Re: [PATCH] char/tty_io: fix legacy pty name when more than 256 pty devices are requested

From: "H. Peter Anvin" <hpa@zytor.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>,
	Alan Cox <alan@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Kay Sievers <kay.sievers@vrfy.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@suse.de>
Subject: Re: [PATCH] char/tty_io: fix legacy pty name when more than 256 pty devices are requested
Date: Thu, 10 Sep 2009 16:25:44 -0700	[thread overview]
Message-ID: <4AA98AF8.7050701@zytor.com> (raw)
In-Reply-To: <20090911002329.07d60484@lxorguk.ukuu.org.uk>

On 09/10/2009 04:23 PM, Alan Cox wrote:
> 
> They won't work because the glibc pty name handling only does the 256
> devices. Given glibc still hasn't picked up tty changes from several
> years ago I doubt it'll ever pick up a naming change.
> 
> BSD pty is dead. It has all sorts of problems including time taken to
> find a new port being dependant on ports currently in use. The amount of
> code that cares about it is close to nil, that which cares about it uses
> glibc BSD pty helper code so won't work with > 256 anyway.
> 

I don't think they use glibc helper code, or they would automatically
end up with Unix98 ptys.  Rather, the remaining users of BSD ptys are
probably those where the application hard-codes the pty naming for each
platform it ran on... which is even worse of a compatibility nightmare,
of course.

	-hpa