Release 4.12 drivers/tty/tty_io.c
  
  
  
/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */
/*
 * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
 * or rs-channels. It also implements echoing, cooked mode etc.
 *
 * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0.
 *
 * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the
 * tty_struct and tty_queue structures.  Previously there was an array
 * of 256 tty_struct's which was statically allocated, and the
 * tty_queue structures were allocated at boot time.  Both are now
 * dynamically allocated only when the tty is open.
 *
 * Also restructured routines so that there is more of a separation
 * between the high-level tty routines (tty_io.c and tty_ioctl.c) and
 * the low-level tty routines (serial.c, pty.c, console.c).  This
 * makes for cleaner and more compact code.  -TYT, 9/17/92
 *
 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
 * which can be dynamically activated and de-activated by the line
 * discipline handling modules (like SLIP).
 *
 * NOTE: pay no attention to the line discipline code (yet); its
 * interface is still subject to change in this version...
 * -- TYT, 1/31/92
 *
 * Added functionality to the OPOST tty handling.  No delays, but all
 * other bits should be there.
 *      -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993.
 *
 * Rewrote canonical mode and added more termios flags.
 *      -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94
 *
 * Reorganized FASYNC support so mouse code can share it.
 *      -- ctm@ardi.com, 9Sep95
 *
 * New TIOCLINUX variants added.
 *      -- mj@k332.feld.cvut.cz, 19-Nov-95
 *
 * Restrict vt switching via ioctl()
 *      -- grif@cs.ucr.edu, 5-Dec-95
 *
 * Move console and virtual terminal code to more appropriate files,
 * implement CONFIG_VT and generalize console device interface.
 *      -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97
 *
 * Rewrote tty_init_dev and tty_release_dev to eliminate races.
 *      -- Bill Hawes <whawes@star.net>, June 97
 *
 * Added devfs support.
 *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998
 *
 * Added support for a Unix98-style ptmx device.
 *      -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
 *
 * Reduced memory usage for older ARM systems
 *      -- Russell King <rmk@arm.linux.org.uk>
 *
 * Move do_SAK() into process context.  Less stack use in devfs functions.
 * alloc_tty_struct() always uses kmalloc()
 *                       -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01
 */
#include <linux/types.h>
#include <linux/major.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/fcntl.h>
#include <linux/sched/signal.h>
#include <linux/sched/task.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/devpts_fs.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/console.h>
#include <linux/timer.h>
#include <linux/ctype.h>
#include <linux/kd.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/seq_file.h>
#include <linux/serial.h>
#include <linux/ratelimit.h>
#include <linux/uaccess.h>
#include <linux/kbd_kern.h>
#include <linux/vt_kern.h>
#include <linux/selection.h>
#include <linux/kmod.h>
#include <linux/nsproxy.h>
#undef TTY_DEBUG_HANGUP
#ifdef TTY_DEBUG_HANGUP
# define tty_debug_hangup(tty, f, args...)	tty_debug(tty, f, ##args)
#else
# define tty_debug_hangup(tty, f, args...)	do { } while (0)
#endif
#define TTY_PARANOIA_CHECK 1
#define CHECK_TTY_COUNT 1
struct ktermios tty_std_termios = {	/* for the benefit of tty drivers  */
	.c_iflag = ICRNL | IXON,
	.c_oflag = OPOST | ONLCR,
	.c_cflag = B38400 | CS8 | CREAD | HUPCL,
	.c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK |
		   ECHOCTL | ECHOKE | IEXTEN,
	.c_cc = INIT_C_CC,
	.c_ispeed = 38400,
	.c_ospeed = 38400,
	/* .c_line = N_TTY, */
};
EXPORT_SYMBOL(tty_std_termios);
/* This list gets poked at by procfs and various bits of boot up code. This
   could do with some rationalisation such as pulling the tty proc function
   into this file */
LIST_HEAD(tty_drivers);			
/* linked list of tty drivers */
/* Mutex to protect creating and releasing a tty */
DEFINE_MUTEX(tty_mutex);
static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *);
ssize_t redirected_tty_write(struct file *, const char __user *,
							size_t, loff_t *);
static unsigned int tty_poll(struct file *, poll_table *);
static int tty_open(struct inode *, struct file *);
long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
#ifdef CONFIG_COMPAT
static long tty_compat_ioctl(struct file *file, unsigned int cmd,
				unsigned long arg);
#else
#define tty_compat_ioctl NULL
#endif
static int __tty_fasync(int fd, struct file *filp, int on);
static int tty_fasync(int fd, struct file *filp, int on);
static void release_tty(struct tty_struct *tty, int idx);
/**
 *      free_tty_struct         -       free a disused tty
 *      @tty: tty struct to free
 *
 *      Free the write buffers, tty queue and tty memory itself.
 *
 *      Locking: none. Must be called after tty is definitely unused
 */
static void free_tty_struct(struct tty_struct *tty)
{
	tty_ldisc_deinit(tty);
	put_device(tty->dev);
	kfree(tty->write_buf);
	tty->magic = 0xDEADDEAD;
	kfree(tty);
}
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| Linus Torvalds | 7 | 17.07% | 1 | 16.67% | 
| Dmitry Baryshkov | 7 | 17.07% | 1 | 16.67% | 
| Peter Hurley | 6 | 14.63% | 2 | 33.33% | 
| Alan Cox | 6 | 14.63% | 1 | 16.67% | 
| Total | 41 | 100.00% | 6 | 100.00% | 
static inline struct tty_struct *file_tty(struct file *file)
{
	return ((struct tty_file_private *)file->private_data)->tty;
}
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| Total | 28 | 100.00% | 1 | 100.00% | 
int tty_alloc_file(struct file *file)
{
	struct tty_file_private *priv;
	priv = kmalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
	file->private_data = priv;
	return 0;
}
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| Nicholas Piggin | 25 | 54.35% | 1 | 33.33% | 
| Jiri Slaby | 11 | 23.91% | 1 | 33.33% | 
| Pekka J Enberg | 10 | 21.74% | 1 | 33.33% | 
| Total | 46 | 100.00% | 3 | 100.00% | 
/* Associate a new file with the tty structure */
void tty_add_file(struct tty_struct *tty, struct file *file)
{
	struct tty_file_private *priv = file->private_data;
	priv->tty = tty;
	priv->file = file;
	spin_lock(&tty->files_lock);
	list_add(&priv->list, &tty->tty_files);
	spin_unlock(&tty->files_lock);
}
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| Person | Tokens | Prop | Commits | CommitProp | 
| Nicholas Piggin | 35 | 53.85% | 1 | 33.33% | 
| Jiri Slaby | 24 | 36.92% | 1 | 33.33% | 
| Peter Hurley | 6 | 9.23% | 1 | 33.33% | 
| Total | 65 | 100.00% | 3 | 100.00% | 
/**
 * tty_free_file - free file->private_data
 *
 * This shall be used only for fail path handling when tty_add_file was not
 * called yet.
