From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH V2 rdma-next 4/4] RDMA/hns: Fix the illegal memory operation when cross page Date: Thu, 24 May 2018 15:40:47 -0600 Message-ID: <20180524214047.GF3948@ziepe.ca> References: <1527070590-94399-1-git-send-email-xavier.huwei@huawei.com> <1527070590-94399-5-git-send-email-xavier.huwei@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1527070590-94399-5-git-send-email-xavier.huwei@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: "Wei Hu (Xavier)" Cc: dledford@redhat.com, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-rdma@vger.kernel.org On Wed, May 23, 2018 at 06:16:30PM +0800, Wei Hu (Xavier) wrote: > This patch fixed the potential illegal operation when using the > extend sge buffer cross page in post send operation. The bug > will cause the calltrace. Should include the oops for reference here.. > Reported-by: Jie Chen > Reported-by: Xiping Zhang (Francis) > Fixes: b1c158350968("RDMA/hns: Get rid of virt_to_page and vmap calls after dma_alloc_coherent") > Signed-off-by: Wei Hu (Xavier) > > v1->v2: Modify the Fixes statement according to Leon's comment. > drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 70 +++++++++++++++++++++--------- > drivers/infiniband/hw/hns/hns_roce_hw_v2.h | 1 + > 2 files changed, 51 insertions(+), 20 deletions(-) > > diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c > index a70d07b..62c1eb5 100644 > +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c > @@ -52,6 +52,52 @@ static void set_data_seg_v2(struct hns_roce_v2_wqe_data_seg *dseg, > dseg->len = cpu_to_le32(sg->length); > } > > +static void set_extend_sge(struct hns_roce_qp *qp, struct ib_send_wr *wr, > + unsigned int *sge_ind) > +{ > + struct hns_roce_v2_wqe_data_seg *dseg; > + struct ib_sge *sg; > + int num_in_wqe = 0; > + int extend_sge_num; > + int fi_sge_num; > + int se_sge_num; > + int shift; > + int i; > + > + if (qp->ibqp.qp_type == IB_QPT_RC || qp->ibqp.qp_type == IB_QPT_UC) > + num_in_wqe = HNS_ROCE_V2_UC_RC_SGE_NUM_IN_WQE; > + extend_sge_num = wr->num_sge - num_in_wqe; > + sg = wr->sg_list + num_in_wqe; > + shift = qp->hr_buf.page_shift; > + > + /* > + * Check whether wr->num_sge sges are in the same page. If not, we > + * should calculate how many sges in the first page and the second > + * page. > + */ > + dseg = get_send_extend_sge(qp, (*sge_ind) & (qp->sge.sge_cnt - 1)); > + fi_sge_num = (((((u64)dseg >> shift) + 1) << shift) - (u64)dseg) / > + sizeof(struct hns_roce_v2_wqe_data_seg); desg is a pointer.. that u64 should be a uinptr_t And it is better written as (round_up((uintptr_t)dseg, 1 << shift) - (uintptr)desg)/sizeof(struct hns_roce_v2_wqe_data_seg) if I got it right.. Jason