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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 75435 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * linux/drivers/char/tty_io.c |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | */ |
6 | |
7 | /* |
8 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles |
9 | * or rs-channels. It also implements echoing, cooked mode etc. |
10 | * |
11 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. |
12 | * |
13 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the |
14 | * tty_struct and tty_queue structures. Previously there was an array |
15 | * of 256 tty_struct's which was statically allocated, and the |
16 | * tty_queue structures were allocated at boot time. Both are now |
17 | * dynamically allocated only when the tty is open. |
18 | * |
19 | * Also restructured routines so that there is more of a separation |
20 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and |
21 | * the low-level tty routines (serial.c, pty.c, console.c). This |
22 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
23 | * |
24 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines |
25 | * which can be dynamically activated and de-activated by the line |
26 | * discipline handling modules (like SLIP). |
27 | * |
28 | * NOTE: pay no attention to the line discipline code (yet); its |
29 | * interface is still subject to change in this version... |
30 | * -- TYT, 1/31/92 |
31 | * |
32 | * Added functionality to the OPOST tty handling. No delays, but all |
33 | * other bits should be there. |
34 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. |
35 | * |
36 | * Rewrote canonical mode and added more termios flags. |
37 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 |
38 | * |
39 | * Reorganized FASYNC support so mouse code can share it. |
40 | * -- ctm@ardi.com, 9Sep95 |
41 | * |
42 | * New TIOCLINUX variants added. |
43 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 |
44 | * |
45 | * Restrict vt switching via ioctl() |
46 | * -- grif@cs.ucr.edu, 5-Dec-95 |
47 | * |
48 | * Move console and virtual terminal code to more appropriate files, |
49 | * implement CONFIG_VT and generalize console device interface. |
50 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 |
51 | * |
52 | * Rewrote init_dev and release_dev to eliminate races. |
53 | * -- Bill Hawes <whawes@star.net>, June 97 |
54 | * |
55 | * Added devfs support. |
56 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 |
57 | * |
58 | * Added support for a Unix98-style ptmx device. |
59 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 |
60 | * |
61 | * Reduced memory usage for older ARM systems |
62 | * -- Russell King <rmk@arm.linux.org.uk> |
63 | * |
64 | * Move do_SAK() into process context. Less stack use in devfs functions. |
65 | * alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 |
66 | */ |
67 | |
68 | #include <linux/config.h> |
69 | #include <linux/types.h> |
70 | #include <linux/major.h> |
71 | #include <linux/errno.h> |
72 | #include <linux/signal.h> |
73 | #include <linux/fcntl.h> |
74 | #include <linux/sched.h> |
75 | #include <linux/interrupt.h> |
76 | #include <linux/tty.h> |
77 | #include <linux/tty_driver.h> |
78 | #include <linux/tty_flip.h> |
79 | #include <linux/devpts_fs.h> |
80 | #include <linux/file.h> |
81 | #include <linux/console.h> |
82 | #include <linux/timer.h> |
83 | #include <linux/ctype.h> |
84 | #include <linux/kd.h> |
85 | #include <linux/mm.h> |
86 | #include <linux/string.h> |
87 | #include <linux/slab.h> |
88 | #include <linux/poll.h> |
89 | #include <linux/proc_fs.h> |
90 | #include <linux/init.h> |
91 | #include <linux/module.h> |
92 | #include <linux/smp_lock.h> |
93 | #include <linux/device.h> |
94 | #include <linux/idr.h> |
95 | #include <linux/wait.h> |
96 | #include <linux/bitops.h> |
97 | |
98 | #include <asm/uaccess.h> |
99 | #include <asm/system.h> |
100 | |
101 | #include <linux/kbd_kern.h> |
102 | #include <linux/vt_kern.h> |
103 | #include <linux/selection.h> |
104 | #include <linux/devfs_fs_kernel.h> |
105 | |
106 | #include <linux/kmod.h> |
107 | |
108 | #undef TTY_DEBUG_HANGUP |
109 | |
110 | #define TTY_PARANOIA_CHECK 1 |
111 | #define CHECK_TTY_COUNT 1 |
112 | |
113 | struct termios tty_std_termios = { /* for the benefit of tty drivers */ |
114 | .c_iflag = ICRNL | IXON, |
115 | .c_oflag = OPOST | ONLCR, |
116 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, |
117 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | |
118 | ECHOCTL | ECHOKE | IEXTEN, |
119 | .c_cc = INIT_C_CC |
120 | }; |
121 | |
122 | EXPORT_SYMBOL(tty_std_termios); |
123 | |
124 | /* This list gets poked at by procfs and various bits of boot up code. This |
125 | could do with some rationalisation such as pulling the tty proc function |
126 | into this file */ |
127 | |
128 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
129 | |
130 | /* Semaphore to protect creating and releasing a tty. This is shared with |
131 | vt.c for deeply disgusting hack reasons */ |
132 | DECLARE_MUTEX(tty_sem); |
133 | |
134 | #ifdef CONFIG_UNIX98_PTYS |
135 | extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ |
136 | extern int pty_limit; /* Config limit on Unix98 ptys */ |
137 | static DEFINE_IDR(allocated_ptys); |
138 | static DECLARE_MUTEX(allocated_ptys_lock); |
139 | static int ptmx_open(struct inode *, struct file *); |
140 | #endif |
141 | |
142 | extern void disable_early_printk(void); |
143 | |
144 | static void initialize_tty_struct(struct tty_struct *tty); |
145 | |
146 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
147 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); |
148 | ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *); |
149 | static unsigned int tty_poll(struct file *, poll_table *); |
150 | static int tty_open(struct inode *, struct file *); |
151 | static int tty_release(struct inode *, struct file *); |
152 | int tty_ioctl(struct inode * inode, struct file * file, |
153 | unsigned int cmd, unsigned long arg); |
154 | static int tty_fasync(int fd, struct file * filp, int on); |
155 | extern void rs_360_init(void); |
156 | static void release_mem(struct tty_struct *tty, int idx); |
157 | |
158 | |
159 | static struct tty_struct *alloc_tty_struct(void) |
160 | { |
161 | struct tty_struct *tty; |
162 | |
163 | tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL); |
164 | if (tty) |
165 | memset(tty, 0, sizeof(struct tty_struct)); |
166 | return tty; |
167 | } |
168 | |
169 | static inline void free_tty_struct(struct tty_struct *tty) |
170 | { |
171 | kfree(tty->write_buf); |
172 | kfree(tty); |
173 | } |
174 | |
175 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
176 | |
177 | char *tty_name(struct tty_struct *tty, char *buf) |
178 | { |
179 | if (!tty) /* Hmm. NULL pointer. That's fun. */ |
180 | strcpy(buf, "NULL tty"); |
181 | else |
182 | strcpy(buf, tty->name); |
183 | return buf; |
184 | } |
185 | |
186 | EXPORT_SYMBOL(tty_name); |
187 | |
188 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
189 | const char *routine) |
190 | { |
191 | #ifdef TTY_PARANOIA_CHECK |
192 | if (!tty) { |
193 | printk(KERN_WARNING |
194 | "null TTY for (%d:%d) in %s\n", |
195 | imajor(inode), iminor(inode), routine); |
196 | return 1; |
197 | } |
198 | if (tty->magic != TTY_MAGIC) { |
199 | printk(KERN_WARNING |
200 | "bad magic number for tty struct (%d:%d) in %s\n", |
201 | imajor(inode), iminor(inode), routine); |
202 | return 1; |
203 | } |
204 | #endif |
205 | return 0; |
206 | } |
207 | |
208 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
209 | { |
210 | #ifdef CHECK_TTY_COUNT |
211 | struct list_head *p; |
212 | int count = 0; |
213 | |
214 | file_list_lock(); |
215 | list_for_each(p, &tty->tty_files) { |
216 | count++; |
217 | } |
218 | file_list_unlock(); |
219 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
220 | tty->driver->subtype == PTY_TYPE_SLAVE && |
221 | tty->link && tty->link->count) |
222 | count++; |
223 | if (tty->count != count) { |
224 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " |
225 | "!= #fd's(%d) in %s\n", |
226 | tty->name, tty->count, count, routine); |
227 | return count; |
228 | } |
229 | #endif |
230 | return 0; |
231 | } |
232 | |
233 | /* |
234 | * This is probably overkill for real world processors but |
235 | * they are not on hot paths so a little discipline won't do |
236 | * any harm. |
237 | */ |
238 | |
239 | static void tty_set_termios_ldisc(struct tty_struct *tty, int num) |
240 | { |
241 | down(&tty->termios_sem); |
242 | tty->termios->c_line = num; |
243 | up(&tty->termios_sem); |
244 | } |
245 | |
246 | /* |
247 | * This guards the refcounted line discipline lists. The lock |
248 | * must be taken with irqs off because there are hangup path |
249 | * callers who will do ldisc lookups and cannot sleep. |
250 | */ |
251 | |
252 | static DEFINE_SPINLOCK(tty_ldisc_lock); |
253 | static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait); |
254 | static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */ |
255 | |
256 | int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) |
257 | { |
258 | unsigned long flags; |
259 | int ret = 0; |
260 | |
261 | if (disc < N_TTY || disc >= NR_LDISCS) |
262 | return -EINVAL; |
263 | |
264 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
265 | if (new_ldisc) { |
266 | tty_ldiscs[disc] = *new_ldisc; |
267 | tty_ldiscs[disc].num = disc; |
268 | tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; |
269 | tty_ldiscs[disc].refcount = 0; |
270 | } else { |
271 | if(tty_ldiscs[disc].refcount) |
272 | ret = -EBUSY; |
273 | else |
274 | tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; |
275 | } |
276 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
277 | |
278 | return ret; |
279 | } |
280 | |
281 | EXPORT_SYMBOL(tty_register_ldisc); |
282 | |
283 | struct tty_ldisc *tty_ldisc_get(int disc) |
284 | { |
285 | unsigned long flags; |
286 | struct tty_ldisc *ld; |
287 | |
288 | if (disc < N_TTY || disc >= NR_LDISCS) |
289 | return NULL; |
290 | |
291 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
292 | |
293 | ld = &tty_ldiscs[disc]; |
294 | /* Check the entry is defined */ |
295 | if(ld->flags & LDISC_FLAG_DEFINED) |
296 | { |
297 | /* If the module is being unloaded we can't use it */ |
298 | if (!try_module_get(ld->owner)) |
299 | ld = NULL; |
300 | else /* lock it */ |
301 | ld->refcount++; |
302 | } |
303 | else |
304 | ld = NULL; |
305 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
306 | return ld; |
307 | } |
308 | |
309 | EXPORT_SYMBOL_GPL(tty_ldisc_get); |
310 | |
311 | void tty_ldisc_put(int disc) |
312 | { |
313 | struct tty_ldisc *ld; |
314 | unsigned long flags; |
315 | |
316 | if (disc < N_TTY || disc >= NR_LDISCS) |
317 | BUG(); |
318 | |
319 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
320 | ld = &tty_ldiscs[disc]; |
321 | if(ld->refcount == 0) |
322 | BUG(); |
323 | ld->refcount --; |
324 | module_put(ld->owner); |
325 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
326 | } |
327 | |
328 | EXPORT_SYMBOL_GPL(tty_ldisc_put); |
329 | |
330 | static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld) |
331 | { |
332 | tty->ldisc = *ld; |
333 | tty->ldisc.refcount = 0; |
334 | } |
335 | |
336 | /** |
337 | * tty_ldisc_try - internal helper |
338 | * @tty: the tty |
339 | * |
340 | * Make a single attempt to grab and bump the refcount on |
341 | * the tty ldisc. Return 0 on failure or 1 on success. This is |
342 | * used to implement both the waiting and non waiting versions |
343 | * of tty_ldisc_ref |
344 | */ |
345 | |
346 | static int tty_ldisc_try(struct tty_struct *tty) |
347 | { |
348 | unsigned long flags; |
349 | struct tty_ldisc *ld; |
350 | int ret = 0; |
351 | |
352 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
353 | ld = &tty->ldisc; |
354 | if(test_bit(TTY_LDISC, &tty->flags)) |
355 | { |
356 | ld->refcount++; |
357 | ret = 1; |
358 | } |
359 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
