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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 CF52AC433E0 for ; Fri, 8 Jan 2021 20:43:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 976FB23A68 for ; Fri, 8 Jan 2021 20:43:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729250AbhAHUn1 (ORCPT ); Fri, 8 Jan 2021 15:43:27 -0500 Received: from casper.infradead.org ([90.155.50.34]:51166 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726227AbhAHUnZ (ORCPT ); Fri, 8 Jan 2021 15:43:25 -0500 X-Greylist: delayed 398 seconds by postgrey-1.27 at vger.kernel.org; Fri, 08 Jan 2021 15:43:25 EST DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Fh1FiaPgximaUf/jTCpsygk/6dDJoGnbhcrl2nWi8C8=; b=HrVyzxCBV/pGgvd8ZD53/tfTMS IK7lQhcX5ydSWkAVEKKoQgNPiFRLnvTp6tNypCovPHhS9smNH3jfL8/mZEpAAo3AdJ3v0g7IfUfUs Xc7AFVJCMMBF3evvGocW6HybrPNUirdz+vm1wRTPvYQ2OfQqfVkTaeUyUjbrgIgFSLWbRRpmRkMqI kXfkd6gJpfM4gG2FVgpfmmQ+5AFRyt14P2JMQ9W1FN3dxmIOip/p0Nd35rRrODpooKJAsTGDa8fxG 3zVGhRwTXLgnWVXPqGhBHW8qzsPoVOt6g/Jd7MlM4AP+NDCEj4HoBpFJE2qXJvAAIm+eiylh4lcAW dH4Zfetw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1kxyY7-0003SS-Gg; Fri, 08 Jan 2021 20:40:35 +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 01D3F305C10; Fri, 8 Jan 2021 21:39:53 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C2C362C8F2DAA; Fri, 8 Jan 2021 21:39:53 +0100 (CET) Date: Fri, 8 Jan 2021 21:39:53 +0100 From: Peter Zijlstra To: Will Deacon Cc: Arnd Bergmann , Catalin Marinas , Arnd Bergmann , Nathan Chancellor , Nick Desaulniers , Boqun Feng , Mark Rutland , Herbert Xu , Thomas Gleixner , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH] arm64: make atomic helpers __always_inline Message-ID: References: <20210108092024.4034860-1-arnd@kernel.org> <20210108093258.GB4031@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210108093258.GB4031@willie-the-truck> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 08, 2021 at 09:32:58AM +0000, Will Deacon wrote: > Hi Arnd, > > On Fri, Jan 08, 2021 at 10:19:56AM +0100, Arnd Bergmann wrote: > > From: Arnd Bergmann > > > > With UBSAN enabled and building with clang, there are occasionally > > warnings like > > > > WARNING: modpost: vmlinux.o(.text+0xc533ec): Section mismatch in reference from the function arch_atomic64_or() to the variable .init.data:numa_nodes_parsed > > The function arch_atomic64_or() references > > the variable __initdata numa_nodes_parsed. > > This is often because arch_atomic64_or lacks a __initdata > > annotation or the annotation of numa_nodes_parsed is wrong. > > > > for functions that end up not being inlined as intended but operating > > on __initdata variables. Mark these as __always_inline, along with > > the corresponding asm-generic wrappers. > > Hmm, I don't fully grok this. Why does it matter if a non '__init' function > is called with a pointer to some '__initdata'? Or is the reference coming > from somewhere else? (where?). FWIW the x86 atomics are __always_inline in part due to the noinstr crud, which I imagine resulted in much the same 'fun'.