 */
void tty_free_file(struct file *file)
{
	struct tty_file_private *priv = file->private_data;
	file->private_data = NULL;
	kfree(priv);
}
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/* Delete file from its tty */
static void tty_del_file(struct file *file)
{
	struct tty_file_private *priv = file->private_data;
	struct tty_struct *tty = priv->tty;
	spin_lock(&tty->files_lock);
	list_del(&priv->list);
	spin_unlock(&tty->files_lock);
	tty_free_file(file);
}
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| Nicholas Piggin | 40 | 68.97% | 1 | 25.00% | 
| Peter Hurley | 15 | 25.86% | 1 | 25.00% | 
| Jiri Slaby | 2 | 3.45% | 1 | 25.00% | 
| Josh Triplett | 1 | 1.72% | 1 | 25.00% | 
| Total | 58 | 100.00% | 4 | 100.00% | 
/**
 *      tty_name        -       return tty naming
 *      @tty: tty structure
 *
 *      Convert a tty structure into a name. The name reflects the kernel
 *      naming policy and if udev is in use may not reflect user space
 *
 *      Locking: none
 */
const char *tty_name(const struct tty_struct *tty)
{
	if (!tty) /* Hmm.  NULL pointer.  That's fun. */
		return "NULL tty";
	return tty->name;
}
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| Linus Torvalds (pre-git) | 20 | 74.07% | 1 | 25.00% | 
| Rasmus Villemoes | 5 | 18.52% | 2 | 50.00% | 
| Al Viro | 2 | 7.41% | 1 | 25.00% | 
| Total | 27 | 100.00% | 4 | 100.00% | 
EXPORT_SYMBOL(tty_name);
const char *tty_driver_name(const struct tty_struct *tty)
{
	if (!tty || !tty->driver)
		return "";
	return tty->driver->name;
}
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| Peter Hurley | 33 | 100.00% | 1 | 100.00% | 
| Total | 33 | 100.00% | 1 | 100.00% | 
static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode,
			      const char *routine)
{
#ifdef TTY_PARANOIA_CHECK
	if (!tty) {
		pr_warn("(%d:%d): %s: NULL tty\n",
			imajor(inode), iminor(inode), routine);
		return 1;
	}
	if (tty->magic != TTY_MAGIC) {
		pr_warn("(%d:%d): %s: bad magic number\n",
			imajor(inode), iminor(inode), routine);
		return 1;
	}
#endif
	return 0;
}
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| Linus Torvalds (pre-git) | 63 | 73.26% | 3 | 42.86% | 
| Al Viro | 18 | 20.93% | 2 | 28.57% | 
| Peter Hurley | 5 | 5.81% | 2 | 28.57% | 
| Total | 86 | 100.00% | 7 | 100.00% | 
/* Caller must hold tty_lock */
static int check_tty_count(struct tty_struct *tty, const char *routine)
{
#ifdef CHECK_TTY_COUNT
	struct list_head *p;
	int count = 0;
	spin_lock(&tty->files_lock);
	list_for_each(p, &tty->tty_files) {
		count++;
	}
	spin_unlock(&tty->files_lock);
	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
	    tty->driver->subtype == PTY_TYPE_SLAVE &&
	    tty->link && tty->link->count)
		count++;
	if (tty->count != count) {
		tty_warn(tty, "%s: tty->count(%d) != #fd's(%d)\n",
			 routine, tty->count, count);
		return count;
	}
#endif
	return 0;
}
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| Alan Cox | 77 | 64.17% | 1 | 16.67% | 
| Linus Torvalds (pre-git) | 24 | 20.00% | 2 | 33.33% | 
| Peter Hurley | 11 | 9.17% | 2 | 33.33% | 
| Nicholas Piggin | 8 | 6.67% | 1 | 16.67% | 
| Total | 120 | 100.00% | 6 | 100.00% | 
/**
 *      get_tty_driver          -       find device of a tty
 *      @dev_t: device identifier
 *      @index: returns the index of the tty
 *
 *      This routine returns a tty driver structure, given a device number
 *      and also passes back the index number.
 *
 *      Locking: caller must hold tty_mutex
 */
static struct tty_driver *get_tty_driver(dev_t device, int *index)
{
	struct tty_driver *p;
	list_for_each_entry(p, &tty_drivers, tty_drivers) {
		dev_t base = MKDEV(p->major, p->minor_start);
		if (device < base || device >= base + p->num)
			continue;
		*index = device - base;
		return tty_driver_kref_get(p);
	}
	return NULL;
}
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| Alan Cox | 75 | 100.00% | 3 | 100.00% | 
| Total | 75 | 100.00% | 3 | 100.00% | 
#ifdef CONFIG_CONSOLE_POLL
/**
 *      tty_find_polling_driver -       find device of a polled tty
 *      @name: name string to match
 *      @line: pointer to resulting tty line nr
 *
 *      This routine returns a tty driver structure, given a name
 *      and the condition that the tty driver is capable of polled
 *      operation.
 */
struct tty_driver *tty_find_polling_driver(char *name, int *line)
{
	struct tty_driver *p, *res = NULL;
	int tty_line = 0;
	int len;
	char *str, *stp;
	for (str = name; *str; str++)
		if ((*str >= '0' && *str <= '9') || *str == ',')
			break;
	if (!*str)
		return NULL;
	len = str - name;
	tty_line = simple_strtoul(str, &str, 10);
	mutex_lock(&tty_mutex);
	/* Search through the tty devices to look for a match */
	list_for_each_entry(p, &tty_drivers, tty_drivers) {
		if (strncmp(name, p->name, len) != 0)
			continue;
		stp = str;
		if (*stp == ',')
			stp++;
		if (*stp == '\0')
			stp = NULL;
		if (tty_line >= 0 && tty_line < p->num && p->ops &&
		    p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) {
			res = tty_driver_kref_get(p);
			*line = tty_line;
			break;
		}
	}
	mutex_unlock(&tty_mutex);
	return res;
}
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| Total | 217 | 100.00% | 7 | 100.00% | 
EXPORT_SYMBOL_GPL(tty_find_polling_driver);
#endif
static ssize_t hung_up_tty_read(struct file *file, char __user *buf,
				size_t count, loff_t *ppos)
{
	return 0;
}
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| Alan Cox | 26 | 100.00% | 2 | 100.00% | 
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static ssize_t hung_up_tty_write(struct file *file, const char __user *buf,
				 size_t count, loff_t *ppos)
{
	return -EIO;
}
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| Alan Cox | 28 | 100.00% | 2 | 100.00% | 
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/* No kernel lock held - none needed ;) */
static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait)
{
	return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM;
}
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| Alan Cox | 29 | 100.00% | 2 | 100.00% | 
| Total | 29 | 100.00% | 2 | 100.00% | 
static long hung_up_tty_ioctl(struct file *file, unsigned int cmd,
		unsigned long arg)
{
	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
}
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| Alan Cox | 27 | 90.00% | 2 | 66.67% | 
| Paul Fulghum | 3 | 10.00% | 1 | 33.33% | 
| Total | 30 | 100.00% | 3 | 100.00% | 
static long hung_up_tty_compat_ioctl(struct file *file,
				     unsigned int cmd, unsigned long arg)
{
	return cmd == TIOCSPGRP ? -ENOTTY : -EIO;
}
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| Alan Cox | 30 | 100.00% | 2 | 100.00% | 
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static int hung_up_tty_fasync(int fd, struct file *file, int on)
{
	return -ENOTTY;
}
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| Peter Hurley | 21 | 100.00% | 1 | 100.00% | 
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static const struct file_operations tty_fops = {
	.llseek		= no_llseek,
	.read		= tty_read,
	.write		= tty_write,
	.poll		= tty_poll,
	.unlocked_ioctl	= tty_ioctl,
	.compat_ioctl	= tty_compat_ioctl,
	.open		= tty_open,
	.release	= tty_release,
	.fasync		= tty_fasync,
};
static const struct file_operations console_fops = {
	.llseek		= no_llseek,
	.read		= tty_read,
	.write		= redirected_tty_write,
	.poll		= tty_poll,
	.unlocked_ioctl	= tty_ioctl,
	.compat_ioctl	= tty_compat_ioctl,
	.open		= tty_open,
	.release	= tty_release,
	.fasync		= tty_fasync,
};
static const struct file_operations hung_up_tty_fops = {
	.llseek		= no_llseek,
	.read		= hung_up_tty_read,
	.write		= hung_up_tty_write,
	.poll		= hung_up_tty_poll,
	.unlocked_ioctl	= hung_up_tty_ioctl,
	.compat_ioctl	= hung_up_tty_compat_ioctl,
	.release	= tty_release,
	.fasync		= hung_up_tty_fasync,
};
static DEFINE_SPINLOCK(redirect_lock);
static struct file *redirect;
/**
 *      tty_wakeup      -       request more data
 *      @tty: terminal
 *
 *      Internal and external helper for wakeups of tty. This function
 *      informs the line discipline if present that the driver is ready
 *      to receive more output data.
 */
void tty_wakeup(struct tty_struct *tty)
{
	struct tty_ldisc *ld;
	if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) {
		ld = tty_ldisc_ref(tty);
		if (ld) {
			if (ld->ops->write_wakeup)
				ld->ops->write_wakeup(tty);
			tty_ldisc_deref(ld);
		}
	}
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
}
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| Alan Cox | 15 | 20.27% | 1 | 16.67% | 
| Peter Hurley | 5 | 6.76% | 1 | 16.67% | 
| Eric W. Biedermann | 3 | 4.05% | 1 | 16.67% | 
| Linus Torvalds (pre-git) | 3 | 4.05% | 2 | 33.33% | 
| Total | 74 | 100.00% | 6 | 100.00% | 
EXPORT_SYMBOL_GPL(tty_wakeup);
/**
 *      __tty_hangup            -       actual handler for hangup events
 *      @work: tty device
 *
 *      This can be called by a "kworker" kernel thread.  That is process
 *      synchronous but doesn't hold any locks, so we need to make sure we
 *      have the appropriate locks for what we're doing.
