Pileus Git - ~andy/linux/blob - arch/um/drivers/line.c

   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.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
  18 static irqreturn_t line_interrupt(int irq, void *data)
  19 {
  20         struct chan *chan = data;
  21         struct line *line = chan->line;
  22         struct tty_struct *tty = tty_port_tty_get(&line->port);
  23
  24         if (line)
  25                 chan_interrupt(line, tty, irq);
  26         tty_kref_put(tty);
  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  */
  35 static 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
  50 int line_write_room(struct tty_struct *tty)
  51 {
  52         struct line *line = tty->driver_data;
  53         unsigned long flags;
  54         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
  63 int line_chars_in_buffer(struct tty_struct *tty)
  64 {
  65         struct line *line = tty->driver_data;
  66         unsigned long flags;
  67         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  */
  86 static 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!*/
 130 static 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->driver->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->driver->write_irq);
 160
 161         if (n < 0)
 162                 return n;
 163
 164         line->head += n;
 165         return line->head == line->tail;
 166 }
 167
 168 void 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  */
 182 void line_flush_chars(struct tty_struct *tty)
 183 {
 184         line_flush_buffer(tty);
 185 }
 186
 187 int line_put_char(struct tty_struct *tty, unsigned char ch)
 188 {
 189         return line_write(tty, &ch, sizeof(ch));
 190 }
 191
 192 int line_write(struct tty_struct *tty, const unsigned char *buf, int len)
 193 {
 194         struct line *line = tty->driver_data;
 195         unsigned long flags;
 196         int n, ret = 0;
 197
 198         spin_lock_irqsave(&line->lock, flags);
 199         if (line->head != line->tail)
 200                 ret = buffer_data(line, buf, len);
 201         else {
 202                 n = write_chan(line->chan_out, buf, len,
 203                                line->driver->write_irq);
 204                 if (n < 0) {
 205                         ret = n;
 206                         goto out_up;
 207                 }
 208
 209                 len -= n;
 210                 ret += n;
 211                 if (len > 0)
 212                         ret += buffer_data(line, buf + n, len);
 213         }
 214 out_up:
 215         spin_unlock_irqrestore(&line->lock, flags);
 216         return ret;
 217 }
 218
 219 void line_set_termios(struct tty_struct *tty, struct ktermios * old)
 220 {
 221         /* nothing */
 222 }
 223
 224 static const struct {
 225         int  cmd;
 226         char *level;
 227         char *name;
 228 } tty_ioctls[] = {
 229         /* don't print these, they flood the log ... */
 230         { TCGETS,      NULL,       "TCGETS"      },
 231         { TCSETS,      NULL,       "TCSETS"      },
 232         { TCSETSW,     NULL,       "TCSETSW"     },
 233         { TCFLSH,      NULL,       "TCFLSH"      },
 234         { TCSBRK,      NULL,       "TCSBRK"      },
 235
 236         /* general tty stuff */
 237         { TCSETSF,     KERN_DEBUG, "TCSETSF"     },
 238         { TCGETA,      KERN_DEBUG, "TCGETA"      },
 239         { TIOCMGET,    KERN_DEBUG, "TIOCMGET"    },
 240         { TCSBRKP,     KERN_DEBUG, "TCSBRKP"     },
 241         { TIOCMSET,    KERN_DEBUG, "TIOCMSET"    },
 242
 243         /* linux-specific ones */
 244         { TIOCLINUX,   KERN_INFO,  "TIOCLINUX"   },
 245         { KDGKBMODE,   KERN_INFO,  "KDGKBMODE"   },
 246         { KDGKBTYPE,   KERN_INFO,  "KDGKBTYPE"   },
 247         { KDSIGACCEPT, KERN_INFO,  "KDSIGACCEPT" },
 248 };
 249
 250 int line_ioctl(struct tty_struct *tty, unsigned int cmd,
 251                                 unsigned long arg)
 252 {
 253         int ret;
 254         int i;
 255
 256         ret = 0;
 257         switch(cmd) {
 258 #ifdef TIOCGETP
 259         case TIOCGETP:
 260         case TIOCSETP:
 261         case TIOCSETN:
 262 #endif
 263 #ifdef TIOCGETC
 264         case TIOCGETC:
 265         case TIOCSETC:
 266 #endif
 267 #ifdef TIOCGLTC
 268         case TIOCGLTC:
 269         case TIOCSLTC:
 270 #endif
 271         /* Note: these are out of date as we now have TCGETS2 etc but this
 272            whole lot should probably go away */
 273         case TCGETS:
 274         case TCSETSF:
 275         case TCSETSW:
 276         case TCSETS:
 277         case TCGETA:
 278         case TCSETAF:
 279         case TCSETAW:
 280         case TCSETA:
 281         case TCXONC:
 282         case TCFLSH:
 283         case TIOCOUTQ:
 284         case TIOCINQ:
 285         case TIOCGLCKTRMIOS:
 286         case TIOCSLCKTRMIOS:
 287         case TIOCPKT:
 288         case TIOCGSOFTCAR:
 289         case TIOCSSOFTCAR:
 290                 return -ENOIOCTLCMD;
 291 #if 0
 292         case TCwhatever:
 293                 /* do something */
 294                 break;
 295 #endif
 296         default:
 297                 for (i = 0; i < ARRAY_SIZE(tty_ioctls); i++)
 298                         if (cmd == tty_ioctls[i].cmd)
 299                                 break;
 300                 if (i == ARRAY_SIZE(tty_ioctls)) {
 301                         printk(KERN_ERR "%s: %s: unknown ioctl: 0x%x\n",
 302                                __func__, tty->name, cmd);
 303                 }
 304                 ret = -ENOIOCTLCMD;
 305                 break;
 306         }
 307         return ret;
 308 }
 309
 310 void line_throttle(struct tty_struct *tty)
 311 {
 312         struct line *line = tty->driver_data;
 313
 314         deactivate_chan(line->chan_in, line->driver->read_irq);
 315         line->throttled = 1;
 316 }
 317
 318 void line_unthrottle(struct tty_struct *tty)
 319 {
 320         struct line *line = tty->driver_data;
 321
 322         line->throttled = 0;
 323         chan_interrupt(line, tty, line->driver->read_irq);
 324
 325         /*
 326          * Maybe there is enough stuff pending that calling the interrupt
 327          * throttles us again.  In this case, line->throttled will be 1
 328          * again and we shouldn't turn the interrupt back on.
 329          */
 330         if (!line->throttled)
 331                 reactivate_chan(line->chan_in, line->driver->read_irq);
 332 }
 333
 334 static irqreturn_t line_write_interrupt(int irq, void *data)
 335 {
 336         struct chan *chan = data;
 337         struct line *line = chan->line;
 338         struct tty_struct *tty;
 339         int err;
 340
 341         /*
 342          * Interrupts are disabled here because genirq keep irqs disabled when
 343          * calling the action handler.
 344          */
 345
 346         spin_lock(&line->lock);
 347         err = flush_buffer(line);
 348         if (err == 0) {
 349                 spin_unlock(&line->lock);
 350                 return IRQ_NONE;
 351         } else if (err < 0) {
 352                 line->head = line->buffer;
 353                 line->tail = line->buffer;
 354         }
 355         spin_unlock(&line->lock);
 356
 357         tty = tty_port_tty_get(&line->port);
 358         if (tty == NULL)
 359                 return IRQ_NONE;
 360
 361         tty_wakeup(tty);
 362         tty_kref_put(tty);
 363
 364         return IRQ_HANDLED;
 365 }
 366
 367 int line_setup_irq(int fd, int input, int output, struct line *line, void *data)
 368 {
 369         const struct line_driver *driver = line->driver;
 370         int err = 0, flags = IRQF_SHARED | IRQF_SAMPLE_RANDOM;
 371
 372         if (input)
 373                 err = um_request_irq(driver->read_irq, fd, IRQ_READ,
 374                                        line_interrupt, flags,
 375                                        driver->read_irq_name, data);
 376         if (err)
 377                 return err;
 378         if (output)
 379                 err = um_request_irq(driver->write_irq, fd, IRQ_WRITE,
 380                                         line_write_interrupt, flags,
 381                                         driver->write_irq_name, data);
 382         return err;
 383 }
 384
 385 /*
 386  * Normally, a driver like this can rely mostly on the tty layer
 387  * locking, particularly when it comes to the driver structure.
 388  * However, in this case, mconsole requests can come in "from the
 389  * side", and race with opens and closes.
 390  *
 391  * mconsole config requests will want to be sure the device isn't in
 392  * use, and get_config, open, and close will want a stable
 393  * configuration.  The checking and modification of the configuration
 394  * is done under a spinlock.  Checking whether the device is in use is
 395  * line->tty->count > 1, also under the spinlock.
 396  *
 397  * line->count serves to decide whether the device should be enabled or
 398  * disabled on the host.  If it's equal to 0, then we are doing the
 399  * first open or last close.  Otherwise, open and close just return.
 400  */
 401
 402 int line_open(struct line *lines, struct tty_struct *tty)
 403 {
 404         struct line *line = &lines[tty->index];
 405         int err = -ENODEV;
 406
 407         mutex_lock(&line->count_lock);
 408         if (!line->valid)
 409                 goto out_unlock;
 410
 411         err = 0;
 412         if (line->port.count++)
 413                 goto out_unlock;
 414
 415         BUG_ON(tty->driver_data);
 416         tty->driver_data = line;
 417         tty_port_tty_set(&line->port, tty);
 418
 419         err = enable_chan(line);
 420         if (err) /* line_close() will be called by our caller */
 421                 goto out_unlock;
 422
 423         if (!line->sigio) {
 424                 chan_enable_winch(line->chan_out, tty);
 425                 line->sigio = 1;
 426         }
 427
 428         chan_window_size(line, &tty->winsize.ws_row,
 429                          &tty->winsize.ws_col);
 430 out_unlock:
 431         mutex_unlock(&line->count_lock);
 432         return err;
 433 }
 434
 435 static void unregister_winch(struct tty_struct *tty);
 436
 437 void line_close(struct tty_struct *tty, struct file * filp)
 438 {
 439         struct line *line = tty->driver_data;
 440
 441         /*
 442          * If line_open fails (and tty->driver_data is never set),
 443          * tty_open will call line_close.  So just return in this case.
 444          */
 445         if (line == NULL)
 446                 return;
 447
 448         /* We ignore the error anyway! */
 449         flush_buffer(line);
 450
 451         mutex_lock(&line->count_lock);
 452         BUG_ON(!line->valid);
 453
 454         if (--line->port.count)
 455                 goto out_unlock;
 456
 457         tty_port_tty_set(&line->port, NULL);
 458         tty->driver_data = NULL;
 459
 460         if (line->sigio) {
 461                 unregister_winch(tty);
 462                 line->sigio = 0;
 463         }
 464
 465 out_unlock:
 466         mutex_unlock(&line->count_lock);
 467 }
 468
 469 void close_lines(struct line *lines, int nlines)
 470 {
 471         int i;
 472
 473         for(i = 0; i < nlines; i++)
 474                 close_chan(&lines[i]);
 475 }
 476
 477 int setup_one_line(struct line *lines, int n, char *init,
 478                    const struct chan_opts *opts, char **error_out)
 479 {
 480         struct line *line = &lines[n];
 481         struct tty_driver *driver = line->driver->driver;
 482         int err = -EINVAL;
 483
 484         mutex_lock(&line->count_lock);
 485
 486         if (line->port.count) {
 487                 *error_out = "Device is already open";
 488                 goto out;
 489         }
 490
 491         if (!strcmp(init, "none")) {
 492                 if (line->valid) {
 493                         line->valid = 0;
 494                         kfree(line->init_str);
 495                         tty_unregister_device(driver, n);
 496                         parse_chan_pair(NULL, line, n, opts, error_out);
 497                         err = 0;
 498                 }
 499         } else {
 500                 char *new = kstrdup(init, GFP_KERNEL);
 501                 if (!new) {
 502                         *error_out = "Failed to allocate memory";
 503                         return -ENOMEM;
 504                 }
