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 7CF68C433F5 for ; Fri, 25 Feb 2022 02:12:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236721AbiBYCNO (ORCPT ); Thu, 24 Feb 2022 21:13:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232225AbiBYCNM (ORCPT ); Thu, 24 Feb 2022 21:13:12 -0500 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F5DD16FDD7 for ; Thu, 24 Feb 2022 18:12:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1645755161; x=1677291161; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=OjwBjKUhnyQUaR178VPG79ZiTP2RcSZHYXmNw8T4lRs=; b=kreVgetDWUuDrk3j/29lgeEMzTxzI9XRT957pYqrB6petQ6d3IqHZtVY ifrVPTYwNrBw19pbN3nK9/jxzpuoaYwwvtlgxSfJ3Tq0HCm7N57bPJo6L Ss0s/BlOqjTDkacBetFWV1Och/R70cMet8k4pAcvv6aw4dQSlcB1fCIJj ff4KP0DLozE876UvJHQCmROaw/T7I476K4aSK9OKKcKrkiMSXcx5VjvY9 NpP7iWhmySRTHRbXQ9Ze2iL4PTGMeHKEQnNIpYOT0oWelhR9MYciYcUig 4wLSfOAVlOn3+cpiytAACveqBzsMB5kCAC9pXXT+oiCKhxlDGRz8bsX9K A==; X-IronPort-AV: E=McAfee;i="6200,9189,10268"; a="313118146" X-IronPort-AV: E=Sophos;i="5.90,134,1643702400"; d="scan'208";a="313118146" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2022 18:12:41 -0800 X-IronPort-AV: E=Sophos;i="5.90,134,1643702400"; d="scan'208";a="639958422" Received: from rongch2-mobl.ccr.corp.intel.com (HELO [10.255.31.203]) ([10.255.31.203]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2022 18:12:34 -0800 Subject: Re: [kbuild-all] Re: [PATCH v2 6/9] KVM: arm64: Detect and handle hypervisor stack overflows To: Marc Zyngier , Ard Biesheuvel Cc: Kalesh Singh , kernel test robot , llvm@lists.linux.dev, kbuild-all@lists.01.org, Will Deacon , Quentin Perret , Fuad Tabba , surenb@google.com, Android Kernel Team , Catalin Marinas , James Morse , Alexandru Elisei , Suzuki K Poulose , Mark Rutland , Pasha Tatashin , Joey Gouly , Peter Collingbourne , Andrew Scull , Paolo Bonzini , Zenghui Yu , Linux ARM , Linux Kernel Mailing List , kvmarm References: <20220222165212.2005066-7-kaleshsingh@google.com> <202202231727.L621fVgD-lkp@intel.com> <875yp63ptg.wl-maz@kernel.org> <89c48bd2a9b32b4607d1515714fa3c1b@kernel.org> From: "Chen, Rong A" Message-ID: <16f47fa9-90b4-0b5c-33cb-cb004fc39266@intel.com> Date: Fri, 25 Feb 2022 10:12:32 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <89c48bd2a9b32b4607d1515714fa3c1b@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/24/2022 6:39 PM, Marc Zyngier wrote: > On 2022-02-23 12:56, Ard Biesheuvel wrote: >> On Wed, 23 Feb 2022 at 13:54, Marc Zyngier wrote: >>> >>> On 2022-02-23 12:34, Philip Li wrote: >>> > On Wed, Feb 23, 2022 at 09:16:59AM +0000, Marc Zyngier wrote: >>> >> On Wed, 23 Feb 2022 09:05:18 +0000, >>> >> kernel test robot wrote: >>> >> > >>> >> > Hi Kalesh, >>> >> > >>> >> > Thank you for the patch! Perhaps something to improve: >>> >> > >>> >> > [auto build test WARNING on >>> cfb92440ee71adcc2105b0890bb01ac3cddb8507] >>> >> > >>> >> > url: >>> https://github.com/0day-ci/linux/commits/Kalesh-Singh/KVM-arm64-Hypervisor-stack-enhancements/20220223-010522 >>> >>> >> > base:   cfb92440ee71adcc2105b0890bb01ac3cddb8507 >>> >> > config: arm64-randconfig-r011-20220221 >>> (https://download.01.org/0day-ci/archive/20220223/202202231727.L621fVgD-lkp@intel.com/config) >>> >>> >> > compiler: clang version 15.0.0 >>> (https://github.com/llvm/llvm-project >>> d271fc04d5b97b12e6b797c6067d3c96a8d7470e) >>> >> > reproduce (this