diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/tty_io.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/char/tty_io.c')
-rw-r--r-- | drivers/char/tty_io.c | 2980 |
1 files changed, 2980 insertions, 0 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c new file mode 100644 index 000000000000..06e5a3f1836d --- /dev/null +++ b/drivers/char/tty_io.c | |||
@@ -0,0 +1,2980 @@ | |||
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 | inline 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); | ||