Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/drivers/char/tty_io.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | /* |
| 8 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles |
| 9 | * or rs-channels. It also implements echoing, cooked mode etc. |
| 10 | * |
| 11 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. |
| 12 | * |
| 13 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the |
| 14 | * tty_struct and tty_queue structures. Previously there was an array |
| 15 | * of 256 tty_struct's which was statically allocated, and the |
| 16 | * tty_queue structures were allocated at boot time. Both are now |
| 17 | * dynamically allocated only when the tty is open. |
| 18 | * |
| 19 | * Also restructured routines so that there is more of a separation |
| 20 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and |
| 21 | * the low-level tty routines (serial.c, pty.c, console.c). This |
| 22 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
| 23 | * |
| 24 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines |
| 25 | * which can be dynamically activated and de-activated by the line |
| 26 | * discipline handling modules (like SLIP). |
| 27 | * |
| 28 | * NOTE: pay no attention to the line discipline code (yet); its |
| 29 | * interface is still subject to change in this version... |
| 30 | * -- TYT, 1/31/92 |
| 31 | * |
| 32 | * Added functionality to the OPOST tty handling. No delays, but all |
| 33 | * other bits should be there. |
| 34 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. |
| 35 | * |
| 36 | * Rewrote canonical mode and added more termios flags. |
| 37 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 |
| 38 | * |
| 39 | * Reorganized FASYNC support so mouse code can share it. |
| 40 | * -- ctm@ardi.com, 9Sep95 |
| 41 | * |
| 42 | * New TIOCLINUX variants added. |
| 43 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 |
| 44 | * |
| 45 | * Restrict vt switching via ioctl() |
| 46 | * -- grif@cs.ucr.edu, 5-Dec-95 |
| 47 | * |
| 48 | * Move console and virtual terminal code to more appropriate files, |
| 49 | * implement CONFIG_VT and generalize console device interface. |
| 50 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 |
| 51 | * |
| 52 | * Rewrote init_dev and release_dev to eliminate races. |
| 53 | * -- Bill Hawes <whawes@star.net>, June 97 |
| 54 | * |
| 55 | * Added devfs support. |
| 56 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 |
| 57 | * |
| 58 | * Added support for a Unix98-style ptmx device. |
| 59 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 |
| 60 | * |
| 61 | * Reduced memory usage for older ARM systems |
| 62 | * -- Russell King <rmk@arm.linux.org.uk> |
| 63 | * |
| 64 | * Move do_SAK() into process context. Less stack use in devfs functions. |
| 65 | * alloc_tty_struct() always uses kmalloc() -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 |
| 66 | */ |
| 67 | |
| 68 | #include <linux/config.h> |
| 69 | #include <linux/types.h> |
| 70 | #include <linux/major.h> |
| 71 | #include <linux/errno.h> |
| 72 | #include <linux/signal.h> |
| 73 | #include <linux/fcntl.h> |
| 74 | #include <linux/sched.h> |
| 75 | #include <linux/interrupt.h> |
| 76 | #include <linux/tty.h> |
| 77 | #include <linux/tty_driver.h> |
| 78 | #include <linux/tty_flip.h> |
| 79 | #include <linux/devpts_fs.h> |
| 80 | #include <linux/file.h> |
| 81 | #include <linux/console.h> |
| 82 | #include <linux/timer.h> |
| 83 | #include <linux/ctype.h> |
| 84 | #include <linux/kd.h> |
| 85 | #include <linux/mm.h> |
| 86 | #include <linux/string.h> |
| 87 | #include <linux/slab.h> |
| 88 | #include <linux/poll.h> |
| 89 | #include <linux/proc_fs.h> |
| 90 | #include <linux/init.h> |
| 91 | #include <linux/module.h> |
| 92 | #include <linux/smp_lock.h> |
| 93 | #include <linux/device.h> |
| 94 | #include <linux/idr.h> |
| 95 | #include <linux/wait.h> |
| 96 | #include <linux/bitops.h> |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 97 | #include <linux/delay.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | |
| 99 | #include <asm/uaccess.h> |
| 100 | #include <asm/system.h> |
| 101 | |
| 102 | #include <linux/kbd_kern.h> |
| 103 | #include <linux/vt_kern.h> |
| 104 | #include <linux/selection.h> |
| 105 | #include <linux/devfs_fs_kernel.h> |
| 106 | |
| 107 | #include <linux/kmod.h> |
| 108 | |
| 109 | #undef TTY_DEBUG_HANGUP |
| 110 | |
| 111 | #define TTY_PARANOIA_CHECK 1 |
| 112 | #define CHECK_TTY_COUNT 1 |
| 113 | |
| 114 | struct termios tty_std_termios = { /* for the benefit of tty drivers */ |
| 115 | .c_iflag = ICRNL | IXON, |
| 116 | .c_oflag = OPOST | ONLCR, |
| 117 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, |
| 118 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | |
| 119 | ECHOCTL | ECHOKE | IEXTEN, |
| 120 | .c_cc = INIT_C_CC |
| 121 | }; |
| 122 | |
| 123 | EXPORT_SYMBOL(tty_std_termios); |
| 124 | |
| 125 | /* This list gets poked at by procfs and various bits of boot up code. This |
| 126 | could do with some rationalisation such as pulling the tty proc function |
| 127 | into this file */ |
| 128 | |
| 129 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
| 130 | |
| 131 | /* Semaphore to protect creating and releasing a tty. This is shared with |
| 132 | vt.c for deeply disgusting hack reasons */ |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 133 | DEFINE_MUTEX(tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | |
| 135 | #ifdef CONFIG_UNIX98_PTYS |
| 136 | extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ |
| 137 | extern int pty_limit; /* Config limit on Unix98 ptys */ |
| 138 | static DEFINE_IDR(allocated_ptys); |
| 139 | static DECLARE_MUTEX(allocated_ptys_lock); |
| 140 | static int ptmx_open(struct inode *, struct file *); |
| 141 | #endif |
| 142 | |
| 143 | extern void disable_early_printk(void); |
| 144 | |
| 145 | static void initialize_tty_struct(struct tty_struct *tty); |
| 146 | |
| 147 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
| 148 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); |
| 149 | ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *); |
| 150 | static unsigned int tty_poll(struct file *, poll_table *); |
| 151 | static int tty_open(struct inode *, struct file *); |
| 152 | static int tty_release(struct inode *, struct file *); |
| 153 | int tty_ioctl(struct inode * inode, struct file * file, |
| 154 | unsigned int cmd, unsigned long arg); |
| 155 | static int tty_fasync(int fd, struct file * filp, int on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | static void release_mem(struct tty_struct *tty, int idx); |
| 157 | |
| 158 | |
| 159 | static struct tty_struct *alloc_tty_struct(void) |
| 160 | { |
| 161 | struct tty_struct *tty; |
| 162 | |
| 163 | tty = kmalloc(sizeof(struct tty_struct), GFP_KERNEL); |
| 164 | if (tty) |
| 165 | memset(tty, 0, sizeof(struct tty_struct)); |
| 166 | return tty; |
| 167 | } |
| 168 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 169 | static void tty_buffer_free_all(struct tty_struct *); |
| 170 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | static inline void free_tty_struct(struct tty_struct *tty) |
| 172 | { |
| 173 | kfree(tty->write_buf); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 174 | tty_buffer_free_all(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | kfree(tty); |
| 176 | } |
| 177 | |
| 178 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
| 179 | |
| 180 | char *tty_name(struct tty_struct *tty, char *buf) |
| 181 | { |
| 182 | if (!tty) /* Hmm. NULL pointer. That's fun. */ |
| 183 | strcpy(buf, "NULL tty"); |
| 184 | else |
| 185 | strcpy(buf, tty->name); |
| 186 | return buf; |
| 187 | } |
| 188 | |
| 189 | EXPORT_SYMBOL(tty_name); |
| 190 | |
Andrew Morton | d769a66 | 2005-05-05 16:15:50 -0700 | [diff] [blame] | 191 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | const char *routine) |
| 193 | { |
| 194 | #ifdef TTY_PARANOIA_CHECK |
| 195 | if (!tty) { |
| 196 | printk(KERN_WARNING |
| 197 | "null TTY for (%d:%d) in %s\n", |
| 198 | imajor(inode), iminor(inode), routine); |
| 199 | return 1; |
| 200 | } |
| 201 | if (tty->magic != TTY_MAGIC) { |
| 202 | printk(KERN_WARNING |
| 203 | "bad magic number for tty struct (%d:%d) in %s\n", |
| 204 | imajor(inode), iminor(inode), routine); |
| 205 | return 1; |
| 206 | } |
| 207 | #endif |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
| 212 | { |
| 213 | #ifdef CHECK_TTY_COUNT |
| 214 | struct list_head *p; |
| 215 | int count = 0; |
| 216 | |
| 217 | file_list_lock(); |
| 218 | list_for_each(p, &tty->tty_files) { |
| 219 | count++; |
| 220 | } |
| 221 | file_list_unlock(); |
| 222 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 223 | tty->driver->subtype == PTY_TYPE_SLAVE && |
| 224 | tty->link && tty->link->count) |
| 225 | count++; |
| 226 | if (tty->count != count) { |
| 227 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " |
| 228 | "!= #fd's(%d) in %s\n", |
| 229 | tty->name, tty->count, count, routine); |
| 230 | return count; |
| 231 | } |
| 232 | #endif |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | /* |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 237 | * Tty buffer allocation management |
| 238 | */ |
| 239 | |
| 240 | static void tty_buffer_free_all(struct tty_struct *tty) |
| 241 | { |
| 242 | struct tty_buffer *thead; |
| 243 | while((thead = tty->buf.head) != NULL) { |
| 244 | tty->buf.head = thead->next; |
| 245 | kfree(thead); |
| 246 | } |
| 247 | while((thead = tty->buf.free) != NULL) { |
| 248 | tty->buf.free = thead->next; |
| 249 | kfree(thead); |
| 250 | } |
| 251 | tty->buf.tail = NULL; |
| 252 | } |
| 253 | |
| 254 | static void tty_buffer_init(struct tty_struct *tty) |
| 255 | { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 256 | spin_lock_init(&tty->buf.lock); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 257 | tty->buf.head = NULL; |
| 258 | tty->buf.tail = NULL; |
| 259 | tty->buf.free = NULL; |
| 260 | } |
| 261 | |
| 262 | static struct tty_buffer *tty_buffer_alloc(size_t size) |
| 263 | { |
| 264 | struct tty_buffer *p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC); |
| 265 | if(p == NULL) |
| 266 | return NULL; |
| 267 | p->used = 0; |
| 268 | p->size = size; |
| 269 | p->next = NULL; |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 270 | p->active = 0; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 271 | p->commit = 0; |
| 272 | p->read = 0; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 273 | p->char_buf_ptr = (char *)(p->data); |
| 274 | p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size; |
| 275 | /* printk("Flip create %p\n", p); */ |
| 276 | return p; |
| 277 | } |
| 278 | |
| 279 | /* Must be called with the tty_read lock held. This needs to acquire strategy |
| 280 | code to decide if we should kfree or relink a given expired buffer */ |
| 281 | |
| 282 | static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b) |
| 283 | { |
| 284 | /* Dumb strategy for now - should keep some stats */ |
| 285 | /* printk("Flip dispose %p\n", b); */ |
| 286 | if(b->size >= 512) |
| 287 | kfree(b); |
| 288 | else { |
| 289 | b->next = tty->buf.free; |
| 290 | tty->buf.free = b; |
| 291 | } |
| 292 | } |
| 293 | |
| 294 | static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size) |
| 295 | { |
| 296 | struct tty_buffer **tbh = &tty->buf.free; |
| 297 | while((*tbh) != NULL) { |
| 298 | struct tty_buffer *t = *tbh; |
| 299 | if(t->size >= size) { |
| 300 | *tbh = t->next; |
| 301 | t->next = NULL; |
| 302 | t->used = 0; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 303 | t->commit = 0; |
| 304 | t->read = 0; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 305 | /* DEBUG ONLY */ |
Paul Fulghum | 6af6aab | 2006-02-28 16:59:15 -0800 | [diff] [blame] | 306 | /* memset(t->data, '*', size); */ |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 307 | /* printk("Flip recycle %p\n", t); */ |
| 308 | return t; |
| 309 | } |
| 310 | tbh = &((*tbh)->next); |
| 311 | } |
| 312 | /* Round the buffer size out */ |
| 313 | size = (size + 0xFF) & ~ 0xFF; |
| 314 | return tty_buffer_alloc(size); |
| 315 | /* Should possibly check if this fails for the largest buffer we |
| 316 | have queued and recycle that ? */ |
| 317 | } |
| 318 | |
| 319 | int tty_buffer_request_room(struct tty_struct *tty, size_t size) |
| 320 | { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 321 | struct tty_buffer *b, *n; |
| 322 | int left; |
| 323 | unsigned long flags; |
| 324 | |
| 325 | spin_lock_irqsave(&tty->buf.lock, flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 326 | |
| 327 | /* OPTIMISATION: We could keep a per tty "zero" sized buffer to |
| 328 | remove this conditional if its worth it. This would be invisible |
| 329 | to the callers */ |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 330 | if ((b = tty->buf.tail) != NULL) { |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 331 | left = b->size - b->used; |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 332 | b->active = 1; |
| 333 | } else |
| 334 | left = 0; |
| 335 | |
| 336 | if (left < size) { |
| 337 | /* This is the slow path - looking for new buffers to use */ |
| 338 | if ((n = tty_buffer_find(tty, size)) != NULL) { |
| 339 | if (b != NULL) { |
| 340 | b->next = n; |
| 341 | b->active = 0; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 342 | b->commit = b->used; |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 343 | } else |
| 344 | tty->buf.head = n; |
| 345 | tty->buf.tail = n; |
| 346 | n->active = 1; |
| 347 | } else |
| 348 | size = left; |
| 349 | } |
| 350 | |
| 351 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 352 | return size; |
| 353 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 354 | EXPORT_SYMBOL_GPL(tty_buffer_request_room); |
| 355 | |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 356 | int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars, |
| 357 | size_t size) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 358 | { |
| 359 | int copied = 0; |
| 360 | do { |
| 361 | int space = tty_buffer_request_room(tty, size - copied); |
| 362 | struct tty_buffer *tb = tty->buf.tail; |
| 363 | /* If there is no space then tb may be NULL */ |
| 364 | if(unlikely(space == 0)) |
| 365 | break; |
| 366 | memcpy(tb->char_buf_ptr + tb->used, chars, space); |
| 367 | memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); |
| 368 | tb->used += space; |
| 369 | copied += space; |
| 370 | chars += space; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 371 | } |
| 372 | /* There is a small chance that we need to split the data over |
| 373 | several buffers. If this is the case we must loop */ |
| 374 | while (unlikely(size > copied)); |
| 375 | return copied; |
| 376 | } |
Andrew Morton | ee37df7 | 2006-03-31 02:30:35 -0800 | [diff] [blame] | 377 | EXPORT_SYMBOL(tty_insert_flip_string); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 378 | |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 379 | int tty_insert_flip_string_flags(struct tty_struct *tty, |
| 380 | const unsigned char *chars, const char *flags, size_t size) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 381 | { |
