Re: [PATCH net-next 1/3] net:tracepoint: replace tcp_set_state tracepoint with sock_set_state tracepoint

From: Yafang Shao
Date: Wed Dec 13 2017 - 04:51:07 EST


2017-12-13 9:19 GMT+08:00 Song Liu <songliubraving@xxxxxx>:
>
>> On Dec 10, 2017, at 7:31 AM, Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>>
>> As sk_state is a common field for struct sock, so the state
>> transition should not be a TCP specific feature.
>> So I rename tcp_set_state tracepoint to sock_set_state tracepoint with
>> some minor changes and move it into file trace/events/sock.h.
>>
>> The minor changes against on the original tcp_set_state tracepoint:
>> - Protocol name is printed to distinguish which protocol it is belonging
>> to
>> - The macros defined in the file are undefed at the end of this file as
>> they are only used in this file
>>
>> Two helpers are introduced to trace sk_state transition
>> - void sk_state_store(struct sock *sk, int state);
>> - void sk_set_state(struct sock *sk, int state);
>>
>> As trace header should not be included in other header files,
>> so they are defined in sock.c.
>>
>> The protocol such as SCTP maybe compiled as a ko, hence export
>> sk_set_state().
>>
>> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
>> ---
>> include/net/sock.h | 15 ++-----
>> include/trace/events/sock.h | 95 +++++++++++++++++++++++++++++++++++++++++
>> include/trace/events/tcp.h | 76 ---------------------------------
>> net/core/sock.c | 13 ++++++
>> net/ipv4/inet_connection_sock.c | 4 +-
>> net/ipv4/inet_hashtables.c | 2 +-
>> net/ipv4/tcp.c | 4 --
>> 7 files changed, 114 insertions(+), 95 deletions(-)
>>
>> diff --git a/include/net/sock.h b/include/net/sock.h
>> index 79e1a2c..b307b60 100644
>> --- a/include/net/sock.h
>> +++ b/include/net/sock.h
>> @@ -2348,18 +2348,9 @@ static inline int sk_state_load(const struct sock *sk)
>> return smp_load_acquire(&sk->sk_state);
>> }
>>
>> -/**
>> - * sk_state_store - update sk->sk_state
>> - * @sk: socket pointer
>> - * @newstate: new state
>> - *
>> - * Paired with sk_state_load(). Should be used in contexts where
>> - * state change might impact lockless readers.
>> - */
>> -static inline void sk_state_store(struct sock *sk, int newstate)
>> -{
>> - smp_store_release(&sk->sk_state, newstate);
>> -}
>> +/* For sock_set_state tracepoint */
>> +void sk_state_store(struct sock *sk, int newstate);
>> +void sk_set_state(struct sock *sk, int state);
>>
>> void sock_enable_timestamp(struct sock *sk, int flag);
>> int sock_get_timestamp(struct sock *, struct timeval __user *);
>> diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h
>> index ec4dade..2728892 100644
>> --- a/include/trace/events/sock.h
>> +++ b/include/trace/events/sock.h
>> @@ -6,7 +6,33 @@
>> #define _TRACE_SOCK_H
>>
>> #include <net/sock.h>
>> +#include <net/ipv6.h>
>> #include <linux/tracepoint.h>
>> +#include <linux/ipv6.h>
>> +#include <linux/tcp.h>
>> +
>> +#define inet_protocol_name(protocol) {IPPROTO_##protocol, #protocol}
>> +#define show_inet_protocol_name(val) \
>> + __print_symbolic(val, \
>> + inet_protocol_name(TCP), \
>> + inet_protocol_name(DCCP), \
>> + inet_protocol_name(SCTP))
>> +
>> +#define tcp_state_name(state) { state, #state }
>> +#define show_tcp_state_name(val) \
>> + __print_symbolic(val, \
>> + tcp_state_name(TCP_ESTABLISHED), \
>> + tcp_state_name(TCP_SYN_SENT), \
>> + tcp_state_name(TCP_SYN_RECV), \
>> + tcp_state_name(TCP_FIN_WAIT1), \
>> + tcp_state_name(TCP_FIN_WAIT2), \
>> + tcp_state_name(TCP_TIME_WAIT), \
>> + tcp_state_name(TCP_CLOSE), \
>> + tcp_state_name(TCP_CLOSE_WAIT), \
>> + tcp_state_name(TCP_LAST_ACK), \
>> + tcp_state_name(TCP_LISTEN), \
>> + tcp_state_name(TCP_CLOSING), \
>> + tcp_state_name(TCP_NEW_SYN_RECV))
>
> Please include Steven's fix to export names to user space:
>
> https://patchwork.kernel.org/patch/10052201/
>

OK.


