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3661 lines
88 KiB
3661 lines
88 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 1991, 1992 Linus Torvalds |
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*/ |
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|
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/* |
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* 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles |
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* or rs-channels. It also implements echoing, cooked mode etc. |
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* |
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* Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. |
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* |
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* Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the |
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* tty_struct and tty_queue structures. Previously there was an array |
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* of 256 tty_struct's which was statically allocated, and the |
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* tty_queue structures were allocated at boot time. Both are now |
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* dynamically allocated only when the tty is open. |
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* |
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* Also restructured routines so that there is more of a separation |
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* between the high-level tty routines (tty_io.c and tty_ioctl.c) and |
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* the low-level tty routines (serial.c, pty.c, console.c). This |
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* makes for cleaner and more compact code. -TYT, 9/17/92 |
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* |
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* Modified by Fred N. van Kempen, 01/29/93, to add line disciplines |
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* which can be dynamically activated and de-activated by the line |
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* discipline handling modules (like SLIP). |
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* |
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* NOTE: pay no attention to the line discipline code (yet); its |
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* interface is still subject to change in this version... |
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* -- TYT, 1/31/92 |
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* |
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* Added functionality to the OPOST tty handling. No delays, but all |
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* other bits should be there. |
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* -- Nick Holloway <[email protected]>, 27th May 1993. |
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* |
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* Rewrote canonical mode and added more termios flags. |
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* -- [email protected] (J. Cowley), 13Jan94 |
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* |
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* Reorganized FASYNC support so mouse code can share it. |
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* -- [email protected], 9Sep95 |
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* |
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* New TIOCLINUX variants added. |
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* -- [email protected], 19-Nov-95 |
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* |
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* Restrict vt switching via ioctl() |
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* -- [email protected], 5-Dec-95 |
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* |
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* Move console and virtual terminal code to more appropriate files, |
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* implement CONFIG_VT and generalize console device interface. |
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* -- Marko Kohtala <[email protected]>, March 97 |
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* |
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* Rewrote tty_init_dev and tty_release_dev to eliminate races. |
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* -- Bill Hawes <[email protected]>, June 97 |
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* |
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* Added devfs support. |
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* -- C. Scott Ananian <[email protected]>, 13-Jan-1998 |
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* |
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* Added support for a Unix98-style ptmx device. |
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* -- C. Scott Ananian <[email protected]>, 14-Jan-1998 |
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* |
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* Reduced memory usage for older ARM systems |
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* -- Russell King <[email protected]> |
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* |
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* Move do_SAK() into process context. Less stack use in devfs functions. |
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* alloc_tty_struct() always uses kmalloc() |
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* -- Andrew Morton <[email protected]> 17Mar01 |
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*/ |
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|
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#include <linux/types.h> |
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#include <linux/major.h> |
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#include <linux/errno.h> |
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#include <linux/signal.h> |
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#include <linux/fcntl.h> |
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#include <linux/sched/signal.h> |
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#include <linux/sched/task.h> |
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#include <linux/interrupt.h> |
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#include <linux/tty.h> |
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#include <linux/tty_driver.h> |
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#include <linux/tty_flip.h> |
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#include <linux/devpts_fs.h> |
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#include <linux/file.h> |
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#include <linux/fdtable.h> |
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#include <linux/console.h> |
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#include <linux/timer.h> |
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#include <linux/ctype.h> |
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#include <linux/kd.h> |
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#include <linux/mm.h> |
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#include <linux/string.h> |
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#include <linux/slab.h> |
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#include <linux/poll.h> |
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#include <linux/ppp-ioctl.h> |
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#include <linux/proc_fs.h> |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/device.h> |
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#include <linux/wait.h> |
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#include <linux/bitops.h> |
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#include <linux/delay.h> |
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#include <linux/seq_file.h> |
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#include <linux/serial.h> |
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#include <linux/ratelimit.h> |
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#include <linux/compat.h> |
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|
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#include <linux/uaccess.h> |
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|
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#include <linux/kbd_kern.h> |
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#include <linux/vt_kern.h> |
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#include <linux/selection.h> |
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|
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#include <linux/kmod.h> |
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#include <linux/nsproxy.h> |
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|
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#undef TTY_DEBUG_HANGUP |
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#ifdef TTY_DEBUG_HANGUP |
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# define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) |
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#else |
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# define tty_debug_hangup(tty, f, args...) do { } while (0) |
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#endif |
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|
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#define TTY_PARANOIA_CHECK 1 |
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#define CHECK_TTY_COUNT 1 |
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struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
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.c_iflag = ICRNL | IXON, |
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.c_oflag = OPOST | ONLCR, |
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.c_cflag = B38400 | CS8 | CREAD | HUPCL, |
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.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | |
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ECHOCTL | ECHOKE | IEXTEN, |
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.c_cc = INIT_C_CC, |
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.c_ispeed = 38400, |
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.c_ospeed = 38400, |
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/* .c_line = N_TTY, */ |
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}; |
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|
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EXPORT_SYMBOL(tty_std_termios); |
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|
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/* This list gets poked at by procfs and various bits of boot up code. This |
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could do with some rationalisation such as pulling the tty proc function |
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into this file */ |
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|
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LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
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|
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/* Mutex to protect creating and releasing a tty */ |
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DEFINE_MUTEX(tty_mutex); |
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|
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static ssize_t tty_read(struct kiocb *, struct iov_iter *); |
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static ssize_t tty_write(struct kiocb *, struct iov_iter *); |
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static __poll_t tty_poll(struct file *, poll_table *); |
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static int tty_open(struct inode *, struct file *); |
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#ifdef CONFIG_COMPAT |
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static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
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unsigned long arg); |
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#else |
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#define tty_compat_ioctl NULL |
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#endif |
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static int __tty_fasync(int fd, struct file *filp, int on); |
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static int tty_fasync(int fd, struct file *filp, int on); |
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static void release_tty(struct tty_struct *tty, int idx); |
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|
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/** |
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* free_tty_struct - free a disused tty |
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* @tty: tty struct to free |
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* |
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* Free the write buffers, tty queue and tty memory itself. |
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* |
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* Locking: none. Must be called after tty is definitely unused |
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*/ |
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static void free_tty_struct(struct tty_struct *tty) |
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{ |
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tty_ldisc_deinit(tty); |
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put_device(tty->dev); |
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kfree(tty->write_buf); |
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tty->magic = 0xDEADDEAD; |
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kfree(tty); |
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} |
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|
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static inline struct tty_struct *file_tty(struct file *file) |
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{ |
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return ((struct tty_file_private *)file->private_data)->tty; |
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} |
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int tty_alloc_file(struct file *file) |
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{ |
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struct tty_file_private *priv; |
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priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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file->private_data = priv; |
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return 0; |
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} |
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/* Associate a new file with the tty structure */ |
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void tty_add_file(struct tty_struct *tty, struct file *file) |
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{ |
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struct tty_file_private *priv = file->private_data; |
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priv->tty = tty; |
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priv->file = file; |
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spin_lock(&tty->files_lock); |
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list_add(&priv->list, &tty->tty_files); |
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spin_unlock(&tty->files_lock); |
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} |
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|
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/* |
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* tty_free_file - free file->private_data |
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* |
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* This shall be used only for fail path handling when tty_add_file was not |
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* called yet. |
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*/ |
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void tty_free_file(struct file *file) |
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{ |
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struct tty_file_private *priv = file->private_data; |
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|
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file->private_data = NULL; |
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kfree(priv); |
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} |
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/* Delete file from its tty */ |
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static void tty_del_file(struct file *file) |
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{ |
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struct tty_file_private *priv = file->private_data; |
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struct tty_struct *tty = priv->tty; |
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|
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spin_lock(&tty->files_lock); |
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list_del(&priv->list); |
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spin_unlock(&tty->files_lock); |
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tty_free_file(file); |
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} |
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|
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/** |
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* tty_name - return tty naming |
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* @tty: tty structure |
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* |
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* Convert a tty structure into a name. The name reflects the kernel |
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* naming policy and if udev is in use may not reflect user space |
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* |
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* Locking: none |
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*/ |
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|
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const char *tty_name(const struct tty_struct *tty) |
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{ |
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if (!tty) /* Hmm. NULL pointer. That's fun. */ |
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return "NULL tty"; |
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return tty->name; |
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} |
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EXPORT_SYMBOL(tty_name); |
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const char *tty_driver_name(const struct tty_struct *tty) |
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{ |
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if (!tty || !tty->driver) |
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return ""; |
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return tty->driver->name; |
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} |
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static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
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const char *routine) |
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{ |
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#ifdef TTY_PARANOIA_CHECK |
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if (!tty) { |
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pr_warn("(%d:%d): %s: NULL tty\n", |
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imajor(inode), iminor(inode), routine); |
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return 1; |
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} |
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if (tty->magic != TTY_MAGIC) { |
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pr_warn("(%d:%d): %s: bad magic number\n", |
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imajor(inode), iminor(inode), routine); |
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return 1; |
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} |
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#endif |
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return 0; |
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} |
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/* Caller must hold tty_lock */ |
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static int check_tty_count(struct tty_struct *tty, const char *routine) |
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{ |
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#ifdef CHECK_TTY_COUNT |
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struct list_head *p; |
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int count = 0, kopen_count = 0; |
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|
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spin_lock(&tty->files_lock); |
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list_for_each(p, &tty->tty_files) { |
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count++; |
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} |
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spin_unlock(&tty->files_lock); |
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if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
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tty->driver->subtype == PTY_TYPE_SLAVE && |
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tty->link && tty->link->count) |
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count++; |
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if (tty_port_kopened(tty->port)) |
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kopen_count++; |
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if (tty->count != (count + kopen_count)) { |
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tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", |
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routine, tty->count, count, kopen_count); |
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return (count + kopen_count); |
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} |
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#endif |
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return 0; |
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} |
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|
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/** |
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* get_tty_driver - find device of a tty |
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* @device: device identifier |
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* @index: returns the index of the tty |
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* |
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* This routine returns a tty driver structure, given a device number |
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* and also passes back the index number. |
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* |
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* Locking: caller must hold tty_mutex |
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*/ |
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static struct tty_driver *get_tty_driver(dev_t device, int *index) |
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{ |
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struct tty_driver *p; |
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list_for_each_entry(p, &tty_drivers, tty_drivers) { |
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dev_t base = MKDEV(p->major, p->minor_start); |
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if (device < base || device >= base + p->num) |
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continue; |
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*index = device - base; |
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return tty_driver_kref_get(p); |
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} |
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return NULL; |
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} |
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/** |
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* tty_dev_name_to_number - return dev_t for device name |
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* @name: user space name of device under /dev |
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* @number: pointer to dev_t that this function will populate |
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* |
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* This function converts device names like ttyS0 or ttyUSB1 into dev_t |
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* like (4, 64) or (188, 1). If no corresponding driver is registered then |
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* the function returns -ENODEV. |
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* |
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* Locking: this acquires tty_mutex to protect the tty_drivers list from |
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* being modified while we are traversing it, and makes sure to |
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* release it before exiting. |
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*/ |
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int tty_dev_name_to_number(const char *name, dev_t *number) |
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{ |
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struct tty_driver *p; |
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int ret; |
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int index, prefix_length = 0; |
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const char *str; |
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for (str = name; *str && !isdigit(*str); str++) |
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; |
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if (!*str) |
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return -EINVAL; |
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ret = kstrtoint(str, 10, &index); |
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if (ret) |
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return ret; |
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prefix_length = str - name; |
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mutex_lock(&tty_mutex); |
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list_for_each_entry(p, &tty_drivers, tty_drivers) |
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if (prefix_length == strlen(p->name) && strncmp(name, |
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p->name, prefix_length) == 0) { |
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if (index < p->num) { |
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*number = MKDEV(p->major, p->minor_start + index); |
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goto out; |
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} |
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} |
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/* if here then driver wasn't found */ |
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ret = -ENODEV; |
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out: |
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mutex_unlock(&tty_mutex); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(tty_dev_name_to_number); |
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#ifdef CONFIG_CONSOLE_POLL |
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|
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/** |
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* tty_find_polling_driver - find device of a polled tty |
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* @name: name string to match |
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* @line: pointer to resulting tty line nr |
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* |
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* This routine returns a tty driver structure, given a name |
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* and the condition that the tty driver is capable of polled |
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* operation. |
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*/ |
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struct tty_driver *tty_find_polling_driver(char *name, int *line) |
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{ |
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struct tty_driver *p, *res = NULL; |
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int tty_line = 0; |
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int len; |
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char *str, *stp; |
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|
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for (str = name; *str; str++) |
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if ((*str >= '0' && *str <= '9') || *str == ',') |
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break; |
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if (!*str) |
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return NULL; |
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len = str - name; |
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tty_line = simple_strtoul(str, &str, 10); |
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|
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mutex_lock(&tty_mutex); |
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/* Search through the tty devices to look for a match */ |
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list_for_each_entry(p, &tty_drivers, tty_drivers) { |
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if (!len || strncmp(name, p->name, len) != 0) |
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continue; |
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stp = str; |
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if (*stp == ',') |
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stp++; |
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if (*stp == '\0') |
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stp = NULL; |
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if (tty_line >= 0 && tty_line < p->num && p->ops && |
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p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
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res = tty_driver_kref_get(p); |
