mirror of
https://github.com/FEX-Emu/linux.git
synced 2024-12-22 09:22:37 +00:00
69f63c5c34
We add a check of the return value of tty_ldisc_ref(), which
is checked 7 out of 8 times, e.g.:
149 ld = tty_ldisc_ref(tty);
150 if (ld != NULL) {
151 if (ld->set_termios)
152 (ld->set_termios)(tty, &old_termios);
153 tty_ldisc_deref(ld);
154 }
This defect was found automatically by Coverity Prevent, a static analysis
tool.
(akpm: presumably `ld' is never NULL. Oh well)
Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
552 lines
14 KiB
C
552 lines
14 KiB
C
/*
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* linux/drivers/char/tty_ioctl.c
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*
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
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* which can be dynamically activated and de-activated by the line
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* discipline handling modules (like SLIP).
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*/
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#include <linux/types.h>
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#include <linux/termios.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/tty.h>
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#include <linux/fcntl.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/system.h>
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#undef TTY_DEBUG_WAIT_UNTIL_SENT
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#undef DEBUG
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/*
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* Internal flag options for termios setting behavior
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*/
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#define TERMIOS_FLUSH 1
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#define TERMIOS_WAIT 2
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#define TERMIOS_TERMIO 4
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void tty_wait_until_sent(struct tty_struct * tty, long timeout)
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{
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DECLARE_WAITQUEUE(wait, current);
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#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
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char buf[64];
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printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
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#endif
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if (!tty->driver->chars_in_buffer)
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return;
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add_wait_queue(&tty->write_wait, &wait);
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if (!timeout)
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timeout = MAX_SCHEDULE_TIMEOUT;
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do {
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#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
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printk(KERN_DEBUG "waiting %s...(%d)\n", tty_name(tty, buf),
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tty->driver->chars_in_buffer(tty));
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#endif
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set_current_state(TASK_INTERRUPTIBLE);
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if (signal_pending(current))
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goto stop_waiting;
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if (!tty->driver->chars_in_buffer(tty))
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break;
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timeout = schedule_timeout(timeout);
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} while (timeout);
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if (tty->driver->wait_until_sent)
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tty->driver->wait_until_sent(tty, timeout);
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stop_waiting:
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set_current_state(TASK_RUNNING);
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remove_wait_queue(&tty->write_wait, &wait);
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}
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EXPORT_SYMBOL(tty_wait_until_sent);
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static void unset_locked_termios(struct termios *termios,
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struct termios *old,
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struct termios *locked)
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{
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int i;
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#define NOSET_MASK(x,y,z) (x = ((x) & ~(z)) | ((y) & (z)))
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if (!locked) {
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printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
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return;
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}
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NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
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NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
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NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
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NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
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termios->c_line = locked->c_line ? old->c_line : termios->c_line;
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for (i=0; i < NCCS; i++)
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termios->c_cc[i] = locked->c_cc[i] ?
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old->c_cc[i] : termios->c_cc[i];
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}
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static void change_termios(struct tty_struct * tty, struct termios * new_termios)
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{
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int canon_change;
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struct termios old_termios = *tty->termios;
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struct tty_ldisc *ld;
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/*
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* Perform the actual termios internal changes under lock.
