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authorCyrill Gorcunov <gorcunov@openvz.org>2012-10-24 21:43:22 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-25 21:07:18 +0200
commit84fd7bdf1266ee6228319903af7e58702745024d (patch)
treec12ab6b589a9443a67b1ddcc00a78af0272a5006 /drivers/tty/tty_io.c
parenttty, ioctls -- Add new ioctl definitions for tty flags fetching (diff)
downloadlinux-84fd7bdf1266ee6228319903af7e58702745024d.tar.xz
linux-84fd7bdf1266ee6228319903af7e58702745024d.zip
tty: Add get- ioctls to fetch tty status v3
For checkpoint/restore we need to know if tty has exclusive or packet mode set, as well as if pty is currently locked. Just to be able to restore this characteristics. For this sake the following ioctl codes are introduced - TIOCGPKT to get packet mode state - TIOCGPTLCK to get Pty locked state - TIOCGEXCL to get Exclusive mode state Note this ioctls are a bit unsafe in terms of data obtained consistency. The tty characteristics might be changed right after ioctl complete. Keep it in mind and use this ioctl carefully. v2: - Use TIOC prefix for ioctl codes (by jslaby@) Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> CC: Alan Cox <alan@lxorguk.ukuu.org.uk> CC: "H. Peter Anvin" <hpa@zytor.com> CC: Pavel Emelyanov <xemul@parallels.com> CC: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/tty_io.c')
-rw-r--r--drivers/tty/tty_io.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index a3eba7f359ed..739ea86c1cf1 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2687,6 +2687,11 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case TIOCNXCL:
clear_bit(TTY_EXCLUSIVE, &tty->flags);
return 0;
+ case TIOCGEXCL:
+ {
+ int excl = test_bit(TTY_EXCLUSIVE, &tty->flags);
+ return put_user(excl, (int __user *)p);
+ }
case TIOCNOTTY:
if (current->signal->tty != tty)
return -ENOTTY;