^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-1.0+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * n_tty.c --- implements the N_TTY line discipline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * This code used to be in tty_io.c, but things are getting hairy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * enough that it made sense to split things off. (The N_TTY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * processing has changed so much that it's hardly recognizable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * anyway...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Note that the open routine for N_TTY is guaranteed never to return
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * an error. This is because Linux will fall back to setting a line
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * to N_TTY if it can not switch to any other line discipline.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * Written by Theodore Ts'o, Copyright 1994.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * This file also contains code originally written by Linus Torvalds,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * Reduced memory usage for older ARM systems - Russell King.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * who actually finally proved there really was a race.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * Also fixed a bug in BLOCKING mode where n_tty_write returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * EAGAIN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/major.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include <linux/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #include <linux/fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) #include <linux/tty.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #include <linux/timer.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) #include <linux/ctype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) #include <linux/poll.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <linux/bitops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) #include <linux/audit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) #include <linux/file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #include <linux/ratelimit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #include <linux/vmalloc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) * Until this number of characters is queued in the xmit buffer, select will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) * return "we have room for writes".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #define WAKEUP_CHARS 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * This defines the low- and high-watermarks for throttling and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) * unthrottling the TTY driver. These watermarks are used for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * controlling the space in the read buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) #define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) #define TTY_THRESHOLD_UNTHROTTLE 128
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * Special byte codes used in the echo buffer to represent operations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * or special handling of characters. Bytes in the echo buffer that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * are not part of such special blocks are treated as normal character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) * codes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) #define ECHO_OP_START 0xff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) #define ECHO_OP_MOVE_BACK_COL 0x80
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) #define ECHO_OP_SET_CANON_COL 0x81
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) #define ECHO_OP_ERASE_TAB 0x82
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) #define ECHO_COMMIT_WATERMARK 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) #define ECHO_BLOCK 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) #define ECHO_DISCARD_WATERMARK N_TTY_BUF_SIZE - (ECHO_BLOCK + 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) #undef N_TTY_TRACE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) #ifdef N_TTY_TRACE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) # define n_tty_trace(f, args...) trace_printk(f, ##args)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) # define n_tty_trace(f, args...) no_printk(f, ##args)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) struct n_tty_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) /* producer-published */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) size_t read_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) size_t commit_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) size_t canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) size_t echo_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) size_t echo_commit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) size_t echo_mark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) DECLARE_BITMAP(char_map, 256);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* private to n_tty_receive_overrun (single-threaded) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) unsigned long overrun_time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) int num_overrun;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) /* non-atomic */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) bool no_room;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) /* must hold exclusive termios_rwsem to reset these */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) unsigned char push:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) /* shared by producer and consumer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) char read_buf[N_TTY_BUF_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) DECLARE_BITMAP(read_flags, N_TTY_BUF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) unsigned char echo_buf[N_TTY_BUF_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) /* consumer-published */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) size_t read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) size_t line_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) /* protected by output lock */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) unsigned int column;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) unsigned int canon_column;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) size_t echo_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) struct mutex atomic_read_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) struct mutex output_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) #define MASK(x) ((x) & (N_TTY_BUF_SIZE - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static inline size_t read_cnt(struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) return ldata->read_head - ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) static inline unsigned char read_buf(struct n_tty_data *ldata, size_t i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) return ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) static inline unsigned char *read_buf_addr(struct n_tty_data *ldata, size_t i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) return &ldata->read_buf[i & (N_TTY_BUF_SIZE - 1)];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) static inline unsigned char echo_buf(struct n_tty_data *ldata, size_t i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) smp_rmb(); /* Matches smp_wmb() in add_echo_byte(). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) return ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) /* If we are not echoing the data, perhaps this is a secret so erase it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) static void zero_buffer(struct tty_struct *tty, u8 *buffer, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) bool icanon = !!L_ICANON(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) bool no_echo = !L_ECHO(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) if (icanon && no_echo)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) memset(buffer, 0x00, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) static void tty_copy(struct tty_struct *tty, void *to, size_t tail, size_t n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) size_t size = N_TTY_BUF_SIZE - tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) void *from = read_buf_addr(ldata, tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) if (n > size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) tty_audit_add_data(tty, from, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) memcpy(to, from, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) zero_buffer(tty, from, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) to += size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) n -= size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) from = ldata->read_buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) tty_audit_add_data(tty, from, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) memcpy(to, from, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) zero_buffer(tty, from, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) * n_tty_kick_worker - start input worker (if required)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) * @tty: terminal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) * Re-schedules the flip buffer work if it may have stopped
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * Caller holds exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) * or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * n_tty_read()/consumer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) * holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) static void n_tty_kick_worker(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) /* Did the input worker stop? Restart it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) if (unlikely(ldata->no_room)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) ldata->no_room = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) WARN_RATELIMIT(tty->port->itty == NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) "scheduling with invalid itty\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) /* see if ldisc has been killed - if so, this means that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) * even though the ldisc has been halted and ->buf.work
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) * cancelled, ->buf.work is about to be rescheduled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) "scheduling buffer work for halted ldisc\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) tty_buffer_restart_work(tty->port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) static ssize_t chars_in_buffer(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) ssize_t n = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) if (!ldata->icanon)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) n = ldata->commit_head - ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) n = ldata->canon_head - ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) return n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * n_tty_write_wakeup - asynchronous I/O notifier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) * @tty: tty device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) * Required for the ptys, serial driver etc. since processes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) * that attach themselves to the master and rely on ASYNC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) * IO must be woken up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) static void n_tty_write_wakeup(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) static void n_tty_check_throttle(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) * Check the remaining room for the input canonicalization
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * mode. We don't want to throttle the driver if we're in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) * canonical mode and don't have a newline yet!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) if (ldata->icanon && ldata->canon_head == ldata->read_tail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) int throttled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) if (N_TTY_BUF_SIZE - read_cnt(ldata) >= TTY_THRESHOLD_THROTTLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) throttled = tty_throttle_safe(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) if (!throttled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) __tty_set_flow_change(tty, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) static void n_tty_check_unthrottle(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) n_tty_kick_worker(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) tty_wakeup(tty->link);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) /* If there is enough space in the read buffer now, let the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * low-level driver know. We use chars_in_buffer() to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) * check the buffer, as it now knows about canonical mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * Otherwise, if the driver is throttled and the line is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * we won't get any more characters.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) int unthrottled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) n_tty_kick_worker(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) unthrottled = tty_unthrottle_safe(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) if (!unthrottled)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) __tty_set_flow_change(tty, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) * put_tty_queue - add character to tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) * @c: character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * @ldata: n_tty data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) * Add a character to the tty read_buf queue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) * n_tty_receive_buf()/producer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) static inline void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) *read_buf_addr(ldata, ldata->read_head) = c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) ldata->read_head++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) * reset_buffer_flags - reset buffer state
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) * @ldata: line disc data to reset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * Reset the read buffer counters and clear the flags.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * Called from n_tty_open() and n_tty_flush_buffer().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * Locking: caller holds exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * (or locking is not required)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) static void reset_buffer_flags(struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) ldata->commit_head = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) ldata->line_start = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) ldata->erasing = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) ldata->push = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) static void n_tty_packet_mode_flush(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) if (tty->link->packet) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) spin_lock_irqsave(&tty->ctrl_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) tty->ctrl_status |= TIOCPKT_FLUSHREAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) spin_unlock_irqrestore(&tty->ctrl_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) wake_up_interruptible(&tty->link->read_wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) * n_tty_flush_buffer - clean input queue
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * Flush the input buffer. Called when the tty layer wants the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * buffer flushed (eg at hangup) or when the N_TTY line discipline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) * internally has to clean the pending queue (for example some signals).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * Holds termios_rwsem to exclude producer/consumer while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) * buffer indices are reset.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) * Locking: ctrl_lock, exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) static void n_tty_flush_buffer(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) down_write(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) reset_buffer_flags(tty->disc_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) n_tty_kick_worker(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) if (tty->link)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) n_tty_packet_mode_flush(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) up_write(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) * is_utf8_continuation - utf8 multibyte check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * @c: byte to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * Returns true if the utf8 character 'c' is a multibyte continuation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * character. We use this to correctly compute the on screen size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) * of the character when printing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) static inline int is_utf8_continuation(unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) return (c & 0xc0) == 0x80;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) * is_continuation - multibyte check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) * @c: byte to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * Returns true if the utf8 character 'c' is a multibyte continuation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) * character and the terminal is in unicode mode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) static inline int is_continuation(unsigned char c, struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) return I_IUTF8(tty) && is_utf8_continuation(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * do_output_char - output one character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * @c: character (or partial unicode symbol)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * @space: space available in tty driver write buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * This is a helper function that handles one output character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) * (including special characters like TAB, CR, LF, etc.),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * doing OPOST processing and putting the results in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) * tty driver's write buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * and NLDLY. They simply aren't relevant in the world today.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * If you ever need them, add them here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * Returns the number of bytes of buffer space used or -1 if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) * no space left.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) * Locking: should be called under the output_lock to protect
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) * the column state and space left in the buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) int spaces;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) if (!space)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) switch (c) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) case '\n':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) if (O_ONLRET(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) ldata->column = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) if (O_ONLCR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) if (space < 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) ldata->canon_column = ldata->column = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) tty->ops->write(tty, "\r\n", 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) return 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) ldata->canon_column = ldata->column;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) case '\r':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) if (O_ONOCR(tty) && ldata->column == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) if (O_OCRNL(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) c = '\n';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) if (O_ONLRET(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) ldata->canon_column = ldata->column = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) ldata->canon_column = ldata->column = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) case '\t':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) spaces = 8 - (ldata->column & 7);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) if (O_TABDLY(tty) == XTABS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) if (space < spaces)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) ldata->column += spaces;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) tty->ops->write(tty, " ", spaces);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) return spaces;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) ldata->column += spaces;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) case '\b':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) if (ldata->column > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) ldata->column--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) if (!iscntrl(c)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) if (O_OLCUC(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) c = toupper(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) if (!is_continuation(c, tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) ldata->column++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) tty_put_char(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) * process_output - output post processor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) * @c: character (or partial unicode symbol)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) * Output one character with OPOST processing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) * Returns -1 when the output device is full and the character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) * must be retried.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) * Locking: output_lock to protect column state and space left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) * (also, this is called from n_tty_write under the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) * tty layer write lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) static int process_output(unsigned char c, struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) int space, retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) space = tty_write_room(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) retval = do_output_char(c, tty, space);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) if (retval < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) * process_output_block - block post processor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) * @buf: character buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) * @nr: number of bytes to output
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) * Output a block of characters with OPOST processing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) * Returns the number of characters output.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) * This path is used to speed up block console writes, among other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) * things when processing blocks of output data. It handles only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) * the simple cases normally found and helps to generate blocks of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) * symbols for the console driver and thus improve performance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) * Locking: output_lock to protect column state and space left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) * (also, this is called from n_tty_write under the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) * tty layer write lock)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) static ssize_t process_output_block(struct tty_struct *tty,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) const unsigned char *buf, unsigned int nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) int space;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) const unsigned char *cp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) space = tty_write_room(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) if (space <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) return space;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) if (nr > space)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) nr = space;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) for (i = 0, cp = buf; i < nr; i++, cp++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) unsigned char c = *cp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) switch (c) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) case '\n':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) if (O_ONLRET(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) ldata->column = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) if (O_ONLCR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) ldata->canon_column = ldata->column;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) case '\r':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) if (O_ONOCR(tty) && ldata->column == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) if (O_OCRNL(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) ldata->canon_column = ldata->column = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) case '\t':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) case '\b':
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) if (ldata->column > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) ldata->column--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) if (!iscntrl(c)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) if (O_OLCUC(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) if (!is_continuation(c, tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) ldata->column++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) break_out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) i = tty->ops->write(tty, buf, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) return i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) * process_echoes - write pending echo characters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) * Write previously buffered echo (and other ldisc-generated)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) * characters to the tty.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) * Characters generated by the ldisc (including echoes) need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) * be buffered because the driver's write buffer can fill during
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) * heavy program output. Echoing straight to the driver will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) * often fail under these conditions, causing lost characters and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) * resulting mismatches of ldisc state information.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) * Since the ldisc state must represent the characters actually sent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) * to the driver at the time of the write, operations like certain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) * changes in column state are also saved in the buffer and executed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) * here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) * A circular fifo buffer is used so that the most recent characters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) * are prioritized. Also, when control characters are echoed with a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) * prefixed "^", the pair is treated atomically and thus not separated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) * Locking: callers must hold output_lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) static size_t __process_echoes(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) int space, old_space;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) size_t tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) unsigned char c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) old_space = space = tty_write_room(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) tail = ldata->echo_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) while (MASK(ldata->echo_commit) != MASK(tail)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) c = echo_buf(ldata, tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) if (c == ECHO_OP_START) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) unsigned char op;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) int no_space_left = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) * Since add_echo_byte() is called without holding
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) * output_lock, we might see only portion of multi-byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) * operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) if (MASK(ldata->echo_commit) == MASK(tail + 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) goto not_yet_stored;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) * If the buffer byte is the start of a multi-byte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) * operation, get the next byte, which is either the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) * op code or a control character value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) op = echo_buf(ldata, tail + 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) switch (op) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) case ECHO_OP_ERASE_TAB: {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) unsigned int num_chars, num_bs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) if (MASK(ldata->echo_commit) == MASK(tail + 2))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) goto not_yet_stored;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) num_chars = echo_buf(ldata, tail + 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) * Determine how many columns to go back
