Re: [PATCH net-next] net: tracepoint: adding new tracepoint arguments in inet_sock_set_state

[Song Liu]

> On Jan 4, 2018, at 10:42 PM, Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
> 
> sk->sk_protocol and sk->sk_family are exposed as tracepoint arguments.
> Then we can conveniently use these two arguments to do the filter.
> 
> Suggested-by: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> ---
> include/trace/events/sock.h | 24 ++++++++++++++++++------
> net/ipv4/af_inet.c          |  6 ++++--
> 2 files changed, 22 insertions(+), 8 deletions(-)
> 
> diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h
> index 3537c5f..c7df70f 100644
> --- a/include/trace/events/sock.h
> +++ b/include/trace/events/sock.h
> @@ -11,7 +11,11 @@
> #include <linux/ipv6.h>
> #include <linux/tcp.h>
> 
> -/* The protocol traced by sock_set_state */
> +#define family_names			\
> +		EM(AF_INET)				\
> +		EMe(AF_INET6)
> +
> +/* The protocol traced by inet_sock_set_state */
> #define inet_protocol_names		\
> 		EM(IPPROTO_TCP)			\
> 		EM(IPPROTO_DCCP)		\
> @@ -37,6 +41,7 @@
> #define EM(a)       TRACE_DEFINE_ENUM(a);
> #define EMe(a)      TRACE_DEFINE_ENUM(a);
> 
> +family_names
> inet_protocol_names
> tcp_state_names
> 
> @@ -45,6 +50,9 @@
> #define EM(a)       { a, #a },
> #define EMe(a)      { a, #a }
> 
> +#define show_family_name(val)	\
> +	__print_symbolic(val, family_names)
> +
> #define show_inet_protocol_name(val)    \
> 	__print_symbolic(val, inet_protocol_names)
> 
> @@ -108,9 +116,10 @@
> 
> TRACE_EVENT(inet_sock_set_state,
> 
> -	TP_PROTO(const struct sock *sk, const int oldstate, const int newstate),
> +	TP_PROTO(const struct sock *sk, const int family, const int protocol,
> +				const int oldstate, const int newstate),

Are there cases we need protocol and/or family that is different to 
sk->sk_protocol/sk_family? If not, I think we don't need to change the 
TP_PROTO. 

Thanks,
Song

> 
> -	TP_ARGS(sk, oldstate, newstate),
> +	TP_ARGS(sk, family, protocol, oldstate, newstate),
> 
> 	TP_STRUCT__entry(
> 		__field(const void *, skaddr)
> @@ -118,6 +127,7 @@
> 		__field(int, newstate)
> 		__field(__u16, sport)
> 		__field(__u16, dport)
> +		__field(__u16, family)
> 		__field(__u8, protocol)
> 		__array(__u8, saddr, 4)
> 		__array(__u8, daddr, 4)
> @@ -133,8 +143,9 @@
> 		__entry->skaddr = sk;
> 		__entry->oldstate = oldstate;
> 		__entry->newstate = newstate;
> +		__entry->family = family;
> +		__entry->protocol = protocol;
> 
> -		__entry->protocol = sk->sk_protocol;
> 		__entry->sport = ntohs(inet->inet_sport);
> 		__entry->dport = ntohs(inet->inet_dport);
> 
> @@ -145,7 +156,7 @@
> 		*p32 =  inet->inet_daddr;
> 
> #if IS_ENABLED(CONFIG_IPV6)
> -		if (sk->sk_family == AF_INET6) {
> +		if (family == AF_INET6) {
> 			pin6 = (struct in6_addr *)__entry->saddr_v6;
> 			*pin6 = sk->sk_v6_rcv_saddr;
> 			pin6 = (struct in6_addr *)__entry->daddr_v6;
> @@ -160,7 +171,8 @@
> 		}
> 	),
> 
> -	TP_printk("protocol=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",
> +	TP_printk("family=%s protocol=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",
> +			show_family_name(__entry->family),
> 			show_inet_protocol_name(__entry->protocol),
> 			__entry->sport, __entry->dport,
> 			__entry->saddr, __entry->daddr,
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index bab98a4..1d52796 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -1223,14 +1223,16 @@ int inet_sk_rebuild_header(struct sock *sk)
> 
> void inet_sk_set_state(struct sock *sk, int state)
> {
> -	trace_inet_sock_set_state(sk, sk->sk_state, state);
> +	trace_inet_sock_set_state(sk, sk->sk_family, sk->sk_protocol,
> +							sk->sk_state, state);
> 	sk->sk_state = state;
> }
> EXPORT_SYMBOL(inet_sk_set_state);
> 
> void inet_sk_state_store(struct sock *sk, int newstate)
> {
> -	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
> +	trace_inet_sock_set_state(sk, sk->sk_family, sk->sk_protocol,
> +							sk->sk_state, newstate);
> 	smp_store_release(&sk->sk_state, newstate);
> }
> 
> --
> 1.8.3.1
>