 *
 *      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 = NULL;
	struct tty_file_private *priv;
	int    closecount = 0, n;
	int refs;
	if (!tty)
		return;
	spin_lock(&redirect_lock);
	if (redirect && file_tty(redirect) == tty) {
		f = redirect;
		redirect = NULL;
	}
	spin_unlock(&redirect_lock);
	tty_lock(tty);
	if (test_bit(TTY_HUPPED, &tty->flags)) {
		tty_unlock(tty);
		return;
	}
	/* 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 == redirected_tty_write)
			cons_filp = filp;
		if (filp->f_op->write != 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);
	tty_unlock(tty);
	if (f)
		fput(f);
}
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| Total | 376 | 100.00% | 6 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Peter Hurley | 18 | 54.55% | 3 | 75.00% | 
| Nico Pitre | 15 | 45.45% | 1 | 25.00% | 
| Total | 33 | 100.00% | 4 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 10 | 40.00% | 1 | 14.29% | 
| Alan Cox | 10 | 40.00% | 2 | 28.57% | 
| Arnd Bergmann | 3 | 12.00% | 2 | 28.57% | 
| Peter Zijlstra | 1 | 4.00% | 1 | 14.29% | 
| Peter Hurley | 1 | 4.00% | 1 | 14.29% | 
| Total | 25 | 100.00% | 7 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 15 | 62.50% | 1 | 33.33% | 
| Peter Hurley | 5 | 20.83% | 1 | 33.33% | 
| Jiri Slaby | 4 | 16.67% | 1 | 33.33% | 
| Total | 24 | 100.00% | 3 | 100.00% | 
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);
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 21 | 63.64% | 1 | 33.33% | 
| Peter Hurley | 11 | 33.33% | 1 | 33.33% | 
| Alan Cox | 1 | 3.03% | 1 | 33.33% | 
| Total | 33 | 100.00% | 3 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 20 | 83.33% | 1 | 33.33% | 
| Alan Cox | 3 | 12.50% | 1 | 33.33% | 
| Peter Zijlstra | 1 | 4.17% | 1 | 33.33% | 
| Total | 24 | 100.00% | 3 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 20 | 90.91% | 1 | 33.33% | 
| Alan Cox | 1 | 4.55% | 1 | 33.33% | 
| Peter Hurley | 1 | 4.55% | 1 | 33.33% | 
| Total | 22 | 100.00% | 3 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 23 | 57.50% | 1 | 20.00% | 
| Alan Cox | 11 | 27.50% | 2 | 40.00% | 
| Peter Hurley | 5 | 12.50% | 1 | 20.00% | 
| Peter Zijlstra | 1 | 2.50% | 1 | 20.00% | 
| Total | 40 | 100.00% | 5 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 30 | 76.92% | 1 | 20.00% | 
| Peter Hurley | 4 | 10.26% | 1 | 20.00% | 
| Alan Cox | 4 | 10.26% | 2 | 40.00% | 
| Linus Torvalds (pre-git) | 1 | 2.56% | 1 | 20.00% | 
| Total | 39 | 100.00% | 5 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 32 | 64.00% | 1 | 14.29% | 
| Peter Hurley | 10 | 20.00% | 2 | 28.57% | 
| Linus Torvalds (pre-git) | 6 | 12.00% | 2 | 28.57% | 
| Alan Cox | 2 | 4.00% | 2 | 28.57% | 
| Total | 50 | 100.00% | 7 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 27 | 69.23% | 1 | 20.00% | 
| Alan Cox | 7 | 17.95% | 2 | 40.00% | 
| Peter Hurley | 3 | 7.69% | 1 | 20.00% | 
| Linus Torvalds (pre-git) | 2 | 5.13% | 1 | 20.00% | 
| Total | 39 | 100.00% | 5 | 100.00% | 
EXPORT_SYMBOL(start_tty);
static void tty_update_time(struct timespec *time)
{
	unsigned long sec = get_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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 32 | 84.21% | 1 | 33.33% | 
| Peter Hurley | 5 | 13.16% | 1 | 33.33% | 
| Samuel Thibault | 1 | 2.63% | 1 | 33.33% | 
| Total | 38 | 100.00% | 3 | 100.00% | 
/**
 *      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 file *file, char __user *buf, size_t count,
			loff_t *ppos)
{
	int i;
	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(file, buf, count, ppos);
	if (ld->ops->read)
		i = ld->ops->read(tty, file, buf, count);
	else
		i = -EIO;
	tty_ldisc_deref(ld);
	if (i > 0)
		tty_update_time(&inode->i_atime);
	return i;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 95 | 60.13% | 1 | 14.29% | 
| Peter Hurley | 52 | 32.91% | 1 | 14.29% | 
| Linus Torvalds (pre-git) | 9 | 5.70% | 3 | 42.86% | 
| Alan Cox | 2 | 1.27% | 2 | 28.57% | 
| Total | 158 | 100.00% | 7 | 100.00% | 
static void tty_write_unlock(struct tty_struct *tty)
{
	mutex_unlock(&tty->atomic_write_lock);
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 16 | 55.17% | 1 | 50.00% | 
| Peter Hurley | 13 | 44.83% | 1 | 50.00% | 
| Total | 29 | 100.00% | 2 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 36 | 69.23% | 1 | 16.67% | 
| Jiri Slaby | 6 | 11.54% | 1 | 16.67% | 
| Hannes Reinecke | 4 | 7.69% | 1 | 16.67% | 
| Peter Hurley | 4 | 7.69% | 1 | 16.67% | 
| Linus Torvalds (pre-git) | 1 | 1.92% | 1 | 16.67% | 
| Alan Cox | 1 | 1.92% | 1 | 16.67% | 
| Total | 52 | 100.00% | 6 | 100.00% | 
/*
 * 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,
	const char __user *buf,
	size_t count)
{
	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_user(tty->write_buf, buf, size))
			break;
		ret = write(tty, file, tty->write_buf, size);
		if (ret <= 0)
			break;
		written += ret;
		buf += 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 226 | 72.90% | 1 | 7.14% | 
| Alan Cox | 51 | 16.45% | 6 | 42.86% | 
| Peter Hurley | 20 | 6.45% | 2 | 14.29% | 
| Sukadev Bhattiprolu | 9 | 2.90% | 2 | 14.29% | 
| Linus Torvalds | 2 | 0.65% | 1 | 7.14% | 
| Jiri Slaby | 1 | 0.32% | 1 | 7.14% | 
| Jason Wessel | 1 | 0.32% | 1 | 7.14% | 
| Total | 310 | 100.00% | 14 | 100.00% | 
/**
 * 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 54 | 72.97% | 1 | 33.33% | 
| Jiri Slaby | 19 | 25.68% | 1 | 33.33% | 
| Alan Cox | 1 | 1.35% | 1 | 33.33% | 
| Total | 74 | 100.00% | 3 | 100.00% | 
/**
 *      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 tty_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	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(file, buf, count, ppos);
	if (!ld->ops->write)
		ret = -EIO;
	else
		ret = do_tty_write(ld->ops->write, tty, file, buf, count);
	tty_ldisc_deref(ld);
	return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 137 | 83.03% | 1 | 33.33% | 
| Alan Cox | 27 | 16.36% | 1 | 33.33% | 
| Peter Hurley | 1 | 0.61% | 1 | 33.33% | 
| Total | 165 | 100.00% | 3 | 100.00% | 
ssize_t redirected_tty_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	struct file *p = NULL;
	spin_lock(&redirect_lock);
	if (redirect)
		p = get_file(redirect);
	spin_unlock(&redirect_lock);
	if (p) {
		ssize_t res;
		res = vfs_write(p, buf, count, &p->f_pos);
		fput(p);
		return res;
	}
	return tty_write(file, buf, count, ppos);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 69 | 70.41% | 1 | 20.00% | 
| Peter Hurley | 16 | 16.33% | 3 | 60.00% | 
| Sukadev Bhattiprolu | 13 | 13.27% | 1 | 20.00% | 
| Total | 98 | 100.00% | 5 | 100.00% | 
/**
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 68 | 51.91% | 1 | 4.55% | 
| Alan Cox | 32 | 24.43% | 7 | 31.82% | 
| Linus Torvalds (pre-git) | 20 | 15.27% | 7 | 31.82% | 
| Jiri Slaby | 7 | 5.34% | 3 | 13.64% | 
| Peter Hurley | 1 | 0.76% | 1 | 4.55% | 
| Andrew Morton | 1 | 0.76% | 1 | 4.55% | 
| Rasmus Villemoes | 1 | 0.76% | 1 | 4.55% | 
| H. Peter Anvin | 1 | 0.76% | 1 | 4.55% | 
| Total | 131 | 100.00% | 22 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 39 | 65.00% | 1 | 9.09% | 
| Alan Cox | 13 | 21.67% | 7 | 63.64% | 
| Dan Carpenter | 5 | 8.33% | 1 | 9.09% | 
