From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933426AbYA2TAc (ORCPT ); Tue, 29 Jan 2008 14:00:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752426AbYA2TAV (ORCPT ); Tue, 29 Jan 2008 14:00:21 -0500 Received: from smtp5.pp.htv.fi ([213.243.153.39]:34909 "EHLO smtp5.pp.htv.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751881AbYA2TAT (ORCPT ); Tue, 29 Jan 2008 14:00:19 -0500 Date: Tue, 29 Jan 2008 21:00:46 +0200 From: Adrian Bunk To: Sam Ravnborg Cc: linux-kernel@vger.kernel.org Subject: Re: sections mismatches: How to mark new false positives? Message-ID: <20080129190046.GR8767@does.not.exist> References: <20080129170255.GP8767@does.not.exist> <20080129181305.GB14056@uranus.ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20080129181305.GB14056@uranus.ravnborg.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 29, 2008 at 07:13:06PM +0100, Sam Ravnborg wrote: > On Tue, Jan 29, 2008 at 07:02:55PM +0200, Adrian Bunk wrote: > > I'm getting the following in the latest -git: > > > > <-- snip --> > > > > ... > > WARNING: arch/x86/kernel/built-in.o(.exit.text+0x1db): Section mismatch in reference from the function msr_exit() to the variable .cpuinit.data:msr_class_cpu_notifier > > ... > > > > <-- snip --> > > > > That's obviously a false positive (unregister_hotcpu_notifier() is a > > noop if CONFIG_HOTPLUG_CPU=n), but how can I silence the warning? > > What is the purpose of __cpuinit? > It seems to be used for two purposes: > > To annotate code that is used to initialize cpu's > if CONFIG_HOTPLUG_CPU=n then discard it after > init has completed > if CONFIG_HOTPLUG_CPU=y then keep it > > To annotate all 'core' cpu hotplug related code > if CONFIG_HOTPLUG_CPU=n then it is not used and > can safely be discarded > if CONFIG_HOTPLUG_CPU=y then keep it > > And the variable msr_class_cpu_notifier belongs to the last category. > So the root cause of all the __cpu* related section mismatch > warnings are the misuse of __cpuinit to mark all core functions. > > How are we going to fix this? > > I see a couple of possibilities: > > 1) annotate like hell to hide the misuse of __cpuinit > 2) introduce __cpu to make cpu hotplug 'core' stuff > 3) drop section mismatch checks for __cpu stuff My main point is not related to __cpu* E.g. look at the following warnings: WARNING: drivers/pci/built-in.o(.text+0xa385): Section mismatch in reference from the function cpci_configure_slot() to the function .devinit.text:pci_do_scan_bus() WARNING: drivers/pci/built-in.o(.text+0x13052): Section mismatch in reference from the function cpqhp_configure_device() to the function .devinit.text:pci_do_scan_bus() WARNING: drivers/pci/built-in.o(.text+0x1561c): Section mismatch in reference from the function ibm_configure_device() to the function .devinit.text:pci_do_scan_bus() WARNING: drivers/pci/built-in.o(.text+0x26176): Section mismatch in reference from the function shpchp_configure_device() to the function .devinit.text:pci_do_scan_bus() The code seems to be 100% correct, but how can I silence the warnings without needlessly bloating the kernel in the CONFIG_HOTPLUG=n case? > Sam cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed