From patchwork Wed Jul 5 16:40:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Giovanni Cabiddu X-Patchwork-Id: 700166 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33E68EB64DA for ; Wed, 5 Jul 2023 16:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232429AbjGEQkj (ORCPT ); Wed, 5 Jul 2023 12:40:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232634AbjGEQkh (ORCPT ); Wed, 5 Jul 2023 12:40:37 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7FF2610EA; Wed, 5 Jul 2023 09:40:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1688575236; x=1720111236; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ORYP0BTPC9UmnZNKGK+aTCKZj4NImzCEscAgvgLWfvs=; b=RXiNreG3+paOmBxsCnkMvf53Q2N0KcC+WPdoNVo6HZ21LY7Bd35VIlQF 7E94E5gGmgaZosxHxs56pktULVtSfMu6BGjExBDS8d31H+vL9UeMRe2oH pjQkoKMnSpmr0WC3jkHt6tDpZRAzMw9RbJavyYDq99isXiam1Est0sXCe UkDZb2leYdzBDSDZq3BK3bpzXy/ZtKped0Fx1k2YYRbSkBO9lEhmD9nN2 LVFlvIoohd+AB41z2cAQOeAoIz+2ovb97j4ghgQPSEqdvu1fWbJykWuVO cJb0z0h7xABLrWzvaRZ+DNM+75mbJfkNLs6O1AcoSo2nTBJ0HaemSukFP A==; X-IronPort-AV: E=McAfee;i="6600,9927,10762"; a="362258287" X-IronPort-AV: E=Sophos;i="6.01,183,1684825200"; d="scan'208";a="362258287" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jul 2023 09:40:36 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10762"; a="893241766" X-IronPort-AV: E=Sophos;i="6.01,183,1684825200"; d="scan'208";a="893241766" Received: from silpixa00400314.ir.intel.com (HELO silpixa00400314.ger.corp.intel.com) ([10.237.222.216]) by orsmga005.jf.intel.com with ESMTP; 05 Jul 2023 09:40:32 -0700 From: Giovanni Cabiddu To: herbert@gondor.apana.org.au, agk@redhat.com, snitzer@kernel.org Cc: linux-crypto@vger.kernel.org, dm-devel@redhat.com, linux-kernel@vger.kernel.org, qat-linux@intel.com, heinzm@redhat.com, meenakshi.aggarwal@nxp.com, ebiggers@kernel.org, horia.geanta@nxp.com, V.Sethi@nxp.com, pankaj.gupta@nxp.com, gaurav.jain@nxp.com, davem@davemloft.net, iuliana.prodan@nxp.com, Giovanni Cabiddu , Eric Biggers , Fiona Trahe Subject: [PATCH 2/3] crypto: api - adjust meaning of CRYPTO_ALG_ALLOCATES_MEMORY Date: Wed, 5 Jul 2023 17:40:08 +0100 Message-Id: <20230705164009.58351-3-giovanni.cabiddu@intel.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230705164009.58351-1-giovanni.cabiddu@intel.com> References: <20230705164009.58351-1-giovanni.cabiddu@intel.com> MIME-Version: 1.0 Organization: Intel Research and Development Ireland Ltd - Co. Reg. #308263 - Collinstown Industrial Park, Leixlip, County Kildare - Ireland Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org The CRYPTO_ALG_ALLOCATES_MEMORY flag doesn't allow to distinguish between implementations which don't allocate memory for scatterlists with 4 or less entries (the typical case for dm-crypt) and those that do. The flag's meaning is adjusted based on the ML discussion below. This patch removes the need to set the flag if the implementation can handle scatterlists up to 4 entries without allocating memory. The documentation is updated accordingly, with an extra clarification regarding sleeping. Suggested-by: Herbert Xu Suggested-by: Eric Biggers Link: https://lore.kernel.org/linux-crypto/20200722072932.GA27544@gondor.apana.org.au/ Link: https://lore.kernel.org/linux-crypto/20230523165503.GA864814@google.com/ Signed-off-by: Giovanni Cabiddu Reviewed-by: Fiona Trahe --- include/linux/crypto.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 31f6fee0c36c..15884790a3d0 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -87,8 +87,13 @@ /* * The algorithm may allocate memory during request processing, i.e. during - * encryption, decryption, or hashing. Users can request an algorithm with this - * flag unset if they can't handle memory allocation failures. + * encryption, decryption, or hashing. Algorithms that do not set this flag will + * guarantee that memory is not allocated during request processing, except in + * the avoidable exception cases described below. + * + * Users can request an algorithm with this flag unset if they can't handle + * memory allocation failures or sleeping during request processing. They should + * also follow the constraints below. * * This flag is currently only implemented for algorithms of type "skcipher", * "aead", "ahash", "shash", and "cipher". Algorithms of other types might not @@ -102,6 +107,9 @@ * - If the data were to be divided into chunks of size * crypto_skcipher_walksize() (with any remainder going at the end), no * chunk can cross a page boundary or a scatterlist element boundary. + * - The input and output scatterlists must have no more than 4 entries. + * If the scatterlists contain more than 4 entries, the algorithm may + * allocate memory. * aead: * - The IV buffer and all scatterlist elements must be aligned to the * algorithm's alignmask. @@ -110,10 +118,16 @@ * - If the plaintext/ciphertext were to be divided into chunks of size * crypto_aead_walksize() (with the remainder going at the end), no chunk * can cross a page boundary or a scatterlist element boundary. + * - The input and output scatterlists must have no more than 4 entries. + * If the scatterlists contain more than 4 entries, the algorithm may + * allocate memory. * ahash: * - The result buffer must be aligned to the algorithm's alignmask. * - crypto_ahash_finup() must not be used unless the algorithm implements * ->finup() natively. + * - The input and output scatterlists must have no more than 4 entries. + * If the scatterlists contain more than 4 entries, the algorithm may + * allocate memory. */ #define CRYPTO_ALG_ALLOCATES_MEMORY 0x00010000