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*line = tty_line; |
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break; |
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} |
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} |
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mutex_unlock(&tty_mutex); |
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return res; |
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} |
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EXPORT_SYMBOL_GPL(tty_find_polling_driver); |
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#endif |
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static ssize_t hung_up_tty_read(struct kiocb *iocb, struct iov_iter *to) |
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{ |
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return 0; |
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} |
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|
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static ssize_t hung_up_tty_write(struct kiocb *iocb, struct iov_iter *from) |
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{ |
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return -EIO; |
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} |
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|
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/* No kernel lock held - none needed ;) */ |
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static __poll_t hung_up_tty_poll(struct file *filp, poll_table *wait) |
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{ |
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return EPOLLIN | EPOLLOUT | EPOLLERR | EPOLLHUP | EPOLLRDNORM | EPOLLWRNORM; |
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} |
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|
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static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
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unsigned long arg) |
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{ |
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return cmd == TIOCSPGRP ? -ENOTTY : -EIO; |
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} |
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|
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static long hung_up_tty_compat_ioctl(struct file *file, |
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unsigned int cmd, unsigned long arg) |
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{ |
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return cmd == TIOCSPGRP ? -ENOTTY : -EIO; |
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} |
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|
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static int hung_up_tty_fasync(int fd, struct file *file, int on) |
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{ |
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return -ENOTTY; |
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} |
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|
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static void tty_show_fdinfo(struct seq_file *m, struct file *file) |
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{ |
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struct tty_struct *tty = file_tty(file); |
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|
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if (tty && tty->ops && tty->ops->show_fdinfo) |
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tty->ops->show_fdinfo(tty, m); |
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} |
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|
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static const struct file_operations tty_fops = { |
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.llseek = no_llseek, |
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.read_iter = tty_read, |
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.write_iter = tty_write, |
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.splice_read = generic_file_splice_read, |
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.splice_write = iter_file_splice_write, |
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.poll = tty_poll, |
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.unlocked_ioctl = tty_ioctl, |
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.compat_ioctl = tty_compat_ioctl, |
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.open = tty_open, |
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.release = tty_release, |
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.fasync = tty_fasync, |
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.show_fdinfo = tty_show_fdinfo, |
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}; |
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|
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static const struct file_operations console_fops = { |
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.llseek = no_llseek, |
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.read_iter = tty_read, |
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.write_iter = redirected_tty_write, |
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.splice_read = generic_file_splice_read, |
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.splice_write = iter_file_splice_write, |
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.poll = tty_poll, |
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.unlocked_ioctl = tty_ioctl, |
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.compat_ioctl = tty_compat_ioctl, |
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.open = tty_open, |
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.release = tty_release, |
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.fasync = tty_fasync, |
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}; |
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static const struct file_operations hung_up_tty_fops = { |
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.llseek = no_llseek, |
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.read_iter = hung_up_tty_read, |
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.write_iter = hung_up_tty_write, |
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.poll = hung_up_tty_poll, |
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.unlocked_ioctl = hung_up_tty_ioctl, |
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.compat_ioctl = hung_up_tty_compat_ioctl, |
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.release = tty_release, |
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.fasync = hung_up_tty_fasync, |
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}; |
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|
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static DEFINE_SPINLOCK(redirect_lock); |
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static struct file *redirect; |
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|
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/** |
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* tty_wakeup - request more data |
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* @tty: terminal |
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* |
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* Internal and external helper for wakeups of tty. This function |
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* informs the line discipline if present that the driver is ready |
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* to receive more output data. |
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*/ |
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|
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void tty_wakeup(struct tty_struct *tty) |
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{ |
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struct tty_ldisc *ld; |
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|
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if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
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ld = tty_ldisc_ref(tty); |
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if (ld) { |
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if (ld->ops->write_wakeup) |
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ld->ops->write_wakeup(tty); |
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tty_ldisc_deref(ld); |
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} |
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} |
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wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
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} |
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|
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EXPORT_SYMBOL_GPL(tty_wakeup); |
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|
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/** |
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* tty_release_redirect - Release a redirect on a pty if present |
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* @tty: tty device |
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* |
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* This is available to the pty code so if the master closes, if the |
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* slave is a redirect it can release the redirect. |
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*/ |
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struct file *tty_release_redirect(struct tty_struct *tty) |
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{ |
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struct file *f = NULL; |
|
|
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spin_lock(&redirect_lock); |
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if (redirect && file_tty(redirect) == tty) { |
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f = redirect; |
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redirect = NULL; |
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} |
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spin_unlock(&redirect_lock); |
|
|
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return f; |
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} |
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EXPORT_SYMBOL_GPL(tty_release_redirect); |
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|
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/** |
|
* __tty_hangup - actual handler for hangup events |
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* @tty: tty device |
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* @exit_session: if non-zero, signal all foreground group processes |
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* |
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* This can be called by a "kworker" kernel thread. That is process |
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* synchronous but doesn't hold any locks, so we need to make sure we |
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* have the appropriate locks for what we're doing. |
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* |
|
* The hangup event clears any pending redirections onto the hung up |
|
* device. It ensures future writes will error and it does the needed |
|
* line discipline hangup and signal delivery. The tty object itself |
|
* remains intact. |
|
* |
|
* Locking: |
|
* BTM |
|
* redirect lock for undoing redirection |
|
* file list lock for manipulating list of ttys |
|
* tty_ldiscs_lock from called functions |
|
* termios_rwsem resetting termios data |
|
* tasklist_lock to walk task list for hangup event |
|
* ->siglock to protect ->signal/->sighand |
|
*/ |
|
static void __tty_hangup(struct tty_struct *tty, int exit_session) |
|
{ |
|
struct file *cons_filp = NULL; |
|
struct file *filp, *f; |
|
struct tty_file_private *priv; |
|
int closecount = 0, n; |
|
int refs; |
|
|
|
if (!tty) |
|
return; |
|
|
|
f = tty_release_redirect(tty); |
|
|
|
tty_lock(tty); |
|
|
|
if (test_bit(TTY_HUPPED, &tty->flags)) { |
|
tty_unlock(tty); |
|
return; |
|
} |
|
|
|
/* |
|
* Some console devices aren't actually hung up for technical and |
|
* historical reasons, which can lead to indefinite interruptible |
|
* sleep in n_tty_read(). The following explicitly tells |
|
* n_tty_read() to abort readers. |
|
*/ |
|
set_bit(TTY_HUPPING, &tty->flags); |
|
|
|
/* inuse_filps is protected by the single tty lock, |
|
this really needs to change if we want to flush the |
|
workqueue with the lock held */ |
|
check_tty_count(tty, "tty_hangup"); |
|
|
|
spin_lock(&tty->files_lock); |
|
/* This breaks for file handles being sent over AF_UNIX sockets ? */ |
|
list_for_each_entry(priv, &tty->tty_files, list) { |
|
filp = priv->file; |
|
if (filp->f_op->write_iter == redirected_tty_write) |
|
cons_filp = filp; |
|
if (filp->f_op->write_iter != tty_write) |
|
continue; |
|
closecount++; |
|
__tty_fasync(-1, filp, 0); /* can't block */ |
|
filp->f_op = &hung_up_tty_fops; |
|
} |
|
spin_unlock(&tty->files_lock); |
|
|
|
refs = tty_signal_session_leader(tty, exit_session); |
|
/* Account for the p->signal references we killed */ |
|
while (refs--) |
|
tty_kref_put(tty); |
|
|
|
tty_ldisc_hangup(tty, cons_filp != NULL); |
|
|
|
spin_lock_irq(&tty->ctrl_lock); |
|
clear_bit(TTY_THROTTLED, &tty->flags); |
|
clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
|
put_pid(tty->session); |
|
put_pid(tty->pgrp); |
|
tty->session = NULL; |
|
tty->pgrp = NULL; |
|
tty->ctrl_status = 0; |
|
spin_unlock_irq(&tty->ctrl_lock); |
|
|
|
/* |
|
* If one of the devices matches a console pointer, we |
|
* cannot just call hangup() because that will cause |
|
* tty->count and state->count to go out of sync. |
|
* So we just call close() the right number of times. |
|
*/ |
|
if (cons_filp) { |
|
if (tty->ops->close) |
|
for (n = 0; n < closecount; n++) |
|
tty->ops->close(tty, cons_filp); |
|
} else if (tty->ops->hangup) |
|
tty->ops->hangup(tty); |
|
/* |
|
* We don't want to have driver/ldisc interactions beyond the ones |
|
* we did here. The driver layer expects no calls after ->hangup() |
|
* from the ldisc side, which is now guaranteed. |
|
*/ |
|
set_bit(TTY_HUPPED, &tty->flags); |
|
clear_bit(TTY_HUPPING, &tty->flags); |
|
tty_unlock(tty); |
|
|
|
if (f) |
|
fput(f); |
|
} |
|
|
|
static void do_tty_hangup(struct work_struct *work) |
|
{ |
|
struct tty_struct *tty = |
|
container_of(work, struct tty_struct, hangup_work); |
|
|
|
__tty_hangup(tty, 0); |
|
} |
|
|
|
/** |
|
* tty_hangup - trigger a hangup event |
|
* @tty: tty to hangup |
|
* |
|
* A carrier loss (virtual or otherwise) has occurred on this like |
|
* schedule a hangup sequence to run after this event. |
|
*/ |
|
|
|
void tty_hangup(struct tty_struct *tty) |
|
{ |
|
tty_debug_hangup(tty, "hangup\n"); |
|
schedule_work(&tty->hangup_work); |
|
} |
|
|
|
EXPORT_SYMBOL(tty_hangup); |
|
|
|
/** |
|
* tty_vhangup - process vhangup |
|
* @tty: tty to hangup |
|
* |
|
* The user has asked via system call for the terminal to be hung up. |
|
* We do this synchronously so that when the syscall returns the process |
|
* is complete. That guarantee is necessary for security reasons. |
|
*/ |
|
|
|
void tty_vhangup(struct tty_struct *tty) |
|
{ |
|
tty_debug_hangup(tty, "vhangup\n"); |
|
__tty_hangup(tty, 0); |
|
} |
|
|
|
EXPORT_SYMBOL(tty_vhangup); |
|
|
|
|
|
/** |
|
* tty_vhangup_self - process vhangup for own ctty |
|
* |
|
* Perform a vhangup on the current controlling tty |
