_KERNEL_ENABLE
505 * Enables tracing for a session (weak enable)
506 * LTTNG_KERNEL_DISABLE
507 * Disables tracing for a session (strong disable)
508 * LTTNG_KERNEL_METADATA
509 * Returns a LTTng metadata file descriptor
510 * LTTNG_KERNEL_SESSION_TRACK_PID
511 * Add PID to session tracker
512 * LTTNG_KERNEL_SESSION_UNTRACK_PID
513 * Remove PID from session tracker
514 *
515 * The returned channel will be deleted when its file descriptor is closed.
516 */
517 static
518 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
519 {
520 struct lttng_session *session = file->private_data;
521
522 switch (cmd) {
523 case LTTNG_KERNEL_OLD_CHANNEL:
524 {
525 struct lttng_kernel_channel chan_param;
526 struct lttng_kernel_old_channel old_chan_param;
527
528 if (copy_from_user(&old_chan_param,
529 (struct lttng_kernel_old_channel __user *) arg,
530 sizeof(struct lttng_kernel_old_channel)))
531 return -EFAULT;
532 chan_param.overwrite = old_chan_param.overwrite;
533 chan_param.subbuf_size = old_chan_param.subbuf_size;
534 chan_param.num_subbuf = old_chan_param.num_subbuf;
535 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
536 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
537 chan_param.output = old_chan_param.output;
538
539 return lttng_abi_create_channel(file, &chan_param,
540 PER_CPU_CHANNEL);
541 }
542 case LTTNG_KERNEL_CHANNEL:
543 {
544 struct lttng_kernel_channel chan_param;
545
546 if (copy_from_user(&chan_param,
547 (struct lttng_kernel_channel __user *) arg,
548 sizeof(struct lttng_kernel_channel)))
549 return -EFAULT;
550 return lttng_abi_create_channel(file, &chan_param,
551 PER_CPU_CHANNEL);
552 }
553 case LTTNG_KERNEL_OLD_SESSION_START:
554 case LTTNG_KERNEL_OLD_ENABLE:
555 case LTTNG_KERNEL_SESSION_START:
556 case LTTNG_KERNEL_ENABLE:
557 return lttng_session_enable(session);
558 case LTTNG_KERNEL_OLD_SESSION_STOP:
559 case LTTNG_KERNEL_OLD_DISABLE:
560 case LTTNG_KERNEL_SESSION_STOP:
561 case LTTNG_KERNEL_DISABLE:
562 return lttng_session_disable(session);
563 case LTTNG_KERNEL_OLD_METADATA:
564 {
565 struct lttng_kernel_channel chan_param;
566 struct lttng_kernel_old_channel old_chan_param;
567
568 if (copy_from_user(&old_chan_param,
569 (struct lttng_kernel_old_channel __user *) arg,
570 sizeof(struct lttng_kernel_old_channel)))
571 return -EFAULT;
572 chan_param.overwrite = old_chan_param.overwrite;
573 chan_param.subbuf_size = old_chan_param.subbuf_size;
574 chan_param.num_subbuf = old_chan_param.num_subbuf;
575 chan_param.switch_timer_interval = old_chan_param.switch_timer_interval;
576 chan_param.read_timer_interval = old_chan_param.read_timer_interval;
577 chan_param.output = old_chan_param.output;
578
579 return lttng_abi_create_channel(file, &chan_param,
580 METADATA_CHANNEL);
581 }
582 case LTTNG_KERNEL_METADATA:
583 {
584 struct lttng_kernel_channel chan_param;
585
586 if (copy_from_user(&chan_param,
587 (struct lttng_kernel_channel __user *) arg,
588 sizeof(struct lttng_kernel_channel)))
589 return -EFAULT;
590 return lttng_abi_create_channel(file, &chan_param,
591 METADATA_CHANNEL);
592 }
593 case LTTNG_KERNEL_SESSION_TRACK_PID:
594 return lttng_session_track_pid(session, (int) arg);
595 case LTTNG_KERNEL_SESSION_UNTRACK_PID:
596 return lttng_session_untrack_pid(session, (int) arg);
597 case LTTNG_KERNEL_SESSION_LIST_TRACKER_PIDS:
598 return lttng_session_list_tracker_pids(session);
599 case LTTNG_KERNEL_SESSION_METADATA_REGEN:
600 return lttng_session_metadata_regenerate(session);
601 case LTTNG_KERNEL_SESSION_STATEDUMP:
602 return lttng_session_statedump(session);
603 default:
604 return -ENOIOCTLCMD;
605 }
606 }
607
608 /*
609 * Called when the last file reference is dropped.
610 *
611 * Big fat note: channels and events are invariant for the whole session after
612 * their creation. So this session destruction also destroys all channel and
613 * event structures specific to this session (they are not destroyed when their
614 * individual file is released).
615 */
616 static
617 int lttng_session_release(struct inode *inode, struct file *file)
618 {
619 struct lttng_session *session = file->private_data;
620
621 if (session)
622 lttng_session_destroy(session);
623 return 0;
624 }
625
626 static const struct file_operations lttng_session_fops = {
627 .owner = THIS_MODULE,
628 .release = lttng_session_release,
629 .unlocked_ioctl = lttng_session_ioctl,
630 #ifdef CONFIG_COMPAT
631 .compat_ioctl = lttng_session_ioctl,
632 #endif
633 };
634
635 /**
636 * lttng_metadata_ring_buffer_poll - LTTng ring buffer poll file operation
637 * @filp: the file
638 * @wait: poll table
639 *
640 * Handles the poll operations for the metadata channels.
641 */
642 static
643 unsigned int lttng_metadata_ring_buffer_poll(struct file *filp,
644 poll_table *wait)
645 {
646 struct lttng_metadata_stream *stream = filp->private_data;
647 struct lib_ring_buffer *buf = stream->priv;
648 int finalized;
649 unsigned int mask = 0;
650
651 if (filp->f_mode & FMODE_READ) {
652 poll_wait_set_exclusive(wait);
653 poll_wait(filp, &stream->read_wait, wait);
654
655 finalized = stream->finalized;
656
657 /*
658 * lib_ring_buffer_is_finalized() contains a smp_rmb()
659 * ordering finalized load before offsets loads.
