Commit 3000024c authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-few-debug-refinements' 

Eric Dumazet says:

====================
net: few debug refinements

Adopt DEBUG_NET_WARN_ON_ONCE() or WARN_ON_ONCE()
in some places where it makes sense.

Add checks in napi_consume_skb() and __napi_alloc_skb()

Make sure napi_get_frags() does not use page fragments
for skb->head.
====================

Link: https://lore.kernel.org/r/20220608160438.1342569-1-eric.dumazet@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents f5f37fc9 fd9ea57f

net/core/dev.c

+19 −1
Original line number Diff line number Diff line
@@ -3925,7 +3925,7 @@ int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) 
	skb->pkt_type = PACKET_LOOPBACK;

	if (skb->ip_summed == CHECKSUM_NONE)

		skb->ip_summed = CHECKSUM_UNNECESSARY;

	WARN_ON(!skb_dst(skb));

	DEBUG_NET_WARN_ON_ONCE(!skb_dst(skb));

	skb_dst_force(skb);

	netif_rx(skb);

	return 0;
@@ -6351,6 +6351,23 @@ int dev_set_threaded(struct net_device *dev, bool threaded) 
}

EXPORT_SYMBOL(dev_set_threaded);



/* Double check that napi_get_frags() allocates skbs with

 * skb->head being backed by slab, not a page fragment.

 * This is to make sure bug fixed in 3226b158e67c

 * ("net: avoid 32 x truesize under-estimation for tiny skbs")

 * does not accidentally come back.

 */

static void napi_get_frags_check(struct napi_struct *napi)

{

	struct sk_buff *skb;



	local_bh_disable();

	skb = napi_get_frags(napi);

	WARN_ON_ONCE(skb && skb->head_frag);

	napi_free_frags(napi);

	local_bh_enable();

}



void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,

			   int (*poll)(struct napi_struct *, int), int weight)

{
@@ -6378,6 +6395,7 @@ void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi, 
	set_bit(NAPI_STATE_NPSVC, &napi->state);

	list_add_rcu(&napi->dev_list, &dev->napi_list);

	napi_hash_add(napi);

	napi_get_frags_check(napi);

	/* Create kthread for this napi if dev->threaded is set.

	 * Clear dev->threaded if kthread creation failed so that

	 * threaded mode will not be enabled in napi_enable().

net/core/skbuff.c

+3 −2
Original line number Diff line number Diff line
@@ -560,6 +560,7 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, 
	struct sk_buff *skb;

	void *data;



	DEBUG_NET_WARN_ON_ONCE(!in_softirq());

	len += NET_SKB_PAD + NET_IP_ALIGN;



	/* If requested length is either too small or too big,
@@ -728,7 +729,7 @@ void skb_release_head_state(struct sk_buff *skb) 
{

	skb_dst_drop(skb);

	if (skb->destructor) {

		WARN_ON(in_hardirq());

		DEBUG_NET_WARN_ON_ONCE(in_hardirq());

		skb->destructor(skb);

	}

#if IS_ENABLED(CONFIG_NF_CONNTRACK)
@@ -981,7 +982,7 @@ void napi_consume_skb(struct sk_buff *skb, int budget) 
		return;

	}



	lockdep_assert_in_softirq();

	DEBUG_NET_WARN_ON_ONCE(!in_softirq());



	if (!skb_unref(skb))

		return;

net/core/sock.c

+1 −1
Original line number Diff line number Diff line
@@ -2844,7 +2844,7 @@ void __release_sock(struct sock *sk) 
		do {

			next = skb->next;

			prefetch(next);

			WARN_ON_ONCE(skb_dst_is_noref(skb));

			DEBUG_NET_WARN_ON_ONCE(skb_dst_is_noref(skb));

			skb_mark_not_on_list(skb);

			sk_backlog_rcv(sk, skb);

net/core/stream.c

+3 −3
Original line number Diff line number Diff line
@@ -196,13 +196,13 @@ void sk_stream_kill_queues(struct sock *sk) 
	__skb_queue_purge(&sk->sk_receive_queue);



	/* Next, the write queue. */

	WARN_ON(!skb_queue_empty(&sk->sk_write_queue));

	WARN_ON_ONCE(!skb_queue_empty(&sk->sk_write_queue));



	/* Account for returned memory. */

	sk_mem_reclaim_final(sk);



	WARN_ON(sk->sk_wmem_queued);

	WARN_ON(sk->sk_forward_alloc);

	WARN_ON_ONCE(sk->sk_wmem_queued);

	WARN_ON_ONCE(sk->sk_forward_alloc);



	/* It is _impossible_ for the backlog to contain anything

	 * when we get here.  All user references to this socket

net/ipv4/af_inet.c

+4 −4
Original line number Diff line number Diff line
@@ -148,10 +148,10 @@ void inet_sock_destruct(struct sock *sk) 
		return;

	}



	WARN_ON(atomic_read(&sk->sk_rmem_alloc));

	WARN_ON(refcount_read(&sk->sk_wmem_alloc));

	WARN_ON(sk->sk_wmem_queued);

	WARN_ON(sk_forward_alloc_get(sk));

	WARN_ON_ONCE(atomic_read(&sk->sk_rmem_alloc));

	WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));

	WARN_ON_ONCE(sk->sk_wmem_queued);

	WARN_ON_ONCE(sk_forward_alloc_get(sk));



	kfree(rcu_dereference_protected(inet->inet_opt, 1));

	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));