Return-path: <linux-wireless-owner@vger.kernel.org>
Received: from mail-wy0-f174.google.com ([74.125.82.174]:61195 "EHLO
	mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751689Ab1HXPxj convert rfc822-to-8bit (ORCPT
	<rfc822;linux-wireless@vger.kernel.org>);
	Wed, 24 Aug 2011 11:53:39 -0400
Received: by wyg24 with SMTP id 24so942120wyg.19
        for <linux-wireless@vger.kernel.org>; Wed, 24 Aug 2011 08:53:38 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <20110823194545.GF9770@tuxdriver.com>
References: <4e472623.xXZaXUueNVRpfmG+%Larry.Finger@lwfinger.net>
	<CAD2nsn2sO+Lj+DntbFVa8QMYq8eTtFqdX06aQGHtNEbnbVTJzQ@mail.gmail.com>
	<20110823194545.GF9770@tuxdriver.com>
Date: Wed, 24 Aug 2011 21:23:38 +0530
Message-ID: <CAD2nsn1VuMvrWtXCq66HuOz8VLDWPnoTy2=p1v36fWohJx8QUA@mail.gmail.com> (sfid-20110824_175348_647583_D2D4267C)
Subject: Re: [RFC/RFT] ath9k_htc: Fix memory leak
From: Mohammed Shafi <shafi.wireless@gmail.com>
To: "John W. Linville" <linville@tuxdriver.com>,
	Larry Finger <Larry.Finger@lwfinger.net>
Cc: lrodriguez@atheros.com, vasanth@atheros.com,
	senthilkumar@atheros.com, ath9k-devel@venema.h4ckr.net,
	linux-wireless@vger.kernel.org, rmanohar@qca.qualcomm.com
Content-Type: text/plain; charset=ISO-8859-1
Sender: linux-wireless-owner@vger.kernel.org
List-ID: <linux-wireless.vger.kernel.org>

On Wed, Aug 24, 2011 at 1:15 AM, John W. Linville
<linville@tuxdriver.com> wrote:
> On Mon, Aug 15, 2011 at 05:56:33PM +0530, Mohammed Shafi wrote:
>> On Sun, Aug 14, 2011 at 7:04 AM, Larry Finger <Larry.Finger@lwfinger.net> wrote:
>> > Kmemleak shows the following kind of memory leak for ath9k_htc:
>> >
>> > unreferenced object 0xffff88004542f200 (size 512):
>> > ?comm "khubd", pid 977, jiffies 4317632516 (age 16855.868s)
>> > ?hex dump (first 32 bytes):
>> > ? ?00 00 00 0a 00 00 00 00 00 02 01 05 00 00 02 01 ?................
>> > ? ?00 00 00 00 00 00 81 38 02 00 00 00 33 33 30 30 ?.......8....3300
>> > ?backtrace:
>> > ? ?[<ffffffff81122d77>] create_object+0x127/0x2b0
>> > ? ?[<ffffffff813580b1>] kmemleak_alloc+0x21/0x50
>> > ? ?[<ffffffff8111f383>] __kmalloc_node_track_caller+0x153/0x220
>> > ? ?[<ffffffff812b703e>] __alloc_skb+0x7e/0x170
>> > ? ?[<ffffffffa0833331>] htc_connect_service+0x111/0x200 [ath9k_htc]
>> > ? ?[<ffffffffa083bb90>] ath9k_init_htc_services+0x240/0x2b0 [ath9k_htc]
>> > ? ?[<ffffffffa083c1ca>] ath9k_htc_probe_device+0xea/0xa50 [ath9k_htc]
>> > ? ?[<ffffffffa08338dc>] ath9k_htc_hw_init+0xc/0x30 [ath9k_htc]
>> > ? ?[<ffffffffa08356ba>] ath9k_hif_usb_probe+0x1ca/0x420 [ath9k_htc]
>> > ? ?[<ffffffffa00a2279>] usb_probe_interface+0xb9/0x160 [usbcore]
>> > ? ?[<ffffffff81279379>] driver_probe_device+0x89/0x1a0
>> > ? ?[<ffffffff8127958b>] __device_attach+0x4b/0x60
>> > ? ?[<ffffffff81278024>] bus_for_each_drv+0x64/0x90
>> > ? ?[<ffffffff81279231>] device_attach+0xa1/0xb0
>> > ? ?[<ffffffff81278a25>] bus_probe_device+0x25/0x40
>> > ? ?[<ffffffff81276d2a>] device_add+0x55a/0x630
>> >
>> > The device is a TP-Link TL-WN722N. The output from lsusb is "ID 0cf3:9271
>> > Atheros Communications, Inc. AR9271 802.11n".
>> >
>> > Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
>> > Cc: Stable <stable@kernel.org>
>> > ---
>> >
>> > This patch certainly fixes a leak. I'm testing to see if there are
>> > others.
>>
>> Hi Larry,
>>
>> thanks for finding this.
>> I remember seeing this memleaks sometime back and thought this patch
>> might help(i think same as yours with some more corner cases)
>> https://patchwork.kernel.org/patch/1016752/
>> but I found there were still some memory leaks, I was unsure where I
>> am missing. if you are sure that this addresses the issue, we can send
>> a patch.
>
> Ping? ?Is this the patch we want? ?Or something else?

Hi John,

the complete patch is posted
http://www.spinics.net/lists/linux-wireless/msg75134.html
Vasanth said that at some scenario's with the above patch it may cause
some panics.
based on the maintainers concerns/doubts lets drop this patch. myself
and Larry still noticed few more memory leaks. I think we better drop
this patch and fix it completely/tested. as I am with some other
critical tasks we will soon address this.

Larry if you have any thoughts, please share.

>
> John
> --
> John W. Linville ? ? ? ? ? ? ? ?Someday the world will need a hero, and you
> linville@tuxdriver.com ? ? ? ? ? ? ? ? ?might be all we have. ?Be ready.
>



-- 
shafi