From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx184.postini.com [74.125.245.184]) by kanga.kvack.org (Postfix) with SMTP id 5C3016B0044 for ; Mon, 7 May 2012 14:07:12 -0400 (EDT) Received: by pbbrp2 with SMTP id rp2so8846728pbb.14 for ; Mon, 07 May 2012 11:07:11 -0700 (PDT) Date: Mon, 7 May 2012 11:07:06 -0700 From: Tejun Heo Subject: Re: [patch 01/10] mm: bootmem: fix checking the bitmap when finally freeing bootmem Message-ID: <20120507180706.GD19417@google.com> References: <1336390672-14421-1-git-send-email-hannes@cmpxchg.org> <1336390672-14421-2-git-send-email-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1336390672-14421-2-git-send-email-hannes@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Andrew Morton , Gavin Shan , David Miller , Yinghai Lu , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, May 07, 2012 at 01:37:43PM +0200, Johannes Weiner wrote: > From: Gavin Shan > > When bootmem releases an unaligned chunk of memory at the beginning of > a node to the page allocator, it iterates from that unaligned PFN but > checks an aligned word of the page bitmap. The checked bits do not > correspond to the PFNs and, as a result, reserved pages can be freed. > > Properly shift the bitmap word so that the lowest bit corresponds to > the starting PFN before entering the freeing loop. > > This bug has been around since 41546c1 "bootmem: clean up > free_all_bootmem_core" (2.6.27) without known reports. > > Signed-off-by: Gavin Shan > Signed-off-by: Johannes Weiner Acked-by: Tejun Heo Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org