[PATCH 3.16 088/305] IB/{cm, umad}: Handle av init error

[Ben Hutchings]

3.16.63-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Parav Pandit <parav@xxxxxxxxxxxx>

commit 0c4386ec77cfcd0ccbdbe8c2e67dd3a49b2a4c7f upstream.

cm_init_av_for_response depends on ib_init_ah_from_wc() whose return
status is ignored.
ib_init_ah_from_wc() can fail and its return status should be handled as
done in this patch.

Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/infiniband/core/cm.c       | 34 ++++++++++++++++++------------
 drivers/infiniband/core/user_mad.c | 10 ++++++---
 2 files changed, 28 insertions(+), 16 deletions(-)

--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -380,13 +380,13 @@ static void cm_set_private_data(struct c
 	cm_id_priv->private_data_len = private_data_len;
 }
 
-static void cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
-				    struct ib_grh *grh, struct cm_av *av)
+static int cm_init_av_for_response(struct cm_port *port, struct ib_wc *wc,
+				   struct ib_grh *grh, struct cm_av *av)
 {
 	av->port = port;
 	av->pkey_index = wc->pkey_index;
-	ib_init_ah_from_wc(port->cm_dev->ib_device, port->port_num, wc,
-			   grh, &av->ah_attr);
+	return ib_init_ah_from_wc(port->cm_dev->ib_device, port->port_num, wc,
+				  grh, &av->ah_attr);
 }
 
 static int cm_init_av_by_path(struct ib_sa_path_rec *path, struct cm_av *av,
@@ -1601,9 +1601,11 @@ static int cm_req_handler(struct cm_work
 
 	cm_id_priv = container_of(cm_id, struct cm_id_private, id);
 	cm_id_priv->id.remote_id = req_msg->local_comm_id;
-	cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
-				work->mad_recv_wc->recv_buf.grh,
-				&cm_id_priv->av);
+	ret = cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
+				      work->mad_recv_wc->recv_buf.grh,
+				      &cm_id_priv->av);
+	if (ret)
+		goto destroy;
 	cm_id_priv->timewait_info = cm_create_timewait_info(cm_id_priv->
 							    id.local_id);
 	if (IS_ERR(cm_id_priv->timewait_info)) {
@@ -2807,9 +2809,11 @@ static int cm_lap_handler(struct cm_work
 
 	cm_id_priv->id.lap_state = IB_CM_LAP_RCVD;
 	cm_id_priv->tid = lap_msg->hdr.tid;
-	cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
-				work->mad_recv_wc->recv_buf.grh,
-				&cm_id_priv->av);
+	ret = cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
+				      work->mad_recv_wc->recv_buf.grh,
+				      &cm_id_priv->av);
+	if (ret)
+		goto unlock;
 	cm_init_av_by_path(param->alternate_path, &cm_id_priv->alt_av,
 			   cm_id_priv);
 	ret = atomic_inc_and_test(&cm_id_priv->work_count);
@@ -3060,6 +3064,7 @@ static int cm_sidr_req_handler(struct cm
 	struct cm_id_private *cm_id_priv, *cur_cm_id_priv;
 	struct cm_sidr_req_msg *sidr_req_msg;
 	struct ib_wc *wc;
+	int ret;
 
 	cm_id = ib_create_cm_id(work->port->cm_dev->ib_device, NULL, NULL);
 	if (IS_ERR(cm_id))
@@ -3072,9 +3077,12 @@ static int cm_sidr_req_handler(struct cm
 	wc = work->mad_recv_wc->wc;
 	cm_id_priv->av.dgid.global.subnet_prefix = cpu_to_be64(wc->slid);
 	cm_id_priv->av.dgid.global.interface_id = 0;
-	cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
-				work->mad_recv_wc->recv_buf.grh,
-				&cm_id_priv->av);
+	ret = cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
+				      work->mad_recv_wc->recv_buf.grh,
+				      &cm_id_priv->av);
+	if (ret)
+		goto out;
+
 	cm_id_priv->id.remote_id = sidr_req_msg->request_id;
 	cm_id_priv->tid = sidr_req_msg->hdr.tid;
 	atomic_inc(&cm_id_priv->work_count);
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -234,10 +234,14 @@ static void recv_handler(struct ib_mad_a
 	packet->mad.hdr.grh_present = !!(mad_recv_wc->wc->wc_flags & IB_WC_GRH);
 	if (packet->mad.hdr.grh_present) {
 		struct ib_ah_attr ah_attr;
+		int ret;
 
-		ib_init_ah_from_wc(agent->device, agent->port_num,
-				   mad_recv_wc->wc, mad_recv_wc->recv_buf.grh,
-				   &ah_attr);
+		ret = ib_init_ah_from_wc(agent->device, agent->port_num,
+					 mad_recv_wc->wc,
+					 mad_recv_wc->recv_buf.grh,
+					 &ah_attr);
+		if (ret)
+			goto err2;
 
 		packet->mad.hdr.gid_index = ah_attr.grh.sgid_index;
 		packet->mad.hdr.hop_limit = ah_attr.grh.hop_limit;