cregit-Linux how code gets into the kernel

Release 4.11 drivers/tty/tty_ioctl.c

Directory: drivers/tty
/*
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 * 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).
 */

#include <linux/types.h>
#include <linux/termios.h>
#include <linux/errno.h>
#include <linux/sched/signal.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/tty.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/compat.h>

#include <asm/io.h>
#include <linux/uaccess.h>


#undef TTY_DEBUG_WAIT_UNTIL_SENT

#ifdef TTY_DEBUG_WAIT_UNTIL_SENT

# define tty_debug_wait_until_sent(tty, f, args...)    tty_debug(tty, f, ##args)
#else

# define tty_debug_wait_until_sent(tty, f, args...)    do {} while (0)
#endif


#undef	DEBUG

/*
 * Internal flag options for termios setting behavior
 */

#define TERMIOS_FLUSH	1

#define TERMIOS_WAIT	2

#define TERMIOS_TERMIO	4

#define TERMIOS_OLD	8


/**
 *      tty_chars_in_buffer     -       characters pending
 *      @tty: terminal
 *
 *      Return the number of bytes of data in the device private
 *      output queue. If no private method is supplied there is assumed
 *      to be no queue on the device.
 */




int tty_chars_in_buffer(struct tty_struct *tty)
{
	if (tty->ops->chars_in_buffer)
		return tty->ops->chars_in_buffer(tty);
	else
		return 0;
}

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EXPORT_SYMBOL(tty_chars_in_buffer);

/**
 *      tty_write_room          -       write queue space
 *      @tty: terminal
 *
 *      Return the number of bytes that can be queued to this device
 *      at the present time. The result should be treated as a guarantee
 *      and the driver cannot offer a value it later shrinks by more than
 *      the number of bytes written. If no method is provided 2K is always
 *      returned and data may be lost as there will be no flow control.
 */
 



int tty_write_room(struct tty_struct *tty)
{
	if (tty->ops->write_room)
		return tty->ops->write_room(tty);
	return 2048;
}

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EXPORT_SYMBOL(tty_write_room);

/**
 *      tty_driver_flush_buffer -       discard internal buffer
 *      @tty: terminal
 *
 *      Discard the internal output buffer for this device. If no method
 *      is provided then either the buffer cannot be hardware flushed or
 *      there is no buffer driver side.
 */



void tty_driver_flush_buffer(struct tty_struct *tty)
{
	if (tty->ops->flush_buffer)
		tty->ops->flush_buffer(tty);
}

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EXPORT_SYMBOL(tty_driver_flush_buffer);

/**
 *      tty_throttle            -       flow control
 *      @tty: terminal
 *
 *      Indicate that a tty should stop transmitting data down the stack.
 *      Takes the termios rwsem to protect against parallel throttle/unthrottle
 *      and also to ensure the driver can consistently reference its own
 *      termios data at this point when implementing software flow control.
 */




void tty_throttle(struct tty_struct *tty)
{
	down_write(&tty->termios_rwsem);
	/* check TTY_THROTTLED first so it indicates our state */
	if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
	    tty->ops->throttle)
		tty->ops->throttle(tty);
	tty->flow_change = 0;
	up_write(&tty->termios_rwsem);
}

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EXPORT_SYMBOL(tty_throttle);

/**
 *      tty_unthrottle          -       flow control
 *      @tty: terminal
 *
 *      Indicate that a tty may continue transmitting data down the stack.
 *      Takes the termios rwsem to protect against parallel throttle/unthrottle
 *      and also to ensure the driver can consistently reference its own
 *      termios data at this point when implementing software flow control.
 *
 *      Drivers should however remember that the stack can issue a throttle,
 *      then change flow control method, then unthrottle.
 */




void tty_unthrottle(struct tty_struct *tty)
{
	down_write(&tty->termios_rwsem);
	if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
	    tty->ops->unthrottle)
		tty->ops->unthrottle(tty);
	tty->flow_change = 0;
	up_write(&tty->termios_rwsem);
}

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EXPORT_SYMBOL(tty_unthrottle);

