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 C63CFC11F76 for ; Sun, 4 Jul 2021 23:23:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5A76613B1 for ; Sun, 4 Jul 2021 23:23:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229941AbhGDXZf (ORCPT ); Sun, 4 Jul 2021 19:25:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:50862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233158AbhGDXON (ORCPT ); Sun, 4 Jul 2021 19:14:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AE51E61985; Sun, 4 Jul 2021 23:09:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625440173; bh=EywfHatNm1SZCrBd4brLnFKJ2Kt742Eq5XgSccTvliA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Em8yaZmUoetNyMMYRrUuy5+KR0GQ1cPU6VVsKBf1bMXWhwWkgA+LL+WgfelIADzBd D9BR+ZslNlJB9InW61CSIwntqV43x8U5sF037cmqVktFSdu3Rl1iCYHMr69n0uvz2p fJU3lR7wb2CvciquXJC5DDdFz1bSpVv8iHdK6whJlP2XCwDIv82O9dOueEGrOb8H3G wCBjlXeXwGVo0reizH1heAN/ILQg3UPWVjsQ/Fj6Cz98AGioweUbFcYwfvaTw8YSLw JYXqzmQ7niB58KwvcMnhpTBD7Lea2CuiOyUjXSGZQsU4n/RvrOCfRmwWCQYb7Caxxc mImn3ACS2GnFg== 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 5.10 67/70] KVM: s390: get rid of register asm usage Date: Sun, 4 Jul 2021 19:08:00 -0400 Message-Id: <20210704230804.1490078-67-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210704230804.1490078-1-sashal@kernel.org> References: <20210704230804.1490078-1-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: linux-kernel@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 20afffd6b982..f94b4f78d4da 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -327,31 +327,31 @@ 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