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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/irqreturn.h>
7#include <linux/kd.h>
8#include <linux/sched/signal.h>
9#include <linux/slab.h>
10
11#include "chan.h"
12#include <irq_kern.h>
13#include <irq_user.h>
14#include <kern_util.h>
15#include <os.h>
16
17#define LINE_BUFSIZE 4096
18
19static irqreturn_t line_interrupt(int irq, void *data)
20{
21 struct chan *chan = data;
22 struct line *line = chan->line;
23
24 if (line)
25 chan_interrupt(line, irq);
26
27 return IRQ_HANDLED;
28}
29
30/*
31 * Returns the free space inside the ring buffer of this line.
32 *
33 * Should be called while holding line->lock (this does not modify data).
34 */
35static unsigned int write_room(struct line *line)
36{
37 int n;
38
39 if (line->buffer == NULL)
40 return LINE_BUFSIZE - 1;
41
42 /* This is for the case where the buffer is wrapped! */
43 n = line->head - line->tail;
44
45 if (n <= 0)
46 n += LINE_BUFSIZE; /* The other case */
47 return n - 1;
48}
49
50unsigned int line_write_room(struct tty_struct *tty)
51{
52 struct line *line = tty->driver_data;
53 unsigned long flags;
54 unsigned int room;
55
56 spin_lock_irqsave(&line->lock, flags);
57 room = write_room(line);
58 spin_unlock_irqrestore(&line->lock, flags);
59
60 return room;
61}
62
63unsigned int line_chars_in_buffer(struct tty_struct *tty)
64{
65 struct line *line = tty->driver_data;
66 unsigned long flags;
67 unsigned int ret;
68
69 spin_lock_irqsave(&line->lock, flags);
70 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
71 ret = LINE_BUFSIZE - (write_room(line) + 1);
72 spin_unlock_irqrestore(&line->lock, flags);
73
74 return ret;
75}
76
77/*
78 * This copies the content of buf into the circular buffer associated with
79 * this line.
80 * The return value is the number of characters actually copied, i.e. the ones
81 * for which there was space: this function is not supposed to ever flush out
82 * the circular buffer.
83 *
84 * Must be called while holding line->lock!
85 */
86static int buffer_data(struct line *line, const char *buf, int len)
87{
88 int end, room;
89
90 if (line->buffer == NULL) {
91 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
92 if (line->buffer == NULL) {
93 printk(KERN_ERR "buffer_data - atomic allocation "
94 "failed\n");
95 return 0;
96 }
97 line->head = line->buffer;
98 line->tail = line->buffer;
99 }
100
101 room = write_room(line);
102 len = (len > room) ? room : len;
103
104 end = line->buffer + LINE_BUFSIZE - line->tail;
105
106 if (len < end) {
107 memcpy(line->tail, buf, len);
108 line->tail += len;
109 }
110 else {
111 /* The circular buffer is wrapping */
112 memcpy(line->tail, buf, end);
113 buf += end;
114 memcpy(line->buffer, buf, len - end);
115 line->tail = line->buffer + len - end;
116 }
117
118 return len;
119}
120
121/*
122 * Flushes the ring buffer to the output channels. That is, write_chan is
123 * called, passing it line->head as buffer, and an appropriate count.
124 *
125 * On exit, returns 1 when the buffer is empty,
126 * 0 when the buffer is not empty on exit,
127 * and -errno when an error occurred.
128 *
129 * Must be called while holding line->lock!*/
130static int flush_buffer(struct line *line)
131{
132 int n, count;
133
134 if ((line->buffer == NULL) || (line->head == line->tail))
135 return 1;
136
137 if (line->tail < line->head) {
138 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
139 count = line->buffer + LINE_BUFSIZE - line->head;
140
141 n = write_chan(line->chan_out, line->head, count,
142 line->write_irq);
143 if (n < 0)
144 return n;
145 if (n == count) {
146 /*
147 * We have flushed from ->head to buffer end, now we
148 * must flush only from the beginning to ->tail.
149 */
150 line->head = line->buffer;
151 } else {
152 line->head += n;
153 return 0;
154 }
155 }
156
157 count = line->tail - line->head;
158 n = write_chan(line->chan_out, line->head, count,
159 line->write_irq);
160
161 if (n < 0)
162 return n;
163
164 line->head += n;
165 return line->head == line->tail;
166}
167
168void line_flush_buffer(struct tty_struct *tty)
169{
170 struct line *line = tty->driver_data;
171 unsigned long flags;
172
173 spin_lock_irqsave(&line->lock, flags);
174 flush_buffer(line);
175 spin_unlock_irqrestore(&line->lock, flags);
176}
177
178/*
179 * We map both ->flush_chars and ->put_char (which go in pair) onto
180 * ->flush_buffer and ->write. Hope it's not that bad.
181 */
182void line_flush_chars(struct tty_struct *tty)
183{
184 line_flush_buffer(tty);
185}
186
187int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
188{
189 struct line *line = tty->driver_data;
190 unsigned long flags;
191 int n, ret = 0;
192
193 spin_lock_irqsave(&line->lock, flags);
194 if (line->head != line->tail)
195 ret = buffer_data(line, buf, len);
196 else {
197 n = write_chan(line->chan_out, buf, len,
198 line->write_irq);
199 if (n < 0) {
200 ret = n;
201 goto out_up;
202 }
203
204 len -= n;
205 ret += n;
206 if (len > 0)
207 ret += buffer_data(line, buf + n, len);
208 }
209out_up:
210 spin_unlock_irqrestore(&line->lock, flags);
211 return ret;
212}
213
214void line_throttle(struct tty_struct *tty)
215{
216 struct line *line = tty->driver_data;
217
218 deactivate_chan(line->chan_in, line->read_irq);
219 line->throttled = 1;
220}
221
222void line_unthrottle(struct tty_struct *tty)
223{
224 struct line *line = tty->driver_data;
225
226 line->throttled = 0;
227 chan_interrupt(line, line->read_irq);
228}
229
230static irqreturn_t line_write_interrupt(int irq, void *data)
231{
232 struct chan *chan = data;
233 struct line *line = chan->line;
234 int err;
235
236 /*
237 * Interrupts are disabled here because genirq keep irqs disabled when
238 * calling the action handler.