/**
 *      tty_throttle_safe       -       flow control
 *      @tty: terminal
 *
 *      Similar to tty_throttle() but will only attempt throttle
 *      if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental
 *      throttle due to race conditions when throttling is conditional
 *      on factors evaluated prior to throttling.
 *
 *      Returns 0 if tty is throttled (or was already throttled)
 */




int tty_throttle_safe(struct tty_struct *tty)
{
	int ret = 0;

	mutex_lock(&tty->throttle_mutex);
	if (!tty_throttled(tty)) {
		if (tty->flow_change != TTY_THROTTLE_SAFE)
			ret = 1;
		else {
			set_bit(TTY_THROTTLED, &tty->flags);
			if (tty->ops->throttle)
				tty->ops->throttle(tty);
		}
	}
	mutex_unlock(&tty->throttle_mutex);

	return ret;
}


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/**
 *      tty_unthrottle_safe     -       flow control
 *      @tty: terminal
 *
 *      Similar to tty_unthrottle() but will only attempt unthrottle
 *      if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
 *      unthrottle due to race conditions when unthrottling is conditional
 *      on factors evaluated prior to unthrottling.
 *
 *      Returns 0 if tty is unthrottled (or was already unthrottled)
 */




int tty_unthrottle_safe(struct tty_struct *tty)
{
	int ret = 0;

	mutex_lock(&tty->throttle_mutex);
	if (tty_throttled(tty)) {
		if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
			ret = 1;
		else {
			clear_bit(TTY_THROTTLED, &tty->flags);
			if (tty->ops->unthrottle)
				tty->ops->unthrottle(tty);
		}
	}
	mutex_unlock(&tty->throttle_mutex);

	return ret;
}


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/**
 *      tty_wait_until_sent     -       wait for I/O to finish
 *      @tty: tty we are waiting for
 *      @timeout: how long we will wait
 *
 *      Wait for characters pending in a tty driver to hit the wire, or
 *      for a timeout to occur (eg due to flow control)
 *
 *      Locking: none
 */




void tty_wait_until_sent(struct tty_struct *tty, long timeout)
{
	tty_debug_wait_until_sent(tty, "wait until sent, timeout=%ld\n", timeout);

	if (!timeout)
		timeout = MAX_SCHEDULE_TIMEOUT;

	timeout = wait_event_interruptible_timeout(tty->write_wait,
			!tty_chars_in_buffer(tty), timeout);
	if (timeout <= 0)
		return;

	if (timeout == MAX_SCHEDULE_TIMEOUT)
		timeout = 0;

	if (tty->ops->wait_until_sent)
		tty->ops->wait_until_sent(tty, timeout);
}

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EXPORT_SYMBOL(tty_wait_until_sent);


/*
 *              Termios Helper Methods
 */




static void unset_locked_termios(struct tty_struct *tty, struct ktermios *old)
{
	struct ktermios *termios = &tty->termios;
	struct ktermios *locked  = &tty->termios_locked;
	int	i;


#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))

	NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
	NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
	NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
	NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
	termios->c_line = locked->c_line ? old->c_line : termios->c_line;
	for (i = 0; i < NCCS; i++)
		termios->c_cc[i] = locked->c_cc[i] ?
			old->c_cc[i] : termios->c_cc[i];
	/* FIXME: What should we do for i/ospeed */
}


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/*
 * Routine which returns the baud rate of the tty
 *
 * Note that the baud_table needs to be kept in sync with the
 * include/asm/termbits.h file.
 */

static const speed_t baud_table[] = {
	0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
	9600, 19200, 38400, 57600, 115200, 230400, 460800,
#ifdef __sparc__
	76800, 153600, 307200, 614400, 921600
#else
	500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
	2500000, 3000000, 3500000, 4000000
#endif
};

#ifndef __sparc__

static const tcflag_t baud_bits[] = {
	B0, B50, B75, B110, B134, B150, B200, B300, B600,
	B1200, B1800, B2400, B4800, B9600, B19200, B38400,
	B57600, B115200, B230400, B460800, B500000, B576000,
	B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
	B3000000, B3500000, B4000000
};
#else

static const tcflag_t baud_bits[] = {
	B0, B50, B75, B110, B134, B150, B200, B300, B600,
	B1200, B1800, B2400, B4800, B9600, B19200, B38400,
	B57600, B115200, B230400, B460800, B76800, B153600,
	B307200, B614400, B921600
};
#endif


static int n_baud_table = ARRAY_SIZE(baud_table);

/**
 *      tty_termios_baud_rate
 *      @termios: termios structure
 *
 *      Convert termios baud rate data into a speed. This should be called
 *      with the termios lock held if this termios is a terminal termios
 *      structure. May change the termios data. Device drivers can call this
 *      function but should use ->c_[io]speed directly as they are updated.
 *
 *      Locking: none
 */




speed_t tty_termios_baud_rate(struct ktermios *termios)
{
	unsigned int cbaud;

	cbaud = termios->c_cflag & CBAUD;

#ifdef BOTHER
	/* Magic token for arbitrary speed via c_ispeed/c_ospeed */
	if (cbaud == BOTHER)
		return termios->c_ospeed;
#endif
	if (cbaud & CBAUDEX) {
		cbaud &= ~CBAUDEX;

		if (cbaud < 1 || cbaud + 15 > n_baud_table)
			termios->c_cflag &= ~CBAUDEX;
		else
			cbaud += 15;
	}
	return baud_table[cbaud];
}

