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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 1967DC4363A for ; Thu, 22 Oct 2020 07:26:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3D9C22248 for ; Thu, 22 Oct 2020 07:26:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="aUN68Sfz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2508493AbgJVH0W (ORCPT ); Thu, 22 Oct 2020 03:26:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2508492AbgJVH0W (ORCPT ); Thu, 22 Oct 2020 03:26:22 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 161C3C0613CE; Thu, 22 Oct 2020 00:26:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=h+rKHFkcR5k6QSt8CeK8lSdFFr+MaETwBr6Mxg4PDmU=; b=aUN68SfzWTPeVbTNit8fy/ZXb0 rRAYaTV5InvSpscM+g5V5UNuxxMIOSNNjdTrr9zBJwTDnIr7HB4kAtF5eelSvpZSzfzi0XB65k49y fMhVyhLkrBDvMABUemD6zpOEa+Q8IzTJx4IZksVwvVIaYHLDJx476sb1mRX2HLMmaKAybchSbXO5G h2Y+yNlzpY2780AC98N7ePm2EJ79MCEo33CoAfryNdBPReXIr4iTyNLwA3Ag8rPF1QkdzEXKCnmAv 01B8rB6S0TBGhXUXekjoFY4MHksCyJY7O4ahmGFdB9hvjhmJ+hNdIUNrUYqknMjnfiTaSOjgjEbDG qxHU9c4w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kVUyy-0002dT-Ax; Thu, 22 Oct 2020 07:25:56 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 8E3203010D2; Thu, 22 Oct 2020 09:25:53 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 7DE3B21463180; Thu, 22 Oct 2020 09:25:53 +0200 (CEST) Date: Thu, 22 Oct 2020 09:25:53 +0200 From: Peter Zijlstra To: Josh Poimboeuf Cc: Sami Tolvanen , Jann Horn , the arch/x86 maintainers , Masahiro Yamada , Steven Rostedt , Will Deacon , Greg Kroah-Hartman , "Paul E. McKenney" , Kees Cook , Nick Desaulniers , clang-built-linux , Kernel Hardening , linux-arch , Linux ARM , linux-kbuild , kernel list , linux-pci@vger.kernel.org Subject: Re: [PATCH v6 22/25] x86/asm: annotate indirect jumps Message-ID: <20201022072553.GN2628@hirez.programming.kicks-ass.net> References: <20201013003203.4168817-23-samitolvanen@google.com> <20201015102216.GB2611@hirez.programming.kicks-ass.net> <20201015203942.f3kwcohcwwa6lagd@treble> <20201020185217.ilg6w5l7ujau2246@treble> <20201021085606.GZ2628@hirez.programming.kicks-ass.net> <20201021093213.GV2651@hirez.programming.kicks-ass.net> <20201021212747.ofk74lugt4hhjdzg@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201021212747.ofk74lugt4hhjdzg@treble> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Oct 21, 2020 at 04:27:47PM -0500, Josh Poimboeuf wrote: > On Wed, Oct 21, 2020 at 11:32:13AM +0200, Peter Zijlstra wrote: > > On Wed, Oct 21, 2020 at 10:56:06AM +0200, Peter Zijlstra wrote: > > > > > I do not see these in particular, although I do see a lot of: > > > > > > "sibling call from callable instruction with modified stack frame" > > > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x10a: sibling call from callable instruction with modified stack frame > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x99: (branch) > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x3e: (branch) > > defconfig-build/vmlinux.o: warning: objtool: msr_write()+0x0: <=== (sym) > > > > $ nm defconfig-build/vmlinux.o | grep msr_write > > 0000000000043250 t msr_write > > 00000000004289c0 T msr_write > > 0000000000003056 t msr_write.cold > > > > Below 'fixes' it. So this is also caused by duplicate symbols. > > There's a new linker flag for renaming duplicates: > > https://sourceware.org/bugzilla/show_bug.cgi?id=26391 > > But I guess that doesn't help us now. Well, depends a bit if clang can do it; we only need this for LTO builds for now. > I don't have access to GCC 10 at the moment so I can't recreate it. > Does this fix it? Doesn't seem to do the trick :/ I'll try and have a poke later.