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*/
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/* FIXME: we need to decide on some locking/ordering semantics
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for the set_termios notification eventually */
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down(&tty->termios_sem);
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*tty->termios = *new_termios;
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unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
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canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
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if (canon_change) {
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memset(&tty->read_flags, 0, sizeof tty->read_flags);
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tty->canon_head = tty->read_tail;
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tty->canon_data = 0;
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tty->erasing = 0;
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}
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if (canon_change && !L_ICANON(tty) && tty->read_cnt)
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/* Get characters left over from canonical mode. */
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wake_up_interruptible(&tty->read_wait);
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/* See if packet mode change of state. */
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if (tty->link && tty->link->packet) {
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int old_flow = ((old_termios.c_iflag & IXON) &&
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(old_termios.c_cc[VSTOP] == '\023') &&
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(old_termios.c_cc[VSTART] == '\021'));
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int new_flow = (I_IXON(tty) &&
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STOP_CHAR(tty) == '\023' &&
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START_CHAR(tty) == '\021');
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if (old_flow != new_flow) {
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tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
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if (new_flow)
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tty->ctrl_status |= TIOCPKT_DOSTOP;
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else
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tty->ctrl_status |= TIOCPKT_NOSTOP;
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wake_up_interruptible(&tty->link->read_wait);
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}
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}
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if (tty->driver->set_termios)
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(*tty->driver->set_termios)(tty, &old_termios);
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ld = tty_ldisc_ref(tty);
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if (ld != NULL) {
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if (ld->set_termios)
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(ld->set_termios)(tty, &old_termios);
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tty_ldisc_deref(ld);
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}
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up(&tty->termios_sem);
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}
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static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
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{
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struct termios tmp_termios;
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struct tty_ldisc *ld;
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int retval = tty_check_change(tty);
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if (retval)
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return retval;
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if (opt & TERMIOS_TERMIO) {
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memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
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if (user_termio_to_kernel_termios(&tmp_termios,
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(struct termio __user *)arg))
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return -EFAULT;
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} else {
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if (user_termios_to_kernel_termios(&tmp_termios,
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(struct termios __user *)arg))
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return -EFAULT;
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}
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ld = tty_ldisc_ref(tty);
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if (ld != NULL) {
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if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
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ld->flush_buffer(tty);
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tty_ldisc_deref(ld);
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}
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if (opt & TERMIOS_WAIT) {
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tty_wait_until_sent(tty, 0);
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if (signal_pending(current))
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return -EINTR;
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}
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change_termios(tty, &tmp_termios);
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return 0;
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}
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static int get_termio(struct tty_struct * tty, struct termio __user * termio)
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{
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if (kernel_termios_to_user_termio(termio, tty->termios))
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return -EFAULT;
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return 0;
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}
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static unsigned long inq_canon(struct tty_struct * tty)
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{
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int nr, head, tail;
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if (!tty->canon_data || !tty->read_buf)
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return 0;
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head = tty->canon_head;
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tail = tty->read_tail;
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nr = (head - tail) & (N_TTY_BUF_SIZE-1);
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/* Skip EOF-chars.. */
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while (head != tail) {
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if (test_bit(tail, tty->read_flags) &&
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tty->read_buf[tail] == __DISABLED_CHAR)
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nr--;
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tail = (tail+1) & (N_TTY_BUF_SIZE-1);
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}
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return nr;
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}
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#ifdef TIOCGETP
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/*
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* These are deprecated, but there is limited support..
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*
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* The "sg_flags" translation is a joke..
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*/
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static int get_sgflags(struct tty_struct * tty)
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{
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int flags = 0;
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if (!(tty->termios->c_lflag & ICANON)) {
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if (tty->termios->c_lflag & ISIG)
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flags |= 0x02; /* cbreak */
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else
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flags |= 0x20; /* raw */
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}
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if (tty->termios->c_lflag & ECHO)
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flags |= 0x08; /* echo */
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if (tty->termios->c_oflag & OPOST)
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if (tty->termios->c_oflag & ONLCR)
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flags |= 0x10; /* crmod */
