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 2DB88C433EF for ; Wed, 13 Jul 2022 16:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237190AbiGMQ1P (ORCPT ); Wed, 13 Jul 2022 12:27:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237165AbiGMQ1L (ORCPT ); Wed, 13 Jul 2022 12:27:11 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9C4FB60FE; Wed, 13 Jul 2022 09:27:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 7DB6ECE231F; Wed, 13 Jul 2022 16:27:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BE32C34114; Wed, 13 Jul 2022 16:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657729625; bh=QsCvpn2gWQQ1jAoqmKwmo/Cv3eyEdtKIBceRVgAOtxA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AZPtdVxsPialzeevmLca0Myws6u+ggFFxfdSyrByJNe/SP5gpXevDD1NpAM8cu8sC BpDecMgFuJS7TdqW7J7+2GuZoBqeA+p0aZ5rz6xC6j+TPlqCBESwHEIuU9vQVg8ikJ qzDNd3RNsCqqRR64oyz+o/dACayVru8aCSpxjbvOKKZuk0kGxSLMq2mApVn4lRTsmW 3sMjxNwZMNkmQkKWNE+YZ2b4J1yXbHzoKpGcyEcsBR0ThC4L9+JfbBl1OqpXLK4m8k AmXW35S/ShAEifVdHrvvJzQxTASyBbNiw7N0IFsBWM+B5ndKuLoqe0daeHdKZlyBqY OfEf5gs73l3GQ== Date: Wed, 13 Jul 2022 09:27:03 -0700 From: Nathan Chancellor To: Peter Zijlstra Cc: Linus Torvalds , x86@kernel.org, Nick Desaulniers , Josh Poimboeuf , linux-kernel@vger.kernel.org, llvm@lists.linux.dev, stable@vger.kernel.org, kernel test robot Subject: Re: [PATCH v2] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current Message-ID: References: <20220713152436.2294819-1-nathan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 13, 2022 at 06:22:41PM +0200, Peter Zijlstra wrote: > On Wed, Jul 13, 2022 at 08:24:37AM -0700, Nathan Chancellor wrote: > > Clang warns: > > > > arch/x86/kernel/cpu/bugs.c:58:21: error: section attribute is specified on redeclared variable [-Werror,-Wsection] > > DEFINE_PER_CPU(u64, x86_spec_ctrl_current); > > ^ > > arch/x86/include/asm/nospec-branch.h:283:12: note: previous declaration is here > > extern u64 x86_spec_ctrl_current; > > ^ > > 1 error generated. > > > > The declaration should be using DECLARE_PER_CPU instead so all > > attributes stay in sync. > > > > Cc: stable@vger.kernel.org > > Fixes: fc02735b14ff ("KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS") > > Reported-by: kernel test robot > > Signed-off-by: Nathan Chancellor > > --- > > > > v1 -> v2: https://lore.kernel.org/20220713152222.1697913-1-nathan@kernel.org/ > > > > * Use asm/percpu.h instead of linux/percpu.h to avoid static call > > include errors. > > > > arch/x86/include/asm/nospec-branch.h | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h > > index bb05ed4f46bd..10a3bfc1eb23 100644 > > --- a/arch/x86/include/asm/nospec-branch.h > > +++ b/arch/x86/include/asm/nospec-branch.h > > @@ -11,6 +11,7 @@ > > #include > > #include > > #include > > +#include > > > > #define RETPOLINE_THUNK_SIZE 32 > > > > When I tried this earlier today I ran into cyclic headers, you sure this > works? Yes, I did my regular set of x86 builds with clang and they all passed. Cheers, Nathan