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

[Yafang Shao]

On Sun, Jan 7, 2018 at 1:46 AM, Song Liu <songliubraving@xxxxxx> wrote:
>
>> On Jan 5, 2018, at 12:09 AM, Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>>
>> On Fri, Jan 5, 2018 at 3:21 PM, Song Liu <songliubraving@xxxxxx> wrote:
>>>
>>>> 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
>>>
>>
>> As of now, there're two sk_family, which are AF_INET and AF_INET6, and
>> three sk_protocol which are  IPPROTO_TCP, IPPROTO_SCTP and
>> IPPROTO_DCCP.
>>
>> Thanks
>> Yafang
>
> How about we do not change the TP_PROTO line? The patch will be like:
>
> @@ -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 = sk->sk_family;
>              __entry->protocol = sk->sk_protocol;
>              __entry->sport = ntohs(inet->inet_sport);
>              __entry->dport = ntohs(inet->inet_dport);
> @@ xxxxx
> -     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),
>

Agreed.
IMO that's a better solution, because we make littler change and could
use the printk message to do the filter as well.

I will submit a new patch.

Thanks
Yafang

>
>>>>
>>>> -     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
>