Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * n_tty.c --- implements the N_TTY line discipline. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 3 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 4 | * This code used to be in tty_io.c, but things are getting hairy |
| 5 | * enough that it made sense to split things off. (The N_TTY |
| 6 | * processing has changed so much that it's hardly recognizable, |
| 7 | * anyway...) |
| 8 | * |
| 9 | * Note that the open routine for N_TTY is guaranteed never to return |
| 10 | * an error. This is because Linux will fall back to setting a line |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 11 | * to N_TTY if it can not switch to any other line discipline. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * |
| 13 | * Written by Theodore Ts'o, Copyright 1994. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 14 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | * This file also contains code originally written by Linus Torvalds, |
| 16 | * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 17 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | * This file may be redistributed under the terms of the GNU General Public |
| 19 | * License. |
| 20 | * |
| 21 | * Reduced memory usage for older ARM systems - Russell King. |
| 22 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 23 | * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu> |
| 25 | * who actually finally proved there really was a race. |
| 26 | * |
| 27 | * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to |
| 28 | * waiting writing processes-Sapan Bhatia <sapan@corewars.org>. |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 29 | * Also fixed a bug in BLOCKING mode where n_tty_write returns |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | * EAGAIN |
| 31 | */ |
| 32 | |
| 33 | #include <linux/types.h> |
| 34 | #include <linux/major.h> |
| 35 | #include <linux/errno.h> |
| 36 | #include <linux/signal.h> |
| 37 | #include <linux/fcntl.h> |
| 38 | #include <linux/sched.h> |
| 39 | #include <linux/interrupt.h> |
| 40 | #include <linux/tty.h> |
| 41 | #include <linux/timer.h> |
| 42 | #include <linux/ctype.h> |
| 43 | #include <linux/mm.h> |
| 44 | #include <linux/string.h> |
| 45 | #include <linux/slab.h> |
| 46 | #include <linux/poll.h> |
| 47 | #include <linux/bitops.h> |
Miloslav Trmac | 522ed77 | 2007-07-15 23:40:56 -0700 | [diff] [blame] | 48 | #include <linux/audit.h> |
| 49 | #include <linux/file.h> |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 50 | #include <linux/uaccess.h> |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 51 | #include <linux/module.h> |
George Spelvin | 593fb1ae4 | 2013-02-12 02:00:43 -0500 | [diff] [blame] | 52 | #include <linux/ratelimit.h> |
Peter Hurley | 86e35ae | 2013-07-24 09:30:05 -0400 | [diff] [blame] | 53 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
| 56 | /* number of characters left in xmit buffer before select has we have room */ |
| 57 | #define WAKEUP_CHARS 256 |
| 58 | |
| 59 | /* |
| 60 | * This defines the low- and high-watermarks for throttling and |
| 61 | * unthrottling the TTY driver. These watermarks are used for |
| 62 | * controlling the space in the read buffer. |
| 63 | */ |
| 64 | #define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */ |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 65 | #define TTY_THRESHOLD_UNTHROTTLE 128 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 67 | /* |
| 68 | * Special byte codes used in the echo buffer to represent operations |
| 69 | * or special handling of characters. Bytes in the echo buffer that |
| 70 | * are not part of such special blocks are treated as normal character |
| 71 | * codes. |
| 72 | */ |
| 73 | #define ECHO_OP_START 0xff |
| 74 | #define ECHO_OP_MOVE_BACK_COL 0x80 |
| 75 | #define ECHO_OP_SET_CANON_COL 0x81 |
| 76 | #define ECHO_OP_ERASE_TAB 0x82 |
| 77 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 78 | #define ECHO_COMMIT_WATERMARK 256 |
| 79 | #define ECHO_BLOCK 256 |
| 80 | #define ECHO_DISCARD_WATERMARK N_TTY_BUF_SIZE - (ECHO_BLOCK + 32) |
| 81 | |
| 82 | |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 83 | #undef N_TTY_TRACE |
| 84 | #ifdef N_TTY_TRACE |
| 85 | # define n_tty_trace(f, args...) trace_printk(f, ##args) |
| 86 | #else |
| 87 | # define n_tty_trace(f, args...) |
| 88 | #endif |
| 89 | |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 90 | struct n_tty_data { |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 91 | /* producer-published */ |
| 92 | size_t read_head; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 93 | size_t commit_head; |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 94 | size_t canon_head; |
Peter Hurley | 9dfd16d | 2013-06-15 10:04:29 -0400 | [diff] [blame] | 95 | size_t echo_head; |
| 96 | size_t echo_commit; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 97 | size_t echo_mark; |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 98 | DECLARE_BITMAP(char_map, 256); |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 99 | |
| 100 | /* private to n_tty_receive_overrun (single-threaded) */ |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 101 | unsigned long overrun_time; |
| 102 | int num_overrun; |
| 103 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 104 | /* non-atomic */ |
| 105 | bool no_room; |
| 106 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 107 | /* must hold exclusive termios_rwsem to reset these */ |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 108 | unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1; |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 109 | unsigned char push:1; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 110 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 111 | /* shared by producer and consumer */ |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 112 | char read_buf[N_TTY_BUF_SIZE]; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 113 | DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 114 | unsigned char echo_buf[N_TTY_BUF_SIZE]; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 115 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 116 | /* consumer-published */ |
| 117 | size_t read_tail; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 118 | size_t line_start; |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 119 | |
Peter Hurley | fb7aa03 | 2013-06-15 09:14:30 -0400 | [diff] [blame] | 120 | /* protected by output lock */ |
| 121 | unsigned int column; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 122 | unsigned int canon_column; |
Peter Hurley | 9dfd16d | 2013-06-15 10:04:29 -0400 | [diff] [blame] | 123 | size_t echo_tail; |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 124 | |
| 125 | struct mutex atomic_read_lock; |
| 126 | struct mutex output_lock; |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 127 | }; |
| 128 | |
Tetsuo Handa | 947dead | 2018-05-26 09:53:13 +0900 | [diff] [blame] | 129 | #define MASK(x) ((x) & (N_TTY_BUF_SIZE - 1)) |
| 130 | |
Carl van Schaik | b38f174 | 2018-07-03 12:02:30 +1000 | [diff] [blame^] | 131 | #if defined(CONFIG_TTY_FLUSH_LOCAL_ECHO) |
| 132 | static void continue_process_echoes(struct work_struct *work); |
| 133 | #endif |
| 134 | |
Peter Hurley | ce74117 | 2013-06-15 09:14:20 -0400 | [diff] [blame] | 135 | static inline size_t read_cnt(struct n_tty_data *ldata) |
| 136 | { |
Peter Hurley | a2f73be | 2013-06-15 09:14:22 -0400 | [diff] [blame] | 137 | return ldata->read_head - ldata->read_tail; |
Peter Hurley | ce74117 | 2013-06-15 09:14:20 -0400 | [diff] [blame] | 138 | } |
| 139 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 140 | static inline unsigned char read_buf(struct n_tty_data *ldata, size_t i) |
| 141 | { |
| 142 | return ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 143 | } |
| 144 | |
| 145 | static inline unsigned char *read_buf_addr(struct n_tty_data *ldata, size_t i) |
| 146 | { |
| 147 | return &ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 148 | } |
| 149 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 150 | static inline unsigned char echo_buf(struct n_tty_data *ldata, size_t i) |
| 151 | { |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 152 | smp_rmb(); /* Matches smp_wmb() in add_echo_byte(). */ |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 153 | return ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 154 | } |
| 155 | |
| 156 | static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i) |
| 157 | { |
| 158 | return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)]; |
| 159 | } |
| 160 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 161 | static int tty_copy_to_user(struct tty_struct *tty, void __user *to, |
| 162 | size_t tail, size_t n) |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 163 | { |
| 164 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 165 | size_t size = N_TTY_BUF_SIZE - tail; |
| 166 | const void *from = read_buf_addr(ldata, tail); |
| 167 | int uncopied; |
| 168 | |
| 169 | if (n > size) { |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 170 | tty_audit_add_data(tty, from, size); |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 171 | uncopied = copy_to_user(to, from, size); |
| 172 | if (uncopied) |
| 173 | return uncopied; |
| 174 | to += size; |
| 175 | n -= size; |
| 176 | from = ldata->read_buf; |
| 177 | } |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 178 | |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 179 | tty_audit_add_data(tty, from, n); |
Laura Abbott | 72586c6 | 2015-05-14 11:42:17 -0700 | [diff] [blame] | 180 | return copy_to_user(to, from, n); |
| 181 | } |
| 182 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 183 | /** |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 184 | * n_tty_kick_worker - start input worker (if required) |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 185 | * @tty: terminal |
| 186 | * |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 187 | * Re-schedules the flip buffer work if it may have stopped |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 188 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 189 | * Caller holds exclusive termios_rwsem |
| 190 | * or |
| 191 | * n_tty_read()/consumer path: |
| 192 | * holds non-exclusive termios_rwsem |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 193 | */ |
| 194 | |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 195 | static void n_tty_kick_worker(struct tty_struct *tty) |
Peter Hurley | 7879a9f | 2013-06-15 07:28:31 -0400 | [diff] [blame] | 196 | { |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 197 | struct n_tty_data *ldata = tty->disc_data; |
| 198 | |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 199 | /* Did the input worker stop? Restart it */ |
| 200 | if (unlikely(ldata->no_room)) { |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 201 | ldata->no_room = 0; |
| 202 | |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 203 | WARN_RATELIMIT(tty->port->itty == NULL, |
Sasha Levin | cadf748 | 2012-10-25 14:26:35 -0400 | [diff] [blame] | 204 | "scheduling with invalid itty\n"); |
Peter Hurley | 2162293 | 2013-03-11 16:44:21 -0400 | [diff] [blame] | 205 | /* see if ldisc has been killed - if so, this means that |
| 206 | * even though the ldisc has been halted and ->buf.work |
| 207 | * cancelled, ->buf.work is about to be rescheduled |
| 208 | */ |
| 209 | WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags), |
| 210 | "scheduling buffer work for halted ldisc\n"); |
Peter Hurley | e176058 | 2015-10-17 16:36:23 -0400 | [diff] [blame] | 211 | tty_buffer_restart_work(tty->port); |
Jiri Slaby | ecbbfd4 | 2012-10-18 22:26:47 +0200 | [diff] [blame] | 212 | } |
Linus Torvalds | 55db4c6 | 2011-06-04 06:33:24 +0900 | [diff] [blame] | 213 | } |
| 214 | |
Peter Hurley | 9a4aec2 | 2013-06-15 09:14:32 -0400 | [diff] [blame] | 215 | static ssize_t chars_in_buffer(struct tty_struct *tty) |
| 216 | { |
| 217 | struct n_tty_data *ldata = tty->disc_data; |
| 218 | ssize_t n = 0; |
| 219 | |
| 220 | if (!ldata->icanon) |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 221 | n = ldata->commit_head - ldata->read_tail; |
Peter Hurley | 9a4aec2 | 2013-06-15 09:14:32 -0400 | [diff] [blame] | 222 | else |
| 223 | n = ldata->canon_head - ldata->read_tail; |
| 224 | return n; |
| 225 | } |
| 226 | |
Peter Hurley | ee0bab8 | 2013-06-15 09:14:34 -0400 | [diff] [blame] | 227 | /** |
| 228 | * n_tty_write_wakeup - asynchronous I/O notifier |
| 229 | * @tty: tty device |
| 230 | * |
| 231 | * Required for the ptys, serial driver etc. since processes |
| 232 | * that attach themselves to the master and rely on ASYNC |
| 233 | * IO must be woken up |
| 234 | */ |
| 235 | |
| 236 | static void n_tty_write_wakeup(struct tty_struct *tty) |
| 237 | { |
Peter Hurley | 7bccc36 | 2016-01-09 21:45:12 -0800 | [diff] [blame] | 238 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
| 239 | kill_fasync(&tty->fasync, SIGIO, POLL_OUT); |
Peter Hurley | ee0bab8 | 2013-06-15 09:14:34 -0400 | [diff] [blame] | 240 | } |
| 241 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 242 | static void n_tty_check_throttle(struct tty_struct *tty) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 243 | { |
Peter Hurley | a342846 | 2015-01-16 15:05:35 -0500 | [diff] [blame] | 244 | struct n_tty_data *ldata = tty->disc_data; |
| 245 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 246 | /* |
| 247 | * Check the remaining room for the input canonicalization |
| 248 | * mode. We don't want to throttle the driver if we're in |
| 249 | * canonical mode and don't have a newline yet! |
| 250 | */ |
Peter Hurley | a342846 | 2015-01-16 15:05:35 -0500 | [diff] [blame] | 251 | if (ldata->icanon && ldata->canon_head == ldata->read_tail) |
| 252 | return; |
| 253 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 254 | while (1) { |
| 255 | int throttled; |
| 256 | tty_set_flow_change(tty, TTY_THROTTLE_SAFE); |
Peter Hurley | 5e28cca | 2015-01-16 15:05:36 -0500 | [diff] [blame] | 257 | if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 258 | break; |
| 259 | throttled = tty_throttle_safe(tty); |
| 260 | if (!throttled) |
| 261 | break; |
| 262 | } |
| 263 | __tty_set_flow_change(tty, 0); |
| 264 | } |
| 265 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 266 | static void n_tty_check_unthrottle(struct tty_struct *tty) |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 267 | { |
Peter Hurley | 6d27a63 | 2016-01-10 22:40:56 -0800 | [diff] [blame] | 268 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { |
Peter Hurley | 3afb1b39 | 2013-07-23 08:47:30 -0400 | [diff] [blame] | 269 | if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) |
| 270 | return; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 271 | n_tty_kick_worker(tty); |
Peter Hurley | 6d27a63 | 2016-01-10 22:40:56 -0800 | [diff] [blame] | 272 | tty_wakeup(tty->link); |
Peter Hurley | 3afb1b39 | 2013-07-23 08:47:30 -0400 | [diff] [blame] | 273 | return; |
| 274 | } |
| 275 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 276 | /* If there is enough space in the read buffer now, let the |
| 277 | * low-level driver know. We use chars_in_buffer() to |
| 278 | * check the buffer, as it now knows about canonical mode. |
| 279 | * Otherwise, if the driver is throttled and the line is |
| 280 | * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, |
| 281 | * we won't get any more characters. |
| 282 | */ |
| 283 | |
| 284 | while (1) { |
| 285 | int unthrottled; |
| 286 | tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); |
| 287 | if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) |
| 288 | break; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 289 | n_tty_kick_worker(tty); |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 290 | unthrottled = tty_unthrottle_safe(tty); |
| 291 | if (!unthrottled) |
| 292 | break; |
| 293 | } |
| 294 | __tty_set_flow_change(tty, 0); |
| 295 | } |
| 296 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 297 | /** |
| 298 | * put_tty_queue - add character to tty |
| 299 | * @c: character |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 300 | * @ldata: n_tty data |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 301 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 302 | * Add a character to the tty read_buf queue. |
| 303 | * |
| 304 | * n_tty_receive_buf()/producer path: |
| 305 | * caller holds non-exclusive termios_rwsem |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 306 | */ |
| 307 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 308 | static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | { |
Christian Riesch | 8bfbe2d | 2014-11-13 05:53:26 +0100 | [diff] [blame] | 310 | *read_buf_addr(ldata, ldata->read_head) = c; |
| 311 | ldata->read_head++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | } |
| 313 | |
| 314 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | * reset_buffer_flags - reset buffer state |
| 316 | * @tty: terminal to reset |
| 317 | * |
Peter Hurley | 25518c6 | 2013-03-11 16:44:31 -0400 | [diff] [blame] | 318 | * Reset the read buffer counters and clear the flags. |
| 319 | * Called from n_tty_open() and n_tty_flush_buffer(). |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 320 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 321 | * Locking: caller holds exclusive termios_rwsem |
| 322 | * (or locking is not required) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 324 | |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 325 | static void reset_buffer_flags(struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | { |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 327 | ldata->read_head = ldata->canon_head = ldata->read_tail = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 328 | ldata->commit_head = 0; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 329 | ldata->line_start = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 330 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 331 | ldata->erasing = 0; |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 332 | bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 333 | ldata->push = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | } |
| 335 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 336 | static void n_tty_packet_mode_flush(struct tty_struct *tty) |
| 337 | { |
| 338 | unsigned long flags; |
| 339 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 340 | if (tty->link->packet) { |
Peter Hurley | 54e8e5f | 2014-10-16 15:33:26 -0400 | [diff] [blame] | 341 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 342 | tty->ctrl_status |= TIOCPKT_FLUSHREAD; |
Peter Hurley | 54e8e5f | 2014-10-16 15:33:26 -0400 | [diff] [blame] | 343 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 344 | wake_up_interruptible(&tty->link->read_wait); |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 345 | } |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 346 | } |
| 347 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 348 | /** |
| 349 | * n_tty_flush_buffer - clean input queue |
| 350 | * @tty: terminal device |
| 351 | * |
Peter Hurley | 25518c6 | 2013-03-11 16:44:31 -0400 | [diff] [blame] | 352 | * Flush the input buffer. Called when the tty layer wants the |
| 353 | * buffer flushed (eg at hangup) or when the N_TTY line discipline |
| 354 | * internally has to clean the pending queue (for example some signals). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 356 | * Holds termios_rwsem to exclude producer/consumer while |
| 357 | * buffer indices are reset. |
| 358 | * |
| 359 | * Locking: ctrl_lock, exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 361 | |
| 362 | static void n_tty_flush_buffer(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | { |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 364 | down_write(&tty->termios_rwsem); |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 365 | reset_buffer_flags(tty->disc_data); |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 366 | n_tty_kick_worker(tty); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 367 | |
Peter Hurley | a30737a | 2013-03-11 16:44:22 -0400 | [diff] [blame] | 368 | if (tty->link) |
| 369 | n_tty_packet_mode_flush(tty); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 370 | up_write(&tty->termios_rwsem); |
| 371 | } |
| 372 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 374 | * is_utf8_continuation - utf8 multibyte check |
| 375 | * @c: byte to check |
| 376 | * |
| 377 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 378 | * character. We use this to correctly compute the on screen size |
| 379 | * of the character when printing |
| 380 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 381 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | static inline int is_utf8_continuation(unsigned char c) |
| 383 | { |
| 384 | return (c & 0xc0) == 0x80; |
| 385 | } |
| 386 | |
| 387 | /** |
| 388 | * is_continuation - multibyte check |
| 389 | * @c: byte to check |
| 390 | * |
| 391 | * Returns true if the utf8 character 'c' is a multibyte continuation |
| 392 | * character and the terminal is in unicode mode. |
| 393 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 394 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | static inline int is_continuation(unsigned char c, struct tty_struct *tty) |
| 396 | { |
| 397 | return I_IUTF8(tty) && is_utf8_continuation(c); |
| 398 | } |
| 399 | |
| 400 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 401 | * do_output_char - output one character |
| 402 | * @c: character (or partial unicode symbol) |
| 403 | * @tty: terminal device |
| 404 | * @space: space available in tty driver write buffer |
| 405 | * |
| 406 | * This is a helper function that handles one output character |
| 407 | * (including special characters like TAB, CR, LF, etc.), |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 408 | * doing OPOST processing and putting the results in the |
| 409 | * tty driver's write buffer. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 410 | * |
| 411 | * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY |
| 412 | * and NLDLY. They simply aren't relevant in the world today. |
| 413 | * If you ever need them, add them here. |
| 414 | * |
| 415 | * Returns the number of bytes of buffer space used or -1 if |
| 416 | * no space left. |
| 417 | * |
| 418 | * Locking: should be called under the output_lock to protect |
| 419 | * the column state and space left in the buffer |
| 420 | */ |
| 421 | |
| 422 | static int do_output_char(unsigned char c, struct tty_struct *tty, int space) |
| 423 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 424 | struct n_tty_data *ldata = tty->disc_data; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 425 | int spaces; |
| 426 | |
| 427 | if (!space) |
| 428 | return -1; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 429 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 430 | switch (c) { |
| 431 | case '\n': |
| 432 | if (O_ONLRET(tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 433 | ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 434 | if (O_ONLCR(tty)) { |
| 435 | if (space < 2) |
| 436 | return -1; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 437 | ldata->canon_column = ldata->column = 0; |
Linus Torvalds | 37f81fa | 2009-09-05 12:46:07 -0700 | [diff] [blame] | 438 | tty->ops->write(tty, "\r\n", 2); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 439 | return 2; |
| 440 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 441 | ldata->canon_column = ldata->column; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 442 | break; |
| 443 | case '\r': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 444 | if (O_ONOCR(tty) && ldata->column == 0) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 445 | return 0; |
| 446 | if (O_OCRNL(tty)) { |
| 447 | c = '\n'; |
| 448 | if (O_ONLRET(tty)) |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 449 | ldata->canon_column = ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 450 | break; |
| 451 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 452 | ldata->canon_column = ldata->column = 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 453 | break; |
| 454 | case '\t': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 455 | spaces = 8 - (ldata->column & 7); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 456 | if (O_TABDLY(tty) == XTABS) { |
| 457 | if (space < spaces) |
| 458 | return -1; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 459 | ldata->column += spaces; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 460 | tty->ops->write(tty, " ", spaces); |
| 461 | return spaces; |
| 462 | } |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 463 | ldata->column += spaces; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 464 | break; |
| 465 | case '\b': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 466 | if (ldata->column > 0) |
| 467 | ldata->column--; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 468 | break; |
| 469 | default: |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 470 | if (!iscntrl(c)) { |
| 471 | if (O_OLCUC(tty)) |
| 472 | c = toupper(c); |
| 473 | if (!is_continuation(c, tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 474 | ldata->column++; |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 475 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 476 | break; |
| 477 | } |
| 478 | |
| 479 | tty_put_char(tty, c); |
| 480 | return 1; |
| 481 | } |
| 482 | |
| 483 | /** |
| 484 | * process_output - output post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | * @c: character (or partial unicode symbol) |
| 486 | * @tty: terminal device |
| 487 | * |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 488 | * Output one character with OPOST processing. |
| 489 | * Returns -1 when the output device is full and the character |
| 490 | * must be retried. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 492 | * Locking: output_lock to protect column state and space left |
| 493 | * (also, this is called from n_tty_write under the |
| 494 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 496 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 497 | static int process_output(unsigned char c, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 498 | { |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 499 | struct n_tty_data *ldata = tty->disc_data; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 500 | int space, retval; |
| 501 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 502 | mutex_lock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 503 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 504 | space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 505 | retval = do_output_char(c, tty, space); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 507 | mutex_unlock(&ldata->output_lock); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 508 | if (retval < 0) |
| 509 | return -1; |
| 510 | else |
| 511 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | } |
| 513 | |
| 514 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 515 | * process_output_block - block post processor |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | * @tty: terminal device |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 517 | * @buf: character buffer |
| 518 | * @nr: number of bytes to output |
| 519 | * |
| 520 | * Output a block of characters with OPOST processing. |
| 521 | * Returns the number of characters output. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 522 | * |
| 523 | * This path is used to speed up block console writes, among other |
| 524 | * things when processing blocks of output data. It handles only |
| 525 | * the simple cases normally found and helps to generate blocks of |
| 526 | * symbols for the console driver and thus improve performance. |
| 527 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 528 | * Locking: output_lock to protect column state and space left |
| 529 | * (also, this is called from n_tty_write under the |
| 530 | * tty layer write lock) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 532 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 533 | static ssize_t process_output_block(struct tty_struct *tty, |
| 534 | const unsigned char *buf, unsigned int nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 536 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | int space; |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 538 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | const unsigned char *cp; |
| 540 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 541 | mutex_lock(&ldata->output_lock); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 542 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 543 | space = tty_write_room(tty); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 544 | if (!space) { |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 545 | mutex_unlock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | return 0; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 547 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 548 | if (nr > space) |
| 549 | nr = space; |
| 550 | |
| 551 | for (i = 0, cp = buf; i < nr; i++, cp++) { |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 552 | unsigned char c = *cp; |
| 553 | |
| 554 | switch (c) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | case '\n': |
| 556 | if (O_ONLRET(tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 557 | ldata->column = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | if (O_ONLCR(tty)) |
| 559 | goto break_out; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 560 | ldata->canon_column = ldata->column; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 561 | break; |
| 562 | case '\r': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 563 | if (O_ONOCR(tty) && ldata->column == 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | goto break_out; |
| 565 | if (O_OCRNL(tty)) |
| 566 | goto break_out; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 567 | ldata->canon_column = ldata->column = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | break; |
| 569 | case '\t': |
| 570 | goto break_out; |
| 571 | case '\b': |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 572 | if (ldata->column > 0) |
| 573 | ldata->column--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | break; |
| 575 | default: |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 576 | if (!iscntrl(c)) { |
| 577 | if (O_OLCUC(tty)) |
| 578 | goto break_out; |
| 579 | if (!is_continuation(c, tty)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 580 | ldata->column++; |
Joe Peterson | a59c0d6 | 2009-01-02 13:43:25 +0000 | [diff] [blame] | 581 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 582 | break; |
| 583 | } |
| 584 | } |
| 585 | break_out: |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 586 | i = tty->ops->write(tty, buf, i); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 587 | |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 588 | mutex_unlock(&ldata->output_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | return i; |
| 590 | } |
| 591 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 592 | /** |
| 593 | * process_echoes - write pending echo characters |
| 594 | * @tty: terminal device |
| 595 | * |
| 596 | * Write previously buffered echo (and other ldisc-generated) |
| 597 | * characters to the tty. |
| 598 | * |
| 599 | * Characters generated by the ldisc (including echoes) need to |
| 600 | * be buffered because the driver's write buffer can fill during |
| 601 | * heavy program output. Echoing straight to the driver will |
| 602 | * often fail under these conditions, causing lost characters and |
| 603 | * resulting mismatches of ldisc state information. |
| 604 | * |
| 605 | * Since the ldisc state must represent the characters actually sent |
| 606 | * to the driver at the time of the write, operations like certain |
| 607 | * changes in column state are also saved in the buffer and executed |
| 608 | * here. |
| 609 | * |
| 610 | * A circular fifo buffer is used so that the most recent characters |
| 611 | * are prioritized. Also, when control characters are echoed with a |
| 612 | * prefixed "^", the pair is treated atomically and thus not separated. |
| 613 | * |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 614 | * Locking: callers must hold output_lock |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 615 | */ |
| 616 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 617 | static size_t __process_echoes(struct tty_struct *tty) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 618 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 619 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 620 | int space, old_space; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 621 | size_t tail; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 622 | unsigned char c; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 623 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 624 | old_space = space = tty_write_room(tty); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 625 | |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 626 | tail = ldata->echo_tail; |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 627 | while (MASK(ldata->echo_commit) != MASK(tail)) { |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 628 | c = echo_buf(ldata, tail); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 629 | if (c == ECHO_OP_START) { |
| 630 | unsigned char op; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 631 | int no_space_left = 0; |
| 632 | |
| 633 | /* |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 634 | * Since add_echo_byte() is called without holding |
| 635 | * output_lock, we might see only portion of multi-byte |
| 636 | * operation. |
| 637 | */ |
| 638 | if (MASK(ldata->echo_commit) == MASK(tail + 1)) |
| 639 | goto not_yet_stored; |
| 640 | /* |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 641 | * If the buffer byte is the start of a multi-byte |
| 642 | * operation, get the next byte, which is either the |
| 643 | * op code or a control character value. |
| 644 | */ |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 645 | op = echo_buf(ldata, tail + 1); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 646 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 647 | switch (op) { |
| 648 | unsigned int num_chars, num_bs; |
| 649 | |
| 650 | case ECHO_OP_ERASE_TAB: |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 651 | if (MASK(ldata->echo_commit) == MASK(tail + 2)) |
| 652 | goto not_yet_stored; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 653 | num_chars = echo_buf(ldata, tail + 2); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 654 | |
| 655 | /* |
| 656 | * Determine how many columns to go back |
| 657 | * in order to erase the tab. |
| 658 | * This depends on the number of columns |
| 659 | * used by other characters within the tab |
| 660 | * area. If this (modulo 8) count is from |
| 661 | * the start of input rather than from a |
| 662 | * previous tab, we offset by canon column. |
| 663 | * Otherwise, tab spacing is normal. |
| 664 | */ |
| 665 | if (!(num_chars & 0x80)) |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 666 | num_chars += ldata->canon_column; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 667 | num_bs = 8 - (num_chars & 7); |
| 668 | |
| 669 | if (num_bs > space) { |
| 670 | no_space_left = 1; |
| 671 | break; |
| 672 | } |
| 673 | space -= num_bs; |
| 674 | while (num_bs--) { |
| 675 | tty_put_char(tty, '\b'); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 676 | if (ldata->column > 0) |
| 677 | ldata->column--; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 678 | } |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 679 | tail += 3; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 680 | break; |
| 681 | |
| 682 | case ECHO_OP_SET_CANON_COL: |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 683 | ldata->canon_column = ldata->column; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 684 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 685 | break; |
| 686 | |
| 687 | case ECHO_OP_MOVE_BACK_COL: |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 688 | if (ldata->column > 0) |
| 689 | ldata->column--; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 690 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 691 | break; |
| 692 | |
| 693 | case ECHO_OP_START: |
| 694 | /* This is an escaped echo op start code */ |
| 695 | if (!space) { |
| 696 | no_space_left = 1; |
| 697 | break; |
| 698 | } |
| 699 | tty_put_char(tty, ECHO_OP_START); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 700 | ldata->column++; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 701 | space--; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 702 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 703 | break; |
| 704 | |
| 705 | default: |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 706 | /* |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 707 | * If the op is not a special byte code, |
| 708 | * it is a ctrl char tagged to be echoed |
| 709 | * as "^X" (where X is the letter |
| 710 | * representing the control char). |
| 711 | * Note that we must ensure there is |
| 712 | * enough space for the whole ctrl pair. |
| 713 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 714 | */ |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 715 | if (space < 2) { |
| 716 | no_space_left = 1; |
| 717 | break; |
| 718 | } |
| 719 | tty_put_char(tty, '^'); |
| 720 | tty_put_char(tty, op ^ 0100); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 721 | ldata->column += 2; |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 722 | space -= 2; |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 723 | tail += 2; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 724 | } |
| 725 | |
| 726 | if (no_space_left) |
| 727 | break; |
| 728 | } else { |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 729 | if (O_OPOST(tty)) { |
Joe Peterson | ee5aa7b | 2009-09-09 15:03:13 -0600 | [diff] [blame] | 730 | int retval = do_output_char(c, tty, space); |
| 731 | if (retval < 0) |
| 732 | break; |
| 733 | space -= retval; |
| 734 | } else { |
| 735 | if (!space) |
| 736 | break; |
| 737 | tty_put_char(tty, c); |
| 738 | space -= 1; |
| 739 | } |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 740 | tail += 1; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 741 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 742 | } |
| 743 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 744 | /* If the echo buffer is nearly full (so that the possibility exists |
| 745 | * of echo overrun before the next commit), then discard enough |
| 746 | * data at the tail to prevent a subsequent overrun */ |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 747 | while (ldata->echo_commit > tail && |
| 748 | ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) { |
Roel Kluin | c476f65 | 2013-10-11 22:08:49 +0200 | [diff] [blame] | 749 | if (echo_buf(ldata, tail) == ECHO_OP_START) { |
Peter Hurley | 6f22253 | 2013-11-08 09:42:18 -0500 | [diff] [blame] | 750 | if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB) |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 751 | tail += 3; |
| 752 | else |
| 753 | tail += 2; |
| 754 | } else |
| 755 | tail++; |
| 756 | } |
| 757 | |
Carl van Schaik | b38f174 | 2018-07-03 12:02:30 +1000 | [diff] [blame^] | 758 | #if defined(CONFIG_TTY_FLUSH_LOCAL_ECHO) |
| 759 | if (ldata->echo_commit != tail) { |
| 760 | if (!tty->delayed_work) { |
| 761 | INIT_DELAYED_WORK(&tty->echo_delayed_work, continue_process_echoes); |
| 762 | schedule_delayed_work(&tty->echo_delayed_work, 1); |
| 763 | } |
| 764 | tty->delayed_work = 1; |
| 765 | } |
| 766 | #endif |
| 767 | |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 768 | not_yet_stored: |
Peter Hurley | addaebc | 2013-06-15 10:04:22 -0400 | [diff] [blame] | 769 | ldata->echo_tail = tail; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 770 | return old_space - space; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 771 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 773 | static void commit_echoes(struct tty_struct *tty) |
| 774 | { |
| 775 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 776 | size_t nr, old, echoed; |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 777 | size_t head; |
| 778 | |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 779 | mutex_lock(&ldata->output_lock); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 780 | head = ldata->echo_head; |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 781 | ldata->echo_mark = head; |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 782 | old = ldata->echo_commit - ldata->echo_tail; |
| 783 | |
| 784 | /* Process committed echoes if the accumulated # of bytes |
| 785 | * is over the threshold (and try again each time another |
| 786 | * block is accumulated) */ |
| 787 | nr = head - ldata->echo_tail; |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 788 | if (nr < ECHO_COMMIT_WATERMARK || |
| 789 | (nr % ECHO_BLOCK > old % ECHO_BLOCK)) { |
| 790 | mutex_unlock(&ldata->output_lock); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 791 | return; |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 792 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 793 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 794 | ldata->echo_commit = head; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 795 | echoed = __process_echoes(tty); |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 796 | mutex_unlock(&ldata->output_lock); |
| 797 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 798 | if (echoed && tty->ops->flush_chars) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 799 | tty->ops->flush_chars(tty); |
| 800 | } |
| 801 | |
| 802 | static void process_echoes(struct tty_struct *tty) |
| 803 | { |
| 804 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 805 | size_t echoed; |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 806 | |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 807 | if (ldata->echo_mark == ldata->echo_tail) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 808 | return; |
| 809 | |
| 810 | mutex_lock(&ldata->output_lock); |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 811 | ldata->echo_commit = ldata->echo_mark; |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 812 | echoed = __process_echoes(tty); |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 813 | mutex_unlock(&ldata->output_lock); |
| 814 | |
Peter Hurley | bc5b1ec | 2013-06-15 10:04:27 -0400 | [diff] [blame] | 815 | if (echoed && tty->ops->flush_chars) |
Peter Hurley | 019ebdf | 2013-06-15 10:04:25 -0400 | [diff] [blame] | 816 | tty->ops->flush_chars(tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 817 | } |
| 818 | |
Peter Hurley | 1075a6e | 2013-12-09 18:06:07 -0500 | [diff] [blame] | 819 | /* NB: echo_mark and echo_head should be equivalent here */ |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 820 | static void flush_echoes(struct tty_struct *tty) |
| 821 | { |
| 822 | struct n_tty_data *ldata = tty->disc_data; |
| 823 | |
Peter Hurley | 39434ab | 2013-11-29 12:56:10 -0500 | [diff] [blame] | 824 | if ((!L_ECHO(tty) && !L_ECHONL(tty)) || |
| 825 | ldata->echo_commit == ldata->echo_head) |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 826 | return; |
| 827 | |
| 828 | mutex_lock(&ldata->output_lock); |
| 829 | ldata->echo_commit = ldata->echo_head; |
| 830 | __process_echoes(tty); |
| 831 | mutex_unlock(&ldata->output_lock); |
| 832 | } |
| 833 | |
Carl van Schaik | b38f174 | 2018-07-03 12:02:30 +1000 | [diff] [blame^] | 834 | #if defined(CONFIG_TTY_FLUSH_LOCAL_ECHO) |
| 835 | static void continue_process_echoes(struct work_struct *work) |
| 836 | { |
| 837 | struct tty_struct *tty = |
| 838 | container_of(work, struct tty_struct, echo_delayed_work.work); |
| 839 | struct n_tty_data *ldata = tty->disc_data; |
| 840 | |
| 841 | mutex_lock(&ldata->output_lock); |
| 842 | tty->delayed_work = 0; |
| 843 | __process_echoes(tty); |
| 844 | mutex_unlock(&ldata->output_lock); |
| 845 | } |
| 846 | #endif |
| 847 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 848 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 849 | * add_echo_byte - add a byte to the echo buffer |
| 850 | * @c: unicode byte to echo |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 851 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 852 | * |
| 853 | * Add a character or operation byte to the echo buffer. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 854 | */ |
| 855 | |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 856 | static inline void add_echo_byte(unsigned char c, struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 857 | { |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 858 | *echo_buf_addr(ldata, ldata->echo_head) = c; |
| 859 | smp_wmb(); /* Matches smp_rmb() in echo_buf(). */ |
| 860 | ldata->echo_head++; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 861 | } |
| 862 | |
| 863 | /** |
| 864 | * echo_move_back_col - add operation to move back a column |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 865 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 866 | * |
| 867 | * Add an operation to the echo buffer to move back one column. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 868 | */ |
| 869 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 870 | static void echo_move_back_col(struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 871 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 872 | add_echo_byte(ECHO_OP_START, ldata); |
| 873 | add_echo_byte(ECHO_OP_MOVE_BACK_COL, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 874 | } |
| 875 | |
| 876 | /** |
| 877 | * echo_set_canon_col - add operation to set the canon column |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 878 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 879 | * |
| 880 | * Add an operation to the echo buffer to set the canon column |
| 881 | * to the current column. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 882 | */ |
| 883 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 884 | static void echo_set_canon_col(struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 885 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 886 | add_echo_byte(ECHO_OP_START, ldata); |
| 887 | add_echo_byte(ECHO_OP_SET_CANON_COL, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 888 | } |
| 889 | |
| 890 | /** |
| 891 | * echo_erase_tab - add operation to erase a tab |
| 892 | * @num_chars: number of character columns already used |
| 893 | * @after_tab: true if num_chars starts after a previous tab |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 894 | * @ldata: n_tty data |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 895 | * |
| 896 | * Add an operation to the echo buffer to erase a tab. |
| 897 | * |
| 898 | * Called by the eraser function, which knows how many character |
| 899 | * columns have been used since either a previous tab or the start |
| 900 | * of input. This information will be used later, along with |
| 901 | * canon column (if applicable), to go back the correct number |
| 902 | * of columns. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 903 | */ |
| 904 | |
| 905 | static void echo_erase_tab(unsigned int num_chars, int after_tab, |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 906 | struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 907 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 908 | add_echo_byte(ECHO_OP_START, ldata); |
| 909 | add_echo_byte(ECHO_OP_ERASE_TAB, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 910 | |
| 911 | /* We only need to know this modulo 8 (tab spacing) */ |
| 912 | num_chars &= 7; |
| 913 | |
| 914 | /* Set the high bit as a flag if num_chars is after a previous tab */ |
| 915 | if (after_tab) |
| 916 | num_chars |= 0x80; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 917 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 918 | add_echo_byte(num_chars, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 919 | } |
| 920 | |
| 921 | /** |
| 922 | * echo_char_raw - echo a character raw |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 923 | * @c: unicode byte to echo |
| 924 | * @tty: terminal device |
| 925 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 926 | * Echo user input back onto the screen. This must be called only when |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 927 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 928 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 929 | * This variant does not treat control characters specially. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 930 | */ |
| 931 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 932 | static void echo_char_raw(unsigned char c, struct n_tty_data *ldata) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 933 | { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 934 | if (c == ECHO_OP_START) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 935 | add_echo_byte(ECHO_OP_START, ldata); |
| 936 | add_echo_byte(ECHO_OP_START, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 937 | } else { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 938 | add_echo_byte(c, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 939 | } |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 940 | } |
| 941 | |
| 942 | /** |
| 943 | * echo_char - echo a character |
| 944 | * @c: unicode byte to echo |
| 945 | * @tty: terminal device |
| 946 | * |
| 947 | * Echo user input back onto the screen. This must be called only when |
| 948 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
| 949 | * |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 950 | * This variant tags control characters to be echoed as "^X" |
| 951 | * (where X is the letter representing the control char). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 952 | */ |
| 953 | |
| 954 | static void echo_char(unsigned char c, struct tty_struct *tty) |
| 955 | { |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 956 | struct n_tty_data *ldata = tty->disc_data; |
| 957 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 958 | if (c == ECHO_OP_START) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 959 | add_echo_byte(ECHO_OP_START, ldata); |
