| 1 | |
| 2 | |
| 3 | * Copyright (C) 1991, 1992 Linus Torvalds
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| 4 |
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| 5 |
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| 6 | |
| 7 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
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| 8 | * or rs-channels. It also implements echoing, cooked mode etc.
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| 9 | *
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| 10 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
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| 11 | *
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| 12 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
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| 13 | * tty_struct and tty_queue structures. Previously there was an array
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| 14 | * of 256 tty_struct's which was statically allocated, and the
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| 15 | * tty_queue structures were allocated at boot time. Both are now
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| 16 | * dynamically allocated only when the tty is open.
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| 17 | *
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| 18 | * Also restructured routines so that there is more of a separation
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| 19 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
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| 20 | * the low-level tty routines (serial.c, pty.c, console.c). This
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| 21 | * makes for cleaner and more compact code. -TYT, 9/17/92
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| 22 | *
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| 23 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
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| 24 | * which can be dynamically activated and de-activated by the line
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| 25 | * discipline handling modules (like SLIP).
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| 26 | *
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| 27 | * NOTE: pay no attention to the line discipline code (yet); its
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| 28 | * interface is still subject to change in this version...
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| 29 | * -- TYT, 1/31/92
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| 30 | *
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| 31 | * Added functionality to the OPOST tty handling. No delays, but all
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| 32 | * other bits should be there.
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| 33 | * -- Nick Holloway <[email protected]>, 27th May 1993.
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| 34 | *
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| 35 | * Rewrote canonical mode and added more termios flags.
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| 36 | * -- [email protected] (J. Cowley), 13Jan94
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| 37 | *
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| 38 | * Reorganized FASYNC support so mouse code can share it.
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| 39 | * -- [email protected], 9Sep95
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| 40 | *
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| 41 | * New TIOCLINUX variants added.
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| 42 | * -- [email protected], 19-Nov-95
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| 43 | *
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| 44 | * Restrict vt switching via ioctl()
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| 45 | * -- [email protected], 5-Dec-95
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| 46 | *
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| 47 | * Move console and virtual terminal code to more appropriate files,
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| 48 | * implement CONFIG_VT and generalize console device interface.
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| 49 | * -- Marko Kohtala <[email protected]>, March 97
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| 50 | *
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| 51 | * Rewrote tty_init_dev and tty_release_dev to eliminate races.
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| 52 | * -- Bill Hawes <[email protected]>, June 97
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| 53 | *
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| 54 | * Added devfs support.
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| 55 | * -- C. Scott Ananian <[email protected]>, 13-Jan-1998
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| 56 | *
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| 57 | * Added support for a Unix98-style ptmx device.
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| 58 | * -- C. Scott Ananian <[email protected]>, 14-Jan-1998
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| 59 | *
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| 60 | * Reduced memory usage for older ARM systems
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| 61 | * -- Russell King <[email protected]>
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| 62 | *
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| 63 | * Move do_SAK() into process context. Less stack use in devfs functions.
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| 64 | * alloc_tty_struct() always uses kmalloc()
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| 65 | * -- Andrew Morton <[email protected]> 17Mar01
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| 66 |
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| 67 |
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| 68 | #include <linux/types.h>
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| 69 | #include <linux/major.h>
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| 70 | #include <linux/errno.h>
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| 71 | #include <linux/signal.h>
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| 72 | #include <linux/fcntl.h>
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| 73 | #include <linux/sched/signal.h>
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| 74 | #include <linux/sched/task.h>
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| 75 | #include <linux/interrupt.h>
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| 76 | #include <linux/tty.h>
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| 77 | #include <linux/tty_driver.h>
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| 78 | #include <linux/tty_flip.h>
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| 79 | #include <linux/devpts_fs.h>
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| 80 | #include <linux/file.h>
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| 81 | #include <linux/fdtable.h>
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| 82 | #include <linux/console.h>
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| 83 | #include <linux/timer.h>
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| 84 | #include <linux/ctype.h>
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| 85 | #include <linux/kd.h>
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| 86 | #include <linux/mm.h>
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| 87 | #include <linux/string.h>
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| 88 | #include <linux/slab.h>
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| 89 | #include <linux/poll.h>
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| 90 | #include <linux/ppp-ioctl.h>
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| 91 | #include <linux/proc_fs.h>
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| 92 | #include <linux/init.h>
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| 93 | #include <linux/module.h>
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| 94 | #include <linux/device.h>
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| 95 | #include <linux/wait.h>
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| 96 | #include <linux/bitops.h>
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| 97 | #include <linux/delay.h>
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| 98 | #include <linux/seq_file.h>
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| 99 | #include <linux/serial.h>
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| 100 | #include <linux/ratelimit.h>
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| 101 | #include <linux/compat.h>
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| 102 | #include <linux/uaccess.h>
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| 103 | #include <linux/termios_internal.h>
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| 104 | #include <linux/fs.h>
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| 105 |
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| 106 | #include <linux/kbd_kern.h>
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| 107 | #include <linux/vt_kern.h>
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| 108 | #include <linux/selection.h>
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| 109 |
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| 110 | #include <linux/kmod.h>
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| 111 | #include <linux/nsproxy.h>
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| 112 | #include "tty.h"
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| 113 |
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| 114 | #undef TTY_DEBUG_HANGUP
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| 115 | #ifdef TTY_DEBUG_HANGUP
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| 116 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args)
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| 117 | #else
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| 118 | # define tty_debug_hangup(tty, f, args...) do { } while (0)
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| 119 | #endif
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| 120 |
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| 121 | #define TTY_PARANOIA_CHECK 1
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| 122 | #define CHECK_TTY_COUNT 1
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| 123 |
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| 124 | struct ktermios tty_std_termios = {
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| 125 | .c_iflag = ICRNL | IXON,
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| 126 | .c_oflag = OPOST | ONLCR,
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| 127 | .c_cflag = B38400 | CS8 | CREAD | HUPCL,
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| 128 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
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| 129 | ECHOCTL | ECHOKE | IEXTEN,
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| 130 | .c_cc = INIT_C_CC,
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| 131 | .c_ispeed = 38400,
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| 132 | .c_ospeed = 38400,
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| 133 |
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| 134 | };
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| 135 | EXPORT_SYMBOL(tty_std_termios);
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| 136 |
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| 137 | |
| 138 | * could do with some rationalisation such as pulling the tty proc function
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| 139 | * into this file.
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| 140 |
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| 141 |
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| 142 | LIST_HEAD(tty_drivers);
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| 143 |
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| 144 |
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| 145 | DEFINE_MUTEX(tty_mutex);
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| 146 |
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| 147 | static ssize_t tty_read(struct kiocb *, struct iov_iter *);
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| 148 | static ssize_t tty_write(struct kiocb *, struct iov_iter *);
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| 149 | static __poll_t tty_poll(struct file *, poll_table *);
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| 150 | static int tty_open(struct inode *, struct file *);
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| 151 | #ifdef CONFIG_COMPAT
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| 152 | static long tty_compat_ioctl(struct file *file, unsigned int cmd,
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| 153 | unsigned long arg);
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| 154 | #else
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| 155 | #define tty_compat_ioctl NULL
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| 156 | #endif
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| 157 | static int __tty_fasync(int fd, struct file *filp, int on);
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| 158 | static int tty_fasync(int fd, struct file *filp, int on);
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| 159 | static void release_tty(struct tty_struct *tty, int idx);
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| 160 |
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| 161 | |
| 162 | * free_tty_struct - free a disused tty
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| 163 | * @tty: tty struct to free
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| 164 | *
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| 165 | * Free the write buffers, tty queue and tty memory itself.
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| 166 | *
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| 167 | * Locking: none. Must be called after tty is definitely unused
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| 168 |
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| 169 | static void free_tty_struct(struct tty_struct *tty)
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| 170 | {
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| 171 | tty_ldisc_deinit(tty);
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| 172 | put_device(tty->dev);
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| 173 | kvfree(tty->write_buf);
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| 174 | kfree(tty);
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| 175 | }
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| 176 |
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| 177 | static inline struct tty_struct *file_tty(struct file *file)
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| 178 | {
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| 179 | return ((struct tty_file_private *)file->private_data)->tty;
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| 180 | }
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| 181 |
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| 182 | int tty_alloc_file(struct file *file)
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| 183 | {
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| 184 | struct tty_file_private *priv;
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| 185 |
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| 186 | priv = kmalloc_obj(*priv);
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| 187 | if (!priv)
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| 188 | return -ENOMEM;
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| 189 |
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| 190 | file->private_data = priv;
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| 191 |
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| 192 | return 0;
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| 193 | }
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| 194 |
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| 195 |
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| 196 | void tty_add_file(struct tty_struct *tty, struct file *file)
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| 197 | {
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| 198 | struct tty_file_private *priv = file->private_data;
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| 199 |
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| 200 | priv->tty = tty;
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| 201 | priv->file = file;
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| 202 |
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| 203 | spin_lock(&tty->files_lock);
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| 204 | list_add(&priv->list, &tty->tty_files);
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| 205 | spin_unlock(&tty->files_lock);
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| 206 | }
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| 207 |
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| 208 | |
| 209 | * tty_free_file - free file->private_data
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| 210 | * @file: to free private_data of
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| 211 | *
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| 212 | * This shall be used only for fail path handling when tty_add_file was not
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| 213 | * called yet.
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| 214 |
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| 215 | void tty_free_file(struct file *file)
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| 216 | {
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| 217 | struct tty_file_private *priv = file->private_data;
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| 218 |
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| 219 | file->private_data = NULL;
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| 220 | kfree(priv);
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| 221 | }
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| 222 |
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| 223 |
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| 224 | static void tty_del_file(struct file *file)
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| 225 | {
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| 226 | struct tty_file_private *priv = file->private_data;
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| 227 | struct tty_struct *tty = priv->tty;
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| 228 |
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| 229 | spin_lock(&tty->files_lock);
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| 230 | list_del(&priv->list);
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| 231 | spin_unlock(&tty->files_lock);
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| 232 | tty_free_file(file);
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| 233 | }
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| 234 |
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| 235 | |
| 236 | * tty_name - return tty naming
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| 237 | * @tty: tty structure
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| 238 | *
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| 239 | * Convert a tty structure into a name. The name reflects the kernel naming
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| 240 | * policy and if udev is in use may not reflect user space
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| 241 | *
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| 242 | * Locking: none
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| 243 |
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| 244 | const char *tty_name(const struct tty_struct *tty)
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| 245 | {
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| 246 | if (!tty)
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| 247 | return "NULL tty";
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| 248 | return tty->name;
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| 249 | }
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| 250 | EXPORT_SYMBOL(tty_name);
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| 251 |
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| 252 | const char *tty_driver_name(const struct tty_struct *tty)
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| 253 | {
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| 254 | if (!tty || !tty->driver)
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| 255 | return "";
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| 256 | return tty->driver->name;
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| 257 | }
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| 258 |
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| 259 | static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
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| 260 | const char *routine)
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| 261 | {
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| 262 | #ifdef TTY_PARANOIA_CHECK
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| 263 | if (!tty) {
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| 264 | pr_warn("(%d:%d): %s: NULL tty\n",
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| 265 | imajor(inode), iminor(inode), routine);
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| 266 | return 1;
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| 267 | }
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| 268 | #endif
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| 269 | return 0;
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| 270 | }
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| 271 |
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| 272 |
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| 273 | static void check_tty_count(struct tty_struct *tty, const char *routine)
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| 274 | {
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| 275 | #ifdef CHECK_TTY_COUNT
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| 276 | struct list_head *p;
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| 277 | int count = 0, kopen_count = 0;
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| 278 |
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| 279 | scoped_guard(spinlock, &tty->files_lock)
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| 280 | list_for_each(p, &tty->tty_files)
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| 281 | count++;
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| 282 |
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| 283 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
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| 284 | tty->driver->subtype == PTY_TYPE_SLAVE &&
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| 285 | tty->link && tty->link->count)
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| 286 | count++;
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| 287 | if (tty_port_kopened(tty->port))
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| 288 | kopen_count++;
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| 289 | if (tty->count != (count + kopen_count)) {
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| 290 | tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n",
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| 291 | routine, tty->count, count, kopen_count);
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| 292 | }
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| 293 | #endif
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| 294 | }
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| 295 |
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| 296 | |
| 297 | * get_tty_driver - find device of a tty
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| 298 | * @device: device identifier
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| 299 | * @index: returns the index of the tty
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| 300 | *
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| 301 | * This routine returns a tty driver structure, given a device number and also
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| 302 | * passes back the index number.
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| 303 | *
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| 304 | * Locking: caller must hold tty_mutex
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| 305 |
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| 306 | static struct tty_driver *get_tty_driver(dev_t device, int *index)
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| 307 | {
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| 308 | struct tty_driver *p;
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| 309 |
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| 310 | list_for_each_entry(p, &tty_drivers, tty_drivers) {
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| 311 | dev_t base = MKDEV(p->major, p->minor_start);
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| 312 |
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| 313 | if (device < base || device >= base + p->num)
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| 314 | continue;
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| 315 | *index = device - base;
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| 316 | return tty_driver_kref_get(p);
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| 317 | }
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| 318 | return NULL;
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| 319 | }
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| 320 |
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| 321 | |
| 322 | * tty_dev_name_to_number - return dev_t for device name
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| 323 | * @name: user space name of device under /dev
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| 324 | * @number: pointer to dev_t that this function will populate
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| 325 | *
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| 326 | * This function converts device names like ttyS0 or ttyUSB1 into dev_t like
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| 327 | * (4, 64) or (188, 1). If no corresponding driver is registered then the
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| 328 | * function returns -%ENODEV.
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| 329 | *
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| 330 | * Locking: this acquires tty_mutex to protect the tty_drivers list from
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| 331 | * being modified while we are traversing it, and makes sure to
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| 332 | * release it before exiting.
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| 333 |
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| 334 | int tty_dev_name_to_number(const char *name, dev_t *number)
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| 335 | {
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| 336 | struct tty_driver *p;
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| 337 | int ret;
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| 338 | int index, prefix_length = 0;
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| 339 | const char *str;
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| 340 |
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| 341 | for (str = name; *str && !isdigit(*str); str++)
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| 342 | ;
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| 343 |
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| 344 | if (!*str)
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| 345 | return -EINVAL;
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| 346 |
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| 347 | ret = kstrtoint(str, 10, &index);
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| 348 | if (ret)
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| 349 | return ret;
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| 350 |
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| 351 | prefix_length = str - name;
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| 352 |
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| 353 | guard(mutex)(&tty_mutex);
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| 354 |
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| 355 | list_for_each_entry(p, &tty_drivers, tty_drivers)
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| 356 | if (prefix_length == strlen(p->name) && strncmp(name,
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| 357 | p->name, prefix_length) == 0) {
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| 358 | if (index < p->num) {
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| 359 | *number = MKDEV(p->major, p->minor_start + index);
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| 360 | return 0;
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| 361 | }
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| 362 | }
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| 363 |
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| 364 | return -ENODEV;
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| 365 | }
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| 366 | EXPORT_SYMBOL_GPL(tty_dev_name_to_number);
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| 367 |
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| 368 | #ifdef CONFIG_CONSOLE_POLL
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| 369 |
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| 370 | |
| 371 | * tty_find_polling_driver - find device of a polled tty
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| 372 | * @name: name string to match
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| 373 | * @line: pointer to resulting tty line nr
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| 374 | *
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| 375 | * This routine returns a tty driver structure, given a name and the condition
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| 376 | * that the tty driver is capable of polled operation.
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| 377 |
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| 378 | struct tty_driver *tty_find_polling_driver(char *name, int *line)
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| 379 | {
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| 380 | struct tty_driver *p;
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| 381 | int tty_line = 0;
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| 382 | int len;
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| 383 | char *str, *stp;
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| 384 |
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| 385 | for (str = name; *str; str++)
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| 386 | if ((*str >= '0' && *str <= '9') || *str == ',')
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| 387 | break;
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| 388 | if (!*str)
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| 389 | return NULL;
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| 390 |
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| 391 | len = str - name;
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| 392 | tty_line = simple_strtoul(str, &str, 10);
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| 393 |
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| 394 | guard(mutex)(&tty_mutex);
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| 395 |
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| 396 |
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| 397 | list_for_each_entry(p, &tty_drivers, tty_drivers) {
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| 398 | if (!len || strncmp(name, p->name, len) != 0)
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| 399 | continue;
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| 400 | stp = str;
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| 401 | if (*stp == ',')
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| 402 | stp++;
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| 403 | if (*stp == '\0')
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| 404 | stp = NULL;
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| 405 |
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| 406 | if (tty_line >= 0 && tty_line < p->num && p->ops &&
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| 407 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
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| 408 | *line = tty_line;
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| 409 | return tty_driver_kref_get(p);
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| 410 | }
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| 411 | }
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| 412 |
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| 413 | return NULL;
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| 414 | }
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| 415 | EXPORT_SYMBOL_GPL(tty_find_polling_driver);
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| 416 | #endif
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| 417 |
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| 418 | static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to)
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| 419 | {
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| 420 | return 0;
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| 421 | }
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| 422 |
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| 423 | static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from)
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| 424 | {
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| 425 | return -EIO;
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| 426 | }
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| 427 |
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| 428 |
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| 429 | static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait)
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| 430 | {
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| 431 | return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM;
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| 432 | }
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| 433 |
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| 434 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
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| 435 | unsigned long arg)
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| 436 | {
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| 437 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
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| 438 | }
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| 439 |
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| 440 | static long hung_up_tty_compat_ioctl(struct file *file,
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| 441 | unsigned int cmd, unsigned long arg)
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| 442 | {
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| 443 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
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| 444 | }
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| 445 |
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| 446 | static int hung_up_tty_fasync(int fd, struct file *file, int on)
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| 447 | {
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| 448 | return -ENOTTY;
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| 449 | }
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| 450 |
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| 451 | static void tty_show_fdinfo(struct seq_file *m, struct file *file)
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| 452 | {
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| 453 | struct tty_struct *tty = file_tty(file);
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| 454 |
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| 455 | if (tty && tty->ops && tty->ops->show_fdinfo)
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| 456 | tty->ops->show_fdinfo(tty, m);
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| 457 | }
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| 458 |
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| 459 | static const struct file_operations tty_fops = {
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| 460 | .read_iter = tty_read,
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| 461 | .write_iter = tty_write,
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| 462 | .splice_read = copy_splice_read,
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| 463 | .splice_write = iter_file_splice_write,
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| 464 | .poll = tty_poll,
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| 465 | .unlocked_ioctl = tty_ioctl,
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| 466 | .compat_ioctl = tty_compat_ioctl,
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| 467 | .open = tty_open,
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| 468 | .release = tty_release,
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| 469 | .fasync = tty_fasync,
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| 470 | .show_fdinfo = tty_show_fdinfo,
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| 471 | };
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| 472 |
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| 473 | static const struct file_operations console_fops = {
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| 474 | .read_iter = tty_read,
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| 475 | .write_iter = redirected_tty_write,
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| 476 | .splice_read = copy_splice_read,
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| 477 | .splice_write = iter_file_splice_write,
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| 478 | .poll = tty_poll,
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| 479 | .unlocked_ioctl = tty_ioctl,
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| 480 | .compat_ioctl = tty_compat_ioctl,
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| 481 | .open = tty_open,
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| 482 | .release = tty_release,
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| 483 | .fasync = tty_fasync,
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| 484 | };
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| 485 |
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| 486 | static const struct file_operations hung_up_tty_fops = {
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| 487 | .read_iter = hung_up_tty_read,
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| 488 | .write_iter = hung_up_tty_write,
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| 489 | .poll = hung_up_tty_poll,
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| 490 | .unlocked_ioctl = hung_up_tty_ioctl,
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| 491 | .compat_ioctl = hung_up_tty_compat_ioctl,
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| 492 | .release = tty_release,
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| 493 | .fasync = hung_up_tty_fasync,
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| 494 | };
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| 495 |
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| 496 | static DEFINE_SPINLOCK(redirect_lock);
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| 497 | static struct file *redirect;
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| 498 |
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| 499 | |
| 500 | * tty_wakeup - request more data
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| 501 | * @tty: terminal
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| 502 | *
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| 503 | * Internal and external helper for wakeups of tty. This function informs the
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| 504 | * line discipline if present that the driver is ready to receive more output
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| 505 | * data.
