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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 39FF6C6379D for ; Wed, 21 Oct 2020 08:57:41 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C53FC22251 for ; Wed, 21 Oct 2020 08:57:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="hpEZI0bD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C53FC22251 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=0SlTvbQplCEDNLkOPIZVGB7C1AlJunvHxXhtTq7YxmA=; b=hpEZI0bD2SyPcOZpaCgpge6Kl dEDCNPxbXW6r8SRdS4NDT3u0jGlxbuie/ZbAWsLiijY93oSdBeh34DcdzVnXAQL1Oit1VQGofYyo1 T4/TCJsjsKy3IE/hhhZQjvM8XjhVcyOHu057ruXSy/kH2mDbtEnNVLwRtVz2CFAseEAD/f40DXIzf 1J3ZKVI4Sm7KiS0OikiS4y/kRyX1pe/RMMQPJ1JgXoMfK8gv2hVC+oml9YJ1nGHS3RCm6inej9ll/ wVP/Hi2JS8zB9VfcHWhSejegVe7v6HEhVYCKime6AlIws9T24/oxBD1McG1zvVa6tGL4+IT3nsoPE goM4t5CSQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kV9uo-0000o9-0v; Wed, 21 Oct 2020 08:56:14 +0000 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 1kV9uj-0000lf-BR; Wed, 21 Oct 2020 08:56:09 +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 D00FE304BAE; Wed, 21 Oct 2020 10:56:06 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C3AF5203CC497; Wed, 21 Oct 2020 10:56:06 +0200 (CEST) Date: Wed, 21 Oct 2020 10:56:06 +0200 From: Peter Zijlstra To: Sami Tolvanen Subject: Re: [PATCH v6 22/25] x86/asm: annotate indirect jumps Message-ID: <20201021085606.GZ2628@hirez.programming.kicks-ass.net> References: <20201013003203.4168817-1-samitolvanen@google.com> <20201013003203.4168817-23-samitolvanen@google.com> <20201015102216.GB2611@hirez.programming.kicks-ass.net> <20201015203942.f3kwcohcwwa6lagd@treble> <20201020185217.ilg6w5l7ujau2246@treble> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch , Kees Cook , "Paul E. McKenney" , Jann Horn , linux-pci@vger.kernel.org, Greg Kroah-Hartman , Masahiro Yamada , the arch/x86 maintainers , Nick Desaulniers , kernel list , Steven Rostedt , linux-kbuild , clang-built-linux , Josh Poimboeuf , Kernel Hardening , Will Deacon , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Oct 20, 2020 at 12:24:37PM -0700, Sami Tolvanen wrote: > > > Building allyesconfig with this series and LTO enabled, I still see > > > the following objtool warnings for vmlinux.o, grouped by source file: > > > > > > arch/x86/entry/entry_64.S: > > > __switch_to_asm()+0x0: undefined stack state > > > .entry.text+0xffd: sibling call from callable instruction with > > > modified stack frame > > > .entry.text+0x48: stack state mismatch: cfa1=7-8 cfa2=-1+0 > > > > Not sure what this one's about, there's no OBJECT_FILES_NON_STANDARD? > > Correct, because with LTO, we won't have an ELF binary to process > until we compile everything into vmlinux.o, and at that point we can > no longer skip individual object files. I think what Josh was trying to say is; this file is subject to objtool on a normal build and does not generate warnings. So why would it generate warnings when subject to objtool as result of a vmlinux run (due to LTO or otherwise). In fact, when I build a x86_64-defconfig and then run: $ objtool check -barf defconfig-build/vmlinux.o I do not see these in particular, although I do see a lot of: "sibling call from callable instruction with modified stack frame" "falls through to next function" that did not show up in the individual objtool runs during the build. The "falls through to next function" seems to be limited to things like: warning: objtool: setup_vq() falls through to next function setup_vq.cold() warning: objtool: e1000_xmit_frame() falls through to next function e1000_xmit_frame.cold() So something's weird with the .cold thing on vmlinux.o runs. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel