From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx110.postini.com [74.125.245.110]) by kanga.kvack.org (Postfix) with SMTP id 3ED2B6B0002 for ; Mon, 15 Apr 2013 19:37:43 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 4658D3EE0AE for ; Tue, 16 Apr 2013 08:37:41 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 2D94445DE51 for ; Tue, 16 Apr 2013 08:37:41 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 1729545DE4D for ; Tue, 16 Apr 2013 08:37:41 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 08D7EE08001 for ; Tue, 16 Apr 2013 08:37:41 +0900 (JST) Received: from G01JPEXCHKW28.g01.fujitsu.local (G01JPEXCHKW28.g01.fujitsu.local [10.0.193.111]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id BB6B61DB802F for ; Tue, 16 Apr 2013 08:37:40 +0900 (JST) Message-ID: <516C8F23.7050209@jp.fujitsu.com> Date: Tue, 16 Apr 2013 08:37:07 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 Subject: Re: [PATCH] firmware, memmap: fix firmware_map_entry leak References: <516B94A1.4040603@jp.fujitsu.com> <516BC25B.9090708@cn.fujitsu.com> In-Reply-To: <516BC25B.9090708@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tang Chen Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, wency@cn.fujitsu.com, toshi.kani@hp.com 2013/04/15 18:03, Tang Chen wrote: > > Reviewed-by: Tang Chen Thank you for your review. Thanks, Yasuaki Ishimatsu > > 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