On Wed, Feb 19, 2014 at 02:40:41PM +0100, Thomas Hellstrom wrote:
> Like for render-nodes, there is no point in maintaining the master concept
> for control nodes, so set the struct drm_file::master pointer to NULL.
>
> At the same time, make sure DRM_MASTER | DRM_CONTROL_ALLOW ioctls are always
> allowed when called through the control node. Previously the caller also
> needed to be master.
>
> Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
> ---
> drivers/gpu/drm/drm_drv.c | 5 +++--
> drivers/gpu/drm/drm_fops.c | 5 +++--
> include/drm/drmP.h | 5 +++++
> 3 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 345be03..42af8bd 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -355,8 +355,9 @@ long drm_ioctl(struct file *filp,
> retcode = -EINVAL;
> } else if (((ioctl->flags & DRM_ROOT_ONLY) && !capable(CAP_SYS_ADMIN)) ||
> ((ioctl->flags & DRM_AUTH) && !drm_is_render_client(file_priv) && !file_priv->authenticated) ||
> - ((ioctl->flags & DRM_MASTER) && !file_priv->is_master) ||
> - (!(ioctl->flags & DRM_CONTROL_ALLOW) && (file_priv->minor->type == DRM_MINOR_CONTROL)) ||
> + (((ioctl->flags & DRM_MASTER) && !file_priv->is_master) &&
> + !(drm_is_control(file_priv) && (ioctl->flags & DRM_CONTROL_ALLOW))) ||
> + (!(ioctl->flags & DRM_CONTROL_ALLOW) && drm_is_control(file_priv)) ||
> (!(ioctl->flags & DRM_RENDER_ALLOW) && drm_is_render_client(file_priv))) {
This is hideous to review ;-) I think it would be really good to extract
this entire condition into a drm_check_ioctl_acces(ioctl, file_priv)
helper and untangle all the different cases a bit by splitting it up into
if checks with individual return false/true; statements.
With that bit of polish for the next reviewer's sanity applied both
patches are Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
I guess with this change we could move the master pointer from drm_minor
to drm_device, which would make it really clear that there's only ever one
master per device. But that's one giant sed job, so meh ;-)
One thing I'm unsure about is whether we want/need to have the master
concept on the control node, too. logind uses set/dropmaster as a
kms-specific revoke support, so if we ever want to switch to using control
nodes for display servers we'd need to shuffle this a bit again.
Otoh no one is using control nodes for real afaik, so we likely need some
interface polishing anyway. And for non-root display servers we can block
out all the awful legacy drm ioctls easily, so just keeping on using
legacy nodes isn't a security issue for that use-case.
Cheers, Daniel
> retcode = -EACCES;
> } else {
> diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
> index 7f2af9a..08a3196 100644
> --- a/drivers/gpu/drm/drm_fops.c
> +++ b/drivers/gpu/drm/drm_fops.c
> @@ -259,7 +259,8 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
> /* if there is no current master make this fd it, but do not create
> * any master object for render clients */
> mutex_lock(&dev->struct_mutex);
> - if (!priv->minor->master && !drm_is_render_client(priv)) {
> + if (!priv->minor->master && !drm_is_render_client(priv) &&
> + !drm_is_control(priv)) {
> /* create a new master */
> priv->minor->master = drm_master_create(priv->minor);
> if (!priv->minor->master) {
> @@ -297,7 +298,7 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
> goto out_close;
> }
> }
> - } else if (!drm_is_render_client(priv)) {
> + } else if (!drm_is_render_client(priv) && !drm_is_control(priv)) {
> /* get a reference to the master */
> priv->master = drm_master_get(priv->minor->master);
> }
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index 04a7f31..ff68e26 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -1246,6 +1246,11 @@ static inline bool drm_is_render_client(struct drm_file *file_priv)
> return file_priv->minor->type == DRM_MINOR_RENDER;
> }
>
> +static inline bool drm_is_control(struct drm_file *file_priv)
> +{
> + return file_priv->minor->type == DRM_MINOR_CONTROL;
> +}
> +
> /******************************************************************/
> /** \name Internal function definitions */
> /*@{*/
> --
> 1.7.10.4
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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