 505                 if (line->valid) {
 506                         tty_unregister_device(driver, n);
 507                         kfree(line->init_str);
 508                 }
 509                 line->init_str = new;
 510                 line->valid = 1;
 511                 err = parse_chan_pair(new, line, n, opts, error_out);
 512                 if (!err) {
 513                         struct device *d = tty_register_device(driver, n, NULL);
 514                         if (IS_ERR(d)) {
 515                                 *error_out = "Failed to register device";
 516                                 err = PTR_ERR(d);
 517                                 parse_chan_pair(NULL, line, n, opts, error_out);
 518                         }
 519                 }
 520                 if (err) {
 521                         line->init_str = NULL;
 522                         line->valid = 0;
 523                         kfree(new);
 524                 }
 525         }
 526 out:
 527         mutex_unlock(&line->count_lock);
 528         return err;
 529 }
 530
 531 /*
 532  * Common setup code for both startup command line and mconsole initialization.
 533  * @lines contains the array (of size @num) to modify;
 534  * @init is the setup string;
 535  * @error_out is an error string in the case of failure;
 536  */
 537
 538 int line_setup(char **conf, unsigned int num, char **def,
 539                char *init, char *name)
 540 {
 541         char *error;
 542
 543         if (*init == '=') {
 544                 /*
 545                  * We said con=/ssl= instead of con#=, so we are configuring all
 546                  * consoles at once.
 547                  */
 548                 *def = init + 1;
 549         } else {
 550                 char *end;
 551                 unsigned n = simple_strtoul(init, &end, 0);
 552
 553                 if (*end != '=') {
 554                         error = "Couldn't parse device number";
 555                         goto out;
 556                 }
 557                 if (n >= num) {
 558                         error = "Device number out of range";
 559                         goto out;
 560                 }
 561                 conf[n] = end + 1;
 562         }
 563         return 0;
 564
 565 out:
 566         printk(KERN_ERR "Failed to set up %s with "
 567                "configuration string \"%s\" : %s\n", name, init, error);
 568         return -EINVAL;
 569 }
 570
 571 int line_config(struct line *lines, unsigned int num, char *str,
 572                 const struct chan_opts *opts, char **error_out)
 573 {
 574         char *end;
 575         int n;
 576
 577         if (*str == '=') {
 578                 *error_out = "Can't configure all devices from mconsole";
 579                 return -EINVAL;
 580         }
 581
 582         n = simple_strtoul(str, &end, 0);
 583         if (*end++ != '=') {
 584                 *error_out = "Couldn't parse device number";
 585                 return -EINVAL;
 586         }
 587         if (n >= num) {
 588                 *error_out = "Device number out of range";
 589                 return -EINVAL;
 590         }
 591
 592         return setup_one_line(lines, n, end, opts, error_out);
 593 }
 594
 595 int 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         mutex_lock(&line->count_lock);
 616         if (!line->valid)
 617                 CONFIG_CHUNK(str, size, n, "none", 1);
 618         else {
 619                 struct tty_struct *tty = tty_port_tty_get(&line->port);
 620                 if (tty == NULL) {
 621                         CONFIG_CHUNK(str, size, n, line->init_str, 1);
 622                 } else {
 623                         n = chan_config_string(line, str, size, error_out);
 624                         tty_kref_put(tty);
 625                 }
 626         }
 627         mutex_unlock(&line->count_lock);
 628
 629         return n;
 630 }
 631
 632 int line_id(char **str, int *start_out, int *end_out)
 633 {
 634         char *end;
 635         int n;
 636
