On Thu, Feb 25, 2021 at 11:30:23AM +0100, Christian König wrote: > > > Am 24.02.21 um 19:46 schrieb Jason Gunthorpe: > > On Wed, Feb 24, 2021 at 09:45:51AM +0100, Daniel Vetter wrote: > > > > > Hm I figured everyone just uses MAP_SHARED for buffer objects since > > > COW really makes absolutely no sense. How would we enforce this? > > In RDMA we test > > > > drivers/infiniband/core/ib_core_uverbs.c: if (!(vma->vm_flags & VM_SHARED)) > > > > During mmap to reject use of MAP_PRIVATE on BAR pages. > > That's a really good idea. MAP_PRIVATE and any driver mappings doesn't > really work at all. Yeah I feel like this is the next patch we need to add on this little series of locking down dma-buf mmap semantics. Probably should also push these into drm gem mmap code (and maybe ttm can switch over to that, it's really the same). One at a time. -Daniel > > Christian. > > > > > Jason > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