360 | return ret; |
361 | } |
362 | |
363 | /** |
364 | * tty_ldisc_ref_wait - wait for the tty ldisc |
365 | * @tty: tty device |
366 | * |
367 | * Dereference the line discipline for the terminal and take a |
368 | * reference to it. If the line discipline is in flux then |
369 | * wait patiently until it changes. |
370 | * |
371 | * Note: Must not be called from an IRQ/timer context. The caller |
372 | * must also be careful not to hold other locks that will deadlock |
373 | * against a discipline change, such as an existing ldisc reference |
374 | * (which we check for) |
375 | */ |
376 | |
377 | struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) |
378 | { |
379 | /* wait_event is a macro */ |
380 | wait_event(tty_ldisc_wait, tty_ldisc_try(tty)); |
381 | if(tty->ldisc.refcount == 0) |
382 | printk(KERN_ERR "tty_ldisc_ref_wait\n"); |
383 | return &tty->ldisc; |
384 | } |
385 | |
386 | EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); |
387 | |
388 | /** |
389 | * tty_ldisc_ref - get the tty ldisc |
390 | * @tty: tty device |
391 | * |
392 | * Dereference the line discipline for the terminal and take a |
393 | * reference to it. If the line discipline is in flux then |
394 | * return NULL. Can be called from IRQ and timer functions. |
395 | */ |
396 | |
397 | struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty) |
398 | { |
399 | if(tty_ldisc_try(tty)) |
400 | return &tty->ldisc; |
401 | return NULL; |
402 | } |
403 | |
404 | EXPORT_SYMBOL_GPL(tty_ldisc_ref); |
405 | |
406 | /** |
407 | * tty_ldisc_deref - free a tty ldisc reference |
408 | * @ld: reference to free up |
409 | * |
410 | * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May |
411 | * be called in IRQ context. |
412 | */ |
413 | |
414 | void tty_ldisc_deref(struct tty_ldisc *ld) |
415 | { |
416 | unsigned long flags; |
417 | |
418 | if(ld == NULL) |
419 | BUG(); |
420 | |
421 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
422 | if(ld->refcount == 0) |
423 | printk(KERN_ERR "tty_ldisc_deref: no references.\n"); |
424 | else |
425 | ld->refcount--; |
426 | if(ld->refcount == 0) |
427 | wake_up(&tty_ldisc_wait); |
428 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
429 | } |
430 | |
431 | EXPORT_SYMBOL_GPL(tty_ldisc_deref); |
432 | |
433 | /** |
434 | * tty_ldisc_enable - allow ldisc use |
435 | * @tty: terminal to activate ldisc on |
436 | * |
437 | * Set the TTY_LDISC flag when the line discipline can be called |
438 | * again. Do neccessary wakeups for existing sleepers. |
439 | * |
440 | * Note: nobody should set this bit except via this function. Clearing |
441 | * directly is allowed. |
442 | */ |
443 | |
444 | static void tty_ldisc_enable(struct tty_struct *tty) |
445 | { |
446 | set_bit(TTY_LDISC, &tty->flags); |
447 | wake_up(&tty_ldisc_wait); |
448 | } |
449 | |
450 | /** |
451 | * tty_set_ldisc - set line discipline |
452 | * @tty: the terminal to set |
453 | * @ldisc: the line discipline |
454 | * |
455 | * Set the discipline of a tty line. Must be called from a process |
456 | * context. |
457 | */ |
458 | |
459 | static int tty_set_ldisc(struct tty_struct *tty, int ldisc) |
460 | { |
461 | int retval = 0; |
462 | struct tty_ldisc o_ldisc; |
463 | char buf[64]; |
464 | int work; |
465 | unsigned long flags; |
466 | struct tty_ldisc *ld; |
467 | |
468 | if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) |
469 | return -EINVAL; |
470 | |
471 | restart: |
472 | |
473 | if (tty->ldisc.num == ldisc) |
474 | return 0; /* We are already in the desired discipline */ |
475 | |
476 | ld = tty_ldisc_get(ldisc); |
477 | /* Eduardo Blanco <ejbs@cs.cs.com.uy> */ |
478 | /* Cyrus Durgin <cider@speakeasy.org> */ |
479 | if (ld == NULL) { |
480 | request_module("tty-ldisc-%d", ldisc); |
481 | ld = tty_ldisc_get(ldisc); |
482 | } |
483 | if (ld == NULL) |
484 | return -EINVAL; |
485 | |
486 | o_ldisc = tty->ldisc; |
487 | |
488 | tty_wait_until_sent(tty, 0); |
489 | |
490 | /* |
491 | * Make sure we don't change while someone holds a |
492 | * reference to the line discipline. The TTY_LDISC bit |
493 | * prevents anyone taking a reference once it is clear. |
494 | * We need the lock to avoid racing reference takers. |
495 | */ |
496 | |
497 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
498 | if(tty->ldisc.refcount) |
499 | { |
500 | /* Free the new ldisc we grabbed. Must drop the lock |
501 | first. */ |
502 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
503 | tty_ldisc_put(ldisc); |
504 | /* |
505 | * There are several reasons we may be busy, including |
506 | * random momentary I/O traffic. We must therefore |
507 | * retry. We could distinguish between blocking ops |
508 | * and retries if we made tty_ldisc_wait() smarter. That |
509 | * is up for discussion. |
510 | */ |
511 | if(wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0) |
512 | return -ERESTARTSYS; |
513 | goto restart; |
514 | } |
515 | clear_bit(TTY_LDISC, &tty->flags); |
516 | clear_bit(TTY_DONT_FLIP, &tty->flags); |
517 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
518 | |
519 | /* |
520 | * From this point on we know nobody has an ldisc |
521 | * usage reference, nor can they obtain one until |
522 | * we say so later on. |
523 | */ |
524 | |
525 | work = cancel_delayed_work(&tty->flip.work); |
526 | /* |
527 | * Wait for ->hangup_work and ->flip.work handlers to terminate |
528 | */ |
529 | |
530 | flush_scheduled_work(); |
531 | /* Shutdown the current discipline. */ |
532 | if (tty->ldisc.close) |
533 | (tty->ldisc.close)(tty); |
534 | |
535 | /* Now set up the new line discipline. */ |
536 | tty_ldisc_assign(tty, ld); |
537 | tty_set_termios_ldisc(tty, ldisc); |
538 | if (tty->ldisc.open) |
539 | retval = (tty->ldisc.open)(tty); |
540 | if (retval < 0) { |
541 | tty_ldisc_put(ldisc); |
542 | /* There is an outstanding reference here so this is safe */ |
543 | tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num)); |
544 | tty_set_termios_ldisc(tty, tty->ldisc.num); |
545 | if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { |
546 | tty_ldisc_put(o_ldisc.num); |
547 | /* This driver is always present */ |
548 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
549 | tty_set_termios_ldisc(tty, N_TTY); |
550 | if (tty->ldisc.open) { |
551 | int r = tty->ldisc.open(tty); |
552 | |
553 | if (r < 0) |
554 | panic("Couldn't open N_TTY ldisc for " |
555 | "%s --- error %d.", |
556 | tty_name(tty, buf), r); |
557 | } |
558 | } |
559 | } |
560 | /* At this point we hold a reference to the new ldisc and a |
561 | a reference to the old ldisc. If we ended up flipping back |
562 | to the existing ldisc we have two references to it */ |
563 | |
564 | if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc) |
565 | tty->driver->set_ldisc(tty); |
566 | |
567 | tty_ldisc_put(o_ldisc.num); |
568 | |
569 | /* |
570 | * Allow ldisc referencing to occur as soon as the driver |
571 | * ldisc callback completes. |
572 | */ |
573 | |
574 | tty_ldisc_enable(tty); |
575 | |
576 | /* Restart it in case no characters kick it off. Safe if |
577 | already running */ |
578 | if(work) |
579 | schedule_delayed_work(&tty->flip.work, 1); |
580 | return retval; |
581 | } |
582 | |
583 | /* |
584 | * This routine returns a tty driver structure, given a device number |
585 | */ |
586 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
587 | { |
588 | struct tty_driver *p; |
589 | |
590 | list_for_each_entry(p, &tty_drivers, tty_drivers) { |
591 | dev_t base = MKDEV(p->major, p->minor_start); |
592 | if (device < base || device >= base + p->num) |
593 | continue; |
594 | *index = device - base; |
595 | return p; |
596 | } |
597 | return NULL; |
598 | } |
599 | |
600 | /* |
601 | * If we try to write to, or set the state of, a terminal and we're |
602 | * not in the foreground, send a SIGTTOU. If the signal is blocked or |
603 | * ignored, go ahead and perform the operation. (POSIX 7.2) |
604 | */ |
605 | int tty_check_change(struct tty_struct * tty) |
606 | { |
607 | if (current->signal->tty != tty) |
608 | return 0; |
609 | if (tty->pgrp <= 0) { |
610 | printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n"); |
611 | return 0; |
612 | } |
613 | if (process_group(current) == tty->pgrp) |
614 | return 0; |
615 | if (is_ignored(SIGTTOU)) |
616 | return 0; |
617 | if (is_orphaned_pgrp(process_group(current))) |
618 | return -EIO; |
619 | (void) kill_pg(process_group(current), SIGTTOU, 1); |
620 | return -ERESTARTSYS; |
621 | } |
622 | |
623 | EXPORT_SYMBOL(tty_check_change); |
624 | |
625 | static ssize_t hung_up_tty_read(struct file * file, char __user * buf, |
626 | size_t count, loff_t *ppos) |
627 | { |
628 | return 0; |
629 | } |
630 | |
631 | static ssize_t hung_up_tty_write(struct file * file, const char __user * buf, |
632 | size_t count, loff_t *ppos) |
633 | { |
634 | return -EIO; |
635 | } |
636 | |
637 | /* No kernel lock held - none needed ;) */ |
638 | static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait) |
639 | { |
640 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; |
641 | } |
642 | |
643 | static int hung_up_tty_ioctl(struct inode * inode, struct file * file, |
644 | unsigned int cmd, unsigned long arg) |
645 | { |
646 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; |
647 | } |
648 | |
649 | static struct file_operations tty_fops = { |
650 | .llseek = no_llseek, |
651 | .read = tty_read, |
652 | .write = tty_write, |
653 | .poll = tty_poll, |
654 | .ioctl = tty_ioctl, |
655 | .open = tty_open, |
656 | .release = tty_release, |
657 | .fasync = tty_fasync, |
658 | }; |
659 | |
660 | #ifdef CONFIG_UNIX98_PTYS |
661 | static struct file_operations ptmx_fops = { |
662 | .llseek = no_llseek, |
663 | .read = tty_read, |
664 | .write = tty_write, |
665 | .poll = tty_poll, |
666 | .ioctl = tty_ioctl, |
667 | .open = ptmx_open, |
668 | .release = tty_release, |
669 | .fasync = tty_fasync, |
670 | }; |
671 | #endif |
672 | |
673 | static struct file_operations console_fops = { |
674 | .llseek = no_llseek, |
675 | .read = tty_read, |
676 | .write = redirected_tty_write, |
677 | .poll = tty_poll, |
678 | .ioctl = tty_ioctl, |
679 | .open = tty_open, |
680 | .release = tty_release, |
681 | .fasync = tty_fasync, |
682 | }; |
683 | |
684 | static struct file_operations hung_up_tty_fops = { |
685 | .llseek = no_llseek, |
686 | .read = hung_up_tty_read, |
687 | .write = hung_up_tty_write, |
688 | .poll = hung_up_tty_poll, |
689 | .ioctl = hung_up_tty_ioctl, |
690 | .release = tty_release, |
691 | }; |
692 | |
693 | static DEFINE_SPINLOCK(redirect_lock); |
694 | static struct file *redirect; |
695 | |
696 | /** |
697 | * tty_wakeup - request more data |
698 | * @tty: terminal |
699 | * |
700 | * Internal and external helper for wakeups of tty. This function |
701 | * informs the line discipline if present that the driver is ready |
702 | * to receive more output data. |
703 | */ |
704 | |
705 | void tty_wakeup(struct tty_struct *tty) |
706 | { |
707 | struct tty_ldisc *ld; |
708 | |
709 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
710 | ld = tty_ldisc_ref(tty); |
711 | if(ld) { |
712 | if(ld->write_wakeup) |
713 | ld->write_wakeup(tty); |
714 | tty_ldisc_deref(ld); |
715 | } |
716 | } |
717 | wake_up_interruptible(&tty->write_wait); |
718 | } |
719 | |
720 | EXPORT_SYMBOL_GPL(tty_wakeup); |
721 | |
722 | /** |
723 | * tty_ldisc_flush - flush line discipline queue |
724 | * @tty: tty |
725 | * |
726 | * Flush the line discipline queue (if any) for this tty. If there |
727 | * is no line discipline active this is a no-op. |
728 | */ |
729 | |
730 | void tty_ldisc_flush(struct tty_struct *tty) |
731 | { |
732 | struct tty_ldisc *ld = tty_ldisc_ref(tty); |
733 | if(ld) { |
734 | if(ld->flush_buffer) |
735 | ld->flush_buffer(tty); |
736 | tty_ldisc_deref(ld); |
737 | } |
738 | } |
739 | |
740 | EXPORT_SYMBOL_GPL(tty_ldisc_flush); |
741 | |
742 | /* |
743 | * This can be called by the "eventd" kernel thread. That is process synchronous, |
744 | * but doesn't hold any locks, so we need to make sure we have the appropriate |
745 | * locks for what we're doing.. |
746 | */ |
747 | static void do_tty_hangup(void *data) |
748 | { |
749 | struct tty_struct *tty = (struct tty_struct *) data; |
750 | struct file * cons_filp = NULL; |
751 | struct file *filp, *f = NULL; |
752 | struct task_struct *p; |
753 | struct tty_ldisc *ld; |
754 | int closecount = 0, n; |
755 | |
756 | if (!tty) |
757 | return; |
758 | |
759 | /* inuse_filps is protected by the single kernel lock */ |
760 | lock_kernel(); |
761 | |
762 | spin_lock(&redirect_lock); |
763 | if (redirect && redirect->private_data == tty) { |
764 | f = redirect; |
765 | redirect = NULL; |
766 | } |
767 | spin_unlock(&redirect_lock); |
768 | |
769 | check_tty_count(tty, "do_tty_hangup"); |
770 | file_list_lock(); |
771 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
772 | list_for_each_entry(filp, &tty->tty_files, f_list) { |
773 | if (filp->f_op->write == redirected_tty_write) |
774 | cons_filp = filp; |
775 | if (filp->f_op->write != tty_write) |
776 | continue; |
777 | closecount++; |
778 | tty_fasync(-1, filp, 0); /* can't block */ |
779 | filp->f_op = &hung_up_tty_fops; |
780 | } |
781 | file_list_unlock(); |
782 | |
783 | /* FIXME! What are the locking issues here? This may me overdoing things.. |
784 | * this question is especially important now that we've removed the irqlock. */ |
785 | |
786 | ld = tty_ldisc_ref(tty); |
787 | if(ld != NULL) /* We may have no line discipline at this point */ |
788 | { |
789 | if (ld->flush_buffer) |
790 | ld->flush_buffer(tty); |
791 | if (tty->driver->flush_buffer) |
792 | tty->driver->flush_buffer(tty); |
793 | if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && |
794 | ld->write_wakeup) |
795 | ld->write_wakeup(tty); |
796 | if (ld->hangup) |
797 | ld->hangup(tty); |
798 | } |
799 | |
800 | /* FIXME: Once we trust the LDISC code better we can wait here for |
801 | ldisc completion and fix the driver call race */ |
802 | |
803 | wake_up_interruptible(&tty->write_wait); |
804 | wake_up_interruptible(&tty->read_wait); |
805 | |
806 | /* |
807 | * Shutdown the current line discipline, and reset it to |
808 | * N_TTY. |
809 | */ |
810 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
811 | { |
812 | down(&tty->termios_sem); |
813 | *tty->termios = tty->driver->init_termios; |
814 | up(&tty->termios_sem); |
815 | } |
816 | |
817 | /* Defer ldisc switch */ |
818 | /* tty_deferred_ldisc_switch(N_TTY); |
819 | |
820 | This should get done automatically when the port closes and |
821 | tty_release is called */ |
822 | |
823 | read_lock(&tasklist_lock); |
824 | if (tty->session > 0) { |
825 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
826 | if (p->signal->tty == tty) |
827 | p->signal->tty = NULL; |
828 | if (!p->signal->leader) |
829 | continue; |
830 | send_group_sig_info(SIGHUP, SEND_SIG_PRIV, p); |
831 | send_group_sig_info(SIGCONT, SEND_SIG_PRIV, p); |
832 | if (tty->pgrp > 0) |
833 | p->signal->tty_old_pgrp = tty->pgrp; |
834 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
835 | } |
836 | read_unlock(&tasklist_lock); |
837 | |
838 | tty->flags = 0; |
839 | tty->session = 0; |
840 | tty->pgrp = -1; |
841 | tty->ctrl_status = 0; |
842 | /* |
843 | * If one of the devices matches a console pointer, we |
844 | * cannot just call hangup() because that will cause |
845 | * tty->count and state->count to go out of sync. |
846 | * So we just call close() the right number of times. |
847 | */ |
848 | if (cons_filp) { |
849 | if (tty->driver->close) |
850 | for (n = 0; n < closecount; n++) |
851 | tty->driver->close(tty, cons_filp); |
852 | } else if (tty->driver->hangup) |
853 | (tty->driver->hangup)(tty); |
854 | |
855 | /* We don't want to have driver/ldisc interactions beyond |
856 | the ones we did here. The driver layer expects no |
857 | calls after ->hangup() from the ldisc side. However we |
858 | can't yet guarantee all that */ |
859 | |
860 | set_bit(TTY_HUPPED, &tty->flags); |
861 | if (ld) { |
862 | tty_ldisc_enable(tty); |
863 | tty_ldisc_deref(ld); |
864 | } |
865 | unlock_kernel(); |
866 | if (f) |
867 | fput(f); |
868 | } |
869 | |
870 | void tty_hangup(struct tty_struct * tty) |
871 | { |
872 | #ifdef TTY_DEBUG_HANGUP |
873 | char buf[64]; |
874 | |
875 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
876 | #endif |
877 | schedule_work(&tty->hangup_work); |
878 | } |
879 | |
880 | EXPORT_SYMBOL(tty_hangup); |
881 | |
882 | void tty_vhangup(struct tty_struct * tty) |
883 | { |
884 | #ifdef TTY_DEBUG_HANGUP |
885 | char buf[64]; |
886 | |
887 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); |
888 | #endif |
889 | do_tty_hangup((void *) tty); |
890 | } |
891 | EXPORT_SYMBOL(tty_vhangup); |
892 | |
893 | int tty_hung_up_p(struct file * filp) |
894 | { |
895 | return (filp->f_op == &hung_up_tty_fops); |
896 | } |
897 | |
898 | EXPORT_SYMBOL(tty_hung_up_p); |
899 | |
900 | /* |
901 | * This function is typically called only by the session leader, when |
902 | * it wants to disassociate itself from its controlling tty. |
903 | * |
904 | * It performs the following functions: |
905 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
906 | * (2) Clears the tty from being controlling the session |
907 | * (3) Clears the controlling tty for all processes in the |
908 | * session group. |
909 | * |
910 | * The argument on_exit is set to 1 if called when a process is |
911 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. |
912 | */ |
913 | void disassociate_ctty(int on_exit) |
914 | { |
915 | struct tty_struct *tty; |
916 | struct task_struct *p; |
917 | int tty_pgrp = -1; |
918 | |
919 | lock_kernel(); |
920 | |
921 | down(&tty_sem); |
922 | tty = current->signal->tty; |
923 | if (tty) { |
924 | tty_pgrp = tty->pgrp; |
925 | up(&tty_sem); |
926 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
927 | tty_vhangup(tty); |
928 | } else { |
929 | if (current->signal->tty_old_pgrp) { |
930 | kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit); |
931 | kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit); |
932 | } |
933 | up(&tty_sem); |
934 | unlock_kernel(); |
935 | return; |
936 | } |
937 | if (tty_pgrp > 0) { |
938 | kill_pg(tty_pgrp, SIGHUP, on_exit); |
939 | if (!on_exit) |
940 | kill_pg(tty_pgrp, SIGCONT, on_exit); |
941 | } |
942 | |
943 | /* Must lock changes to tty_old_pgrp */ |
944 | down(&tty_sem); |
945 | current->signal->tty_old_pgrp = 0; |
946 | tty->session = 0; |
947 | tty->pgrp = -1; |
948 | |
949 | /* Now clear signal->tty under the lock */ |
950 | read_lock(&tasklist_lock); |
951 | do_each_task_pid(current->signal->session, PIDTYPE_SID, p) { |
952 | p->signal->tty = NULL; |
953 | } while_each_task_pid(current->signal->session, PIDTYPE_SID, p); |
954 | read_unlock(&tasklist_lock); |
955 | up(&tty_sem); |
956 | unlock_kernel(); |
957 | } |
958 | |
959 | void stop_tty(struct tty_struct *tty) |
960 | { |
961 | if (tty->stopped) |
962 | return; |
963 | tty->stopped = 1; |
964 | if (tty->link && tty->link->packet) { |
965 | tty->ctrl_status &= ~TIOCPKT_START; |
966 | tty->ctrl_status |= TIOCPKT_STOP; |
967 | wake_up_interruptible(&tty->link->read_wait); |
968 | } |
969 | if (tty->driver->stop) |
970 | (tty->driver->stop)(tty); |
971 | } |
972 | |
973 | EXPORT_SYMBOL(stop_tty); |
974 | |
975 | void start_tty(struct tty_struct *tty) |
976 | { |
977 | if (!tty->stopped || tty->flow_stopped) |
978 | return; |
979 | tty->stopped = 0; |
980 | if (tty->link && tty->link->packet) { |
981 | tty->ctrl_status &= ~TIOCPKT_STOP; |
982 | tty->ctrl_status |= TIOCPKT_START; |
983 | wake_up_interruptible(&tty->link->read_wait); |
984 | } |
985 | if (tty->driver->start) |
986 | (tty->driver->start)(tty); |
987 | |
988 | /* If we have a running line discipline it may need kicking */ |
989 | tty_wakeup(tty); |
990 | wake_up_interruptible(&tty->write_wait); |
991 | } |
992 | |
993 | EXPORT_SYMBOL(start_tty); |
994 | |
995 | static ssize_t tty_read(struct file * file, char __user * buf, size_t count, |
996 | loff_t *ppos) |
997 | { |
998 | int i; |
999 | struct tty_struct * tty; |
1000 | struct inode *inode; |
1001 | struct tty_ldisc *ld; |
1002 | |
1003 | tty = (struct tty_struct *)file->private_data; |
1004 | inode = file->f_dentry->d_inode; |
1005 | if (tty_paranoia_check(tty, inode, "tty_read")) |
1006 | return -EIO; |
1007 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) |
1008 | return -EIO; |
1009 | |
1010 | /* We want to wait for the line discipline to sort out in this |
1011 | situation */ |
1012 | ld = tty_ldisc_ref_wait(tty); |
1013 | lock_kernel(); |
1014 | if (ld->read) |
1015 | i = (ld->read)(tty,file,buf,count); |
1016 | else |
1017 | i = -EIO; |
1018 | tty_ldisc_deref(ld); |
1019 | unlock_kernel(); |
1020 | if (i > 0) |
1021 | inode->i_atime = current_fs_time(inode->i_sb); |
1022 | return i; |
1023 | } |
1024 | |
1025 | /* |
1026 | * Split writes up in sane blocksizes to avoid |
1027 | * denial-of-service type attacks |
1028 | */ |
1029 | static inline ssize_t do_tty_write( |
1030 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), |
1031 | struct tty_struct *tty, |
1032 | struct file *file, |
1033 | const char __user *buf, |
1034 | size_t count) |
1035 | { |
1036 | ssize_t ret = 0, written = 0; |
1037 | unsigned int chunk; |
1038 | |
1039 | if (down_interruptible(&tty->atomic_write)) { |
1040 | return -ERESTARTSYS; |
1041 | } |
1042 | |
1043 | /* |
1044 | * We chunk up writes into a temporary buffer. This |
1045 | * simplifies low-level drivers immensely, since they |
1046 | * don't have locking issues and user mode accesses. |
1047 | * |
1048 | * But if TTY_NO_WRITE_SPLIT is set, we should use a |
1049 | * big chunk-size.. |
1050 | * |
1051 | * The default chunk-size is 2kB, because the NTTY |
1052 | * layer has problems with bigger chunks. It will |
1053 | * claim to be able to handle more characters than |
1054 | * it actually does. |
1055 | */ |
1056 | chunk = 2048; |
1057 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) |
1058 | chunk = 65536; |
1059 | if (count < chunk) |
1060 | chunk = count; |
1061 | |
1062 | /* write_buf/write_cnt is protected by the atomic_write semaphore */ |
1063 | if (tty->write_cnt < chunk) { |
1064 | unsigned char *buf; |
1065 | |
1066 | if (chunk < 1024) |
1067 | chunk = 1024; |
1068 | |
1069 | buf = kmalloc(chunk, GFP_KERNEL); |
1070 | if (!buf) { |
1071 | up(&tty->atomic_write); |
1072 | return -ENOMEM; |
1073 | } |
1074 | kfree(tty->write_buf); |
1075 | tty->write_cnt = chunk; |
1076 | tty->write_buf = buf; |
1077 | } |
1078 | |
1079 | /* Do the write .. */ |
1080 | for (;;) { |
1081 | size_t size = count; |
1082 | if (size > chunk) |
1083 | size = chunk; |
1084 | ret = -EFAULT; |
1085 | if (copy_from_user(tty->write_buf, buf, size)) |
1086 | break; |
1087 | lock_kernel(); |
1088 | ret = write(tty, file, tty->write_buf, size); |
1089 | unlock_kernel(); |
1090 | if (ret <= 0) |
1091 | break; |
1092 | written += ret; |
1093 | buf += ret; |
1094 | count -= ret; |
1095 | if (!count) |
1096 | break; |
1097 | ret = -ERESTARTSYS; |
1098 | if (signal_pending(current)) |
1099 | break; |
1100 | cond_resched(); |
1101 | } |
1102 | if (written) { |
1103 | struct inode *inode = file->f_dentry->d_inode; |
1104 | inode->i_mtime = current_fs_time(inode->i_sb); |
1105 | ret = written; |
1106 | } |
1107 | up(&tty->atomic_write); |
1108 | return ret; |
1109 | } |
1110 | |
1111 | |
1112 | static ssize_t tty_write(struct file * file, const char __user * buf, size_t count, |
1113 | loff_t *ppos) |
1114 | { |
1115 | struct tty_struct * tty; |
1116 | struct inode *inode = file->f_dentry->d_inode; |
1117 | ssize_t ret; |
1118 | struct tty_ldisc *ld; |
1119 | |
1120 | tty = (struct tty_struct *)file->private_data; |
1121 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1122 | return -EIO; |
1123 | if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags))) |
1124 | return -EIO; |
1125 | |
1126 | ld = tty_ldisc_ref_wait(tty); |
1127 | if (!ld->write) |
1128 | ret = -EIO; |
1129 | else |
1130 | ret = do_tty_write(ld->write, tty, file, buf, count); |
1131 | tty_ldisc_deref(ld); |
1132 | return ret; |
1133 | } |
1134 | |
1135 | ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count, |
1136 | loff_t *ppos) |
1137 | { |
1138 | struct file *p = NULL; |
1139 | |
1140 | spin_lock(&redirect_lock); |
1141 | if (redirect) { |
1142 | get_file(redirect); |
1143 | p = redirect; |
1144 | } |
1145 | spin_unlock(&redirect_lock); |
1146 | |
1147 | if (p) { |
1148 | ssize_t res; |
1149 | res = vfs_write(p, buf, count, &p->f_pos); |
1150 | fput(p); |
1151 | return res; |
1152 | } |
1153 | |
1154 | return tty_write(file, buf, count, ppos); |
1155 | } |
1156 | |
1157 | static char ptychar[] = "pqrstuvwxyzabcde"; |
1158 | |
1159 | static inline void pty_line_name(struct tty_driver *driver, int index, char *p) |
1160 | { |
1161 | int i = index + driver->name_base; |
1162 | /* ->name is initialized to "ttyp", but "tty" is expected */ |
1163 | sprintf(p, "%s%c%x", |
1164 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1165 | ptychar[i >> 4 & 0xf], i & 0xf); |
1166 | } |
1167 | |
1168 | static inline void tty_line_name(struct tty_driver *driver, int index, char *p) |
1169 | { |
1170 | sprintf(p, "%s%d", driver->name, index + driver->name_base); |
1171 | } |
1172 | |
1173 | /* |
1174 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
1175 | * failed open. The new code protects the open with a semaphore, so it's |
1176 | * really quite straightforward. The semaphore locking can probably be |
1177 | * relaxed for the (most common) case of reopening a tty. |
1178 | */ |
1179 | static int init_dev(struct tty_driver *driver, int idx, |
1180 | struct tty_struct **ret_tty) |
1181 | { |
1182 | struct tty_struct *tty, *o_tty; |
1183 | struct termios *tp, **tp_loc, *o_tp, **o_tp_loc; |
1184 | struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; |
1185 | int retval=0; |
1186 | |
1187 | /* check whether we're reopening an existing tty */ |
1188 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
1189 | tty = devpts_get_tty(idx); |
1190 | if (tty && driver->subtype == PTY_TYPE_MASTER) |
1191 | tty = tty->link; |
1192 | } else { |
1193 | tty = driver->ttys[idx]; |
1194 | } |
1195 | if (tty) goto fast_track; |
1196 | |
1197 | /* |
1198 | * First time open is complex, especially for PTY devices. |
1199 | * This code guarantees that either everything succeeds and the |
1200 | * TTY is ready for operation, or else the table slots are vacated |
1201 | * and the allocated memory released. (Except that the termios |
1202 | * and locked termios may be retained.) |
1203 | */ |
1204 | |
1205 | if (!try_module_get(driver->owner)) { |
1206 | retval = -ENODEV; |
1207 | goto end_init; |
1208 | } |
1209 | |
1210 | o_tty = NULL; |
1211 | tp = o_tp = NULL; |
1212 | ltp = o_ltp = NULL; |
1213 | |
1214 | tty = alloc_tty_struct(); |
1215 | if(!tty) |
1216 | goto fail_no_mem; |
1217 | initialize_tty_struct(tty); |
1218 | tty->driver = driver; |
1219 | tty->index = idx; |
1220 | tty_line_name(driver, idx, tty->name); |
1221 | |
1222 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
1223 | tp_loc = &tty->termios; |
1224 | ltp_loc = &tty->termios_locked; |
1225 | } else { |
1226 | tp_loc = &driver->termios[idx]; |
1227 | ltp_loc = &driver->termios_locked[idx]; |
1228 | } |
1229 | |
1230 | if (!*tp_loc) { |
1231 | tp = (struct termios *) kmalloc(sizeof(struct termios), |
1232 | GFP_KERNEL); |
1233 | if (!tp) |
1234 | goto free_mem_out; |
1235 | *tp = driver->init_termios; |
1236 | } |
1237 | |
1238 | if (!*ltp_loc) { |
1239 | ltp = (struct termios *) kmalloc(sizeof(struct termios), |
1240 | GFP_KERNEL); |
1241 | if (!ltp) |
1242 | goto free_mem_out; |
1243 | memset(ltp, 0, sizeof(struct termios)); |
1244 | } |
1245 | |
1246 | if (driver->type == TTY_DRIVER_TYPE_PTY) { |
1247 | o_tty = alloc_tty_struct(); |
1248 | if (!o_tty) |
1249 | goto free_mem_out; |
1250 | initialize_tty_struct(o_tty); |
1251 | o_tty->driver = driver->other; |
1252 | o_tty->index = idx; |
1253 | tty_line_name(driver->other, idx, o_tty->name); |
1254 | |
1255 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
1256 | o_tp_loc = &o_tty->termios; |
1257 | o_ltp_loc = &o_tty->termios_locked; |
1258 | } else { |
1259 | o_tp_loc = &driver->other->termios[idx]; |
1260 | o_ltp_loc = &driver->other->termios_locked[idx]; |
1261 | } |
1262 | |
1263 | if (!*o_tp_loc) { |
1264 | o_tp = (struct termios *) |
1265 | kmalloc(sizeof(struct termios), GFP_KERNEL); |
1266 | if (!o_tp) |
1267 | goto free_mem_out; |
1268 | *o_tp = driver->other->init_termios; |
1269 | } |
1270 | |
1271 | if (!*o_ltp_loc) { |
1272 | o_ltp = (struct termios *) |
1273 | kmalloc(sizeof(struct termios), GFP_KERNEL); |
1274 | if (!o_ltp) |
1275 | goto free_mem_out; |
1276 | memset(o_ltp, 0, sizeof(struct termios)); |
1277 | } |
1278 | |
1279 | /* |
1280 | * Everything allocated ... set up the o_tty structure. |
1281 | */ |
1282 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) { |
1283 | driver->other->ttys[idx] = o_tty; |
1284 | } |
1285 | if (!*o_tp_loc) |
1286 | *o_tp_loc = o_tp; |
1287 | if (!*o_ltp_loc) |
1288 | *o_ltp_loc = o_ltp; |
1289 | o_tty->termios = *o_tp_loc; |
1290 | o_tty->termios_locked = *o_ltp_loc; |
1291 | driver->other->refcount++; |
1292 | if (driver->subtype == PTY_TYPE_MASTER) |
1293 | o_tty->count++; |
1294 | |
1295 | /* Establish the links in both directions */ |
1296 | tty->link = o_tty; |
1297 | o_tty->link = tty; |
1298 | } |
1299 | |
1300 | /* |
1301 | * All structures have been allocated, so now we install them. |
1302 | * Failures after this point use release_mem to clean up, so |
1303 | * there's no need to null out the local pointers. |
1304 | */ |
1305 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
1306 | driver->ttys[idx] = tty; |
1307 | } |
1308 | |
1309 | if (!*tp_loc) |
1310 | *tp_loc = tp; |
1311 | if (!*ltp_loc) |
1312 | *ltp_loc = ltp; |
1313 | tty->termios = *tp_loc; |
1314 | tty->termios_locked = *ltp_loc; |
1315 | driver->refcount++; |
1316 | tty->count++; |
1317 | |
1318 | /* |
1319 | * Structures all installed ... call the ldisc open routines. |
1320 | * If we fail here just call release_mem to clean up. No need |
1321 | * to decrement the use counts, as release_mem doesn't care. |
1322 | */ |
1323 | |
1324 | if (tty->ldisc.open) { |
1325 | retval = (tty->ldisc.open)(tty); |
1326 | if (retval) |
1327 | goto release_mem_out; |
1328 | } |
1329 | if (o_tty && o_tty->ldisc.open) { |
1330 | retval = (o_tty->ldisc.open)(o_tty); |
1331 | if (retval) { |
1332 | if (tty->ldisc.close) |
1333 | (tty->ldisc.close)(tty); |
1334 | goto release_mem_out; |
1335 | } |
1336 | tty_ldisc_enable(o_tty); |
1337 | } |
1338 | tty_ldisc_enable(tty); |
1339 | goto success; |
1340 | |
1341 | /* |
1342 | * This fast open can be used if the tty is already open. |
1343 | * No memory is allocated, and the only failures are from |
1344 | * attempting to open a closing tty or attempting multiple |
1345 | * opens on a pty master. |
1346 | */ |
1347 | fast_track: |
1348 | if (test_bit(TTY_CLOSING, &tty->flags)) { |
1349 | retval = -EIO; |
1350 | goto end_init; |
1351 | } |
1352 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
1353 | driver->subtype == PTY_TYPE_MASTER) { |
1354 | /* |
1355 | * special case for PTY masters: only one open permitted, |
1356 | * and the slave side open count is incremented as well. |
1357 | */ |
1358 | if (tty->count) { |
1359 | retval = -EIO; |
1360 | goto end_init; |
1361 | } |
1362 | tty->link->count++; |
1363 | } |
1364 | tty->count++; |
1365 | tty->driver = driver; /* N.B. why do this every time?? */ |
1366 | |
1367 | /* FIXME */ |
1368 | if(!test_bit(TTY_LDISC, &tty->flags)) |
1369 | printk(KERN_ERR "init_dev but no ldisc\n"); |
1370 | success: |
1371 | *ret_tty = tty; |
1372 | |
1373 | /* All paths come through here to release the semaphore */ |
1374 | end_init: |
1375 | return retval; |
1376 | |
1377 | /* Release locally allocated memory ... nothing placed in slots */ |
1378 | free_mem_out: |
1379 | if (o_tp) |
1380 | kfree(o_tp); |
1381 | if (o_tty) |
1382 | free_tty_struct(o_tty); |
1383 | if (ltp) |
1384 | kfree(ltp); |
1385 | if (tp) |
1386 | kfree(tp); |
1387 | free_tty_struct(tty); |
1388 | |
1389 | fail_no_mem: |
1390 | module_put(driver->owner); |
1391 | retval = -ENOMEM; |
1392 | goto end_init; |
1393 | |
1394 | /* call the tty release_mem routine to clean out this slot */ |
1395 | release_mem_out: |
1396 | printk(KERN_INFO "init_dev: ldisc open failed, " |
1397 | "clearing slot %d\n", idx); |
1398 | release_mem(tty, idx); |
1399 | goto end_init; |
1400 | } |
1401 | |
1402 | /* |
1403 | * Releases memory associated with a tty structure, and clears out the |
1404 | * driver table slots. |
1405 | */ |
1406 | static void release_mem(struct tty_struct *tty, int idx) |
1407 | { |
1408 | struct tty_struct *o_tty; |
1409 | struct termios *tp; |
1410 | int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; |
1411 | |
1412 | if ((o_tty = tty->link) != NULL) { |
1413 | if (!devpts) |
1414 | o_tty->driver->ttys[idx] = NULL; |
1415 | if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
1416 | tp = o_tty->termios; |
1417 | if (!devpts) |
1418 | o_tty->driver->termios[idx] = NULL; |
1419 | kfree(tp); |
1420 | |
1421 | tp = o_tty->termios_locked; |
1422 | if (!devpts) |
1423 | o_tty->driver->termios_locked[idx] = NULL; |
1424 | kfree(tp); |
1425 | } |
1426 | o_tty->magic = 0; |
1427 | o_tty->driver->refcount--; |
1428 | file_list_lock(); |
1429 | list_del_init(&o_tty->tty_files); |
1430 | file_list_unlock(); |
1431 | free_tty_struct(o_tty); |
1432 | } |
1433 | |
1434 | if (!devpts) |
1435 | tty->driver->ttys[idx] = NULL; |
1436 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
1437 | tp = tty->termios; |
1438 | if (!devpts) |
1439 | tty->driver->termios[idx] = NULL; |
1440 | kfree(tp); |
1441 | |
1442 | tp = tty->termios_locked; |
1443 | if (!devpts) |
1444 | tty->driver->termios_locked[idx] = NULL; |
1445 | kfree(tp); |
1446 | } |
1447 | |
1448 | tty->magic = 0; |
1449 | tty->driver->refcount--; |
1450 | file_list_lock(); |
1451 | list_del_init(&tty->tty_files); |
1452 | file_list_unlock(); |
1453 | module_put(tty->driver->owner); |
1454 | free_tty_struct(tty); |
1455 | } |
1456 | |
1457 | /* |
1458 | * Even releasing the tty structures is a tricky business.. We have |
1459 | * to be very careful that the structures are all released at the |
1460 | * same time, as interrupts might otherwise get the wrong pointers. |
1461 | * |
1462 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could |
1463 | * lead to double frees or releasing memory still in use. |
1464 | */ |
1465 | static void release_dev(struct file * filp) |
1466 | { |
1467 | struct tty_struct *tty, *o_tty; |
1468 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
1469 | int devpts_master, devpts; |
1470 | int idx; |
1471 | char buf[64]; |
1472 | unsigned long flags; |
1473 | |
1474 | tty = (struct tty_struct *)filp->private_data; |
1475 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev")) |
1476 | return; |
1477 | |
1478 | check_tty_count(tty, "release_dev"); |
1479 | |
1480 | tty_fasync(-1, filp, 0); |
1481 | |
1482 | idx = tty->index; |
1483 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1484 | tty->driver->subtype == PTY_TYPE_MASTER); |
1485 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; |
1486 | devpts_master = pty_master && devpts; |
1487 | o_tty = tty->link; |
1488 | |
1489 | #ifdef TTY_PARANOIA_CHECK |
1490 | if (idx < 0 || idx >= tty->driver->num) { |
1491 | printk(KERN_DEBUG "release_dev: bad idx when trying to " |
1492 | "free (%s)\n", tty->name); |
1493 | return; |
1494 | } |
1495 | if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
1496 | if (tty != tty->driver->ttys[idx]) { |
1497 | printk(KERN_DEBUG "release_dev: driver.table[%d] not tty " |
1498 | "for (%s)\n", idx, tty->name); |
1499 | return; |
1500 | } |
1501 | if (tty->termios != tty->driver->termios[idx]) { |
1502 | printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios " |
1503 | "for (%s)\n", |
1504 | idx, tty->name); |
1505 | return; |
1506 | } |
1507 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { |
1508 | printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not " |
1509 | "termios_locked for (%s)\n", |
1510 | idx, tty->name); |
1511 | return; |
1512 | } |
1513 | } |
1514 | #endif |
1515 | |
1516 | #ifdef TTY_DEBUG_HANGUP |
1517 | printk(KERN_DEBUG "release_dev of %s (tty count=%d)...", |
1518 | tty_name(tty, buf), tty->count); |
1519 | #endif |
1520 | |
1521 | #ifdef TTY_PARANOIA_CHECK |
1522 | if (tty->driver->other && |
1523 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
1524 | if (o_tty != tty->driver->other->ttys[idx]) { |
1525 | printk(KERN_DEBUG "release_dev: other->table[%d] " |
1526 | "not o_tty for (%s)\n", |
1527 | idx, tty->name); |
1528 | return; |
1529 | } |
1530 | if (o_tty->termios != tty->driver->other->termios[idx]) { |
1531 | printk(KERN_DEBUG "release_dev: other->termios[%d] " |
1532 | "not o_termios for (%s)\n", |
1533 | idx, tty->name); |
1534 | return; |
1535 | } |
1536 | if (o_tty->termios_locked != |
1537 | tty->driver->other->termios_locked[idx]) { |
1538 | printk(KERN_DEBUG "release_dev: other->termios_locked[" |
1539 | "%d] not o_termios_locked for (%s)\n", |
1540 | idx, tty->name); |
1541 | return; |
1542 | } |
1543 | if (o_tty->link != tty) { |
1544 | printk(KERN_DEBUG "release_dev: bad pty pointers\n"); |
1545 | return; |
1546 | } |
1547 | } |
1548 | #endif |
1549 | if (tty->driver->close) |
1550 | tty->driver->close(tty, filp); |
1551 | |
1552 | /* |
1553 | * Sanity check: if tty->count is going to zero, there shouldn't be |
1554 | * any waiters on tty->read_wait or tty->write_wait. We test the |
1555 | * wait queues and kick everyone out _before_ actually starting to |
1556 | * close. This ensures that we won't block while releasing the tty |
1557 | * structure. |
1558 | * |
1559 | * The test for the o_tty closing is necessary, since the master and |
1560 | * slave sides may close in any order. If the slave side closes out |
1561 | * first, its count will be one, since the master side holds an open. |
1562 | * Thus this test wouldn't be triggered at the time the slave closes, |
1563 | * so we do it now. |
1564 | * |
1565 | * Note that it's possible for the tty to be opened again while we're |
1566 | * flushing out waiters. By recalculating the closing flags before |
1567 | * each iteration we avoid any problems. |
1568 | */ |
1569 | while (1) { |
1570 | /* Guard against races with tty->count changes elsewhere and |
1571 | opens on /dev/tty */ |
1572 | |
1573 | down(&tty_sem); |
1574 | tty_closing = tty->count <= 1; |
1575 | o_tty_closing = o_tty && |
1576 | (o_tty->count <= (pty_master ? 1 : 0)); |
1577 | up(&tty_sem); |
1578 | do_sleep = 0; |
1579 | |
1580 | if (tty_closing) { |
1581 | if (waitqueue_active(&tty->read_wait)) { |
1582 | wake_up(&tty->read_wait); |
1583 | do_sleep++; |
1584 | } |
1585 | if (waitqueue_active(&tty->write_wait)) { |
1586 | wake_up(&tty->write_wait); |
1587 | do_sleep++; |
1588 | } |
1589 | } |
1590 | if (o_tty_closing) { |
1591 | if (waitqueue_active(&o_tty->read_wait)) { |
1592 | wake_up(&o_tty->read_wait); |
1593 | do_sleep++; |
1594 | } |
1595 | if (waitqueue_active(&o_tty->write_wait)) { |
1596 | wake_up(&o_tty->write_wait); |
1597 | do_sleep++; |
1598 | } |
1599 | } |
1600 | if (!do_sleep) |
1601 | break; |
1602 | |
1603 | printk(KERN_WARNING "release_dev: %s: read/write wait queue " |
1604 | "active!\n", tty_name(tty, buf)); |
1605 | schedule(); |
1606 | } |
1607 | |
1608 | /* |
1609 | * The closing flags are now consistent with the open counts on |
1610 | * both sides, and we've completed the last operation that could |
1611 | * block, so it's safe to proceed with closing. |
1612 | */ |
1613 | |
1614 | down(&tty_sem); |
1615 | if (pty_master) { |
1616 | if (--o_tty->count < 0) { |
1617 | printk(KERN_WARNING "release_dev: bad pty slave count " |
1618 | "(%d) for %s\n", |
1619 | o_tty->count, tty_name(o_tty, buf)); |
1620 | o_tty->count = 0; |
1621 | } |
1622 | } |
1623 | if (--tty->count < 0) { |
1624 | printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n", |
1625 | tty->count, tty_name(tty, buf)); |
1626 | tty->count = 0; |
1627 | } |
1628 | up(&tty_sem); |
1629 | |
1630 | /* |
1631 | * We've decremented tty->count, so we need to remove this file |
1632 | * descriptor off the tty->tty_files list; this serves two |
1633 | * purposes: |
1634 | * - check_tty_count sees the correct number of file descriptors |
1635 | * associated with this tty. |
1636 | * - do_tty_hangup no longer sees this file descriptor as |
1637 | * something that needs to be handled for hangups. |
1638 | */ |
1639 | file_kill(filp); |
1640 | filp->private_data = NULL; |
1641 | |
1642 | /* |
1643 | * Perform some housekeeping before deciding whether to return. |
1644 | * |
1645 | * Set the TTY_CLOSING flag if this was the last open. In the |
1646 | * case of a pty we may have to wait around for the other side |
1647 | * to close, and TTY_CLOSING makes sure we can't be reopened. |
1648 | */ |
1649 | if(tty_closing) |
1650 | set_bit(TTY_CLOSING, &tty->flags); |
1651 | if(o_tty_closing) |
1652 | set_bit(TTY_CLOSING, &o_tty->flags); |
1653 | |
1654 | /* |
1655 | * If _either_ side is closing, make sure there aren't any |
1656 | * processes that still think tty or o_tty is their controlling |
1657 | * tty. |
1658 | */ |
1659 | if (tty_closing || o_tty_closing) { |
1660 | struct task_struct *p; |
1661 | |
1662 | read_lock(&tasklist_lock); |
1663 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
1664 | p->signal->tty = NULL; |
1665 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
1666 | if (o_tty) |
1667 | do_each_task_pid(o_tty->session, PIDTYPE_SID, p) { |
1668 | p->signal->tty = NULL; |
1669 | } while_each_task_pid(o_tty->session, PIDTYPE_SID, p); |
1670 | read_unlock(&tasklist_lock); |
1671 | } |
1672 | |
1673 | /* check whether both sides are closing ... */ |
1674 | if (!tty_closing || (o_tty && !o_tty_closing)) |
1675 | return; |
1676 | |
1677 | #ifdef TTY_DEBUG_HANGUP |
1678 | printk(KERN_DEBUG "freeing tty structure..."); |
1679 | #endif |
1680 | /* |
1681 | * Prevent flush_to_ldisc() from rescheduling the work for later. Then |
1682 | * kill any delayed work. As this is the final close it does not |
1683 | * race with the set_ldisc code path. |
1684 | */ |
1685 | clear_bit(TTY_LDISC, &tty->flags); |
1686 | clear_bit(TTY_DONT_FLIP, &tty->flags); |
1687 | cancel_delayed_work(&tty->flip.work); |
1688 | |
1689 | /* |
1690 | * Wait for ->hangup_work and ->flip.work handlers to terminate |
1691 | */ |
1692 | |
1693 | flush_scheduled_work(); |
1694 | |
1695 | /* |
1696 | * Wait for any short term users (we know they are just driver |
1697 | * side waiters as the file is closing so user count on the file |
1698 | * side is zero. |
1699 | */ |
1700 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
1701 | while(tty->ldisc.refcount) |
1702 | { |
1703 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
1704 | wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0); |
1705 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
1706 | } |
1707 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
1708 | /* |
1709 | * Shutdown the current line discipline, and reset it to N_TTY. |
1710 | * N.B. why reset ldisc when we're releasing the memory?? |
1711 | * |
1712 | * FIXME: this MUST get fixed for the new reflocking |
1713 | */ |
1714 | if (tty->ldisc.close) |
1715 | (tty->ldisc.close)(tty); |
1716 | tty_ldisc_put(tty->ldisc.num); |
1717 | |
1718 | /* |
1719 | * Switch the line discipline back |
1720 | */ |
1721 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
1722 | tty_set_termios_ldisc(tty,N_TTY); |
1723 | if (o_tty) { |
1724 | /* FIXME: could o_tty be in setldisc here ? */ |
1725 | clear_bit(TTY_LDISC, &o_tty->flags); |
1726 | if (o_tty->ldisc.close) |
1727 | (o_tty->ldisc.close)(o_tty); |
1728 | tty_ldisc_put(o_tty->ldisc.num); |
1729 | tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY)); |
1730 | tty_set_termios_ldisc(o_tty,N_TTY); |
1731 | } |
1732 | /* |
1733 | * The release_mem function takes care of the details of clearing |
1734 | * the slots and preserving the termios structure. |
1735 | */ |
1736 | release_mem(tty, idx); |
1737 | |
1738 | #ifdef CONFIG_UNIX98_PTYS |
1739 | /* Make this pty number available for reallocation */ |
1740 | if (devpts) { |
1741 | down(&allocated_ptys_lock); |
1742 | idr_remove(&allocated_ptys, idx); |
1743 | up(&allocated_ptys_lock); |
1744 | } |
1745 | #endif |
1746 | |
1747 | } |
1748 | |
1749 | /* |
1750 | * tty_open and tty_release keep up the tty count that contains the |
1751 | * number of opens done on a tty. We cannot use the inode-count, as |
1752 | * different inodes might point to the same tty. |
1753 | * |
1754 | * Open-counting is needed for pty masters, as well as for keeping |
1755 | * track of serial lines: DTR is dropped when the last close happens. |
1756 | * (This is not done solely through tty->count, now. - Ted 1/27/92) |
1757 | * |
1758 | * The termios state of a pty is reset on first open so that |
1759 | * settings don't persist across reuse. |
1760 | */ |
1761 | static int tty_open(struct inode * inode, struct file * filp) |
1762 | { |
1763 | struct tty_struct *tty; |
1764 | int noctty, retval; |
1765 | struct tty_driver *driver; |
1766 | int index; |
1767 | dev_t device = inode->i_rdev; |
1768 | unsigned short saved_flags = filp->f_flags; |
1769 | |
1770 | nonseekable_open(inode, filp); |
1771 | |
1772 | retry_open: |
1773 | noctty = filp->f_flags & O_NOCTTY; |
1774 | index = -1; |
1775 | retval = 0; |
1776 | |
1777 | down(&tty_sem); |
1778 | |
1779 | if (device == MKDEV(TTYAUX_MAJOR,0)) { |
1780 | if (!current->signal->tty) { |
1781 | up(&tty_sem); |
1782 | return -ENXIO; |
1783 | } |
1784 | driver = current->signal->tty->driver; |
1785 | index = current->signal->tty->index; |
1786 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
1787 | /* noctty = 1; */ |
1788 | goto got_driver; |
1789 | } |
1790 | #ifdef CONFIG_VT |
1791 | if (device == MKDEV(TTY_MAJOR,0)) { |
1792 | extern struct tty_driver *console_driver; |
1793 | driver = console_driver; |
1794 | index = fg_console; |
1795 | noctty = 1; |
1796 | goto got_driver; |
1797 | } |
1798 | #endif |
1799 | if (device == MKDEV(TTYAUX_MAJOR,1)) { |
1800 | driver = console_device(&index); |
1801 | if (driver) { |
1802 | /* Don't let /dev/console block */ |
1803 | filp->f_flags |= O_NONBLOCK; |
1804 | noctty = 1; |
1805 | goto got_driver; |
1806 | } |
1807 | up(&tty_sem); |
1808 | return -ENODEV; |
1809 | } |
1810 | |
1811 | driver = get_tty_driver(device, &index); |
1812 | if (!driver) { |
1813 | up(&tty_sem); |
1814 | return -ENODEV; |
1815 | } |
1816 | got_driver: |
1817 | retval = init_dev(driver, index, &tty); |
1818 | up(&tty_sem); |
1819 | if (retval) |
1820 | return retval; |
1821 | |
1822 | filp->private_data = tty; |
1823 | file_move(filp, &tty->tty_files); |
1824 | check_tty_count(tty, "tty_open"); |
1825 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1826 | tty->driver->subtype == PTY_TYPE_MASTER) |
1827 | noctty = 1; |
1828 | #ifdef TTY_DEBUG_HANGUP |
1829 | printk(KERN_DEBUG "opening %s...", tty->name); |
1830 | #endif |
1831 | if (!retval) { |
1832 | if (tty->driver->open) |
1833 | retval = tty->driver->open(tty, filp); |
1834 | else |
1835 | retval = -ENODEV; |
1836 | } |
1837 | filp->f_flags = saved_flags; |
1838 | |
1839 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
1840 | retval = -EBUSY; |
1841 | |
1842 | if (retval) { |
1843 | #ifdef TTY_DEBUG_HANGUP |
1844 | printk(KERN_DEBUG "error %d in opening %s...", retval, |
1845 | tty->name); |
1846 | #endif |
1847 | release_dev(filp); |
1848 | if (retval != -ERESTARTSYS) |
1849 | return retval; |
1850 | if (signal_pending(current)) |
1851 | return retval; |
1852 | schedule(); |
1853 | /* |
1854 | * Need to reset f_op in case a hangup happened. |
1855 | */ |
1856 | if (filp->f_op == &hung_up_tty_fops) |
1857 | filp->f_op = &tty_fops; |
1858 | goto retry_open; |
1859 | } |
1860 | if (!noctty && |
1861 | current->signal->leader && |
1862 | !current->signal->tty && |
1863 | tty->session == 0) { |
1864 | task_lock(current); |
1865 | current->signal->tty = tty; |
1866 | task_unlock(current); |
1867 | current->signal->tty_old_pgrp = 0; |
1868 | tty->session = current->signal->session; |
1869 | tty->pgrp = process_group(current); |
1870 | } |
1871 | return 0; |
1872 | } |
1873 | |
1874 | #ifdef CONFIG_UNIX98_PTYS |
1875 | static int ptmx_open(struct inode * inode, struct file * filp) |
1876 | { |
1877 | struct tty_struct *tty; |
1878 | int retval; |
1879 | int index; |
1880 | int idr_ret; |
1881 | |
1882 | nonseekable_open(inode, filp); |
1883 | |
1884 | /* find a device that is not in use. */ |
1885 | down(&allocated_ptys_lock); |
1886 | if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) { |
1887 | up(&allocated_ptys_lock); |
1888 | return -ENOMEM; |
1889 | } |
1890 | idr_ret = idr_get_new(&allocated_ptys, NULL, &index); |
1891 | if (idr_ret < 0) { |
1892 | up(&allocated_ptys_lock); |
1893 | if (idr_ret == -EAGAIN) |
1894 | return -ENOMEM; |
1895 | return -EIO; |
1896 | } |
1897 | if (index >= pty_limit) { |
1898 | idr_remove(&allocated_ptys, index); |
1899 | up(&allocated_ptys_lock); |
1900 | return -EIO; |
1901 | } |
1902 | up(&allocated_ptys_lock); |
1903 | |
1904 | down(&tty_sem); |
1905 | retval = init_dev(ptm_driver, index, &tty); |
1906 | up(&tty_sem); |
1907 | |
1908 | if (retval) |
1909 | goto out; |
1910 | |
1911 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ |
1912 | filp->private_data = tty; |
1913 | file_move(filp, &tty->tty_files); |
1914 | |
1915 | retval = -ENOMEM; |
1916 | if (devpts_pty_new(tty->link)) |
1917 | goto out1; |
1918 | |
1919 | check_tty_count(tty, "tty_open"); |
1920 | retval = ptm_driver->open(tty, filp); |
1921 | if (!retval) |
1922 | return 0; |
1923 | out1: |
1924 | release_dev(filp); |
1925 | out: |
1926 | down(&allocated_ptys_lock); |
1927 | idr_remove(&allocated_ptys, index); |
1928 | up(&allocated_ptys_lock); |
1929 | return retval; |
1930 | } |
1931 | #endif |
1932 | |
1933 | static int tty_release(struct inode * inode, struct file * filp) |
1934 | { |
1935 | lock_kernel(); |
1936 | release_dev(filp); |
1937 | unlock_kernel(); |
1938 | return 0; |
1939 | } |
1940 | |
1941 | /* No kernel lock held - fine */ |
1942 | static unsigned int tty_poll(struct file * filp, poll_table * wait) |
1943 | { |
1944 | struct tty_struct * tty; |
1945 | struct tty_ldisc *ld; |
1946 | int ret = 0; |
1947 | |
1948 | tty = (struct tty_struct *)filp->private_data; |
1949 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll")) |
1950 | return 0; |
1951 | |
1952 | ld = tty_ldisc_ref_wait(tty); |
1953 | if (ld->poll) |
1954 | ret = (ld->poll)(tty, filp, wait); |
1955 | tty_ldisc_deref(ld); |
1956 | return ret; |
1957 | } |
1958 | |
1959 | static int tty_fasync(int fd, struct file * filp, int on) |
1960 | { |
1961 | struct tty_struct * tty; |
1962 | int retval; |
1963 | |
1964 | tty = (struct tty_struct *)filp->private_data; |
1965 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync")) |
1966 | return 0; |
1967 | |
1968 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
1969 | if (retval <= 0) |
1970 | return retval; |
1971 | |
1972 | if (on) { |
1973 | if (!waitqueue_active(&tty->read_wait)) |
1974 | tty->minimum_to_wake = 1; |
1975 | retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0); |
1976 | if (retval) |
1977 | return retval; |
1978 | } else { |
1979 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) |
1980 | tty->minimum_to_wake = N_TTY_BUF_SIZE; |
1981 | } |
1982 | return 0; |
1983 | } |
1984 | |
1985 | static int tiocsti(struct tty_struct *tty, char __user *p) |
1986 | { |
1987 | char ch, mbz = 0; |
1988 | struct tty_ldisc *ld; |
1989 | |
1990 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
1991 | return -EPERM; |
1992 | if (get_user(ch, p)) |
1993 | return -EFAULT; |
1994 | ld = tty_ldisc_ref_wait(tty); |
1995 | ld->receive_buf(tty, &ch, &mbz, 1); |
1996 | tty_ldisc_deref(ld); |
1997 | return 0; |
1998 | } |
1999 | |
2000 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) |
2001 | { |
2002 | if (copy_to_user(arg, &tty->winsize, sizeof(*arg))) |
2003 | return -EFAULT; |
2004 | return 0; |
2005 | } |
2006 | |
2007 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, |
2008 | struct winsize __user * arg) |
2009 | { |
2010 | struct winsize tmp_ws; |
2011 | |
2012 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
2013 | return -EFAULT; |
2014 | if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) |
2015 | return 0; |
2016 | #ifdef CONFIG_VT |
2017 | if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { |
2018 | int rc; |
2019 | |
2020 | acquire_console_sem(); |
2021 | rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row); |
2022 | release_console_sem(); |
2023 | if (rc) |
2024 | return -ENXIO; |
2025 | } |
2026 | #endif |
2027 | if (tty->pgrp > 0) |
2028 | kill_pg(tty->pgrp, SIGWINCH, 1); |
2029 | if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0)) |
2030 | kill_pg(real_tty->pgrp, SIGWINCH, 1); |
2031 | tty->winsize = tmp_ws; |
2032 | real_tty->winsize = tmp_ws; |
2033 | return 0; |
2034 | } |
2035 | |
2036 | static int tioccons(struct file *file) |
2037 | { |
2038 | if (!capable(CAP_SYS_ADMIN)) |
2039 | return -EPERM; |
2040 | if (file->f_op->write == redirected_tty_write) { |
2041 | struct file *f; |
2042 | spin_lock(&redirect_lock); |
2043 | f = redirect; |
2044 | redirect = NULL; |
2045 | spin_unlock(&redirect_lock); |
2046 | if (f) |
2047 | fput(f); |
2048 | return 0; |
2049 | } |
2050 | spin_lock(&redirect_lock); |
2051 | if (redirect) { |
2052 | spin_unlock(&redirect_lock); |
2053 | return -EBUSY; |
2054 | } |
2055 | get_file(file); |
2056 | redirect = file; |
2057 | spin_unlock(&redirect_lock); |
2058 | return 0; |
2059 | } |
2060 | |
2061 | |
2062 | static int fionbio(struct file *file, int __user *p) |
2063 | { |
2064 | int nonblock; |
2065 | |
2066 | if (get_user(nonblock, p)) |
2067 | return -EFAULT; |
2068 | |
2069 | if (nonblock) |
2070 | file->f_flags |= O_NONBLOCK; |
2071 | else |
2072 | file->f_flags &= ~O_NONBLOCK; |
2073 | return 0; |
2074 | } |
2075 | |
2076 | static int tiocsctty(struct tty_struct *tty, int arg) |
2077 | { |
2078 | task_t *p; |
2079 | |
2080 | if (current->signal->leader && |
2081 | (current->signal->session == tty->session)) |
2082 | return 0; |
2083 | /* |
2084 | * The process must be a session leader and |
2085 | * not have a controlling tty already. |
2086 | */ |
2087 | if (!current->signal->leader || current->signal->tty) |
2088 | return -EPERM; |
2089 | if (tty->session > 0) { |
2090 | /* |
2091 | * This tty is already the controlling |
2092 | * tty for another session group! |
2093 | */ |
2094 | if ((arg == 1) && capable(CAP_SYS_ADMIN)) { |
2095 | /* |
2096 | * Steal it away |
2097 | */ |
2098 | |
2099 | read_lock(&tasklist_lock); |
2100 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
2101 | p->signal->tty = NULL; |
2102 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
2103 | read_unlock(&tasklist_lock); |
2104 | } else |
2105 | return -EPERM; |
2106 | } |
2107 | task_lock(current); |
2108 | current->signal->tty = tty; |
2109 | task_unlock(current); |
2110 | current->signal->tty_old_pgrp = 0; |
2111 | tty->session = current->signal->session; |
2112 | tty->pgrp = process_group(current); |
2113 | return 0; |
2114 | } |
2115 | |
2116 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2117 | { |
2118 | /* |
2119 | * (tty == real_tty) is a cheap way of |
2120 | * testing if the tty is NOT a master pty. |
2121 | */ |
2122 | if (tty == real_tty && current->signal->tty != real_tty) |
2123 | return -ENOTTY; |
2124 | return put_user(real_tty->pgrp, p); |
2125 | } |
2126 | |
2127 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2128 | { |
2129 | pid_t pgrp; |
2130 | int retval = tty_check_change(real_tty); |
2131 | |
2132 | if (retval == -EIO) |
2133 | return -ENOTTY; |
2134 | if (retval) |
2135 | return retval; |
2136 | if (!current->signal->tty || |
2137 | (current->signal->tty != real_tty) || |
2138 | (real_tty->session != current->signal->session)) |
2139 | return -ENOTTY; |
2140 | if (get_user(pgrp, p)) |
2141 | return -EFAULT; |
2142 | if (pgrp < 0) |
2143 | return -EINVAL; |
2144 | if (session_of_pgrp(pgrp) != current->signal->session) |
2145 | return -EPERM; |
2146 | real_tty->pgrp = pgrp; |
2147 | return 0; |
2148 | } |
2149 | |
2150 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2151 | { |
2152 | /* |
2153 | * (tty == real_tty) is a cheap way of |
2154 | * testing if the tty is NOT a master pty. |
2155 | */ |
2156 | if (tty == real_tty && current->signal->tty != real_tty) |
2157 | return -ENOTTY; |
2158 | if (real_tty->session <= 0) |
2159 | return -ENOTTY; |
2160 | return put_user(real_tty->session, p); |
2161 | } |
2162 | |
2163 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2164 | { |
2165 | int ldisc; |
2166 | |
2167 | if (get_user(ldisc, p)) |
2168 | return -EFAULT; |
2169 | return tty_set_ldisc(tty, ldisc); |
2170 | } |
2171 | |
2172 | static int send_break(struct tty_struct *tty, int duration) |
2173 | { |
2174 | tty->driver->break_ctl(tty, -1); |
2175 | if (!signal_pending(current)) { |
2176 | set_current_state(TASK_INTERRUPTIBLE); |
2177 | schedule_timeout(duration); |
2178 | } |
2179 | tty->driver->break_ctl(tty, 0); |
2180 | if (signal_pending(current)) |
2181 | return -EINTR; |
2182 | return 0; |
2183 | } |
2184 | |
2185 | static int |
2186 | tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) |
2187 | { |
2188 | int retval = -EINVAL; |
2189 | |
2190 | if (tty->driver->tiocmget) { |
2191 | retval = tty->driver->tiocmget(tty, file); |
2192 | |
2193 | if (retval >= 0) |
2194 | retval = put_user(retval, p); |
2195 | } |
2196 | return retval; |
2197 | } |
2198 | |
2199 | static int |
2200 | tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, |
2201 | unsigned __user *p) |
2202 | { |
2203 | int retval = -EINVAL; |
2204 | |
2205 | if (tty->driver->tiocmset) { |
2206 | unsigned int set, clear, val; |
2207 | |
2208 | retval = get_user(val, p); |
2209 | if (retval) |
2210 | return retval; |
2211 | |
2212 | set = clear = 0; |
2213 | switch (cmd) { |
2214 | case TIOCMBIS: |
2215 | set = val; |
2216 | break; |
2217 | case TIOCMBIC: |
2218 | clear = val; |
2219 | break; |
2220 | case TIOCMSET: |
2221 | set = val; |
2222 | clear = ~val; |
2223 | break; |
2224 | } |
2225 | |
2226 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
2227 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
2228 | |
2229 | retval = tty->driver->tiocmset(tty, file, set, clear); |
2230 | } |
2231 | return retval; |
2232 | } |
2233 | |
2234 | /* |
2235 | * Split this up, as gcc can choke on it otherwise.. |
2236 | */ |
2237 | int tty_ioctl(struct inode * inode, struct file * file, |
2238 | unsigned int cmd, unsigned long arg) |
2239 | { |
2240 | struct tty_struct *tty, *real_tty; |
2241 | void __user *p = (void __user *)arg; |
2242 | int retval; |
2243 | struct tty_ldisc *ld; |
2244 | |
2245 | tty = (struct tty_struct *)file->private_data; |
2246 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2247 | return -EINVAL; |
2248 | |
2249 | real_tty = tty; |
2250 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
2251 | tty->driver->subtype == PTY_TYPE_MASTER) |
2252 | real_tty = tty->link; |
2253 | |
2254 | /* |
2255 | * Break handling by driver |
2256 | */ |
2257 | if (!tty->driver->break_ctl) { |
2258 | switch(cmd) { |
2259 | case TIOCSBRK: |
2260 | case TIOCCBRK: |
2261 | if (tty->driver->ioctl) |
2262 | return tty->driver->ioctl(tty, file, cmd, arg); |
2263 | return -EINVAL; |
2264 | |
2265 | /* These two ioctl's always return success; even if */ |
2266 | /* the driver doesn't support them. */ |
2267 | case TCSBRK: |
2268 | case TCSBRKP: |
2269 | if (!tty->driver->ioctl) |
2270 | return 0; |
2271 | retval = tty->driver->ioctl(tty, file, cmd, arg); |
2272 | if (retval == -ENOIOCTLCMD) |
2273 | retval = 0; |
2274 | return retval; |
2275 | } |
2276 | } |
2277 | |
2278 | /* |
2279 | * Factor out some common prep work |
2280 | */ |
2281 | switch (cmd) { |
2282 | case TIOCSETD: |
2283 | case TIOCSBRK: |
2284 | case TIOCCBRK: |
2285 | case TCSBRK: |
2286 | case TCSBRKP: |
2287 | retval = tty_check_change(tty); |
2288 | if (retval) |
2289 | return retval; |
2290 | if (cmd != TIOCCBRK) { |
2291 | tty_wait_until_sent(tty, 0); |
2292 | if (signal_pending(current)) |
2293 | return -EINTR; |
2294 | } |
2295 | break; |
2296 | } |
2297 | |
2298 | switch (cmd) { |
2299 | case TIOCSTI: |
2300 | return tiocsti(tty, p); |
2301 | case TIOCGWINSZ: |
2302 | return tiocgwinsz(tty, p); |
2303 | case TIOCSWINSZ: |
2304 | return tiocswinsz(tty, real_tty, p); |
2305 | case TIOCCONS: |
2306 | return real_tty!=tty ? -EINVAL : tioccons(file); |
2307 | case FIONBIO: |
2308 | return fionbio(file, p); |
2309 | case TIOCEXCL: |
2310 | set_bit(TTY_EXCLUSIVE, &tty->flags); |
2311 | return 0; |
2312 | case TIOCNXCL: |
2313 | clear_bit(TTY_EXCLUSIVE, &tty->flags); |
2314 | return 0; |
2315 | case TIOCNOTTY: |
2316 | if (current->signal->tty != tty) |
2317 | return -ENOTTY; |
2318 | if (current->signal->leader) |
2319 | disassociate_ctty(0); |
2320 | task_lock(current); |
2321 | current->signal->tty = NULL; |
2322 | task_unlock(current); |
2323 | return 0; |
2324 | case TIOCSCTTY: |
2325 | return tiocsctty(tty, arg); |
2326 | case TIOCGPGRP: |
2327 | return tiocgpgrp(tty, real_tty, p); |
2328 | case TIOCSPGRP: |
2329 | return tiocspgrp(tty, real_tty, p); |
2330 | case TIOCGSID: |
2331 | return tiocgsid(tty, real_tty, p); |
2332 | case TIOCGETD: |
2333 | /* FIXME: check this is ok */ |
2334 | return put_user(tty->ldisc.num, (int __user *)p); |
2335 | case TIOCSETD: |
2336 | return tiocsetd(tty, p); |
2337 | #ifdef CONFIG_VT |
2338 | case TIOCLINUX: |
2339 | return tioclinux(tty, arg); |
2340 | #endif |
2341 | /* |
2342 | * Break handling |
2343 | */ |
2344 | case TIOCSBRK: /* Turn break on, unconditionally */ |
2345 | tty->driver->break_ctl(tty, -1); |
2346 | return 0; |
2347 | |
2348 | case TIOCCBRK: /* Turn break off, unconditionally */ |
2349 | tty->driver->break_ctl(tty, 0); |
2350 | return 0; |
2351 | case TCSBRK: /* SVID version: non-zero arg --> no break */ |
2352 | /* |
2353 | * XXX is the above comment correct, or the |
2354 | * code below correct? Is this ioctl used at |
2355 | * all by anyone? |
2356 | */ |
2357 | if (!arg) |
2358 | return send_break(tty, HZ/4); |
2359 | return 0; |
2360 | case TCSBRKP: /* support for POSIX tcsendbreak() */ |
2361 | return send_break(tty, arg ? arg*(HZ/10) : HZ/4); |
2362 | |
2363 | case TIOCMGET: |
2364 | return tty_tiocmget(tty, file, p); |
2365 | |
2366 | case TIOCMSET: |
2367 | case TIOCMBIC: |
2368 | case TIOCMBIS: |
2369 | return tty_tiocmset(tty, file, cmd, p); |
2370 | } |
2371 | if (tty->driver->ioctl) { |
2372 | retval = (tty->driver->ioctl)(tty, file, cmd, arg); |
2373 | if (retval != -ENOIOCTLCMD) |
2374 | return retval; |
2375 | } |
2376 | ld = tty_ldisc_ref_wait(tty); |
2377 | retval = -EINVAL; |
2378 | if (ld->ioctl) { |
2379 | retval = ld->ioctl(tty, file, cmd, arg); |
2380 | if (retval == -ENOIOCTLCMD) |
2381 | retval = -EINVAL; |
2382 | } |
2383 | tty_ldisc_deref(ld); |
2384 | return retval; |
2385 | } |
2386 | |
2387 | |
2388 | /* |
2389 | * This implements the "Secure Attention Key" --- the idea is to |
2390 | * prevent trojan horses by killing all processes associated with this |
2391 | * tty when the user hits the "Secure Attention Key". Required for |
2392 | * super-paranoid applications --- see the Orange Book for more details. |
2393 | * |
2394 | * This code could be nicer; ideally it should send a HUP, wait a few |
2395 | * seconds, then send a INT, and then a KILL signal. But you then |
2396 | * have to coordinate with the init process, since all processes associated |
2397 | * with the current tty must be dead before the new getty is allowed |
2398 | * to spawn. |
2399 | * |
2400 | * Now, if it would be correct ;-/ The current code has a nasty hole - |
2401 | * it doesn't catch files in flight. We may send the descriptor to ourselves |
2402 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. |
2403 | * |
2404 | * Nasty bug: do_SAK is being called in interrupt context. This can |
2405 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 |
2406 | */ |
2407 | static void __do_SAK(void *arg) |
2408 | { |
2409 | #ifdef TTY_SOFT_SAK |
2410 | tty_hangup(tty); |
2411 | #else |
2412 | struct tty_struct *tty = arg; |
2413 | struct task_struct *p; |
2414 | int session; |
2415 | int i; |
2416 | struct file *filp; |
2417 | struct tty_ldisc *disc; |
2418 | |
2419 | if (!tty) |
2420 | return; |
2421 | session = tty->session; |
2422 | |
2423 | /* We don't want an ldisc switch during this */ |
2424 | disc = tty_ldisc_ref(tty); |
2425 | if (disc && disc->flush_buffer) |
2426 | disc->flush_buffer(tty); |
2427 | tty_ldisc_deref(disc); |
2428 | |
2429 | if (tty->driver->flush_buffer) |
2430 | tty->driver->flush_buffer(tty); |
2431 | |
2432 | read_lock(&tasklist_lock); |
2433 | do_each_task_pid(session, PIDTYPE_SID, p) { |
2434 | if (p->signal->tty == tty || session > 0) { |
2435 | printk(KERN_NOTICE "SAK: killed process %d" |
2436 | " (%s): p->signal->session==tty->session\n", |
2437 | p->pid, p->comm); |
2438 | send_sig(SIGKILL, p, 1); |
2439 | continue; |
2440 | } |
2441 | task_lock(p); |
2442 | if (p->files) { |
2443 | spin_lock(&p->files->file_lock); |
2444 | for (i=0; i < p->files->max_fds; i++) { |
2445 | filp = fcheck_files(p->files, i); |
2446 | if (!filp) |
2447 | continue; |
2448 | if (filp->f_op->read == tty_read && |
2449 | filp->private_data == tty) { |
2450 | printk(KERN_NOTICE "SAK: killed process %d" |
2451 | " (%s): fd#%d opened to the tty\n", |
2452 | p->pid, p->comm, i); |
2453 | send_sig(SIGKILL, p, 1); |
2454 | break; |
2455 | } |
2456 | } |
2457 | spin_unlock(&p->files->file_lock); |
2458 | } |
2459 | task_unlock(p); |
2460 | } while_each_task_pid(session, PIDTYPE_SID, p); |
2461 | read_unlock(&tasklist_lock); |
2462 | #endif |
2463 | } |
2464 | |
2465 | /* |
2466 | * The tq handling here is a little racy - tty->SAK_work may already be queued. |
2467 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, |
2468 | * the values which we write to it will be identical to the values which it |
2469 | * already has. --akpm |
2470 | */ |
2471 | void do_SAK(struct tty_struct *tty) |
2472 | { |
2473 | if (!tty) |
2474 | return; |
2475 | PREPARE_WORK(&tty->SAK_work, __do_SAK, tty); |
2476 | schedule_work(&tty->SAK_work); |
2477 | } |
2478 | |
2479 | EXPORT_SYMBOL(do_SAK); |
2480 | |
2481 | /* |
2482 | * This routine is called out of the software interrupt to flush data |
2483 | * from the flip buffer to the line discipline. |
2484 | */ |
2485 | |
2486 | static void flush_to_ldisc(void *private_) |
2487 | { |
2488 | struct tty_struct *tty = (struct tty_struct *) private_; |
2489 | unsigned char *cp; |
2490 | char *fp; |
2491 | int count; |
2492 | unsigned long flags; |
2493 | struct tty_ldisc *disc; |
2494 | |
2495 | disc = tty_ldisc_ref(tty); |
2496 | if (disc == NULL) /* !TTY_LDISC */ |
2497 | return; |
2498 | |
2499 | if (test_bit(TTY_DONT_FLIP, &tty->flags)) { |
2500 | /* |
2501 | * Do it after the next timer tick: |
2502 | */ |
2503 | schedule_delayed_work(&tty->flip.work, 1); |
2504 | goto out; |
2505 | } |
2506 | spin_lock_irqsave(&tty->read_lock, flags); |
2507 | if (tty->flip.buf_num) { |
2508 | cp = tty->flip.char_buf + TTY_FLIPBUF_SIZE; |
2509 | fp = tty->flip.flag_buf + TTY_FLIPBUF_SIZE; |
2510 | tty->flip.buf_num = 0; |
2511 | tty->flip.char_buf_ptr = tty->flip.char_buf; |
2512 | tty->flip.flag_buf_ptr = tty->flip.flag_buf; |
2513 | } else { |
2514 | cp = tty->flip.char_buf; |
2515 | fp = tty->flip.flag_buf; |
2516 | tty->flip.buf_num = 1; |
2517 | tty->flip.char_buf_ptr = tty->flip.char_buf + TTY_FLIPBUF_SIZE; |
2518 | tty->flip.flag_buf_ptr = tty->flip.flag_buf + TTY_FLIPBUF_SIZE; |
2519 | } |
2520 | count = tty->flip.count; |
2521 | tty->flip.count = 0; |
2522 | spin_unlock_irqrestore(&tty->read_lock, flags); |
2523 | |
2524 | disc->receive_buf(tty, cp, fp, count); |
2525 | out: |
2526 | tty_ldisc_deref(disc); |
2527 | } |
2528 | |
2529 | /* |
2530 | * Routine which returns the baud rate of the tty |
2531 | * |
2532 | * Note that the baud_table needs to be kept in sync with the |
2533 | * include/asm/termbits.h file. |
2534 | */ |
2535 | static int baud_table[] = { |
2536 | 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, |
2537 | 9600, 19200, 38400, 57600, 115200, 230400, 460800, |
2538 | #ifdef __sparc__ |
2539 | 76800, 153600, 307200, 614400, 921600 |
2540 | #else |
2541 | 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, |
2542 | 2500000, 3000000, 3500000, 4000000 |
2543 | #endif |
2544 | }; |
2545 | |
2546 | static int n_baud_table = ARRAY_SIZE(baud_table); |
2547 | |
2548 | /** |
2549 | * tty_termios_baud_rate |
2550 | * @termios: termios structure |
2551 | * |
2552 | * Convert termios baud rate data into a speed. This should be called |
2553 | * with the termios lock held if this termios is a terminal termios |
2554 | * structure. May change the termios data. |
2555 | */ |
2556 | |
2557 | int tty_termios_baud_rate(struct termios *termios) |
2558 | { |
2559 | unsigned int cbaud; |
2560 | |
2561 | cbaud = termios->c_cflag & CBAUD; |
2562 | |
2563 | if (cbaud & CBAUDEX) { |
2564 | cbaud &= ~CBAUDEX; |
2565 | |
2566 | if (cbaud < 1 || cbaud + 15 > n_baud_table) |
2567 | termios->c_cflag &= ~CBAUDEX; |
2568 | else |
2569 | cbaud += 15; |
2570 | } |
2571 | return baud_table[cbaud]; |
2572 | } |
2573 | |
2574 | EXPORT_SYMBOL(tty_termios_baud_rate); |
2575 | |
2576 | /** |
2577 | * tty_get_baud_rate - get tty bit rates |
2578 | * @tty: tty to query |
2579 | * |
2580 | * Returns the baud rate as an integer for this terminal. The |
2581 | * termios lock must be held by the caller and the terminal bit |
2582 | * flags may be updated. |
2583 | */ |
2584 | |
2585 | int tty_get_baud_rate(struct tty_struct *tty) |
2586 | { |
2587 | int baud = tty_termios_baud_rate(tty->termios); |
2588 | |
2589 | if (baud == 38400 && tty->alt_speed) { |
2590 | if (!tty->warned) { |
2591 | printk(KERN_WARNING "Use of setserial/setrocket to " |
2592 | "set SPD_* flags is deprecated\n"); |
2593 | tty->warned = 1; |
2594 | } |
2595 | baud = tty->alt_speed; |
2596 | } |
2597 | |
2598 | return baud; |
2599 | } |
2600 | |
2601 | EXPORT_SYMBOL(tty_get_baud_rate); |
2602 | |
2603 | /** |
2604 | * tty_flip_buffer_push - terminal |
2605 | * @tty: tty to push |
2606 | * |
2607 | * Queue a push of the terminal flip buffers to the line discipline. This |
2608 | * function must not be called from IRQ context if tty->low_latency is set. |
2609 | * |
2610 | * In the event of the queue being busy for flipping the work will be |
2611 | * held off and retried later. |
2612 | */ |
2613 | |
2614 | void tty_flip_buffer_push(struct tty_struct *tty) |
2615 | { |
2616 | if (tty->low_latency) |
2617 | flush_to_ldisc((void *) tty); |
2618 | else |
2619 | schedule_delayed_work(&tty->flip.work, 1); |
2620 | } |
2621 | |
2622 | EXPORT_SYMBOL(tty_flip_buffer_push); |
2623 | |
2624 | /* |
2625 | * This subroutine initializes a tty structure. |
2626 | */ |
2627 | static void initialize_tty_struct(struct tty_struct *tty) |
2628 | { |
2629 | memset(tty, 0, sizeof(struct tty_struct)); |
2630 | tty->magic = TTY_MAGIC; |
2631 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
2632 | tty->pgrp = -1; |
2633 | tty->overrun_time = jiffies; |
2634 | tty->flip.char_buf_ptr = tty->flip.char_buf; |
2635 | tty->flip.flag_buf_ptr = tty->flip.flag_buf; |
2636 | INIT_WORK(&tty->flip.work, flush_to_ldisc, tty); |
2637 | init_MUTEX(&tty->flip.pty_sem); |
2638 | init_MUTEX(&tty->termios_sem); |