| 382 | int copied = 0; |
| 383 | do { |
| 384 | int space = tty_buffer_request_room(tty, size - copied); |
| 385 | struct tty_buffer *tb = tty->buf.tail; |
| 386 | /* If there is no space then tb may be NULL */ |
| 387 | if(unlikely(space == 0)) |
| 388 | break; |
| 389 | memcpy(tb->char_buf_ptr + tb->used, chars, space); |
| 390 | memcpy(tb->flag_buf_ptr + tb->used, flags, space); |
| 391 | tb->used += space; |
| 392 | copied += space; |
| 393 | chars += space; |
| 394 | flags += space; |
| 395 | } |
| 396 | /* There is a small chance that we need to split the data over |
| 397 | several buffers. If this is the case we must loop */ |
| 398 | while (unlikely(size > copied)); |
| 399 | return copied; |
| 400 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 401 | EXPORT_SYMBOL_GPL(tty_insert_flip_string_flags); |
| 402 | |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 403 | void tty_schedule_flip(struct tty_struct *tty) |
| 404 | { |
| 405 | unsigned long flags; |
| 406 | spin_lock_irqsave(&tty->buf.lock, flags); |
| 407 | if (tty->buf.tail != NULL) { |
| 408 | tty->buf.tail->active = 0; |
| 409 | tty->buf.tail->commit = tty->buf.tail->used; |
| 410 | } |
| 411 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
| 412 | schedule_delayed_work(&tty->buf.work, 1); |
| 413 | } |
| 414 | EXPORT_SYMBOL(tty_schedule_flip); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 415 | |
| 416 | /* |
| 417 | * Prepare a block of space in the buffer for data. Returns the length |
| 418 | * available and buffer pointer to the space which is now allocated and |
| 419 | * accounted for as ready for normal characters. This is used for drivers |
| 420 | * that need their own block copy routines into the buffer. There is no |
| 421 | * guarantee the buffer is a DMA target! |
| 422 | */ |
| 423 | |
| 424 | int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size) |
| 425 | { |
| 426 | int space = tty_buffer_request_room(tty, size); |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 427 | if (likely(space)) { |
| 428 | struct tty_buffer *tb = tty->buf.tail; |
| 429 | *chars = tb->char_buf_ptr + tb->used; |
| 430 | memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); |
| 431 | tb->used += space; |
| 432 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 433 | return space; |
| 434 | } |
| 435 | |
| 436 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string); |
| 437 | |
| 438 | /* |
| 439 | * Prepare a block of space in the buffer for data. Returns the length |
| 440 | * available and buffer pointer to the space which is now allocated and |
| 441 | * accounted for as ready for characters. This is used for drivers |
| 442 | * that need their own block copy routines into the buffer. There is no |
| 443 | * guarantee the buffer is a DMA target! |
| 444 | */ |
| 445 | |
| 446 | int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size) |
| 447 | { |
| 448 | int space = tty_buffer_request_room(tty, size); |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 449 | if (likely(space)) { |
| 450 | struct tty_buffer *tb = tty->buf.tail; |
| 451 | *chars = tb->char_buf_ptr + tb->used; |
| 452 | *flags = tb->flag_buf_ptr + tb->used; |
| 453 | tb->used += space; |
| 454 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 455 | return space; |
| 456 | } |
| 457 | |
| 458 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); |
| 459 | |
| 460 | |
| 461 | |
| 462 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | * This is probably overkill for real world processors but |
| 464 | * they are not on hot paths so a little discipline won't do |
| 465 | * any harm. |
| 466 | */ |
| 467 | |
| 468 | static void tty_set_termios_ldisc(struct tty_struct *tty, int num) |
| 469 | { |
| 470 | down(&tty->termios_sem); |
| 471 | tty->termios->c_line = num; |
| 472 | up(&tty->termios_sem); |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * This guards the refcounted line discipline lists. The lock |
| 477 | * must be taken with irqs off because there are hangup path |
| 478 | * callers who will do ldisc lookups and cannot sleep. |
| 479 | */ |
| 480 | |
| 481 | static DEFINE_SPINLOCK(tty_ldisc_lock); |
| 482 | static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait); |
Alexey Dobriyan | bfb0759 | 2005-06-23 00:10:32 -0700 | [diff] [blame] | 483 | static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
| 485 | int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) |
| 486 | { |
| 487 | unsigned long flags; |
| 488 | int ret = 0; |
| 489 | |
| 490 | if (disc < N_TTY || disc >= NR_LDISCS) |
| 491 | return -EINVAL; |
| 492 | |
| 493 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
Alexey Dobriyan | bfb0759 | 2005-06-23 00:10:32 -0700 | [diff] [blame] | 494 | tty_ldiscs[disc] = *new_ldisc; |
| 495 | tty_ldiscs[disc].num = disc; |
| 496 | tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; |
| 497 | tty_ldiscs[disc].refcount = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 499 | |
| 500 | return ret; |
| 501 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | EXPORT_SYMBOL(tty_register_ldisc); |
| 503 | |
Alexey Dobriyan | bfb0759 | 2005-06-23 00:10:32 -0700 | [diff] [blame] | 504 | int tty_unregister_ldisc(int disc) |
| 505 | { |
| 506 | unsigned long flags; |
| 507 | int ret = 0; |
| 508 | |
| 509 | if (disc < N_TTY || disc >= NR_LDISCS) |
| 510 | return -EINVAL; |
| 511 | |
| 512 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 513 | if (tty_ldiscs[disc].refcount) |
| 514 | ret = -EBUSY; |
| 515 | else |
| 516 | tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; |
| 517 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 518 | |
| 519 | return ret; |
| 520 | } |
| 521 | EXPORT_SYMBOL(tty_unregister_ldisc); |
| 522 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | struct tty_ldisc *tty_ldisc_get(int disc) |
| 524 | { |
| 525 | unsigned long flags; |
| 526 | struct tty_ldisc *ld; |
| 527 | |
| 528 | if (disc < N_TTY || disc >= NR_LDISCS) |
| 529 | return NULL; |
| 530 | |
| 531 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 532 | |
| 533 | ld = &tty_ldiscs[disc]; |
| 534 | /* Check the entry is defined */ |
| 535 | if(ld->flags & LDISC_FLAG_DEFINED) |
| 536 | { |
| 537 | /* If the module is being unloaded we can't use it */ |
| 538 | if (!try_module_get(ld->owner)) |
| 539 | ld = NULL; |
| 540 | else /* lock it */ |
| 541 | ld->refcount++; |
| 542 | } |
| 543 | else |
| 544 | ld = NULL; |
| 545 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 546 | return ld; |
| 547 | } |
| 548 | |
| 549 | EXPORT_SYMBOL_GPL(tty_ldisc_get); |
| 550 | |
| 551 | void tty_ldisc_put(int disc) |
| 552 | { |
| 553 | struct tty_ldisc *ld; |
| 554 | unsigned long flags; |
| 555 | |
Eric Sesterhenn | 56ee482 | 2006-03-26 18:17:21 +0200 | [diff] [blame] | 556 | BUG_ON(disc < N_TTY || disc >= NR_LDISCS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | |
| 558 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 559 | ld = &tty_ldiscs[disc]; |
Eric Sesterhenn | 56ee482 | 2006-03-26 18:17:21 +0200 | [diff] [blame] | 560 | BUG_ON(ld->refcount == 0); |
| 561 | ld->refcount--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | module_put(ld->owner); |
| 563 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 564 | } |
| 565 | |
| 566 | EXPORT_SYMBOL_GPL(tty_ldisc_put); |
| 567 | |
| 568 | static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld) |
| 569 | { |
| 570 | tty->ldisc = *ld; |
| 571 | tty->ldisc.refcount = 0; |
| 572 | } |
| 573 | |
| 574 | /** |
| 575 | * tty_ldisc_try - internal helper |
| 576 | * @tty: the tty |
| 577 | * |
| 578 | * Make a single attempt to grab and bump the refcount on |
| 579 | * the tty ldisc. Return 0 on failure or 1 on success. This is |
| 580 | * used to implement both the waiting and non waiting versions |
| 581 | * of tty_ldisc_ref |
| 582 | */ |
| 583 | |
| 584 | static int tty_ldisc_try(struct tty_struct *tty) |
| 585 | { |
| 586 | unsigned long flags; |
| 587 | struct tty_ldisc *ld; |
| 588 | int ret = 0; |
| 589 | |
| 590 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 591 | ld = &tty->ldisc; |
| 592 | if(test_bit(TTY_LDISC, &tty->flags)) |
| 593 | { |
| 594 | ld->refcount++; |
| 595 | ret = 1; |
| 596 | } |
| 597 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 598 | return ret; |
| 599 | } |
| 600 | |
| 601 | /** |
| 602 | * tty_ldisc_ref_wait - wait for the tty ldisc |
| 603 | * @tty: tty device |
| 604 | * |
| 605 | * Dereference the line discipline for the terminal and take a |
| 606 | * reference to it. If the line discipline is in flux then |
| 607 | * wait patiently until it changes. |
| 608 | * |
| 609 | * Note: Must not be called from an IRQ/timer context. The caller |
| 610 | * must also be careful not to hold other locks that will deadlock |
| 611 | * against a discipline change, such as an existing ldisc reference |
| 612 | * (which we check for) |
| 613 | */ |
| 614 | |
| 615 | struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) |
| 616 | { |
| 617 | /* wait_event is a macro */ |
| 618 | wait_event(tty_ldisc_wait, tty_ldisc_try(tty)); |
| 619 | if(tty->ldisc.refcount == 0) |
| 620 | printk(KERN_ERR "tty_ldisc_ref_wait\n"); |
| 621 | return &tty->ldisc; |
| 622 | } |
| 623 | |
| 624 | EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); |
| 625 | |
| 626 | /** |
| 627 | * tty_ldisc_ref - get the tty ldisc |
| 628 | * @tty: tty device |
| 629 | * |
| 630 | * Dereference the line discipline for the terminal and take a |
| 631 | * reference to it. If the line discipline is in flux then |
| 632 | * return NULL. Can be called from IRQ and timer functions. |
| 633 | */ |
| 634 | |
| 635 | struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty) |
| 636 | { |
| 637 | if(tty_ldisc_try(tty)) |
| 638 | return &tty->ldisc; |
| 639 | return NULL; |
| 640 | } |
| 641 | |
| 642 | EXPORT_SYMBOL_GPL(tty_ldisc_ref); |
| 643 | |
| 644 | /** |
| 645 | * tty_ldisc_deref - free a tty ldisc reference |
| 646 | * @ld: reference to free up |
| 647 | * |
| 648 | * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May |
| 649 | * be called in IRQ context. |
| 650 | */ |
| 651 | |
| 652 | void tty_ldisc_deref(struct tty_ldisc *ld) |
| 653 | { |
| 654 | unsigned long flags; |
| 655 | |
Eric Sesterhenn | 56ee482 | 2006-03-26 18:17:21 +0200 | [diff] [blame] | 656 | BUG_ON(ld == NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | |
| 658 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 659 | if(ld->refcount == 0) |
| 660 | printk(KERN_ERR "tty_ldisc_deref: no references.\n"); |
| 661 | else |
| 662 | ld->refcount--; |
| 663 | if(ld->refcount == 0) |
| 664 | wake_up(&tty_ldisc_wait); |
| 665 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 666 | } |
| 667 | |
| 668 | EXPORT_SYMBOL_GPL(tty_ldisc_deref); |
| 669 | |
| 670 | /** |
| 671 | * tty_ldisc_enable - allow ldisc use |
| 672 | * @tty: terminal to activate ldisc on |
| 673 | * |
| 674 | * Set the TTY_LDISC flag when the line discipline can be called |
| 675 | * again. Do neccessary wakeups for existing sleepers. |
| 676 | * |
| 677 | * Note: nobody should set this bit except via this function. Clearing |
| 678 | * directly is allowed. |
| 679 | */ |
| 680 | |
| 681 | static void tty_ldisc_enable(struct tty_struct *tty) |
| 682 | { |
| 683 | set_bit(TTY_LDISC, &tty->flags); |
| 684 | wake_up(&tty_ldisc_wait); |
| 685 | } |
| 686 | |
| 687 | /** |
| 688 | * tty_set_ldisc - set line discipline |
| 689 | * @tty: the terminal to set |
| 690 | * @ldisc: the line discipline |
| 691 | * |
| 692 | * Set the discipline of a tty line. Must be called from a process |
| 693 | * context. |
| 694 | */ |
| 695 | |
| 696 | static int tty_set_ldisc(struct tty_struct *tty, int ldisc) |
| 697 | { |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 698 | int retval = 0; |
| 699 | struct tty_ldisc o_ldisc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | char buf[64]; |
| 701 | int work; |
| 702 | unsigned long flags; |
| 703 | struct tty_ldisc *ld; |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 704 | struct tty_struct *o_tty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | |
| 706 | if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) |
| 707 | return -EINVAL; |
| 708 | |
| 709 | restart: |
| 710 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 711 | ld = tty_ldisc_get(ldisc); |
| 712 | /* Eduardo Blanco <ejbs@cs.cs.com.uy> */ |
| 713 | /* Cyrus Durgin <cider@speakeasy.org> */ |
| 714 | if (ld == NULL) { |
| 715 | request_module("tty-ldisc-%d", ldisc); |
| 716 | ld = tty_ldisc_get(ldisc); |
| 717 | } |
| 718 | if (ld == NULL) |
| 719 | return -EINVAL; |
| 720 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 721 | /* |
| 722 | * No more input please, we are switching. The new ldisc |
| 723 | * will update this value in the ldisc open function |
| 724 | */ |
| 725 | |
| 726 | tty->receive_room = 0; |
| 727 | |
| 728 | /* |
| 729 | * Problem: What do we do if this blocks ? |
| 730 | */ |
| 731 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 732 | tty_wait_until_sent(tty, 0); |
| 733 | |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 734 | if (tty->ldisc.num == ldisc) { |
| 735 | tty_ldisc_put(ldisc); |
| 736 | return 0; |
| 737 | } |
| 738 | |
| 739 | o_ldisc = tty->ldisc; |
| 740 | o_tty = tty->link; |
| 741 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 742 | /* |
| 743 | * Make sure we don't change while someone holds a |
| 744 | * reference to the line discipline. The TTY_LDISC bit |
| 745 | * prevents anyone taking a reference once it is clear. |
| 746 | * We need the lock to avoid racing reference takers. |
| 747 | */ |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 748 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 749 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 750 | if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) { |
| 751 | if(tty->ldisc.refcount) { |
| 752 | /* Free the new ldisc we grabbed. Must drop the lock |
| 753 | first. */ |
| 754 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 755 | tty_ldisc_put(ldisc); |
| 756 | /* |
| 757 | * There are several reasons we may be busy, including |
| 758 | * random momentary I/O traffic. We must therefore |
| 759 | * retry. We could distinguish between blocking ops |
| 760 | * and retries if we made tty_ldisc_wait() smarter. That |
| 761 | * is up for discussion. |
| 762 | */ |
| 763 | if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0) |
| 764 | return -ERESTARTSYS; |
| 765 | goto restart; |
| 766 | } |
| 767 | if(o_tty && o_tty->ldisc.refcount) { |
| 768 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 769 | tty_ldisc_put(ldisc); |
| 770 | if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0) |
| 771 | return -ERESTARTSYS; |
| 772 | goto restart; |
| 773 | } |
| 774 | } |
| 775 | |
| 776 | /* if the TTY_LDISC bit is set, then we are racing against another ldisc change */ |
| 777 | |
| 778 | if (!test_bit(TTY_LDISC, &tty->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 780 | tty_ldisc_put(ldisc); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 781 | ld = tty_ldisc_ref_wait(tty); |
| 782 | tty_ldisc_deref(ld); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | goto restart; |
| 784 | } |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 785 | |
| 786 | clear_bit(TTY_LDISC, &tty->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | clear_bit(TTY_DONT_FLIP, &tty->flags); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 788 | if (o_tty) { |
| 789 | clear_bit(TTY_LDISC, &o_tty->flags); |
| 790 | clear_bit(TTY_DONT_FLIP, &o_tty->flags); |
| 791 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 792 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 793 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 794 | /* |
| 795 | * From this point on we know nobody has an ldisc |
| 796 | * usage reference, nor can they obtain one until |
| 797 | * we say so later on. |
| 798 | */ |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 799 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 800 | work = cancel_delayed_work(&tty->buf.work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | /* |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 802 | * Wait for ->hangup_work and ->buf.work handlers to terminate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 803 | */ |
| 804 | |
| 805 | flush_scheduled_work(); |
| 806 | /* Shutdown the current discipline. */ |
| 807 | if (tty->ldisc.close) |
| 808 | (tty->ldisc.close)(tty); |
| 809 | |
| 810 | /* Now set up the new line discipline. */ |
| 811 | tty_ldisc_assign(tty, ld); |
| 812 | tty_set_termios_ldisc(tty, ldisc); |
| 813 | if (tty->ldisc.open) |
| 814 | retval = (tty->ldisc.open)(tty); |
| 815 | if (retval < 0) { |
| 816 | tty_ldisc_put(ldisc); |
| 817 | /* There is an outstanding reference here so this is safe */ |
| 818 | tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num)); |
| 819 | tty_set_termios_ldisc(tty, tty->ldisc.num); |
| 820 | if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { |
| 821 | tty_ldisc_put(o_ldisc.num); |
| 822 | /* This driver is always present */ |
| 823 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
| 824 | tty_set_termios_ldisc(tty, N_TTY); |
| 825 | if (tty->ldisc.open) { |
| 826 | int r = tty->ldisc.open(tty); |
| 827 | |
| 828 | if (r < 0) |
| 829 | panic("Couldn't open N_TTY ldisc for " |
| 830 | "%s --- error %d.", |
| 831 | tty_name(tty, buf), r); |
| 832 | } |
| 833 | } |
| 834 | } |
| 835 | /* At this point we hold a reference to the new ldisc and a |
| 836 | a reference to the old ldisc. If we ended up flipping back |
| 837 | to the existing ldisc we have two references to it */ |
| 838 | |
| 839 | if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc) |
| 840 | tty->driver->set_ldisc(tty); |
| 841 | |
| 842 | tty_ldisc_put(o_ldisc.num); |
| 843 | |
| 844 | /* |
| 845 | * Allow ldisc referencing to occur as soon as the driver |
| 846 | * ldisc callback completes. |
| 847 | */ |
| 848 | |
| 849 | tty_ldisc_enable(tty); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 850 | if (o_tty) |
| 851 | tty_ldisc_enable(o_tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | |
| 853 | /* Restart it in case no characters kick it off. Safe if |
| 854 | already running */ |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 855 | if (work) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 856 | schedule_delayed_work(&tty->buf.work, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | return retval; |
| 858 | } |
| 859 | |
| 860 | /* |
| 861 | * This routine returns a tty driver structure, given a device number |
| 862 | */ |
| 863 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
| 864 | { |
| 865 | struct tty_driver *p; |
| 866 | |
| 867 | list_for_each_entry(p, &tty_drivers, tty_drivers) { |
| 868 | dev_t base = MKDEV(p->major, p->minor_start); |
| 869 | if (device < base || device >= base + p->num) |
| 870 | continue; |
| 871 | *index = device - base; |
| 872 | return p; |
| 873 | } |
| 874 | return NULL; |
| 875 | } |
| 876 | |
| 877 | /* |
| 878 | * If we try to write to, or set the state of, a terminal and we're |
| 879 | * not in the foreground, send a SIGTTOU. If the signal is blocked or |
| 880 | * ignored, go ahead and perform the operation. (POSIX 7.2) |
| 881 | */ |
| 882 | int tty_check_change(struct tty_struct * tty) |
| 883 | { |
| 884 | if (current->signal->tty != tty) |
| 885 | return 0; |
| 886 | if (tty->pgrp <= 0) { |
| 887 | printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n"); |
| 888 | return 0; |
| 889 | } |
| 890 | if (process_group(current) == tty->pgrp) |
| 891 | return 0; |
| 892 | if (is_ignored(SIGTTOU)) |
| 893 | return 0; |
| 894 | if (is_orphaned_pgrp(process_group(current))) |
| 895 | return -EIO; |
| 896 | (void) kill_pg(process_group(current), SIGTTOU, 1); |
| 897 | return -ERESTARTSYS; |
| 898 | } |
| 899 | |
| 900 | EXPORT_SYMBOL(tty_check_change); |
| 901 | |
| 902 | static ssize_t hung_up_tty_read(struct file * file, char __user * buf, |
| 903 | size_t count, loff_t *ppos) |
| 904 | { |
| 905 | return 0; |
| 906 | } |
| 907 | |
| 908 | static ssize_t hung_up_tty_write(struct file * file, const char __user * buf, |
| 909 | size_t count, loff_t *ppos) |
| 910 | { |
| 911 | return -EIO; |
| 912 | } |
| 913 | |
| 914 | /* No kernel lock held - none needed ;) */ |
| 915 | static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait) |
| 916 | { |
| 917 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; |
| 918 | } |
| 919 | |
| 920 | static int hung_up_tty_ioctl(struct inode * inode, struct file * file, |
| 921 | unsigned int cmd, unsigned long arg) |
| 922 | { |
| 923 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; |
| 924 | } |
| 925 | |
| 926 | static struct file_operations tty_fops = { |
| 927 | .llseek = no_llseek, |
| 928 | .read = tty_read, |
| 929 | .write = tty_write, |
| 930 | .poll = tty_poll, |
| 931 | .ioctl = tty_ioctl, |
| 932 | .open = tty_open, |
| 933 | .release = tty_release, |
| 934 | .fasync = tty_fasync, |
| 935 | }; |
| 936 | |
| 937 | #ifdef CONFIG_UNIX98_PTYS |
| 938 | static struct file_operations ptmx_fops = { |
| 939 | .llseek = no_llseek, |
| 940 | .read = tty_read, |
| 941 | .write = tty_write, |
| 942 | .poll = tty_poll, |
| 943 | .ioctl = tty_ioctl, |
| 944 | .open = ptmx_open, |
| 945 | .release = tty_release, |
| 946 | .fasync = tty_fasync, |
| 947 | }; |
| 948 | #endif |
| 949 | |
| 950 | static struct file_operations console_fops = { |
| 951 | .llseek = no_llseek, |
| 952 | .read = tty_read, |
| 953 | .write = redirected_tty_write, |
| 954 | .poll = tty_poll, |
| 955 | .ioctl = tty_ioctl, |
| 956 | .open = tty_open, |
| 957 | .release = tty_release, |
| 958 | .fasync = tty_fasync, |
| 959 | }; |
| 960 | |
| 961 | static struct file_operations hung_up_tty_fops = { |
| 962 | .llseek = no_llseek, |
| 963 | .read = hung_up_tty_read, |
| 964 | .write = hung_up_tty_write, |
| 965 | .poll = hung_up_tty_poll, |
| 966 | .ioctl = hung_up_tty_ioctl, |
| 967 | .release = tty_release, |
| 968 | }; |
| 969 | |
| 970 | static DEFINE_SPINLOCK(redirect_lock); |
| 971 | static struct file *redirect; |
| 972 | |
| 973 | /** |
| 974 | * tty_wakeup - request more data |
| 975 | * @tty: terminal |
| 976 | * |
| 977 | * Internal and external helper for wakeups of tty. This function |
| 978 | * informs the line discipline if present that the driver is ready |
| 979 | * to receive more output data. |
| 980 | */ |
| 981 | |
| 982 | void tty_wakeup(struct tty_struct *tty) |
| 983 | { |
| 984 | struct tty_ldisc *ld; |
| 985 | |
| 986 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
| 987 | ld = tty_ldisc_ref(tty); |
| 988 | if(ld) { |
| 989 | if(ld->write_wakeup) |
| 990 | ld->write_wakeup(tty); |
| 991 | tty_ldisc_deref(ld); |
| 992 | } |
| 993 | } |
| 994 | wake_up_interruptible(&tty->write_wait); |
| 995 | } |
| 996 | |
| 997 | EXPORT_SYMBOL_GPL(tty_wakeup); |
| 998 | |
| 999 | /** |
| 1000 | * tty_ldisc_flush - flush line discipline queue |
| 1001 | * @tty: tty |
| 1002 | * |
| 1003 | * Flush the line discipline queue (if any) for this tty. If there |
| 1004 | * is no line discipline active this is a no-op. |
| 1005 | */ |
| 1006 | |
| 1007 | void tty_ldisc_flush(struct tty_struct *tty) |
| 1008 | { |
| 1009 | struct tty_ldisc *ld = tty_ldisc_ref(tty); |
| 1010 | if(ld) { |
| 1011 | if(ld->flush_buffer) |
| 1012 | ld->flush_buffer(tty); |
| 1013 | tty_ldisc_deref(ld); |
| 1014 | } |
| 1015 | } |
| 1016 | |
| 1017 | EXPORT_SYMBOL_GPL(tty_ldisc_flush); |
| 1018 | |
| 1019 | /* |
| 1020 | * This can be called by the "eventd" kernel thread. That is process synchronous, |
| 1021 | * but doesn't hold any locks, so we need to make sure we have the appropriate |
| 1022 | * locks for what we're doing.. |
| 1023 | */ |
| 1024 | static void do_tty_hangup(void *data) |
| 1025 | { |
| 1026 | struct tty_struct *tty = (struct tty_struct *) data; |
| 1027 | struct file * cons_filp = NULL; |
| 1028 | struct file *filp, *f = NULL; |
| 1029 | struct task_struct *p; |
| 1030 | struct tty_ldisc *ld; |
| 1031 | int closecount = 0, n; |
| 1032 | |
| 1033 | if (!tty) |
| 1034 | return; |
| 1035 | |
| 1036 | /* inuse_filps is protected by the single kernel lock */ |
| 1037 | lock_kernel(); |
| 1038 | |
| 1039 | spin_lock(&redirect_lock); |
| 1040 | if (redirect && redirect->private_data == tty) { |
| 1041 | f = redirect; |
| 1042 | redirect = NULL; |
| 1043 | } |
| 1044 | spin_unlock(&redirect_lock); |
| 1045 | |
| 1046 | check_tty_count(tty, "do_tty_hangup"); |
| 1047 | file_list_lock(); |
| 1048 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
Eric Dumazet | 2f51201 | 2005-10-30 15:02:16 -0800 | [diff] [blame] | 1049 | list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1050 | if (filp->f_op->write == redirected_tty_write) |
| 1051 | cons_filp = filp; |
| 1052 | if (filp->f_op->write != tty_write) |
| 1053 | continue; |
| 1054 | closecount++; |
| 1055 | tty_fasync(-1, filp, 0); /* can't block */ |
| 1056 | filp->f_op = &hung_up_tty_fops; |
| 1057 | } |
| 1058 | file_list_unlock(); |
| 1059 | |
| 1060 | /* FIXME! What are the locking issues here? This may me overdoing things.. |
| 1061 | * this question is especially important now that we've removed the irqlock. */ |
| 1062 | |
| 1063 | ld = tty_ldisc_ref(tty); |
| 1064 | if(ld != NULL) /* We may have no line discipline at this point */ |
| 1065 | { |
| 1066 | if (ld->flush_buffer) |
| 1067 | ld->flush_buffer(tty); |
| 1068 | if (tty->driver->flush_buffer) |
| 1069 | tty->driver->flush_buffer(tty); |
| 1070 | if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && |
| 1071 | ld->write_wakeup) |
| 1072 | ld->write_wakeup(tty); |
| 1073 | if (ld->hangup) |
| 1074 | ld->hangup(tty); |
| 1075 | } |
| 1076 | |
| 1077 | /* FIXME: Once we trust the LDISC code better we can wait here for |
| 1078 | ldisc completion and fix the driver call race */ |
| 1079 | |
| 1080 | wake_up_interruptible(&tty->write_wait); |
| 1081 | wake_up_interruptible(&tty->read_wait); |
| 1082 | |
| 1083 | /* |
| 1084 | * Shutdown the current line discipline, and reset it to |
| 1085 | * N_TTY. |
| 1086 | */ |
| 1087 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
| 1088 | { |
| 1089 | down(&tty->termios_sem); |
| 1090 | *tty->termios = tty->driver->init_termios; |
| 1091 | up(&tty->termios_sem); |
| 1092 | } |
| 1093 | |
| 1094 | /* Defer ldisc switch */ |
| 1095 | /* tty_deferred_ldisc_switch(N_TTY); |
| 1096 | |
| 1097 | This should get done automatically when the port closes and |
| 1098 | tty_release is called */ |
| 1099 | |
| 1100 | read_lock(&tasklist_lock); |
| 1101 | if (tty->session > 0) { |
| 1102 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
| 1103 | if (p->signal->tty == tty) |
| 1104 | p->signal->tty = NULL; |
| 1105 | if (!p->signal->leader) |
| 1106 | continue; |
Eric W. Biederman | f96a795 | 2006-03-28 16:11:01 -0800 | [diff] [blame] | 1107 | group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); |
| 1108 | group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1109 | if (tty->pgrp > 0) |
| 1110 | p->signal->tty_old_pgrp = tty->pgrp; |
| 1111 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
| 1112 | } |
| 1113 | read_unlock(&tasklist_lock); |
| 1114 | |
| 1115 | tty->flags = 0; |
| 1116 | tty->session = 0; |
| 1117 | tty->pgrp = -1; |
| 1118 | tty->ctrl_status = 0; |
| 1119 | /* |
| 1120 | * If one of the devices matches a console pointer, we |
| 1121 | * cannot just call hangup() because that will cause |
| 1122 | * tty->count and state->count to go out of sync. |
| 1123 | * So we just call close() the right number of times. |
| 1124 | */ |
| 1125 | if (cons_filp) { |
| 1126 | if (tty->driver->close) |
| 1127 | for (n = 0; n < closecount; n++) |
| 1128 | tty->driver->close(tty, cons_filp); |
| 1129 | } else if (tty->driver->hangup) |
| 1130 | (tty->driver->hangup)(tty); |
| 1131 | |
| 1132 | /* We don't want to have driver/ldisc interactions beyond |
| 1133 | the ones we did here. The driver layer expects no |
| 1134 | calls after ->hangup() from the ldisc side. However we |
| 1135 | can't yet guarantee all that */ |
| 1136 | |
| 1137 | set_bit(TTY_HUPPED, &tty->flags); |
| 1138 | if (ld) { |
| 1139 | tty_ldisc_enable(tty); |
| 1140 | tty_ldisc_deref(ld); |
| 1141 | } |
| 1142 | unlock_kernel(); |
| 1143 | if (f) |
| 1144 | fput(f); |
| 1145 | } |
| 1146 | |
| 1147 | void tty_hangup(struct tty_struct * tty) |
| 1148 | { |
| 1149 | #ifdef TTY_DEBUG_HANGUP |
| 1150 | char buf[64]; |
| 1151 | |
| 1152 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
| 1153 | #endif |
| 1154 | schedule_work(&tty->hangup_work); |
| 1155 | } |
| 1156 | |
| 1157 | EXPORT_SYMBOL(tty_hangup); |
| 1158 | |
| 1159 | void tty_vhangup(struct tty_struct * tty) |
| 1160 | { |
| 1161 | #ifdef TTY_DEBUG_HANGUP |
| 1162 | char buf[64]; |
| 1163 | |
| 1164 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); |
| 1165 | #endif |
| 1166 | do_tty_hangup((void *) tty); |
| 1167 | } |
| 1168 | EXPORT_SYMBOL(tty_vhangup); |
| 1169 | |
| 1170 | int tty_hung_up_p(struct file * filp) |
| 1171 | { |
| 1172 | return (filp->f_op == &hung_up_tty_fops); |
| 1173 | } |
| 1174 | |
| 1175 | EXPORT_SYMBOL(tty_hung_up_p); |
| 1176 | |
| 1177 | /* |
| 1178 | * This function is typically called only by the session leader, when |
| 1179 | * it wants to disassociate itself from its controlling tty. |
| 1180 | * |
| 1181 | * It performs the following functions: |
| 1182 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
| 1183 | * (2) Clears the tty from being controlling the session |
| 1184 | * (3) Clears the controlling tty for all processes in the |
| 1185 | * session group. |
| 1186 | * |
| 1187 | * The argument on_exit is set to 1 if called when a process is |
| 1188 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. |
| 1189 | */ |
| 1190 | void disassociate_ctty(int on_exit) |
| 1191 | { |
| 1192 | struct tty_struct *tty; |
| 1193 | struct task_struct *p; |
| 1194 | int tty_pgrp = -1; |
| 1195 | |
| 1196 | lock_kernel(); |
| 1197 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1198 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1199 | tty = current->signal->tty; |
| 1200 | if (tty) { |
| 1201 | tty_pgrp = tty->pgrp; |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1202 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1203 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
