net: ipv{6,4}: 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 sysctl_route_net_init And ipv6_route_sysctl_init.
  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.
* Remove extra sentinel element in the declaration of devinet_vars.
* Removed the "-1" in __devinet_sysctl_register, sysctl_route_net_init,
  ipv6_sysctl_net_init and ipv4_sysctl_init_net that adjusted for having
  an extra empty element when looping over ctl_table arrays
* Replace the for loop stop condition in __addrconf_sysctl_register that
  tests for procname == NULL with one that depends on array size
* Removing the unprivileged user check in ipv6_route_sysctl_init is
  safe as it is replaced by calling ipv6_route_sysctl_table_size;
  introduced in commit c899710fe7f9 ("networking: Update to
  register_net_sysctl_sz")
* 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, 3 insertions, 5 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 9aa0900abfa1..5c424a0e7232 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -7184,14 +7184,12 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= SYSCTL_TWO,
 	},
-	{
-		/* sentinel */
-	}
 };
 
 static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 		struct inet6_dev *idev, struct ipv6_devconf *p)
 {
+	size_t table_size = ARRAY_SIZE(addrconf_sysctl);
 	int i, ifindex;
 	struct ctl_table *table;
 	char path[sizeof("net/ipv6/conf/") + IFNAMSIZ];
@@ -7200,7 +7198,7 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 	if (!table)
 		goto out;
 
-	for (i = 0; table[i].data; i++) {
+	for (i = 0; i < table_size; i++) {
 		table[i].data += (char *)p - (char *)&ipv6_devconf;
 		/* If one of these is already set, then it is not safe to
 		 * overwrite either of them: this makes proc_dointvec_minmax
@@ -7215,7 +7213,7 @@ static int __addrconf_sysctl_register(struct net *net, char *dev_name,
 	snprintf(path, sizeof(path), "net/ipv6/conf/%s", dev_name);
 
 	p->sysctl_header = register_net_sysctl_sz(net, path, table,
-						  ARRAY_SIZE(addrconf_sysctl));
+						  table_size);
 	if (!p->sysctl_header)
 		goto free;