| 960 | add_echo_byte(ECHO_OP_START, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 961 | } else { |
Joe Peterson | 62b2635 | 2009-09-09 15:03:47 -0600 | [diff] [blame] | 962 | if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 963 | add_echo_byte(ECHO_OP_START, ldata); |
| 964 | add_echo_byte(c, ldata); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 965 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 966 | } |
| 967 | |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 968 | /** |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 969 | * finish_erasing - complete erase |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 970 | * @ldata: n_tty data |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 971 | */ |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 972 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 973 | static inline void finish_erasing(struct n_tty_data *ldata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 974 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 975 | if (ldata->erasing) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 976 | echo_char_raw('/', ldata); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 977 | ldata->erasing = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | } |
| 979 | } |
| 980 | |
| 981 | /** |
| 982 | * eraser - handle erase function |
| 983 | * @c: character input |
| 984 | * @tty: terminal device |
| 985 | * |
Robert P. J. Day | 3a4fa0a | 2007-10-19 23:10:43 +0200 | [diff] [blame] | 986 | * Perform erase and necessary output when an erase character is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 987 | * present in the stream from the driver layer. Handles the complexities |
| 988 | * of UTF-8 multibyte symbols. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 989 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 990 | * n_tty_receive_buf()/producer path: |
| 991 | * caller holds non-exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 993 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | static void eraser(unsigned char c, struct tty_struct *tty) |
| 995 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 996 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | enum { ERASE, WERASE, KILL } kill_type; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 998 | size_t head; |
| 999 | size_t cnt; |
| 1000 | int seen_alnums; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1001 | |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1002 | if (ldata->read_head == ldata->canon_head) { |
Joe Peterson | 7e94b1d | 2009-01-02 13:43:40 +0000 | [diff] [blame] | 1003 | /* process_output('\a', tty); */ /* what do you think? */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | return; |
| 1005 | } |
| 1006 | if (c == ERASE_CHAR(tty)) |
| 1007 | kill_type = ERASE; |
| 1008 | else if (c == WERASE_CHAR(tty)) |
| 1009 | kill_type = WERASE; |
| 1010 | else { |
| 1011 | if (!L_ECHO(tty)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1012 | ldata->read_head = ldata->canon_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1013 | return; |
| 1014 | } |
| 1015 | if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1016 | ldata->read_head = ldata->canon_head; |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1017 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1018 | echo_char(KILL_CHAR(tty), tty); |
| 1019 | /* Add a newline if ECHOK is on and ECHOKE is off. */ |
| 1020 | if (L_ECHOK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1021 | echo_char_raw('\n', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | return; |
| 1023 | } |
| 1024 | kill_type = KILL; |
| 1025 | } |
| 1026 | |
| 1027 | seen_alnums = 0; |
Tetsuo Handa | 947dead | 2018-05-26 09:53:13 +0900 | [diff] [blame] | 1028 | while (MASK(ldata->read_head) != MASK(ldata->canon_head)) { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1029 | head = ldata->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1030 | |
| 1031 | /* erase a single possibly multibyte character */ |
| 1032 | do { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1033 | head--; |
| 1034 | c = read_buf(ldata, head); |
Tetsuo Handa | 947dead | 2018-05-26 09:53:13 +0900 | [diff] [blame] | 1035 | } while (is_continuation(c, tty) && |
| 1036 | MASK(head) != MASK(ldata->canon_head)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1037 | |
| 1038 | /* do not partially erase */ |
| 1039 | if (is_continuation(c, tty)) |
| 1040 | break; |
| 1041 | |
| 1042 | if (kill_type == WERASE) { |
| 1043 | /* Equivalent to BSD's ALTWERASE. */ |
| 1044 | if (isalnum(c) || c == '_') |
| 1045 | seen_alnums++; |
| 1046 | else if (seen_alnums) |
| 1047 | break; |
| 1048 | } |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1049 | cnt = ldata->read_head - head; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1050 | ldata->read_head = head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1051 | if (L_ECHO(tty)) { |
| 1052 | if (L_ECHOPRT(tty)) { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1053 | if (!ldata->erasing) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1054 | echo_char_raw('\\', ldata); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1055 | ldata->erasing = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1056 | } |
| 1057 | /* if cnt > 1, output a multi-byte character */ |
| 1058 | echo_char(c, tty); |
| 1059 | while (--cnt > 0) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1060 | head++; |
| 1061 | echo_char_raw(read_buf(ldata, head), ldata); |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1062 | echo_move_back_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1063 | } |
| 1064 | } else if (kill_type == ERASE && !L_ECHOE(tty)) { |
| 1065 | echo_char(ERASE_CHAR(tty), tty); |
| 1066 | } else if (c == '\t') { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1067 | unsigned int num_chars = 0; |
| 1068 | int after_tab = 0; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1069 | size_t tail = ldata->read_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1070 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1071 | /* |
| 1072 | * Count the columns used for characters |
| 1073 | * since the start of input or after a |
| 1074 | * previous tab. |
| 1075 | * This info is used to go back the correct |
| 1076 | * number of columns. |
| 1077 | */ |
Tetsuo Handa | 947dead | 2018-05-26 09:53:13 +0900 | [diff] [blame] | 1078 | while (MASK(tail) != MASK(ldata->canon_head)) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1079 | tail--; |
| 1080 | c = read_buf(ldata, tail); |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1081 | if (c == '\t') { |
| 1082 | after_tab = 1; |
| 1083 | break; |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 1084 | } else if (iscntrl(c)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1085 | if (L_ECHOCTL(tty)) |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 1086 | num_chars += 2; |
| 1087 | } else if (!is_continuation(c, tty)) { |
| 1088 | num_chars++; |
| 1089 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | } |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1091 | echo_erase_tab(num_chars, after_tab, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1092 | } else { |
| 1093 | if (iscntrl(c) && L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1094 | echo_char_raw('\b', ldata); |
| 1095 | echo_char_raw(' ', ldata); |
| 1096 | echo_char_raw('\b', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1097 | } |
| 1098 | if (!iscntrl(c) || L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1099 | echo_char_raw('\b', ldata); |
| 1100 | echo_char_raw(' ', ldata); |
| 1101 | echo_char_raw('\b', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1102 | } |
| 1103 | } |
| 1104 | } |
| 1105 | if (kill_type == ERASE) |
| 1106 | break; |
| 1107 | } |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1108 | if (ldata->read_head == ldata->canon_head && L_ECHO(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1109 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1110 | } |
| 1111 | |
| 1112 | /** |
| 1113 | * isig - handle the ISIG optio |
| 1114 | * @sig: signal |
| 1115 | * @tty: terminal |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1116 | * |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1117 | * Called when a signal is being sent due to terminal input. |
| 1118 | * Called from the driver receive_buf path so serialized. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1119 | * |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1120 | * Performs input and output flush if !NOFLSH. In this context, the echo |
| 1121 | * buffer is 'output'. The signal is processed first to alert any current |
| 1122 | * readers or writers to discontinue and exit their i/o loops. |
| 1123 | * |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1124 | * Locking: ctrl_lock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1125 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1126 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1127 | static void __isig(int sig, struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1128 | { |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1129 | struct pid *tty_pgrp = tty_get_pgrp(tty); |
| 1130 | if (tty_pgrp) { |
| 1131 | kill_pgrp(tty_pgrp, sig, 1); |
| 1132 | put_pid(tty_pgrp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | } |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1134 | } |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1135 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1136 | static void isig(int sig, struct tty_struct *tty) |
| 1137 | { |
| 1138 | struct n_tty_data *ldata = tty->disc_data; |
| 1139 | |
| 1140 | if (L_NOFLSH(tty)) { |
| 1141 | /* signal only */ |
| 1142 | __isig(sig, tty); |
| 1143 | |
| 1144 | } else { /* signal and flush */ |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1145 | up_read(&tty->termios_rwsem); |
| 1146 | down_write(&tty->termios_rwsem); |
| 1147 | |
Peter Hurley | 3b19e03 | 2015-06-27 09:21:32 -0400 | [diff] [blame] | 1148 | __isig(sig, tty); |
| 1149 | |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1150 | /* clear echo buffer */ |
| 1151 | mutex_lock(&ldata->output_lock); |
| 1152 | ldata->echo_head = ldata->echo_tail = 0; |
| 1153 | ldata->echo_mark = ldata->echo_commit = 0; |
| 1154 | mutex_unlock(&ldata->output_lock); |
| 1155 | |
| 1156 | /* clear output buffer */ |
| 1157 | tty_driver_flush_buffer(tty); |
| 1158 | |
| 1159 | /* clear input buffer */ |
| 1160 | reset_buffer_flags(tty->disc_data); |
| 1161 | |
| 1162 | /* notify pty master of flush */ |
| 1163 | if (tty->link) |
| 1164 | n_tty_packet_mode_flush(tty); |
| 1165 | |
| 1166 | up_write(&tty->termios_rwsem); |
| 1167 | down_read(&tty->termios_rwsem); |
| 1168 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1169 | } |
| 1170 | |
| 1171 | /** |
| 1172 | * n_tty_receive_break - handle break |
| 1173 | * @tty: terminal |
| 1174 | * |
| 1175 | * An RS232 break event has been hit in the incoming bitstream. This |
| 1176 | * can cause a variety of events depending upon the termios settings. |
| 1177 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1178 | * n_tty_receive_buf()/producer path: |
| 1179 | * caller holds non-exclusive termios_rwsem |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1180 | * |
| 1181 | * Note: may get exclusive termios_rwsem if flushing input buffer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1182 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1183 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1184 | static void n_tty_receive_break(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1185 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1186 | struct n_tty_data *ldata = tty->disc_data; |
| 1187 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1188 | if (I_IGNBRK(tty)) |
| 1189 | return; |
| 1190 | if (I_BRKINT(tty)) { |
Peter Hurley | 8c985d1 | 2013-03-06 08:38:19 -0500 | [diff] [blame] | 1191 | isig(SIGINT, tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1192 | return; |
| 1193 | } |
| 1194 | if (I_PARMRK(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1195 | put_tty_queue('\377', ldata); |
| 1196 | put_tty_queue('\0', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1197 | } |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1198 | put_tty_queue('\0', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1199 | } |
| 1200 | |
| 1201 | /** |
| 1202 | * n_tty_receive_overrun - handle overrun reporting |
| 1203 | * @tty: terminal |
| 1204 | * |
| 1205 | * Data arrived faster than we could process it. While the tty |
| 1206 | * driver has flagged this the bits that were missed are gone |
| 1207 | * forever. |
| 1208 | * |
| 1209 | * Called from the receive_buf path so single threaded. Does not |
| 1210 | * need locking as num_overrun and overrun_time are function |
| 1211 | * private. |
| 1212 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1213 | |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1214 | static void n_tty_receive_overrun(struct tty_struct *tty) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1215 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1216 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1217 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1218 | ldata->num_overrun++; |
| 1219 | if (time_after(jiffies, ldata->overrun_time + HZ) || |
| 1220 | time_after(ldata->overrun_time, jiffies)) { |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 1221 | tty_warn(tty, "%d input overrun(s)\n", ldata->num_overrun); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1222 | ldata->overrun_time = jiffies; |
| 1223 | ldata->num_overrun = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1224 | } |
| 1225 | } |
| 1226 | |
| 1227 | /** |
| 1228 | * n_tty_receive_parity_error - error notifier |
| 1229 | * @tty: terminal device |
| 1230 | * @c: character |
| 1231 | * |
| 1232 | * Process a parity error and queue the right data to indicate |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1233 | * the error case if necessary. |
| 1234 | * |
| 1235 | * n_tty_receive_buf()/producer path: |
| 1236 | * caller holds non-exclusive termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1237 | */ |
Peter Hurley | 4b29349 | 2013-07-24 08:29:55 -0400 | [diff] [blame] | 1238 | static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1239 | { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1240 | struct n_tty_data *ldata = tty->disc_data; |
| 1241 | |
Peter Hurley | 66528f9 | 2014-06-16 08:10:42 -0400 | [diff] [blame] | 1242 | if (I_INPCK(tty)) { |
| 1243 | if (I_IGNPAR(tty)) |
| 1244 | return; |
| 1245 | if (I_PARMRK(tty)) { |
| 1246 | put_tty_queue('\377', ldata); |
| 1247 | put_tty_queue('\0', ldata); |
| 1248 | put_tty_queue(c, ldata); |
| 1249 | } else |
| 1250 | put_tty_queue('\0', ldata); |
| 1251 | } else |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1252 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | } |
| 1254 | |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1255 | static void |
| 1256 | n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c) |
| 1257 | { |
Peter Hurley | d2b6f44 | 2015-01-17 15:42:06 -0500 | [diff] [blame] | 1258 | isig(signal, tty); |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1259 | if (I_IXON(tty)) |
| 1260 | start_tty(tty); |
| 1261 | if (L_ECHO(tty)) { |
| 1262 | echo_char(c, tty); |
| 1263 | commit_echoes(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1264 | } else |
| 1265 | process_echoes(tty); |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1266 | return; |
| 1267 | } |
| 1268 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1269 | /** |
| 1270 | * n_tty_receive_char - perform processing |
| 1271 | * @tty: terminal device |
| 1272 | * @c: character |
| 1273 | * |
| 1274 | * Process an individual character of input received from the driver. |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1275 | * This is serialized with respect to itself by the rules for the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1276 | * driver above. |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1277 | * |
| 1278 | * n_tty_receive_buf()/producer path: |
| 1279 | * caller holds non-exclusive termios_rwsem |
| 1280 | * publishes canon_head if canonical mode is active |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1281 | * |
| 1282 | * Returns 1 if LNEXT was received, else returns 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | */ |
| 1284 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1285 | static int |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1286 | n_tty_receive_char_special(struct tty_struct *tty, unsigned char c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1287 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1288 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1289 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1290 | if (I_IXON(tty)) { |