| 1204 | tty_vhangup(tty); |
| 1205 | } else { |
| 1206 | if (current->signal->tty_old_pgrp) { |
| 1207 | kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit); |
| 1208 | kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit); |
| 1209 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1210 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1211 | unlock_kernel(); |
| 1212 | return; |
| 1213 | } |
| 1214 | if (tty_pgrp > 0) { |
| 1215 | kill_pg(tty_pgrp, SIGHUP, on_exit); |
| 1216 | if (!on_exit) |
| 1217 | kill_pg(tty_pgrp, SIGCONT, on_exit); |
| 1218 | } |
| 1219 | |
| 1220 | /* Must lock changes to tty_old_pgrp */ |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1221 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1222 | current->signal->tty_old_pgrp = 0; |
| 1223 | tty->session = 0; |
| 1224 | tty->pgrp = -1; |
| 1225 | |
| 1226 | /* Now clear signal->tty under the lock */ |
| 1227 | read_lock(&tasklist_lock); |
| 1228 | do_each_task_pid(current->signal->session, PIDTYPE_SID, p) { |
| 1229 | p->signal->tty = NULL; |
| 1230 | } while_each_task_pid(current->signal->session, PIDTYPE_SID, p); |
| 1231 | read_unlock(&tasklist_lock); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1232 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1233 | unlock_kernel(); |
| 1234 | } |
| 1235 | |
| 1236 | void stop_tty(struct tty_struct *tty) |
| 1237 | { |
| 1238 | if (tty->stopped) |
| 1239 | return; |
| 1240 | tty->stopped = 1; |
| 1241 | if (tty->link && tty->link->packet) { |
| 1242 | tty->ctrl_status &= ~TIOCPKT_START; |
| 1243 | tty->ctrl_status |= TIOCPKT_STOP; |
| 1244 | wake_up_interruptible(&tty->link->read_wait); |
| 1245 | } |
| 1246 | if (tty->driver->stop) |
| 1247 | (tty->driver->stop)(tty); |
| 1248 | } |
| 1249 | |
| 1250 | EXPORT_SYMBOL(stop_tty); |
| 1251 | |
| 1252 | void start_tty(struct tty_struct *tty) |
| 1253 | { |
| 1254 | if (!tty->stopped || tty->flow_stopped) |
| 1255 | return; |
| 1256 | tty->stopped = 0; |
| 1257 | if (tty->link && tty->link->packet) { |
| 1258 | tty->ctrl_status &= ~TIOCPKT_STOP; |
| 1259 | tty->ctrl_status |= TIOCPKT_START; |
| 1260 | wake_up_interruptible(&tty->link->read_wait); |
| 1261 | } |
| 1262 | if (tty->driver->start) |
| 1263 | (tty->driver->start)(tty); |
| 1264 | |
| 1265 | /* If we have a running line discipline it may need kicking */ |
| 1266 | tty_wakeup(tty); |
| 1267 | wake_up_interruptible(&tty->write_wait); |
| 1268 | } |
| 1269 | |
| 1270 | EXPORT_SYMBOL(start_tty); |
| 1271 | |
| 1272 | static ssize_t tty_read(struct file * file, char __user * buf, size_t count, |
| 1273 | loff_t *ppos) |
| 1274 | { |
| 1275 | int i; |
| 1276 | struct tty_struct * tty; |
| 1277 | struct inode *inode; |
| 1278 | struct tty_ldisc *ld; |
| 1279 | |
| 1280 | tty = (struct tty_struct *)file->private_data; |
| 1281 | inode = file->f_dentry->d_inode; |
| 1282 | if (tty_paranoia_check(tty, inode, "tty_read")) |
| 1283 | return -EIO; |
| 1284 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) |
| 1285 | return -EIO; |
| 1286 | |
| 1287 | /* We want to wait for the line discipline to sort out in this |
| 1288 | situation */ |
| 1289 | ld = tty_ldisc_ref_wait(tty); |
| 1290 | lock_kernel(); |
| 1291 | if (ld->read) |
| 1292 | i = (ld->read)(tty,file,buf,count); |
| 1293 | else |
| 1294 | i = -EIO; |
| 1295 | tty_ldisc_deref(ld); |
| 1296 | unlock_kernel(); |
| 1297 | if (i > 0) |
| 1298 | inode->i_atime = current_fs_time(inode->i_sb); |
| 1299 | return i; |
| 1300 | } |
| 1301 | |
| 1302 | /* |
| 1303 | * Split writes up in sane blocksizes to avoid |
| 1304 | * denial-of-service type attacks |
| 1305 | */ |
| 1306 | static inline ssize_t do_tty_write( |
| 1307 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), |
| 1308 | struct tty_struct *tty, |
| 1309 | struct file *file, |
| 1310 | const char __user *buf, |
| 1311 | size_t count) |
| 1312 | { |
| 1313 | ssize_t ret = 0, written = 0; |
| 1314 | unsigned int chunk; |
| 1315 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1316 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1317 | return -ERESTARTSYS; |
| 1318 | } |
| 1319 | |
| 1320 | /* |
| 1321 | * We chunk up writes into a temporary buffer. This |
| 1322 | * simplifies low-level drivers immensely, since they |
| 1323 | * don't have locking issues and user mode accesses. |
| 1324 | * |
| 1325 | * But if TTY_NO_WRITE_SPLIT is set, we should use a |
| 1326 | * big chunk-size.. |
| 1327 | * |
| 1328 | * The default chunk-size is 2kB, because the NTTY |
| 1329 | * layer has problems with bigger chunks. It will |
| 1330 | * claim to be able to handle more characters than |
| 1331 | * it actually does. |
| 1332 | */ |
| 1333 | chunk = 2048; |
| 1334 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) |
| 1335 | chunk = 65536; |
| 1336 | if (count < chunk) |
| 1337 | chunk = count; |
| 1338 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1339 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | if (tty->write_cnt < chunk) { |
| 1341 | unsigned char *buf; |
| 1342 | |
| 1343 | if (chunk < 1024) |
| 1344 | chunk = 1024; |
| 1345 | |
| 1346 | buf = kmalloc(chunk, GFP_KERNEL); |
| 1347 | if (!buf) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1348 | mutex_unlock(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | return -ENOMEM; |
| 1350 | } |
| 1351 | kfree(tty->write_buf); |
| 1352 | tty->write_cnt = chunk; |
| 1353 | tty->write_buf = buf; |
| 1354 | } |
| 1355 | |
| 1356 | /* Do the write .. */ |
| 1357 | for (;;) { |
| 1358 | size_t size = count; |
| 1359 | if (size > chunk) |
| 1360 | size = chunk; |
| 1361 | ret = -EFAULT; |
| 1362 | if (copy_from_user(tty->write_buf, buf, size)) |
| 1363 | break; |
| 1364 | lock_kernel(); |
| 1365 | ret = write(tty, file, tty->write_buf, size); |
| 1366 | unlock_kernel(); |
| 1367 | if (ret <= 0) |
| 1368 | break; |
| 1369 | written += ret; |
| 1370 | buf += ret; |
| 1371 | count -= ret; |
| 1372 | if (!count) |
| 1373 | break; |
| 1374 | ret = -ERESTARTSYS; |
| 1375 | if (signal_pending(current)) |
| 1376 | break; |
| 1377 | cond_resched(); |
| 1378 | } |
| 1379 | if (written) { |
| 1380 | struct inode *inode = file->f_dentry->d_inode; |
| 1381 | inode->i_mtime = current_fs_time(inode->i_sb); |
| 1382 | ret = written; |
| 1383 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1384 | mutex_unlock(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | return ret; |
| 1386 | } |
| 1387 | |
| 1388 | |
| 1389 | static ssize_t tty_write(struct file * file, const char __user * buf, size_t count, |
| 1390 | loff_t *ppos) |
| 1391 | { |
| 1392 | struct tty_struct * tty; |
| 1393 | struct inode *inode = file->f_dentry->d_inode; |
| 1394 | ssize_t ret; |
| 1395 | struct tty_ldisc *ld; |
| 1396 | |
| 1397 | tty = (struct tty_struct *)file->private_data; |
| 1398 | if (tty_paranoia_check(tty, inode, "tty_write")) |
| 1399 | return -EIO; |
| 1400 | if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags))) |
| 1401 | return -EIO; |
| 1402 | |
| 1403 | ld = tty_ldisc_ref_wait(tty); |
| 1404 | if (!ld->write) |
| 1405 | ret = -EIO; |
| 1406 | else |
| 1407 | ret = do_tty_write(ld->write, tty, file, buf, count); |
| 1408 | tty_ldisc_deref(ld); |
| 1409 | return ret; |
| 1410 | } |
| 1411 | |
| 1412 | ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count, |
| 1413 | loff_t *ppos) |
| 1414 | { |
| 1415 | struct file *p = NULL; |
| 1416 | |
| 1417 | spin_lock(&redirect_lock); |
| 1418 | if (redirect) { |
| 1419 | get_file(redirect); |
| 1420 | p = redirect; |
| 1421 | } |
| 1422 | spin_unlock(&redirect_lock); |
| 1423 | |
| 1424 | if (p) { |
| 1425 | ssize_t res; |
| 1426 | res = vfs_write(p, buf, count, &p->f_pos); |
| 1427 | fput(p); |
| 1428 | return res; |
| 1429 | } |
| 1430 | |
| 1431 | return tty_write(file, buf, count, ppos); |
| 1432 | } |
| 1433 | |
| 1434 | static char ptychar[] = "pqrstuvwxyzabcde"; |
| 1435 | |
| 1436 | static inline void pty_line_name(struct tty_driver *driver, int index, char *p) |
| 1437 | { |
| 1438 | int i = index + driver->name_base; |
| 1439 | /* ->name is initialized to "ttyp", but "tty" is expected */ |
| 1440 | sprintf(p, "%s%c%x", |
| 1441 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
| 1442 | ptychar[i >> 4 & 0xf], i & 0xf); |
| 1443 | } |
| 1444 | |
| 1445 | static inline void tty_line_name(struct tty_driver *driver, int index, char *p) |
| 1446 | { |
| 1447 | sprintf(p, "%s%d", driver->name, index + driver->name_base); |
| 1448 | } |
| 1449 | |
| 1450 | /* |
| 1451 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1452 | * failed open. The new code protects the open with a mutex, so it's |
| 1453 | * really quite straightforward. The mutex locking can probably be |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1454 | * relaxed for the (most common) case of reopening a tty. |
| 1455 | */ |
| 1456 | static int init_dev(struct tty_driver *driver, int idx, |
| 1457 | struct tty_struct **ret_tty) |
| 1458 | { |
| 1459 | struct tty_struct *tty, *o_tty; |
| 1460 | struct termios *tp, **tp_loc, *o_tp, **o_tp_loc; |
| 1461 | struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; |
| 1462 | int retval=0; |
| 1463 | |
| 1464 | /* check whether we're reopening an existing tty */ |
| 1465 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
| 1466 | tty = devpts_get_tty(idx); |
| 1467 | if (tty && driver->subtype == PTY_TYPE_MASTER) |
| 1468 | tty = tty->link; |
| 1469 | } else { |
| 1470 | tty = driver->ttys[idx]; |
| 1471 | } |
| 1472 | if (tty) goto fast_track; |
| 1473 | |
| 1474 | /* |
| 1475 | * First time open is complex, especially for PTY devices. |
| 1476 | * This code guarantees that either everything succeeds and the |
| 1477 | * TTY is ready for operation, or else the table slots are vacated |
| 1478 | * and the allocated memory released. (Except that the termios |
| 1479 | * and locked termios may be retained.) |
| 1480 | */ |
| 1481 | |
| 1482 | if (!try_module_get(driver->owner)) { |
| 1483 | retval = -ENODEV; |
| 1484 | goto end_init; |
| 1485 | } |
| 1486 | |
| 1487 | o_tty = NULL; |
| 1488 | tp = o_tp = NULL; |
| 1489 | ltp = o_ltp = NULL; |
| 1490 | |
| 1491 | tty = alloc_tty_struct(); |
| 1492 | if(!tty) |
| 1493 | goto fail_no_mem; |
| 1494 | initialize_tty_struct(tty); |
| 1495 | tty->driver = driver; |
| 1496 | tty->index = idx; |
| 1497 | tty_line_name(driver, idx, tty->name); |
| 1498 | |
| 1499 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
| 1500 | tp_loc = &tty->termios; |
| 1501 | ltp_loc = &tty->termios_locked; |
| 1502 | } else { |
| 1503 | tp_loc = &driver->termios[idx]; |
| 1504 | ltp_loc = &driver->termios_locked[idx]; |
| 1505 | } |
| 1506 | |
| 1507 | if (!*tp_loc) { |
| 1508 | tp = (struct termios *) kmalloc(sizeof(struct termios), |
| 1509 | GFP_KERNEL); |
| 1510 | if (!tp) |
| 1511 | goto free_mem_out; |
| 1512 | *tp = driver->init_termios; |
| 1513 | } |
| 1514 | |
| 1515 | if (!*ltp_loc) { |
| 1516 | ltp = (struct termios *) kmalloc(sizeof(struct termios), |
| 1517 | GFP_KERNEL); |
| 1518 | if (!ltp) |
| 1519 | goto free_mem_out; |
| 1520 | memset(ltp, 0, sizeof(struct termios)); |
| 1521 | } |
| 1522 | |
| 1523 | if (driver->type == TTY_DRIVER_TYPE_PTY) { |
| 1524 | o_tty = alloc_tty_struct(); |
| 1525 | if (!o_tty) |
| 1526 | goto free_mem_out; |
| 1527 | initialize_tty_struct(o_tty); |
| 1528 | o_tty->driver = driver->other; |
| 1529 | o_tty->index = idx; |
| 1530 | tty_line_name(driver->other, idx, o_tty->name); |
| 1531 | |
| 1532 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
| 1533 | o_tp_loc = &o_tty->termios; |
| 1534 | o_ltp_loc = &o_tty->termios_locked; |
| 1535 | } else { |
| 1536 | o_tp_loc = &driver->other->termios[idx]; |
| 1537 | o_ltp_loc = &driver->other->termios_locked[idx]; |
| 1538 | } |
| 1539 | |
| 1540 | if (!*o_tp_loc) { |
| 1541 | o_tp = (struct termios *) |
| 1542 | kmalloc(sizeof(struct termios), GFP_KERNEL); |
| 1543 | if (!o_tp) |
| 1544 | goto free_mem_out; |
| 1545 | *o_tp = driver->other->init_termios; |
| 1546 | } |
| 1547 | |
| 1548 | if (!*o_ltp_loc) { |
| 1549 | o_ltp = (struct termios *) |
| 1550 | kmalloc(sizeof(struct termios), GFP_KERNEL); |
| 1551 | if (!o_ltp) |
| 1552 | goto free_mem_out; |
| 1553 | memset(o_ltp, 0, sizeof(struct termios)); |
| 1554 | } |
| 1555 | |
| 1556 | /* |
| 1557 | * Everything allocated ... set up the o_tty structure. |
| 1558 | */ |
| 1559 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 1560 | driver->other->ttys[idx] = o_tty; |
| 1561 | } |
| 1562 | if (!*o_tp_loc) |
| 1563 | *o_tp_loc = o_tp; |
| 1564 | if (!*o_ltp_loc) |
| 1565 | *o_ltp_loc = o_ltp; |
| 1566 | o_tty->termios = *o_tp_loc; |
| 1567 | o_tty->termios_locked = *o_ltp_loc; |
| 1568 | driver->other->refcount++; |
| 1569 | if (driver->subtype == PTY_TYPE_MASTER) |
| 1570 | o_tty->count++; |
| 1571 | |
| 1572 | /* Establish the links in both directions */ |
| 1573 | tty->link = o_tty; |
| 1574 | o_tty->link = tty; |
| 1575 | } |
| 1576 | |
| 1577 | /* |
| 1578 | * All structures have been allocated, so now we install them. |
| 1579 | * Failures after this point use release_mem to clean up, so |
| 1580 | * there's no need to null out the local pointers. |
| 1581 | */ |
| 1582 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 1583 | driver->ttys[idx] = tty; |
| 1584 | } |
| 1585 | |
| 1586 | if (!*tp_loc) |
| 1587 | *tp_loc = tp; |
| 1588 | if (!*ltp_loc) |
| 1589 | *ltp_loc = ltp; |
| 1590 | tty->termios = *tp_loc; |
| 1591 | tty->termios_locked = *ltp_loc; |
| 1592 | driver->refcount++; |
| 1593 | tty->count++; |
| 1594 | |
| 1595 | /* |
| 1596 | * Structures all installed ... call the ldisc open routines. |
| 1597 | * If we fail here just call release_mem to clean up. No need |
| 1598 | * to decrement the use counts, as release_mem doesn't care. |
| 1599 | */ |
| 1600 | |
| 1601 | if (tty->ldisc.open) { |
| 1602 | retval = (tty->ldisc.open)(tty); |
| 1603 | if (retval) |
| 1604 | goto release_mem_out; |
| 1605 | } |
| 1606 | if (o_tty && o_tty->ldisc.open) { |
| 1607 | retval = (o_tty->ldisc.open)(o_tty); |
| 1608 | if (retval) { |
| 1609 | if (tty->ldisc.close) |
| 1610 | (tty->ldisc.close)(tty); |
| 1611 | goto release_mem_out; |
| 1612 | } |
| 1613 | tty_ldisc_enable(o_tty); |
| 1614 | } |
| 1615 | tty_ldisc_enable(tty); |
| 1616 | goto success; |
| 1617 | |
| 1618 | /* |
| 1619 | * This fast open can be used if the tty is already open. |
| 1620 | * No memory is allocated, and the only failures are from |
| 1621 | * attempting to open a closing tty or attempting multiple |
| 1622 | * opens on a pty master. |
| 1623 | */ |
| 1624 | fast_track: |
| 1625 | if (test_bit(TTY_CLOSING, &tty->flags)) { |
| 1626 | retval = -EIO; |
| 1627 | goto end_init; |
| 1628 | } |
| 1629 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
| 1630 | driver->subtype == PTY_TYPE_MASTER) { |
| 1631 | /* |
| 1632 | * special case for PTY masters: only one open permitted, |
| 1633 | * and the slave side open count is incremented as well. |
| 1634 | */ |
| 1635 | if (tty->count) { |
| 1636 | retval = -EIO; |
| 1637 | goto end_init; |
| 1638 | } |
| 1639 | tty->link->count++; |
| 1640 | } |
| 1641 | tty->count++; |
| 1642 | tty->driver = driver; /* N.B. why do this every time?? */ |
