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>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index af270c202d9a96f64a409cb7f37f1d4620d948f8..45fd88405b6b89d373328e44276adf54be194dc1 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -3733,7 +3733,7 @@ static int neigh_proc_base_reachable_time(struct ctl_table *ctl, int write,
 
 static struct neigh_sysctl_table {
        struct ctl_table_header *sysctl_header;
-       struct ctl_table neigh_vars[NEIGH_VAR_MAX + 1];
+       struct ctl_table neigh_vars[NEIGH_VAR_MAX];
 } neigh_sysctl_template __read_mostly = {
        .neigh_vars = {
                NEIGH_SYSCTL_ZERO_INTMAX_ENTRY(MCAST_PROBES, "mcast_solicit"),
@@ -3784,7 +3784,6 @@ static struct neigh_sysctl_table {
                        .extra2         = SYSCTL_INT_MAX,
                        .proc_handler   = proc_dointvec_minmax,
                },
-               {},
        },
 };
 
@@ -3812,8 +3811,6 @@ int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p,
        if (dev) {
                dev_name_source = dev->name;
                /* Terminate the table early */
-               memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
-                      sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
                neigh_vars_size = NEIGH_VAR_BASE_REACHABLE_TIME_MS + 1;
        } else {
                struct neigh_table *tbl = p->tbl;

diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 6da5995ac86a08a58e63af9a1e62c7a136c08dc9..c9fb9ad874857311537cd50924e29caa6d202e07 100644 (file)
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -661,7 +661,6 @@ static struct ctl_table net_core_table[] = {
                .proc_handler   = proc_dointvec_minmax,
                .extra1         = SYSCTL_ZERO,
        },
-       { }
 };
 
 static struct ctl_table netns_core_table[] = {
@@ -698,7 +697,6 @@ static struct ctl_table netns_core_table[] = {
                .extra2         = SYSCTL_ONE,
                .proc_handler   = proc_dou8vec_minmax,
        },
-       { }
 };
 
 static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
@@ -716,20 +714,21 @@ __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
 
 static __net_init int sysctl_core_net_init(struct net *net)
 {
-       struct ctl_table *tbl, *tmp;
+       size_t table_size = ARRAY_SIZE(netns_core_table);
+       struct ctl_table *tbl;
 
        tbl = netns_core_table;
        if (!net_eq(net, &init_net)) {
+               int i;
                tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
                if (tbl == NULL)
                        goto err_dup;
 
-               for (tmp = tbl; tmp->procname; tmp++)
-                       tmp->data += (char *)net - (char *)&init_net;
+               for (i = 0; i < table_size; ++i)
+                       tbl[i].data += (char *)net - (char *)&init_net;
        }
 
-       net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl,
-                                                     ARRAY_SIZE(netns_core_table));
+       net->core.sysctl_hdr = register_net_sysctl_sz(net, "net/core", tbl, table_size);
        if (net->core.sysctl_hdr == NULL)
                goto err_reg;
 

diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c
index ee8d4f5afa72262c96b220bfdd5ef954d11daa38..3fc474d6e57ddacb00ef7c03b965d79fda3f5873 100644 (file)
--- a/net/dccp/sysctl.c
+++ b/net/dccp/sysctl.c
@@ -90,8 +90,6 @@ static struct ctl_table dccp_default_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_ms_jiffies,
        },
-
-       { }
 };
 
 static struct ctl_table_header *dccp_table_header;

diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c
index 2a983cf450daf1b7b83c63ea02657f8904d5b31b..56ef873828f40e9d4681d67f6a7b67b5c11b6e95 100644 (file)
--- a/net/ieee802154/6lowpan/reassembly.c
+++ b/net/ieee802154/6lowpan/reassembly.c
@@ -338,7 +338,6 @@ static struct ctl_table lowpan_frags_ns_ctl_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
-       { }
 };
 
 /* secret interval has been deprecated */
@@ -351,7 +350,6 @@ static struct ctl_table lowpan_frags_ctl_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec_jiffies,
        },
-       { }
 };
 
 static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
@@ -370,10 +368,8 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net)
                        goto err_alloc;
 
                /* Don't export sysctls to unprivileged users */
-               if (net->user_ns != &init_user_ns) {
-                       table[0].procname = NULL;
+               if (net->user_ns != &init_user_ns)
                        table_size = 0;
-               }
        }
 
        table[0].data   = &ieee802154_lowpan->fqdir->high_thresh;

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 5d2012d1cf4afd4dfed1d2978e049e1b8ed4e50d..2dc7a908a6bb9cdf9fdaf1ff8be54d9d5618482e 100644 (file)
--- 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;

diff --git a/net/unix/sysctl_net_unix.c b/net/unix/sysctl_net_unix.c
index 44996af61999b5eabc6813c6d7563eac82ad2fe2..357b3e5f38472dc40ebc50f80775e5a30f3e8927 100644 (file)
--- a/net/unix/sysctl_net_unix.c
+++ b/net/unix/sysctl_net_unix.c
@@ -19,7 +19,6 @@ static struct ctl_table unix_table[] = {
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
-       { }
 };
 
 int __net_init unix_sysctl_register(struct net *net)