From: Jason Xing <kerneljasonxing@xxxxxxxxx>
Date: Sat, 11 Feb 2023 14:51:53 +0800
> From: Jason Xing <kernelxing@xxxxxxxxxxx>
>
> Since commit 463c84b97f24 ("[NET]: Introduce inet_connection_sock")
> commented out the definition of SOCK_REFCNT_DEBUG and later another
> patch deleted it,
e48c414ee61f ("[INET]: Generalise the TCP sock ID lookup routines")
is the commit which commented out SOCK_REFCNT_DEBUG, and 463c84b97f24
removed it.
> we need to enable it through defining it manually
> somewhere. Wrapping it into an option in Kconfig.debug could make
> it much clearer and easier for some developers to do things based
> on this change.
Considering SOCK_REFCNT_DEBUG is removed in 2005, how about removing
the whole feature? I think we can track the same info easily with
bpftrace + kprobe.
>
> Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx>
> ---
> include/net/sock.h | 8 ++++----
> net/Kconfig.debug | 8 ++++++++
> net/ipv4/inet_timewait_sock.c | 2 +-
> 3 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index dcd72e6285b2..1b001efeb9b5 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -1349,7 +1349,7 @@ struct proto {
> char name[32];
>
> struct list_head node;
> -#ifdef SOCK_REFCNT_DEBUG
> +#ifdef CONFIG_SOCK_REFCNT_DEBUG
> atomic_t socks;
> #endif
> int (*diag_destroy)(struct sock *sk, int err);
> @@ -1359,7 +1359,7 @@ 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
> +#ifdef CONFIG_SOCK_REFCNT_DEBUG
> static inline void sk_refcnt_debug_inc(struct sock *sk)
> {
> atomic_inc(&sk->sk_prot->socks);
> @@ -1378,11 +1378,11 @@ static inline void sk_refcnt_debug_release(const struct sock *sk)
> 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 */
> +#else /* CONFIG_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 */
> +#endif /* CONFIG_SOCK_REFCNT_DEBUG */
>
> INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
>
> diff --git a/net/Kconfig.debug b/net/Kconfig.debug
> index 5e3fffe707dd..667396d70e10 100644
> --- a/net/Kconfig.debug
> +++ b/net/Kconfig.debug
> @@ -18,6 +18,14 @@ config NET_NS_REFCNT_TRACKER
> Enable debugging feature to track netns references.
> This adds memory and cpu costs.
>
> +config SOCK_REFCNT_DEBUG
> + bool "Enable socket refcount debug"
> + depends on DEBUG_KERNEL && NET
> + default n
> + help
> + Enable debugging feature to track socket references.
> + This adds memory and cpu costs.
> +
> config DEBUG_NET
> bool "Add generic networking debug"
> depends on DEBUG_KERNEL && NET
> diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
> index beed32fff484..e313516b64ce 100644
> --- a/net/ipv4/inet_timewait_sock.c
> +++ b/net/ipv4/inet_timewait_sock.c
> @@ -77,7 +77,7 @@ 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
> +#ifdef CONFIG_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);
> --
> 2.37.3