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) * in order to erase the tab.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) * This depends on the number of columns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) * used by other characters within the tab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) * area. If this (modulo 8) count is from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) * the start of input rather than from a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) * previous tab, we offset by canon column.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) * Otherwise, tab spacing is normal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) if (!(num_chars & 0x80))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) num_chars += ldata->canon_column;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) num_bs = 8 - (num_chars & 7);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) if (num_bs > space) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) no_space_left = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) space -= num_bs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) while (num_bs--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) tty_put_char(tty, '\b');
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) if (ldata->column > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) ldata->column--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) tail += 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) case ECHO_OP_SET_CANON_COL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) ldata->canon_column = ldata->column;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) tail += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) case ECHO_OP_MOVE_BACK_COL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) if (ldata->column > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) ldata->column--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) tail += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) case ECHO_OP_START:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) /* This is an escaped echo op start code */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) if (!space) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) no_space_left = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) tty_put_char(tty, ECHO_OP_START);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) ldata->column++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) space--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) tail += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) * If the op is not a special byte code,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) * it is a ctrl char tagged to be echoed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) * as "^X" (where X is the letter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) * representing the control char).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) * Note that we must ensure there is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) * enough space for the whole ctrl pair.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) if (space < 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) no_space_left = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) tty_put_char(tty, '^');
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) tty_put_char(tty, op ^ 0100);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) ldata->column += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) space -= 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) tail += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) if (no_space_left)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) if (O_OPOST(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) int retval = do_output_char(c, tty, space);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) if (retval < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) space -= retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) if (!space)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) tty_put_char(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) space -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) tail += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) /* If the echo buffer is nearly full (so that the possibility exists
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) * of echo overrun before the next commit), then discard enough
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) * data at the tail to prevent a subsequent overrun */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) while (ldata->echo_commit > tail &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) if (echo_buf(ldata, tail) == ECHO_OP_START) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) tail += 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) tail += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) tail++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) not_yet_stored:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) ldata->echo_tail = tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) return old_space - space;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) static void commit_echoes(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) size_t nr, old, echoed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) size_t head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) head = ldata->echo_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) ldata->echo_mark = head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) old = ldata->echo_commit - ldata->echo_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) /* Process committed echoes if the accumulated # of bytes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) * is over the threshold (and try again each time another
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) * block is accumulated) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) nr = head - ldata->echo_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) if (nr < ECHO_COMMIT_WATERMARK ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) (nr % ECHO_BLOCK > old % ECHO_BLOCK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) ldata->echo_commit = head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) echoed = __process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) if (echoed && tty->ops->flush_chars)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) tty->ops->flush_chars(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) static void process_echoes(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) size_t echoed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) if (ldata->echo_mark == ldata->echo_tail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) ldata->echo_commit = ldata->echo_mark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) echoed = __process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) if (echoed && tty->ops->flush_chars)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) tty->ops->flush_chars(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) /* NB: echo_mark and echo_head should be equivalent here */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) static void flush_echoes(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) ldata->echo_commit == ldata->echo_head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) ldata->echo_commit = ldata->echo_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) __process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) * add_echo_byte - add a byte to the echo buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) * @c: unicode byte to echo
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) * @ldata: n_tty data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) * Add a character or operation byte to the echo buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) static inline void add_echo_byte(unsigned char c, struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) *echo_buf_addr(ldata, ldata->echo_head) = c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) smp_wmb(); /* Matches smp_rmb() in echo_buf(). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) ldata->echo_head++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) * echo_move_back_col - add operation to move back a column
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) * @ldata: n_tty data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) * Add an operation to the echo buffer to move back one column.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) static void echo_move_back_col(struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) add_echo_byte(ECHO_OP_MOVE_BACK_COL, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) * echo_set_canon_col - add operation to set the canon column
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) * @ldata: n_tty data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) * Add an operation to the echo buffer to set the canon column
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) * to the current column.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) static void echo_set_canon_col(struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) add_echo_byte(ECHO_OP_SET_CANON_COL, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) * echo_erase_tab - add operation to erase a tab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) * @num_chars: number of character columns already used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) * @after_tab: true if num_chars starts after a previous tab
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) * @ldata: n_tty data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) * Add an operation to the echo buffer to erase a tab.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) * Called by the eraser function, which knows how many character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) * columns have been used since either a previous tab or the start
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) * of input. This information will be used later, along with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) * canon column (if applicable), to go back the correct number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) * of columns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) static void echo_erase_tab(unsigned int num_chars, int after_tab,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) add_echo_byte(ECHO_OP_ERASE_TAB, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) /* We only need to know this modulo 8 (tab spacing) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) num_chars &= 7;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) /* Set the high bit as a flag if num_chars is after a previous tab */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) if (after_tab)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) num_chars |= 0x80;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) add_echo_byte(num_chars, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) * echo_char_raw - echo a character raw
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) * @c: unicode byte to echo
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) * @ldata: line disc data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) * Echo user input back onto the screen. This must be called only when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) * L_ECHO(tty) is true. Called from the driver receive_buf path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) * This variant does not treat control characters specially.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) static void echo_char_raw(unsigned char c, struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) if (c == ECHO_OP_START) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) add_echo_byte(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) * echo_char - echo a character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) * @c: unicode byte to echo
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) * Echo user input back onto the screen. This must be called only when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) * L_ECHO(tty) is true. Called from the driver receive_buf path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) * This variant tags control characters to be echoed as "^X"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) * (where X is the letter representing the control char).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) static void echo_char(unsigned char c, struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) if (c == ECHO_OP_START) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) add_echo_byte(ECHO_OP_START, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) add_echo_byte(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) * finish_erasing - complete erase
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) * @ldata: n_tty data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) static inline void finish_erasing(struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) if (ldata->erasing) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) echo_char_raw('/', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) ldata->erasing = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) * eraser - handle erase function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) * @c: character input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) * Perform erase and necessary output when an erase character is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) * present in the stream from the driver layer. Handles the complexities
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) * of UTF-8 multibyte symbols.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) * n_tty_receive_buf()/producer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) static void eraser(unsigned char c, struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) enum { ERASE, WERASE, KILL } kill_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) size_t head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) size_t cnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) int seen_alnums;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) if (ldata->read_head == ldata->canon_head) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) /* process_output('\a', tty); */ /* what do you think? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) if (c == ERASE_CHAR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) kill_type = ERASE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) else if (c == WERASE_CHAR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) kill_type = WERASE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) if (!L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) ldata->read_head = ldata->canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) ldata->read_head = ldata->canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) echo_char(KILL_CHAR(tty), tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) /* Add a newline if ECHOK is on and ECHOKE is off. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) if (L_ECHOK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) echo_char_raw('\n', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) kill_type = KILL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) seen_alnums = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) while (MASK(ldata->read_head) != MASK(ldata->canon_head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) head = ldata->read_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) /* erase a single possibly multibyte character */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) head--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) c = read_buf(ldata, head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) } while (is_continuation(c, tty) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) MASK(head) != MASK(ldata->canon_head));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) /* do not partially erase */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) if (is_continuation(c, tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) if (kill_type == WERASE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) /* Equivalent to BSD's ALTWERASE. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) if (isalnum(c) || c == '_')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) seen_alnums++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) else if (seen_alnums)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) cnt = ldata->read_head - head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) ldata->read_head = head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) if (L_ECHOPRT(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) if (!ldata->erasing) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) echo_char_raw('\\', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) ldata->erasing = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) /* if cnt > 1, output a multi-byte character */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) while (--cnt > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) head++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) echo_char_raw(read_buf(ldata, head), ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) echo_move_back_col(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) } else if (kill_type == ERASE && !L_ECHOE(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) echo_char(ERASE_CHAR(tty), tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) } else if (c == '\t') {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) unsigned int num_chars = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) int after_tab = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) size_t tail = ldata->read_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) * Count the columns used for characters
