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authorPeter Hurley <peter@hurleysoftware.com>2013-01-30 17:43:50 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-02-04 23:40:28 (GMT)
commit699390354da6c258b65bf8fa79cfd5feaede50b6 (patch)
treea2a1cde7fdc06a6ca684ac1c9bf57bef5d6f75ca /drivers/tty
parent7acf6cd80b201f77371a5374a786144153629be8 (diff)
downloadlinux-699390354da6c258b65bf8fa79cfd5feaede50b6.tar.xz
pty: Ignore slave pty close() if never successfully opened
If the master and slave ptys are opened in parallel, the slave open fails because the pty is still locked. This is as designed. However, pty_close() is still called for the slave pty which sets TTY_OTHER_CLOSED in the master pty. This can cause the master open to fail as well. Use a common pattern in other tty drivers by setting TTY_IO_ERROR until the open is successful and only closing the pty if not set. Note: the master pty always closes regardless of whether the open was successful, so that proper cleanup can occur. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/pty.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 96dc6dd..d38455f 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -38,9 +38,12 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
if (tty->driver->subtype == PTY_TYPE_MASTER)
WARN_ON(tty->count > 1);
else {
+ if (test_bit(TTY_IO_ERROR, &tty->flags))
+ return;
if (tty->count > 2)
return;
}
+ set_bit(TTY_IO_ERROR, &tty->flags);
wake_up_interruptible(&tty->read_wait);
wake_up_interruptible(&tty->write_wait);
tty->packet = 0;
@@ -246,6 +249,8 @@ static int pty_open(struct tty_struct *tty, struct file *filp)
if (!tty || !tty->link)
goto out;
+ set_bit(TTY_IO_ERROR, &tty->flags);
+
retval = -EIO;
if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
goto out;
@@ -254,6 +259,7 @@ static int pty_open(struct tty_struct *tty, struct file *filp)
if (tty->link->count != 1)
goto out;
+ clear_bit(TTY_IO_ERROR, &tty->flags);
clear_bit(TTY_OTHER_CLOSED, &tty->link->flags);
set_bit(TTY_THROTTLED, &tty->flags);
retval = 0;