Date:   Sat, 2 Feb 2019 22:38:24 -0800
From:   Myungho Jung <mhjungk@gmail.com>
To:     Johan Hovold <johan@kernel.org>
Cc:     Marcel Holtmann <marcel@holtmann.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] Bluetooth: Add NULL check for tiocmget() and
 tiocmset()
Message-ID: <20190203063823.GA8228@myunghoj-Precision-5530>
References: <20190130053925.GA26699@myunghoj-Precision-5530>
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On Thu, Jan 31, 2019 at 04:40:00PM +0100, Johan Hovold wrote:
> On Tue, Jan 29, 2019 at 09:39:28PM -0800, Myungho Jung wrote:
> > tiocmget() and tiocmset() operations are optional and some tty drivers
> > like pty miss the operations. We need NULL check to prevent from
> > dereference.
> > 
> > Signed-off-by: Myungho Jung <mhjungk@gmail.com>
> > ---
> >  drivers/bluetooth/hci_ath.c   | 6 ++++++
> >  drivers/bluetooth/hci_ldisc.c | 4 ++++
> >  2 files changed, 10 insertions(+)
> 
> Ah, you had already submitted a v2.
> 
> I still suggest splitting this one in two patches and that you add a
> Fixes and stable tag to each so that they both get backported to stable.
> 
> Also, when resubmitting, make sure to include a short changelog here
> below the cut-off line (---).
> 
> > 
> > diff --git a/drivers/bluetooth/hci_ath.c b/drivers/bluetooth/hci_ath.c
> > index d568fbd94d6c..fb9f6323a911 100644
> > --- a/drivers/bluetooth/hci_ath.c
> > +++ b/drivers/bluetooth/hci_ath.c
> > @@ -185,8 +185,14 @@ static int ath_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
> >  
> >  static int ath_setup(struct hci_uart *hu)
> >  {
> > +	struct tty_struct *tty = hu->tty;
> > +
> >  	BT_DBG("hu %p", hu);
> >  
> > +	/* tty driver should support operations to set RTS */
> > +	if (!tty->driver->ops->tiocmget || !tty->driver->ops->tiocmset)
> > +		return -EOPNOTSUPP;
> 
> -ENODEV might be more appropriate.
> 
> Johan

I'll split into 2 seperate patches. So, do I need to add stable tag on each
patch like below to be cherry-picked?

Cc: <stable@vger.kernel.org> # <hash>: <summary>

I looked for a good example from mailing list but didn't find one.

Thanks,
Myungho