|
*/ |
|
|
|
void tty_vhangup_self(void) |
|
{ |
|
struct tty_struct *tty; |
|
|
|
tty = get_current_tty(); |
|
if (tty) { |
|
tty_vhangup(tty); |
|
tty_kref_put(tty); |
|
} |
|
} |
|
|
|
/** |
|
* tty_vhangup_session - hangup session leader exit |
|
* @tty: tty to hangup |
|
* |
|
* The session leader is exiting and hanging up its controlling terminal. |
|
* Every process in the foreground process group is signalled SIGHUP. |
|
* |
|
* We do this synchronously so that when the syscall returns the process |
|
* is complete. That guarantee is necessary for security reasons. |
|
*/ |
|
|
|
void tty_vhangup_session(struct tty_struct *tty) |
|
{ |
|
tty_debug_hangup(tty, "session hangup\n"); |
|
__tty_hangup(tty, 1); |
|
} |
|
|
|
/** |
|
* tty_hung_up_p - was tty hung up |
|
* @filp: file pointer of tty |
|
* |
|
* Return true if the tty has been subject to a vhangup or a carrier |
|
* loss |
|
*/ |
|
|
|
int tty_hung_up_p(struct file *filp) |
|
{ |
|
return (filp && filp->f_op == &hung_up_tty_fops); |
|
} |
|
|
|
EXPORT_SYMBOL(tty_hung_up_p); |
|
|
|
/** |
|
* stop_tty - propagate flow control |
|
* @tty: tty to stop |
|
* |
|
* Perform flow control to the driver. May be called |
|
* on an already stopped device and will not re-call the driver |
|
* method. |
|
* |
|
* This functionality is used by both the line disciplines for |
|
* halting incoming flow and by the driver. It may therefore be |
|
* called from any context, may be under the tty atomic_write_lock |
|
* but not always. |
|
* |
|
* Locking: |
|
* flow_lock |
|
*/ |
|
|
|
void __stop_tty(struct tty_struct *tty) |
|
{ |
|
if (tty->stopped) |
|
return; |
|
tty->stopped = 1; |
|
if (tty->ops->stop) |
|
tty->ops->stop(tty); |
|
} |
|
|
|
void stop_tty(struct tty_struct *tty) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&tty->flow_lock, flags); |
|
__stop_tty(tty); |
|
spin_unlock_irqrestore(&tty->flow_lock, flags); |
|
} |
|
EXPORT_SYMBOL(stop_tty); |
|
|
|
/** |
|
* start_tty - propagate flow control |
|
* @tty: tty to start |
|
* |
|
* Start a tty that has been stopped if at all possible. If this |
|
* tty was previous stopped and is now being started, the driver |
|
* start method is invoked and the line discipline woken. |
|
* |
|
* Locking: |
|
* flow_lock |
|
*/ |
|
|
|
void __start_tty(struct tty_struct *tty) |
|
{ |
|
if (!tty->stopped || tty->flow_stopped) |
|
return; |
|
tty->stopped = 0; |
|
if (tty->ops->start) |
|
tty->ops->start(tty); |
|
tty_wakeup(tty); |
|
} |
|
|
|
void start_tty(struct tty_struct *tty) |
|
{ |
|
unsigned long flags; |
|
|
|
spin_lock_irqsave(&tty->flow_lock, flags); |
|
__start_tty(tty); |
|
spin_unlock_irqrestore(&tty->flow_lock, flags); |
|
} |
|
EXPORT_SYMBOL(start_tty); |
|
|
|
static void tty_update_time(struct timespec64 *time) |
|
{ |
|
time64_t sec = ktime_get_real_seconds(); |
|
|
|
/* |
|
* We only care if the two values differ in anything other than the |
|
* lower three bits (i.e every 8 seconds). If so, then we can update |
|
* the time of the tty device, otherwise it could be construded as a |
|
* security leak to let userspace know the exact timing of the tty. |
|
*/ |
|
if ((sec ^ time->tv_sec) & ~7) |
|
time->tv_sec = sec; |
|
} |
|
|
|
/* |
|
* Iterate on the ldisc ->read() function until we've gotten all |
|
* the data the ldisc has for us. |
|
* |
|
* The "cookie" is something that the ldisc read function can fill |
|
* in to let us know that there is more data to be had. |
|
* |
|
* We promise to continue to call the ldisc until it stops returning |
|
* data or clears the cookie. The cookie may be something that the |
|
* ldisc maintains state for and needs to free. |
|
*/ |
|
static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, |
|
struct file *file, struct iov_iter *to) |
|
{ |
|
int retval = 0; |
|
void *cookie = NULL; |
|
unsigned long offset = 0; |
|
char kernel_buf[64]; |
|
size_t count = iov_iter_count(to); |
|
|
|
do { |
|
int size, copied; |
|
|
|
size = count > sizeof(kernel_buf) ? sizeof(kernel_buf) : count; |
|
size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset); |
|
if (!size) |
|
break; |
|
|
|
if (size < 0) { |
|
/* Did we have an earlier error (ie -EFAULT)? */ |
|
if (retval) |
|
break; |
|
retval = size; |
|
|
|
/* |
|
* -EOVERFLOW means we didn't have enough space |
|
* for a whole packet, and we shouldn't return |
|
* a partial result. |
|
*/ |
|
if (retval == -EOVERFLOW) |
|
offset = 0; |
|
break; |
|
} |
|
|
|
copied = copy_to_iter(kernel_buf, size, to); |
|
offset += copied; |
|
count -= copied; |
|
|
|
/* |
|
* If the user copy failed, we still need to do another ->read() |
|
* call if we had a cookie to let the ldisc clear up. |
|
* |
|
* But make sure size is zeroed. |
|
*/ |
|
if (unlikely(copied != size)) { |
|
count = 0; |
|
retval = -EFAULT; |
|
} |
|
} while (cookie); |
|
|
|
/* We always clear tty buffer in case they contained passwords */ |
|
memzero_explicit(kernel_buf, sizeof(kernel_buf)); |
|
return offset ? offset : retval; |
|
} |
|
|
|
|
|
/** |
|
* tty_read - read method for tty device files |
|
* @file: pointer to tty file |
|
* @buf: user buffer |
|
* @count: size of user buffer |
|
* @ppos: unused |
|
* |
|
* Perform the read system call function on this terminal device. Checks |
|
* for hung up devices before calling the line discipline method. |
|
* |
|
* Locking: |
|
* Locks the line discipline internally while needed. Multiple |
|
* read calls may be outstanding in parallel. |
|
*/ |
|
|
|
static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) |
|
{ |
|
int i; |
|
struct file *file = iocb->ki_filp; |
|
struct inode *inode = file_inode(file); |
|
struct tty_struct *tty = file_tty(file); |
|
struct tty_ldisc *ld; |
|
|
|
if (tty_paranoia_check(tty, inode, "tty_read")) |
|
return -EIO; |
|
if (!tty || tty_io_error(tty)) |
|
return -EIO; |
|
|
|
/* We want to wait for the line discipline to sort out in this |
|
situation */ |
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return hung_up_tty_read(iocb, to); |
|
i = -EIO; |
|
if (ld->ops->read) |
|
i = iterate_tty_read(ld, tty, file, to); |
|
tty_ldisc_deref(ld); |
|
|
|
if (i > 0) |
|
tty_update_time(&inode->i_atime); |
|
|
|
return i; |
|
} |
|
|
|
static void tty_write_unlock(struct tty_struct *tty) |
|
{ |
|
mutex_unlock(&tty->atomic_write_lock); |
|
wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); |
|
} |
|
|
|
static int tty_write_lock(struct tty_struct *tty, int ndelay) |
|
{ |
|
if (!mutex_trylock(&tty->atomic_write_lock)) { |
|
if (ndelay) |
|
return -EAGAIN; |
|
if (mutex_lock_interruptible(&tty->atomic_write_lock)) |
|
return -ERESTARTSYS; |
|
} |
|
return 0; |
|
} |
|
|
|
/* |
|
* Split writes up in sane blocksizes to avoid |
|
* denial-of-service type attacks |
|
*/ |
|
static inline ssize_t do_tty_write( |
|
ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), |
|
struct tty_struct *tty, |
|
struct file *file, |
|
struct iov_iter *from) |
|
{ |
|
size_t count = iov_iter_count(from); |
|
ssize_t ret, written = 0; |
|
unsigned int chunk; |
|
|
|
ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
|
if (ret < 0) |
|
return ret; |
|
|
|
/* |
|
* We chunk up writes into a temporary buffer. This |
|
* simplifies low-level drivers immensely, since they |
|
* don't have locking issues and user mode accesses. |
|
* |
|
* But if TTY_NO_WRITE_SPLIT is set, we should use a |
|
* big chunk-size.. |
|
* |
|
* The default chunk-size is 2kB, because the NTTY |
|
* layer has problems with bigger chunks. It will |
|
* claim to be able to handle more characters than |
|
* it actually does. |
|
* |
|
* FIXME: This can probably go away now except that 64K chunks |
|
* are too likely to fail unless switched to vmalloc... |
|
*/ |
|
chunk = 2048; |
|
if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) |
|
chunk = 65536; |
|
if (count < chunk) |
|
chunk = count; |
|
|
|
/* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
|
if (tty->write_cnt < chunk) { |
|
unsigned char *buf_chunk; |
|
|
|
if (chunk < 1024) |
|
chunk = 1024; |
|
|
|
buf_chunk = kmalloc(chunk, GFP_KERNEL); |
|
if (!buf_chunk) { |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
kfree(tty->write_buf); |
|
tty->write_cnt = chunk; |
|
tty->write_buf = buf_chunk; |
|
} |
|
|
|
/* Do the write .. */ |
|
for (;;) { |
|
size_t size = count; |
|
if (size > chunk) |
|
size = chunk; |
|
|
|
ret = -EFAULT; |
|
if (copy_from_iter(tty->write_buf, size, from) != size) |
|
break; |
|
|
|
ret = write(tty, file, tty->write_buf, size); |
|
if (ret <= 0) |
|
break; |
|
|
|
written += ret; |
|
if (ret > size) |
|
break; |
|
|
|
/* FIXME! Have Al check this! */ |
|
if (ret != size) |
|
iov_iter_revert(from, size-ret); |
|
|
|
count -= ret; |
|
if (!count) |
|
break; |
|
ret = -ERESTARTSYS; |
|
if (signal_pending(current)) |
|
break; |
|
cond_resched(); |
|
} |
|
if (written) { |
|
tty_update_time(&file_inode(file)->i_mtime); |
|
ret = written; |
|
} |
|
out: |
|
tty_write_unlock(tty); |
|
return ret; |
|
} |
|
|
|
/** |
|
* tty_write_message - write a message to a certain tty, not just the console. |
|
* @tty: the destination tty_struct |
|
* @msg: the message to write |
|
* |
|
* This is used for messages that need to be redirected to a specific tty. |
|
* We don't put it into the syslog queue right now maybe in the future if |
|
* really needed. |
|
* |
|
* We must still hold the BTM and test the CLOSING flag for the moment. |
|
*/ |
|
|
|
void tty_write_message(struct tty_struct *tty, char *msg) |
|
{ |
|
if (tty) { |
|
mutex_lock(&tty->atomic_write_lock); |
|
tty_lock(tty); |
|
if (tty->ops->write && tty->count > 0) |
|
tty->ops->write(tty, msg, strlen(msg)); |
|
tty_unlock(tty); |
|
tty_write_unlock(tty); |
|
} |
|
return; |
|
} |
|
|
|
|
|
/** |
|
* tty_write - write method for tty device file |
|
* @file: tty file pointer |
|
* @buf: user data to write |
|
* @count: bytes to write |
|
* @ppos: unused |
|
* |
|
* Write data to a tty device via the line discipline. |
|
* |
|
* Locking: |
|
* Locks the line discipline as required |
|
* Writes to the tty driver are serialized by the atomic_write_lock |
|
* and are then processed in chunks to the device. The line discipline |
|
* write method will not be invoked in parallel for each device. |
|
*/ |
|
|
|
static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct tty_struct *tty = file_tty(file); |
|
struct tty_ldisc *ld; |
|
ssize_t ret; |
|
|
|
if (tty_paranoia_check(tty, file_inode(file), "tty_write")) |
|
return -EIO; |
|
if (!tty || !tty->ops->write || tty_io_error(tty)) |
|
return -EIO; |
|
/* Short term debug to catch buggy drivers */ |
|
if (tty->ops->write_room == NULL) |
|
tty_err(tty, "missing write_room method\n"); |
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return hung_up_tty_write(iocb, from); |
|
if (!ld->ops->write) |
|
ret = -EIO; |
|
else |
|
ret = do_tty_write(ld->ops->write, tty, file, from); |
|
tty_ldisc_deref(ld); |
|
return ret; |
|
} |
|
|
|
static ssize_t tty_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
return file_tty_write(iocb->ki_filp, iocb, from); |
|
} |
|
|
|
ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) |
|
{ |
|
struct file *p = NULL; |
|
|
|
spin_lock(&redirect_lock); |
|
if (redirect) |
|
p = get_file(redirect); |
|
spin_unlock(&redirect_lock); |
|
|
|
/* |
|
* We know the redirected tty is just another tty, we can can |
|
* call file_tty_write() directly with that file pointer. |
|
*/ |
|
if (p) { |
|
ssize_t res; |
|
res = file_tty_write(p, iocb, iter); |
|
fput(p); |
|
return res; |
|
} |
|
return tty_write(iocb, iter); |
|
} |
|
|
|
/* |
|
* tty_send_xchar - send priority character |
|
* |
|
* Send a high priority character to the tty even if stopped |
|
* |
|
* Locking: none for xchar method, write ordering for write method. |
|
*/ |
|
|
|
int tty_send_xchar(struct tty_struct *tty, char ch) |
|
{ |
|
int was_stopped = tty->stopped; |
|
|
|
if (tty->ops->send_xchar) { |
|
down_read(&tty->termios_rwsem); |
|
tty->ops->send_xchar(tty, ch); |
|
up_read(&tty->termios_rwsem); |
|
return 0; |
|
} |
|
|
|
if (tty_write_lock(tty, 0) < 0) |
|
return -ERESTARTSYS; |
|
|
|
down_read(&tty->termios_rwsem); |
|
if (was_stopped) |
|
start_tty(tty); |
|
tty->ops->write(tty, &ch, 1); |
|
if (was_stopped) |
|
stop_tty(tty); |
|
up_read(&tty->termios_rwsem); |
|
tty_write_unlock(tty); |
|
return 0; |
|
} |
|
|
|
static char ptychar[] = "pqrstuvwxyzabcde"; |
|
|
|
/** |
|
* pty_line_name - generate name for a pty |
|
* @driver: the tty driver in use |
|
* @index: the minor number |
|
* @p: output buffer of at least 6 bytes |
|
* |
|
* Generate a name from a driver reference and write it to the output |
|
* buffer. |
|
* |
|
* Locking: None |
|
*/ |
|
static void pty_line_name(struct tty_driver *driver, int index, char *p) |
|
{ |
|
int i = index + driver->name_base; |
|
/* ->name is initialized to "ttyp", but "tty" is expected */ |
|
sprintf(p, "%s%c%x", |
|
driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
|
ptychar[i >> 4 & 0xf], i & 0xf); |
|
} |
|
|
|
/** |
|
* tty_line_name - generate name for a tty |
|
* @driver: the tty driver in use |
|
* @index: the minor number |
|
* @p: output buffer of at least 7 bytes |
|
* |
|
* Generate a name from a driver reference and write it to the output |
|
* buffer. |
|
* |
|
* Locking: None |
|
*/ |
|
static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p) |
|
{ |
|
if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE) |
|
return sprintf(p, "%s", driver->name); |
|
else |
|
return sprintf(p, "%s%d", driver->name, |
|
index + driver->name_base); |
|
} |
|
|
|
/** |
|
* tty_driver_lookup_tty() - find an existing tty, if any |
|
* @driver: the driver for the tty |
|
* @file: file object |
|
* @idx: the minor number |
|
* |
|
* Return the tty, if found. If not found, return NULL or ERR_PTR() if the |
|
* driver lookup() method returns an error. |
|
* |
|
* Locking: tty_mutex must be held. If the tty is found, bump the tty kref. |
|
*/ |
|
static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
|
struct file *file, int idx) |
|
{ |
|
struct tty_struct *tty; |
|
|
|
if (driver->ops->lookup) |
|
if (!file) |
|
tty = ERR_PTR(-EIO); |
|
else |
|
tty = driver->ops->lookup(driver, file, idx); |
|
else |
|
tty = driver->ttys[idx]; |
|
|
|
if (!IS_ERR(tty)) |
|
tty_kref_get(tty); |
|
return tty; |
|
} |
|
|
|
/** |
|
* tty_init_termios - helper for termios setup |
|
* @tty: the tty to set up |
|
* |
|
* Initialise the termios structure for this tty. This runs under |
|
* the tty_mutex currently so we can be relaxed about ordering. |
|
*/ |
|
|
|
void tty_init_termios(struct tty_struct *tty) |
|
{ |
|
struct ktermios *tp; |
|
int idx = tty->index; |
|
|
|
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
|
tty->termios = tty->driver->init_termios; |
|
else { |
|
/* Check for lazy saved data */ |
|
tp = tty->driver->termios[idx]; |
|
if (tp != NULL) { |
|
tty->termios = *tp; |
|
tty->termios.c_line = tty->driver->init_termios.c_line; |
|
} else |
|
tty->termios = tty->driver->init_termios; |
|
} |
|
/* Compatibility until drivers always set this */ |
|
tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios); |
|
tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_init_termios); |
|
|
|
int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
|
{ |
|
tty_init_termios(tty); |
|
tty_driver_kref_get(driver); |
|
tty->count++; |
|
driver->ttys[tty->index] = tty; |
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(tty_standard_install); |
|
|
|
/** |
|
* tty_driver_install_tty() - install a tty entry in the driver |
|
* @driver: the driver for the tty |
|
* @tty: the tty |
|
* |
|
* Install a tty object into the driver tables. The tty->index field |
|
* will be set by the time this is called. This method is responsible |
|
* for ensuring any need additional structures are allocated and |
|
* configured. |
|
* |
|
