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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | #include <linux/types.h> |
| 69 | #include <linux/major.h> |
| 70 | #include <linux/errno.h> |
| 71 | #include <linux/signal.h> |
| 72 | #include <linux/fcntl.h> |
| 73 | #include <linux/sched.h> |
| 74 | #include <linux/interrupt.h> |
| 75 | #include <linux/tty.h> |
| 76 | #include <linux/tty_driver.h> |
| 77 | #include <linux/tty_flip.h> |
| 78 | #include <linux/devpts_fs.h> |
| 79 | #include <linux/file.h> |
| 80 | #include <linux/console.h> |
| 81 | #include <linux/timer.h> |
| 82 | #include <linux/ctype.h> |
| 83 | #include <linux/kd.h> |
| 84 | #include <linux/mm.h> |
| 85 | #include <linux/string.h> |
| 86 | #include <linux/slab.h> |
| 87 | #include <linux/poll.h> |
| 88 | #include <linux/proc_fs.h> |
| 89 | #include <linux/init.h> |
| 90 | #include <linux/module.h> |
| 91 | #include <linux/smp_lock.h> |
| 92 | #include <linux/device.h> |
| 93 | #include <linux/idr.h> |
| 94 | #include <linux/wait.h> |
| 95 | #include <linux/bitops.h> |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 96 | #include <linux/delay.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | |
| 98 | #include <asm/uaccess.h> |
| 99 | #include <asm/system.h> |
| 100 | |
| 101 | #include <linux/kbd_kern.h> |
| 102 | #include <linux/vt_kern.h> |
| 103 | #include <linux/selection.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | |
| 105 | #include <linux/kmod.h> |
| 106 | |
| 107 | #undef TTY_DEBUG_HANGUP |
| 108 | |
| 109 | #define TTY_PARANOIA_CHECK 1 |
| 110 | #define CHECK_TTY_COUNT 1 |
| 111 | |
| 112 | struct termios tty_std_termios = { /* for the benefit of tty drivers */ |
| 113 | .c_iflag = ICRNL | IXON, |
| 114 | .c_oflag = OPOST | ONLCR, |
| 115 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, |
| 116 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | |
| 117 | ECHOCTL | ECHOKE | IEXTEN, |
| 118 | .c_cc = INIT_C_CC |
| 119 | }; |
| 120 | |
| 121 | EXPORT_SYMBOL(tty_std_termios); |
| 122 | |
| 123 | /* This list gets poked at by procfs and various bits of boot up code. This |
| 124 | could do with some rationalisation such as pulling the tty proc function |
| 125 | into this file */ |
| 126 | |
| 127 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
| 128 | |
| 129 | /* Semaphore to protect creating and releasing a tty. This is shared with |
| 130 | vt.c for deeply disgusting hack reasons */ |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 131 | DEFINE_MUTEX(tty_mutex); |
Alan Cox | de2a84f | 2006-09-29 02:00:57 -0700 | [diff] [blame] | 132 | EXPORT_SYMBOL(tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
| 134 | #ifdef CONFIG_UNIX98_PTYS |
| 135 | extern struct tty_driver *ptm_driver; /* Unix98 pty masters; for /dev/ptmx */ |
| 136 | extern int pty_limit; /* Config limit on Unix98 ptys */ |
| 137 | static DEFINE_IDR(allocated_ptys); |
| 138 | static DECLARE_MUTEX(allocated_ptys_lock); |
| 139 | static int ptmx_open(struct inode *, struct file *); |
| 140 | #endif |
| 141 | |
| 142 | extern void disable_early_printk(void); |
| 143 | |
| 144 | static void initialize_tty_struct(struct tty_struct *tty); |
| 145 | |
| 146 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
| 147 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); |
| 148 | ssize_t redirected_tty_write(struct file *, const char __user *, size_t, loff_t *); |
| 149 | static unsigned int tty_poll(struct file *, poll_table *); |
| 150 | static int tty_open(struct inode *, struct file *); |
| 151 | static int tty_release(struct inode *, struct file *); |
| 152 | int tty_ioctl(struct inode * inode, struct file * file, |
| 153 | unsigned int cmd, unsigned long arg); |
| 154 | static int tty_fasync(int fd, struct file * filp, int on); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | static void release_mem(struct tty_struct *tty, int idx); |
| 156 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 157 | /** |
| 158 | * alloc_tty_struct - allocate a tty object |
| 159 | * |
| 160 | * Return a new empty tty structure. The data fields have not |
| 161 | * been initialized in any way but has been zeroed |
| 162 | * |
| 163 | * Locking: none |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 164 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
| 166 | static struct tty_struct *alloc_tty_struct(void) |
| 167 | { |
Alan Cox | 1266b1e | 2006-09-29 02:00:40 -0700 | [diff] [blame] | 168 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | } |
| 170 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 171 | static void tty_buffer_free_all(struct tty_struct *); |
| 172 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 173 | /** |
| 174 | * free_tty_struct - free a disused tty |
| 175 | * @tty: tty struct to free |
| 176 | * |
| 177 | * Free the write buffers, tty queue and tty memory itself. |
| 178 | * |
| 179 | * Locking: none. Must be called after tty is definitely unused |
| 180 | */ |
| 181 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | static inline void free_tty_struct(struct tty_struct *tty) |
| 183 | { |
| 184 | kfree(tty->write_buf); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 185 | tty_buffer_free_all(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | kfree(tty); |
| 187 | } |
| 188 | |
| 189 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
| 190 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 191 | /** |
| 192 | * tty_name - return tty naming |
| 193 | * @tty: tty structure |
| 194 | * @buf: buffer for output |
| 195 | * |
| 196 | * Convert a tty structure into a name. The name reflects the kernel |
| 197 | * naming policy and if udev is in use may not reflect user space |
| 198 | * |
| 199 | * Locking: none |
| 200 | */ |
| 201 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | char *tty_name(struct tty_struct *tty, char *buf) |
| 203 | { |
| 204 | if (!tty) /* Hmm. NULL pointer. That's fun. */ |
| 205 | strcpy(buf, "NULL tty"); |
| 206 | else |
| 207 | strcpy(buf, tty->name); |
| 208 | return buf; |
| 209 | } |
| 210 | |
| 211 | EXPORT_SYMBOL(tty_name); |
| 212 | |
Andrew Morton | d769a66 | 2005-05-05 16:15:50 -0700 | [diff] [blame] | 213 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | const char *routine) |
| 215 | { |
| 216 | #ifdef TTY_PARANOIA_CHECK |
| 217 | if (!tty) { |
| 218 | printk(KERN_WARNING |
| 219 | "null TTY for (%d:%d) in %s\n", |
| 220 | imajor(inode), iminor(inode), routine); |
| 221 | return 1; |
| 222 | } |
| 223 | if (tty->magic != TTY_MAGIC) { |
| 224 | printk(KERN_WARNING |
| 225 | "bad magic number for tty struct (%d:%d) in %s\n", |
| 226 | imajor(inode), iminor(inode), routine); |
| 227 | return 1; |
| 228 | } |
| 229 | #endif |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | static int check_tty_count(struct tty_struct *tty, const char *routine) |
| 234 | { |
| 235 | #ifdef CHECK_TTY_COUNT |
| 236 | struct list_head *p; |
| 237 | int count = 0; |
| 238 | |
| 239 | file_list_lock(); |
| 240 | list_for_each(p, &tty->tty_files) { |
| 241 | count++; |
| 242 | } |
| 243 | file_list_unlock(); |
| 244 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 245 | tty->driver->subtype == PTY_TYPE_SLAVE && |
| 246 | tty->link && tty->link->count) |
| 247 | count++; |
| 248 | if (tty->count != count) { |
| 249 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " |
| 250 | "!= #fd's(%d) in %s\n", |
| 251 | tty->name, tty->count, count, routine); |
| 252 | return count; |
| 253 | } |
| 254 | #endif |
| 255 | return 0; |
| 256 | } |
| 257 | |
| 258 | /* |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 259 | * Tty buffer allocation management |
| 260 | */ |
| 261 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 262 | |
| 263 | /** |
| 264 | * tty_buffer_free_all - free buffers used by a tty |
| 265 | * @tty: tty to free from |
| 266 | * |
| 267 | * Remove all the buffers pending on a tty whether queued with data |
| 268 | * or in the free ring. Must be called when the tty is no longer in use |
| 269 | * |
| 270 | * Locking: none |
| 271 | */ |
| 272 | |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 273 | |
| 274 | /** |
| 275 | * tty_buffer_free_all - free buffers used by a tty |
| 276 | * @tty: tty to free from |
| 277 | * |
| 278 | * Remove all the buffers pending on a tty whether queued with data |
| 279 | * or in the free ring. Must be called when the tty is no longer in use |
| 280 | * |
| 281 | * Locking: none |
| 282 | */ |
| 283 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 284 | static void tty_buffer_free_all(struct tty_struct *tty) |
| 285 | { |
| 286 | struct tty_buffer *thead; |
| 287 | while((thead = tty->buf.head) != NULL) { |
| 288 | tty->buf.head = thead->next; |
| 289 | kfree(thead); |
| 290 | } |
| 291 | while((thead = tty->buf.free) != NULL) { |
| 292 | tty->buf.free = thead->next; |
| 293 | kfree(thead); |
| 294 | } |
| 295 | tty->buf.tail = NULL; |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 296 | tty->buf.memory_used = 0; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 297 | } |
| 298 | |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 299 | /** |
| 300 | * tty_buffer_init - prepare a tty buffer structure |
| 301 | * @tty: tty to initialise |
| 302 | * |
| 303 | * Set up the initial state of the buffer management for a tty device. |
| 304 | * Must be called before the other tty buffer functions are used. |
| 305 | * |
| 306 | * Locking: none |
| 307 | */ |
| 308 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 309 | static void tty_buffer_init(struct tty_struct *tty) |
| 310 | { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 311 | spin_lock_init(&tty->buf.lock); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 312 | tty->buf.head = NULL; |
| 313 | tty->buf.tail = NULL; |
| 314 | tty->buf.free = NULL; |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 315 | tty->buf.memory_used = 0; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 316 | } |
| 317 | |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 318 | /** |
| 319 | * tty_buffer_alloc - allocate a tty buffer |
| 320 | * @tty: tty device |
| 321 | * @size: desired size (characters) |
| 322 | * |
| 323 | * Allocate a new tty buffer to hold the desired number of characters. |
| 324 | * Return NULL if out of memory or the allocation would exceed the |
| 325 | * per device queue |
| 326 | * |
| 327 | * Locking: Caller must hold tty->buf.lock |
| 328 | */ |
| 329 | |
| 330 | static struct tty_buffer *tty_buffer_alloc(struct tty_struct *tty, size_t size) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 331 | { |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 332 | struct tty_buffer *p; |
| 333 | |
| 334 | if (tty->buf.memory_used + size > 65536) |
| 335 | return NULL; |
| 336 | p = kmalloc(sizeof(struct tty_buffer) + 2 * size, GFP_ATOMIC); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 337 | if(p == NULL) |
| 338 | return NULL; |
| 339 | p->used = 0; |
| 340 | p->size = size; |
| 341 | p->next = NULL; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 342 | p->commit = 0; |
| 343 | p->read = 0; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 344 | p->char_buf_ptr = (char *)(p->data); |
| 345 | p->flag_buf_ptr = (unsigned char *)p->char_buf_ptr + size; |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 346 | tty->buf.memory_used += size; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 347 | return p; |
| 348 | } |
| 349 | |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 350 | /** |
| 351 | * tty_buffer_free - free a tty buffer |
| 352 | * @tty: tty owning the buffer |
| 353 | * @b: the buffer to free |
| 354 | * |
| 355 | * Free a tty buffer, or add it to the free list according to our |
| 356 | * internal strategy |
| 357 | * |
| 358 | * Locking: Caller must hold tty->buf.lock |
| 359 | */ |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 360 | |
| 361 | static void tty_buffer_free(struct tty_struct *tty, struct tty_buffer *b) |
| 362 | { |
| 363 | /* Dumb strategy for now - should keep some stats */ |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 364 | tty->buf.memory_used -= b->size; |
| 365 | WARN_ON(tty->buf.memory_used < 0); |
| 366 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 367 | if(b->size >= 512) |
| 368 | kfree(b); |
| 369 | else { |
| 370 | b->next = tty->buf.free; |
| 371 | tty->buf.free = b; |
| 372 | } |
| 373 | } |
| 374 | |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 375 | /** |
| 376 | * tty_buffer_find - find a free tty buffer |
| 377 | * @tty: tty owning the buffer |
| 378 | * @size: characters wanted |
| 379 | * |
| 380 | * Locate an existing suitable tty buffer or if we are lacking one then |
| 381 | * allocate a new one. We round our buffers off in 256 character chunks |
| 382 | * to get better allocation behaviour. |
| 383 | * |
| 384 | * Locking: Caller must hold tty->buf.lock |
| 385 | */ |
| 386 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 387 | static struct tty_buffer *tty_buffer_find(struct tty_struct *tty, size_t size) |
| 388 | { |
| 389 | struct tty_buffer **tbh = &tty->buf.free; |
| 390 | while((*tbh) != NULL) { |
| 391 | struct tty_buffer *t = *tbh; |
| 392 | if(t->size >= size) { |
| 393 | *tbh = t->next; |
| 394 | t->next = NULL; |
| 395 | t->used = 0; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 396 | t->commit = 0; |
| 397 | t->read = 0; |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 398 | tty->buf.memory_used += t->size; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 399 | return t; |
| 400 | } |
| 401 | tbh = &((*tbh)->next); |
| 402 | } |
| 403 | /* Round the buffer size out */ |
| 404 | size = (size + 0xFF) & ~ 0xFF; |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 405 | return tty_buffer_alloc(tty, size); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 406 | /* Should possibly check if this fails for the largest buffer we |
| 407 | have queued and recycle that ? */ |
| 408 | } |
| 409 | |
Alan Cox | 01da5fd | 2006-08-27 01:24:02 -0700 | [diff] [blame] | 410 | /** |
| 411 | * tty_buffer_request_room - grow tty buffer if needed |
| 412 | * @tty: tty structure |
| 413 | * @size: size desired |
| 414 | * |
| 415 | * Make at least size bytes of linear space available for the tty |
| 416 | * buffer. If we fail return the size we managed to find. |
| 417 | * |
| 418 | * Locking: Takes tty->buf.lock |
| 419 | */ |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 420 | int tty_buffer_request_room(struct tty_struct *tty, size_t size) |
| 421 | { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 422 | struct tty_buffer *b, *n; |
| 423 | int left; |
| 424 | unsigned long flags; |
| 425 | |
| 426 | spin_lock_irqsave(&tty->buf.lock, flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 427 | |
| 428 | /* OPTIMISATION: We could keep a per tty "zero" sized buffer to |
| 429 | remove this conditional if its worth it. This would be invisible |
| 430 | to the callers */ |
Paul Fulghum | 33b37a3 | 2006-06-28 04:26:49 -0700 | [diff] [blame] | 431 | if ((b = tty->buf.tail) != NULL) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 432 | left = b->size - b->used; |
Paul Fulghum | 33b37a3 | 2006-06-28 04:26:49 -0700 | [diff] [blame] | 433 | else |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 434 | left = 0; |
| 435 | |
| 436 | if (left < size) { |
| 437 | /* This is the slow path - looking for new buffers to use */ |
| 438 | if ((n = tty_buffer_find(tty, size)) != NULL) { |
| 439 | if (b != NULL) { |
| 440 | b->next = n; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 441 | b->commit = b->used; |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 442 | } else |
| 443 | tty->buf.head = n; |
| 444 | tty->buf.tail = n; |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 445 | } else |
| 446 | size = left; |
| 447 | } |
| 448 | |
| 449 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 450 | return size; |
| 451 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 452 | EXPORT_SYMBOL_GPL(tty_buffer_request_room); |
| 453 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 454 | /** |
| 455 | * tty_insert_flip_string - Add characters to the tty buffer |
| 456 | * @tty: tty structure |
| 457 | * @chars: characters |
| 458 | * @size: size |
| 459 | * |
| 460 | * Queue a series of bytes to the tty buffering. All the characters |
| 461 | * passed are marked as without error. Returns the number added. |
| 462 | * |
| 463 | * Locking: Called functions may take tty->buf.lock |
| 464 | */ |
| 465 | |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 466 | int tty_insert_flip_string(struct tty_struct *tty, const unsigned char *chars, |
| 467 | size_t size) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 468 | { |
| 469 | int copied = 0; |
| 470 | do { |
| 471 | int space = tty_buffer_request_room(tty, size - copied); |
| 472 | struct tty_buffer *tb = tty->buf.tail; |
| 473 | /* If there is no space then tb may be NULL */ |
| 474 | if(unlikely(space == 0)) |
| 475 | break; |
| 476 | memcpy(tb->char_buf_ptr + tb->used, chars, space); |
| 477 | memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); |
| 478 | tb->used += space; |
| 479 | copied += space; |
| 480 | chars += space; |
Alexey Dobriyan | 527063b | 2006-09-29 01:59:50 -0700 | [diff] [blame] | 481 | /* There is a small chance that we need to split the data over |
| 482 | several buffers. If this is the case we must loop */ |
| 483 | } while (unlikely(size > copied)); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 484 | return copied; |
| 485 | } |
Andrew Morton | ee37df7 | 2006-03-31 02:30:35 -0800 | [diff] [blame] | 486 | EXPORT_SYMBOL(tty_insert_flip_string); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 487 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 488 | /** |
| 489 | * tty_insert_flip_string_flags - Add characters to the tty buffer |
| 490 | * @tty: tty structure |
| 491 | * @chars: characters |
| 492 | * @flags: flag bytes |
| 493 | * @size: size |
| 494 | * |
| 495 | * Queue a series of bytes to the tty buffering. For each character |
| 496 | * the flags array indicates the status of the character. Returns the |
| 497 | * number added. |
| 498 | * |
| 499 | * Locking: Called functions may take tty->buf.lock |
| 500 | */ |
| 501 | |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 502 | int tty_insert_flip_string_flags(struct tty_struct *tty, |
| 503 | const unsigned char *chars, const char *flags, size_t size) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 504 | { |
| 505 | int copied = 0; |
| 506 | do { |
| 507 | int space = tty_buffer_request_room(tty, size - copied); |
| 508 | struct tty_buffer *tb = tty->buf.tail; |
| 509 | /* If there is no space then tb may be NULL */ |
| 510 | if(unlikely(space == 0)) |
| 511 | break; |
| 512 | memcpy(tb->char_buf_ptr + tb->used, chars, space); |
| 513 | memcpy(tb->flag_buf_ptr + tb->used, flags, space); |
| 514 | tb->used += space; |
| 515 | copied += space; |
| 516 | chars += space; |
| 517 | flags += space; |
Alexey Dobriyan | 527063b | 2006-09-29 01:59:50 -0700 | [diff] [blame] | 518 | /* There is a small chance that we need to split the data over |
| 519 | several buffers. If this is the case we must loop */ |
| 520 | } while (unlikely(size > copied)); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 521 | return copied; |
| 522 | } |
Tobias Powalowski | ff4547f | 2006-05-22 22:35:28 -0700 | [diff] [blame] | 523 | EXPORT_SYMBOL(tty_insert_flip_string_flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 524 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 525 | /** |
