On Fri, Oct 21, 2022 at 3:53 PM Li Zhijian <lizhijian@xxxxxxxxxxx> wrote:
>
> Before the testing, we already passed it to rxe_mr_copy() where mr could
> be dereferenced. so this checking is not exactly correct.
>
> I tried to figure out the details how/when mr could be NULL, but failed
> at last. Add a WARN_ON(!mr) to that path to tell us more when it
> happends.
If I get you correctly, you confronted a problem, but you can not figure it out.
So you send it upstream as a patch?
I am not sure if it is a good idea.
Zhu Yanjun
>
> Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
> ---
> drivers/infiniband/sw/rxe/rxe_resp.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
> index ed5a09e86417..218c14fb07c6 100644
> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
> @@ -778,6 +778,7 @@ static enum resp_states read_reply(struct rxe_qp *qp,
> if (res->state == rdatm_res_state_new) {
> if (!res->replay) {
> mr = qp->resp.mr;
> + WARN_ON(!mr);
> qp->resp.mr = NULL;
> } else {
> mr = rxe_recheck_mr(qp, res->read.rkey);
> @@ -811,8 +812,7 @@ static enum resp_states read_reply(struct rxe_qp *qp,
>
> rxe_mr_copy(mr, res->read.va, payload_addr(&ack_pkt),
> payload, RXE_FROM_MR_OBJ);
> - if (mr)
> - rxe_put(mr);
> + rxe_put(mr);
>
> if (bth_pad(&ack_pkt)) {
> u8 *pad = payload_addr(&ack_pkt) + payload;
> --
> 2.31.1
>
