From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25332C433DF for ; Mon, 20 Jul 2020 17:12:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F3FCA2176B for ; Mon, 20 Jul 2020 17:12:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=chronox.de header.i=@chronox.de header.b="Bw5gCP/q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729744AbgGTRMh (ORCPT ); Mon, 20 Jul 2020 13:12:37 -0400 Received: from mo4-p02-ob.smtp.rzone.de ([81.169.146.168]:24475 "EHLO mo4-p02-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729621AbgGTRMh (ORCPT ); Mon, 20 Jul 2020 13:12:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1595265154; s=strato-dkim-0002; d=chronox.de; h=References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: X-RZG-CLASS-ID:X-RZG-AUTH:From:Subject:Sender; bh=wdmligHdkLrEqkLoRjSHZWa576Vg87I0/kFtCnfKltw=; b=Bw5gCP/q7Pd6LORZPAkKrr+VeGF4ktuqx1GASAowJjVhQczzcRXEPDwrTPBgPBlXLc T9djIPFiM2h1jKqrzvBx5InsgAD0y0M6P4iUlWMkWuuvOwKDKvxjprrDYmY8fU7oWMNF FQDB4sut2BYh0oTAmZV0TuTiZ7+7jxutBVIIJGpOF1WoVFz7jcfNDQOep6YqJYLz1Y6g DBMHTTrVsxSzfpCK7tZkcdl1tk4546JmHemuz2/OcfPc0tqmMHtAFumFuQsdeO9RDq3G sMd1it5VtN6g1nsh3sDJbNM2lBCdyufbN2u/Mzz4KzYnU53cxpXVmD0SLag1PN6DC05/ j5pg== X-RZG-AUTH: ":P2ERcEykfu11Y98lp/T7+hdri+uKZK8TKWEqNyiHySGSa9k9xmwdNnzGHXPZJPScHiDh" X-RZG-CLASS-ID: mo00 Received: from positron.chronox.de by smtp.strato.de (RZmta 46.10.5 DYNA|AUTH) with ESMTPSA id y0546bw6KH9tULM (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Mon, 20 Jul 2020 19:09:55 +0200 (CEST) From: Stephan =?ISO-8859-1?Q?M=FCller?= To: herbert@gondor.apana.org.au Cc: linux-crypto@vger.kernel.org, Marcelo Cerri , Tianjia Zhang , ard.biesheuvel@linaro.org, nhorman@redhat.com, simo@redhat.com Subject: [PATCH v3 2/5] lib/mpi: Add mpi_sub_ui() Date: Mon, 20 Jul 2020 19:08:09 +0200 Message-ID: <12569375.uLZWGnKmhe@positron.chronox.de> In-Reply-To: <2544426.mvXUDI8C0e@positron.chronox.de> References: <2543601.mvXUDI8C0e@positron.chronox.de> <5722559.lOV4Wx5bFT@positron.chronox.de> <2544426.mvXUDI8C0e@positron.chronox.de> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org From: Marcelo Henrique Cerri Add mpi_sub_ui() based on Gnu MP mpz_sub_ui() function from file mpz/aors_ui.h[1] from change id 510b83519d1c adapting the code to the kernel's data structures, helper functions and coding style and also removing the defines used to produce mpz_sub_ui() and mpz_add_ui() from the same code. [1] https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors.h Signed-off-by: Marcelo Henrique Cerri Signed-off-by: Stephan Mueller --- include/linux/mpi.h | 3 ++ lib/mpi/Makefile | 1 + lib/mpi/mpi-sub-ui.c | 78 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 82 insertions(+) create mode 100644 lib/mpi/mpi-sub-ui.c diff --git a/include/linux/mpi.h b/include/linux/mpi.h index 7bd6d8af0004..5d906dfbf3ed 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -63,6 +63,9 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod); int mpi_cmp_ui(MPI u, ulong v); int mpi_cmp(MPI u, MPI v); +/*-- mpi-sub-ui.c --*/ +int mpi_sub_ui(MPI w, MPI u, unsigned long vval); + /*-- mpi-bit.c --*/ void mpi_normalize(MPI a); unsigned mpi_get_nbits(MPI a); diff --git a/lib/mpi/Makefile b/lib/mpi/Makefile index d5874a7f5ff9..43b8fce14079 100644 --- a/lib/mpi/Makefile +++ b/lib/mpi/Makefile @@ -16,6 +16,7 @@ mpi-y = \ mpicoder.o \ mpi-bit.o \ mpi-cmp.o \ + mpi-sub-ui.o \ mpih-cmp.o \ mpih-div.o \ mpih-mul.o \ diff --git a/lib/mpi/mpi-sub-ui.c b/lib/mpi/mpi-sub-ui.c new file mode 100644 index 000000000000..b41b082b5f3e --- /dev/null +++ b/lib/mpi/mpi-sub-ui.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* mpi-sub-ui.c - Subtract an unsigned integer from an MPI. + * + * Copyright 1991, 1993, 1994, 1996, 1999-2002, 2004, 2012, 2013, 2015 + * Free Software Foundation, Inc. + * + * This file was based on the GNU MP Library source file: + * https://gmplib.org/repo/gmp-6.2/file/510b83519d1c/mpz/aors_ui.h + * + * The GNU MP Library is free software; you can redistribute it and/or modify + * it under the terms of either: + * + * * the GNU Lesser General Public License as published by the Free + * Software Foundation; either version 3 of the License, or (at your + * option) any later version. + * + * or + * + * * the GNU General Public License as published by the Free Software + * Foundation; either version 2 of the License, or (at your option) any + * later version. + * + * or both in parallel, as here. + * + * The GNU MP Library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received copies of the GNU General Public License and the + * GNU Lesser General Public License along with the GNU MP Library. If not, + * see https://www.gnu.org/licenses/. + */ + +#include "mpi-internal.h" + +int mpi_sub_ui(MPI w, MPI u, unsigned long vval) +{ + if (u->nlimbs == 0) { + if (mpi_resize(w, 1) < 0) + return -ENOMEM; + w->d[0] = vval; + w->nlimbs = (vval != 0); + w->sign = (vval != 0); + return 0; + } + + /* If not space for W (and possible carry), increase space. */ + if (mpi_resize(w, u->nlimbs + 1)) + return -ENOMEM; + + if (u->sign) { + mpi_limb_t cy; + + cy = mpihelp_add_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval); + w->d[u->nlimbs] = cy; + w->nlimbs = u->nlimbs + cy; + w->sign = 1; + } else { + /* The signs are different. Need exact comparison to determine + * which operand to subtract from which. + */ + if (u->nlimbs == 1 && u->d[0] < vval) { + w->d[0] = vval - u->d[0]; + w->nlimbs = 1; + w->sign = 1; + } else { + mpihelp_sub_1(w->d, u->d, u->nlimbs, (mpi_limb_t) vval); + /* Size can decrease with at most one limb. */ + w->nlimbs = (u->nlimbs - (w->d[u->nlimbs - 1] == 0)); + w->sign = 0; + } + } + + mpi_normalize(w); + return 0; +} +EXPORT_SYMBOL_GPL(mpi_sub_ui); -- 2.26.2