| 526 | * tty_schedule_flip - push characters to ldisc |
| 527 | * @tty: tty to push from |
| 528 | * |
| 529 | * Takes any pending buffers and transfers their ownership to the |
| 530 | * ldisc side of the queue. It then schedules those characters for |
| 531 | * processing by the line discipline. |
| 532 | * |
| 533 | * Locking: Takes tty->buf.lock |
| 534 | */ |
| 535 | |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 536 | void tty_schedule_flip(struct tty_struct *tty) |
| 537 | { |
| 538 | unsigned long flags; |
| 539 | spin_lock_irqsave(&tty->buf.lock, flags); |
Paul Fulghum | 33b37a3 | 2006-06-28 04:26:49 -0700 | [diff] [blame] | 540 | if (tty->buf.tail != NULL) |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 541 | tty->buf.tail->commit = tty->buf.tail->used; |
Andrew Morton | e1a2509 | 2006-04-10 22:54:05 -0700 | [diff] [blame] | 542 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
| 543 | schedule_delayed_work(&tty->buf.work, 1); |
| 544 | } |
| 545 | EXPORT_SYMBOL(tty_schedule_flip); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 546 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 547 | /** |
| 548 | * tty_prepare_flip_string - make room for characters |
| 549 | * @tty: tty |
| 550 | * @chars: return pointer for character write area |
| 551 | * @size: desired size |
| 552 | * |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 553 | * Prepare a block of space in the buffer for data. Returns the length |
| 554 | * available and buffer pointer to the space which is now allocated and |
| 555 | * accounted for as ready for normal characters. This is used for drivers |
| 556 | * that need their own block copy routines into the buffer. There is no |
| 557 | * guarantee the buffer is a DMA target! |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 558 | * |
| 559 | * Locking: May call functions taking tty->buf.lock |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 560 | */ |
| 561 | |
| 562 | int tty_prepare_flip_string(struct tty_struct *tty, unsigned char **chars, size_t size) |
| 563 | { |
| 564 | int space = tty_buffer_request_room(tty, size); |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 565 | if (likely(space)) { |
| 566 | struct tty_buffer *tb = tty->buf.tail; |
| 567 | *chars = tb->char_buf_ptr + tb->used; |
| 568 | memset(tb->flag_buf_ptr + tb->used, TTY_NORMAL, space); |
| 569 | tb->used += space; |
| 570 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 571 | return space; |
| 572 | } |
| 573 | |
| 574 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string); |
| 575 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 576 | /** |
| 577 | * tty_prepare_flip_string_flags - make room for characters |
| 578 | * @tty: tty |
| 579 | * @chars: return pointer for character write area |
| 580 | * @flags: return pointer for status flag write area |
| 581 | * @size: desired size |
| 582 | * |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 583 | * Prepare a block of space in the buffer for data. Returns the length |
| 584 | * available and buffer pointer to the space which is now allocated and |
| 585 | * accounted for as ready for characters. This is used for drivers |
| 586 | * that need their own block copy routines into the buffer. There is no |
| 587 | * guarantee the buffer is a DMA target! |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 588 | * |
| 589 | * Locking: May call functions taking tty->buf.lock |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 590 | */ |
| 591 | |
| 592 | int tty_prepare_flip_string_flags(struct tty_struct *tty, unsigned char **chars, char **flags, size_t size) |
| 593 | { |
| 594 | int space = tty_buffer_request_room(tty, size); |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 595 | if (likely(space)) { |
| 596 | struct tty_buffer *tb = tty->buf.tail; |
| 597 | *chars = tb->char_buf_ptr + tb->used; |
| 598 | *flags = tb->flag_buf_ptr + tb->used; |
| 599 | tb->used += space; |
| 600 | } |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 601 | return space; |
| 602 | } |
| 603 | |
| 604 | EXPORT_SYMBOL_GPL(tty_prepare_flip_string_flags); |
| 605 | |
| 606 | |
| 607 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 608 | /** |
| 609 | * tty_set_termios_ldisc - set ldisc field |
| 610 | * @tty: tty structure |
| 611 | * @num: line discipline number |
| 612 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | * This is probably overkill for real world processors but |
| 614 | * they are not on hot paths so a little discipline won't do |
| 615 | * any harm. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 616 | * |
| 617 | * Locking: takes termios_sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 618 | */ |
| 619 | |
| 620 | static void tty_set_termios_ldisc(struct tty_struct *tty, int num) |
| 621 | { |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 622 | mutex_lock(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | tty->termios->c_line = num; |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 624 | mutex_unlock(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | } |
| 626 | |
| 627 | /* |
| 628 | * This guards the refcounted line discipline lists. The lock |
| 629 | * must be taken with irqs off because there are hangup path |
| 630 | * callers who will do ldisc lookups and cannot sleep. |
| 631 | */ |
| 632 | |
| 633 | static DEFINE_SPINLOCK(tty_ldisc_lock); |
| 634 | static DECLARE_WAIT_QUEUE_HEAD(tty_ldisc_wait); |
Alexey Dobriyan | bfb0759 | 2005-06-23 00:10:32 -0700 | [diff] [blame] | 635 | static struct tty_ldisc tty_ldiscs[NR_LDISCS]; /* line disc dispatch table */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 636 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 637 | /** |
| 638 | * tty_register_ldisc - install a line discipline |
| 639 | * @disc: ldisc number |
| 640 | * @new_ldisc: pointer to the ldisc object |
| 641 | * |
| 642 | * Installs a new line discipline into the kernel. The discipline |
| 643 | * is set up as unreferenced and then made available to the kernel |
| 644 | * from this point onwards. |
| 645 | * |
| 646 | * Locking: |
| 647 | * takes tty_ldisc_lock to guard against ldisc races |
| 648 | */ |
| 649 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | int tty_register_ldisc(int disc, struct tty_ldisc *new_ldisc) |
| 651 | { |
| 652 | unsigned long flags; |
| 653 | int ret = 0; |
| 654 | |
| 655 | if (disc < N_TTY || disc >= NR_LDISCS) |
| 656 | return -EINVAL; |
| 657 | |
| 658 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
Alexey Dobriyan | bfb0759 | 2005-06-23 00:10:32 -0700 | [diff] [blame] | 659 | tty_ldiscs[disc] = *new_ldisc; |
| 660 | tty_ldiscs[disc].num = disc; |
| 661 | tty_ldiscs[disc].flags |= LDISC_FLAG_DEFINED; |
| 662 | tty_ldiscs[disc].refcount = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 664 | |
| 665 | return ret; |
| 666 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | EXPORT_SYMBOL(tty_register_ldisc); |
| 668 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 669 | /** |
| 670 | * tty_unregister_ldisc - unload a line discipline |
| 671 | * @disc: ldisc number |
| 672 | * @new_ldisc: pointer to the ldisc object |
| 673 | * |
| 674 | * Remove a line discipline from the kernel providing it is not |
| 675 | * currently in use. |
| 676 | * |
| 677 | * Locking: |
| 678 | * takes tty_ldisc_lock to guard against ldisc races |
| 679 | */ |
| 680 | |
Alexey Dobriyan | bfb0759 | 2005-06-23 00:10:32 -0700 | [diff] [blame] | 681 | int tty_unregister_ldisc(int disc) |
| 682 | { |
| 683 | unsigned long flags; |
| 684 | int ret = 0; |
| 685 | |
| 686 | if (disc < N_TTY || disc >= NR_LDISCS) |
| 687 | return -EINVAL; |
| 688 | |
| 689 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 690 | if (tty_ldiscs[disc].refcount) |
| 691 | ret = -EBUSY; |
| 692 | else |
| 693 | tty_ldiscs[disc].flags &= ~LDISC_FLAG_DEFINED; |
| 694 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 695 | |
| 696 | return ret; |
| 697 | } |
| 698 | EXPORT_SYMBOL(tty_unregister_ldisc); |
| 699 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 700 | /** |
| 701 | * tty_ldisc_get - take a reference to an ldisc |
| 702 | * @disc: ldisc number |
| 703 | * |
| 704 | * Takes a reference to a line discipline. Deals with refcounts and |
| 705 | * module locking counts. Returns NULL if the discipline is not available. |
| 706 | * Returns a pointer to the discipline and bumps the ref count if it is |
| 707 | * available |
| 708 | * |
| 709 | * Locking: |
| 710 | * takes tty_ldisc_lock to guard against ldisc races |
| 711 | */ |
| 712 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | struct tty_ldisc *tty_ldisc_get(int disc) |
| 714 | { |
| 715 | unsigned long flags; |
| 716 | struct tty_ldisc *ld; |
| 717 | |
| 718 | if (disc < N_TTY || disc >= NR_LDISCS) |
| 719 | return NULL; |
| 720 | |
| 721 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 722 | |
| 723 | ld = &tty_ldiscs[disc]; |
| 724 | /* Check the entry is defined */ |
| 725 | if(ld->flags & LDISC_FLAG_DEFINED) |
| 726 | { |
| 727 | /* If the module is being unloaded we can't use it */ |
| 728 | if (!try_module_get(ld->owner)) |
| 729 | ld = NULL; |
| 730 | else /* lock it */ |
| 731 | ld->refcount++; |
| 732 | } |
| 733 | else |
| 734 | ld = NULL; |
| 735 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 736 | return ld; |
| 737 | } |
| 738 | |
| 739 | EXPORT_SYMBOL_GPL(tty_ldisc_get); |
| 740 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 741 | /** |
| 742 | * tty_ldisc_put - drop ldisc reference |
| 743 | * @disc: ldisc number |
| 744 | * |
| 745 | * Drop a reference to a line discipline. Manage refcounts and |
| 746 | * module usage counts |
| 747 | * |
| 748 | * Locking: |
| 749 | * takes tty_ldisc_lock to guard against ldisc races |
| 750 | */ |
| 751 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | void tty_ldisc_put(int disc) |
| 753 | { |
| 754 | struct tty_ldisc *ld; |
| 755 | unsigned long flags; |
| 756 | |
Eric Sesterhenn | 56ee482 | 2006-03-26 18:17:21 +0200 | [diff] [blame] | 757 | BUG_ON(disc < N_TTY || disc >= NR_LDISCS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 758 | |
| 759 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 760 | ld = &tty_ldiscs[disc]; |
Eric Sesterhenn | 56ee482 | 2006-03-26 18:17:21 +0200 | [diff] [blame] | 761 | BUG_ON(ld->refcount == 0); |
| 762 | ld->refcount--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 763 | module_put(ld->owner); |
| 764 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 765 | } |
| 766 | |
| 767 | EXPORT_SYMBOL_GPL(tty_ldisc_put); |
| 768 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 769 | /** |
| 770 | * tty_ldisc_assign - set ldisc on a tty |
| 771 | * @tty: tty to assign |
| 772 | * @ld: line discipline |
| 773 | * |
| 774 | * Install an instance of a line discipline into a tty structure. The |
| 775 | * ldisc must have a reference count above zero to ensure it remains/ |
| 776 | * The tty instance refcount starts at zero. |
| 777 | * |
| 778 | * Locking: |
| 779 | * Caller must hold references |
| 780 | */ |
| 781 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | static void tty_ldisc_assign(struct tty_struct *tty, struct tty_ldisc *ld) |
| 783 | { |
| 784 | tty->ldisc = *ld; |
| 785 | tty->ldisc.refcount = 0; |
| 786 | } |
| 787 | |
| 788 | /** |
| 789 | * tty_ldisc_try - internal helper |
| 790 | * @tty: the tty |
| 791 | * |
| 792 | * Make a single attempt to grab and bump the refcount on |
| 793 | * the tty ldisc. Return 0 on failure or 1 on success. This is |
| 794 | * used to implement both the waiting and non waiting versions |
| 795 | * of tty_ldisc_ref |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 796 | * |
| 797 | * Locking: takes tty_ldisc_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | */ |
| 799 | |
| 800 | static int tty_ldisc_try(struct tty_struct *tty) |
| 801 | { |
| 802 | unsigned long flags; |
| 803 | struct tty_ldisc *ld; |
| 804 | int ret = 0; |
| 805 | |
| 806 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 807 | ld = &tty->ldisc; |
| 808 | if(test_bit(TTY_LDISC, &tty->flags)) |
| 809 | { |
| 810 | ld->refcount++; |
| 811 | ret = 1; |
| 812 | } |
| 813 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 814 | return ret; |
| 815 | } |
| 816 | |
| 817 | /** |
| 818 | * tty_ldisc_ref_wait - wait for the tty ldisc |
| 819 | * @tty: tty device |
| 820 | * |
| 821 | * Dereference the line discipline for the terminal and take a |
| 822 | * reference to it. If the line discipline is in flux then |
| 823 | * wait patiently until it changes. |
| 824 | * |
| 825 | * Note: Must not be called from an IRQ/timer context. The caller |
| 826 | * must also be careful not to hold other locks that will deadlock |
| 827 | * against a discipline change, such as an existing ldisc reference |
| 828 | * (which we check for) |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 829 | * |
| 830 | * Locking: call functions take tty_ldisc_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | */ |
| 832 | |
| 833 | struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *tty) |
| 834 | { |
| 835 | /* wait_event is a macro */ |
| 836 | wait_event(tty_ldisc_wait, tty_ldisc_try(tty)); |
| 837 | if(tty->ldisc.refcount == 0) |
| 838 | printk(KERN_ERR "tty_ldisc_ref_wait\n"); |
| 839 | return &tty->ldisc; |
| 840 | } |
| 841 | |
| 842 | EXPORT_SYMBOL_GPL(tty_ldisc_ref_wait); |
| 843 | |
| 844 | /** |
| 845 | * tty_ldisc_ref - get the tty ldisc |
| 846 | * @tty: tty device |
| 847 | * |
| 848 | * Dereference the line discipline for the terminal and take a |
| 849 | * reference to it. If the line discipline is in flux then |
| 850 | * return NULL. Can be called from IRQ and timer functions. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 851 | * |
| 852 | * Locking: called functions take tty_ldisc_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | */ |
| 854 | |
| 855 | struct tty_ldisc *tty_ldisc_ref(struct tty_struct *tty) |
| 856 | { |
| 857 | if(tty_ldisc_try(tty)) |
| 858 | return &tty->ldisc; |
| 859 | return NULL; |
| 860 | } |
| 861 | |
| 862 | EXPORT_SYMBOL_GPL(tty_ldisc_ref); |
| 863 | |
| 864 | /** |
| 865 | * tty_ldisc_deref - free a tty ldisc reference |
| 866 | * @ld: reference to free up |
| 867 | * |
| 868 | * Undoes the effect of tty_ldisc_ref or tty_ldisc_ref_wait. May |
| 869 | * be called in IRQ context. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 870 | * |
| 871 | * Locking: takes tty_ldisc_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 872 | */ |
| 873 | |
| 874 | void tty_ldisc_deref(struct tty_ldisc *ld) |
| 875 | { |
| 876 | unsigned long flags; |
| 877 | |
Eric Sesterhenn | 56ee482 | 2006-03-26 18:17:21 +0200 | [diff] [blame] | 878 | BUG_ON(ld == NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 879 | |
| 880 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 881 | if(ld->refcount == 0) |
| 882 | printk(KERN_ERR "tty_ldisc_deref: no references.\n"); |
| 883 | else |
| 884 | ld->refcount--; |
| 885 | if(ld->refcount == 0) |
| 886 | wake_up(&tty_ldisc_wait); |
| 887 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 888 | } |
| 889 | |
| 890 | EXPORT_SYMBOL_GPL(tty_ldisc_deref); |
| 891 | |
| 892 | /** |
| 893 | * tty_ldisc_enable - allow ldisc use |
| 894 | * @tty: terminal to activate ldisc on |
| 895 | * |
| 896 | * Set the TTY_LDISC flag when the line discipline can be called |
| 897 | * again. Do neccessary wakeups for existing sleepers. |
| 898 | * |
| 899 | * Note: nobody should set this bit except via this function. Clearing |
| 900 | * directly is allowed. |
| 901 | */ |
| 902 | |
| 903 | static void tty_ldisc_enable(struct tty_struct *tty) |
| 904 | { |
| 905 | set_bit(TTY_LDISC, &tty->flags); |
| 906 | wake_up(&tty_ldisc_wait); |
| 907 | } |
| 908 | |
| 909 | /** |
| 910 | * tty_set_ldisc - set line discipline |
| 911 | * @tty: the terminal to set |
| 912 | * @ldisc: the line discipline |
| 913 | * |
| 914 | * Set the discipline of a tty line. Must be called from a process |
| 915 | * context. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 916 | * |
| 917 | * Locking: takes tty_ldisc_lock. |
| 918 | * called functions take termios_sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 919 | */ |
| 920 | |
| 921 | static int tty_set_ldisc(struct tty_struct *tty, int ldisc) |
| 922 | { |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 923 | int retval = 0; |
| 924 | struct tty_ldisc o_ldisc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | char buf[64]; |
| 926 | int work; |
| 927 | unsigned long flags; |
| 928 | struct tty_ldisc *ld; |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 929 | struct tty_struct *o_tty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | |
| 931 | if ((ldisc < N_TTY) || (ldisc >= NR_LDISCS)) |
| 932 | return -EINVAL; |
| 933 | |
| 934 | restart: |
| 935 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 936 | ld = tty_ldisc_get(ldisc); |
| 937 | /* Eduardo Blanco <ejbs@cs.cs.com.uy> */ |
| 938 | /* Cyrus Durgin <cider@speakeasy.org> */ |
| 939 | if (ld == NULL) { |
| 940 | request_module("tty-ldisc-%d", ldisc); |
| 941 | ld = tty_ldisc_get(ldisc); |
| 942 | } |
| 943 | if (ld == NULL) |
| 944 | return -EINVAL; |
| 945 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 946 | /* |
| 947 | * No more input please, we are switching. The new ldisc |
| 948 | * will update this value in the ldisc open function |
| 949 | */ |
| 950 | |
| 951 | tty->receive_room = 0; |
| 952 | |
| 953 | /* |
| 954 | * Problem: What do we do if this blocks ? |
| 955 | */ |
| 956 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 957 | tty_wait_until_sent(tty, 0); |
| 958 | |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 959 | if (tty->ldisc.num == ldisc) { |
| 960 | tty_ldisc_put(ldisc); |
| 961 | return 0; |
| 962 | } |
| 963 | |
| 964 | o_ldisc = tty->ldisc; |
| 965 | o_tty = tty->link; |
| 966 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 967 | /* |
| 968 | * Make sure we don't change while someone holds a |
| 969 | * reference to the line discipline. The TTY_LDISC bit |
| 970 | * prevents anyone taking a reference once it is clear. |
| 971 | * We need the lock to avoid racing reference takers. |
| 972 | */ |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 973 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 975 | if (tty->ldisc.refcount || (o_tty && o_tty->ldisc.refcount)) { |
| 976 | if(tty->ldisc.refcount) { |
| 977 | /* Free the new ldisc we grabbed. Must drop the lock |
| 978 | first. */ |
| 979 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 980 | tty_ldisc_put(ldisc); |
| 981 | /* |
| 982 | * There are several reasons we may be busy, including |
| 983 | * random momentary I/O traffic. We must therefore |
| 984 | * retry. We could distinguish between blocking ops |
| 985 | * and retries if we made tty_ldisc_wait() smarter. That |
| 986 | * is up for discussion. |
| 987 | */ |
| 988 | if (wait_event_interruptible(tty_ldisc_wait, tty->ldisc.refcount == 0) < 0) |
| 989 | return -ERESTARTSYS; |
| 990 | goto restart; |
| 991 | } |
| 992 | if(o_tty && o_tty->ldisc.refcount) { |
| 993 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 994 | tty_ldisc_put(ldisc); |
| 995 | if (wait_event_interruptible(tty_ldisc_wait, o_tty->ldisc.refcount == 0) < 0) |
| 996 | return -ERESTARTSYS; |
| 997 | goto restart; |
| 998 | } |
| 999 | } |
| 1000 | |
