On Wed, Nov 20, 2019 at 1:18 PM Gerd Hoffmann <kra...@redhat.com> wrote: > > Hi, > > > > > I think for ttm just consistently using the one per-device mapping for > > > > everything, with all the fake offsets, is probably the quickest route. > > > > > > Hmm, not clear how to fit dmabufs into this. dmabufs already have their > > > own file, inode and address space. I'm not sure you can switch that > > > over to the per-device mapping in the first place, and even if you can I > > > have my doubts this is a good idea from a security point of view ... > > > > You can (plenty drivers do that already), > > Have pointer(s) to code?
dma_buf_mmap() does the same trick, but the other way round: It converts from gem mapping and fake offset to dma-buf mapping and 0 offset. I think we'd simply need the inverse. > > and not sure how that breaks > > security? > > Go try mmap(fake-offset) on the dma-buf file handle to access other > buffers of the drm device? Hmm, thinking again, I guess the > verify-access restrictions should prevent that. Ah, we're not going to replace the mapping on the dma-buf file. Only the file of the vma structure. Doing the former would indeed be pretty bad from a security pov. So don't do what amdgpu_gem_prime_export does, that's the bad stuff :-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
