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=-20.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 07FB0C07E9B for ; Sun, 4 Jul 2021 23:06:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7787613F7 for ; Sun, 4 Jul 2021 23:06:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231426AbhGDXJN (ORCPT ); Sun, 4 Jul 2021 19:09:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:46816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230406AbhGDXIp (ORCPT ); Sun, 4 Jul 2021 19:08:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B6A5561410; Sun, 4 Jul 2021 23:06:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625439969; bh=mqd9n6vs1xgm7ByR8C/nW5XpQdznqzFjhFlNcwkIRYM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vG86QOkLre/UmuyIHrTu9TVJVWwf7bcWN/sgfL4wJw1Ibew68qy3PhAaFXYmJ88LV qu2QU11OkkxYnmRfNf97TwQNZ+siNKUO0wGeLTrrEXBSq0zsftG5AcUJxTziWcu2dc kVYovkUNLfg4PUuK8BhE7LorHGMrHjFgxLdJtcPgS4PtMxA8aOQJu+iSmB4YWHMVv6 dCZwp8PKPyMV2az/Da8e/oiZ6eYRvZ2CKzp/n/fnr4LXa1X7QZXoEixbZC/DAR2NKP cpRJl+ON5bIEi6l7Q/jSAVNYiM9pmaEXddtKnXNOJB8+81hefe10Ev11NK9zMl5hlT nIwkUUv92PYwA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Heiko Carstens , Christian Borntraeger , Thomas Huth , Cornelia Huck , Claudio Imbrenda , Sasha Levin , kvm@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 5.13 81/85] KVM: s390: get rid of register asm usage Date: Sun, 4 Jul 2021 19:04:16 -0400 Message-Id: <20210704230420.1488358-81-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210704230420.1488358-1-sashal@kernel.org> References: <20210704230420.1488358-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Heiko Carstens [ Upstream commit 4fa3b91bdee1b08348c82660668ca0ca34e271ad ] Using register asm statements has been proven to be very error prone, especially when using code instrumentation where gcc may add function calls, which clobbers register contents in an unexpected way. Therefore get rid of register asm statements in kvm code, even though there is currently nothing wrong with them. This way we know for sure that this bug class won't be introduced here. Signed-off-by: Heiko Carstens Reviewed-by: Christian Borntraeger Reviewed-by: Thomas Huth Reviewed-by: Cornelia Huck Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20210621140356.1210771-1-hca@linux.ibm.com [borntraeger@de.ibm.com: checkpatch strict fix] Signed-off-by: Christian Borntraeger Signed-off-by: Sasha Levin --- arch/s390/kvm/kvm-s390.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 1296fc10f80c..876fc1f7282a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -329,31 +329,31 @@ static void allow_cpu_feat(unsigned long nr) static inline int plo_test_bit(unsigned char nr) { - register unsigned long r0 asm("0") = (unsigned long) nr | 0x100; + unsigned long function = (unsigned long)nr | 0x100; int cc; asm volatile( + " lgr 0,%[function]\n" /* Parameter registers are ignored for "test bit" */ " plo 0,0,0,0(0)\n" " ipm %0\n" " srl %0,28\n" : "=d" (cc) - : "d" (r0) - : "cc"); + : [function] "d" (function) + : "cc", "0"); return cc == 0; } static __always_inline void __insn32_query(unsigned int opcode, u8 *query) { - register unsigned long r0 asm("0") = 0; /* query function */ - register unsigned long r1 asm("1") = (unsigned long) query; - asm volatile( - /* Parameter regs are ignored */ + " lghi 0,0\n" + " lgr 1,%[query]\n" + /* Parameter registers are ignored */ " .insn rrf,%[opc] << 16,2,4,6,0\n" : - : "d" (r0), "a" (r1), [opc] "i" (opcode) - : "cc", "memory"); + : [query] "d" ((unsigned long)query), [opc] "i" (opcode) + : "cc", "memory", "0", "1"); } #define INSN_SORTL 0xb938 -- 2.30.2