Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block
[linux-2.6] / arch / um / drivers / line.c
1 /*
2  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5
6 #include "linux/sched.h"
7 #include "linux/slab.h"
8 #include "linux/list.h"
9 #include "linux/kd.h"
10 #include "linux/interrupt.h"
11 #include "linux/devfs_fs_kernel.h"
12 #include "asm/uaccess.h"
13 #include "chan_kern.h"
14 #include "irq_user.h"
15 #include "line.h"
16 #include "kern.h"
17 #include "user_util.h"
18 #include "kern_util.h"
19 #include "os.h"
20 #include "irq_kern.h"
21
22 #define LINE_BUFSIZE 4096
23
24 static irqreturn_t line_interrupt(int irq, void *data, struct pt_regs *unused)
25 {
26         struct chan *chan = data;
27         struct line *line = chan->line;
28         struct tty_struct *tty = line->tty;
29
30         if (line)
31                 chan_interrupt(&line->chan_list, &line->task, tty, irq);
32         return IRQ_HANDLED;
33 }
34
35 static void line_timer_cb(void *arg)
36 {
37         struct line *line = arg;
38
39         if(!line->throttled)
40                 chan_interrupt(&line->chan_list, &line->task, line->tty,
41                                line->driver->read_irq);
42 }
43
44 /* Returns the free space inside the ring buffer of this line.
45  *
46  * Should be called while holding line->lock (this does not modify datas).
47  */
48 static int write_room(struct line *line)
49 {
50         int n;
51
52         if (line->buffer == NULL)
53                 return LINE_BUFSIZE - 1;
54
55         /* This is for the case where the buffer is wrapped! */
56         n = line->head - line->tail;
57
58         if (n <= 0)
59                 n = LINE_BUFSIZE + n; /* The other case */
60         return n - 1;
61 }
62
63 int line_write_room(struct tty_struct *tty)
64 {
65         struct line *line = tty->driver_data;
66         unsigned long flags;
67         int room;
68
69         if (tty->stopped)
70                 return 0;
71
72         spin_lock_irqsave(&line->lock, flags);
73         room = write_room(line);
74         spin_unlock_irqrestore(&line->lock, flags);
75
76         /*XXX: Warning to remove */
77         if (0 == room)
78                 printk(KERN_DEBUG "%s: %s: no room left in buffer\n",
79                        __FUNCTION__,tty->name);
80         return room;
81 }
82
83 int line_chars_in_buffer(struct tty_struct *tty)
84 {
85         struct line *line = tty->driver_data;
86         unsigned long flags;
87         int ret;
88
89         spin_lock_irqsave(&line->lock, flags);
90
91         /*write_room subtracts 1 for the needed NULL, so we readd it.*/
92         ret = LINE_BUFSIZE - (write_room(line) + 1);
93         spin_unlock_irqrestore(&line->lock, flags);
94
95         return ret;
96 }
97
98 /*
99  * This copies the content of buf into the circular buffer associated with
100  * this line.
101  * The return value is the number of characters actually copied, i.e. the ones
102  * for which there was space: this function is not supposed to ever flush out
103  * the circular buffer.
104  *
105  * Must be called while holding line->lock!
106  */
107 static int buffer_data(struct line *line, const char *buf, int len)
108 {
109         int end, room;
110
111         if(line->buffer == NULL){
112                 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
113                 if (line->buffer == NULL) {
114                         printk("buffer_data - atomic allocation failed\n");
115                         return(0);
116                 }
117                 line->head = line->buffer;
118                 line->tail = line->buffer;
119         }
120
121         room = write_room(line);
122         len = (len > room) ? room : len;
123
124         end = line->buffer + LINE_BUFSIZE - line->tail;
125
126         if (len < end){
127                 memcpy(line->tail, buf, len);
128                 line->tail += len;
129         }
130         else {
131                 /* The circular buffer is wrapping */
132                 memcpy(line->tail, buf, end);
133                 buf += end;
134                 memcpy(line->buffer, buf, len - end);
135                 line->tail = line->buffer + len - end;
136         }
137
138         return len;
139 }
140
141 /*
142  * Flushes the ring buffer to the output channels. That is, write_chan is
143  * called, passing it line->head as buffer, and an appropriate count.
