When skb is sent, it will pass the following functions in soft roce.
rxe_send [rdma_rxe]
ip_local_out
__ip_local_out
ip_output
ip_finish_output
ip_finish_output2
dev_queue_xmit
__dev_queue_xmit
dev_hard_start_xmit
In the above functions, if error occurs in the above functions or
iptables rules drop skb after ip_local_out, kfree_skb will be called.
So it is not necessary to call kfree_skb in soft roce module again.
Or else crash will occur.
The steps to reproduce:
server client
--------- ---------
|1.1.1.1|<----rxe-channel--->|1.1.1.2|
--------- ---------
On server: rping -s -a 1.1.1.1 -v -C 10000 -S 512
On client: rping -c -a 1.1.1.1 -v -C 10000 -S 512
The kernel configs CONFIG_DEBUG_KMEMLEAK and
CONFIG_DEBUG_OBJECTS are enabled on both server and client.
When rping runs, run the following command in server:
iptables -I OUTPUT -p udp --dport 4791 -j DROP
Without this patch, crash will occur.
CC: Srinivas Eeda <srinivas.eeda@xxxxxxxxxx>
CC: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Signed-off-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxxx>
Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx>
---
V1->V2: Not only the dropped skb is freed, but also the error skb
is also freed. So in soft roce, it is not necessary to call
kfree_skb again.
---
drivers/infiniband/sw/rxe/rxe_req.c | 1 -
drivers/infiniband/sw/rxe/rxe_resp.c | 6 +-----
2 files changed, 1 insertion(+), 6 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
index 7bdaf71..7851999 100644
--- a/drivers/infiniband/sw/rxe/rxe_req.c
+++ b/drivers/infiniband/sw/rxe/rxe_req.c
@@ -728,7 +728,6 @@ int rxe_requester(void *arg)
rollback_state(wqe, qp, &rollback_wqe, rollback_psn);
if (ret == -EAGAIN) {
- kfree_skb(skb);
rxe_run_task(&qp->req.task, 1);
goto exit;
}
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index a65c996..955ff3b 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -742,7 +742,6 @@ static enum resp_states read_reply(struct rxe_qp *qp,
err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
if (err) {
pr_err("Failed sending RDMA reply.\n");
- kfree_skb(skb);
return RESPST_ERR_RNR;
}
@@ -954,10 +953,8 @@ static int send_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt,
}
err = rxe_xmit_packet(rxe, qp, &ack_pkt, skb);
- if (err) {
+ if (err)
pr_err_ratelimited("Failed sending ack\n");
- kfree_skb(skb);
- }
err1:
return err;
@@ -1141,7 +1138,6 @@ static enum resp_states duplicate_request(struct rxe_qp *qp,
if (rc) {
pr_err("Failed resending result. This flow is not handled - skb ignored\n");
rxe_drop_ref(qp);
- kfree_skb(skb_copy);
rc = RESPST_CLEANUP;
goto out;
}
--
2.7.4
--
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