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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8409AC4167B for ; Thu, 30 Nov 2023 17:49:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346668AbjK3Rtm (ORCPT ); Thu, 30 Nov 2023 12:49:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346604AbjK3Rtj (ORCPT ); Thu, 30 Nov 2023 12:49:39 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65EE2106 for ; Thu, 30 Nov 2023 09:49:45 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5ce16bc121aso20972307b3.1 for ; Thu, 30 Nov 2023 09:49:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701366584; x=1701971384; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=poBE260KekrwVAOgg+M3fF5Kt/ICZ7GAjNWMaWtdSzg=; b=ICJLpAgwZbOfuOu7k3JAI8dnsLJszQlCa7NVU62wiaNNst73XZK+ES47fhiEdEnOvr +ooCzCai9wy//ibux1cb7ujsI8CBtyd6yNgvkU7/j5GR/ayIOoctD0ru18+Kn9qD9m+Y DfTZk91fk6FEGAhmHKo0z6QDnnXKcIkJDo6OMSUfn3yvwk5IJvySTa+WaqWBCP2Ws68M dLQ3scKQZPQf1Gzhjc0NWW9X23qBHYlOm3iikWABViIXwRyb++EDa8kSZbv58tmmpmx3 HungqifzqNzLLedVOx3m6Iou29MVdurIlDvusdm4c7bNvLj1r7cl5fluDDOlpph5DVHi VA1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701366584; x=1701971384; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=poBE260KekrwVAOgg+M3fF5Kt/ICZ7GAjNWMaWtdSzg=; b=eU+T8QsgrcERA1yg6wEi2GQ8m1vZIF6LJOMD9bQpVkk04zp4wrCyOv3U9N+Mt1uxp+ 0J3na/QtcCByyobkc7b2BIfyONsSP8jrYxf5oPl8Qbq1KqCU99BUcsEhGwDcADF3JQry e/IKPu1c+7VS0rqWy75KZh+lgYgeztIu5MeCV/uQ/bXzs1ZRRE6cYbvtUkyZUnKmNMOQ PSTpAImNRvk8EMGp3T2KOPyKXQsBTkojrjuXX+k5iUCZjGaaPQEa2OHGWbtN9nRMQLZ9 mBsQfFhK7P3x7mjKgD+1FOUrf5XHPNkOTa+uuHdNCk6003FlbPfxGSepLEMiId4DgM6j suzQ== X-Gm-Message-State: AOJu0YzmJPI0jg1s7ClKj7kJJGLfW+o6NEhYLjJlCgdpn9rWLMhNuXeQ e24nTCB/8M8PpYN04iA7jmkn9ShuMeA= X-Google-Smtp-Source: AGHT+IFKIQiSFMhY9qIDegdCeGs56VhwQM1SLPMyPsnHTxpb4uIQIzrRqUJpJKjBsiy/h0VKitgvRRcgueU= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:3383:0:b0:da0:c6d7:8231 with SMTP id z125-20020a253383000000b00da0c6d78231mr749060ybz.0.1701366584635; Thu, 30 Nov 2023 09:49:44 -0800 (PST) Date: Thu, 30 Nov 2023 09:49:43 -0800 In-Reply-To: <87v89jmc3q.fsf@redhat.com> Mime-Version: 1.0 References: <202311302231.sinLrAig-lkp@intel.com> <87v89jmc3q.fsf@redhat.com> Message-ID: Subject: Re: arch/x86/kvm/vmx/hyperv.h:79:30: sparse: sparse: cast truncates bits from constant value (1b009b becomes 9b) From: Sean Christopherson To: Vitaly Kuznetsov Cc: kernel test robot , oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org, Paolo Bonzini , kvm@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 30, 2023, Vitaly Kuznetsov wrote: > kernel test robot writes: > > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master > > head: 3b47bc037bd44f142ac09848e8d3ecccc726be99 > > commit: a789aeba419647c44d7e7320de20fea037c211d0 KVM: VMX: Rename "vmx/evmcs.{ch}" to "vmx/hyperv.{ch}" > > date: 1 year ago > > config: x86_64-randconfig-123-20231130 (https://download.01.org/0day-ci/archive/20231130/202311302231.sinLrAig-lkp@intel.com/config) > > compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07) > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231130/202311302231.sinLrAig-lkp@intel.com/reproduce) > > > > If you fix the issue in a separate patch/commit (i.e. not just a new version of > > the same patch/commit), kindly add following tags > > | Reported-by: kernel test robot > > | Closes: https://lore.kernel.org/oe-kbuild-all/202311302231.sinLrAig-lkp@intel.com/ > > > > sparse warnings: (new ones prefixed by >>) > > arch/x86/kvm/vmx/hyperv.h:79:30: sparse: sparse: cast truncates bits from constant value (a000a becomes a) > > This is what ROL16() macro does but the thing is: we actually want to > truncate bits by doing an explicit (u16) cast. We can probably replace > this with '& 0xffff': > > #define ROL16(val, n) ((((u16)(val) << (n)) | ((u16)(val) >> (16 - (n)))) & 0xffff) > > but honestly I don't see much point... Yeah, just ignore 'em, we get the exact same sparse complaints in vmcs12.c and have had great success ignoring those too :-)