Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752020AbZJQOnz (ORCPT ); Sat, 17 Oct 2009 10:43:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751274AbZJQOny (ORCPT ); Sat, 17 Oct 2009 10:43:54 -0400 Received: from mail-qy0-f194.google.com ([209.85.221.194]:33186 "EHLO mail-qy0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751180AbZJQOnw convert rfc822-to-8bit (ORCPT ); Sat, 17 Oct 2009 10:43:52 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=BPzWFucl65eTVKJ9hbHS2Vu3EK7vxE5dco/xKLI3hsugmyY04qsCR558BacsIHuT5H D6ev4BypcDUpQxNiHr+uMTp7A4RQ2Cvgpr+546X6lHwSQfYS+YsDTATgKF5l4YD0Z+Fz 7XyooSyEJHWcLIAodKI7ZwaSzN/h3snccuoP4= MIME-Version: 1.0 In-Reply-To: <20091017224028V.fujita.tomonori@lab.ntt.co.jp> References: <20091009164100.85a36188.akpm@linux-foundation.org> <20091013021818.GA3898@localhost.localdomain> <20091013091017.GA18431@localhost.localdomain> <20091017224028V.fujita.tomonori@lab.ntt.co.jp> Date: Sat, 17 Oct 2009 23:43:56 +0900 Message-ID: <961aa3350910170743n4c9947d1ka0bd31aa1c7b9917@mail.gmail.com> Subject: Re: [PATCH 2/8] bitmap: Introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area From: Akinobu Mita To: FUJITA Tomonori Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, davem@davemloft.net, sparclinux@vger.kernel.org, benh@kernel.crashing.org, paulus@samba.org, linuxppc-dev@ozlabs.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, gregkh@suse.de, LW@karo-electronics.de, linux-usb@vger.kernel.org, rolandd@cisco.com, yevgenyp@mellanox.co.il, netdev@vger.kernel.org, tony.luck@intel.com, fenghua.yu@intel.com, linux-ia64@vger.kernel.org, linux-altix@sgi.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1522 Lines: 46 2009/10/17 FUJITA Tomonori : > On Tue, 13 Oct 2009 18:10:17 +0900 > Akinobu Mita wrote: > >> My user space testing exposed off-by-one error find_next_zero_area >> in iommu-helper. Some zero area cannot be found by this bug. >> >> Subject: [PATCH] Fix off-by-one error in find_next_zero_area >> >> Signed-off-by: Akinobu Mita >> --- >> ?lib/iommu-helper.c | ? ?2 +- >> ?1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c >> index 75dbda0..afc58bc 100644 >> --- a/lib/iommu-helper.c >> +++ b/lib/iommu-helper.c >> @@ -19,7 +19,7 @@ again: >> ? ? ? index = (index + align_mask) & ~align_mask; >> >> ? ? ? end = index + nr; >> - ? ? if (end >= size) >> + ? ? if (end > size) > > I think that this is intentional; the last byte of the limit doesn't > work. It looks ok to me. Without above change, find_next_zero_area cannot find a 64 bits zeroed area in next sample code. unsigned long offset; DECLARE_BITMAP(map, 64); bitmap_clear(map, 0, 64); offset = find_next_zero_area(map, 64, 0, 64, 0); if (offset >= 64) printf("not found\n"); else printf("found\n"); -- 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/