| 1643 | |
| 1644 | /* FIXME */ |
| 1645 | if(!test_bit(TTY_LDISC, &tty->flags)) |
| 1646 | printk(KERN_ERR "init_dev but no ldisc\n"); |
| 1647 | success: |
| 1648 | *ret_tty = tty; |
| 1649 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1650 | /* All paths come through here to release the mutex */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1651 | end_init: |
| 1652 | return retval; |
| 1653 | |
| 1654 | /* Release locally allocated memory ... nothing placed in slots */ |
| 1655 | free_mem_out: |
Jesper Juhl | 735d566 | 2005-11-07 01:01:29 -0800 | [diff] [blame] | 1656 | kfree(o_tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1657 | if (o_tty) |
| 1658 | free_tty_struct(o_tty); |
Jesper Juhl | 735d566 | 2005-11-07 01:01:29 -0800 | [diff] [blame] | 1659 | kfree(ltp); |
| 1660 | kfree(tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1661 | free_tty_struct(tty); |
| 1662 | |
| 1663 | fail_no_mem: |
| 1664 | module_put(driver->owner); |
| 1665 | retval = -ENOMEM; |
| 1666 | goto end_init; |
| 1667 | |
| 1668 | /* call the tty release_mem routine to clean out this slot */ |
| 1669 | release_mem_out: |
| 1670 | printk(KERN_INFO "init_dev: ldisc open failed, " |
| 1671 | "clearing slot %d\n", idx); |
| 1672 | release_mem(tty, idx); |
| 1673 | goto end_init; |
| 1674 | } |
| 1675 | |
| 1676 | /* |
| 1677 | * Releases memory associated with a tty structure, and clears out the |
| 1678 | * driver table slots. |
| 1679 | */ |
| 1680 | static void release_mem(struct tty_struct *tty, int idx) |
| 1681 | { |
| 1682 | struct tty_struct *o_tty; |
| 1683 | struct termios *tp; |
| 1684 | int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; |
| 1685 | |
| 1686 | if ((o_tty = tty->link) != NULL) { |
| 1687 | if (!devpts) |
| 1688 | o_tty->driver->ttys[idx] = NULL; |
| 1689 | if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
| 1690 | tp = o_tty->termios; |
| 1691 | if (!devpts) |
| 1692 | o_tty->driver->termios[idx] = NULL; |
| 1693 | kfree(tp); |
| 1694 | |
| 1695 | tp = o_tty->termios_locked; |
| 1696 | if (!devpts) |
| 1697 | o_tty->driver->termios_locked[idx] = NULL; |
| 1698 | kfree(tp); |
| 1699 | } |
| 1700 | o_tty->magic = 0; |
| 1701 | o_tty->driver->refcount--; |
| 1702 | file_list_lock(); |
| 1703 | list_del_init(&o_tty->tty_files); |
| 1704 | file_list_unlock(); |
| 1705 | free_tty_struct(o_tty); |
| 1706 | } |
| 1707 | |
| 1708 | if (!devpts) |
| 1709 | tty->driver->ttys[idx] = NULL; |
| 1710 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
| 1711 | tp = tty->termios; |
| 1712 | if (!devpts) |
| 1713 | tty->driver->termios[idx] = NULL; |
| 1714 | kfree(tp); |
| 1715 | |
| 1716 | tp = tty->termios_locked; |
| 1717 | if (!devpts) |
| 1718 | tty->driver->termios_locked[idx] = NULL; |
| 1719 | kfree(tp); |
| 1720 | } |
| 1721 | |
| 1722 | tty->magic = 0; |
| 1723 | tty->driver->refcount--; |
| 1724 | file_list_lock(); |
| 1725 | list_del_init(&tty->tty_files); |
| 1726 | file_list_unlock(); |
| 1727 | module_put(tty->driver->owner); |
| 1728 | free_tty_struct(tty); |
| 1729 | } |
| 1730 | |
| 1731 | /* |
| 1732 | * Even releasing the tty structures is a tricky business.. We have |
| 1733 | * to be very careful that the structures are all released at the |
| 1734 | * same time, as interrupts might otherwise get the wrong pointers. |
| 1735 | * |
| 1736 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could |
| 1737 | * lead to double frees or releasing memory still in use. |
| 1738 | */ |
| 1739 | static void release_dev(struct file * filp) |
| 1740 | { |
| 1741 | struct tty_struct *tty, *o_tty; |
| 1742 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
Paul Fulghum | 14a6283 | 2006-04-10 22:54:19 -0700 | [diff] [blame] | 1743 | int devpts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1744 | int idx; |
| 1745 | char buf[64]; |
| 1746 | unsigned long flags; |
| 1747 | |
| 1748 | tty = (struct tty_struct *)filp->private_data; |
| 1749 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev")) |
| 1750 | return; |
| 1751 | |
| 1752 | check_tty_count(tty, "release_dev"); |
| 1753 | |
| 1754 | tty_fasync(-1, filp, 0); |
| 1755 | |
| 1756 | idx = tty->index; |
| 1757 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 1758 | tty->driver->subtype == PTY_TYPE_MASTER); |
| 1759 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1760 | o_tty = tty->link; |
| 1761 | |
| 1762 | #ifdef TTY_PARANOIA_CHECK |
| 1763 | if (idx < 0 || idx >= tty->driver->num) { |
| 1764 | printk(KERN_DEBUG "release_dev: bad idx when trying to " |
| 1765 | "free (%s)\n", tty->name); |
| 1766 | return; |
| 1767 | } |
| 1768 | if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 1769 | if (tty != tty->driver->ttys[idx]) { |
| 1770 | printk(KERN_DEBUG "release_dev: driver.table[%d] not tty " |
| 1771 | "for (%s)\n", idx, tty->name); |
| 1772 | return; |
| 1773 | } |
| 1774 | if (tty->termios != tty->driver->termios[idx]) { |
| 1775 | printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios " |
| 1776 | "for (%s)\n", |
| 1777 | idx, tty->name); |
| 1778 | return; |
| 1779 | } |
| 1780 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { |
| 1781 | printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not " |
| 1782 | "termios_locked for (%s)\n", |
| 1783 | idx, tty->name); |
| 1784 | return; |
| 1785 | } |
| 1786 | } |
| 1787 | #endif |
| 1788 | |
| 1789 | #ifdef TTY_DEBUG_HANGUP |
| 1790 | printk(KERN_DEBUG "release_dev of %s (tty count=%d)...", |
| 1791 | tty_name(tty, buf), tty->count); |
| 1792 | #endif |
| 1793 | |
| 1794 | #ifdef TTY_PARANOIA_CHECK |
| 1795 | if (tty->driver->other && |
| 1796 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 1797 | if (o_tty != tty->driver->other->ttys[idx]) { |
| 1798 | printk(KERN_DEBUG "release_dev: other->table[%d] " |
| 1799 | "not o_tty for (%s)\n", |
| 1800 | idx, tty->name); |
| 1801 | return; |
| 1802 | } |
| 1803 | if (o_tty->termios != tty->driver->other->termios[idx]) { |
| 1804 | printk(KERN_DEBUG "release_dev: other->termios[%d] " |
| 1805 | "not o_termios for (%s)\n", |
| 1806 | idx, tty->name); |
| 1807 | return; |
| 1808 | } |
| 1809 | if (o_tty->termios_locked != |
| 1810 | tty->driver->other->termios_locked[idx]) { |
| 1811 | printk(KERN_DEBUG "release_dev: other->termios_locked[" |
| 1812 | "%d] not o_termios_locked for (%s)\n", |
| 1813 | idx, tty->name); |
| 1814 | return; |
| 1815 | } |
| 1816 | if (o_tty->link != tty) { |
| 1817 | printk(KERN_DEBUG "release_dev: bad pty pointers\n"); |
| 1818 | return; |
| 1819 | } |
| 1820 | } |
| 1821 | #endif |
| 1822 | if (tty->driver->close) |
| 1823 | tty->driver->close(tty, filp); |
| 1824 | |
| 1825 | /* |
| 1826 | * Sanity check: if tty->count is going to zero, there shouldn't be |
| 1827 | * any waiters on tty->read_wait or tty->write_wait. We test the |
| 1828 | * wait queues and kick everyone out _before_ actually starting to |
| 1829 | * close. This ensures that we won't block while releasing the tty |
| 1830 | * structure. |
| 1831 | * |
| 1832 | * The test for the o_tty closing is necessary, since the master and |
| 1833 | * slave sides may close in any order. If the slave side closes out |
| 1834 | * first, its count will be one, since the master side holds an open. |
| 1835 | * Thus this test wouldn't be triggered at the time the slave closes, |
| 1836 | * so we do it now. |
| 1837 | * |
| 1838 | * Note that it's possible for the tty to be opened again while we're |
| 1839 | * flushing out waiters. By recalculating the closing flags before |
| 1840 | * each iteration we avoid any problems. |
| 1841 | */ |
| 1842 | while (1) { |
| 1843 | /* Guard against races with tty->count changes elsewhere and |
| 1844 | opens on /dev/tty */ |
| 1845 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1846 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1847 | tty_closing = tty->count <= 1; |
| 1848 | o_tty_closing = o_tty && |
| 1849 | (o_tty->count <= (pty_master ? 1 : 0)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1850 | do_sleep = 0; |
| 1851 | |
| 1852 | if (tty_closing) { |
| 1853 | if (waitqueue_active(&tty->read_wait)) { |
| 1854 | wake_up(&tty->read_wait); |
| 1855 | do_sleep++; |
| 1856 | } |
| 1857 | if (waitqueue_active(&tty->write_wait)) { |
| 1858 | wake_up(&tty->write_wait); |
| 1859 | do_sleep++; |
| 1860 | } |
| 1861 | } |
| 1862 | if (o_tty_closing) { |
| 1863 | if (waitqueue_active(&o_tty->read_wait)) { |
| 1864 | wake_up(&o_tty->read_wait); |
| 1865 | do_sleep++; |
| 1866 | } |
| 1867 | if (waitqueue_active(&o_tty->write_wait)) { |
| 1868 | wake_up(&o_tty->write_wait); |
| 1869 | do_sleep++; |
| 1870 | } |
| 1871 | } |
| 1872 | if (!do_sleep) |
| 1873 | break; |
| 1874 | |
| 1875 | printk(KERN_WARNING "release_dev: %s: read/write wait queue " |
| 1876 | "active!\n", tty_name(tty, buf)); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1877 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1878 | schedule(); |
| 1879 | } |
| 1880 | |
| 1881 | /* |
| 1882 | * The closing flags are now consistent with the open counts on |
| 1883 | * both sides, and we've completed the last operation that could |
| 1884 | * block, so it's safe to proceed with closing. |
| 1885 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1886 | if (pty_master) { |
| 1887 | if (--o_tty->count < 0) { |
| 1888 | printk(KERN_WARNING "release_dev: bad pty slave count " |
| 1889 | "(%d) for %s\n", |
| 1890 | o_tty->count, tty_name(o_tty, buf)); |
| 1891 | o_tty->count = 0; |
| 1892 | } |
| 1893 | } |
| 1894 | if (--tty->count < 0) { |
| 1895 | printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n", |
| 1896 | tty->count, tty_name(tty, buf)); |
| 1897 | tty->count = 0; |
| 1898 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1899 | |
| 1900 | /* |
| 1901 | * We've decremented tty->count, so we need to remove this file |
| 1902 | * descriptor off the tty->tty_files list; this serves two |
| 1903 | * purposes: |
| 1904 | * - check_tty_count sees the correct number of file descriptors |
| 1905 | * associated with this tty. |
| 1906 | * - do_tty_hangup no longer sees this file descriptor as |
| 1907 | * something that needs to be handled for hangups. |
| 1908 | */ |
| 1909 | file_kill(filp); |
| 1910 | filp->private_data = NULL; |
| 1911 | |
| 1912 | /* |
| 1913 | * Perform some housekeeping before deciding whether to return. |
| 1914 | * |
| 1915 | * Set the TTY_CLOSING flag if this was the last open. In the |
| 1916 | * case of a pty we may have to wait around for the other side |
| 1917 | * to close, and TTY_CLOSING makes sure we can't be reopened. |
| 1918 | */ |
| 1919 | if(tty_closing) |
| 1920 | set_bit(TTY_CLOSING, &tty->flags); |
| 1921 | if(o_tty_closing) |
| 1922 | set_bit(TTY_CLOSING, &o_tty->flags); |
| 1923 | |
| 1924 | /* |
| 1925 | * If _either_ side is closing, make sure there aren't any |
| 1926 | * processes that still think tty or o_tty is their controlling |
| 1927 | * tty. |
| 1928 | */ |
| 1929 | if (tty_closing || o_tty_closing) { |
| 1930 | struct task_struct *p; |
| 1931 | |
| 1932 | read_lock(&tasklist_lock); |
| 1933 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
| 1934 | p->signal->tty = NULL; |
| 1935 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
| 1936 | if (o_tty) |
| 1937 | do_each_task_pid(o_tty->session, PIDTYPE_SID, p) { |
| 1938 | p->signal->tty = NULL; |
| 1939 | } while_each_task_pid(o_tty->session, PIDTYPE_SID, p); |
| 1940 | read_unlock(&tasklist_lock); |
| 1941 | } |
| 1942 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1943 | mutex_unlock(&tty_mutex); |
Paul Fulghum | da96582 | 2006-02-14 13:53:00 -0800 | [diff] [blame] | 1944 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1945 | /* check whether both sides are closing ... */ |
| 1946 | if (!tty_closing || (o_tty && !o_tty_closing)) |
| 1947 | return; |
| 1948 | |
| 1949 | #ifdef TTY_DEBUG_HANGUP |
| 1950 | printk(KERN_DEBUG "freeing tty structure..."); |
| 1951 | #endif |
| 1952 | /* |
| 1953 | * Prevent flush_to_ldisc() from rescheduling the work for later. Then |
| 1954 | * kill any delayed work. As this is the final close it does not |
| 1955 | * race with the set_ldisc code path. |
| 1956 | */ |
| 1957 | clear_bit(TTY_LDISC, &tty->flags); |
| 1958 | clear_bit(TTY_DONT_FLIP, &tty->flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1959 | cancel_delayed_work(&tty->buf.work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1960 | |
| 1961 | /* |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1962 | * Wait for ->hangup_work and ->buf.work handlers to terminate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1963 | */ |
| 1964 | |
| 1965 | flush_scheduled_work(); |
| 1966 | |
| 1967 | /* |
| 1968 | * Wait for any short term users (we know they are just driver |
| 1969 | * side waiters as the file is closing so user count on the file |
| 1970 | * side is zero. |
| 1971 | */ |
| 1972 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 1973 | while(tty->ldisc.refcount) |
| 1974 | { |
| 1975 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 1976 | wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0); |
| 1977 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 1978 | } |
| 1979 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 1980 | /* |
| 1981 | * Shutdown the current line discipline, and reset it to N_TTY. |
| 1982 | * N.B. why reset ldisc when we're releasing the memory?? |
| 1983 | * |
| 1984 | * FIXME: this MUST get fixed for the new reflocking |
| 1985 | */ |
| 1986 | if (tty->ldisc.close) |
| 1987 | (tty->ldisc.close)(tty); |
| 1988 | tty_ldisc_put(tty->ldisc.num); |
| 1989 | |
| 1990 | /* |
| 1991 | * Switch the line discipline back |
| 1992 | */ |
| 1993 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
| 1994 | tty_set_termios_ldisc(tty,N_TTY); |
| 1995 | if (o_tty) { |
| 1996 | /* FIXME: could o_tty be in setldisc here ? */ |
| 1997 | clear_bit(TTY_LDISC, &o_tty->flags); |
| 1998 | if (o_tty->ldisc.close) |
| 1999 | (o_tty->ldisc.close)(o_tty); |
| 2000 | tty_ldisc_put(o_tty->ldisc.num); |
| 2001 | tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY)); |
| 2002 | tty_set_termios_ldisc(o_tty,N_TTY); |
| 2003 | } |
| 2004 | /* |
| 2005 | * The release_mem function takes care of the details of clearing |
| 2006 | * the slots and preserving the termios structure. |
| 2007 | */ |
| 2008 | release_mem(tty, idx); |
| 2009 | |
| 2010 | #ifdef CONFIG_UNIX98_PTYS |
| 2011 | /* Make this pty number available for reallocation */ |
| 2012 | if (devpts) { |
| 2013 | down(&allocated_ptys_lock); |
| 2014 | idr_remove(&allocated_ptys, idx); |
| 2015 | up(&allocated_ptys_lock); |
| 2016 | } |
| 2017 | #endif |
| 2018 | |
| 2019 | } |
| 2020 | |
| 2021 | /* |
| 2022 | * tty_open and tty_release keep up the tty count that contains the |
| 2023 | * number of opens done on a tty. We cannot use the inode-count, as |
| 2024 | * different inodes might point to the same tty. |
| 2025 | * |
| 2026 | * Open-counting is needed for pty masters, as well as for keeping |
| 2027 | * track of serial lines: DTR is dropped when the last close happens. |
| 2028 | * (This is not done solely through tty->count, now. - Ted 1/27/92) |
| 2029 | * |