| Linus Torvalds (pre-git) | 2 | 3.33% | 1 | 9.09% | 
| Peter Hurley | 1 | 1.67% | 1 | 9.09% | 
| Total | 60 | 100.00% | 11 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 39 | 68.42% | 1 | 33.33% | 
| Peter Hurley | 18 | 31.58% | 2 | 66.67% | 
| Total | 57 | 100.00% | 3 | 100.00% | 
/**
 *      tty_driver_lookup_tty() - find an existing tty, if any
 *      @driver: the driver for the tty
 *      @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)
		tty = driver->ops->lookup(driver, file, idx);
	else
		tty = driver->ttys[idx];
	if (!IS_ERR(tty))
		tty_kref_get(tty);
	return tty;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 37 | 49.33% | 1 | 11.11% | 
| Alan Cox | 24 | 32.00% | 2 | 22.22% | 
| Oleg Nesterov | 7 | 9.33% | 1 | 11.11% | 
| Cyrill V. Gorcunov | 3 | 4.00% | 1 | 11.11% | 
| Linus Torvalds (pre-git) | 2 | 2.67% | 2 | 22.22% | 
| Peter Hurley | 1 | 1.33% | 1 | 11.11% | 
| Al Viro | 1 | 1.33% | 1 | 11.11% | 
| Total | 75 | 100.00% | 9 | 100.00% | 
/**
 *      tty_init_termios        -  helper for termios setup
 *      @tty: the tty to set up
 *
 *      Initialise the termios structures for this tty. Thus 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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 99 | 78.57% | 1 | 33.33% | 
| Alan Cox | 27 | 21.43% | 2 | 66.67% | 
| Total | 126 | 100.00% | 3 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 20 | 45.45% | 1 | 16.67% | 
| Alan Cox | 16 | 36.36% | 2 | 33.33% | 
| Peter Hurley | 4 | 9.09% | 1 | 16.67% | 
| Jiri Slaby | 3 | 6.82% | 1 | 16.67% | 
| Linus Torvalds (pre-git) | 1 | 2.27% | 1 | 16.67% | 
| Total | 44 | 100.00% | 6 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 19 | 46.34% | 1 | 12.50% | 
| Alan Cox | 11 | 26.83% | 2 | 25.00% | 
| Jiri Slaby | 5 | 12.20% | 1 | 12.50% | 
| Al Viro | 2 | 4.88% | 1 | 12.50% | 
| H. Peter Anvin | 2 | 4.88% | 1 | 12.50% | 
| Peter Hurley | 1 | 2.44% | 1 | 12.50% | 
| Linus Torvalds (pre-git) | 1 | 2.44% | 1 | 12.50% | 
| Total | 41 | 100.00% | 8 | 100.00% | 
/**
 *      tty_driver_remove_tty() - remove a tty from the driver tables
 *      @driver: the driver for the tty
 *      @idx:    the minor number
 *
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 25 | 53.19% | 1 | 16.67% | 
| Peter Hurley | 10 | 21.28% | 2 | 33.33% | 
| Alan Cox | 9 | 19.15% | 1 | 16.67% | 
| Jonathan Corbet | 2 | 4.26% | 1 | 16.67% | 
| Peter Zijlstra | 1 | 2.13% | 1 | 16.67% | 
| Total | 47 | 100.00% | 6 | 100.00% | 
/*
 *      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;
	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;
	tty->count++;
	if (!tty->ldisc)
		return tty_ldisc_reinit(tty, tty->termios.c_line);
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 78 | 79.59% | 1 | 50.00% | 
| Rob Herring | 20 | 20.41% | 1 | 50.00% | 
| Total | 98 | 100.00% | 2 | 100.00% | 
/**
 *      tty_init_dev            -       initialise a tty device
 *      @driver: tty driver we are opening a device on
 *      @idx: device index
 *      @ret_tty: returned tty structure
 *
 *      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.
 */
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];
	WARN_RATELIMIT(!tty->port,
			"%s: %s driver does not set tty->port. This will crash the kernel later. Fix the driver!\n",
			__func__, tty->driver->name);
	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;
	/* 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_unlock(tty);
	tty_info_ratelimited(tty, "ldisc open failed (%d), clearing slot %d\n",
			     retval, idx);
	release_tty(tty, idx);
	return ERR_PTR(retval);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 154 | 71.96% | 1 | 14.29% | 
| Jiri Slaby | 49 | 22.90% | 1 | 14.29% | 
| Peter Hurley | 6 | 2.80% | 4 | 57.14% | 
| Alan Cox | 5 | 2.34% | 1 | 14.29% | 
| Total | 214 | 100.00% | 7 | 100.00% | 
static void tty_free_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(struct ktermios), GFP_KERNEL);
		if (tp == NULL)
			return;
		tty->driver->termios[idx] = tp;
	}
	*tp = tty->termios;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 70 | 75.27% | 1 | 14.29% | 
| Alan Cox | 11 | 11.83% | 3 | 42.86% | 
| Al Viro | 8 | 8.60% | 1 | 14.29% | 
| Peter Hurley | 3 | 3.23% | 1 | 14.29% | 
| Sukadev Bhattiprolu | 1 | 1.08% | 1 | 14.29% | 
| Total | 93 | 100.00% | 7 | 100.00% | 
/**
 *      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);
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 25 | 45.45% | 1 | 14.29% | 
| Alan Cox | 15 | 27.27% | 2 | 28.57% | 
| Al Viro | 10 | 18.18% | 1 | 14.29% | 
| Linus Torvalds (pre-git) | 2 | 3.64% | 1 | 14.29% | 
| Jonathan Corbet | 2 | 3.64% | 1 | 14.29% | 
| Peter Hurley | 1 | 1.82% | 1 | 14.29% | 
| Total | 55 | 100.00% | 7 | 100.00% | 
/**
 *      release_one_tty         -       release tty structure memory
 *      @kref: kref 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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 65 | 54.17% | 1 | 4.76% | 
| Alan Cox | 26 | 21.67% | 4 | 19.05% | 
| Peter Hurley | 12 | 10.00% | 6 | 28.57% | 
| Linus Torvalds (pre-git) | 9 | 7.50% | 6 | 28.57% | 
| Eric W. Biedermann | 3 | 2.50% | 1 | 4.76% | 
| Nicholas Piggin | 3 | 2.50% | 1 | 4.76% | 
| James Morris | 1 | 0.83% | 1 | 4.76% | 
| Jonathan Corbet | 1 | 0.83% | 1 | 4.76% | 
| Total | 120 | 100.00% | 21 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 24 | 53.33% | 1 | 14.29% | 
| Alan Cox | 12 | 26.67% | 3 | 42.86% | 
| Peter Hurley | 4 | 8.89% | 1 | 14.29% | 
| Linus Torvalds (pre-git) | 4 | 8.89% | 1 | 14.29% | 
| Jiri Slaby | 1 | 2.22% | 1 | 14.29% | 
| Total | 45 | 100.00% | 7 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 16 | 66.67% | 1 | 50.00% | 
| Peter Hurley | 8 | 33.33% | 1 | 50.00% | 
| Total | 24 | 100.00% | 2 | 100.00% | 
EXPORT_SYMBOL(tty_kref_put);
/**
 *      release_tty             -       release tty structure memory
 *
 *      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_free_termios(tty);
	tty_driver_remove_tty(tty->driver, tty);
	tty->port->itty = NULL;
	if (tty->link)
		tty->link->port->itty = NULL;
	tty_buffer_cancel_work(tty->port);
	tty_kref_put(tty->link);
	tty_kref_put(tty);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 70 | 64.81% | 1 | 7.69% | 
| Alan Cox | 19 | 17.59% | 5 | 38.46% | 
| Jiri Slaby | 12 | 11.11% | 3 | 23.08% | 
| Linus Torvalds (pre-git) | 4 | 3.70% | 3 | 23.08% | 
| Sukadev Bhattiprolu | 3 | 2.78% | 1 | 7.69% | 
| Total | 108 | 100.00% | 13 | 100.00% | 
/**
 *      tty_release_checks - check a tty before real release
 *      @tty: tty to check
 *      @o_tty: link of @tty (if any)
 *      @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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 146 | 78.07% | 1 | 10.00% | 
| Sukadev Bhattiprolu | 18 | 9.63% | 2 | 20.00% | 
| Peter Hurley | 16 | 8.56% | 3 | 30.00% | 
| Alan Cox | 4 | 2.14% | 2 | 20.00% | 
| Jiri Slaby | 2 | 1.07% | 1 | 10.00% | 
| Eric Paris | 1 | 0.53% | 1 | 10.00% | 
| Total | 187 | 100.00% | 10 | 100.00% | 
/**
 *      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. The tty_unlock_pair
         * should be safe as we keep a kref while the tty is locked (so the
         * unlock never unlocks a freed tty).
