Commit 5acc614a authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm: Protect master->unique with dev->master_mutex 



No one looks at the major/minor versions except the unique/busid
stuff. If we protect that with the master_mutex (since it also affects
the unique of each master, oh well) we can mark these two IOCTL with
DRM_UNLOCKED.

While doing this I realized that the comment for the magic_map is
outdated, I've forgotten to update it in:

commit d2b34ee6
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Jun 17 09:33:21 2016 +0200

    drm: Protect authmagic with master_mutex

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarEmil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161210215255.7765-1-daniel.vetter@ffwll.ch
parent b9fb2a21

drivers/gpu/drm/drm_ioctl.c

+9 −3
Original line number Diff line number Diff line
@@ -115,11 +115,15 @@ static int drm_getunique(struct drm_device *dev, void *data, 
	struct drm_unique *u = data;

	struct drm_master *master = file_priv->master;



	mutex_lock(&master->dev->master_mutex);

	if (u->unique_len >= master->unique_len) {

		if (copy_to_user(u->unique, master->unique, master->unique_len))

		if (copy_to_user(u->unique, master->unique, master->unique_len)) {

			mutex_unlock(&master->dev->master_mutex);

			return -EFAULT;

		}

	}

	u->unique_len = master->unique_len;

	mutex_unlock(&master->dev->master_mutex);



	return 0;

}
@@ -340,6 +344,7 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f 
	struct drm_set_version *sv = data;

	int if_version, retcode = 0;



	mutex_lock(&dev->master_mutex);

	if (sv->drm_di_major != -1) {

		if (sv->drm_di_major != DRM_IF_MAJOR ||

		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
@@ -374,6 +379,7 @@ static int drm_setversion(struct drm_device *dev, void *data, struct drm_file *f 
	sv->drm_di_minor = DRM_IF_MINOR;

	sv->drm_dd_major = dev->driver->major;

	sv->drm_dd_minor = dev->driver->minor;

	mutex_unlock(&dev->master_mutex);



	return retcode;

}
@@ -528,7 +534,7 @@ EXPORT_SYMBOL(drm_ioctl_permit); 
static const struct drm_ioctl_desc drm_ioctls[] = {

	DRM_IOCTL_DEF(DRM_IOCTL_VERSION, drm_version,

		      DRM_UNLOCKED|DRM_RENDER_ALLOW|DRM_CONTROL_ALLOW),

	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0),

	DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY),

	DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_legacy_getmap_ioctl, DRM_UNLOCKED),
@@ -536,7 +542,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = { 
	DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED|DRM_RENDER_ALLOW),

	DRM_IOCTL_DEF(DRM_IOCTL_SET_CLIENT_CAP, drm_setclientcap, 0),

	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER),

	DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_UNLOCKED | DRM_MASTER),



	DRM_IOCTL_DEF(DRM_IOCTL_SET_UNIQUE, drm_invalid_op, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

	DRM_IOCTL_DEF(DRM_IOCTL_BLOCK, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),

include/drm/drm_auth.h

+13 −4
Original line number Diff line number Diff line
@@ -33,10 +33,7 @@ 
 *

 * @refcount: Refcount for this master object.

 * @dev: Link back to the DRM device

 * @unique: Unique identifier: e.g. busid. Protected by drm_global_mutex.

 * @unique_len: Length of unique field. Protected by drm_global_mutex.

 * @magic_map: Map of used authentication tokens. Protected by struct_mutex.

 * @lock: DRI lock information.

 * @lock: DRI1 lock information.

 * @driver_priv: Pointer to driver-private information.

 *

 * Note that master structures are only relevant for the legacy/primary device
@@ -45,8 +42,20 @@ 
struct drm_master {

	struct kref refcount;

	struct drm_device *dev;

	/**

	 * @unique: Unique identifier: e.g. busid. Protected by struct

	 * &drm_device master_mutex.

	 */

	char *unique;

	/**

	 * @unique_len: Length of unique field. Protected by struct &drm_device

	 * master_mutex.

	 */

	int unique_len;

	/**

	 * @magic_map: Map of used authentication tokens. Protected by struct

	 * &drm_device master_mutex.

	 */

	struct idr magic_map;

	struct drm_lock_data lock;

	void *driver_priv;