[PATCH RT 3/4] net: netfilter: Serialize xt_write_recseq sections on RT
flat view
STALE5090d
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2012-10-31 00:31:30
Also in:
lkml
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Thomas Gleixner <redacted> The netfilter code relies only on the implicit semantics of local_bh_disable() for serializing wt_write_recseq sections. RT breaks that and needs explicit serialization here. Reported-by: Peter LaDow <redacted> Signed-off-by: Thomas Gleixner <redacted> Cc: stable-rt@vger.kernel.org --- include/linux/locallock.h | 4 ++++ include/linux/netfilter/x_tables.h | 7 +++++++ net/netfilter/core.c | 6 ++++++ 3 files changed, 17 insertions(+)
diff --git a/include/linux/locallock.h b/include/linux/locallock.h
index f1804a3..a5eea5d 100644
--- a/include/linux/locallock.h
+++ b/include/linux/locallock.h@@ -25,6 +25,9 @@ struct local_irq_lock { DEFINE_PER_CPU(struct local_irq_lock, lvar) = { \ .lock = __SPIN_LOCK_UNLOCKED((lvar).lock) } +#define DECLARE_LOCAL_IRQ_LOCK(lvar) \ + DECLARE_PER_CPU(struct local_irq_lock, lvar) + #define local_irq_lock_init(lvar) \ do { \ int __cpu; \
@@ -220,6 +223,7 @@ static inline int __local_unlock_irqrestore(struct local_irq_lock *lv, #else /* PREEMPT_RT_BASE */ #define DEFINE_LOCAL_IRQ_LOCK(lvar) __typeof__(const int) lvar +#define DECLARE_LOCAL_IRQ_LOCK(lvar) extern __typeof__(const int) lvar static inline void local_irq_lock_init(int lvar) { }
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 32cddf7..bed90da2 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h@@ -186,6 +186,7 @@ struct xt_counters_info { #ifdef __KERNEL__ #include <linux/netdevice.h> +#include <linux/locallock.h> /** * struct xt_action_param - parameters for matches/targets
@@ -466,6 +467,8 @@ extern void xt_free_table_info(struct xt_table_info *info); */ DECLARE_PER_CPU(seqcount_t, xt_recseq); +DECLARE_LOCAL_IRQ_LOCK(xt_write_lock); + /** * xt_write_recseq_begin - start of a write section *
@@ -480,6 +483,9 @@ static inline unsigned int xt_write_recseq_begin(void) { unsigned int addend; + /* RT protection */ + local_lock(xt_write_lock); + /* * Low order bit of sequence is set if we already * called xt_write_recseq_begin().
@@ -510,6 +516,7 @@ static inline void xt_write_recseq_end(unsigned int addend) /* this is kind of a write_seqcount_end(), but addend is 0 or 1 */ smp_wmb(); __this_cpu_add(xt_recseq.sequence, addend); + local_unlock(xt_write_lock); } /*
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index afca6c7..aa3f87b 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c@@ -20,11 +20,17 @@ #include <linux/proc_fs.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/locallock.h> #include <net/net_namespace.h> #include <net/sock.h> #include "nf_internals.h" +#ifdef CONFIG_PREEMPT_RT_BASE +DEFINE_LOCAL_IRQ_LOCK(xt_write_lock); +EXPORT_PER_CPU_SYMBOL(xt_write_lock); +#endif + static DEFINE_MUTEX(afinfo_mutex); const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO] __read_mostly;
--
1.7.10.4