Re: [PATCH v8 3/7] drm/lease: Add a helper to tell whether a lease was revoked

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] drm/lease: false revocation report for empty leases in
  drm_lease_revoked()
--

commit 15b02cb8a3b3d4a5372c96b45134239f8d815a69
Author: Maxime Ripard <mripard@kernel.org>

drm/lease: Add a helper to tell whether a lease was revoked

This commit adds drm_lease_revoked() to check whether a drm_file's lease
has been revoked by testing if its master->leases IDR is empty.

> diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c
> index 5d2cf724cbd7b..dd59df14dcc02 100644
> --- a/drivers/gpu/drm/drm_lease.c
> +++ b/drivers/gpu/drm/drm_lease.c
> @@ -147,6 +147,32 @@ bool drm_lease_held(struct drm_file *file_priv, int id)
>  	return ret;
>  }
>  
> +/*
> + * Checks whether the file is a lessee whose lease has been revoked. A
> + * lease is always revoked as a whole, so an empty one has been revoked.
> + */
> +bool drm_lease_revoked(struct drm_file *file_priv)
> +{
> +	struct drm_master *master;
> +	bool ret = false;
> +
> +	if (!file_priv)
> +		return false;
> +
> +	master = drm_file_get_master(file_priv);
> +	if (!master)
> +		return false;
> +
> +	if (master->lessor) {
> +		mutex_lock(&master->dev->mode_config.idr_mutex);
> +		ret = idr_is_empty(&master->leases);
> +		mutex_unlock(&master->dev->mode_config.idr_mutex);
> +	}

[Severity: Medium]
Does drm_lease_revoked() falsely report valid empty leases as revoked?

Since 4bb2d367a5a2 ("drm/lease: allow empty leases"),
drm_mode_create_lease_ioctl() permits creating a lease with
object_count == 0, which leaves master->leases empty from creation.
Callers of drm_lease_revoked() will treat any such unrevoked empty lease
as revoked.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261106-drm-reset-state-flag-v8-0-50fd046b705f@kernel.org?part=3