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EXPORT_SYMBOL(tty_termios_baud_rate);

/**
 *      tty_termios_input_baud_rate
 *      @termios: termios structure
 *
 *      Convert termios baud rate data into a speed. This should be called
 *      with the termios lock held if this termios is a terminal termios
 *      structure. May change the termios data. Device drivers can call this
 *      function but should use ->c_[io]speed directly as they are updated.
 *
 *      Locking: none
 */




speed_t tty_termios_input_baud_rate(struct ktermios *termios)
{
#ifdef IBSHIFT
	unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;

	if (cbaud == B0)
		return tty_termios_baud_rate(termios);

	/* Magic token for arbitrary speed via c_ispeed*/
	if (cbaud == BOTHER)
		return termios->c_ispeed;

	if (cbaud & CBAUDEX) {
		cbaud &= ~CBAUDEX;

		if (cbaud < 1 || cbaud + 15 > n_baud_table)
			termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
		else
			cbaud += 15;
	}
	return baud_table[cbaud];
#else
	return tty_termios_baud_rate(termios);
#endif
}

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EXPORT_SYMBOL(tty_termios_input_baud_rate);

/**
 *      tty_termios_encode_baud_rate
 *      @termios: ktermios structure holding user requested state
 *      @ispeed: input speed
 *      @ospeed: output speed
 *
 *      Encode the speeds set into the passed termios structure. This is
 *      used as a library helper for drivers so that they can report back
 *      the actual speed selected when it differs from the speed requested
 *
 *      For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
 *      we need to carefully set the bits when the user does not get the
 *      desired speed. We allow small margins and preserve as much of possible
 *      of the input intent to keep compatibility.
 *
 *      Locking: Caller should hold termios lock. This is already held
 *      when calling this function from the driver termios handler.
 *
 *      The ifdefs deal with platforms whose owners have yet to update them
 *      and will all go away once this is done.
 */




void tty_termios_encode_baud_rate(struct ktermios *termios,
				  speed_t ibaud, speed_t obaud)
{
	int i = 0;
	int ifound = -1, ofound = -1;
	int iclose = ibaud/50, oclose = obaud/50;
	int ibinput = 0;

	if (obaud == 0)			/* CD dropped             */
		ibaud = 0;		/* Clear ibaud to be sure */

	termios->c_ispeed = ibaud;
	termios->c_ospeed = obaud;

#ifdef BOTHER
	/* If the user asked for a precise weird speed give a precise weird
           answer. If they asked for a Bfoo speed they may have problems
           digesting non-exact replies so fuzz a bit */

	if ((termios->c_cflag & CBAUD) == BOTHER)
		oclose = 0;
	if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
		iclose = 0;
	if ((termios->c_cflag >> IBSHIFT) & CBAUD)
		ibinput = 1;	/* An input speed was specified */
#endif
	termios->c_cflag &= ~CBAUD;

	/*
         *      Our goal is to find a close match to the standard baud rate
         *      returned. Walk the baud rate table and if we get a very close
         *      match then report back the speed as a POSIX Bxxxx value by
         *      preference
         */

	do {
		if (obaud - oclose <= baud_table[i] &&
		    obaud + oclose >= baud_table[i]) {
			termios->c_cflag |= baud_bits[i];
			ofound = i;
		}
		if (ibaud - iclose <= baud_table[i] &&
		    ibaud + iclose >= baud_table[i]) {
			/* For the case input == output don't set IBAUD bits
                           if the user didn't do so */
			if (ofound == i && !ibinput)
				ifound  = i;
#ifdef IBSHIFT
			else {
				ifound = i;
				termios->c_cflag |= (baud_bits[i] << IBSHIFT);
			}
#endif
		}
	} while (++i < n_baud_table);

	/*
         *      If we found no match then use BOTHER if provided or warn
         *      the user their platform maintainer needs to wake up if not.
         */
#ifdef BOTHER
	if (ofound == -1)
		termios->c_cflag |= BOTHER;
	/* Set exact input bits only if the input and output differ or the
           user already did */
	if (ifound == -1 && (ibaud != obaud || ibinput))
		termios->c_cflag |= (BOTHER << IBSHIFT);
#else
	if (ifound == -1 || ofound == -1)
		pr_warn_once("tty: Unable to return correct speed data as your architecture needs updating.\n");
#endif
}

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EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);

/**
 *      tty_encode_baud_rate            -       set baud rate of the tty
 *      @ibaud: input baud rate
 *      @obad: output baud rate
 *
 *      Update the current termios data for the tty with the new speed
 *      settings. The caller must hold the termios_rwsem for the tty in
 *      question.
 */




void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
{
	tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
}

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EXPORT_SYMBOL_GPL(tty_encode_baud_rate);