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| 506 |
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| 507 | void tty_wakeup(struct tty_struct *tty)
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| 508 | {
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| 509 | struct tty_ldisc *ld;
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| 510 |
|
| 511 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
|
| 512 | ld = tty_ldisc_ref(tty);
|
| 513 | if (ld) {
|
| 514 | if (ld->ops->write_wakeup)
|
| 515 | ld->ops->write_wakeup(tty);
|
| 516 | tty_ldisc_deref(ld);
|
| 517 | }
|
| 518 | }
|
| 519 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
|
| 520 | }
|
| 521 | EXPORT_SYMBOL_GPL(tty_wakeup);
|
| 522 |
|
| 523 | |
| 524 | * tty_release_redirect - Release a redirect on a pty if present
|
| 525 | * @tty: tty device
|
| 526 | *
|
| 527 | * This is available to the pty code so if the master closes, if the slave is a
|
| 528 | * redirect it can release the redirect.
|
| 529 |
|
| 530 | static struct file *tty_release_redirect(struct tty_struct *tty)
|
| 531 | {
|
| 532 | guard(spinlock)(&redirect_lock);
|
| 533 |
|
| 534 | if (redirect && file_tty(redirect) == tty) {
|
| 535 | struct file *f = redirect;
|
| 536 | redirect = NULL;
|
| 537 | return f;
|
| 538 | }
|
| 539 |
|
| 540 | return NULL;
|
| 541 | }
|
| 542 |
|
| 543 | |
| 544 | * __tty_hangup - actual handler for hangup events
|
| 545 | * @tty: tty device
|
| 546 | * @exit_session: if non-zero, signal all foreground group processes
|
| 547 | *
|
| 548 | * This can be called by a "kworker" kernel thread. That is process synchronous
|
| 549 | * but doesn't hold any locks, so we need to make sure we have the appropriate
|
| 550 | * locks for what we're doing.
|
| 551 | *
|
| 552 | * The hangup event clears any pending redirections onto the hung up device. It
|
| 553 | * ensures future writes will error and it does the needed line discipline
|
| 554 | * hangup and signal delivery. The tty object itself remains intact.
|
| 555 | *
|
| 556 | * Locking:
|
| 557 | * * BTM
|
| 558 | *
|
| 559 | * * redirect lock for undoing redirection
|
| 560 | * * file list lock for manipulating list of ttys
|
| 561 | * * tty_ldiscs_lock from called functions
|
| 562 | * * termios_rwsem resetting termios data
|
| 563 | * * tasklist_lock to walk task list for hangup event
|
| 564 | *
|
| 565 | * * ->siglock to protect ->signal/->sighand
|
| 566 | *
|
| 567 |
|
| 568 | static void __tty_hangup(struct tty_struct *tty, int exit_session)
|
| 569 | {
|
| 570 | struct file *cons_filp = NULL;
|
| 571 | struct file *filp, *f;
|
| 572 | struct tty_file_private *priv;
|
| 573 | int closecount = 0, n;
|
| 574 | int refs;
|
| 575 |
|
| 576 | if (!tty)
|
| 577 | return;
|
| 578 |
|
| 579 | f = tty_release_redirect(tty);
|
| 580 |
|
| 581 | tty_lock(tty);
|
| 582 |
|
| 583 | if (test_bit(TTY_HUPPED, &tty->flags)) {
|
| 584 | tty_unlock(tty);
|
| 585 | return;
|
| 586 | }
|
| 587 |
|
| 588 | |
| 589 | * Some console devices aren't actually hung up for technical and
|
| 590 | * historical reasons, which can lead to indefinite interruptible
|
| 591 | * sleep in n_tty_read(). The following explicitly tells
|
| 592 | * n_tty_read() to abort readers.
|
| 593 |
|
| 594 | set_bit(TTY_HUPPING, &tty->flags);
|
| 595 |
|
| 596 | |
| 597 | * this really needs to change if we want to flush the
|
| 598 | * workqueue with the lock held.
|
| 599 |
|
| 600 | check_tty_count(tty, "tty_hangup");
|
| 601 |
|
| 602 | spin_lock(&tty->files_lock);
|
| 603 |
|
| 604 | list_for_each_entry(priv, &tty->tty_files, list) {
|
| 605 | filp = priv->file;
|
| 606 | if (filp->f_op->write_iter == redirected_tty_write)
|
| 607 | cons_filp = filp;
|
| 608 | if (filp->f_op->write_iter != tty_write)
|
| 609 | continue;
|
| 610 | closecount++;
|
| 611 | __tty_fasync(-1, filp, 0);
|
| 612 | filp->f_op = &hung_up_tty_fops;
|
| 613 | }
|
| 614 | spin_unlock(&tty->files_lock);
|
| 615 |
|
| 616 | refs = tty_signal_session_leader(tty, exit_session);
|
| 617 |
|
| 618 | while (refs--)
|
| 619 | tty_kref_put(tty);
|
| 620 |
|
| 621 | tty_ldisc_hangup(tty, cons_filp != NULL);
|
| 622 |
|
| 623 | wake_up_interruptible(&tty->break_wait);
|
| 624 |
|
| 625 | spin_lock_irq(&tty->ctrl.lock);
|
| 626 | clear_bit(TTY_THROTTLED, &tty->flags);
|
| 627 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
|
| 628 | put_pid(tty->ctrl.session);
|
| 629 | put_pid(tty->ctrl.pgrp);
|
| 630 | tty->ctrl.session = NULL;
|
| 631 | tty->ctrl.pgrp = NULL;
|
| 632 | tty->ctrl.pktstatus = 0;
|
| 633 | spin_unlock_irq(&tty->ctrl.lock);
|
| 634 |
|
| 635 | |
| 636 | * If one of the devices matches a console pointer, we
|
| 637 | * cannot just call hangup() because that will cause
|
| 638 | * tty->count and state->count to go out of sync.
|
| 639 | * So we just call close() the right number of times.
|
| 640 |
|
| 641 | if (cons_filp) {
|
| 642 | if (tty->ops->close)
|
| 643 | for (n = 0; n < closecount; n++)
|
| 644 | tty->ops->close(tty, cons_filp);
|
| 645 | } else if (tty->ops->hangup)
|
| 646 | tty->ops->hangup(tty);
|
| 647 | |
| 648 | * We don't want to have driver/ldisc interactions beyond the ones
|
| 649 | * we did here. The driver layer expects no calls after ->hangup()
|
| 650 | * from the ldisc side, which is now guaranteed.
|
| 651 |
|
| 652 | set_bit(TTY_HUPPED, &tty->flags);
|
| 653 | clear_bit(TTY_HUPPING, &tty->flags);
|
| 654 | tty_unlock(tty);
|
| 655 |
|
| 656 | if (f)
|
| 657 | fput(f);
|
| 658 | }
|
| 659 |
|
| 660 | static void do_tty_hangup(struct work_struct *work)
|
| 661 | {
|
| 662 | struct tty_struct *tty =
|
| 663 | container_of(work, struct tty_struct, hangup_work);
|
| 664 |
|
| 665 | __tty_hangup(tty, 0);
|
| 666 | }
|
| 667 |
|
| 668 | |
| 669 | * tty_hangup - trigger a hangup event
|
| 670 | * @tty: tty to hangup
|
| 671 | *
|
| 672 | * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a
|
| 673 | * hangup sequence to run after this event.
|
| 674 |
|
| 675 | void tty_hangup(struct tty_struct *tty)
|
| 676 | {
|
| 677 | tty_debug_hangup(tty, "hangup\n");
|
| 678 | schedule_work(&tty->hangup_work);
|
| 679 | }
|
| 680 | EXPORT_SYMBOL(tty_hangup);
|
| 681 |
|
| 682 | |
| 683 | * tty_vhangup - process vhangup
|
| 684 | * @tty: tty to hangup
|
| 685 | *
|
| 686 | * The user has asked via system call for the terminal to be hung up. We do
|
| 687 | * this synchronously so that when the syscall returns the process is complete.
|
| 688 | * That guarantee is necessary for security reasons.
|
| 689 |
|
| 690 | void tty_vhangup(struct tty_struct *tty)
|
| 691 | {
|
| 692 | tty_debug_hangup(tty, "vhangup\n");
|
| 693 | __tty_hangup(tty, 0);
|
| 694 | }
|
| 695 | EXPORT_SYMBOL(tty_vhangup);
|
| 696 |
|
| 697 |
|
| 698 | |
| 699 | * tty_vhangup_self - process vhangup for own ctty
|
| 700 | *
|
| 701 | * Perform a vhangup on the current controlling tty
|
| 702 |
|
| 703 | void tty_vhangup_self(void)
|
| 704 | {
|
| 705 | struct tty_struct *tty;
|
| 706 |
|
| 707 | tty = get_current_tty();
|
| 708 | if (tty) {
|
| 709 | tty_vhangup(tty);
|
| 710 | tty_kref_put(tty);
|
| 711 | }
|
| 712 | }
|
| 713 |
|
| 714 | |
| 715 | * tty_vhangup_session - hangup session leader exit
|
| 716 | * @tty: tty to hangup
|
| 717 | *
|
| 718 | * The session leader is exiting and hanging up its controlling terminal.
|
| 719 | * Every process in the foreground process group is signalled %SIGHUP.
|
| 720 | *
|
| 721 | * We do this synchronously so that when the syscall returns the process is
|
| 722 | * complete. That guarantee is necessary for security reasons.
|
| 723 |
|
| 724 | void tty_vhangup_session(struct tty_struct *tty)
|
| 725 | {
|
| 726 | tty_debug_hangup(tty, "session hangup\n");
|
| 727 | __tty_hangup(tty, 1);
|
| 728 | }
|
| 729 |
|
| 730 | |
| 731 | * tty_hung_up_p - was tty hung up
|
| 732 | * @filp: file pointer of tty
|
| 733 | *
|
| 734 | * Return: true if the tty has been subject to a vhangup or a carrier loss
|
| 735 |
|
| 736 | int tty_hung_up_p(struct file *filp)
|
| 737 | {
|
| 738 | return (filp && filp->f_op == &hung_up_tty_fops);
|
| 739 | }
|
| 740 | EXPORT_SYMBOL(tty_hung_up_p);
|
| 741 |
|
| 742 | void __stop_tty(struct tty_struct *tty)
|
| 743 | {
|
| 744 | if (tty->flow.stopped)
|
| 745 | return;
|
| 746 | tty->flow.stopped = true;
|
| 747 | if (tty->ops->stop)
|
| 748 | tty->ops->stop(tty);
|
| 749 | }
|
| 750 |
|
| 751 | |
| 752 | * stop_tty - propagate flow control
|
| 753 | * @tty: tty to stop
|
| 754 | *
|
| 755 | * Perform flow control to the driver. May be called on an already stopped
|
| 756 | * device and will not re-call the &tty_driver->stop() method.
|
| 757 | *
|
| 758 | * This functionality is used by both the line disciplines for halting incoming
|
| 759 | * flow and by the driver. It may therefore be called from any context, may be
|
| 760 | * under the tty %atomic_write_lock but not always.
|
| 761 | *
|
| 762 | * Locking:
|
| 763 | * flow.lock
|
| 764 |
|
| 765 | void stop_tty(struct tty_struct *tty)
|
| 766 | {
|
| 767 | guard(spinlock_irqsave)(&tty->flow.lock);
|
| 768 | __stop_tty(tty);
|
| 769 | }
|
| 770 | EXPORT_SYMBOL(stop_tty);
|
| 771 |
|
| 772 | void __start_tty(struct tty_struct *tty)
|
| 773 | {
|
| 774 | if (!tty->flow.stopped || tty->flow.tco_stopped)
|
| 775 | return;
|
| 776 | tty->flow.stopped = false;
|
| 777 | if (tty->ops->start)
|
| 778 | tty->ops->start(tty);
|
| 779 | tty_wakeup(tty);
|
| 780 | }
|
| 781 |
|
| 782 | |
| 783 | * start_tty - propagate flow control
|
| 784 | * @tty: tty to start
|
| 785 | *
|
| 786 | * Start a tty that has been stopped if at all possible. If @tty was previously
|
| 787 | * stopped and is now being started, the &tty_driver->start() method is invoked
|
| 788 | * and the line discipline woken.
|
| 789 | *
|
| 790 | * Locking:
|
| 791 | * flow.lock
|
| 792 |
|
| 793 | void start_tty(struct tty_struct *tty)
|
| 794 | {
|
| 795 | guard(spinlock_irqsave)(&tty->flow.lock);
|
| 796 | __start_tty(tty);
|
| 797 | }
|
| 798 | EXPORT_SYMBOL(start_tty);
|
| 799 |
|
| 800 | static void tty_update_time(struct tty_struct *tty, bool mtime)
|
| 801 | {
|
| 802 | time64_t sec = ktime_get_real_seconds();
|
| 803 | struct tty_file_private *priv;
|
| 804 |
|
| 805 | guard(spinlock)(&tty->files_lock);
|
| 806 |
|
| 807 | list_for_each_entry(priv, &tty->tty_files, list) {
|
| 808 | struct inode *inode = file_inode(priv->file);
|
| 809 | struct timespec64 time = mtime ? inode_get_mtime(inode) : inode_get_atime(inode);
|
| 810 |
|
| 811 | |
| 812 | * We only care if the two values differ in anything other than the
|
| 813 | * lower three bits (i.e every 8 seconds). If so, then we can update
|
| 814 | * the time of the tty device, otherwise it could be construded as a
|
| 815 | * security leak to let userspace know the exact timing of the tty.
|
| 816 |
|
| 817 | if ((sec ^ time.tv_sec) & ~7) {
|
| 818 | if (mtime)
|
| 819 | inode_set_mtime(inode, sec, 0);
|
| 820 | else
|
| 821 | inode_set_atime(inode, sec, 0);
|
| 822 | }
|
| 823 | }
|
| 824 | }
|
| 825 |
|
| 826 | |
| 827 | * Iterate on the ldisc ->read() function until we've gotten all
|
| 828 | * the data the ldisc has for us.
|
| 829 | *
|
| 830 | * The "cookie" is something that the ldisc read function can fill
|
| 831 | * in to let us know that there is more data to be had.
|
| 832 | *
|
| 833 | * We promise to continue to call the ldisc until it stops returning
|
| 834 | * data or clears the cookie. The cookie may be something that the
|
| 835 | * ldisc maintains state for and needs to free.
|
| 836 |
|
| 837 | static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,
|
| 838 | struct file *file, struct iov_iter *to)
|
| 839 | {
|
| 840 | void *cookie = NULL;
|
| 841 | unsigned long offset = 0;
|
| 842 | ssize_t retval = 0;
|
| 843 | size_t copied, count = iov_iter_count(to);
|
| 844 | u8 kernel_buf[64];
|
| 845 |
|
| 846 | do {
|
| 847 | ssize_t size = min(count, sizeof(kernel_buf));
|
| 848 |
|
| 849 | size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset);
|
| 850 | if (!size)
|
| 851 | break;
|
| 852 |
|
| 853 | if (size < 0) {
|
| 854 |
|
| 855 | if (retval)
|
| 856 | break;
|
| 857 | retval = size;
|
| 858 |
|
| 859 | |
| 860 | * -EOVERFLOW means we didn't have enough space
|
| 861 | * for a whole packet, and we shouldn't return
|
| 862 | * a partial result.
|
| 863 |
|
| 864 | if (retval == -EOVERFLOW)
|
| 865 | offset = 0;
|
| 866 | break;
|
| 867 | }
|
| 868 |
|
| 869 | copied = copy_to_iter(kernel_buf, size, to);
|
| 870 | offset += copied;
|
| 871 | count -= copied;
|
| 872 |
|
| 873 | |
| 874 | * If the user copy failed, we still need to do another ->read()
|
| 875 | * call if we had a cookie to let the ldisc clear up.
|
| 876 | *
|
| 877 | * But make sure size is zeroed.
|
| 878 |
|
| 879 | if (unlikely(copied != size)) {
|
| 880 | count = 0;
|
| 881 | retval = -EFAULT;
|
| 882 | }
|
| 883 | } while (cookie);
|
| 884 |
|
| 885 |
|
| 886 | memzero_explicit(kernel_buf, sizeof(kernel_buf));
|
| 887 | return offset ? offset : retval;
|
| 888 | }
|
| 889 |
|
| 890 |
|
| 891 | |
| 892 | * tty_read - read method for tty device files
|
| 893 | * @iocb: kernel I/O control block
|
| 894 | * @to: destination for the data read
|
| 895 | *
|
| 896 | * Perform the read system call function on this terminal device. Checks
|
| 897 | * for hung up devices before calling the line discipline method.
|
| 898 | *
|
| 899 | * Locking:
|
| 900 | * Locks the line discipline internally while needed. Multiple read calls
|
| 901 | * may be outstanding in parallel.
|
| 902 |
|
| 903 | static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to)
|
| 904 | {
|
| 905 | struct file *file = iocb->ki_filp;
|
| 906 | struct inode *inode = file_inode(file);
|
| 907 | struct tty_struct *tty = file_tty(file);
|
| 908 | struct tty_ldisc *ld;
|
| 909 | ssize_t ret;
|
| 910 |
|
| 911 | if (tty_paranoia_check(tty, inode, "tty_read"))
|
| 912 | return -EIO;
|
| 913 | if (!tty || tty_io_error(tty))
|
| 914 | return -EIO;
|
| 915 |
|
| 916 | |
| 917 | * situation.
|
| 918 |
|
| 919 | ld = tty_ldisc_ref_wait(tty);
|
| 920 | if (!ld)
|
| 921 | return hung_up_tty_read(iocb, to);
|
| 922 | ret = -EIO;
|
| 923 | if (ld->ops->read)
|
| 924 | ret = iterate_tty_read(ld, tty, file, to);
|
| 925 | tty_ldisc_deref(ld);
|
| 926 |
|
| 927 | if (ret > 0)
|
| 928 | tty_update_time(tty, false);
|
| 929 |
|
| 930 | return ret;
|
| 931 | }
|
| 932 |
|
| 933 | void tty_write_unlock(struct tty_struct *tty)
|
| 934 | {
|
| 935 | mutex_unlock(&tty->atomic_write_lock);
|
| 936 | wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT);
|
| 937 | }
|
| 938 |
|
| 939 | int tty_write_lock(struct tty_struct *tty, bool ndelay)
|
| 940 | {
|
| 941 | if (!mutex_trylock(&tty->atomic_write_lock)) {
|
| 942 | if (ndelay)
|
| 943 | return -EAGAIN;
|
| 944 | if (mutex_lock_interruptible(&tty->atomic_write_lock))
|
| 945 | return -ERESTARTSYS;
|
| 946 | }
|
| 947 | return 0;
|
| 948 | }
|
| 949 |
|
| 950 | |
| 951 | * Split writes up in sane blocksizes to avoid
|
| 952 | * denial-of-service type attacks
|
| 953 |
|
| 954 | static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty,
|
| 955 | struct file *file, struct iov_iter *from)
|
| 956 | {
|
| 957 | size_t chunk, count = iov_iter_count(from);
|
| 958 | ssize_t ret, written = 0;
|
| 959 |
|
| 960 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY);
|
| 961 | if (ret < 0)
|
| 962 | return ret;
|
| 963 |
|
| 964 | |
| 965 | * We chunk up writes into a temporary buffer. This
|
| 966 | * simplifies low-level drivers immensely, since they
|
| 967 | * don't have locking issues and user mode accesses.
