On Thu, Sep 17, 2020 at 10:09:12AM +0200, Daniel Vetter wrote: > Yeah, but it doesn't work when forwarding from the drm chardev to the > dma-buf on the importer side, since you'd need a ton of different > address spaces. And you still rely on the core code picking up your > pgoff mangling, which feels about as risky to me as the vma file > pointer wrangling - if it's not consistently applied the reverse map > is toast and unmap_mapping_range doesn't work correctly for our needs. I would think the pgoff has to be translated at the same time the vm->vm_file is changed? The owner of the dma_buf should have one virtual address space and FD, all its dma bufs should be linked to it, and all pgoffs translated to that space. Jason
