Commit 9c607d4b authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Paolo Abeni
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xfrm: Use nested-BH locking for nat_keepalive_sk_ipv[46] 



nat_keepalive_sk_ipv[46] is a per-CPU variable and relies on disabled BH
for its locking. Without per-CPU locking in local_bh_disable() on
PREEMPT_RT this data structure requires explicit locking.

Use sock_bh_locked which has a sock pointer and a local_lock_t. Use
local_lock_nested_bh() for locking. This change adds only lockdep
coverage and does not alter the functional behaviour for !PREEMPT_RT.

Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-7-bigeasy@linutronix.de


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent b9eef339

net/xfrm/xfrm_nat_keepalive.c

+20 −10
Original line number Diff line number Diff line
@@ -9,9 +9,13 @@ 
#include <net/ip6_checksum.h>

#include <net/xfrm.h>



static DEFINE_PER_CPU(struct sock *, nat_keepalive_sk_ipv4);

static DEFINE_PER_CPU(struct sock_bh_locked, nat_keepalive_sk_ipv4) = {

	.bh_lock = INIT_LOCAL_LOCK(bh_lock),

};

#if IS_ENABLED(CONFIG_IPV6)

static DEFINE_PER_CPU(struct sock *, nat_keepalive_sk_ipv6);

static DEFINE_PER_CPU(struct sock_bh_locked, nat_keepalive_sk_ipv6) = {

	.bh_lock = INIT_LOCAL_LOCK(bh_lock),

};

#endif



struct nat_keepalive {
@@ -56,10 +60,12 @@ static int nat_keepalive_send_ipv4(struct sk_buff *skb, 


	skb_dst_set(skb, &rt->dst);



	sk = *this_cpu_ptr(&nat_keepalive_sk_ipv4);

	local_lock_nested_bh(&nat_keepalive_sk_ipv4.bh_lock);

	sk = this_cpu_read(nat_keepalive_sk_ipv4.sock);

	sock_net_set(sk, net);

	err = ip_build_and_send_pkt(skb, sk, fl4.saddr, fl4.daddr, NULL, tos);

	sock_net_set(sk, &init_net);

	local_unlock_nested_bh(&nat_keepalive_sk_ipv4.bh_lock);

	return err;

}
@@ -89,15 +95,19 @@ static int nat_keepalive_send_ipv6(struct sk_buff *skb, 
	fl6.fl6_sport = ka->encap_sport;

	fl6.fl6_dport = ka->encap_dport;



	sk = *this_cpu_ptr(&nat_keepalive_sk_ipv6);

	local_lock_nested_bh(&nat_keepalive_sk_ipv6.bh_lock);

	sk = this_cpu_read(nat_keepalive_sk_ipv6.sock);

	sock_net_set(sk, net);

	dst = ipv6_stub->ipv6_dst_lookup_flow(net, sk, &fl6, NULL);

	if (IS_ERR(dst))

	if (IS_ERR(dst)) {

		local_unlock_nested_bh(&nat_keepalive_sk_ipv6.bh_lock);

		return PTR_ERR(dst);

	}



	skb_dst_set(skb, dst);

	err = ipv6_stub->ip6_xmit(sk, skb, &fl6, skb->mark, NULL, 0, 0);

	sock_net_set(sk, &init_net);

	local_unlock_nested_bh(&nat_keepalive_sk_ipv6.bh_lock);

	return err;

}

#endif
@@ -202,7 +212,7 @@ static void nat_keepalive_work(struct work_struct *work) 
				      (ctx.next_run - ctx.now) * HZ);

}



static int nat_keepalive_sk_init(struct sock * __percpu *socks,

static int nat_keepalive_sk_init(struct sock_bh_locked __percpu *socks,

				 unsigned short family)

{

	struct sock *sk;
@@ -214,22 +224,22 @@ static int nat_keepalive_sk_init(struct sock * __percpu *socks, 
		if (err < 0)

			goto err;



		*per_cpu_ptr(socks, i) = sk;

		per_cpu_ptr(socks, i)->sock = sk;

	}



	return 0;

err:

	for_each_possible_cpu(i)

		inet_ctl_sock_destroy(*per_cpu_ptr(socks, i));

		inet_ctl_sock_destroy(per_cpu_ptr(socks, i)->sock);

	return err;

}



static void nat_keepalive_sk_fini(struct sock * __percpu *socks)

static void nat_keepalive_sk_fini(struct sock_bh_locked __percpu *socks)

{

	int i;



	for_each_possible_cpu(i)

		inet_ctl_sock_destroy(*per_cpu_ptr(socks, i));

		inet_ctl_sock_destroy(per_cpu_ptr(socks, i)->sock);

}



void xfrm_nat_keepalive_state_updated(struct xfrm_state *x)