Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754720Ab2HTI2K (ORCPT ); Mon, 20 Aug 2012 04:28:10 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:43106 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753906Ab2HTI2H (ORCPT ); Mon, 20 Aug 2012 04:28:07 -0400 MIME-Version: 1.0 In-Reply-To: <1345450620.2848.12.camel@sauron.fi.intel.com> References: <1341937423-16516-1-git-send-email-richard.genoud@gmail.com> <1341937423-16516-5-git-send-email-richard.genoud@gmail.com> <20120816115713.726da8f2@pixies.home.jungo.com> <20120816134234.32b468f6@pixies.home.jungo.com> <1345124012.3393.239.camel@sauron.fi.intel.com> <20120819100946.646cbb8a@pixies.home.jungo.com> <1345403092.1930.4.camel@kyv> <1345450620.2848.12.camel@sauron.fi.intel.com> From: Richard Genoud Date: Mon, 20 Aug 2012 10:27:45 +0200 Message-ID: Subject: Re: [PATCH 4/4] UBI: replace MTD_UBI_BEB_LIMIT with user-space parameter To: dedekind1@gmail.com Cc: Shmulik Ladkani , linux-mtd@lists.infradead.org, David Woodhouse , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1481 Lines: 40 2012/8/20 Artem Bityutskiy : > On Mon, 2012-08-20 at 08:55 +0200, Richard Genoud wrote: >> Hi Artem, >> 2012/8/19 Artem Bityutskiy : >> > Yeah, I wanted to make it 1..256 but forgot, will do now. 0..256 would >> > need some more work to avoid division by 0. >> Division by 0 is handled in the get_bad_peb_limit() function, I don't >> see another dangerous place. > > if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs) > > will divide by 0 if max_beb_per1024 is 0. > just a few lines before, you've got: /* * We don't want a division by 0, and having max_beb_per1024 == 0 is ok */ if (!max_beb_per1024) return 0; from commit abae1f1 (or I'm not looking at the right line ?) >> (and if we want to be coherent with user-space, it should be 0..255, >> as the range is coded with an u8) > > I think it should be uint16_t instead, because we are defining ABI here > and we should not assume no one will ever nee values higher than 255. I agree with you, even if 25% of reserved space for bad block seems insane, we never know... I'll update that. -- for me, ck means con kolivas and not calvin klein... does it mean I'm a geek ? -- 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/