infiniband: i40iw: Replace GFP_ATOMIC with GFP_KERNEL in i40iw_add_mqh_4

i40iw_add_mqh_4() is never called in atomic context, because it
calls rtnl_lock() that can sleep.

Despite never getting called from atomic context,
i40iw_add_mqh_4() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

diff --git a/drivers/infiniband/hw/i40iw/i40iw_cm.c b/drivers/infiniband/hw/i40iw/i40iw_cm.c
index 4cfa8f4..8310d24 100644 (file)
--- a/drivers/infiniband/hw/i40iw/i40iw_cm.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_cm.c
@@ -1788,7 +1788,7 @@ static enum i40iw_status_code i40iw_add_mqh_4(
                                            &ifa->ifa_address,
                                            rdma_vlan_dev_vlan_id(dev),
                                            dev->dev_addr);
-                               child_listen_node = kzalloc(sizeof(*child_listen_node), GFP_ATOMIC);
+                               child_listen_node = kzalloc(sizeof(*child_listen_node), GFP_KERNEL);
                                cm_parent_listen_node->cm_core->stats_listen_nodes_created++;
                                i40iw_debug(&iwdev->sc_dev,
                                            I40IW_DEBUG_CM,