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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 44D2EC33CB3 for ; Wed, 29 Jan 2020 00:47:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 12DE021739 for ; Wed, 29 Jan 2020 00:47:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580258823; bh=HlE3Pgkk7dDEKRsCD3nPkyOTqjP2QeWR8StyZLq5bEU=; h=Date:From:To:cc:Subject:In-Reply-To:References:List-ID:From; b=sAFRP0DB4LdBL9EyIyaBy0CwPBtCrH0I5bxoB3jNVFzgyaETI5CId+WINSZ661cNS m2Z0pp+lYT/2z0L9lkRUeh7Z8TMshAE3qYR8CyUfws4nMEBYLMUpTJ0F8ki0vAdgWR wkN6av+F7YtLuOTbvCgwtotzeZjC3AmSbAGBGgOM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730443AbgA2ArC (ORCPT ); Tue, 28 Jan 2020 19:47:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:34932 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726487AbgA2ArB (ORCPT ); Tue, 28 Jan 2020 19:47:01 -0500 Received: from pobox.suse.cz (prg-ext-pat.suse.com [213.151.95.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EE5D92073A; Wed, 29 Jan 2020 00:46:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580258821; bh=HlE3Pgkk7dDEKRsCD3nPkyOTqjP2QeWR8StyZLq5bEU=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=ejFuWz0R0R5TUCGRjF1ncZbRCpNQnOzeg4EbChz9OwyAw/MXIMQ0RSbDFvmatWHiN p2yt1ooPKKzdqA08a1zpdEFEkZnsraGQGqnIpixjfh2zWKgVH0MT5+3zncz83HVsYd BHKAm0jnw6VbpsPEdkGqJTfVrhTdl+8+n222325Q= Date: Wed, 29 Jan 2020 01:46:55 +0100 (CET) From: Jiri Kosina To: Josh Poimboeuf cc: Petr Mladek , Miroslav Benes , Peter Zijlstra , Steven Rostedt , Joe Lawrence , Jessica Yu , x86@kernel.org, linux-kernel@vger.kernel.org, mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com, torvalds@linux-foundation.org, tglx@linutronix.de, mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org, ard.biesheuvel@linaro.org, live-patching@vger.kernel.org, Randy Dunlap Subject: Re: [PATCH v3 5/6] x86/ftrace: Use text_poke() In-Reply-To: <20200128170254.igb72ib5n7lvn3ds@treble> Message-ID: References: <20191016074217.GL2328@hirez.programming.kicks-ass.net> <20191021150549.bitgqifqk2tbd3aj@treble> <20200120165039.6hohicj5o52gdghu@treble> <20200121161045.dhihqibnpyrk2lsu@treble> <20200122214239.ivnebi7hiabi5tbs@treble> <20200128150014.juaxfgivneiv6lje@treble> <20200128154046.trkpkdaz7qeovhii@pathway.suse.cz> <20200128170254.igb72ib5n7lvn3ds@treble> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 Jan 2020, Josh Poimboeuf wrote: > > Anyway, I think that we might make your life easier with using the > > proposed -Wsuggest-attribute=noreturn. > > Maybe. Though if I understand correctly, this doesn't help for any of > the new warnings because they're for static functions, and this only > warns about global functions. Could you please provide a pointer where those have been reported/analyzed? For the cases I've seen so far, it has always been gcc deciding under certain circumstances not to propagate __attribute__((__noreturn__)) from callee to caller even in the cases when caller unconditionally called callee. AFAIU, the behavior is (and always will) be dependent on the state of gcc optimizations, and therefore I don't see any other way than adding __noreturn anotation transitively everywhere in order to silence objtool. So those cases have to be fixed anyway. What are the other cases please? Either I have completely missed those, or they haven't been mentioned in this thread. Thanks, -- Jiri Kosina SUSE Labs