239 */
240
241 spin_lock(&line->lock);
242 err = flush_buffer(line);
243 if (err == 0) {
244 spin_unlock(&line->lock);
245 return IRQ_NONE;
246 } else if ((err < 0) && (err != -EAGAIN)) {
247 line->head = line->buffer;
248 line->tail = line->buffer;
249 }
250 spin_unlock(&line->lock);
251
252 tty_port_tty_wakeup(&line->port);
253
254 return IRQ_HANDLED;
255}
256
257int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
258{
259 const struct line_driver *driver = line->driver;
260 int err;
261
262 if (input) {
263 err = um_request_irq(UM_IRQ_ALLOC, fd, IRQ_READ,
264 line_interrupt, 0,
265 driver->read_irq_name, data);
266 if (err < 0)
267 return err;
268
269 line->read_irq = err;
270 }
271
272 if (output) {
273 err = um_request_irq(UM_IRQ_ALLOC, fd, IRQ_WRITE,
274 line_write_interrupt, 0,
275 driver->write_irq_name, data);
276 if (err < 0)
277 return err;
278
279 line->write_irq = err;
280 }
281
282 return 0;
283}
284
285static int line_activate(struct tty_port *port, struct tty_struct *tty)
286{
287 int ret;
288 struct line *line = tty->driver_data;
289
290 ret = enable_chan(line);
291 if (ret)
292 return ret;
293
294 if (!line->sigio) {
295 chan_enable_winch(line->chan_out, port);
296 line->sigio = 1;
297 }
298
299 chan_window_size(line, &tty->winsize.ws_row,
300 &tty->winsize.ws_col);
301
302 return 0;
303}
304
305static void unregister_winch(struct tty_struct *tty);
306
307static void line_destruct(struct tty_port *port)
308{
309 struct tty_struct *tty = tty_port_tty_get(port);
310 struct line *line = tty->driver_data;
311
312 if (line->sigio) {
313 unregister_winch(tty);
314 line->sigio = 0;
315 }
316}
317
318static const struct tty_port_operations line_port_ops = {
319 .activate = line_activate,
320 .destruct = line_destruct,
321};
322
323int line_open(struct tty_struct *tty, struct file *filp)
324{
325 struct line *line = tty->driver_data;
326
327 return tty_port_open(&line->port, tty, filp);
328}
329
330int line_install(struct tty_driver *driver, struct tty_struct *tty,
331 struct line *line)
332{
333 int ret;
334
335 ret = tty_standard_install(driver, tty);
336 if (ret)
337 return ret;
338
339 tty->driver_data = line;
340
341 return 0;
342}
343
344void line_close(struct tty_struct *tty, struct file * filp)
345{
346 struct line *line = tty->driver_data;
347
348 tty_port_close(&line->port, tty, filp);
349}
350
351void line_hangup(struct tty_struct *tty)
352{
353 struct line *line = tty->driver_data;
354
355 tty_port_hangup(&line->port);
356}
357
358void close_lines(struct line *lines, int nlines)
359{
360 int i;
361
362 for(i = 0; i < nlines; i++)
363 close_chan(&lines[i]);
364}
365
366int setup_one_line(struct line *lines, int n, char *init,
367 const struct chan_opts *opts, char **error_out)
368{
369 struct line *line = &lines[n];
370 struct tty_driver *driver = line->driver->driver;
371 int err = -EINVAL;
372
373 if (line->port.count) {
374 *error_out = "Device is already open";
375 goto out;
376 }
377
378 if (!strcmp(init, "none")) {
379 if (line->valid) {
380 line->valid = 0;
381 kfree(line->init_str);
382 tty_unregister_device(driver, n);
383 parse_chan_pair(NULL, line, n, opts, error_out);
384 err = 0;
385 }
386 } else {
387 char *new = kstrdup(init, GFP_KERNEL);
388 if (!new) {
389 *error_out = "Failed to allocate memory";
390 return -ENOMEM;
391 }
392 if (line->valid) {
393 tty_unregister_device(driver, n);
394 kfree(line->init_str);
395 }
396 line->init_str = new;
397 line->valid = 1;
398 err = parse_chan_pair(new, line, n, opts, error_out);
399 if (!err) {
400 struct device *d = tty_port_register_device(&line->port,
401 driver, n, NULL);
402 if (IS_ERR(d)) {
403 *error_out = "Failed to register device";
404 err = PTR_ERR(d);
405 parse_chan_pair(NULL, line, n, opts, error_out);
406 }
407 }
408 if (err) {
409 line->init_str = NULL;
410 line->valid = 0;
411 kfree(new);
412 }
413 }
414out:
415 return err;
416}
417
418/*
419 * Common setup code for both startup command line and mconsole initialization.
420 * @lines contains the array (of size @num) to modify;
421 * @init is the setup string;
422 * @error_out is an error string in the case of failure;
423 */
424
425int line_setup(char **conf, unsigned int num, char **def,
426 char *init, char *name)
427{
428 char *error;
429
430 if (*init == '=') {
431 /*
432 * We said con=/ssl= instead of con#=, so we are configuring all
433 * consoles at once.
