Commit 2798ffcc authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm: Remove locking for legacy ioctls and DRM_UNLOCKED 



Modern DRM drivers acquire ioctl locks by themselves. Legacy ioctls
for user-space mode setting used to acquire drm_global_mutex. After
removing the ioctl entry points, also remove the locking code. The only
legacy ioctl without global locking was VBLANK_WAIT, which has been
removed as well. Hence remove the related DRM_UNLOCKED flag.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarDavid Airlie <airlied@gmail.com>
Reviewed-by: default avatarDaniel Vetter <daniel@ffwll.ch>
Acked-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231122122449.11588-12-tzimmermann@suse.de
parent 2722ac1c

drivers/gpu/drm/drm_ioc32.c

+1 −1
Original line number Diff line number Diff line
@@ -273,7 +273,7 @@ static int compat_drm_wait_vblank(struct file *file, unsigned int cmd, 
	req.request.type = req32.request.type;

	req.request.sequence = req32.request.sequence;

	req.request.signal = req32.request.signal;

	err = drm_ioctl_kernel(file, drm_wait_vblank_ioctl, &req, DRM_UNLOCKED);

	err = drm_ioctl_kernel(file, drm_wait_vblank_ioctl, &req, 0);



	req32.reply.type = req.reply.type;

	req32.reply.sequence = req.reply.sequence;

drivers/gpu/drm/drm_ioctl.c

+7 −16
Original line number Diff line number Diff line
@@ -596,7 +596,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = { 


	DRM_IOCTL_DEF(DRM_IOCTL_FINISH, drm_noop, DRM_AUTH),



	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, DRM_UNLOCKED),

	DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank_ioctl, 0),



	DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
@@ -729,7 +729,7 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, 
{

	struct drm_file *file_priv = file->private_data;

	struct drm_device *dev = file_priv->minor->dev;

	int retcode;

	int ret;



	/* Update drm_file owner if fd was passed along. */

	drm_file_update_pid(file_priv);
@@ -737,20 +737,11 @@ long drm_ioctl_kernel(struct file *file, drm_ioctl_t *func, void *kdata, 
	if (drm_dev_is_unplugged(dev))

		return -ENODEV;



	retcode = drm_ioctl_permit(flags, file_priv);

	if (unlikely(retcode))

		return retcode;

	ret = drm_ioctl_permit(flags, file_priv);

	if (unlikely(ret))

		return ret;



	/* Enforce sane locking for modern driver ioctls. */

	if (likely(!drm_core_check_feature(dev, DRIVER_LEGACY)) ||

	    (flags & DRM_UNLOCKED))

		retcode = func(dev, kdata, file_priv);

	else {

		mutex_lock(&drm_global_mutex);

		retcode = func(dev, kdata, file_priv);

		mutex_unlock(&drm_global_mutex);

	}

	return retcode;

	return func(dev, kdata, file_priv);

}

EXPORT_SYMBOL(drm_ioctl_kernel);

include/drm/drm_ioctl.h

+0 −11
Original line number Diff line number Diff line
@@ -109,17 +109,6 @@ enum drm_ioctl_flags { 
	 * This is equivalent to callers with the SYSADMIN capability.

	 */

	DRM_ROOT_ONLY		= BIT(2),

	/**

	 * @DRM_UNLOCKED:

	 *

	 * Whether &drm_ioctl_desc.func should be called with the DRM BKL held

	 * or not. Enforced as the default for all modern drivers, hence there

	 * should never be a need to set this flag.

	 *

	 * Do not use anywhere else than for the VBLANK_WAIT IOCTL, which is the

	 * only legacy IOCTL which needs this.

	 */

	DRM_UNLOCKED		= BIT(4),

	/**

	 * @DRM_RENDER_ALLOW:

	 *