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