434 */
435 *def = init + 1;
436 } else {
437 char *end;
438 unsigned n = simple_strtoul(init, &end, 0);
439
440 if (*end != '=') {
441 error = "Couldn't parse device number";
442 goto out;
443 }
444 if (n >= num) {
445 error = "Device number out of range";
446 goto out;
447 }
448 conf[n] = end + 1;
449 }
450 return 0;
451
452out:
453 printk(KERN_ERR "Failed to set up %s with "
454 "configuration string \"%s\" : %s\n", name, init, error);
455 return -EINVAL;
456}
457
458int line_config(struct line *lines, unsigned int num, char *str,
459 const struct chan_opts *opts, char **error_out)
460{
461 char *end;
462 int n;
463
464 if (*str == '=') {
465 *error_out = "Can't configure all devices from mconsole";
466 return -EINVAL;
467 }
468
469 n = simple_strtoul(str, &end, 0);
470 if (*end++ != '=') {
471 *error_out = "Couldn't parse device number";
472 return -EINVAL;
473 }
474 if (n >= num) {
475 *error_out = "Device number out of range";
476 return -EINVAL;
477 }
478
479 return setup_one_line(lines, n, end, opts, error_out);
480}
481
482int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
483 int size, char **error_out)
484{
485 struct line *line;
486 char *end;
487 int dev, n = 0;
488
489 dev = simple_strtoul(name, &end, 0);
490 if ((*end != '\0') || (end == name)) {
491 *error_out = "line_get_config failed to parse device number";
492 return 0;
493 }
494
495 if ((dev < 0) || (dev >= num)) {
496 *error_out = "device number out of range";
497 return 0;
498 }
499
500 line = &lines[dev];
501
502 if (!line->valid)
503 CONFIG_CHUNK(str, size, n, "none", 1);
504 else {
505 struct tty_struct *tty = tty_port_tty_get(&line->port);
506 if (tty == NULL) {
507 CONFIG_CHUNK(str, size, n, line->init_str, 1);
508 } else {
509 n = chan_config_string(line, str, size, error_out);
510 tty_kref_put(tty);
511 }
512 }
513
514 return n;
515}
516
517int line_id(char **str, int *start_out, int *end_out)
518{
519 char *end;
520 int n;
521
522 n = simple_strtoul(*str, &end, 0);
523 if ((*end != '\0') || (end == *str))
524 return -1;
525
526 *str = end;
527 *start_out = n;
528 *end_out = n;
529 return n;
530}
531
532int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
533{
534 if (n >= num) {
535 *error_out = "Device number out of range";
536 return -EINVAL;
537 }
538 return setup_one_line(lines, n, "none", NULL, error_out);
539}
540
541int register_lines(struct line_driver *line_driver,
542 const struct tty_operations *ops,
543 struct line *lines, int nlines)
544{
545 struct tty_driver *driver;
546 int err;
547 int i;
548
549 driver = tty_alloc_driver(nlines, TTY_DRIVER_REAL_RAW |
550 TTY_DRIVER_DYNAMIC_DEV);
551 if (IS_ERR(driver))
552 return PTR_ERR(driver);
553
554 driver->driver_name = line_driver->name;
555 driver->name = line_driver->device_name;
556 driver->major = line_driver->major;
557 driver->minor_start = line_driver->minor_start;
558 driver->type = line_driver->type;
559 driver->subtype = line_driver->subtype;
560 driver->init_termios = tty_std_termios;
561
562 for (i = 0; i < nlines; i++) {
563 tty_port_init(&lines[i].port);
564 lines[i].port.ops = &line_port_ops;
565 spin_lock_init(&lines[i].lock);
566 lines[i].driver = line_driver;
567 INIT_LIST_HEAD(&lines[i].chan_list);
568 }
569 tty_set_operations(driver, ops);
570
571 err = tty_register_driver(driver);
572 if (err) {
573 printk(KERN_ERR "register_lines : can't register %s driver\n",
574 line_driver->name);
575 tty_driver_kref_put(driver);
576 for (i = 0; i < nlines; i++)
577 tty_port_destroy(&lines[i].port);
578 return err;
579 }
580
581 line_driver->driver = driver;
582 mconsole_register_dev(&line_driver->mc);
583 return 0;
584}
585
586static DEFINE_SPINLOCK(winch_handler_lock);
587static LIST_HEAD(winch_handlers);
588
589struct winch {
590 struct list_head list;
591 int fd;
592 int tty_fd;
593 int pid;
594 struct tty_port *port;
595 unsigned long stack;
596 struct work_struct work;
597};
598
599static void __free_winch(struct work_struct *work)
600{
601 struct winch *winch = container_of(work, struct winch, work);
602 um_free_irq(WINCH_IRQ, winch);
603
604 if (winch->pid != -1)
605 os_kill_process(winch->pid, 1);
606 if (winch->stack != 0)
607 free_stack(winch->stack, 0);
608 kfree(winch);
609}
610
611static void free_winch(struct winch *winch)
612{
613 int fd = winch->fd;
614 winch->fd = -1;
615 if (fd != -1)
616 os_close_file(fd);
617 __free_winch(&winch->work);
618}
619
620static irqreturn_t winch_interrupt(int irq, void *data)
621{
622 struct winch *winch = data;
623 struct tty_struct *tty;
624 struct line *line;
625 int fd = winch->fd;
626 int err;
627 char c;
628 struct pid *pgrp;
629
630 if (fd != -1) {
631 err = generic_read(fd, &c, NULL);
632 if (err < 0) {
633 if (err != -EAGAIN) {
634 winch->fd = -1;
635 list_del(&winch->list);
636 os_close_file(fd);
637 printk(KERN_ERR "winch_interrupt : "
638 "read failed, errno = %d\n", -err);
