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From: Benedikt Spranger <b.spranger@linutronix.de>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: netdev@vger.kernel.org,
	Alexander Frank <Alexander.Frank@eberspaecher.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	"Hans J. Koch" <hjk@hansjkoch.de>,
	Holger Dengler <dengler@linutronix.de>
Subject: Re: [PATCH 1/7] uio: add module owner to prevent inappropriate module unloading
Date: Wed, 14 Aug 2013 09:19:46 +0200	[thread overview]
Message-ID: <20130814091946.2643a124@mitra.spranger.biz> (raw)
In-Reply-To: <20130813174814.GE4098@kroah.com>

Am Tue, 13 Aug 2013 10:48:14 -0700
schrieb Greg Kroah-Hartman <gregkh@linuxfoundation.org>:

> On Tue, Aug 13, 2013 at 11:08:36AM +0200, Benedikt Spranger wrote:
> > If an UIO device is created by another driver (MFD for instance) it has to be
> > ensured that the MFD driver isn't removed while the UIO is still in use.
> 
> Shouldn't if the MFD driver is removed, the UIO device will be cleaned
> up and also removed?
That is part of the problem:

1) MFD driver creates platform device "uio_pdrv"
2) uio_pdrv creates "UIOX"
3) userspace opens "UIOX"
4) MFD driver unload (remove platform device "uio_pdrv")
5) userspace reads from "UIOX" --> crash

> You shouldn't need a module reference for this type of thing.
The driver uio_pdrv has no chance to recognize that the underlaying platform
device has gone.

Regards
    Benedikt Spranger

  reply	other threads:[~2013-08-14  7:19 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-13  9:08 [PATCH 0/7] add FlexRay support Benedikt Spranger
2013-08-13  9:08 ` Benedikt Spranger
2013-08-13  9:08 ` [PATCH 1/7] uio: add module owner to prevent inappropriate module unloading Benedikt Spranger
2013-08-13 17:48   ` Greg Kroah-Hartman
2013-08-14  7:19     ` Benedikt Spranger [this message]
2013-08-14 16:33       ` Greg Kroah-Hartman
2013-08-15  6:42         ` Benedikt Spranger
2013-08-15  6:59           ` Greg Kroah-Hartman
2013-08-15  7:27             ` Benedikt Spranger
2013-08-15  8:09               ` Greg Kroah-Hartman
2013-08-15  8:18                 ` Sebastian Andrzej Siewior
2013-08-15 15:55                   ` Greg Kroah-Hartman
2013-08-15 16:03                     ` Sebastian Andrzej Siewior
2013-08-15 16:42                       ` Greg Kroah-Hartman
2013-08-15 16:54                         ` Sebastian Andrzej Siewior
2013-08-15 17:13                           ` Greg Kroah-Hartman
2013-08-13  9:08 ` [PATCH 2/7] uio: Allow to create custom UIO attributes Benedikt Spranger
2013-08-13 17:54   ` Greg Kroah-Hartman
2013-08-13  9:08 ` [PATCH 3/7] mfd: core: copy DMA mask and params from parent Benedikt Spranger
2013-08-13 10:03   ` Lee Jones
2013-08-13  9:08 ` [PATCH 4/7] mfd: add MFD based flexcard driver Benedikt Spranger
2013-08-13  9:55   ` Lee Jones
2013-08-14  8:12     ` Benedikt Spranger
2013-08-14  9:45       ` Lee Jones
2013-08-13  9:08 ` [PATCH 5/7] clocksource: Add flexcard support Benedikt Spranger
2013-08-13  9:08 ` [PATCH 6/7] net: add the AF_FLEXRAY protocol Benedikt Spranger
2013-08-18 18:50   ` Oliver Hartkopp
2013-08-13  9:08 ` [PATCH 7/7] net: add a flexray driver Benedikt Spranger

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