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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, 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 E4EE9C433E0 for ; Mon, 18 May 2020 22:53:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BBD1C20829 for ; Mon, 18 May 2020 22:53:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GXnDhDr0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728182AbgERWxe (ORCPT ); Mon, 18 May 2020 18:53:34 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:52305 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726500AbgERWxe (ORCPT ); Mon, 18 May 2020 18:53:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1589842413; 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=Ge02D+vMtH+KKLBjcerJB21jPgtxIQMEv9lA24a7Lpg=; b=GXnDhDr0/LfdbSUpOjmTBfICTY+Nqb2GA6xTX+umgXiatyudp4QjgIpbcjqf5KGLEPSR1I zHyjJ8yAwCewNC6qTJONiw6kAB1ks+xgZ3jG+uFOGQ3WFAA54TZb7JTptIvoHxrzMPLPdf RMIWAaCsNZ9B+BrQzZ04+9ee1R5XhV8= 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-191-DotPqO2TMOuWWHAGZDGNFw-1; Mon, 18 May 2020 18:53:29 -0400 X-MC-Unique: DotPqO2TMOuWWHAGZDGNFw-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 69F21460; Mon, 18 May 2020 22:53:28 +0000 (UTC) Received: from treble (ovpn-113-47.rdu2.redhat.com [10.10.113.47]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BA3AD1C92D; Mon, 18 May 2020 22:53:27 +0000 (UTC) Date: Mon, 18 May 2020 17:53:25 -0500 From: Josh Poimboeuf To: Arnd Bergmann Cc: Peter Zijlstra , Linux Kernel Mailing List , clang-built-linux Subject: Re: objtool warning breaks build for fs/dlm/lock.o Message-ID: <20200518225325.is5ojipcc5uq5y5n@treble> References: <20200507232941.jccuywl56bppxfyp@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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 18, 2020 at 09:57:50PM +0200, Arnd Bergmann wrote: > On Fri, May 8, 2020 at 1:29 AM Josh Poimboeuf wrote: > > > > On Wed, May 06, 2020 at 04:07:25PM +0200, Arnd Bergmann wrote: > > > Hi, > > > > > > During randconfig testing with clang-10 I came across a number > > > of additional objtool warnings, I'll send another mail about those > > > when I have collected more information and some object files. > > > > > > This one sticks out however, as objtool returns an error code that > > > stops the build: > > > > > fs/dlm/lock.o: warning: objtool: __receive_convert_reply()+0x1e5: can't find jump dest instruction at .text+0xcaa7 > > > > Thanks for sending the patch for this one. Objtool always gets confused > > by new compiler versions, I really think we need to revert > > > > 644592d32837 ("objtool: Fail the kernel build on fatal errors") > > > > because objtool is never going to be reliable enough such that we can be > > confident that failing the build is the right thing to do. > > I'm now struggling with a clang -fintegrated-as related failure: > > arch/x86/kernel/ftrace_64.o: warning: objtool: missing symbol for insn at offset 0x16 > make[4]: *** [/git/arm-soc/scripts/Makefile.build:355: > arch/x86/kernel/ftrace_64.o] Error 255 > > Using this as a local workaround, but I'd like to find out if this is a bug > in clang or in objtool: It seems like an objtool bug, though at first glance I don't know where exactly. It could be a problem with the rb-tree stuff Peter added recently. That instruction should be part of the __fentry__ function: 4: 0000000000000000 165 FUNC GLOBAL DEFAULT 3 __fentry__ So find_symbol_containing() should associate it with __fentry__. -- Josh