From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx193.postini.com [74.125.245.193]) by kanga.kvack.org (Postfix) with SMTP id BD3206B0002 for ; Mon, 15 Apr 2013 05:00:29 -0400 (EDT) Message-ID: <516BC25B.9090708@cn.fujitsu.com> Date: Mon, 15 Apr 2013 17:03:23 +0800 From: Tang Chen MIME-Version: 1.0 Subject: Re: [PATCH] firmware, memmap: fix firmware_map_entry leak References: <516B94A1.4040603@jp.fujitsu.com> In-Reply-To: <516B94A1.4040603@jp.fujitsu.com> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-2022-JP Sender: owner-linux-mm@kvack.org List-ID: 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 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, 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/ . Don't email: email@kvack.org