netns: Register net/core/ sysctls at read-only root.
Most of the net/core/xxx sysctls are read-only now, but this
goal is achieved with excessive memory consumption in each
namespace - the whole table is cloned and most of the entries
in it are ~= 0222.
Split it into two parts and register (the largest) one at the
read-only root.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 5fc8010..a570e2a 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -125,14 +125,6 @@
#endif /* CONFIG_XFRM */
#endif /* CONFIG_NET */
{
- .ctl_name = NET_CORE_SOMAXCONN,
- .procname = "somaxconn",
- .data = &init_net.core.sysctl_somaxconn,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec
- },
- {
.ctl_name = NET_CORE_BUDGET,
.procname = "netdev_budget",
.data = &netdev_budget,
@@ -151,6 +143,18 @@
{ .ctl_name = 0 }
};
+static struct ctl_table netns_core_table[] = {
+ {
+ .ctl_name = NET_CORE_SOMAXCONN,
+ .procname = "somaxconn",
+ .data = &init_net.core.sysctl_somaxconn,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec
+ },
+ { .ctl_name = 0 }
+};
+
static __net_initdata struct ctl_path net_core_path[] = {
{ .procname = "net", .ctl_name = CTL_NET, },
{ .procname = "core", .ctl_name = NET_CORE, },
@@ -159,23 +163,17 @@
static __net_init int sysctl_core_net_init(struct net *net)
{
- struct ctl_table *tbl, *tmp;
+ struct ctl_table *tbl;
net->core.sysctl_somaxconn = SOMAXCONN;
- tbl = net_core_table;
+ tbl = netns_core_table;
if (net != &init_net) {
- tbl = kmemdup(tbl, sizeof(net_core_table), GFP_KERNEL);
+ tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
if (tbl == NULL)
goto err_dup;
- for (tmp = tbl; tmp->procname; tmp++) {
- if (tmp->data >= (void *)&init_net &&
- tmp->data < (void *)(&init_net + 1))
- tmp->data += (char *)net - (char *)&init_net;
- else
- tmp->mode &= ~0222;
- }
+ tbl[0].data = &net->core.sysctl_somaxconn;
}
net->core.sysctl_hdr = register_net_sysctl_table(net,
@@ -186,7 +184,7 @@
return 0;
err_reg:
- if (tbl != net_core_table)
+ if (tbl != netns_core_table)
kfree(tbl);
err_dup:
return -ENOMEM;
@@ -198,7 +196,7 @@
tbl = net->core.sysctl_hdr->ctl_table_arg;
unregister_net_sysctl_table(net->core.sysctl_hdr);
- BUG_ON(tbl == net_core_table);
+ BUG_ON(tbl == netns_core_table);
kfree(tbl);
}
@@ -209,6 +207,7 @@
static __init int sysctl_core_init(void)
{
+ register_net_sysctl_rotable(net_core_path, net_core_table);
return register_pernet_subsys(&sysctl_core_ops);
}