| 1001 | /* if the TTY_LDISC bit is set, then we are racing against another ldisc change */ |
| 1002 | |
| 1003 | if (!test_bit(TTY_LDISC, &tty->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 1005 | tty_ldisc_put(ldisc); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1006 | ld = tty_ldisc_ref_wait(tty); |
| 1007 | tty_ldisc_deref(ld); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1008 | goto restart; |
| 1009 | } |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1010 | |
| 1011 | clear_bit(TTY_LDISC, &tty->flags); |
Paul Fulghum | 817d6d3 | 2006-06-28 04:26:47 -0700 | [diff] [blame] | 1012 | if (o_tty) |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1013 | clear_bit(TTY_LDISC, &o_tty->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1014 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1015 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1016 | /* |
| 1017 | * From this point on we know nobody has an ldisc |
| 1018 | * usage reference, nor can they obtain one until |
| 1019 | * we say so later on. |
| 1020 | */ |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1021 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1022 | work = cancel_delayed_work(&tty->buf.work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1023 | /* |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1024 | * Wait for ->hangup_work and ->buf.work handlers to terminate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | */ |
| 1026 | |
| 1027 | flush_scheduled_work(); |
| 1028 | /* Shutdown the current discipline. */ |
| 1029 | if (tty->ldisc.close) |
| 1030 | (tty->ldisc.close)(tty); |
| 1031 | |
| 1032 | /* Now set up the new line discipline. */ |
| 1033 | tty_ldisc_assign(tty, ld); |
| 1034 | tty_set_termios_ldisc(tty, ldisc); |
| 1035 | if (tty->ldisc.open) |
| 1036 | retval = (tty->ldisc.open)(tty); |
| 1037 | if (retval < 0) { |
| 1038 | tty_ldisc_put(ldisc); |
| 1039 | /* There is an outstanding reference here so this is safe */ |
| 1040 | tty_ldisc_assign(tty, tty_ldisc_get(o_ldisc.num)); |
| 1041 | tty_set_termios_ldisc(tty, tty->ldisc.num); |
| 1042 | if (tty->ldisc.open && (tty->ldisc.open(tty) < 0)) { |
| 1043 | tty_ldisc_put(o_ldisc.num); |
| 1044 | /* This driver is always present */ |
| 1045 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
| 1046 | tty_set_termios_ldisc(tty, N_TTY); |
| 1047 | if (tty->ldisc.open) { |
| 1048 | int r = tty->ldisc.open(tty); |
| 1049 | |
| 1050 | if (r < 0) |
| 1051 | panic("Couldn't open N_TTY ldisc for " |
| 1052 | "%s --- error %d.", |
| 1053 | tty_name(tty, buf), r); |
| 1054 | } |
| 1055 | } |
| 1056 | } |
| 1057 | /* At this point we hold a reference to the new ldisc and a |
| 1058 | a reference to the old ldisc. If we ended up flipping back |
| 1059 | to the existing ldisc we have two references to it */ |
| 1060 | |
| 1061 | if (tty->ldisc.num != o_ldisc.num && tty->driver->set_ldisc) |
| 1062 | tty->driver->set_ldisc(tty); |
| 1063 | |
| 1064 | tty_ldisc_put(o_ldisc.num); |
| 1065 | |
| 1066 | /* |
| 1067 | * Allow ldisc referencing to occur as soon as the driver |
| 1068 | * ldisc callback completes. |
| 1069 | */ |
| 1070 | |
| 1071 | tty_ldisc_enable(tty); |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1072 | if (o_tty) |
| 1073 | tty_ldisc_enable(o_tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | |
| 1075 | /* Restart it in case no characters kick it off. Safe if |
| 1076 | already running */ |
Jason Baron | ff55fe2 | 2005-09-09 13:01:57 -0700 | [diff] [blame] | 1077 | if (work) |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1078 | schedule_delayed_work(&tty->buf.work, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1079 | return retval; |
| 1080 | } |
| 1081 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1082 | /** |
| 1083 | * get_tty_driver - find device of a tty |
| 1084 | * @dev_t: device identifier |
| 1085 | * @index: returns the index of the tty |
| 1086 | * |
| 1087 | * This routine returns a tty driver structure, given a device number |
| 1088 | * and also passes back the index number. |
| 1089 | * |
| 1090 | * Locking: caller must hold tty_mutex |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1091 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1092 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1093 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
| 1094 | { |
| 1095 | struct tty_driver *p; |
| 1096 | |
| 1097 | list_for_each_entry(p, &tty_drivers, tty_drivers) { |
| 1098 | dev_t base = MKDEV(p->major, p->minor_start); |
| 1099 | if (device < base || device >= base + p->num) |
| 1100 | continue; |
| 1101 | *index = device - base; |
| 1102 | return p; |
| 1103 | } |
| 1104 | return NULL; |
| 1105 | } |
| 1106 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1107 | /** |
| 1108 | * tty_check_change - check for POSIX terminal changes |
| 1109 | * @tty: tty to check |
| 1110 | * |
| 1111 | * If we try to write to, or set the state of, a terminal and we're |
| 1112 | * not in the foreground, send a SIGTTOU. If the signal is blocked or |
| 1113 | * ignored, go ahead and perform the operation. (POSIX 7.2) |
| 1114 | * |
| 1115 | * Locking: none |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1116 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1117 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | int tty_check_change(struct tty_struct * tty) |
| 1119 | { |
| 1120 | if (current->signal->tty != tty) |
| 1121 | return 0; |
| 1122 | if (tty->pgrp <= 0) { |
| 1123 | printk(KERN_WARNING "tty_check_change: tty->pgrp <= 0!\n"); |
| 1124 | return 0; |
| 1125 | } |
| 1126 | if (process_group(current) == tty->pgrp) |
| 1127 | return 0; |
| 1128 | if (is_ignored(SIGTTOU)) |
| 1129 | return 0; |
| 1130 | if (is_orphaned_pgrp(process_group(current))) |
| 1131 | return -EIO; |
| 1132 | (void) kill_pg(process_group(current), SIGTTOU, 1); |
| 1133 | return -ERESTARTSYS; |
| 1134 | } |
| 1135 | |
| 1136 | EXPORT_SYMBOL(tty_check_change); |
| 1137 | |
| 1138 | static ssize_t hung_up_tty_read(struct file * file, char __user * buf, |
| 1139 | size_t count, loff_t *ppos) |
| 1140 | { |
| 1141 | return 0; |
| 1142 | } |
| 1143 | |
| 1144 | static ssize_t hung_up_tty_write(struct file * file, const char __user * buf, |
| 1145 | size_t count, loff_t *ppos) |
| 1146 | { |
| 1147 | return -EIO; |
| 1148 | } |
| 1149 | |
| 1150 | /* No kernel lock held - none needed ;) */ |
| 1151 | static unsigned int hung_up_tty_poll(struct file * filp, poll_table * wait) |
| 1152 | { |
| 1153 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; |
| 1154 | } |
| 1155 | |
| 1156 | static int hung_up_tty_ioctl(struct inode * inode, struct file * file, |
| 1157 | unsigned int cmd, unsigned long arg) |
| 1158 | { |
| 1159 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; |
| 1160 | } |
| 1161 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 1162 | static const struct file_operations tty_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | .llseek = no_llseek, |
| 1164 | .read = tty_read, |
| 1165 | .write = tty_write, |
| 1166 | .poll = tty_poll, |
| 1167 | .ioctl = tty_ioctl, |
| 1168 | .open = tty_open, |
| 1169 | .release = tty_release, |
| 1170 | .fasync = tty_fasync, |
| 1171 | }; |
| 1172 | |
| 1173 | #ifdef CONFIG_UNIX98_PTYS |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 1174 | static const struct file_operations ptmx_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1175 | .llseek = no_llseek, |
| 1176 | .read = tty_read, |
| 1177 | .write = tty_write, |
| 1178 | .poll = tty_poll, |
| 1179 | .ioctl = tty_ioctl, |
| 1180 | .open = ptmx_open, |
| 1181 | .release = tty_release, |
| 1182 | .fasync = tty_fasync, |
| 1183 | }; |
| 1184 | #endif |
| 1185 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 1186 | static const struct file_operations console_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1187 | .llseek = no_llseek, |
| 1188 | .read = tty_read, |
| 1189 | .write = redirected_tty_write, |
| 1190 | .poll = tty_poll, |
| 1191 | .ioctl = tty_ioctl, |
| 1192 | .open = tty_open, |
| 1193 | .release = tty_release, |
| 1194 | .fasync = tty_fasync, |
| 1195 | }; |
| 1196 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 1197 | static const struct file_operations hung_up_tty_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1198 | .llseek = no_llseek, |
| 1199 | .read = hung_up_tty_read, |
| 1200 | .write = hung_up_tty_write, |
| 1201 | .poll = hung_up_tty_poll, |
| 1202 | .ioctl = hung_up_tty_ioctl, |
| 1203 | .release = tty_release, |
| 1204 | }; |
| 1205 | |
| 1206 | static DEFINE_SPINLOCK(redirect_lock); |
| 1207 | static struct file *redirect; |
| 1208 | |
| 1209 | /** |
| 1210 | * tty_wakeup - request more data |
| 1211 | * @tty: terminal |
| 1212 | * |
| 1213 | * Internal and external helper for wakeups of tty. This function |
| 1214 | * informs the line discipline if present that the driver is ready |
| 1215 | * to receive more output data. |
| 1216 | */ |
| 1217 | |
| 1218 | void tty_wakeup(struct tty_struct *tty) |
| 1219 | { |
| 1220 | struct tty_ldisc *ld; |
| 1221 | |
| 1222 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
| 1223 | ld = tty_ldisc_ref(tty); |
| 1224 | if(ld) { |
| 1225 | if(ld->write_wakeup) |
| 1226 | ld->write_wakeup(tty); |
| 1227 | tty_ldisc_deref(ld); |
| 1228 | } |
| 1229 | } |
| 1230 | wake_up_interruptible(&tty->write_wait); |
| 1231 | } |
| 1232 | |
| 1233 | EXPORT_SYMBOL_GPL(tty_wakeup); |
| 1234 | |
| 1235 | /** |
| 1236 | * tty_ldisc_flush - flush line discipline queue |
| 1237 | * @tty: tty |
| 1238 | * |
| 1239 | * Flush the line discipline queue (if any) for this tty. If there |
| 1240 | * is no line discipline active this is a no-op. |
| 1241 | */ |
| 1242 | |
| 1243 | void tty_ldisc_flush(struct tty_struct *tty) |
| 1244 | { |
| 1245 | struct tty_ldisc *ld = tty_ldisc_ref(tty); |
| 1246 | if(ld) { |
| 1247 | if(ld->flush_buffer) |
| 1248 | ld->flush_buffer(tty); |
| 1249 | tty_ldisc_deref(ld); |
| 1250 | } |
| 1251 | } |
| 1252 | |
| 1253 | EXPORT_SYMBOL_GPL(tty_ldisc_flush); |
| 1254 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1255 | /** |
| 1256 | * do_tty_hangup - actual handler for hangup events |
| 1257 | * @data: tty device |
| 1258 | * |
| 1259 | * This can be called by the "eventd" kernel thread. That is process |
| 1260 | * synchronous but doesn't hold any locks, so we need to make sure we |
| 1261 | * have the appropriate locks for what we're doing. |
| 1262 | * |
| 1263 | * The hangup event clears any pending redirections onto the hung up |
| 1264 | * device. It ensures future writes will error and it does the needed |
| 1265 | * line discipline hangup and signal delivery. The tty object itself |
| 1266 | * remains intact. |
| 1267 | * |
| 1268 | * Locking: |
| 1269 | * BKL |
| 1270 | * redirect lock for undoing redirection |
| 1271 | * file list lock for manipulating list of ttys |
| 1272 | * tty_ldisc_lock from called functions |
| 1273 | * termios_sem resetting termios data |
| 1274 | * tasklist_lock to walk task list for hangup event |
| 1275 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | */ |
| 1277 | static void do_tty_hangup(void *data) |
| 1278 | { |
| 1279 | struct tty_struct *tty = (struct tty_struct *) data; |
| 1280 | struct file * cons_filp = NULL; |
| 1281 | struct file *filp, *f = NULL; |
| 1282 | struct task_struct *p; |
| 1283 | struct tty_ldisc *ld; |
| 1284 | int closecount = 0, n; |
| 1285 | |
| 1286 | if (!tty) |
| 1287 | return; |
| 1288 | |
| 1289 | /* inuse_filps is protected by the single kernel lock */ |
| 1290 | lock_kernel(); |
| 1291 | |
| 1292 | spin_lock(&redirect_lock); |
| 1293 | if (redirect && redirect->private_data == tty) { |
| 1294 | f = redirect; |
| 1295 | redirect = NULL; |
| 1296 | } |
| 1297 | spin_unlock(&redirect_lock); |
| 1298 | |
| 1299 | check_tty_count(tty, "do_tty_hangup"); |
| 1300 | file_list_lock(); |
| 1301 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
Eric Dumazet | 2f51201 | 2005-10-30 15:02:16 -0800 | [diff] [blame] | 1302 | list_for_each_entry(filp, &tty->tty_files, f_u.fu_list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | if (filp->f_op->write == redirected_tty_write) |
| 1304 | cons_filp = filp; |
| 1305 | if (filp->f_op->write != tty_write) |
| 1306 | continue; |
| 1307 | closecount++; |
| 1308 | tty_fasync(-1, filp, 0); /* can't block */ |
| 1309 | filp->f_op = &hung_up_tty_fops; |
| 1310 | } |
| 1311 | file_list_unlock(); |
| 1312 | |
| 1313 | /* FIXME! What are the locking issues here? This may me overdoing things.. |
| 1314 | * this question is especially important now that we've removed the irqlock. */ |
| 1315 | |
| 1316 | ld = tty_ldisc_ref(tty); |
| 1317 | if(ld != NULL) /* We may have no line discipline at this point */ |
| 1318 | { |
| 1319 | if (ld->flush_buffer) |
| 1320 | ld->flush_buffer(tty); |
| 1321 | if (tty->driver->flush_buffer) |
| 1322 | tty->driver->flush_buffer(tty); |
| 1323 | if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) && |
| 1324 | ld->write_wakeup) |
| 1325 | ld->write_wakeup(tty); |
| 1326 | if (ld->hangup) |
| 1327 | ld->hangup(tty); |
| 1328 | } |
| 1329 | |
| 1330 | /* FIXME: Once we trust the LDISC code better we can wait here for |
| 1331 | ldisc completion and fix the driver call race */ |
| 1332 | |
| 1333 | wake_up_interruptible(&tty->write_wait); |
| 1334 | wake_up_interruptible(&tty->read_wait); |
| 1335 | |
| 1336 | /* |
| 1337 | * Shutdown the current line discipline, and reset it to |
| 1338 | * N_TTY. |
| 1339 | */ |
| 1340 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
| 1341 | { |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 1342 | mutex_lock(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | *tty->termios = tty->driver->init_termios; |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 1344 | mutex_unlock(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1345 | } |
| 1346 | |
| 1347 | /* Defer ldisc switch */ |
| 1348 | /* tty_deferred_ldisc_switch(N_TTY); |
| 1349 | |
| 1350 | This should get done automatically when the port closes and |
| 1351 | tty_release is called */ |
| 1352 | |
| 1353 | read_lock(&tasklist_lock); |
| 1354 | if (tty->session > 0) { |
| 1355 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
| 1356 | if (p->signal->tty == tty) |
| 1357 | p->signal->tty = NULL; |
| 1358 | if (!p->signal->leader) |
| 1359 | continue; |
Eric W. Biederman | f96a795 | 2006-03-28 16:11:01 -0800 | [diff] [blame] | 1360 | group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); |
| 1361 | group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | if (tty->pgrp > 0) |
| 1363 | p->signal->tty_old_pgrp = tty->pgrp; |
| 1364 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
| 1365 | } |
| 1366 | read_unlock(&tasklist_lock); |
| 1367 | |
| 1368 | tty->flags = 0; |
| 1369 | tty->session = 0; |
| 1370 | tty->pgrp = -1; |
| 1371 | tty->ctrl_status = 0; |
| 1372 | /* |
| 1373 | * If one of the devices matches a console pointer, we |
| 1374 | * cannot just call hangup() because that will cause |
| 1375 | * tty->count and state->count to go out of sync. |
| 1376 | * So we just call close() the right number of times. |
| 1377 | */ |
| 1378 | if (cons_filp) { |
| 1379 | if (tty->driver->close) |
| 1380 | for (n = 0; n < closecount; n++) |
| 1381 | tty->driver->close(tty, cons_filp); |
| 1382 | } else if (tty->driver->hangup) |
| 1383 | (tty->driver->hangup)(tty); |
| 1384 | |
| 1385 | /* We don't want to have driver/ldisc interactions beyond |
| 1386 | the ones we did here. The driver layer expects no |
| 1387 | calls after ->hangup() from the ldisc side. However we |
| 1388 | can't yet guarantee all that */ |
| 1389 | |
| 1390 | set_bit(TTY_HUPPED, &tty->flags); |
| 1391 | if (ld) { |
| 1392 | tty_ldisc_enable(tty); |
| 1393 | tty_ldisc_deref(ld); |
| 1394 | } |
| 1395 | unlock_kernel(); |
| 1396 | if (f) |
| 1397 | fput(f); |
| 1398 | } |
| 1399 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1400 | /** |
| 1401 | * tty_hangup - trigger a hangup event |
| 1402 | * @tty: tty to hangup |
| 1403 | * |
| 1404 | * A carrier loss (virtual or otherwise) has occurred on this like |
| 1405 | * schedule a hangup sequence to run after this event. |
| 1406 | */ |
| 1407 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | void tty_hangup(struct tty_struct * tty) |
| 1409 | { |
| 1410 | #ifdef TTY_DEBUG_HANGUP |
| 1411 | char buf[64]; |
| 1412 | |
| 1413 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
| 1414 | #endif |
| 1415 | schedule_work(&tty->hangup_work); |
| 1416 | } |
| 1417 | |
| 1418 | EXPORT_SYMBOL(tty_hangup); |
| 1419 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1420 | /** |
| 1421 | * tty_vhangup - process vhangup |
| 1422 | * @tty: tty to hangup |
| 1423 | * |
| 1424 | * The user has asked via system call for the terminal to be hung up. |
| 1425 | * We do this synchronously so that when the syscall returns the process |
| 1426 | * is complete. That guarantee is neccessary for security reasons. |
| 1427 | */ |
| 1428 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1429 | void tty_vhangup(struct tty_struct * tty) |
| 1430 | { |
| 1431 | #ifdef TTY_DEBUG_HANGUP |
| 1432 | char buf[64]; |
| 1433 | |
| 1434 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); |
| 1435 | #endif |
| 1436 | do_tty_hangup((void *) tty); |
| 1437 | } |
| 1438 | EXPORT_SYMBOL(tty_vhangup); |
| 1439 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1440 | /** |
| 1441 | * tty_hung_up_p - was tty hung up |
| 1442 | * @filp: file pointer of tty |
| 1443 | * |
| 1444 | * Return true if the tty has been subject to a vhangup or a carrier |
| 1445 | * loss |
| 1446 | */ |
| 1447 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1448 | int tty_hung_up_p(struct file * filp) |
| 1449 | { |
| 1450 | return (filp->f_op == &hung_up_tty_fops); |
| 1451 | } |
| 1452 | |
| 1453 | EXPORT_SYMBOL(tty_hung_up_p); |
| 1454 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1455 | /** |
| 1456 | * disassociate_ctty - disconnect controlling tty |
| 1457 | * @on_exit: true if exiting so need to "hang up" the session |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1459 | * This function is typically called only by the session leader, when |
| 1460 | * it wants to disassociate itself from its controlling tty. |
| 1461 | * |
| 1462 | * It performs the following functions: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1463 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
| 1464 | * (2) Clears the tty from being controlling the session |
| 1465 | * (3) Clears the controlling tty for all processes in the |
| 1466 | * session group. |
| 1467 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1468 | * The argument on_exit is set to 1 if called when a process is |
| 1469 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. |
| 1470 | * |
| 1471 | * Locking: tty_mutex is taken to protect current->signal->tty |
| 1472 | * BKL is taken for hysterical raisins |
| 1473 | * Tasklist lock is taken (under tty_mutex) to walk process |
| 1474 | * lists for the session. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1475 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1476 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1477 | void disassociate_ctty(int on_exit) |
| 1478 | { |
| 1479 | struct tty_struct *tty; |
| 1480 | struct task_struct *p; |
| 1481 | int tty_pgrp = -1; |
| 1482 | |
| 1483 | lock_kernel(); |
| 1484 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1485 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1486 | tty = current->signal->tty; |
| 1487 | if (tty) { |
| 1488 | tty_pgrp = tty->pgrp; |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1489 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1490 | if (on_exit && tty->driver->type != TTY_DRIVER_TYPE_PTY) |
| 1491 | tty_vhangup(tty); |
| 1492 | } else { |
| 1493 | if (current->signal->tty_old_pgrp) { |
| 1494 | kill_pg(current->signal->tty_old_pgrp, SIGHUP, on_exit); |
| 1495 | kill_pg(current->signal->tty_old_pgrp, SIGCONT, on_exit); |
| 1496 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1497 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1498 | unlock_kernel(); |
| 1499 | return; |
| 1500 | } |
| 1501 | if (tty_pgrp > 0) { |
| 1502 | kill_pg(tty_pgrp, SIGHUP, on_exit); |
| 1503 | if (!on_exit) |
| 1504 | kill_pg(tty_pgrp, SIGCONT, on_exit); |
| 1505 | } |
| 1506 | |
| 1507 | /* Must lock changes to tty_old_pgrp */ |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1508 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1509 | current->signal->tty_old_pgrp = 0; |
| 1510 | tty->session = 0; |
| 1511 | tty->pgrp = -1; |
| 1512 | |
| 1513 | /* Now clear signal->tty under the lock */ |
| 1514 | read_lock(&tasklist_lock); |
| 1515 | do_each_task_pid(current->signal->session, PIDTYPE_SID, p) { |
| 1516 | p->signal->tty = NULL; |
| 1517 | } while_each_task_pid(current->signal->session, PIDTYPE_SID, p); |
| 1518 | read_unlock(&tasklist_lock); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1519 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1520 | unlock_kernel(); |
| 1521 | } |
| 1522 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1523 | |
| 1524 | /** |
| 1525 | * stop_tty - propogate flow control |
| 1526 | * @tty: tty to stop |
| 1527 | * |
| 1528 | * Perform flow control to the driver. For PTY/TTY pairs we |
| 1529 | * must also propogate the TIOCKPKT status. May be called |
| 1530 | * on an already stopped device and will not re-call the driver |
| 1531 | * method. |
| 1532 | * |
| 1533 | * This functionality is used by both the line disciplines for |
| 1534 | * halting incoming flow and by the driver. It may therefore be |
| 1535 | * called from any context, may be under the tty atomic_write_lock |
| 1536 | * but not always. |
| 1537 | * |
| 1538 | * Locking: |
| 1539 | * Broken. Relies on BKL which is unsafe here. |
| 1540 | */ |
| 1541 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1542 | void stop_tty(struct tty_struct *tty) |
| 1543 | { |
| 1544 | if (tty->stopped) |
| 1545 | return; |
| 1546 | tty->stopped = 1; |
| 1547 | if (tty->link && tty->link->packet) { |
| 1548 | tty->ctrl_status &= ~TIOCPKT_START; |
| 1549 | tty->ctrl_status |= TIOCPKT_STOP; |
| 1550 | wake_up_interruptible(&tty->link->read_wait); |
| 1551 | } |
| 1552 | if (tty->driver->stop) |
| 1553 | (tty->driver->stop)(tty); |
| 1554 | } |
| 1555 | |
| 1556 | EXPORT_SYMBOL(stop_tty); |
| 1557 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1558 | /** |
| 1559 | * start_tty - propogate flow control |
| 1560 | * @tty: tty to start |
| 1561 | * |
| 1562 | * Start a tty that has been stopped if at all possible. Perform |
| 1563 | * any neccessary wakeups and propogate the TIOCPKT status. If this |
| 1564 | * is the tty was previous stopped and is being started then the |
| 1565 | * driver start method is invoked and the line discipline woken. |
| 1566 | * |
| 1567 | * Locking: |
| 1568 | * Broken. Relies on BKL which is unsafe here. |
| 1569 | */ |
| 1570 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1571 | void start_tty(struct tty_struct *tty) |
| 1572 | { |
| 1573 | if (!tty->stopped || tty->flow_stopped) |
| 1574 | return; |
| 1575 | tty->stopped = 0; |
| 1576 | if (tty->link && tty->link->packet) { |
| 1577 | tty->ctrl_status &= ~TIOCPKT_STOP; |
| 1578 | tty->ctrl_status |= TIOCPKT_START; |
| 1579 | wake_up_interruptible(&tty->link->read_wait); |
| 1580 | } |
| 1581 | if (tty->driver->start) |
| 1582 | (tty->driver->start)(tty); |
| 1583 | |
| 1584 | /* If we have a running line discipline it may need kicking */ |
| 1585 | tty_wakeup(tty); |
| 1586 | wake_up_interruptible(&tty->write_wait); |
| 1587 | } |
| 1588 | |
| 1589 | EXPORT_SYMBOL(start_tty); |
| 1590 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1591 | /** |
| 1592 | * tty_read - read method for tty device files |
| 1593 | * @file: pointer to tty file |
| 1594 | * @buf: user buffer |
| 1595 | * @count: size of user buffer |
| 1596 | * @ppos: unused |
| 1597 | * |
| 1598 | * Perform the read system call function on this terminal device. Checks |
| 1599 | * for hung up devices before calling the line discipline method. |
| 1600 | * |
| 1601 | * Locking: |
| 1602 | * Locks the line discipline internally while needed |
| 1603 | * For historical reasons the line discipline read method is |
| 1604 | * invoked under the BKL. This will go away in time so do not rely on it |
| 1605 | * in new code. Multiple read calls may be outstanding in parallel. |
| 1606 | */ |
| 1607 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1608 | static ssize_t tty_read(struct file * file, char __user * buf, size_t count, |
| 1609 | loff_t *ppos) |
| 1610 | { |
| 1611 | int i; |
| 1612 | struct tty_struct * tty; |
| 1613 | struct inode *inode; |
| 1614 | struct tty_ldisc *ld; |
| 1615 | |
| 1616 | tty = (struct tty_struct *)file->private_data; |
| 1617 | inode = file->f_dentry->d_inode; |
| 1618 | if (tty_paranoia_check(tty, inode, "tty_read")) |
| 1619 | return -EIO; |
| 1620 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) |
| 1621 | return -EIO; |
| 1622 | |
| 1623 | /* We want to wait for the line discipline to sort out in this |
| 1624 | situation */ |
| 1625 | ld = tty_ldisc_ref_wait(tty); |
| 1626 | lock_kernel(); |
| 1627 | if (ld->read) |
| 1628 | i = (ld->read)(tty,file,buf,count); |
| 1629 | else |
| 1630 | i = -EIO; |
| 1631 | tty_ldisc_deref(ld); |
| 1632 | unlock_kernel(); |
| 1633 | if (i > 0) |
| 1634 | inode->i_atime = current_fs_time(inode->i_sb); |
| 1635 | return i; |
| 1636 | } |
| 1637 | |
| 1638 | /* |
| 1639 | * Split writes up in sane blocksizes to avoid |
| 1640 | * denial-of-service type attacks |
| 1641 | */ |
| 1642 | static inline ssize_t do_tty_write( |
| 1643 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), |
| 1644 | struct tty_struct *tty, |
| 1645 | struct file *file, |
| 1646 | const char __user *buf, |
| 1647 | size_t count) |
| 1648 | { |
| 1649 | ssize_t ret = 0, written = 0; |
| 1650 | unsigned int chunk; |
| 1651 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1652 | /* FIXME: O_NDELAY ... */ |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1653 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1654 | return -ERESTARTSYS; |
| 1655 | } |
| 1656 | |
| 1657 | /* |
| 1658 | * We chunk up writes into a temporary buffer. This |
| 1659 | * simplifies low-level drivers immensely, since they |
| 1660 | * don't have locking issues and user mode accesses. |
| 1661 | * |
| 1662 | * But if TTY_NO_WRITE_SPLIT is set, we should use a |
| 1663 | * big chunk-size.. |
| 1664 | * |
| 1665 | * The default chunk-size is 2kB, because the NTTY |
| 1666 | * layer has problems with bigger chunks. It will |
| 1667 | * claim to be able to handle more characters than |
| 1668 | * it actually does. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1669 | * |
| 1670 | * FIXME: This can probably go away now except that 64K chunks |
| 1671 | * are too likely to fail unless switched to vmalloc... |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1672 | */ |
| 1673 | chunk = 2048; |
| 1674 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) |
| 1675 | chunk = 65536; |
| 1676 | if (count < chunk) |
| 1677 | chunk = count; |
| 1678 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1679 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1680 | if (tty->write_cnt < chunk) { |
| 1681 | unsigned char *buf; |
| 1682 | |
| 1683 | if (chunk < 1024) |
| 1684 | chunk = 1024; |
| 1685 | |
| 1686 | buf = kmalloc(chunk, GFP_KERNEL); |
| 1687 | if (!buf) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1688 | mutex_unlock(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1689 | return -ENOMEM; |
| 1690 | } |
| 1691 | kfree(tty->write_buf); |
| 1692 | tty->write_cnt = chunk; |
| 1693 | tty->write_buf = buf; |
| 1694 | } |
| 1695 | |
| 1696 | /* Do the write .. */ |
| 1697 | for (;;) { |
| 1698 | size_t size = count; |
| 1699 | if (size > chunk) |
| 1700 | size = chunk; |
| 1701 | ret = -EFAULT; |
| 1702 | if (copy_from_user(tty->write_buf, buf, size)) |
| 1703 | break; |
| 1704 | lock_kernel(); |
| 1705 | ret = write(tty, file, tty->write_buf, size); |
| 1706 | unlock_kernel(); |
| 1707 | if (ret <= 0) |
| 1708 | break; |
| 1709 | written += ret; |
| 1710 | buf += ret; |
| 1711 | count -= ret; |
| 1712 | if (!count) |
| 1713 | break; |
| 1714 | ret = -ERESTARTSYS; |
| 1715 | if (signal_pending(current)) |
| 1716 | break; |
| 1717 | cond_resched(); |
| 1718 | } |
| 1719 | if (written) { |
| 1720 | struct inode *inode = file->f_dentry->d_inode; |
| 1721 | inode->i_mtime = current_fs_time(inode->i_sb); |
| 1722 | ret = written; |
| 1723 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 1724 | mutex_unlock(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1725 | return ret; |
| 1726 | } |
| 1727 | |
| 1728 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1729 | /** |
| 1730 | * tty_write - write method for tty device file |
| 1731 | * @file: tty file pointer |
| 1732 | * @buf: user data to write |
| 1733 | * @count: bytes to write |
| 1734 | * @ppos: unused |
| 1735 | * |
| 1736 | * Write data to a tty device via the line discipline. |
| 1737 | * |
| 1738 | * Locking: |
| 1739 | * Locks the line discipline as required |
| 1740 | * Writes to the tty driver are serialized by the atomic_write_lock |
| 1741 | * and are then processed in chunks to the device. The line discipline |
| 1742 | * write method will not be involked in parallel for each device |
| 1743 | * The line discipline write method is called under the big |
| 1744 | * kernel lock for historical reasons. New code should not rely on this. |
| 1745 | */ |
| 1746 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1747 | static ssize_t tty_write(struct file * file, const char __user * buf, size_t count, |
| 1748 | loff_t *ppos) |
| 1749 | { |
| 1750 | struct tty_struct * tty; |
| 1751 | struct inode *inode = file->f_dentry->d_inode; |
| 1752 | ssize_t ret; |
| 1753 | struct tty_ldisc *ld; |
| 1754 | |
| 1755 | tty = (struct tty_struct *)file->private_data; |
| 1756 | if (tty_paranoia_check(tty, inode, "tty_write")) |
| 1757 | return -EIO; |
| 1758 | if (!tty || !tty->driver->write || (test_bit(TTY_IO_ERROR, &tty->flags))) |
| 1759 | return -EIO; |
| 1760 | |
| 1761 | ld = tty_ldisc_ref_wait(tty); |
| 1762 | if (!ld->write) |
| 1763 | ret = -EIO; |
| 1764 | else |
| 1765 | ret = do_tty_write(ld->write, tty, file, buf, count); |
| 1766 | tty_ldisc_deref(ld); |
| 1767 | return ret; |
| 1768 | } |
| 1769 | |
| 1770 | ssize_t redirected_tty_write(struct file * file, const char __user * buf, size_t count, |
| 1771 | loff_t *ppos) |
| 1772 | { |
| 1773 | struct file *p = NULL; |
| 1774 | |
| 1775 | spin_lock(&redirect_lock); |
| 1776 | if (redirect) { |
| 1777 | get_file(redirect); |
| 1778 | p = redirect; |
| 1779 | } |
| 1780 | spin_unlock(&redirect_lock); |
| 1781 | |
| 1782 | if (p) { |
| 1783 | ssize_t res; |
| 1784 | res = vfs_write(p, buf, count, &p->f_pos); |
| 1785 | fput(p); |
| 1786 | return res; |
| 1787 | } |
| 1788 | |
| 1789 | return tty_write(file, buf, count, ppos); |
| 1790 | } |
| 1791 | |
| 1792 | static char ptychar[] = "pqrstuvwxyzabcde"; |
| 1793 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1794 | /** |
| 1795 | * pty_line_name - generate name for a pty |
| 1796 | * @driver: the tty driver in use |
| 1797 | * @index: the minor number |
| 1798 | * @p: output buffer of at least 6 bytes |
| 1799 | * |
| 1800 | * Generate a name from a driver reference and write it to the output |
| 1801 | * buffer. |
| 1802 | * |
| 1803 | * Locking: None |
| 1804 | */ |
| 1805 | static void pty_line_name(struct tty_driver *driver, int index, char *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1806 | { |
| 1807 | int i = index + driver->name_base; |
| 1808 | /* ->name is initialized to "ttyp", but "tty" is expected */ |
| 1809 | sprintf(p, "%s%c%x", |
| 1810 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
| 1811 | ptychar[i >> 4 & 0xf], i & 0xf); |
| 1812 | } |
| 1813 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1814 | /** |
| 1815 | * pty_line_name - generate name for a tty |
| 1816 | * @driver: the tty driver in use |
| 1817 | * @index: the minor number |
| 1818 | * @p: output buffer of at least 7 bytes |
| 1819 | * |
| 1820 | * Generate a name from a driver reference and write it to the output |
| 1821 | * buffer. |
| 1822 | * |
| 1823 | * Locking: None |
| 1824 | */ |
| 1825 | static void tty_line_name(struct tty_driver *driver, int index, char *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1826 | { |
| 1827 | sprintf(p, "%s%d", driver->name, index + driver->name_base); |
| 1828 | } |
| 1829 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1830 | /** |
| 1831 | * init_dev - initialise a tty device |
| 1832 | * @driver: tty driver we are opening a device on |
| 1833 | * @idx: device index |
| 1834 | * @tty: returned tty structure |
| 1835 | * |
| 1836 | * Prepare a tty device. This may not be a "new" clean device but |
| 1837 | * could also be an active device. The pty drivers require special |
| 1838 | * handling because of this. |
| 1839 | * |
| 1840 | * Locking: |
| 1841 | * The function is called under the tty_mutex, which |
| 1842 | * protects us from the tty struct or driver itself going away. |
| 1843 | * |
| 1844 | * On exit the tty device has the line discipline attached and |
| 1845 | * a reference count of 1. If a pair was created for pty/tty use |
| 1846 | * and the other was a pty master then it too has a reference count of 1. |
| 1847 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1848 | * 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] | 1849 | * failed open. The new code protects the open with a mutex, so it's |
| 1850 | * really quite straightforward. The mutex locking can probably be |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1851 | * relaxed for the (most common) case of reopening a tty. |
| 1852 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1853 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1854 | static int init_dev(struct tty_driver *driver, int idx, |
| 1855 | struct tty_struct **ret_tty) |
| 1856 | { |
| 1857 | struct tty_struct *tty, *o_tty; |
| 1858 | struct termios *tp, **tp_loc, *o_tp, **o_tp_loc; |
| 1859 | struct termios *ltp, **ltp_loc, *o_ltp, **o_ltp_loc; |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 1860 | int retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | |
| 1862 | /* check whether we're reopening an existing tty */ |
| 1863 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
| 1864 | tty = devpts_get_tty(idx); |
| 1865 | if (tty && driver->subtype == PTY_TYPE_MASTER) |
| 1866 | tty = tty->link; |
| 1867 | } else { |
| 1868 | tty = driver->ttys[idx]; |
| 1869 | } |
| 1870 | if (tty) goto fast_track; |
| 1871 | |
| 1872 | /* |
| 1873 | * First time open is complex, especially for PTY devices. |
| 1874 | * This code guarantees that either everything succeeds and the |
| 1875 | * TTY is ready for operation, or else the table slots are vacated |
| 1876 | * and the allocated memory released. (Except that the termios |
| 1877 | * and locked termios may be retained.) |
| 1878 | */ |
| 1879 | |
| 1880 | if (!try_module_get(driver->owner)) { |
| 1881 | retval = -ENODEV; |
| 1882 | goto end_init; |
| 1883 | } |
| 1884 | |
| 1885 | o_tty = NULL; |
| 1886 | tp = o_tp = NULL; |
| 1887 | ltp = o_ltp = NULL; |
| 1888 | |
| 1889 | tty = alloc_tty_struct(); |
| 1890 | if(!tty) |
| 1891 | goto fail_no_mem; |
| 1892 | initialize_tty_struct(tty); |
| 1893 | tty->driver = driver; |
| 1894 | tty->index = idx; |
| 1895 | tty_line_name(driver, idx, tty->name); |
| 1896 | |
| 1897 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
| 1898 | tp_loc = &tty->termios; |
| 1899 | ltp_loc = &tty->termios_locked; |
| 1900 | } else { |
| 1901 | tp_loc = &driver->termios[idx]; |
| 1902 | ltp_loc = &driver->termios_locked[idx]; |
| 1903 | } |
| 1904 | |
| 1905 | if (!*tp_loc) { |
| 1906 | tp = (struct termios *) kmalloc(sizeof(struct termios), |
| 1907 | GFP_KERNEL); |
| 1908 | if (!tp) |
| 1909 | goto free_mem_out; |
| 1910 | *tp = driver->init_termios; |
| 1911 | } |
| 1912 | |
| 1913 | if (!*ltp_loc) { |
| 1914 | ltp = (struct termios *) kmalloc(sizeof(struct termios), |
| 1915 | GFP_KERNEL); |
| 1916 | if (!ltp) |
| 1917 | goto free_mem_out; |
| 1918 | memset(ltp, 0, sizeof(struct termios)); |
| 1919 | } |
| 1920 | |
| 1921 | if (driver->type == TTY_DRIVER_TYPE_PTY) { |
| 1922 | o_tty = alloc_tty_struct(); |
| 1923 | if (!o_tty) |
| 1924 | goto free_mem_out; |
| 1925 | initialize_tty_struct(o_tty); |
| 1926 | o_tty->driver = driver->other; |
| 1927 | o_tty->index = idx; |
| 1928 | tty_line_name(driver->other, idx, o_tty->name); |
| 1929 | |
| 1930 | if (driver->flags & TTY_DRIVER_DEVPTS_MEM) { |
| 1931 | o_tp_loc = &o_tty->termios; |
| 1932 | o_ltp_loc = &o_tty->termios_locked; |
| 1933 | } else { |
| 1934 | o_tp_loc = &driver->other->termios[idx]; |
| 1935 | o_ltp_loc = &driver->other->termios_locked[idx]; |
| 1936 | } |
| 1937 | |
| 1938 | if (!*o_tp_loc) { |
| 1939 | o_tp = (struct termios *) |
| 1940 | kmalloc(sizeof(struct termios), GFP_KERNEL); |
| 1941 | if (!o_tp) |
| 1942 | goto free_mem_out; |
| 1943 | *o_tp = driver->other->init_termios; |
| 1944 | } |
| 1945 | |
| 1946 | if (!*o_ltp_loc) { |
| 1947 | o_ltp = (struct termios *) |
| 1948 | kmalloc(sizeof(struct termios), GFP_KERNEL); |
| 1949 | if (!o_ltp) |
| 1950 | goto free_mem_out; |
| 1951 | memset(o_ltp, 0, sizeof(struct termios)); |
| 1952 | } |
| 1953 | |
| 1954 | /* |
| 1955 | * Everything allocated ... set up the o_tty structure. |
| 1956 | */ |
| 1957 | if (!(driver->other->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 1958 | driver->other->ttys[idx] = o_tty; |
| 1959 | } |
| 1960 | if (!*o_tp_loc) |
| 1961 | *o_tp_loc = o_tp; |
| 1962 | if (!*o_ltp_loc) |
| 1963 | *o_ltp_loc = o_ltp; |
| 1964 | o_tty->termios = *o_tp_loc; |
| 1965 | o_tty->termios_locked = *o_ltp_loc; |
| 1966 | driver->other->refcount++; |
| 1967 | if (driver->subtype == PTY_TYPE_MASTER) |
| 1968 | o_tty->count++; |
| 1969 | |
| 1970 | /* Establish the links in both directions */ |
| 1971 | tty->link = o_tty; |
| 1972 | o_tty->link = tty; |
| 1973 | } |
| 1974 | |
| 1975 | /* |
| 1976 | * All structures have been allocated, so now we install them. |
| 1977 | * Failures after this point use release_mem to clean up, so |
| 1978 | * there's no need to null out the local pointers. |
| 1979 | */ |
| 1980 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 1981 | driver->ttys[idx] = tty; |
| 1982 | } |
| 1983 | |
| 1984 | if (!*tp_loc) |
| 1985 | *tp_loc = tp; |
| 1986 | if (!*ltp_loc) |
| 1987 | *ltp_loc = ltp; |
| 1988 | tty->termios = *tp_loc; |
| 1989 | tty->termios_locked = *ltp_loc; |
| 1990 | driver->refcount++; |
| 1991 | tty->count++; |
| 1992 | |
| 1993 | /* |
| 1994 | * Structures all installed ... call the ldisc open routines. |
| 1995 | * If we fail here just call release_mem to clean up. No need |
