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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 5C8B2C433DF for ; Mon, 8 Jun 2020 16:31:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3860F2053B for ; Mon, 8 Jun 2020 16:31:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591633888; bh=NVh0BXCEcSYUCxgi2WuQ2scVS8On68D+KDFWkURkQNI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=IQ865jpFdoyhrJwfLiDDHMTJeYCJL7PLlMnAQ2RfygmvP5vtY54TrNBqs8LcQ6iUC N8sKolaoMv/mkZtjYLdz3zxM1FrADSsORWW4jxthVzdtIHWQe596vKDaRjJ+23UYae o8sF0O1XVACcoznkhLwtIFTeryKjetZUZDcT2fkA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730554AbgFHQb1 (ORCPT ); Mon, 8 Jun 2020 12:31:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:43650 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730432AbgFHQb1 (ORCPT ); Mon, 8 Jun 2020 12:31:27 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 58D382072F; Mon, 8 Jun 2020 16:31:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591633886; bh=NVh0BXCEcSYUCxgi2WuQ2scVS8On68D+KDFWkURkQNI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=1yhp1ZRDSuYK7i83ihjg/yHmweypv6NQ/77/U3CTmS+RXR22mEBnduexBjUSyAETM Ie5g+KHVJcV56V5Oo1zi2XTOTWrAl7XOurArMNdjX38IVuk21e7q/mAT9IkczpFgn0 8uAFcVnl1bXVWzhDjuRZyzmQi9DE8RQ87fBSjAgI= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jiKgG-001AZA-UF; Mon, 08 Jun 2020 17:31:25 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 08 Jun 2020 17:31:24 +0100 From: Marc Zyngier To: Andrew Scull Cc: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, James Morse , Julien Thierry , Suzuki K Poulose , kernel-team@android.com Subject: Re: [PATCH] KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr In-Reply-To: <20200608150035.GB96714@google.com> References: <20200608085731.1405854-1-maz@kernel.org> <20200608150035.GB96714@google.com> User-Agent: Roundcube Webmail/1.4.4 Message-ID: <61b7e8e75b2d60b21b20d9919fc8bafc@kernel.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: ascull@google.com, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020-06-08 16:00, Andrew Scull wrote: > On Mon, Jun 08, 2020 at 09:57:31AM +0100, Marc Zyngier wrote: >> Sparse complains that __hyp_this_cpu_ptr() returns something >> that is flagged noderef and not in the correct address space >> (both being the result of the __percpu annotation). >> >> Pretend that __hyp_this_cpu_ptr() knows what it is doing by >> forcefully casting the pointer with __kernel __force. >> >> Signed-off-by: Marc Zyngier >> --- >> arch/arm64/include/asm/kvm_asm.h | 9 +++++++-- >> 1 file changed, 7 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/include/asm/kvm_asm.h >> b/arch/arm64/include/asm/kvm_asm.h >> index 0c9b5fc4ba0a..82691406d493 100644 >> --- a/arch/arm64/include/asm/kvm_asm.h >> +++ b/arch/arm64/include/asm/kvm_asm.h >> @@ -81,12 +81,17 @@ extern u32 __kvm_get_mdcr_el2(void); >> >> extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; >> >> -/* Home-grown __this_cpu_{ptr,read} variants that always work at HYP >> */ >> +/* >> + * Home-grown __this_cpu_{ptr,read} variants that always work at HYP, >> + * provided that sym is really a *symbol* and not a pointer obtained >> from > > Look at `this_cpu_ptr` one thing that stood out was `__verify_pcpu_ptr` > that is documented to be suitable for used in custom per CPU macros. I > didn't get how it worked (a type check?) but maybe it would work here > to validate the argment was indeed a per CPU symbol? It only works for sparse, but that is definitely a good addition while we're fixing the sparse compliance. Thanks, M. -- Jazz is not dead. It just smells funny...