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From: Daniel Vetter <daniel@ffwll.ch>
To: Jeffy Chen <jeffy.chen@rock-chips.com>
Cc: linux-kernel@vger.kernel.org, briannorris@chromium.org,
	dianders@chromium.org, tfiga@chromium.org,
	dri-devel@lists.freedesktop.org, zyw@rock-chips.com,
	Daniel Vetter <daniel.vetter@intel.com>
Subject: Re: [PATCH v5 12/12] drm/drm_ioctl.c: Break ioctl when drm device not registered
Date: Fri, 7 Apr 2017 09:16:59 +0200	[thread overview]
Message-ID: <20170407071659.hwf5f7jf2bjjdata@phenom.ffwll.local> (raw)
In-Reply-To: <1491481885-13775-13-git-send-email-jeffy.chen@rock-chips.com>

On Thu, Apr 06, 2017 at 08:31:25PM +0800, Jeffy Chen wrote:
> After unbinding drm, the user space may still owns the drm dev fd,
> and may still be able to call drm ioctl.
> 
> Add a sanity check here to prevent that from happening.
> 
> Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
> ---
> 
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
> 
>  drivers/gpu/drm/drm_ioctl.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index 7d6deaa..15beb11 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -674,7 +674,7 @@ long drm_ioctl(struct file *filp,
>  
>  	dev = file_priv->minor->dev;
>  
> -	if (drm_device_is_unplugged(dev))
> +	if (drm_device_is_unplugged(dev) || !dev->registered)

Shouldn't we instead automatically unplug the device in
drm_dev_unregister, instead of sprinkling tons of drm_device_is_unplugged
|| !registered all over the place?

That should catch a few more issues where userspace might creep into the
driver after unregistering ...
-Daniel

>  		return -ENODEV;
>  
>  	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
> -- 
> 2.1.4
> 
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

  reply	other threads:[~2017-04-07  7:17 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-06 12:31 [PATCH v5 00/12] drm: rockchip: Fix rockchip drm unbind crash error Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 01/12] drm: bridge: analogix: Detach panel when unbinding analogix dp Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 02/12] drm: bridge: analogix: Unregister dp aux when unbinding Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 03/12] drm: bridge: analogix: Disable clock " Jeffy Chen
2017-04-07 11:32   ` Andrzej Hajda
2017-04-06 12:31 ` [PATCH v5 04/12] drm: bridge: analogix: Destroy connector & encoder " Jeffy Chen
2017-04-07 12:01   ` Andrzej Hajda
2017-04-06 12:31 ` [PATCH v5 05/12] drm/rockchip: cdn-dp: Don't try to release firmware when not loaded Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 06/12] drm/rockchip: cdn-dp: Don't unregister audio dev when unbinding Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 07/12] drm/rockchip: vop: Enable pm domain before vop_initial Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 08/12] drm/rockchip: vop: Unprepare clocks when unbinding Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 09/12] drm/rockchip: analogix_dp: Disable clock " Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 10/12] drm/rockchip: Reoder drm bind/unbind sequence Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 11/12] drm/rockchip: Shutdown all crtcs when unbinding drm Jeffy Chen
2017-04-06 12:31 ` [PATCH v5 12/12] drm/drm_ioctl.c: Break ioctl when drm device not registered Jeffy Chen
2017-04-07  7:16   ` Daniel Vetter [this message]
2017-04-07  9:24     ` jeffy
2017-04-07 18:34       ` Daniel Vetter
2017-04-07 17:36 ` [PATCH v5 00/12] drm: rockchip: Fix rockchip drm unbind crash error Sean Paul

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