Received: by 2002:a05:6358:1087:b0:cb:c9d3:cd90 with SMTP id j7csp428314rwi; Wed, 12 Oct 2022 23:22:15 -0700 (PDT) X-Google-Smtp-Source: AMsMyM4Z42WuW6LLaeF3jFwBhNe5hs6daNAJTbW/CWo4amjAlZXxtHeifhMwjG/dS+maEkLwWGgn X-Received: by 2002:a17:907:1deb:b0:78d:4a0e:f654 with SMTP id og43-20020a1709071deb00b0078d4a0ef654mr25558700ejc.757.1665642135325; Wed, 12 Oct 2022 23:22:15 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1665642135; cv=none; d=google.com; s=arc-20160816; b=aD5K6p/fFJ7rqvKbmeWJ9vT4se0Bi3TZhAVU0RH/1guiVBB+N3/yV9BWMuDrYKVaan fi9hd4CQjYTHVSWspm5tFDpWi+78KUZvRJmWeDh0AOGchFv51s/bPEfEjNJK++r9f3v8 LUnX10E/W/tuSmFV2f9Vdm39IQ1Sad/TEVvsR76GDyfBLlAEg4kojEOXqmAKt3DlUjpd a4eyr42mQ82IxbyMRCqGs/yDPc+kM6F24DsSrXdrSG3PadcpYDaFlfmsWDehD/AaV/Kh 6LJ/T1GKl8liPUH2ts36eJprXRMhea1quXTHfaI0TMkM65QM3ZQAixbuZDmFdMNTa6mo lMeA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature; bh=M3cdnmz0Vg2B+CYHCgK7ndAEOGDtojZfaRY+t62dbm8=; b=f9Kh/NgK2eAb4svGvPFpQcY6HhUZCl39dpT2sdmwgaLdFmnLUJX0t6yW6jz3n+L99x 17aQ2reAKQH+Uml0dbt/IdUJJTRUEYXq8KZ5GSEgxaZE+ww7qKSWT9KbZVY2QvGWwhUN l5IiYcdOsXTeseOJ9TUI6bpzXpShYRwtKLf0kaCaK2CKc8rCidN/HX/g/s8GQoS4h7uo UXiRywr151SNH6R3z5yyWguj9H0w+sb/hvr2pMIZ8vGrDWTtMnhskekNH62Zmmqxwyqh ITzrU0/Nc0l/Sbdqx97fx7r36T7pamUvo4idyz/0Ja1xbpmqEhalkpI6eN616mPqqvlM epcQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=bCwMgpN2; spf=pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id hw19-20020a170907a0d300b0073146b3f95asi12649985ejc.632.2022.10.12.23.21.46; Wed, 12 Oct 2022 23:22:15 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=bCwMgpN2; spf=pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229769AbiJMGI6 (ORCPT + 99 others); Thu, 13 Oct 2022 02:08:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229797AbiJMGI5 (ORCPT ); Thu, 13 Oct 2022 02:08:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E57612C8A9; Wed, 12 Oct 2022 23:08:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D6992616FF; Thu, 13 Oct 2022 06:08:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC585C433D6; Thu, 13 Oct 2022 06:08:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665641335; bh=qHJMJEcih6so6BSzh3Q2gwqEnOlegjhfiSsSBu1WH+4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bCwMgpN2NFm8ny18yJEmxvIZNxPQFDDV277F93hsyKONkNcKoEkxBJG3jD3V5rhx3 kV5U25IQhZ2gi/i3ILOKgpiuEGkPEAW/59psMoED2p+N6nVN4nnxsClNrYu1hTJhdz 11+Kl0R1jaLVffsHoIc9U4WCR+A9Bor4KozjzeE5YO4107ZyXlePTXrUqVGncy/a+M xMV/t0PjO4NyYQm6q5p0KbyVrcvlxUeNxB99ug9y/9+owthOnQG4jThY9E++fQqgNI EdBOYhDv6i8GSWOQ9S+gk5UIjJ5F2OoViNKXfpqhh3cQ0GYfBg3sk6NPVSR4Ycx23p gKzeS102hvYNw== Date: Wed, 12 Oct 2022 23:08:53 -0700 From: Eric Biggers To: Herbert Xu Cc: Robert Elliott , davem@davemloft.net, tim.c.chen@linux.intel.com, ap420073@gmail.com, ardb@kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 04/19] crypto: x86/sha - limit FPU preemption Message-ID: References: <20221006223151.22159-1-elliott@hpe.com> <20221012215931.3896-1-elliott@hpe.com> <20221012215931.3896-5-elliott@hpe.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Thu, Oct 13, 2022 at 02:04:43PM +0800, Herbert Xu wrote: > On Wed, Oct 12, 2022 at 10:57:04PM -0700, Eric Biggers wrote: > > > > 'len' can't be 0 at the beginning of this loop, so the 'if (chunk)' check isn't > > needed. And it wouldn't make sense even if 'len' could be 0, since a while loop > > could just be used in that case. > > I don't see anything preventing len from being zero if this gets > called directly by a user of the Crypto API through crypto_shash_update. > But yes a while loop would be a lot cleaner. > When len == 0, the following path is taken instead: if (!crypto_simd_usable() || (sctx->count % SHA1_BLOCK_SIZE) + len < SHA1_BLOCK_SIZE) return crypto_sha1_update(desc, data, len); - Eric