 637         n = simple_strtoul(*str, &end, 0);
 638         if ((*end != '\0') || (end == *str))
 639                 return -1;
 640
 641         *str = end;
 642         *start_out = n;
 643         *end_out = n;
 644         return n;
 645 }
 646
 647 int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
 648 {
 649         if (n >= num) {
 650                 *error_out = "Device number out of range";
 651                 return -EINVAL;
 652         }
 653         return setup_one_line(lines, n, "none", NULL, error_out);
 654 }
 655
 656 int register_lines(struct line_driver *line_driver,
 657                    const struct tty_operations *ops,
 658                    struct line *lines, int nlines)
 659 {
 660         struct tty_driver *driver = alloc_tty_driver(nlines);
 661         int err;
 662         int i;
 663
 664         if (!driver)
 665                 return -ENOMEM;
 666
 667         driver->driver_name = line_driver->name;
 668         driver->name = line_driver->device_name;
 669         driver->major = line_driver->major;
 670         driver->minor_start = line_driver->minor_start;
 671         driver->type = line_driver->type;
 672         driver->subtype = line_driver->subtype;
 673         driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
 674         driver->init_termios = tty_std_termios;
 675
 676         for (i = 0; i < nlines; i++) {
 677                 tty_port_init(&lines[i].port);
 678                 spin_lock_init(&lines[i].lock);
 679                 mutex_init(&lines[i].count_lock);
 680                 lines[i].driver = line_driver;
 681                 INIT_LIST_HEAD(&lines[i].chan_list);
 682         }
 683         tty_set_operations(driver, ops);
 684
 685         err = tty_register_driver(driver);
 686         if (err) {
 687                 printk(KERN_ERR "register_lines : can't register %s driver\n",
 688                        line_driver->name);
 689                 put_tty_driver(driver);
 690                 return err;
 691         }
 692
 693         line_driver->driver = driver;
 694         mconsole_register_dev(&line_driver->mc);
 695         return 0;
 696 }
 697
 698 static DEFINE_SPINLOCK(winch_handler_lock);
 699 static LIST_HEAD(winch_handlers);
 700
 701 struct winch {
 702         struct list_head list;
 703         int fd;
 704         int tty_fd;
 705         int pid;
 706         struct tty_struct *tty;
 707         unsigned long stack;
 708         struct work_struct work;
 709 };
 710
 711 static void __free_winch(struct work_struct *work)
 712 {
 713         struct winch *winch = container_of(work, struct winch, work);
 714         um_free_irq(WINCH_IRQ, winch);
 715
 716         if (winch->pid != -1)
 717                 os_kill_process(winch->pid, 1);
 718         if (winch->stack != 0)
 719                 free_stack(winch->stack, 0);
 720         kfree(winch);
 721 }
 722
 723 static void free_winch(struct winch *winch)
 724 {
 725         int fd = winch->fd;
 726         winch->fd = -1;
 727         if (fd != -1)
 728                 os_close_file(fd);
 729         list_del(&winch->list);
 730         __free_winch(&winch->work);
 731 }
 732
 733 static irqreturn_t winch_interrupt(int irq, void *data)
 734 {
 735         struct winch *winch = data;
 736         struct tty_struct *tty;
 737         struct line *line;
 738         int fd = winch->fd;
 739         int err;
 740         char c;
 741
 742         if (fd != -1) {
 743                 err = generic_read(fd, &c, NULL);
 744                 if (err < 0) {
 745                         if (err != -EAGAIN) {
 746                                 winch->fd = -1;
 747                                 list_del(&winch->list);
 748                                 os_close_file(fd);
 749                                 printk(KERN_ERR "winch_interrupt : "
 750                                        "read failed, errno = %d\n", -err);
 751                                 printk(KERN_ERR "fd %d is losing SIGWINCH "