144  *
145  * On exit, returns 1 when the buffer is empty,
146  * 0 when the buffer is not empty on exit,
147  * and -errno when an error occurred.
148  *
149  * Must be called while holding line->lock!*/
150 static int flush_buffer(struct line *line)
151 {
152         int n, count;
153
154         if ((line->buffer == NULL) || (line->head == line->tail))
155                 return 1;
156
157         if (line->tail < line->head) {
158                 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
159                 count = line->buffer + LINE_BUFSIZE - line->head;
160
161                 n = write_chan(&line->chan_list, line->head, count,
162                                line->driver->write_irq);
163                 if (n < 0)
164                         return n;
165                 if (n == count) {
166                         /* We have flushed from ->head to buffer end, now we
167                          * must flush only from the beginning to ->tail.*/
168                         line->head = line->buffer;
169                 } else {
170                         line->head += n;
171                         return 0;
172                 }
173         }
174
175         count = line->tail - line->head;
176         n = write_chan(&line->chan_list, line->head, count,
177                        line->driver->write_irq);
178
179         if(n < 0)
180                 return n;
181
182         line->head += n;
183         return line->head == line->tail;
184 }
185
186 void line_flush_buffer(struct tty_struct *tty)
187 {
188         struct line *line = tty->driver_data;
189         unsigned long flags;
190         int err;
191
192         /*XXX: copied from line_write, verify if it is correct!*/
193         if(tty->stopped)
194                 return;
195                 //return 0;
196
197         spin_lock_irqsave(&line->lock, flags);
198         err = flush_buffer(line);
199         /*if (err == 1)
200                 err = 0;*/
201         spin_unlock_irqrestore(&line->lock, flags);
202         //return err;
203 }
204
205 /* We map both ->flush_chars and ->put_char (which go in pair) onto ->flush_buffer
206  * and ->write. Hope it's not that bad.*/
207 void line_flush_chars(struct tty_struct *tty)
208 {
209         line_flush_buffer(tty);
210 }
211
212 void line_put_char(struct tty_struct *tty, unsigned char ch)
213 {
214         line_write(tty, &ch, sizeof(ch));
215 }
216
217 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
218 {
219         struct line *line = tty->driver_data;
220         unsigned long flags;
221         int n, err, ret = 0;
222
223         if(tty->stopped)
224                 return 0;
225
226         spin_lock_irqsave(&line->lock, flags);
227         if (line->head != line->tail) {
228                 ret = buffer_data(line, buf, len);
229                 err = flush_buffer(line);
230                 if (err <= 0 && (err != -EAGAIN || !ret))
231                         ret = err;
232         } else {
233                 n = write_chan(&line->chan_list, buf, len,
234                                line->driver->write_irq);
235                 if (n < 0) {
236                         ret = n;
237                         goto out_up;
238                 }
239
240                 len -= n;
241                 ret += n;
242                 if (len > 0)
243                         ret += buffer_data(line, buf + n, len);
244         }
245 out_up:
246         spin_unlock_irqrestore(&line->lock, flags);
247         return ret;
248 }
249
250 void line_set_termios(struct tty_struct *tty, struct termios * old)
251 {
252         /* nothing */
253 }
254
255 static struct {
256         int  cmd;
257         char *level;
258         char *name;
259 } tty_ioctls[] = {
260         /* don't print these, they flood the log ... */
261         { TCGETS,      NULL,       "TCGETS"      },
262         { TCSETS,      NULL,       "TCSETS"      },
263         { TCSETSW,     NULL,       "TCSETSW"     },
264         { TCFLSH,      NULL,       "TCFLSH"      },
265         { TCSBRK,      NULL,       "TCSBRK"      },
266
267         /* general tty stuff */
268         { TCSETSF,     KERN_DEBUG, "TCSETSF"     },
269         { TCGETA,      KERN_DEBUG, "TCGETA"      },
270         { TIOCMGET,    KERN_DEBUG, "TIOCMGET"    },
271         { TCSBRKP,     KERN_DEBUG, "TCSBRKP"     },
