From: Nigel Cunningham Subject: Re: LZO irreversible output? Date: Mon, 08 Feb 2010 19:33:11 +1100 Message-ID: <4B6FCC47.2030705@crca.org.au> References: <4B69ECE5.5060505@crca.org.au> <201002032354.11284.rjw@sisk.pl> <4B6A4F07.3090509@crca.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-2 Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, tuxonice-devel@lists.tuxonice.net To: Bill Davidsen Return-path: Received: from mail.crca.org.au ([67.207.131.56]:40513 "EHLO crca.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751066Ab0BHIbG (ORCPT ); Mon, 8 Feb 2010 03:31:06 -0500 In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: Hi Bill. Bill Davidsen wrote: > I would hope someone will look at the real problem, though, that LZO > isn't working properly. I have to assume that either the kernel > decompress is broken or that the page you have given is invalid, and the > error lies in the compression. > > It doesn't look as if you are doing something wrong, it looks broken. I did get hold of Richard Purdie and Nitin Gupta, who were the guys in the know. We discovered that LZO is expecting decomp_size to be initialised to the amount of available space when the decompression code is called, so there was a bug in my testing code. Nitin was talking about sending a patch to the documentation to make this requirement clearer. That said, the actual code that TuxOnIce uses does already initialise the variable to PAGE_SIZE, so it seems that I might just have to run with the checking code enabled (with this fix) for a while, until the issue is found. Regards, Nigel