tty: the vhangup syscall is racy

We now have the infrastructure to sort this out but rather than teaching
the syscall tty lock rules we move the hard work into a tty helper

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/open.c b/fs/open.c
index 07da9359481c..5596049863bf 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1141,8 +1141,7 @@ EXPORT_SYMBOL(sys_close);
 asmlinkage long sys_vhangup(void)
 {
         if (capable(CAP_SYS_TTY_CONFIG)) {
-                /* XXX: this needs locking */
-                tty_vhangup(current->signal->tty);
+                tty_vhangup_self();
                 return 0;
         }
         return -EPERM;