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path: root/drivers/char/pty.c
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Diffstat (limited to 'drivers/char/pty.c')
-rw-r--r--drivers/char/pty.c57
1 files changed, 53 insertions, 4 deletions
diff --git a/drivers/char/pty.c b/drivers/char/pty.c
index 6d4582712b1..112a6ba9a96 100644
--- a/drivers/char/pty.c
+++ b/drivers/char/pty.c
@@ -5,8 +5,6 @@
*
* Added support for a Unix98-style ptmx device.
* -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998
- * Added TTY_DO_WRITE_WAKEUP to enable n_tty to send POLL_OUT to
- * waiting writers -- Sapan Bhatia <sapan@corewars.org>
*
* When reading this code see also fs/devpts. In particular note that the
* driver_data field is used by the devpts side as a binding to the devpts
@@ -217,7 +215,6 @@ static int pty_open(struct tty_struct *tty, struct file *filp)
clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
set_bit(TTY_THROTTLED, &tty->flags);
- set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
retval = 0;
out:
return retval;
@@ -230,6 +227,55 @@ static void pty_set_termios(struct tty_struct *tty,
tty->termios->c_cflag |= (CS8 | CREAD);
}
+/**
+ * pty_do_resize - resize event
+ * @tty: tty being resized
+ * @real_tty: real tty (not the same as tty if using a pty/tty pair)
+ * @rows: rows (character)
+ * @cols: cols (character)
+ *
+ * Update the termios variables and send the neccessary signals to
+ * peform a terminal resize correctly
+ */
+
+int pty_resize(struct tty_struct *tty, struct winsize *ws)
+{
+ struct pid *pgrp, *rpgrp;
+ unsigned long flags;
+ struct tty_struct *pty = tty->link;
+
+ /* For a PTY we need to lock the tty side */
+ mutex_lock(&tty->termios_mutex);
+ if (!memcmp(ws, &tty->winsize, sizeof(*ws)))
+ goto done;
+
+ /* Get the PID values and reference them so we can
+ avoid holding the tty ctrl lock while sending signals.
+ We need to lock these individually however. */
+
+ spin_lock_irqsave(&tty->ctrl_lock, flags);
+ pgrp = get_pid(tty->pgrp);
+ spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+
+ spin_lock_irqsave(&pty->ctrl_lock, flags);
+ rpgrp = get_pid(pty->pgrp);
+ spin_unlock_irqrestore(&pty->ctrl_lock, flags);
+
+ if (pgrp)
+ kill_pgrp(pgrp, SIGWINCH, 1);
+ if (rpgrp != pgrp && rpgrp)
+ kill_pgrp(rpgrp, SIGWINCH, 1);
+
+ put_pid(pgrp);
+ put_pid(rpgrp);
+
+ tty->winsize = *ws;
+ pty->winsize = *ws; /* Never used so will go away soon */
+done:
+ mutex_unlock(&tty->termios_mutex);
+ return 0;
+}
+
static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct tty_struct *o_tty;
@@ -290,6 +336,7 @@ static const struct tty_operations pty_ops = {
.chars_in_buffer = pty_chars_in_buffer,
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
+ .resize = pty_resize
};
/* Traditional BSD devices */
@@ -319,6 +366,7 @@ static const struct tty_operations pty_ops_bsd = {
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
.ioctl = pty_bsd_ioctl,
+ .resize = pty_resize
};
static void __init legacy_pty_init(void)
@@ -561,7 +609,8 @@ static const struct tty_operations ptm_unix98_ops = {
.unthrottle = pty_unthrottle,
.set_termios = pty_set_termios,
.ioctl = pty_unix98_ioctl,
- .shutdown = pty_unix98_shutdown
+ .shutdown = pty_unix98_shutdown,
+ .resize = pty_resize
};
static const struct tty_operations pty_unix98_ops = {