Commit 67253b28 authored by Jonathan Cavitt's avatar Jonathan Cavitt Committed by Thomas Hellström
Browse files

drm/pagemap_util: Ensure proper cache lock management on free 



For the sake of consistency, ensure that the cache lock is always
unlocked after drm_pagemap_cache_fini. Spinlocks typically disable
preemption and if the code-path missing the unlock is hit, preemption
will remain disabled even if the lock is subsequently freed.

Fixes static analysis issue.

v2:
- Use requested code flow (Maarten)

v3:
- Clear cache->dpagemap (Matt Brost, Maarten)

v4:
- Reword commit message (Thomas)

Fixes: 77f14f2f ("drm/pagemap: Add a drm_pagemap cache and shrinker")
Signed-off-by: default avatarJonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Thomas Hellstrom <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patch.msgid.link/20260316151555.7553-2-jonathan.cavitt@intel.com
parent 74ef7844

drivers/gpu/drm/drm_pagemap_util.c

+5 −9
Original line number Diff line number Diff line
@@ -65,18 +65,14 @@ static void drm_pagemap_cache_fini(void *arg) 
	drm_dbg(cache->shrinker->drm, "Destroying dpagemap cache.\n");

	spin_lock(&cache->lock);

	dpagemap = cache->dpagemap;

	if (!dpagemap) {

		spin_unlock(&cache->lock);

		goto out;

	}



	if (drm_pagemap_shrinker_cancel(dpagemap)) {

	cache->dpagemap = NULL;

	if (dpagemap && !drm_pagemap_shrinker_cancel(dpagemap))

		dpagemap = NULL;

	spin_unlock(&cache->lock);



	if (dpagemap)

		drm_pagemap_destroy(dpagemap, false);

	}



out:

	mutex_destroy(&cache->lookup_mutex);

	kfree(cache);

}