* Locking: tty_mutex for now |
|
*/ |
|
static int tty_driver_install_tty(struct tty_driver *driver, |
|
struct tty_struct *tty) |
|
{ |
|
return driver->ops->install ? driver->ops->install(driver, tty) : |
|
tty_standard_install(driver, tty); |
|
} |
|
|
|
/** |
|
* tty_driver_remove_tty() - remove a tty from the driver tables |
|
* @driver: the driver for the tty |
|
* @tty: tty to remove |
|
* |
|
* Remvoe a tty object from the driver tables. The tty->index field |
|
* will be set by the time this is called. |
|
* |
|
* Locking: tty_mutex for now |
|
*/ |
|
static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
|
{ |
|
if (driver->ops->remove) |
|
driver->ops->remove(driver, tty); |
|
else |
|
driver->ttys[tty->index] = NULL; |
|
} |
|
|
|
/** |
|
* tty_reopen() - fast re-open of an open tty |
|
* @tty: the tty to open |
|
* |
|
* Return 0 on success, -errno on error. |
|
* Re-opens on master ptys are not allowed and return -EIO. |
|
* |
|
* Locking: Caller must hold tty_lock |
|
*/ |
|
static int tty_reopen(struct tty_struct *tty) |
|
{ |
|
struct tty_driver *driver = tty->driver; |
|
struct tty_ldisc *ld; |
|
int retval = 0; |
|
|
|
if (driver->type == TTY_DRIVER_TYPE_PTY && |
|
driver->subtype == PTY_TYPE_MASTER) |
|
return -EIO; |
|
|
|
if (!tty->count) |
|
return -EAGAIN; |
|
|
|
if (test_bit(TTY_EXCLUSIVE, &tty->flags) && !capable(CAP_SYS_ADMIN)) |
|
return -EBUSY; |
|
|
|
ld = tty_ldisc_ref_wait(tty); |
|
if (ld) { |
|
tty_ldisc_deref(ld); |
|
} else { |
|
retval = tty_ldisc_lock(tty, 5 * HZ); |
|
if (retval) |
|
return retval; |
|
|
|
if (!tty->ldisc) |
|
retval = tty_ldisc_reinit(tty, tty->termios.c_line); |
|
tty_ldisc_unlock(tty); |
|
} |
|
|
|
if (retval == 0) |
|
tty->count++; |
|
|
|
return retval; |
|
} |
|
|
|
/** |
|
* tty_init_dev - initialise a tty device |
|
* @driver: tty driver we are opening a device on |
|
* @idx: device index |
|
* |
|
* Prepare a tty device. This may not be a "new" clean device but |
|
* could also be an active device. The pty drivers require special |
|
* handling because of this. |
|
* |
|
* Locking: |
|
* The function is called under the tty_mutex, which |
|
* protects us from the tty struct or driver itself going away. |
|
* |
|
* On exit the tty device has the line discipline attached and |
|
* a reference count of 1. If a pair was created for pty/tty use |
|
* and the other was a pty master then it too has a reference count of 1. |
|
* |
|
* WSH 06/09/97: Rewritten to remove races and properly clean up after a |
|
* failed open. The new code protects the open with a mutex, so it's |
|
* really quite straightforward. The mutex locking can probably be |
|
* relaxed for the (most common) case of reopening a tty. |
|
* |
|
* Return: returned tty structure |
|
*/ |
|
|
|
struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
|
{ |
|
struct tty_struct *tty; |
|
int retval; |
|
|
|
/* |
|
* First time open is complex, especially for PTY devices. |
|
* This code guarantees that either everything succeeds and the |
|
* TTY is ready for operation, or else the table slots are vacated |
|
* and the allocated memory released. (Except that the termios |
|
* may be retained.) |
|
*/ |
|
|
|
if (!try_module_get(driver->owner)) |
|
return ERR_PTR(-ENODEV); |
|
|
|
tty = alloc_tty_struct(driver, idx); |
|
if (!tty) { |
|
retval = -ENOMEM; |
|
goto err_module_put; |
|
} |
|
|
|
tty_lock(tty); |
|
retval = tty_driver_install_tty(driver, tty); |
|
if (retval < 0) |
|
goto err_free_tty; |
|
|
|
if (!tty->port) |
|
tty->port = driver->ports[idx]; |
|
|
|
if (WARN_RATELIMIT(!tty->port, |
|
"%s: %s driver does not set tty->port. This would crash the kernel. Fix the driver!\n", |
|
__func__, tty->driver->name)) { |
|
retval = -EINVAL; |
|
goto err_release_lock; |
|
} |
|
|
|
retval = tty_ldisc_lock(tty, 5 * HZ); |
|
if (retval) |
|
goto err_release_lock; |
|
tty->port->itty = tty; |
|
|
|
/* |
|
* Structures all installed ... call the ldisc open routines. |
|
* If we fail here just call release_tty to clean up. No need |
|
* to decrement the use counts, as release_tty doesn't care. |
|
*/ |
|
retval = tty_ldisc_setup(tty, tty->link); |
|
if (retval) |
|
goto err_release_tty; |
|
tty_ldisc_unlock(tty); |
|
/* Return the tty locked so that it cannot vanish under the caller */ |
|
return tty; |
|
|
|
err_free_tty: |
|
tty_unlock(tty); |
|
free_tty_struct(tty); |
|
err_module_put: |
|
module_put(driver->owner); |
|
return ERR_PTR(retval); |
|
|
|
/* call the tty release_tty routine to clean out this slot */ |
|
err_release_tty: |
|
tty_ldisc_unlock(tty); |
|
tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n", |
|
retval, idx); |
|
err_release_lock: |
|
tty_unlock(tty); |
|
release_tty(tty, idx); |
|
return ERR_PTR(retval); |
|
} |
|
|
|
/** |
|
* tty_save_termios() - save tty termios data in driver table |
|
* @tty: tty whose termios data to save |
|
* |
|
* Locking: Caller guarantees serialisation with tty_init_termios(). |
|
*/ |
|
void tty_save_termios(struct tty_struct *tty) |
|
{ |
|
struct ktermios *tp; |
|
int idx = tty->index; |
|
|
|
/* If the port is going to reset then it has no termios to save */ |
|
if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) |
|
return; |
|
|
|
/* Stash the termios data */ |
|
tp = tty->driver->termios[idx]; |
|
if (tp == NULL) { |
|
tp = kmalloc(sizeof(*tp), GFP_KERNEL); |
|
if (tp == NULL) |
|
return; |
|
tty->driver->termios[idx] = tp; |
|
} |
|
*tp = tty->termios; |
|
} |
|
EXPORT_SYMBOL_GPL(tty_save_termios); |
|
|
|
/** |
|
* tty_flush_works - flush all works of a tty/pty pair |
|
* @tty: tty device to flush works for (or either end of a pty pair) |
|
* |
|
* Sync flush all works belonging to @tty (and the 'other' tty). |
|
*/ |
|
static void tty_flush_works(struct tty_struct *tty) |
|
{ |
|
flush_work(&tty->SAK_work); |
|
flush_work(&tty->hangup_work); |
|
if (tty->link) { |
|
flush_work(&tty->link->SAK_work); |
|
flush_work(&tty->link->hangup_work); |
|
} |
|
} |
|
|
|
/** |
|
* release_one_tty - release tty structure memory |
|
* @work: work of tty we are obliterating |
|
* |
|
* Releases memory associated with a tty structure, and clears out the |
|
* driver table slots. This function is called when a device is no longer |
|
* in use. It also gets called when setup of a device fails. |
|
* |
|
* Locking: |
|
* takes the file list lock internally when working on the list |
|
* of ttys that the driver keeps. |
|
* |
|
* This method gets called from a work queue so that the driver private |
|
* cleanup ops can sleep (needed for USB at least) |
|
*/ |
|
static void release_one_tty(struct work_struct *work) |
|
{ |
|
struct tty_struct *tty = |
|
container_of(work, struct tty_struct, hangup_work); |
|
struct tty_driver *driver = tty->driver; |
|
struct module *owner = driver->owner; |
|
|
|
if (tty->ops->cleanup) |
|
tty->ops->cleanup(tty); |
|
|
|
tty->magic = 0; |
|
tty_driver_kref_put(driver); |
|
module_put(owner); |
|
|
|
spin_lock(&tty->files_lock); |
|
list_del_init(&tty->tty_files); |
|
spin_unlock(&tty->files_lock); |
|
|
|
put_pid(tty->pgrp); |
|
put_pid(tty->session); |
|
free_tty_struct(tty); |
|
} |
|
|
|
static void queue_release_one_tty(struct kref *kref) |
|
{ |
|
struct tty_struct *tty = container_of(kref, struct tty_struct, kref); |
|
|
|
/* The hangup queue is now free so we can reuse it rather than |
|
waste a chunk of memory for each port */ |
|
INIT_WORK(&tty->hangup_work, release_one_tty); |
|
schedule_work(&tty->hangup_work); |
|
} |
|
|
|
/** |
|
* tty_kref_put - release a tty kref |
|
* @tty: tty device |
|
* |
|
* Release a reference to a tty device and if need be let the kref |
|
* layer destruct the object for us |
|
*/ |
|
|
|
void tty_kref_put(struct tty_struct *tty) |
|
{ |
|
if (tty) |
|
kref_put(&tty->kref, queue_release_one_tty); |
|
} |
|
EXPORT_SYMBOL(tty_kref_put); |
|
|
|
/** |
|
* release_tty - release tty structure memory |
|
* @tty: tty device release |
|
* @idx: index of the tty device release |
|
* |
|
* Release both @tty and a possible linked partner (think pty pair), |
|
* and decrement the refcount of the backing module. |
|
* |
|
* Locking: |
|
* tty_mutex |
|
* takes the file list lock internally when working on the list |
|
* of ttys that the driver keeps. |
|
* |
|
*/ |
|
static void release_tty(struct tty_struct *tty, int idx) |
|
{ |
|
/* This should always be true but check for the moment */ |
|
WARN_ON(tty->index != idx); |
|
WARN_ON(!mutex_is_locked(&tty_mutex)); |
|
if (tty->ops->shutdown) |
|
tty->ops->shutdown(tty); |
|
tty_save_termios(tty); |
|
tty_driver_remove_tty(tty->driver, tty); |
|
if (tty->port) |
|
tty->port->itty = NULL; |
|
if (tty->link) |
|
tty->link->port->itty = NULL; |
|
if (tty->port) |
|
tty_buffer_cancel_work(tty->port); |
|
if (tty->link) |
|
tty_buffer_cancel_work(tty->link->port); |
|
|
|
tty_kref_put(tty->link); |
|
tty_kref_put(tty); |
|
} |
|
|
|
/** |
|
* tty_release_checks - check a tty before real release |
|
* @tty: tty to check |
|
* @idx: index of the tty |
|
* |
|
* Performs some paranoid checking before true release of the @tty. |
|
* This is a no-op unless TTY_PARANOIA_CHECK is defined. |
|
*/ |
|
static int tty_release_checks(struct tty_struct *tty, int idx) |
|
{ |
|
#ifdef TTY_PARANOIA_CHECK |
|
if (idx < 0 || idx >= tty->driver->num) { |
|
tty_debug(tty, "bad idx %d\n", idx); |
|
return -1; |
|
} |
|
|
|
/* not much to check for devpts */ |
|
if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) |
|
return 0; |
|
|
|
if (tty != tty->driver->ttys[idx]) { |
|
tty_debug(tty, "bad driver table[%d] = %p\n", |
|
idx, tty->driver->ttys[idx]); |
|
return -1; |
|
} |
|
if (tty->driver->other) { |
|
struct tty_struct *o_tty = tty->link; |
|
|
|
if (o_tty != tty->driver->other->ttys[idx]) { |
|
tty_debug(tty, "bad other table[%d] = %p\n", |
|
idx, tty->driver->other->ttys[idx]); |
|
return -1; |
|
} |
|
if (o_tty->link != tty) { |
|
tty_debug(tty, "bad link = %p\n", o_tty->link); |
|
return -1; |
|
} |
|
} |
|
#endif |
|
return 0; |
|
} |
|
|
|
/** |
|
* tty_kclose - closes tty opened by tty_kopen |
|
* @tty: tty device |
|
* |
|
* Performs the final steps to release and free a tty device. It is the |
|
* same as tty_release_struct except that it also resets TTY_PORT_KOPENED |
|
* flag on tty->port. |
|
*/ |
|
void tty_kclose(struct tty_struct *tty) |
|
{ |
|
/* |
|
* Ask the line discipline code to release its structures |
|
*/ |
|
tty_ldisc_release(tty); |
|
|
|
/* Wait for pending work before tty destruction commmences */ |
|
tty_flush_works(tty); |
|
|
|
tty_debug_hangup(tty, "freeing structure\n"); |
|
/* |
|
* The release_tty function takes care of the details of clearing |
|
* the slots and preserving the termios structure. |
|
*/ |
|
mutex_lock(&tty_mutex); |
|
tty_port_set_kopened(tty->port, 0); |
|
release_tty(tty, tty->index); |
|
mutex_unlock(&tty_mutex); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_kclose); |
|
|
|
/** |
|
* tty_release_struct - release a tty struct |
|
* @tty: tty device |
|
* @idx: index of the tty |
|
* |
|
* Performs the final steps to release and free a tty device. It is |
|
* roughly the reverse of tty_init_dev. |
|
*/ |
|
void tty_release_struct(struct tty_struct *tty, int idx) |
|
{ |
|
/* |
|
* Ask the line discipline code to release its structures |
|
*/ |
|
tty_ldisc_release(tty); |
|
|
|
/* Wait for pending work before tty destruction commmences */ |
|
tty_flush_works(tty); |
|
|
|
tty_debug_hangup(tty, "freeing structure\n"); |
|
/* |
|
* The release_tty function takes care of the details of clearing |
|
* the slots and preserving the termios structure. |
|
*/ |
|
mutex_lock(&tty_mutex); |
|
release_tty(tty, idx); |
|
mutex_unlock(&tty_mutex); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_release_struct); |
|
|
|
/** |
|
* tty_release - vfs callback for close |
|
* @inode: inode of tty |
|
* @filp: file pointer for handle to tty |
|
* |
|
* Called the last time each file handle is closed that references |
|
* this tty. There may however be several such references. |
|
* |
|
* Locking: |
|
* Takes bkl. See tty_release_dev |
|
* |
|
* Even releasing the tty structures is a tricky business.. We have |
|
* to be very careful that the structures are all released at the |
|
* same time, as interrupts might otherwise get the wrong pointers. |
|
* |
|
* WSH 09/09/97: rewritten to avoid some nasty race conditions that could |
|
* lead to double frees or releasing memory still in use. |
|
*/ |
|
|
|
int tty_release(struct inode *inode, struct file *filp) |
|
{ |
|
struct tty_struct *tty = file_tty(filp); |
|
struct tty_struct *o_tty = NULL; |
|
int do_sleep, final; |
|
int idx; |
|
long timeout = 0; |
|
int once = 1; |
|
|
|
if (tty_paranoia_check(tty, inode, __func__)) |
|
return 0; |
|
|
|
tty_lock(tty); |
|
check_tty_count(tty, __func__); |
|
|
|
__tty_fasync(-1, filp, 0); |
|
|
|
idx = tty->index; |
|
if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
|
tty->driver->subtype == PTY_TYPE_MASTER) |
|
o_tty = tty->link; |
|
|
|
if (tty_release_checks(tty, idx)) { |
|
tty_unlock(tty); |
|
return 0; |
|
} |
|
|
|
tty_debug_hangup(tty, "releasing (count=%d)\n", tty->count); |
|
|
|
if (tty->ops->close) |
|
tty->ops->close(tty, filp); |
|
|
|
/* If tty is pty master, lock the slave pty (stable lock order) */ |
|
tty_lock_slave(o_tty); |
|
|
|
/* |
|
* Sanity check: if tty->count is going to zero, there shouldn't be |
|
* any waiters on tty->read_wait or tty->write_wait. We test the |
|
* wait queues and kick everyone out _before_ actually starting to |
|
* close. This ensures that we won't block while releasing the tty |
|
* structure. |
|
* |
|
* The test for the o_tty closing is necessary, since the master and |
|
* slave sides may close in any order. If the slave side closes out |
|
* first, its count will be one, since the master side holds an open. |
|
* Thus this test wouldn't be triggered at the time the slave closed, |
|
* so we do it now. |
|
*/ |
|
while (1) { |
|
do_sleep = 0; |
|
|
|
if (tty->count <= 1) { |
|
if (waitqueue_active(&tty->read_wait)) { |
|
wake_up_poll(&tty->read_wait, EPOLLIN); |
|
do_sleep++; |
|
} |
|
if (waitqueue_active(&tty->write_wait)) { |
|
wake_up_poll(&tty->write_wait, EPOLLOUT); |
|
do_sleep++; |
|
} |
|
} |
|
if (o_tty && o_tty->count <= 1) { |
|
if (waitqueue_active(&o_tty->read_wait)) { |
|
wake_up_poll(&o_tty->read_wait, EPOLLIN); |
|
do_sleep++; |
|
} |
|
if (waitqueue_active(&o_tty->write_wait)) { |
|
wake_up_poll(&o_tty->write_wait, EPOLLOUT); |
|
do_sleep++; |
|
} |
|
} |
|
if (!do_sleep) |
|
break; |
|
|
|
if (once) { |
|
once = 0; |
|
tty_warn(tty, "read/write wait queue active!\n"); |
|
} |
|
schedule_timeout_killable(timeout); |
|
if (timeout < 120 * HZ) |
|
timeout = 2 * timeout + 1; |
|
else |
|
timeout = MAX_SCHEDULE_TIMEOUT; |
|
} |
|
|
|
if (o_tty) { |
|
if (--o_tty->count < 0) { |
|
tty_warn(tty, "bad slave count (%d)\n", o_tty->count); |
|
o_tty->count = 0; |
|
} |
|
} |
|
if (--tty->count < 0) { |
|
tty_warn(tty, "bad tty->count (%d)\n", tty->count); |
|
tty->count = 0; |
|
} |
|
|
|
/* |
|
* We've decremented tty->count, so we need to remove this file |
|
* descriptor off the tty->tty_files list; this serves two |
|
* purposes: |
|
* - check_tty_count sees the correct number of file descriptors |
|
* associated with this tty. |
|
* - do_tty_hangup no longer sees this file descriptor as |
|
* something that needs to be handled for hangups. |
|
*/ |
|
tty_del_file(filp); |
|
|
|
/* |
|
* Perform some housekeeping before deciding whether to return. |
|
* |
|
* If _either_ side is closing, make sure there aren't any |
|
* processes that still think tty or o_tty is their controlling |
|
* tty. |
|
*/ |
|
if (!tty->count) { |
|
read_lock(&tasklist_lock); |
|
session_clear_tty(tty->session); |
|
if (o_tty) |
|
session_clear_tty(o_tty->session); |
|
read_unlock(&tasklist_lock); |
|
} |
|
|
|
/* check whether both sides are closing ... */ |
