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

From: Wei Hu (Xavier)
Date: Fri May 25 2018 - 07:59:44 EST




On 2018/5/25 5:40, Jason Gunthorpe wrote:
> 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..
OK, we will fix it in v3.
Thanks
>> 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
>> +++ 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..
Ok, we will fix it v3.
Thanks

Wei Hu
> Jason
>
> .
>