From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1MVtne-00061p-SM for mharc-grub-devel@gnu.org; Tue, 28 Jul 2009 17:01:30 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MVtna-0005yq-5j for grub-devel@gnu.org; Tue, 28 Jul 2009 17:01:26 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MVtnV-0005vB-10 for grub-devel@gnu.org; Tue, 28 Jul 2009 17:01:25 -0400 Received: from [199.232.76.173] (port=40412 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MVtnU-0005v0-My for grub-devel@gnu.org; Tue, 28 Jul 2009 17:01:20 -0400 Received: from xvm-190-8.ghst.net ([217.70.190.8]:47916 helo=aybabtu.com) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MVtnU-0007kC-2S for grub-devel@gnu.org; Tue, 28 Jul 2009 17:01:20 -0400 Received: from [192.168.10.10] (helo=thorin) by aybabtu.com with esmtp (Exim 4.69) (envelope-from ) id 1MVtn6-0001DX-4N for grub-devel@gnu.org; Tue, 28 Jul 2009 21:00:56 +0000 Received: from rmh by thorin with local (Exim 4.69) (envelope-from ) id 1MVqtO-00007r-VL for grub-devel@gnu.org; Tue, 28 Jul 2009 19:55:14 +0200 Date: Tue, 28 Jul 2009 19:55:14 +0200 From: Robert Millan To: The development of GRUB 2 Message-ID: <20090728175514.GE32726@thorin> References: <1248454704.3510.67.camel@fz.local> <1248463471.3510.77.camel@fz.local> <20090725163636.GL12326@thorin> <1248559576.11389.33.camel@mj> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: GNU/Linux 2.6 (newer, 3) Subject: Re: [PATCH] fix an infinite loop with a corrupted pc partition table 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: Tue, 28 Jul 2009 21:01:27 -0000 On Sun, Jul 26, 2009 at 12:58:59AM +0200, Vladimir 'phcoder' Serbinenko wrote: > + /* This is our loop-detection algorithm. It works the following way: > + It saves last position which was a power of two. Then it compares the > + saved value with a current one. This way it's guaranteed that the loop > + will be broken by at most third walk. > + */ > + if (lastaddr == p.offset) > + return grub_error (GRUB_ERR_BAD_PART_TABLE, "loop detected"); > + > + labeln++; > + if (labeln == (lastlabeln << 1)) > + { > + lastaddr = p.offset; > + lastlabeln <<= 1; > + } I would prefer something simpler, but if that's not possible, this is better than hardcoding a number IMO. Unless Pavel has any objection, I think it's ok. -- 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."