|
| 968 | *
|
| 969 | * But if TTY_NO_WRITE_SPLIT is set, we should use a
|
| 970 | * big chunk-size..
|
| 971 | *
|
| 972 | * The default chunk-size is 2kB, because the NTTY
|
| 973 | * layer has problems with bigger chunks. It will
|
| 974 | * claim to be able to handle more characters than
|
| 975 | * it actually does.
|
| 976 |
|
| 977 | chunk = 2048;
|
| 978 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags))
|
| 979 | chunk = 65536;
|
| 980 | if (count < chunk)
|
| 981 | chunk = count;
|
| 982 |
|
| 983 |
|
| 984 | if (tty->write_cnt < chunk) {
|
| 985 | u8 *buf_chunk;
|
| 986 |
|
| 987 | if (chunk < 1024)
|
| 988 | chunk = 1024;
|
| 989 |
|
| 990 | buf_chunk = kvmalloc(chunk, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
|
| 991 | if (!buf_chunk) {
|
| 992 | ret = -ENOMEM;
|
| 993 | goto out;
|
| 994 | }
|
| 995 | kvfree(tty->write_buf);
|
| 996 | tty->write_cnt = chunk;
|
| 997 | tty->write_buf = buf_chunk;
|
| 998 | }
|
| 999 |
|
| 1000 |
|
| 1001 | for (;;) {
|
| 1002 | size_t size = min(chunk, count);
|
| 1003 |
|
| 1004 | ret = -EFAULT;
|
| 1005 | if (copy_from_iter(tty->write_buf, size, from) != size)
|
| 1006 | break;
|
| 1007 |
|
| 1008 | ret = ld->ops->write(tty, file, tty->write_buf, size);
|
| 1009 | if (ret <= 0)
|
| 1010 | break;
|
| 1011 |
|
| 1012 | written += ret;
|
| 1013 | if (ret > size)
|
| 1014 | break;
|
| 1015 |
|
| 1016 |
|
| 1017 | if (ret != size)
|
| 1018 | iov_iter_revert(from, size-ret);
|
| 1019 |
|
| 1020 | count -= ret;
|
| 1021 | if (!count)
|
| 1022 | break;
|
| 1023 | ret = -ERESTARTSYS;
|
| 1024 | if (signal_pending(current))
|
| 1025 | break;
|
| 1026 | cond_resched();
|
| 1027 | }
|
| 1028 | if (written) {
|
| 1029 | tty_update_time(tty, true);
|
| 1030 | ret = written;
|
| 1031 | }
|
| 1032 | out:
|
| 1033 | tty_write_unlock(tty);
|
| 1034 | return ret;
|
| 1035 | }
|
| 1036 |
|
| 1037 | static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from)
|
| 1038 | {
|
| 1039 | struct tty_struct *tty = file_tty(file);
|
| 1040 | struct tty_ldisc *ld;
|
| 1041 | ssize_t ret;
|
| 1042 |
|
| 1043 | if (tty_paranoia_check(tty, file_inode(file), "tty_write"))
|
| 1044 | return -EIO;
|
| 1045 | if (!tty || !tty->ops->write || tty_io_error(tty))
|
| 1046 | return -EIO;
|
| 1047 |
|
| 1048 | if (tty->ops->write_room == NULL)
|
| 1049 | tty_err(tty, "missing write_room method\n");
|
| 1050 | ld = tty_ldisc_ref_wait(tty);
|
| 1051 | if (!ld)
|
| 1052 | return hung_up_tty_write(iocb, from);
|
| 1053 | if (!ld->ops->write)
|
| 1054 | ret = -EIO;
|
| 1055 | else
|
| 1056 | ret = iterate_tty_write(ld, tty, file, from);
|
| 1057 | tty_ldisc_deref(ld);
|
| 1058 | return ret;
|
| 1059 | }
|
| 1060 |
|
| 1061 | |
| 1062 | * tty_write - write method for tty device file
|
| 1063 | * @iocb: kernel I/O control block
|
| 1064 | * @from: iov_iter with data to write
|
| 1065 | *
|
| 1066 | * Write data to a tty device via the line discipline.
|
| 1067 | *
|
| 1068 | * Locking:
|
| 1069 | * Locks the line discipline as required
|
| 1070 | * Writes to the tty driver are serialized by the atomic_write_lock
|
| 1071 | * and are then processed in chunks to the device. The line
|
| 1072 | * discipline write method will not be invoked in parallel for
|
| 1073 | * each device.
|
| 1074 |
|
| 1075 | static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from)
|
| 1076 | {
|
| 1077 | return file_tty_write(iocb->ki_filp, iocb, from);
|
| 1078 | }
|
| 1079 |
|
| 1080 | ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter)
|
| 1081 | {
|
| 1082 | struct file *p = NULL;
|
| 1083 |
|
| 1084 | spin_lock(&redirect_lock);
|
| 1085 | if (redirect)
|
| 1086 | p = get_file(redirect);
|
| 1087 | spin_unlock(&redirect_lock);
|
| 1088 |
|
| 1089 | |
| 1090 | * We know the redirected tty is just another tty, we can
|
| 1091 | * call file_tty_write() directly with that file pointer.
|
| 1092 |
|
| 1093 | if (p) {
|
| 1094 | ssize_t res;
|
| 1095 |
|
| 1096 | res = file_tty_write(p, iocb, iter);
|
| 1097 | fput(p);
|
| 1098 | return res;
|
| 1099 | }
|
| 1100 | return tty_write(iocb, iter);
|
| 1101 | }
|
| 1102 |
|
| 1103 | |
| 1104 | * tty_send_xchar - send priority character
|
| 1105 | * @tty: the tty to send to
|
| 1106 | * @ch: xchar to send
|
| 1107 | *
|
| 1108 | * Send a high priority character to the tty even if stopped.
|
| 1109 | *
|
| 1110 | * Locking: none for xchar method, write ordering for write method.
|
| 1111 |
|
| 1112 | int tty_send_xchar(struct tty_struct *tty, u8 ch)
|
| 1113 | {
|
| 1114 | bool was_stopped = tty->flow.stopped;
|
| 1115 |
|
| 1116 | if (tty->ops->send_xchar) {
|
| 1117 | down_read(&tty->termios_rwsem);
|
| 1118 | tty->ops->send_xchar(tty, ch);
|
| 1119 | up_read(&tty->termios_rwsem);
|
| 1120 | return 0;
|
| 1121 | }
|
| 1122 |
|
| 1123 | if (tty_write_lock(tty, false) < 0)
|
| 1124 | return -ERESTARTSYS;
|
| 1125 |
|
| 1126 | down_read(&tty->termios_rwsem);
|
| 1127 | if (was_stopped)
|
| 1128 | start_tty(tty);
|
| 1129 | tty->ops->write(tty, &ch, 1);
|
| 1130 | if (was_stopped)
|
| 1131 | stop_tty(tty);
|
| 1132 | up_read(&tty->termios_rwsem);
|
| 1133 | tty_write_unlock(tty);
|
| 1134 | return 0;
|
| 1135 | }
|
| 1136 |
|
| 1137 | |
| 1138 | * pty_line_name - generate name for a pty
|
| 1139 | * @driver: the tty driver in use
|
| 1140 | * @index: the minor number
|
| 1141 | * @p: output buffer of at least 6 bytes
|
| 1142 | *
|
| 1143 | * Generate a name from a @driver reference and write it to the output buffer
|
| 1144 | * @p.
|
| 1145 | *
|
| 1146 | * Locking: None
|
| 1147 |
|
| 1148 | static void pty_line_name(struct tty_driver *driver, int index, char *p)
|
| 1149 | {
|
| 1150 | static const char ptychar[] = "pqrstuvwxyzabcde";
|
| 1151 | int i = index + driver->name_base;
|
| 1152 |
|
| 1153 | sprintf(p, "%s%c%x",
|
| 1154 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name,
|
| 1155 | ptychar[i >> 4 & 0xf], i & 0xf);
|
| 1156 | }
|
| 1157 |
|
| 1158 | |
| 1159 | * tty_line_name - generate name for a tty
|
| 1160 | * @driver: the tty driver in use
|
| 1161 | * @index: the minor number
|
| 1162 | * @p: output buffer of at least 7 bytes
|
| 1163 | *
|
| 1164 | * Generate a name from a @driver reference and write it to the output buffer
|
| 1165 | * @p.
|
| 1166 | *
|
| 1167 | * Locking: None
|
| 1168 |
|
| 1169 | static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
|
| 1170 | {
|
| 1171 | if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE)
|
| 1172 | return sprintf(p, "%s", driver->name);
|
| 1173 | else
|
| 1174 | return sprintf(p, "%s%d", driver->name,
|
| 1175 | index + driver->name_base);
|
| 1176 | }
|
| 1177 |
|
| 1178 | |
| 1179 | * tty_driver_lookup_tty() - find an existing tty, if any
|
| 1180 | * @driver: the driver for the tty
|
| 1181 | * @file: file object
|
| 1182 | * @idx: the minor number
|
| 1183 | *
|
| 1184 | * Return: the tty, if found. If not found, return %NULL or ERR_PTR() if the
|
| 1185 | * driver lookup() method returns an error.
|
| 1186 | *
|
| 1187 | * Locking: tty_mutex must be held. If the tty is found, bump the tty kref.
|
| 1188 |
|
| 1189 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver,
|
| 1190 | struct file *file, int idx)
|
| 1191 | {
|
| 1192 | struct tty_struct *tty;
|
| 1193 |
|
| 1194 | if (driver->ops->lookup) {
|
| 1195 | if (!file)
|
| 1196 | tty = ERR_PTR(-EIO);
|
| 1197 | else
|
| 1198 | tty = driver->ops->lookup(driver, file, idx);
|
| 1199 | } else {
|
| 1200 | if (idx >= driver->num)
|
| 1201 | return ERR_PTR(-EINVAL);
|
| 1202 | tty = driver->ttys[idx];
|
| 1203 | }
|
| 1204 | if (!IS_ERR(tty))
|
| 1205 | tty_kref_get(tty);
|
| 1206 | return tty;
|
| 1207 | }
|
| 1208 |
|
| 1209 | |
| 1210 | * tty_init_termios - helper for termios setup
|
| 1211 | * @tty: the tty to set up
|
| 1212 | *
|
| 1213 | * Initialise the termios structure for this tty. This runs under the
|
| 1214 | * %tty_mutex currently so we can be relaxed about ordering.
|
| 1215 |
|
| 1216 | void tty_init_termios(struct tty_struct *tty)
|
| 1217 | {
|
| 1218 | struct ktermios *tp;
|
| 1219 | int idx = tty->index;
|
| 1220 |
|
| 1221 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
|
| 1222 | tty->termios = tty->driver->init_termios;
|
| 1223 | else {
|
| 1224 |
|
| 1225 | tp = tty->driver->termios[idx];
|
| 1226 | if (tp != NULL) {
|
| 1227 | tty->termios = *tp;
|
| 1228 | tty->termios.c_line = tty->driver->init_termios.c_line;
|
| 1229 | } else
|
| 1230 | tty->termios = tty->driver->init_termios;
|
| 1231 | }
|
| 1232 |
|
| 1233 | tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
|
| 1234 | tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
|
| 1235 | }
|
| 1236 | EXPORT_SYMBOL_GPL(tty_init_termios);
|
| 1237 |
|
| 1238 | |
| 1239 | * tty_standard_install - usual tty->ops->install
|
| 1240 | * @driver: the driver for the tty
|
| 1241 | * @tty: the tty
|
| 1242 | *
|
| 1243 | * If the @driver overrides @tty->ops->install, it still can call this function
|
| 1244 | * to perform the standard install operations.
|
| 1245 |
|
| 1246 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty)
|
| 1247 | {
|
| 1248 | tty_init_termios(tty);
|
| 1249 | tty_driver_kref_get(driver);
|
| 1250 | tty->count++;
|
| 1251 | driver->ttys[tty->index] = tty;
|
| 1252 | return 0;
|
| 1253 | }
|
| 1254 | EXPORT_SYMBOL_GPL(tty_standard_install);
|
| 1255 |
|
| 1256 | |
| 1257 | * tty_driver_install_tty() - install a tty entry in the driver
|
| 1258 | * @driver: the driver for the tty
|
| 1259 | * @tty: the tty
|
| 1260 | *
|
| 1261 | * Install a tty object into the driver tables. The @tty->index field will be
|
| 1262 | * set by the time this is called. This method is responsible for ensuring any
|
| 1263 | * need additional structures are allocated and configured.
|
| 1264 | *
|
| 1265 | * Locking: tty_mutex for now
|
| 1266 |
|
| 1267 | static int tty_driver_install_tty(struct tty_driver *driver,
|
| 1268 | struct tty_struct *tty)
|
| 1269 | {
|
| 1270 | return driver->ops->install ? driver->ops->install(driver, tty) :
|
| 1271 | tty_standard_install(driver, tty);
|
| 1272 | }
|
| 1273 |
|
| 1274 | |
| 1275 | * tty_driver_remove_tty() - remove a tty from the driver tables
|
| 1276 | * @driver: the driver for the tty
|
| 1277 | * @tty: tty to remove
|
| 1278 | *
|
| 1279 | * Remove a tty object from the driver tables. The tty->index field will be set
|
| 1280 | * by the time this is called.
|
| 1281 | *
|
| 1282 | * Locking: tty_mutex for now
|
| 1283 |
|
| 1284 | static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty)
|
| 1285 | {
|
| 1286 | if (driver->ops->remove)
|
| 1287 | driver->ops->remove(driver, tty);
|
| 1288 | else
|
| 1289 | driver->ttys[tty->index] = NULL;
|
| 1290 | }
|
| 1291 |
|
| 1292 | |
| 1293 | * tty_reopen() - fast re-open of an open tty
|
| 1294 | * @tty: the tty to open
|
| 1295 | *
|
| 1296 | * Re-opens on master ptys are not allowed and return -%EIO.
|
| 1297 | *
|
| 1298 | * Locking: Caller must hold tty_lock
|
| 1299 | * Return: 0 on success, -errno on error.
|
| 1300 |
|
| 1301 | static int tty_reopen(struct tty_struct *tty)
|
| 1302 | {
|
| 1303 | struct tty_driver *driver = tty->driver;
|
| 1304 | struct tty_ldisc *ld;
|
| 1305 | int retval = 0;
|
| 1306 |
|
| 1307 | if (driver->type == TTY_DRIVER_TYPE_PTY &&
|
| 1308 | driver->subtype == PTY_TYPE_MASTER)
|
| 1309 | return -EIO;
|
| 1310 |
|
| 1311 | if (!tty->count)
|
| 1312 | return -EAGAIN;
|
| 1313 |
|
| 1314 | if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN))
|
| 1315 | return -EBUSY;
|
| 1316 |
|
| 1317 | ld = tty_ldisc_ref_wait(tty);
|
| 1318 | if (ld) {
|
| 1319 | tty_ldisc_deref(ld);
|
| 1320 | } else {
|
| 1321 | retval = tty_ldisc_lock(tty, 5 * HZ);
|
| 1322 | if (retval)
|
| 1323 | return retval;
|
| 1324 |
|
| 1325 | if (!tty->ldisc)
|
| 1326 | retval = tty_ldisc_reinit(tty, tty->termios.c_line);
|
| 1327 | tty_ldisc_unlock(tty);
|
| 1328 | }
|
| 1329 |
|
| 1330 | if (retval == 0)
|
| 1331 | tty->count++;
|
| 1332 |
|
| 1333 | return retval;
|
| 1334 | }
|
| 1335 |
|
| 1336 | |
| 1337 | * tty_init_dev - initialise a tty device
|
| 1338 | * @driver: tty driver we are opening a device on
|
| 1339 | * @idx: device index
|
| 1340 | *
|
| 1341 | * Prepare a tty device. This may not be a "new" clean device but could also be
|
| 1342 | * an active device. The pty drivers require special handling because of this.
|
| 1343 | *
|
| 1344 | * Locking:
|
| 1345 | * The function is called under the tty_mutex, which protects us from the
|
| 1346 | * tty struct or driver itself going away.
|
| 1347 | *
|
| 1348 | * On exit the tty device has the line discipline attached and a reference
|
| 1349 | * count of 1. If a pair was created for pty/tty use and the other was a pty
|
| 1350 | * master then it too has a reference count of 1.
|
| 1351 | *
|
| 1352 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a failed
|
| 1353 | * open. The new code protects the open with a mutex, so it's really quite
|
| 1354 | * straightforward. The mutex locking can probably be relaxed for the (most
|
| 1355 | * common) case of reopening a tty.
|
| 1356 | *
|
| 1357 | * Return: new tty structure
|
| 1358 |
|
| 1359 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
|
| 1360 | {
|
| 1361 | struct tty_struct *tty;
|
| 1362 | int retval;
|
| 1363 |
|
| 1364 | |
| 1365 | * First time open is complex, especially for PTY devices.
|
| 1366 | * This code guarantees that either everything succeeds and the
|
| 1367 | * TTY is ready for operation, or else the table slots are vacated
|
| 1368 | * and the allocated memory released. (Except that the termios
|
| 1369 | * may be retained.)
|
| 1370 |
|
| 1371 |
|
| 1372 | if (!try_module_get(driver->owner))
|
| 1373 | return ERR_PTR(-ENODEV);
|
| 1374 |
|
| 1375 | tty = alloc_tty_struct(driver, idx);
|
| 1376 | if (!tty) {
|
| 1377 | retval = -ENOMEM;
|
| 1378 | goto err_module_put;
|
| 1379 | }
|
| 1380 |
|
| 1381 | tty_lock(tty);
|
| 1382 | retval = tty_driver_install_tty(driver, tty);
|
| 1383 | if (retval < 0)
|
| 1384 | goto err_free_tty;
|
| 1385 |
|
| 1386 | if (!tty->port)
|
| 1387 | tty->port = driver->ports[idx];
|
| 1388 |
|
| 1389 | if (WARN_RATELIMIT(!tty->port,
|
| 1390 | "%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n",
|
| 1391 | __func__, tty->driver->name)) {
|
| 1392 | retval = -EINVAL;
|
| 1393 | goto err_release_lock;
|
| 1394 | }
|
| 1395 |
|
| 1396 | retval = tty_ldisc_lock(tty, 5 * HZ);
|
| 1397 | if (retval)
|
| 1398 | goto err_release_lock;
|
| 1399 | tty->port->itty = tty;
|
| 1400 |
|
| 1401 | |
| 1402 | * Structures all installed ... call the ldisc open routines.
|
| 1403 | * If we fail here just call release_tty to clean up. No need
|
| 1404 | * to decrement the use counts, as release_tty doesn't care.
|
| 1405 |
|
| 1406 | retval = tty_ldisc_setup(tty, tty->link);
|
| 1407 | if (retval)
|
| 1408 | goto err_release_tty;
|
| 1409 | tty_ldisc_unlock(tty);
|
| 1410 |
|
| 1411 | return tty;
|
| 1412 |
|
| 1413 | err_free_tty:
|
| 1414 | tty_unlock(tty);
|
| 1415 | free_tty_struct(tty);
|
| 1416 | err_module_put:
|
| 1417 | module_put(driver->owner);
|
| 1418 | return ERR_PTR(retval);
|
| 1419 |
|
| 1420 |
|
| 1421 | err_release_tty:
|
| 1422 | tty_ldisc_unlock(tty);
|
| 1423 | tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n",
|
| 1424 | retval, idx);
|
| 1425 | err_release_lock:
|
| 1426 | tty_unlock(tty);
|
| 1427 | release_tty(tty, idx);
|
| 1428 | return ERR_PTR(retval);
|
| 1429 | }
|
| 1430 |
|
| 1431 | |
| 1432 | * tty_save_termios() - save tty termios data in driver table
|
| 1433 | * @tty: tty whose termios data to save
|
| 1434 | *
|
| 1435 | * Locking: Caller guarantees serialisation with tty_init_termios().
