RDMA/mad: Allocate zeroed MAD buffer

Ensure that MAD output buffer is zero-based allocated in all the callers
of process_mad and remove the various memset()'s from the drivers.

Link: https://lore.kernel.org/r/20191029062745.7932-3-leon@kernel.orgSigned-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/sysfs.c

@@ -481,8 +481,8 @@ static int get_perf_mad(struct ib_device *dev, int port_num, __be16 attr,
 	if (!dev->ops.process_mad)
 		return -ENOSYS;
 
-	in_mad  = kzalloc(sizeof *in_mad, GFP_KERNEL);
-	out_mad = kmalloc(sizeof *out_mad, GFP_KERNEL);
+	in_mad = kzalloc(sizeof(*in_mad), GFP_KERNEL);
+	out_mad = kzalloc(sizeof(*out_mad), GFP_KERNEL);
 	if (!in_mad || !out_mad) {
 		ret = -ENOMEM;
 		goto out;

drivers/infiniband/hw/mlx4/mad.c

@@ -966,7 +966,6 @@ static int iboe_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 	}
 	mutex_unlock(&dev->counters_table[port_num - 1].mutex);
 	if (stats_avail) {
-		memset(out_mad->data, 0, sizeof out_mad->data);
 		switch (counter_stats.counter_mode & 0xf) {
 		case 0:
 			edit_counter(&counter_stats,

drivers/infiniband/hw/mlx5/mad.c

@@ -284,8 +284,6 @@ int mlx5_ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 			 *out_mad_size != sizeof(*out_mad)))
 		return IB_MAD_RESULT_FAILURE;
 
-	memset(out_mad->data, 0, sizeof(out_mad->data));
-
 	if (MLX5_CAP_GEN(dev->mdev, vport_counters) &&
 	    in_mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_PERF_MGMT &&
 	    in_mad->mad_hdr.method == IB_MGMT_METHOD_GET) {

drivers/infiniband/hw/ocrdma/ocrdma_stats.c

@@ -675,7 +675,6 @@ int ocrdma_pma_counters(struct ocrdma_dev *dev,
 {
 	struct ib_pma_portcounters *pma_cnt;
 
-	memset(out_mad->data, 0, sizeof out_mad->data);
 	pma_cnt = (void *)(out_mad->data + 40);
 	ocrdma_update_stats(dev);
 

drivers/infiniband/hw/qib/qib_mad.c

@@ -2098,8 +2098,6 @@ static int cc_get_classportinfo(struct ib_cc_mad *ccp,
 	struct ib_cc_classportinfo_attr *p =
 		(struct ib_cc_classportinfo_attr *)ccp->mgmt_data;
 
-	memset(ccp->mgmt_data, 0, sizeof(ccp->mgmt_data));
-
 	p->base_version = 1;
 	p->class_version = 1;
 	p->cap_mask = 0;
@@ -2120,8 +2118,6 @@ static int cc_get_congestion_info(struct ib_cc_mad *ccp,
 	struct qib_ibport *ibp = to_iport(ibdev, port);
 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 
-	memset(ccp->mgmt_data, 0, sizeof(ccp->mgmt_data));
-
 	p->congestion_info = 0;
 	p->control_table_cap = ppd->cc_max_table_entries;
 
@@ -2138,8 +2134,6 @@ static int cc_get_congestion_setting(struct ib_cc_mad *ccp,
 	struct qib_pportdata *ppd = ppd_from_ibp(ibp);
 	struct ib_cc_congestion_entry_shadow *entries;
 
-	memset(ccp->mgmt_data, 0, sizeof(ccp->mgmt_data));
-
 	spin_lock(&ppd->cc_shadow_lock);
 
 	entries = ppd->congestion_entries_shadow->entries;
@@ -2176,8 +2170,6 @@ static int cc_get_congestion_control_table(struct ib_cc_mad *ccp,
 	if (cct_block_index > IB_CC_TABLE_CAP_DEFAULT - 1)
 		goto bail;
 
-	memset(ccp->mgmt_data, 0, sizeof(ccp->mgmt_data));
-
 	spin_lock(&ppd->cc_shadow_lock);
 
 	max_cct_block =