Message-ID: <51F66B0E.40408@ispras.ru>
Date: Mon, 29 Jul 2013 17:15:58 +0400
From: Alexey Khoroshilov <khoroshilov@ispras.ru>
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To: balbi@ti.com
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org
Subject: Re: [PATCH] usb: gadget: mv_u3d_core: fix violation of locking discipline
 in mv_u3d_ep_disable()
References: <1374610817-14894-1-git-send-email-khoroshilov@ispras.ru> <20130725173017.GK25415@radagast> <51F2950D.3070103@ispras.ru> <20130729125250.GB13938@radagast>
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On 07/29/2013 04:52 PM, Felipe Balbi wrote:
> Hi,
>
> On Fri, Jul 26, 2013 at 07:26:05PM +0400, Alexey Khoroshilov wrote:
>> On 07/25/2013 09:30 PM, Felipe Balbi wrote:
>>> On Wed, Jul 24, 2013 at 12:20:17AM +0400, Alexey Khoroshilov wrote:
>>>> mv_u3d_nuke() expects to be calles with ep->u3d->lock held,
>>>> because mv_u3d_done() does. But mv_u3d_ep_disable() calls it
>>>> without lock that can lead to unpleasant consequences.
>>>>
>>>> Found by Linux Driver Verification project (linuxtesting.org).
>>>>
>>>> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
>>> which commit introduced the bug ? Which kernels are affected by this bug ?
>> The bug is present from the very beginning: commit 3d4eb9d of 15 June 2012.
>> So it is in the mainline since v3.5.
> Alright, do you want to have the same fix in stable kernels ? Is it
> necessary at all or do we consider it 'never worked before' and send it
> in the next merge window ?

It is a tricky point. From one point of view it 'never worked before',
but as far as the bug leads to a data race with unpredictable
consequences I would prefer to have it fixed within 3.11 timeframe.

--
Alexey

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