|
| 1436 |
|
| 1437 | void tty_save_termios(struct tty_struct *tty)
|
| 1438 | {
|
| 1439 | struct ktermios *tp;
|
| 1440 | int idx = tty->index;
|
| 1441 |
|
| 1442 |
|
| 1443 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
|
| 1444 | return;
|
| 1445 |
|
| 1446 |
|
| 1447 | tp = tty->driver->termios[idx];
|
| 1448 | if (tp == NULL) {
|
| 1449 | tp = kmalloc_obj(*tp);
|
| 1450 | if (tp == NULL)
|
| 1451 | return;
|
| 1452 | tty->driver->termios[idx] = tp;
|
| 1453 | }
|
| 1454 | *tp = tty->termios;
|
| 1455 | }
|
| 1456 | EXPORT_SYMBOL_GPL(tty_save_termios);
|
| 1457 |
|
| 1458 | |
| 1459 | * tty_flush_works - flush all works of a tty/pty pair
|
| 1460 | * @tty: tty device to flush works for (or either end of a pty pair)
|
| 1461 | *
|
| 1462 | * Sync flush all works belonging to @tty (and the 'other' tty).
|
| 1463 |
|
| 1464 | static void tty_flush_works(struct tty_struct *tty)
|
| 1465 | {
|
| 1466 | flush_work(&tty->SAK_work);
|
| 1467 | flush_work(&tty->hangup_work);
|
| 1468 | if (tty->link) {
|
| 1469 | flush_work(&tty->link->SAK_work);
|
| 1470 | flush_work(&tty->link->hangup_work);
|
| 1471 | }
|
| 1472 | }
|
| 1473 |
|
| 1474 | |
| 1475 | * release_one_tty - release tty structure memory
|
| 1476 | * @work: work of tty we are obliterating
|
| 1477 | *
|
| 1478 | * Releases memory associated with a tty structure, and clears out the
|
| 1479 | * driver table slots. This function is called when a device is no longer
|
| 1480 | * in use. It also gets called when setup of a device fails.
|
| 1481 | *
|
| 1482 | * Locking:
|
| 1483 | * takes the file list lock internally when working on the list of ttys
|
| 1484 | * that the driver keeps.
|
| 1485 | *
|
| 1486 | * This method gets called from a work queue so that the driver private
|
| 1487 | * cleanup ops can sleep (needed for USB at least)
|
| 1488 |
|
| 1489 | static void release_one_tty(struct work_struct *work)
|
| 1490 | {
|
| 1491 | struct tty_struct *tty =
|
| 1492 | container_of(work, struct tty_struct, hangup_work);
|
| 1493 | struct tty_driver *driver = tty->driver;
|
| 1494 | struct module *owner = driver->owner;
|
| 1495 |
|
| 1496 | if (tty->ops->cleanup)
|
| 1497 | tty->ops->cleanup(tty);
|
| 1498 |
|
| 1499 | tty_driver_kref_put(driver);
|
| 1500 | module_put(owner);
|
| 1501 |
|
| 1502 | spin_lock(&tty->files_lock);
|
| 1503 | list_del_init(&tty->tty_files);
|
| 1504 | spin_unlock(&tty->files_lock);
|
| 1505 |
|
| 1506 | put_pid(tty->ctrl.pgrp);
|
| 1507 | put_pid(tty->ctrl.session);
|
| 1508 | free_tty_struct(tty);
|
| 1509 | }
|
| 1510 |
|
| 1511 | static void queue_release_one_tty(struct kref *kref)
|
| 1512 | {
|
| 1513 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref);
|
| 1514 |
|
| 1515 | |
| 1516 | * waste a chunk of memory for each port.
|
| 1517 |
|
| 1518 | INIT_WORK(&tty->hangup_work, release_one_tty);
|
| 1519 | schedule_work(&tty->hangup_work);
|
| 1520 | }
|
| 1521 |
|
| 1522 | |
| 1523 | * tty_kref_put - release a tty kref
|
| 1524 | * @tty: tty device
|
| 1525 | *
|
| 1526 | * Release a reference to the @tty device and if need be let the kref layer
|
| 1527 | * destruct the object for us.
|
| 1528 |
|
| 1529 | void tty_kref_put(struct tty_struct *tty)
|
| 1530 | {
|
| 1531 | if (tty)
|
| 1532 | kref_put(&tty->kref, queue_release_one_tty);
|
| 1533 | }
|
| 1534 | EXPORT_SYMBOL(tty_kref_put);
|
| 1535 |
|
| 1536 | |
| 1537 | * release_tty - release tty structure memory
|
| 1538 | * @tty: tty device release
|
| 1539 | * @idx: index of the tty device release
|
| 1540 | *
|
| 1541 | * Release both @tty and a possible linked partner (think pty pair),
|
| 1542 | * and decrement the refcount of the backing module.
|
| 1543 | *
|
| 1544 | * Locking:
|
| 1545 | * tty_mutex
|
| 1546 | * takes the file list lock internally when working on the list of ttys
|
| 1547 | * that the driver keeps.
|
| 1548 |
|
| 1549 | static void release_tty(struct tty_struct *tty, int idx)
|
| 1550 | {
|
| 1551 |
|
| 1552 | WARN_ON(tty->index != idx);
|
| 1553 | WARN_ON(!mutex_is_locked(&tty_mutex));
|
| 1554 | if (tty->ops->shutdown)
|
| 1555 | tty->ops->shutdown(tty);
|
| 1556 | tty_save_termios(tty);
|
| 1557 | tty_driver_remove_tty(tty->driver, tty);
|
| 1558 | if (tty->port)
|
| 1559 | tty->port->itty = NULL;
|
| 1560 | if (tty->link)
|
| 1561 | tty->link->port->itty = NULL;
|
| 1562 | if (tty->port)
|
| 1563 | tty_buffer_cancel_work(tty->port);
|
| 1564 | if (tty->link)
|
| 1565 | tty_buffer_cancel_work(tty->link->port);
|
| 1566 |
|
| 1567 | tty_kref_put(tty->link);
|
| 1568 | tty_kref_put(tty);
|
| 1569 | }
|
| 1570 |
|
| 1571 | |
| 1572 | * tty_release_checks - check a tty before real release
|
| 1573 | * @tty: tty to check
|
| 1574 | * @idx: index of the tty
|
| 1575 | *
|
| 1576 | * Performs some paranoid checking before true release of the @tty. This is a
|
| 1577 | * no-op unless %TTY_PARANOIA_CHECK is defined.
|
| 1578 |
|
| 1579 | static int tty_release_checks(struct tty_struct *tty, int idx)
|
| 1580 | {
|
| 1581 | #ifdef TTY_PARANOIA_CHECK
|
| 1582 | if (idx < 0 || idx >= tty->driver->num) {
|
| 1583 | tty_debug(tty, "bad idx %d\n", idx);
|
| 1584 | return -1;
|
| 1585 | }
|
| 1586 |
|
| 1587 |
|
| 1588 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM)
|
| 1589 | return 0;
|
| 1590 |
|
| 1591 | if (tty != tty->driver->ttys[idx]) {
|
| 1592 | tty_debug(tty, "bad driver table[%d] = %p\n",
|
| 1593 | idx, tty->driver->ttys[idx]);
|
| 1594 | return -1;
|
| 1595 | }
|
| 1596 | if (tty->driver->other) {
|
| 1597 | struct tty_struct *o_tty = tty->link;
|
| 1598 |
|
| 1599 | if (o_tty != tty->driver->other->ttys[idx]) {
|
| 1600 | tty_debug(tty, "bad other table[%d] = %p\n",
|
| 1601 | idx, tty->driver->other->ttys[idx]);
|
| 1602 | return -1;
|
| 1603 | }
|
| 1604 | if (o_tty->link != tty) {
|
| 1605 | tty_debug(tty, "bad link = %p\n", o_tty->link);
|
| 1606 | return -1;
|
| 1607 | }
|
| 1608 | }
|
| 1609 | #endif
|
| 1610 | return 0;
|
| 1611 | }
|
| 1612 |
|
| 1613 | |
| 1614 | * tty_kclose - closes tty opened by tty_kopen
|
| 1615 | * @tty: tty device
|
| 1616 | *
|
| 1617 | * Performs the final steps to release and free a tty device. It is the same as
|
| 1618 | * tty_release_struct() except that it also resets %TTY_PORT_KOPENED flag on
|
| 1619 | * @tty->port.
|
| 1620 |
|
| 1621 | void tty_kclose(struct tty_struct *tty)
|
| 1622 | {
|
| 1623 | |
| 1624 | * Ask the line discipline code to release its structures
|
| 1625 |
|
| 1626 | tty_ldisc_release(tty);
|
| 1627 |
|
| 1628 |
|
| 1629 | tty_flush_works(tty);
|
| 1630 |
|
| 1631 | tty_debug_hangup(tty, "freeing structure\n");
|
| 1632 | |
| 1633 | * The release_tty function takes care of the details of clearing
|
| 1634 | * the slots and preserving the termios structure.
|
| 1635 |
|
| 1636 | mutex_lock(&tty_mutex);
|
| 1637 | tty_port_set_kopened(tty->port, 0);
|
| 1638 | release_tty(tty, tty->index);
|
| 1639 | mutex_unlock(&tty_mutex);
|
| 1640 | }
|
| 1641 | EXPORT_SYMBOL_GPL(tty_kclose);
|
| 1642 |
|
| 1643 | |
| 1644 | * tty_release_struct - release a tty struct
|
| 1645 | * @tty: tty device
|
| 1646 | * @idx: index of the tty
|
| 1647 | *
|
| 1648 | * Performs the final steps to release and free a tty device. It is roughly the
|
| 1649 | * reverse of tty_init_dev().
|
| 1650 |
|
| 1651 | void tty_release_struct(struct tty_struct *tty, int idx)
|
| 1652 | {
|
| 1653 | |
| 1654 | * Ask the line discipline code to release its structures
|
| 1655 |
|
| 1656 | tty_ldisc_release(tty);
|
| 1657 |
|
| 1658 |
|
| 1659 | tty_flush_works(tty);
|
| 1660 |
|
| 1661 | tty_debug_hangup(tty, "freeing structure\n");
|
| 1662 | |
| 1663 | * The release_tty function takes care of the details of clearing
|
| 1664 | * the slots and preserving the termios structure.
|
| 1665 |
|
| 1666 | mutex_lock(&tty_mutex);
|
| 1667 | release_tty(tty, idx);
|
| 1668 | mutex_unlock(&tty_mutex);
|
| 1669 | }
|
| 1670 | EXPORT_SYMBOL_GPL(tty_release_struct);
|
| 1671 |
|
| 1672 | |
| 1673 | * tty_release - vfs callback for close
|
| 1674 | * @inode: inode of tty
|
| 1675 | * @filp: file pointer for handle to tty
|
| 1676 | *
|
| 1677 | * Called the last time each file handle is closed that references this tty.
|
| 1678 | * There may however be several such references.
|
| 1679 | *
|
| 1680 | * Locking:
|
| 1681 | * Takes BKL. See tty_release_dev().
|
| 1682 | *
|
| 1683 | * Even releasing the tty structures is a tricky business. We have to be very
|
| 1684 | * careful that the structures are all released at the same time, as interrupts
|
| 1685 | * might otherwise get the wrong pointers.
|
| 1686 | *
|
| 1687 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could
|
| 1688 | * lead to double frees or releasing memory still in use.
|
| 1689 |
|
| 1690 | int tty_release(struct inode *inode, struct file *filp)
|
| 1691 | {
|
| 1692 | struct tty_struct *tty = file_tty(filp);
|
| 1693 | struct tty_struct *o_tty = NULL;
|
| 1694 | int do_sleep, final;
|
| 1695 | int idx;
|
| 1696 | long timeout = 0;
|
| 1697 | int once = 1;
|
| 1698 |
|
| 1699 | if (tty_paranoia_check(tty, inode, __func__))
|
| 1700 | return 0;
|
| 1701 |
|
| 1702 | tty_lock(tty);
|
| 1703 | check_tty_count(tty, __func__);
|
| 1704 |
|
| 1705 | __tty_fasync(-1, filp, 0);
|
| 1706 |
|
| 1707 | idx = tty->index;
|
| 1708 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
| 1709 | tty->driver->subtype == PTY_TYPE_MASTER)
|
| 1710 | o_tty = tty->link;
|
| 1711 |
|
| 1712 | if (tty_release_checks(tty, idx)) {
|
| 1713 | tty_unlock(tty);
|
| 1714 | return 0;
|
| 1715 | }
|
| 1716 |
|
| 1717 | tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count);
|
| 1718 |
|
| 1719 | if (tty->ops->close)
|
| 1720 | tty->ops->close(tty, filp);
|
| 1721 |
|
| 1722 |
|
| 1723 | tty_lock_slave(o_tty);
|
| 1724 |
|
| 1725 | |
| 1726 | * Sanity check: if tty->count is going to zero, there shouldn't be
|
| 1727 | * any waiters on tty->read_wait or tty->write_wait. We test the
|
| 1728 | * wait queues and kick everyone out _before_ actually starting to
|
| 1729 | * close. This ensures that we won't block while releasing the tty
|
| 1730 | * structure.
|
| 1731 | *
|
| 1732 | * The test for the o_tty closing is necessary, since the master and
|
| 1733 | * slave sides may close in any order. If the slave side closes out
|
| 1734 | * first, its count will be one, since the master side holds an open.
|
| 1735 | * Thus this test wouldn't be triggered at the time the slave closed,
|
| 1736 | * so we do it now.
|
| 1737 |
|
| 1738 | while (1) {
|
| 1739 | do_sleep = 0;
|
| 1740 |
|
| 1741 | if (tty->count <= 1) {
|
| 1742 | if (waitqueue_active(&tty->read_wait)) {
|
| 1743 | wake_up_poll(&tty->read_wait, EPOLLIN);
|
| 1744 | do_sleep++;
|
| 1745 | }
|
| 1746 | if (waitqueue_active(&tty->write_wait)) {
|
| 1747 | wake_up_poll(&tty->write_wait, EPOLLOUT);
|
| 1748 | do_sleep++;
|
| 1749 | }
|
| 1750 | }
|
| 1751 | if (o_tty && o_tty->count <= 1) {
|
| 1752 | if (waitqueue_active(&o_tty->read_wait)) {
|
| 1753 | wake_up_poll(&o_tty->read_wait, EPOLLIN);
|
| 1754 | do_sleep++;
|
| 1755 | }
|
| 1756 | if (waitqueue_active(&o_tty->write_wait)) {
|
| 1757 | wake_up_poll(&o_tty->write_wait, EPOLLOUT);
|
| 1758 | do_sleep++;
|
| 1759 | }
|
| 1760 | }
|
| 1761 | if (!do_sleep)
|
| 1762 | break;
|
| 1763 |
|
| 1764 | if (once) {
|
| 1765 | once = 0;
|
| 1766 | tty_warn(tty, "read/write wait queue active!\n");
|
| 1767 | }
|
| 1768 | schedule_timeout_killable(timeout);
|
| 1769 | if (timeout < 120 * HZ)
|
| 1770 | timeout = 2 * timeout + 1;
|
| 1771 | else
|
| 1772 | timeout = MAX_SCHEDULE_TIMEOUT;
|
| 1773 | }
|
| 1774 |
|
| 1775 | if (o_tty) {
|
| 1776 | if (--o_tty->count < 0) {
|
| 1777 | tty_warn(tty, "bad slave count (%d)\n", o_tty->count);
|
| 1778 | o_tty->count = 0;
|
| 1779 | }
|
| 1780 | }
|
| 1781 | if (--tty->count < 0) {
|
| 1782 | tty_warn(tty, "bad tty->count (%d)\n", tty->count);
|
| 1783 | tty->count = 0;
|
| 1784 | }
|
| 1785 |
|
| 1786 | |
| 1787 | * We've decremented tty->count, so we need to remove this file
|
| 1788 | * descriptor off the tty->tty_files list; this serves two
|
| 1789 | * purposes:
|
| 1790 | * - check_tty_count sees the correct number of file descriptors
|
| 1791 | * associated with this tty.
|
| 1792 | * - do_tty_hangup no longer sees this file descriptor as
|
| 1793 | * something that needs to be handled for hangups.
|
| 1794 |
|
| 1795 | tty_del_file(filp);
|
| 1796 |
|
| 1797 | |
| 1798 | * Perform some housekeeping before deciding whether to return.
|
| 1799 | *
|
| 1800 | * If _either_ side is closing, make sure there aren't any
|
| 1801 | * processes that still think tty or o_tty is their controlling
|
| 1802 | * tty.
|
| 1803 |
|
| 1804 | if (!tty->count) {
|
| 1805 | read_lock(&tasklist_lock);
|
| 1806 | session_clear_tty(tty->ctrl.session);
|
| 1807 | if (o_tty)
|
| 1808 | session_clear_tty(o_tty->ctrl.session);
|
| 1809 | read_unlock(&tasklist_lock);
|
| 1810 | }
|
| 1811 |
|
| 1812 |
|
| 1813 | final = !tty->count && !(o_tty && o_tty->count);
|
| 1814 |
|
| 1815 | tty_unlock_slave(o_tty);
|
| 1816 | tty_unlock(tty);
|
| 1817 |
|
| 1818 | |
| 1819 | * cannot be re-opened by a racing opener.
|
| 1820 |
|
| 1821 |
|
| 1822 | if (!final)
|
| 1823 | return 0;
|
| 1824 |
|
| 1825 | tty_debug_hangup(tty, "final close\n");
|
| 1826 |
|
| 1827 | tty_release_struct(tty, idx);
|
| 1828 | return 0;
|
| 1829 | }
|
| 1830 |
|
| 1831 | |
| 1832 | * tty_open_current_tty - get locked tty of current task
|
| 1833 | * @device: device number
|
| 1834 | * @filp: file pointer to tty
|
| 1835 | * @return: locked tty of the current task iff @device is /dev/tty
|
| 1836 | *
|
| 1837 | * Performs a re-open of the current task's controlling tty.
|
| 1838 | *
|
| 1839 | * We cannot return driver and index like for the other nodes because devpts
|
| 1840 | * will not work then. It expects inodes to be from devpts FS.
|
| 1841 |
|
| 1842 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
|
| 1843 | {
|
| 1844 | struct tty_struct *tty;
|
| 1845 | int retval;
|
| 1846 |
|
| 1847 | if (device != MKDEV(TTYAUX_MAJOR, 0))
|
| 1848 | return NULL;
|
| 1849 |
|
| 1850 | tty = get_current_tty();
|
| 1851 | if (!tty)
|
| 1852 | return ERR_PTR(-ENXIO);
|
| 1853 |
|
| 1854 | filp->f_flags |= O_NONBLOCK;
|
| 1855 |
|
| 1856 | tty_lock(tty);
|
| 1857 | tty_kref_put(tty);
|
| 1858 |
|
| 1859 | retval = tty_reopen(tty);
|
| 1860 | if (retval < 0) {
|
| 1861 | tty_unlock(tty);
|
| 1862 | tty = ERR_PTR(retval);
|
| 1863 | }
|
| 1864 | return tty;
|
| 1865 | }
|
| 1866 |
|
| 1867 | |
| 1868 | * tty_lookup_driver - lookup a tty driver for a given device file
|
| 1869 | * @device: device number
|
| 1870 | * @filp: file pointer to tty
|
| 1871 | * @index: index for the device in the @return driver
|
| 1872 | *
|
| 1873 | * If returned value is not erroneous, the caller is responsible to decrement
|
| 1874 | * the refcount by tty_driver_kref_put().
