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=-6.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 712D8C55ABD for ; Fri, 13 Nov 2020 22:56:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34A9A2225B for ; Fri, 13 Nov 2020 22:56:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="U9Pli40N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726199AbgKMW4c (ORCPT ); Fri, 13 Nov 2020 17:56:32 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:60982 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726094AbgKMW4a (ORCPT ); Fri, 13 Nov 2020 17:56:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605308189; 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=PXuUO/jzK6PC0ArsPRfFmIFBybv98p5k0ll08mBK9vw=; b=U9Pli40NwWQRepbitv4YCZsEAM77o6qhj1hOBLr3VZzEfI94FF5413vLM2wo4B1oS9Y6E7 v8SBULUFzVH5LYx9Q+rYqlBAHI7gl4zSyp3F7OGcgQGR0vUw2Br33b8H3SzYFGw+Ucn3Ep aSzBT2suv+yDgl2rvpWoLceP8t8/Kpo= 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-562-gA0AbIuzMxWJynkYsYRo7A-1; Fri, 13 Nov 2020 17:56:25 -0500 X-MC-Unique: gA0AbIuzMxWJynkYsYRo7A-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id C331A87309E; Fri, 13 Nov 2020 22:56:22 +0000 (UTC) Received: from treble (ovpn-117-69.rdu2.redhat.com [10.10.117.69]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 47C611A3D6; Fri, 13 Nov 2020 22:56:16 +0000 (UTC) Date: Fri, 13 Nov 2020 16:56:14 -0600 From: Josh Poimboeuf To: Sami Tolvanen Cc: Peter Zijlstra , 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: <20201113225614.ry73o4knb6mvv4dq@treble> References: <20201023173617.GA3021099@google.com> <20201110022924.tekltjo25wtrao7z@treble> <20201110174606.mp5m33lgqksks4mt@treble> <20201113195408.atbpjizijnhuinzy@treble> <20201113223412.inono2ekrs7ky7rm@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Nov 13, 2020 at 02:54:32PM -0800, Sami Tolvanen wrote: > On Fri, Nov 13, 2020 at 2:34 PM Josh Poimboeuf wrote: > > > > On Fri, Nov 13, 2020 at 12:24:32PM -0800, Sami Tolvanen wrote: > > > > I still don't see this warning for some reason. > > > > > > Do you have CONFIG_XEN enabled? I can reproduce this on ToT master as follows: > > > > > > $ git rev-parse HEAD > > > 585e5b17b92dead8a3aca4e3c9876fbca5f7e0ba > > > $ make defconfig && \ > > > ./scripts/config -e HYPERVISOR_GUEST -e PARAVIRT -e XEN && \ > > > make olddefconfig && \ > > > make -j110 > > > ... > > > $ ./tools/objtool/objtool check -arfld vmlinux.o 2>&1 | grep secondary > > > vmlinux.o: warning: objtool: __startup_secondary_64()+0x2: return with > > > modified stack frame > > > > > > > Is it fixed by adding cpu_bringup_and_idle() to global_noreturns[] in > > > > tools/objtool/check.c? > > > > > > No, that didn't fix the warning. Here's what I tested: > > > > I think this fixes it: > > > > From: Josh Poimboeuf > > Subject: [PATCH] x86/xen: Fix objtool vmlinux.o validation of xen hypercalls > > > > Objtool vmlinux.o validation is showing warnings like the following: > > > > # tools/objtool/objtool check -barfld vmlinux.o > > vmlinux.o: warning: objtool: __startup_secondary_64()+0x2: return with modified stack frame > > vmlinux.o: warning: objtool: xen_hypercall_set_trap_table()+0x0: <=== (sym) > > > > Objtool falls through all the empty hypercall text and gets confused > > when it encounters the first real function afterwards. The empty unwind > > hints in the hypercalls aren't working for some reason. Replace them > > with a more straightforward use of STACK_FRAME_NON_STANDARD. > > > > Reported-by: Sami Tolvanen > > Signed-off-by: Josh Poimboeuf > > --- > > arch/x86/xen/xen-head.S | 9 ++++----- > > include/linux/objtool.h | 8 ++++++++ > > 2 files changed, 12 insertions(+), 5 deletions(-) > > Confirmed, this fixes the warning, also in LTO builds. Thanks! > > Tested-by: Sami Tolvanen Good... I'll work through the rest of them. -- Josh