Patch "drm/gem: Internally test import_attach for imported objects" has been added to the 6.6-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    drm/gem: Internally test import_attach for imported objects

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-gem-internally-test-import_attach-for-imported-objects.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.


>From 8260731ccad0451207b45844bb66eb161a209218 Mon Sep 17 00:00:00 2001
From: Thomas Zimmermann <tzimmermann at suse.de>
Date: Wed, 16 Apr 2025 08:57:45 +0200
Subject: drm/gem: Internally test import_attach for imported objects
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Thomas Zimmermann <tzimmermann at suse.de>

commit 8260731ccad0451207b45844bb66eb161a209218 upstream.

Test struct drm_gem_object.import_attach to detect imported objects.

During object clenanup, the dma_buf field might be NULL. Testing it in
an object's free callback then incorrectly does a cleanup as for native
objects. Happens for calls to drm_mode_destroy_dumb_ioctl() that
clears the dma_buf field in drm_gem_object_exported_dma_buf_free().

v3:
- only test for import_attach (Boris)
v2:
- use import_attach.dmabuf instead of dma_buf (Christian)

Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
Fixes: b57aa47d39e9 ("drm/gem: Test for imported GEM buffers with helper")
Reported-by: Andy Yan <andyshrk at 163.com>
Closes: https://lore.kernel.org/dri-devel/38d09d34.4354.196379aa560.Coremail.andyshrk@163.com/
Tested-by: Andy Yan <andyshrk at 163.com>
Cc: Thomas Zimmermann <tzimmermann at suse.de>
Cc: Anusha Srivatsa <asrivats at redhat.com>
Cc: Christian König <christian.koenig at amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: David Airlie <airlied at gmail.com>
Cc: Simona Vetter <simona at ffwll.ch>
Cc: Sumit Semwal <sumit.semwal at linaro.org>
Cc: "Christian König" <christian.koenig at amd.com>
Cc: dri-devel at lists.freedesktop.org
Cc: linux-media at vger.kernel.org
Cc: linaro-mm-sig at lists.linaro.org
Reviewed-by: Boris Brezillon <boris.brezillon at collabora.com>
Reviewed-by: Simona Vetter <simona.vetter at ffwll.ch>
Link: https://lore.kernel.org/r/20250416065820.26076-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 include/drm/drm_gem.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -567,8 +567,7 @@ static inline bool drm_gem_object_is_sha
  */
 static inline bool drm_gem_is_imported(const struct drm_gem_object *obj)
 {
-	/* The dma-buf's priv field points to the original GEM object. */
-	return obj->dma_buf && (obj->dma_buf->priv != obj);
+	return !!obj->import_attach;
 }
 
 #ifdef CONFIG_LOCKDEP


Patches currently in stable-queue which might be from tzimmermann at suse.de are

queue-6.6/drm-gem-internally-test-import_attach-for-imported-objects.patch
queue-6.6/drm-ast-find-vbios-mode-from-regular-display-size.patch
queue-6.6/drm-gem-test-for-imported-gem-buffers-with-helper.patch
queue-6.6/drm-atomic-clarify-the-rules-around-drm_atomic_state.patch