|
| 1875 | *
|
| 1876 | * Locking: %tty_mutex protects get_tty_driver()
|
| 1877 | *
|
| 1878 | * Return: driver for this inode (with increased refcount)
|
| 1879 |
|
| 1880 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
|
| 1881 | int *index)
|
| 1882 | {
|
| 1883 | struct tty_driver *driver = NULL;
|
| 1884 |
|
| 1885 | switch (device) {
|
| 1886 | #ifdef CONFIG_VT
|
| 1887 | case MKDEV(TTY_MAJOR, 0): {
|
| 1888 | extern struct tty_driver *console_driver;
|
| 1889 |
|
| 1890 | driver = tty_driver_kref_get(console_driver);
|
| 1891 | *index = fg_console;
|
| 1892 | break;
|
| 1893 | }
|
| 1894 | #endif
|
| 1895 | case MKDEV(TTYAUX_MAJOR, 1): {
|
| 1896 | struct tty_driver *console_driver = console_device(index);
|
| 1897 |
|
| 1898 | if (console_driver) {
|
| 1899 | driver = tty_driver_kref_get(console_driver);
|
| 1900 | if (driver && filp) {
|
| 1901 |
|
| 1902 | filp->f_flags |= O_NONBLOCK;
|
| 1903 | break;
|
| 1904 | }
|
| 1905 | }
|
| 1906 | if (driver)
|
| 1907 | tty_driver_kref_put(driver);
|
| 1908 | return ERR_PTR(-ENODEV);
|
| 1909 | }
|
| 1910 | default:
|
| 1911 | driver = get_tty_driver(device, index);
|
| 1912 | if (!driver)
|
| 1913 | return ERR_PTR(-ENODEV);
|
| 1914 | break;
|
| 1915 | }
|
| 1916 | return driver;
|
| 1917 | }
|
| 1918 |
|
| 1919 | static struct tty_struct *tty_kopen(dev_t device, int shared)
|
| 1920 | {
|
| 1921 | struct tty_struct *tty;
|
| 1922 | struct tty_driver *driver;
|
| 1923 | int index = -1;
|
| 1924 |
|
| 1925 | mutex_lock(&tty_mutex);
|
| 1926 | driver = tty_lookup_driver(device, NULL, &index);
|
| 1927 | if (IS_ERR(driver)) {
|
| 1928 | mutex_unlock(&tty_mutex);
|
| 1929 | return ERR_CAST(driver);
|
| 1930 | }
|
| 1931 |
|
| 1932 |
|
| 1933 | tty = tty_driver_lookup_tty(driver, NULL, index);
|
| 1934 | if (IS_ERR(tty) || shared)
|
| 1935 | goto out;
|
| 1936 |
|
| 1937 | if (tty) {
|
| 1938 |
|
| 1939 | tty_kref_put(tty);
|
| 1940 | tty = ERR_PTR(-EBUSY);
|
| 1941 | } else {
|
| 1942 | tty = tty_init_dev(driver, index);
|
| 1943 | if (IS_ERR(tty))
|
| 1944 | goto out;
|
| 1945 | tty_port_set_kopened(tty->port, 1);
|
| 1946 | }
|
| 1947 | out:
|
| 1948 | mutex_unlock(&tty_mutex);
|
| 1949 | tty_driver_kref_put(driver);
|
| 1950 | return tty;
|
| 1951 | }
|
| 1952 |
|
| 1953 | |
| 1954 | * tty_kopen_exclusive - open a tty device for kernel
|
| 1955 | * @device: dev_t of device to open
|
| 1956 | *
|
| 1957 | * Opens tty exclusively for kernel. Performs the driver lookup, makes sure
|
| 1958 | * it's not already opened and performs the first-time tty initialization.
|
| 1959 | *
|
| 1960 | * Claims the global %tty_mutex to serialize:
|
| 1961 | * * concurrent first-time tty initialization
|
| 1962 | * * concurrent tty driver removal w/ lookup
|
| 1963 | * * concurrent tty removal from driver table
|
| 1964 | *
|
| 1965 | * Return: the locked initialized &tty_struct
|
| 1966 |
|
| 1967 | struct tty_struct *tty_kopen_exclusive(dev_t device)
|
| 1968 | {
|
| 1969 | return tty_kopen(device, 0);
|
| 1970 | }
|
| 1971 | EXPORT_SYMBOL_GPL(tty_kopen_exclusive);
|
| 1972 |
|
| 1973 | |
| 1974 | * tty_kopen_shared - open a tty device for shared in-kernel use
|
| 1975 | * @device: dev_t of device to open
|
| 1976 | *
|
| 1977 | * Opens an already existing tty for in-kernel use. Compared to
|
| 1978 | * tty_kopen_exclusive() above it doesn't ensure to be the only user.
|
| 1979 | *
|
| 1980 | * Locking: identical to tty_kopen() above.
|
| 1981 |
|
| 1982 | struct tty_struct *tty_kopen_shared(dev_t device)
|
| 1983 | {
|
| 1984 | return tty_kopen(device, 1);
|
| 1985 | }
|
| 1986 | EXPORT_SYMBOL_GPL(tty_kopen_shared);
|
| 1987 |
|
| 1988 | |
| 1989 | * tty_open_by_driver - open a tty device
|
| 1990 | * @device: dev_t of device to open
|
| 1991 | * @filp: file pointer to tty
|
| 1992 | *
|
| 1993 | * Performs the driver lookup, checks for a reopen, or otherwise performs the
|
| 1994 | * first-time tty initialization.
|
| 1995 | *
|
| 1996 | *
|
| 1997 | * Claims the global tty_mutex to serialize:
|
| 1998 | * * concurrent first-time tty initialization
|
| 1999 | * * concurrent tty driver removal w/ lookup
|
| 2000 | * * concurrent tty removal from driver table
|
| 2001 | *
|
| 2002 | * Return: the locked initialized or re-opened &tty_struct
|
| 2003 |
|
| 2004 | static struct tty_struct *tty_open_by_driver(dev_t device,
|
| 2005 | struct file *filp)
|
| 2006 | {
|
| 2007 | struct tty_struct *tty;
|
| 2008 | struct tty_driver *driver = NULL;
|
| 2009 | int index = -1;
|
| 2010 | int retval;
|
| 2011 |
|
| 2012 | mutex_lock(&tty_mutex);
|
| 2013 | driver = tty_lookup_driver(device, filp, &index);
|
| 2014 | if (IS_ERR(driver)) {
|
| 2015 | mutex_unlock(&tty_mutex);
|
| 2016 | return ERR_CAST(driver);
|
| 2017 | }
|
| 2018 |
|
| 2019 |
|
| 2020 | tty = tty_driver_lookup_tty(driver, filp, index);
|
| 2021 | if (IS_ERR(tty)) {
|
| 2022 | mutex_unlock(&tty_mutex);
|
| 2023 | goto out;
|
| 2024 | }
|
| 2025 |
|
| 2026 | if (tty) {
|
| 2027 | if (tty_port_kopened(tty->port)) {
|
| 2028 | tty_kref_put(tty);
|
| 2029 | mutex_unlock(&tty_mutex);
|
| 2030 | tty = ERR_PTR(-EBUSY);
|
| 2031 | goto out;
|
| 2032 | }
|
| 2033 | mutex_unlock(&tty_mutex);
|
| 2034 | retval = tty_lock_interruptible(tty);
|
| 2035 | tty_kref_put(tty);
|
| 2036 | if (retval) {
|
| 2037 | if (retval == -EINTR)
|
| 2038 | retval = -ERESTARTSYS;
|
| 2039 | tty = ERR_PTR(retval);
|
| 2040 | goto out;
|
| 2041 | }
|
| 2042 | retval = tty_reopen(tty);
|
| 2043 | if (retval < 0) {
|
| 2044 | tty_unlock(tty);
|
| 2045 | tty = ERR_PTR(retval);
|
| 2046 | }
|
| 2047 | } else {
|
| 2048 | tty = tty_init_dev(driver, index);
|
| 2049 | mutex_unlock(&tty_mutex);
|
| 2050 | }
|
| 2051 | out:
|
| 2052 | tty_driver_kref_put(driver);
|
| 2053 | return tty;
|
| 2054 | }
|
| 2055 |
|
| 2056 | |
| 2057 | * tty_open - open a tty device
|
| 2058 | * @inode: inode of device file
|
| 2059 | * @filp: file pointer to tty
|
| 2060 | *
|
| 2061 | * tty_open() and tty_release() keep up the tty count that contains the number
|
| 2062 | * of opens done on a tty. We cannot use the inode-count, as different inodes
|
| 2063 | * might point to the same tty.
|
| 2064 | *
|
| 2065 | * Open-counting is needed for pty masters, as well as for keeping track of
|
| 2066 | * serial lines: DTR is dropped when the last close happens.
|
| 2067 | * (This is not done solely through tty->count, now. - Ted 1/27/92)
|
| 2068 | *
|
| 2069 | * The termios state of a pty is reset on the first open so that settings don't
|
| 2070 | * persist across reuse.
|
| 2071 | *
|
| 2072 | * Locking:
|
| 2073 | * * %tty_mutex protects tty, tty_lookup_driver() and tty_init_dev().
|
| 2074 | * * @tty->count should protect the rest.
|
| 2075 | * * ->siglock protects ->signal/->sighand
|
| 2076 | *
|
| 2077 | * Note: the tty_unlock/lock cases without a ref are only safe due to %tty_mutex
|
| 2078 |
|
| 2079 | static int tty_open(struct inode *inode, struct file *filp)
|
| 2080 | {
|
| 2081 | struct tty_struct *tty;
|
| 2082 | int noctty, retval;
|
| 2083 | dev_t device = inode->i_rdev;
|
| 2084 | unsigned saved_flags = filp->f_flags;
|
| 2085 |
|
| 2086 | nonseekable_open(inode, filp);
|
| 2087 |
|
| 2088 | retry_open:
|
| 2089 | retval = tty_alloc_file(filp);
|
| 2090 | if (retval)
|
| 2091 | return -ENOMEM;
|
| 2092 |
|
| 2093 | tty = tty_open_current_tty(device, filp);
|
| 2094 | if (!tty)
|
| 2095 | tty = tty_open_by_driver(device, filp);
|
| 2096 |
|
| 2097 | if (IS_ERR(tty)) {
|
| 2098 | tty_free_file(filp);
|
| 2099 | retval = PTR_ERR(tty);
|
| 2100 | if (retval != -EAGAIN || signal_pending(current))
|
| 2101 | return retval;
|
| 2102 | schedule();
|
| 2103 | goto retry_open;
|
| 2104 | }
|
| 2105 |
|
| 2106 | tty_add_file(tty, filp);
|
| 2107 |
|
| 2108 | check_tty_count(tty, __func__);
|
| 2109 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count);
|
| 2110 |
|
| 2111 | if (tty->ops->open)
|
| 2112 | retval = tty->ops->open(tty, filp);
|
| 2113 | else
|
| 2114 | retval = -ENODEV;
|
| 2115 | filp->f_flags = saved_flags;
|
| 2116 |
|
| 2117 | if (retval) {
|
| 2118 | tty_debug_hangup(tty, "open error %d, releasing\n", retval);
|
| 2119 |
|
| 2120 | tty_unlock(tty);
|
| 2121 | tty_release(inode, filp);
|
| 2122 | if (retval != -ERESTARTSYS)
|
| 2123 | return retval;
|
| 2124 |
|
| 2125 | if (signal_pending(current))
|
| 2126 | return retval;
|
| 2127 |
|
| 2128 | schedule();
|
| 2129 | |
| 2130 | * Need to reset f_op in case a hangup happened.
|
| 2131 |
|
| 2132 | if (tty_hung_up_p(filp))
|
| 2133 | filp->f_op = &tty_fops;
|
| 2134 | goto retry_open;
|
| 2135 | }
|
| 2136 | clear_bit(TTY_HUPPED, &tty->flags);
|
| 2137 |
|
| 2138 | noctty = (filp->f_flags & O_NOCTTY) ||
|
| 2139 | (IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) ||
|
| 2140 | device == MKDEV(TTYAUX_MAJOR, 1) ||
|
| 2141 | (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
| 2142 | tty->driver->subtype == PTY_TYPE_MASTER);
|
| 2143 | if (!noctty)
|
| 2144 | tty_open_proc_set_tty(filp, tty);
|
| 2145 | tty_unlock(tty);
|
| 2146 | return 0;
|
| 2147 | }
|
| 2148 |
|
| 2149 |
|
| 2150 | |
| 2151 | * tty_poll - check tty status
|
| 2152 | * @filp: file being polled
|
| 2153 | * @wait: poll wait structures to update
|
| 2154 | *
|
| 2155 | * Call the line discipline polling method to obtain the poll status of the
|
| 2156 | * device.
|
| 2157 | *
|
| 2158 | * Locking: locks called line discipline but ldisc poll method may be
|
| 2159 | * re-entered freely by other callers.
|
| 2160 |
|
| 2161 | static __poll_t tty_poll(struct file *filp, poll_table *wait)
|
| 2162 | {
|
| 2163 | struct tty_struct *tty = file_tty(filp);
|
| 2164 | struct tty_ldisc *ld;
|
| 2165 | __poll_t ret = 0;
|
| 2166 |
|
| 2167 | if (tty_paranoia_check(tty, file_inode(filp), "tty_poll"))
|
| 2168 | return 0;
|
| 2169 |
|
| 2170 | ld = tty_ldisc_ref_wait(tty);
|
| 2171 | if (!ld)
|
| 2172 | return hung_up_tty_poll(filp, wait);
|
| 2173 | if (ld->ops->poll)
|
| 2174 | ret = ld->ops->poll(tty, filp, wait);
|
| 2175 | tty_ldisc_deref(ld);
|
| 2176 | return ret;
|
| 2177 | }
|
| 2178 |
|
| 2179 | static int __tty_fasync(int fd, struct file *filp, int on)
|
| 2180 | {
|
| 2181 | struct tty_struct *tty = file_tty(filp);
|
| 2182 | unsigned long flags;
|
| 2183 | int retval = 0;
|
| 2184 |
|
| 2185 | if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync"))
|
| 2186 | goto out;
|
| 2187 |
|
| 2188 | if (on) {
|
| 2189 | retval = file_f_owner_allocate(filp);
|
| 2190 | if (retval)
|
| 2191 | goto out;
|
| 2192 | }
|
| 2193 |
|
| 2194 | retval = fasync_helper(fd, filp, on, &tty->fasync);
|
| 2195 | if (retval <= 0)
|
| 2196 | goto out;
|
| 2197 |
|
| 2198 | if (on) {
|
| 2199 | enum pid_type type;
|
| 2200 | struct pid *pid;
|
| 2201 |
|
| 2202 | spin_lock_irqsave(&tty->ctrl.lock, flags);
|
| 2203 | if (tty->ctrl.pgrp) {
|
| 2204 | pid = tty->ctrl.pgrp;
|
| 2205 | type = PIDTYPE_PGID;
|
| 2206 | } else {
|
| 2207 | pid = task_pid(current);
|
| 2208 | type = PIDTYPE_TGID;
|
| 2209 | }
|
| 2210 | get_pid(pid);
|
| 2211 | spin_unlock_irqrestore(&tty->ctrl.lock, flags);
|
| 2212 | __f_setown(filp, pid, type, 0);
|
| 2213 | put_pid(pid);
|
| 2214 | retval = 0;
|
| 2215 | }
|
| 2216 | out:
|
| 2217 | return retval;
|
| 2218 | }
|
| 2219 |
|
| 2220 | static int tty_fasync(int fd, struct file *filp, int on)
|
| 2221 | {
|
| 2222 | struct tty_struct *tty = file_tty(filp);
|
| 2223 | int retval = -ENOTTY;
|
| 2224 |
|
| 2225 | tty_lock(tty);
|
| 2226 | if (!tty_hung_up_p(filp))
|
| 2227 | retval = __tty_fasync(fd, filp, on);
|
| 2228 | tty_unlock(tty);
|
| 2229 |
|
| 2230 | return retval;
|
| 2231 | }
|
| 2232 |
|
| 2233 | static bool tty_legacy_tiocsti __read_mostly = IS_ENABLED(CONFIG_LEGACY_TIOCSTI);
|
| 2234 | |
| 2235 | * tiocsti - fake input character
|
| 2236 | * @tty: tty to fake input into
|
| 2237 | * @p: pointer to character
|
| 2238 | *
|
| 2239 | * Fake input to a tty device. Does the necessary locking and input management.
|
| 2240 | *
|
| 2241 | * FIXME: does not honour flow control ??
|
| 2242 | *
|
| 2243 | * Locking:
|
| 2244 | * * Called functions take tty_ldiscs_lock
|
| 2245 | * * current->signal->tty check is safe without locks
|
| 2246 |
|
| 2247 | static int tiocsti(struct tty_struct *tty, u8 __user *p)
|
| 2248 | {
|
| 2249 | struct tty_ldisc *ld;
|
| 2250 | u8 ch;
|
| 2251 |
|
| 2252 | if (!tty_legacy_tiocsti && !capable(CAP_SYS_ADMIN))
|
| 2253 | return -EIO;
|
| 2254 |
|
| 2255 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN))
|
| 2256 | return -EPERM;
|
| 2257 | if (get_user(ch, p))
|
| 2258 | return -EFAULT;
|
| 2259 | tty_audit_tiocsti(tty, ch);
|
| 2260 | ld = tty_ldisc_ref_wait(tty);
|
| 2261 | if (!ld)
|
| 2262 | return -EIO;
|
| 2263 | tty_buffer_lock_exclusive(tty->port);
|
| 2264 | if (ld->ops->receive_buf)
|
| 2265 | ld->ops->receive_buf(tty, &ch, NULL, 1);
|
| 2266 | tty_buffer_unlock_exclusive(tty->port);
|
| 2267 | tty_ldisc_deref(ld);
|
| 2268 | return 0;
|
| 2269 | }
|
| 2270 |
|
| 2271 | |
| 2272 | * tiocgwinsz - implement window query ioctl
|
| 2273 | * @tty: tty
|
| 2274 | * @arg: user buffer for result
|
| 2275 | *
|
| 2276 | * Copies the kernel idea of the window size into the user buffer.
|
| 2277 | *
|
| 2278 | * Locking: @tty->winsize_mutex is taken to ensure the winsize data is
|
| 2279 | * consistent.
|
| 2280 |
|
| 2281 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg)
|
| 2282 | {
|
| 2283 | guard(mutex)(&tty->winsize_mutex);
|
| 2284 |
|
| 2285 | if (copy_to_user(arg, &tty->winsize, sizeof(*arg)))
|
| 2286 | return -EFAULT;
|
| 2287 |
|
| 2288 | return 0;
|
| 2289 | }
|
| 2290 |
|
| 2291 | |
| 2292 | * tty_do_resize - resize event
|
| 2293 | * @tty: tty being resized
|
| 2294 | * @ws: new dimensions
|
| 2295 | *
|
| 2296 | * Update the termios variables and send the necessary signals to peform a
|
| 2297 | * terminal resize correctly.
|
| 2298 |
|
| 2299 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws)
|
| 2300 | {
|
| 2301 | struct pid *pgrp;
|
| 2302 |
|
| 2303 | guard(mutex)(&tty->winsize_mutex);
|
| 2304 |
|
| 2305 | if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
|
| 2306 | return 0;
|
| 2307 |
|
| 2308 |
|
| 2309 | pgrp = tty_get_pgrp(tty);
|
| 2310 | if (pgrp)
|
| 2311 | kill_pgrp(pgrp, SIGWINCH, 1);
|
| 2312 | put_pid(pgrp);
|
| 2313 |
|
| 2314 | tty->winsize = *ws;
|
| 2315 |
|
| 2316 | return 0;
|
| 2317 | }
|
| 2318 | EXPORT_SYMBOL(tty_do_resize);
|
| 2319 |
|
| 2320 | |
| 2321 | * tiocswinsz - implement window size set ioctl
|
| 2322 | * @tty: tty side of tty
|
| 2323 | * @arg: user buffer for result
|
| 2324 | *
|
| 2325 | * Copies the user idea of the window size to the kernel. Traditionally this is
|
| 2326 | * just advisory information but for the Linux console it actually has driver
|
| 2327 | * level meaning and triggers a VC resize.
