[PATCH 5/6] drm: Check mode object lease status in all master ioctl paths [v2]

From: Keith Packard
Date: Wed Jul 05 2017 - 18:25:01 EST


Attempts to modify un-leased objects are rejected with an error.
Information returned about unleased objects is modified to make them
appear unusable and/or disconnected.

Changes for v2 as suggested by Daniel Vetter <daniel.vetter@xxxxxxxx>:

With the change in the __drm_mode_object_find API to pass the
file_priv along, we can now centralize most of the lease-based access
checks in that function.

A few places skip that API and require in-line checks.

Signed-off-by: Keith Packard <keithp@xxxxxxxxxx>
---
drivers/gpu/drm/drm_auth.c | 2 +-
drivers/gpu/drm/drm_connector.c | 5 +++--
drivers/gpu/drm/drm_encoder.c | 8 +++++---
drivers/gpu/drm/drm_mode_config.c | 32 +++++++++++++++++++-------------
drivers/gpu/drm/drm_mode_object.c | 22 ++++++++++++++++++++++
drivers/gpu/drm/drm_plane.c | 8 +++++---
drivers/gpu/drm/drm_vblank.c | 18 ++++++++++++++++--
7 files changed, 71 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c
index 541177c71d51..bab26b477738 100644
--- a/drivers/gpu/drm/drm_auth.c
+++ b/drivers/gpu/drm/drm_auth.c
@@ -310,7 +310,7 @@ void drm_master_release(struct drm_file *file_priv)
*/
bool drm_is_current_master(struct drm_file *fpriv)
{
- return fpriv->is_master && fpriv->master == fpriv->minor->dev->master;
+ return fpriv->is_master && drm_lease_owner(fpriv->master) == fpriv->minor->dev->master;
}
EXPORT_SYMBOL(drm_is_current_master);

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index cd3c106dc5e2..436e99a2d5eb 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1295,7 +1295,7 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,

drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
encoder = drm_connector_get_encoder(connector);
- if (encoder)
+ if (encoder && drm_lease_held(file_priv, encoder->base.id))
out_resp->encoder_id = encoder->base.id;
else
out_resp->encoder_id = 0;
@@ -1309,7 +1309,8 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
goto out_unref;

for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++)
- if (connector->encoder_ids[i] != 0)
+ if (connector->encoder_ids[i] != 0 &&
+ drm_lease_held(file_priv, connector->encoder_ids[i]))
encoders_count++;

if ((out_resp->count_encoders >= encoders_count) && encoders_count) {
diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
index 43f644844b83..6ad6416f2ede 100644
--- a/drivers/gpu/drm/drm_encoder.c
+++ b/drivers/gpu/drm/drm_encoder.c
@@ -226,7 +226,7 @@ int drm_mode_getencoder(struct drm_device *dev, void *data,

drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
crtc = drm_encoder_get_crtc(encoder);
- if (crtc)
+ if (crtc && drm_lease_held(file_priv, crtc->base.id))
enc_resp->crtc_id = crtc->base.id;
else
enc_resp->crtc_id = 0;
@@ -234,8 +234,10 @@ int drm_mode_getencoder(struct drm_device *dev, void *data,

enc_resp->encoder_type = encoder->encoder_type;
enc_resp->encoder_id = encoder->base.id;
- enc_resp->possible_crtcs = encoder->possible_crtcs;
- enc_resp->possible_clones = encoder->possible_clones;
+ enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
+ encoder->possible_crtcs);
+ enc_resp->possible_clones = drm_lease_filter_encoders(file_priv,
+ encoder->possible_clones);

return 0;
}
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index d9862259a2a7..f7ceee2ae340 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -122,20 +122,24 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
count = 0;
crtc_id = u64_to_user_ptr(card_res->crtc_id_ptr);
drm_for_each_crtc(crtc, dev) {
- if (count < card_res->count_crtcs &&
- put_user(crtc->base.id, crtc_id + count))
- return -EFAULT;
- count++;
+ if (drm_lease_held(file_priv, crtc->base.id)) {
+ if (count < card_res->count_crtcs &&
+ put_user(crtc->base.id, crtc_id + count))
+ return -EFAULT;
+ count++;
+ }
}
card_res->count_crtcs = count;

count = 0;
encoder_id = u64_to_user_ptr(card_res->encoder_id_ptr);
drm_for_each_encoder(encoder, dev) {
- if (count < card_res->count_encoders &&
- put_user(encoder->base.id, encoder_id + count))
- return -EFAULT;
- count++;
+ if (drm_lease_held(file_priv, encoder->base.id)) {
+ if (count < card_res->count_encoders &&
+ put_user(encoder->base.id, encoder_id + count))
+ return -EFAULT;
+ count++;
+ }
}
card_res->count_encoders = count;

