diff options
| author | Thomas Zimmermann <tzimmermann@suse.de> | 2025-07-15 17:58:12 +0200 |
|---|---|---|
| committer | Thomas Zimmermann <tzimmermann@suse.de> | 2025-07-17 12:26:19 +0200 |
| commit | 1e9d2aed7c2248bc5ba7d0dfea4fcc0b2f80b4f7 (patch) | |
| tree | fb2cabe5319d18514e0aa47f3bae97f544f25dcf | |
| parent | 0ecfb8ddb953605cadd806de5b62e632c8e0e49e (diff) | |
Revert "drm/vmwgfx: Use dma_buf from GEM object instance"
This reverts commit aec8a40228acb385d60feec59b54573d307e60f3.
The dma_buf field in struct drm_gem_object is not stable over the
object instance's lifetime. The field becomes NULL when user space
releases the final GEM handle on the buffer object. This resulted
in a NULL-pointer deref.
Workarounds in commit 5307dce878d4 ("drm/gem: Acquire references on
GEM handles for framebuffers") and commit f6bfc9afc751 ("drm/framebuffer:
Acquire internal references on GEM handles") only solved the problem
partially. They especially don't work for buffer objects without a DRM
framebuffer associated.
Hence, this revert to going back to using .import_attach->dmabuf.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://lore.kernel.org/r/20250715155934.150656-3-tzimmermann@suse.de
| -rw-r--r-- | drivers/gpu/drm/vmwgfx/vmwgfx_gem.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_gem.c b/drivers/gpu/drm/vmwgfx/vmwgfx_gem.c index c55382167c1b..e417921af584 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_gem.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_gem.c @@ -85,10 +85,10 @@ static int vmw_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map) int ret; if (drm_gem_is_imported(obj)) { - ret = dma_buf_vmap(obj->dma_buf, map); + ret = dma_buf_vmap(obj->import_attach->dmabuf, map); if (!ret) { if (drm_WARN_ON(obj->dev, map->is_iomem)) { - dma_buf_vunmap(obj->dma_buf, map); + dma_buf_vunmap(obj->import_attach->dmabuf, map); return -EIO; } } @@ -102,7 +102,7 @@ static int vmw_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map) static void vmw_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map) { if (drm_gem_is_imported(obj)) - dma_buf_vunmap(obj->dma_buf, map); + dma_buf_vunmap(obj->import_attach->dmabuf, map); else drm_gem_ttm_vunmap(obj, map); } |