On Mon, 24 Jul 2023 13:26:10 +0200 Boris Brezillon boris.brezillon@collabora.com wrote:
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 roman.stratiienko@globallogic.com
Adding Roman's tested-by coming from [1]
Tested-by: Roman Stratiienko r.stratiienko@gmail.com
[1]https://gitlab.freedesktop.org/mesa/mesa/-/issues/9416#note_2013722
Signed-off-by: Boris Brezillon boris.brezillon@collabora.com
drivers/gpu/drm/drm_gem_shmem_helper.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 4ea6507a77e5..baaf0e0feb06 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -623,7 +623,13 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct 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_ops = NULL;- ret = dma_buf_mmap(obj->dma_buf, vma, 0);
/* Drop the reference drm_gem_mmap_obj() acquired.*/