| 2030 | * The termios state of a pty is reset on first open so that |
| 2031 | * settings don't persist across reuse. |
| 2032 | */ |
| 2033 | static int tty_open(struct inode * inode, struct file * filp) |
| 2034 | { |
| 2035 | struct tty_struct *tty; |
| 2036 | int noctty, retval; |
| 2037 | struct tty_driver *driver; |
| 2038 | int index; |
| 2039 | dev_t device = inode->i_rdev; |
| 2040 | unsigned short saved_flags = filp->f_flags; |
| 2041 | |
| 2042 | nonseekable_open(inode, filp); |
| 2043 | |
| 2044 | retry_open: |
| 2045 | noctty = filp->f_flags & O_NOCTTY; |
| 2046 | index = -1; |
| 2047 | retval = 0; |
| 2048 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2049 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2050 | |
| 2051 | if (device == MKDEV(TTYAUX_MAJOR,0)) { |
| 2052 | if (!current->signal->tty) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2053 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2054 | return -ENXIO; |
| 2055 | } |
| 2056 | driver = current->signal->tty->driver; |
| 2057 | index = current->signal->tty->index; |
| 2058 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
| 2059 | /* noctty = 1; */ |
| 2060 | goto got_driver; |
| 2061 | } |
| 2062 | #ifdef CONFIG_VT |
| 2063 | if (device == MKDEV(TTY_MAJOR,0)) { |
| 2064 | extern struct tty_driver *console_driver; |
| 2065 | driver = console_driver; |
| 2066 | index = fg_console; |
| 2067 | noctty = 1; |
| 2068 | goto got_driver; |
| 2069 | } |
| 2070 | #endif |
| 2071 | if (device == MKDEV(TTYAUX_MAJOR,1)) { |
| 2072 | driver = console_device(&index); |
| 2073 | if (driver) { |
| 2074 | /* Don't let /dev/console block */ |
| 2075 | filp->f_flags |= O_NONBLOCK; |
| 2076 | noctty = 1; |
| 2077 | goto got_driver; |
| 2078 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2079 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2080 | return -ENODEV; |
| 2081 | } |
| 2082 | |
| 2083 | driver = get_tty_driver(device, &index); |
| 2084 | if (!driver) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2085 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2086 | return -ENODEV; |
| 2087 | } |
| 2088 | got_driver: |
| 2089 | retval = init_dev(driver, index, &tty); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2090 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2091 | if (retval) |
| 2092 | return retval; |
| 2093 | |
| 2094 | filp->private_data = tty; |
| 2095 | file_move(filp, &tty->tty_files); |
| 2096 | check_tty_count(tty, "tty_open"); |
| 2097 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 2098 | tty->driver->subtype == PTY_TYPE_MASTER) |
| 2099 | noctty = 1; |
| 2100 | #ifdef TTY_DEBUG_HANGUP |
| 2101 | printk(KERN_DEBUG "opening %s...", tty->name); |
| 2102 | #endif |
| 2103 | if (!retval) { |
| 2104 | if (tty->driver->open) |
| 2105 | retval = tty->driver->open(tty, filp); |
| 2106 | else |
| 2107 | retval = -ENODEV; |
| 2108 | } |
| 2109 | filp->f_flags = saved_flags; |
| 2110 | |
| 2111 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
| 2112 | retval = -EBUSY; |
| 2113 | |
| 2114 | if (retval) { |
| 2115 | #ifdef TTY_DEBUG_HANGUP |
| 2116 | printk(KERN_DEBUG "error %d in opening %s...", retval, |
| 2117 | tty->name); |
| 2118 | #endif |
| 2119 | release_dev(filp); |
| 2120 | if (retval != -ERESTARTSYS) |
| 2121 | return retval; |
| 2122 | if (signal_pending(current)) |
| 2123 | return retval; |
| 2124 | schedule(); |
| 2125 | /* |
| 2126 | * Need to reset f_op in case a hangup happened. |
| 2127 | */ |
| 2128 | if (filp->f_op == &hung_up_tty_fops) |
| 2129 | filp->f_op = &tty_fops; |
| 2130 | goto retry_open; |
| 2131 | } |
| 2132 | if (!noctty && |
| 2133 | current->signal->leader && |
| 2134 | !current->signal->tty && |
| 2135 | tty->session == 0) { |
| 2136 | task_lock(current); |
| 2137 | current->signal->tty = tty; |
| 2138 | task_unlock(current); |
| 2139 | current->signal->tty_old_pgrp = 0; |
| 2140 | tty->session = current->signal->session; |
| 2141 | tty->pgrp = process_group(current); |
| 2142 | } |
| 2143 | return 0; |
| 2144 | } |
| 2145 | |
| 2146 | #ifdef CONFIG_UNIX98_PTYS |
| 2147 | static int ptmx_open(struct inode * inode, struct file * filp) |
| 2148 | { |
| 2149 | struct tty_struct *tty; |
| 2150 | int retval; |
| 2151 | int index; |
| 2152 | int idr_ret; |
| 2153 | |
| 2154 | nonseekable_open(inode, filp); |
| 2155 | |
| 2156 | /* find a device that is not in use. */ |
| 2157 | down(&allocated_ptys_lock); |
| 2158 | if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) { |
| 2159 | up(&allocated_ptys_lock); |
| 2160 | return -ENOMEM; |
| 2161 | } |
| 2162 | idr_ret = idr_get_new(&allocated_ptys, NULL, &index); |
| 2163 | if (idr_ret < 0) { |
| 2164 | up(&allocated_ptys_lock); |
| 2165 | if (idr_ret == -EAGAIN) |
| 2166 | return -ENOMEM; |
| 2167 | return -EIO; |
| 2168 | } |
| 2169 | if (index >= pty_limit) { |
| 2170 | idr_remove(&allocated_ptys, index); |
| 2171 | up(&allocated_ptys_lock); |
| 2172 | return -EIO; |
| 2173 | } |
| 2174 | up(&allocated_ptys_lock); |
| 2175 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2176 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2177 | retval = init_dev(ptm_driver, index, &tty); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2178 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2179 | |
| 2180 | if (retval) |
| 2181 | goto out; |
| 2182 | |
| 2183 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ |
| 2184 | filp->private_data = tty; |
| 2185 | file_move(filp, &tty->tty_files); |
| 2186 | |
| 2187 | retval = -ENOMEM; |
| 2188 | if (devpts_pty_new(tty->link)) |
| 2189 | goto out1; |
| 2190 | |
| 2191 | check_tty_count(tty, "tty_open"); |
| 2192 | retval = ptm_driver->open(tty, filp); |
| 2193 | if (!retval) |
| 2194 | return 0; |
| 2195 | out1: |
| 2196 | release_dev(filp); |
Paul Fulghum | 9453a5a | 2006-04-10 22:54:18 -0700 | [diff] [blame] | 2197 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2198 | out: |
| 2199 | down(&allocated_ptys_lock); |
| 2200 | idr_remove(&allocated_ptys, index); |
| 2201 | up(&allocated_ptys_lock); |
| 2202 | return retval; |
| 2203 | } |
| 2204 | #endif |
| 2205 | |
| 2206 | static int tty_release(struct inode * inode, struct file * filp) |
| 2207 | { |
| 2208 | lock_kernel(); |
| 2209 | release_dev(filp); |
| 2210 | unlock_kernel(); |
| 2211 | return 0; |
| 2212 | } |
| 2213 | |
| 2214 | /* No kernel lock held - fine */ |
| 2215 | static unsigned int tty_poll(struct file * filp, poll_table * wait) |
| 2216 | { |
| 2217 | struct tty_struct * tty; |
| 2218 | struct tty_ldisc *ld; |
| 2219 | int ret = 0; |
| 2220 | |
| 2221 | tty = (struct tty_struct *)filp->private_data; |
| 2222 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll")) |
| 2223 | return 0; |
| 2224 | |
| 2225 | ld = tty_ldisc_ref_wait(tty); |
| 2226 | if (ld->poll) |
| 2227 | ret = (ld->poll)(tty, filp, wait); |
| 2228 | tty_ldisc_deref(ld); |
| 2229 | return ret; |
| 2230 | } |
| 2231 | |
| 2232 | static int tty_fasync(int fd, struct file * filp, int on) |
| 2233 | { |
| 2234 | struct tty_struct * tty; |
| 2235 | int retval; |
| 2236 | |
| 2237 | tty = (struct tty_struct *)filp->private_data; |
| 2238 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync")) |
| 2239 | return 0; |
| 2240 | |
| 2241 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
| 2242 | if (retval <= 0) |
| 2243 | return retval; |
| 2244 | |
| 2245 | if (on) { |
| 2246 | if (!waitqueue_active(&tty->read_wait)) |
| 2247 | tty->minimum_to_wake = 1; |
| 2248 | retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0); |
| 2249 | if (retval) |
| 2250 | return retval; |
| 2251 | } else { |
| 2252 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) |
| 2253 | tty->minimum_to_wake = N_TTY_BUF_SIZE; |
| 2254 | } |
| 2255 | return 0; |
| 2256 | } |
| 2257 | |
| 2258 | static int tiocsti(struct tty_struct *tty, char __user *p) |
| 2259 | { |
| 2260 | char ch, mbz = 0; |
| 2261 | struct tty_ldisc *ld; |
| 2262 | |
| 2263 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
| 2264 | return -EPERM; |
| 2265 | if (get_user(ch, p)) |
| 2266 | return -EFAULT; |
| 2267 | ld = tty_ldisc_ref_wait(tty); |
| 2268 | ld->receive_buf(tty, &ch, &mbz, 1); |
| 2269 | tty_ldisc_deref(ld); |
| 2270 | return 0; |
| 2271 | } |
| 2272 | |
| 2273 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) |
| 2274 | { |
| 2275 | if (copy_to_user(arg, &tty->winsize, sizeof(*arg))) |
| 2276 | return -EFAULT; |
| 2277 | return 0; |
| 2278 | } |
| 2279 | |
| 2280 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, |
| 2281 | struct winsize __user * arg) |
| 2282 | { |
| 2283 | struct winsize tmp_ws; |
| 2284 | |
| 2285 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
| 2286 | return -EFAULT; |
| 2287 | if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) |
| 2288 | return 0; |
| 2289 | #ifdef CONFIG_VT |
| 2290 | if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { |
| 2291 | int rc; |
| 2292 | |
| 2293 | acquire_console_sem(); |
| 2294 | rc = vc_resize(tty->driver_data, tmp_ws.ws_col, tmp_ws.ws_row); |
| 2295 | release_console_sem(); |
| 2296 | if (rc) |
| 2297 | return -ENXIO; |
| 2298 | } |
| 2299 | #endif |
| 2300 | if (tty->pgrp > 0) |
| 2301 | kill_pg(tty->pgrp, SIGWINCH, 1); |
| 2302 | if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0)) |
| 2303 | kill_pg(real_tty->pgrp, SIGWINCH, 1); |
| 2304 | tty->winsize = tmp_ws; |
| 2305 | real_tty->winsize = tmp_ws; |
| 2306 | return 0; |
| 2307 | } |
| 2308 | |
| 2309 | static int tioccons(struct file *file) |
| 2310 | { |
| 2311 | if (!capable(CAP_SYS_ADMIN)) |
| 2312 | return -EPERM; |
| 2313 | if (file->f_op->write == redirected_tty_write) { |
| 2314 | struct file *f; |
| 2315 | spin_lock(&redirect_lock); |
| 2316 | f = redirect; |
| 2317 | redirect = NULL; |
| 2318 | spin_unlock(&redirect_lock); |
| 2319 | if (f) |
| 2320 | fput(f); |
| 2321 | return 0; |
| 2322 | } |
| 2323 | spin_lock(&redirect_lock); |
| 2324 | if (redirect) { |
| 2325 | spin_unlock(&redirect_lock); |
| 2326 | return -EBUSY; |
| 2327 | } |
| 2328 | get_file(file); |
| 2329 | redirect = file; |
| 2330 | spin_unlock(&redirect_lock); |
| 2331 | return 0; |
| 2332 | } |
| 2333 | |
| 2334 | |
| 2335 | static int fionbio(struct file *file, int __user *p) |
| 2336 | { |
| 2337 | int nonblock; |
| 2338 | |
| 2339 | if (get_user(nonblock, p)) |
| 2340 | return -EFAULT; |
| 2341 | |
| 2342 | if (nonblock) |
| 2343 | file->f_flags |= O_NONBLOCK; |
| 2344 | else |
| 2345 | file->f_flags &= ~O_NONBLOCK; |
| 2346 | return 0; |
| 2347 | } |
| 2348 | |
| 2349 | static int tiocsctty(struct tty_struct *tty, int arg) |
| 2350 | { |
| 2351 | task_t *p; |
| 2352 | |
| 2353 | if (current->signal->leader && |
| 2354 | (current->signal->session == tty->session)) |
| 2355 | return 0; |
| 2356 | /* |
| 2357 | * The process must be a session leader and |
| 2358 | * not have a controlling tty already. |
| 2359 | */ |
| 2360 | if (!current->signal->leader || current->signal->tty) |
| 2361 | return -EPERM; |
| 2362 | if (tty->session > 0) { |
| 2363 | /* |
| 2364 | * This tty is already the controlling |
| 2365 | * tty for another session group! |
| 2366 | */ |
| 2367 | if ((arg == 1) && capable(CAP_SYS_ADMIN)) { |
| 2368 | /* |
| 2369 | * Steal it away |
| 2370 | */ |
| 2371 | |
| 2372 | read_lock(&tasklist_lock); |
| 2373 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
| 2374 | p->signal->tty = NULL; |
| 2375 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
| 2376 | read_unlock(&tasklist_lock); |
| 2377 | } else |
| 2378 | return -EPERM; |
| 2379 | } |
| 2380 | task_lock(current); |
| 2381 | current->signal->tty = tty; |
| 2382 | task_unlock(current); |
| 2383 | current->signal->tty_old_pgrp = 0; |
| 2384 | tty->session = current->signal->session; |
| 2385 | tty->pgrp = process_group(current); |
| 2386 | return 0; |
| 2387 | } |
| 2388 | |
| 2389 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| 2390 | { |
| 2391 | /* |
| 2392 | * (tty == real_tty) is a cheap way of |
| 2393 | * testing if the tty is NOT a master pty. |
| 2394 | */ |
| 2395 | if (tty == real_tty && current->signal->tty != real_tty) |
| 2396 | return -ENOTTY; |
| 2397 | return put_user(real_tty->pgrp, p); |
| 2398 | } |
| 2399 | |
| 2400 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| 2401 | { |
| 2402 | pid_t pgrp; |
| 2403 | int retval = tty_check_change(real_tty); |
| 2404 | |
| 2405 | if (retval == -EIO) |
| 2406 | return -ENOTTY; |
| 2407 | if (retval) |
| 2408 | return retval; |
| 2409 | if (!current->signal->tty || |
| 2410 | (current->signal->tty != real_tty) || |
| 2411 | (real_tty->session != current->signal->session)) |
| 2412 | return -ENOTTY; |
| 2413 | if (get_user(pgrp, p)) |
| 2414 | return -EFAULT; |
| 2415 | if (pgrp < 0) |
| 2416 | return -EINVAL; |
| 2417 | if (session_of_pgrp(pgrp) != current->signal->session) |
| 2418 | return -EPERM; |
| 2419 | real_tty->pgrp = pgrp; |
| 2420 | return 0; |
| 2421 | } |
| 2422 | |
| 2423 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| 2424 | { |
| 2425 | /* |
| 2426 | * (tty == real_tty) is a cheap way of |
| 2427 | * testing if the tty is NOT a master pty. |
| 2428 | */ |
| 2429 | if (tty == real_tty && current->signal->tty != real_tty) |
| 2430 | return -ENOTTY; |
| 2431 | if (real_tty->session <= 0) |
| 2432 | return -ENOTTY; |
| 2433 | return put_user(real_tty->session, p); |
| 2434 | } |
| 2435 | |
| 2436 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
| 2437 | { |
| 2438 | int ldisc; |
| 2439 | |
| 2440 | if (get_user(ldisc, p)) |
| 2441 | return -EFAULT; |
| 2442 | return tty_set_ldisc(tty, ldisc); |
| 2443 | } |
| 2444 | |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 2445 | static int send_break(struct tty_struct *tty, unsigned int duration) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2446 | { |
| 2447 | tty->driver->break_ctl(tty, -1); |
| 2448 | if (!signal_pending(current)) { |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 2449 | msleep_interruptible(duration); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2450 | } |
| 2451 | tty->driver->break_ctl(tty, 0); |
| 2452 | if (signal_pending(current)) |
| 2453 | return -EINTR; |
| 2454 | return 0; |
| 2455 | } |
| 2456 | |
| 2457 | static int |
| 2458 | tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) |
| 2459 | { |
| 2460 | int retval = -EINVAL; |
| 2461 | |
| 2462 | if (tty->driver->tiocmget) { |
| 2463 | retval = tty->driver->tiocmget(tty, file); |
| 2464 | |
| 2465 | if (retval >= 0) |
| 2466 | retval = put_user(retval, p); |
| 2467 | } |
| 2468 | return retval; |
| 2469 | } |
| 2470 | |
| 2471 | static int |
| 2472 | tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, |
| 2473 | unsigned __user *p) |
| 2474 | { |
| 2475 | int retval = -EINVAL; |
| 2476 | |
| 2477 | if (tty->driver->tiocmset) { |
| 2478 | unsigned int set, clear, val; |
| 2479 | |
| 2480 | retval = get_user(val, p); |
| 2481 | if (retval) |
| 2482 | return retval; |
| 2483 | |
| 2484 | set = clear = 0; |
| 2485 | switch (cmd) { |
| 2486 | case TIOCMBIS: |
| 2487 | set = val; |
| 2488 | break; |
| 2489 | case TIOCMBIC: |
| 2490 | clear = val; |
| 2491 | break; |
| 2492 | case TIOCMSET: |
| 2493 | set = val; |
| 2494 | clear = ~val; |
| 2495 | break; |
| 2496 | } |
| 2497 | |
| 2498 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
| 2499 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
| 2500 | |
| 2501 | retval = tty->driver->tiocmset(tty, file, set, clear); |
| 2502 | } |
| 2503 | return retval; |
| 2504 | } |
| 2505 | |
| 2506 | /* |
| 2507 | * Split this up, as gcc can choke on it otherwise.. |
| 2508 | */ |
| 2509 | int tty_ioctl(struct inode * inode, struct file * file, |
| 2510 | unsigned int cmd, unsigned long arg) |
| 2511 | { |
| 2512 | struct tty_struct *tty, *real_tty; |
| 2513 | void __user *p = (void __user *)arg; |
| 2514 | int retval; |
| 2515 | struct tty_ldisc *ld; |
| 2516 | |
| 2517 | tty = (struct tty_struct *)file->private_data; |
| 2518 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
| 2519 | return -EINVAL; |
| 2520 | |
| 2521 | real_tty = tty; |
| 2522 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 2523 | tty->driver->subtype == PTY_TYPE_MASTER) |
| 2524 | real_tty = tty->link; |
| 2525 | |
| 2526 | /* |
| 2527 | * Break handling by driver |
| 2528 | */ |
| 2529 | if (!tty->driver->break_ctl) { |
| 2530 | switch(cmd) { |
| 2531 | case TIOCSBRK: |
| 2532 | case TIOCCBRK: |
| 2533 | if (tty->driver->ioctl) |
| 2534 | return tty->driver->ioctl(tty, file, cmd, arg); |
| 2535 | return -EINVAL; |
| 2536 | |
| 2537 | /* These two ioctl's always return success; even if */ |
| 2538 | /* the driver doesn't support them. */ |
| 2539 | case TCSBRK: |
| 2540 | case TCSBRKP: |
| 2541 | if (!tty->driver->ioctl) |
| 2542 | return 0; |
| 2543 | retval = tty->driver->ioctl(tty, file, cmd, arg); |
| 2544 | if (retval == -ENOIOCTLCMD) |
| 2545 | retval = 0; |
| 2546 | return retval; |
| 2547 | } |
| 2548 | } |
| 2549 | |
| 2550 | /* |
| 2551 | * Factor out some common prep work |
| 2552 | */ |
| 2553 | switch (cmd) { |
| 2554 | case TIOCSETD: |
| 2555 | case TIOCSBRK: |
| 2556 | case TIOCCBRK: |
| 2557 | case TCSBRK: |
| 2558 | case TCSBRKP: |
| 2559 | retval = tty_check_change(tty); |
| 2560 | if (retval) |
| 2561 | return retval; |
| 2562 | if (cmd != TIOCCBRK) { |
| 2563 | tty_wait_until_sent(tty, 0); |
| 2564 | if (signal_pending(current)) |
| 2565 | return -EINTR; |
| 2566 | } |
| 2567 | break; |
| 2568 | } |
| 2569 | |
| 2570 | switch (cmd) { |
| 2571 | case TIOCSTI: |
| 2572 | return tiocsti(tty, p); |
| 2573 | case TIOCGWINSZ: |
| 2574 | return tiocgwinsz(tty, p); |
| 2575 | case TIOCSWINSZ: |
| 2576 | return tiocswinsz(tty, real_tty, p); |
| 2577 | case TIOCCONS: |
| 2578 | return real_tty!=tty ? -EINVAL : tioccons(file); |
| 2579 | case FIONBIO: |
| 2580 | return fionbio(file, p); |
| 2581 | case TIOCEXCL: |
| 2582 | set_bit(TTY_EXCLUSIVE, &tty->flags); |
| 2583 | return 0; |
| 2584 | case TIOCNXCL: |
| 2585 | clear_bit(TTY_EXCLUSIVE, &tty->flags); |
| 2586 | return 0; |
| 2587 | case TIOCNOTTY: |
| 2588 | if (current->signal->tty != tty) |
| 2589 | return -ENOTTY; |
| 2590 | if (current->signal->leader) |
| 2591 | disassociate_ctty(0); |
| 2592 | task_lock(current); |
| 2593 | current->signal->tty = NULL; |
| 2594 | task_unlock(current); |
| 2595 | return 0; |
| 2596 | case TIOCSCTTY: |
| 2597 | return tiocsctty(tty, arg); |
| 2598 | case TIOCGPGRP: |
| 2599 | return tiocgpgrp(tty, real_tty, p); |
| 2600 | case TIOCSPGRP: |
| 2601 | return tiocspgrp(tty, real_tty, p); |
| 2602 | case TIOCGSID: |
| 2603 | return tiocgsid(tty, real_tty, p); |
| 2604 | case TIOCGETD: |
| 2605 | /* FIXME: check this is ok */ |
| 2606 | return put_user(tty->ldisc.num, (int __user *)p); |
| 2607 | case TIOCSETD: |
| 2608 | return tiocsetd(tty, p); |
| 2609 | #ifdef CONFIG_VT |
| 2610 | case TIOCLINUX: |
| 2611 | return tioclinux(tty, arg); |
| 2612 | #endif |
| 2613 | /* |
| 2614 | * Break handling |
| 2615 | */ |
| 2616 | case TIOCSBRK: /* Turn break on, unconditionally */ |
| 2617 | tty->driver->break_ctl(tty, -1); |
| 2618 | return 0; |
| 2619 | |
| 2620 | case TIOCCBRK: /* Turn break off, unconditionally */ |
| 2621 | tty->driver->break_ctl(tty, 0); |
| 2622 | return 0; |
| 2623 | case TCSBRK: /* SVID version: non-zero arg --> no break */ |
| 2624 | /* |
| 2625 | * XXX is the above comment correct, or the |
| 2626 | * code below correct? Is this ioctl used at |
| 2627 | * all by anyone? |
| 2628 | */ |
| 2629 | if (!arg) |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 2630 | return send_break(tty, 250); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2631 | return 0; |
| 2632 | case TCSBRKP: /* support for POSIX tcsendbreak() */ |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 2633 | return send_break(tty, arg ? arg*100 : 250); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2634 | |
| 2635 | case TIOCMGET: |
| 2636 | return tty_tiocmget(tty, file, p); |
| 2637 | |
| 2638 | case TIOCMSET: |
| 2639 | case TIOCMBIC: |
| 2640 | case TIOCMBIS: |
| 2641 | return tty_tiocmset(tty, file, cmd, p); |
| 2642 | } |
| 2643 | if (tty->driver->ioctl) { |
| 2644 | retval = (tty->driver->ioctl)(tty, file, cmd, arg); |
| 2645 | if (retval != -ENOIOCTLCMD) |
| 2646 | return retval; |
| 2647 | } |
| 2648 | ld = tty_ldisc_ref_wait(tty); |
| 2649 | retval = -EINVAL; |
| 2650 | if (ld->ioctl) { |
| 2651 | retval = ld->ioctl(tty, file, cmd, arg); |
| 2652 | if (retval == -ENOIOCTLCMD) |
| 2653 | retval = -EINVAL; |
| 2654 | } |
| 2655 | tty_ldisc_deref(ld); |
| 2656 | return retval; |
| 2657 | } |
| 2658 | |
| 2659 | |
| 2660 | /* |
| 2661 | * This implements the "Secure Attention Key" --- the idea is to |
| 2662 | * prevent trojan horses by killing all processes associated with this |
| 2663 | * tty when the user hits the "Secure Attention Key". Required for |
| 2664 | * super-paranoid applications --- see the Orange Book for more details. |
| 2665 | * |
| 2666 | * This code could be nicer; ideally it should send a HUP, wait a few |
| 2667 | * seconds, then send a INT, and then a KILL signal. But you then |
| 2668 | * have to coordinate with the init process, since all processes associated |
| 2669 | * with the current tty must be dead before the new getty is allowed |
| 2670 | * to spawn. |
| 2671 | * |
| 2672 | * Now, if it would be correct ;-/ The current code has a nasty hole - |
| 2673 | * it doesn't catch files in flight. We may send the descriptor to ourselves |
| 2674 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. |
| 2675 | * |
| 2676 | * Nasty bug: do_SAK is being called in interrupt context. This can |
| 2677 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 |
| 2678 | */ |
| 2679 | static void __do_SAK(void *arg) |
| 2680 | { |
| 2681 | #ifdef TTY_SOFT_SAK |
| 2682 | tty_hangup(tty); |
| 2683 | #else |
| 2684 | struct tty_struct *tty = arg; |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 2685 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2686 | int session; |
| 2687 | int i; |
| 2688 | struct file *filp; |
| 2689 | struct tty_ldisc *disc; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 2690 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2691 | |
| 2692 | if (!tty) |
| 2693 | return; |
| 2694 | session = tty->session; |
| 2695 | |
| 2696 | /* We don't want an ldisc switch during this */ |
| 2697 | disc = tty_ldisc_ref(tty); |
| 2698 | if (disc && disc->flush_buffer) |
| 2699 | disc->flush_buffer(tty); |
| 2700 | tty_ldisc_deref(disc); |
| 2701 | |
| 2702 | if (tty->driver->flush_buffer) |
| 2703 | tty->driver->flush_buffer(tty); |
| 2704 | |
| 2705 | read_lock(&tasklist_lock); |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 2706 | /* Kill the entire session */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2707 | do_each_task_pid(session, PIDTYPE_SID, p) { |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 2708 | printk(KERN_NOTICE "SAK: killed process %d" |
| 2709 | " (%s): p->signal->session==tty->session\n", |
| 2710 | p->pid, p->comm); |
| 2711 | send_sig(SIGKILL, p, 1); |
| 2712 | } while_each_task_pid(session, PIDTYPE_SID, p); |
| 2713 | /* Now kill any processes that happen to have the |
| 2714 | * tty open. |
| 2715 | */ |
| 2716 | do_each_thread(g, p) { |
| 2717 | if (p->signal->tty == tty) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2718 | printk(KERN_NOTICE "SAK: killed process %d" |
| 2719 | " (%s): p->signal->session==tty->session\n", |
| 2720 | p->pid, p->comm); |
| 2721 | send_sig(SIGKILL, p, 1); |
| 2722 | continue; |
| 2723 | } |
| 2724 | task_lock(p); |
| 2725 | if (p->files) { |
Dipankar Sarma | ca99c1d | 2006-04-18 22:21:46 -0700 | [diff] [blame] | 2726 | /* |
| 2727 | * We don't take a ref to the file, so we must |
| 2728 | * hold ->file_lock instead. |
| 2729 | */ |
| 2730 | spin_lock(&p->files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 2731 | fdt = files_fdtable(p->files); |
| 2732 | for (i=0; i < fdt->max_fds; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2733 | filp = fcheck_files(p->files, i); |
| 2734 | if (!filp) |
| 2735 | continue; |
| 2736 | if (filp->f_op->read == tty_read && |
| 2737 | filp->private_data == tty) { |
| 2738 | printk(KERN_NOTICE "SAK: killed process %d" |
| 2739 | " (%s): fd#%d opened to the tty\n", |
| 2740 | p->pid, p->comm, i); |
Eric W. Biederman | 20ac943 | 2006-04-13 04:49:07 -0600 | [diff] [blame] | 2741 | force_sig(SIGKILL, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2742 | break; |
| 2743 | } |
| 2744 | } |
Dipankar Sarma | ca99c1d | 2006-04-18 22:21:46 -0700 | [diff] [blame] | 2745 | spin_unlock(&p->files->file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2746 | } |
| 2747 | task_unlock(p); |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 2748 | } while_each_thread(g, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2749 | read_unlock(&tasklist_lock); |
| 2750 | #endif |
| 2751 | } |
| 2752 | |
| 2753 | /* |
| 2754 | * The tq handling here is a little racy - tty->SAK_work may already be queued. |
| 2755 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, |
| 2756 | * the values which we write to it will be identical to the values which it |
| 2757 | * already has. --akpm |
| 2758 | */ |
| 2759 | void do_SAK(struct tty_struct *tty) |
| 2760 | { |
| 2761 | if (!tty) |
| 2762 | return; |
| 2763 | PREPARE_WORK(&tty->SAK_work, __do_SAK, tty); |
| 2764 | schedule_work(&tty->SAK_work); |
| 2765 | } |
| 2766 | |
| 2767 | EXPORT_SYMBOL(do_SAK); |
| 2768 | |
| 2769 | /* |
| 2770 | * This routine is called out of the software interrupt to flush data |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2771 | * from the buffer chain to the line discipline. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2772 | */ |
| 2773 | |
| 2774 | static void flush_to_ldisc(void *private_) |
| 2775 | { |
| 2776 | struct tty_struct *tty = (struct tty_struct *) private_; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2777 | unsigned long flags; |
| 2778 | struct tty_ldisc *disc; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2779 | struct tty_buffer *tbuf; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 2780 | int count; |
| 2781 | char *char_buf; |
| 2782 | unsigned char *flag_buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2783 | |
| 2784 | disc = tty_ldisc_ref(tty); |
| 2785 | if (disc == NULL) /* !TTY_LDISC */ |
| 2786 | return; |
| 2787 | |
| 2788 | if (test_bit(TTY_DONT_FLIP, &tty->flags)) { |
| 2789 | /* |
| 2790 | * Do it after the next timer tick: |
| 2791 | */ |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2792 | schedule_delayed_work(&tty->buf.work, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2793 | goto out; |
| 2794 | } |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 2795 | spin_lock_irqsave(&tty->buf.lock, flags); |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 2796 | while((tbuf = tty->buf.head) != NULL) { |
| 2797 | while ((count = tbuf->commit - tbuf->read) != 0) { |
| 2798 | char_buf = tbuf->char_buf_ptr + tbuf->read; |
| 2799 | flag_buf = tbuf->flag_buf_ptr + tbuf->read; |
| 2800 | tbuf->read += count; |
| 2801 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
| 2802 | disc->receive_buf(tty, char_buf, flag_buf, count); |
| 2803 | spin_lock_irqsave(&tty->buf.lock, flags); |
| 2804 | } |
| 2805 | if (tbuf->active) |
| 2806 | break; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2807 | tty->buf.head = tbuf->next; |
Paul Fulghum | 607f4e3 | 2006-01-11 17:51:48 -0600 | [diff] [blame] | 2808 | if (tty->buf.head == NULL) |
| 2809 | tty->buf.tail = NULL; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2810 | tty_buffer_free(tty, tbuf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2811 | } |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 2812 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2813 | out: |
| 2814 | tty_ldisc_deref(disc); |
| 2815 | } |
| 2816 | |
| 2817 | /* |
| 2818 | * Routine which returns the baud rate of the tty |
| 2819 | * |
| 2820 | * Note that the baud_table needs to be kept in sync with the |
| 2821 | * include/asm/termbits.h file. |
| 2822 | */ |
| 2823 | static int baud_table[] = { |
| 2824 | 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, |
| 2825 | 9600, 19200, 38400, 57600, 115200, 230400, 460800, |
| 2826 | #ifdef __sparc__ |
| 2827 | 76800, 153600, 307200, 614400, 921600 |
| 2828 | #else |
| 2829 | 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, |
| 2830 | 2500000, 3000000, 3500000, 4000000 |
| 2831 | #endif |
| 2832 | }; |
| 2833 | |
| 2834 | static int n_baud_table = ARRAY_SIZE(baud_table); |
| 2835 | |
| 2836 | /** |
| 2837 | * tty_termios_baud_rate |
| 2838 | * @termios: termios structure |
| 2839 | * |
| 2840 | * Convert termios baud rate data into a speed. This should be called |
| 2841 | * with the termios lock held if this termios is a terminal termios |
| 2842 | * structure. May change the termios data. |
| 2843 | */ |
| 2844 | |
| 2845 | int tty_termios_baud_rate(struct termios *termios) |
| 2846 | { |
| 2847 | unsigned int cbaud; |
| 2848 | |
| 2849 | cbaud = termios->c_cflag & CBAUD; |
| 2850 | |
| 2851 | if (cbaud & CBAUDEX) { |
| 2852 | cbaud &= ~CBAUDEX; |
| 2853 | |
| 2854 | if (cbaud < 1 || cbaud + 15 > n_baud_table) |
| 2855 | termios->c_cflag &= ~CBAUDEX; |
| 2856 | else |
| 2857 | cbaud += 15; |
| 2858 | } |
| 2859 | return baud_table[cbaud]; |
| 2860 | } |
| 2861 | |
| 2862 | EXPORT_SYMBOL(tty_termios_baud_rate); |
| 2863 | |
| 2864 | /** |
| 2865 | * tty_get_baud_rate - get tty bit rates |
| 2866 | * @tty: tty to query |
| 2867 | * |
| 2868 | * Returns the baud rate as an integer for this terminal. The |
| 2869 | * termios lock must be held by the caller and the terminal bit |
| 2870 | * flags may be updated. |
| 2871 | */ |
| 2872 | |
| 2873 | int tty_get_baud_rate(struct tty_struct *tty) |
| 2874 | { |
| 2875 | int baud = tty_termios_baud_rate(tty->termios); |
| 2876 | |
| 2877 | if (baud == 38400 && tty->alt_speed) { |
| 2878 | if (!tty->warned) { |
| 2879 | printk(KERN_WARNING "Use of setserial/setrocket to " |
| 2880 | "set SPD_* flags is deprecated\n"); |
| 2881 | tty->warned = 1; |
| 2882 | } |
| 2883 | baud = tty->alt_speed; |
| 2884 | } |
| 2885 | |
| 2886 | return baud; |
| 2887 | } |
| 2888 | |
| 2889 | EXPORT_SYMBOL(tty_get_baud_rate); |
| 2890 | |
| 2891 | /** |
| 2892 | * tty_flip_buffer_push - terminal |
| 2893 | * @tty: tty to push |
