linux-kernel - [PATCH v16 05/20] drm/v3d: Replace open-coded drm_gem_shmem_free() with drm_gem_object

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230903170736.513347-6-dmitry.osipenko@collabora.com>
Date:   Sun,  3 Sep 2023 20:07:21 +0300
From:   Dmitry Osipenko <dmitry.osipenko@...labora.com>
To:     David Airlie <airlied@...il.com>,
        Gerd Hoffmann <kraxel@...hat.com>,
        Gurchetan Singh <gurchetansingh@...omium.org>,
        Chia-I Wu <olvaffe@...il.com>, Daniel Vetter <daniel@...ll.ch>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        Thomas Zimmermann <tzimmermann@...e.de>,
        Christian König <christian.koenig@....com>,
        Qiang Yu <yuq825@...il.com>,
        Steven Price <steven.price@....com>,
        Boris Brezillon <boris.brezillon@...labora.com>,
        Emma Anholt <emma@...olt.net>, Melissa Wen <mwen@...lia.com>
Cc:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        kernel@...labora.com, virtualization@...ts.linux-foundation.org
Subject: [PATCH v16 05/20] drm/v3d: Replace open-coded drm_gem_shmem_free() with drm_gem_object_put()

The drm_gem_shmem_free() doesn't put GEM's kref to zero, which becomes
important with addition of the shrinker support to drm-shmem that will
use kref=0 in order to prevent taking lock during special GEM-freeing
time in order to avoid spurious lockdep warning about locking ordering
vs fs_reclaim code paths.

Replace open-coded drm_gem_shmem_free() with drm_gem_object_put() that
drops kref to zero before freeing GEM.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@...labora.com>
---
 drivers/gpu/drm/v3d/v3d_bo.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c
index 8b3229a37c6d..70c1095d6eec 100644
--- a/drivers/gpu/drm/v3d/v3d_bo.c
+++ b/drivers/gpu/drm/v3d/v3d_bo.c
@@ -33,16 +33,18 @@ void v3d_free_object(struct drm_gem_object *obj)
 	struct v3d_dev *v3d = to_v3d_dev(obj->dev);
 	struct v3d_bo *bo = to_v3d_bo(obj);
 
-	v3d_mmu_remove_ptes(bo);
+	if (drm_mm_node_allocated(&bo->node)) {
+		v3d_mmu_remove_ptes(bo);
 
-	mutex_lock(&v3d->bo_lock);
-	v3d->bo_stats.num_allocated--;
-	v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
-	mutex_unlock(&v3d->bo_lock);
+		mutex_lock(&v3d->bo_lock);
+		v3d->bo_stats.num_allocated--;
+		v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
+		mutex_unlock(&v3d->bo_lock);
 
-	spin_lock(&v3d->mm_lock);
-	drm_mm_remove_node(&bo->node);
-	spin_unlock(&v3d->mm_lock);
+		spin_lock(&v3d->mm_lock);
+		drm_mm_remove_node(&bo->node);
+		spin_unlock(&v3d->mm_lock);
+	}
 
 	/* GPU execution may have dirtied any pages in the BO. */
 	bo->base.pages_mark_dirty_on_put = true;
@@ -142,7 +144,7 @@ struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
 	return bo;
 
 free_obj:
-	drm_gem_shmem_free(shmem_obj);
+	drm_gem_object_put(&shmem_obj->base);
 	return ERR_PTR(ret);
 }
 
@@ -160,7 +162,7 @@ v3d_prime_import_sg_table(struct drm_device *dev,
 
 	ret = v3d_bo_create_finish(obj);
 	if (ret) {
-		drm_gem_shmem_free(&to_v3d_bo(obj)->base);
+		drm_gem_object_put(obj);
 		return ERR_PTR(ret);
 	}
 
-- 
2.41.0