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authorThomas Gleixner <tglx@linutronix.de>2012-10-28 10:18:08 (GMT)
committerScott Wood <scottwood@freescale.com>2015-02-13 22:21:06 (GMT)
commit8b9cc0e9ce1b2ddc42deca0c2187160254c876ea (patch)
tree4db5e2d1dff2f377b80f87bbe662eafedcec16da /include
parentddfd2eb507c698249704a242b395c23225092572 (diff)
downloadlinux-fsl-qoriq-8b9cc0e9ce1b2ddc42deca0c2187160254c876ea.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
Diffstat (limited to 'include')
-rw-r--r--include/linux/netfilter/x_tables.h7
1 files changed, 7 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);
}
/*