|
| 2328 | *
|
| 2329 | * Locking:
|
| 2330 | * Driver dependent. The default do_resize method takes the tty termios
|
| 2331 | * mutex and ctrl.lock. The console takes its own lock then calls into the
|
| 2332 | * default method.
|
| 2333 |
|
| 2334 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg)
|
| 2335 | {
|
| 2336 | struct winsize tmp_ws;
|
| 2337 |
|
| 2338 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg)))
|
| 2339 | return -EFAULT;
|
| 2340 |
|
| 2341 | if (tty->ops->resize)
|
| 2342 | return tty->ops->resize(tty, &tmp_ws);
|
| 2343 | else
|
| 2344 | return tty_do_resize(tty, &tmp_ws);
|
| 2345 | }
|
| 2346 |
|
| 2347 | |
| 2348 | * tioccons - allow admin to move logical console
|
| 2349 | * @file: the file to become console
|
| 2350 | *
|
| 2351 | * Allow the administrator to move the redirected console device.
|
| 2352 | *
|
| 2353 | * Locking: uses redirect_lock to guard the redirect information
|
| 2354 |
|
| 2355 | static int tioccons(struct file *file)
|
| 2356 | {
|
| 2357 | if (!capable(CAP_SYS_ADMIN))
|
| 2358 | return -EPERM;
|
| 2359 | if (file->f_op->write_iter == redirected_tty_write) {
|
| 2360 | struct file *f;
|
| 2361 |
|
| 2362 | spin_lock(&redirect_lock);
|
| 2363 | f = redirect;
|
| 2364 | redirect = NULL;
|
| 2365 | spin_unlock(&redirect_lock);
|
| 2366 | if (f)
|
| 2367 | fput(f);
|
| 2368 | return 0;
|
| 2369 | }
|
| 2370 | if (file->f_op->write_iter != tty_write)
|
| 2371 | return -ENOTTY;
|
| 2372 | if (!(file->f_mode & FMODE_WRITE))
|
| 2373 | return -EBADF;
|
| 2374 | if (!(file->f_mode & FMODE_CAN_WRITE))
|
| 2375 | return -EINVAL;
|
| 2376 |
|
| 2377 | guard(spinlock)(&redirect_lock);
|
| 2378 |
|
| 2379 | if (redirect)
|
| 2380 | return -EBUSY;
|
| 2381 |
|
| 2382 | redirect = get_file(file);
|
| 2383 |
|
| 2384 | return 0;
|
| 2385 | }
|
| 2386 |
|
| 2387 | |
| 2388 | * tiocsetd - set line discipline
|
| 2389 | * @tty: tty device
|
| 2390 | * @p: pointer to user data
|
| 2391 | *
|
| 2392 | * Set the line discipline according to user request.
|
| 2393 | *
|
| 2394 | * Locking: see tty_set_ldisc(), this function is just a helper
|
| 2395 |
|
| 2396 | static int tiocsetd(struct tty_struct *tty, int __user *p)
|
| 2397 | {
|
| 2398 | int disc;
|
| 2399 | int ret;
|
| 2400 |
|
| 2401 | if (get_user(disc, p))
|
| 2402 | return -EFAULT;
|
| 2403 |
|
| 2404 | ret = tty_set_ldisc(tty, disc);
|
| 2405 |
|
| 2406 | return ret;
|
| 2407 | }
|
| 2408 |
|
| 2409 | |
| 2410 | * tiocgetd - get line discipline
|
| 2411 | * @tty: tty device
|
| 2412 | * @p: pointer to user data
|
| 2413 | *
|
| 2414 | * Retrieves the line discipline id directly from the ldisc.
|
| 2415 | *
|
| 2416 | * Locking: waits for ldisc reference (in case the line discipline is changing
|
| 2417 | * or the @tty is being hungup)
|
| 2418 |
|
| 2419 | static int tiocgetd(struct tty_struct *tty, int __user *p)
|
| 2420 | {
|
| 2421 | struct tty_ldisc *ld;
|
| 2422 | int ret;
|
| 2423 |
|
| 2424 | ld = tty_ldisc_ref_wait(tty);
|
| 2425 | if (!ld)
|
| 2426 | return -EIO;
|
| 2427 | ret = put_user(ld->ops->num, p);
|
| 2428 | tty_ldisc_deref(ld);
|
| 2429 | return ret;
|
| 2430 | }
|
| 2431 |
|
| 2432 | |
| 2433 | * send_break - performed time break
|
| 2434 | * @tty: device to break on
|
| 2435 | * @duration: timeout in mS
|
| 2436 | * @file: file object
|
| 2437 | *
|
| 2438 | * Perform a timed break on hardware that lacks its own driver level timed
|
| 2439 | * break functionality.
|
| 2440 | *
|
| 2441 | * Locking:
|
| 2442 | * @tty->atomic_write_lock serializes
|
| 2443 |
|
| 2444 | static int send_break(struct file *file, struct tty_struct *tty, unsigned int duration)
|
| 2445 | {
|
| 2446 | long timeout;
|
| 2447 | int retval;
|
| 2448 |
|
| 2449 | if (tty->ops->break_ctl == NULL)
|
| 2450 | return 0;
|
| 2451 |
|
| 2452 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
|
| 2453 | return tty->ops->break_ctl(tty, duration);
|
| 2454 |
|
| 2455 |
|
| 2456 | if (tty_write_lock(tty, false) < 0)
|
| 2457 | return -EINTR;
|
| 2458 |
|
| 2459 | retval = tty->ops->break_ctl(tty, -1);
|
| 2460 | if (retval) {
|
| 2461 | if (retval == -EOPNOTSUPP) {
|
| 2462 |
|
| 2463 | retval = 0;
|
| 2464 | }
|
| 2465 | goto out_unlock;
|
| 2466 | }
|
| 2467 |
|
| 2468 | timeout = msecs_to_jiffies(duration);
|
| 2469 | timeout = wait_event_interruptible_timeout(tty->break_wait,
|
| 2470 | tty_hung_up_p(file),
|
| 2471 | timeout);
|
| 2472 |
|
| 2473 | if (timeout > 0) {
|
| 2474 | retval = -EIO;
|
| 2475 | goto out_unlock;
|
| 2476 | }
|
| 2477 |
|
| 2478 | retval = tty->ops->break_ctl(tty, 0);
|
| 2479 | out_unlock:
|
| 2480 | tty_write_unlock(tty);
|
| 2481 |
|
| 2482 | if (signal_pending(current))
|
| 2483 | retval = -EINTR;
|
| 2484 |
|
| 2485 | return retval;
|
| 2486 | }
|
| 2487 |
|
| 2488 | |
| 2489 | * tty_get_tiocm - get tiocm status register
|
| 2490 | * @tty: tty device
|
| 2491 | *
|
| 2492 | * Obtain the modem status bits from the tty driver if the feature
|
| 2493 | * is supported.
|
| 2494 |
|
| 2495 | int tty_get_tiocm(struct tty_struct *tty)
|
| 2496 | {
|
| 2497 | int retval = -ENOTTY;
|
| 2498 |
|
| 2499 | if (tty->ops->tiocmget)
|
| 2500 | retval = tty->ops->tiocmget(tty);
|
| 2501 |
|
| 2502 | return retval;
|
| 2503 | }
|
| 2504 | EXPORT_SYMBOL_GPL(tty_get_tiocm);
|
| 2505 |
|
| 2506 | |
| 2507 | * tty_tiocmget - get modem status
|
| 2508 | * @tty: tty device
|
| 2509 | * @p: pointer to result
|
| 2510 | *
|
| 2511 | * Obtain the modem status bits from the tty driver if the feature is
|
| 2512 | * supported. Return -%ENOTTY if it is not available.
|
| 2513 | *
|
| 2514 | * Locking: none (up to the driver)
|
| 2515 |
|
| 2516 | static int tty_tiocmget(struct tty_struct *tty, int __user *p)
|
| 2517 | {
|
| 2518 | int retval;
|
| 2519 |
|
| 2520 | retval = tty_get_tiocm(tty);
|
| 2521 | if (retval >= 0)
|
| 2522 | retval = put_user(retval, p);
|
| 2523 |
|
| 2524 | return retval;
|
| 2525 | }
|
| 2526 |
|
| 2527 | |
| 2528 | * tty_tiocmset - set modem status
|
| 2529 | * @tty: tty device
|
| 2530 | * @cmd: command - clear bits, set bits or set all
|
| 2531 | * @p: pointer to desired bits
|
| 2532 | *
|
| 2533 | * Set the modem status bits from the tty driver if the feature
|
| 2534 | * is supported. Return -%ENOTTY if it is not available.
|
| 2535 | *
|
| 2536 | * Locking: none (up to the driver)
|
| 2537 |
|
| 2538 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd,
|
| 2539 | unsigned __user *p)
|
| 2540 | {
|
| 2541 | int retval;
|
| 2542 | unsigned int set, clear, val;
|
| 2543 |
|
| 2544 | if (tty->ops->tiocmset == NULL)
|
| 2545 | return -ENOTTY;
|
| 2546 |
|
| 2547 | retval = get_user(val, p);
|
| 2548 | if (retval)
|
| 2549 | return retval;
|
| 2550 | set = clear = 0;
|
| 2551 | switch (cmd) {
|
| 2552 | case TIOCMBIS:
|
| 2553 | set = val;
|
| 2554 | break;
|
| 2555 | case TIOCMBIC:
|
| 2556 | clear = val;
|
| 2557 | break;
|
| 2558 | case TIOCMSET:
|
| 2559 | set = val;
|
| 2560 | clear = ~val;
|
| 2561 | break;
|
| 2562 | }
|
| 2563 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
|
| 2564 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP;
|
| 2565 | return tty->ops->tiocmset(tty, set, clear);
|
| 2566 | }
|
| 2567 |
|
| 2568 | |
| 2569 | * tty_get_icount - get tty statistics
|
| 2570 | * @tty: tty device
|
| 2571 | * @icount: output parameter
|
| 2572 | *
|
| 2573 | * Gets a copy of the @tty's icount statistics.
|
| 2574 | *
|
| 2575 | * Locking: none (up to the driver)
|
| 2576 |
|
| 2577 | int tty_get_icount(struct tty_struct *tty,
|
| 2578 | struct serial_icounter_struct *icount)
|
| 2579 | {
|
| 2580 | memset(icount, 0, sizeof(*icount));
|
| 2581 |
|
| 2582 | if (tty->ops->get_icount)
|
| 2583 | return tty->ops->get_icount(tty, icount);
|
| 2584 | else
|
| 2585 | return -ENOTTY;
|
| 2586 | }
|
| 2587 | EXPORT_SYMBOL_GPL(tty_get_icount);
|
| 2588 |
|
| 2589 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
|
| 2590 | {
|
| 2591 | struct serial_icounter_struct icount;
|
| 2592 | int retval;
|
| 2593 |
|
| 2594 | retval = tty_get_icount(tty, &icount);
|
| 2595 | if (retval != 0)
|
| 2596 | return retval;
|
| 2597 |
|
| 2598 | if (copy_to_user(arg, &icount, sizeof(icount)))
|
| 2599 | return -EFAULT;
|
| 2600 | return 0;
|
| 2601 | }
|
| 2602 |
|
| 2603 | static int tty_set_serial(struct tty_struct *tty, struct serial_struct *ss)
|
| 2604 | {
|
| 2605 | int flags;
|
| 2606 |
|
| 2607 | flags = ss->flags & ASYNC_DEPRECATED;
|
| 2608 |
|
| 2609 | if (flags)
|
| 2610 | pr_warn_ratelimited("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n",
|
| 2611 | __func__, current->comm, flags);
|
| 2612 |
|
| 2613 | if (!tty->ops->set_serial)
|
| 2614 | return -ENOTTY;
|
| 2615 |
|
| 2616 | return tty->ops->set_serial(tty, ss);
|
| 2617 | }
|
| 2618 |
|
| 2619 | static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss)
|
| 2620 | {
|
| 2621 | struct serial_struct v;
|
| 2622 |
|
| 2623 | if (copy_from_user(&v, ss, sizeof(*ss)))
|
| 2624 | return -EFAULT;
|
| 2625 |
|
| 2626 | return tty_set_serial(tty, &v);
|
| 2627 | }
|
| 2628 |
|
| 2629 | static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss)
|
| 2630 | {
|
| 2631 | struct serial_struct v;
|
| 2632 | int err;
|
| 2633 |
|
| 2634 | memset(&v, 0, sizeof(v));
|
| 2635 | if (!tty->ops->get_serial)
|
| 2636 | return -ENOTTY;
|
| 2637 | err = tty->ops->get_serial(tty, &v);
|
| 2638 | if (!err && copy_to_user(ss, &v, sizeof(v)))
|
| 2639 | err = -EFAULT;
|
| 2640 | return err;
|
| 2641 | }
|
| 2642 |
|
| 2643 | |
| 2644 | * if pty, return the slave side (real_tty)
|
| 2645 | * otherwise, return self
|
| 2646 |
|
| 2647 | static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty)
|
| 2648 | {
|
| 2649 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
| 2650 | tty->driver->subtype == PTY_TYPE_MASTER)
|
| 2651 | tty = tty->link;
|
| 2652 | return tty;
|
| 2653 | }
|
| 2654 |
|
| 2655 | |
| 2656 | * Split this up, as gcc can choke on it otherwise..
|
| 2657 |
|
| 2658 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
| 2659 | {
|
| 2660 | struct tty_struct *tty = file_tty(file);
|
| 2661 | struct tty_struct *real_tty;
|
| 2662 | void __user *p = (void __user *)arg;
|
| 2663 | int retval;
|
| 2664 | struct tty_ldisc *ld;
|
| 2665 |
|
| 2666 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
|
| 2667 | return -EINVAL;
|
| 2668 |
|
| 2669 | real_tty = tty_pair_get_tty(tty);
|
| 2670 |
|
| 2671 | |
| 2672 | * Factor out some common prep work
|
| 2673 |
|
| 2674 | switch (cmd) {
|
| 2675 | case TIOCSETD:
|
| 2676 | case TIOCSBRK:
|
| 2677 | case TIOCCBRK:
|
| 2678 | case TCSBRK:
|
| 2679 | case TCSBRKP:
|
| 2680 | retval = tty_check_change(tty);
|
| 2681 | if (retval)
|
| 2682 | return retval;
|
| 2683 | if (cmd != TIOCCBRK) {
|
| 2684 | tty_wait_until_sent(tty, 0);
|
| 2685 | if (signal_pending(current))
|
| 2686 | return -EINTR;
|
| 2687 | }
|
| 2688 | break;
|
| 2689 | }
|
| 2690 |
|
| 2691 | |
| 2692 | * Now do the stuff.
|
| 2693 |
|
| 2694 | switch (cmd) {
|
| 2695 | case TIOCSTI:
|
| 2696 | return tiocsti(tty, p);
|
| 2697 | case TIOCGWINSZ:
|
| 2698 | return tiocgwinsz(real_tty, p);
|
| 2699 | case TIOCSWINSZ:
|
| 2700 | return tiocswinsz(real_tty, p);
|
| 2701 | case TIOCCONS:
|
| 2702 | return real_tty != tty ? -EINVAL : tioccons(file);
|
| 2703 | case TIOCEXCL:
|
| 2704 | set_bit(TTY_EXCLUSIVE, &tty->flags);
|
| 2705 | return 0;
|
| 2706 | case TIOCNXCL:
|
| 2707 | clear_bit(TTY_EXCLUSIVE, &tty->flags);
|
| 2708 | return 0;
|
| 2709 | case TIOCGEXCL:
|
| 2710 | {
|
| 2711 | int excl = test_bit(TTY_EXCLUSIVE, &tty->flags);
|
| 2712 |
|
| 2713 | return put_user(excl, (int __user *)p);
|
| 2714 | }
|
| 2715 | case TIOCGETD:
|
| 2716 | return tiocgetd(tty, p);
|
| 2717 | case TIOCSETD:
|
| 2718 | return tiocsetd(tty, p);
|
| 2719 | case TIOCVHANGUP:
|
| 2720 | if (!capable(CAP_SYS_ADMIN))
|
| 2721 | return -EPERM;
|
| 2722 | tty_vhangup(tty);
|
| 2723 | return 0;
|
| 2724 | case TIOCGDEV:
|
| 2725 | {
|
| 2726 | unsigned int ret = new_encode_dev(tty_devnum(real_tty));
|
| 2727 |
|
| 2728 | return put_user(ret, (unsigned int __user *)p);
|
| 2729 | }
|
| 2730 | |
| 2731 | * Break handling
|
| 2732 |
|
| 2733 | case TIOCSBRK:
|
| 2734 | if (tty->ops->break_ctl)
|
| 2735 | return tty->ops->break_ctl(tty, -1);
|
| 2736 | return 0;
|
| 2737 | case TIOCCBRK:
|
| 2738 | if (tty->ops->break_ctl)
|
| 2739 | return tty->ops->break_ctl(tty, 0);
|
| 2740 | return 0;
|
| 2741 | case TCSBRK:
|
| 2742 | |
| 2743 | * to be sent (performed above) but don't send break.
|
| 2744 | * This is used by the tcdrain() termios function.
|
| 2745 |
|
| 2746 | if (!arg)
|
| 2747 | return send_break(file, tty, 250);
|
| 2748 | return 0;
|
| 2749 | case TCSBRKP:
|
| 2750 | return send_break(file, tty, arg ? arg * 100 : 250);
|
| 2751 |
|
| 2752 | case TIOCMGET:
|
| 2753 | return tty_tiocmget(tty, p);
|
| 2754 | case TIOCMSET:
|
| 2755 | case TIOCMBIC:
|
| 2756 | case TIOCMBIS:
|
| 2757 | return tty_tiocmset(tty, cmd, p);
|
| 2758 | case TIOCGICOUNT:
|
| 2759 | return tty_tiocgicount(tty, p);
|
| 2760 | case TCFLSH:
|
| 2761 | switch (arg) {
|
| 2762 | case TCIFLUSH:
|
| 2763 | case TCIOFLUSH:
|
| 2764 |
|
| 2765 | tty_buffer_flush(tty, NULL);
|
| 2766 | break;
|
| 2767 | }
|
| 2768 | break;
|
| 2769 | case TIOCSSERIAL:
|
| 2770 | return tty_tiocsserial(tty, p);
|
| 2771 | case TIOCGSERIAL:
|
| 2772 | return tty_tiocgserial(tty, p);
|
| 2773 | case TIOCGPTPEER:
|
| 2774 |
|
| 2775 | return ptm_open_peer(file, tty, (int)arg);
|
| 2776 | default:
|
| 2777 | retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg);
|
| 2778 | if (retval != -ENOIOCTLCMD)
|
| 2779 | return retval;
|
| 2780 | }
|
| 2781 | if (tty->ops->ioctl) {
|
| 2782 | retval = tty->ops->ioctl(tty, cmd, arg);
|
| 2783 | if (retval != -ENOIOCTLCMD)
|
| 2784 | return retval;
|
| 2785 | }
|
| 2786 | ld = tty_ldisc_ref_wait(tty);
|
| 2787 | if (!ld)
|
| 2788 | return hung_up_tty_ioctl(file, cmd, arg);
|
| 2789 | retval = -EINVAL;
|
| 2790 | if (ld->ops->ioctl) {
|
| 2791 | retval = ld->ops->ioctl(tty, cmd, arg);
|
| 2792 | if (retval == -ENOIOCTLCMD)
|
| 2793 | retval = -ENOTTY;
|
| 2794 | }
|
| 2795 | tty_ldisc_deref(ld);
|
| 2796 | return retval;
|
| 2797 | }
|
| 2798 |
|
| 2799 | #ifdef CONFIG_COMPAT
|
| 2800 |
|
| 2801 | struct serial_struct32 {
|
| 2802 | compat_int_t type;
|
| 2803 | compat_int_t line;
|
| 2804 | compat_uint_t port;
|
| 2805 | compat_int_t irq;
|
| 2806 | compat_int_t flags;
|
| 2807 | compat_int_t xmit_fifo_size;
|
| 2808 | compat_int_t custom_divisor;
|
| 2809 | compat_int_t baud_base;
|
| 2810 | unsigned short close_delay;
|
| 2811 | char io_type;
|
| 2812 | char reserved_char;
|
| 2813 | compat_int_t hub6;
|
| 2814 | unsigned short closing_wait;
|
| 2815 | unsigned short closing_wait2;
|
| 2816 | compat_uint_t iomem_base;
|
| 2817 | unsigned short iomem_reg_shift;
|
| 2818 | unsigned int port_high;
|
| 2819 |
|
| 2820 | compat_int_t reserved;
|
| 2821 | };
|
| 2822 |
|
| 2823 | static int compat_tty_tiocsserial(struct tty_struct *tty,
|
| 2824 | struct serial_struct32 __user *ss)
|
| 2825 | {
|
| 2826 | struct serial_struct32 v32;
|
| 2827 | struct serial_struct v;
|
| 2828 |
|
| 2829 | if (copy_from_user(&v32, ss, sizeof(*ss)))
|
| 2830 | return -EFAULT;
|
| 2831 |
|
| 2832 | memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base));
|
| 2833 | v.iomem_base = compat_ptr(v32.iomem_base);
|
| 2834 | v.iomem_reg_shift = v32.iomem_reg_shift;
|
| 2835 | v.port_high = v32.port_high;
|
| 2836 | v.iomap_base = 0;
|
| 2837 |
|
| 2838 | return tty_set_serial(tty, &v);
|
| 2839 | }
|
| 2840 |
|
| 2841 | static int compat_tty_tiocgserial(struct tty_struct *tty,
|
| 2842 | struct serial_struct32 __user *ss)
|
| 2843 | {
|
| 2844 | struct serial_struct32 v32;
|
| 2845 | struct serial_struct v;
|
| 2846 | int err;
|
| 2847 |
|
| 2848 | memset(&v, 0, sizeof(v));
|
| 2849 | memset(&v32, 0, sizeof(v32));
|
| 2850 |
|
| 2851 | if (!tty->ops->get_serial)
|
| 2852 | return -ENOTTY;
|
| 2853 | err = tty->ops->get_serial(tty, &v);
|
| 2854 | if (!err) {
|
| 2855 | memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base));
|
| 2856 | v32.iomem_base = (unsigned long)v.iomem_base >> 32 ?
