On Tue, Jun 20, 2017 at 05:40:25PM -0400, Sean Paul wrote:
> On Tue, Jun 20, 2017 at 10:28:37PM +0200, Daniel Vetter wrote:
> > In
> >
> > commit 91eefc05f0ac71902906b2058360e61bd25137fe
> > Author: Daniel Vetter <daniel.vetter@xxxxxxxx>
> > Date: Wed Dec 14 00:08:10 2016 +0100
> >
> > drm: Tighten locking in drm_mode_getconnector
> >
> > I reordered the logic a bit in that IOCTL, but that broke userspace
> > since it'll get the new mode list, but not the new property values.
> > Fix that again.
> >
> > v2: Fix up the error path handling when copy_to_user for the modes
> > failes (Dhinakaran).
> >
> > Fixes: 91eefc05f0ac ("drm: Tighten locking in drm_mode_getconnector")
> > Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
> > Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
> > Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
> > Cc: David Airlie <airlied@xxxxxxxx>
> > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > Reported-by: "H.J. Lu" <hjl.tools@xxxxxxxxx>
> > Tested-by: "H.J. Lu" <hjl.tools@xxxxxxxxx>
> > Cc: <stable@xxxxxxxxxxxxxxx> # v4.11+
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100576
> > Cc: "H.J. Lu" <hjl.tools@xxxxxxxxx>
> > Cc: "Pandiyan, Dhinakaran" <dhinakaran.pandiyan@xxxxxxxxx>
> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
>
> Yep, lgtm
>
>
> Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Pushed to -fixes, thanks for the review.
-Daniel
>
> > ---
> > drivers/gpu/drm/drm_connector.c | 38 ++++++++++++++++++++------------------
> > 1 file changed, 20 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> > index 5cd61aff7857..8072e6e4c62c 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -1293,21 +1293,6 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
> > if (!connector)
> > return -ENOENT;
> >
> > - drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> > - encoder = drm_connector_get_encoder(connector);
> > - if (encoder)
> > - out_resp->encoder_id = encoder->base.id;
> > - else
> > - out_resp->encoder_id = 0;
> > -
> > - ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
> > - (uint32_t __user *)(unsigned long)(out_resp->props_ptr),
> > - (uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
> > - &out_resp->count_props);
> > - drm_modeset_unlock(&dev->mode_config.connection_mutex);
> > - if (ret)
> > - goto out_unref;
> > -
> > for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
> > if (connector->encoder_ids[i] != 0)
> > encoders_count++;
> > @@ -1320,7 +1305,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
> > if (put_user(connector->encoder_ids[i],
> > encoder_ptr + copied)) {
> > ret = -EFAULT;
> > - goto out_unref;
> > + goto out;
> > }
> > copied++;
> > }
> > @@ -1364,15 +1349,32 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
> > if (copy_to_user(mode_ptr + copied,
> > &u_mode, sizeof(u_mode))) {
> > ret = -EFAULT;
> > + mutex_unlock(&dev->mode_config.mutex);
> > +
> > goto out;
> > }
> > copied++;
> > }
> > }
> > out_resp->count_modes = mode_count;
> > -out:
> > mutex_unlock(&dev->mode_config.mutex);
> > -out_unref:
> > +
> > + drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
> > + encoder = drm_connector_get_encoder(connector);
> > + if (encoder)
> > + out_resp->encoder_id = encoder->base.id;
> > + else
> > + out_resp->encoder_id = 0;
> > +
> > + /* Only grab properties after probing, to make sure EDID and other
> > + * properties reflect the latest status. */
> > + ret = drm_mode_object_get_properties(&connector->base, file_priv->atomic,
> > + (uint32_t __user *)(unsigned long)(out_resp->props_ptr),
> > + (uint64_t __user *)(unsigned long)(out_resp->prop_values_ptr),
> > + &out_resp->count_props);
> > + drm_modeset_unlock(&dev->mode_config.connection_mutex);
> > +
> > +out:
> > drm_connector_put(connector);
> >
> > return ret;
> > --
> > 2.11.0
>
> --
> Sean Paul, Software Engineer, Google / Chromium OS
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch