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 3D986C55ABD for ; Fri, 13 Nov 2020 19:57:13 +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 BF1E821D79 for ; Fri, 13 Nov 2020 19:57:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="mvC/fAq0"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JThYnW4X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF1E821D79 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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=pIfL2wMj7H2B4sWdY5P3xJMi+BuGUicRbMYxie5MMGQ=; b=mvC/fAq0CzBZK7eKmmonz5pXx 9SsZV4qBKKhYNb5x/YgXjgeXA0m72KU6uXk2K47OXUPpK/KW+VQxTKay7P4bVrnoyqsuPd4X8IiUR hsvHowC0JMWsKQ5+bjydAWno5sddTefaHF0GHlyo9b349hW1Owg5nXGxQ/BN5HW2kMgW0oGMZGomm tGaLm1lcyStiRc1fqhpGjm9qBDhfUHumMfbaRzpgBzD2drX4O2TAU8h4DBlA+3ZHmn8lcJ3bmSx8B L9fs69nkExrgqGAon0Wds1GHoZ1OUJoNiIRRNNt6jCMFJnhvpkRXbNgMCa51t9cH0/p7fSWLmXNLt 2L61/g9NA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdfB1-0002WP-GC; Fri, 13 Nov 2020 19:56:07 +0000 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kdfAy-0002VP-ST for linux-arm-kernel@lists.infradead.org; Fri, 13 Nov 2020 19:56:05 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605297364; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=yYOZqfS1DftClANj54I945kAOQfBrrvPepHj2JAwlgE=; b=JThYnW4XO9agfLg/cF1rJLB90k59LJTU/A97oTViwAUPazSGkTLezAi1ZD8NE563A9rWBS baI61V6Pj0mhOMX+NZqLLLoaNxsd1+hqpImoqX9tIVXLlkmmXwMrisaPPoQroNwLFCPFoo okZA7sutQQ/ralbEDJHuC7fnU1q2Ukw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-192-o3eHZUV6NbaT1cJ-TJ4RWQ-1; Fri, 13 Nov 2020 14:54:18 -0500 X-MC-Unique: o3eHZUV6NbaT1cJ-TJ4RWQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8F5778730A8; Fri, 13 Nov 2020 19:54:15 +0000 (UTC) Received: from treble (ovpn-112-111.rdu2.redhat.com [10.10.112.111]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 54ADF62A16; Fri, 13 Nov 2020 19:54:11 +0000 (UTC) Date: Fri, 13 Nov 2020 13:54:08 -0600 From: Josh Poimboeuf To: Sami Tolvanen Subject: Re: [PATCH v6 22/25] x86/asm: annotate indirect jumps Message-ID: <20201113195408.atbpjizijnhuinzy@treble> References: <20201020185217.ilg6w5l7ujau2246@treble> <20201021085606.GZ2628@hirez.programming.kicks-ass.net> <20201023173617.GA3021099@google.com> <20201110022924.tekltjo25wtrao7z@treble> <20201110174606.mp5m33lgqksks4mt@treble> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201113_145604_947696_5D23ED99 X-CRM114-Status: GOOD ( 18.51 ) 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 , Peter Zijlstra , Greg Kroah-Hartman , Masahiro Yamada , the arch/x86 maintainers , Nick Desaulniers , kernel list , Steven Rostedt , linux-kbuild , clang-built-linux , linux-pci@vger.kernel.org, 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, Nov 10, 2020 at 10:59:55AM -0800, Sami Tolvanen wrote: > On Tue, Nov 10, 2020 at 9:46 AM Josh Poimboeuf wrote: > > > > On Mon, Nov 09, 2020 at 08:29:24PM -0600, Josh Poimboeuf wrote: > > > On Mon, Nov 09, 2020 at 03:11:41PM -0800, Sami Tolvanen wrote: > > > > CONFIG_XEN > > > > > > > > __switch_to_asm()+0x0: undefined stack state > > > > xen_hypercall_set_trap_table()+0x0: <=== (sym) > > > > With your branch + GCC 9 I can recreate all the warnings except this > > one. > > In a gcc build this warning is replaced with a different one: > > vmlinux.o: warning: objtool: __startup_secondary_64()+0x7: return with > modified stack frame > > This just seems to depend on which function is placed right after the > code in xen-head.S. With gcc, the disassembly looks like this: > > 0000000000000000 : > 0: e8 00 00 00 00 callq 5 > 1: R_X86_64_PLT32 cpu_bringup_and_idle-0x4 > 5: e9 f6 0f 00 00 jmpq 1000 > > ... > 0000000000001000 : > ... > ... > 0000000000002000 <__startup_secondary_64>: > > With Clang+LTO, we end up with __switch_to_asm here instead of > __startup_secondary_64. I still don't see this warning for some reason. Is it fixed by adding cpu_bringup_and_idle() to global_noreturns[] in tools/objtool/check.c? -- Josh _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel