3.16.63-rc1 review patch. If anyone has any objections, please let me know.
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From: Parav Pandit parav@mellanox.com
commit a5c57d327272bdf3a8b19686eaca2ec683449e67 upstream.
AH attribute of the cm_id can be overwritten if LAP message is received on CM request which is in progress. This bug got introduced to avoid sleeping when spin lock is held as part of commit in Fixes tag.
Therefore validate the cm_id state first and continue to perform AV ah_attr initialization.
Given that Aleternative path related messages are not supported for RoCE, init_av_from_response/path is such messages are ok to be called from blocking context.
Fixes: 33f93e1ebcf5 ("IB/cm: Fix sleeping while spin lock is held") Signed-off-by: Parav Pandit parav@mellanox.com Signed-off-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/infiniband/core/cm.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-)
--- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -2770,12 +2770,6 @@ static int cm_lap_handler(struct cm_work if (!cm_id_priv) return -EINVAL;
- 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 deref; - param = &work->cm_event.param.lap_rcvd; param->alternate_path = &work->path[0]; cm_format_path_from_lap(cm_id_priv, param->alternate_path, lap_msg); @@ -2813,10 +2807,16 @@ static int cm_lap_handler(struct cm_work goto unlock; }
- cm_id_priv->id.lap_state = IB_CM_LAP_RCVD; - cm_id_priv->tid = lap_msg->hdr.tid; + 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); + cm_id_priv->id.lap_state = IB_CM_LAP_RCVD; + cm_id_priv->tid = lap_msg->hdr.tid; ret = atomic_inc_and_test(&cm_id_priv->work_count); if (!ret) list_add_tail(&work->list, &cm_id_priv->work_list);