linux-kernel - Re: [PATCH 3/3] vt: Fix refcounting use

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Message-ID: <4B7C0DBB.5010801@rsk.demon.co.uk>
Date:	Wed, 17 Feb 2010 15:39:39 +0000
From:	Richard Kennedy <richard@....demon.co.uk>
To:	Alan Cox <alan@...ux.intel.com>
CC:	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] vt: Fix refcounting use

On 17/02/10 13:23, Alan Cox wrote:
> We want to properly refcount the vc tty because of the cases where a vc is
> disassociated from a tty (eg destroyed). At the moment the code isn't safe
> and in fact input even tries to patch up broken pointers as a result!
>
>   static void applkey(struct vc_data *vc, int key, char mode)
> @@ -497,10 +499,12 @@ static void fn_show_ptregs(struct vc_data *vc)
>
>   static void fn_hold(struct vc_data *vc)
>   {
> -	struct tty_struct *tty = vc->port.tty;
> +	struct tty_struct *tty = tty_port_tty_get(&vc->port);
>
> -	if (rep || !tty)
> +	if (rep || !tty) {
> +	        tty_kref_put(tty);
>   		return;
> +        }
>

This is the only bit that immediately stands out..
maybe?
	if (rep || !tty) {
		if (tty)
			tty_kref_put(tty);
		return;
	}

regards
Richard

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