net: Remove the now superfluous sentinel elements from ctl_table array

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

* Remove sentinel element from ctl_table structs.
* Remove the zeroing out of an array element (to make it look like a
  sentinel) in neigh_sysctl_register and lowpan_frags_ns_sysctl_register
  This is not longer needed and is safe after commit c899710fe7f9
  ("networking: Update to register_net_sysctl_sz") added the array size
  to the ctl_table registration.
* Replace the for loop stop condition in sysctl_core_net_init that tests
  for procname == NULL with one that depends on array size
* Removed the "-1" in mpls_net_init that adjusted for having an extra
  empty element when looping over ctl_table arrays
* Use a table_size variable to keep the value of ARRAY_SIZE

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 7 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 5d2012d1cf4a..2dc7a908a6bb 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1377,13 +1377,13 @@ static const struct ctl_table mpls_dev_table[] = {
 		.proc_handler	= mpls_conf_proc,
 		.data		= MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
 	},
-	{ }
 };
 
 static int mpls_dev_sysctl_register(struct net_device *dev,
 				    struct mpls_dev *mdev)
 {
 	char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
+	size_t table_size = ARRAY_SIZE(mpls_dev_table);
 	struct net *net = dev_net(dev);
 	struct ctl_table *table;
 	int i;
@@ -1395,7 +1395,7 @@ static int mpls_dev_sysctl_register(struct net_device *dev,
 	/* Table data contains only offsets relative to the base of
 	 * the mdev at this point, so make them absolute.
 	 */
-	for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
+	for (i = 0; i < table_size; i++) {
 		table[i].data = (char *)mdev + (uintptr_t)table[i].data;
 		table[i].extra1 = mdev;
 		table[i].extra2 = net;
@@ -1403,8 +1403,7 @@ static int mpls_dev_sysctl_register(struct net_device *dev,
 
 	snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
 
-	mdev->sysctl = register_net_sysctl_sz(net, path, table,
-					      ARRAY_SIZE(mpls_dev_table));
+	mdev->sysctl = register_net_sysctl_sz(net, path, table, table_size);
 	if (!mdev->sysctl)
 		goto free;
 
@@ -2653,11 +2652,11 @@ static const struct ctl_table mpls_table[] = {
 		.extra1		= SYSCTL_ONE,
 		.extra2		= &ttl_max,
 	},
-	{ }
 };
 
 static int mpls_net_init(struct net *net)
 {
+	size_t table_size = ARRAY_SIZE(mpls_table);
 	struct ctl_table *table;
 	int i;
 
@@ -2673,11 +2672,11 @@ static int mpls_net_init(struct net *net)
 	/* Table data contains only offsets relative to the base of
 	 * the mdev at this point, so make them absolute.
 	 */
-	for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
+	for (i = 0; i < table_size; i++)
 		table[i].data = (char *)net + (uintptr_t)table[i].data;
 
 	net->mpls.ctl = register_net_sysctl_sz(net, "net/mpls", table,
-					       ARRAY_SIZE(mpls_table));
+					       table_size);
 	if (net->mpls.ctl == NULL) {
 		kfree(table);
 		return -ENOMEM;