| 1996 | * to decrement the use counts, as release_mem doesn't care. |
| 1997 | */ |
| 1998 | |
| 1999 | if (tty->ldisc.open) { |
| 2000 | retval = (tty->ldisc.open)(tty); |
| 2001 | if (retval) |
| 2002 | goto release_mem_out; |
| 2003 | } |
| 2004 | if (o_tty && o_tty->ldisc.open) { |
| 2005 | retval = (o_tty->ldisc.open)(o_tty); |
| 2006 | if (retval) { |
| 2007 | if (tty->ldisc.close) |
| 2008 | (tty->ldisc.close)(tty); |
| 2009 | goto release_mem_out; |
| 2010 | } |
| 2011 | tty_ldisc_enable(o_tty); |
| 2012 | } |
| 2013 | tty_ldisc_enable(tty); |
| 2014 | goto success; |
| 2015 | |
| 2016 | /* |
| 2017 | * This fast open can be used if the tty is already open. |
| 2018 | * No memory is allocated, and the only failures are from |
| 2019 | * attempting to open a closing tty or attempting multiple |
| 2020 | * opens on a pty master. |
| 2021 | */ |
| 2022 | fast_track: |
| 2023 | if (test_bit(TTY_CLOSING, &tty->flags)) { |
| 2024 | retval = -EIO; |
| 2025 | goto end_init; |
| 2026 | } |
| 2027 | if (driver->type == TTY_DRIVER_TYPE_PTY && |
| 2028 | driver->subtype == PTY_TYPE_MASTER) { |
| 2029 | /* |
| 2030 | * special case for PTY masters: only one open permitted, |
| 2031 | * and the slave side open count is incremented as well. |
| 2032 | */ |
| 2033 | if (tty->count) { |
| 2034 | retval = -EIO; |
| 2035 | goto end_init; |
| 2036 | } |
| 2037 | tty->link->count++; |
| 2038 | } |
| 2039 | tty->count++; |
| 2040 | tty->driver = driver; /* N.B. why do this every time?? */ |
| 2041 | |
| 2042 | /* FIXME */ |
| 2043 | if(!test_bit(TTY_LDISC, &tty->flags)) |
| 2044 | printk(KERN_ERR "init_dev but no ldisc\n"); |
| 2045 | success: |
| 2046 | *ret_tty = tty; |
| 2047 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2048 | /* All paths come through here to release the mutex */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2049 | end_init: |
| 2050 | return retval; |
| 2051 | |
| 2052 | /* Release locally allocated memory ... nothing placed in slots */ |
| 2053 | free_mem_out: |
Jesper Juhl | 735d566 | 2005-11-07 01:01:29 -0800 | [diff] [blame] | 2054 | kfree(o_tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2055 | if (o_tty) |
| 2056 | free_tty_struct(o_tty); |
Jesper Juhl | 735d566 | 2005-11-07 01:01:29 -0800 | [diff] [blame] | 2057 | kfree(ltp); |
| 2058 | kfree(tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2059 | free_tty_struct(tty); |
| 2060 | |
| 2061 | fail_no_mem: |
| 2062 | module_put(driver->owner); |
| 2063 | retval = -ENOMEM; |
| 2064 | goto end_init; |
| 2065 | |
| 2066 | /* call the tty release_mem routine to clean out this slot */ |
| 2067 | release_mem_out: |
Akinobu Mita | 4050914 | 2006-09-29 02:01:27 -0700 | [diff] [blame] | 2068 | if (printk_ratelimit()) |
| 2069 | printk(KERN_INFO "init_dev: ldisc open failed, " |
| 2070 | "clearing slot %d\n", idx); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2071 | release_mem(tty, idx); |
| 2072 | goto end_init; |
| 2073 | } |
| 2074 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2075 | /** |
| 2076 | * release_mem - release tty structure memory |
| 2077 | * |
| 2078 | * Releases memory associated with a tty structure, and clears out the |
| 2079 | * driver table slots. This function is called when a device is no longer |
| 2080 | * in use. It also gets called when setup of a device fails. |
| 2081 | * |
| 2082 | * Locking: |
| 2083 | * tty_mutex - sometimes only |
| 2084 | * takes the file list lock internally when working on the list |
| 2085 | * of ttys that the driver keeps. |
| 2086 | * FIXME: should we require tty_mutex is held here ?? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2087 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2088 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2089 | static void release_mem(struct tty_struct *tty, int idx) |
| 2090 | { |
| 2091 | struct tty_struct *o_tty; |
| 2092 | struct termios *tp; |
| 2093 | int devpts = tty->driver->flags & TTY_DRIVER_DEVPTS_MEM; |
| 2094 | |
| 2095 | if ((o_tty = tty->link) != NULL) { |
| 2096 | if (!devpts) |
| 2097 | o_tty->driver->ttys[idx] = NULL; |
| 2098 | if (o_tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
| 2099 | tp = o_tty->termios; |
| 2100 | if (!devpts) |
| 2101 | o_tty->driver->termios[idx] = NULL; |
| 2102 | kfree(tp); |
| 2103 | |
| 2104 | tp = o_tty->termios_locked; |
| 2105 | if (!devpts) |
| 2106 | o_tty->driver->termios_locked[idx] = NULL; |
| 2107 | kfree(tp); |
| 2108 | } |
| 2109 | o_tty->magic = 0; |
| 2110 | o_tty->driver->refcount--; |
| 2111 | file_list_lock(); |
| 2112 | list_del_init(&o_tty->tty_files); |
| 2113 | file_list_unlock(); |
| 2114 | free_tty_struct(o_tty); |
| 2115 | } |
| 2116 | |
| 2117 | if (!devpts) |
| 2118 | tty->driver->ttys[idx] = NULL; |
| 2119 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { |
| 2120 | tp = tty->termios; |
| 2121 | if (!devpts) |
| 2122 | tty->driver->termios[idx] = NULL; |
| 2123 | kfree(tp); |
| 2124 | |
| 2125 | tp = tty->termios_locked; |
| 2126 | if (!devpts) |
| 2127 | tty->driver->termios_locked[idx] = NULL; |
| 2128 | kfree(tp); |
| 2129 | } |
| 2130 | |
| 2131 | tty->magic = 0; |
| 2132 | tty->driver->refcount--; |
| 2133 | file_list_lock(); |
| 2134 | list_del_init(&tty->tty_files); |
| 2135 | file_list_unlock(); |
| 2136 | module_put(tty->driver->owner); |
| 2137 | free_tty_struct(tty); |
| 2138 | } |
| 2139 | |
| 2140 | /* |
| 2141 | * Even releasing the tty structures is a tricky business.. We have |
| 2142 | * to be very careful that the structures are all released at the |
| 2143 | * same time, as interrupts might otherwise get the wrong pointers. |
| 2144 | * |
| 2145 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could |
| 2146 | * lead to double frees or releasing memory still in use. |
| 2147 | */ |
| 2148 | static void release_dev(struct file * filp) |
| 2149 | { |
| 2150 | struct tty_struct *tty, *o_tty; |
| 2151 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
Paul Fulghum | 14a6283 | 2006-04-10 22:54:19 -0700 | [diff] [blame] | 2152 | int devpts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2153 | int idx; |
| 2154 | char buf[64]; |
| 2155 | unsigned long flags; |
| 2156 | |
| 2157 | tty = (struct tty_struct *)filp->private_data; |
| 2158 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "release_dev")) |
| 2159 | return; |
| 2160 | |
| 2161 | check_tty_count(tty, "release_dev"); |
| 2162 | |
| 2163 | tty_fasync(-1, filp, 0); |
| 2164 | |
| 2165 | idx = tty->index; |
| 2166 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 2167 | tty->driver->subtype == PTY_TYPE_MASTER); |
| 2168 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2169 | o_tty = tty->link; |
| 2170 | |
| 2171 | #ifdef TTY_PARANOIA_CHECK |
| 2172 | if (idx < 0 || idx >= tty->driver->num) { |
| 2173 | printk(KERN_DEBUG "release_dev: bad idx when trying to " |
| 2174 | "free (%s)\n", tty->name); |
| 2175 | return; |
| 2176 | } |
| 2177 | if (!(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 2178 | if (tty != tty->driver->ttys[idx]) { |
| 2179 | printk(KERN_DEBUG "release_dev: driver.table[%d] not tty " |
| 2180 | "for (%s)\n", idx, tty->name); |
| 2181 | return; |
| 2182 | } |
| 2183 | if (tty->termios != tty->driver->termios[idx]) { |
| 2184 | printk(KERN_DEBUG "release_dev: driver.termios[%d] not termios " |
| 2185 | "for (%s)\n", |
| 2186 | idx, tty->name); |
| 2187 | return; |
| 2188 | } |
| 2189 | if (tty->termios_locked != tty->driver->termios_locked[idx]) { |
| 2190 | printk(KERN_DEBUG "release_dev: driver.termios_locked[%d] not " |
| 2191 | "termios_locked for (%s)\n", |
| 2192 | idx, tty->name); |
| 2193 | return; |
| 2194 | } |
| 2195 | } |
| 2196 | #endif |
| 2197 | |
| 2198 | #ifdef TTY_DEBUG_HANGUP |
| 2199 | printk(KERN_DEBUG "release_dev of %s (tty count=%d)...", |
| 2200 | tty_name(tty, buf), tty->count); |
| 2201 | #endif |
| 2202 | |
| 2203 | #ifdef TTY_PARANOIA_CHECK |
| 2204 | if (tty->driver->other && |
| 2205 | !(tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 2206 | if (o_tty != tty->driver->other->ttys[idx]) { |
| 2207 | printk(KERN_DEBUG "release_dev: other->table[%d] " |
| 2208 | "not o_tty for (%s)\n", |
| 2209 | idx, tty->name); |
| 2210 | return; |
| 2211 | } |
| 2212 | if (o_tty->termios != tty->driver->other->termios[idx]) { |
| 2213 | printk(KERN_DEBUG "release_dev: other->termios[%d] " |
| 2214 | "not o_termios for (%s)\n", |
| 2215 | idx, tty->name); |
| 2216 | return; |
| 2217 | } |
| 2218 | if (o_tty->termios_locked != |
| 2219 | tty->driver->other->termios_locked[idx]) { |
| 2220 | printk(KERN_DEBUG "release_dev: other->termios_locked[" |
| 2221 | "%d] not o_termios_locked for (%s)\n", |
| 2222 | idx, tty->name); |
| 2223 | return; |
| 2224 | } |
| 2225 | if (o_tty->link != tty) { |
| 2226 | printk(KERN_DEBUG "release_dev: bad pty pointers\n"); |
| 2227 | return; |
| 2228 | } |
| 2229 | } |
| 2230 | #endif |
| 2231 | if (tty->driver->close) |
| 2232 | tty->driver->close(tty, filp); |
| 2233 | |
| 2234 | /* |
| 2235 | * Sanity check: if tty->count is going to zero, there shouldn't be |
| 2236 | * any waiters on tty->read_wait or tty->write_wait. We test the |
| 2237 | * wait queues and kick everyone out _before_ actually starting to |
| 2238 | * close. This ensures that we won't block while releasing the tty |
| 2239 | * structure. |
| 2240 | * |
| 2241 | * The test for the o_tty closing is necessary, since the master and |
| 2242 | * slave sides may close in any order. If the slave side closes out |
| 2243 | * first, its count will be one, since the master side holds an open. |
| 2244 | * Thus this test wouldn't be triggered at the time the slave closes, |
| 2245 | * so we do it now. |
| 2246 | * |
| 2247 | * Note that it's possible for the tty to be opened again while we're |
| 2248 | * flushing out waiters. By recalculating the closing flags before |
| 2249 | * each iteration we avoid any problems. |
| 2250 | */ |
| 2251 | while (1) { |
| 2252 | /* Guard against races with tty->count changes elsewhere and |
| 2253 | opens on /dev/tty */ |
| 2254 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2255 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2256 | tty_closing = tty->count <= 1; |
| 2257 | o_tty_closing = o_tty && |
| 2258 | (o_tty->count <= (pty_master ? 1 : 0)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2259 | do_sleep = 0; |
| 2260 | |
| 2261 | if (tty_closing) { |
| 2262 | if (waitqueue_active(&tty->read_wait)) { |
| 2263 | wake_up(&tty->read_wait); |
| 2264 | do_sleep++; |
| 2265 | } |
| 2266 | if (waitqueue_active(&tty->write_wait)) { |
| 2267 | wake_up(&tty->write_wait); |
| 2268 | do_sleep++; |
| 2269 | } |
| 2270 | } |
| 2271 | if (o_tty_closing) { |
| 2272 | if (waitqueue_active(&o_tty->read_wait)) { |
| 2273 | wake_up(&o_tty->read_wait); |
| 2274 | do_sleep++; |
| 2275 | } |
| 2276 | if (waitqueue_active(&o_tty->write_wait)) { |
| 2277 | wake_up(&o_tty->write_wait); |
| 2278 | do_sleep++; |
| 2279 | } |
| 2280 | } |
| 2281 | if (!do_sleep) |
| 2282 | break; |
| 2283 | |
| 2284 | printk(KERN_WARNING "release_dev: %s: read/write wait queue " |
| 2285 | "active!\n", tty_name(tty, buf)); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2286 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2287 | schedule(); |
| 2288 | } |
| 2289 | |
| 2290 | /* |
| 2291 | * The closing flags are now consistent with the open counts on |
| 2292 | * both sides, and we've completed the last operation that could |
| 2293 | * block, so it's safe to proceed with closing. |
| 2294 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2295 | if (pty_master) { |
| 2296 | if (--o_tty->count < 0) { |
| 2297 | printk(KERN_WARNING "release_dev: bad pty slave count " |
| 2298 | "(%d) for %s\n", |
| 2299 | o_tty->count, tty_name(o_tty, buf)); |
| 2300 | o_tty->count = 0; |
| 2301 | } |
| 2302 | } |
| 2303 | if (--tty->count < 0) { |
| 2304 | printk(KERN_WARNING "release_dev: bad tty->count (%d) for %s\n", |
| 2305 | tty->count, tty_name(tty, buf)); |
| 2306 | tty->count = 0; |
| 2307 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2308 | |
| 2309 | /* |
| 2310 | * We've decremented tty->count, so we need to remove this file |
| 2311 | * descriptor off the tty->tty_files list; this serves two |
| 2312 | * purposes: |
| 2313 | * - check_tty_count sees the correct number of file descriptors |
| 2314 | * associated with this tty. |
| 2315 | * - do_tty_hangup no longer sees this file descriptor as |
| 2316 | * something that needs to be handled for hangups. |
| 2317 | */ |
| 2318 | file_kill(filp); |
| 2319 | filp->private_data = NULL; |
| 2320 | |
| 2321 | /* |
| 2322 | * Perform some housekeeping before deciding whether to return. |
| 2323 | * |
| 2324 | * Set the TTY_CLOSING flag if this was the last open. In the |
| 2325 | * case of a pty we may have to wait around for the other side |
| 2326 | * to close, and TTY_CLOSING makes sure we can't be reopened. |
| 2327 | */ |
| 2328 | if(tty_closing) |
| 2329 | set_bit(TTY_CLOSING, &tty->flags); |
| 2330 | if(o_tty_closing) |
| 2331 | set_bit(TTY_CLOSING, &o_tty->flags); |
| 2332 | |
| 2333 | /* |
| 2334 | * If _either_ side is closing, make sure there aren't any |
| 2335 | * processes that still think tty or o_tty is their controlling |
| 2336 | * tty. |
| 2337 | */ |
| 2338 | if (tty_closing || o_tty_closing) { |
| 2339 | struct task_struct *p; |
| 2340 | |
| 2341 | read_lock(&tasklist_lock); |
| 2342 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
| 2343 | p->signal->tty = NULL; |
| 2344 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
| 2345 | if (o_tty) |
| 2346 | do_each_task_pid(o_tty->session, PIDTYPE_SID, p) { |
| 2347 | p->signal->tty = NULL; |
| 2348 | } while_each_task_pid(o_tty->session, PIDTYPE_SID, p); |
| 2349 | read_unlock(&tasklist_lock); |
| 2350 | } |
| 2351 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2352 | mutex_unlock(&tty_mutex); |
Paul Fulghum | da96582 | 2006-02-14 13:53:00 -0800 | [diff] [blame] | 2353 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2354 | /* check whether both sides are closing ... */ |
| 2355 | if (!tty_closing || (o_tty && !o_tty_closing)) |
| 2356 | return; |
| 2357 | |
| 2358 | #ifdef TTY_DEBUG_HANGUP |
| 2359 | printk(KERN_DEBUG "freeing tty structure..."); |
| 2360 | #endif |
| 2361 | /* |
| 2362 | * Prevent flush_to_ldisc() from rescheduling the work for later. Then |
| 2363 | * kill any delayed work. As this is the final close it does not |
| 2364 | * race with the set_ldisc code path. |
| 2365 | */ |
| 2366 | clear_bit(TTY_LDISC, &tty->flags); |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2367 | cancel_delayed_work(&tty->buf.work); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2368 | |
| 2369 | /* |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 2370 | * Wait for ->hangup_work and ->buf.work handlers to terminate |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2371 | */ |
| 2372 | |
| 2373 | flush_scheduled_work(); |
| 2374 | |
| 2375 | /* |
| 2376 | * Wait for any short term users (we know they are just driver |
| 2377 | * side waiters as the file is closing so user count on the file |
| 2378 | * side is zero. |
| 2379 | */ |
| 2380 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 2381 | while(tty->ldisc.refcount) |
| 2382 | { |
| 2383 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 2384 | wait_event(tty_ldisc_wait, tty->ldisc.refcount == 0); |
| 2385 | spin_lock_irqsave(&tty_ldisc_lock, flags); |
| 2386 | } |
| 2387 | spin_unlock_irqrestore(&tty_ldisc_lock, flags); |
| 2388 | /* |
| 2389 | * Shutdown the current line discipline, and reset it to N_TTY. |
| 2390 | * N.B. why reset ldisc when we're releasing the memory?? |
| 2391 | * |
| 2392 | * FIXME: this MUST get fixed for the new reflocking |
| 2393 | */ |
| 2394 | if (tty->ldisc.close) |
| 2395 | (tty->ldisc.close)(tty); |
| 2396 | tty_ldisc_put(tty->ldisc.num); |
| 2397 | |
| 2398 | /* |
| 2399 | * Switch the line discipline back |
| 2400 | */ |
| 2401 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
| 2402 | tty_set_termios_ldisc(tty,N_TTY); |
| 2403 | if (o_tty) { |
| 2404 | /* FIXME: could o_tty be in setldisc here ? */ |
| 2405 | clear_bit(TTY_LDISC, &o_tty->flags); |
| 2406 | if (o_tty->ldisc.close) |
| 2407 | (o_tty->ldisc.close)(o_tty); |
| 2408 | tty_ldisc_put(o_tty->ldisc.num); |
| 2409 | tty_ldisc_assign(o_tty, tty_ldisc_get(N_TTY)); |
| 2410 | tty_set_termios_ldisc(o_tty,N_TTY); |
| 2411 | } |
| 2412 | /* |
| 2413 | * The release_mem function takes care of the details of clearing |
| 2414 | * the slots and preserving the termios structure. |
| 2415 | */ |
| 2416 | release_mem(tty, idx); |
| 2417 | |
| 2418 | #ifdef CONFIG_UNIX98_PTYS |
| 2419 | /* Make this pty number available for reallocation */ |
| 2420 | if (devpts) { |
| 2421 | down(&allocated_ptys_lock); |
| 2422 | idr_remove(&allocated_ptys, idx); |
| 2423 | up(&allocated_ptys_lock); |
| 2424 | } |
| 2425 | #endif |
| 2426 | |
| 2427 | } |
| 2428 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2429 | /** |
| 2430 | * tty_open - open a tty device |
| 2431 | * @inode: inode of device file |
| 2432 | * @filp: file pointer to tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2433 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2434 | * tty_open and tty_release keep up the tty count that contains the |
| 2435 | * number of opens done on a tty. We cannot use the inode-count, as |
| 2436 | * different inodes might point to the same tty. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2437 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2438 | * Open-counting is needed for pty masters, as well as for keeping |
| 2439 | * track of serial lines: DTR is dropped when the last close happens. |
| 2440 | * (This is not done solely through tty->count, now. - Ted 1/27/92) |
| 2441 | * |
| 2442 | * The termios state of a pty is reset on first open so that |
| 2443 | * settings don't persist across reuse. |
| 2444 | * |
| 2445 | * Locking: tty_mutex protects current->signal->tty, get_tty_driver and |
| 2446 | * init_dev work. tty->count should protect the rest. |
| 2447 | * task_lock is held to update task details for sessions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2448 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2449 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2450 | static int tty_open(struct inode * inode, struct file * filp) |
| 2451 | { |
| 2452 | struct tty_struct *tty; |
| 2453 | int noctty, retval; |
| 2454 | struct tty_driver *driver; |
| 2455 | int index; |
| 2456 | dev_t device = inode->i_rdev; |
| 2457 | unsigned short saved_flags = filp->f_flags; |
| 2458 | |
| 2459 | nonseekable_open(inode, filp); |
| 2460 | |
| 2461 | retry_open: |
| 2462 | noctty = filp->f_flags & O_NOCTTY; |
| 2463 | index = -1; |
| 2464 | retval = 0; |
| 2465 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2466 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2467 | |
| 2468 | if (device == MKDEV(TTYAUX_MAJOR,0)) { |
| 2469 | if (!current->signal->tty) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2470 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2471 | return -ENXIO; |
| 2472 | } |
| 2473 | driver = current->signal->tty->driver; |
| 2474 | index = current->signal->tty->index; |
| 2475 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
| 2476 | /* noctty = 1; */ |
| 2477 | goto got_driver; |
| 2478 | } |
| 2479 | #ifdef CONFIG_VT |
| 2480 | if (device == MKDEV(TTY_MAJOR,0)) { |
| 2481 | extern struct tty_driver *console_driver; |
| 2482 | driver = console_driver; |
| 2483 | index = fg_console; |
| 2484 | noctty = 1; |
| 2485 | goto got_driver; |
| 2486 | } |
| 2487 | #endif |
| 2488 | if (device == MKDEV(TTYAUX_MAJOR,1)) { |
| 2489 | driver = console_device(&index); |
| 2490 | if (driver) { |
| 2491 | /* Don't let /dev/console block */ |
| 2492 | filp->f_flags |= O_NONBLOCK; |
| 2493 | noctty = 1; |
| 2494 | goto got_driver; |
| 2495 | } |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2496 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2497 | return -ENODEV; |
| 2498 | } |
| 2499 | |
| 2500 | driver = get_tty_driver(device, &index); |
| 2501 | if (!driver) { |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2502 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2503 | return -ENODEV; |
| 2504 | } |
| 2505 | got_driver: |
| 2506 | retval = init_dev(driver, index, &tty); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2507 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2508 | if (retval) |
| 2509 | return retval; |
| 2510 | |
| 2511 | filp->private_data = tty; |
| 2512 | file_move(filp, &tty->tty_files); |
| 2513 | check_tty_count(tty, "tty_open"); |
| 2514 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 2515 | tty->driver->subtype == PTY_TYPE_MASTER) |
| 2516 | noctty = 1; |
| 2517 | #ifdef TTY_DEBUG_HANGUP |
| 2518 | printk(KERN_DEBUG "opening %s...", tty->name); |
| 2519 | #endif |
| 2520 | if (!retval) { |
| 2521 | if (tty->driver->open) |
| 2522 | retval = tty->driver->open(tty, filp); |
| 2523 | else |
| 2524 | retval = -ENODEV; |
| 2525 | } |
| 2526 | filp->f_flags = saved_flags; |
| 2527 | |
| 2528 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
| 2529 | retval = -EBUSY; |
| 2530 | |
| 2531 | if (retval) { |
| 2532 | #ifdef TTY_DEBUG_HANGUP |
| 2533 | printk(KERN_DEBUG "error %d in opening %s...", retval, |
| 2534 | tty->name); |
| 2535 | #endif |
| 2536 | release_dev(filp); |
| 2537 | if (retval != -ERESTARTSYS) |
| 2538 | return retval; |
| 2539 | if (signal_pending(current)) |
| 2540 | return retval; |
| 2541 | schedule(); |
| 2542 | /* |
| 2543 | * Need to reset f_op in case a hangup happened. |
| 2544 | */ |
| 2545 | if (filp->f_op == &hung_up_tty_fops) |
| 2546 | filp->f_op = &tty_fops; |
| 2547 | goto retry_open; |
| 2548 | } |
| 2549 | if (!noctty && |
| 2550 | current->signal->leader && |
| 2551 | !current->signal->tty && |
| 2552 | tty->session == 0) { |
| 2553 | task_lock(current); |
| 2554 | current->signal->tty = tty; |
| 2555 | task_unlock(current); |
| 2556 | current->signal->tty_old_pgrp = 0; |
| 2557 | tty->session = current->signal->session; |
| 2558 | tty->pgrp = process_group(current); |
| 2559 | } |
| 2560 | return 0; |
| 2561 | } |
| 2562 | |
| 2563 | #ifdef CONFIG_UNIX98_PTYS |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2564 | /** |
| 2565 | * ptmx_open - open a unix 98 pty master |
| 2566 | * @inode: inode of device file |
| 2567 | * @filp: file pointer to tty |
| 2568 | * |
| 2569 | * Allocate a unix98 pty master device from the ptmx driver. |
| 2570 | * |
| 2571 | * Locking: tty_mutex protects theinit_dev work. tty->count should |
| 2572 | protect the rest. |
| 2573 | * allocated_ptys_lock handles the list of free pty numbers |
| 2574 | */ |
| 2575 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2576 | static int ptmx_open(struct inode * inode, struct file * filp) |
| 2577 | { |
| 2578 | struct tty_struct *tty; |
| 2579 | int retval; |
| 2580 | int index; |
| 2581 | int idr_ret; |
| 2582 | |
| 2583 | nonseekable_open(inode, filp); |
| 2584 | |
| 2585 | /* find a device that is not in use. */ |
| 2586 | down(&allocated_ptys_lock); |
| 2587 | if (!idr_pre_get(&allocated_ptys, GFP_KERNEL)) { |
| 2588 | up(&allocated_ptys_lock); |
| 2589 | return -ENOMEM; |
| 2590 | } |
| 2591 | idr_ret = idr_get_new(&allocated_ptys, NULL, &index); |
| 2592 | if (idr_ret < 0) { |
| 2593 | up(&allocated_ptys_lock); |
| 2594 | if (idr_ret == -EAGAIN) |
| 2595 | return -ENOMEM; |
| 2596 | return -EIO; |
| 2597 | } |
| 2598 | if (index >= pty_limit) { |
| 2599 | idr_remove(&allocated_ptys, index); |
| 2600 | up(&allocated_ptys_lock); |
| 2601 | return -EIO; |
| 2602 | } |
| 2603 | up(&allocated_ptys_lock); |
| 2604 | |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2605 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2606 | retval = init_dev(ptm_driver, index, &tty); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 2607 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2608 | |
| 2609 | if (retval) |
| 2610 | goto out; |
| 2611 | |
| 2612 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ |
| 2613 | filp->private_data = tty; |
| 2614 | file_move(filp, &tty->tty_files); |
| 2615 | |
| 2616 | retval = -ENOMEM; |
| 2617 | if (devpts_pty_new(tty->link)) |
| 2618 | goto out1; |
| 2619 | |
| 2620 | check_tty_count(tty, "tty_open"); |
| 2621 | retval = ptm_driver->open(tty, filp); |
| 2622 | if (!retval) |
| 2623 | return 0; |
| 2624 | out1: |
| 2625 | release_dev(filp); |
Paul Fulghum | 9453a5a | 2006-04-10 22:54:18 -0700 | [diff] [blame] | 2626 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2627 | out: |
| 2628 | down(&allocated_ptys_lock); |
| 2629 | idr_remove(&allocated_ptys, index); |
| 2630 | up(&allocated_ptys_lock); |
| 2631 | return retval; |
| 2632 | } |
| 2633 | #endif |
| 2634 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2635 | /** |
| 2636 | * tty_release - vfs callback for close |
| 2637 | * @inode: inode of tty |
| 2638 | * @filp: file pointer for handle to tty |
| 2639 | * |
| 2640 | * Called the last time each file handle is closed that references |
| 2641 | * this tty. There may however be several such references. |
| 2642 | * |
| 2643 | * Locking: |
| 2644 | * Takes bkl. See release_dev |
| 2645 | */ |
| 2646 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2647 | static int tty_release(struct inode * inode, struct file * filp) |
| 2648 | { |
| 2649 | lock_kernel(); |
| 2650 | release_dev(filp); |
| 2651 | unlock_kernel(); |
| 2652 | return 0; |
| 2653 | } |
| 2654 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2655 | /** |
| 2656 | * tty_poll - check tty status |
| 2657 | * @filp: file being polled |
| 2658 | * @wait: poll wait structures to update |
| 2659 | * |
| 2660 | * Call the line discipline polling method to obtain the poll |
| 2661 | * status of the device. |
| 2662 | * |
| 2663 | * Locking: locks called line discipline but ldisc poll method |
| 2664 | * may be re-entered freely by other callers. |
| 2665 | */ |
| 2666 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2667 | static unsigned int tty_poll(struct file * filp, poll_table * wait) |
| 2668 | { |
| 2669 | struct tty_struct * tty; |
| 2670 | struct tty_ldisc *ld; |
| 2671 | int ret = 0; |
| 2672 | |
| 2673 | tty = (struct tty_struct *)filp->private_data; |
| 2674 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_poll")) |
| 2675 | return 0; |
| 2676 | |
| 2677 | ld = tty_ldisc_ref_wait(tty); |
| 2678 | if (ld->poll) |
| 2679 | ret = (ld->poll)(tty, filp, wait); |
| 2680 | tty_ldisc_deref(ld); |
| 2681 | return ret; |
| 2682 | } |
| 2683 | |
| 2684 | static int tty_fasync(int fd, struct file * filp, int on) |
| 2685 | { |
| 2686 | struct tty_struct * tty; |
| 2687 | int retval; |
| 2688 | |
| 2689 | tty = (struct tty_struct *)filp->private_data; |
| 2690 | if (tty_paranoia_check(tty, filp->f_dentry->d_inode, "tty_fasync")) |
| 2691 | return 0; |
| 2692 | |
| 2693 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
| 2694 | if (retval <= 0) |
| 2695 | return retval; |
| 2696 | |
| 2697 | if (on) { |
| 2698 | if (!waitqueue_active(&tty->read_wait)) |
| 2699 | tty->minimum_to_wake = 1; |
| 2700 | retval = f_setown(filp, (-tty->pgrp) ? : current->pid, 0); |
| 2701 | if (retval) |
| 2702 | return retval; |
| 2703 | } else { |
| 2704 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) |
| 2705 | tty->minimum_to_wake = N_TTY_BUF_SIZE; |
| 2706 | } |
| 2707 | return 0; |
| 2708 | } |
| 2709 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2710 | /** |
| 2711 | * tiocsti - fake input character |
| 2712 | * @tty: tty to fake input into |
| 2713 | * @p: pointer to character |
| 2714 | * |
| 2715 | * Fake input to a tty device. Does the neccessary locking and |
| 2716 | * input management. |
| 2717 | * |
| 2718 | * FIXME: does not honour flow control ?? |
| 2719 | * |
| 2720 | * Locking: |
| 2721 | * Called functions take tty_ldisc_lock |
| 2722 | * current->signal->tty check is safe without locks |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 2723 | * |
| 2724 | * FIXME: may race normal receive processing |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2725 | */ |
| 2726 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2727 | static int tiocsti(struct tty_struct *tty, char __user *p) |
| 2728 | { |
| 2729 | char ch, mbz = 0; |
| 2730 | struct tty_ldisc *ld; |
| 2731 | |
| 2732 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
| 2733 | return -EPERM; |
| 2734 | if (get_user(ch, p)) |
| 2735 | return -EFAULT; |
| 2736 | ld = tty_ldisc_ref_wait(tty); |
| 2737 | ld->receive_buf(tty, &ch, &mbz, 1); |
| 2738 | tty_ldisc_deref(ld); |
| 2739 | return 0; |
| 2740 | } |
| 2741 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2742 | /** |
| 2743 | * tiocgwinsz - implement window query ioctl |
| 2744 | * @tty; tty |
| 2745 | * @arg: user buffer for result |
| 2746 | * |
Alan Cox | 808a0d3 | 2006-09-29 02:00:40 -0700 | [diff] [blame] | 2747 | * Copies the kernel idea of the window size into the user buffer. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2748 | * |
Alan Cox | 808a0d3 | 2006-09-29 02:00:40 -0700 | [diff] [blame] | 2749 | * Locking: tty->termios_sem is taken to ensure the winsize data |
| 2750 | * is consistent. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2751 | */ |
| 2752 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2753 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user * arg) |
| 2754 | { |
Alan Cox | 808a0d3 | 2006-09-29 02:00:40 -0700 | [diff] [blame] | 2755 | int err; |
| 2756 | |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 2757 | mutex_lock(&tty->termios_mutex); |
Alan Cox | 808a0d3 | 2006-09-29 02:00:40 -0700 | [diff] [blame] | 2758 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 2759 | mutex_unlock(&tty->termios_mutex); |
Alan Cox | 808a0d3 | 2006-09-29 02:00:40 -0700 | [diff] [blame] | 2760 | |
| 2761 | return err ? -EFAULT: 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2762 | } |
| 2763 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2764 | /** |
| 2765 | * tiocswinsz - implement window size set ioctl |
| 2766 | * @tty; tty |
| 2767 | * @arg: user buffer for result |
| 2768 | * |
| 2769 | * Copies the user idea of the window size to the kernel. Traditionally |
| 2770 | * this is just advisory information but for the Linux console it |
| 2771 | * actually has driver level meaning and triggers a VC resize. |
| 2772 | * |
| 2773 | * Locking: |
Alan Cox | ca9bda0 | 2006-09-29 02:00:03 -0700 | [diff] [blame] | 2774 | * Called function use the console_sem is used to ensure we do |
| 2775 | * not try and resize the console twice at once. |
| 2776 | * The tty->termios_sem is used to ensure we don't double |
| 2777 | * resize and get confused. Lock order - tty->termios.sem before |
| 2778 | * console sem |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2779 | */ |
| 2780 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2781 | static int tiocswinsz(struct tty_struct *tty, struct tty_struct *real_tty, |
| 2782 | struct winsize __user * arg) |
| 2783 | { |
| 2784 | struct winsize tmp_ws; |
| 2785 | |
| 2786 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
| 2787 | return -EFAULT; |
Alan Cox | ca9bda0 | 2006-09-29 02:00:03 -0700 | [diff] [blame] | 2788 | |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 2789 | mutex_lock(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2790 | if (!memcmp(&tmp_ws, &tty->winsize, sizeof(*arg))) |
Alan Cox | ca9bda0 | 2006-09-29 02:00:03 -0700 | [diff] [blame] | 2791 | goto done; |
| 2792 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2793 | #ifdef CONFIG_VT |
| 2794 | if (tty->driver->type == TTY_DRIVER_TYPE_CONSOLE) { |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 2795 | if (vc_lock_resize(tty->driver_data, tmp_ws.ws_col, |
| 2796 | tmp_ws.ws_row)) { |
| 2797 | mutex_unlock(&tty->termios_mutex); |
Alan Cox | ca9bda0 | 2006-09-29 02:00:03 -0700 | [diff] [blame] | 2798 | return -ENXIO; |
| 2799 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2800 | } |
| 2801 | #endif |
| 2802 | if (tty->pgrp > 0) |
| 2803 | kill_pg(tty->pgrp, SIGWINCH, 1); |
| 2804 | if ((real_tty->pgrp != tty->pgrp) && (real_tty->pgrp > 0)) |
| 2805 | kill_pg(real_tty->pgrp, SIGWINCH, 1); |
| 2806 | tty->winsize = tmp_ws; |
| 2807 | real_tty->winsize = tmp_ws; |
Alan Cox | ca9bda0 | 2006-09-29 02:00:03 -0700 | [diff] [blame] | 2808 | done: |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 2809 | mutex_unlock(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2810 | return 0; |
| 2811 | } |
| 2812 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2813 | /** |
| 2814 | * tioccons - allow admin to move logical console |
| 2815 | * @file: the file to become console |
| 2816 | * |
| 2817 | * Allow the adminstrator to move the redirected console device |
| 2818 | * |
| 2819 | * Locking: uses redirect_lock to guard the redirect information |
| 2820 | */ |
| 2821 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2822 | static int tioccons(struct file *file) |
| 2823 | { |
| 2824 | if (!capable(CAP_SYS_ADMIN)) |
| 2825 | return -EPERM; |
| 2826 | if (file->f_op->write == redirected_tty_write) { |
| 2827 | struct file *f; |
| 2828 | spin_lock(&redirect_lock); |
| 2829 | f = redirect; |
| 2830 | redirect = NULL; |
| 2831 | spin_unlock(&redirect_lock); |
| 2832 | if (f) |
| 2833 | fput(f); |
| 2834 | return 0; |
| 2835 | } |
| 2836 | spin_lock(&redirect_lock); |
| 2837 | if (redirect) { |
| 2838 | spin_unlock(&redirect_lock); |
| 2839 | return -EBUSY; |
| 2840 | } |
| 2841 | get_file(file); |
| 2842 | redirect = file; |
| 2843 | spin_unlock(&redirect_lock); |
| 2844 | return 0; |
| 2845 | } |
| 2846 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2847 | /** |
| 2848 | * fionbio - non blocking ioctl |
| 2849 | * @file: file to set blocking value |
| 2850 | * @p: user parameter |
| 2851 | * |
| 2852 | * Historical tty interfaces had a blocking control ioctl before |
| 2853 | * the generic functionality existed. This piece of history is preserved |
| 2854 | * in the expected tty API of posix OS's. |
| 2855 | * |
| 2856 | * Locking: none, the open fle handle ensures it won't go away. |
| 2857 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2858 | |
| 2859 | static int fionbio(struct file *file, int __user *p) |
| 2860 | { |
| 2861 | int nonblock; |
| 2862 | |
| 2863 | if (get_user(nonblock, p)) |
| 2864 | return -EFAULT; |
| 2865 | |
| 2866 | if (nonblock) |
| 2867 | file->f_flags |= O_NONBLOCK; |
| 2868 | else |
| 2869 | file->f_flags &= ~O_NONBLOCK; |
| 2870 | return 0; |
| 2871 | } |
| 2872 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2873 | /** |
| 2874 | * tiocsctty - set controlling tty |
| 2875 | * @tty: tty structure |
| 2876 | * @arg: user argument |
| 2877 | * |
| 2878 | * This ioctl is used to manage job control. It permits a session |
| 2879 | * leader to set this tty as the controlling tty for the session. |
| 2880 | * |
| 2881 | * Locking: |
| 2882 | * Takes tasklist lock internally to walk sessions |
| 2883 | * Takes task_lock() when updating signal->tty |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 2884 | * Takes tty_mutex() to protect tty instance |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2885 | * |
| 2886 | */ |
| 2887 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2888 | static int tiocsctty(struct tty_struct *tty, int arg) |
| 2889 | { |
Ingo Molnar | 36c8b58 | 2006-07-03 00:25:41 -0700 | [diff] [blame] | 2890 | struct task_struct *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2891 | |
| 2892 | if (current->signal->leader && |
| 2893 | (current->signal->session == tty->session)) |
| 2894 | return 0; |
| 2895 | /* |
| 2896 | * The process must be a session leader and |
| 2897 | * not have a controlling tty already. |
| 2898 | */ |
| 2899 | if (!current->signal->leader || current->signal->tty) |
| 2900 | return -EPERM; |
| 2901 | if (tty->session > 0) { |
| 2902 | /* |
| 2903 | * This tty is already the controlling |
| 2904 | * tty for another session group! |
| 2905 | */ |
| 2906 | if ((arg == 1) && capable(CAP_SYS_ADMIN)) { |
| 2907 | /* |
| 2908 | * Steal it away |
| 2909 | */ |
| 2910 | |
| 2911 | read_lock(&tasklist_lock); |
| 2912 | do_each_task_pid(tty->session, PIDTYPE_SID, p) { |
| 2913 | p->signal->tty = NULL; |
| 2914 | } while_each_task_pid(tty->session, PIDTYPE_SID, p); |
| 2915 | read_unlock(&tasklist_lock); |
| 2916 | } else |
| 2917 | return -EPERM; |
| 2918 | } |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 2919 | mutex_lock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2920 | task_lock(current); |
| 2921 | current->signal->tty = tty; |
| 2922 | task_unlock(current); |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 2923 | mutex_unlock(&tty_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2924 | current->signal->tty_old_pgrp = 0; |
| 2925 | tty->session = current->signal->session; |
| 2926 | tty->pgrp = process_group(current); |
| 2927 | return 0; |
| 2928 | } |
| 2929 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2930 | /** |
| 2931 | * tiocgpgrp - get process group |
| 2932 | * @tty: tty passed by user |
| 2933 | * @real_tty: tty side of the tty pased by the user if a pty else the tty |
| 2934 | * @p: returned pid |
| 2935 | * |
| 2936 | * Obtain the process group of the tty. If there is no process group |
| 2937 | * return an error. |
| 2938 | * |
| 2939 | * Locking: none. Reference to ->signal->tty is safe. |
| 2940 | */ |
| 2941 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2942 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| 2943 | { |
| 2944 | /* |
| 2945 | * (tty == real_tty) is a cheap way of |
| 2946 | * testing if the tty is NOT a master pty. |
| 2947 | */ |
| 2948 | if (tty == real_tty && current->signal->tty != real_tty) |
| 2949 | return -ENOTTY; |
| 2950 | return put_user(real_tty->pgrp, p); |
| 2951 | } |
| 2952 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2953 | /** |
| 2954 | * tiocspgrp - attempt to set process group |
| 2955 | * @tty: tty passed by user |
| 2956 | * @real_tty: tty side device matching tty passed by user |
| 2957 | * @p: pid pointer |
| 2958 | * |
| 2959 | * Set the process group of the tty to the session passed. Only |
| 2960 | * permitted where the tty session is our session. |
| 2961 | * |
| 2962 | * Locking: None |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2963 | */ |
| 2964 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2965 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| 2966 | { |
| 2967 | pid_t pgrp; |
| 2968 | int retval = tty_check_change(real_tty); |
| 2969 | |
| 2970 | if (retval == -EIO) |
| 2971 | return -ENOTTY; |
| 2972 | if (retval) |
| 2973 | return retval; |
| 2974 | if (!current->signal->tty || |
| 2975 | (current->signal->tty != real_tty) || |
| 2976 | (real_tty->session != current->signal->session)) |
| 2977 | return -ENOTTY; |
| 2978 | if (get_user(pgrp, p)) |