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) * since the start of input or after a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) * previous tab.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) * This info is used to go back the correct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) * number of columns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) while (MASK(tail) != MASK(ldata->canon_head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) tail--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) c = read_buf(ldata, tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) if (c == '\t') {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) after_tab = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) } else if (iscntrl(c)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) if (L_ECHOCTL(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) num_chars += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) } else if (!is_continuation(c, tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) num_chars++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) echo_erase_tab(num_chars, after_tab, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) if (iscntrl(c) && L_ECHOCTL(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) echo_char_raw('\b', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) echo_char_raw(' ', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) echo_char_raw('\b', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) if (!iscntrl(c) || L_ECHOCTL(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) echo_char_raw('\b', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) echo_char_raw(' ', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) echo_char_raw('\b', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) if (kill_type == ERASE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) if (ldata->read_head == ldata->canon_head && L_ECHO(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) * isig - handle the ISIG optio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) * @sig: signal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) * @tty: terminal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) * Called when a signal is being sent due to terminal input.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) * Called from the driver receive_buf path so serialized.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) * Performs input and output flush if !NOFLSH. In this context, the echo
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) * buffer is 'output'. The signal is processed first to alert any current
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) * readers or writers to discontinue and exit their i/o loops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) * Locking: ctrl_lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) static void __isig(int sig, struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) struct pid *tty_pgrp = tty_get_pgrp(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) if (tty_pgrp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) kill_pgrp(tty_pgrp, sig, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) put_pid(tty_pgrp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) static void isig(int sig, struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) if (L_NOFLSH(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) /* signal only */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) __isig(sig, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) } else { /* signal and flush */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) down_write(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) __isig(sig, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) /* clear echo buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) ldata->echo_head = ldata->echo_tail = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) ldata->echo_mark = ldata->echo_commit = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) /* clear output buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) tty_driver_flush_buffer(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) /* clear input buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) reset_buffer_flags(tty->disc_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) /* notify pty master of flush */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) if (tty->link)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) n_tty_packet_mode_flush(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) up_write(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) * n_tty_receive_break - handle break
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) * @tty: terminal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) * An RS232 break event has been hit in the incoming bitstream. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) * can cause a variety of events depending upon the termios settings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) * n_tty_receive_buf()/producer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) * Note: may get exclusive termios_rwsem if flushing input buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) static void n_tty_receive_break(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) if (I_IGNBRK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) if (I_BRKINT(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) isig(SIGINT, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) if (I_PARMRK(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) put_tty_queue('\377', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) put_tty_queue('\0', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) put_tty_queue('\0', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) * n_tty_receive_overrun - handle overrun reporting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) * @tty: terminal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) * Data arrived faster than we could process it. While the tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) * driver has flagged this the bits that were missed are gone
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) * forever.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) * Called from the receive_buf path so single threaded. Does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) * need locking as num_overrun and overrun_time are function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) * private.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) static void n_tty_receive_overrun(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) ldata->num_overrun++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) if (time_after(jiffies, ldata->overrun_time + HZ) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) time_after(ldata->overrun_time, jiffies)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) tty_warn(tty, "%d input overrun(s)\n", ldata->num_overrun);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) ldata->overrun_time = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) ldata->num_overrun = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) * n_tty_receive_parity_error - error notifier
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) * @c: character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) * Process a parity error and queue the right data to indicate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) * the error case if necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) * n_tty_receive_buf()/producer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) if (I_INPCK(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) if (I_IGNPAR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) if (I_PARMRK(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) put_tty_queue('\377', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) put_tty_queue('\0', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) put_tty_queue('\0', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) isig(signal, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) if (I_IXON(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) * n_tty_receive_char - perform processing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) * @c: character
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) * Process an individual character of input received from the driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) * This is serialized with respect to itself by the rules for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) * driver above.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) * n_tty_receive_buf()/producer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) * publishes canon_head if canonical mode is active
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) * Returns 1 if LNEXT was received, else returns 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) if (I_IXON(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) if (c == START_CHAR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) if (c == STOP_CHAR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) stop_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) if (L_ISIG(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) if (c == INTR_CHAR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) n_tty_receive_signal_char(tty, SIGINT, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) } else if (c == QUIT_CHAR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) n_tty_receive_signal_char(tty, SIGQUIT, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) } else if (c == SUSP_CHAR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) n_tty_receive_signal_char(tty, SIGTSTP, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) if (c == '\r') {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) if (I_IGNCR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) if (I_ICRNL(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) c = '\n';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) } else if (c == '\n' && I_INLCR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) c = '\r';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) if (ldata->icanon) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) eraser(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) ldata->lnext = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) if (L_ECHOCTL(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) echo_char_raw('^', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) echo_char_raw('\b', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && L_IEXTEN(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) size_t tail = ldata->canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) echo_char_raw('\n', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) while (MASK(tail) != MASK(ldata->read_head)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) echo_char(read_buf(ldata, tail), tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) tail++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) if (c == '\n') {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341) if (L_ECHO(tty) || L_ECHONL(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) echo_char_raw('\n', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) goto handle_newline;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347) if (c == EOF_CHAR(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) c = __DISABLED_CHAR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) goto handle_newline;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) if ((c == EOL_CHAR(tty)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) /* Record the column of first canon char. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) if (ldata->canon_head == ldata->read_head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) echo_set_canon_col(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) * XXX does PARMRK doubling happen for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) * EOL_CHAR and EOL2_CHAR?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) if (c == (unsigned char) '\377' && I_PARMRK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) handle_newline:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) set_bit(ldata->read_head & (N_TTY_BUF_SIZE - 1), ldata->read_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) smp_store_release(&ldata->canon_head, ldata->read_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) kill_fasync(&tty->fasync, SIGIO, POLL_IN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) wake_up_interruptible_poll(&tty->read_wait, EPOLLIN | EPOLLRDNORM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) if (c == '\n')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) echo_char_raw('\n', ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) /* Record the column of first canon char. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) if (ldata->canon_head == ldata->read_head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) echo_set_canon_col(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) /* PARMRK doubling check */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) if (c == (unsigned char) '\377' && I_PARMRK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) static inline void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) n_tty_receive_char_inline(struct tty_struct *tty, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) /* Record the column of first canon char. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) if (ldata->canon_head == ldata->read_head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) echo_set_canon_col(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) /* PARMRK doubling check */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) if (c == (unsigned char) '\377' && I_PARMRK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) static void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) n_tty_receive_char_inline(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) static inline void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) if (L_ECHO(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) finish_erasing(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) /* Record the column of first canon char. