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,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 1F12CC76191 for ; Fri, 26 Jul 2019 13:42:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC11522BF5 for ; Fri, 26 Jul 2019 13:42:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148571; bh=xcrPwqvyu0V0LBKurqlo82+0cYsgFDQ2imAbyZfWuw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wcvjz/OKUYbnNT7zG4Tjn2VW6e+bDGtAi61y3bcLNe7pMn0Bo+1g6DnBkiyZ6v22g 6X+/xFtNaDdDwblSQKD/THyt1R9xO7XzcXexnnS+NTSN0m2mGgJfGAQjr/sHRcEn3N tsN5yF9dptp1x1NLSF/J7dGxgceGWS1hJLUXScPE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388051AbfGZNmt (ORCPT ); Fri, 26 Jul 2019 09:42:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:50168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388047AbfGZNmt (ORCPT ); Fri, 26 Jul 2019 09:42:49 -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 3D88022CBF; Fri, 26 Jul 2019 13:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564148569; bh=xcrPwqvyu0V0LBKurqlo82+0cYsgFDQ2imAbyZfWuw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I45MlmzvuS/OTGHy2Glg2oyMXykjiqtIN8s2Md0kix+L2OzrkuobjqrCgPLtnqxak S6Qte4rwe/hdcloO5XS+nUQ2GHaEOhDb7TlhoP0HmzUALSv7C2WoCQ3EBoc8Ky8YgC mjiXq+y2a6oKswJAb0ppCwfqLo6HV538wiYn8ELA= 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 4.19 24/47] x86: kvm: avoid constant-conversion warning Date: Fri, 26 Jul 2019 09:41:47 -0400 Message-Id: <20190726134210.12156-24-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190726134210.12156-1-sashal@kernel.org> References: <20190726134210.12156-1-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 e0f982e35c96..cdc0c460950f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4532,11 +4532,11 @@ 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