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=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham 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 D9A28C76190 for ; Fri, 26 Jul 2019 13:51:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B38EE22CD8 for ; Fri, 26 Jul 2019 13:51:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564149077; bh=0Gb08muBv98DTLQL3LipRqh0c9UU8aTqxL/YMxmBZU4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yKkCvUMLXDep1rCsIp3jdJEWyqVd6nPdU6bJym9LzKenCWcI8dZCC1+7+8vZcbjGW qmberdo0YAN+FhHgPe0Ufl7vMpzjNGUpWo8nQSxaCx+p1+Hp59dfy/y9DLgPm02OyK iWEIdR5Dmzk/NNLZOQzvW+OwO7mI/14guu204ugk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727356AbfGZNvR (ORCPT ); Fri, 26 Jul 2019 09:51:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:51868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727794AbfGZNnz (ORCPT ); Fri, 26 Jul 2019 09:43:55 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 51DF022CC2; Fri, 26 Jul 2019 13:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148635; bh=0Gb08muBv98DTLQL3LipRqh0c9UU8aTqxL/YMxmBZU4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=avuMpCqEF/kn+lup9gOBnajumscWAIxICekM8dkdXGuZzBpqAlaEpAw8kQEL+j5KF Uyig6ZVjx1PC9J/LH1ePgMu6ydjfwR5dhJa0QicLlJgv/2uQUjr18SqkADfhDbr5IL zuoQ8FMSt6xJhoRMTSniaoKukM0nLg+VV13J3Dbo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arnd Bergmann , Paolo Bonzini , Sasha Levin , kvm@vger.kernel.org, clang-built-linux@googlegroups.com Subject: [PATCH AUTOSEL 4.14 17/37] x86: kvm: avoid constant-conversion warning Date: Fri, 26 Jul 2019 09:43:12 -0400 Message-Id: <20190726134332.12626-17-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726134332.12626-1-sashal@kernel.org> References: <20190726134332.12626-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Arnd Bergmann [ Upstream commit a6a6d3b1f867d34ba5bd61aa7bb056b48ca67cff ] clang finds a contruct suspicious that converts an unsigned character to a signed integer and back, causing an overflow: arch/x86/kvm/mmu.c:4605:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -205 to 51 [-Werror,-Wconstant-conversion] u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0; ~~ ^~ arch/x86/kvm/mmu.c:4607:38: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -241 to 15 [-Werror,-Wconstant-conversion] u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0; ~~ ^~ arch/x86/kvm/mmu.c:4609:39: error: implicit conversion from 'int' to 'u8' (aka 'unsigned char') changes value from -171 to 85 [-Werror,-Wconstant-conversion] u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0; ~~ ^~ Add an explicit cast to tell clang that everything works as intended here. Signed-off-by: Arnd Bergmann Link: https://github.com/ClangBuiltLinux/linux/issues/95 Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/mmu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index f97b533bc6e6..87a0601b1c20 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4313,11 +4313,11 @@ static void update_permission_bitmask(struct kvm_vcpu *vcpu, */ /* Faults from writes to non-writable pages */ - u8 wf = (pfec & PFERR_WRITE_MASK) ? ~w : 0; + u8 wf = (pfec & PFERR_WRITE_MASK) ? (u8)~w : 0; /* Faults from user mode accesses to supervisor pages */ - u8 uf = (pfec & PFERR_USER_MASK) ? ~u : 0; + u8 uf = (pfec & PFERR_USER_MASK) ? (u8)~u : 0; /* Faults from fetches of non-executable pages*/ - u8 ff = (pfec & PFERR_FETCH_MASK) ? ~x : 0; + u8 ff = (pfec & PFERR_FETCH_MASK) ? (u8)~x : 0; /* Faults from kernel mode fetches of user pages */ u8 smepf = 0; /* Faults from kernel mode accesses of user pages */ -- 2.20.1