639 printk(KERN_ERR "fd %d is losing SIGWINCH "
640 "support\n", winch->tty_fd);
641 INIT_WORK(&winch->work, __free_winch);
642 schedule_work(&winch->work);
643 return IRQ_HANDLED;
644 }
645 goto out;
646 }
647 }
648 tty = tty_port_tty_get(winch->port);
649 if (tty != NULL) {
650 line = tty->driver_data;
651 if (line != NULL) {
652 chan_window_size(line, &tty->winsize.ws_row,
653 &tty->winsize.ws_col);
654 pgrp = tty_get_pgrp(tty);
655 if (pgrp)
656 kill_pgrp(pgrp, SIGWINCH, 1);
657 put_pid(pgrp);
658 }
659 tty_kref_put(tty);
660 }
661 out:
662 return IRQ_HANDLED;
663}
664
665void register_winch_irq(int fd, int tty_fd, int pid, struct tty_port *port,
666 unsigned long stack)
667{
668 struct winch *winch;
669
670 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
671 if (winch == NULL) {
672 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
673 goto cleanup;
674 }
675
676 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
677 .fd = fd,
678 .tty_fd = tty_fd,
679 .pid = pid,
680 .port = port,
681 .stack = stack });
682
683 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
684 IRQF_SHARED, "winch", winch) < 0) {
685 printk(KERN_ERR "register_winch_irq - failed to register "
686 "IRQ\n");
687 goto out_free;
688 }
689
690 spin_lock(&winch_handler_lock);
691 list_add(&winch->list, &winch_handlers);
692 spin_unlock(&winch_handler_lock);
693
694 return;
695
696 out_free:
697 kfree(winch);
698 cleanup:
699 os_kill_process(pid, 1);
700 os_close_file(fd);
701 if (stack != 0)
702 free_stack(stack, 0);
703}
704
705static void unregister_winch(struct tty_struct *tty)
706{
707 struct list_head *ele, *next;
708 struct winch *winch;
709 struct tty_struct *wtty;
710
711 spin_lock(&winch_handler_lock);
712
713 list_for_each_safe(ele, next, &winch_handlers) {
714 winch = list_entry(ele, struct winch, list);
715 wtty = tty_port_tty_get(winch->port);
716 if (wtty == tty) {
717 list_del(&winch->list);
718 spin_unlock(&winch_handler_lock);
719 free_winch(winch);
720 break;
721 }
722 tty_kref_put(wtty);
723 }
724 spin_unlock(&winch_handler_lock);
725}
726
727static void winch_cleanup(void)
728{
729 struct winch *winch;
730
731 spin_lock(&winch_handler_lock);
732 while ((winch = list_first_entry_or_null(&winch_handlers,
733 struct winch, list))) {
734 list_del(&winch->list);
735 spin_unlock(&winch_handler_lock);
736
737 free_winch(winch);
738
739 spin_lock(&winch_handler_lock);
740 }
741
742 spin_unlock(&winch_handler_lock);
743}
744__uml_exitcall(winch_cleanup);
745
746char *add_xterm_umid(char *base)
747{
748 char *umid, *title;
749 int len;
750
751 umid = get_umid();
752 if (*umid == '\0')
753 return base;
754
755 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
756 title = kmalloc(len, GFP_KERNEL);
757 if (title == NULL) {
758 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
759 return base;
760 }
761
762 snprintf(title, len, "%s (%s)", base, umid);
763 return title;
764}
1/*
2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include "linux/irqreturn.h"
7#include "linux/kd.h"
8#include "linux/sched.h"
9#include "linux/slab.h"
10#include "chan_kern.h"
11#include "irq_kern.h"
12#include "irq_user.h"
13#include "kern_util.h"
14#include "os.h"
15
16#define LINE_BUFSIZE 4096
17
18static irqreturn_t line_interrupt(int irq, void *data)
19{
20 struct chan *chan = data;
21 struct line *line = chan->line;
22
23 if (line)
24 chan_interrupt(&line->chan_list, &line->task, line->tty, irq);
25 return IRQ_HANDLED;
26}
27
28static void line_timer_cb(struct work_struct *work)
29{
30 struct line *line = container_of(work, struct line, task.work);
31
32 if (!line->throttled)
33 chan_interrupt(&line->chan_list, &line->task, line->tty,
34 line->driver->read_irq);
35}
36
37/*
38 * Returns the free space inside the ring buffer of this line.
39 *
40 * Should be called while holding line->lock (this does not modify data).
41 */
42static int write_room(struct line *line)
43{
44 int n;
45
46 if (line->buffer == NULL)
47 return LINE_BUFSIZE - 1;
48
49 /* This is for the case where the buffer is wrapped! */
50 n = line->head - line->tail;
51
52 if (n <= 0)
53 n += LINE_BUFSIZE; /* The other case */
54 return n - 1;
55}
56
57int line_write_room(struct tty_struct *tty)
58{
59 struct line *line = tty->driver_data;
60 unsigned long flags;
61 int room;
62
63 spin_lock_irqsave(&line->lock, flags);
64 room = write_room(line);
65 spin_unlock_irqrestore(&line->lock, flags);
66
67 return room;
68}
69
70int line_chars_in_buffer(struct tty_struct *tty)
71{
72 struct line *line = tty->driver_data;
73 unsigned long flags;
74 int ret;
75
76 spin_lock_irqsave(&line->lock, flags);
77 /* write_room subtracts 1 for the needed NULL, so we readd it.*/
78 ret = LINE_BUFSIZE - (write_room(line) + 1);
79 spin_unlock_irqrestore(&line->lock, flags);
80
81 return ret;
82}
83
84/*
85 * This copies the content of buf into the circular buffer associated with
86 * this line.
87 * The return value is the number of characters actually copied, i.e. the ones
88 * for which there was space: this function is not supposed to ever flush out
89 * the circular buffer.
90 *
91 * Must be called while holding line->lock!
92 */
93static int buffer_data(struct line *line, const char *buf, int len)
94{
95 int end, room;
96
97 if (line->buffer == NULL) {
98 line->buffer = kmalloc(LINE_BUFSIZE, GFP_ATOMIC);
99 if (line->buffer == NULL) {
100 printk(KERN_ERR "buffer_data - atomic allocation "
101 "failed\n");
102 return 0;
103 }
104 line->head = line->buffer;
105 line->tail = line->buffer;
106 }
107
108 room = write_room(line);
109 len = (len > room) ? room : len;
110
111 end = line->buffer + LINE_BUFSIZE - line->tail;
112
113 if (len < end) {
114 memcpy(line->tail, buf, len);
115 line->tail += len;
116 }
117 else {
118 /* The circular buffer is wrapping */
119 memcpy(line->tail, buf, end);
120 buf += end;
121 memcpy(line->buffer, buf, len - end);
122 line->tail = line->buffer + len - end;
123 }
124
125 return len;
126}
127
128/*
129 * Flushes the ring buffer to the output channels. That is, write_chan is
130 * called, passing it line->head as buffer, and an appropriate count.
131 *
132 * On exit, returns 1 when the buffer is empty,
133 * 0 when the buffer is not empty on exit,
134 * and -errno when an error occurred.
135 *
136 * Must be called while holding line->lock!*/
137static int flush_buffer(struct line *line)
138{
139 int n, count;
140
141 if ((line->buffer == NULL) || (line->head == line->tail))
142 return 1;
143
144 if (line->tail < line->head) {
145 /* line->buffer + LINE_BUFSIZE is the end of the buffer! */
146 count = line->buffer + LINE_BUFSIZE - line->head;
147
148 n = write_chan(&line->chan_list, line->head, count,
149 line->driver->write_irq);
150 if (n < 0)
151 return n;
152 if (n == count) {
153 /*
154 * We have flushed from ->head to buffer end, now we
155 * must flush only from the beginning to ->tail.
156 */
157 line->head = line->buffer;
158 } else {
159 line->head += n;
160 return 0;
161 }
162 }
163
164 count = line->tail - line->head;
165 n = write_chan(&line->chan_list, line->head, count,
166 line->driver->write_irq);
167
168 if (n < 0)
169 return n;
170
171 line->head += n;
172 return line->head == line->tail;
173}
174
175void line_flush_buffer(struct tty_struct *tty)
176{
177 struct line *line = tty->driver_data;
178 unsigned long flags;
179
180 spin_lock_irqsave(&line->lock, flags);
181 flush_buffer(line);
182 spin_unlock_irqrestore(&line->lock, flags);
183}
184
185/*
186 * We map both ->flush_chars and ->put_char (which go in pair) onto
187 * ->flush_buffer and ->write. Hope it's not that bad.
188 */
189void line_flush_chars(struct tty_struct *tty)
190{
191 line_flush_buffer(tty);
192}
193
194int line_put_char(struct tty_struct *tty, unsigned char ch)
195{
196 return line_write(tty, &ch, sizeof(ch));
197}
198
199int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
200{
201 struct line *line = tty->driver_data;
202 unsigned long flags;
203 int n, ret = 0;
204
205 spin_lock_irqsave(&line->lock, flags);
206 if (line->head != line->tail)
207 ret = buffer_data(line, buf, len);
208 else {
209 n = write_chan(&line->chan_list, buf, len,
210 line->driver->write_irq);
211 if (n < 0) {
212 ret = n;
213 goto out_up;
214 }
215
216 len -= n;
217 ret += n;
218 if (len > 0)
219 ret += buffer_data(line, buf + n, len);
220 }
221out_up:
222 spin_unlock_irqrestore(&line->lock, flags);
223 return ret;
224}
225
226void line_set_termios(struct tty_struct *tty, struct ktermios * old)
227{
228 /* nothing */
229}
230
231static const struct {
232 int cmd;
233 char *level;
234 char *name;
235} tty_ioctls[] = {
236 /* don't print these, they flood the log ... */
237 { TCGETS, NULL, "TCGETS" },
238 { TCSETS, NULL, "TCSETS" },
239 { TCSETSW, NULL, "TCSETSW" },
240 { TCFLSH, NULL, "TCFLSH" },
241 { TCSBRK, NULL, "TCSBRK" },
242
243 /* general tty stuff */
244 { TCSETSF, KERN_DEBUG, "TCSETSF" },
245 { TCGETA, KERN_DEBUG, "TCGETA" },
246 { TIOCMGET, KERN_DEBUG, "TIOCMGET" },
247 { TCSBRKP, KERN_DEBUG, "TCSBRKP" },
248 { TIOCMSET, KERN_DEBUG, "TIOCMSET" },
249
250 /* linux-specific ones */
251 { TIOCLINUX, KERN_INFO, "TIOCLINUX" },
252 { KDGKBMODE, KERN_INFO, "KDGKBMODE" },
253 { KDGKBTYPE, KERN_INFO, "KDGKBTYPE" },
254 { KDSIGACCEPT, KERN_INFO, "KDSIGACCEPT" },
255};
256
257int line_ioctl(struct tty_struct *tty, unsigned int cmd,
258 unsigned long arg)
259{
260 int ret;
261 int i;
262
263 ret = 0;
264 switch(cmd) {
265#ifdef TIOCGETP
266 case TIOCGETP:
267 case TIOCSETP:
268 case TIOCSETN:
269#endif
270#ifdef TIOCGETC
271 case TIOCGETC:
272 case TIOCSETC:
273#endif
274#ifdef TIOCGLTC
275 case TIOCGLTC:
276 case TIOCSLTC:
277#endif