272         { TIOCMSET,    KERN_DEBUG, "TIOCMSET"    },
273
274         /* linux-specific ones */
275         { TIOCLINUX,   KERN_INFO,  "TIOCLINUX"   },
276         { KDGKBMODE,   KERN_INFO,  "KDGKBMODE"   },
277         { KDGKBTYPE,   KERN_INFO,  "KDGKBTYPE"   },
278         { KDSIGACCEPT, KERN_INFO,  "KDSIGACCEPT" },
279 };
280
281 int line_ioctl(struct tty_struct *tty, struct file * file,
282                unsigned int cmd, unsigned long arg)
283 {
284         int ret;
285         int i;
286
287         ret = 0;
288         switch(cmd) {
289 #ifdef TIOCGETP
290         case TIOCGETP:
291         case TIOCSETP:
292         case TIOCSETN:
293 #endif
294 #ifdef TIOCGETC
295         case TIOCGETC:
296         case TIOCSETC:
297 #endif
298 #ifdef TIOCGLTC
299         case TIOCGLTC:
300         case TIOCSLTC:
301 #endif
302         case TCGETS:
303         case TCSETSF:
304         case TCSETSW:
305         case TCSETS:
306         case TCGETA:
307         case TCSETAF:
308         case TCSETAW:
309         case TCSETA:
310         case TCXONC:
311         case TCFLSH:
312         case TIOCOUTQ:
313         case TIOCINQ:
314         case TIOCGLCKTRMIOS:
315         case TIOCSLCKTRMIOS:
316         case TIOCPKT:
317         case TIOCGSOFTCAR:
318         case TIOCSSOFTCAR:
319                 return -ENOIOCTLCMD;
320 #if 0
321         case TCwhatever:
322                 /* do something */
323                 break;
324 #endif
325         default:
326                 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
327                         if (cmd == tty_ioctls[i].cmd)
328                                 break;
329                 if (i < ARRAY_SIZE(tty_ioctls)) {
330                         if (NULL != tty_ioctls[i].level)
331                                 printk("%s%s: %s: ioctl %s called\n",
332                                        tty_ioctls[i].level, __FUNCTION__,
333                                        tty->name, tty_ioctls[i].name);
334                 } else {
335                         printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
336                                __FUNCTION__, tty->name, cmd);
337                 }
338                 ret = -ENOIOCTLCMD;
339                 break;
340         }
341         return ret;
342 }
343
344 void line_throttle(struct tty_struct *tty)
345 {
346         struct line *line = tty->driver_data;
347
348         deactivate_chan(&line->chan_list, line->driver->read_irq);
349         line->throttled = 1;
350 }
351
352 void line_unthrottle(struct tty_struct *tty)
353 {
354         struct line *line = tty->driver_data;
355
356         line->throttled = 0;
357         chan_interrupt(&line->chan_list, &line->task, tty,
358                        line->driver->read_irq);
359
360         /* Maybe there is enough stuff pending that calling the interrupt
361          * throttles us again.  In this case, line->throttled will be 1
362          * again and we shouldn't turn the interrupt back on.
363          */
364         if(!line->throttled)
365                 reactivate_chan(&line->chan_list, line->driver->read_irq);
366 }
367
368 static irqreturn_t line_write_interrupt(int irq, void *data,
369                                         struct pt_regs *unused)
370 {
371         struct chan *chan = data;
372         struct line *line = chan->line;
373         struct tty_struct *tty = line->tty;
374         int err;
375
376         /* Interrupts are enabled here because we registered the interrupt with
377          * SA_INTERRUPT (see line_setup_irq).*/
378
379         spin_lock_irq(&line->lock);
380         err = flush_buffer(line);
381         if (err == 0) {
382                 return IRQ_NONE;
383         } else if(err < 0) {
384                 line->head = line->buffer;
385                 line->tail = line->buffer;
386         }
387         spin_unlock_irq(&line->lock);
388
389         if(tty == NULL)
390                 return IRQ_NONE;
391
392         if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags) &&
393            (tty->ldisc.write_wakeup != NULL))
394                 (tty->ldisc.write_wakeup)(tty);
395
396         /* BLOCKING mode
397          * In blocking mode, everything sleeps on tty->write_wait.
398          * Sleeping in the console driver would break non-blocking
399          * writes.