660 */
661 WARN_ON(atomic_long_read(&buf->active_readers) != 1);
662
663 if (finalized)
664 mask |= POLLHUP;
665
666 mutex_lock(&stream->metadata_cache->lock);
667 if (stream->metadata_cache->metadata_written >
668 stream->metadata_out)
669 mask |= POLLIN;
670 mutex_unlock(&stream->metadata_cache->lock);
671 }
672
673 return mask;
674 }
675
676 static
677 void lttng_metadata_ring_buffer_ioctl_put_next_subbuf(struct file *filp,
678 unsigned int cmd, unsigned long arg)
679 {
680 struct lttng_metadata_stream *stream = filp->private_data;
681
682 stream->metadata_out = stream->metadata_in;
683 }
684
685 /*
686 * Reset the counter of how much metadata has been consumed to 0. That way,
687 * the consumer receives the content of the metadata cache unchanged. This is
688 * different from the metadata_regenerate where the offset from epoch is
689 * resampled, here we want the exact same content as the last time the metadata
690 * was generated. This command is only possible if all the metadata written
691 * in the cache has been output to the metadata stream to avoid corrupting the
692 * metadata file.
693 *
694 * Return 0 on success, a negative value on error.
695 */
696 static
697 int lttng_metadata_cache_dump(struct lttng_metadata_stream *stream)
698 {
699 int ret;
700 struct lttng_metadata_cache *cache = stream->metadata_cache;
701
702 mutex_lock(&cache->lock);
703 if (stream->metadata_out != cache->metadata_written) {
704 ret = -EBUSY;
705 goto end;
706 }
707 stream->metadata_out = 0;
708 stream->metadata_in = 0;
709 wake_up_interruptible(&stream->read_wait);
710 ret = 0;
711
712 end:
713 mutex_unlock(&cache->lock);
714 return ret;
715 }
716
717 static
718 long lttng_metadata_ring_buffer_ioctl(struct file *filp,
719 unsigned int cmd, unsigned long arg)
720 {
721 int ret;
722 struct lttng_metadata_stream *stream = filp->private_data;
723 struct lib_ring_buffer *buf = stream->priv;
724
725 switch (cmd) {
726 case RING_BUFFER_GET_NEXT_SUBBUF:
727 {
728 struct lttng_metadata_stream *stream = filp->private_data;
729 struct lib_ring_buffer *buf = stream->priv;
730 struct channel *chan = buf->backend.chan;
731
732 ret = lttng_metadata_output_channel(stream, chan);
733 if (ret > 0) {
734 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
735 ret = 0;
736 } else if (ret < 0)
737 goto err;
738 break;
739 }
740 case RING_BUFFER_GET_SUBBUF:
741 {
742 /*
743 * Random access is not allowed for metadata channel.
744 */
745 return -ENOSYS;
746 }
747 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
748 case RING_BUFFER_FLUSH:
749 {
750 struct lttng_metadata_stream *stream = filp->private_data;
751 struct lib_ring_buffer *buf = stream->priv;
752 struct channel *chan = buf->backend.chan;
753
754 /*
755 * Before doing the actual ring buffer flush, write up to one
756 * packet of metadata in the ring buffer.
757 */
758 ret = lttng_metadata_output_channel(stream, chan);
759 if (ret < 0)
760 goto err;
761 break;
762 }
763 case RING_BUFFER_GET_METADATA_VERSION:
764 {
765 struct lttng_metadata_stream *stream = filp->private_data;
766
767 return put_u64(stream->version, arg);
768 }
769 case RING_BUFFER_METADATA_CACHE_DUMP:
770 {
771 struct lttng_metadata_stream *stream = filp->private_data;
772
773 return lttng_metadata_cache_dump(stream);
774 }
775 default:
776 break;
777 }
778 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
779
780 /* Performing lib ring buffer ioctl after our own. */
781 ret = lib_ring_buffer_ioctl(filp, cmd, arg, buf);
782 if (ret < 0)
783 goto err;
784
785 switch (cmd) {
786 case RING_BUFFER_PUT_NEXT_SUBBUF:
787 {
788 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
789 cmd, arg);
790 break;
791 }
792 default:
793 break;
794 }
795 err:
796 return ret;
797 }
798
799 #ifdef CONFIG_COMPAT
800 static
801 long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
802 unsigned int cmd, unsigned long arg)
803 {
804 int ret;
805 struct lttng_metadata_stream *stream = filp->private_data;
806 struct lib_ring_buffer *buf = stream->priv;
807
808 switch (cmd) {
809 case RING_BUFFER_GET_NEXT_SUBBUF:
810 {
811 struct lttng_metadata_stream *stream = filp->private_data;
812 struct lib_ring_buffer *buf = stream->priv;
813 struct channel *chan = buf->backend.chan;
814
815 ret = lttng_metadata_output_channel(stream, chan);
816 if (ret > 0) {
817 lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE);
818 ret = 0;
819 } else if (ret < 0)
820 goto err;
821 break;
822 }
823 case RING_BUFFER_GET_SUBBUF:
824 {
825 /*
826 * Random access is not allowed for metadata channel.
827 */
828 return -ENOSYS;
829 }
830 case RING_BUFFER_FLUSH_EMPTY: /* Fall-through. */
831 case RING_BUFFER_FLUSH:
832 {
833 struct lttng_metadata_stream *stream = filp->private_data;
834 struct lib_ring_buffer *buf = stream->priv;
835 struct channel *chan = buf->backend.chan;
836
837 /*
838 * Before doing the actual ring buffer flush, write up to one
839 * packet of metadata in the ring buffer.