278 /* Note: these are out of date as we now have TCGETS2 etc but this
279 whole lot should probably go away */
280 case TCGETS:
281 case TCSETSF:
282 case TCSETSW:
283 case TCSETS:
284 case TCGETA:
285 case TCSETAF:
286 case TCSETAW:
287 case TCSETA:
288 case TCXONC:
289 case TCFLSH:
290 case TIOCOUTQ:
291 case TIOCINQ:
292 case TIOCGLCKTRMIOS:
293 case TIOCSLCKTRMIOS:
294 case TIOCPKT:
295 case TIOCGSOFTCAR:
296 case TIOCSSOFTCAR:
297 return -ENOIOCTLCMD;
298#if 0
299 case TCwhatever:
300 /* do something */
301 break;
302#endif
303 default:
304 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
305 if (cmd == tty_ioctls[i].cmd)
306 break;
307 if (i == ARRAY_SIZE(tty_ioctls)) {
308 printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
309 __func__, tty->name, cmd);
310 }
311 ret = -ENOIOCTLCMD;
312 break;
313 }
314 return ret;
315}
316
317void line_throttle(struct tty_struct *tty)
318{
319 struct line *line = tty->driver_data;
320
321 deactivate_chan(&line->chan_list, line->driver->read_irq);
322 line->throttled = 1;
323}
324
325void line_unthrottle(struct tty_struct *tty)
326{
327 struct line *line = tty->driver_data;
328
329 line->throttled = 0;
330 chan_interrupt(&line->chan_list, &line->task, tty,
331 line->driver->read_irq);
332
333 /*
334 * Maybe there is enough stuff pending that calling the interrupt
335 * throttles us again. In this case, line->throttled will be 1
336 * again and we shouldn't turn the interrupt back on.
337 */
338 if (!line->throttled)
339 reactivate_chan(&line->chan_list, line->driver->read_irq);
340}
341
342static irqreturn_t line_write_interrupt(int irq, void *data)
343{
344 struct chan *chan = data;
345 struct line *line = chan->line;
346 struct tty_struct *tty = line->tty;
347 int err;
348
349 /*
350 * Interrupts are disabled here because we registered the interrupt with
351 * IRQF_DISABLED (see line_setup_irq).
352 */
353
354 spin_lock(&line->lock);
355 err = flush_buffer(line);
356 if (err == 0) {
357 return IRQ_NONE;
358 } else if (err < 0) {
359 line->head = line->buffer;
360 line->tail = line->buffer;
361 }
362 spin_unlock(&line->lock);
363
364 if (tty == NULL)
365 return IRQ_NONE;
366
367 tty_wakeup(tty);
368 return IRQ_HANDLED;
369}
370
371int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
372{
373 const struct line_driver *driver = line->driver;
374 int err = 0, flags = IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM;
375
376 if (input)
377 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
378 line_interrupt, flags,
379 driver->read_irq_name, data);
380 if (err)
381 return err;
382 if (output)
383 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
384 line_write_interrupt, flags,
385 driver->write_irq_name, data);
386 line->have_irq = 1;
387 return err;
388}
389
390/*
391 * Normally, a driver like this can rely mostly on the tty layer
392 * locking, particularly when it comes to the driver structure.
393 * However, in this case, mconsole requests can come in "from the
394 * side", and race with opens and closes.
395 *
396 * mconsole config requests will want to be sure the device isn't in
397 * use, and get_config, open, and close will want a stable
398 * configuration. The checking and modification of the configuration
399 * is done under a spinlock. Checking whether the device is in use is
400 * line->tty->count > 1, also under the spinlock.
401 *
402 * line->count serves to decide whether the device should be enabled or
403 * disabled on the host. If it's equal to 0, then we are doing the
404 * first open or last close. Otherwise, open and close just return.
405 */
406
407int line_open(struct line *lines, struct tty_struct *tty)
408{
409 struct line *line = &lines[tty->index];
410 int err = -ENODEV;
411
412 spin_lock(&line->count_lock);
413 if (!line->valid)
414 goto out_unlock;
415
416 err = 0;
417 if (line->count++)
418 goto out_unlock;
419
420 BUG_ON(tty->driver_data);
421 tty->driver_data = line;
422 line->tty = tty;
423
424 spin_unlock(&line->count_lock);
425 err = enable_chan(line);
426 if (err) /* line_close() will be called by our caller */
427 return err;
428
429 INIT_DELAYED_WORK(&line->task, line_timer_cb);
430
431 if (!line->sigio) {
432 chan_enable_winch(&line->chan_list, tty);
433 line->sigio = 1;
434 }
435
436 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
437 &tty->winsize.ws_col);
438
439 return 0;
440
441out_unlock:
442 spin_unlock(&line->count_lock);
443 return err;
444}
445
446static void unregister_winch(struct tty_struct *tty);
447
448void line_close(struct tty_struct *tty, struct file * filp)
449{
450 struct line *line = tty->driver_data;
451
452 /*
453 * If line_open fails (and tty->driver_data is never set),
454 * tty_open will call line_close. So just return in this case.
