From mboxrd@z Thu Jan 1 00:00:00 1970 From: jeffy Subject: Re: [PATCH v5 12/12] drm/drm_ioctl.c: Break ioctl when drm device not registered Date: Fri, 07 Apr 2017 17:24:59 +0800 Message-ID: <58E75AEB.6070700@rock-chips.com> References: <1491481885-13775-1-git-send-email-jeffy.chen@rock-chips.com> <1491481885-13775-13-git-send-email-jeffy.chen@rock-chips.com> <20170407071659.hwf5f7jf2bjjdata@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170407071659.hwf5f7jf2bjjdata@phenom.ffwll.local> Sender: linux-kernel-owner@vger.kernel.org To: 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 List-Id: dri-devel@lists.freedesktop.org Hi Daniel, On 04/07/2017 03:16 PM, Daniel Vetter wrote: > 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 >> --- >> >> 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? > it looks like the drm_unplug_dev would call drm_dev_unregister... maybe we can: 1/ replace the dev_unplug_dev in udl_drv.c to drm_dev_unregister 2/ call dev_unplug_dev in drm_dev_unregister, and remove drm_dev_unregister in dev_unplug_dev 3/ add a drm_plug_dev or drm_device_set_plugged, and call it in drm_dev_register > 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 >