840 */
841 ret = lttng_metadata_output_channel(stream, chan);
842 if (ret < 0)
843 goto err;
844 break;
845 }
846 case RING_BUFFER_GET_METADATA_VERSION:
847 {
848 struct lttng_metadata_stream *stream = filp->private_data;
849
850 return put_u64(stream->version, arg);
851 }
852 case RING_BUFFER_METADATA_CACHE_DUMP:
853 {
854 struct lttng_metadata_stream *stream = filp->private_data;
855
856 return lttng_metadata_cache_dump(stream);
857 }
858 default:
859 break;
860 }
861 /* PUT_SUBBUF is the one from lib ring buffer, unmodified. */
862
863 /* Performing lib ring buffer ioctl after our own. */
864 ret = lib_ring_buffer_compat_ioctl(filp, cmd, arg, buf);
865 if (ret < 0)
866 goto err;
867
868 switch (cmd) {
869 case RING_BUFFER_PUT_NEXT_SUBBUF:
870 {
871 lttng_metadata_ring_buffer_ioctl_put_next_subbuf(filp,
872 cmd, arg);
873 break;
874 }
875 default:
876 break;
877 }
878 err:
879 return ret;
880 }
881 #endif
882
883 /*
884 * This is not used by anonymous file descriptors. This code is left
885 * there if we ever want to implement an inode with open() operation.
886 */
887 static
888 int lttng_metadata_ring_buffer_open(struct inode *inode, struct file *file)
889 {
890 struct lttng_metadata_stream *stream = inode->i_private;
891 struct lib_ring_buffer *buf = stream->priv;
892
893 file->private_data = buf;
894 /*
895 * Since life-time of metadata cache differs from that of
896 * session, we need to keep our own reference on the transport.
897 */
898 if (!try_module_get(stream->transport->owner)) {
899 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
900 return -EBUSY;
901 }
902 return lib_ring_buffer_open(inode, file, buf);
903 }
904
905 static
906 int lttng_metadata_ring_buffer_release(struct inode *inode, struct file *file)
907 {
908 struct lttng_metadata_stream *stream = file->private_data;
909 struct lib_ring_buffer *buf = stream->priv;
910
911 kref_put(&stream->metadata_cache->refcount, metadata_cache_destroy);
912 module_put(stream->transport->owner);
913 return lib_ring_buffer_release(inode, file, buf);
914 }
915
916 static
917 ssize_t lttng_metadata_ring_buffer_splice_read(struct file *in, loff_t *ppos,
918 struct pipe_inode_info *pipe, size_t len,
919 unsigned int flags)
920 {
921 struct lttng_metadata_stream *stream = in->private_data;
922 struct lib_ring_buffer *buf = stream->priv;
923
924 return lib_ring_buffer_splice_read(in, ppos, pipe, len,
925 flags, buf);
926 }
927
928 static
929 int lttng_metadata_ring_buffer_mmap(struct file *filp,
930 struct vm_area_struct *vma)
931 {
932 struct lttng_metadata_stream *stream = filp->private_data;
933 struct lib_ring_buffer *buf = stream->priv;
934
935 return lib_ring_buffer_mmap(filp, vma, buf);
936 }
937
938 static
939 const struct file_operations lttng_metadata_ring_buffer_file_operations = {
940 .owner = THIS_MODULE,
941 .open = lttng_metadata_ring_buffer_open,
942 .release = lttng_metadata_ring_buffer_release,
943 .poll = lttng_metadata_ring_buffer_poll,
944 .splice_read = lttng_metadata_ring_buffer_splice_read,
945 .mmap = lttng_metadata_ring_buffer_mmap,
946 .unlocked_ioctl = lttng_metadata_ring_buffer_ioctl,
947 .llseek = vfs_lib_ring_buffer_no_llseek,
948 #ifdef CONFIG_COMPAT
949 .compat_ioctl = lttng_metadata_ring_buffer_compat_ioctl,
950 #endif
951 };
952
953 static
954 int lttng_abi_create_stream_fd(struct file *channel_file, void *stream_priv,
955 const struct file_operations *fops)
956 {
957 int stream_fd, ret;
958 struct file *stream_file;
959
960 stream_fd = lttng_get_unused_fd();
961 if (stream_fd < 0) {
962 ret = stream_fd;
963 goto fd_error;
964 }
965 stream_file = anon_inode_getfile("[lttng_stream]", fops,
966 stream_priv, O_RDWR);
967 if (IS_ERR(stream_file)) {
968 ret = PTR_ERR(stream_file);
969 goto file_error;
970 }
971 /*
972 * OPEN_FMODE, called within anon_inode_getfile/alloc_file, don't honor
973 * FMODE_LSEEK, FMODE_PREAD nor FMODE_PWRITE. We need to read from this
974 * file descriptor, so we set FMODE_PREAD here.
975 */
976 stream_file->f_mode |= FMODE_PREAD;
977 fd_install(stream_fd, stream_file);
978 /*
979 * The stream holds a reference to the channel within the generic ring
980 * buffer library, so no need to hold a refcount on the channel and
981 * session files here.