| 1291 | if (c == START_CHAR(tty)) { |
| 1292 | start_tty(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1293 | process_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1294 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | } |
| 1296 | if (c == STOP_CHAR(tty)) { |
| 1297 | stop_tty(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1298 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1299 | } |
| 1300 | } |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1301 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1302 | if (L_ISIG(tty)) { |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1303 | if (c == INTR_CHAR(tty)) { |
| 1304 | n_tty_receive_signal_char(tty, SIGINT, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1305 | return 0; |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1306 | } else if (c == QUIT_CHAR(tty)) { |
| 1307 | n_tty_receive_signal_char(tty, SIGQUIT, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1308 | return 0; |
Peter Hurley | b0ac50b | 2013-06-15 10:21:23 -0400 | [diff] [blame] | 1309 | } else if (c == SUSP_CHAR(tty)) { |
| 1310 | n_tty_receive_signal_char(tty, SIGTSTP, c); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1311 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1312 | } |
| 1313 | } |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1314 | |
Peter Hurley | 855df3c | 2013-07-24 08:29:50 -0400 | [diff] [blame] | 1315 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1316 | start_tty(tty); |
| 1317 | process_echoes(tty); |
| 1318 | } |
| 1319 | |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1320 | if (c == '\r') { |
| 1321 | if (I_IGNCR(tty)) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1322 | return 0; |
Joe Peterson | 575537b3 | 2008-04-30 00:53:30 -0700 | [diff] [blame] | 1323 | if (I_ICRNL(tty)) |
| 1324 | c = '\n'; |
| 1325 | } else if (c == '\n' && I_INLCR(tty)) |
| 1326 | c = '\r'; |
| 1327 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1328 | if (ldata->icanon) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1329 | if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) || |
| 1330 | (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) { |
| 1331 | eraser(c, tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1332 | commit_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1333 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1334 | } |
| 1335 | if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1336 | ldata->lnext = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | if (L_ECHO(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1338 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1339 | if (L_ECHOCTL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1340 | echo_char_raw('^', ldata); |
| 1341 | echo_char_raw('\b', ldata); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1342 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | } |
| 1344 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1345 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1346 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1347 | if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1348 | size_t tail = ldata->canon_head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1349 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1350 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1351 | echo_char(c, tty); |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1352 | echo_char_raw('\n', ldata); |
Tetsuo Handa | 947dead | 2018-05-26 09:53:13 +0900 | [diff] [blame] | 1353 | while (MASK(tail) != MASK(ldata->read_head)) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1354 | echo_char(read_buf(ldata, tail), tty); |
| 1355 | tail++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1356 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1357 | commit_echoes(tty); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1358 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1359 | } |
| 1360 | if (c == '\n') { |
Joe Peterson | acc71bb | 2009-01-02 13:43:32 +0000 | [diff] [blame] | 1361 | if (L_ECHO(tty) || L_ECHONL(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1362 | echo_char_raw('\n', ldata); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1363 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1364 | } |
| 1365 | goto handle_newline; |
| 1366 | } |
| 1367 | if (c == EOF_CHAR(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1368 | c = __DISABLED_CHAR; |
| 1369 | goto handle_newline; |
| 1370 | } |
| 1371 | if ((c == EOL_CHAR(tty)) || |
| 1372 | (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) { |
| 1373 | /* |
| 1374 | * XXX are EOL_CHAR and EOL2_CHAR echoed?!? |
| 1375 | */ |
| 1376 | if (L_ECHO(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1377 | /* Record the column of first canon char. */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1378 | if (ldata->canon_head == ldata->read_head) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1379 | echo_set_canon_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1380 | echo_char(c, tty); |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1381 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1382 | } |
| 1383 | /* |
| 1384 | * XXX does PARMRK doubling happen for |
| 1385 | * EOL_CHAR and EOL2_CHAR? |
| 1386 | */ |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1387 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1388 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1389 | |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1390 | handle_newline: |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1391 | set_bit(ldata->read_head & (N_TTY_BUF_SIZE - 1), ldata->read_flags); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1392 | put_tty_queue(c, ldata); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1393 | smp_store_release(&ldata->canon_head, ldata->read_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1394 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1395 | wake_up_interruptible_poll(&tty->read_wait, POLLIN); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1396 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1397 | } |
| 1398 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1399 | |
Joe Peterson | acc71bb | 2009-01-02 13:43:32 +0000 | [diff] [blame] | 1400 | if (L_ECHO(tty)) { |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1401 | finish_erasing(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1402 | if (c == '\n') |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1403 | echo_char_raw('\n', ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1404 | else { |
| 1405 | /* Record the column of first canon char. */ |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 1406 | if (ldata->canon_head == ldata->read_head) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1407 | echo_set_canon_col(ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | echo_char(c, tty); |
| 1409 | } |
Peter Hurley | 17bd790 | 2013-06-15 10:04:24 -0400 | [diff] [blame] | 1410 | commit_echoes(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1411 | } |
| 1412 | |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1413 | /* PARMRK doubling check */ |
| 1414 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1415 | put_tty_queue(c, ldata); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1416 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 1417 | put_tty_queue(c, ldata); |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1418 | return 0; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1419 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1420 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1421 | static inline void |
| 1422 | n_tty_receive_char_inline(struct tty_struct *tty, unsigned char c) |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1423 | { |
| 1424 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1425 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1426 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1427 | start_tty(tty); |
| 1428 | process_echoes(tty); |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1429 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1430 | if (L_ECHO(tty)) { |
| 1431 | finish_erasing(ldata); |
| 1432 | /* Record the column of first canon char. */ |
| 1433 | if (ldata->canon_head == ldata->read_head) |
| 1434 | echo_set_canon_col(ldata); |
| 1435 | echo_char(c, tty); |
| 1436 | commit_echoes(tty); |
| 1437 | } |
Peter Hurley | 001ba92 | 2013-12-02 14:24:44 -0500 | [diff] [blame] | 1438 | /* PARMRK doubling check */ |
| 1439 | if (c == (unsigned char) '\377' && I_PARMRK(tty)) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1440 | put_tty_queue(c, ldata); |
| 1441 | put_tty_queue(c, ldata); |
| 1442 | } |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1443 | |
Peter Hurley | eb3e466 | 2013-12-02 14:24:42 -0500 | [diff] [blame] | 1444 | static void n_tty_receive_char(struct tty_struct *tty, unsigned char c) |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1445 | { |
| 1446 | n_tty_receive_char_inline(tty, c); |
Peter Hurley | 4b1f79c | 2013-07-24 08:29:51 -0400 | [diff] [blame] | 1447 | } |
| 1448 | |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1449 | static inline void |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1450 | n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c) |
| 1451 | { |
| 1452 | struct n_tty_data *ldata = tty->disc_data; |
| 1453 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1454 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) { |
| 1455 | start_tty(tty); |
| 1456 | process_echoes(tty); |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1457 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1458 | if (L_ECHO(tty)) { |
| 1459 | finish_erasing(ldata); |
| 1460 | /* Record the column of first canon char. */ |
| 1461 | if (ldata->canon_head == ldata->read_head) |
| 1462 | echo_set_canon_col(ldata); |
| 1463 | echo_char(c, tty); |
| 1464 | commit_echoes(tty); |
| 1465 | } |
| 1466 | put_tty_queue(c, ldata); |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1467 | } |
| 1468 | |
Peter Hurley | 8dc4b25 | 2013-12-02 14:24:43 -0500 | [diff] [blame] | 1469 | static void n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c) |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1470 | { |
| 1471 | if (I_ISTRIP(tty)) |
| 1472 | c &= 0x7f; |
| 1473 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1474 | c = tolower(c); |
| 1475 | |
| 1476 | if (I_IXON(tty)) { |
| 1477 | if (c == STOP_CHAR(tty)) |
| 1478 | stop_tty(tty); |
| 1479 | else if (c == START_CHAR(tty) || |
| 1480 | (tty->stopped && !tty->flow_stopped && I_IXANY(tty) && |
| 1481 | c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && |
| 1482 | c != SUSP_CHAR(tty))) { |
| 1483 | start_tty(tty); |
| 1484 | process_echoes(tty); |
| 1485 | } |
| 1486 | } |
| 1487 | } |
| 1488 | |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1489 | static void |
| 1490 | n_tty_receive_char_flagged(struct tty_struct *tty, unsigned char c, char flag) |
| 1491 | { |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1492 | switch (flag) { |
| 1493 | case TTY_BREAK: |
| 1494 | n_tty_receive_break(tty); |
| 1495 | break; |
| 1496 | case TTY_PARITY: |
| 1497 | case TTY_FRAME: |
| 1498 | n_tty_receive_parity_error(tty, c); |
| 1499 | break; |
| 1500 | case TTY_OVERRUN: |
| 1501 | n_tty_receive_overrun(tty); |
| 1502 | break; |
| 1503 | default: |
Peter Hurley | 339f36b | 2015-11-08 13:01:13 -0500 | [diff] [blame] | 1504 | tty_err(tty, "unknown flag %d\n", flag); |
Peter Hurley | d2f8d7a | 2013-06-15 10:21:24 -0400 | [diff] [blame] | 1505 | break; |
| 1506 | } |
| 1507 | } |
| 1508 | |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1509 | static void |
| 1510 | n_tty_receive_char_lnext(struct tty_struct *tty, unsigned char c, char flag) |
| 1511 | { |
| 1512 | struct n_tty_data *ldata = tty->disc_data; |
| 1513 | |
| 1514 | ldata->lnext = 0; |
| 1515 | if (likely(flag == TTY_NORMAL)) { |
| 1516 | if (I_ISTRIP(tty)) |
| 1517 | c &= 0x7f; |
| 1518 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1519 | c = tolower(c); |
| 1520 | n_tty_receive_char(tty, c); |
| 1521 | } else |
| 1522 | n_tty_receive_char_flagged(tty, c, flag); |
| 1523 | } |
| 1524 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1525 | static void |
| 1526 | n_tty_receive_buf_real_raw(struct tty_struct *tty, const unsigned char *cp, |
| 1527 | char *fp, int count) |
| 1528 | { |
| 1529 | struct n_tty_data *ldata = tty->disc_data; |
| 1530 | size_t n, head; |
| 1531 | |
| 1532 | head = ldata->read_head & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1533 | n = min_t(size_t, count, N_TTY_BUF_SIZE - head); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1534 | memcpy(read_buf_addr(ldata, head), cp, n); |
| 1535 | ldata->read_head += n; |
| 1536 | cp += n; |
| 1537 | count -= n; |
| 1538 | |
| 1539 | head = ldata->read_head & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1540 | n = min_t(size_t, count, N_TTY_BUF_SIZE - head); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1541 | memcpy(read_buf_addr(ldata, head), cp, n); |
| 1542 | ldata->read_head += n; |
| 1543 | } |
| 1544 | |
Peter Hurley | 554117b | 2013-06-15 10:21:25 -0400 | [diff] [blame] | 1545 | static void |
| 1546 | n_tty_receive_buf_raw(struct tty_struct *tty, const unsigned char *cp, |
| 1547 | char *fp, int count) |
| 1548 | { |
| 1549 | struct n_tty_data *ldata = tty->disc_data; |
| 1550 | char flag = TTY_NORMAL; |
| 1551 | |
| 1552 | while (count--) { |
| 1553 | if (fp) |
| 1554 | flag = *fp++; |
| 1555 | if (likely(flag == TTY_NORMAL)) |
| 1556 | put_tty_queue(*cp++, ldata); |
| 1557 | else |
| 1558 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1559 | } |
| 1560 | } |
| 1561 | |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1562 | static void |
| 1563 | n_tty_receive_buf_closing(struct tty_struct *tty, const unsigned char *cp, |
| 1564 | char *fp, int count) |
| 1565 | { |
| 1566 | char flag = TTY_NORMAL; |
| 1567 | |
| 1568 | while (count--) { |
| 1569 | if (fp) |
| 1570 | flag = *fp++; |
| 1571 | if (likely(flag == TTY_NORMAL)) |
| 1572 | n_tty_receive_char_closing(tty, *cp++); |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1573 | } |
| 1574 | } |
| 1575 | |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1576 | static void |
| 1577 | n_tty_receive_buf_standard(struct tty_struct *tty, const unsigned char *cp, |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1578 | char *fp, int count) |
| 1579 | { |
| 1580 | struct n_tty_data *ldata = tty->disc_data; |
| 1581 | char flag = TTY_NORMAL; |
| 1582 | |
| 1583 | while (count--) { |
| 1584 | if (fp) |
| 1585 | flag = *fp++; |
| 1586 | if (likely(flag == TTY_NORMAL)) { |
| 1587 | unsigned char c = *cp++; |
| 1588 | |
| 1589 | if (I_ISTRIP(tty)) |
| 1590 | c &= 0x7f; |
| 1591 | if (I_IUCLC(tty) && L_IEXTEN(tty)) |
| 1592 | c = tolower(c); |
| 1593 | if (L_EXTPROC(tty)) { |
| 1594 | put_tty_queue(c, ldata); |
| 1595 | continue; |
| 1596 | } |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1597 | if (!test_bit(c, ldata->char_map)) |
| 1598 | n_tty_receive_char_inline(tty, c); |
| 1599 | else if (n_tty_receive_char_special(tty, c) && count) { |
| 1600 | if (fp) |
| 1601 | flag = *fp++; |
| 1602 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1603 | count--; |
| 1604 | } |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1605 | } else |
| 1606 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1607 | } |
| 1608 | } |
| 1609 | |
| 1610 | static void |
| 1611 | n_tty_receive_buf_fast(struct tty_struct *tty, const unsigned char *cp, |
| 1612 | char *fp, int count) |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1613 | { |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1614 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1615 | char flag = TTY_NORMAL; |
| 1616 | |
| 1617 | while (count--) { |
| 1618 | if (fp) |
| 1619 | flag = *fp++; |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1620 | if (likely(flag == TTY_NORMAL)) { |
| 1621 | unsigned char c = *cp++; |
| 1622 | |
| 1623 | if (!test_bit(c, ldata->char_map)) |
| 1624 | n_tty_receive_char_fast(tty, c); |
| 1625 | else if (n_tty_receive_char_special(tty, c) && count) { |
| 1626 | if (fp) |
| 1627 | flag = *fp++; |
| 1628 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1629 | count--; |
| 1630 | } |
| 1631 | } else |
Peter Hurley | 7d88d63 | 2013-07-24 08:29:49 -0400 | [diff] [blame] | 1632 | n_tty_receive_char_flagged(tty, *cp++, flag); |
| 1633 | } |
| 1634 | } |
