From patchwork Fri May 8 12:30:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226076 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 29163C47247 for ; Fri, 8 May 2020 13:23:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08B00206B9 for ; Fri, 8 May 2020 13:23:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588944207; bh=i+T718m1aIGBAyTqzaq4+biCQ9TNEUltVR2+ml15jU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NCrFjqdLu89JNg/Xq2HqHHIlEW/PW80FidKmZ5S64k+lz4xI8ZC5QdFsM9orEFgoX b4Y81DEAipDQSuuCRH+JYmCmaIm+8QgUxU5OKJZOS2ZPyFrGPuUQG45qu/EYAfcdgI 1gd6wZLQ9XMkcaUUjlVbwQ+fl3mAQPOdUQuJJ1+w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728607AbgEHNXX (ORCPT ); Fri, 8 May 2020 09:23:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:54120 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728389AbgEHMi1 (ORCPT ); Fri, 8 May 2020 08:38:27 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 01C7F24964; Fri, 8 May 2020 12:38:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588941506; bh=i+T718m1aIGBAyTqzaq4+biCQ9TNEUltVR2+ml15jU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OZpsqg5QCpIFvzvCqj/LYkoKaIe7FEonAjy+OX1McXnJTu4K6gVzB0krovKtFW7n/ 4TiI7AO5gue1+BkIvo2gVmNl4wl6MhRkM4voPZ9ON19b3hJ6YweGQ4SHQYEBRldtRx I5y7Bjy7Scfv4hT6vr14KVT3JkUs+T5KTmH7SNYs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Burton , Adam Buchbinder , "Maciej W. Rozycki" , linux-mips@linux-mips.org, Ralf Baechle Subject: [PATCH 4.4 022/312] MIPS: math-emu: Fix m{add,sub}.s shifts Date: Fri, 8 May 2020 14:30:13 +0200 Message-Id: <20200508123126.046827568@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200508123124.574959822@linuxfoundation.org> References: <20200508123124.574959822@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paul Burton commit db57f29d50683afd75c7f8b9908af7669837c3a9 upstream. The code in _sp_maddf (formerly ieee754sp_madd) appears to have been copied verbatim from ieee754sp_add, and although it's adding the unpacked "r" & "z" floats it kept using macros that operate on "x" & "y". This led to the addition being carried out incorrectly on some mismash of the product, accumulator & multiplicand fields. Typically this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing since ze & re hadn't been operated upon. Signed-off-by: Paul Burton Fixes: e24c3bec3e8e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction") Cc: Adam Buchbinder Cc: Maciej W. Rozycki Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13159/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman --- arch/mips/math-emu/ieee754sp.c | 3 ++- arch/mips/math-emu/ieee754sp.h | 16 +++++++--------- arch/mips/math-emu/sp_add.c | 6 ++++-- arch/mips/math-emu/sp_maddf.c | 13 ++++++++----- arch/mips/math-emu/sp_sub.c | 6 ++++-- 5 files changed, 25 insertions(+), 19 deletions(-) --- a/arch/mips/math-emu/ieee754sp.c +++ b/arch/mips/math-emu/ieee754sp.c @@ -130,7 +130,8 @@ union ieee754sp ieee754sp_format(int sn, } else { /* sticky right shift es bits */ - SPXSRSXn(es); + xm = XSPSRS(xm, es); + xe += es; assert((xm & (SP_HIDDEN_BIT << 3)) == 0); assert(xe == SP_EMIN); } --- a/arch/mips/math-emu/ieee754sp.h +++ b/arch/mips/math-emu/ieee754sp.h @@ -46,19 +46,17 @@ static inline int ieee754sp_finite(union } /* 3bit extended single precision sticky right shift */ -#define SPXSRSXn(rs) \ - (xe += rs, \ - xm = (rs > (SP_FBITS+3))?1:((xm) >> (rs)) | ((xm) << (32-(rs)) != 0)) +#define XSPSRS(v, rs) \ + ((rs > (SP_FBITS+3))?1:((v) >> (rs)) | ((v) << (32-(rs)) != 0)) -#define SPXSRSX1() \ - (xe++, (xm = (xm >> 1) | (xm & 1))) +#define XSPSRS1(m) \ + ((m >> 1) | (m & 1)) -#define SPXSRSYn(rs) \ - (ye+=rs, \ - ym = (rs > (SP_FBITS+3))?1:((ym) >> (rs)) | ((ym) << (32-(rs)) != 0)) +#define SPXSRSX1() \ + (xe++, (xm = XSPSRS1(xm))) #define SPXSRSY1() \ - (ye++, (ym = (ym >> 1) | (ym & 1))) + (ye++, (ym = XSPSRS1(ym))) /* convert denormal to normalized with extended exponent */ #define SPDNORMx(m,e) \ --- a/arch/mips/math-emu/sp_add.c +++ b/arch/mips/math-emu/sp_add.c @@ -132,13 +132,15 @@ union ieee754sp ieee754sp_add(union ieee * Have to shift y fraction right to align. */ s = xe - ye; - SPXSRSYn(s); + ym = XSPSRS(ym, s); + ye += s; } else if (ye > xe) { /* * Have to shift x fraction right to align. */ s = ye - xe; - SPXSRSXn(s); + xm = XSPSRS(xm, s); + xe += s; } assert(xe == ye); assert(xe <= SP_EMAX); --- a/arch/mips/math-emu/sp_maddf.c +++ b/arch/mips/math-emu/sp_maddf.c @@ -208,16 +208,18 @@ union ieee754sp ieee754sp_maddf(union ie if (ze > re) { /* - * Have to shift y fraction right to align. + * Have to shift r fraction right to align. */ s = ze - re; - SPXSRSYn(s); + rm = XSPSRS(rm, s); + re += s; } else if (re > ze) { /* - * Have to shift x fraction right to align. + * Have to shift z fraction right to align. */ s = re - ze; - SPXSRSYn(s); + zm = XSPSRS(zm, s); + ze += s; } assert(ze == re); assert(ze <= SP_EMAX); @@ -230,7 +232,8 @@ union ieee754sp ieee754sp_maddf(union ie zm = zm + rm; if (zm >> (SP_FBITS + 1 + 3)) { /* carry out */ - SPXSRSX1(); + zm = XSPSRS1(zm); + ze++; } } else { if (zm >= rm) { --- a/arch/mips/math-emu/sp_sub.c +++ b/arch/mips/math-emu/sp_sub.c @@ -134,13 +134,15 @@ union ieee754sp ieee754sp_sub(union ieee * have to shift y fraction right to align */ s = xe - ye; - SPXSRSYn(s); + ym = XSPSRS(ym, s); + ye += s; } else if (ye > xe) { /* * have to shift x fraction right to align */ s = ye - xe; - SPXSRSXn(s); + xm = XSPSRS(xm, s); + xe += s; } assert(xe == ye); assert(xe <= SP_EMAX);