[PATCH 4.9 61/86] netfilter: x_tables: pass xt_counters struct instead of packet counter

Greg Kroah-Hartman
2018-03-16T15:23:24Z

From: Florian Westphal <fw@strlen.de>

commit 4d31eef5176df06f218201bc9c0ce40babb41660 upstream.

On SMP we overload the packet counter (unsigned long) to contain
percpu offset. Hide this from callers and pass xt_counters address
instead.

Preparation patch to allocate the percpu counters in page-sized batch
chunks.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/netfilter/x_tables.h | 6 +-----
net/ipv4/netfilter/arp_tables.c | 4 ++--
net/ipv4/netfilter/ip_tables.c | 4 ++--
net/ipv6/netfilter/ip6_tables.c | 5 ++---
net/netfilter/x_tables.c | 9 +++++++++
5 files changed, 16 insertions(+), 12 deletions(-)

--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -402,11 +402,7 @@ static inline unsigned long xt_percpu_co

return 0;
}
-static inline void xt_percpu_counter_free(u64 pcnt)
-{
- if (nr_cpu_ids > 1)
- free_percpu((void __percpu *) (unsigned long) pcnt);
-}
+void xt_percpu_counter_free(struct xt_counters *cnt);

static inline struct xt_counters *
xt_get_this_cpu_counter(struct xt_counters *cnt)
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -447,7 +447,7 @@ find_check_entry(struct arpt_entry *e, c
err:
module_put(t->u.kernel.target->me);
out:
- xt_percpu_counter_free(e->counters.pcnt);
+ xt_percpu_counter_free(&e->counters);

return ret;
}
@@ -527,7 +527,7 @@ static inline void cleanup_entry(struct
if (par.target->destroy != NULL)
par.target->destroy(&par);
module_put(par.target->me);
- xt_percpu_counter_free(e->counters.pcnt);
+ xt_percpu_counter_free(&e->counters);
}

/* Checks and translates the user-supplied table segment (held in
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -591,7 +591,7 @@ find_check_entry(struct ipt_entry *e, st
cleanup_match(ematch, net);
}

- xt_percpu_counter_free(e->counters.pcnt);
+ xt_percpu_counter_free(&e->counters);

return ret;
}
@@ -679,7 +679,7 @@ cleanup_entry(struct ipt_entry *e, struc
if (par.target->destroy != NULL)
par.target->destroy(&par);
module_put(par.target->me);
- xt_percpu_counter_free(e->counters.pcnt);
+ xt_percpu_counter_free(&e->counters);
}

/* Checks and translates the user-supplied table segment (held in
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -620,7 +620,7 @@ find_check_entry(struct ip6t_entry *e, s
cleanup_match(ematch, net);
}

- xt_percpu_counter_free(e->counters.pcnt);
+ xt_percpu_counter_free(&e->counters);

return ret;
}
@@ -707,8 +707,7 @@ static void cleanup_entry(struct ip6t_en
if (par.target->destroy != NULL)
par.target->destroy(&par);
module_put(par.target->me);
-
- xt_percpu_counter_free(e->counters.pcnt);
+ xt_percpu_counter_free(&e->counters);
}

/* Checks and translates the user-supplied table segment (held in
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -1619,6 +1619,15 @@ void xt_proto_fini(struct net *net, u_in
}
EXPORT_SYMBOL_GPL(xt_proto_fini);

+void xt_percpu_counter_free(struct xt_counters *counters)
+{
+ unsigned long pcnt = counters->pcnt;
+
+ if (nr_cpu_ids > 1)
+ free_percpu((void __percpu *)pcnt);
+}
+EXPORT_SYMBOL_GPL(xt_percpu_counter_free);
+
static int __net_init xt_net_init(struct net *net)
{
int i;