2639 | init_waitqueue_head(&tty->write_wait); |
2640 | init_waitqueue_head(&tty->read_wait); |
2641 | INIT_WORK(&tty->hangup_work, do_tty_hangup, tty); |
2642 | sema_init(&tty->atomic_read, 1); |
2643 | sema_init(&tty->atomic_write, 1); |
2644 | spin_lock_init(&tty->read_lock); |
2645 | INIT_LIST_HEAD(&tty->tty_files); |
2646 | INIT_WORK(&tty->SAK_work, NULL, NULL); |
2647 | } |
2648 | |
2649 | /* |
2650 | * The default put_char routine if the driver did not define one. |
2651 | */ |
2652 | static void tty_default_put_char(struct tty_struct *tty, unsigned char ch) |
2653 | { |
2654 | tty->driver->write(tty, &ch, 1); |
2655 | } |
2656 | |
2657 | static struct class_simple *tty_class; |
2658 | |
2659 | /** |
2660 | * tty_register_device - register a tty device |
2661 | * @driver: the tty driver that describes the tty device |
2662 | * @index: the index in the tty driver for this tty device |
2663 | * @device: a struct device that is associated with this tty device. |
2664 | * This field is optional, if there is no known struct device for this |
2665 | * tty device it can be set to NULL safely. |
2666 | * |
2667 | * This call is required to be made to register an individual tty device if |
2668 | * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that |
2669 | * bit is not set, this function should not be called. |
2670 | */ |
2671 | void tty_register_device(struct tty_driver *driver, unsigned index, |
2672 | struct device *device) |
2673 | { |
2674 | char name[64]; |
2675 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; |
2676 | |
2677 | if (index >= driver->num) { |
2678 | printk(KERN_ERR "Attempt to register invalid tty line number " |
2679 | " (%d).\n", index); |
2680 | return; |
2681 | } |
2682 | |
2683 | devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR, |
2684 | "%s%d", driver->devfs_name, index + driver->name_base); |
2685 | |
2686 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
2687 | pty_line_name(driver, index, name); |
2688 | else |
2689 | tty_line_name(driver, index, name); |
2690 | class_simple_device_add(tty_class, dev, device, name); |
2691 | } |
2692 | |
2693 | /** |
2694 | * tty_unregister_device - unregister a tty device |
2695 | * @driver: the tty driver that describes the tty device |
2696 | * @index: the index in the tty driver for this tty device |
2697 | * |
2698 | * If a tty device is registered with a call to tty_register_device() then |
2699 | * this function must be made when the tty device is gone. |
2700 | */ |
2701 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
2702 | { |
2703 | devfs_remove("%s%d", driver->devfs_name, index + driver->name_base); |
2704 | class_simple_device_remove(MKDEV(driver->major, driver->minor_start) + index); |
2705 | } |
2706 | |
2707 | EXPORT_SYMBOL(tty_register_device); |
2708 | EXPORT_SYMBOL(tty_unregister_device); |
2709 | |
2710 | struct tty_driver *alloc_tty_driver(int lines) |
2711 | { |
2712 | struct tty_driver *driver; |
2713 | |
2714 | driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL); |
2715 | if (driver) { |
2716 | memset(driver, 0, sizeof(struct tty_driver)); |
2717 | driver->magic = TTY_DRIVER_MAGIC; |
2718 | driver->num = lines; |
2719 | /* later we'll move allocation of tables here */ |
2720 | } |
2721 | return driver; |
2722 | } |
2723 | |
2724 | void put_tty_driver(struct tty_driver *driver) |
2725 | { |
2726 | kfree(driver); |
2727 | } |
2728 | |
2729 | void tty_set_operations(struct tty_driver *driver, struct tty_operations *op) |
2730 | { |
2731 | driver->open = op->open; |
2732 | driver->close = op->close; |
2733 | driver->write = op->write; |
2734 | driver->put_char = op->put_char; |
2735 | driver->flush_chars = op->flush_chars; |
2736 | driver->write_room = op->write_room; |
2737 | driver->chars_in_buffer = op->chars_in_buffer; |
2738 | driver->ioctl = op->ioctl; |
2739 | driver->set_termios = op->set_termios; |
2740 | driver->throttle = op->throttle; |
2741 | driver->unthrottle = op->unthrottle; |
2742 | driver->stop = op->stop; |
2743 | driver->start = op->start; |
2744 | driver->hangup = op->hangup; |
2745 | driver->break_ctl = op->break_ctl; |
2746 | driver->flush_buffer = op->flush_buffer; |
2747 | driver->set_ldisc = op->set_ldisc; |
2748 | driver->wait_until_sent = op->wait_until_sent; |
2749 | driver->send_xchar = op->send_xchar; |
2750 | driver->read_proc = op->read_proc; |
2751 | driver->write_proc = op->write_proc; |
2752 | driver->tiocmget = op->tiocmget; |
2753 | driver->tiocmset = op->tiocmset; |
2754 | } |
2755 | |
2756 | |
2757 | EXPORT_SYMBOL(alloc_tty_driver); |
2758 | EXPORT_SYMBOL(put_tty_driver); |
2759 | EXPORT_SYMBOL(tty_set_operations); |
2760 | |
2761 | /* |
2762 | * Called by a tty driver to register itself. |
2763 | */ |
2764 | int tty_register_driver(struct tty_driver *driver) |
2765 | { |
2766 | int error; |
2767 | int i; |
2768 | dev_t dev; |
2769 | void **p = NULL; |
2770 | |
2771 | if (driver->flags & TTY_DRIVER_INSTALLED) |
2772 | return 0; |
2773 | |
2774 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
2775 | p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); |
2776 | if (!p) |
2777 | return -ENOMEM; |
2778 | memset(p, 0, driver->num * 3 * sizeof(void *)); |
2779 | } |
2780 | |
2781 | if (!driver->major) { |
2782 | error = alloc_chrdev_region(&dev, driver->minor_start, driver->num, |
2783 | (char*)driver->name); |
2784 | if (!error) { |
2785 | driver->major = MAJOR(dev); |
2786 | driver->minor_start = MINOR(dev); |
2787 | } |
2788 | } else { |
2789 | dev = MKDEV(driver->major, driver->minor_start); |
2790 | error = register_chrdev_region(dev, driver->num, |
2791 | (char*)driver->name); |
2792 | } |
2793 | if (error < 0) { |
2794 | kfree(p); |
2795 | return error; |
2796 | } |
2797 | |
2798 | if (p) { |
2799 | driver->ttys = (struct tty_struct **)p; |
2800 | driver->termios = (struct termios **)(p + driver->num); |
2801 | driver->termios_locked = (struct termios **)(p + driver->num * 2); |
2802 | } else { |
2803 | driver->ttys = NULL; |
2804 | driver->termios = NULL; |
2805 | driver->termios_locked = NULL; |
2806 | } |
2807 | |
2808 | cdev_init(&driver->cdev, &tty_fops); |
2809 | driver->cdev.owner = driver->owner; |
2810 | error = cdev_add(&driver->cdev, dev, driver->num); |
2811 | if (error) { |
2812 | cdev_del(&driver->cdev); |
2813 | unregister_chrdev_region(dev, driver->num); |
2814 | driver->ttys = NULL; |
2815 | driver->termios = driver->termios_locked = NULL; |
2816 | kfree(p); |
2817 | return error; |
2818 | } |
2819 | |
2820 | if (!driver->put_char) |
2821 | driver->put_char = tty_default_put_char; |
2822 | |
2823 | list_add(&driver->tty_drivers, &tty_drivers); |
2824 | |
2825 | if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) { |
2826 | for(i = 0; i < driver->num; i++) |
2827 | tty_register_device(driver, i, NULL); |
2828 | } |
2829 | proc_tty_register_driver(driver); |
2830 | return 0; |
2831 | } |
2832 | |
2833 | EXPORT_SYMBOL(tty_register_driver); |
2834 | |
2835 | /* |
2836 | * Called by a tty driver to unregister itself. |
2837 | */ |
2838 | int tty_unregister_driver(struct tty_driver *driver) |
2839 | { |
2840 | int i; |
2841 | struct termios *tp; |
2842 | void *p; |
2843 | |
2844 | if (driver->refcount) |
2845 | return -EBUSY; |
2846 | |
2847 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
2848 | driver->num); |
2849 | |
2850 | list_del(&driver->tty_drivers); |
2851 | |
2852 | /* |
2853 | * Free the termios and termios_locked structures because |
2854 | * we don't want to get memory leaks when modular tty |
2855 | * drivers are removed from the kernel. |
2856 | */ |
2857 | for (i = 0; i < driver->num; i++) { |
2858 | tp = driver->termios[i]; |
2859 | if (tp) { |
2860 | driver->termios[i] = NULL; |
2861 | kfree(tp); |
2862 | } |
2863 | tp = driver->termios_locked[i]; |
2864 | if (tp) { |
2865 | driver->termios_locked[i] = NULL; |
2866 | kfree(tp); |
2867 | } |
2868 | if (!(driver->flags & TTY_DRIVER_NO_DEVFS)) |
2869 | tty_unregister_device(driver, i); |
2870 | } |
2871 | p = driver->ttys; |
2872 | proc_tty_unregister_driver(driver); |
2873 | driver->ttys = NULL; |
2874 | driver->termios = driver->termios_locked = NULL; |
2875 | kfree(p); |
2876 | cdev_del(&driver->cdev); |
2877 | return 0; |
2878 | } |
2879 | |
2880 | EXPORT_SYMBOL(tty_unregister_driver); |
2881 | |
2882 | |
2883 | /* |
2884 | * Initialize the console device. This is called *early*, so |
2885 | * we can't necessarily depend on lots of kernel help here. |
2886 | * Just do some early initializations, and do the complex setup |
2887 | * later. |
2888 | */ |
2889 | void __init console_init(void) |
2890 | { |
2891 | initcall_t *call; |
2892 | |
2893 | /* Setup the default TTY line discipline. */ |
2894 | (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); |
2895 | |
2896 | /* |
2897 | * set up the console device so that later boot sequences can |
2898 | * inform about problems etc.. |
2899 | */ |
2900 | #ifdef CONFIG_EARLY_PRINTK |
2901 | disable_early_printk(); |
2902 | #endif |
2903 | #ifdef CONFIG_SERIAL_68360 |
2904 | /* This is not a console initcall. I know not what it's doing here. |
2905 | So I haven't moved it. dwmw2 */ |
2906 | rs_360_init(); |
2907 | #endif |
2908 | call = __con_initcall_start; |
2909 | while (call < __con_initcall_end) { |
2910 | (*call)(); |
2911 | call++; |
2912 | } |
2913 | } |
2914 | |
2915 | #ifdef CONFIG_VT |
2916 | extern int vty_init(void); |
2917 | #endif |
2918 | |
2919 | static int __init tty_class_init(void) |
2920 | { |
2921 | tty_class = class_simple_create(THIS_MODULE, "tty"); |
2922 | if (IS_ERR(tty_class)) |
2923 | return PTR_ERR(tty_class); |
2924 | return 0; |
2925 | } |
2926 | |
2927 | postcore_initcall(tty_class_init); |
2928 | |
2929 | /* 3/2004 jmc: why do these devices exist? */ |
2930 | |
2931 | static struct cdev tty_cdev, console_cdev; |
2932 | #ifdef CONFIG_UNIX98_PTYS |
2933 | static struct cdev ptmx_cdev; |
2934 | #endif |
2935 | #ifdef CONFIG_VT |
2936 | static struct cdev vc0_cdev; |
2937 | #endif |
2938 | |
2939 | /* |
2940 | * Ok, now we can initialize the rest of the tty devices and can count |
2941 | * on memory allocations, interrupts etc.. |
2942 | */ |
2943 | static int __init tty_init(void) |
2944 | { |
2945 | cdev_init(&tty_cdev, &tty_fops); |
2946 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || |
2947 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) |
2948 | panic("Couldn't register /dev/tty driver\n"); |
2949 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty"); |
2950 | class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
2951 | |
2952 | cdev_init(&console_cdev, &console_fops); |
2953 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || |
2954 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) |
2955 | panic("Couldn't register /dev/console driver\n"); |
2956 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console"); |
2957 | class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 1), NULL, "console"); |
2958 | |
2959 | #ifdef CONFIG_UNIX98_PTYS |
2960 | cdev_init(&ptmx_cdev, &ptmx_fops); |
2961 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || |
2962 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) |
2963 | panic("Couldn't register /dev/ptmx driver\n"); |
2964 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx"); |
2965 | class_simple_device_add(tty_class, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); |
2966 | #endif |
2967 | |
2968 | #ifdef CONFIG_VT |
2969 | cdev_init(&vc0_cdev, &console_fops); |
2970 | if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || |
2971 | register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) |
2972 | panic("Couldn't register /dev/tty0 driver\n"); |
2973 | devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0"); |
2974 | class_simple_device_add(tty_class, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); |
2975 | |
2976 | vty_init(); |
2977 | #endif |
2978 | return 0; |
2979 | } |
2980 | module_init(tty_init); |