patch "USB: serial: console: fix uninitialised spinlock" added to usb-testing

patch "USB: serial: console: fix uninitialised spinlock" added to usb-testing

[gregkh]

This is a note to let you know that I've just added the patch titled

    USB: serial: console: fix uninitialised spinlock

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


>From 14816b16fa0adac24f82492f18fa62c55acabbbe Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Wed, 8 Feb 2017 18:53:08 +0100
Subject: USB: serial: console: fix uninitialised spinlock

Since commit 4a510969374a ("tty: Make tty_files_lock per-tty") a new
tty_struct spin lock is taken in the tty release path, but the
USB-serial-console hack was never updated hence leaving the lock of its
"fake" tty uninitialised. This was eventually detected by lockdep.

Make sure to initialise the new lock also for the fake tty to address
this regression.

Yes, this code is a mess, but cleaning it up is left for another day.

Fixes: 4a510969374a ("tty: Make tty_files_lock per-tty")
Cc: stable <stable@vger.kernel.org>	# 4.6
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/console.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/serial/console.c b/drivers/usb/serial/console.c
index 8967715fe6fc..b6f1adefb758 100644
--- a/drivers/usb/serial/console.c
+++ b/drivers/usb/serial/console.c
@@ -143,6 +143,7 @@ static int usb_console_setup(struct console *co, char *options)
 			tty->driver = usb_serial_tty_driver;
 			tty->index = co->index;
 			init_ldsem(&tty->ldisc_sem);
+			spin_lock_init(&tty->files_lock);
 			INIT_LIST_HEAD(&tty->tty_files);
 			kref_get(&tty->driver->kref);
 			__module_get(tty->driver->owner);
-- 
2.11.1