| 1635 | |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1636 | static void __receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1637 | char *fp, int count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1638 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1639 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | a1dd30e | 2013-06-15 10:21:26 -0400 | [diff] [blame] | 1640 | bool preops = I_ISTRIP(tty) || (I_IUCLC(tty) && L_IEXTEN(tty)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1641 | |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1642 | if (ldata->real_raw) |
| 1643 | n_tty_receive_buf_real_raw(tty, cp, fp, count); |
Peter Hurley | a1dd30e | 2013-06-15 10:21:26 -0400 | [diff] [blame] | 1644 | else if (ldata->raw || (L_EXTPROC(tty) && !preops)) |
Peter Hurley | 554117b | 2013-06-15 10:21:25 -0400 | [diff] [blame] | 1645 | n_tty_receive_buf_raw(tty, cp, fp, count); |
Peter Hurley | ad0cc7b | 2013-06-15 10:21:27 -0400 | [diff] [blame] | 1646 | else if (tty->closing && !L_EXTPROC(tty)) |
| 1647 | n_tty_receive_buf_closing(tty, cp, fp, count); |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1648 | else { |
Peter Hurley | e60d27c | 2013-07-24 08:29:56 -0400 | [diff] [blame] | 1649 | if (ldata->lnext) { |
| 1650 | char flag = TTY_NORMAL; |
| 1651 | |
| 1652 | if (fp) |
| 1653 | flag = *fp++; |
| 1654 | n_tty_receive_char_lnext(tty, *cp++, flag); |
| 1655 | count--; |
| 1656 | } |
| 1657 | |
Peter Hurley | 7de971b | 2013-07-24 08:29:53 -0400 | [diff] [blame] | 1658 | if (!preops && !I_PARMRK(tty)) |
Peter Hurley | 6baad00 | 2013-07-24 08:29:52 -0400 | [diff] [blame] | 1659 | n_tty_receive_buf_fast(tty, cp, fp, count); |
| 1660 | else |
| 1661 | n_tty_receive_buf_standard(tty, cp, fp, count); |
Peter Hurley | cbfd034 | 2013-06-15 10:04:26 -0400 | [diff] [blame] | 1662 | |
| 1663 | flush_echoes(tty); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1664 | if (tty->ops->flush_chars) |
| 1665 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1666 | } |
| 1667 | |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1668 | if (ldata->icanon && !L_EXTPROC(tty)) |
| 1669 | return; |
| 1670 | |
| 1671 | /* publish read_head to consumer */ |
| 1672 | smp_store_release(&ldata->commit_head, ldata->read_head); |
| 1673 | |
Peter Hurley | 33d7136 | 2016-01-09 21:45:08 -0800 | [diff] [blame] | 1674 | if (read_cnt(ldata)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1675 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1676 | wake_up_interruptible_poll(&tty->read_wait, POLLIN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1677 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1678 | } |
| 1679 | |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1680 | /** |
| 1681 | * n_tty_receive_buf_common - process input |
| 1682 | * @tty: device to receive input |
| 1683 | * @cp: input chars |
| 1684 | * @fp: flags for each char (if NULL, all chars are TTY_NORMAL) |
| 1685 | * @count: number of input chars in @cp |
| 1686 | * |
| 1687 | * Called by the terminal driver when a block of characters has |
| 1688 | * been received. This function must be called from soft contexts |
| 1689 | * not from interrupt context. The driver is responsible for making |
| 1690 | * calls one at a time and in order (or using flush_to_ldisc) |
| 1691 | * |
| 1692 | * Returns the # of input chars from @cp which were processed. |
| 1693 | * |
| 1694 | * In canonical mode, the maximum line length is 4096 chars (including |
| 1695 | * the line termination char); lines longer than 4096 chars are |
| 1696 | * truncated. After 4095 chars, input data is still processed but |
| 1697 | * not stored. Overflow processing ensures the tty can always |
| 1698 | * receive more input until at least one line can be read. |
| 1699 | * |
| 1700 | * In non-canonical mode, the read buffer will only accept 4095 chars; |
| 1701 | * this provides the necessary space for a newline char if the input |
| 1702 | * mode is switched to canonical. |
| 1703 | * |
| 1704 | * Note it is possible for the read buffer to _contain_ 4096 chars |
| 1705 | * in non-canonical mode: the read buffer could already contain the |
| 1706 | * maximum canon line of 4096 chars when the mode is switched to |
| 1707 | * non-canonical. |
| 1708 | * |
| 1709 | * n_tty_receive_buf()/producer path: |
| 1710 | * claims non-exclusive termios_rwsem |
| 1711 | * publishes commit_head or canon_head |
| 1712 | */ |
Peter Hurley | 5c32d12 | 2013-12-02 14:24:41 -0500 | [diff] [blame] | 1713 | static int |
| 1714 | n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp, |
| 1715 | char *fp, int count, int flow) |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1716 | { |
| 1717 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1718 | int room, n, rcvd = 0, overflow; |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1719 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 1720 | down_read(&tty->termios_rwsem); |
| 1721 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1722 | while (1) { |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1723 | /* |
Peter Hurley | 06c49f9 | 2015-01-16 15:05:38 -0500 | [diff] [blame] | 1724 | * When PARMRK is set, each input char may take up to 3 chars |
| 1725 | * in the read buf; reduce the buffer space avail by 3x |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1726 | * |
| 1727 | * If we are doing input canonicalization, and there are no |
| 1728 | * pending newlines, let characters through without limit, so |
| 1729 | * that erase characters will be handled. Other excess |
| 1730 | * characters will be beeped. |
| 1731 | * |
| 1732 | * paired with store in *_copy_from_read_buf() -- guarantees |
| 1733 | * the consumer has loaded the data in read_buf up to the new |
| 1734 | * read_tail (so this producer will not overwrite unread data) |
| 1735 | */ |
| 1736 | size_t tail = smp_load_acquire(&ldata->read_tail); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1737 | |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1738 | room = N_TTY_BUF_SIZE - (ldata->read_head - tail); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1739 | if (I_PARMRK(tty)) |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1740 | room = (room + 2) / 3; |
| 1741 | room--; |
| 1742 | if (room <= 0) { |
| 1743 | overflow = ldata->icanon && ldata->canon_head == tail; |
| 1744 | if (overflow && room < 0) |
| 1745 | ldata->read_head--; |
| 1746 | room = overflow; |
| 1747 | ldata->no_room = flow && !room; |
| 1748 | } else |
| 1749 | overflow = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1750 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1751 | n = min(count, room); |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1752 | if (!n) |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1753 | break; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1754 | |
| 1755 | /* ignore parity errors if handling overflow */ |
| 1756 | if (!overflow || !fp || *fp != TTY_PARITY) |
| 1757 | __receive_buf(tty, cp, fp, n); |
| 1758 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1759 | cp += n; |
| 1760 | if (fp) |
| 1761 | fp += n; |
| 1762 | count -= n; |
| 1763 | rcvd += n; |
Peter Hurley | 4a23a4d | 2013-06-15 10:21:22 -0400 | [diff] [blame] | 1764 | } |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1765 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1766 | tty->receive_room = room; |
Peter Hurley | fb5ef9e | 2015-01-16 15:05:39 -0500 | [diff] [blame] | 1767 | |
| 1768 | /* Unthrottle if handling overflow on pty */ |
| 1769 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY) { |
| 1770 | if (overflow) { |
| 1771 | tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); |
| 1772 | tty_unthrottle_safe(tty); |
| 1773 | __tty_set_flow_change(tty, 0); |
| 1774 | } |
| 1775 | } else |
| 1776 | n_tty_check_throttle(tty); |
| 1777 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 1778 | up_read(&tty->termios_rwsem); |
| 1779 | |
Peter Hurley | 19e2ad6 | 2013-07-24 08:29:54 -0400 | [diff] [blame] | 1780 | return rcvd; |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 1781 | } |
| 1782 | |
Peter Hurley | 5c32d12 | 2013-12-02 14:24:41 -0500 | [diff] [blame] | 1783 | static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
| 1784 | char *fp, int count) |
| 1785 | { |
| 1786 | n_tty_receive_buf_common(tty, cp, fp, count, 0); |
| 1787 | } |
| 1788 | |
| 1789 | static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp, |
| 1790 | char *fp, int count) |
| 1791 | { |
| 1792 | return n_tty_receive_buf_common(tty, cp, fp, count, 1); |
| 1793 | } |
| 1794 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1795 | /** |
| 1796 | * n_tty_set_termios - termios data changed |
| 1797 | * @tty: terminal |
| 1798 | * @old: previous data |
| 1799 | * |
| 1800 | * Called by the tty layer when the user changes termios flags so |
| 1801 | * that the line discipline can plan ahead. This function cannot sleep |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1802 | * and is protected from re-entry by the tty layer. The user is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1803 | * guaranteed that this function will not be re-entered or in progress |
| 1804 | * when the ldisc is closed. |
Alan Cox | 17b8206 | 2008-10-13 10:45:06 +0100 | [diff] [blame] | 1805 | * |
Peter Hurley | 6a1c068 | 2013-06-15 09:14:23 -0400 | [diff] [blame] | 1806 | * Locking: Caller holds tty->termios_rwsem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1807 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1808 | |
| 1809 | static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1810 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1811 | struct n_tty_data *ldata = tty->disc_data; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1812 | |
Linus Torvalds | 00fc57a | 2017-12-20 17:57:06 -0800 | [diff] [blame] | 1813 | if (!old || (old->c_lflag ^ tty->termios.c_lflag) & (ICANON | EXTPROC)) { |
Jiri Slaby | 3fe780b | 2012-10-18 22:26:40 +0200 | [diff] [blame] | 1814 | bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE); |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 1815 | ldata->line_start = ldata->read_tail; |
| 1816 | if (!L_ICANON(tty) || !read_cnt(ldata)) { |
| 1817 | ldata->canon_head = ldata->read_tail; |
| 1818 | ldata->push = 0; |
| 1819 | } else { |
| 1820 | set_bit((ldata->read_head - 1) & (N_TTY_BUF_SIZE - 1), |
| 1821 | ldata->read_flags); |
| 1822 | ldata->canon_head = ldata->read_head; |
| 1823 | ldata->push = 1; |
| 1824 | } |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1825 | ldata->commit_head = ldata->read_head; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1826 | ldata->erasing = 0; |
Peter Hurley | 6f9b028 | 2013-06-15 09:14:27 -0400 | [diff] [blame] | 1827 | ldata->lnext = 0; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 1828 | } |
| 1829 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1830 | ldata->icanon = (L_ICANON(tty) != 0); |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 1831 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1832 | if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || |
| 1833 | I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || |
| 1834 | I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || |
| 1835 | I_PARMRK(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1836 | bitmap_zero(ldata->char_map, 256); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1837 | |
| 1838 | if (I_IGNCR(tty) || I_ICRNL(tty)) |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1839 | set_bit('\r', ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1840 | if (I_INLCR(tty)) |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1841 | set_bit('\n', ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1842 | |
| 1843 | if (L_ICANON(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1844 | set_bit(ERASE_CHAR(tty), ldata->char_map); |
| 1845 | set_bit(KILL_CHAR(tty), ldata->char_map); |
| 1846 | set_bit(EOF_CHAR(tty), ldata->char_map); |
| 1847 | set_bit('\n', ldata->char_map); |
| 1848 | set_bit(EOL_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1849 | if (L_IEXTEN(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1850 | set_bit(WERASE_CHAR(tty), ldata->char_map); |
| 1851 | set_bit(LNEXT_CHAR(tty), ldata->char_map); |
| 1852 | set_bit(EOL2_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1853 | if (L_ECHO(tty)) |
| 1854 | set_bit(REPRINT_CHAR(tty), |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1855 | ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1856 | } |
| 1857 | } |
| 1858 | if (I_IXON(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1859 | set_bit(START_CHAR(tty), ldata->char_map); |
| 1860 | set_bit(STOP_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1861 | } |
| 1862 | if (L_ISIG(tty)) { |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1863 | set_bit(INTR_CHAR(tty), ldata->char_map); |
| 1864 | set_bit(QUIT_CHAR(tty), ldata->char_map); |
| 1865 | set_bit(SUSP_CHAR(tty), ldata->char_map); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1866 | } |
Peter Hurley | 1bb9d56 | 2013-06-15 10:21:20 -0400 | [diff] [blame] | 1867 | clear_bit(__DISABLED_CHAR, ldata->char_map); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1868 | ldata->raw = 0; |
| 1869 | ldata->real_raw = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1870 | } else { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1871 | ldata->raw = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1872 | if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && |
| 1873 | (I_IGNPAR(tty) || !I_INPCK(tty)) && |
| 1874 | (tty->driver->flags & TTY_DRIVER_REAL_RAW)) |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1875 | ldata->real_raw = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1876 | else |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1877 | ldata->real_raw = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1878 | } |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1879 | /* |
| 1880 | * Fix tty hang when I_IXON(tty) is cleared, but the tty |
| 1881 | * been stopped by STOP_CHAR(tty) before it. |
| 1882 | */ |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1883 | if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) { |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1884 | start_tty(tty); |
Peter Hurley | e2613be | 2014-02-11 16:34:55 -0500 | [diff] [blame] | 1885 | process_echoes(tty); |
| 1886 | } |
Wang YanQing | dab73b4 | 2013-05-09 14:16:47 +0800 | [diff] [blame] | 1887 | |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 1888 | /* The termios change make the tty ready for I/O */ |
Kosuke Tatsukawa | e81107d | 2015-10-02 08:27:05 +0000 | [diff] [blame] | 1889 | wake_up_interruptible(&tty->write_wait); |
| 1890 | wake_up_interruptible(&tty->read_wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1891 | } |
| 1892 | |
| 1893 | /** |
| 1894 | * n_tty_close - close the ldisc for this tty |
| 1895 | * @tty: device |
| 1896 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1897 | * Called from the terminal layer when this line discipline is |
| 1898 | * being shut down, either because of a close or becsuse of a |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1899 | * discipline change. The function will not be called while other |
| 1900 | * ldisc methods are in progress. |
| 1901 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1902 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1903 | static void n_tty_close(struct tty_struct *tty) |
| 1904 | { |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1905 | struct n_tty_data *ldata = tty->disc_data; |
| 1906 | |
Peter Hurley | 7990131 | 2013-03-11 16:44:23 -0400 | [diff] [blame] | 1907 | if (tty->link) |
| 1908 | n_tty_packet_mode_flush(tty); |
| 1909 | |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1910 | vfree(ldata); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1911 | tty->disc_data = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1912 | } |
| 1913 | |
| 1914 | /** |
| 1915 | * n_tty_open - open an ldisc |
| 1916 | * @tty: terminal to open |
| 1917 | * |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1918 | * Called when this line discipline is being attached to the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1919 | * terminal device. Can sleep. Called serialized so that no |
| 1920 | * other events will occur in parallel. No further open will occur |
| 1921 | * until a close. |
| 1922 | */ |
| 1923 | |
| 1924 | static int n_tty_open(struct tty_struct *tty) |
| 1925 | { |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1926 | struct n_tty_data *ldata; |
| 1927 | |
Peter Hurley | 20bafb3 | 2013-06-15 10:21:19 -0400 | [diff] [blame] | 1928 | /* Currently a malloc failure here can panic */ |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 1929 | ldata = vzalloc(sizeof(*ldata)); |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1930 | if (!ldata) |
