Thread (6 messages) flat view 6 messages, 3 authors, 2014-11-22
STALE4267d

Revision v2 of 2 in this series.

Revisions (2)
  1. rfc [diff vs current]
  2. v2 current

[PATCH v2 9/9] netfilter: Replace smp_read_barrier_depends() with lockless_dereference()

From: Pranith Kumar <hidden>
Date: 2014-11-21 15:07:37
Also in: lkml, netfilter-devel
Subsystem: networking [general], the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

Recently lockless_dereference() was added which can be used in place of
hard-coding smp_read_barrier_depends(). The following PATCH makes the change.

Signed-off-by: Pranith Kumar <redacted>
---
 net/ipv4/netfilter/arp_tables.c | 3 +--
 net/ipv4/netfilter/ip_tables.c  | 3 +--
 net/ipv6/netfilter/ip6_tables.c | 3 +--
 3 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index f95b6f9..fc7533d 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -270,12 +270,11 @@ unsigned int arpt_do_table(struct sk_buff *skb,
 
 	local_bh_disable();
 	addend = xt_write_recseq_begin();
-	private = table->private;
 	/*
 	 * Ensure we load private-> members after we've fetched the base
 	 * pointer.
 	 */
-	smp_read_barrier_depends();
+	private = lockless_dereference(table->private);
 	table_base = private->entries[smp_processor_id()];
 
 	e = get_entry(table_base, private->hook_entry[hook]);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 99e810f..e0fd044 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -325,13 +325,12 @@ ipt_do_table(struct sk_buff *skb,
 	IP_NF_ASSERT(table->valid_hooks & (1 << hook));
 	local_bh_disable();
 	addend = xt_write_recseq_begin();
-	private = table->private;
 	cpu        = smp_processor_id();
 	/*
 	 * Ensure we load private-> members after we've fetched the base
 	 * pointer.
 	 */
-	smp_read_barrier_depends();
+	private = lockless_dereference(table->private);
 	table_base = private->entries[cpu];
 	jumpstack  = (struct ipt_entry **)private->jumpstack[cpu];
 	stackptr   = per_cpu_ptr(private->stackptr, cpu);
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index e080fbb..0459d6a 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -348,12 +348,11 @@ ip6t_do_table(struct sk_buff *skb,
 
 	local_bh_disable();
 	addend = xt_write_recseq_begin();
-	private = table->private;
 	/*
 	 * Ensure we load private-> members after we've fetched the base
 	 * pointer.
 	 */
-	smp_read_barrier_depends();
+	private = lockless_dereference(table->private);
 	cpu        = smp_processor_id();
 	table_base = private->entries[cpu];
 	jumpstack  = (struct ip6t_entry **)private->jumpstack[cpu];
-- 
1.9.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help