Revert "RDMA/core: Don't expose hw_counters outside of init net namespace"

This reverts commit df45ae2a4f which is
commit a1ecb30f90856b0be4168ad51b8875148e285c1f upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Ibdc0ab01798b9814e1b5e39e2cc1718e9856a4fd
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/infiniband/core/device.c

@@ -544,8 +544,6 @@ static struct class ib_class = {
 static void rdma_init_coredev(struct ib_core_device *coredev,
 			      struct ib_device *dev, struct net *net)
 {
-	bool is_full_dev = &dev->coredev == coredev;
-
 	/* This BUILD_BUG_ON is intended to catch layout change
 	 * of union of ib_core_device and device.
 	 * dev must be the first element as ib_core and providers
@@ -557,13 +555,6 @@ static void rdma_init_coredev(struct ib_core_device *coredev,
 
 	coredev->dev.class = &ib_class;
 	coredev->dev.groups = dev->groups;
-
-	/*
-	 * Don't expose hw counters outside of the init namespace.
-	 */
-	if (!is_full_dev && dev->hw_stats_attr_index)
-		coredev->dev.groups[dev->hw_stats_attr_index] = NULL;
-
 	device_initialize(&coredev->dev);
 	coredev->owner = dev;
 	INIT_LIST_HEAD(&coredev->port_list);

drivers/infiniband/core/sysfs.c

@@ -988,7 +988,6 @@ int ib_setup_device_attrs(struct ib_device *ibdev)
 	for (i = 0; i != ARRAY_SIZE(ibdev->groups); i++)
 		if (!ibdev->groups[i]) {
 			ibdev->groups[i] = &data->group;
-			ibdev->hw_stats_attr_index = i;
 			return 0;
 		}
 	WARN(true, "struct ib_device->groups is too small");

include/rdma/ib_verbs.h

@@ -2737,7 +2737,6 @@ struct ib_device {
 	 * It is a NULL terminated array.
 	 */
 	const struct attribute_group	*groups[4];
-	u8				hw_stats_attr_index;
 
 	u64			     uverbs_cmd_mask;