/**
 *      tty_termios_copy_hw     -       copy hardware settings
 *      @new: New termios
 *      @old: Old termios
 *
 *      Propagate the hardware specific terminal setting bits from
 *      the old termios structure to the new one. This is used in cases
 *      where the hardware does not support reconfiguration or as a helper
 *      in some cases where only minimal reconfiguration is supported
 */




void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
{
	/* The bits a dumb device handles in software. Smart devices need
           to always provide a set_termios method */
	new->c_cflag &= HUPCL | CREAD | CLOCAL;
	new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
	new->c_ispeed = old->c_ispeed;
	new->c_ospeed = old->c_ospeed;
}

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EXPORT_SYMBOL(tty_termios_copy_hw);

/**
 *      tty_termios_hw_change   -       check for setting change
 *      @a: termios
 *      @b: termios to compare
 *
 *      Check if any of the bits that affect a dumb device have changed
 *      between the two termios structures, or a speed change is needed.
 */




int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
{
	if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
		return 1;
	if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
		return 1;
	return 0;
}

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EXPORT_SYMBOL(tty_termios_hw_change);

/**
 *      tty_set_termios         -       update termios values
 *      @tty: tty to update
 *      @new_termios: desired new value
 *
 *      Perform updates to the termios values set on this terminal.
 *      A master pty's termios should never be set.
 *
 *      Locking: termios_rwsem
 */




int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
{
	struct ktermios old_termios;
	struct tty_ldisc *ld;

	WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
		tty->driver->subtype == PTY_TYPE_MASTER);
	/*
         *      Perform the actual termios internal changes under lock.
         */


	/* FIXME: we need to decide on some locking/ordering semantics
           for the set_termios notification eventually */
	down_write(&tty->termios_rwsem);
	old_termios = tty->termios;
	tty->termios = *new_termios;
	unset_locked_termios(tty, &old_termios);

	if (tty->ops->set_termios)
		tty->ops->set_termios(tty, &old_termios);
	else
		tty_termios_copy_hw(&tty->termios, &old_termios);

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		if (ld->ops->set_termios)
			ld->ops->set_termios(tty, &old_termios);
		tty_ldisc_deref(ld);
	}
	up_write(&tty->termios_rwsem);
	return 0;
}

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EXPORT_SYMBOL_GPL(tty_set_termios);

/**
 *      set_termios             -       set termios values for a tty
 *      @tty: terminal device
 *      @arg: user data
 *      @opt: option information
 *
 *      Helper function to prepare termios data and run necessary other
 *      functions before using tty_set_termios to do the actual changes.
 *
 *      Locking:
 *              Called functions take ldisc and termios_rwsem locks
 */




static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
{
	struct ktermios tmp_termios;
	struct tty_ldisc *ld;
	int retval = tty_check_change(tty);

	if (retval)
		return retval;

	down_read(&tty->termios_rwsem);
	tmp_termios = tty->termios;
	up_read(&tty->termios_rwsem);

	if (opt & TERMIOS_TERMIO) {
		if (user_termio_to_kernel_termios(&tmp_termios,
						(struct termio __user *)arg))
			return -EFAULT;
#ifdef TCGETS2
	} else if (opt & TERMIOS_OLD) {
		if (user_termios_to_kernel_termios_1(&tmp_termios,
						(struct termios __user *)arg))
			return -EFAULT;
	} else {
		if (user_termios_to_kernel_termios(&tmp_termios,
						(struct termios2 __user *)arg))
			return -EFAULT;
	}
#else
	} 
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else if (user_termios_to_kernel_termios(&tmp_termios,
					(struct termios __user *)arg))
		return -EFAULT;
#endif

	/* If old style Bfoo values are used then load c_ispeed/c_ospeed
         * with the real speed so its unconditionally usable */
	tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
	tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);

	ld = tty_ldisc_ref(tty);

	if (ld != NULL) {
		if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}

	if (opt & TERMIOS_WAIT) {
		tty_wait_until_sent(tty, 0);
		if (signal_pending(current))
			return -ERESTARTSYS;
	}

	tty_set_termios(tty, &tmp_termios);

	/* FIXME: Arguably if tmp_termios == tty->termios AND the
           actual requested termios was not tmp_termios then we may
           want to return an error as no user requested change has
           succeeded */
	return 0;


}

static 
void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
{
	down_read(&tty->termios_rwsem);
	*kterm = tty->termios;
	up_read(&tty->termios_rwsem);
}


Contributors
PersonTokensPropCommitsCommitProp
Alan Cox3589.74%375.00%


Peter Hurley410.26%125.00%


Total39100.00%4100.00%






static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
{
	down_read(&tty->termios_rwsem);
	*kterm = tty->termios_locked;
	up_read(&tty->termios_rwsem);
}