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return flags;
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}
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static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
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{
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struct sgttyb tmp;
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down(&tty->termios_sem);
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tmp.sg_ispeed = 0;
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tmp.sg_ospeed = 0;
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tmp.sg_erase = tty->termios->c_cc[VERASE];
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tmp.sg_kill = tty->termios->c_cc[VKILL];
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tmp.sg_flags = get_sgflags(tty);
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up(&tty->termios_sem);
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return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
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}
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static void set_sgflags(struct termios * termios, int flags)
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{
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termios->c_iflag = ICRNL | IXON;
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termios->c_oflag = 0;
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termios->c_lflag = ISIG | ICANON;
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if (flags & 0x02) { /* cbreak */
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termios->c_iflag = 0;
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termios->c_lflag &= ~ICANON;
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}
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if (flags & 0x08) { /* echo */
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termios->c_lflag |= ECHO | ECHOE | ECHOK |
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ECHOCTL | ECHOKE | IEXTEN;
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}
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if (flags & 0x10) { /* crmod */
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termios->c_oflag |= OPOST | ONLCR;
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}
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if (flags & 0x20) { /* raw */
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termios->c_iflag = 0;
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termios->c_lflag &= ~(ISIG | ICANON);
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}
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if (!(termios->c_lflag & ICANON)) {
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termios->c_cc[VMIN] = 1;
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termios->c_cc[VTIME] = 0;
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}
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}
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static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
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{
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int retval;
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struct sgttyb tmp;
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struct termios termios;
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retval = tty_check_change(tty);
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if (retval)
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return retval;
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if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
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return -EFAULT;
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down(&tty->termios_sem);
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termios = *tty->termios;
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termios.c_cc[VERASE] = tmp.sg_erase;
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termios.c_cc[VKILL] = tmp.sg_kill;
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set_sgflags(&termios, tmp.sg_flags);
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up(&tty->termios_sem);
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change_termios(tty, &termios);
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return 0;
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}
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#endif
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#ifdef TIOCGETC
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static int get_tchars(struct tty_struct * tty, struct tchars __user * tchars)
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{
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struct tchars tmp;
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tmp.t_intrc = tty->termios->c_cc[VINTR];
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tmp.t_quitc = tty->termios->c_cc[VQUIT];
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tmp.t_startc = tty->termios->c_cc[VSTART];
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tmp.t_stopc = tty->termios->c_cc[VSTOP];
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tmp.t_eofc = tty->termios->c_cc[VEOF];
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tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
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return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
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}
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static int set_tchars(struct tty_struct * tty, struct tchars __user * tchars)
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{
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struct tchars tmp;
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if (copy_from_user(&tmp, tchars, sizeof(tmp)))
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return -EFAULT;
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tty->termios->c_cc[VINTR] = tmp.t_intrc;
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tty->termios->c_cc[VQUIT] = tmp.t_quitc;
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tty->termios->c_cc[VSTART] = tmp.t_startc;
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tty->termios->c_cc[VSTOP] = tmp.t_stopc;
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tty->termios->c_cc[VEOF] = tmp.t_eofc;
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tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
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return 0;
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}
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#endif
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#ifdef TIOCGLTC
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static int get_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
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{
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struct ltchars tmp;
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tmp.t_suspc = tty->termios->c_cc[VSUSP];
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tmp.t_dsuspc = tty->termios->c_cc[VSUSP]; /* what is dsuspc anyway? */
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tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
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tmp.t_flushc = tty->termios->c_cc[VEOL2]; /* what is flushc anyway? */
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tmp.t_werasc = tty->termios->c_cc[VWERASE];
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tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
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return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
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}
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static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
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{
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struct ltchars tmp;
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if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
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return -EFAULT;
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tty->termios->c_cc[VSUSP] = tmp.t_suspc;
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tty->termios->c_cc[VEOL2] = tmp.t_dsuspc; /* what is dsuspc anyway? */
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tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
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tty->termios->c_cc[VEOL2] = tmp.t_flushc; /* what is flushc anyway? */
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tty->termios->c_cc[VWERASE] = tmp.t_werasc;
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tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
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return 0;
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}
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#endif
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/*
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* Send a high priority character to the tty.