         */
	mutex_lock(&tty_mutex);
	release_tty(tty, idx);
	mutex_unlock(&tty_mutex);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 32 | 61.54% | 1 | 16.67% | 
| Alan Cox | 15 | 28.85% | 3 | 50.00% | 
| Sukadev Bhattiprolu | 4 | 7.69% | 1 | 16.67% | 
| Peter Hurley | 1 | 1.92% | 1 | 16.67% | 
| Total | 52 | 100.00% | 6 | 100.00% | 
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, POLLIN);
				do_sleep++;
			}
			if (waitqueue_active(&tty->write_wait)) {
				wake_up_poll(&tty->write_wait, POLLOUT);
				do_sleep++;
			}
		}
		if (o_tty && o_tty->count <= 1) {
			if (waitqueue_active(&o_tty->read_wait)) {
				wake_up_poll(&o_tty->read_wait, POLLIN);
				do_sleep++;
			}
			if (waitqueue_active(&o_tty->write_wait)) {
				wake_up_poll(&o_tty->write_wait, POLLOUT);
				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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 352 | 68.48% | 1 | 4.35% | 
| Peter Hurley | 76 | 14.79% | 7 | 30.43% | 
| Alan Cox | 57 | 11.09% | 5 | 21.74% | 
| Linus Torvalds (pre-git) | 20 | 3.89% | 5 | 21.74% | 
| Nicholas Piggin | 5 | 0.97% | 2 | 8.70% | 
| Jann Horn | 2 | 0.39% | 1 | 4.35% | 
| Jiri Slaby | 1 | 0.19% | 1 | 4.35% | 
| Arnd Bergmann | 1 | 0.19% | 1 | 4.35% | 
| Total | 514 | 100.00% | 23 | 100.00% | 
/**
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 58 | 55.77% | 1 | 10.00% | 
| Linus Torvalds (pre-git) | 22 | 21.15% | 5 | 50.00% | 
| Alan Cox | 15 | 14.42% | 2 | 20.00% | 
| Peter Hurley | 8 | 7.69% | 1 | 10.00% | 
| Al Viro | 1 | 0.96% | 1 | 10.00% | 
| Total | 104 | 100.00% | 10 | 100.00% | 
/**
 *      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;
	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) {
				/* Don't let /dev/console block */
				filp->f_flags |= O_NONBLOCK;
				break;
			}
		}
		return ERR_PTR(-ENODEV);
	}
	default:
		driver = get_tty_driver(device, index);
		if (!driver)
			return ERR_PTR(-ENODEV);
		break;
	}
	return driver;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 95 | 65.52% | 1 | 7.14% | 
| Alan Cox | 24 | 16.55% | 2 | 14.29% | 
| Linus Torvalds (pre-git) | 11 | 7.59% | 3 | 21.43% | 
| Arnd Bergmann | 3 | 2.07% | 1 | 7.14% | 
| Peter Zijlstra | 3 | 2.07% | 1 | 7.14% | 
| Linus Torvalds | 2 | 1.38% | 1 | 7.14% | 
| Kirill Korotaev | 2 | 1.38% | 1 | 7.14% | 
| Greg Kroah-Hartman | 2 | 1.38% | 1 | 7.14% | 
| Al Viro | 1 | 0.69% | 1 | 7.14% | 
| Ingo Molnar | 1 | 0.69% | 1 | 7.14% | 
| Cédric Le Goater | 1 | 0.69% | 1 | 7.14% | 
| Total | 145 | 100.00% | 14 | 100.00% | 
/**
 *      tty_open_by_driver      -       open a tty device
 *      @device: dev_t of device to open
 *      @inode: inode of device file
 *      @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 inode *inode,
					     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) {
		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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 136 | 61.82% | 1 | 6.25% | 
| Alan Cox | 44 | 20.00% | 4 | 25.00% | 
| Arnd Bergmann | 19 | 8.64% | 1 | 6.25% | 
| Peter Hurley | 11 | 5.00% | 3 | 18.75% | 
| Linus Torvalds (pre-git) | 6 | 2.73% | 5 | 31.25% | 
| Al Viro | 3 | 1.36% | 1 | 6.25% | 
| Andrew Morton | 1 | 0.45% | 1 | 6.25% | 
| Total | 220 | 100.00% | 16 | 100.00% | 
/**
 *      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, inode, 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 236 | 69.21% | 1 | 6.67% | 
| Alan Cox | 69 | 20.23% | 3 | 20.00% | 
| Linus Torvalds (pre-git) | 24 | 7.04% | 5 | 33.33% | 
| Eric W. Biedermann | 4 | 1.17% | 2 | 13.33% | 
| Martin Schwidefsky | 3 | 0.88% | 1 | 6.67% | 
| Cédric Le Goater | 2 | 0.59% | 1 | 6.67% | 
| Linus Torvalds | 2 | 0.59% | 1 | 6.67% | 
| Andrew Morton | 1 | 0.29% | 1 | 6.67% | 
| Total | 341 | 100.00% | 15 | 100.00% | 
/**
 *      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 unsigned int tty_poll(struct file *filp, poll_table *wait)
{
	struct tty_struct *tty = file_tty(filp);
	struct tty_ldisc *ld;
	int 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 70 | 67.31% | 1 | 12.50% | 
| Linus Torvalds (pre-git) | 18 | 17.31% | 3 | 37.50% | 
| Alan Cox | 10 | 9.62% | 2 | 25.00% | 
| Jonathan Corbet | 4 | 3.85% | 1 | 12.50% | 
| Linus Torvalds | 2 | 1.92% | 1 | 12.50% | 
| Total | 104 | 100.00% | 8 | 100.00% | 
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_PID;
		}
		get_pid(pid);
		spin_unlock_irqrestore(&tty->ctrl_lock, flags);
		__f_setown(filp, pid, type, 0);
		put_pid(pid);
		retval = 0;
	}
out:
	return retval;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 137 | 78.29% | 1 | 11.11% | 
| Alan Cox | 14 | 8.00% | 3 | 33.33% | 
| Peter Hurley | 9 | 5.14% | 2 | 22.22% | 
| Linus Torvalds (pre-git) | 7 | 4.00% | 1 | 11.11% | 
| Jann Horn | 4 | 2.29% | 1 | 11.11% | 
| Russell King | 4 | 2.29% | 1 | 11.11% | 
| Total | 175 | 100.00% | 9 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 40 | 61.54% | 1 | 16.67% | 
| Jann Horn | 7 | 10.77% | 1 | 16.67% | 
| Russell King | 7 | 10.77% | 1 | 16.67% | 
| Alan Cox | 6 | 9.23% | 1 | 16.67% | 
| Peter Hurley | 5 | 7.69% | 2 | 33.33% | 
| Total | 65 | 100.00% | 6 | 100.00% | 
/**
 *      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;
	ld->ops->receive_buf(tty, &ch, &mbz, 1);
	tty_ldisc_deref(ld);
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 82 | 73.87% | 1 | 25.00% | 
| Russell King | 16 | 14.41% | 1 | 25.00% | 
| Alan Cox | 13 | 11.71% | 2 | 50.00% | 
| Total | 111 | 100.00% | 4 | 100.00% | 
/**
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 40 | 64.52% | 1 | 50.00% | 
| Peter Hurley | 22 | 35.48% | 1 | 50.00% | 
| Total | 62 | 100.00% | 2 | 100.00% | 
/**
 *      tty_do_resize           -       resize event
 *      @tty: tty being resized
 *      @rows: rows (character)
 *      @cols: cols (character)
 *
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 61 | 62.89% | 1 | 25.00% | 
| Alan Cox | 30 | 30.93% | 1 | 25.00% | 
| Russell King | 5 | 5.15% | 1 | 25.00% | 
| Al Viro | 1 | 1.03% | 1 | 25.00% | 
| Total | 97 | 100.00% | 4 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 40 | 55.56% | 1 | 14.29% | 
| Alan Cox | 15 | 20.83% | 2 | 28.57% | 
| Linus Torvalds (pre-git) | 14 | 19.44% | 2 | 28.57% | 
| Al Viro | 3 | 4.17% | 2 | 28.57% | 
| Total | 72 | 100.00% | 7 | 100.00% | 
/**
 *      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 == redirected_tty_write) {
		struct file *f;
		spin_lock(&redirect_lock);
		f = redirect;
		redirect = NULL;
		spin_unlock(&redirect_lock);
		if (f)
			fput(f);
		return 0;
	}
	spin_lock(&redirect_lock);
	if (redirect) {
		spin_unlock(&redirect_lock);
		return -EBUSY;
	}
	redirect = get_file(file);
	spin_unlock(&redirect_lock);
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 69 | 62.73% | 1 | 33.33% | 
| Alan Cox | 26 | 23.64% | 1 | 33.33% | 
| Linus Torvalds (pre-git) | 15 | 13.64% | 1 | 33.33% | 
| Total | 110 | 100.00% | 3 | 100.00% | 
/**
 *      fionbio         -       non blocking ioctl
 *      @file: file to set blocking value
 *      @p: user parameter
 *
 *      Historical tty interfaces had a blocking control ioctl before
 *      the generic functionality existed. This piece of history is preserved
 *      in the expected tty API of posix OS's.
 *
 *      Locking: none, the open file handle ensures it won't go away.
 */
static int fionbio(struct file *file, int __user *p)
{
	int nonblock;
	if (get_user(nonblock, p))
		return -EFAULT;
	spin_lock(&file->f_lock);
	if (nonblock)
		file->f_flags |= O_NONBLOCK;
	else
		file->f_flags &= ~O_NONBLOCK;
	spin_unlock(&file->f_lock);
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 44 | 63.77% | 1 | 20.00% | 
| Alan Cox | 20 | 28.99% | 1 | 20.00% | 
| Linus Torvalds (pre-git) | 3 | 4.35% | 1 | 20.00% | 
| Al Viro | 2 | 2.90% | 2 | 40.00% | 
| Total | 69 | 100.00% | 5 | 100.00% | 
/**
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 33 | 70.21% | 1 | 16.67% | 
| Linus Torvalds (pre-git) | 11 | 23.40% | 4 | 66.67% | 
| Peter Hurley | 3 | 6.38% | 1 | 16.67% | 
| Total | 47 | 100.00% | 6 | 100.00% | 
/**
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Peter Hurley | 61 | 100.00% | 2 | 100.00% | 
| Total | 61 | 100.00% | 2 | 100.00% | 
/**
 *      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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 112 | 78.87% | 3 | 25.00% | 
| Linus Torvalds (pre-git) | 27 | 19.01% | 6 | 50.00% | 
| Al Viro | 1 | 0.70% | 1 | 8.33% | 
| Linus Torvalds | 1 | 0.70% | 1 | 8.33% | 
| Andrew Morton | 1 | 0.70% | 1 | 8.33% | 
| Total | 142 | 100.00% | 12 | 100.00% | 
/**
 *      tty_tiocmget            -       get modem status
 *      @tty: tty device
 *      @file: user file pointer
 *      @p: pointer to result
 *
 *      Obtain the modem status bits from the tty driver if the feature
 *      is supported. Return -EINVAL if it is not available.
 *
 *      Locking: none (up to the driver)
 */
static int tty_tiocmget(struct tty_struct *tty, int __user *p)
{
	int retval = -EINVAL;
	if (tty->ops->tiocmget) {
		retval = tty->ops->tiocmget(tty);
		if (retval >= 0)
			retval = put_user(retval, p);
	}
	return retval;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 46 | 75.41% | 2 | 33.33% | 
| Linus Torvalds (pre-git) | 9 | 14.75% | 1 | 16.67% | 
| Russell King | 4 | 6.56% | 1 | 16.67% | 
| Al Viro | 2 | 3.28% | 2 | 33.33% | 
| Total | 61 | 100.00% | 6 | 100.00% | 
/**
 *      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 -EINVAL 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 -EINVAL;
	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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 111 | 79.29% | 4 | 30.77% | 
| Linus Torvalds (pre-git) | 23 | 16.43% | 5 | 38.46% | 
| Russell King | 3 | 2.14% | 1 | 7.69% | 
| Al Viro | 2 | 1.43% | 2 | 15.38% | 
| Paul Fulghum | 1 | 0.71% | 1 | 7.69% | 
| Total | 140 | 100.00% | 13 | 100.00% | 
static int tty_tiocgicount(struct tty_struct *tty, void __user *arg)
{
	int retval = -EINVAL;
	struct serial_icounter_struct icount;
	memset(&icount, 0, sizeof(icount));
	if (tty->ops->get_icount)
		retval = tty->ops->get_icount(tty, &icount);
	if (retval != 0)
		return retval;
	if (copy_to_user(arg, &icount, sizeof(icount)))
		return -EFAULT;
	return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 92 | 100.00% | 1 | 100.00% | 
| Total | 92 | 100.00% | 1 | 100.00% | 
static void tty_warn_deprecated_flags(struct serial_struct __user *ss)
{
	static DEFINE_RATELIMIT_STATE(depr_flags,
			DEFAULT_RATELIMIT_INTERVAL,
			DEFAULT_RATELIMIT_BURST);
	char comm[TASK_COMM_LEN];
	int flags;
	if (get_user(flags, &ss->flags))
		return;
	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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Jiri Slaby | 73 | 98.65% | 1 | 50.00% | 
| Joe Perches | 1 | 1.35% | 1 | 50.00% | 
| Total | 74 | 100.00% | 2 | 100.00% | 
/*
 * 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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 39 | 97.50% | 1 | 50.00% | 
| Peter Hurley | 1 | 2.50% | 1 | 50.00% | 
| Total | 40 | 100.00% | 2 | 100.00% | 
/*
 * 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 FIONBIO:
		return fionbio(file, p);
	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:
		retval = tty_tiocgicount(tty, p);
		/* For the moment allow fall through to the old method */
        	if (retval != -EINVAL)
			return retval;
		break;
	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:
		tty_warn_deprecated_flags(p);
		break;
	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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 396 | 59.55% | 4 | 11.76% | 
| Linus Torvalds (pre-git) | 50 | 7.52% | 10 | 29.41% | 
| Werner Fink | 31 | 4.66% | 1 | 2.94% | 
| Paul Fulghum | 31 | 4.66% | 1 | 2.94% | 
| Cyrill V. Gorcunov | 31 | 4.66% | 1 | 2.94% | 
| Nico Pitre | 26 | 3.91% | 1 | 2.94% | 
| Kay Sievers | 23 | 3.46% | 1 | 2.94% | 
| Peter Hurley | 18 | 2.71% | 3 | 8.82% | 
| Eric W. Biedermann | 17 | 2.56% | 1 | 2.94% | 
| Jiri Slaby | 9 | 1.35% | 1 | 2.94% | 
| Nicholas Piggin | 8 | 1.20% | 1 | 2.94% | 
| Dipankar Sarma | 7 | 1.05% | 2 | 5.88% | 
| Al Viro | 5 | 0.75% | 2 | 5.88% | 
| Rusty Russell | 4 | 0.60% | 1 | 2.94% | 
| Kirill Korotaev | 4 | 0.60% | 1 | 2.94% | 
| Pavel Emelyanov | 3 | 0.45% | 1 | 2.94% | 
| Wanlong Gao | 1 | 0.15% | 1 | 2.94% | 
| Andrew Morton | 1 | 0.15% | 1 | 2.94% | 
| Total | 665 | 100.00% | 34 | 100.00% | 
#ifdef CONFIG_COMPAT
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;
	if (tty_paranoia_check(tty, file_inode(file), "tty_ioctl"))
		return -EINVAL;
	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);
	else
		retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg);
	tty_ldisc_deref(ld);
	return retval;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 95 | 58.64% | 1 | 11.11% | 
| Eric W. Biedermann | 20 | 12.35% | 1 | 11.11% | 
| Peter Hurley | 15 | 9.26% | 1 | 11.11% | 
| Thomas Meyer | 14 | 8.64% | 1 | 11.11% | 
| Linus Torvalds | 8 | 4.94% | 2 | 22.22% | 
| Al Viro | 4 | 2.47% | 1 | 11.11% | 
| Russell King | 3 | 1.85% | 1 | 11.11% | 
| Nicholas Piggin | 3 | 1.85% | 1 | 11.11% | 
| Total | 162 | 100.00% | 9 | 100.00% | 
#endif
static int this_tty(const void *t, struct file *file, unsigned fd)
{
	if (likely(file->f_op->read != tty_read))
		return 0;
	return file_tty(file) != t ? 0 : fd + 1;
}
	
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Al Viro | 49 | 100.00% | 1 | 100.00% | 
| Total | 49 | 100.00% | 1 | 100.00% | 
/*
 * 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;
	if (!tty)
		return;
	session = tty->session;
	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);
		send_sig(SIGKILL, p, 1);
	} 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);
			send_sig(SIGKILL, p, 1);
			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);
			force_sig(SIGKILL, p);
		}
		task_unlock(p);
	} while_each_thread(g, p);
	read_unlock(&tasklist_lock);
#endif
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 171 | 74.03% | 4 | 36.36% | 
| Paul Fulghum | 26 | 11.26% | 2 | 18.18% | 
| Peter Hurley | 13 | 5.63% | 1 | 9.09% | 
| Al Viro | 11 | 4.76% | 1 | 9.09% | 
| Linus Torvalds (pre-git) | 7 | 3.03% | 2 | 18.18% | 
| Nico Pitre | 3 | 1.30% | 1 | 9.09% | 
| Total | 231 | 100.00% | 11 | 100.00% | 
static void do_SAK_work(struct work_struct *work)
{
	struct tty_struct *tty =
		container_of(work, struct tty_struct, SAK_work);
	__do_SAK(tty);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 28 | 90.32% | 3 | 60.00% | 
| Linus Torvalds (pre-git) | 2 | 6.45% | 1 | 20.00% | 
| Nico Pitre | 1 | 3.23% | 1 | 20.00% | 