Contributors
PersonTokensPropCommitsCommitProp
Alan Cox3589.74%266.67%


Peter Hurley410.26%133.33%


Total39100.00%3100.00%






static int get_termio(struct tty_struct *tty, struct termio __user *termio)
{
	struct ktermios kterm;
	copy_termios(tty, &kterm);
	if (kernel_termios_to_user_termio(termio, &kterm))
		return -EFAULT;
	return 0;
}



Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)3065.22%360.00%


Alan Cox1532.61%120.00%


Al Viro12.17%120.00%


Total46100.00%5100.00%



#ifdef TCGETX

/**
 *      set_termiox     -       set termiox fields if possible
 *      @tty: terminal
 *      @arg: termiox structure from user
 *      @opt: option flags for ioctl type
 *
 *      Implement the device calling points for the SYS5 termiox ioctl
 *      interface in Linux
 */




static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
{
	struct termiox tnew;
	struct tty_ldisc *ld;

	if (tty->termiox == NULL)
		return -EINVAL;
	if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
		return -EFAULT;

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
			ld->ops->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
	if (opt & TERMIOS_WAIT) {
		tty_wait_until_sent(tty, 0);
		if (signal_pending(current))
			return -ERESTARTSYS;
	}

	down_write(&tty->termios_rwsem);
	if (tty->ops->set_termiox)
		tty->ops->set_termiox(tty, &tnew);
	up_write(&tty->termios_rwsem);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Alan Cox16397.02%133.33%


Peter Hurley42.38%133.33%


Oleg Nesterov10.60%133.33%


Total168100.00%3100.00%



#endif


#ifdef TIOCGETP
/*
 * These are deprecated, but there is limited support..
 *
 * The "sg_flags" translation is a joke..
 */



static int get_sgflags(struct tty_struct *tty)
{
	int flags = 0;

	if (!L_ICANON(tty)) {
		if (L_ISIG(tty))
			flags |= 0x02;		/* cbreak */
		else
			flags |= 0x20;		/* raw */
	}
	if (L_ECHO(tty))
		flags |= 0x08;			/* echo */
	if (O_OPOST(tty))
		if (O_ONLCR(tty))
			flags |= 0x10;		/* crmod */
	return flags;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)6380.77%266.67%


Peter Hurley1519.23%133.33%


Total78100.00%3100.00%






static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
{
	struct sgttyb tmp;

	down_read(&tty->termios_rwsem);
	tmp.sg_ispeed = tty->termios.c_ispeed;
	tmp.sg_ospeed = tty->termios.c_ospeed;
	tmp.sg_erase = tty->termios.c_cc[VERASE];
	tmp.sg_kill = tty->termios.c_cc[VKILL];
	tmp.sg_flags = get_sgflags(tty);
	up_read(&tty->termios_rwsem);

	return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)7971.17%327.27%


Alan Cox2421.62%545.45%


Peter Hurley43.60%19.09%


Linus Torvalds32.70%19.09%


Al Viro10.90%19.09%


Total111100.00%11100.00%






static void set_sgflags(struct ktermios *termios, int flags)
{
	termios->c_iflag = ICRNL | IXON;
	termios->c_oflag = 0;
	termios->c_lflag = ISIG | ICANON;
	if (flags & 0x02) {	/* cbreak */
		termios->c_iflag = 0;
		termios->c_lflag &= ~ICANON;
	}
	if (flags & 0x08) {		/* echo */
		termios->c_lflag |= ECHO | ECHOE | ECHOK |
				    ECHOCTL | ECHOKE | IEXTEN;
	}
	if (flags & 0x10) {		/* crmod */
		termios->c_oflag |= OPOST | ONLCR;
	}
	if (flags & 0x20) {	/* raw */
		termios->c_iflag = 0;
		termios->c_lflag &= ~(ISIG | ICANON);
	}
	if (!(termios->c_lflag & ICANON)) {
		termios->c_cc[VMIN] = 1;
		termios->c_cc[VTIME] = 0;
	}
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)14491.72%133.33%


Alan Cox138.28%266.67%


Total157100.00%3100.00%



/**
 *      set_sgttyb              -       set legacy terminal values
 *      @tty: tty structure
 *      @sgttyb: pointer to old style terminal structure
 *
 *      Updates a terminal from the legacy BSD style terminal information
 *      structure.
 *
 *      Locking: termios_rwsem
 */




static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
{
	int retval;
	struct sgttyb tmp;
	struct ktermios termios;

	retval = tty_check_change(tty);
	if (retval)
		return retval;

	if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
		return -EFAULT;

	down_write(&tty->termios_rwsem);
	termios = tty->termios;
	termios.c_cc[VERASE] = tmp.sg_erase;
	termios.c_cc[VKILL] = tmp.sg_kill;
	set_sgflags(&termios, tmp.sg_flags);
	/* Try and encode into Bfoo format */
#ifdef BOTHER
	tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
						termios.c_ospeed);
#endif
	up_write(&tty->termios_rwsem);
	tty_set_termios(tty, &termios);
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10169.18%333.33%