982 */
983 return stream_fd;
984
985 file_error:
986 put_unused_fd(stream_fd);
987 fd_error:
988 return ret;
989 }
990
991 static
992 int lttng_abi_open_stream(struct file *channel_file)
993 {
994 struct lttng_channel *channel = channel_file->private_data;
995 struct lib_ring_buffer *buf;
996 int ret;
997 void *stream_priv;
998
999 buf = channel->ops->buffer_read_open(channel->chan);
1000 if (!buf)
1001 return -ENOENT;
1002
1003 stream_priv = buf;
1004 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1005 &lttng_stream_ring_buffer_file_operations);
1006 if (ret < 0)
1007 goto fd_error;
1008
1009 return ret;
1010
1011 fd_error:
1012 channel->ops->buffer_read_close(buf);
1013 return ret;
1014 }
1015
1016 static
1017 int lttng_abi_open_metadata_stream(struct file *channel_file)
1018 {
1019 struct lttng_channel *channel = channel_file->private_data;
1020 struct lttng_session *session = channel->session;
1021 struct lib_ring_buffer *buf;
1022 int ret;
1023 struct lttng_metadata_stream *metadata_stream;
1024 void *stream_priv;
1025
1026 buf = channel->ops->buffer_read_open(channel->chan);
1027 if (!buf)
1028 return -ENOENT;
1029
1030 metadata_stream = kzalloc(sizeof(struct lttng_metadata_stream),
1031 GFP_KERNEL);
1032 if (!metadata_stream) {
1033 ret = -ENOMEM;
1034 goto nomem;
1035 }
1036 metadata_stream->metadata_cache = session->metadata_cache;
1037 init_waitqueue_head(&metadata_stream->read_wait);
1038 metadata_stream->priv = buf;
1039 stream_priv = metadata_stream;
1040 metadata_stream->transport = channel->transport;
1041
1042 /*
1043 * Since life-time of metadata cache differs from that of
1044 * session, we need to keep our own reference on the transport.
1045 */
1046 if (!try_module_get(metadata_stream->transport->owner)) {
1047 printk(KERN_WARNING "LTT : Can't lock transport module.\n");
1048 ret = -EINVAL;
1049 goto notransport;
1050 }
1051
1052 if (!lttng_kref_get(&session->metadata_cache->refcount)) {
1053 ret = -EOVERFLOW;
1054 goto kref_error;
1055 }
1056
1057 ret = lttng_abi_create_stream_fd(channel_file, stream_priv,
1058 &lttng_metadata_ring_buffer_file_operations);
1059 if (ret < 0)
1060 goto fd_error;
1061
1062 list_add(&metadata_stream->list,
1063 &session->metadata_cache->metadata_stream);
1064 return ret;
1065
1066 fd_error:
1067 kref_put(&session->metadata_cache->refcount, metadata_cache_destroy);
1068 kref_error:
1069 module_put(metadata_stream->transport->owner);
1070 notransport:
1071 kfree(metadata_stream);
1072 nomem:
1073 channel->ops->buffer_read_close(buf);
1074 return ret;
1075 }
1076
1077 static
1078 int lttng_abi_create_event(struct file *channel_file,
1079 struct lttng_kernel_event *event_param)
1080 {
1081 struct lttng_channel *channel = channel_file->private_data;
1082 int event_fd, ret;
1083 struct file *event_file;
1084 void *priv;
1085
1086 event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1087 switch (event_param->instrumentation) {
1088 case LTTNG_KERNEL_KRETPROBE:
1089 event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1090 break;
1091 case LTTNG_KERNEL_KPROBE:
1092 event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1093 break;
1094 case LTTNG_KERNEL_FUNCTION:
1095 event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
1096 break;
1097 default:
1098 break;
1099 }
1100 event_fd = lttng_get_unused_fd();
1101 if (event_fd < 0) {
1102 ret = event_fd;
1103 goto fd_error;
1104 }
1105 event_file = anon_inode_getfile("[lttng_event]",
1106 &lttng_event_fops,
1107 NULL, O_RDWR);
1108 if (IS_ERR(event_file)) {
1109 ret = PTR_ERR(event_file);
1110 goto file_error;
1111 }
1112 /* The event holds a reference on the channel */
1113 if (!atomic_long_add_unless(&channel_file->f_count, 1, LONG_MAX)) {
1114 ret = -EOVERFLOW;
1115 goto refcount_error;
1116 }
1117 if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
1118 || event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
1119 struct lttng_enabler *enabler;
1120
1121 if (strutils_is_star_glob_pattern(event_param->name)) {
1122 /*
1123 * If the event name is a star globbing pattern,
1124 * we create the special star globbing enabler.
1125 */
1126 enabler = lttng_enabler_create(LTTNG_ENABLER_STAR_GLOB,
1127 event_param, channel);
1128 } else {
1129 enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
1130 event_param, channel);
1131 }
1132 priv = enabler;
1133 } else {
1134 struct lttng_event *event;
1135
1136 /*
1137 * We tolerate no failure path after event creation. It
1138 * will stay invariant for the rest of the session.
1139 */
1140 event = lttng_event_create(channel, event_param,
1141 NULL, NULL,
1142 event_param->instrumentation);
1143 WARN_ON_ONCE(!event);
1144 if (IS_ERR(event)) {
1145 ret = PTR_ERR(event);
1146 goto event_error;
1147 }
1148 priv = event;
1149 }
1150 event_file->private_data = priv;
1151 fd_install(event_fd, event_file);
1152 return event_fd;
1153
1154 event_error:
1155 atomic_long_dec(&channel_file->f_count);
1156 refcount_error:
1157 fput(event_file);
1158 file_error:
1159 put_unused_fd(event_fd);
1160 fd_error:
1161 return ret;
1162 }
1163
1164 /**
1165 * lttng_channel_ioctl - lttng syscall through ioctl
1166 *
1167 * @file: the file
1168 * @cmd: the command
1169 * @arg: command arg
1170 *
1171 * This ioctl implements lttng commands:
1172 * LTTNG_KERNEL_STREAM
1173 * Returns an event stream file descriptor or failure.
1174 * (typically, one event stream records events from one CPU)
1175 * LTTNG_KERNEL_EVENT
1176 * Returns an event file descriptor or failure.
1177 * LTTNG_KERNEL_CONTEXT
1178 * Prepend a context field to each event in the channel
1179 * LTTNG_KERNEL_ENABLE
1180 * Enable recording for events in this channel (weak enable)
1181 * LTTNG_KERNEL_DISABLE
1182 * Disable recording for events in this channel (strong disable)
1183 *
1184 * Channel and event file descriptors also hold a reference on the session.
1185 */
1186 static
1187 long lttng_channel_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1188 {
1189 struct lttng_channel *channel = file->private_data;
1190
1191 switch (cmd) {
1192 case LTTNG_KERNEL_OLD_STREAM:
1193 case LTTNG_KERNEL_STREAM:
1194 return lttng_abi_open_stream(file);
1195 case LTTNG_KERNEL_OLD_EVENT:
1196 {
1197 struct lttng_kernel_event *uevent_param;
1198 struct lttng_kernel_old_event *old_uevent_param;
1199 int ret;
1200
1201 uevent_param = kmalloc(sizeof(struct lttng_kernel_event),
1202 GFP_KERNEL);
1203 if (!uevent_param) {
1204 ret = -ENOMEM;
1205 goto old_event_end;
1206 }
1207 old_uevent_param = kmalloc(
1208 sizeof(struct lttng_kernel_old_event),
1209 GFP_KERNEL);
1210 if (!old_uevent_param) {
1211 ret = -ENOMEM;
1212 goto old_event_error_free_param;
1213 }
1214 if (copy_from_user(old_uevent_param,
1215 (struct lttng_kernel_old_event __user *) arg,
1216 sizeof(struct lttng_kernel_old_event))) {
1217 ret = -EFAULT;
1218 goto old_event_error_free_old_param;
1219 }
1220
1221 memcpy(uevent_param->name, old_uevent_param->name,
1222 sizeof(uevent_param->name));
1223 uevent_param->instrumentation =
1224 old_uevent_param->instrumentation;
1225
1226 switch (old_uevent_param->instrumentation) {
1227 case LTTNG_KERNEL_KPROBE:
1228 uevent_param->u.kprobe.addr =
1229 old_uevent_param->u.kprobe.addr;
1230 uevent_param->u.kprobe.offset =
1231 old_uevent_param->u.kprobe.offset;
1232 memcpy(uevent_param->u.kprobe.symbol_name,
1233 old_uevent_param->u.kprobe.symbol_name,
1234 sizeof(uevent_param->u.kprobe.symbol_name));
1235 break;
1236 case LTTNG_KERNEL_KRETPROBE:
1237 uevent_param->u.kretprobe.addr =
1238 old_uevent_param->u.kretprobe.addr;
1239 uevent_param->u.kretprobe.offset =
1240 old_uevent_param->u.kretprobe.offset;
1241 memcpy(uevent_param->u.kretprobe.symbol_name,
1242 old_uevent_param->u.kretprobe.symbol_name,
1243 sizeof(uevent_param->u.kretprobe.symbol_name));
1244 break;
1245 case LTTNG_KERNEL_FUNCTION:
1246 memcpy(uevent_param->u.ftrace.symbol_name,
1247 old_uevent_param->u.ftrace.symbol_name,
1248 sizeof(uevent_param->u.ftrace.symbol_name));
1249 break;
1250 default:
1251 break;
1252 }
1253 ret = lttng_abi_create_event(file, uevent_param);
1254
1255 old_event_error_free_old_param:
1256 kfree(old_uevent_param);
1257 old_event_error_free_param:
1258 kfree(uevent_param);
1259 old_event_end:
1260 return ret;
1261 }
1262 case LTTNG_KERNEL_EVENT:
1263 {
1264 struct lttng_kernel_event uevent_param;
1265
1266 if (copy_from_user(&uevent_param,
1267 (struct lttng_kernel_event __user *) arg,
1268 sizeof(uevent_param)))
1269 return -EFAULT;
1270 return lttng_abi_create_event(file, &uevent_param);
1271 }
1272 case LTTNG_KERNEL_OLD_CONTEXT:
1273 {
1274 struct lttng_kernel_context *ucontext_param;
1275 struct lttng_kernel_old_context *old_ucontext_param;
1276 int ret;
1277
1278 ucontext_param = kmalloc(sizeof(struct lttng_kernel_context),
1279 GFP_KERNEL);
1280 if (!ucontext_param) {
1281 ret = -ENOMEM;
1282 goto old_ctx_end;
1283 }
1284 old_ucontext_param = kmalloc(sizeof(struct lttng_kernel_old_context),
1285 GFP_KERNEL);
1286 if (!old_ucontext_param) {
1287 ret = -ENOMEM;
1288 goto old_ctx_error_free_param;
1289 }
1290
1291 if (copy_from_user(old_ucontext_param,
1292 (struct lttng_kernel_old_context __user *) arg,
1293 sizeof(struct lttng_kernel_old_context))) {
1294 ret = -EFAULT;
1295 goto old_ctx_error_free_old_param;
1296 }
1297 ucontext_param->ctx = old_ucontext_param->ctx;
1298 memcpy(ucontext_param->padding, old_ucontext_param->padding,
1299 sizeof(ucontext_param->padding));
1300 /* only type that uses the union */
1301 if (old_ucontext_param->ctx == LTTNG_KERNEL_CONTEXT_PERF_COUNTER) {
1302 ucontext_param->u.perf_counter.type =
1303 old_ucontext_param->u.perf_counter.type;
1304 ucontext_param->u.perf_counter.config =
1305 old_ucontext_param->u.perf_counter.config;
1306 memcpy(ucontext_param->u.perf_counter.name,
1307 old_ucontext_param->u.perf_counter.name,
1308 sizeof(ucontext_param->u.perf_counter.name));
1309 }
1310
1311 ret = lttng_abi_add_context(file,
1312 ucontext_param,
1313 &channel->ctx, channel->session);
1314
1315 old_ctx_error_free_old_param:
1316 kfree(old_ucontext_param);
1317 old_ctx_error_free_param:
1318 kfree(ucontext_param);
1319 old_ctx_end:
1320 return ret;
1321 }
1322 case LTTNG_KERNEL_CONTEXT:
1323 {
1324 struct lttng_kernel_context ucontext_param;
1325
1326 if (copy_from_user(&ucontext_param,
1327 (struct lttng_kernel_context __user *) arg,
1328 sizeof(ucontext_param)))
1329 return -EFAULT;
1330 return lttng_abi_add_context(file,
1331 &ucontext_param,
1332 &channel->ctx, channel->session);
1333 }
1334 case LTTNG_KERNEL_OLD_ENABLE:
1335 case LTTNG_KERNEL_ENABLE:
1336 return lttng_channel_enable(channel);
1337 case LTTNG_KERNEL_OLD_DISABLE:
1338 case LTTNG_KERNEL_DISABLE:
1339 return lttng_channel_disable(channel);
1340 case LTTNG_KERNEL_SYSCALL_MASK:
1341 return lttng_channel_syscall_mask(channel,
1342 (struct lttng_kernel_syscall_mask __user *) arg);
1343 default:
1344 return -ENOIOCTLCMD;
1345 }
1346 }
1347
1348 /**
1349 * lttng_metadata_ioctl - lttng syscall through ioctl
1350 *
1351 * @file: the file
1352 * @cmd: the command
1353 * @arg: command arg
1354 *
1355 * This ioctl implements lttng commands:
1356 * LTTNG_KERNEL_STREAM
1357 * Returns an event stream file descriptor or failure.
1358 *
1359 * Channel and event file descriptors also hold a reference on the session.
1360 */
1361 static
1362 long lttng_metadata_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1363 {
1364 switch (cmd) {
1365 case LTTNG_KERNEL_OLD_STREAM:
1366 case LTTNG_KERNEL_STREAM:
1367 return lttng_abi_open_metadata_stream(file);
1368 default:
1369 return -ENOIOCTLCMD;
1370 }
1371 }
1372
1373 /**
1374 * lttng_channel_poll - lttng stream addition/removal monitoring
1375 *
1376 * @file: the file
1377 * @wait: poll table
1378 */
1379 unsigned int lttng_channel_poll(struct file *file, poll_table *wait)
1380 {
1381 struct lttng_channel *channel = file->private_data;
1382 unsigned int mask = 0;
1383
1384 if (file->f_mode & FMODE_READ) {
1385 poll_wait_set_exclusive(wait);
1386 poll_wait(file, channel->ops->get_hp_wait_queue(channel->chan),
1387 wait);
1388
1389 if (channel->ops->is_disabled(channel->chan))
1390 return POLLERR;
1391 if (channel->ops->is_finalized(channel->chan))
1392 return POLLHUP;
1393 if (channel->ops->buffer_has_read_closed_stream(channel->chan))
1394 return POLLIN | POLLRDNORM;
1395 return 0;
1396 }
1397 return mask;
1398
1399 }
1400
1401 static
1402 int lttng_channel_release(struct inode *inode, struct file *file)
1403 {
1404 struct lttng_channel *channel = file->private_data;
1405
1406 if (channel)
1407 fput(channel->session->file);
1408 return 0;
1409 }
1410
1411 static
1412 int lttng_metadata_channel_release(struct inode *inode, struct file *file)
1413 {
1414 struct lttng_channel *channel = file->private_data;
1415
1416 if (channel) {
1417 fput(channel->session->file);
1418 lttng_metadata_channel_destroy(channel);
1419 }
1420
1421 return 0;
1422 }
1423
1424 static const struct file_operations lttng_channel_fops = {
1425 .owner = THIS_MODULE,
1426 .release = lttng_channel_release,
1427 .poll = lttng_channel_poll,
1428 .unlocked_ioctl = lttng_channel_ioctl,
1429 #ifdef CONFIG_COMPAT
1430 .compat_ioctl = lttng_channel_ioctl,
1431 #endif
1432 };
1433
1434 static const struct file_operations lttng_metadata_fops = {
1435 .owner = THIS_MODULE,
1436 .release = lttng_metadata_channel_release,
1437 .unlocked_ioctl = lttng_metadata_ioctl,
1438 #ifdef CONFIG_COMPAT
1439 .compat_ioctl = lttng_metadata_ioctl,
1440 #endif
1441 };
1442
1443 /**
1444 * lttng_event_ioctl - lttng syscall through ioctl
1445 *
1446 * @file: the file
1447 * @cmd: the command
1448 * @arg: command arg
1449 *
1450 * This ioctl implements lttng commands:
1451 * LTTNG_KERNEL_CONTEXT
1452 * Prepend a context field to each record of this event
1453 * LTTNG_KERNEL_ENABLE
1454 * Enable recording for this event (weak enable)
1455 * LTTNG_KERNEL_DISABLE
1456 * Disable recording for this event (strong disable)
1457 */
1458 static
1459 long lttng_event_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1460 {
1461 struct lttng_event *event;
1462 struct lttng_enabler *enabler;
1463 enum lttng_event_type *evtype = file->private_data;
1464
1465 switch (cmd) {
1466 case LTTNG_KERNEL_OLD_CONTEXT:
1467 {
1468 /* Not implemented */
1469 return -ENOSYS;
1470 }
1471 case LTTNG_KERNEL_CONTEXT:
1472 {
1473 /* Not implemented */
1474 return -ENOSYS;
1475 }
1476 case LTTNG_KERNEL_OLD_ENABLE:
1477 case LTTNG_KERNEL_ENABLE:
1478 switch (*evtype) {
1479 case LTTNG_TYPE_EVENT:
1480 event = file->private_data;
1481 return lttng_event_enable(event);
1482 case LTTNG_TYPE_ENABLER:
1483 enabler = file->private_data;
1484 return lttng_enabler_enable(enabler);
1485 default:
1486 WARN_ON_ONCE(1);
1487 return -ENOSYS;
1488 }
1489 case LTTNG_KERNEL_OLD_DISABLE:
1490 case LTTNG_KERNEL_DISABLE:
1491 switch (*evtype) {
1492 case LTTNG_TYPE_EVENT:
1493 event = file->private_data;
1494 return lttng_event_disable(event);
1495 case LTTNG_TYPE_ENABLER:
1496 enabler = file->private_data;
1497 return lttng_enabler_disable(enabler);
1498 default:
1499 WARN_ON_ONCE(1);
1500 return -ENOSYS;
1501 }
1502 case LTTNG_KERNEL_FILTER:
1503 switch (*evtype) {
1504 case LTTNG_TYPE_EVENT:
1505 return -EINVAL;
1506 case LTTNG_TYPE_ENABLER:
1507 {
1508 enabler = file->private_data;
1509 return lttng_enabler_attach_bytecode(enabler,
1510 (struct lttng_kernel_filter_bytecode __user *) arg);
