vt: hold console_sem across sysfs operations

Hold console sem while creating/destroying sysfs files.  Serialisation is
so far done by BKL held in tty release_dev and chrdev_open, but no other
locks are held in open path.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Aristeu Rozanski <aris@ruivo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index e32a076..ab53a1d 100644 (file)
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -2749,8 +2749,8 @@ static int con_open(struct tty_struct *tty, struct file *filp)
                                tty->termios->c_iflag |= IUTF8;
                        else
                                tty->termios->c_iflag &= ~IUTF8;
-                       release_console_sem();
                        vcs_make_sysfs(tty);
+                       release_console_sem();
                        return ret;
                }
        }
@@ -2775,8 +2775,8 @@ static void con_close(struct tty_struct *tty, struct file *filp)
                if (vc)
                        vc->vc_tty = NULL;
                tty->driver_data = NULL;
-               release_console_sem();
                vcs_remove_sysfs(tty);
+               release_console_sem();
                mutex_unlock(&tty_mutex);
                /*
                 * tty_mutex is released, but we still hold BKL, so there is