Alan Cox4027.40%444.44%


Peter Hurley42.74%111.11%


Al Viro10.68%111.11%


Total146100.00%9100.00%



#endif

#ifdef TIOCGETC



static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
{
	struct tchars tmp;

	down_read(&tty->termios_rwsem);
	tmp.t_intrc = tty->termios.c_cc[VINTR];
	tmp.t_quitc = tty->termios.c_cc[VQUIT];
	tmp.t_startc = tty->termios.c_cc[VSTART];
	tmp.t_stopc = tty->termios.c_cc[VSTOP];
	tmp.t_eofc = tty->termios.c_cc[VEOF];
	tmp.t_brkc = tty->termios.c_cc[VEOL2];	/* what is brkc anyway? */
	up_read(&tty->termios_rwsem);
	return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10980.74%337.50%


Alan Cox1813.33%225.00%


Peter Hurley42.96%112.50%


Linus Torvalds32.22%112.50%


Al Viro10.74%112.50%


Total135100.00%8100.00%






static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
{
	struct tchars tmp;

	if (copy_from_user(&tmp, tchars, sizeof(tmp)))
		return -EFAULT;
	down_write(&tty->termios_rwsem);
	tty->termios.c_cc[VINTR] = tmp.t_intrc;
	tty->termios.c_cc[VQUIT] = tmp.t_quitc;
	tty->termios.c_cc[VSTART] = tmp.t_startc;
	tty->termios.c_cc[VSTOP] = tmp.t_stopc;
	tty->termios.c_cc[VEOF] = tmp.t_eofc;
	tty->termios.c_cc[VEOL2] = tmp.t_brkc;	/* what is brkc anyway? */
	up_write(&tty->termios_rwsem);
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)11583.33%660.00%


Alan Cox1813.04%220.00%


Peter Hurley42.90%110.00%


Al Viro10.72%110.00%


Total138100.00%10100.00%



#endif

#ifdef TIOCGLTC



static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
{
	struct ltchars tmp;

	down_read(&tty->termios_rwsem);
	tmp.t_suspc = tty->termios.c_cc[VSUSP];
	/* what is dsuspc anyway? */
	tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
	tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
	/* what is flushc anyway? */
	tmp.t_flushc = tty->termios.c_cc[VEOL2];
	tmp.t_werasc = tty->termios.c_cc[VWERASE];
	tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
	up_read(&tty->termios_rwsem);
	return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10879.41%545.45%


Alan Cox2014.71%327.27%


Peter Hurley42.94%19.09%


Linus Torvalds32.21%19.09%


Al Viro10.74%19.09%


Total136100.00%11100.00%






static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
{
	struct ltchars tmp;

	if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
		return -EFAULT;

	down_write(&tty->termios_rwsem);
	tty->termios.c_cc[VSUSP] = tmp.t_suspc;
	/* what is dsuspc anyway? */
	tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
	tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
	/* what is flushc anyway? */
	tty->termios.c_cc[VEOL2] = tmp.t_flushc;
	tty->termios.c_cc[VWERASE] = tmp.t_werasc;
	tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
	up_write(&tty->termios_rwsem);
	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)11482.01%861.54%


Alan Cox2014.39%323.08%


Peter Hurley42.88%17.69%


Al Viro10.72%17.69%


Total139100.00%13100.00%



#endif

/**
 *      tty_change_softcar      -       carrier change ioctl helper
 *      @tty: tty to update
 *      @arg: enable/disable CLOCAL
 *
 *      Perform a change to the CLOCAL state and call into the driver
 *      layer to make it visible. All done with the termios rwsem
 */




static int tty_change_softcar(struct tty_struct *tty, int arg)
{
	int ret = 0;
	int bit = arg ? CLOCAL : 0;
	struct ktermios old;

	down_write(&tty->termios_rwsem);
	old = tty->termios;
	tty->termios.c_cflag &= ~CLOCAL;
	tty->termios.c_cflag |= bit;
	if (tty->ops->set_termios)
		tty->ops->set_termios(tty, &old);
	if (C_CLOCAL(tty) != bit)
		ret = -EINVAL;
	up_write(&tty->termios_rwsem);
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
Alan Cox10193.52%360.00%