455 */
456 if (line == NULL)
457 return;
458
459 /* We ignore the error anyway! */
460 flush_buffer(line);
461
462 spin_lock(&line->count_lock);
463 BUG_ON(!line->valid);
464
465 if (--line->count)
466 goto out_unlock;
467
468 line->tty = NULL;
469 tty->driver_data = NULL;
470
471 spin_unlock(&line->count_lock);
472
473 if (line->sigio) {
474 unregister_winch(tty);
475 line->sigio = 0;
476 }
477
478 return;
479
480out_unlock:
481 spin_unlock(&line->count_lock);
482}
483
484void close_lines(struct line *lines, int nlines)
485{
486 int i;
487
488 for(i = 0; i < nlines; i++)
489 close_chan(&lines[i].chan_list, 0);
490}
491
492static int setup_one_line(struct line *lines, int n, char *init, int init_prio,
493 char **error_out)
494{
495 struct line *line = &lines[n];
496 int err = -EINVAL;
497
498 spin_lock(&line->count_lock);
499
500 if (line->count) {
501 *error_out = "Device is already open";
502 goto out;
503 }
504
505 if (line->init_pri <= init_prio) {
506 line->init_pri = init_prio;
507 if (!strcmp(init, "none"))
508 line->valid = 0;
509 else {
510 line->init_str = init;
511 line->valid = 1;
512 }
513 }
514 err = 0;
515out:
516 spin_unlock(&line->count_lock);
517 return err;
518}
519
520/*
521 * Common setup code for both startup command line and mconsole initialization.
522 * @lines contains the array (of size @num) to modify;
523 * @init is the setup string;
524 * @error_out is an error string in the case of failure;
525 */
526
527int line_setup(struct line *lines, unsigned int num, char *init,
528 char **error_out)
529{
530 int i, n, err;
531 char *end;
532
533 if (*init == '=') {
534 /*
535 * We said con=/ssl= instead of con#=, so we are configuring all
536 * consoles at once.
537 */
538 n = -1;
539 }
540 else {
541 n = simple_strtoul(init, &end, 0);
542 if (*end != '=') {
543 *error_out = "Couldn't parse device number";
544 return -EINVAL;
545 }
546 init = end;
547 }
548 init++;
549
550 if (n >= (signed int) num) {
551 *error_out = "Device number out of range";
552 return -EINVAL;
553 }
554 else if (n >= 0) {
555 err = setup_one_line(lines, n, init, INIT_ONE, error_out);
556 if (err)
557 return err;
558 }
559 else {
560 for(i = 0; i < num; i++) {
561 err = setup_one_line(lines, i, init, INIT_ALL,
562 error_out);
563 if (err)
564 return err;
565 }
566 }
567 return n == -1 ? num : n;
568}
569
570int line_config(struct line *lines, unsigned int num, char *str,
571 const struct chan_opts *opts, char **error_out)
572{
573 struct line *line;
574 char *new;
575 int n;
576
577 if (*str == '=') {
578 *error_out = "Can't configure all devices from mconsole";
579 return -EINVAL;
580 }
581
582 new = kstrdup(str, GFP_KERNEL);
583 if (new == NULL) {
584 *error_out = "Failed to allocate memory";
585 return -ENOMEM;
586 }
587 n = line_setup(lines, num, new, error_out);
588 if (n < 0)
589 return n;
590
591 line = &lines[n];
592 return parse_chan_pair(line->init_str, line, n, opts, error_out);
593}
594
595int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
596 int size, char **error_out)
597{
598 struct line *line;
599 char *end;
600 int dev, n = 0;
601
602 dev = simple_strtoul(name, &end, 0);
603 if ((*end != '\0') || (end == name)) {
604 *error_out = "line_get_config failed to parse device number";
605 return 0;
606 }
607
608 if ((dev < 0) || (dev >= num)) {
609 *error_out = "device number out of range";
610 return 0;
611 }
612
613 line = &lines[dev];
614
615 spin_lock(&line->count_lock);
616 if (!line->valid)
617 CONFIG_CHUNK(str, size, n, "none", 1);
618 else if (line->tty == NULL)
619 CONFIG_CHUNK(str, size, n, line->init_str, 1);
620 else n = chan_config_string(&line->chan_list, str, size, error_out);
621 spin_unlock(&line->count_lock);
622
623 return n;
624}
625
626int line_id(char **str, int *start_out, int *end_out)
627{
628 char *end;
629 int n;
630
631 n = simple_strtoul(*str, &end, 0);
632 if ((*end != '\0') || (end == *str))
633 return -1;
634
635 *str = end;
636 *start_out = n;
637 *end_out = n;
638 return n;
639}
640
641int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
642{
643 int err;
644 char config[sizeof("conxxxx=none\0")];
645
646 sprintf(config, "%d=none", n);
647 err = line_setup(lines, num, config, error_out);
648 if (err >= 0)
649 err = 0;
650 return err;
651}
652
653struct tty_driver *register_lines(struct line_driver *line_driver,
654 const struct tty_operations *ops,
655 struct line *lines, int nlines)
656{
657 int i;
658 struct tty_driver *driver = alloc_tty_driver(nlines);
659
660 if (!driver)
661 return NULL;
662
663 driver->driver_name = line_driver->name;
664 driver->name = line_driver->device_name;
665 driver->major = line_driver->major;
666 driver->minor_start = line_driver->minor_start;
667 driver->type = line_driver->type;
668 driver->subtype = line_driver->subtype;
669 driver->flags = TTY_DRIVER_REAL_RAW;
670 driver->init_termios = tty_std_termios;
671 tty_set_operations(driver, ops);
672
