Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933250Ab3DOJAd (ORCPT ); Mon, 15 Apr 2013 05:00:33 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:55324 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751287Ab3DOJAb (ORCPT ); Mon, 15 Apr 2013 05:00:31 -0400 X-IronPort-AV: E=Sophos;i="4.87,475,1363104000"; d="scan'208";a="7056747" Message-ID: <516BC25B.9090708@cn.fujitsu.com> Date: Mon, 15 Apr 2013 17:03:23 +0800 From: Tang Chen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, wency@cn.fujitsu.co, toshi.kani@hp.com Subject: Re: [PATCH] firmware, memmap: fix firmware_map_entry leak References: <516B94A1.4040603@jp.fujitsu.com> In-Reply-To: <516B94A1.4040603@jp.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/04/15 16:59:08, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/04/15 16:59:08, Serialize complete at 2013/04/15 16:59:08 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-2022-JP Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2532 Lines: 63 Reviewed-by: Tang Chen Thanks. :) On 04/15/2013 01:48 PM, Yasuaki Ishimatsu wrote: > When hot removing a memory, a firmware_map_entry which has memory range > of the memory is released by release_firmware_map_entry(). If the entry > is allocated by bootmem, release_firmware_map_entry() adds the entry to > map_entires_bootmem list when firmware_map_find_entry() finds the entry > from map_entries list. But firmware_map_find_entry never find the entry > sicne map_entires list does not have the entry. So the entry just leaks. > > Here are steps of leaking firmware_map_entry: > firmware_map_remove() > -> firmware_map_find_entry() > Find released entry from map_entries list > -> firmware_map_remove_entry() > Delete the entry from map_entries list > -> remove_sysfs_fw_map_entry() > ... > -> release_firmware_map_entry() > -> firmware_map_find_entry() > Find the entry from map_entries list but the entry has been > deleted from map_entries list. So the entry is not added > to map_entries_bootmem. Thus the entry leaks > > release_firmware_map_entry() should not call firmware_map_find_entry() > since releaed entry has been deleted from map_entries list. > So the patch delete firmware_map_find_entry() from releae_firmware_map_entry() > > Signed-off-by: Yasuaki Ishimatsu > --- > drivers/firmware/memmap.c | 9 +++------ > 1 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c > index 0b5b5f6..e2e04b0 100644 > --- a/drivers/firmware/memmap.c > +++ b/drivers/firmware/memmap.c > @@ -114,12 +114,9 @@ static void __meminit release_firmware_map_entry(struct kobject *kobj) > * map_entries_bootmem here, and deleted from&map_entries in > * firmware_map_remove_entry(). > */ > - if (firmware_map_find_entry(entry->start, entry->end, > - entry->type)) { > - spin_lock(&map_entries_bootmem_lock); > - list_add(&entry->list,&map_entries_bootmem); > - spin_unlock(&map_entries_bootmem_lock); > - } > + spin_lock(&map_entries_bootmem_lock); > + list_add(&entry->list,&map_entries_bootmem); > + spin_unlock(&map_entries_bootmem_lock); > > return; > } > > -- 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/