Peter Hurley76.48%240.00%


Total108100.00%5100.00%



/**
 *      tty_mode_ioctl          -       mode related ioctls
 *      @tty: tty for the ioctl
 *      @file: file pointer for the tty
 *      @cmd: command
 *      @arg: ioctl argument
 *
 *      Perform non line discipline specific mode control ioctls. This
 *      is designed to be called by line disciplines to ensure they provide
 *      consistent mode setting.
 */




int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	struct tty_struct *real_tty;
	void __user *p = (void __user *)arg;
	int ret = 0;
	struct ktermios kterm;

	BUG_ON(file == NULL);

	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
	    tty->driver->subtype == PTY_TYPE_MASTER)
		real_tty = tty->link;
	else
		real_tty = tty;

	switch (cmd) {
#ifdef TIOCGETP
	case TIOCGETP:
		return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
	case TIOCSETP:
	case TIOCSETN:
		return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
#endif
#ifdef TIOCGETC
	case TIOCGETC:
		return get_tchars(real_tty, p);
	case TIOCSETC:
		return set_tchars(real_tty, p);
#endif
#ifdef TIOCGLTC
	case TIOCGLTC:
		return get_ltchars(real_tty, p);
	case TIOCSLTC:
		return set_ltchars(real_tty, p);
#endif
	case TCSETSF:
		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
	case TCSETSW:
		return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
	case TCSETS:
		return set_termios(real_tty, p, TERMIOS_OLD);
#ifndef TCGETS2
	case TCGETS:
		copy_termios(real_tty, &kterm);
		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
			ret = -EFAULT;
		return ret;
#else
	case TCGETS:
		copy_termios(real_tty, &kterm);
		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
			ret = -EFAULT;
		return ret;
	case TCGETS2:
		copy_termios(real_tty, &kterm);
		if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
			ret = -EFAULT;
		return ret;
	case TCSETSF2:
		return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
	case TCSETSW2:
		return set_termios(real_tty, p, TERMIOS_WAIT);
	case TCSETS2:
		return set_termios(real_tty, p, 0);
#endif
	case TCGETA:
		return get_termio(real_tty, p);
	case TCSETAF:
		return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
	case TCSETAW:
		return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
	case TCSETA:
		return set_termios(real_tty, p, TERMIOS_TERMIO);
#ifndef TCGETS2
	case TIOCGLCKTRMIOS:
		copy_termios_locked(real_tty, &kterm);
		if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
			ret = -EFAULT;
		return ret;
	case TIOCSLCKTRMIOS:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		copy_termios_locked(real_tty, &kterm);
		if (user_termios_to_kernel_termios(&kterm,
					       (struct termios __user *) arg))
			return -EFAULT;
		down_write(&real_tty->termios_rwsem);
		real_tty->termios_locked = kterm;
		up_write(&real_tty->termios_rwsem);
		return 0;
#else
	case TIOCGLCKTRMIOS:
		copy_termios_locked(real_tty, &kterm);
		if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
			ret = -EFAULT;
		return ret;
	case TIOCSLCKTRMIOS:
		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;
		copy_termios_locked(real_tty, &kterm);
		if (user_termios_to_kernel_termios_1(&kterm,
					       (struct termios __user *) arg))
			return -EFAULT;
		down_write(&real_tty->termios_rwsem);
		real_tty->termios_locked = kterm;
		up_write(&real_tty->termios_rwsem);
		return ret;
#endif
#ifdef TCGETX
	case TCGETX: {
		struct termiox ktermx;
		if (real_tty->termiox == NULL)
			return -EINVAL;
		down_read(&real_tty->termios_rwsem);
		memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
		up_read(&real_tty->termios_rwsem);
		if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
			ret = -EFAULT;
		return ret;
	}
	case TCSETX:
		return set_termiox(real_tty, p, 0);
	case TCSETXW:
		return set_termiox(real_tty, p, TERMIOS_WAIT);
	case TCSETXF:
		return set_termiox(real_tty, p, TERMIOS_FLUSH);
#endif		
	case TIOCGSOFTCAR:
		copy_termios(real_tty, &kterm);
		ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
						(int __user *)arg);
		return ret;
	case TIOCSSOFTCAR:
		if (get_user(arg, (unsigned int __user *) arg))
			return -EFAULT;
		return tty_change_softcar(real_tty, arg);
	default:
		return -ENOIOCTLCMD;
	}
}

Contributors
PersonTokensPropCommitsCommitProp
Alan Cox50259.20%1133.33%


Linus Torvalds (pre-git)29634.91%1751.52%


Al Viro283.30%26.06%


Peter Hurley121.42%13.03%


Mike Frysinger60.71%13.03%


Dave Jones40.47%13.03%


Total848100.00%33100.00%




EXPORT_SYMBOL_GPL(tty_mode_ioctl);


