[PATCH V2 rdma-next 4/4] RDMA/hns: Fix the illegal memory operation when cross page

From: Wei Hu (Xavier)
Date: Wed May 23 2018 - 04:51:30 EST


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.

Reported-by: Jie Chen <chenjie103@xxxxxxxxxx>
Reported-by: Xiping Zhang (Francis) <zhangxiping3@xxxxxxxxxx>
Fixes: b1c158350968("RDMA/hns: Get rid of virt_to_page and vmap calls after dma_alloc_coherent")
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx>

---
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
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c
+++ 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);
+ if (extend_sge_num > fi_sge_num) {
+ se_sge_num = extend_sge_num - fi_sge_num;
+ for (i = 0; i < fi_sge_num; i++) {
+ set_data_seg_v2(dseg++, sg + i);
+ (*sge_ind)++;
+ }
+ dseg = get_send_extend_sge(qp,
+ (*sge_ind) & (qp->sge.sge_cnt - 1));
+ for (i = 0; i < se_sge_num; i++) {
+ set_data_seg_v2(dseg++, sg + fi_sge_num + i);
+ (*sge_ind)++;
+ }
+ } else {
+ for (i = 0; i < extend_sge_num; i++) {
+ set_data_seg_v2(dseg++, sg + i);
+ (*sge_ind)++;
+ }
+ }
+}
+
static int set_rwqe_data_seg(struct ib_qp *ibqp, struct ib_send_wr *wr,
struct hns_roce_v2_rc_send_wqe *rc_sq_wqe,
void *wqe, unsigned int *sge_ind,
@@ -85,7 +131,7 @@ static int set_rwqe_data_seg(struct ib_qp *ibqp, struct ib_send_wr *wr,
roce_set_bit(rc_sq_wqe->byte_4, V2_RC_SEND_WQE_BYTE_4_INLINE_S,
1);
} else {
- if (wr->num_sge <= 2) {
+ if (wr->num_sge <= HNS_ROCE_V2_UC_RC_SGE_NUM_IN_WQE) {
for (i = 0; i < wr->num_sge; i++) {
if (likely(wr->sg_list[i].length)) {
set_data_seg_v2(dseg, wr->sg_list + i);
@@ -98,24 +144,14 @@ static int set_rwqe_data_seg(struct ib_qp *ibqp, struct ib_send_wr *wr,
V2_RC_SEND_WQE_BYTE_20_MSG_START_SGE_IDX_S,
(*sge_ind) & (qp->sge.sge_cnt - 1));

- for (i = 0; i < 2; i++) {
+ for (i = 0; i < HNS_ROCE_V2_UC_RC_SGE_NUM_IN_WQE; i++) {
if (likely(wr->sg_list[i].length)) {
set_data_seg_v2(dseg, wr->sg_list + i);
dseg++;
}
}

- dseg = get_send_extend_sge(qp,
- (*sge_ind) & (qp->sge.sge_cnt - 1));
-
- for (i = 0; i < wr->num_sge - 2; i++) {
- if (likely(wr->sg_list[i + 2].length)) {
- set_data_seg_v2(dseg,
- wr->sg_list + 2 + i);
- dseg++;
- (*sge_ind)++;
- }
- }
+ set_extend_sge(qp, wr, sge_ind);
}

roce_set_field(rc_sq_wqe->byte_16,
@@ -318,13 +354,7 @@ static int hns_roce_v2_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
memcpy(&ud_sq_wqe->dgid[0], &ah->av.dgid[0],
GID_LEN_V2);

- dseg = get_send_extend_sge(qp,
- sge_ind & (qp->sge.sge_cnt - 1));
- for (i = 0; i < wr->num_sge; i++) {
- set_data_seg_v2(dseg + i, wr->sg_list + i);
- sge_ind++;
- }
-
+ set_extend_sge(qp, wr, &sge_ind);
ind++;
} else if (ibqp->qp_type == IB_QPT_RC) {
rc_sq_wqe = wqe;
diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.h b/drivers/infiniband/hw/hns/hns_roce_hw_v2.h
index f16df1b..97f9bef 100644
--- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.h
+++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.h
@@ -77,6 +77,7 @@
#define HNS_ROCE_V2_MAX_INNER_MTPT_NUM 2
#define HNS_ROCE_INVALID_LKEY 0x100
#define HNS_ROCE_CMQ_TX_TIMEOUT 30000
+#define HNS_ROCE_V2_UC_RC_SGE_NUM_IN_WQE 2

#define HNS_ROCE_CONTEXT_HOP_NUM 1
#define HNS_ROCE_MTT_HOP_NUM 1
--
1.9.1