is a W=1 build): >>> >> >         wget >>> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross >>> -O ~/bin/make.cross >>> >> >         chmod +x ~/bin/make.cross >>> >> >         # install arm64 cross compiling tool for clang build >>> >> >         # apt-get install binutils-aarch64-linux-gnu >>> >> >         # >>> https://github.com/0day-ci/linux/commit/7fe99fd40f7c4b2973218045ca5b9c9160524db1 >>> >>> >> >         git remote add linux-review >>> https://github.com/0day-ci/linux >>> >> >         git fetch --no-tags linux-review >>> Kalesh-Singh/KVM-arm64-Hypervisor-stack-enhancements/20220223-010522 >>> >> >         git checkout 7fe99fd40f7c4b2973218045ca5b9c9160524db1 >>> >> >         # save the config file to linux build tree >>> >> >         mkdir build_dir >>> >> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang >>> make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash arch/arm64/ >>> >> > >>> >> > If you fix the issue, kindly add following tag as appropriate >>> >> > Reported-by: kernel test robot >>> >> > >>> >> > All warnings (new ones prefixed by >>): >>> >> > >>> >> >    include/linux/stddef.h:8:14: note: expanded from macro 'NULL' >>> >> >    #define NULL ((void *)0) >>> >> >                 ^~~~~~~~~~~ >>> >> >    arch/arm64/kvm/hyp/nvhe/switch.c:200:27: warning: initializer >>> overrides prior initialization of this subobject >>> [-Winitializer-overrides] >>> >> >            [ESR_ELx_EC_FP_ASIMD]           = kvm_hyp_handle_fpsimd, >>> >> >                                              ^~~~~~~~~~~~~~~~~~~~~ >>> >> >    arch/arm64/kvm/hyp/nvhe/switch.c:196:28: note: previous >>> initialization is here >>> >> >            [0 ... ESR_ELx_EC_MAX]          = NULL, >>> >> >                                              ^~~~ >>> >> >    include/linux/stddef.h:8:14: note: expanded from macro 'NULL' >>> >> >    #define NULL ((void *)0) >>> >> >                 ^~~~~~~~~~~ >>> >> >>> >> Kalesh, please ignore this nonsense. There may be things to improve, >>> >> but this is *NOT* one of them. >>> >> >>> >> These reports are pretty useless, and just lead people to ignore real >>> >> bug reports. >>> > >>> > Hi Kalesh, sorry there're some irrelevant issues mixed in the report, >>> > kindly ignore them. And the valuable ones are the new ones that >>> > prefixed by >>, as the below one in original report. >>> > >>> >>> arch/arm64/kvm/hyp/nvhe/switch.c:372:17: warning: no previous >>> >>> prototype for function 'hyp_panic_bad_stack' [-Wmissing-prototypes] >>> >    void __noreturn hyp_panic_bad_stack(void) >>> >                    ^ >>> >>> This is only called from assembly code, so a prototype wouldn't bring >>> much. >>> >> >> Should probably be marked as 'asmlinkage' then. I've suggested many >> times already that this bogus diagnostic should either be disabled, or >> disregard 'asmlinkage' symbols. > > Yes, asmlinkage is definitely missing. > > But it is pretty obvious that the robot people aren't interested in > fixing this particular issue, given how long we have been suggesting > this... > >         M. Hi Marc, Ard, We have ignored the warning related to asmlinkage according to the below advice: https://lore.kernel.org/lkml/CAMj1kXHrRYagSVniSetHdG15rkQS+fm4zVOtN=Zda3W0QaEoJA@mail.gmail.com/ do you want the bot ignore such warning if asmlinkage not specified? Best Regards, Rong Chen