drm/tests: shmem: Hold reservation lock around madvise

Acquire and release the GEM object's reservation lock around calls
to the object's madvide operation. The tests use
drm_gem_shmem_madvise_locked(), which led to errors such as show below.

[   58.339389] WARNING: CPU: 1 PID: 1352 at drivers/gpu/drm/drm_gem_shmem_helper.c:499 drm_gem_shmem_madvise_locked+0xde/0x140

Only export the new helper drm_gem_shmem_madvise() for Kunit tests.
This is not an interface for regular drivers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 954907f7147d ("drm/shmem-helper: Refactor locked/unlocked functions")
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.16+
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patch.msgid.link/20251212160317.287409-5-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index de4de594c78b3afa8b083ef8f6df71d150a92fab..d377802b9dfdc1f3f289ec82c461b9feed2fa69a 100644 (file)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -932,6 +932,21 @@ void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *
        dma_resv_unlock(obj->resv);
 }
 EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_vunmap);
+
+int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
+{
+       struct drm_gem_object *obj = &shmem->base;
+       int ret;
+
+       ret = dma_resv_lock_interruptible(obj->resv, NULL);
+       if (ret)
+               return ret;
+       ret = drm_gem_shmem_madvise_locked(shmem, madv);
+       dma_resv_unlock(obj->resv);
+
+       return ret;
+}
+EXPORT_SYMBOL_IF_KUNIT(drm_gem_shmem_madvise);
 #endif
 
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");

diff --git a/drivers/gpu/drm/tests/drm_gem_shmem_test.c b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
index 3e7c6f20fbccaf7fd6ec52cd4abbc3f1962809b9..d639848e3c8ea6af002e5d2160396ee3d3512e6b 100644 (file)
--- a/drivers/gpu/drm/tests/drm_gem_shmem_test.c
+++ b/drivers/gpu/drm/tests/drm_gem_shmem_test.c
@@ -292,17 +292,17 @@ static void drm_gem_shmem_test_madvise(struct kunit *test)
        ret = kunit_add_action_or_reset(test, drm_gem_shmem_free_wrapper, shmem);
        KUNIT_ASSERT_EQ(test, ret, 0);
 
-       ret = drm_gem_shmem_madvise_locked(shmem, 1);
+       ret = drm_gem_shmem_madvise(shmem, 1);
        KUNIT_EXPECT_TRUE(test, ret);
        KUNIT_ASSERT_EQ(test, shmem->madv, 1);
 
        /* Set madv to a negative value */
-       ret = drm_gem_shmem_madvise_locked(shmem, -1);
+       ret = drm_gem_shmem_madvise(shmem, -1);
        KUNIT_EXPECT_FALSE(test, ret);
        KUNIT_ASSERT_EQ(test, shmem->madv, -1);
 
        /* Check that madv cannot be set back to a positive value */
-       ret = drm_gem_shmem_madvise_locked(shmem, 0);
+       ret = drm_gem_shmem_madvise(shmem, 0);
        KUNIT_EXPECT_FALSE(test, ret);
        KUNIT_ASSERT_EQ(test, shmem->madv, -1);
 }
@@ -330,7 +330,7 @@ static void drm_gem_shmem_test_purge(struct kunit *test)
        ret = drm_gem_shmem_is_purgeable(shmem);
        KUNIT_EXPECT_FALSE(test, ret);
 
-       ret = drm_gem_shmem_madvise_locked(shmem, 1);
+       ret = drm_gem_shmem_madvise(shmem, 1);
        KUNIT_EXPECT_TRUE(test, ret);
 
        /* The scatter/gather table will be freed by drm_gem_shmem_free */

diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index a80b5bda92714b2c30728a9fe251c502f1baba38..dd9a7c67195ea79ac242f9bd14e1e349574431a7 100644 (file)
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -307,6 +307,7 @@ struct drm_gem_object *drm_gem_shmem_prime_import_no_map(struct drm_device *dev,
 #if IS_ENABLED(CONFIG_KUNIT)
 int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map);
 void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem, struct iosys_map *map);
+int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
 #endif
 
 #endif /* __DRM_GEM_SHMEM_HELPER_H__ */