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 CB4CAC07E9A for ; Sun, 4 Jul 2021 23:09:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B92206194B for ; Sun, 4 Jul 2021 23:09:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231428AbhGDXLq (ORCPT ); Sun, 4 Jul 2021 19:11:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:49050 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231144AbhGDXKy (ORCPT ); Sun, 4 Jul 2021 19:10:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id F25756194B; Sun, 4 Jul 2021 23:07:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625440079; bh=2Wi38nQN3VKnV4ahUhGFIElpkM/7DNUZ3EbizulaLTc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hAaIUVFn3+bGzW7u0EtvEsw4AAhadKX4tk8cvcLwrIyH0DsYXIAwyZeyqua7xem8N rblsFhvXdLRxOLjpvH4S23MQx6qRy/9qfNcA6C9sQKigvNSwHnnfFW2eT57wsuhNBf nKDq9djkVbj34ADGSml/cEVwptmbYShKfGEIJztjIRvsqmpW/lmXGUAo6Y8PFaRTAZ ZM9zxf9RwjmA2HlEI9Q4Z4RFg4PB8lJP+yYoYzVUtq7AwomxyueV3iSjdN43q86WoU y9hSdxQ215HCYM+ID9fMomDrx4buqA4+WWKRoAfH4f01RCwtLixehIAra+DZo7uhpg yLHblX+l3Cu3w== 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 5.12 77/80] KVM: s390: get rid of register asm usage Date: Sun, 4 Jul 2021 19:06:13 -0400 Message-Id: <20210704230616.1489200-77-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210704230616.1489200-1-sashal@kernel.org> References: <20210704230616.1489200-1-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 24ad447e648c..dd7136b3ed9a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -323,31 +323,31 @@ 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