@@ -143,12 +147,14 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
count = 0;
connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
drm_for_each_connector_iter(connector, &conn_iter) {
- if (count < card_res->count_connectors &&
- put_user(connector->base.id, connector_id + count)) {
- drm_connector_list_iter_end(&conn_iter);
- return -EFAULT;
+ if (drm_lease_held(file_priv, connector->base.id)) {
+ if (count < card_res->count_connectors &&
+ put_user(connector->base.id, connector_id + count)) {
+ drm_connector_list_iter_end(&conn_iter);
+ return -EFAULT;
+ }
+ count++;
}
- count++;
}
card_res->count_connectors = count;
drm_connector_list_iter_end(&conn_iter);
diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
index ccc3a35d2de2..dbc280ddef9b 100644
--- a/drivers/gpu/drm/drm_mode_object.c
+++ b/drivers/gpu/drm/drm_mode_object.c
@@ -104,6 +104,25 @@ void drm_mode_object_unregister(struct drm_device *dev,
mutex_unlock(&dev->mode_config.idr_mutex);
}

+/**
+ * drm_lease_required - check types which must be leased to be used
+ * @type: type of object
+ *
+ * Returns whether the provided type of drm_mode_object must
+ * be owned or leased to be used by a process.
+ */
+static bool drm_lease_required(uint32_t type)
+{
+ switch(type) {
+ case DRM_MODE_OBJECT_CRTC:
+ case DRM_MODE_OBJECT_CONNECTOR:
+ case DRM_MODE_OBJECT_ENCODER:
+ return true;
+ default:
+ return false;
+ }
+}
+
struct drm_mode_object *__drm_mode_object_find(struct drm_device *dev,
struct drm_file *file_priv,
uint32_t id, uint32_t type)
@@ -117,6 +136,9 @@ struct drm_mode_object *__drm_mode_object_find(struct drm_device *dev,
if (obj && obj->id != id)
obj = NULL;

+ if (obj && drm_lease_required(obj->type) && !_drm_lease_held(file_priv, obj->id))
+ obj = NULL;
+
if (obj && obj->free_cb) {
if (!kref_get_unless_zero(&obj->refcount))
obj = NULL;
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 462c244498e2..9a7306a912b6 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -400,9 +400,9 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
return -ENOENT;

drm_modeset_lock(&plane->mutex, NULL);
- if (plane->state && plane->state->crtc)
+ if (plane->state && plane->state->crtc && drm_lease_held(file_priv, plane->state->crtc->base.id))
plane_resp->crtc_id = plane->state->crtc->base.id;
- else if (!plane->state && plane->crtc)
+ else if (!plane->state && plane->crtc && drm_lease_held(file_priv, plane->crtc->base.id))
plane_resp->crtc_id = plane->crtc->base.id;
else
plane_resp->crtc_id = 0;
@@ -416,7 +416,9 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
drm_modeset_unlock(&plane->mutex);

plane_resp->plane_id = plane->base.id;
- plane_resp->possible_crtcs = plane->possible_crtcs;
+ plane_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
+ plane->possible_crtcs);
+
plane_resp->gamma_size = 0;

/*
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 463e4d81fb0d..66fe329e7d2b 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -1436,9 +1436,11 @@ static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait)
int drm_wait_vblank(struct drm_device *dev, void *data,
struct drm_file *file_priv)
{
+ struct drm_crtc *crtc;
struct drm_vblank_crtc *vblank;
union drm_wait_vblank *vblwait = data;
int ret;
+ unsigned int pipe_index;
unsigned int flags, seq, pipe, high_pipe;

if (!dev->irq_enabled)
@@ -1460,9 +1462,21 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
if (high_pipe)
- pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
+ pipe_index = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
else
- pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
+ pipe_index = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
+
+ /* Convert lease-relative crtc index into global crtc index */
+ pipe = 0;
+ drm_for_each_crtc(crtc, dev) {
+ if (drm_lease_held(file_priv, crtc->base.id)) {
+ if (pipe_index == 0)
+ break;
+ pipe_index--;
+ }
+ pipe++;
+ }
+
if (pipe >= dev->num_crtcs)
return -EINVAL;

--
2.11.0