Commit | Line | Data |
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e3b3d0f5 | 1 | // SPDX-License-Identifier: GPL-2.0 |
a1235b3e NP |
2 | /* |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | */ | |
5 | ||
6 | #include <linux/types.h> | |
7 | #include <linux/errno.h> | |
8 | #include <linux/signal.h> | |
9 | #include <linux/sched/signal.h> | |
10 | #include <linux/sched/task.h> | |
11 | #include <linux/tty.h> | |
12 | #include <linux/fcntl.h> | |
13 | #include <linux/uaccess.h> | |
98602c01 | 14 | #include "tty.h" |
a1235b3e NP |
15 | |
16 | static int is_ignored(int sig) | |
17 | { | |
18 | return (sigismember(¤t->blocked, sig) || | |
19 | current->sighand->action[sig-1].sa.sa_handler == SIG_IGN); | |
20 | } | |
21 | ||
22 | /** | |
6ef6785d | 23 | * __tty_check_change - check for POSIX terminal changes |
a1235b3e | 24 | * @tty: tty to check |
bc38fe24 | 25 | * @sig: signal to send |
a1235b3e NP |
26 | * |
27 | * If we try to write to, or set the state of, a terminal and we're | |
28 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
29 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
30 | * | |
64d608db | 31 | * Locking: ctrl.lock |
a1235b3e NP |
32 | */ |
33 | int __tty_check_change(struct tty_struct *tty, int sig) | |
34 | { | |
35 | unsigned long flags; | |
36 | struct pid *pgrp, *tty_pgrp; | |
37 | int ret = 0; | |
38 | ||
39 | if (current->signal->tty != tty) | |
40 | return 0; | |
41 | ||
42 | rcu_read_lock(); | |
43 | pgrp = task_pgrp(current); | |
44 | ||
64d608db JS |
45 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
46 | tty_pgrp = tty->ctrl.pgrp; | |
47 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
a1235b3e | 48 | |
cf90c06f | 49 | if (tty_pgrp && pgrp != tty_pgrp) { |
a1235b3e NP |
50 | if (is_ignored(sig)) { |
51 | if (sig == SIGTTIN) | |
52 | ret = -EIO; | |
53 | } else if (is_current_pgrp_orphaned()) | |
54 | ret = -EIO; | |
55 | else { | |
56 | kill_pgrp(pgrp, sig, 1); | |
57 | set_thread_flag(TIF_SIGPENDING); | |
58 | ret = -ERESTARTSYS; | |
59 | } | |
60 | } | |
61 | rcu_read_unlock(); | |
62 | ||
63 | if (!tty_pgrp) | |
64 | tty_warn(tty, "sig=%d, tty->pgrp == NULL!\n", sig); | |
65 | ||
66 | return ret; | |
67 | } | |
68 | ||
69 | int tty_check_change(struct tty_struct *tty) | |
70 | { | |
71 | return __tty_check_change(tty, SIGTTOU); | |
72 | } | |
73 | EXPORT_SYMBOL(tty_check_change); | |
74 | ||
75 | void proc_clear_tty(struct task_struct *p) | |
76 | { | |
77 | unsigned long flags; | |
78 | struct tty_struct *tty; | |
d4e1d903 | 79 | |
a1235b3e NP |
80 | spin_lock_irqsave(&p->sighand->siglock, flags); |
81 | tty = p->signal->tty; | |
82 | p->signal->tty = NULL; | |
83 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | |
84 | tty_kref_put(tty); | |
85 | } | |
86 | ||
87 | /** | |
6ef6785d | 88 | * __proc_set_tty - set the controlling terminal |
bc38fe24 | 89 | * @tty: tty structure |
a1235b3e NP |
90 | * |
91 | * Only callable by the session leader and only if it does not already have | |
92 | * a controlling terminal. | |
93 | * | |
94 | * Caller must hold: tty_lock() | |
95 | * a readlock on tasklist_lock | |
96 | * sighand lock | |
97 | */ | |
98 | static void __proc_set_tty(struct tty_struct *tty) | |
99 | { | |
100 | unsigned long flags; | |
101 | ||
64d608db | 102 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
a1235b3e NP |
103 | /* |
104 | * The session and fg pgrp references will be non-NULL if | |
105 | * tiocsctty() is stealing the controlling tty | |
106 | */ | |
64d608db JS |
107 | put_pid(tty->ctrl.session); |
108 | put_pid(tty->ctrl.pgrp); | |
109 | tty->ctrl.pgrp = get_pid(task_pgrp(current)); | |
110 | tty->ctrl.session = get_pid(task_session(current)); | |
111 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
a1235b3e NP |
112 | if (current->signal->tty) { |
113 | tty_debug(tty, "current tty %s not NULL!!\n", | |
114 | current->signal->tty->name); | |
115 | tty_kref_put(current->signal->tty); | |
116 | } | |
117 | put_pid(current->signal->tty_old_pgrp); | |
118 | current->signal->tty = tty_kref_get(tty); | |
119 | current->signal->tty_old_pgrp = NULL; | |
120 | } | |
121 | ||
122 | static void proc_set_tty(struct tty_struct *tty) | |
123 | { | |
124 | spin_lock_irq(¤t->sighand->siglock); | |
125 | __proc_set_tty(tty); | |
126 | spin_unlock_irq(¤t->sighand->siglock); | |
127 | } | |
128 | ||
129 | /* | |
130 | * Called by tty_open() to set the controlling tty if applicable. | |
131 | */ | |
132 | void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty) | |
133 | { | |
134 | read_lock(&tasklist_lock); | |
135 | spin_lock_irq(¤t->sighand->siglock); | |
136 | if (current->signal->leader && | |
137 | !current->signal->tty && | |
64d608db | 138 | tty->ctrl.session == NULL) { |
a1235b3e NP |
139 | /* |
140 | * Don't let a process that only has write access to the tty | |
141 | * obtain the privileges associated with having a tty as | |
142 | * controlling terminal (being able to reopen it with full | |
143 | * access through /dev/tty, being able to perform pushback). | |
144 | * Many distributions set the group of all ttys to "tty" and | |
145 | * grant write-only access to all terminals for setgid tty | |
146 | * binaries, which should not imply full privileges on all ttys. | |
147 | * | |
148 | * This could theoretically break old code that performs open() | |
149 | * on a write-only file descriptor. In that case, it might be | |
150 | * necessary to also permit this if | |
151 | * inode_permission(inode, MAY_READ) == 0. | |
152 | */ | |
153 | if (filp->f_mode & FMODE_READ) | |
154 | __proc_set_tty(tty); | |
155 | } | |
156 | spin_unlock_irq(¤t->sighand->siglock); | |
157 | read_unlock(&tasklist_lock); | |
158 | } | |
159 | ||
160 | struct tty_struct *get_current_tty(void) | |
161 | { | |
162 | struct tty_struct *tty; | |
163 | unsigned long flags; | |
164 | ||
165 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
166 | tty = tty_kref_get(current->signal->tty); | |
167 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
168 | return tty; | |
169 | } | |
170 | EXPORT_SYMBOL_GPL(get_current_tty); | |
171 | ||
172 | /* | |
173 | * Called from tty_release(). | |
174 | */ | |
175 | void session_clear_tty(struct pid *session) | |
176 | { | |
177 | struct task_struct *p; | |
d4e1d903 | 178 | |
a1235b3e NP |
179 | do_each_pid_task(session, PIDTYPE_SID, p) { |
180 | proc_clear_tty(p); | |
181 | } while_each_pid_task(session, PIDTYPE_SID, p); | |
182 | } | |
183 | ||
184 | /** | |
185 | * tty_signal_session_leader - sends SIGHUP to session leader | |
fa441954 JS |
186 | * @tty: controlling tty |
187 | * @exit_session: if non-zero, signal all foreground group processes | |
a1235b3e NP |
188 | * |
189 | * Send SIGHUP and SIGCONT to the session leader and its process group. | |
190 | * Optionally, signal all processes in the foreground process group. | |
191 | * | |
192 | * Returns the number of processes in the session with this tty | |
193 | * as their controlling terminal. This value is used to drop | |
194 | * tty references for those processes. | |
195 | */ | |
196 | int tty_signal_session_leader(struct tty_struct *tty, int exit_session) | |
197 | { | |
198 | struct task_struct *p; | |
199 | int refs = 0; | |
200 | struct pid *tty_pgrp = NULL; | |
201 | ||
202 | read_lock(&tasklist_lock); | |
64d608db JS |
203 | if (tty->ctrl.session) { |
204 | do_each_pid_task(tty->ctrl.session, PIDTYPE_SID, p) { | |
a1235b3e NP |
205 | spin_lock_irq(&p->sighand->siglock); |
206 | if (p->signal->tty == tty) { | |
207 | p->signal->tty = NULL; | |
63eeafd4 XT |
208 | /* |
209 | * We defer the dereferences outside of | |
210 | * the tasklist lock. | |
211 | */ | |
a1235b3e NP |
212 | refs++; |
213 | } | |
214 | if (!p->signal->leader) { | |
215 | spin_unlock_irq(&p->sighand->siglock); | |
216 | continue; | |
217 | } | |
e71ba124 EB |
218 | send_signal_locked(SIGHUP, SEND_SIG_PRIV, p, PIDTYPE_TGID); |
219 | send_signal_locked(SIGCONT, SEND_SIG_PRIV, p, PIDTYPE_TGID); | |
a1235b3e | 220 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
64d608db JS |
221 | spin_lock(&tty->ctrl.lock); |
222 | tty_pgrp = get_pid(tty->ctrl.pgrp); | |
223 | if (tty->ctrl.pgrp) | |
224 | p->signal->tty_old_pgrp = | |
225 | get_pid(tty->ctrl.pgrp); | |
226 | spin_unlock(&tty->ctrl.lock); | |
a1235b3e | 227 | spin_unlock_irq(&p->sighand->siglock); |
64d608db | 228 | } while_each_pid_task(tty->ctrl.session, PIDTYPE_SID, p); |
a1235b3e NP |
229 | } |
230 | read_unlock(&tasklist_lock); | |
231 | ||
232 | if (tty_pgrp) { | |
233 | if (exit_session) | |
234 | kill_pgrp(tty_pgrp, SIGHUP, exit_session); | |
235 | put_pid(tty_pgrp); | |
236 | } | |
237 | ||
238 | return refs; | |
239 | } | |
240 | ||
241 | /** | |
242 | * disassociate_ctty - disconnect controlling tty | |
243 | * @on_exit: true if exiting so need to "hang up" the session | |
244 | * | |
245 | * This function is typically called only by the session leader, when | |
246 | * it wants to disassociate itself from its controlling tty. | |
247 | * | |
248 | * It performs the following functions: | |
96d50825 XT |
249 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
250 | * (2) Clears the tty from being controlling the session | |
251 | * (3) Clears the controlling tty for all processes in the | |
252 | * session group. | |
a1235b3e NP |
253 | * |
254 | * The argument on_exit is set to 1 if called when a process is | |
255 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
256 | * | |
257 | * Locking: | |
258 | * BTM is taken for hysterical raisons, and held when | |
259 | * called from no_tty(). | |
260 | * tty_mutex is taken to protect tty | |
261 | * ->siglock is taken to protect ->signal/->sighand | |
262 | * tasklist_lock is taken to walk process list for sessions | |
263 | * ->siglock is taken to protect ->signal/->sighand | |
264 | */ | |
265 | void disassociate_ctty(int on_exit) | |
266 | { | |
267 | struct tty_struct *tty; | |
268 | ||
269 | if (!current->signal->leader) | |
270 | return; | |
271 | ||
272 | tty = get_current_tty(); | |
273 | if (tty) { | |
274 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) { | |
275 | tty_vhangup_session(tty); | |
276 | } else { | |
277 | struct pid *tty_pgrp = tty_get_pgrp(tty); | |
d4e1d903 | 278 | |
a1235b3e NP |
279 | if (tty_pgrp) { |
280 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
281 | if (!on_exit) | |
282 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
283 | put_pid(tty_pgrp); | |
284 | } | |
285 | } | |
286 | tty_kref_put(tty); | |
287 | ||
288 | } else if (on_exit) { | |
289 | struct pid *old_pgrp; | |
d4e1d903 | 290 | |
a1235b3e NP |
291 | spin_lock_irq(¤t->sighand->siglock); |
292 | old_pgrp = current->signal->tty_old_pgrp; | |
293 | current->signal->tty_old_pgrp = NULL; | |
294 | spin_unlock_irq(¤t->sighand->siglock); | |
295 | if (old_pgrp) { | |
296 | kill_pgrp(old_pgrp, SIGHUP, on_exit); | |
297 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
298 | put_pid(old_pgrp); | |
299 | } | |
300 | return; | |
301 | } | |
302 | ||
11e7f27b | 303 | tty = get_current_tty(); |
a1235b3e NP |
304 | if (tty) { |
305 | unsigned long flags; | |
c8bcd9c5 JH |
306 | |
307 | tty_lock(tty); | |
64d608db JS |
308 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
309 | put_pid(tty->ctrl.session); | |
310 | put_pid(tty->ctrl.pgrp); | |
311 | tty->ctrl.session = NULL; | |
312 | tty->ctrl.pgrp = NULL; | |
313 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
c8bcd9c5 | 314 | tty_unlock(tty); |
a1235b3e NP |
315 | tty_kref_put(tty); |
316 | } | |
317 | ||
11e7f27b YY |
318 | /* If tty->ctrl.pgrp is not NULL, it may be assigned to |
319 | * current->signal->tty_old_pgrp in a race condition, and | |
320 | * cause pid memleak. Release current->signal->tty_old_pgrp | |
321 | * after tty->ctrl.pgrp set to NULL. | |
322 | */ | |
323 | spin_lock_irq(¤t->sighand->siglock); | |
324 | put_pid(current->signal->tty_old_pgrp); | |
325 | current->signal->tty_old_pgrp = NULL; | |
326 | spin_unlock_irq(¤t->sighand->siglock); | |
327 | ||
a1235b3e NP |
328 | /* Now clear signal->tty under the lock */ |
329 | read_lock(&tasklist_lock); | |
330 | session_clear_tty(task_session(current)); | |
331 | read_unlock(&tasklist_lock); | |
332 | } | |
333 | ||
3adf2aa8 | 334 | /* |
a1235b3e NP |
335 | * |
336 | * no_tty - Ensure the current process does not have a controlling tty | |
337 | */ | |
338 | void no_tty(void) | |
339 | { | |
63eeafd4 XT |
340 | /* |
341 | * FIXME: Review locking here. The tty_lock never covered any race | |
342 | * between a new association and proc_clear_tty but possibly we need | |
343 | * to protect against this anyway. | |
344 | */ | |
a1235b3e | 345 | struct task_struct *tsk = current; |
d4e1d903 | 346 | |
a1235b3e NP |
347 | disassociate_ctty(0); |
348 | proc_clear_tty(tsk); | |
349 | } | |
350 | ||
351 | /** | |
352 | * tiocsctty - set controlling tty | |
353 | * @tty: tty structure | |
bc38fe24 | 354 | * @file: file structure used to check permissions |
a1235b3e NP |
355 | * @arg: user argument |
356 | * | |
357 | * This ioctl is used to manage job control. It permits a session | |
358 | * leader to set this tty as the controlling tty for the session. | |
359 | * | |
360 | * Locking: | |
361 | * Takes tty_lock() to serialize proc_set_tty() for this tty | |
362 | * Takes tasklist_lock internally to walk sessions | |
363 | * Takes ->siglock() when updating signal->tty | |
364 | */ | |
365 | static int tiocsctty(struct tty_struct *tty, struct file *file, int arg) | |
366 | { | |
367 | int ret = 0; | |
368 | ||
369 | tty_lock(tty); | |
370 | read_lock(&tasklist_lock); | |
371 | ||
64d608db JS |
372 | if (current->signal->leader && |
373 | task_session(current) == tty->ctrl.session) | |
a1235b3e NP |
374 | goto unlock; |
375 | ||
376 | /* | |
377 | * The process must be a session leader and | |
378 | * not have a controlling tty already. | |
379 | */ | |
380 | if (!current->signal->leader || current->signal->tty) { | |
381 | ret = -EPERM; | |