 752                                        "support\n", winch->tty_fd);
 753                                 INIT_WORK(&winch->work, __free_winch);
 754                                 schedule_work(&winch->work);
 755                                 return IRQ_HANDLED;
 756                         }
 757                         goto out;
 758                 }
 759         }
 760         tty = winch->tty;
 761         if (tty != NULL) {
 762                 line = tty->driver_data;
 763                 if (line != NULL) {
 764                         chan_window_size(line, &tty->winsize.ws_row,
 765                                          &tty->winsize.ws_col);
 766                         kill_pgrp(tty->pgrp, SIGWINCH, 1);
 767                 }
 768         }
 769  out:
 770         if (winch->fd != -1)
 771                 reactivate_fd(winch->fd, WINCH_IRQ);
 772         return IRQ_HANDLED;
 773 }
 774
 775 void register_winch_irq(int fd, int tty_fd, int pid, struct tty_struct *tty,
 776                         unsigned long stack)
 777 {
 778         struct winch *winch;
 779
 780         winch = kmalloc(sizeof(*winch), GFP_KERNEL);
 781         if (winch == NULL) {
 782                 printk(KERN_ERR "register_winch_irq - kmalloc failed\n");
 783                 goto cleanup;
 784         }
 785
 786         *winch = ((struct winch) { .list        = LIST_HEAD_INIT(winch->list),
 787                                    .fd          = fd,
 788                                    .tty_fd      = tty_fd,
 789                                    .pid         = pid,
 790                                    .tty         = tty,
 791                                    .stack       = stack });
 792
 793         if (um_request_irq(WINCH_IRQ, fd, IRQ_READ, winch_interrupt,
 794                            IRQF_SHARED | IRQF_SAMPLE_RANDOM,
 795                            "winch", winch) < 0) {
 796                 printk(KERN_ERR "register_winch_irq - failed to register "
 797                        "IRQ\n");
 798                 goto out_free;
 799         }
 800
 801         spin_lock(&winch_handler_lock);
 802         list_add(&winch->list, &winch_handlers);
 803         spin_unlock(&winch_handler_lock);
 804
 805         return;
 806
 807  out_free:
 808         kfree(winch);
 809  cleanup:
 810         os_kill_process(pid, 1);
 811         os_close_file(fd);
 812         if (stack != 0)
 813                 free_stack(stack, 0);
 814 }
 815
 816 static void unregister_winch(struct tty_struct *tty)
 817 {
 818         struct list_head *ele, *next;
 819         struct winch *winch;
 820
 821         spin_lock(&winch_handler_lock);
 822
 823         list_for_each_safe(ele, next, &winch_handlers) {
 824                 winch = list_entry(ele, struct winch, list);
 825                 if (winch->tty == tty) {
 826                         free_winch(winch);
 827                         break;
 828                 }
 829         }
 830         spin_unlock(&winch_handler_lock);
 831 }
 832
 833 static void winch_cleanup(void)
 834 {
 835         struct list_head *ele, *next;
 836         struct winch *winch;
 837
 838         spin_lock(&winch_handler_lock);
 839
 840         list_for_each_safe(ele, next, &winch_handlers) {
 841                 winch = list_entry(ele, struct winch, list);
 842                 free_winch(winch);
 843         }
 844
 845         spin_unlock(&winch_handler_lock);
 846 }
 847 __uml_exitcall(winch_cleanup);
 848
 849 char *add_xterm_umid(char *base)
 850 {
 851         char *umid, *title;
 852         int len;
 853
 854         umid = get_umid();
 855         if (*umid == '\0')
 856                 return base;
 857
 858         len = strlen(base) + strlen(" ()") + strlen(umid) + 1;
 859         title = kmalloc(len, GFP_KERNEL);
 860         if (title == NULL) {
 861                 printk(KERN_ERR "Failed to allocate buffer for xterm title\n");
 862                 return base;
 863         }
 864
 865         snprintf(title, len, "%s (%s)", base, umid);
 866         return title;
 867 }