Commit 7b6b53a7 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
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ipv6: anycast: Don't use rtnl_dereference(). 



inet6_dev->ac_list is protected by inet6_dev->lock, so rtnl_dereference()
is a bit rough annotation.

As done in mcast.c, we can use ac_dereference() that checks if
inet6_dev->lock is held.

Let's replace rtnl_dereference() with a new helper ac_dereference().

Note that now addrconf_join_solict() / addrconf_leave_solict() in
__ipv6_dev_ac_inc() / __ipv6_dev_ac_dec() does not need RTNL, so we
can remove ASSERT_RTNL() there.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250702230210.3115355-12-kuni1840@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 49b8223f

net/ipv6/addrconf.c

+0 −2
Original line number Diff line number Diff line
@@ -2252,7 +2252,6 @@ void addrconf_leave_solict(struct inet6_dev *idev, const struct in6_addr *addr) 
	__ipv6_dev_mc_dec(idev, &maddr);

}



/* caller must hold RTNL */

static void addrconf_join_anycast(struct inet6_ifaddr *ifp)

{

	struct in6_addr addr;
@@ -2265,7 +2264,6 @@ static void addrconf_join_anycast(struct inet6_ifaddr *ifp) 
	__ipv6_dev_ac_inc(ifp->idev, &addr);

}



/* caller must hold RTNL */

static void addrconf_leave_anycast(struct inet6_ifaddr *ifp)

{

	struct in6_addr addr;

net/ipv6/anycast.c

+8 −9
Original line number Diff line number Diff line
@@ -47,6 +47,9 @@ 
static struct hlist_head inet6_acaddr_lst[IN6_ADDR_HSIZE];

static DEFINE_SPINLOCK(acaddr_hash_lock);



#define ac_dereference(a, idev)						\

	rcu_dereference_protected(a, lockdep_is_held(&(idev)->lock))



static int ipv6_dev_ac_dec(struct net_device *dev, const struct in6_addr *addr);



static u32 inet6_acaddr_hash(const struct net *net,
@@ -319,16 +322,14 @@ int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr) 
	struct net *net;

	int err;



	ASSERT_RTNL();



	write_lock_bh(&idev->lock);

	if (idev->dead) {

		err = -ENODEV;

		goto out;

	}



	for (aca = rtnl_dereference(idev->ac_list); aca;

	     aca = rtnl_dereference(aca->aca_next)) {

	for (aca = ac_dereference(idev->ac_list, idev); aca;

	     aca = ac_dereference(aca->aca_next, idev)) {

		if (ipv6_addr_equal(&aca->aca_addr, addr)) {

			aca->aca_users++;

			err = 0;
@@ -380,12 +381,10 @@ int __ipv6_dev_ac_dec(struct inet6_dev *idev, const struct in6_addr *addr) 
{

	struct ifacaddr6 *aca, *prev_aca;



	ASSERT_RTNL();



	write_lock_bh(&idev->lock);

	prev_aca = NULL;

	for (aca = rtnl_dereference(idev->ac_list); aca;

	     aca = rtnl_dereference(aca->aca_next)) {

	for (aca = ac_dereference(idev->ac_list, idev); aca;

	     aca = ac_dereference(aca->aca_next, idev)) {

		if (ipv6_addr_equal(&aca->aca_addr, addr))

			break;

		prev_aca = aca;
@@ -429,7 +428,7 @@ void ipv6_ac_destroy_dev(struct inet6_dev *idev) 
	struct ifacaddr6 *aca;



	write_lock_bh(&idev->lock);

	while ((aca = rtnl_dereference(idev->ac_list)) != NULL) {

	while ((aca = ac_dereference(idev->ac_list, idev)) != NULL) {

		rcu_assign_pointer(idev->ac_list, aca->aca_next);

		write_unlock_bh(&idev->lock);