Tetsuo Handa | 9264e98 | 2018-05-26 09:53:14 +0900 | [diff] [blame] | 1931 | return -ENOMEM; |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1932 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1933 | ldata->overrun_time = jiffies; |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 1934 | mutex_init(&ldata->atomic_read_lock); |
| 1935 | mutex_init(&ldata->output_lock); |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1936 | |
Jiri Slaby | 70ece7a | 2012-10-18 22:26:38 +0200 | [diff] [blame] | 1937 | tty->disc_data = ldata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1938 | tty->closing = 0; |
Peter Hurley | b66f4fa | 2013-03-11 16:44:32 -0400 | [diff] [blame] | 1939 | /* indicate buffer work may resume */ |
| 1940 | clear_bit(TTY_LDISC_HALTED, &tty->flags); |
| 1941 | n_tty_set_termios(tty, NULL); |
| 1942 | tty_unthrottle(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1943 | return 0; |
| 1944 | } |
| 1945 | |
Peter Hurley | eafbe67 | 2013-12-02 14:24:45 -0500 | [diff] [blame] | 1946 | static inline int input_available_p(struct tty_struct *tty, int poll) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1947 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1948 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | a593480 | 2014-02-11 11:49:58 -0500 | [diff] [blame] | 1949 | int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1950 | |
Peter Hurley | 25e8d0e | 2014-02-11 18:55:30 -0500 | [diff] [blame] | 1951 | if (ldata->icanon && !L_EXTPROC(tty)) |
| 1952 | return ldata->canon_head != ldata->read_tail; |
| 1953 | else |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1954 | return ldata->commit_head - ldata->read_tail >= amt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1955 | } |
| 1956 | |
| 1957 | /** |
Thorsten Wißmann | bbd2075 | 2011-12-08 17:47:33 +0100 | [diff] [blame] | 1958 | * copy_from_read_buf - copy read data directly |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1959 | * @tty: terminal device |
| 1960 | * @b: user data |
| 1961 | * @nr: size of data |
| 1962 | * |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 1963 | * Helper function to speed up n_tty_read. It is only called when |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1964 | * ICANON is off; it copies characters straight from the tty queue to |
| 1965 | * user space directly. It can be profitably called twice; once to |
| 1966 | * drain the space from the tail pointer to the (physical) end of the |
| 1967 | * buffer, and once to drain the space from the (physical) beginning of |
| 1968 | * the buffer to head pointer. |
| 1969 | * |
Jiri Slaby | bddc715 | 2012-10-18 22:26:42 +0200 | [diff] [blame] | 1970 | * Called under the ldata->atomic_read_lock sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1971 | * |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 1972 | * n_tty_read()/consumer path: |
| 1973 | * caller holds non-exclusive termios_rwsem |
| 1974 | * read_tail published |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1975 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 1976 | |
Alan Cox | 33f0f88 | 2006-01-09 20:54:13 -0800 | [diff] [blame] | 1977 | static int copy_from_read_buf(struct tty_struct *tty, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1978 | unsigned char __user **b, |
| 1979 | size_t *nr) |
| 1980 | |
| 1981 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 1982 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1983 | int retval; |
| 1984 | size_t n; |
Jiri Slaby | 3fa10cc | 2012-04-26 20:13:00 +0200 | [diff] [blame] | 1985 | bool is_eof; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1986 | size_t head = smp_load_acquire(&ldata->commit_head); |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 1987 | size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1988 | |
| 1989 | retval = 0; |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1990 | n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1991 | n = min(*nr, n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1992 | if (n) { |
Peter Hurley | e661cf7 | 2015-11-27 14:11:03 -0500 | [diff] [blame] | 1993 | const unsigned char *from = read_buf_addr(ldata, tail); |
| 1994 | retval = copy_to_user(*b, from, n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1995 | n -= retval; |
Peter Hurley | e661cf7 | 2015-11-27 14:11:03 -0500 | [diff] [blame] | 1996 | is_eof = n == 1 && *from == EOF_CHAR(tty); |
Peter Hurley | 309426a | 2016-01-09 22:55:27 -0800 | [diff] [blame] | 1997 | tty_audit_add_data(tty, from, n); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 1998 | smp_store_release(&ldata->read_tail, ldata->read_tail + n); |
hyc@symas.com | 26df6d1 | 2010-06-22 10:14:49 -0700 | [diff] [blame] | 1999 | /* Turn single EOF into zero-length read */ |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 2000 | if (L_EXTPROC(tty) && ldata->icanon && is_eof && |
| 2001 | (head == ldata->read_tail)) |
Jiri Slaby | 3fa10cc | 2012-04-26 20:13:00 +0200 | [diff] [blame] | 2002 | n = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2003 | *b += n; |
| 2004 | *nr -= n; |
| 2005 | } |
| 2006 | return retval; |
| 2007 | } |
| 2008 | |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2009 | /** |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2010 | * canon_copy_from_read_buf - copy read data in canonical mode |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2011 | * @tty: terminal device |
| 2012 | * @b: user data |
| 2013 | * @nr: size of data |
| 2014 | * |
| 2015 | * Helper function for n_tty_read. It is only called when ICANON is on; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2016 | * it copies one line of input up to and including the line-delimiting |
| 2017 | * character into the user-space buffer. |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2018 | * |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 2019 | * NB: When termios is changed from non-canonical to canonical mode and |
| 2020 | * the read buffer contains data, n_tty_set_termios() simulates an EOF |
| 2021 | * push (as if C-d were input) _without_ the DISABLED_CHAR in the buffer. |
| 2022 | * This causes data already processed as input to be immediately available |
| 2023 | * as input although a newline has not been received. |
| 2024 | * |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2025 | * Called under the atomic_read_lock mutex |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2026 | * |
| 2027 | * n_tty_read()/consumer path: |
| 2028 | * caller holds non-exclusive termios_rwsem |
| 2029 | * read_tail published |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2030 | */ |
| 2031 | |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2032 | static int canon_copy_from_read_buf(struct tty_struct *tty, |
| 2033 | unsigned char __user **b, |
| 2034 | size_t *nr) |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2035 | { |
| 2036 | struct n_tty_data *ldata = tty->disc_data; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2037 | size_t n, size, more, c; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2038 | size_t eol; |
| 2039 | size_t tail; |
| 2040 | int ret, found = 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2041 | |
| 2042 | /* N.B. avoid overrun if nr == 0 */ |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2043 | if (!*nr) |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2044 | return 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2045 | |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2046 | n = min(*nr + 1, smp_load_acquire(&ldata->canon_head) - ldata->read_tail); |
| 2047 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2048 | tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2049 | size = min_t(size_t, tail + n, N_TTY_BUF_SIZE); |
| 2050 | |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2051 | n_tty_trace("%s: nr:%zu tail:%zu n:%zu size:%zu\n", |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2052 | __func__, *nr, tail, n, size); |
| 2053 | |
| 2054 | eol = find_next_bit(ldata->read_flags, size, tail); |
| 2055 | more = n - (size - tail); |
| 2056 | if (eol == N_TTY_BUF_SIZE && more) { |
| 2057 | /* scan wrapped without finding set bit */ |
| 2058 | eol = find_next_bit(ldata->read_flags, more, 0); |
Peter Hurley | b985e9e | 2015-11-27 14:11:04 -0500 | [diff] [blame] | 2059 | found = eol != more; |
| 2060 | } else |
| 2061 | found = eol != size; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2062 | |
Peter Hurley | c77569d | 2013-11-22 07:16:25 -0500 | [diff] [blame] | 2063 | n = eol - tail; |
Mark Tomlinson | da555db | 2015-05-18 12:01:48 +1200 | [diff] [blame] | 2064 | if (n > N_TTY_BUF_SIZE) |
| 2065 | n += N_TTY_BUF_SIZE; |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2066 | c = n + found; |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2067 | |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2068 | if (!found || read_buf(ldata, eol) != __DISABLED_CHAR) { |
| 2069 | c = min(*nr, c); |
| 2070 | n = c; |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2071 | } |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2072 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 2073 | n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n", |
| 2074 | __func__, eol, found, n, c, tail, more); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2075 | |
Peter Hurley | 679e7c2 | 2015-11-27 14:11:02 -0500 | [diff] [blame] | 2076 | ret = tty_copy_to_user(tty, *b, tail, n); |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2077 | if (ret) |
| 2078 | return -EFAULT; |
| 2079 | *b += n; |
| 2080 | *nr -= n; |
| 2081 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 2082 | if (found) |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2083 | clear_bit(eol, ldata->read_flags); |
Peter Hurley | 70aca71 | 2015-01-16 15:05:37 -0500 | [diff] [blame] | 2084 | smp_store_release(&ldata->read_tail, ldata->read_tail + c); |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2085 | |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2086 | if (found) { |
Peter Hurley | 4d0ed18 | 2013-12-10 17:12:02 -0500 | [diff] [blame] | 2087 | if (!ldata->push) |
| 2088 | ldata->line_start = ldata->read_tail; |
| 2089 | else |
| 2090 | ldata->push = 0; |
Peter Hurley | b50819f | 2016-01-09 22:55:30 -0800 | [diff] [blame] | 2091 | tty_audit_push(); |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2092 | } |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2093 | return 0; |
Peter Hurley | 88bb0de | 2013-06-15 09:14:16 -0400 | [diff] [blame] | 2094 | } |
| 2095 | |
Al Viro | cc4191d | 2008-03-29 03:08:48 +0000 | [diff] [blame] | 2096 | extern ssize_t redirected_tty_write(struct file *, const char __user *, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2097 | size_t, loff_t *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2098 | |
| 2099 | /** |
| 2100 | * job_control - check job control |
| 2101 | * @tty: tty |
| 2102 | * @file: file handle |
| 2103 | * |
| 2104 | * Perform job control management checks on this file/tty descriptor |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2105 | * and if appropriate send any needed signals and return a negative |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2106 | * error code if action should be taken. |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2107 | * |
Peter Hurley | 01a5e44 | 2013-03-06 08:38:20 -0500 | [diff] [blame] | 2108 | * Locking: redirected write test is safe |
| 2109 | * current->signal->tty check is safe |
| 2110 | * ctrl_lock to safely reference tty->pgrp |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2111 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2112 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2113 | static int job_control(struct tty_struct *tty, struct file *file) |
| 2114 | { |
| 2115 | /* Job control check -- must be done at start and after |
| 2116 | every sleep (POSIX.1 7.1.1.4). */ |
| 2117 | /* NOTE: not yet done after every sleep pending a thorough |
| 2118 | check of the logic of this change. -- jlc */ |
| 2119 | /* don't stop on /dev/console */ |
Peter Hurley | 2812d9e | 2015-10-10 20:28:42 -0400 | [diff] [blame] | 2120 | if (file->f_op->write == redirected_tty_write) |
Peter Hurley | 01a5e44 | 2013-03-06 08:38:20 -0500 | [diff] [blame] | 2121 | return 0; |
| 2122 | |
Peter Hurley | 2812d9e | 2015-10-10 20:28:42 -0400 | [diff] [blame] | 2123 | return __tty_check_change(tty, SIGTTIN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2124 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2125 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2126 | |
| 2127 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2128 | * n_tty_read - read function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2129 | * @tty: tty device |
| 2130 | * @file: file object |
| 2131 | * @buf: userspace buffer pointer |
| 2132 | * @nr: size of I/O |
| 2133 | * |
| 2134 | * Perform reads for the line discipline. We are guaranteed that the |
| 2135 | * line discipline will not be closed under us but we may get multiple |
| 2136 | * parallel readers and must handle this ourselves. We may also get |
| 2137 | * a hangup. Always called in user context, may sleep. |
| 2138 | * |
| 2139 | * This code must be sure never to sleep through a hangup. |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2140 | * |
| 2141 | * n_tty_read()/consumer path: |
| 2142 | * claims non-exclusive termios_rwsem |
| 2143 | * publishes read_tail |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2144 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2145 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2146 | static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2147 | unsigned char __user *buf, size_t nr) |
| 2148 | { |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2149 | struct n_tty_data *ldata = tty->disc_data; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2150 | unsigned char __user *b = buf; |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2151 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2152 | int c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2153 | int minimum, time; |
| 2154 | ssize_t retval = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2155 | long timeout; |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2156 | int packet; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2157 | size_t tail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2158 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2159 | c = job_control(tty, file); |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2160 | if (c < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2161 | return c; |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2162 | |
Peter Hurley | aefceaf | 2013-08-11 08:04:23 -0400 | [diff] [blame] | 2163 | /* |
| 2164 | * Internal serialization of reads. |
| 2165 | */ |
| 2166 | if (file->f_flags & O_NONBLOCK) { |
| 2167 | if (!mutex_trylock(&ldata->atomic_read_lock)) |
| 2168 | return -EAGAIN; |
| 2169 | } else { |
| 2170 | if (mutex_lock_interruptible(&ldata->atomic_read_lock)) |
| 2171 | return -ERESTARTSYS; |
| 2172 | } |
| 2173 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2174 | down_read(&tty->termios_rwsem); |
| 2175 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2176 | minimum = time = 0; |
| 2177 | timeout = MAX_SCHEDULE_TIMEOUT; |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2178 | if (!ldata->icanon) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2179 | minimum = MIN_CHAR(tty); |
| 2180 | if (minimum) { |
Peter Hurley | a6e5431 | 2013-06-15 07:28:29 -0400 | [diff] [blame] | 2181 | time = (HZ / 10) * TIME_CHAR(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2182 | } else { |
Peter Hurley | a6e5431 | 2013-06-15 07:28:29 -0400 | [diff] [blame] | 2183 | timeout = (HZ / 10) * TIME_CHAR(tty); |
Peter Hurley | 33d7136 | 2016-01-09 21:45:08 -0800 | [diff] [blame] | 2184 | minimum = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2185 | } |
| 2186 | } |
| 2187 | |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2188 | packet = tty->packet; |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2189 | tail = ldata->read_tail; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2190 | |
| 2191 | add_wait_queue(&tty->read_wait, &wait); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2192 | while (nr) { |
| 2193 | /* First test for status change. */ |
Alan Cox | 04f378b | 2008-04-30 00:53:29 -0700 | [diff] [blame] | 2194 | if (packet && tty->link->ctrl_status) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2195 | unsigned char cs; |
| 2196 | if (b != buf) |
| 2197 | break; |
Peter Hurley | 6054c16e | 2014-10-16 15:33:25 -0400 | [diff] [blame] | 2198 | spin_lock_irq(&tty->link->ctrl_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2199 | cs = tty->link->ctrl_status; |
| 2200 | tty->link->ctrl_status = 0; |
Peter Hurley | 6054c16e | 2014-10-16 15:33:25 -0400 | [diff] [blame] | 2201 | spin_unlock_irq(&tty->link->ctrl_lock); |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2202 | if (put_user(cs, b)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2203 | retval = -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2204 | break; |
| 2205 | } |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2206 | b++; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2207 | nr--; |
| 2208 | break; |
| 2209 | } |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2211 | if (!input_available_p(tty, 0)) { |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2212 | up_read(&tty->termios_rwsem); |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2213 | tty_buffer_flush_work(tty->port); |
Peter Hurley | 52bce7f | 2014-11-05 12:13:05 -0500 | [diff] [blame] | 2214 | down_read(&tty->termios_rwsem); |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2215 | if (!input_available_p(tty, 0)) { |
| 2216 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { |
| 2217 | retval = -EIO; |
| 2218 | break; |
| 2219 | } |
| 2220 | if (tty_hung_up_p(file)) |
| 2221 | break; |
Tejun Heo | a7e1906 | 2018-02-13 07:38:08 -0800 | [diff] [blame] | 2222 | /* |
| 2223 | * Abort readers for ttys which never actually |
| 2224 | * get hung up. See __tty_hangup(). |
| 2225 | */ |
| 2226 | if (test_bit(TTY_HUPPING, &tty->flags)) |
| 2227 | break; |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2228 | if (!timeout) |
| 2229 | break; |
| 2230 | if (file->f_flags & O_NONBLOCK) { |
| 2231 | retval = -EAGAIN; |
| 2232 | break; |
| 2233 | } |
| 2234 | if (signal_pending(current)) { |
| 2235 | retval = -ERESTARTSYS; |
| 2236 | break; |
| 2237 | } |
| 2238 | up_read(&tty->termios_rwsem); |
| 2239 | |
| 2240 | timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, |
| 2241 | timeout); |
| 2242 | |
| 2243 | down_read(&tty->termios_rwsem); |
| 2244 | continue; |
| 2245 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2246 | } |
| 2247 | |
Jiri Slaby | 53c5ee2 | 2012-10-18 22:26:39 +0200 | [diff] [blame] | 2248 | if (ldata->icanon && !L_EXTPROC(tty)) { |
Peter Hurley | 32f1352 | 2013-06-15 09:14:17 -0400 | [diff] [blame] | 2249 | retval = canon_copy_from_read_buf(tty, &b, &nr); |
Peter Hurley | ac8f3bf | 2015-11-27 13:59:20 -0500 | [diff] [blame] | 2250 | if (retval) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2251 | break; |
| 2252 | } else { |
| 2253 | int uncopied; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2254 | |
| 2255 | /* Deal with packet mode. */ |
| 2256 | if (packet && b == buf) { |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2257 | if (put_user(TIOCPKT_DATA, b)) { |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2258 | retval = -EFAULT; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2259 | break; |
| 2260 | } |
Peter Hurley | eab25a5 | 2016-01-09 22:55:26 -0800 | [diff] [blame] | 2261 | b++; |
Peter Hurley | 95ea90d | 2014-10-16 15:33:30 -0400 | [diff] [blame] | 2262 | nr--; |
| 2263 | } |
| 2264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2265 | uncopied = copy_from_read_buf(tty, &b, &nr); |
| 2266 | uncopied += copy_from_read_buf(tty, &b, &nr); |
| 2267 | if (uncopied) { |
| 2268 | retval = -EFAULT; |
| 2269 | break; |
| 2270 | } |
| 2271 | } |
| 2272 | |
Peter Hurley | 6367ca7 | 2013-06-15 09:14:33 -0400 | [diff] [blame] | 2273 | n_tty_check_unthrottle(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2274 | |
| 2275 | if (b - buf >= minimum) |
| 2276 | break; |
| 2277 | if (time) |
| 2278 | timeout = time; |
| 2279 | } |
Peter Hurley | 2c5dc46 | 2015-01-16 15:05:34 -0500 | [diff] [blame] | 2280 | if (tail != ldata->read_tail) |
| 2281 | n_tty_kick_worker(tty); |
Peter Hurley | 42458f4 | 2013-11-07 13:59:46 -0500 | [diff] [blame] | 2282 | up_read(&tty->termios_rwsem); |
| 2283 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2284 | remove_wait_queue(&tty->read_wait, &wait); |
Peter Hurley | aebf0453 | 2013-11-07 14:01:57 -0500 | [diff] [blame] | 2285 | mutex_unlock(&ldata->atomic_read_lock); |
| 2286 | |
Peter Hurley | 40d5e09 | 2013-06-15 10:21:17 -0400 | [diff] [blame] | 2287 | if (b - buf) |
| 2288 | retval = b - buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2289 | |
| 2290 | return retval; |
| 2291 | } |
| 2292 | |
| 2293 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2294 | * n_tty_write - write function for tty |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2295 | * @tty: tty device |
| 2296 | * @file: file object |
| 2297 | * @buf: userspace buffer pointer |
| 2298 | * @nr: size of I/O |
| 2299 | * |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2300 | * Write function of the terminal device. This is serialized with |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2301 | * respect to other write callers but not to termios changes, reads |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2302 | * and other such events. Since the receive code will echo characters, |
| 2303 | * thus calling driver write methods, the output_lock is used in |
| 2304 | * the output processing functions called here as well as in the |
| 2305 | * echo processing function to protect the column state and space |
| 2306 | * left in the buffer. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2307 | * |
| 2308 | * This code must be sure never to sleep through a hangup. |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2309 | * |
| 2310 | * Locking: output_lock to protect column state and space left |
| 2311 | * (note that the process_output*() functions take this |
| 2312 | * lock themselves) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2313 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2314 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2315 | static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2316 | const unsigned char *buf, size_t nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2317 | { |
| 2318 | const unsigned char *b = buf; |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2319 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2320 | int c; |
| 2321 | ssize_t retval = 0; |
| 2322 | |
| 2323 | /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */ |
| 2324 | if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) { |
| 2325 | retval = tty_check_change(tty); |
| 2326 | if (retval) |
| 2327 | return retval; |
| 2328 | } |
| 2329 | |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2330 | down_read(&tty->termios_rwsem); |
| 2331 | |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2332 | /* Write out any echoed characters that are still pending */ |
| 2333 | process_echoes(tty); |
Alan Cox | 300a620 | 2009-01-02 13:41:04 +0000 | [diff] [blame] | 2334 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2335 | add_wait_queue(&tty->write_wait, &wait); |
| 2336 | while (1) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2337 | if (signal_pending(current)) { |
| 2338 | retval = -ERESTARTSYS; |
| 2339 | break; |
| 2340 | } |
| 2341 | if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) { |
| 2342 | retval = -EIO; |
| 2343 | break; |
| 2344 | } |
Peter Hurley | 582f559 | 2013-05-17 12:49:48 -0400 | [diff] [blame] | 2345 | if (O_OPOST(tty)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2346 | while (nr > 0) { |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2347 | ssize_t num = process_output_block(tty, b, nr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2348 | if (num < 0) { |
| 2349 | if (num == -EAGAIN) |
| 2350 | break; |
| 2351 | retval = num; |
| 2352 | goto break_out; |
| 2353 | } |
| 2354 | b += num; |
| 2355 | nr -= num; |
| 2356 | if (nr == 0) |
| 2357 | break; |
| 2358 | c = *b; |
Joe Peterson | a88a69c | 2009-01-02 13:40:53 +0000 | [diff] [blame] | 2359 | if (process_output(c, tty) < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2360 | break; |
| 2361 | b++; nr--; |
| 2362 | } |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2363 | if (tty->ops->flush_chars) |
| 2364 | tty->ops->flush_chars(tty); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2365 | } else { |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2366 | struct n_tty_data *ldata = tty->disc_data; |
| 2367 | |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 2368 | while (nr > 0) { |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2369 | mutex_lock(&ldata->output_lock); |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2370 | c = tty->ops->write(tty, b, nr); |
Peter Hurley | 4291086 | 2014-05-03 14:04:59 +0200 | [diff] [blame] | 2371 | mutex_unlock(&ldata->output_lock); |
Roman Zippel | d6afe27 | 2005-07-07 17:56:55 -0700 | [diff] [blame] | 2372 | if (c < 0) { |
| 2373 | retval = c; |
| 2374 | goto break_out; |
| 2375 | } |
| 2376 | if (!c) |
| 2377 | break; |
| 2378 | b += c; |
| 2379 | nr -= c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2380 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2381 | } |
| 2382 | if (!nr) |
| 2383 | break; |
| 2384 | if (file->f_flags & O_NONBLOCK) { |
| 2385 | retval = -EAGAIN; |
| 2386 | break; |
| 2387 | } |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2388 | up_read(&tty->termios_rwsem); |
| 2389 | |
Peter Zijlstra | 97d9e28 | 2014-09-24 10:18:51 +0200 | [diff] [blame] | 2390 | wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2391 | |
| 2392 | down_read(&tty->termios_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2393 | } |
| 2394 | break_out: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2395 | remove_wait_queue(&tty->write_wait, &wait); |
Peter Hurley | 87108bc | 2016-01-09 21:45:14 -0800 | [diff] [blame] | 2396 | if (nr && tty->fasync) |
Thomas Pfaff | ff8cb0f | 2009-01-02 13:47:13 +0000 | [diff] [blame] | 2397 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
Peter Hurley | 9356b53 | 2013-06-15 09:14:24 -0400 | [diff] [blame] | 2398 | up_read(&tty->termios_rwsem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2399 | return (b - buf) ? b - buf : retval; |
| 2400 | } |
| 2401 | |
| 2402 | /** |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2403 | * n_tty_poll - poll method for N_TTY |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2404 | * @tty: terminal device |
| 2405 | * @file: file accessing it |
| 2406 | * @wait: poll table |
| 2407 | * |
| 2408 | * Called when the line discipline is asked to poll() for data or |
| 2409 | * for special events. This code is not serialized with respect to |
| 2410 | * other events save open/close. |
| 2411 | * |
| 2412 | * This code must be sure never to sleep through a hangup. |
| 2413 | * Called without the kernel lock held - fine |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2414 | */ |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2415 | |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2416 | static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file, |
Alan Cox | 4edf182 | 2008-02-08 04:18:44 -0800 | [diff] [blame] | 2417 | poll_table *wait) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2418 | { |
| 2419 | unsigned int mask = 0; |
| 2420 | |
| 2421 | poll_wait(file, &tty->read_wait, wait); |
| 2422 | poll_wait(file, &tty->write_wait, wait); |
Francesco Ruggeri | c4dc304 | 2014-10-10 13:09:53 -0700 | [diff] [blame] | 2423 | if (input_available_p(tty, 1)) |
| 2424 | mask |= POLLIN | POLLRDNORM; |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2425 | else { |
| 2426 | tty_buffer_flush_work(tty->port); |
| 2427 | if (input_available_p(tty, 1)) |
| 2428 | mask |= POLLIN | POLLRDNORM; |
| 2429 | } |
Francesco Ruggeri | c4dc304 | 2014-10-10 13:09:53 -0700 | [diff] [blame] | 2430 | if (tty->packet && tty->link->ctrl_status) |
| 2431 | mask |= POLLPRI | POLLIN | POLLRDNORM; |
Brian Bloniarz | 0f40fbb | 2016-03-06 13:16:30 -0800 | [diff] [blame] | 2432 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
| 2433 | mask |= POLLHUP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2434 | if (tty_hung_up_p(file)) |
| 2435 | mask |= POLLHUP; |
Alan Cox | f34d7a5 | 2008-04-30 00:54:13 -0700 | [diff] [blame] | 2436 | if (tty->ops->write && !tty_is_writelocked(tty) && |
| 2437 | tty_chars_in_buffer(tty) < WAKEUP_CHARS && |
| 2438 | tty_write_room(tty) > 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2439 | mask |= POLLOUT | POLLWRNORM; |
| 2440 | return mask; |
| 2441 | } |
| 2442 | |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 2443 | static unsigned long inq_canon(struct n_tty_data *ldata) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2444 | { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2445 | size_t nr, head, tail; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2446 | |
Peter Hurley | a73d3d6 | 2013-06-15 09:14:25 -0400 | [diff] [blame] | 2447 | if (ldata->canon_head == ldata->read_tail) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2448 | return 0; |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 2449 | head = ldata->canon_head; |
| 2450 | tail = ldata->read_tail; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2451 | nr = head - tail; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2452 | /* Skip EOF-chars.. */ |
Tetsuo Handa | 947dead | 2018-05-26 09:53:13 +0900 | [diff] [blame] | 2453 | while (MASK(head) != MASK(tail)) { |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2454 | if (test_bit(tail & (N_TTY_BUF_SIZE - 1), ldata->read_flags) && |
| 2455 | read_buf(ldata, tail) == __DISABLED_CHAR) |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2456 | nr--; |
Peter Hurley | bc5a5e3 | 2013-06-15 09:14:21 -0400 | [diff] [blame] | 2457 | tail++; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2458 | } |
| 2459 | return nr; |
| 2460 | } |
| 2461 | |
| 2462 | static int n_tty_ioctl(struct tty_struct *tty, struct file *file, |
| 2463 | unsigned int cmd, unsigned long arg) |
| 2464 | { |
Jiri Slaby | ba2e68a | 2012-10-18 22:26:41 +0200 | [diff] [blame] | 2465 | struct n_tty_data *ldata = tty->disc_data; |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2466 | int retval; |
| 2467 | |
| 2468 | switch (cmd) { |
| 2469 | case TIOCOUTQ: |
| 2470 | return put_user(tty_chars_in_buffer(tty), (int __user *) arg); |
| 2471 | case TIOCINQ: |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2472 | down_write(&tty->termios_rwsem); |
Linus Torvalds | 00fc57a | 2017-12-20 17:57:06 -0800 | [diff] [blame] | 2473 | if (L_ICANON(tty) && !L_EXTPROC(tty)) |
Jiri Slaby | 57c9412 | 2012-10-18 22:26:43 +0200 | [diff] [blame] | 2474 | retval = inq_canon(ldata); |
Peter Hurley | 6d76bd2 | 2013-06-15 09:14:26 -0400 | [diff] [blame] | 2475 | else |
| 2476 | retval = read_cnt(ldata); |
| 2477 | up_write(&tty->termios_rwsem); |
Alan Cox | 47afa7a | 2008-10-13 10:44:17 +0100 | [diff] [blame] | 2478 | return put_user(retval, (unsigned int __user *) arg); |
| 2479 | default: |
| 2480 | return n_tty_ioctl_helper(tty, file, cmd, arg); |
| 2481 | } |
| 2482 | } |
| 2483 | |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2484 | static struct tty_ldisc_ops n_tty_ops = { |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2485 | .magic = TTY_LDISC_MAGIC, |
| 2486 | .name = "n_tty", |
| 2487 | .open = n_tty_open, |
| 2488 | .close = n_tty_close, |
| 2489 | .flush_buffer = n_tty_flush_buffer, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2490 | .read = n_tty_read, |
| 2491 | .write = n_tty_write, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2492 | .ioctl = n_tty_ioctl, |
| 2493 | .set_termios = n_tty_set_termios, |
Alan Cox | 11a96d1 | 2008-10-13 10:46:24 +0100 | [diff] [blame] | 2494 | .poll = n_tty_poll, |
Paul Fulghum | e10cc1d | 2007-05-10 22:22:50 -0700 | [diff] [blame] | 2495 | .receive_buf = n_tty_receive_buf, |
Peter Hurley | f6c8dbe | 2013-06-15 07:28:28 -0400 | [diff] [blame] | 2496 | .write_wakeup = n_tty_write_wakeup, |
Peter Hurley | 24a89d1 | 2013-06-15 09:14:15 -0400 | [diff] [blame] | 2497 | .receive_buf2 = n_tty_receive_buf2, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2498 | }; |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2499 | |
| 2500 | /** |
| 2501 | * n_tty_inherit_ops - inherit N_TTY methods |
| 2502 | * @ops: struct tty_ldisc_ops where to save N_TTY methods |
| 2503 | * |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2504 | * Enables a 'subclass' line discipline to 'inherit' N_TTY methods. |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2505 | */ |
| 2506 | |
| 2507 | void n_tty_inherit_ops(struct tty_ldisc_ops *ops) |
| 2508 | { |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2509 | *ops = n_tty_ops; |
Rodolfo Giometti | 572b9ad | 2010-03-10 15:23:46 -0800 | [diff] [blame] | 2510 | ops->owner = NULL; |
| 2511 | ops->refcount = ops->flags = 0; |
| 2512 | } |
| 2513 | EXPORT_SYMBOL_GPL(n_tty_inherit_ops); |
Peter Hurley | 2722873 | 2016-01-09 21:35:19 -0800 | [diff] [blame] | 2514 | |
| 2515 | void __init n_tty_init(void) |
| 2516 | { |
| 2517 | tty_register_ldisc(N_TTY, &n_tty_ops); |
| 2518 | } |