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) if (ldata->canon_head == ldata->read_head)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) echo_set_canon_col(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) echo_char(c, tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) commit_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) static void n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) if (I_ISTRIP(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452) c &= 0x7f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) if (I_IUCLC(tty) && L_IEXTEN(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) c = tolower(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) if (I_IXON(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) if (c == STOP_CHAR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) stop_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) else if (c == START_CHAR(tty) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) (tty->stopped && !tty->flow_stopped && I_IXANY(tty) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) c != SUSP_CHAR(tty))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) n_tty_receive_char_flagged(struct tty_struct *tty, unsigned char c, char flag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) switch (flag) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) case TTY_BREAK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) n_tty_receive_break(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) case TTY_PARITY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) case TTY_FRAME:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) n_tty_receive_parity_error(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) case TTY_OVERRUN:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) n_tty_receive_overrun(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) tty_err(tty, "unknown flag %d\n", flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) n_tty_receive_char_lnext(struct tty_struct *tty, unsigned char c, char flag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494) ldata->lnext = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) if (likely(flag == TTY_NORMAL)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) if (I_ISTRIP(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) c &= 0x7f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) if (I_IUCLC(tty) && L_IEXTEN(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) c = tolower(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) n_tty_receive_char(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) n_tty_receive_char_flagged(tty, c, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) n_tty_receive_buf_real_raw(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) size_t n, head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) head = ldata->read_head & (N_TTY_BUF_SIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) n = min_t(size_t, count, N_TTY_BUF_SIZE - head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) memcpy(read_buf_addr(ldata, head), cp, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) ldata->read_head += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) cp += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) count -= n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) head = ldata->read_head & (N_TTY_BUF_SIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) n = min_t(size_t, count, N_TTY_BUF_SIZE - head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) memcpy(read_buf_addr(ldata, head), cp, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) ldata->read_head += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) n_tty_receive_buf_raw(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) char flag = TTY_NORMAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) while (count--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) if (likely(flag == TTY_NORMAL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) put_tty_queue(*cp++, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) n_tty_receive_char_flagged(tty, *cp++, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) n_tty_receive_buf_closing(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) char flag = TTY_NORMAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) while (count--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) if (likely(flag == TTY_NORMAL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) n_tty_receive_char_closing(tty, *cp++);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) n_tty_receive_buf_standard(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) char flag = TTY_NORMAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) while (count--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) if (likely(flag == TTY_NORMAL)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) unsigned char c = *cp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) if (I_ISTRIP(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) c &= 0x7f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) if (I_IUCLC(tty) && L_IEXTEN(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) c = tolower(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573) if (L_EXTPROC(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) put_tty_queue(c, ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) if (!test_bit(c, ldata->char_map))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) n_tty_receive_char_inline(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579) else if (n_tty_receive_char_special(tty, c) && count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) n_tty_receive_char_lnext(tty, *cp++, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) n_tty_receive_char_flagged(tty, *cp++, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) n_tty_receive_buf_fast(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) char flag = TTY_NORMAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) while (count--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) if (likely(flag == TTY_NORMAL)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) unsigned char c = *cp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) if (!test_bit(c, ldata->char_map))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) n_tty_receive_char_fast(tty, c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605) else if (n_tty_receive_char_special(tty, c) && count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) n_tty_receive_char_lnext(tty, *cp++, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) n_tty_receive_char_flagged(tty, *cp++, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620) bool preops = I_ISTRIP(tty) || (I_IUCLC(tty) && L_IEXTEN(tty));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) if (ldata->real_raw)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623) n_tty_receive_buf_real_raw(tty, cp, fp, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) else if (ldata->raw || (L_EXTPROC(tty) && !preops))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) n_tty_receive_buf_raw(tty, cp, fp, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) else if (tty->closing && !L_EXTPROC(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) n_tty_receive_buf_closing(tty, cp, fp, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) if (ldata->lnext) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) char flag = TTY_NORMAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) flag = *fp++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) n_tty_receive_char_lnext(tty, *cp++, flag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) count--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) if (!preops && !I_PARMRK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) n_tty_receive_buf_fast(tty, cp, fp, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) n_tty_receive_buf_standard(tty, cp, fp, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) flush_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) if (tty->ops->flush_chars)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) tty->ops->flush_chars(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) if (ldata->icanon && !L_EXTPROC(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) /* publish read_head to consumer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) smp_store_release(&ldata->commit_head, ldata->read_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) if (read_cnt(ldata)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) kill_fasync(&tty->fasync, SIGIO, POLL_IN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) wake_up_interruptible_poll(&tty->read_wait, EPOLLIN | EPOLLRDNORM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) * n_tty_receive_buf_common - process input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) * @tty: device to receive input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) * @cp: input chars
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) * @fp: flags for each char (if NULL, all chars are TTY_NORMAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665) * @count: number of input chars in @cp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) * Called by the terminal driver when a block of characters has
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) * been received. This function must be called from soft contexts
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) * not from interrupt context. The driver is responsible for making
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) * calls one at a time and in order (or using flush_to_ldisc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) * Returns the # of input chars from @cp which were processed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) * In canonical mode, the maximum line length is 4096 chars (including
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) * the line termination char); lines longer than 4096 chars are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) * truncated. After 4095 chars, input data is still processed but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) * not stored. Overflow processing ensures the tty can always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) * receive more input until at least one line can be read.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) * In non-canonical mode, the read buffer will only accept 4095 chars;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) * this provides the necessary space for a newline char if the input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) * mode is switched to canonical.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) * Note it is possible for the read buffer to _contain_ 4096 chars
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) * in non-canonical mode: the read buffer could already contain the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) * maximum canon line of 4096 chars when the mode is switched to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) * non-canonical.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) * n_tty_receive_buf()/producer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) * claims non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) * publishes commit_head or canon_head
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) char *fp, int count, int flow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) int room, n, rcvd = 0, overflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) * When PARMRK is set, each input char may take up to 3 chars
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) * in the read buf; reduce the buffer space avail by 3x
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) * If we are doing input canonicalization, and there are no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) * pending newlines, let characters through without limit, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) * that erase characters will be handled. Other excess
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) * characters will be beeped.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712) * paired with store in *_copy_from_read_buf() -- guarantees
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) * the consumer has loaded the data in read_buf up to the new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) * read_tail (so this producer will not overwrite unread data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) size_t tail = smp_load_acquire(&ldata->read_tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) room = N_TTY_BUF_SIZE - (ldata->read_head - tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) if (I_PARMRK(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) room = (room + 2) / 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) room--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) if (room <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) overflow = ldata->icanon && ldata->canon_head == tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) if (overflow && room < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) ldata->read_head--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) room = overflow;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) ldata->no_room = flow && !room;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) overflow = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) n = min(count, room);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) if (!n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) /* ignore parity errors if handling overflow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) if (!overflow || !fp || *fp != TTY_PARITY)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) __receive_buf(tty, cp, fp, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) cp += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) if (fp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) fp += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) count -= n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) rcvd += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) } while (!test_bit(TTY_LDISC_CHANGING, &tty->flags));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) tty->receive_room = room;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) /* Unthrottle if handling overflow on pty */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) if (overflow) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) tty_unthrottle_safe(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) __tty_set_flow_change(tty, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) n_tty_check_throttle(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) return rcvd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766) n_tty_receive_buf_common(tty, cp, fp, count, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) char *fp, int count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) return n_tty_receive_buf_common(tty, cp, fp, count, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) * n_tty_set_termios - termios data changed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777) * @tty: terminal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778) * @old: previous data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780) * Called by the tty layer when the user changes termios flags so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781) * that the line discipline can plan ahead. This function cannot sleep
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) * and is protected from re-entry by the tty layer. The user is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783) * guaranteed that this function will not be re-entered or in progress
