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