/* Caller guarantees ldisc reference is held */



static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
{
	struct tty_ldisc *ld = tty->ldisc;

	switch (arg) {
	case TCIFLUSH:
		if (ld && ld->ops->flush_buffer) {
			ld->ops->flush_buffer(tty);
			tty_unthrottle(tty);
		}
		break;
	case TCIOFLUSH:
		if (ld && ld->ops->flush_buffer) {
			ld->ops->flush_buffer(tty);
			tty_unthrottle(tty);
		}
		/* fall through */
	case TCOFLUSH:
		tty_driver_flush_buffer(tty);
		break;
	default:
		return -EINVAL;
	}
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Alan Cox6257.94%444.44%


Linus Torvalds (pre-git)2119.63%222.22%


Ilya Zykov1413.08%111.11%


Peter Hurley87.48%111.11%


Zaur Kambarov21.87%111.11%


Total107100.00%9100.00%






int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
{
	struct tty_ldisc *ld;
	int retval = tty_check_change(tty);
	if (retval)
		return retval;

	ld = tty_ldisc_ref_wait(tty);
	retval = __tty_perform_flush(tty, arg);
	if (ld)
		tty_ldisc_deref(ld);
	return retval;
}

Contributors
PersonTokensPropCommitsCommitProp
Peter Hurley5487.10%150.00%


Alan Cox812.90%150.00%


Total62100.00%2100.00%




EXPORT_SYMBOL_GPL(tty_perform_flush);




int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
		       unsigned int cmd, unsigned long arg)
{
	int retval;

	switch (cmd) {
	case TCXONC:
		retval = tty_check_change(tty);
		if (retval)
			return retval;
		switch (arg) {
		case TCOOFF:
			spin_lock_irq(&tty->flow_lock);
			if (!tty->flow_stopped) {
				tty->flow_stopped = 1;
				__stop_tty(tty);
			}
			spin_unlock_irq(&tty->flow_lock);
			break;
		case TCOON:
			spin_lock_irq(&tty->flow_lock);
			if (tty->flow_stopped) {
				tty->flow_stopped = 0;
				__start_tty(tty);
			}
			spin_unlock_irq(&tty->flow_lock);
			break;
		case TCIOFF:
			if (STOP_CHAR(tty) != __DISABLED_CHAR)
				retval = tty_send_xchar(tty, STOP_CHAR(tty));
			break;
		case TCION:
			if (START_CHAR(tty) != __DISABLED_CHAR)
				retval = tty_send_xchar(tty, START_CHAR(tty));
			break;
		default:
			return -EINVAL;
		}
		return retval;
	case TCFLSH:
		retval = tty_check_change(tty);
		if (retval)
			return retval;
		return __tty_perform_flush(tty, arg);
	default:
		/* Try the mode commands */
		return tty_mode_ioctl(tty, file, cmd, arg);
	}
}

Contributors
PersonTokensPropCommitsCommitProp
Alan Cox15466.67%320.00%


Peter Hurley5825.11%533.33%


Linus Torvalds (pre-git)198.23%746.67%


Total231100.00%15100.00%




EXPORT_SYMBOL(n_tty_ioctl_helper);

#ifdef CONFIG_COMPAT



long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
					unsigned int cmd, unsigned long arg)
{
	switch (cmd) {
	case TIOCGLCKTRMIOS:
	case TIOCSLCKTRMIOS:
		return tty_mode_ioctl(tty, file, cmd, (unsigned long) compat_ptr(arg));
	default:
		return -ENOIOCTLCMD;
	}
}

Contributors
PersonTokensPropCommitsCommitProp
Thomas Meyer59100.00%1100.00%


Total59100.00%1100.00%




EXPORT_SYMBOL(n_tty_compat_ioctl_helper);
#endif


Overall Contributors
PersonTokensPropCommitsCommitProp
Alan Cox265053.74%2723.89%


Linus Torvalds (pre-git)159032.24%4539.82%


Peter Hurley4769.65%1715.04%


Thomas Meyer721.46%10.88%


Al Viro440.89%21.77%


Linus Torvalds190.39%21.77%


Johan Hovold180.37%21.77%


Ilya Zykov140.28%10.88%


Mike Frysinger60.12%10.88%


Jiri Slaby60.12%10.88%


Arnaldo Carvalho de Melo50.10%10.88%


Frederic Danis50.10%10.88%


Maciej W. Rozycki50.10%10.88%


Dave Jones40.08%10.88%


Lucas De Marchi30.06%10.88%


Arjan van de Ven30.06%10.88%


Zaur Kambarov20.04%10.88%


Oleg Nesterov20.04%10.88%


Adrian Bunk20.04%10.88%


Cory T. Tusar10.02%10.88%


Matthias Brugger10.02%10.88%


Uwe Kleine-König10.02%10.88%


Ingo Molnar10.02%10.88%


Jovi Zhang10.02%10.88%


Total4931100.00%113100.00%


Directory: drivers/tty



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