400          */
401
402         if (waitqueue_active(&tty->write_wait))
403                 wake_up_interruptible(&tty->write_wait);
404         return IRQ_HANDLED;
405 }
406
407 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
408 {
409         struct line_driver *driver = line->driver;
410         int err = 0, flags = SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM;
411
412         if (input)
413                 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
414                                        line_interrupt, flags,
415                                        driver->read_irq_name, data);
416         if (err)
417                 return err;
418         if (output)
419                 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
420                                         line_write_interrupt, flags,
421                                         driver->write_irq_name, data);
422         line->have_irq = 1;
423         return err;
424 }
425
426 int line_open(struct line *lines, struct tty_struct *tty)
427 {
428         struct line *line;
429         int err = -ENODEV;
430
431         line = &lines[tty->index];
432         tty->driver_data = line;
433
434         /* The IRQ which takes this lock is not yet enabled and won't be run
435          * before the end, so we don't need to use spin_lock_irq.*/
436         spin_lock(&line->lock);
437
438         tty->driver_data = line;
439         line->tty = tty;
440         if(!line->valid)
441                 goto out;
442
443         if(tty->count == 1){
444                 /* Here the device is opened, if necessary, and interrupt
445                  * is registered.
446                  */
447                 enable_chan(line);
448                 INIT_WORK(&line->task, line_timer_cb, line);
449
450                 if(!line->sigio){
451                         chan_enable_winch(&line->chan_list, tty);
452                         line->sigio = 1;
453                 }
454
455                 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
456                                  &tty->winsize.ws_col);
457         }
458
459         err = 0;
460 out:
461         spin_unlock(&line->lock);
462         return err;
463 }
464
465 static void unregister_winch(struct tty_struct *tty);
466
467 void line_close(struct tty_struct *tty, struct file * filp)
468 {
469         struct line *line = tty->driver_data;
470
471         /* XXX: I assume this should be called in process context, not with
472          *  interrupts disabled!
473          */
474         spin_lock_irq(&line->lock);
475
476         /* We ignore the error anyway! */
477         flush_buffer(line);
478
479         if(tty->count == 1){
480                 line->tty = NULL;
481                 tty->driver_data = NULL;
482
483                 if(line->sigio){
484                         unregister_winch(tty);
485                         line->sigio = 0;
486                 }
487         }
488
489         spin_unlock_irq(&line->lock);
490 }
491
492 void close_lines(struct line *lines, int nlines)
493 {
494         int i;
495
496         for(i = 0; i < nlines; i++)
497                 close_chan(&lines[i].chan_list, 0);
498 }
499
500 /* Common setup code for both startup command line and mconsole initialization.
501  * @lines contains the the array (of size @num) to modify;
502  * @init is the setup string;
503  */
504
505 int line_setup(struct line *lines, unsigned int num, char *init)
506 {
507         int i, n;
508         char *end;
509
510         if(*init == '=') {
511                 /* We said con=/ssl= instead of con#=, so we are configuring all
512                  * consoles at once.*/
513                 n = -1;
514         }
515         else {
516                 n = simple_strtoul(init, &end, 0);
517                 if(*end != '='){
518                         printk(KERN_ERR "line_setup failed to parse \"%s\"\n",
519                                init);
520                         return 0;
521                 }
522                 init = end;
523         }
524         init++;
525
526         if (n >= (signed int) num) {
527                 printk("line_setup - %d out of range ((0 ... %d) allowed)\n",
528                        n, num - 1);
529                 return 0;
530         }
531         else if (n >= 0){
532                 if (lines[n].tty != NULL) {
533                         printk("line_setup - device %d is open\n", n);
534                         return 0;
535                 }
536                 if (lines[n].init_pri <= INIT_ONE){
537                         lines[n].init_pri = INIT_ONE;
538                         if (!strcmp(init, "none"))
539                                 lines[n].valid = 0;
540                         else {
541                                 lines[n].init_str = init;
542                                 lines[n].valid = 1;
543                         }