|
final = !tty->count && !(o_tty && o_tty->count); |
|
|
|
tty_unlock_slave(o_tty); |
|
tty_unlock(tty); |
|
|
|
/* At this point, the tty->count == 0 should ensure a dead tty |
|
cannot be re-opened by a racing opener */ |
|
|
|
if (!final) |
|
return 0; |
|
|
|
tty_debug_hangup(tty, "final close\n"); |
|
|
|
tty_release_struct(tty, idx); |
|
return 0; |
|
} |
|
|
|
/** |
|
* tty_open_current_tty - get locked tty of current task |
|
* @device: device number |
|
* @filp: file pointer to tty |
|
* @return: locked tty of the current task iff @device is /dev/tty |
|
* |
|
* Performs a re-open of the current task's controlling tty. |
|
* |
|
* We cannot return driver and index like for the other nodes because |
|
* devpts will not work then. It expects inodes to be from devpts FS. |
|
*/ |
|
static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) |
|
{ |
|
struct tty_struct *tty; |
|
int retval; |
|
|
|
if (device != MKDEV(TTYAUX_MAJOR, 0)) |
|
return NULL; |
|
|
|
tty = get_current_tty(); |
|
if (!tty) |
|
return ERR_PTR(-ENXIO); |
|
|
|
filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ |
|
/* noctty = 1; */ |
|
tty_lock(tty); |
|
tty_kref_put(tty); /* safe to drop the kref now */ |
|
|
|
retval = tty_reopen(tty); |
|
if (retval < 0) { |
|
tty_unlock(tty); |
|
tty = ERR_PTR(retval); |
|
} |
|
return tty; |
|
} |
|
|
|
/** |
|
* tty_lookup_driver - lookup a tty driver for a given device file |
|
* @device: device number |
|
* @filp: file pointer to tty |
|
* @index: index for the device in the @return driver |
|
* @return: driver for this inode (with increased refcount) |
|
* |
|
* If @return is not erroneous, the caller is responsible to decrement the |
|
* refcount by tty_driver_kref_put. |
|
* |
|
* Locking: tty_mutex protects get_tty_driver |
|
*/ |
|
static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, |
|
int *index) |
|
{ |
|
struct tty_driver *driver = NULL; |
|
|
|
switch (device) { |
|
#ifdef CONFIG_VT |
|
case MKDEV(TTY_MAJOR, 0): { |
|
extern struct tty_driver *console_driver; |
|
driver = tty_driver_kref_get(console_driver); |
|
*index = fg_console; |
|
break; |
|
} |
|
#endif |
|
case MKDEV(TTYAUX_MAJOR, 1): { |
|
struct tty_driver *console_driver = console_device(index); |
|
if (console_driver) { |
|
driver = tty_driver_kref_get(console_driver); |
|
if (driver && filp) { |
|
/* Don't let /dev/console block */ |
|
filp->f_flags |= O_NONBLOCK; |
|
break; |
|
} |
|
} |
|
if (driver) |
|
tty_driver_kref_put(driver); |
|
return ERR_PTR(-ENODEV); |
|
} |
|
default: |
|
driver = get_tty_driver(device, index); |
|
if (!driver) |
|
return ERR_PTR(-ENODEV); |
|
break; |
|
} |
|
return driver; |
|
} |
|
|
|
static struct tty_struct *tty_kopen(dev_t device, int shared) |
|
{ |
|
struct tty_struct *tty; |
|
struct tty_driver *driver; |
|
int index = -1; |
|
|
|
mutex_lock(&tty_mutex); |
|
driver = tty_lookup_driver(device, NULL, &index); |
|
if (IS_ERR(driver)) { |
|
mutex_unlock(&tty_mutex); |
|
return ERR_CAST(driver); |
|
} |
|
|
|
/* check whether we're reopening an existing tty */ |
|
tty = tty_driver_lookup_tty(driver, NULL, index); |
|
if (IS_ERR(tty) || shared) |
|
goto out; |
|
|
|
if (tty) { |
|
/* drop kref from tty_driver_lookup_tty() */ |
|
tty_kref_put(tty); |
|
tty = ERR_PTR(-EBUSY); |
|
} else { /* tty_init_dev returns tty with the tty_lock held */ |
|
tty = tty_init_dev(driver, index); |
|
if (IS_ERR(tty)) |
|
goto out; |
|
tty_port_set_kopened(tty->port, 1); |
|
} |
|
out: |
|
mutex_unlock(&tty_mutex); |
|
tty_driver_kref_put(driver); |
|
return tty; |
|
} |
|
|
|
/** |
|
* tty_kopen_exclusive - open a tty device for kernel |
|
* @device: dev_t of device to open |
|
* |
|
* Opens tty exclusively for kernel. Performs the driver lookup, |
|
* makes sure it's not already opened and performs the first-time |
|
* tty initialization. |
|
* |
|
* Returns the locked initialized &tty_struct |
|
* |
|
* Claims the global tty_mutex to serialize: |
|
* - concurrent first-time tty initialization |
|
* - concurrent tty driver removal w/ lookup |
|
* - concurrent tty removal from driver table |
|
*/ |
|
struct tty_struct *tty_kopen_exclusive(dev_t device) |
|
{ |
|
return tty_kopen(device, 0); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_kopen_exclusive); |
|
|
|
/** |
|
* tty_kopen_shared - open a tty device for shared in-kernel use |
|
* @device: dev_t of device to open |
|
* |
|
* Opens an already existing tty for in-kernel use. Compared to |
|
* tty_kopen_exclusive() above it doesn't ensure to be the only user. |
|
* |
|
* Locking is identical to tty_kopen() above. |
|
*/ |
|
struct tty_struct *tty_kopen_shared(dev_t device) |
|
{ |
|
return tty_kopen(device, 1); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_kopen_shared); |
|
|
|
/** |
|
* tty_open_by_driver - open a tty device |
|
* @device: dev_t of device to open |
|
* @filp: file pointer to tty |
|
* |
|
* Performs the driver lookup, checks for a reopen, or otherwise |
|
* performs the first-time tty initialization. |
|
* |
|
* Returns the locked initialized or re-opened &tty_struct |
|
* |
|
* Claims the global tty_mutex to serialize: |
|
* - concurrent first-time tty initialization |
|
* - concurrent tty driver removal w/ lookup |
|
* - concurrent tty removal from driver table |
|
*/ |
|
static struct tty_struct *tty_open_by_driver(dev_t device, |
|
struct file *filp) |
|
{ |
|
struct tty_struct *tty; |
|
struct tty_driver *driver = NULL; |
|
int index = -1; |
|
int retval; |
|
|
|
mutex_lock(&tty_mutex); |
|
driver = tty_lookup_driver(device, filp, &index); |
|
if (IS_ERR(driver)) { |
|
mutex_unlock(&tty_mutex); |
|
return ERR_CAST(driver); |
|
} |
|
|
|
/* check whether we're reopening an existing tty */ |
|
tty = tty_driver_lookup_tty(driver, filp, index); |
|
if (IS_ERR(tty)) { |
|
mutex_unlock(&tty_mutex); |
|
goto out; |
|
} |
|
|
|
if (tty) { |
|
if (tty_port_kopened(tty->port)) { |
|
tty_kref_put(tty); |
|
mutex_unlock(&tty_mutex); |
|
tty = ERR_PTR(-EBUSY); |
|
goto out; |
|
} |
|
mutex_unlock(&tty_mutex); |
|
retval = tty_lock_interruptible(tty); |
|
tty_kref_put(tty); /* drop kref from tty_driver_lookup_tty() */ |
|
if (retval) { |
|
if (retval == -EINTR) |
|
retval = -ERESTARTSYS; |
|
tty = ERR_PTR(retval); |
|
goto out; |
|
} |
|
retval = tty_reopen(tty); |
|
if (retval < 0) { |
|
tty_unlock(tty); |
|
tty = ERR_PTR(retval); |
|
} |
|
} else { /* Returns with the tty_lock held for now */ |
|
tty = tty_init_dev(driver, index); |
|
mutex_unlock(&tty_mutex); |
|
} |
|
out: |
|
tty_driver_kref_put(driver); |
|
return tty; |
|
} |
|
|
|
/** |
|
* tty_open - open a tty device |
|
* @inode: inode of device file |
|
* @filp: file pointer to tty |
|
* |
|
* tty_open and tty_release keep up the tty count that contains the |
|
* number of opens done on a tty. We cannot use the inode-count, as |
|
* different inodes might point to the same tty. |
|
* |
|
* Open-counting is needed for pty masters, as well as for keeping |
|
* track of serial lines: DTR is dropped when the last close happens. |
|
* (This is not done solely through tty->count, now. - Ted 1/27/92) |
|
* |
|
* The termios state of a pty is reset on first open so that |
|
* settings don't persist across reuse. |
|
* |
|
* Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
|
* tty->count should protect the rest. |
|
* ->siglock protects ->signal/->sighand |
|
* |
|
* Note: the tty_unlock/lock cases without a ref are only safe due to |
|
* tty_mutex |
|
*/ |
|
|
|
static int tty_open(struct inode *inode, struct file *filp) |
|
{ |
|
struct tty_struct *tty; |
|
int noctty, retval; |
|
dev_t device = inode->i_rdev; |
|
unsigned saved_flags = filp->f_flags; |
|
|
|
nonseekable_open(inode, filp); |
|
|
|
retry_open: |
|
retval = tty_alloc_file(filp); |
|
if (retval) |
|
return -ENOMEM; |
|
|
|
tty = tty_open_current_tty(device, filp); |
|
if (!tty) |
|
tty = tty_open_by_driver(device, filp); |
|
|
|
if (IS_ERR(tty)) { |
|
tty_free_file(filp); |
|
retval = PTR_ERR(tty); |
|
if (retval != -EAGAIN || signal_pending(current)) |
|
return retval; |
|
schedule(); |
|
goto retry_open; |
|
} |
|
|
|
tty_add_file(tty, filp); |
|
|
|
check_tty_count(tty, __func__); |
|
tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
|
|
|
if (tty->ops->open) |
|
retval = tty->ops->open(tty, filp); |
|
else |
|
retval = -ENODEV; |
|
filp->f_flags = saved_flags; |
|
|
|
if (retval) { |
|
tty_debug_hangup(tty, "open error %d, releasing\n", retval); |
|
|
|
tty_unlock(tty); /* need to call tty_release without BTM */ |
|
tty_release(inode, filp); |
|
if (retval != -ERESTARTSYS) |
|
return retval; |
|
|
|
if (signal_pending(current)) |
|
return retval; |
|
|
|
schedule(); |
|
/* |
|
* Need to reset f_op in case a hangup happened. |
|
*/ |
|
if (tty_hung_up_p(filp)) |
|
filp->f_op = &tty_fops; |
|
goto retry_open; |
|
} |
|
clear_bit(TTY_HUPPED, &tty->flags); |
|
|
|
noctty = (filp->f_flags & O_NOCTTY) || |
|
(IS_ENABLED(CONFIG_VT) && device == MKDEV(TTY_MAJOR, 0)) || |
|
device == MKDEV(TTYAUX_MAJOR, 1) || |
|
(tty->driver->type == TTY_DRIVER_TYPE_PTY && |
|
tty->driver->subtype == PTY_TYPE_MASTER); |
|
if (!noctty) |
|
tty_open_proc_set_tty(filp, tty); |
|
tty_unlock(tty); |
|
return 0; |
|
} |
|
|
|
|
|
|
|
/** |
|
* tty_poll - check tty status |
|
* @filp: file being polled |
|
* @wait: poll wait structures to update |
|
* |
|
* Call the line discipline polling method to obtain the poll |
|
* status of the device. |
|
* |
|
* Locking: locks called line discipline but ldisc poll method |
|
* may be re-entered freely by other callers. |
|
*/ |
|
|
|
static __poll_t tty_poll(struct file *filp, poll_table *wait) |
|
{ |
|
struct tty_struct *tty = file_tty(filp); |
|
struct tty_ldisc *ld; |
|
__poll_t ret = 0; |
|
|
|
if (tty_paranoia_check(tty, file_inode(filp), "tty_poll")) |
|
return 0; |
|
|
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return hung_up_tty_poll(filp, wait); |
|
if (ld->ops->poll) |
|
ret = ld->ops->poll(tty, filp, wait); |
|
tty_ldisc_deref(ld); |
|
return ret; |
|
} |
|
|
|
static int __tty_fasync(int fd, struct file *filp, int on) |
|
{ |
|
struct tty_struct *tty = file_tty(filp); |
|
unsigned long flags; |
|
int retval = 0; |
|
|
|
if (tty_paranoia_check(tty, file_inode(filp), "tty_fasync")) |
|
goto out; |
|
|
|
retval = fasync_helper(fd, filp, on, &tty->fasync); |
|
if (retval <= 0) |
|
goto out; |
|
|
|
if (on) { |
|
enum pid_type type; |
|
struct pid *pid; |
|
|
|
spin_lock_irqsave(&tty->ctrl_lock, flags); |
|
if (tty->pgrp) { |
|
pid = tty->pgrp; |
|
type = PIDTYPE_PGID; |
|
} else { |
|
pid = task_pid(current); |
|
type = PIDTYPE_TGID; |
|
} |
|
get_pid(pid); |
|
spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
|
__f_setown(filp, pid, type, 0); |
|
put_pid(pid); |
|
retval = 0; |
|
} |
|
out: |
|
return retval; |
|
} |
|
|
|
static int tty_fasync(int fd, struct file *filp, int on) |
|
{ |
|
struct tty_struct *tty = file_tty(filp); |
|
int retval = -ENOTTY; |
|
|
|
tty_lock(tty); |
|
if (!tty_hung_up_p(filp)) |
|
retval = __tty_fasync(fd, filp, on); |
|
tty_unlock(tty); |
|
|
|
return retval; |
|
} |
|
|
|
/** |
|
* tiocsti - fake input character |
|
* @tty: tty to fake input into |
|
* @p: pointer to character |
|
* |
|
* Fake input to a tty device. Does the necessary locking and |
|
* input management. |
|
* |
|
* FIXME: does not honour flow control ?? |
|
* |
|
* Locking: |
|
* Called functions take tty_ldiscs_lock |
|
* current->signal->tty check is safe without locks |
|
* |
|
* FIXME: may race normal receive processing |
|
*/ |
|
|
|
static int tiocsti(struct tty_struct *tty, char __user *p) |
|
{ |
|
char ch, mbz = 0; |
|
struct tty_ldisc *ld; |
|
|
|
if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
|
return -EPERM; |
|
if (get_user(ch, p)) |
|
return -EFAULT; |
|
tty_audit_tiocsti(tty, ch); |
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return -EIO; |
|
if (ld->ops->receive_buf) |
|
ld->ops->receive_buf(tty, &ch, &mbz, 1); |
|
tty_ldisc_deref(ld); |
|
return 0; |
|
} |
|
|
|
/** |
|
* tiocgwinsz - implement window query ioctl |
|
* @tty: tty |
|
* @arg: user buffer for result |
|
* |
|
* Copies the kernel idea of the window size into the user buffer. |
|
* |
|
* Locking: tty->winsize_mutex is taken to ensure the winsize data |
|
* is consistent. |
|
*/ |
|
|
|
static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
|
{ |
|
int err; |
|
|
|
mutex_lock(&tty->winsize_mutex); |
|
err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
|
mutex_unlock(&tty->winsize_mutex); |
|
|
|
return err ? -EFAULT: 0; |
|
} |
|
|
|
/** |
|
* tty_do_resize - resize event |
|
* @tty: tty being resized |
|
* @ws: new dimensions |
|
* |
|
* Update the termios variables and send the necessary signals to |
|
* peform a terminal resize correctly |
|
*/ |
|
|
|
int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
|
{ |
|
struct pid *pgrp; |
|
|
|
/* Lock the tty */ |
|
mutex_lock(&tty->winsize_mutex); |
|
if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
|
goto done; |
|
|
|
/* Signal the foreground process group */ |
|
pgrp = tty_get_pgrp(tty); |
|
if (pgrp) |
|
kill_pgrp(pgrp, SIGWINCH, 1); |
|
put_pid(pgrp); |
|
|
|
tty->winsize = *ws; |
|
done: |
|
mutex_unlock(&tty->winsize_mutex); |
|
return 0; |
|
} |
|
EXPORT_SYMBOL(tty_do_resize); |
|
|
|
/** |
|
* tiocswinsz - implement window size set ioctl |
|
* @tty: tty side of tty |
|
* @arg: user buffer for result |
|
* |
|
* Copies the user idea of the window size to the kernel. Traditionally |
|
* this is just advisory information but for the Linux console it |
|
* actually has driver level meaning and triggers a VC resize. |
|
* |
|
* Locking: |
|
* Driver dependent. The default do_resize method takes the |
|
* tty termios mutex and ctrl_lock. The console takes its own lock |
|
* then calls into the default method. |
|
*/ |
|
|
|
static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
|
{ |
|
struct winsize tmp_ws; |
|
if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) |
|
return -EFAULT; |
|
|
|
if (tty->ops->resize) |
|
return tty->ops->resize(tty, &tmp_ws); |
|
else |
|
return tty_do_resize(tty, &tmp_ws); |
|
} |
|
|
|
/** |
|
* tioccons - allow admin to move logical console |
|
* @file: the file to become console |
|
* |
|
* Allow the administrator to move the redirected console device |
|
* |
|
* Locking: uses redirect_lock to guard the redirect information |
|
*/ |
|
|
|
static int tioccons(struct file *file) |
|
{ |
|
if (!capable(CAP_SYS_ADMIN)) |
|
return -EPERM; |
|
if (file->f_op->write_iter == redirected_tty_write) { |
|
struct file *f; |
|
spin_lock(&redirect_lock); |
|
f = redirect; |
|
redirect = NULL; |
|
spin_unlock(&redirect_lock); |
|
if (f) |
|
fput(f); |
|
return 0; |
|
} |
|
if (file->f_op->write_iter != tty_write) |
|
return -ENOTTY; |
|
if (!(file->f_mode & FMODE_WRITE)) |
|
return -EBADF; |
|
if (!(file->f_mode & FMODE_CAN_WRITE)) |
|
return -EINVAL; |
|
spin_lock(&redirect_lock); |
|
if (redirect) { |
|
spin_unlock(&redirect_lock); |
|
return -EBUSY; |
|
} |
|
redirect = get_file(file); |
|
spin_unlock(&redirect_lock); |
|
return 0; |
|
} |
|
|
|
/** |
|
* tiocsetd - set line discipline |
|
* @tty: tty device |
|
* @p: pointer to user data |
|
* |
|
* Set the line discipline according to user request. |
|
* |
|
* Locking: see tty_set_ldisc, this function is just a helper |
|
*/ |
|
|
|
static int tiocsetd(struct tty_struct *tty, int __user *p) |
|
{ |
|
int disc; |
|
int ret; |
|
|
|
if (get_user(disc, p)) |
|
return -EFAULT; |
|
|
|
ret = tty_set_ldisc(tty, disc); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* tiocgetd - get line discipline |
|
* @tty: tty device |
|
* @p: pointer to user data |
|
* |
|
* Retrieves the line discipline id directly from the ldisc. |
|
* |
|
* Locking: waits for ldisc reference (in case the line discipline |
|
* is changing or the tty is being hungup) |
|
*/ |
|
|
|
static int tiocgetd(struct tty_struct *tty, int __user *p) |
|
{ |
|
struct tty_ldisc *ld; |
|
int ret; |
|
|
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return -EIO; |
|
ret = put_user(ld->ops->num, p); |
|
tty_ldisc_deref(ld); |
|
return ret; |
|
} |
|
|
|
/** |
|
* send_break - performed time break |
|
* @tty: device to break on |
|
* @duration: timeout in mS |
|
* |
|
* Perform a timed break on hardware that lacks its own driver level |
|
* timed break functionality. |
|
* |
|
* Locking: |
|
* atomic_write_lock serializes |
|
* |
|
*/ |
|
|
|
static int send_break(struct tty_struct *tty, unsigned int duration) |
|
{ |
|
int retval; |
|
|
|
if (tty->ops->break_ctl == NULL) |
|
return 0; |
|
|
|
if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) |
|
retval = tty->ops->break_ctl(tty, duration); |
|
else { |
|
/* Do the work ourselves */ |
|
if (tty_write_lock(tty, 0) < 0) |
|
return -EINTR; |
|
retval = tty->ops->break_ctl(tty, -1); |
|
if (retval) |
|
goto out; |
|
if (!signal_pending(current)) |
|
msleep_interruptible(duration); |
|
retval = tty->ops->break_ctl(tty, 0); |
|
out: |
|
tty_write_unlock(tty); |
|
if (signal_pending(current)) |
|
retval = -EINTR; |
|
} |
|
return retval; |
|
} |
|
|
|
/** |
|
* tty_tiocmget - get modem status |
|
* @tty: tty device |
|
* @p: pointer to result |
|
* |
|
* Obtain the modem status bits from the tty driver if the feature |
|
* is supported. Return -ENOTTY if it is not available. |
|
* |
|
* Locking: none (up to the driver) |
|
*/ |
|
|
|
static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
|
{ |
|
int retval = -ENOTTY; |
|
|
|
if (tty->ops->tiocmget) { |
|
retval = tty->ops->tiocmget(tty); |
|
|
|
if (retval >= 0) |
|
retval = put_user(retval, p); |
|
} |
|
return retval; |
|
} |
|
|
|
/** |
|
* tty_tiocmset - set modem status |
|
* @tty: tty device |
|
* @cmd: command - clear bits, set bits or set all |
|
* @p: pointer to desired bits |
|
* |
|
* Set the modem status bits from the tty driver if the feature |
|
* is supported. Return -ENOTTY if it is not available. |
|
* |
|
* Locking: none (up to the driver) |
|
*/ |
|
|
|
static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
|
unsigned __user *p) |
|
{ |
|
int retval; |
|
unsigned int set, clear, val; |
|
|
|
if (tty->ops->tiocmset == NULL) |
|
return -ENOTTY; |
|
|
|
retval = get_user(val, p); |
|
if (retval) |
|
return retval; |
|
set = clear = 0; |
|
switch (cmd) { |
|
case TIOCMBIS: |
|
set = val; |
|
break; |
|
case TIOCMBIC: |
|
clear = val; |
|
break; |
|
case TIOCMSET: |
|
set = val; |
|
clear = ~val; |
|
break; |
|
} |
|
set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
|
clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; |
|
return tty->ops->tiocmset(tty, set, clear); |
|
} |
|
|
|
/** |
|
* tty_get_icount - get tty statistics |
|
* @tty: tty device |
|
* @icount: output parameter |
|
* |
|
* Gets a copy of the tty's icount statistics. |
|
* |
|
* Locking: none (up to the driver) |
|
*/ |
|
int tty_get_icount(struct tty_struct *tty, |
|
struct serial_icounter_struct *icount) |
|
{ |
|
memset(icount, 0, sizeof(*icount)); |
|
|
|
if (tty->ops->get_icount) |
|
return tty->ops->get_icount(tty, icount); |
|
else |
|
return -ENOTTY; |
|
} |
|
EXPORT_SYMBOL_GPL(tty_get_icount); |
|
|
|
static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
|
{ |
|
struct serial_icounter_struct icount; |
|
int retval; |
|
|
|
retval = tty_get_icount(tty, &icount); |
|
if (retval != 0) |
|
return retval; |
|
|
|
if (copy_to_user(arg, &icount, sizeof(icount))) |
|
return -EFAULT; |
|
return 0; |
|
} |
|
|
|
static int tty_tiocsserial(struct tty_struct *tty, struct serial_struct __user *ss) |
|
{ |
|
static DEFINE_RATELIMIT_STATE(depr_flags, |
|
DEFAULT_RATELIMIT_INTERVAL, |
|
DEFAULT_RATELIMIT_BURST); |
|
char comm[TASK_COMM_LEN]; |
|
struct serial_struct v; |
|
int flags; |
|
|
|
if (copy_from_user(&v, ss, sizeof(*ss))) |
|
return -EFAULT; |
|
|
|
flags = v.flags & ASYNC_DEPRECATED; |
|
|
|
if (flags && __ratelimit(&depr_flags)) |
|
pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", |
|
__func__, get_task_comm(comm, current), flags); |
|
if (!tty->ops->set_serial) |
|
return -ENOTTY; |
|
return tty->ops->set_serial(tty, &v); |
|
} |
|
|
|
static int tty_tiocgserial(struct tty_struct *tty, struct serial_struct __user *ss) |
|
{ |
|
struct serial_struct v; |
|
int err; |
|
|
|
memset(&v, 0, sizeof(v)); |
|
if (!tty->ops->get_serial) |
|
return -ENOTTY; |
|
err = tty->ops->get_serial(tty, &v); |
|
if (!err && copy_to_user(ss, &v, sizeof(v))) |
|
err = -EFAULT; |
|
return err; |
|
} |
|
|
|
/* |
|
* if pty, return the slave side (real_tty) |
|
* otherwise, return self |
|
*/ |
|
static struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
|
{ |
|
if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
|
tty->driver->subtype == PTY_TYPE_MASTER) |
|
tty = tty->link; |
|
return tty; |
|
} |
|
|
|
/* |
|
* Split this up, as gcc can choke on it otherwise.. |
|
*/ |
|
long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
|
{ |
|
struct tty_struct *tty = file_tty(file); |
|
struct tty_struct *real_tty; |
|
void __user *p = (void __user *)arg; |
|
int retval; |
|
struct tty_ldisc *ld; |
|
|
|
if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
|
return -EINVAL; |
|
|
|
real_tty = tty_pair_get_tty(tty); |
|
|
|
/* |
|
* Factor out some common prep work |
|
*/ |
|
switch (cmd) { |
|
case TIOCSETD: |
|
case TIOCSBRK: |
|
case TIOCCBRK: |
|
case TCSBRK: |
|
case TCSBRKP: |
|
retval = tty_check_change(tty); |
|
if (retval) |
|
return retval; |
|
if (cmd != TIOCCBRK) { |
|
tty_wait_until_sent(tty, 0); |
|
if (signal_pending(current)) |
|
return -EINTR; |
|
} |
|
break; |
|
} |
|
|
|
/* |
|
* Now do the stuff. |
|
*/ |
|
switch (cmd) { |
|
case TIOCSTI: |
|
return tiocsti(tty, p); |
|
case TIOCGWINSZ: |
|
return tiocgwinsz(real_tty, p); |
|
case TIOCSWINSZ: |
|
return tiocswinsz(real_tty, p); |
|
case TIOCCONS: |
|
return real_tty != tty ? -EINVAL : tioccons(file); |
|
case TIOCEXCL: |
|
set_bit(TTY_EXCLUSIVE, &tty->flags); |
|
return 0; |
|
case TIOCNXCL: |
|
clear_bit(TTY_EXCLUSIVE, &tty->flags); |
|
return 0; |
|
case TIOCGEXCL: |
|
{ |
|
int excl = test_bit(TTY_EXCLUSIVE, &tty->flags); |
|
return put_user(excl, (int __user *)p); |
|
} |
|
case TIOCGETD: |
|
return tiocgetd(tty, p); |
|
case TIOCSETD: |
|
return tiocsetd(tty, p); |
|
case TIOCVHANGUP: |
|
if (!capable(CAP_SYS_ADMIN)) |
|
return -EPERM; |
|
tty_vhangup(tty); |
|
return 0; |
|
case TIOCGDEV: |
|
{ |
|
unsigned int ret = new_encode_dev(tty_devnum(real_tty)); |
|
return put_user(ret, (unsigned int __user *)p); |
|
} |
|
/* |
|
* Break handling |
|
*/ |
|
case TIOCSBRK: /* Turn break on, unconditionally */ |
|
if (tty->ops->break_ctl) |
|
return tty->ops->break_ctl(tty, -1); |
|
return 0; |
|
case TIOCCBRK: /* Turn break off, unconditionally */ |
|
if (tty->ops->break_ctl) |
|
return tty->ops->break_ctl(tty, 0); |
|
return 0; |
|
case TCSBRK: /* SVID version: non-zero arg --> no break */ |
|
/* non-zero arg means wait for all output data |
|
* to be sent (performed above) but don't send break. |
|
* This is used by the tcdrain() termios function. |
|
*/ |
|
if (!arg) |
|
return send_break(tty, 250); |
|
return 0; |
|
case TCSBRKP: /* support for POSIX tcsendbreak() */ |
|
return send_break(tty, arg ? arg*100 : 250); |
|
|
|
case TIOCMGET: |
|
return tty_tiocmget(tty, p); |
|
case TIOCMSET: |
|
case TIOCMBIC: |
|
case TIOCMBIS: |
|
return tty_tiocmset(tty, cmd, p); |
|
case TIOCGICOUNT: |
|
return tty_tiocgicount(tty, p); |
|
case TCFLSH: |
|
switch (arg) { |
|
case TCIFLUSH: |
|
case TCIOFLUSH: |
|
/* flush tty buffer and allow ldisc to process ioctl */ |
|
tty_buffer_flush(tty, NULL); |
|
break; |
|
} |
|
break; |
|
case TIOCSSERIAL: |
|
return tty_tiocsserial(tty, p); |
|
case TIOCGSERIAL: |
|
return tty_tiocgserial(tty, p); |
|
case TIOCGPTPEER: |
|
/* Special because the struct file is needed */ |
|
return ptm_open_peer(file, tty, (int)arg); |
|
default: |
|
retval = tty_jobctrl_ioctl(tty, real_tty, file, cmd, arg); |
|
if (retval != -ENOIOCTLCMD) |
|
return retval; |
|
} |
|
if (tty->ops->ioctl) { |
|
retval = tty->ops->ioctl(tty, cmd, arg); |
|
if (retval != -ENOIOCTLCMD) |
|
return retval; |
|
} |
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return hung_up_tty_ioctl(file, cmd, arg); |
|
retval = -EINVAL; |
|
if (ld->ops->ioctl) { |
|
retval = ld->ops->ioctl(tty, file, cmd, arg); |
|
if (retval == -ENOIOCTLCMD) |
|
retval = -ENOTTY; |
|
} |
|
tty_ldisc_deref(ld); |
|
return retval; |
|
} |
|
|
|
#ifdef CONFIG_COMPAT |
|
|
|
struct serial_struct32 { |
|
compat_int_t type; |
|
compat_int_t line; |
|
compat_uint_t port; |
|
compat_int_t irq; |
|
compat_int_t flags; |
|
compat_int_t xmit_fifo_size; |
|
compat_int_t custom_divisor; |
|
compat_int_t baud_base; |
|
unsigned short close_delay; |
|
char io_type; |
|
char reserved_char; |
|
compat_int_t hub6; |
|
unsigned short closing_wait; /* time to wait before closing */ |
|
unsigned short closing_wait2; /* no longer used... */ |
|
compat_uint_t iomem_base; |
|
unsigned short iomem_reg_shift; |
|
unsigned int port_high; |
|
/* compat_ulong_t iomap_base FIXME */ |
|
compat_int_t reserved; |
|
}; |
|
|
|
static int compat_tty_tiocsserial(struct tty_struct *tty, |
|
struct serial_struct32 __user *ss) |
|
{ |
|
static DEFINE_RATELIMIT_STATE(depr_flags, |
|
DEFAULT_RATELIMIT_INTERVAL, |
|
DEFAULT_RATELIMIT_BURST); |
|
char comm[TASK_COMM_LEN]; |
|
struct serial_struct32 v32; |
|
struct serial_struct v; |
|
int flags; |
|
|
|
if (copy_from_user(&v32, ss, sizeof(*ss))) |
|
return -EFAULT; |
|
|
|
memcpy(&v, &v32, offsetof(struct serial_struct32, iomem_base)); |
|
v.iomem_base = compat_ptr(v32.iomem_base); |
|
v.iomem_reg_shift = v32.iomem_reg_shift; |
|
v.port_high = v32.port_high; |
|
v.iomap_base = 0; |
|
|
|
flags = v.flags & ASYNC_DEPRECATED; |
|
|
|
if (flags && __ratelimit(&depr_flags)) |
|
pr_warn("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", |
|
__func__, get_task_comm(comm, current), flags); |
|
if (!tty->ops->set_serial) |
|
return -ENOTTY; |
|
return tty->ops->set_serial(tty, &v); |
|
} |
|
|
|
static int compat_tty_tiocgserial(struct tty_struct *tty, |
|
struct serial_struct32 __user *ss) |
|
{ |
|
struct serial_struct32 v32; |
|
struct serial_struct v; |
|
int err; |
|
|
|
memset(&v, 0, sizeof(v)); |
|
memset(&v32, 0, sizeof(v32)); |
|
|
|
if (!tty->ops->get_serial) |
|
return -ENOTTY; |
|
err = tty->ops->get_serial(tty, &v); |
|
if (!err) { |
|
memcpy(&v32, &v, offsetof(struct serial_struct32, iomem_base)); |
|
v32.iomem_base = (unsigned long)v.iomem_base >> 32 ? |
|
0xfffffff : ptr_to_compat(v.iomem_base); |
|
v32.iomem_reg_shift = v.iomem_reg_shift; |
|
v32.port_high = v.port_high; |
|
if (copy_to_user(ss, &v32, sizeof(v32))) |
|
err = -EFAULT; |
|
} |
|
return err; |
|
} |
|
static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
|
unsigned long arg) |
|
{ |
|
struct tty_struct *tty = file_tty(file); |
|
struct tty_ldisc *ld; |
|
int retval = -ENOIOCTLCMD; |
|
|
|
switch (cmd) { |
|
case TIOCOUTQ: |
|
case TIOCSTI: |
|
case TIOCGWINSZ: |
|
case TIOCSWINSZ: |
|
case TIOCGEXCL: |
|
case TIOCGETD: |
|
case TIOCSETD: |
|
case TIOCGDEV: |
|
case TIOCMGET: |
|
case TIOCMSET: |
|
case TIOCMBIC: |
|
case TIOCMBIS: |
|
case TIOCGICOUNT: |
|
case TIOCGPGRP: |
|
case TIOCSPGRP: |
|
case TIOCGSID: |
|
case TIOCSERGETLSR: |
|
case TIOCGRS485: |
|
case TIOCSRS485: |
|
#ifdef TIOCGETP |
|
case TIOCGETP: |
|
case TIOCSETP: |
|
case TIOCSETN: |
|
#endif |
|
#ifdef TIOCGETC |
|
case TIOCGETC: |
|
case TIOCSETC: |
|
#endif |
|
#ifdef TIOCGLTC |
|
case TIOCGLTC: |
|
case TIOCSLTC: |
|
#endif |
|
case TCSETSF: |
|
case TCSETSW: |
|
case TCSETS: |
|
case TCGETS: |
|
#ifdef TCGETS2 |
|
case TCGETS2: |
|
case TCSETSF2: |
|
case TCSETSW2: |
|
case TCSETS2: |
|
#endif |
|
case TCGETA: |
|
case TCSETAF: |
|
case TCSETAW: |
|
case TCSETA: |
|
case TIOCGLCKTRMIOS: |
|
case TIOCSLCKTRMIOS: |
|
#ifdef TCGETX |
|
case TCGETX: |
|
case TCSETX: |
|
case TCSETXW: |
|
case TCSETXF: |
|
#endif |
|
case TIOCGSOFTCAR: |
|
case TIOCSSOFTCAR: |
|
|
|
case PPPIOCGCHAN: |
|
case PPPIOCGUNIT: |
|
return tty_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); |
|
case TIOCCONS: |
|
case TIOCEXCL: |
|
case TIOCNXCL: |
|
case TIOCVHANGUP: |
|
case TIOCSBRK: |
|
case TIOCCBRK: |
|
case TCSBRK: |
|
case TCSBRKP: |
|
case TCFLSH: |
|
case TIOCGPTPEER: |
|
case TIOCNOTTY: |
|
case TIOCSCTTY: |
|
case TCXONC: |
|
case TIOCMIWAIT: |
|
case TIOCSERCONFIG: |
|
return tty_ioctl(file, cmd, arg); |
|
} |
|
|
|
if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl")) |
|
return -EINVAL; |
|
|
|
switch (cmd) { |
|
case TIOCSSERIAL: |
|
return compat_tty_tiocsserial(tty, compat_ptr(arg)); |
|
case TIOCGSERIAL: |
|
return compat_tty_tiocgserial(tty, compat_ptr(arg)); |
|
} |
|
if (tty->ops->compat_ioctl) { |
|
retval = tty->ops->compat_ioctl(tty, cmd, arg); |
|
if (retval != -ENOIOCTLCMD) |
|
return retval; |
|
} |
|
|
|
ld = tty_ldisc_ref_wait(tty); |
|
if (!ld) |
|
return hung_up_tty_compat_ioctl(file, cmd, arg); |
|
if (ld->ops->compat_ioctl) |
|
retval = ld->ops->compat_ioctl(tty, file, cmd, arg); |
|
if (retval == -ENOIOCTLCMD && ld->ops->ioctl) |
|
retval = ld->ops->ioctl(tty, file, |
|
(unsigned long)compat_ptr(cmd), arg); |
|
tty_ldisc_deref(ld); |
|
|
|
return retval; |
|
} |
|
#endif |
|
|
|
static int this_tty(const void *t, struct file *file, unsigned fd) |
|
{ |
|
if (likely(file->f_op->read_iter != tty_read)) |
|
return 0; |
|
return file_tty(file) != t ? 0 : fd + 1; |
|
} |
|
|
|
/* |
|
* This implements the "Secure Attention Key" --- the idea is to |
|
* prevent trojan horses by killing all processes associated with this |
|
* tty when the user hits the "Secure Attention Key". Required for |
|
* super-paranoid applications --- see the Orange Book for more details. |
|
* |
|
* This code could be nicer; ideally it should send a HUP, wait a few |
|
* seconds, then send a INT, and then a KILL signal. But you then |
|
* have to coordinate with the init process, since all processes associated |
|
* with the current tty must be dead before the new getty is allowed |
|
* to spawn. |
|
* |
|
* Now, if it would be correct ;-/ The current code has a nasty hole - |
|
* it doesn't catch files in flight. We may send the descriptor to ourselves |
|
* via AF_UNIX socket, close it and later fetch from socket. FIXME. |
|
* |
|
* Nasty bug: do_SAK is being called in interrupt context. This can |
|
* deadlock. We punt it up to process context. AKPM - 16Mar2001 |
|
*/ |
|
void __do_SAK(struct tty_struct *tty) |
|
{ |
|
#ifdef TTY_SOFT_SAK |
|
tty_hangup(tty); |
|
#else |
|
struct task_struct *g, *p; |
|
struct pid *session; |
|
int i; |
|
unsigned long flags; |
|
|
|
if (!tty) |
|
return; |
|
|
|
spin_lock_irqsave(&tty->ctrl_lock, flags); |
|
session = get_pid(tty->session); |
|
spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
|
|
|
tty_ldisc_flush(tty); |
|
|
|
tty_driver_flush_buffer(tty); |
|
|
|
read_lock(&tasklist_lock); |
|
/* Kill the entire session */ |
|
do_each_pid_task(session, PIDTYPE_SID, p) { |
|
tty_notice(tty, "SAK: killed process %d (%s): by session\n", |
|
task_pid_nr(p), p->comm); |
|
group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
|
} while_each_pid_task(session, PIDTYPE_SID, p); |
|
|
|
/* Now kill any processes that happen to have the tty open */ |
|
do_each_thread(g, p) { |
|
if (p->signal->tty == tty) { |
|
tty_notice(tty, "SAK: killed process %d (%s): by controlling tty\n", |
|
task_pid_nr(p), p->comm); |
|
group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
|
continue; |
|
} |
|
task_lock(p); |
|
i = iterate_fd(p->files, 0, this_tty, tty); |
|
if (i != 0) { |
|
tty_notice(tty, "SAK: killed process %d (%s): by fd#%d\n", |
|
task_pid_nr(p), p->comm, i - 1); |
|
group_send_sig_info(SIGKILL, SEND_SIG_PRIV, p, PIDTYPE_SID); |
|
} |
|
task_unlock(p); |
|