| Total | 31 | 100.00% | 5 | 100.00% | 
/*
 * 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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Linus Torvalds (pre-git) | 19 | 79.17% | 1 | 50.00% | 
| Alan Cox | 5 | 20.83% | 1 | 50.00% | 
| Total | 24 | 100.00% | 2 | 100.00% | 
EXPORT_SYMBOL(do_SAK);
static int dev_match_devt(struct device *dev, const void *data)
{
	const dev_t *devt = data;
	return dev->devt == *devt;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Dmitry Baryshkov | 29 | 93.55% | 1 | 50.00% | 
| Greg Kroah-Hartman | 2 | 6.45% | 1 | 50.00% | 
| Total | 31 | 100.00% | 2 | 100.00% | 
/* 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(tty_class, NULL, &devt, dev_match_devt);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Dmitry Baryshkov | 34 | 100.00% | 1 | 100.00% | 
| Total | 34 | 100.00% | 1 | 100.00% | 
/**
 *      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;
	tty_ldisc_init(tty);
	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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 77 | 33.33% | 9 | 28.12% | 
| Linus Torvalds (pre-git) | 58 | 25.11% | 9 | 28.12% | 
| Peter Hurley | 36 | 15.58% | 6 | 18.75% | 
| Rasmus Villemoes | 25 | 10.82% | 1 | 3.12% | 
| Ingo Molnar | 10 | 4.33% | 2 | 6.25% | 
| Dmitry Baryshkov | 9 | 3.90% | 1 | 3.12% | 
| Eric W. Biedermann | 8 | 3.46% | 2 | 6.25% | 
| Linus Torvalds | 7 | 3.03% | 1 | 3.12% | 
| Arjan van de Ven | 1 | 0.43% | 1 | 3.12% | 
| Total | 231 | 100.00% | 32 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 25 | 51.02% | 1 | 16.67% | 
| Linus Torvalds (pre-git) | 23 | 46.94% | 4 | 66.67% | 
| Al Viro | 1 | 2.04% | 1 | 16.67% | 
| Total | 49 | 100.00% | 6 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Jiri Slaby | 58 | 52.25% | 1 | 33.33% | 
| Leon Yu | 28 | 25.23% | 1 | 33.33% | 
| Richard Watts | 25 | 22.52% | 1 | 33.33% | 
| Total | 111 | 100.00% | 3 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Tomas Hlavacek | 15 | 44.12% | 1 | 14.29% | 
| Linus Torvalds (pre-git) | 9 | 26.47% | 2 | 28.57% | 
| Greg Kroah-Hartman | 7 | 20.59% | 2 | 28.57% | 
| Hansjoerg Lipp | 2 | 5.88% | 1 | 14.29% | 
| Al Viro | 1 | 2.94% | 1 | 14.29% | 
| Total | 34 | 100.00% | 7 | 100.00% | 
EXPORT_SYMBOL(tty_register_device);
static void tty_device_create_release(struct device *dev)
{
	dev_dbg(dev, "releasing...\n");
	kfree(dev);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Tomas Hlavacek | 21 | 91.30% | 1 | 50.00% | 
| Peter Hurley | 2 | 8.70% | 1 | 50.00% | 
| Total | 23 | 100.00% | 2 | 100.00% | 
/**
 *      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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Tomas Hlavacek | 108 | 34.18% | 2 | 9.09% | 
| Johan Hovold | 104 | 32.91% | 2 | 9.09% | 
| Linus Torvalds (pre-git) | 20 | 6.33% | 3 | 13.64% | 
| Olaf Hering | 16 | 5.06% | 1 | 4.55% | 
| Jiri Slaby | 15 | 4.75% | 1 | 4.55% | 
| Greg Kroah-Hartman | 13 | 4.11% | 5 | 22.73% | 
| Al Viro | 10 | 3.16% | 2 | 9.09% | 
| Andrew Morton | 10 | 3.16% | 1 | 4.55% | 
| Hansjoerg Lipp | 8 | 2.53% | 1 | 4.55% | 
| Peter Hurley | 6 | 1.90% | 1 | 4.55% | 
| Linus Torvalds | 3 | 0.95% | 2 | 9.09% | 
| Richard Watts | 3 | 0.95% | 1 | 4.55% | 
| Total | 316 | 100.00% | 22 | 100.00% | 
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;
	}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Greg Kroah-Hartman | 29 | 46.03% | 4 | 57.14% | 
| Jiri Slaby | 21 | 33.33% | 1 | 14.29% | 
| Richard Watts | 11 | 17.46% | 1 | 14.29% | 
| Al Viro | 2 | 3.17% | 1 | 14.29% | 
| Total | 63 | 100.00% | 7 | 100.00% | 
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(struct tty_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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Jiri Slaby | 254 | 80.63% | 5 | 55.56% | 
| Al Viro | 45 | 14.29% | 1 | 11.11% | 
| Alan Cox | 8 | 2.54% | 1 | 11.11% | 
| Richard Watts | 7 | 2.22% | 1 | 11.11% | 
| Jean Delvare | 1 | 0.32% | 1 | 11.11% | 
| Total | 315 | 100.00% | 9 | 100.00% | 
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);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 116 | 70.73% | 1 | 20.00% | 
| Jiri Slaby | 35 | 21.34% | 3 | 60.00% | 
| Al Viro | 13 | 7.93% | 1 | 20.00% | 
| Total | 164 | 100.00% | 5 | 100.00% | 
void tty_driver_kref_put(struct tty_driver *driver)
{
	kref_put(&driver->kref, destruct_tty_driver);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 20 | 100.00% | 1 | 100.00% | 
| Total | 20 | 100.00% | 1 | 100.00% | 
EXPORT_SYMBOL(tty_driver_kref_put);
void tty_set_operations(struct tty_driver *driver,
			const struct tty_operations *op)
{
	driver->ops = op;
}Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Al Viro | 20 | 90.91% | 1 | 33.33% | 
| Alan Cox | 1 | 4.55% | 1 | 33.33% | 
| Jeff Dike | 1 | 4.55% | 1 | 33.33% | 
| Total | 22 | 100.00% | 3 | 100.00% | 
;
EXPORT_SYMBOL(tty_set_operations);
void put_tty_driver(struct tty_driver *d)
{
	tty_driver_kref_put(d);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 12 | 80.00% | 1 | 50.00% | 
| Al Viro | 3 | 20.00% | 1 | 50.00% | 
| Total | 15 | 100.00% | 2 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Al Viro | 115 | 37.83% | 3 | 13.64% | 
| Vasiliy Kulikov | 79 | 25.99% | 1 | 4.55% | 
| Linus Torvalds (pre-git) | 55 | 18.09% | 7 | 31.82% | 
| Jiri Slaby | 22 | 7.24% | 3 | 13.64% | 
| Alexey Dobriyan | 12 | 3.95% | 1 | 4.55% | 
| Brian Gerst | 6 | 1.97% | 1 | 4.55% | 
| Alan Cox | 6 | 1.97% | 1 | 4.55% | 
| Greg Kroah-Hartman | 4 | 1.32% | 3 | 13.64% | 
| Paul Fulghum | 4 | 1.32% | 1 | 4.55% | 
| Andrew Morton | 1 | 0.33% | 1 | 4.55% | 
| Total | 304 | 100.00% | 22 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Linus Torvalds (pre-git) | 20 | 34.48% | 1 | 20.00% | 
| Al Viro | 14 | 24.14% | 1 | 20.00% | 
| Alexey Dobriyan | 12 | 20.69% | 1 | 20.00% | 
| Alan Cox | 7 | 12.07% | 1 | 20.00% | 
| Brian Gerst | 5 | 8.62% | 1 | 20.00% | 
| Total | 58 | 100.00% | 5 | 100.00% | 
EXPORT_SYMBOL(tty_unregister_driver);
dev_t tty_devnum(struct tty_struct *tty)
{
	return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Peter Zijlstra | 30 | 100.00% | 1 | 100.00% | 
| Total | 30 | 100.00% | 1 | 100.00% | 
EXPORT_SYMBOL(tty_devnum);
void tty_default_fops(struct file_operations *fops)
{
	*fops = tty_fops;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Alan Cox | 15 | 100.00% | 1 | 100.00% | 
| Total | 15 | 100.00% | 1 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Kay Sievers | 55 | 98.21% | 1 | 50.00% | 
| Al Viro | 1 | 1.79% | 1 | 50.00% | 
| Total | 56 | 100.00% | 2 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Greg Kroah-Hartman | 22 | 55.00% | 3 | 60.00% | 
| Russell King | 12 | 30.00% | 1 | 20.00% | 
| Kay Sievers | 6 | 15.00% | 1 | 20.00% | 
| Total | 40 | 100.00% | 5 | 100.00% | 
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Kay Sievers | 119 | 53.85% | 2 | 33.33% | 
| Hannes Reinecke | 90 | 40.72% | 2 | 33.33% | 
| Greg Kroah-Hartman | 10 | 4.52% | 1 | 16.67% | 
| Torben Hohn | 2 | 0.90% | 1 | 16.67% | 
| Total | 221 | 100.00% | 6 | 100.00% | 
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");
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Kay Sievers | 23 | 100.00% | 1 | 100.00% | 
| Total | 23 | 100.00% | 1 | 100.00% | 
/*
 * Ok, now we can initialize the rest of the tty devices and can count
 * on memory allocations, interrupts etc..