1511 }
1512 default:
1513 WARN_ON_ONCE(1);
1514 return -ENOSYS;
1515 }
1516 case LTTNG_KERNEL_ADD_CALLSITE:
1517 switch (*evtype) {
1518 case LTTNG_TYPE_EVENT:
1519 event = file->private_data;
1520 return lttng_event_add_callsite(event,
1521 (struct lttng_kernel_event_callsite __user *) arg);
1522 case LTTNG_TYPE_ENABLER:
1523 return -EINVAL;
1524 }
1525 default:
1526 return -ENOIOCTLCMD;
1527 }
1528 }
1529
1530 static
1531 int lttng_event_release(struct inode *inode, struct file *file)
1532 {
1533 struct lttng_event *event;
1534 struct lttng_enabler *enabler;
1535 enum lttng_event_type *evtype = file->private_data;
1536
1537 if (!evtype)
1538 return 0;
1539
1540 switch (*evtype) {
1541 case LTTNG_TYPE_EVENT:
1542 event = file->private_data;
1543 if (event)
1544 fput(event->chan->file);
1545 break;
1546 case LTTNG_TYPE_ENABLER:
1547 enabler = file->private_data;
1548 if (enabler)
1549 fput(enabler->chan->file);
1550 break;
1551 default:
1552 WARN_ON_ONCE(1);
1553 break;
1554 }
1555
1556 return 0;
1557 }
1558
1559 /* TODO: filter control ioctl */
1560 static const struct file_operations lttng_event_fops = {
1561 .owner = THIS_MODULE,
1562 .release = lttng_event_release,
1563 .unlocked_ioctl = lttng_event_ioctl,
1564 #ifdef CONFIG_COMPAT
1565 .compat_ioctl = lttng_event_ioctl,
1566 #endif
1567 };
1568
1569 static int put_u64(uint64_t val, unsigned long arg)
1570 {
1571 return put_user(val, (uint64_t __user *) arg);
1572 }
1573
1574 static long lttng_stream_ring_buffer_ioctl(struct file *filp,
1575 unsigned int cmd, unsigned long arg)
1576 {
1577 struct lib_ring_buffer *buf = filp->private_data;
1578 struct channel *chan = buf->backend.chan;
1579 const struct lib_ring_buffer_config *config = &chan->backend.config;
1580 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1581 int ret;
1582
1583 if (atomic_read(&chan->record_disabled))
1584 return -EIO;
1585
1586 switch (cmd) {
1587 case LTTNG_RING_BUFFER_GET_TIMESTAMP_BEGIN:
1588 {
1589 uint64_t ts;
1590
1591 ret = ops->timestamp_begin(config, buf, &ts);
1592 if (ret < 0)
1593 goto error;
1594 return put_u64(ts, arg);
1595 }
1596 case LTTNG_RING_BUFFER_GET_TIMESTAMP_END:
1597 {
1598 uint64_t ts;
1599
1600 ret = ops->timestamp_end(config, buf, &ts);
1601 if (ret < 0)
1602 goto error;
1603 return put_u64(ts, arg);
1604 }
1605 case LTTNG_RING_BUFFER_GET_EVENTS_DISCARDED:
1606 {
1607 uint64_t ed;
1608
1609 ret = ops->events_discarded(config, buf, &ed);
1610 if (ret < 0)
1611 goto error;
1612 return put_u64(ed, arg);
1613 }
1614 case LTTNG_RING_BUFFER_GET_CONTENT_SIZE:
1615 {
1616 uint64_t cs;
1617
1618 ret = ops->content_size(config, buf, &cs);
1619 if (ret < 0)
1620 goto error;
1621 return put_u64(cs, arg);
1622 }
1623 case LTTNG_RING_BUFFER_GET_PACKET_SIZE:
1624 {
1625 uint64_t ps;
1626
1627 ret = ops->packet_size(config, buf, &ps);
1628 if (ret < 0)
1629 goto error;
1630 return put_u64(ps, arg);
1631 }
1632 case LTTNG_RING_BUFFER_GET_STREAM_ID:
1633 {
1634 uint64_t si;
1635
1636 ret = ops->stream_id(config, buf, &si);
1637 if (ret < 0)
1638 goto error;
1639 return put_u64(si, arg);
1640 }
1641 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1642 {
1643 uint64_t ts;
1644
1645 ret = ops->current_timestamp(config, buf, &ts);
1646 if (ret < 0)
1647 goto error;
1648 return put_u64(ts, arg);
1649 }
1650 case LTTNG_RING_BUFFER_GET_SEQ_NUM:
1651 {
1652 uint64_t seq;
1653
1654 ret = ops->sequence_number(config, buf, &seq);
1655 if (ret < 0)
1656 goto error;
1657 return put_u64(seq, arg);
1658 }
1659 case LTTNG_RING_BUFFER_INSTANCE_ID:
1660 {
1661 uint64_t id;
1662
1663 ret = ops->instance_id(config, buf, &id);
1664 if (ret < 0)
1665 goto error;
1666 return put_u64(id, arg);
1667 }
1668 default:
1669 return lib_ring_buffer_file_operations.unlocked_ioctl(filp,
1670 cmd, arg);
1671 }
1672
1673 error:
1674 return -ENOSYS;
1675 }
1676
1677 #ifdef CONFIG_COMPAT
1678 static long lttng_stream_ring_buffer_compat_ioctl(struct file *filp,
1679 unsigned int cmd, unsigned long arg)
1680 {
1681 struct lib_ring_buffer *buf = filp->private_data;
1682 struct channel *chan = buf->backend.chan;
1683 const struct lib_ring_buffer_config *config = &chan->backend.config;