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) * when the ldisc is closed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) * Locking: Caller holds tty->termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793) if (!old || (old->c_lflag ^ tty->termios.c_lflag) & (ICANON | EXTPROC)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) ldata->line_start = ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) if (!L_ICANON(tty) || !read_cnt(ldata)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) ldata->canon_head = ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798) ldata->push = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800) set_bit((ldata->read_head - 1) & (N_TTY_BUF_SIZE - 1),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) ldata->read_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) ldata->canon_head = ldata->read_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) ldata->push = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) ldata->commit_head = ldata->read_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806) ldata->erasing = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) ldata->lnext = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) ldata->icanon = (L_ICANON(tty) != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812) if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) I_PARMRK(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) bitmap_zero(ldata->char_map, 256);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818) if (I_IGNCR(tty) || I_ICRNL(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) set_bit('\r', ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) if (I_INLCR(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) set_bit('\n', ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) if (L_ICANON(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) set_bit(ERASE_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) set_bit(KILL_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) set_bit(EOF_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827) set_bit('\n', ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) set_bit(EOL_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829) if (L_IEXTEN(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830) set_bit(WERASE_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831) set_bit(LNEXT_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) set_bit(EOL2_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) if (L_ECHO(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834) set_bit(REPRINT_CHAR(tty),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835) ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) if (I_IXON(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839) set_bit(START_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840) set_bit(STOP_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842) if (L_ISIG(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843) set_bit(INTR_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844) set_bit(QUIT_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845) set_bit(SUSP_CHAR(tty), ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847) clear_bit(__DISABLED_CHAR, ldata->char_map);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848) ldata->raw = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) ldata->real_raw = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) ldata->raw = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853) (I_IGNPAR(tty) || !I_INPCK(tty)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) (tty->driver->flags & TTY_DRIVER_REAL_RAW))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) ldata->real_raw = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857) ldata->real_raw = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) * Fix tty hang when I_IXON(tty) is cleared, but the tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861) * been stopped by STOP_CHAR(tty) before it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863) if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) start_tty(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) /* The termios change make the tty ready for I/O */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869) wake_up_interruptible(&tty->write_wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870) wake_up_interruptible(&tty->read_wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874) * n_tty_close - close the ldisc for this tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875) * @tty: device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) * Called from the terminal layer when this line discipline is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) * being shut down, either because of a close or becsuse of a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879) * discipline change. The function will not be called while other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) * ldisc methods are in progress.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) static void n_tty_close(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887) if (tty->link)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) n_tty_packet_mode_flush(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) vfree(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) tty->disc_data = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895) * n_tty_open - open an ldisc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896) * @tty: terminal to open
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) * Called when this line discipline is being attached to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899) * terminal device. Can sleep. Called serialized so that no
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900) * other events will occur in parallel. No further open will occur
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) * until a close.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) static int n_tty_open(struct tty_struct *tty)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) struct n_tty_data *ldata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908) /* Currently a malloc failure here can panic */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) ldata = vzalloc(sizeof(*ldata));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910) if (!ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913) ldata->overrun_time = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) mutex_init(&ldata->atomic_read_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915) mutex_init(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917) tty->disc_data = ldata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918) tty->closing = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) /* indicate buffer work may resume */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920) clear_bit(TTY_LDISC_HALTED, &tty->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) n_tty_set_termios(tty, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) tty_unthrottle(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) static inline int input_available_p(struct tty_struct *tty, int poll)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) if (ldata->icanon && !L_EXTPROC(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) return ldata->canon_head != ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934) return ldata->commit_head - ldata->read_tail >= amt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938) * copy_from_read_buf - copy read data directly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940) * @kbp: data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) * @nr: size of data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943) * Helper function to speed up n_tty_read. It is only called when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944) * ICANON is off; it copies characters straight from the tty queue.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946) * Called under the ldata->atomic_read_lock sem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) * Returns true if it successfully copied data, but there is still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) * more data to be had.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) * n_tty_read()/consumer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) * read_tail published
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) static bool copy_from_read_buf(struct tty_struct *tty,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957) unsigned char **kbp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) size_t *nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) size_t n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963) bool is_eof;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) size_t head = smp_load_acquire(&ldata->commit_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965) size_t tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) n = min(*nr, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) if (n) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) unsigned char *from = read_buf_addr(ldata, tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) memcpy(*kbp, from, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) is_eof = n == 1 && *from == EOF_CHAR(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973) tty_audit_add_data(tty, from, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) zero_buffer(tty, from, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975) smp_store_release(&ldata->read_tail, ldata->read_tail + n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) /* Turn single EOF into zero-length read */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) if (L_EXTPROC(tty) && ldata->icanon && is_eof &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978) (head == ldata->read_tail))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) *kbp += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981) *nr -= n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983) /* If we have more to copy, let the caller know */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984) return head != ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990) * canon_copy_from_read_buf - copy read data in canonical mode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) * @kbp: data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993) * @nr: size of data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1994) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1995) * Helper function for n_tty_read. It is only called when ICANON is on;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1996) * it copies one line of input up to and including the line-delimiting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1997) * character into the result buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1998) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1999) * NB: When termios is changed from non-canonical to canonical mode and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2000) * the read buffer contains data, n_tty_set_termios() simulates an EOF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2001) * push (as if C-d were input) _without_ the DISABLED_CHAR in the buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2002) * This causes data already processed as input to be immediately available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2003) * as input although a newline has not been received.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2004) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2005) * Called under the atomic_read_lock mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2006) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2007) * n_tty_read()/consumer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2008) * caller holds non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2009) * read_tail published
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2010) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2011)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2012) static bool canon_copy_from_read_buf(struct tty_struct *tty,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2013) unsigned char **kbp,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2014) size_t *nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2015) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2016) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2017) size_t n, size, more, c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2018) size_t eol;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2019) size_t tail, canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2020) int found = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2022) /* N.B. avoid overrun if nr == 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2023) if (!*nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2024) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2025)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2026) canon_head = smp_load_acquire(&ldata->canon_head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2027) n = min(*nr, canon_head - ldata->read_tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2028)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2029) tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2030) size = min_t(size_t, tail + n, N_TTY_BUF_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2031)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2032) n_tty_trace("%s: nr:%zu tail:%zu n:%zu size:%zu\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2033) __func__, *nr, tail, n, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2034)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2035) eol = find_next_bit(ldata->read_flags, size, tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2036) more = n - (size - tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2037) if (eol == N_TTY_BUF_SIZE && more) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2038) /* scan wrapped without finding set bit */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2039) eol = find_next_bit(ldata->read_flags, more, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2040) found = eol != more;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2041) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2042) found = eol != size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2043)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2044) n = eol - tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2045) if (n > N_TTY_BUF_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2046) n += N_TTY_BUF_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2047) c = n + found;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2048)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2049) if (!found || read_buf(ldata, eol) != __DISABLED_CHAR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2050) n = c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2051)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2052) n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2053) __func__, eol, found, n, c, tail, more);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2054)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2055) tty_copy(tty, *kbp, tail, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2056) *kbp += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2057) *nr -= n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2058)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2059) if (found)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2060) clear_bit(eol, ldata->read_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2061) smp_store_release(&ldata->read_tail, ldata->read_tail + c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2062)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2063) if (found) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2064) if (!ldata->push)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2065) ldata->line_start = ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2066) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2067) ldata->push = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2068) tty_audit_push();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2069) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2070) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2071)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2072) /* No EOL found - do a continuation retry if there is more data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2073) return ldata->read_tail != canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2074) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2075)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2076) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2077) * job_control - check job control
