On Fri, Nov 06, 2020 at 04:34:07PM +0000, Xiong, Jianxin wrote: > > The user could specify a length that is beyond the dma buf, can > > the dma buf length be checked during get? > > In order to check the length, the buffer needs to be mapped. That can be done. Do DMA bufs even have definitate immutable lengths? Going to be a probelm if they can shrink > > Also page_size can be 0 because iova is not OK. iova should be > > checked for alignment during get as well: > > > > iova & (PAGE_SIZE-1) == umem->addr & (PAGE_SIZE-1) > > If ib_umem_dmabuf_map_pages is called during get this error is automatically caught. The ib_umem_find_best_pgsz() checks this equation, yes. So you'd map the sgl before allocating the mkey? This then checks the length and iova? Jason
