From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Jarod Wilson <jarod@redhat.com>
Cc: Ted Ts'o <tytso@mit.edu>, Sasha Levin <levinsasha928@gmail.com>,
linux-crypto@vger.kernel.org, Matt Mackall <mpm@selenic.com>,
Neil Horman <nhorman@redhat.com>,
Herbert Xu <herbert.xu@redhat.com>,
Steve Grubb <sgrubb@redhat.com>,
Stephan Mueller <stephan.mueller@atsec.com>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] random: add blocking facility to urandom
Date: Mon, 12 Sep 2011 18:06:57 +0100 [thread overview]
Message-ID: <20110912170657.GA10452@sirena.org.uk> (raw)
In-Reply-To: <4E6E1103.2000408@redhat.com>
On Mon, Sep 12, 2011 at 10:02:43AM -0400, Jarod Wilson wrote:
> Ted Ts'o wrote:
> >Yeah, but there are userspace programs that depend on urandom not
> >blocking... so your proposed change would break them.
> I'm already consigned to the fact this isn't going to fly, but I'm
> still curious to know examples of programs that are going to break
> here, for my own education. Its already possible for urandom reads
> to fail as the code is now (-ERESTARTSYS and -EFAULT are possible),
> so a sane program ought to already be handling error cases, though
> not -EAGAIN, which this would add.
It's not just a question of error handling existing, it's also about the
expectations the system has for the behaviour of the file - if urandom
is expected to always be able to return data an application is likely to
rely on the fact that it's effectively non-blocking anyway and not bother
setting non-blocking mode at all and so have no graceful handling for
this.
prev parent reply other threads:[~2011-09-12 17:07 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-02 14:37 [PATCH] random: add blocking facility to urandom Jarod Wilson
2011-09-05 2:36 ` Sandy Harris
2011-09-06 14:09 ` Stephan Mueller
2011-09-07 17:38 ` Jarod Wilson
2011-09-07 18:12 ` Sasha Levin
2011-09-07 18:26 ` Jarod Wilson
2011-09-07 19:05 ` Sasha Levin
2011-09-07 19:30 ` Jarod Wilson
2011-09-07 20:00 ` Sasha Levin
2011-09-07 19:35 ` Neil Horman
2011-09-07 19:27 ` Ted Ts'o
2011-09-07 19:36 ` Jarod Wilson
2011-09-08 2:43 ` Sandy Harris
2011-09-07 19:49 ` David Miller
2011-09-07 20:02 ` Steve Grubb
2011-09-07 20:23 ` Sasha Levin
2011-09-07 20:30 ` Steve Grubb
2011-09-07 20:37 ` Sasha Levin
2011-09-07 20:56 ` Steve Grubb
2011-09-07 21:10 ` Sasha Levin
2011-09-07 21:28 ` Steve Grubb
2011-09-07 21:38 ` Sasha Levin
2011-09-07 21:35 ` Jarod Wilson
2011-09-07 21:43 ` Steve Grubb
2011-09-07 22:46 ` Sven-Haegar Koch
2011-09-08 7:21 ` Sasha Levin
2011-09-07 23:57 ` Neil Horman
2011-09-08 6:41 ` Tomas Mraz
2011-09-08 12:52 ` Neil Horman
2011-09-08 13:11 ` Steve Grubb
2011-09-08 13:49 ` Neil Horman
2011-09-09 2:21 ` Sandy Harris
2011-09-09 13:04 ` Steve Grubb
2011-09-09 16:25 ` Ted Ts'o
2011-09-09 21:27 ` Thomas Gleixner
2011-09-12 13:56 ` Jarod Wilson
2011-09-13 10:58 ` Peter Zijlstra
2011-09-13 12:18 ` Jarod Wilson
2011-09-11 2:05 ` Valdis.Kletnieks
2011-09-12 13:55 ` Jarod Wilson
2011-09-12 16:58 ` Valdis.Kletnieks
2011-09-12 18:26 ` Jarod Wilson
2011-09-07 20:33 ` Neil Horman
2011-09-07 20:48 ` Steve Grubb
2011-09-07 21:18 ` Ted Ts'o
2011-09-07 21:27 ` Stephan Mueller
2011-09-07 21:38 ` Ted Ts'o
2011-09-08 8:44 ` Christoph Hellwig
2011-09-08 11:48 ` Steve Grubb
2011-09-08 16:13 ` David Miller
2011-09-09 19:08 ` Eric Paris
2011-09-09 19:12 ` Neil Horman
2011-09-08 8:42 ` Christoph Hellwig
2011-09-07 21:20 ` Nikos Mavrogiannopoulos
2011-09-08 8:41 ` Christoph Hellwig
2011-09-12 14:02 ` Jarod Wilson
2011-09-12 14:58 ` Neil Horman
2011-09-12 17:06 ` Mark Brown [this message]
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