382 | goto unlock; | |
383 | } | |
384 | ||
64d608db | 385 | if (tty->ctrl.session) { |
a1235b3e NP |
386 | /* |
387 | * This tty is already the controlling | |
388 | * tty for another session group! | |
389 | */ | |
390 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { | |
391 | /* | |
392 | * Steal it away | |
393 | */ | |
64d608db | 394 | session_clear_tty(tty->ctrl.session); |
a1235b3e NP |
395 | } else { |
396 | ret = -EPERM; | |
397 | goto unlock; | |
398 | } | |
399 | } | |
400 | ||
401 | /* See the comment in tty_open_proc_set_tty(). */ | |
402 | if ((file->f_mode & FMODE_READ) == 0 && !capable(CAP_SYS_ADMIN)) { | |
403 | ret = -EPERM; | |
404 | goto unlock; | |
405 | } | |
406 | ||
407 | proc_set_tty(tty); | |
408 | unlock: | |
409 | read_unlock(&tasklist_lock); | |
410 | tty_unlock(tty); | |
411 | return ret; | |
412 | } | |
413 | ||
414 | /** | |
415 | * tty_get_pgrp - return a ref counted pgrp pid | |
416 | * @tty: tty to read | |
417 | * | |
418 | * Returns a refcounted instance of the pid struct for the process | |
419 | * group controlling the tty. | |
420 | */ | |
421 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
422 | { | |
423 | unsigned long flags; | |
424 | struct pid *pgrp; | |
425 | ||
64d608db JS |
426 | spin_lock_irqsave(&tty->ctrl.lock, flags); |
427 | pgrp = get_pid(tty->ctrl.pgrp); | |
428 | spin_unlock_irqrestore(&tty->ctrl.lock, flags); | |
a1235b3e NP |
429 | |
430 | return pgrp; | |
431 | } | |
432 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
433 | ||
434 | /* | |
435 | * This checks not only the pgrp, but falls back on the pid if no | |
436 | * satisfactory pgrp is found. I dunno - gdb doesn't work correctly | |
437 | * without this... | |
438 | * | |
439 | * The caller must hold rcu lock or the tasklist lock. | |
440 | */ | |
441 | static struct pid *session_of_pgrp(struct pid *pgrp) | |
442 | { | |
443 | struct task_struct *p; | |
444 | struct pid *sid = NULL; | |
445 | ||
446 | p = pid_task(pgrp, PIDTYPE_PGID); | |
447 | if (p == NULL) | |
448 | p = pid_task(pgrp, PIDTYPE_PID); | |
449 | if (p != NULL) | |
450 | sid = task_session(p); | |
451 | ||
452 | return sid; | |
453 | } | |
454 | ||
455 | /** | |
456 | * tiocgpgrp - get process group | |
457 | * @tty: tty passed by user | |
458 | * @real_tty: tty side of the tty passed by the user if a pty else the tty | |
459 | * @p: returned pid | |
460 | * | |
461 | * Obtain the process group of the tty. If there is no process group | |
462 | * return an error. | |
463 | * | |
464 | * Locking: none. Reference to current->signal->tty is safe. | |
465 | */ | |
466 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) | |
467 | { | |
468 | struct pid *pid; | |
469 | int ret; | |
470 | /* | |
471 | * (tty == real_tty) is a cheap way of | |
472 | * testing if the tty is NOT a master pty. | |
473 | */ | |
474 | if (tty == real_tty && current->signal->tty != real_tty) | |
475 | return -ENOTTY; | |
476 | pid = tty_get_pgrp(real_tty); | |
477 | ret = put_user(pid_vnr(pid), p); | |
478 | put_pid(pid); | |
479 | return ret; | |
480 | } | |
481 | ||
482 | /** | |
483 | * tiocspgrp - attempt to set process group | |
484 | * @tty: tty passed by user | |
485 | * @real_tty: tty side device matching tty passed by user | |
486 | * @p: pid pointer | |
487 | * | |
488 | * Set the process group of the tty to the session passed. Only | |
489 | * permitted where the tty session is our session. | |
490 | * | |
491 | * Locking: RCU, ctrl lock | |
492 | */ | |
493 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) | |
494 | { | |
495 | struct pid *pgrp; | |
496 | pid_t pgrp_nr; | |
497 | int retval = tty_check_change(real_tty); | |
498 | ||
499 | if (retval == -EIO) | |
500 | return -ENOTTY; | |
501 | if (retval) | |
502 | return retval; | |
c8bcd9c5 | 503 | |
a1235b3e NP |
504 | if (get_user(pgrp_nr, p)) |
505 | return -EFAULT; | |
506 | if (pgrp_nr < 0) | |
507 | return -EINVAL; | |
c8bcd9c5 | 508 | |
64d608db | 509 | spin_lock_irq(&real_tty->ctrl.lock); |
c8bcd9c5 JH |
510 | if (!current->signal->tty || |
511 | (current->signal->tty != real_tty) || | |
64d608db | 512 | (real_tty->ctrl.session != task_session(current))) { |
c8bcd9c5 JH |
513 | retval = -ENOTTY; |
514 | goto out_unlock_ctrl; | |
515 | } | |
a1235b3e NP |
516 | rcu_read_lock(); |
517 | pgrp = find_vpid(pgrp_nr); | |
518 | retval = -ESRCH; | |
519 | if (!pgrp) | |
520 | goto out_unlock; | |
521 | retval = -EPERM; | |
522 | if (session_of_pgrp(pgrp) != task_session(current)) | |
523 | goto out_unlock; | |
524 | retval = 0; | |
64d608db JS |
525 | put_pid(real_tty->ctrl.pgrp); |
526 | real_tty->ctrl.pgrp = get_pid(pgrp); | |
a1235b3e NP |
527 | out_unlock: |
528 | rcu_read_unlock(); | |
c8bcd9c5 | 529 | out_unlock_ctrl: |
64d608db | 530 | spin_unlock_irq(&real_tty->ctrl.lock); |
a1235b3e NP |
531 | return retval; |
532 | } | |
533 | ||
534 | /** | |
535 | * tiocgsid - get session id | |
536 | * @tty: tty passed by user | |
537 | * @real_tty: tty side of the tty passed by the user if a pty else the tty | |
538 | * @p: pointer to returned session id | |
539 | * | |
540 | * Obtain the session id of the tty. If there is no session | |
541 | * return an error. | |
a1235b3e NP |
542 | */ |
543 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) | |
544 | { | |
c8bcd9c5 JH |
545 | unsigned long flags; |
546 | pid_t sid; | |
547 | ||
a1235b3e NP |
548 | /* |
549 | * (tty == real_tty) is a cheap way of | |
550 | * testing if the tty is NOT a master pty. | |
63eeafd4 | 551 | */ |
a1235b3e NP |
552 | if (tty == real_tty && current->signal->tty != real_tty) |
553 | return -ENOTTY; | |
c8bcd9c5 | 554 | |
64d608db JS |
555 | spin_lock_irqsave(&real_tty->ctrl.lock, flags); |
556 | if (!real_tty->ctrl.session) | |
c8bcd9c5 | 557 | goto err; |
64d608db JS |
558 | sid = pid_vnr(real_tty->ctrl.session); |
559 | spin_unlock_irqrestore(&real_tty->ctrl.lock, flags); | |
c8bcd9c5 JH |
560 | |
561 | return put_user(sid, p); | |
562 | ||
563 | err: | |
64d608db | 564 | spin_unlock_irqrestore(&real_tty->ctrl.lock, flags); |
c8bcd9c5 | 565 | return -ENOTTY; |
a1235b3e NP |
566 | } |
567 | ||
568 | /* | |
569 | * Called from tty_ioctl(). If tty is a pty then real_tty is the slave side, | |
570 | * if not then tty == real_tty. | |
571 | */ | |
572 | long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty, | |
573 | struct file *file, unsigned int cmd, unsigned long arg) | |
574 | { | |
575 | void __user *p = (void __user *)arg; | |
576 | ||
577 | switch (cmd) { | |
578 | case TIOCNOTTY: | |
579 | if (current->signal->tty != tty) | |
580 | return -ENOTTY; | |
581 | no_tty(); | |
582 | return 0; | |
583 | case TIOCSCTTY: | |
584 | return tiocsctty(real_tty, file, arg); | |
585 | case TIOCGPGRP: | |
586 | return tiocgpgrp(tty, real_tty, p); | |
587 | case TIOCSPGRP: | |
588 | return tiocspgrp(tty, real_tty, p); | |
589 | case TIOCGSID: | |
590 | return tiocgsid(tty, real_tty, p); | |
591 | } | |
592 | return -ENOIOCTLCMD; | |
593 | } |