drm: Make control nodes master-less v3

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.

v2: Adapt to refactoring of ioctl permission check.
v3: Formatting of logical expression. Use drm_is_control_client() instead of
    drm_is_control().

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
(cherry picked from commit ac05dbc57ef2b8709bf48693bb25e16a63e8e71f)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 002596c..36c00d4 100644 (file)
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -306,13 +306,14 @@ static int drm_ioctl_permit(u32 flags, struct drm_file *file_priv)
                     !file_priv->authenticated))
                return -EACCES;
 
-       /* MASTER is only for master */
-       if (unlikely((flags & DRM_MASTER) && !file_priv->is_master))
+       /* MASTER is only for master or control clients */
+       if (unlikely((flags & DRM_MASTER) && !file_priv->is_master &&
+                    !drm_is_control_client(file_priv)))
                return -EACCES;
 
        /* Control clients must be explicitly allowed */
        if (unlikely(!(flags & DRM_CONTROL_ALLOW) &&
-                    file_priv->minor->type == DRM_MINOR_CONTROL))
+                    drm_is_control_client(file_priv)))
                return -EACCES;
 
        /* Render clients must be explicitly allowed */

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 1ec4498..5020998 100644 (file)
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -241,7 +241,8 @@ 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_client(priv)) {
                /* create a new master */
                priv->minor->master = drm_master_create(priv->minor);
                if (!priv->minor->master) {
@@ -279,7 +280,8 @@ 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_client(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 2900f65..5307f5a 100644 (file)
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1248,6 +1248,11 @@ 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_client(const struct drm_file *file_priv)
+{
+       return file_priv->minor->type == DRM_MINOR_CONTROL;
+}
+
 /******************************************************************/
 /** \name Internal function definitions */
 /*@{*/