Commit 01c445a4 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'soreuseport-mixed-v4-v6-fixes' 



Craig Gallek says:

====================
Fixes for SO_REUSEPORT and mixed v4/v6 sockets

Recent changes to the datastructures associated with SO_REUSEPORT broke
an existing behavior when equivalent SO_REUSEPORT sockets are created
using both AF_INET and AF_INET6.  This patch series restores the previous
behavior and includes a test to validate it.

This series should be a trivial merge to stable kernels (if deemed
necessary), but will have conflicts in net-next.  The following patches
recently replaced the use of hlist_nulls with hlists for UDP and TCP
socket lists:
ca065d0c ("udp: no longer use SLAB_DESTROY_BY_RCU")
3b24d854 ("tcp/dccp: do not touch listener sk_refcnt under synflood")

If this series is accepted, I will send an RFC for the net-next change
to assist with the merge.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents c5b5343c d6a61f80

include/linux/rculist_nulls.h

+39 −0
Original line number Diff line number Diff line
@@ -98,6 +98,45 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n, 
	if (!is_a_nulls(first))

		first->pprev = &n->next;

}



/**

 * hlist_nulls_add_tail_rcu

 * @n: the element to add to the hash list.

 * @h: the list to add to.

 *

 * Description:

 * Adds the specified element to the end of the specified hlist_nulls,

 * while permitting racing traversals.  NOTE: tail insertion requires

 * list traversal.

 *

 * The caller must take whatever precautions are necessary

 * (such as holding appropriate locks) to avoid racing

 * with another list-mutation primitive, such as hlist_nulls_add_head_rcu()

 * or hlist_nulls_del_rcu(), running on this same list.

 * However, it is perfectly legal to run concurrently with

 * the _rcu list-traversal primitives, such as

 * hlist_nulls_for_each_entry_rcu(), used to prevent memory-consistency

 * problems on Alpha CPUs.  Regardless of the type of CPU, the

 * list-traversal primitive must be guarded by rcu_read_lock().

 */

static inline void hlist_nulls_add_tail_rcu(struct hlist_nulls_node *n,

					struct hlist_nulls_head *h)

{

	struct hlist_nulls_node *i, *last = NULL;



	for (i = hlist_nulls_first_rcu(h); !is_a_nulls(i);

	     i = hlist_nulls_next_rcu(i))

		last = i;



	if (last) {

		n->next = last->next;

		n->pprev = &last->next;

		rcu_assign_pointer(hlist_nulls_next_rcu(last), n);

	} else {

		hlist_nulls_add_head_rcu(n, h);

	}

}



/**

 * hlist_nulls_for_each_entry_rcu - iterate over rcu list of given type

 * @tpos:	the type * to use as a loop cursor.

include/net/sock.h

+5 −1
Original line number Diff line number Diff line
@@ -630,6 +630,10 @@ static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list) 


static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)

{

	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&

	    sk->sk_family == AF_INET6)

		hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);

	else

		hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);

}

net/ipv4/udp.c

+7 −2
Original line number Diff line number Diff line
@@ -339,6 +339,11 @@ found: 


		hslot2 = udp_hashslot2(udptable, udp_sk(sk)->udp_portaddr_hash);

		spin_lock(&hslot2->lock);

		if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&

			sk->sk_family == AF_INET6)

			hlist_nulls_add_tail_rcu(&udp_sk(sk)->udp_portaddr_node,

						 &hslot2->head);

		else

			hlist_nulls_add_head_rcu(&udp_sk(sk)->udp_portaddr_node,

						 &hslot2->head);

		hslot2->count++;

tools/testing/selftests/net/.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -3,3 +3,4 @@ psock_fanout 
psock_tpacket

reuseport_bpf

reuseport_bpf_cpu

reuseport_dualstack

tools/testing/selftests/net/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ CFLAGS = -Wall -O2 -g 


CFLAGS += -I../../../../usr/include/



NET_PROGS = socket psock_fanout psock_tpacket reuseport_bpf reuseport_bpf_cpu

NET_PROGS = socket psock_fanout psock_tpacket reuseport_bpf reuseport_bpf_cpu reuseport_dualstack



all: $(NET_PROGS)

%: %.c

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