From: Sebastian Siewior Subject: Re: [PATCH] [crypto] load the SHA1[1|256] module by an alias (v2) Date: Sun, 7 Oct 2007 00:02:20 +0200 Message-ID: <20071006220220.GC3645@Chamillionaire.breakpoint.cc> References: <20070820101618.GE16680@bingen.suse.de> <20070820120605.GA13163@gondor.apana.org.au> <20070930124239.GB24811@Chamillionaire.breakpoint.cc> <20071003073522.GA7285@gondor.apana.org.au> <20071004083512.GA11305@Chamillionaire.breakpoint.cc> <20071005085744.GC10959@gondor.apana.org.au> <20071005151051.GA13666@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Cc: linux-crypto@vger.kernel.org To: Herbert Xu Return-path: Received: from Chamillionaire.breakpoint.cc ([85.10.199.196]:52265 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753850AbXJFWCX (ORCPT ); Sat, 6 Oct 2007 18:02:23 -0400 Content-Disposition: inline In-Reply-To: <20071005151051.GA13666@gondor.apana.org.au> Sender: linux-crypto-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org * Herbert Xu | 2007-10-05 23:10:51 [+0800]: >On Fri, Oct 05, 2007 at 03:12:10PM +0200, Sebastian Siewior wrote: >> Loading the crypto algorithm by the alias instead of by module directly >> has the advantage that all possible implementations of this algorithm >> are loaded automatically and the crypto API can choose the best one >> depending on its priority. >> Additionally it ensures that the generic implementation as well as the >> HW driver (if available) is loaded in case the HW driver needs the >> generic version as fallback in corner cases. >> Also remove the probe for sha1 in padlock's init code. >> Quote from Herbert: >> The probe is actually pointless since we can always probe when >> the algorithm is actually used which does not lead to dead-locks >> like this. > >Thanks. I'll apply this tomorrow. > >BTW, the dead-lock does exist after all. The lock that's held >is the user-space file lock held by modprobe. Assuming that >padlock-sha comes before sha in the alias list, then the second >modprobe will hit padlock-sha again and dead-lock. Really, hmm. That CRYPTO_ALG_NEED_FALLBACK flag is unused than? I try to remove the hardware specific code and test the via-sha code as it once I have some time in my hands :) >Cheers, Sebastian