} while_each_thread(g, p); |
|
read_unlock(&tasklist_lock); |
|
put_pid(session); |
|
#endif |
|
} |
|
|
|
static void do_SAK_work(struct work_struct *work) |
|
{ |
|
struct tty_struct *tty = |
|
container_of(work, struct tty_struct, SAK_work); |
|
__do_SAK(tty); |
|
} |
|
|
|
/* |
|
* The tq handling here is a little racy - tty->SAK_work may already be queued. |
|
* Fortunately we don't need to worry, because if ->SAK_work is already queued, |
|
* the values which we write to it will be identical to the values which it |
|
* already has. --akpm |
|
*/ |
|
void do_SAK(struct tty_struct *tty) |
|
{ |
|
if (!tty) |
|
return; |
|
schedule_work(&tty->SAK_work); |
|
} |
|
|
|
EXPORT_SYMBOL(do_SAK); |
|
|
|
/* Must put_device() after it's unused! */ |
|
static struct device *tty_get_device(struct tty_struct *tty) |
|
{ |
|
dev_t devt = tty_devnum(tty); |
|
return class_find_device_by_devt(tty_class, devt); |
|
} |
|
|
|
|
|
/* |
|
* alloc_tty_struct |
|
* |
|
* This subroutine allocates and initializes a tty structure. |
|
* |
|
* Locking: none - tty in question is not exposed at this point |
|
*/ |
|
|
|
struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) |
|
{ |
|
struct tty_struct *tty; |
|
|
|
tty = kzalloc(sizeof(*tty), GFP_KERNEL); |
|
if (!tty) |
|
return NULL; |
|
|
|
kref_init(&tty->kref); |
|
tty->magic = TTY_MAGIC; |
|
if (tty_ldisc_init(tty)) { |
|
kfree(tty); |
|
return NULL; |
|
} |
|
tty->session = NULL; |
|
tty->pgrp = NULL; |
|
mutex_init(&tty->legacy_mutex); |
|
mutex_init(&tty->throttle_mutex); |
|
init_rwsem(&tty->termios_rwsem); |
|
mutex_init(&tty->winsize_mutex); |
|
init_ldsem(&tty->ldisc_sem); |
|
init_waitqueue_head(&tty->write_wait); |
|
init_waitqueue_head(&tty->read_wait); |
|
INIT_WORK(&tty->hangup_work, do_tty_hangup); |
|
mutex_init(&tty->atomic_write_lock); |
|
spin_lock_init(&tty->ctrl_lock); |
|
spin_lock_init(&tty->flow_lock); |
|
spin_lock_init(&tty->files_lock); |
|
INIT_LIST_HEAD(&tty->tty_files); |
|
INIT_WORK(&tty->SAK_work, do_SAK_work); |
|
|
|
tty->driver = driver; |
|
tty->ops = driver->ops; |
|
tty->index = idx; |
|
tty_line_name(driver, idx, tty->name); |
|
tty->dev = tty_get_device(tty); |
|
|
|
return tty; |
|
} |
|
|
|
/** |
|
* tty_put_char - write one character to a tty |
|
* @tty: tty |
|
* @ch: character |
|
* |
|
* Write one byte to the tty using the provided put_char method |
|
* if present. Returns the number of characters successfully output. |
|
* |
|
* Note: the specific put_char operation in the driver layer may go |
|
* away soon. Don't call it directly, use this method |
|
*/ |
|
|
|
int tty_put_char(struct tty_struct *tty, unsigned char ch) |
|
{ |
|
if (tty->ops->put_char) |
|
return tty->ops->put_char(tty, ch); |
|
return tty->ops->write(tty, &ch, 1); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_put_char); |
|
|
|
struct class *tty_class; |
|
|
|
static int tty_cdev_add(struct tty_driver *driver, dev_t dev, |
|
unsigned int index, unsigned int count) |
|
{ |
|
int err; |
|
|
|
/* init here, since reused cdevs cause crashes */ |
|
driver->cdevs[index] = cdev_alloc(); |
|
if (!driver->cdevs[index]) |
|
return -ENOMEM; |
|
driver->cdevs[index]->ops = &tty_fops; |
|
driver->cdevs[index]->owner = driver->owner; |
|
err = cdev_add(driver->cdevs[index], dev, count); |
|
if (err) |
|
kobject_put(&driver->cdevs[index]->kobj); |
|
return err; |
|
} |
|
|
|
/** |
|
* tty_register_device - register a tty device |
|
* @driver: the tty driver that describes the tty device |
|
* @index: the index in the tty driver for this tty device |
|
* @device: a struct device that is associated with this tty device. |
|
* This field is optional, if there is no known struct device |
|
* for this tty device it can be set to NULL safely. |
|
* |
|
* Returns a pointer to the struct device for this tty device |
|
* (or ERR_PTR(-EFOO) on error). |
|
* |
|
* This call is required to be made to register an individual tty device |
|
* if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If |
|
* that bit is not set, this function should not be called by a tty |
|
* driver. |
|
* |
|
* Locking: ?? |
|
*/ |
|
|
|
struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
|
struct device *device) |
|
{ |
|
return tty_register_device_attr(driver, index, device, NULL, NULL); |
|
} |
|
EXPORT_SYMBOL(tty_register_device); |
|
|
|
static void tty_device_create_release(struct device *dev) |
|
{ |
|
dev_dbg(dev, "releasing...\n"); |
|
kfree(dev); |
|
} |
|
|
|
/** |
|
* tty_register_device_attr - register a tty device |
|
* @driver: the tty driver that describes the tty device |
|
* @index: the index in the tty driver for this tty device |
|
* @device: a struct device that is associated with this tty device. |
|
* This field is optional, if there is no known struct device |
|
* for this tty device it can be set to NULL safely. |
|
* @drvdata: Driver data to be set to device. |
|
* @attr_grp: Attribute group to be set on device. |
|
* |
|
* Returns a pointer to the struct device for this tty device |
|
* (or ERR_PTR(-EFOO) on error). |
|
* |
|
* This call is required to be made to register an individual tty device |
|
* if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If |
|
* that bit is not set, this function should not be called by a tty |
|
* driver. |
|
* |
|
* Locking: ?? |
|
*/ |
|
struct device *tty_register_device_attr(struct tty_driver *driver, |
|
unsigned index, struct device *device, |
|
void *drvdata, |
|
const struct attribute_group **attr_grp) |
|
{ |
|
char name[64]; |
|
dev_t devt = MKDEV(driver->major, driver->minor_start) + index; |
|
struct ktermios *tp; |
|
struct device *dev; |
|
int retval; |
|
|
|
if (index >= driver->num) { |
|
pr_err("%s: Attempt to register invalid tty line number (%d)\n", |
|
driver->name, index); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
if (driver->type == TTY_DRIVER_TYPE_PTY) |
|
pty_line_name(driver, index, name); |
|
else |
|
tty_line_name(driver, index, name); |
|
|
|
dev = kzalloc(sizeof(*dev), GFP_KERNEL); |
|
if (!dev) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
dev->devt = devt; |
|
dev->class = tty_class; |
|
dev->parent = device; |
|
dev->release = tty_device_create_release; |
|
dev_set_name(dev, "%s", name); |
|
dev->groups = attr_grp; |
|
dev_set_drvdata(dev, drvdata); |
|
|
|
dev_set_uevent_suppress(dev, 1); |
|
|
|
retval = device_register(dev); |
|
if (retval) |
|
goto err_put; |
|
|
|
if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
|
/* |
|
* Free any saved termios data so that the termios state is |
|
* reset when reusing a minor number. |
|
*/ |
|
tp = driver->termios[index]; |
|
if (tp) { |
|
driver->termios[index] = NULL; |
|
kfree(tp); |
|
} |
|
|
|
retval = tty_cdev_add(driver, devt, index, 1); |
|
if (retval) |
|
goto err_del; |
|
} |
|
|
|
dev_set_uevent_suppress(dev, 0); |
|
kobject_uevent(&dev->kobj, KOBJ_ADD); |
|
|
|
return dev; |
|
|
|
err_del: |
|
device_del(dev); |
|
err_put: |
|
put_device(dev); |
|
|
|
return ERR_PTR(retval); |
|
} |
|
EXPORT_SYMBOL_GPL(tty_register_device_attr); |
|
|
|
/** |
|
* tty_unregister_device - unregister a tty device |
|
* @driver: the tty driver that describes the tty device |
|
* @index: the index in the tty driver for this tty device |
|
* |
|
* If a tty device is registered with a call to tty_register_device() then |
|
* this function must be called when the tty device is gone. |
|
* |
|
* Locking: ?? |
|
*/ |
|
|
|
void tty_unregister_device(struct tty_driver *driver, unsigned index) |
|
{ |
|
device_destroy(tty_class, |
|
MKDEV(driver->major, driver->minor_start) + index); |
|
if (!(driver->flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
|
cdev_del(driver->cdevs[index]); |
|
driver->cdevs[index] = NULL; |
|
} |
|
} |
|
EXPORT_SYMBOL(tty_unregister_device); |
|
|
|
/** |
|
* __tty_alloc_driver -- allocate tty driver |
|
* @lines: count of lines this driver can handle at most |
|
* @owner: module which is responsible for this driver |
|
* @flags: some of TTY_DRIVER_* flags, will be set in driver->flags |
|
* |
|
* This should not be called directly, some of the provided macros should be |
|
* used instead. Use IS_ERR and friends on @retval. |
|
*/ |
|
struct tty_driver *__tty_alloc_driver(unsigned int lines, struct module *owner, |
|
unsigned long flags) |
|
{ |
|
struct tty_driver *driver; |
|
unsigned int cdevs = 1; |
|
int err; |
|
|
|
if (!lines || (flags & TTY_DRIVER_UNNUMBERED_NODE && lines > 1)) |
|
return ERR_PTR(-EINVAL); |
|
|
|
driver = kzalloc(sizeof(*driver), GFP_KERNEL); |
|
if (!driver) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
kref_init(&driver->kref); |
|
driver->magic = TTY_DRIVER_MAGIC; |
|
driver->num = lines; |
|
driver->owner = owner; |
|
driver->flags = flags; |
|
|
|
if (!(flags & TTY_DRIVER_DEVPTS_MEM)) { |
|
driver->ttys = kcalloc(lines, sizeof(*driver->ttys), |
|
GFP_KERNEL); |
|
driver->termios = kcalloc(lines, sizeof(*driver->termios), |
|
GFP_KERNEL); |
|
if (!driver->ttys || !driver->termios) { |
|
err = -ENOMEM; |
|
goto err_free_all; |
|
} |
|
} |
|
|
|
if (!(flags & TTY_DRIVER_DYNAMIC_ALLOC)) { |
|
driver->ports = kcalloc(lines, sizeof(*driver->ports), |
|
GFP_KERNEL); |
|
if (!driver->ports) { |
|
err = -ENOMEM; |
|
goto err_free_all; |
|
} |
|
cdevs = lines; |
|
} |
|
|
|
driver->cdevs = kcalloc(cdevs, sizeof(*driver->cdevs), GFP_KERNEL); |
|
if (!driver->cdevs) { |
|
err = -ENOMEM; |
|
goto err_free_all; |
|
} |
|
|
|
return driver; |
|
err_free_all: |
|
kfree(driver->ports); |
|
kfree(driver->ttys); |
|
kfree(driver->termios); |
|
kfree(driver->cdevs); |
|
kfree(driver); |
|
return ERR_PTR(err); |
|
} |
|
EXPORT_SYMBOL(__tty_alloc_driver); |
|
|
|
static void destruct_tty_driver(struct kref *kref) |
|
{ |
|
struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
|
int i; |
|
struct ktermios *tp; |
|
|
|
if (driver->flags & TTY_DRIVER_INSTALLED) { |
|
for (i = 0; i < driver->num; i++) { |
|
tp = driver->termios[i]; |
|
if (tp) { |
|
driver->termios[i] = NULL; |
|
kfree(tp); |
|
} |
|
if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
|
tty_unregister_device(driver, i); |
|
} |
|
proc_tty_unregister_driver(driver); |
|
if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) |
|
cdev_del(driver->cdevs[0]); |
|
} |
|
kfree(driver->cdevs); |
|
kfree(driver->ports); |
|
kfree(driver->termios); |
|
kfree(driver->ttys); |
|
kfree(driver); |
|
} |
|
|
|
void tty_driver_kref_put(struct tty_driver *driver) |
|
{ |
|
kref_put(&driver->kref, destruct_tty_driver); |
|
} |
|
EXPORT_SYMBOL(tty_driver_kref_put); |
|
|
|
void tty_set_operations(struct tty_driver *driver, |
|
const struct tty_operations *op) |
|
{ |
|
driver->ops = op; |
|
}; |
|
EXPORT_SYMBOL(tty_set_operations); |
|
|
|
void put_tty_driver(struct tty_driver *d) |
|
{ |
|
tty_driver_kref_put(d); |
|
} |
|
EXPORT_SYMBOL(put_tty_driver); |
|
|
|
/* |
|
* Called by a tty driver to register itself. |
|
*/ |
|
int tty_register_driver(struct tty_driver *driver) |
|
{ |
|
int error; |
|
int i; |
|
dev_t dev; |
|
struct device *d; |
|
|
|
if (!driver->major) { |
|
error = alloc_chrdev_region(&dev, driver->minor_start, |
|
driver->num, driver->name); |
|
if (!error) { |
|
driver->major = MAJOR(dev); |
|
driver->minor_start = MINOR(dev); |
|
} |
|
} else { |
|
dev = MKDEV(driver->major, driver->minor_start); |
|
error = register_chrdev_region(dev, driver->num, driver->name); |
|
} |
|
if (error < 0) |
|
goto err; |
|
|
|
if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) { |
|
error = tty_cdev_add(driver, dev, 0, driver->num); |
|
if (error) |
|
goto err_unreg_char; |
|
} |
|
|
|
mutex_lock(&tty_mutex); |
|
list_add(&driver->tty_drivers, &tty_drivers); |
|
mutex_unlock(&tty_mutex); |
|
|
|
if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { |
|
for (i = 0; i < driver->num; i++) { |
|
d = tty_register_device(driver, i, NULL); |
|
if (IS_ERR(d)) { |
|
error = PTR_ERR(d); |
|
goto err_unreg_devs; |
|
} |
|
} |
|
} |
|
proc_tty_register_driver(driver); |
|
driver->flags |= TTY_DRIVER_INSTALLED; |
|
return 0; |
|
|
|
err_unreg_devs: |
|
for (i--; i >= 0; i--) |
|
tty_unregister_device(driver, i); |
|
|
|
mutex_lock(&tty_mutex); |
|
list_del(&driver->tty_drivers); |
|
mutex_unlock(&tty_mutex); |
|
|
|
err_unreg_char: |
|
unregister_chrdev_region(dev, driver->num); |
|
err: |
|
return error; |
|
} |
|
EXPORT_SYMBOL(tty_register_driver); |
|
|
|
/* |
|
* Called by a tty driver to unregister itself. |
|
*/ |
|
int tty_unregister_driver(struct tty_driver *driver) |
|
{ |
|
#if 0 |
|
/* FIXME */ |
|
if (driver->refcount) |
|
return -EBUSY; |
|
#endif |
|
unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
|
driver->num); |
|
mutex_lock(&tty_mutex); |
|
list_del(&driver->tty_drivers); |
|
mutex_unlock(&tty_mutex); |
|
return 0; |
|
} |
|
|
|
EXPORT_SYMBOL(tty_unregister_driver); |
|
|
|
dev_t tty_devnum(struct tty_struct *tty) |
|
{ |
|
return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; |
|
} |
|
EXPORT_SYMBOL(tty_devnum); |
|
|
|
void tty_default_fops(struct file_operations *fops) |
|
{ |
|
*fops = tty_fops; |
|
} |
|
|
|
static char *tty_devnode(struct device *dev, umode_t *mode) |
|
{ |
|
if (!mode) |
|
return NULL; |
|
if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || |
|
dev->devt == MKDEV(TTYAUX_MAJOR, 2)) |
|
*mode = 0666; |
|
return NULL; |
|
} |
|
|
|
static int __init tty_class_init(void) |
|
{ |
|
tty_class = class_create(THIS_MODULE, "tty"); |
|
if (IS_ERR(tty_class)) |
|
return PTR_ERR(tty_class); |
|
tty_class->devnode = tty_devnode; |
|
return 0; |
|
} |
|
|
|
postcore_initcall(tty_class_init); |
|
|
|
/* 3/2004 jmc: why do these devices exist? */ |
|
static struct cdev tty_cdev, console_cdev; |
|
|
|
static ssize_t show_cons_active(struct device *dev, |
|
struct device_attribute *attr, char *buf) |
|
{ |
|
struct console *cs[16]; |
|
int i = 0; |
|
struct console *c; |
|
ssize_t count = 0; |
|
|
|
console_lock(); |
|
for_each_console(c) { |
|
if (!c->device) |
|
continue; |
|
if (!c->write) |
|
continue; |
|
if ((c->flags & CON_ENABLED) == 0) |
|
continue; |
|
cs[i++] = c; |
|
if (i >= ARRAY_SIZE(cs)) |
|
break; |
|
} |
|
while (i--) { |
|
int index = cs[i]->index; |
|
struct tty_driver *drv = cs[i]->device(cs[i], &index); |
|
|
|
/* don't resolve tty0 as some programs depend on it */ |
|
if (drv && (cs[i]->index > 0 || drv->major != TTY_MAJOR)) |
|
count += tty_line_name(drv, index, buf + count); |
|
else |
|
count += sprintf(buf + count, "%s%d", |
|
cs[i]->name, cs[i]->index); |
|
|
|
count += sprintf(buf + count, "%c", i ? ' ':'\n'); |
|
} |
|
console_unlock(); |
|
|
|
return count; |
|
} |
|
static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); |
|
|
|
static struct attribute *cons_dev_attrs[] = { |
|
&dev_attr_active.attr, |
|
NULL |
|
}; |
|
|
|
ATTRIBUTE_GROUPS(cons_dev); |
|
|
|
static struct device *consdev; |
|
|
|
void console_sysfs_notify(void) |
|
{ |
|
if (consdev) |
|
sysfs_notify(&consdev->kobj, NULL, "active"); |
|
} |
|
|
|
/* |
|
* Ok, now we can initialize the rest of the tty devices and can count |
|
* on memory allocations, interrupts etc.. |
|
*/ |
|
int __init tty_init(void) |
|
{ |
|
tty_sysctl_init(); |
|
cdev_init(&tty_cdev, &tty_fops); |
|
if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || |
|
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) |
|
panic("Couldn't register /dev/tty driver\n"); |
|
device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
|
|
|
cdev_init(&console_cdev, &console_fops); |
|
if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || |
|
register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) |
|
panic("Couldn't register /dev/console driver\n"); |
|
consdev = device_create_with_groups(tty_class, NULL, |
|
MKDEV(TTYAUX_MAJOR, 1), NULL, |
|
cons_dev_groups, "console"); |
|
if (IS_ERR(consdev)) |
|
consdev = NULL; |
|
|
|
#ifdef CONFIG_VT |
|
vty_init(&console_fops); |
|
#endif |
|
return 0; |
|
} |
|
|
|
|