Commit fe33311c authored by Jason Xing's avatar Jason Xing Committed by David S. Miller
Browse files

net: no longer support SOCK_REFCNT_DEBUG feature 

Commit e48c414e ("[INET]: Generalise the TCP sock ID lookup routines")
commented out the definition of SOCK_REFCNT_DEBUG in 2005 and later another
commit 463c84b9 ("[NET]: Introduce inet_connection_sock") removed it.
Since we could track all of them through bpf and kprobe related tools
and the feature could print loads of information which might not be
that helpful even under a little bit pressure, the whole feature which
has been inactive for many years is no longer supported.

Link: https://lore.kernel.org/lkml/20230211065153.54116-1-kerneljasonxing@gmail.com/


Suggested-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarJason Xing <kernelxing@tencent.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: default avatarWenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ed32ad4

include/net/sock.h

+0 −28
Original line number Diff line number Diff line
@@ -1349,9 +1349,6 @@ struct proto { 
	char			name[32];



	struct list_head	node;

#ifdef SOCK_REFCNT_DEBUG

	atomic_t		socks;

#endif

	int			(*diag_destroy)(struct sock *sk, int err);

} __randomize_layout;
@@ -1359,31 +1356,6 @@ int proto_register(struct proto *prot, int alloc_slab); 
void proto_unregister(struct proto *prot);

int sock_load_diag_module(int family, int protocol);



#ifdef SOCK_REFCNT_DEBUG

static inline void sk_refcnt_debug_inc(struct sock *sk)

{

	atomic_inc(&sk->sk_prot->socks);

}



static inline void sk_refcnt_debug_dec(struct sock *sk)

{

	atomic_dec(&sk->sk_prot->socks);

	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",

	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));

}



static inline void sk_refcnt_debug_release(const struct sock *sk)

{

	if (refcount_read(&sk->sk_refcnt) != 1)

		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",

		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));

}

#else /* SOCK_REFCNT_DEBUG */

#define sk_refcnt_debug_inc(sk) do { } while (0)

#define sk_refcnt_debug_dec(sk) do { } while (0)

#define sk_refcnt_debug_release(sk) do { } while (0)

#endif /* SOCK_REFCNT_DEBUG */



INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));



static inline int sk_forward_alloc_get(const struct sock *sk)

net/core/sock.c

+0 −13
Original line number Diff line number Diff line
@@ -2340,17 +2340,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) 
	smp_wmb();

	refcount_set(&newsk->sk_refcnt, 2);



	/* Increment the counter in the same struct proto as the master

	 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that

	 * is the same as sk->sk_prot->socks, as this field was copied

	 * with memcpy).

	 *

	 * This _changes_ the previous behaviour, where

	 * tcp_create_openreq_child always was incrementing the

	 * equivalent to tcp_prot->socks (inet_sock_nr), so this have

	 * to be taken into account in all callers. -acme

	 */

	sk_refcnt_debug_inc(newsk);

	sk_set_socket(newsk, NULL);

	sk_tx_queue_clear(newsk);

	RCU_INIT_POINTER(newsk->sk_wq, NULL);
@@ -3710,8 +3699,6 @@ void sk_common_release(struct sock *sk) 


	xfrm_sk_free_policy(sk);



	sk_refcnt_debug_release(sk);



	sock_put(sk);

}

EXPORT_SYMBOL(sk_common_release);

net/ipv4/af_inet.c

+0 −3
Original line number Diff line number Diff line
@@ -156,7 +156,6 @@ void inet_sock_destruct(struct sock *sk) 
	kfree(rcu_dereference_protected(inet->inet_opt, 1));

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

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

	sk_refcnt_debug_dec(sk);

}

EXPORT_SYMBOL(inet_sock_destruct);
@@ -357,8 +356,6 @@ static int inet_create(struct net *net, struct socket *sock, int protocol, 
	inet->mc_list	= NULL;

	inet->rcv_tos	= 0;



	sk_refcnt_debug_inc(sk);



	if (inet->inet_num) {

		/* It assumes that any protocol which allows

		 * the user to assign a number at socket

net/ipv4/inet_connection_sock.c

+0 −2
Original line number Diff line number Diff line
@@ -1199,8 +1199,6 @@ void inet_csk_destroy_sock(struct sock *sk) 


	xfrm_sk_free_policy(sk);



	sk_refcnt_debug_release(sk);



	this_cpu_dec(*sk->sk_prot->orphan_count);



	sock_put(sk);

net/ipv4/inet_timewait_sock.c

+0 −3
Original line number Diff line number Diff line
@@ -77,9 +77,6 @@ void inet_twsk_free(struct inet_timewait_sock *tw) 
{

	struct module *owner = tw->tw_prot->owner;

	twsk_destructor((struct sock *)tw);

#ifdef SOCK_REFCNT_DEBUG

	pr_debug("%s timewait_sock %p released\n", tw->tw_prot->name, tw);

#endif

	kmem_cache_free(tw->tw_prot->twsk_prot->twsk_slab, tw);

	module_put(owner);

}