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*/
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static void send_prio_char(struct tty_struct *tty, char ch)
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{
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int was_stopped = tty->stopped;
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if (tty->driver->send_xchar) {
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tty->driver->send_xchar(tty, ch);
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return;
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}
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if (was_stopped)
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start_tty(tty);
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tty->driver->write(tty, &ch, 1);
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if (was_stopped)
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stop_tty(tty);
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}
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int n_tty_ioctl(struct tty_struct * tty, struct file * file,
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unsigned int cmd, unsigned long arg)
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{
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struct tty_struct * real_tty;
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void __user *p = (void __user *)arg;
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int retval;
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struct tty_ldisc *ld;
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if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
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tty->driver->subtype == PTY_TYPE_MASTER)
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real_tty = tty->link;
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else
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real_tty = tty;
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switch (cmd) {
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#ifdef TIOCGETP
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case TIOCGETP:
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return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
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case TIOCSETP:
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case TIOCSETN:
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return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
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#endif
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#ifdef TIOCGETC
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case TIOCGETC:
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return get_tchars(real_tty, p);
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case TIOCSETC:
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return set_tchars(real_tty, p);
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#endif
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#ifdef TIOCGLTC
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case TIOCGLTC:
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return get_ltchars(real_tty, p);
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case TIOCSLTC:
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return set_ltchars(real_tty, p);
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#endif
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case TCGETS:
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if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
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return -EFAULT;
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return 0;
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case TCSETSF:
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return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
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case TCSETSW:
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return set_termios(real_tty, p, TERMIOS_WAIT);
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case TCSETS:
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return set_termios(real_tty, p, 0);
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case TCGETA:
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return get_termio(real_tty, p);
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case TCSETAF:
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return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
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case TCSETAW:
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return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
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case TCSETA:
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return set_termios(real_tty, p, TERMIOS_TERMIO);
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case TCXONC:
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retval = tty_check_change(tty);
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if (retval)
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return retval;
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switch (arg) {
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case TCOOFF:
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if (!tty->flow_stopped) {
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tty->flow_stopped = 1;
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stop_tty(tty);
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}
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break;
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case TCOON:
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if (tty->flow_stopped) {
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tty->flow_stopped = 0;
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start_tty(tty);
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}
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break;
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case TCIOFF:
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if (STOP_CHAR(tty) != __DISABLED_CHAR)
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send_prio_char(tty, STOP_CHAR(tty));
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break;
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case TCION:
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if (START_CHAR(tty) != __DISABLED_CHAR)
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send_prio_char(tty, START_CHAR(tty));
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
case TCFLSH:
|
|
retval = tty_check_change(tty);
|
|
if (retval)
|
|
return retval;
|
|
|
|
ld = tty_ldisc_ref(tty);
|
|
switch (arg) {
|
|
case TCIFLUSH:
|
|
if (ld && ld->flush_buffer)
|
|
ld->flush_buffer(tty);
|
|
break;
|
|
case TCIOFLUSH:
|
|
if (ld && ld->flush_buffer)
|
|
ld->flush_buffer(tty);
|
|
/* fall through */
|
|
case TCOFLUSH:
|
|
if (tty->driver->flush_buffer)
|
|
tty->driver->flush_buffer(tty);
|
|
break;
|
|
default:
|
|
tty_ldisc_deref(ld);
|
|
return -EINVAL;
|
|
}
|
|
tty_ldisc_deref(ld);
|
|
return 0;
|
|
case TIOCOUTQ:
|
|
return put_user(tty->driver->chars_in_buffer ?
|
|
tty->driver->chars_in_buffer(tty) : 0,
|
|
(int __user *) arg);
|
|
case TIOCINQ:
|
|
retval = tty->read_cnt;
|
|
if (L_ICANON(tty))
|
|
retval = inq_canon(tty);
|
|
return put_user(retval, (unsigned int __user *) arg);
|
|
case TIOCGLCKTRMIOS:
|
|
if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
|
|
return -EFAULT;
|
|
return 0;
|
|
|
|
case TIOCSLCKTRMIOS:
|
|
if (!capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
|
|
return -EFAULT;
|
|
return 0;
|
|
|
|
case TIOCPKT:
|
|
{
|
|
int pktmode;
|
|
|
|
if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
|
|
tty->driver->subtype != PTY_TYPE_MASTER)
|
|
return -ENOTTY;
|
|
if (get_user(pktmode, (int __user *) arg))
|
|
return -EFAULT;
|
|
if (pktmode) {
|
|
if (!tty->packet) {
|
|
tty->packet = 1;
|
|
tty->link->ctrl_status = 0;
|
|
}
|
|
} else
|
|
tty->packet = 0;
|
|
return 0;
|
|
}
|
|
case TIOCGSOFTCAR:
|
|
return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
|
|
case TIOCSSOFTCAR:
|
|
if (get_user(arg, (unsigned int __user *) arg))
|
|
return -EFAULT;
|
|
down(&tty->termios_sem);
|
|
tty->termios->c_cflag =
|
|
((tty->termios->c_cflag & ~CLOCAL) |
|
|
(arg ? CLOCAL : 0));
|
|
up(&tty->termios_sem);
|
|
return 0;
|
|
default:
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(n_tty_ioctl);
|