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>
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 913b502..b5f57d0 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -730,6 +730,25 @@
EXPORT_SYMBOL(tty_vhangup);
/**
+ * tty_vhangup_self - process vhangup for own ctty
+ *
+ * Perform a vhangup on the current controlling tty
+ */
+
+void tty_vhangup_self(void)
+{
+ struct tty_struct *tty;
+
+ mutex_lock(&tty_mutex);
+ tty = get_current_tty();
+ if (tty) {
+ tty_vhangup(tty);
+ tty_kref_put(tty);
+ }
+ mutex_unlock(&tty_mutex);
+}
+
+/**
* tty_hung_up_p - was tty hung up
* @filp: file pointer of tty
*