544                 }
545         }
546         else {
547                 for(i = 0; i < num; i++){
548                         if(lines[i].init_pri <= INIT_ALL){
549                                 lines[i].init_pri = INIT_ALL;
550                                 if(!strcmp(init, "none")) lines[i].valid = 0;
551                                 else {
552                                         lines[i].init_str = init;
553                                         lines[i].valid = 1;
554                                 }
555                         }
556                 }
557         }
558         return n == -1 ? num : n;
559 }
560
561 int line_config(struct line *lines, unsigned int num, char *str,
562                 struct chan_opts *opts)
563 {
564         struct line *line;
565         char *new;
566         int n;
567
568         if(*str == '='){
569                 printk("line_config - can't configure all devices from "
570                        "mconsole\n");
571                 return 1;
572         }
573
574         new = kstrdup(str, GFP_KERNEL);
575         if(new == NULL){
576                 printk("line_config - kstrdup failed\n");
577                 return 1;
578         }
579         n = line_setup(lines, num, new);
580         if(n < 0)
581                 return 1;
582
583         line = &lines[n];
584         return parse_chan_pair(line->init_str, line, n, opts);
585 }
586
587 int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
588                     int size, char **error_out)
589 {
590         struct line *line;
591         char *end;
592         int dev, n = 0;
593
594         dev = simple_strtoul(name, &end, 0);
595         if((*end != '\0') || (end == name)){
596                 *error_out = "line_get_config failed to parse device number";
597                 return 0;
598         }
599
600         if((dev < 0) || (dev >= num)){
601                 *error_out = "device number out of range";
602                 return 0;
603         }
604
605         line = &lines[dev];
606
607         spin_lock(&line->lock);
608         if(!line->valid)
609                 CONFIG_CHUNK(str, size, n, "none", 1);
610         else if(line->tty == NULL)
611                 CONFIG_CHUNK(str, size, n, line->init_str, 1);
612         else n = chan_config_string(&line->chan_list, str, size, error_out);
613         spin_unlock(&line->lock);
614
615         return n;
616 }
617
618 int line_id(char **str, int *start_out, int *end_out)
619 {
620         char *end;
621         int n;
622
623         n = simple_strtoul(*str, &end, 0);
624         if((*end != '\0') || (end == *str))
625                 return -1;
626
627         *str = end;
628         *start_out = n;
629         *end_out = n;
630         return n;
631 }
632
633 int line_remove(struct line *lines, unsigned int num, int n)
634 {
635         int err;
636         char config[sizeof("conxxxx=none\0")];
637
638         sprintf(config, "%d=none", n);
639         err = line_setup(lines, num, config);
640         if(err >= 0)
641                 err = 0;
642         return err;
643 }
644
645 struct tty_driver *line_register_devfs(struct lines *set,
646                          struct line_driver *line_driver,
647                          struct tty_operations *ops, struct line *lines,
648                          int nlines)
649 {
650         int i;
651         struct tty_driver *driver = alloc_tty_driver(nlines);
652
653         if (!driver)
654                 return NULL;
655
656         driver->driver_name = line_driver->name;
657         driver->name = line_driver->device_name;
658         driver->devfs_name = line_driver->devfs_name;
659         driver->major = line_driver->major;
660         driver->minor_start = line_driver->minor_start;
661         driver->type = line_driver->type;
662         driver->subtype = line_driver->subtype;
663         driver->flags = TTY_DRIVER_REAL_RAW;
664         driver->init_termios = tty_std_termios;
665         tty_set_operations(driver, ops);
666
667         if (tty_register_driver(driver)) {
668                 printk("%s: can't register %s driver\n",
669                        __FUNCTION__,line_driver->name);
670                 put_tty_driver(driver);
671                 return NULL;
672         }
673
674         for(i = 0; i < nlines; i++){
675                 if(!lines[i].valid)
676                         tty_unregister_device(driver, i);
677         }
678
679         mconsole_register_dev(&line_driver->mc);
680         return driver;
681 }
682
683 static DEFINE_SPINLOCK(winch_handler_lock);
684 static LIST_HEAD(winch_handlers);
685
686 void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
687 {
688         struct line *line;
689         int i;
690
691         for(i = 0; i < nlines; i++){
692                 line = &lines[i];
693                 INIT_LIST_HEAD(&line->chan_list);
694