673 if (tty_register_driver(driver)) {
674 printk(KERN_ERR "register_lines : can't register %s driver\n",
675 line_driver->name);
676 put_tty_driver(driver);
677 return NULL;
678 }
679
680 for(i = 0; i < nlines; i++) {
681 if (!lines[i].valid)
682 tty_unregister_device(driver, i);
683 }
684
685 mconsole_register_dev(&line_driver->mc);
686 return driver;
687}
688
689static DEFINE_SPINLOCK(winch_handler_lock);
690static LIST_HEAD(winch_handlers);
691
692void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
693{
694 struct line *line;
695 char *error;
696 int i;
697
698 for(i = 0; i < nlines; i++) {
699 line = &lines[i];
700 INIT_LIST_HEAD(&line->chan_list);
701
702 if (line->init_str == NULL)
703 continue;
704
705 line->init_str = kstrdup(line->init_str, GFP_KERNEL);
706 if (line->init_str == NULL)
707 printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
708
709 if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
710 printk(KERN_ERR "parse_chan_pair failed for "
711 "device %d : %s\n", i, error);
712 line->valid = 0;
713 }
714 }
715}
716
717struct winch {
718 struct list_head list;
719 int fd;
720 int tty_fd;
721 int pid;
722 struct tty_struct *tty;
723 unsigned long stack;
724 struct work_struct work;
725};
726
727static void __free_winch(struct work_struct *work)
728{
729 struct winch *winch = container_of(work, struct winch, work);
730 free_irq(WINCH_IRQ, winch);
731
732 if (winch->pid != -1)
733 os_kill_process(winch->pid, 1);
734 if (winch->stack != 0)
735 free_stack(winch->stack, 0);
736 kfree(winch);
737}
738
739static void free_winch(struct winch *winch)
740{
741 int fd = winch->fd;
742 winch->fd = -1;
743 if (fd != -1)
744 os_close_file(fd);
745 list_del(&winch->list);
746 __free_winch(&winch->work);
747}
748
749static irqreturn_t winch_interrupt(int irq, void *data)
750{
751 struct winch *winch = data;
752 struct tty_struct *tty;
753 struct line *line;
754 int fd = winch->fd;
755 int err;
756 char c;
757
758 if (fd != -1) {
759 err = generic_read(fd, &c, NULL);
760 if (err < 0) {
761 if (err != -EAGAIN) {
762 winch->fd = -1;
763 list_del(&winch->list);
764 os_close_file(fd);
765 printk(KERN_ERR "winch_interrupt : "
766 "read failed, errno = %d\n", -err);
767 printk(KERN_ERR "fd %d is losing SIGWINCH "
768 "support\n", winch->tty_fd);
769 INIT_WORK(&winch->work, __free_winch);
770 schedule_work(&winch->work);
771 return IRQ_HANDLED;
772 }
773 goto out;
774 }
775 }
776 tty = winch->tty;
777 if (tty != NULL) {
778 line = tty->driver_data;
779 if (line != NULL) {
780 chan_window_size(&line->chan_list, &tty->winsize.ws_row,
781 &tty->winsize.ws_col);
782 kill_pgrp(tty->pgrp, SIGWINCH, 1);
783 }
784 }
785 out:
786 if (winch->fd != -1)
787 reactivate_fd(winch->fd, WINCH_IRQ);
788 return IRQ_HANDLED;
789}
790
791void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
792 unsigned long stack)
793{
794 struct winch *winch;
795
796 winch = kmalloc(sizeof(*winch), GFP_KERNEL);
797 if (winch == NULL) {
798 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
799 goto cleanup;
800 }
801
802 *winch = ((struct winch) { .list = LIST_HEAD_INIT(winch->list),
803 .fd = fd,
804 .tty_fd = tty_fd,
805 .pid = pid,
806 .tty = tty,
807 .stack = stack });
808
809 if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
810 IRQF_DISABLED | IRQF_SHARED | IRQF_SAMPLE_RANDOM,
811 "winch", winch) < 0) {
812 printk(KERN_ERR "register_winch_irq - failed to register "
813 "IRQ\n");
814 goto out_free;
815 }
816
817 spin_lock(&winch_handler_lock);
818 list_add(&winch->list, &winch_handlers);
819 spin_unlock(&winch_handler_lock);
820
821 return;
822
823 out_free:
824 kfree(winch);
825 cleanup:
826 os_kill_process(pid, 1);
827 os_close_file(fd);
828 if (stack != 0)
829 free_stack(stack, 0);
830}
831
832static void unregister_winch(struct tty_struct *tty)
833{
834 struct list_head *ele, *next;
835 struct winch *winch;
836
837 spin_lock(&winch_handler_lock);
838
839 list_for_each_safe(ele, next, &winch_handlers) {
840 winch = list_entry(ele, struct winch, list);
841 if (winch->tty == tty) {
842 free_winch(winch);
843 break;
844 }
845 }
846 spin_unlock(&winch_handler_lock);
847}
848
849static void winch_cleanup(void)
850{
851 struct list_head *ele, *next;
852 struct winch *winch;
853
854 spin_lock(&winch_handler_lock);
855
856 list_for_each_safe(ele, next, &winch_handlers) {
857 winch = list_entry(ele, struct winch, list);
858 free_winch(winch);
859 }
860
861 spin_unlock(&winch_handler_lock);
862}
863__uml_exitcall(winch_cleanup);
864
865char *add_xterm_umid(char *base)
866{
867 char *umid, *title;
868 int len;
869
870 umid = get_umid();
871 if (*umid == '\0')
872 return base;
873
874 len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
875 title = kmalloc(len, GFP_KERNEL);
876 if (title == NULL) {
877 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
878 return base;
879 }
880
881 snprintf(title, len, "%s (%s)", base, umid);
882 return title;
883}