From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1LiVFa-0000FK-Bn for mharc-grub-devel@gnu.org; Sat, 14 Mar 2009 10:54:10 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LiVFY-0000Ef-PT for grub-devel@gnu.org; Sat, 14 Mar 2009 10:54:08 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LiVFT-0000D5-7J for grub-devel@gnu.org; Sat, 14 Mar 2009 10:54:07 -0400 Received: from [199.232.76.173] (port=43683 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LiVFT-0000D0-57 for grub-devel@gnu.org; Sat, 14 Mar 2009 10:54:03 -0400 Received: from aybabtu.com ([69.60.117.155]:60510) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LiVFS-000363-LN for grub-devel@gnu.org; Sat, 14 Mar 2009 10:54:02 -0400 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1LiV6s-00035N-Rm for grub-devel@gnu.org; Sat, 14 Mar 2009 15:45:11 +0100 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1LiVFN-0003X4-9X for grub-devel@gnu.org; Sat, 14 Mar 2009 15:53:57 +0100 Date: Sat, 14 Mar 2009 15:53:57 +0100 From: Robert Millan To: The development of GRUB 2 Message-ID: <20090314145357.GB13451@thorin> References: <49AB29BA.6040609@gmail.com> <20090311211541.GC29956@thorin> <49B82B65.3080506@gmail.com> <20090313191442.GC17068@thorin> <49BAC506.2030006@gmail.com> <20090313224629.GA781@thorin> <49BAE5B9.4020303@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49BAE5B9.4020303@gmail.com> Organization: free as in freedom X-Message-Flag: Worried about Outlook viruses? Switch to Thunderbird! www.mozilla.com/thunderbird X-Debbugs-No-Ack: true User-Agent: Mutt/1.5.18 (2008-05-17) X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. Subject: Re: ELF bugfixes X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 Mar 2009 14:54:08 -0000 On Sat, Mar 14, 2009 at 12:01:13AM +0100, phcoder wrote: > Robert Millan wrote: >> On Fri, Mar 13, 2009 at 09:41:42PM +0100, phcoder wrote: >>> Robert Millan wrote: >>>> On Wed, Mar 11, 2009 at 10:21:41PM +0100, phcoder wrote: >>>>> Robert Millan wrote: >>>>>> On Mon, Mar 02, 2009 at 01:35:06AM +0100, phcoder wrote: >>>>>>> + * include/grub/elf.h: added missing attributes >>>>>> This should be a bit more descriptive. >>>>>> >>>>>>> for (i = 0; i < ehdr->e_phnum; i++) >>>>>>> if (phdr(i)->p_type == PT_LOAD && phdr(i)->p_filesz != 0) >>>>>>> { >>>>>>> - if (phdr(i)->p_paddr < phdr(lowest_segment)->p_paddr) >>>>>>> + if (lowest_segment == -1 + || phdr(i)->p_paddr < >>>>>>> phdr(lowest_segment)->p_paddr) >>>>>>> lowest_segment = i; >>>>>>> - if (phdr(i)->p_paddr > phdr(highest_segment)->p_paddr) >>>>>>> + if (highest_segment == -1 >>>>>>> + || phdr(i)->p_paddr > phdr(highest_segment)->p_paddr) >>>>>>> highest_segment = i; >>>>>>> } >>>>>> Why? >>>>> Because if first segment doesn't have the PT_LOAD attribute set >>>>> then it should be considered in this comparison >>>> But you didn't remove the PT_LOAD check. And in the routine below that >>>> does the actual segment load, we still check for PT_LOAD. Those should be >>>> consistent, right? >>>> >>> No I expressed myself badly. Original code assumed that first segment >>> has PT_LOAD always set (lowest_segment is 0 initally). I removed >>> this assumption >> >> Why do we care about non-PT_LOAD segments? > > We don't but without this fix non-PT_LOAD segment 1 wasn't correctly ignored Oh, of course... This part of the patch is fine. Perhaps a comment would be a good idea, so we don't forget. -- Robert Millan The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and how) you may access your data; but nobody's threatening your freedom: we still allow you to remove your data and not access it at all."