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2078) * @tty: tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2079) * @file: file handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2080) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2081) * Perform job control management checks on this file/tty descriptor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2082) * and if appropriate send any needed signals and return a negative
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2083) * error code if action should be taken.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2084) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2085) * Locking: redirected write test is safe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2086) * current->signal->tty check is safe
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2087) * ctrl_lock to safely reference tty->pgrp
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2088) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2089)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2090) static int job_control(struct tty_struct *tty, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2091) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2092) /* Job control check -- must be done at start and after
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2093) every sleep (POSIX.1 7.1.1.4). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2094) /* NOTE: not yet done after every sleep pending a thorough
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2095) check of the logic of this change. -- jlc */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2096) /* don't stop on /dev/console */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2097) if (file->f_op->write_iter == redirected_tty_write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2098) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2099)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2100) return __tty_check_change(tty, SIGTTIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2104) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2105) * n_tty_read - read function for tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2106) * @tty: tty device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2107) * @file: file object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2108) * @buf: userspace buffer pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2109) * @nr: size of I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2110) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2111) * Perform reads for the line discipline. We are guaranteed that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2112) * line discipline will not be closed under us but we may get multiple
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2113) * parallel readers and must handle this ourselves. We may also get
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2114) * a hangup. Always called in user context, may sleep.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2115) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2116) * This code must be sure never to sleep through a hangup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2117) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2118) * n_tty_read()/consumer path:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2119) * claims non-exclusive termios_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2120) * publishes read_tail
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2121) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2123) static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2124) unsigned char *kbuf, size_t nr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2125) void **cookie, unsigned long offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2126) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2127) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2128) unsigned char *kb = kbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2129) DEFINE_WAIT_FUNC(wait, woken_wake_function);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2130) int c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2131) int minimum, time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2132) ssize_t retval = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2133) long timeout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2134) int packet;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2135) size_t tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2136)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2137) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2138) * Is this a continuation of a read started earler?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2139) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2140) * If so, we still hold the atomic_read_lock and the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2141) * termios_rwsem, and can just continue to copy data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2142) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2143) if (*cookie) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2144) if (ldata->icanon && !L_EXTPROC(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2145) if (canon_copy_from_read_buf(tty, &kb, &nr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2146) return kb - kbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2147) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2148) if (copy_from_read_buf(tty, &kb, &nr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2149) return kb - kbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2150) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2152) /* No more data - release locks and stop retries */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2153) n_tty_kick_worker(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2154) n_tty_check_unthrottle(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2155) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2156) mutex_unlock(&ldata->atomic_read_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2157) *cookie = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2158) return kb - kbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2159) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2161) c = job_control(tty, file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2162) if (c < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2163) return c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2165) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2166) * Internal serialization of reads.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2167) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2168) if (file->f_flags & O_NONBLOCK) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2169) if (!mutex_trylock(&ldata->atomic_read_lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2170) return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2171) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2172) if (mutex_lock_interruptible(&ldata->atomic_read_lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2173) return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2176) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2178) minimum = time = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2179) timeout = MAX_SCHEDULE_TIMEOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2180) if (!ldata->icanon) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2181) minimum = MIN_CHAR(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2182) if (minimum) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2183) time = (HZ / 10) * TIME_CHAR(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2184) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2185) timeout = (HZ / 10) * TIME_CHAR(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2186) minimum = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2190) packet = tty->packet;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2191) tail = ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2193) add_wait_queue(&tty->read_wait, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2194) while (nr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2195) /* First test for status change. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2196) if (packet && tty->link->ctrl_status) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2197) unsigned char cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2198) if (kb != kbuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2199) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2200) spin_lock_irq(&tty->link->ctrl_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2201) cs = tty->link->ctrl_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2202) tty->link->ctrl_status = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2203) spin_unlock_irq(&tty->link->ctrl_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2204) *kb++ = cs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2205) nr--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2206) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2207) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2208)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2209) if (!input_available_p(tty, 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2210) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2211) tty_buffer_flush_work(tty->port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2212) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2213) if (!input_available_p(tty, 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2214) if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2215) retval = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2216) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2217) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2218) if (tty_hung_up_p(file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2219) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2220) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2221) * Abort readers for ttys which never actually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2222) * get hung up. See __tty_hangup().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2223) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2224) if (test_bit(TTY_HUPPING, &tty->flags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2225) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2226) if (!timeout)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2227) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2228) if (tty_io_nonblock(tty, file)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2229) retval = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2230) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2231) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2232) if (signal_pending(current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2233) retval = -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2234) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2236) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2238) timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2239) timeout);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2241) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2242) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2243) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2244) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2246) if (ldata->icanon && !L_EXTPROC(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2247) if (canon_copy_from_read_buf(tty, &kb, &nr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2248) goto more_to_be_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2249) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2250) /* Deal with packet mode. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2251) if (packet && kb == kbuf) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2252) *kb++ = TIOCPKT_DATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2253) nr--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2254) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2255)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2256) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2257) * Copy data, and if there is more to be had
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2258) * and we have nothing more to wait for, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2259) * let's mark us for retries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2260) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2261) * NOTE! We return here with both the termios_sem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2262) * and atomic_read_lock still held, the retries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2263) * will release them when done.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2264) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2265) if (copy_from_read_buf(tty, &kb, &nr) && kb - kbuf >= minimum) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2266) more_to_be_read:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2267) remove_wait_queue(&tty->read_wait, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2268) *cookie = cookie;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2269) return kb - kbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2271) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2272)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2273) n_tty_check_unthrottle(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2275) if (kb - kbuf >= minimum)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2276) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2277) if (time)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2278) timeout = time;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2280) if (tail != ldata->read_tail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2281) n_tty_kick_worker(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2282) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2284) remove_wait_queue(&tty->read_wait, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2285) mutex_unlock(&ldata->atomic_read_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2287) if (kb - kbuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2288) retval = kb - kbuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2289)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2290) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2291) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2293) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2294) * n_tty_write - write function for tty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2295) * @tty: tty device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2296) * @file: file object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2297) * @buf: userspace buffer pointer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2298) * @nr: size of I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2299) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2300) * Write function of the terminal device. This is serialized with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2301) * respect to other write callers but not to termios changes, reads
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2302) * and other such events. Since the receive code will echo characters,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2303) * thus calling driver write methods, the output_lock is used in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2304) * the output processing functions called here as well as in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2305) * echo processing function to protect the column state and space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2306) * left in the buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2307) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2308) * This code must be sure never to sleep through a hangup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2309) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2310) * Locking: output_lock to protect column state and space left
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2311) * (note that the process_output*() functions take this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2312) * lock themselves)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2313) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2314)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2315) static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2316) const unsigned char *buf, size_t nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2318) const unsigned char *b = buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2319) DEFINE_WAIT_FUNC(wait, woken_wake_function);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2320) int c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2321) ssize_t retval = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2323) /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2324) if (L_TOSTOP(tty) && file->f_op->write_iter != redirected_tty_write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2325) retval = tty_check_change(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2326) if (retval)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2327) return retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2328) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2330) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2332) /* Write out any echoed characters that are still pending */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2333) process_echoes(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2335) add_wait_queue(&tty->write_wait, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2336) while (1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2337) if (signal_pending(current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2338) retval = -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2339) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2341) if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2342) retval = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2343) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2344) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2345) if (O_OPOST(tty)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2346) while (nr > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2347) ssize_t num = process_output_block(tty, b, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2348) if (num < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2349) if (num == -EAGAIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2350) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2351) retval = num;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2352) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2354) b += num;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2355) nr -= num;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2356) if (nr == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2357) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2358) c = *b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2359) if (process_output(c, tty) < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2360) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2361) b++; nr--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2363) if (tty->ops->flush_chars)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2364) tty->ops->flush_chars(tty);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2365) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2366) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2368) while (nr > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2369) mutex_lock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2370) c = tty->ops->write(tty, b, nr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2371) mutex_unlock(&ldata->output_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2372) if (c < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2373) retval = c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2374) goto break_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2375) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2376) if (!c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2377) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2378) b += c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2379) nr -= c;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2380) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2381) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2382) if (!nr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2383) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2384) if (tty_io_nonblock(tty, file)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2385) retval = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2386) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2387) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2388) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2390) wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2392) down_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2393) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2394) break_out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2395) remove_wait_queue(&tty->write_wait, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2396) if (nr && tty->fasync)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2397) set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2398) up_read(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2399) return (b - buf) ? b - buf : retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2400) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2401)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2402) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2403) * n_tty_poll - poll method for N_TTY
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2404) * @tty: terminal device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2405) * @file: file accessing it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2406) * @wait: poll table
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2407) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2408) * Called when the line discipline is asked to poll() for data or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2409) * for special events. This code is not serialized with respect to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2410) * other events save open/close.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2411) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2412) * This code must be sure never to sleep through a hangup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2413) * Called without the kernel lock held - fine
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2414) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2415)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2416) static __poll_t n_tty_poll(struct tty_struct *tty, struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2417) poll_table *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2418) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2419) __poll_t mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2421) poll_wait(file, &tty->read_wait, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2422) poll_wait(file, &tty->write_wait, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2423) if (input_available_p(tty, 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2424) mask |= EPOLLIN | EPOLLRDNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2425) else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2426) tty_buffer_flush_work(tty->port);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2427) if (input_available_p(tty, 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2428) mask |= EPOLLIN | EPOLLRDNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2429) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2430) if (tty->packet && tty->link->ctrl_status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2431) mask |= EPOLLPRI | EPOLLIN | EPOLLRDNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2432) if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2433) mask |= EPOLLHUP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2434) if (tty_hung_up_p(file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2435) mask |= EPOLLHUP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2436) if (tty->ops->write && !tty_is_writelocked(tty) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2437) tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2438) tty_write_room(tty) > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2439) mask |= EPOLLOUT | EPOLLWRNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2440) return mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2441) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2443) static unsigned long inq_canon(struct n_tty_data *ldata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2444) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2445) size_t nr, head, tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2447) if (ldata->canon_head == ldata->read_tail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2448) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2449) head = ldata->canon_head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2450) tail = ldata->read_tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2451) nr = head - tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2452) /* Skip EOF-chars.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2453) while (MASK(head) != MASK(tail)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2454) if (test_bit(tail & (N_TTY_BUF_SIZE - 1), ldata->read_flags) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2455) read_buf(ldata, tail) == __DISABLED_CHAR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2456) nr--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2457) tail++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2458) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2459) return nr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2460) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2461)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2462) static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2463) unsigned int cmd, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2464) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2465) struct n_tty_data *ldata = tty->disc_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2466) int retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2467)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2468) switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2469) case TIOCOUTQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2470) return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2471) case TIOCINQ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2472) down_write(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2473) if (L_ICANON(tty) && !L_EXTPROC(tty))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2474) retval = inq_canon(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2475) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2476) retval = read_cnt(ldata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2477) up_write(&tty->termios_rwsem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2478) return put_user(retval, (unsigned int __user *) arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2479) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2480) return n_tty_ioctl_helper(tty, file, cmd, arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2482) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2484) static struct tty_ldisc_ops n_tty_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2485) .magic = TTY_LDISC_MAGIC,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2486) .name = "n_tty",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2487) .open = n_tty_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2488) .close = n_tty_close,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2489) .flush_buffer = n_tty_flush_buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2490) .read = n_tty_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2491) .write = n_tty_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2492) .ioctl = n_tty_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2493) .set_termios = n_tty_set_termios,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2494) .poll = n_tty_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2495) .receive_buf = n_tty_receive_buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2496) .write_wakeup = n_tty_write_wakeup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2497) .receive_buf2 = n_tty_receive_buf2,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2498) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2500) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2501) * n_tty_inherit_ops - inherit N_TTY methods
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2502) * @ops: struct tty_ldisc_ops where to save N_TTY methods
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2503) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2504) * Enables a 'subclass' line discipline to 'inherit' N_TTY methods.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2505) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2506)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2507) void n_tty_inherit_ops(struct tty_ldisc_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2508) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2509) *ops = n_tty_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2510) ops->owner = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2511) ops->refcount = ops->flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2512) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2513) EXPORT_SYMBOL_GPL(n_tty_inherit_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2514)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2515) void __init n_tty_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2516) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2517) tty_register_ldisc(N_TTY, &n_tty_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2518) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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