|
| 2857 | 0xfffffff : ptr_to_compat(v.iomem_base);
|
| 2858 | v32.iomem_reg_shift = v.iomem_reg_shift;
|
| 2859 | v32.port_high = v.port_high;
|
| 2860 | if (copy_to_user(ss, &v32, sizeof(v32)))
|
| 2861 | err = -EFAULT;
|
| 2862 | }
|
| 2863 | return err;
|
| 2864 | }
|
| 2865 | static long tty_compat_ioctl(struct file *file, unsigned int cmd,
|
| 2866 | unsigned long arg)
|
| 2867 | {
|
| 2868 | struct tty_struct *tty = file_tty(file);
|
| 2869 | struct tty_ldisc *ld;
|
| 2870 | int retval = -ENOIOCTLCMD;
|
| 2871 |
|
| 2872 | switch (cmd) {
|
| 2873 | case TIOCOUTQ:
|
| 2874 | case TIOCSTI:
|
| 2875 | case TIOCGWINSZ:
|
| 2876 | case TIOCSWINSZ:
|
| 2877 | case TIOCGEXCL:
|
| 2878 | case TIOCGETD:
|
| 2879 | case TIOCSETD:
|
| 2880 | case TIOCGDEV:
|
| 2881 | case TIOCMGET:
|
| 2882 | case TIOCMSET:
|
| 2883 | case TIOCMBIC:
|
| 2884 | case TIOCMBIS:
|
| 2885 | case TIOCGICOUNT:
|
| 2886 | case TIOCGPGRP:
|
| 2887 | case TIOCSPGRP:
|
| 2888 | case TIOCGSID:
|
| 2889 | case TIOCSERGETLSR:
|
| 2890 | case TIOCGRS485:
|
| 2891 | case TIOCSRS485:
|
| 2892 | #ifdef TIOCGETP
|
| 2893 | case TIOCGETP:
|
| 2894 | case TIOCSETP:
|
| 2895 | case TIOCSETN:
|
| 2896 | #endif
|
| 2897 | #ifdef TIOCGETC
|
| 2898 | case TIOCGETC:
|
| 2899 | case TIOCSETC:
|
| 2900 | #endif
|
| 2901 | #ifdef TIOCGLTC
|
| 2902 | case TIOCGLTC:
|
| 2903 | case TIOCSLTC:
|
| 2904 | #endif
|
| 2905 | case TCSETSF:
|
| 2906 | case TCSETSW:
|
| 2907 | case TCSETS:
|
| 2908 | case TCGETS:
|
| 2909 | #ifdef TCGETS2
|
| 2910 | case TCGETS2:
|
| 2911 | case TCSETSF2:
|
| 2912 | case TCSETSW2:
|
| 2913 | case TCSETS2:
|
| 2914 | #endif
|
| 2915 | case TCGETA:
|
| 2916 | case TCSETAF:
|
| 2917 | case TCSETAW:
|
| 2918 | case TCSETA:
|
| 2919 | case TIOCGLCKTRMIOS:
|
| 2920 | case TIOCSLCKTRMIOS:
|
| 2921 | #ifdef TCGETX
|
| 2922 | case TCGETX:
|
| 2923 | case TCSETX:
|
| 2924 | case TCSETXW:
|
| 2925 | case TCSETXF:
|
| 2926 | #endif
|
| 2927 | case TIOCGSOFTCAR:
|
| 2928 | case TIOCSSOFTCAR:
|
| 2929 |
|
| 2930 | case PPPIOCGCHAN:
|
| 2931 | case PPPIOCGUNIT:
|
| 2932 | return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
|
| 2933 | case TIOCCONS:
|
| 2934 | case TIOCEXCL:
|
| 2935 | case TIOCNXCL:
|
| 2936 | case TIOCVHANGUP:
|
| 2937 | case TIOCSBRK:
|
| 2938 | case TIOCCBRK:
|
| 2939 | case TCSBRK:
|
| 2940 | case TCSBRKP:
|
| 2941 | case TCFLSH:
|
| 2942 | case TIOCGPTPEER:
|
| 2943 | case TIOCNOTTY:
|
| 2944 | case TIOCSCTTY:
|
| 2945 | case TCXONC:
|
| 2946 | case TIOCMIWAIT:
|
| 2947 | case TIOCSERCONFIG:
|
| 2948 | return tty_ioctl(file, cmd, arg);
|
| 2949 | }
|
| 2950 |
|
| 2951 | if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
|
| 2952 | return -EINVAL;
|
| 2953 |
|
| 2954 | switch (cmd) {
|
| 2955 | case TIOCSSERIAL:
|
| 2956 | return compat_tty_tiocsserial(tty, compat_ptr(arg));
|
| 2957 | case TIOCGSERIAL:
|
| 2958 | return compat_tty_tiocgserial(tty, compat_ptr(arg));
|
| 2959 | }
|
| 2960 | if (tty->ops->compat_ioctl) {
|
| 2961 | retval = tty->ops->compat_ioctl(tty, cmd, arg);
|
| 2962 | if (retval != -ENOIOCTLCMD)
|
| 2963 | return retval;
|
| 2964 | }
|
| 2965 |
|
| 2966 | ld = tty_ldisc_ref_wait(tty);
|
| 2967 | if (!ld)
|
| 2968 | return hung_up_tty_compat_ioctl(file, cmd, arg);
|
| 2969 | if (ld->ops->compat_ioctl)
|
| 2970 | retval = ld->ops->compat_ioctl(tty, cmd, arg);
|
| 2971 | if (retval == -ENOIOCTLCMD && ld->ops->ioctl)
|
| 2972 | retval = ld->ops->ioctl(tty, (unsigned long)compat_ptr(cmd),
|
| 2973 | arg);
|
| 2974 | tty_ldisc_deref(ld);
|
| 2975 |
|
| 2976 | return retval;
|
| 2977 | }
|
| 2978 | #endif
|
| 2979 |
|
| 2980 | static int this_tty(const void *t, struct file *file, unsigned fd)
|
| 2981 | {
|
| 2982 | if (likely(file->f_op->read_iter != tty_read))
|
| 2983 | return 0;
|
| 2984 | return file_tty(file) != t ? 0 : fd + 1;
|
| 2985 | }
|
| 2986 |
|
| 2987 | |
| 2988 | * This implements the "Secure Attention Key" --- the idea is to
|
| 2989 | * prevent trojan horses by killing all processes associated with this
|
| 2990 | * tty when the user hits the "Secure Attention Key". Required for
|
| 2991 | * super-paranoid applications --- see the Orange Book for more details.
|
| 2992 | *
|
| 2993 | * This code could be nicer; ideally it should send a HUP, wait a few
|
| 2994 | * seconds, then send a INT, and then a KILL signal. But you then
|
| 2995 | * have to coordinate with the init process, since all processes associated
|
| 2996 | * with the current tty must be dead before the new getty is allowed
|
| 2997 | * to spawn.
|
| 2998 | *
|
| 2999 | * Now, if it would be correct ;-/ The current code has a nasty hole -
|
| 3000 | * it doesn't catch files in flight. We may send the descriptor to ourselves
|
| 3001 | * via AF_UNIX socket, close it and later fetch from socket. FIXME.
|
| 3002 | *
|
| 3003 | * Nasty bug: do_SAK is being called in interrupt context. This can
|
| 3004 | * deadlock. We punt it up to process context. AKPM - 16Mar2001
|
| 3005 |
|
| 3006 | void __do_SAK(struct tty_struct *tty)
|
| 3007 | {
|
| 3008 | struct task_struct *g, *p;
|
| 3009 | struct pid *session;
|
| 3010 | int i;
|
| 3011 |
|
| 3012 | scoped_guard(spinlock_irqsave, &tty->ctrl.lock)
|
| 3013 | session = get_pid(tty->ctrl.session);
|
| 3014 |
|
| 3015 | tty_ldisc_flush(tty);
|
| 3016 |
|
| 3017 | tty_driver_flush_buffer(tty);
|
| 3018 |
|
| 3019 | read_lock(&tasklist_lock);
|
| 3020 |
|
| 3021 | do_each_pid_task(session, PIDTYPE_SID, p) {
|
| 3022 | tty_notice(tty, "SAK: killed process %d (%s): by session\n",
|
| 3023 | task_pid_nr(p), p->comm);
|
| 3024 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID);
|
| 3025 | } while_each_pid_task(session, PIDTYPE_SID, p);
|
| 3026 |
|
| 3027 |
|
| 3028 | for_each_process_thread(g, p) {
|
| 3029 | if (p->signal->tty == tty) {
|
| 3030 | tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n",
|
| 3031 | task_pid_nr(p), p->comm);
|
| 3032 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p,
|
| 3033 | PIDTYPE_SID);
|
| 3034 | continue;
|
| 3035 | }
|
| 3036 | guard(task_lock)(p);
|
| 3037 | i = iterate_fd(p->files, 0, this_tty, tty);
|
| 3038 | if (i != 0) {
|
| 3039 | tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n",
|
| 3040 | task_pid_nr(p), p->comm, i - 1);
|
| 3041 | group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p,
|
| 3042 | PIDTYPE_SID);
|
| 3043 | }
|
| 3044 | }
|
| 3045 | read_unlock(&tasklist_lock);
|
| 3046 | put_pid(session);
|
| 3047 | }
|
| 3048 |
|
| 3049 | static void do_SAK_work(struct work_struct *work)
|
| 3050 | {
|
| 3051 | struct tty_struct *tty =
|
| 3052 | container_of(work, struct tty_struct, SAK_work);
|
| 3053 | __do_SAK(tty);
|
| 3054 | }
|
| 3055 |
|
| 3056 | |
| 3057 | * The tq handling here is a little racy - tty->SAK_work may already be queued.
|
| 3058 | * Fortunately we don't need to worry, because if ->SAK_work is already queued,
|
| 3059 | * the values which we write to it will be identical to the values which it
|
| 3060 | * already has. --akpm
|
| 3061 |
|
| 3062 | void do_SAK(struct tty_struct *tty)
|
| 3063 | {
|
| 3064 | if (!tty)
|
| 3065 | return;
|
| 3066 | schedule_work(&tty->SAK_work);
|
| 3067 | }
|
| 3068 | EXPORT_SYMBOL(do_SAK);
|
| 3069 |
|
| 3070 |
|
| 3071 | static struct device *tty_get_device(struct tty_struct *tty)
|
| 3072 | {
|
| 3073 | dev_t devt = tty_devnum(tty);
|
| 3074 |
|
| 3075 | return class_find_device_by_devt(&tty_class, devt);
|
| 3076 | }
|
| 3077 |
|
| 3078 |
|
| 3079 | |
| 3080 | * alloc_tty_struct - allocate a new tty
|
| 3081 | * @driver: driver which will handle the returned tty
|
| 3082 | * @idx: minor of the tty
|
| 3083 | *
|
| 3084 | * This subroutine allocates and initializes a tty structure.
|
| 3085 | *
|
| 3086 | * Locking: none - @tty in question is not exposed at this point
|
| 3087 |
|
| 3088 | struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx)
|
| 3089 | {
|
| 3090 | struct tty_struct *tty;
|
| 3091 |
|
| 3092 | tty = kzalloc_obj(*tty, GFP_KERNEL_ACCOUNT);
|
| 3093 | if (!tty)
|
| 3094 | return NULL;
|
| 3095 |
|
| 3096 | kref_init(&tty->kref);
|
| 3097 | if (tty_ldisc_init(tty)) {
|
| 3098 | kfree(tty);
|
| 3099 | return NULL;
|
| 3100 | }
|
| 3101 | tty->ctrl.session = NULL;
|
| 3102 | tty->ctrl.pgrp = NULL;
|
| 3103 | mutex_init(&tty->legacy_mutex);
|
| 3104 | mutex_init(&tty->throttle_mutex);
|
| 3105 | init_rwsem(&tty->termios_rwsem);
|
| 3106 | mutex_init(&tty->winsize_mutex);
|
| 3107 | init_ldsem(&tty->ldisc_sem);
|
| 3108 | init_waitqueue_head(&tty->write_wait);
|
| 3109 | init_waitqueue_head(&tty->read_wait);
|
| 3110 | init_waitqueue_head(&tty->break_wait);
|
| 3111 | INIT_WORK(&tty->hangup_work, do_tty_hangup);
|
| 3112 | mutex_init(&tty->atomic_write_lock);
|
| 3113 | spin_lock_init(&tty->ctrl.lock);
|
| 3114 | spin_lock_init(&tty->flow.lock);
|
| 3115 | spin_lock_init(&tty->files_lock);
|
| 3116 | INIT_LIST_HEAD(&tty->tty_files);
|
| 3117 | INIT_WORK(&tty->SAK_work, do_SAK_work);
|
| 3118 |
|
| 3119 | tty->driver = driver;
|
| 3120 | tty->ops = driver->ops;
|
| 3121 | tty->index = idx;
|
| 3122 | tty_line_name(driver, idx, tty->name);
|
| 3123 | tty->dev = tty_get_device(tty);
|
| 3124 |
|
| 3125 | return tty;
|
| 3126 | }
|
| 3127 |
|
| 3128 | |
| 3129 | * tty_put_char - write one character to a tty
|
| 3130 | * @tty: tty
|
| 3131 | * @ch: character to write
|
| 3132 | *
|
| 3133 | * Write one byte to the @tty using the provided @tty->ops->put_char() method
|
| 3134 | * if present.
|
| 3135 | *
|
| 3136 | * Note: the specific put_char operation in the driver layer may go
|
| 3137 | * away soon. Don't call it directly, use this method
|
| 3138 | *
|
| 3139 | * Return: the number of characters successfully output.
|
| 3140 |
|
| 3141 | int tty_put_char(struct tty_struct *tty, u8 ch)
|
| 3142 | {
|
| 3143 | if (tty->ops->put_char)
|
| 3144 | return tty->ops->put_char(tty, ch);
|
| 3145 | return tty->ops->write(tty, &ch, 1);
|
| 3146 | }
|
| 3147 | EXPORT_SYMBOL_GPL(tty_put_char);
|
| 3148 |
|
| 3149 | static int tty_cdev_add(struct tty_driver *driver, dev_t dev,
|
| 3150 | unsigned int index, unsigned int count)
|
| 3151 | {
|
| 3152 | int err;
|
| 3153 |
|
| 3154 |
|
| 3155 | driver->cdevs[index] = cdev_alloc();
|
| 3156 | if (!driver->cdevs[index])
|
| 3157 | return -ENOMEM;
|
| 3158 | driver->cdevs[index]->ops = &tty_fops;
|
| 3159 | driver->cdevs[index]->owner = driver->owner;
|
| 3160 | err = cdev_add(driver->cdevs[index], dev, count);
|
| 3161 | if (err) {
|
| 3162 | kobject_put(&driver->cdevs[index]->kobj);
|
| 3163 | driver->cdevs[index] = NULL;
|
| 3164 | }
|
| 3165 | return err;
|
| 3166 | }
|
| 3167 |
|
| 3168 | |
| 3169 | * tty_register_device - register a tty device
|
| 3170 | * @driver: the tty driver that describes the tty device
|
| 3171 | * @index: the index in the tty driver for this tty device
|
| 3172 | * @device: a struct device that is associated with this tty device.
|
| 3173 | * This field is optional, if there is no known struct device
|
| 3174 | * for this tty device it can be set to NULL safely.
|
| 3175 | *
|
| 3176 | * This call is required to be made to register an individual tty device
|
| 3177 | * if the tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If
|
| 3178 | * that bit is not set, this function should not be called by a tty
|
| 3179 | * driver.
|
| 3180 | *
|
| 3181 | * Locking: ??
|
| 3182 | *
|
| 3183 | * Return: A pointer to the struct device for this tty device (or
|
| 3184 | * ERR_PTR(-EFOO) on error).
|
| 3185 |
|
| 3186 | struct device *tty_register_device(struct tty_driver *driver, unsigned index,
|
| 3187 | struct device *device)
|
| 3188 | {
|
| 3189 | return tty_register_device_attr(driver, index, device, NULL, NULL);
|
| 3190 | }
|
| 3191 | EXPORT_SYMBOL(tty_register_device);
|
| 3192 |
|
| 3193 | static void tty_device_create_release(struct device *dev)
|
| 3194 | {
|
| 3195 | dev_dbg(dev, "releasing...\n");
|
| 3196 | kfree(dev);
|
| 3197 | }
|
| 3198 |
|
| 3199 | |
| 3200 | * tty_register_device_attr - register a tty device
|
| 3201 | * @driver: the tty driver that describes the tty device
|
| 3202 | * @index: the index in the tty driver for this tty device
|
| 3203 | * @device: a struct device that is associated with this tty device.
|
| 3204 | * This field is optional, if there is no known struct device
|
| 3205 | * for this tty device it can be set to %NULL safely.
|
| 3206 | * @drvdata: Driver data to be set to device.
|
| 3207 | * @attr_grp: Attribute group to be set on device.
|
| 3208 | *
|
| 3209 | * This call is required to be made to register an individual tty device if the
|
| 3210 | * tty driver's flags have the %TTY_DRIVER_DYNAMIC_DEV bit set. If that bit is
|
| 3211 | * not set, this function should not be called by a tty driver.
|
| 3212 | *
|
| 3213 | * Locking: ??
|
| 3214 | *
|
| 3215 | * Return: A pointer to the struct device for this tty device (or
|
| 3216 | * ERR_PTR(-EFOO) on error).