>
>> TRACE_EVENT(sock_rcvqueue_full,
>>
>> @@ -63,6 +89,75 @@
>> __entry->rmem_alloc)
>> );
>>
>> +TRACE_EVENT(sock_set_state,
>> +
>> + TP_PROTO(const struct sock *sk, const int oldstate, const int newstate),
>> +
>> + TP_ARGS(sk, oldstate, newstate),
>> +
>> + TP_STRUCT__entry(
>> + __field(const void *, skaddr)
>> + __field(int, oldstate)
>> + __field(int, newstate)
>> + __field(__u16, sport)
>> + __field(__u16, dport)
>> + __field(__u8, protocol);
>> + __array(__u8, saddr, 4)
>> + __array(__u8, daddr, 4)
>> + __array(__u8, saddr_v6, 16)
>> + __array(__u8, daddr_v6, 16)
>> + ),
>> +
>> + TP_fast_assign(
>> + struct inet_sock *inet = inet_sk(sk);
>> + struct in6_addr *pin6;
>> + __be32 *p32;
>> +
>> + __entry->skaddr = sk;
>> + __entry->oldstate = oldstate;
>> + __entry->newstate = newstate;
>> +
>> + __entry->protocol = sk->sk_protocol;
>> + __entry->sport = ntohs(inet->inet_sport);
>> + __entry->dport = ntohs(inet->inet_dport);
>> +
>> + p32 = (__be32 *) __entry->saddr;
>> + *p32 = inet->inet_saddr;
>> +
>> + p32 = (__be32 *) __entry->daddr;
>> + *p32 = inet->inet_daddr;
>> +
>> +#if IS_ENABLED(CONFIG_IPV6)
>> + if (sk->sk_family == AF_INET6) {
>> + pin6 = (struct in6_addr *)__entry->saddr_v6;
>> + *pin6 = sk->sk_v6_rcv_saddr;
>> + pin6 = (struct in6_addr *)__entry->daddr_v6;
>> + *pin6 = sk->sk_v6_daddr;
>> + } else
>> +#endif
>> + {
>> + pin6 = (struct in6_addr *)__entry->saddr_v6;
>> + ipv6_addr_set_v4mapped(inet->inet_saddr, pin6);
>> + pin6 = (struct in6_addr *)__entry->daddr_v6;
>> + ipv6_addr_set_v4mapped(inet->inet_daddr, pin6);
>> + }
>> + ),
>> +
>> + TP_printk("protocol=%s sport=%hu dport=%hu saddr=%pI4 daddr=%pI4"
>> + "saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",
>> + show_inet_protocol_name(__entry->protocol),
>> + __entry->sport, __entry->dport,
>> + __entry->saddr, __entry->daddr,
>> + __entry->saddr_v6, __entry->daddr_v6,
>> + show_tcp_state_name(__entry->oldstate),
>> + show_tcp_state_name(__entry->newstate))
>> +);
>> +
>> +#undef show_tcp_state_name
>> +#undef tcp_state_name
>> +#undef show_inet_protocol_name
>> +#undef inet_protocol_name
>> +
>> #endif /* _TRACE_SOCK_H */
>>
>> /* This part must be outside protection */
>> diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h
>> index 07cccca..7399399 100644
>> --- a/include/trace/events/tcp.h
>> +++ b/include/trace/events/tcp.h
>> @@ -9,22 +9,6 @@
>> #include <linux/tracepoint.h>
>> #include <net/ipv6.h>
>>
>> -#define tcp_state_name(state) { state, #state }
>> -#define show_tcp_state_name(val) \
>> - __print_symbolic(val, \
>> - tcp_state_name(TCP_ESTABLISHED), \
>> - tcp_state_name(TCP_SYN_SENT), \
>> - tcp_state_name(TCP_SYN_RECV), \
>> - tcp_state_name(TCP_FIN_WAIT1), \
>> - tcp_state_name(TCP_FIN_WAIT2), \
>> - tcp_state_name(TCP_TIME_WAIT), \
>> - tcp_state_name(TCP_CLOSE), \
>> - tcp_state_name(TCP_CLOSE_WAIT), \
>> - tcp_state_name(TCP_LAST_ACK), \
>> - tcp_state_name(TCP_LISTEN), \
>> - tcp_state_name(TCP_CLOSING), \
>> - tcp_state_name(TCP_NEW_SYN_RECV))
>> -
>> /*
>> * tcp event with arguments sk and skb
>> *
>> @@ -177,66 +161,6 @@
>> TP_ARGS(sk)
>> );
>>
>> -TRACE_EVENT(tcp_set_state,
>> -
>> - TP_PROTO(const struct sock *sk, const int oldstate, const int newstate),
>> -
>> - TP_ARGS(sk, oldstate, newstate),
>> -
>> - TP_STRUCT__entry(
>> - __field(const void *, skaddr)
>> - __field(int, oldstate)
>> - __field(int, newstate)
>> - __field(__u16, sport)
>> - __field(__u16, dport)
>> - __array(__u8, saddr, 4)
>> - __array(__u8, daddr, 4)
>> - __array(__u8, saddr_v6, 16)
>> - __array(__u8, daddr_v6, 16)
>> - ),
>> -
>> - TP_fast_assign(
>> - struct inet_sock *inet = inet_sk(sk);
>> - struct in6_addr *pin6;
>> - __be32 *p32;
>> -
>> - __entry->skaddr = sk;
>> - __entry->oldstate = oldstate;
>> - __entry->newstate = newstate;
>> -
>> - __entry->sport = ntohs(inet->inet_sport);
>> - __entry->dport = ntohs(inet->inet_dport);
>> -
>> - p32 = (__be32 *) __entry->saddr;
>> - *p32 = inet->inet_saddr;
>> -
>> - p32 = (__be32 *) __entry->daddr;
>> - *p32 = inet->inet_daddr;
>> -
>> -#if IS_ENABLED(CONFIG_IPV6)
>> - if (sk->sk_family == AF_INET6) {
>> - pin6 = (struct in6_addr *)__entry->saddr_v6;
>> - *pin6 = sk->sk_v6_rcv_saddr;
>> - pin6 = (struct in6_addr *)__entry->daddr_v6;
>> - *pin6 = sk->sk_v6_daddr;
>> - } else
>> -#endif
>> - {
>> - pin6 = (struct in6_addr *)__entry->saddr_v6;
>> - ipv6_addr_set_v4mapped(inet->inet_saddr, pin6);
>> - pin6 = (struct in6_addr *)__entry->daddr_v6;
>> - ipv6_addr_set_v4mapped(inet->inet_daddr, pin6);
>> - }
>> - ),
>> -
>> - TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",
>> - __entry->sport, __entry->dport,
>> - __entry->saddr, __entry->daddr,
>> - __entry->saddr_v6, __entry->daddr_v6,
>> - show_tcp_state_name(__entry->oldstate),
>> - show_tcp_state_name(__entry->newstate))
>> -);
>> -
>> TRACE_EVENT(tcp_retransmit_synack,
>>
>> TP_PROTO(const struct sock *sk, const struct request_sock *req),
>> diff --git a/net/core/sock.c b/net/core/sock.c
>> index c0b5b2f..ee0c1bc 100644
>> --- a/net/core/sock.c
>> +++ b/net/core/sock.c
>> @@ -2859,6 +2859,19 @@ int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
>> }
>> EXPORT_SYMBOL(sock_get_timestampns);
>>
>> +void sk_state_store(struct sock *sk, int state)
>> +{
>> + trace_sock_set_state(sk, sk->sk_state, state);
>> + smp_store_release(&sk->sk_state, state);
>> +}
>> +
>> +void sk_set_state(struct sock *sk, int state)
>> +{
>> + trace_sock_set_state(sk, sk->sk_state, state);
>> + sk->sk_state = state;
>> +}
>> +EXPORT_SYMBOL(sk_set_state);
>
> These two functions are short. Can we keep this in sock.h?

sock.h is included in trace/events/sock.h, so it will cause compile
error if hese two functions are defined in sock.h.

>
> Thanks,
> Song
>
>> +
>> void sock_enable_timestamp(struct sock *sk, int flag)
>> {
>> if (!sock_flag(sk, flag)) {
>> diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
>> index 4ca46dc..001f7b0 100644
>> --- a/net/ipv4/inet_connection_sock.c
>> +++ b/net/ipv4/inet_connection_sock.c
>> @@ -783,7 +783,7 @@ struct sock *inet_csk_clone_lock(const struct sock *sk,
>> if (newsk) {
>> struct inet_connection_sock *newicsk = inet_csk(newsk);
>>
>> - newsk->sk_state = TCP_SYN_RECV;
>> + sk_set_state(newsk, TCP_SYN_RECV);
>> newicsk->icsk_bind_hash = NULL;
>>
>> inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
>> @@ -888,7 +888,7 @@ int inet_csk_listen_start(struct sock *sk, int backlog)
>> return 0;
>> }
>>
>> - sk->sk_state = TCP_CLOSE;
>> + sk_set_state(sk, TCP_CLOSE);
>> return err;
>> }
>> EXPORT_SYMBOL_GPL(inet_csk_listen_start);
>> diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
>> index f6f5810..5973693 100644
>> --- a/net/ipv4/inet_hashtables.c
>> +++ b/net/ipv4/inet_hashtables.c
>> @@ -544,7 +544,7 @@ bool inet_ehash_nolisten(struct sock *sk, struct sock *osk)
>> sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
>> } else {
>> percpu_counter_inc(sk->sk_prot->orphan_count);
>> - sk->sk_state = TCP_CLOSE;
>> + sk_set_state(sk, TCP_CLOSE);
>> sock_set_flag(sk, SOCK_DEAD);
>> inet_csk_destroy_sock(sk);
>> }
>> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
>> index 1803116..000504f 100644
>> --- a/net/ipv4/tcp.c
>> +++ b/net/ipv4/tcp.c
>> @@ -283,8 +283,6 @@
>> #include <asm/ioctls.h>
>> #include <net/busy_poll.h>
>>
>> -#include <trace/events/tcp.h>
>> -
>> struct percpu_counter tcp_orphan_count;
>> EXPORT_SYMBOL_GPL(tcp_orphan_count);
>>
>> @@ -2040,8 +2038,6 @@ void tcp_set_state(struct sock *sk, int state)
>> {
>> int oldstate = sk->sk_state;
>>
>> - trace_tcp_set_state(sk, oldstate, state);
>> -
>> switch (state) {
>> case TCP_ESTABLISHED:
>> if (oldstate != TCP_ESTABLISHED)
>> --
>> 1.8.3.1
>>
>