| 2894 | * |
| 2895 | * Queue a push of the terminal flip buffers to the line discipline. This |
| 2896 | * function must not be called from IRQ context if tty->low_latency is set. |
| 2897 | * |
| 2898 | * In the event of the queue being busy for flipping the work will be |
| 2899 | * held off and retried later. |
| 2900 | */ |
| 2901 | |
| 2902 | void tty_flip_buffer_push(struct tty_struct *tty) |
| 2903 | { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 2904 | unsigned long flags; |
| 2905 | spin_lock_irqsave(&tty->buf.lock, flags); |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 2906 | if (tty->buf.tail != NULL) { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 2907 | tty->buf.tail->active = 0; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 2908 | tty->buf.tail->commit = tty->buf.tail->used; |
| 2909 | } |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 2910 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
| 2911 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2912 | if (tty->low_latency) |
| 2913 | flush_to_ldisc((void *) tty); |
| 2914 | else |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2915 | schedule_delayed_work(&tty->buf.work, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2916 | } |
| 2917 | |
| 2918 | EXPORT_SYMBOL(tty_flip_buffer_push); |
| 2919 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2920 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2921 | /* |
| 2922 | * This subroutine initializes a tty structure. |
| 2923 | */ |
| 2924 | static void initialize_tty_struct(struct tty_struct *tty) |
| 2925 | { |
| 2926 | memset(tty, 0, sizeof(struct tty_struct)); |
| 2927 | tty->magic = TTY_MAGIC; |
| 2928 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
| 2929 | tty->pgrp = -1; |
| 2930 | tty->overrun_time = jiffies; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2931 | tty->buf.head = tty->buf.tail = NULL; |
| 2932 | tty_buffer_init(tty); |
| 2933 | INIT_WORK(&tty->buf.work, flush_to_ldisc, tty); |
| 2934 | init_MUTEX(&tty->buf.pty_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2935 | init_MUTEX(&tty->termios_sem); |
| 2936 | init_waitqueue_head(&tty->write_wait); |
| 2937 | init_waitqueue_head(&tty->read_wait); |
| 2938 | INIT_WORK(&tty->hangup_work, do_tty_hangup, tty); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2939 | mutex_init(&tty->atomic_read_lock); |
| 2940 | mutex_init(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2941 | spin_lock_init(&tty->read_lock); |
| 2942 | INIT_LIST_HEAD(&tty->tty_files); |
| 2943 | INIT_WORK(&tty->SAK_work, NULL, NULL); |
| 2944 | } |
| 2945 | |
| 2946 | /* |
| 2947 | * The default put_char routine if the driver did not define one. |
| 2948 | */ |
| 2949 | static void tty_default_put_char(struct tty_struct *tty, unsigned char ch) |
| 2950 | { |
| 2951 | tty->driver->write(tty, &ch, 1); |
| 2952 | } |
| 2953 | |
gregkh@suse.de | 7fe845d | 2005-03-15 14:23:15 -0800 | [diff] [blame] | 2954 | static struct class *tty_class; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2955 | |
| 2956 | /** |
| 2957 | * tty_register_device - register a tty device |
| 2958 | * @driver: the tty driver that describes the tty device |
| 2959 | * @index: the index in the tty driver for this tty device |
| 2960 | * @device: a struct device that is associated with this tty device. |
| 2961 | * This field is optional, if there is no known struct device for this |
| 2962 | * tty device it can be set to NULL safely. |
| 2963 | * |
| 2964 | * This call is required to be made to register an individual tty device if |
| 2965 | * the tty driver's flags have the TTY_DRIVER_NO_DEVFS bit set. If that |
| 2966 | * bit is not set, this function should not be called. |
| 2967 | */ |
| 2968 | void tty_register_device(struct tty_driver *driver, unsigned index, |
| 2969 | struct device *device) |
| 2970 | { |
| 2971 | char name[64]; |
| 2972 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; |
| 2973 | |
| 2974 | if (index >= driver->num) { |
| 2975 | printk(KERN_ERR "Attempt to register invalid tty line number " |
| 2976 | " (%d).\n", index); |
| 2977 | return; |
| 2978 | } |
| 2979 | |
| 2980 | devfs_mk_cdev(dev, S_IFCHR | S_IRUSR | S_IWUSR, |
| 2981 | "%s%d", driver->devfs_name, index + driver->name_base); |
| 2982 | |
| 2983 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
| 2984 | pty_line_name(driver, index, name); |
| 2985 | else |
| 2986 | tty_line_name(driver, index, name); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 2987 | class_device_create(tty_class, NULL, dev, device, "%s", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2988 | } |
| 2989 | |
| 2990 | /** |
| 2991 | * tty_unregister_device - unregister a tty device |
| 2992 | * @driver: the tty driver that describes the tty device |
| 2993 | * @index: the index in the tty driver for this tty device |
| 2994 | * |
| 2995 | * If a tty device is registered with a call to tty_register_device() then |
| 2996 | * this function must be made when the tty device is gone. |
| 2997 | */ |
| 2998 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
| 2999 | { |
| 3000 | devfs_remove("%s%d", driver->devfs_name, index + driver->name_base); |
gregkh@suse.de | 7fe845d | 2005-03-15 14:23:15 -0800 | [diff] [blame] | 3001 | class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3002 | } |
| 3003 | |
| 3004 | EXPORT_SYMBOL(tty_register_device); |
| 3005 | EXPORT_SYMBOL(tty_unregister_device); |
| 3006 | |
| 3007 | struct tty_driver *alloc_tty_driver(int lines) |
| 3008 | { |
| 3009 | struct tty_driver *driver; |
| 3010 | |
| 3011 | driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL); |
| 3012 | if (driver) { |
| 3013 | memset(driver, 0, sizeof(struct tty_driver)); |
| 3014 | driver->magic = TTY_DRIVER_MAGIC; |
| 3015 | driver->num = lines; |
| 3016 | /* later we'll move allocation of tables here */ |
| 3017 | } |
| 3018 | return driver; |
| 3019 | } |
| 3020 | |
| 3021 | void put_tty_driver(struct tty_driver *driver) |
| 3022 | { |
| 3023 | kfree(driver); |
| 3024 | } |
| 3025 | |
| 3026 | void tty_set_operations(struct tty_driver *driver, struct tty_operations *op) |
| 3027 | { |
| 3028 | driver->open = op->open; |
| 3029 | driver->close = op->close; |
| 3030 | driver->write = op->write; |
| 3031 | driver->put_char = op->put_char; |
| 3032 | driver->flush_chars = op->flush_chars; |
| 3033 | driver->write_room = op->write_room; |
| 3034 | driver->chars_in_buffer = op->chars_in_buffer; |
| 3035 | driver->ioctl = op->ioctl; |
| 3036 | driver->set_termios = op->set_termios; |
| 3037 | driver->throttle = op->throttle; |
| 3038 | driver->unthrottle = op->unthrottle; |
| 3039 | driver->stop = op->stop; |
| 3040 | driver->start = op->start; |
| 3041 | driver->hangup = op->hangup; |
| 3042 | driver->break_ctl = op->break_ctl; |
| 3043 | driver->flush_buffer = op->flush_buffer; |
| 3044 | driver->set_ldisc = op->set_ldisc; |
| 3045 | driver->wait_until_sent = op->wait_until_sent; |
| 3046 | driver->send_xchar = op->send_xchar; |
| 3047 | driver->read_proc = op->read_proc; |
| 3048 | driver->write_proc = op->write_proc; |
| 3049 | driver->tiocmget = op->tiocmget; |
| 3050 | driver->tiocmset = op->tiocmset; |
| 3051 | } |
| 3052 | |
| 3053 | |
| 3054 | EXPORT_SYMBOL(alloc_tty_driver); |
| 3055 | EXPORT_SYMBOL(put_tty_driver); |
| 3056 | EXPORT_SYMBOL(tty_set_operations); |
| 3057 | |
| 3058 | /* |
| 3059 | * Called by a tty driver to register itself. |
| 3060 | */ |
| 3061 | int tty_register_driver(struct tty_driver *driver) |
| 3062 | { |
| 3063 | int error; |
| 3064 | int i; |
| 3065 | dev_t dev; |
| 3066 | void **p = NULL; |
| 3067 | |
| 3068 | if (driver->flags & TTY_DRIVER_INSTALLED) |
| 3069 | return 0; |
| 3070 | |
| 3071 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 3072 | p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); |
| 3073 | if (!p) |
| 3074 | return -ENOMEM; |
| 3075 | memset(p, 0, driver->num * 3 * sizeof(void *)); |
| 3076 | } |
| 3077 | |
| 3078 | if (!driver->major) { |
| 3079 | error = alloc_chrdev_region(&dev, driver->minor_start, driver->num, |
| 3080 | (char*)driver->name); |
| 3081 | if (!error) { |
| 3082 | driver->major = MAJOR(dev); |
| 3083 | driver->minor_start = MINOR(dev); |
| 3084 | } |
| 3085 | } else { |
| 3086 | dev = MKDEV(driver->major, driver->minor_start); |
| 3087 | error = register_chrdev_region(dev, driver->num, |
| 3088 | (char*)driver->name); |
| 3089 | } |
| 3090 | if (error < 0) { |
| 3091 | kfree(p); |
| 3092 | return error; |
| 3093 | } |
| 3094 | |
| 3095 | if (p) { |
| 3096 | driver->ttys = (struct tty_struct **)p; |
| 3097 | driver->termios = (struct termios **)(p + driver->num); |
| 3098 | driver->termios_locked = (struct termios **)(p + driver->num * 2); |
| 3099 | } else { |
| 3100 | driver->ttys = NULL; |
| 3101 | driver->termios = NULL; |
| 3102 | driver->termios_locked = NULL; |
| 3103 | } |
| 3104 | |
| 3105 | cdev_init(&driver->cdev, &tty_fops); |
| 3106 | driver->cdev.owner = driver->owner; |
| 3107 | error = cdev_add(&driver->cdev, dev, driver->num); |
| 3108 | if (error) { |
| 3109 | cdev_del(&driver->cdev); |
| 3110 | unregister_chrdev_region(dev, driver->num); |
| 3111 | driver->ttys = NULL; |
| 3112 | driver->termios = driver->termios_locked = NULL; |
| 3113 | kfree(p); |
| 3114 | return error; |
| 3115 | } |
| 3116 | |
| 3117 | if (!driver->put_char) |
| 3118 | driver->put_char = tty_default_put_char; |
| 3119 | |
| 3120 | list_add(&driver->tty_drivers, &tty_drivers); |
| 3121 | |
| 3122 | if ( !(driver->flags & TTY_DRIVER_NO_DEVFS) ) { |
| 3123 | for(i = 0; i < driver->num; i++) |
| 3124 | tty_register_device(driver, i, NULL); |
| 3125 | } |
| 3126 | proc_tty_register_driver(driver); |
| 3127 | return 0; |
| 3128 | } |
| 3129 | |
| 3130 | EXPORT_SYMBOL(tty_register_driver); |
| 3131 | |
| 3132 | /* |
| 3133 | * Called by a tty driver to unregister itself. |
| 3134 | */ |
| 3135 | int tty_unregister_driver(struct tty_driver *driver) |
| 3136 | { |
| 3137 | int i; |
| 3138 | struct termios *tp; |
| 3139 | void *p; |
| 3140 | |
| 3141 | if (driver->refcount) |
| 3142 | return -EBUSY; |
| 3143 | |
| 3144 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
| 3145 | driver->num); |
| 3146 | |
| 3147 | list_del(&driver->tty_drivers); |
| 3148 | |
| 3149 | /* |
| 3150 | * Free the termios and termios_locked structures because |
| 3151 | * we don't want to get memory leaks when modular tty |
| 3152 | * drivers are removed from the kernel. |
| 3153 | */ |
| 3154 | for (i = 0; i < driver->num; i++) { |
| 3155 | tp = driver->termios[i]; |
| 3156 | if (tp) { |
| 3157 | driver->termios[i] = NULL; |
| 3158 | kfree(tp); |
| 3159 | } |
| 3160 | tp = driver->termios_locked[i]; |
| 3161 | if (tp) { |
| 3162 | driver->termios_locked[i] = NULL; |
| 3163 | kfree(tp); |
| 3164 | } |
| 3165 | if (!(driver->flags & TTY_DRIVER_NO_DEVFS)) |
| 3166 | tty_unregister_device(driver, i); |
| 3167 | } |
| 3168 | p = driver->ttys; |
| 3169 | proc_tty_unregister_driver(driver); |
| 3170 | driver->ttys = NULL; |
| 3171 | driver->termios = driver->termios_locked = NULL; |
| 3172 | kfree(p); |
| 3173 | cdev_del(&driver->cdev); |
| 3174 | return 0; |
| 3175 | } |
| 3176 | |
| 3177 | EXPORT_SYMBOL(tty_unregister_driver); |
| 3178 | |
| 3179 | |
| 3180 | /* |
| 3181 | * Initialize the console device. This is called *early*, so |
| 3182 | * we can't necessarily depend on lots of kernel help here. |
| 3183 | * Just do some early initializations, and do the complex setup |
| 3184 | * later. |
| 3185 | */ |
| 3186 | void __init console_init(void) |
| 3187 | { |
| 3188 | initcall_t *call; |
| 3189 | |
| 3190 | /* Setup the default TTY line discipline. */ |
| 3191 | (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); |
| 3192 | |
| 3193 | /* |
| 3194 | * set up the console device so that later boot sequences can |
| 3195 | * inform about problems etc.. |
| 3196 | */ |
| 3197 | #ifdef CONFIG_EARLY_PRINTK |
| 3198 | disable_early_printk(); |
| 3199 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3200 | call = __con_initcall_start; |
| 3201 | while (call < __con_initcall_end) { |
| 3202 | (*call)(); |
| 3203 | call++; |
| 3204 | } |
| 3205 | } |
| 3206 | |
| 3207 | #ifdef CONFIG_VT |
| 3208 | extern int vty_init(void); |
| 3209 | #endif |
| 3210 | |
| 3211 | static int __init tty_class_init(void) |
| 3212 | { |
gregkh@suse.de | 7fe845d | 2005-03-15 14:23:15 -0800 | [diff] [blame] | 3213 | tty_class = class_create(THIS_MODULE, "tty"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3214 | if (IS_ERR(tty_class)) |
| 3215 | return PTR_ERR(tty_class); |
| 3216 | return 0; |
| 3217 | } |
| 3218 | |
| 3219 | postcore_initcall(tty_class_init); |
| 3220 | |
| 3221 | /* 3/2004 jmc: why do these devices exist? */ |
| 3222 | |
| 3223 | static struct cdev tty_cdev, console_cdev; |
| 3224 | #ifdef CONFIG_UNIX98_PTYS |
| 3225 | static struct cdev ptmx_cdev; |
| 3226 | #endif |
| 3227 | #ifdef CONFIG_VT |
| 3228 | static struct cdev vc0_cdev; |
| 3229 | #endif |
| 3230 | |
| 3231 | /* |
| 3232 | * Ok, now we can initialize the rest of the tty devices and can count |
| 3233 | * on memory allocations, interrupts etc.. |
| 3234 | */ |
| 3235 | static int __init tty_init(void) |
| 3236 | { |
| 3237 | cdev_init(&tty_cdev, &tty_fops); |
| 3238 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || |
| 3239 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) |
| 3240 | panic("Couldn't register /dev/tty driver\n"); |
| 3241 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 0), S_IFCHR|S_IRUGO|S_IWUGO, "tty"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3242 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3243 | |
| 3244 | cdev_init(&console_cdev, &console_fops); |
| 3245 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || |
| 3246 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) |
| 3247 | panic("Couldn't register /dev/console driver\n"); |
| 3248 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 1), S_IFCHR|S_IRUSR|S_IWUSR, "console"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3249 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3250 | |
| 3251 | #ifdef CONFIG_UNIX98_PTYS |
| 3252 | cdev_init(&ptmx_cdev, &ptmx_fops); |
| 3253 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || |
| 3254 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) |
| 3255 | panic("Couldn't register /dev/ptmx driver\n"); |
| 3256 | devfs_mk_cdev(MKDEV(TTYAUX_MAJOR, 2), S_IFCHR|S_IRUGO|S_IWUGO, "ptmx"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3257 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3258 | #endif |
| 3259 | |
| 3260 | #ifdef CONFIG_VT |
| 3261 | cdev_init(&vc0_cdev, &console_fops); |
| 3262 | if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || |
| 3263 | register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) |
| 3264 | panic("Couldn't register /dev/tty0 driver\n"); |
| 3265 | devfs_mk_cdev(MKDEV(TTY_MAJOR, 0), S_IFCHR|S_IRUSR|S_IWUSR, "vc/0"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3266 | class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3267 | |
| 3268 | vty_init(); |
| 3269 | #endif |
| 3270 | return 0; |
| 3271 | } |
| 3272 | module_init(tty_init); |