Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935587AbXEWQgJ (ORCPT ); Wed, 23 May 2007 12:36:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761899AbXEWQfy (ORCPT ); Wed, 23 May 2007 12:35:54 -0400 Received: from pne-smtpout4-sn1.fre.skanova.net ([81.228.11.168]:37764 "EHLO pne-smtpout4-sn1.fre.skanova.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759703AbXEWQfx (ORCPT ); Wed, 23 May 2007 12:35:53 -0400 X-Greylist: delayed 4155 seconds by postgrey-1.27 at vger.kernel.org; Wed, 23 May 2007 12:35:52 EDT Message-ID: <46545C65.3030806@kolumbus.fi> Date: Wed, 23 May 2007 18:23:17 +0300 From: =?ISO-8859-1?Q?Mika_Penttil=E4?= User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Atsushi Nemoto CC: torvalds@linux-foundation.org, ben.collins@ubuntu.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, sam@ravnborg.org, dwmw2@infradead.org, adobriyan@gmail.com Subject: Re: [RFC] Crash on modpost, addend_386_rel() References: <20070522.142929.05161433.nemoto@toshiba-tops.co.jp> <20070522.182739.48825006.nemoto@toshiba-tops.co.jp> <465302A9.8080701@kolumbus.fi> <20070523.235103.128617660.anemo@mba.ocn.ne.jp> In-Reply-To: <20070523.235103.128617660.anemo@mba.ocn.ne.jp> Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1853 Lines: 46 Atsushi Nemoto wrote: > On Tue, 22 May 2007 17:48:09 +0300, Mika_Penttil? wrote: > >> I can't see how this use of r_attend is going to work. find_elf_symbol >> compares relsym->st_value to Elf_Rela->r_attend. I think it doesn't work >> for RELA archs and even with this patch for REL. >> > > It seems works fine with RELA archs, at least mips64. > > For example, set_up_list3s is correctly reported. > > WARNING: mm/built-in.o - Section mismatch: reference to .init.text:set_up_list3s from .text between 'kmem_cache_create' (at offset 0x26358) and 'cache_reap' > > Here is excerpt from readelf output. Addend value 0x21d8 matches > st_value of its target symbol. > > $ mips64-linux-readelf -sr ../build-sb1250/mm/built-in.o > Relocation section '.rela.text' at offset 0x33fe0 contains 5100 entries: > Offset Info Type Sym. Value Sym. Name + Addend > ... > 000000026358 000400000004 R_MIPS_26 0000000000000000 .init.text + 21d8 > Type2: R_MIPS_NONE > Type3: R_MIPS_NONE > ... > Symbol table '.symtab' contains 1652 entries: > Num: Value Size Type Bind Vis Ndx Name > ... > 746: 00000000000021d8 148 FUNC LOCAL DEFAULT 4 set_up_list3s > > --- > Atsushi Nemoto > > So with mips64 you are lucky because the relocation symbol is .init.text and hence addend matches (has to match) symbol's offset. I can't find any spec where it is stated that addend == address, maybe it's in mips64 abi or something. It is quite normal to have addend of 0. --Mika - 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/