Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934523Ab3GRWRX (ORCPT ); Thu, 18 Jul 2013 18:17:23 -0400 Received: from mga14.intel.com ([143.182.124.37]:38782 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932956Ab3GRWRT (ORCPT ); Thu, 18 Jul 2013 18:17:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.89,696,1367996400"; d="scan'208";a="333556320" Message-ID: <51E8696A.7090406@intel.com> Date: Fri, 19 Jul 2013 00:17:14 +0200 From: "Rafael J. Wysocki" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Tim Chen CC: Tetsuo Handa , herbert@gondor.hengli.com.au, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, ak , rjw@rjwysocki.net Subject: Re: [PATCH 3.11-rc1] crypto: Fix boot failure due to module dependency. References: <201307180550.BDB51536.LHMQOOOVFJFSFt@I-love.SAKURA.ne.jp> <1374098936.22432.322.camel@schen9-DESK> <201307180347.r6I3l5e9077577@www262.sakura.ne.jp> <1374181200.22432.350.camel@schen9-DESK> In-Reply-To: <1374181200.22432.350.camel@schen9-DESK> Content-Type: text/plain; charset="utf-8"; format="flowed" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r6IMHTOR006586 Content-Length: 6445 Lines: 151 On 7/18/2013 11:00 PM, Tim Chen wrote: > On Thu, 2013-07-18 at 12:47 +0900, Tetsuo Handa wrote: >> Tim Chen wrote: >>>>> Your approach is quite complicated. I think something simpler like the >>>>> following will work: >>>> We cannot benefit from PCLMULQDQ. Is it acceptable for you? >>> >>> The following code in crct10dif-pclmul_glue.c >>> >>> static const struct x86_cpu_id crct10dif_cpu_id[] = { >>> X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), >>> {} >>> }; >>> MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id); >>> >>> will put the module in the device table and get the module >>> loaded, as long as the cpu support PCLMULQDQ. So we should be able >>> to benefit. >> Excuse me, how can crct10dif-pclmul.ko get loaded automatically? >> Did you test CONFIG_CRYPTO_CRCT10DIF_PCLMUL=m with below debug message? > The code: > > static const struct x86_cpu_id crct10dif_cpu_id[] = { > X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), > {} > }; > MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id); > > causes the following line to be added to modules.alias file: > > alias x86cpu:vendor:*:family:*:model:*:feature:*0081* crct10dif_pclmul > > This should cause udev to load the crct10dif_pclml module when cpu > support the PCLMULQDQ (feature code 0081). I did my testing during > development on 3.10 and the module was indeed loaded. > > However, I found that the following commit under 3.11-rc1 broke > the mechanism after some bisection. > > commit ac212b6980d8d5eda705864fc5a8ecddc6d6eacc > Author: Rafael J. Wysocki > Date: Fri May 3 00:26:22 2013 +0200 > > ACPI / processor: Use common hotplug infrastructure > > Split the ACPI processor driver into two parts, one that is > non-modular, resides in the ACPI core and handles the enumeration > and hotplug of processors and one that implements the rest of the > existing processor driver functionality. > > Rafael, can you check and see if this can be fixed so those optimized > crypto modules for Intel cpu that support them can be loaded? I think this is an ordering issue between udev startup and the time when devices are registered. I wonder what happens if you put those modules into the initramfs image? Rafael > Herbert, we had a discussion earlier on a separate issue regarding the > module load order. We wanted to load all supported crypto t10dif modules > before the crc-t10dif module. You mentioned that the MODULE_ALIAS also > need some fixing and wonder if those changes have been merged into > 3.11-rc1? See https://lkml.org/lkml/2013/5/21/216 . Theoretically, that > fix should also get all the crypto modules support t10dif be loaded. > > Thanks. > > Tim > >> diff --git a/arch/x86/crypto/crct10dif-pclmul_glue.c b/arch/x86/crypto/crct10dif-pclmul_glue.c >> index 7845d7f..a8a95aa 100644 >> --- a/arch/x86/crypto/crct10dif-pclmul_glue.c >> +++ b/arch/x86/crypto/crct10dif-pclmul_glue.c >> @@ -129,9 +129,10 @@ MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id); >> >> static int __init crct10dif_intel_mod_init(void) >> { >> + printk(KERN_WARNING "********** Checking for X86_FEATURE_PCLMULQDQ\n"); >> if (!x86_match_cpu(crct10dif_cpu_id)) >> return -ENODEV; >> - >> + printk(KERN_WARNING "********** Registering crct10dif-pclmul\n"); >> return crypto_register_shash(&alg); >> } >> >> As far as I tested, crct10dif-pclmul.ko will not be loaded unless manually >> adding "modprobe crct10dif-pclmul" to initramfs's /init or choosing >> CONFIG_CRYPTO_CRCT10DIF_PCLMUL=y. >> >>> So as long as the crct10dif.ko and crct10dif-pclmul.ko are loaded, >>> the pclmulqdq t10dif will have a higher priority and get allocated >>> and used. >> What I'm talking are >> >> (1) Since mkinitramfs is unable to know that crct10dif-pclmul.ko has higher >> priority than crct10dif.ko , mkinitramfs will not include >> "modprobe crct10dif-pclmul" line in the generated initramfs. >> >> (2) In order to get benefit from PCLMULQDQ, users have to manually make sure >> that "modprobe crct10dif-pclmul" is called before crc-t10dif.ko (which is >> loaded before sd_mod.ko is loaded) is loaded by their initramfs's /init >> script. >> >> (3) The cause of (1) is that crct10dif-pclmul.ko will not be loaded >> automatically unless choosing CONFIG_CRYPTO_CRCT10DIF_PCLMUL=y. >> >> (4) The cause of (3) is that modules.dep does not describe that users will >> benefit by loading crct10dif-pclmul.ko before loading crc-t10dif.ko . >> >> (5) Currently crct10dif-pclmul.ko cannot be loaded if PCLMULQDQ is not >> supported. This leads to boot failure (since sd_mod.ko cannot be loaded) >> if modules.dep says that "crct10dif-pclmul.ko is required by >> crc-t10dif.ko". >> >> (6) To solve (4) and (5), modules.dep should say "crct10dif-pclmul.ko is >> preferred for crc-t10dif.ko but is not required by crc-t10dif.ko". >> But there is no such mechanism. Thus, currently available choice is >> "allow loading crct10dif-pclmul.ko even if PCLMULQDQ is not supported" >> or "ignore errors by built-in the crct10dif-pclmul.ko module". >> >> My patch (b) seems to be complicated but is required in order to solve (4) >> without asking users to manually add "modprobe crct10dif-pclmul" into their >> initramfs. If we choose patch (b) rather than patch (a), we need to solve (5). >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > --------------------------------------------------------------------- Intel Technology Poland sp. z o.o. z siedziba w Gdansku ul. Slowackiego 173 80-298 Gdansk Sad Rejonowy Gdansk Polnoc w Gdansku, VII Wydzial Gospodarczy Krajowego Rejestru Sadowego, numer KRS 101882 NIP 957-07-52-316 Kapital zakladowy 200.000 zl This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. 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