On Tue, Jan 18, 2022 at 08:01:59AM +0000, yangx.jy@xxxxxxxxxxx wrote:
> On 2022/1/17 21:16, Jason Gunthorpe wrote:
> > On Thu, Jan 13, 2022 at 11:03:50AM +0800, Xiao Yang wrote:
> >> +static enum resp_states process_atomic_write(struct rxe_qp *qp,
> >> + struct rxe_pkt_info *pkt)
> >> +{
> >> + struct rxe_mr *mr = qp->resp.mr;
> >> +
> >> + u64 *src = payload_addr(pkt);
> >> +
> >> + u64 *dst = iova_to_vaddr(mr, qp->resp.va + qp->resp.offset, sizeof(u64));
> >> + if (!dst || (uintptr_t)dst& 7)
> >> + return RESPST_ERR_MISALIGNED_ATOMIC;
> > It looks to me like iova_to_vaddr is completely broken, where is the
> > kmap on that flow?
> Hi Jason,
>
> I think rxe_mr_init_user() maps the user addr space to the kernel addr
> space during memory region registration, the mapping records are saved
> into mr->cur_map_set->map[x].
There is no way to touch user memory from the CPU in the kernel
without calling one of the kmap's, so I don't know what this thinks it
is doing.
Jason
