v4.19.13 snapshot.
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
new file mode 100644
index 0000000..d99fec4
--- /dev/null
+++ b/drivers/tty/tty_ioctl.c
@@ -0,0 +1,959 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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;
+}
+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;
+}
+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);
+}
+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);
+}
+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);
+}
+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;
+}
+
+/**
+ * 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;
+}
+
+/**
+ * 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);
+}
+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 */
+}
+
+/**
+ * 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;
+}
+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(const struct ktermios *a, const 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;
+}
+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;
+}
+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
+ } 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);
+}
+
+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);
+}
+
+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;
+}
+
+
+#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;
+}
+
+#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;
+}
+
+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;
+}
+
+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;
+ }
+}
+
+/**
+ * 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;
+}
+#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;
+}
+
+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;
+}
+#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;
+}
+
+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;
+}
+#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;
+}
+
+/**
+ * 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;
+ }
+}
+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;
+}
+
+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;
+}
+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);
+ }
+}
+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;
+ }
+}
+EXPORT_SYMBOL(n_tty_compat_ioctl_helper);
+#endif
+