| 2979 | return -EFAULT; |
| 2980 | if (pgrp < 0) |
| 2981 | return -EINVAL; |
| 2982 | if (session_of_pgrp(pgrp) != current->signal->session) |
| 2983 | return -EPERM; |
| 2984 | real_tty->pgrp = pgrp; |
| 2985 | return 0; |
| 2986 | } |
| 2987 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 2988 | /** |
| 2989 | * tiocgsid - get session id |
| 2990 | * @tty: tty passed by user |
| 2991 | * @real_tty: tty side of the tty pased by the user if a pty else the tty |
| 2992 | * @p: pointer to returned session id |
| 2993 | * |
| 2994 | * Obtain the session id of the tty. If there is no session |
| 2995 | * return an error. |
| 2996 | * |
| 2997 | * Locking: none. Reference to ->signal->tty is safe. |
| 2998 | */ |
| 2999 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3000 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
| 3001 | { |
| 3002 | /* |
| 3003 | * (tty == real_tty) is a cheap way of |
| 3004 | * testing if the tty is NOT a master pty. |
| 3005 | */ |
| 3006 | if (tty == real_tty && current->signal->tty != real_tty) |
| 3007 | return -ENOTTY; |
| 3008 | if (real_tty->session <= 0) |
| 3009 | return -ENOTTY; |
| 3010 | return put_user(real_tty->session, p); |
| 3011 | } |
| 3012 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3013 | /** |
| 3014 | * tiocsetd - set line discipline |
| 3015 | * @tty: tty device |
| 3016 | * @p: pointer to user data |
| 3017 | * |
| 3018 | * Set the line discipline according to user request. |
| 3019 | * |
| 3020 | * Locking: see tty_set_ldisc, this function is just a helper |
| 3021 | */ |
| 3022 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3023 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
| 3024 | { |
| 3025 | int ldisc; |
| 3026 | |
| 3027 | if (get_user(ldisc, p)) |
| 3028 | return -EFAULT; |
| 3029 | return tty_set_ldisc(tty, ldisc); |
| 3030 | } |
| 3031 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3032 | /** |
| 3033 | * send_break - performed time break |
| 3034 | * @tty: device to break on |
| 3035 | * @duration: timeout in mS |
| 3036 | * |
| 3037 | * Perform a timed break on hardware that lacks its own driver level |
| 3038 | * timed break functionality. |
| 3039 | * |
| 3040 | * Locking: |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 3041 | * atomic_write_lock serializes |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3042 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3043 | */ |
| 3044 | |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 3045 | static int send_break(struct tty_struct *tty, unsigned int duration) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3046 | { |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 3047 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) |
| 3048 | return -EINTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3049 | tty->driver->break_ctl(tty, -1); |
| 3050 | if (!signal_pending(current)) { |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 3051 | msleep_interruptible(duration); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3052 | } |
| 3053 | tty->driver->break_ctl(tty, 0); |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 3054 | mutex_unlock(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3055 | if (signal_pending(current)) |
| 3056 | return -EINTR; |
| 3057 | return 0; |
| 3058 | } |
| 3059 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3060 | /** |
| 3061 | * tiocmget - get modem status |
| 3062 | * @tty: tty device |
| 3063 | * @file: user file pointer |
| 3064 | * @p: pointer to result |
| 3065 | * |
| 3066 | * Obtain the modem status bits from the tty driver if the feature |
| 3067 | * is supported. Return -EINVAL if it is not available. |
| 3068 | * |
| 3069 | * Locking: none (up to the driver) |
| 3070 | */ |
| 3071 | |
| 3072 | static int tty_tiocmget(struct tty_struct *tty, struct file *file, int __user *p) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3073 | { |
| 3074 | int retval = -EINVAL; |
| 3075 | |
| 3076 | if (tty->driver->tiocmget) { |
| 3077 | retval = tty->driver->tiocmget(tty, file); |
| 3078 | |
| 3079 | if (retval >= 0) |
| 3080 | retval = put_user(retval, p); |
| 3081 | } |
| 3082 | return retval; |
| 3083 | } |
| 3084 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3085 | /** |
| 3086 | * tiocmset - set modem status |
| 3087 | * @tty: tty device |
| 3088 | * @file: user file pointer |
| 3089 | * @cmd: command - clear bits, set bits or set all |
| 3090 | * @p: pointer to desired bits |
| 3091 | * |
| 3092 | * Set the modem status bits from the tty driver if the feature |
| 3093 | * is supported. Return -EINVAL if it is not available. |
| 3094 | * |
| 3095 | * Locking: none (up to the driver) |
| 3096 | */ |
| 3097 | |
| 3098 | static int tty_tiocmset(struct tty_struct *tty, struct file *file, unsigned int cmd, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3099 | unsigned __user *p) |
| 3100 | { |
| 3101 | int retval = -EINVAL; |
| 3102 | |
| 3103 | if (tty->driver->tiocmset) { |
| 3104 | unsigned int set, clear, val; |
| 3105 | |
| 3106 | retval = get_user(val, p); |
| 3107 | if (retval) |
| 3108 | return retval; |
| 3109 | |
| 3110 | set = clear = 0; |
| 3111 | switch (cmd) { |
| 3112 | case TIOCMBIS: |
| 3113 | set = val; |
| 3114 | break; |
| 3115 | case TIOCMBIC: |
| 3116 | clear = val; |
| 3117 | break; |
| 3118 | case TIOCMSET: |
| 3119 | set = val; |
| 3120 | clear = ~val; |
| 3121 | break; |
| 3122 | } |
| 3123 | |
| 3124 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
| 3125 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
| 3126 | |
| 3127 | retval = tty->driver->tiocmset(tty, file, set, clear); |
| 3128 | } |
| 3129 | return retval; |
| 3130 | } |
| 3131 | |
| 3132 | /* |
| 3133 | * Split this up, as gcc can choke on it otherwise.. |
| 3134 | */ |
| 3135 | int tty_ioctl(struct inode * inode, struct file * file, |
| 3136 | unsigned int cmd, unsigned long arg) |
| 3137 | { |
| 3138 | struct tty_struct *tty, *real_tty; |
| 3139 | void __user *p = (void __user *)arg; |
| 3140 | int retval; |
| 3141 | struct tty_ldisc *ld; |
| 3142 | |
| 3143 | tty = (struct tty_struct *)file->private_data; |
| 3144 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
| 3145 | return -EINVAL; |
| 3146 | |
Alan Cox | 2829823 | 2006-09-29 02:00:58 -0700 | [diff] [blame] | 3147 | /* CHECKME: is this safe as one end closes ? */ |
| 3148 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3149 | real_tty = tty; |
| 3150 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
| 3151 | tty->driver->subtype == PTY_TYPE_MASTER) |
| 3152 | real_tty = tty->link; |
| 3153 | |
| 3154 | /* |
| 3155 | * Break handling by driver |
| 3156 | */ |
| 3157 | if (!tty->driver->break_ctl) { |
| 3158 | switch(cmd) { |
| 3159 | case TIOCSBRK: |
| 3160 | case TIOCCBRK: |
| 3161 | if (tty->driver->ioctl) |
| 3162 | return tty->driver->ioctl(tty, file, cmd, arg); |
| 3163 | return -EINVAL; |
| 3164 | |
| 3165 | /* These two ioctl's always return success; even if */ |
| 3166 | /* the driver doesn't support them. */ |
| 3167 | case TCSBRK: |
| 3168 | case TCSBRKP: |
| 3169 | if (!tty->driver->ioctl) |
| 3170 | return 0; |
| 3171 | retval = tty->driver->ioctl(tty, file, cmd, arg); |
| 3172 | if (retval == -ENOIOCTLCMD) |
| 3173 | retval = 0; |
| 3174 | return retval; |
| 3175 | } |
| 3176 | } |
| 3177 | |
| 3178 | /* |
| 3179 | * Factor out some common prep work |
| 3180 | */ |
| 3181 | switch (cmd) { |
| 3182 | case TIOCSETD: |
| 3183 | case TIOCSBRK: |
| 3184 | case TIOCCBRK: |
| 3185 | case TCSBRK: |
| 3186 | case TCSBRKP: |
| 3187 | retval = tty_check_change(tty); |
| 3188 | if (retval) |
| 3189 | return retval; |
| 3190 | if (cmd != TIOCCBRK) { |
| 3191 | tty_wait_until_sent(tty, 0); |
| 3192 | if (signal_pending(current)) |
| 3193 | return -EINTR; |
| 3194 | } |
| 3195 | break; |
| 3196 | } |
| 3197 | |
| 3198 | switch (cmd) { |
| 3199 | case TIOCSTI: |
| 3200 | return tiocsti(tty, p); |
| 3201 | case TIOCGWINSZ: |
| 3202 | return tiocgwinsz(tty, p); |
| 3203 | case TIOCSWINSZ: |
| 3204 | return tiocswinsz(tty, real_tty, p); |
| 3205 | case TIOCCONS: |
| 3206 | return real_tty!=tty ? -EINVAL : tioccons(file); |
| 3207 | case FIONBIO: |
| 3208 | return fionbio(file, p); |
| 3209 | case TIOCEXCL: |
| 3210 | set_bit(TTY_EXCLUSIVE, &tty->flags); |
| 3211 | return 0; |
| 3212 | case TIOCNXCL: |
| 3213 | clear_bit(TTY_EXCLUSIVE, &tty->flags); |
| 3214 | return 0; |
| 3215 | case TIOCNOTTY: |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3216 | /* FIXME: taks lock or tty_mutex ? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3217 | if (current->signal->tty != tty) |
| 3218 | return -ENOTTY; |
| 3219 | if (current->signal->leader) |
| 3220 | disassociate_ctty(0); |
| 3221 | task_lock(current); |
| 3222 | current->signal->tty = NULL; |
| 3223 | task_unlock(current); |
| 3224 | return 0; |
| 3225 | case TIOCSCTTY: |
| 3226 | return tiocsctty(tty, arg); |
| 3227 | case TIOCGPGRP: |
| 3228 | return tiocgpgrp(tty, real_tty, p); |
| 3229 | case TIOCSPGRP: |
| 3230 | return tiocspgrp(tty, real_tty, p); |
| 3231 | case TIOCGSID: |
| 3232 | return tiocgsid(tty, real_tty, p); |
| 3233 | case TIOCGETD: |
| 3234 | /* FIXME: check this is ok */ |
| 3235 | return put_user(tty->ldisc.num, (int __user *)p); |
| 3236 | case TIOCSETD: |
| 3237 | return tiocsetd(tty, p); |
| 3238 | #ifdef CONFIG_VT |
| 3239 | case TIOCLINUX: |
| 3240 | return tioclinux(tty, arg); |
| 3241 | #endif |
| 3242 | /* |
| 3243 | * Break handling |
| 3244 | */ |
| 3245 | case TIOCSBRK: /* Turn break on, unconditionally */ |
| 3246 | tty->driver->break_ctl(tty, -1); |
| 3247 | return 0; |
| 3248 | |
| 3249 | case TIOCCBRK: /* Turn break off, unconditionally */ |
| 3250 | tty->driver->break_ctl(tty, 0); |
| 3251 | return 0; |
| 3252 | case TCSBRK: /* SVID version: non-zero arg --> no break */ |
Paul Fulghum | 283fef5 | 2006-06-27 02:54:00 -0700 | [diff] [blame] | 3253 | /* non-zero arg means wait for all output data |
| 3254 | * to be sent (performed above) but don't send break. |
| 3255 | * This is used by the tcdrain() termios function. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3256 | */ |
| 3257 | if (!arg) |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 3258 | return send_break(tty, 250); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3259 | return 0; |
| 3260 | case TCSBRKP: /* support for POSIX tcsendbreak() */ |
Domen Puncer | b20f3ae | 2005-06-25 14:58:42 -0700 | [diff] [blame] | 3261 | return send_break(tty, arg ? arg*100 : 250); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3262 | |
| 3263 | case TIOCMGET: |
| 3264 | return tty_tiocmget(tty, file, p); |
| 3265 | |
| 3266 | case TIOCMSET: |
| 3267 | case TIOCMBIC: |
| 3268 | case TIOCMBIS: |
| 3269 | return tty_tiocmset(tty, file, cmd, p); |
| 3270 | } |
| 3271 | if (tty->driver->ioctl) { |
| 3272 | retval = (tty->driver->ioctl)(tty, file, cmd, arg); |
| 3273 | if (retval != -ENOIOCTLCMD) |
| 3274 | return retval; |
| 3275 | } |
| 3276 | ld = tty_ldisc_ref_wait(tty); |
| 3277 | retval = -EINVAL; |
| 3278 | if (ld->ioctl) { |
| 3279 | retval = ld->ioctl(tty, file, cmd, arg); |
| 3280 | if (retval == -ENOIOCTLCMD) |
| 3281 | retval = -EINVAL; |
| 3282 | } |
| 3283 | tty_ldisc_deref(ld); |
| 3284 | return retval; |
| 3285 | } |
| 3286 | |
| 3287 | |
| 3288 | /* |
| 3289 | * This implements the "Secure Attention Key" --- the idea is to |
| 3290 | * prevent trojan horses by killing all processes associated with this |
| 3291 | * tty when the user hits the "Secure Attention Key". Required for |
| 3292 | * super-paranoid applications --- see the Orange Book for more details. |
| 3293 | * |
| 3294 | * This code could be nicer; ideally it should send a HUP, wait a few |
| 3295 | * seconds, then send a INT, and then a KILL signal. But you then |
| 3296 | * have to coordinate with the init process, since all processes associated |
| 3297 | * with the current tty must be dead before the new getty is allowed |
| 3298 | * to spawn. |
| 3299 | * |
| 3300 | * Now, if it would be correct ;-/ The current code has a nasty hole - |
| 3301 | * it doesn't catch files in flight. We may send the descriptor to ourselves |
| 3302 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. |
| 3303 | * |
| 3304 | * Nasty bug: do_SAK is being called in interrupt context. This can |
| 3305 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 |
| 3306 | */ |
| 3307 | static void __do_SAK(void *arg) |
| 3308 | { |
| 3309 | #ifdef TTY_SOFT_SAK |
| 3310 | tty_hangup(tty); |
| 3311 | #else |
| 3312 | struct tty_struct *tty = arg; |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 3313 | struct task_struct *g, *p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3314 | int session; |
| 3315 | int i; |
| 3316 | struct file *filp; |
| 3317 | struct tty_ldisc *disc; |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 3318 | struct fdtable *fdt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3319 | |
| 3320 | if (!tty) |
| 3321 | return; |
| 3322 | session = tty->session; |
| 3323 | |
| 3324 | /* We don't want an ldisc switch during this */ |
| 3325 | disc = tty_ldisc_ref(tty); |
| 3326 | if (disc && disc->flush_buffer) |
| 3327 | disc->flush_buffer(tty); |
| 3328 | tty_ldisc_deref(disc); |
| 3329 | |
| 3330 | if (tty->driver->flush_buffer) |
| 3331 | tty->driver->flush_buffer(tty); |
| 3332 | |
| 3333 | read_lock(&tasklist_lock); |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 3334 | /* Kill the entire session */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3335 | do_each_task_pid(session, PIDTYPE_SID, p) { |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 3336 | printk(KERN_NOTICE "SAK: killed process %d" |
| 3337 | " (%s): p->signal->session==tty->session\n", |
| 3338 | p->pid, p->comm); |
| 3339 | send_sig(SIGKILL, p, 1); |
| 3340 | } while_each_task_pid(session, PIDTYPE_SID, p); |
| 3341 | /* Now kill any processes that happen to have the |
| 3342 | * tty open. |
| 3343 | */ |
| 3344 | do_each_thread(g, p) { |
| 3345 | if (p->signal->tty == tty) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3346 | printk(KERN_NOTICE "SAK: killed process %d" |
| 3347 | " (%s): p->signal->session==tty->session\n", |
| 3348 | p->pid, p->comm); |
| 3349 | send_sig(SIGKILL, p, 1); |
| 3350 | continue; |
| 3351 | } |
| 3352 | task_lock(p); |
| 3353 | if (p->files) { |
Dipankar Sarma | ca99c1d | 2006-04-18 22:21:46 -0700 | [diff] [blame] | 3354 | /* |
| 3355 | * We don't take a ref to the file, so we must |
| 3356 | * hold ->file_lock instead. |
| 3357 | */ |
| 3358 | spin_lock(&p->files->file_lock); |
Dipankar Sarma | badf166 | 2005-09-09 13:04:10 -0700 | [diff] [blame] | 3359 | fdt = files_fdtable(p->files); |
| 3360 | for (i=0; i < fdt->max_fds; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3361 | filp = fcheck_files(p->files, i); |
| 3362 | if (!filp) |
| 3363 | continue; |
| 3364 | if (filp->f_op->read == tty_read && |
| 3365 | filp->private_data == tty) { |
| 3366 | printk(KERN_NOTICE "SAK: killed process %d" |
| 3367 | " (%s): fd#%d opened to the tty\n", |
| 3368 | p->pid, p->comm, i); |
Eric W. Biederman | 20ac943 | 2006-04-13 04:49:07 -0600 | [diff] [blame] | 3369 | force_sig(SIGKILL, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3370 | break; |
| 3371 | } |
| 3372 | } |
Dipankar Sarma | ca99c1d | 2006-04-18 22:21:46 -0700 | [diff] [blame] | 3373 | spin_unlock(&p->files->file_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3374 | } |
| 3375 | task_unlock(p); |
Eric W. Biederman | 652486f | 2006-03-28 16:11:02 -0800 | [diff] [blame] | 3376 | } while_each_thread(g, p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3377 | read_unlock(&tasklist_lock); |
| 3378 | #endif |
| 3379 | } |
| 3380 | |
| 3381 | /* |
| 3382 | * The tq handling here is a little racy - tty->SAK_work may already be queued. |
| 3383 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, |
| 3384 | * the values which we write to it will be identical to the values which it |
| 3385 | * already has. --akpm |
| 3386 | */ |
| 3387 | void do_SAK(struct tty_struct *tty) |
| 3388 | { |
| 3389 | if (!tty) |
| 3390 | return; |
| 3391 | PREPARE_WORK(&tty->SAK_work, __do_SAK, tty); |
| 3392 | schedule_work(&tty->SAK_work); |
| 3393 | } |
| 3394 | |
| 3395 | EXPORT_SYMBOL(do_SAK); |
| 3396 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3397 | /** |
| 3398 | * flush_to_ldisc |
| 3399 | * @private_: tty structure passed from work queue. |
| 3400 | * |
| 3401 | * This routine is called out of the software interrupt to flush data |
| 3402 | * from the buffer chain to the line discipline. |
| 3403 | * |
| 3404 | * Locking: holds tty->buf.lock to guard buffer list. Drops the lock |
| 3405 | * while invoking the line discipline receive_buf method. The |
| 3406 | * receive_buf method is single threaded for each tty instance. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3407 | */ |
| 3408 | |
| 3409 | static void flush_to_ldisc(void *private_) |
| 3410 | { |
| 3411 | struct tty_struct *tty = (struct tty_struct *) private_; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3412 | unsigned long flags; |
| 3413 | struct tty_ldisc *disc; |
Paul Fulghum | 2c3bb20 | 2006-06-28 04:26:48 -0700 | [diff] [blame] | 3414 | struct tty_buffer *tbuf, *head; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 3415 | char *char_buf; |
| 3416 | unsigned char *flag_buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3417 | |
| 3418 | disc = tty_ldisc_ref(tty); |
| 3419 | if (disc == NULL) /* !TTY_LDISC */ |
| 3420 | return; |
| 3421 | |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 3422 | spin_lock_irqsave(&tty->buf.lock, flags); |
Paul Fulghum | 2c3bb20 | 2006-06-28 04:26:48 -0700 | [diff] [blame] | 3423 | head = tty->buf.head; |
| 3424 | if (head != NULL) { |
| 3425 | tty->buf.head = NULL; |
| 3426 | for (;;) { |
| 3427 | int count = head->commit - head->read; |
| 3428 | if (!count) { |
| 3429 | if (head->next == NULL) |
| 3430 | break; |
| 3431 | tbuf = head; |
| 3432 | head = head->next; |
| 3433 | tty_buffer_free(tty, tbuf); |
| 3434 | continue; |
| 3435 | } |
| 3436 | if (!tty->receive_room) { |
| 3437 | schedule_delayed_work(&tty->buf.work, 1); |
| 3438 | break; |
| 3439 | } |
| 3440 | if (count > tty->receive_room) |
| 3441 | count = tty->receive_room; |
| 3442 | char_buf = head->char_buf_ptr + head->read; |
| 3443 | flag_buf = head->flag_buf_ptr + head->read; |
| 3444 | head->read += count; |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 3445 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
| 3446 | disc->receive_buf(tty, char_buf, flag_buf, count); |
| 3447 | spin_lock_irqsave(&tty->buf.lock, flags); |
| 3448 | } |
Paul Fulghum | 2c3bb20 | 2006-06-28 04:26:48 -0700 | [diff] [blame] | 3449 | tty->buf.head = head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3450 | } |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 3451 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
Paul Fulghum | 817d6d3 | 2006-06-28 04:26:47 -0700 | [diff] [blame] | 3452 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3453 | tty_ldisc_deref(disc); |
| 3454 | } |
| 3455 | |
| 3456 | /* |
| 3457 | * Routine which returns the baud rate of the tty |
| 3458 | * |
| 3459 | * Note that the baud_table needs to be kept in sync with the |
| 3460 | * include/asm/termbits.h file. |
| 3461 | */ |
| 3462 | static int baud_table[] = { |
| 3463 | 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, |
| 3464 | 9600, 19200, 38400, 57600, 115200, 230400, 460800, |
