From: Boris Brezillon boris.brezillon@collabora.com
commit 07dd476f6116966cb2006e25fdcf48f0715115ff upstream.
The dma-buf backend is supposed to provide its own vm_ops, but some implementation just have nothing special to do and leave vm_ops untouched, probably expecting this field to be zero initialized (this is the case with the system_heap implementation for instance). Let's reset vma->vm_ops to NULL to keep things working with these implementations.
Fixes: 26d3ac3cb04d ("drm/shmem-helpers: Redirect mmap for imported dma-buf") Cc: stable@vger.kernel.org Cc: Daniel Vetter daniel.vetter@ffwll.ch Reported-by: Roman Stratiienko r.stratiienko@gmail.com Signed-off-by: Boris Brezillon boris.brezillon@collabora.com Tested-by: Roman Stratiienko r.stratiienko@gmail.com Reviewed-by: Thomas Zimmermann tzimmermann@suse.de Link: https://patchwork.freedesktop.org/patch/msgid/20230724112610.60974-1-boris.b... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/drm_gem_shmem_helper.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -591,7 +591,13 @@ int drm_gem_shmem_mmap(struct drm_gem_sh int ret;
if (obj->import_attach) { + /* Reset both vm_ops and vm_private_data, so we don't end up with + * vm_ops pointing to our implementation if the dma-buf backend + * doesn't set those fields. + */ vma->vm_private_data = NULL; + vma->vm_ops = NULL; + ret = dma_buf_mmap(obj->dma_buf, vma, 0);
/* Drop the reference drm_gem_mmap_obj() acquired.*/