Revert "netfilter: x_tables: Update remaining dereference to RCU"

[ Upstream commit abe7034b9a8d57737e80cc16d60ed3666990bdbf ]

This reverts commit 443d6e86f821a165fae3fc3fc13086d27ac140b1.

This (and the following) patch basically re-implemented the RCU
mechanisms of patch 784544739a25. That patch was replaced because of the
performance problems that it created when replacing tables. Now, we have
the same issue: the call to synchronize_rcu() makes replacing tables
slower by as much as an order of magnitude.

Revert these patches and fix the issue in a different way.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 04a2010755a618e2ac7d3066d7d68b099a20a6a5..d1e04d2b5170ec0d054764f2f116ef6d818d03ef 100644 (file)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1379,7 +1379,7 @@ static int compat_get_entries(struct net *net,
        xt_compat_lock(NFPROTO_ARP);
        t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
        if (!IS_ERR(t)) {
-               const struct xt_table_info *private = xt_table_get_private_protected(t);
+               const struct xt_table_info *private = t->private;
                struct xt_table_info info;
 
                ret = compat_table_info(private, &info);

diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index a5b63f92b7f35ae1c7054183b3d50bcc78ac5f55..f15bc21d730164baf6cd2e8bf982c851685ee3c5 100644 (file)
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1589,7 +1589,7 @@ compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
        xt_compat_lock(AF_INET);
        t = xt_find_table_lock(net, AF_INET, get.name);
        if (!IS_ERR(t)) {
-               const struct xt_table_info *private = xt_table_get_private_protected(t);
+               const struct xt_table_info *private = t->private;
                struct xt_table_info info;
                ret = compat_table_info(private, &info);
                if (!ret && get.size == info.size)

diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 81c042940b215d31c67a15b9af0df1f2253ce34f..2e2119bfcf137348e1ee77dcd360267e2ef47d77 100644 (file)
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1598,7 +1598,7 @@ compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
        xt_compat_lock(AF_INET6);
        t = xt_find_table_lock(net, AF_INET6, get.name);
        if (!IS_ERR(t)) {
-               const struct xt_table_info *private = xt_table_get_private_protected(t);
+               const struct xt_table_info *private = t->private;
                struct xt_table_info info;
                ret = compat_table_info(private, &info);
                if (!ret && get.size == info.size)