 */
int __init tty_init(void)
{
	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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Al Viro | 77 | 46.11% | 4 | 21.05% | 
| Linus Torvalds (pre-git) | 34 | 20.36% | 7 | 36.84% | 
| Greg Kroah-Hartman | 34 | 20.36% | 4 | 21.05% | 
| Kay Sievers | 13 | 7.78% | 1 | 5.26% | 
| Andrew Morton | 4 | 2.40% | 1 | 5.26% | 
| Takashi Iwai | 3 | 1.80% | 1 | 5.26% | 
| Alan Cox | 2 | 1.20% | 1 | 5.26% | 
| Total | 167 | 100.00% | 19 | 100.00% | 
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp | 
| Nico Pitre | 3794 | 33.08% | 2 | 0.57% | 
| Alan Cox | 2920 | 25.46% | 45 | 12.93% | 
| Linus Torvalds (pre-git) | 901 | 7.86% | 76 | 21.84% | 
| Peter Hurley | 795 | 6.93% | 60 | 17.24% | 
| Jiri Slaby | 666 | 5.81% | 19 | 5.46% | 
| Al Viro | 468 | 4.08% | 20 | 5.75% | 
| Kay Sievers | 257 | 2.24% | 4 | 1.15% | 
| Nicholas Piggin | 158 | 1.38% | 2 | 0.57% | 
| Tomas Hlavacek | 152 | 1.33% | 2 | 0.57% | 
| Greg Kroah-Hartman | 134 | 1.17% | 14 | 4.02% | 
| Johan Hovold | 104 | 0.91% | 2 | 0.57% | 
| Paul Fulghum | 99 | 0.86% | 6 | 1.72% | 
| Hannes Reinecke | 94 | 0.82% | 2 | 0.57% | 
| Dmitry Baryshkov | 80 | 0.70% | 1 | 0.29% | 
| Vasiliy Kulikov | 79 | 0.69% | 1 | 0.29% | 
| Russell King | 61 | 0.53% | 3 | 0.86% | 
| Eric W. Biedermann | 57 | 0.50% | 6 | 1.72% | 
| Sukadev Bhattiprolu | 48 | 0.42% | 4 | 1.15% | 
| Peter Zijlstra | 46 | 0.40% | 1 | 0.29% | 
| Richard Watts | 46 | 0.40% | 1 | 0.29% | 
| Andrew Morton | 43 | 0.37% | 7 | 2.01% | 
| Arnd Bergmann | 42 | 0.37% | 3 | 0.86% | 
| Linus Torvalds | 35 | 0.31% | 9 | 2.59% | 
| Cyrill V. Gorcunov | 34 | 0.30% | 2 | 0.57% | 
| Rasmus Villemoes | 33 | 0.29% | 4 | 1.15% | 
| Werner Fink | 31 | 0.27% | 1 | 0.29% | 
| Leon Yu | 28 | 0.24% | 1 | 0.29% | 
| Alexey Dobriyan | 24 | 0.21% | 1 | 0.29% | 
| Takashi Iwai | 24 | 0.21% | 1 | 0.29% | 
| Rob Herring | 20 | 0.17% | 1 | 0.29% | 
| Arnaldo Carvalho de Melo | 19 | 0.17% | 1 | 0.29% | 
| Ingo Molnar | 17 | 0.15% | 5 | 1.44% | 
| Olaf Hering | 16 | 0.14% | 1 | 0.29% | 
| Brian Gerst | 15 | 0.13% | 1 | 0.29% | 
| Thomas Meyer | 14 | 0.12% | 1 | 0.29% | 
| Jann Horn | 13 | 0.11% | 1 | 0.29% | 
| Pekka J Enberg | 10 | 0.09% | 1 | 0.29% | 
| Hansjoerg Lipp | 10 | 0.09% | 1 | 0.29% | 
| Jonathan Corbet | 10 | 0.09% | 4 | 1.15% | 
| Dipankar Sarma | 7 | 0.06% | 2 | 0.57% | 
| Oleg Nesterov | 7 | 0.06% | 1 | 0.29% | 
| Pavel Emelyanov | 6 | 0.05% | 2 | 0.57% | 
| Kirill Korotaev | 6 | 0.05% | 1 | 0.29% | 
| Dan Carpenter | 5 | 0.04% | 1 | 0.29% | 
| Vojtech Pavlik | 5 | 0.04% | 1 | 0.29% | 
| Rusty Russell | 4 | 0.03% | 1 | 0.29% | 
| Cédric Le Goater | 3 | 0.03% | 1 | 0.29% | 
| Domen Puncer | 3 | 0.03% | 1 | 0.29% | 
| Martin Schwidefsky | 3 | 0.03% | 1 | 0.29% | 
| Manuel Zerpies | 3 | 0.03% | 1 | 0.29% | 
| H. Peter Anvin | 3 | 0.03% | 1 | 0.29% | 
| Torben Hohn | 2 | 0.02% | 1 | 0.29% | 
| Thomas Koeller | 1 | 0.01% | 1 | 0.29% | 
| Nathael Pajani | 1 | 0.01% | 1 | 0.29% | 
| Josh Triplett | 1 | 0.01% | 1 | 0.29% | 
| Wanlong Gao | 1 | 0.01% | 1 | 0.29% | 
| Jean Delvare | 1 | 0.01% | 1 | 0.29% | 
| Jovi Zhang | 1 | 0.01% | 1 | 0.29% | 
| Jason Wessel | 1 | 0.01% | 1 | 0.29% | 
| Samuel Thibault | 1 | 0.01% | 1 | 0.29% | 
| Jeff Dike | 1 | 0.01% | 1 | 0.29% | 
| Adrian Bunk | 1 | 0.01% | 1 | 0.29% | 
| Christoph Hellwig | 1 | 0.01% | 1 | 0.29% | 
| James Morris | 1 | 0.01% | 1 | 0.29% | 
| Thadeu Lima de Souza Cascardo | 1 | 0.01% | 1 | 0.29% | 
| Joe Perches | 1 | 0.01% | 1 | 0.29% | 
| Arjan van de Ven | 1 | 0.01% | 1 | 0.29% | 
| Eric Paris | 1 | 0.01% | 1 | 0.29% | 
| Total | 11470 | 100.00% | 348 | 100.00% | 
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