diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2012-10-28 10:18:08 (GMT) |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2014-05-14 18:38:50 (GMT) |
| commit | 8231158a432dab1bb241f54b35a862e284df7007 (patch) | |
| tree | 9e67b2c0eccd1e49a85c67c0ee7d7f2c8a954106 | |
| parent | 08e37b3bad7807a5419efd1caa2d44c3632f27c9 (diff) | |
| download | linux-fsl-qoriq-8231158a432dab1bb241f54b35a862e284df7007.tar.xz | |
net: netfilter: Serialize xt_write_recseq sections on RT
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 <petela@gocougs.wsu.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable-rt@vger.kernel.org
| -rw-r--r-- | include/linux/netfilter/x_tables.h | 7 | ||||
| -rw-r--r-- | net/netfilter/core.c | 6 |
2 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h index dd49566..7d083af 100644 --- a/include/linux/netfilter/x_tables.h +++ b/include/linux/netfilter/x_tables.h @@ -3,6 +3,7 @@ #include <linux/netdevice.h> +#include <linux/locallock.h> #include <uapi/linux/netfilter/x_tables.h> /** @@ -284,6 +285,8 @@ 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 * @@ -298,6 +301,9 @@ 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(). @@ -328,6 +334,7 @@ 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 593b16e..6bd22aa 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -21,11 +21,17 @@ #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; |