[PATCH 1/1] netfilter/jump_label: use HAVE_JUMP_LABEL?

From: Zhouyi Zhou
Date: Wed Aug 20 2014 - 22:53:34 EST



CONFIG_JUMP_LABEL doesn't ensure HAVE_JUMP_LABEL, if it
is not the case use maintainers's own mutex to guard
the modification of global values.

Signed-off-by: Zhouyi Zhou <yizhouzhou@xxxxxxxxx>
---
include/linux/netfilter.h | 5 +++--
net/netfilter/core.c | 6 +++---
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 2077489..83a1952 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -9,6 +9,7 @@
#include <linux/in6.h>
#include <linux/wait.h>
#include <linux/list.h>
+#include <linux/static_key.h>
#include <uapi/linux/netfilter.h>
#ifdef CONFIG_NETFILTER
static inline int NF_DROP_GETERR(int verdict)
@@ -99,8 +100,8 @@ void nf_unregister_sockopt(struct nf_sockopt_ops *reg);

extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];

-#if defined(CONFIG_JUMP_LABEL)
-#include <linux/static_key.h>
+#ifdef HAVE_JUMP_LABEL
+
extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
{
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index a93c97f..024a2e2 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -54,7 +54,7 @@ EXPORT_SYMBOL_GPL(nf_unregister_afinfo);
struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS] __read_mostly;
EXPORT_SYMBOL(nf_hooks);

-#if defined(CONFIG_JUMP_LABEL)
+#ifdef HAVE_JUMP_LABEL
struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
EXPORT_SYMBOL(nf_hooks_needed);
#endif
@@ -72,7 +72,7 @@ int nf_register_hook(struct nf_hook_ops *reg)
}
list_add_rcu(&reg->list, elem->list.prev);
mutex_unlock(&nf_hook_mutex);
-#if defined(CONFIG_JUMP_LABEL)
+#ifdef HAVE_JUMP_LABEL
static_key_slow_inc(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
return 0;
@@ -84,7 +84,7 @@ void nf_unregister_hook(struct nf_hook_ops *reg)
mutex_lock(&nf_hook_mutex);
list_del_rcu(&reg->list);
mutex_unlock(&nf_hook_mutex);
-#if defined(CONFIG_JUMP_LABEL)
+#ifdef HAVE_JUMP_LABEL
static_key_slow_dec(&nf_hooks_needed[reg->pf][reg->hooknum]);
#endif
synchronize_net();
--
1.7.10.4

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