1684 const struct lttng_channel_ops *ops = chan->backend.priv_ops;
1685 int ret;
1686
1687 if (atomic_read(&chan->record_disabled))
1688 return -EIO;
1689
1690 switch (cmd) {
1691 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_BEGIN:
1692 {
1693 uint64_t ts;
1694
1695 ret = ops->timestamp_begin(config, buf, &ts);
1696 if (ret < 0)
1697 goto error;
1698 return put_u64(ts, arg);
1699 }
1700 case LTTNG_RING_BUFFER_COMPAT_GET_TIMESTAMP_END:
1701 {
1702 uint64_t ts;
1703
1704 ret = ops->timestamp_end(config, buf, &ts);
1705 if (ret < 0)
1706 goto error;
1707 return put_u64(ts, arg);
1708 }
1709 case LTTNG_RING_BUFFER_COMPAT_GET_EVENTS_DISCARDED:
1710 {
1711 uint64_t ed;
1712
1713 ret = ops->events_discarded(config, buf, &ed);
1714 if (ret < 0)
1715 goto error;
1716 return put_u64(ed, arg);
1717 }
1718 case LTTNG_RING_BUFFER_COMPAT_GET_CONTENT_SIZE:
1719 {
1720 uint64_t cs;
1721
1722 ret = ops->content_size(config, buf, &cs);
1723 if (ret < 0)
1724 goto error;
1725 return put_u64(cs, arg);
1726 }
1727 case LTTNG_RING_BUFFER_COMPAT_GET_PACKET_SIZE:
1728 {
1729 uint64_t ps;
1730
1731 ret = ops->packet_size(config, buf, &ps);
1732 if (ret < 0)
1733 goto error;
1734 return put_u64(ps, arg);
1735 }
1736 case LTTNG_RING_BUFFER_COMPAT_GET_STREAM_ID:
1737 {
1738 uint64_t si;
1739
1740 ret = ops->stream_id(config, buf, &si);
1741 if (ret < 0)
1742 goto error;
1743 return put_u64(si, arg);
1744 }
1745 case LTTNG_RING_BUFFER_GET_CURRENT_TIMESTAMP:
1746 {
1747 uint64_t ts;
1748
1749 ret = ops->current_timestamp(config, buf, &ts);
1750 if (ret < 0)
1751 goto error;
1752 return put_u64(ts, arg);
1753 }
1754 case LTTNG_RING_BUFFER_COMPAT_GET_SEQ_NUM:
1755 {
1756 uint64_t seq;
1757
1758 ret = ops->sequence_number(config, buf, &seq);
1759 if (ret < 0)
1760 goto error;
1761 return put_u64(seq, arg);
1762 }
1763 case LTTNG_RING_BUFFER_COMPAT_INSTANCE_ID:
1764 {
1765 uint64_t id;
1766
1767 ret = ops->instance_id(config, buf, &id);
1768 if (ret < 0)
1769 goto error;
1770 return put_u64(id, arg);
1771 }
1772 default:
1773 return lib_ring_buffer_file_operations.compat_ioctl(filp,
1774 cmd, arg);
1775 }
1776
1777 error:
1778 return -ENOSYS;
1779 }
1780 #endif /* CONFIG_COMPAT */
1781
1782 static void lttng_stream_override_ring_buffer_fops(void)
1783 {
1784 lttng_stream_ring_buffer_file_operations.owner = THIS_MODULE;
1785 lttng_stream_ring_buffer_file_operations.open =
1786 lib_ring_buffer_file_operations.open;
1787 lttng_stream_ring_buffer_file_operations.release =
1788 lib_ring_buffer_file_operations.release;
1789 lttng_stream_ring_buffer_file_operations.poll =
1790 lib_ring_buffer_file_operations.poll;
1791 lttng_stream_ring_buffer_file_operations.splice_read =
1792 lib_ring_buffer_file_operations.splice_read;
1793 lttng_stream_ring_buffer_file_operations.mmap =
1794 lib_ring_buffer_file_operations.mmap;
1795 lttng_stream_ring_buffer_file_operations.unlocked_ioctl =
1796 lttng_stream_ring_buffer_ioctl;
1797 lttng_stream_ring_buffer_file_operations.llseek =
1798 lib_ring_buffer_file_operations.llseek;
1799 #ifdef CONFIG_COMPAT
1800 lttng_stream_ring_buffer_file_operations.compat_ioctl =
1801 lttng_stream_ring_buffer_compat_ioctl;
1802 #endif
1803 }
1804
1805 int __init lttng_abi_init(void)
1806 {
1807 int ret = 0;
1808
1809 wrapper_vmalloc_sync_all();
1810 lttng_clock_ref();
1811
1812 ret = lttng_tp_mempool_init();
1813 if (ret) {
1814 goto error;
1815 }
1816
1817 lttng_proc_dentry = proc_create_data("lttng", S_IRUSR | S_IWUSR, NULL,
1818 &lttng_fops, NULL);
1819
1820 if (!lttng_proc_dentry) {
1821 printk(KERN_ERR "Error creating LTTng control file\n");
1822 ret = -ENOMEM;
1823 goto error;
1824 }
1825 lttng_stream_override_ring_buffer_fops();
1826 return 0;
1827
1828 error:
1829 lttng_tp_mempool_destroy();
1830 lttng_clock_unref();
1831 return ret;
1832 }
1833
1834 /* No __exit annotation because used by init error path too. */
1835 void lttng_abi_exit(void)
1836 {
1837 lttng_tp_mempool_destroy();
1838 lttng_clock_unref();
1839 if (lttng_proc_dentry)
1840 remove_proc_entry("lttng", NULL);
1841 }
LTTng modules - Deliverables
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