|
| 3217 |
|
| 3218 | struct device *tty_register_device_attr(struct tty_driver *driver,
|
| 3219 | unsigned index, struct device *device,
|
| 3220 | void *drvdata,
|
| 3221 | const struct attribute_group **attr_grp)
|
| 3222 | {
|
| 3223 | char name[64];
|
| 3224 | dev_t devt = MKDEV(driver->major, driver->minor_start) + index;
|
| 3225 | struct ktermios *tp;
|
| 3226 | struct device *dev;
|
| 3227 | int retval;
|
| 3228 |
|
| 3229 | if (index >= driver->num) {
|
| 3230 | pr_err("%s: Attempt to register invalid tty line number (%d)\n",
|
| 3231 | driver->name, index);
|
| 3232 | return ERR_PTR(-EINVAL);
|
| 3233 | }
|
| 3234 |
|
| 3235 | if (driver->type == TTY_DRIVER_TYPE_PTY)
|
| 3236 | pty_line_name(driver, index, name);
|
| 3237 | else
|
| 3238 | tty_line_name(driver, index, name);
|
| 3239 |
|
| 3240 | dev = kzalloc_obj(*dev);
|
| 3241 | if (!dev)
|
| 3242 | return ERR_PTR(-ENOMEM);
|
| 3243 |
|
| 3244 | dev->devt = devt;
|
| 3245 | dev->class = &tty_class;
|
| 3246 | dev->parent = device;
|
| 3247 | dev->release = tty_device_create_release;
|
| 3248 | dev_set_name(dev, "%s", name);
|
| 3249 | dev->groups = attr_grp;
|
| 3250 | dev_set_drvdata(dev, drvdata);
|
| 3251 |
|
| 3252 | dev_set_uevent_suppress(dev, 1);
|
| 3253 |
|
| 3254 | retval = device_register(dev);
|
| 3255 | if (retval)
|
| 3256 | goto err_put;
|
| 3257 |
|
| 3258 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
|
| 3259 | if (driver->flags & TTY_DRIVER_RESET_SAVED_TERMIOS) {
|
| 3260 | |
| 3261 | * Free any saved termios data so that the termios
|
| 3262 | * state is reset when reusing a minor number.
|
| 3263 |
|
| 3264 | tp = driver->termios[index];
|
| 3265 | if (tp) {
|
| 3266 | driver->termios[index] = NULL;
|
| 3267 | kfree(tp);
|
| 3268 | }
|
| 3269 | }
|
| 3270 |
|
| 3271 | retval = tty_cdev_add(driver, devt, index, 1);
|
| 3272 | if (retval)
|
| 3273 | goto err_del;
|
| 3274 | }
|
| 3275 |
|
| 3276 | dev_set_uevent_suppress(dev, 0);
|
| 3277 | kobject_uevent(&dev->kobj, KOBJ_ADD);
|
| 3278 |
|
| 3279 | return dev;
|
| 3280 |
|
| 3281 | err_del:
|
| 3282 | device_del(dev);
|
| 3283 | err_put:
|
| 3284 | put_device(dev);
|
| 3285 |
|
| 3286 | return ERR_PTR(retval);
|
| 3287 | }
|
| 3288 | EXPORT_SYMBOL_GPL(tty_register_device_attr);
|
| 3289 |
|
| 3290 | |
| 3291 | * tty_unregister_device - unregister a tty device
|
| 3292 | * @driver: the tty driver that describes the tty device
|
| 3293 | * @index: the index in the tty driver for this tty device
|
| 3294 | *
|
| 3295 | * If a tty device is registered with a call to tty_register_device() then
|
| 3296 | * this function must be called when the tty device is gone.
|
| 3297 | *
|
| 3298 | * Locking: ??
|
| 3299 |
|
| 3300 | void tty_unregister_device(struct tty_driver *driver, unsigned index)
|
| 3301 | {
|
| 3302 | device_destroy(&tty_class, MKDEV(driver->major, driver->minor_start) + index);
|
| 3303 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) && driver->cdevs[index]) {
|
| 3304 | cdev_del(driver->cdevs[index]);
|
| 3305 | driver->cdevs[index] = NULL;
|
| 3306 | }
|
| 3307 | }
|
| 3308 | EXPORT_SYMBOL(tty_unregister_device);
|
| 3309 |
|
| 3310 | |
| 3311 | * __tty_alloc_driver - allocate tty driver
|
| 3312 | * @lines: count of lines this driver can handle at most
|
| 3313 | * @owner: module which is responsible for this driver
|
| 3314 | * @flags: some of enum tty_driver_flag, will be set in driver->flags
|
| 3315 | *
|
| 3316 | * This should not be called directly, tty_alloc_driver() should be used
|
| 3317 | * instead.
|
| 3318 | *
|
| 3319 | * Returns: struct tty_driver or a PTR-encoded error (use IS_ERR() and friends).
|
| 3320 |
|
| 3321 | struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner,
|
| 3322 | unsigned long flags)
|
| 3323 | {
|
| 3324 | struct tty_driver *driver;
|
| 3325 | unsigned int cdevs = 1;
|
| 3326 | int err;
|
| 3327 |
|
| 3328 | if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1))
|
| 3329 | return ERR_PTR(-EINVAL);
|
| 3330 |
|
| 3331 | driver = kzalloc_obj(*driver);
|
| 3332 | if (!driver)
|
| 3333 | return ERR_PTR(-ENOMEM);
|
| 3334 |
|
| 3335 | kref_init(&driver->kref);
|
| 3336 | driver->num = lines;
|
| 3337 | driver->owner = owner;
|
| 3338 | driver->flags = flags;
|
| 3339 |
|
| 3340 | if (!(flags & TTY_DRIVER_DEVPTS_MEM)) {
|
| 3341 | driver->ttys = kzalloc_objs(*driver->ttys, lines);
|
| 3342 | driver->termios = kzalloc_objs(*driver->termios, lines);
|
| 3343 | if (!driver->ttys || !driver->termios) {
|
| 3344 | err = -ENOMEM;
|
| 3345 | goto err_free_all;
|
| 3346 | }
|
| 3347 | }
|
| 3348 |
|
| 3349 | if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) {
|
| 3350 | driver->ports = kzalloc_objs(*driver->ports, lines);
|
| 3351 | if (!driver->ports) {
|
| 3352 | err = -ENOMEM;
|
| 3353 | goto err_free_all;
|
| 3354 | }
|
| 3355 | cdevs = lines;
|
| 3356 | }
|
| 3357 |
|
| 3358 | driver->cdevs = kzalloc_objs(*driver->cdevs, cdevs);
|
| 3359 | if (!driver->cdevs) {
|
| 3360 | err = -ENOMEM;
|
| 3361 | goto err_free_all;
|
| 3362 | }
|
| 3363 |
|
| 3364 | return driver;
|
| 3365 | err_free_all:
|
| 3366 | kfree(driver->ports);
|
| 3367 | kfree(driver->ttys);
|
| 3368 | kfree(driver->termios);
|
| 3369 | kfree(driver->cdevs);
|
| 3370 | kfree(driver);
|
| 3371 | return ERR_PTR(err);
|
| 3372 | }
|
| 3373 | EXPORT_SYMBOL(__tty_alloc_driver);
|
| 3374 |
|
| 3375 | static void destruct_tty_driver(struct kref *kref)
|
| 3376 | {
|
| 3377 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref);
|
| 3378 | int i;
|
| 3379 | struct ktermios *tp;
|
| 3380 |
|
| 3381 | if (driver->flags & TTY_DRIVER_INSTALLED) {
|
| 3382 | for (i = 0; i < driver->num; i++) {
|
| 3383 | tp = driver->termios[i];
|
| 3384 | if (tp) {
|
| 3385 | driver->termios[i] = NULL;
|
| 3386 | kfree(tp);
|
| 3387 | }
|
| 3388 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
|
| 3389 | tty_unregister_device(driver, i);
|
| 3390 | }
|
| 3391 | proc_tty_unregister_driver(driver);
|
| 3392 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)
|
| 3393 | cdev_del(driver->cdevs[0]);
|
| 3394 | }
|
| 3395 | kfree(driver->cdevs);
|
| 3396 | kfree(driver->ports);
|
| 3397 | kfree(driver->termios);
|
| 3398 | kfree(driver->ttys);
|
| 3399 | kfree(driver);
|
| 3400 | }
|
| 3401 |
|
| 3402 | |
| 3403 | * tty_driver_kref_put - drop a reference to a tty driver
|
| 3404 | * @driver: driver of which to drop the reference
|
| 3405 | *
|
| 3406 | * The final put will destroy and free up the driver.
|
| 3407 |
|
| 3408 | void tty_driver_kref_put(struct tty_driver *driver)
|
| 3409 | {
|
| 3410 | kref_put(&driver->kref, destruct_tty_driver);
|
| 3411 | }
|
| 3412 | EXPORT_SYMBOL(tty_driver_kref_put);
|
| 3413 |
|
| 3414 | |
| 3415 | * tty_register_driver - register a tty driver
|
| 3416 | * @driver: driver to register
|
| 3417 | *
|
| 3418 | * Called by a tty driver to register itself.
|
| 3419 |
|
| 3420 | int tty_register_driver(struct tty_driver *driver)
|
| 3421 | {
|
| 3422 | int error;
|
| 3423 | int i;
|
| 3424 | dev_t dev;
|
| 3425 | struct device *d;
|
| 3426 |
|
| 3427 | if (!driver->major) {
|
| 3428 | error = alloc_chrdev_region(&dev, driver->minor_start,
|
| 3429 | driver->num, driver->name);
|
| 3430 | if (!error) {
|
| 3431 | driver->major = MAJOR(dev);
|
| 3432 | driver->minor_start = MINOR(dev);
|
| 3433 | }
|
| 3434 | } else {
|
| 3435 | dev = MKDEV(driver->major, driver->minor_start);
|
| 3436 | error = register_chrdev_region(dev, driver->num, driver->name);
|
| 3437 | }
|
| 3438 | if (error < 0)
|
| 3439 | goto err;
|
| 3440 |
|
| 3441 | |
| 3442 | * Drivers that do not define driver_name are potentially in-memory devices
|
| 3443 | * like vty, which generally do not require special workqueue settings.
|
| 3444 |
|
| 3445 | if (!(driver->flags & TTY_DRIVER_NO_WORKQUEUE) && driver->driver_name) {
|
| 3446 | driver->flip_wq = alloc_workqueue("%s-%s", WQ_UNBOUND | WQ_SYSFS,
|
| 3447 | 0, driver->name, driver->driver_name);
|
| 3448 | if (!driver->flip_wq) {
|
| 3449 | error = -ENOMEM;
|
| 3450 | goto err_unreg_char;
|
| 3451 | }
|
| 3452 | for (i = 0; i < driver->num; i++) {
|
| 3453 | if (driver->ports[i])
|
| 3454 | tty_port_link_driver_wq(driver->ports[i], driver);
|
| 3455 | }
|
| 3456 | }
|
| 3457 |
|
| 3458 | if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) {
|
| 3459 | error = tty_cdev_add(driver, dev, 0, driver->num);
|
| 3460 | if (error)
|
| 3461 | goto err_destroy_wq;
|
| 3462 | }
|
| 3463 |
|
| 3464 | scoped_guard(mutex, &tty_mutex)
|
| 3465 | list_add(&driver->tty_drivers, &tty_drivers);
|
| 3466 |
|
| 3467 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) {
|
| 3468 | for (i = 0; i < driver->num; i++) {
|
| 3469 | d = tty_register_device(driver, i, NULL);
|
| 3470 | if (IS_ERR(d)) {
|
| 3471 | error = PTR_ERR(d);
|
| 3472 | goto err_unreg_devs;
|
| 3473 | }
|
| 3474 | }
|
| 3475 | }
|
| 3476 | proc_tty_register_driver(driver);
|
| 3477 | driver->flags |= TTY_DRIVER_INSTALLED;
|
| 3478 | return 0;
|
| 3479 |
|
| 3480 | err_unreg_devs:
|
| 3481 | for (i--; i >= 0; i--)
|
| 3482 | tty_unregister_device(driver, i);
|
| 3483 |
|
| 3484 | scoped_guard(mutex, &tty_mutex)
|
| 3485 | list_del(&driver->tty_drivers);
|
| 3486 |
|
| 3487 | err_destroy_wq:
|
| 3488 | if (driver->flip_wq)
|
| 3489 | destroy_workqueue(driver->flip_wq);
|
| 3490 |
|
| 3491 | err_unreg_char:
|
| 3492 | unregister_chrdev_region(dev, driver->num);
|
| 3493 | err:
|
| 3494 | return error;
|
| 3495 | }
|
| 3496 | EXPORT_SYMBOL(tty_register_driver);
|
| 3497 |
|
| 3498 | |
| 3499 | * tty_unregister_driver - unregister a tty driver
|
| 3500 | * @driver: driver to unregister
|
| 3501 | *
|
| 3502 | * Called by a tty driver to unregister itself.
|
| 3503 |
|
| 3504 | void tty_unregister_driver(struct tty_driver *driver)
|
| 3505 | {
|
| 3506 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start),
|
| 3507 | driver->num);
|
| 3508 | scoped_guard(mutex, &tty_mutex)
|
| 3509 | list_del(&driver->tty_drivers);
|
| 3510 | if (driver->flip_wq)
|
| 3511 | destroy_workqueue(driver->flip_wq);
|
| 3512 | }
|
| 3513 | EXPORT_SYMBOL(tty_unregister_driver);
|
| 3514 |
|
| 3515 | dev_t tty_devnum(struct tty_struct *tty)
|
| 3516 | {
|
| 3517 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
|
| 3518 | }
|
| 3519 | EXPORT_SYMBOL(tty_devnum);
|
| 3520 |
|
| 3521 | void tty_default_fops(struct file_operations *fops)
|
| 3522 | {
|
| 3523 | *fops = tty_fops;
|
| 3524 | }
|
| 3525 |
|
| 3526 | static char *tty_devnode(const struct device *dev, umode_t *mode)
|
| 3527 | {
|
| 3528 | if (!mode)
|
| 3529 | return NULL;
|
| 3530 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) ||
|
| 3531 | dev->devt == MKDEV(TTYAUX_MAJOR, 2))
|
| 3532 | *mode = 0666;
|
| 3533 | return NULL;
|
| 3534 | }
|
| 3535 |
|
| 3536 | const struct class tty_class = {
|
| 3537 | .name = "tty",
|
| 3538 | .devnode = tty_devnode,
|
| 3539 | };
|
| 3540 |
|
| 3541 | static int __init tty_class_init(void)
|
| 3542 | {
|
| 3543 | return class_register(&tty_class);
|
| 3544 | }
|
| 3545 |
|
| 3546 | postcore_initcall(tty_class_init);
|
| 3547 |
|
| 3548 |
|
| 3549 | static struct cdev tty_cdev, console_cdev;
|
| 3550 |
|
| 3551 | static ssize_t show_cons_active(struct device *dev,
|
| 3552 | struct device_attribute *attr, char *buf)
|
| 3553 | {
|
| 3554 | struct console *cs[16];
|
| 3555 | int i = 0;
|
| 3556 | struct console *c;
|
| 3557 | ssize_t count = 0;
|
| 3558 |
|
| 3559 | |
| 3560 | * Hold the console_list_lock to guarantee that no consoles are
|
| 3561 | * unregistered until all console processing is complete.
|
| 3562 | * This also allows safe traversal of the console list and
|
| 3563 | * race-free reading of @flags.
|
| 3564 |
|
| 3565 | console_list_lock();
|
| 3566 |
|
| 3567 | for_each_console(c) {
|
| 3568 | if (!c->device)
|
| 3569 | continue;
|
| 3570 | if (!(c->flags & CON_NBCON) && !c->write)
|
| 3571 | continue;
|
| 3572 | if ((c->flags & CON_ENABLED) == 0)
|
| 3573 | continue;
|
| 3574 | cs[i++] = c;
|
| 3575 | if (i >= ARRAY_SIZE(cs))
|
| 3576 | break;
|
| 3577 | }
|
| 3578 |
|
| 3579 | |
| 3580 | * Take console_lock to serialize device() callback with
|
| 3581 | * other console operations. For example, fg_console is
|
| 3582 | * modified under console_lock when switching vt.
|
| 3583 |
|
| 3584 | console_lock();
|
| 3585 | while (i--) {
|
| 3586 | int index = cs[i]->index;
|
| 3587 | struct tty_driver *drv = cs[i]->device(cs[i], &index);
|
| 3588 |
|
| 3589 |
|
| 3590 | if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR))
|
| 3591 | count += tty_line_name(drv, index, buf + count);
|
| 3592 | else
|
| 3593 | count += sprintf(buf + count, "%s%d",
|
| 3594 | cs[i]->name, cs[i]->index);
|
| 3595 |
|
| 3596 | count += sprintf(buf + count, "%c", i ? ' ':'\n');
|
| 3597 | }
|
| 3598 | console_unlock();
|
| 3599 |
|
| 3600 | console_list_unlock();
|
| 3601 |
|
| 3602 | return count;
|
| 3603 | }
|
| 3604 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL);
|
| 3605 |
|
| 3606 | static struct attribute *cons_dev_attrs[] = {
|
| 3607 | &dev_attr_active.attr,
|
| 3608 | NULL
|
| 3609 | };
|
| 3610 |
|
| 3611 | ATTRIBUTE_GROUPS(cons_dev);
|
| 3612 |
|
| 3613 | static struct device *consdev;
|
| 3614 |
|
| 3615 | void console_sysfs_notify(void)
|
| 3616 | {
|
| 3617 | if (consdev)
|
| 3618 | sysfs_notify(&consdev->kobj, NULL, "active");
|
| 3619 | }
|
| 3620 |
|
| 3621 | static const struct ctl_table tty_table[] = {
|
| 3622 | {
|
| 3623 | .procname = "legacy_tiocsti",
|
| 3624 | .data = &tty_legacy_tiocsti,
|
| 3625 | .maxlen = sizeof(tty_legacy_tiocsti),
|
| 3626 | .mode = 0644,
|
| 3627 | .proc_handler = proc_dobool,
|
| 3628 | },
|
| 3629 | {
|
| 3630 | .procname = "ldisc_autoload",
|
| 3631 | .data = &tty_ldisc_autoload,
|
| 3632 | .maxlen = sizeof(tty_ldisc_autoload),
|
| 3633 | .mode = 0644,
|
| 3634 | .proc_handler = proc_dointvec_minmax,
|
| 3635 | .extra1 = SYSCTL_ZERO,
|
| 3636 | .extra2 = SYSCTL_ONE,
|
| 3637 | },
|
| 3638 | };
|
| 3639 |
|
| 3640 | |
| 3641 | * Ok, now we can initialize the rest of the tty devices and can count
|
| 3642 | * on memory allocations, interrupts etc..
|
| 3643 |
|
| 3644 | int __init tty_init(void)
|
| 3645 | {
|
| 3646 | register_sysctl_init("dev/tty", tty_table);
|
| 3647 | cdev_init(&tty_cdev, &tty_fops);
|
| 3648 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) ||
|
| 3649 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0)
|
| 3650 | panic("Couldn't register /dev/tty driver\n");
|
| 3651 | device_create(&tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty");
|
| 3652 |
|
| 3653 | cdev_init(&console_cdev, &console_fops);
|
| 3654 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) ||
|
| 3655 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0)
|
| 3656 | panic("Couldn't register /dev/console driver\n");
|
| 3657 | consdev = device_create_with_groups(&tty_class, NULL,
|
| 3658 | MKDEV(TTYAUX_MAJOR, 1), NULL,
|
| 3659 | cons_dev_groups, "console");
|
| 3660 | if (IS_ERR(consdev))
|
| 3661 | consdev = NULL;
|
| 3662 |
|
| 3663 | #ifdef CONFIG_VT
|
| 3664 | vty_init(&console_fops);
|
| 3665 | #endif
|
| 3666 | return 0;
|
| 3667 | }
|