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Commit fd706d69 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
Browse files

[NETFILTER]: Switch nf_register_hook/nf_unregister_hook to mutex 



The spinlock is only used in process context (register/unregister)
since RCU is used for the nf_hook lists, switch to a mutex.

Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d486dd1f

net/netfilter/core.c

+8 −5
Original line number Diff line number Diff line
@@ -61,28 +61,31 @@ EXPORT_SYMBOL_GPL(nf_unregister_afinfo); 
 * packets come back: if the hook is gone, the packet is discarded. */

struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS] __read_mostly;

EXPORT_SYMBOL(nf_hooks);

static DEFINE_SPINLOCK(nf_hook_lock);

static DEFINE_MUTEX(nf_hook_mutex);



int nf_register_hook(struct nf_hook_ops *reg)

{

	struct list_head *i;

	int err;



	spin_lock_bh(&nf_hook_lock);

	err = mutex_lock_interruptible(&nf_hook_mutex);

	if (err < 0)

		return err;

	list_for_each(i, &nf_hooks[reg->pf][reg->hooknum]) {

		if (reg->priority < ((struct nf_hook_ops *)i)->priority)

			break;

	}

	list_add_rcu(&reg->list, i->prev);

	spin_unlock_bh(&nf_hook_lock);

	mutex_unlock(&nf_hook_mutex);

	return 0;

}

EXPORT_SYMBOL(nf_register_hook);



void nf_unregister_hook(struct nf_hook_ops *reg)

{

	spin_lock_bh(&nf_hook_lock);

	mutex_lock(&nf_hook_mutex);

	list_del_rcu(&reg->list);

	spin_unlock_bh(&nf_hook_lock);

	mutex_unlock(&nf_hook_mutex);



	synchronize_net();

}