| 3465 | #ifdef __sparc__ |
| 3466 | 76800, 153600, 307200, 614400, 921600 |
| 3467 | #else |
| 3468 | 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, |
| 3469 | 2500000, 3000000, 3500000, 4000000 |
| 3470 | #endif |
| 3471 | }; |
| 3472 | |
| 3473 | static int n_baud_table = ARRAY_SIZE(baud_table); |
| 3474 | |
| 3475 | /** |
| 3476 | * tty_termios_baud_rate |
| 3477 | * @termios: termios structure |
| 3478 | * |
| 3479 | * Convert termios baud rate data into a speed. This should be called |
| 3480 | * with the termios lock held if this termios is a terminal termios |
| 3481 | * structure. May change the termios data. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3482 | * |
| 3483 | * Locking: none |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3484 | */ |
| 3485 | |
| 3486 | int tty_termios_baud_rate(struct termios *termios) |
| 3487 | { |
| 3488 | unsigned int cbaud; |
| 3489 | |
| 3490 | cbaud = termios->c_cflag & CBAUD; |
| 3491 | |
| 3492 | if (cbaud & CBAUDEX) { |
| 3493 | cbaud &= ~CBAUDEX; |
| 3494 | |
| 3495 | if (cbaud < 1 || cbaud + 15 > n_baud_table) |
| 3496 | termios->c_cflag &= ~CBAUDEX; |
| 3497 | else |
| 3498 | cbaud += 15; |
| 3499 | } |
| 3500 | return baud_table[cbaud]; |
| 3501 | } |
| 3502 | |
| 3503 | EXPORT_SYMBOL(tty_termios_baud_rate); |
| 3504 | |
| 3505 | /** |
| 3506 | * tty_get_baud_rate - get tty bit rates |
| 3507 | * @tty: tty to query |
| 3508 | * |
| 3509 | * Returns the baud rate as an integer for this terminal. The |
| 3510 | * termios lock must be held by the caller and the terminal bit |
| 3511 | * flags may be updated. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3512 | * |
| 3513 | * Locking: none |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3514 | */ |
| 3515 | |
| 3516 | int tty_get_baud_rate(struct tty_struct *tty) |
| 3517 | { |
| 3518 | int baud = tty_termios_baud_rate(tty->termios); |
| 3519 | |
| 3520 | if (baud == 38400 && tty->alt_speed) { |
| 3521 | if (!tty->warned) { |
| 3522 | printk(KERN_WARNING "Use of setserial/setrocket to " |
| 3523 | "set SPD_* flags is deprecated\n"); |
| 3524 | tty->warned = 1; |
| 3525 | } |
| 3526 | baud = tty->alt_speed; |
| 3527 | } |
| 3528 | |
| 3529 | return baud; |
| 3530 | } |
| 3531 | |
| 3532 | EXPORT_SYMBOL(tty_get_baud_rate); |
| 3533 | |
| 3534 | /** |
| 3535 | * tty_flip_buffer_push - terminal |
| 3536 | * @tty: tty to push |
| 3537 | * |
| 3538 | * Queue a push of the terminal flip buffers to the line discipline. This |
| 3539 | * function must not be called from IRQ context if tty->low_latency is set. |
| 3540 | * |
| 3541 | * In the event of the queue being busy for flipping the work will be |
| 3542 | * held off and retried later. |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3543 | * |
| 3544 | * Locking: tty buffer lock. Driver locks in low latency mode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3545 | */ |
| 3546 | |
| 3547 | void tty_flip_buffer_push(struct tty_struct *tty) |
| 3548 | { |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 3549 | unsigned long flags; |
| 3550 | spin_lock_irqsave(&tty->buf.lock, flags); |
Paul Fulghum | 33b37a3 | 2006-06-28 04:26:49 -0700 | [diff] [blame] | 3551 | if (tty->buf.tail != NULL) |
Paul Fulghum | 8977d92 | 2006-02-10 01:51:14 -0800 | [diff] [blame] | 3552 | tty->buf.tail->commit = tty->buf.tail->used; |
Paul Fulghum | 808249c | 2006-02-03 03:04:41 -0800 | [diff] [blame] | 3553 | spin_unlock_irqrestore(&tty->buf.lock, flags); |
| 3554 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3555 | if (tty->low_latency) |
| 3556 | flush_to_ldisc((void *) tty); |
| 3557 | else |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 3558 | schedule_delayed_work(&tty->buf.work, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3559 | } |
| 3560 | |
| 3561 | EXPORT_SYMBOL(tty_flip_buffer_push); |
| 3562 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 3563 | |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3564 | /** |
| 3565 | * initialize_tty_struct |
| 3566 | * @tty: tty to initialize |
| 3567 | * |
| 3568 | * This subroutine initializes a tty structure that has been newly |
| 3569 | * allocated. |
| 3570 | * |
| 3571 | * Locking: none - tty in question must not be exposed at this point |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3572 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3573 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3574 | static void initialize_tty_struct(struct tty_struct *tty) |
| 3575 | { |
| 3576 | memset(tty, 0, sizeof(struct tty_struct)); |
| 3577 | tty->magic = TTY_MAGIC; |
| 3578 | tty_ldisc_assign(tty, tty_ldisc_get(N_TTY)); |
| 3579 | tty->pgrp = -1; |
| 3580 | tty->overrun_time = jiffies; |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 3581 | tty->buf.head = tty->buf.tail = NULL; |
| 3582 | tty_buffer_init(tty); |
| 3583 | INIT_WORK(&tty->buf.work, flush_to_ldisc, tty); |
| 3584 | init_MUTEX(&tty->buf.pty_sem); |
Arjan van de Ven | 5785c95 | 2006-09-29 02:00:43 -0700 | [diff] [blame] | 3585 | mutex_init(&tty->termios_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3586 | init_waitqueue_head(&tty->write_wait); |
| 3587 | init_waitqueue_head(&tty->read_wait); |
| 3588 | INIT_WORK(&tty->hangup_work, do_tty_hangup, tty); |
Ingo Molnar | 70522e1 | 2006-03-23 03:00:31 -0800 | [diff] [blame] | 3589 | mutex_init(&tty->atomic_read_lock); |
| 3590 | mutex_init(&tty->atomic_write_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3591 | spin_lock_init(&tty->read_lock); |
| 3592 | INIT_LIST_HEAD(&tty->tty_files); |
| 3593 | INIT_WORK(&tty->SAK_work, NULL, NULL); |
| 3594 | } |
| 3595 | |
| 3596 | /* |
| 3597 | * The default put_char routine if the driver did not define one. |
| 3598 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3599 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3600 | static void tty_default_put_char(struct tty_struct *tty, unsigned char ch) |
| 3601 | { |
| 3602 | tty->driver->write(tty, &ch, 1); |
| 3603 | } |
| 3604 | |
gregkh@suse.de | 7fe845d | 2005-03-15 14:23:15 -0800 | [diff] [blame] | 3605 | static struct class *tty_class; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3606 | |
| 3607 | /** |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3608 | * tty_register_device - register a tty device |
| 3609 | * @driver: the tty driver that describes the tty device |
| 3610 | * @index: the index in the tty driver for this tty device |
| 3611 | * @device: a struct device that is associated with this tty device. |
| 3612 | * This field is optional, if there is no known struct device |
| 3613 | * for this tty device it can be set to NULL safely. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3614 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3615 | * Returns a pointer to the class device (or ERR_PTR(-EFOO) on error). |
Hansjoerg Lipp | 1cdcb6b | 2006-04-22 18:36:53 +0200 | [diff] [blame] | 3616 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3617 | * This call is required to be made to register an individual tty device |
| 3618 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If |
| 3619 | * that bit is not set, this function should not be called by a tty |
| 3620 | * driver. |
| 3621 | * |
| 3622 | * Locking: ?? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3623 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3624 | |
Hansjoerg Lipp | 1cdcb6b | 2006-04-22 18:36:53 +0200 | [diff] [blame] | 3625 | struct class_device *tty_register_device(struct tty_driver *driver, |
| 3626 | unsigned index, struct device *device) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3627 | { |
| 3628 | char name[64]; |
| 3629 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; |
| 3630 | |
| 3631 | if (index >= driver->num) { |
| 3632 | printk(KERN_ERR "Attempt to register invalid tty line number " |
| 3633 | " (%d).\n", index); |
Hansjoerg Lipp | 1cdcb6b | 2006-04-22 18:36:53 +0200 | [diff] [blame] | 3634 | return ERR_PTR(-EINVAL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3635 | } |
| 3636 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3637 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
| 3638 | pty_line_name(driver, index, name); |
| 3639 | else |
| 3640 | tty_line_name(driver, index, name); |
Hansjoerg Lipp | 1cdcb6b | 2006-04-22 18:36:53 +0200 | [diff] [blame] | 3641 | |
| 3642 | return class_device_create(tty_class, NULL, dev, device, "%s", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3643 | } |
| 3644 | |
| 3645 | /** |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3646 | * tty_unregister_device - unregister a tty device |
| 3647 | * @driver: the tty driver that describes the tty device |
| 3648 | * @index: the index in the tty driver for this tty device |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3649 | * |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3650 | * If a tty device is registered with a call to tty_register_device() then |
| 3651 | * this function must be called when the tty device is gone. |
| 3652 | * |
| 3653 | * Locking: ?? |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3654 | */ |
Alan Cox | af9b897 | 2006-08-27 01:24:01 -0700 | [diff] [blame] | 3655 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3656 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
| 3657 | { |
gregkh@suse.de | 7fe845d | 2005-03-15 14:23:15 -0800 | [diff] [blame] | 3658 | class_device_destroy(tty_class, MKDEV(driver->major, driver->minor_start) + index); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3659 | } |
| 3660 | |
| 3661 | EXPORT_SYMBOL(tty_register_device); |
| 3662 | EXPORT_SYMBOL(tty_unregister_device); |
| 3663 | |
| 3664 | struct tty_driver *alloc_tty_driver(int lines) |
| 3665 | { |
| 3666 | struct tty_driver *driver; |
| 3667 | |
| 3668 | driver = kmalloc(sizeof(struct tty_driver), GFP_KERNEL); |
| 3669 | if (driver) { |
| 3670 | memset(driver, 0, sizeof(struct tty_driver)); |
| 3671 | driver->magic = TTY_DRIVER_MAGIC; |
| 3672 | driver->num = lines; |
| 3673 | /* later we'll move allocation of tables here */ |
| 3674 | } |
| 3675 | return driver; |
| 3676 | } |
| 3677 | |
| 3678 | void put_tty_driver(struct tty_driver *driver) |
| 3679 | { |
| 3680 | kfree(driver); |
| 3681 | } |
| 3682 | |
Jeff Dike | b68e31d | 2006-10-02 02:17:18 -0700 | [diff] [blame] | 3683 | void tty_set_operations(struct tty_driver *driver, |
| 3684 | const struct tty_operations *op) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3685 | { |
| 3686 | driver->open = op->open; |
| 3687 | driver->close = op->close; |
| 3688 | driver->write = op->write; |
| 3689 | driver->put_char = op->put_char; |
| 3690 | driver->flush_chars = op->flush_chars; |
| 3691 | driver->write_room = op->write_room; |
| 3692 | driver->chars_in_buffer = op->chars_in_buffer; |
| 3693 | driver->ioctl = op->ioctl; |
| 3694 | driver->set_termios = op->set_termios; |
| 3695 | driver->throttle = op->throttle; |
| 3696 | driver->unthrottle = op->unthrottle; |
| 3697 | driver->stop = op->stop; |
| 3698 | driver->start = op->start; |
| 3699 | driver->hangup = op->hangup; |
| 3700 | driver->break_ctl = op->break_ctl; |
| 3701 | driver->flush_buffer = op->flush_buffer; |
| 3702 | driver->set_ldisc = op->set_ldisc; |
| 3703 | driver->wait_until_sent = op->wait_until_sent; |
| 3704 | driver->send_xchar = op->send_xchar; |
| 3705 | driver->read_proc = op->read_proc; |
| 3706 | driver->write_proc = op->write_proc; |
| 3707 | driver->tiocmget = op->tiocmget; |
| 3708 | driver->tiocmset = op->tiocmset; |
| 3709 | } |
| 3710 | |
| 3711 | |
| 3712 | EXPORT_SYMBOL(alloc_tty_driver); |
| 3713 | EXPORT_SYMBOL(put_tty_driver); |
| 3714 | EXPORT_SYMBOL(tty_set_operations); |
| 3715 | |
| 3716 | /* |
| 3717 | * Called by a tty driver to register itself. |
| 3718 | */ |
| 3719 | int tty_register_driver(struct tty_driver *driver) |
| 3720 | { |
| 3721 | int error; |
| 3722 | int i; |
| 3723 | dev_t dev; |
| 3724 | void **p = NULL; |
| 3725 | |
| 3726 | if (driver->flags & TTY_DRIVER_INSTALLED) |
| 3727 | return 0; |
| 3728 | |
| 3729 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM)) { |
| 3730 | p = kmalloc(driver->num * 3 * sizeof(void *), GFP_KERNEL); |
| 3731 | if (!p) |
| 3732 | return -ENOMEM; |
| 3733 | memset(p, 0, driver->num * 3 * sizeof(void *)); |
| 3734 | } |
| 3735 | |
| 3736 | if (!driver->major) { |
| 3737 | error = alloc_chrdev_region(&dev, driver->minor_start, driver->num, |
| 3738 | (char*)driver->name); |
| 3739 | if (!error) { |
| 3740 | driver->major = MAJOR(dev); |
| 3741 | driver->minor_start = MINOR(dev); |
| 3742 | } |
| 3743 | } else { |
| 3744 | dev = MKDEV(driver->major, driver->minor_start); |
| 3745 | error = register_chrdev_region(dev, driver->num, |
| 3746 | (char*)driver->name); |
| 3747 | } |
| 3748 | if (error < 0) { |
| 3749 | kfree(p); |
| 3750 | return error; |
| 3751 | } |
| 3752 | |
| 3753 | if (p) { |
| 3754 | driver->ttys = (struct tty_struct **)p; |
| 3755 | driver->termios = (struct termios **)(p + driver->num); |
| 3756 | driver->termios_locked = (struct termios **)(p + driver->num * 2); |
| 3757 | } else { |
| 3758 | driver->ttys = NULL; |
| 3759 | driver->termios = NULL; |
| 3760 | driver->termios_locked = NULL; |
| 3761 | } |
| 3762 | |
| 3763 | cdev_init(&driver->cdev, &tty_fops); |
| 3764 | driver->cdev.owner = driver->owner; |
| 3765 | error = cdev_add(&driver->cdev, dev, driver->num); |
| 3766 | if (error) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3767 | unregister_chrdev_region(dev, driver->num); |
| 3768 | driver->ttys = NULL; |
| 3769 | driver->termios = driver->termios_locked = NULL; |
| 3770 | kfree(p); |
| 3771 | return error; |
| 3772 | } |
| 3773 | |
| 3774 | if (!driver->put_char) |
| 3775 | driver->put_char = tty_default_put_char; |
| 3776 | |
| 3777 | list_add(&driver->tty_drivers, &tty_drivers); |
| 3778 | |
Greg Kroah-Hartman | 331b831 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 3779 | if ( !(driver->flags & TTY_DRIVER_DYNAMIC_DEV) ) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3780 | for(i = 0; i < driver->num; i++) |
| 3781 | tty_register_device(driver, i, NULL); |
| 3782 | } |
| 3783 | proc_tty_register_driver(driver); |
| 3784 | return 0; |
| 3785 | } |
| 3786 | |
| 3787 | EXPORT_SYMBOL(tty_register_driver); |
| 3788 | |
| 3789 | /* |
| 3790 | * Called by a tty driver to unregister itself. |
| 3791 | */ |
| 3792 | int tty_unregister_driver(struct tty_driver *driver) |
| 3793 | { |
| 3794 | int i; |
| 3795 | struct termios *tp; |
| 3796 | void *p; |
| 3797 | |
| 3798 | if (driver->refcount) |
| 3799 | return -EBUSY; |
| 3800 | |
| 3801 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
| 3802 | driver->num); |
| 3803 | |
| 3804 | list_del(&driver->tty_drivers); |
| 3805 | |
| 3806 | /* |
| 3807 | * Free the termios and termios_locked structures because |
| 3808 | * we don't want to get memory leaks when modular tty |
| 3809 | * drivers are removed from the kernel. |
| 3810 | */ |
| 3811 | for (i = 0; i < driver->num; i++) { |
| 3812 | tp = driver->termios[i]; |
| 3813 | if (tp) { |
| 3814 | driver->termios[i] = NULL; |
| 3815 | kfree(tp); |
| 3816 | } |
| 3817 | tp = driver->termios_locked[i]; |
| 3818 | if (tp) { |
| 3819 | driver->termios_locked[i] = NULL; |
| 3820 | kfree(tp); |
| 3821 | } |
Greg Kroah-Hartman | 331b831 | 2005-06-20 21:15:16 -0700 | [diff] [blame] | 3822 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3823 | tty_unregister_device(driver, i); |
| 3824 | } |
| 3825 | p = driver->ttys; |
| 3826 | proc_tty_unregister_driver(driver); |
| 3827 | driver->ttys = NULL; |
| 3828 | driver->termios = driver->termios_locked = NULL; |
| 3829 | kfree(p); |
| 3830 | cdev_del(&driver->cdev); |
| 3831 | return 0; |
| 3832 | } |
| 3833 | |
| 3834 | EXPORT_SYMBOL(tty_unregister_driver); |
| 3835 | |
| 3836 | |
| 3837 | /* |
| 3838 | * Initialize the console device. This is called *early*, so |
| 3839 | * we can't necessarily depend on lots of kernel help here. |
| 3840 | * Just do some early initializations, and do the complex setup |
| 3841 | * later. |
| 3842 | */ |
| 3843 | void __init console_init(void) |
| 3844 | { |
| 3845 | initcall_t *call; |
| 3846 | |
| 3847 | /* Setup the default TTY line discipline. */ |
| 3848 | (void) tty_register_ldisc(N_TTY, &tty_ldisc_N_TTY); |
| 3849 | |
| 3850 | /* |
| 3851 | * set up the console device so that later boot sequences can |
| 3852 | * inform about problems etc.. |
| 3853 | */ |
| 3854 | #ifdef CONFIG_EARLY_PRINTK |
| 3855 | disable_early_printk(); |
| 3856 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3857 | call = __con_initcall_start; |
| 3858 | while (call < __con_initcall_end) { |
| 3859 | (*call)(); |
| 3860 | call++; |
| 3861 | } |
| 3862 | } |
| 3863 | |
| 3864 | #ifdef CONFIG_VT |
| 3865 | extern int vty_init(void); |
| 3866 | #endif |
| 3867 | |
| 3868 | static int __init tty_class_init(void) |
| 3869 | { |
gregkh@suse.de | 7fe845d | 2005-03-15 14:23:15 -0800 | [diff] [blame] | 3870 | tty_class = class_create(THIS_MODULE, "tty"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3871 | if (IS_ERR(tty_class)) |
| 3872 | return PTR_ERR(tty_class); |
| 3873 | return 0; |
| 3874 | } |
| 3875 | |
| 3876 | postcore_initcall(tty_class_init); |
| 3877 | |
| 3878 | /* 3/2004 jmc: why do these devices exist? */ |
| 3879 | |
| 3880 | static struct cdev tty_cdev, console_cdev; |
| 3881 | #ifdef CONFIG_UNIX98_PTYS |
| 3882 | static struct cdev ptmx_cdev; |
| 3883 | #endif |
| 3884 | #ifdef CONFIG_VT |
| 3885 | static struct cdev vc0_cdev; |
| 3886 | #endif |
| 3887 | |
| 3888 | /* |
| 3889 | * Ok, now we can initialize the rest of the tty devices and can count |
| 3890 | * on memory allocations, interrupts etc.. |
| 3891 | */ |
| 3892 | static int __init tty_init(void) |
| 3893 | { |
| 3894 | cdev_init(&tty_cdev, &tty_fops); |
| 3895 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || |
| 3896 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) |
| 3897 | panic("Couldn't register /dev/tty driver\n"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3898 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3899 | |
| 3900 | cdev_init(&console_cdev, &console_fops); |
| 3901 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || |
| 3902 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) |
| 3903 | panic("Couldn't register /dev/console driver\n"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3904 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, "console"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3905 | |
| 3906 | #ifdef CONFIG_UNIX98_PTYS |
| 3907 | cdev_init(&ptmx_cdev, &ptmx_fops); |
| 3908 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || |
| 3909 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) |
| 3910 | panic("Couldn't register /dev/ptmx driver\n"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3911 | class_device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3912 | #endif |
| 3913 | |
| 3914 | #ifdef CONFIG_VT |
| 3915 | cdev_init(&vc0_cdev, &console_fops); |
| 3916 | if (cdev_add(&vc0_cdev, MKDEV(TTY_MAJOR, 0), 1) || |
| 3917 | register_chrdev_region(MKDEV(TTY_MAJOR, 0), 1, "/dev/vc/0") < 0) |
| 3918 | panic("Couldn't register /dev/tty0 driver\n"); |
Greg Kroah-Hartman | 53f4654 | 2005-10-27 22:25:43 -0700 | [diff] [blame] | 3919 | class_device_create(tty_class, NULL, MKDEV(TTY_MAJOR, 0), NULL, "tty0"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3920 | |
| 3921 | vty_init(); |
| 3922 | #endif |
| 3923 | return 0; |
| 3924 | } |
| 3925 | module_init(tty_init); |