Commit 697cc9c8 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm: Simplify GETRESOURCES ioctl 



Looping twice when we can do it once is silly. Also use a consistent
style. Note that there's a good race with the connector list walking,
since that is no longer protected by mode_config.mutex. But that's for
a later patch to fix.

v2: Actually try to not blow up, somehow I lost the hunk that checks
we don't copy too much. Noticed by Chris.

v3:
- squash all drm_mode_getresources cleanups into one
- use consistent style for walking objects (Chris)

v4:
- Use u64_to_user_ptr (Chris)
- Don't forget to copy the last connector (Chris)

v5: Chris was right ...

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161211192019.29603-1-daniel.vetter@ffwll.ch
parent 122020af

drivers/gpu/drm/drm_mode_config.c

+39 −72
Original line number Diff line number Diff line
@@ -84,17 +84,11 @@ int drm_mode_getresources(struct drm_device *dev, void *data, 
			  struct drm_file *file_priv)

{

	struct drm_mode_card_res *card_res = data;

	struct list_head *lh;

	struct drm_framebuffer *fb;

	struct drm_connector *connector;

	struct drm_crtc *crtc;

	struct drm_encoder *encoder;

	int ret = 0;

	int connector_count = 0;

	int crtc_count = 0;

	int fb_count = 0;

	int encoder_count = 0;

	int copied = 0;

	int count, ret = 0;

	uint32_t __user *fb_id;

	uint32_t __user *crtc_id;

	uint32_t __user *connector_id;
@@ -105,89 +99,62 @@ int drm_mode_getresources(struct drm_device *dev, void *data, 




	mutex_lock(&file_priv->fbs_lock);

	/*

	 * For the non-control nodes we need to limit the list of resources

	 * by IDs in the group list for this node

	 */

	list_for_each(lh, &file_priv->fbs)

		fb_count++;



	/* handle this in 4 parts */

	/* FBs */

	if (card_res->count_fbs >= fb_count) {

		copied = 0;

		fb_id = (uint32_t __user *)(unsigned long)card_res->fb_id_ptr;

	count = 0;

	fb_id = u64_to_user_ptr(card_res->fb_id_ptr);

	list_for_each_entry(fb, &file_priv->fbs, filp_head) {

			if (put_user(fb->base.id, fb_id + copied)) {

		if (count < card_res->count_fbs &&

		    put_user(fb->base.id, fb_id + count)) {

			mutex_unlock(&file_priv->fbs_lock);

			return -EFAULT;

		}

			copied++;

		}

		count++;

	}

	card_res->count_fbs = fb_count;

	card_res->count_fbs = count;

	mutex_unlock(&file_priv->fbs_lock);



	/* mode_config.mutex protects the connector list against e.g. DP MST

	 * connector hot-adding. CRTC/Plane lists are invariant. */

	mutex_lock(&dev->mode_config.mutex);

	drm_for_each_crtc(crtc, dev)

		crtc_count++;



	drm_for_each_connector(connector, dev)

		connector_count++;



	drm_for_each_encoder(encoder, dev)

		encoder_count++;



	card_res->max_height = dev->mode_config.max_height;

	card_res->min_height = dev->mode_config.min_height;

	card_res->max_width = dev->mode_config.max_width;

	card_res->min_width = dev->mode_config.min_width;



	/* CRTCs */

	if (card_res->count_crtcs >= crtc_count) {

		copied = 0;

		crtc_id = (uint32_t __user *)(unsigned long)card_res->crtc_id_ptr;

	count = 0;

	crtc_id = u64_to_user_ptr(card_res->crtc_id_ptr);

	drm_for_each_crtc(crtc, dev) {

			if (put_user(crtc->base.id, crtc_id + copied)) {

		if (count < card_res->count_crtcs &&

		    put_user(crtc->base.id, crtc_id + count)) {

			ret = -EFAULT;

			goto out;

		}

			copied++;

		count++;

	}

	}

	card_res->count_crtcs = crtc_count;

	card_res->count_crtcs = count;



	/* Encoders */

	if (card_res->count_encoders >= encoder_count) {

		copied = 0;

		encoder_id = (uint32_t __user *)(unsigned long)card_res->encoder_id_ptr;

	count = 0;

	encoder_id = u64_to_user_ptr(card_res->encoder_id_ptr);

	drm_for_each_encoder(encoder, dev) {

			if (put_user(encoder->base.id, encoder_id +

				     copied)) {

		if (count < card_res->count_encoders &&

		    put_user(encoder->base.id, encoder_id + count)) {

			ret = -EFAULT;

			goto out;

		}

			copied++;

		}

		count++;

	}

	card_res->count_encoders = encoder_count;

	card_res->count_encoders = count;



	/* Connectors */

	if (card_res->count_connectors >= connector_count) {

		copied = 0;

		connector_id = (uint32_t __user *)(unsigned long)card_res->connector_id_ptr;

	count = 0;

	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);

	drm_for_each_connector(connector, dev) {

			if (put_user(connector->base.id,

				     connector_id + copied)) {

		if (count < card_res->count_connectors &&

		    put_user(connector->base.id, connector_id + count)) {

			ret = -EFAULT;

			goto out;

		}

			copied++;

		}

		count++;

	}

	card_res->count_connectors = connector_count;

	card_res->count_connectors = count;



out:

	mutex_unlock(&dev->mode_config.mutex);