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Subject: Re: PATCH: Lock tty directly in acct layer
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Arjan van de Ven <arjan@infradead.org>
Cc: akpm@osdl.org, linux-kernel@vger.kernel.org
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Date: Wed, 16 Aug 2006 18:09:54 +0100
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Ar Mer, 2006-08-16 am 18:24 +0200, ysgrifennodd Arjan van de Ven:
> > -	read_lock(&tasklist_lock);	/* pin current->signal */
> > +	mutex_lock(&tty_mutex);
> >  	ac.ac_tty = current->signal->tty ?
> 
> but.. can't ->signal still change, even if signal->tty isn't ?

I'm not sure, thats a good question (as if so is how to lock it). Will
investigate.