695                 if(line->init_str == NULL)
696                         continue;
697
698                 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
699                 if(line->init_str == NULL)
700                         printk("lines_init - kstrdup returned NULL\n");
701
702                 if(parse_chan_pair(line->init_str, line, i, opts)){
703                         printk("parse_chan_pair failed for device %d\n", i);
704                         line->valid = 0;
705                 }
706         }
707 }
708
709 struct winch {
710         struct list_head list;
711         int fd;
712         int tty_fd;
713         int pid;
714         struct tty_struct *tty;
715 };
716
717 static irqreturn_t winch_interrupt(int irq, void *data, struct pt_regs *unused)
718 {
719         struct winch *winch = data;
720         struct tty_struct *tty;
721         struct line *line;
722         int err;
723         char c;
724
725         if(winch->fd != -1){
726                 err = generic_read(winch->fd, &c, NULL);
727                 if(err < 0){
728                         if(err != -EAGAIN){
729                                 printk("winch_interrupt : read failed, "
730                                        "errno = %d\n", -err);
731                                 printk("fd %d is losing SIGWINCH support\n",
732                                        winch->tty_fd);
733                                 return IRQ_HANDLED;
734                         }
735                         goto out;
736                 }
737         }
738         tty  = winch->tty;
739         if (tty != NULL) {
740                 line = tty->driver_data;
741                 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
742                                  &tty->winsize.ws_col);
743                 kill_pg(tty->pgrp, SIGWINCH, 1);
744         }
745  out:
746         if(winch->fd != -1)
747                 reactivate_fd(winch->fd, WINCH_IRQ);
748         return IRQ_HANDLED;
749 }
750
751 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty)
752 {
753         struct winch *winch;
754
755         winch = kmalloc(sizeof(*winch), GFP_KERNEL);
756         if (winch == NULL) {
757                 printk("register_winch_irq - kmalloc failed\n");
758                 return;
759         }
760
761         *winch = ((struct winch) { .list        = LIST_HEAD_INIT(winch->list),
762                                    .fd          = fd,
763                                    .tty_fd      = tty_fd,
764                                    .pid         = pid,
765                                    .tty         = tty });
766
767         spin_lock(&winch_handler_lock);
768         list_add(&winch->list, &winch_handlers);
769         spin_unlock(&winch_handler_lock);
770
771         if(um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
772                           SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM,
773                           "winch", winch) < 0)
774                 printk("register_winch_irq - failed to register IRQ\n");
775 }
776
777 static void free_winch(struct winch *winch)
778 {
779         list_del(&winch->list);
780
781         if(winch->pid != -1)
782                 os_kill_process(winch->pid, 1);
783         if(winch->fd != -1)
784                 os_close_file(winch->fd);
785
786         free_irq(WINCH_IRQ, winch);
787         kfree(winch);
788 }
789
790 static void unregister_winch(struct tty_struct *tty)
791 {
792         struct list_head *ele;
793         struct winch *winch;
794
795         spin_lock(&winch_handler_lock);
796
797         list_for_each(ele, &winch_handlers){
798                 winch = list_entry(ele, struct winch, list);
799                 if(winch->tty == tty){
800                         free_winch(winch);
801                         break;
802                 }
803         }
804         spin_unlock(&winch_handler_lock);
805 }
806
807 static void winch_cleanup(void)
808 {
809         struct list_head *ele, *next;
810         struct winch *winch;
811
812         spin_lock(&winch_handler_lock);
813
814         list_for_each_safe(ele, next, &winch_handlers){
815                 winch = list_entry(ele, struct winch, list);
816                 free_winch(winch);
817         }
818
819         spin_unlock(&winch_handler_lock);
820 }
821 __uml_exitcall(winch_cleanup);
822
823 char *add_xterm_umid(char *base)
824 {
825         char *umid, *title;
826         int len;
827
828         umid = get_umid();
829         if(*umid == '\0')
830                 return base;
831
832         len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
833         title = kmalloc(len, GFP_KERNEL);
834         if(title == NULL){
835                 printk("Failed to allocate buffer for xterm title\n");
836                 return base;
837         }
838
839         snprintf(title, len, "%s (%s)", base, umid);
840         return title;
841 }