Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755153Ab2FERWN (ORCPT ); Tue, 5 Jun 2012 13:22:13 -0400 Received: from smtp.snhosting.dk ([87.238.248.203]:15637 "EHLO smtp.domainteam.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753663Ab2FERWM (ORCPT ); Tue, 5 Jun 2012 13:22:12 -0400 Date: Tue, 5 Jun 2012 19:22:08 +0200 From: Sam Ravnborg To: Jan Beulich Cc: x86@kernel.org, Don Zickus , LKML Subject: Re: [PATCH] x86,nmi: Fix section mismatch warnings on 32-bit Message-ID: <20120605172208.GA29862@merkur.ravnborg.org> References: <1338839763-11140-1-git-send-email-dzickus@redhat.com> <4FCDDB7D0200007800088390@nat28.tlf.novell.com> <20120605144734.GU32472@redhat.com> <20120605161318.GA29751@merkur.ravnborg.org> <4FCE4D800200007800088546@nat28.tlf.novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FCE4D800200007800088546@nat28.tlf.novell.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1995 Lines: 43 On Tue, Jun 05, 2012 at 05:18:40PM +0100, Jan Beulich wrote: > >>> On 05.06.12 at 18:13, Sam Ravnborg wrote: > > On Tue, Jun 05, 2012 at 10:47:34AM -0400, Don Zickus wrote: > >> On Tue, Jun 05, 2012 at 09:12:13AM +0100, Jan Beulich wrote: > >> > >>> On 04.06.12 at 21:56, Don Zickus wrote: > >> > > It was reported that compiling for 32-bit caused a bunch of section > >> > > mismatch warnings: > >> > > > >> > > VDSOSYM arch/x86/vdso/vdso32-syms.lds > >> > > LD arch/x86/vdso/built-in.o > >> > > LD arch/x86/built-in.o > >> > > WARNING: arch/x86/built-in.o(.data+0x5af0): Section mismatch in reference > >> > > from the variable > >> > > test_nmi_ipi_callback_na.10451 to the function > >> > > >> > Did you check what this (compiler introduced) variable actually > >> > represents? The problem clearly is that the compiler has no way > >> > of knowing that data it generates referencing an __init function > >> > would actually need to go into .init.data or alike. > >> > >> I do not know enough about behind the scene compiler magic to track this > >> down correctly. So any insight/help is greatly appreciated. :-) > > > > We register a function annotated __init. And the normal use of this > > register() > > is for functions that survive the init phase. > > So drop the __init annotation on the function we register and the mismatch > > is fixed. > > But in the case here the function really is being used at init time > only. This is only for testing. Ando nly if CONFIG_DEBUG_NMI_SELFTEST is set. > Plus it still escapes me why there would be differences in > behavior depending on bit-ness or compiler version. It is often different inline decisions that has influence. Sam -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/