> From: Jason Xing <[email protected]>
> Sent: Monday, March 11, 2024 10:30 AM
> To: Ratheesh Kannoth <[email protected]>
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; linux-
> [email protected]; Jason Xing <[email protected]>
> Subject: [EXTERNAL] Re: [PATCH net-next 2/2] trace: tcp: fully support
> trace_tcp_send_reset
>
> > > + ),
> > > +
> > > + TP_printk("skbaddr=%p skaddr=%p src=%pISpc dest=%pISpc
> > > + state=%s",
> > Could you consider using %px ? is it permitted ? it will be easy to track
> > skb.
>
> I prefer not to use %px because we cannot make use of the real address of
> skb. Besides, using %px would leak kernel addresses.
>
> Here is the Documentation (see Documentation/core-api/printk-formats.rst):
> "Pointers printed without a specifier extension (i.e unadorned %p) are
> hashed to give a unique identifier without leaking kernel addresses to user
> space."
>
> Perhaps, that's the reason why all the tracepoints didn't print in %px
> format:)
>
ACK, I understand that. In offload cases, or in mostly in IOVA space, we often
end up changing this locally to %px to debug and track skb.
That is why I asked the question.
> Thanks,
> Jason
>
> >
> > > + __entry->skbaddr, __entry->skaddr,
> > > + __entry->saddr, __entry->daddr,
> > > + __entry->state ? show_tcp_state_name(__entry->state)
> > > + : "UNKNOWN")
> > > );
> > >
> > > /*
> > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index
> > > a22ee5838751..d5c4a969c066 100644
> > > --- a/net/ipv4/tcp_ipv4.c
> > > +++ b/net/ipv4/tcp_ipv4.c
> > > @@ -868,10 +868,10 @@ static void tcp_v4_send_reset(const struct sock
> *sk, struct sk_buff *skb)
> > > */
> > > if (sk) {
> > > arg.bound_dev_if = sk->sk_bound_dev_if;
> > > - if (sk_fullsock(sk))
> > > - trace_tcp_send_reset(sk, skb);
> > > }
> > >
> > > + trace_tcp_send_reset(sk, skb);
> > > +
> > > BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) !=
> > > offsetof(struct inet_timewait_sock,
> > > tw_bound_dev_if));
> > >
> > > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index
> > > 3f4cba49e9ee..8e9c59b6c00c 100644
> > > --- a/net/ipv6/tcp_ipv6.c
> > > +++ b/net/ipv6/tcp_ipv6.c
> > > @@ -1113,7 +1113,6 @@ static void tcp_v6_send_reset(const struct sock
> *sk, struct sk_buff *skb)
> > > if (sk) {
> > > oif = sk->sk_bound_dev_if;
> > > if (sk_fullsock(sk)) {
> > > - trace_tcp_send_reset(sk, skb);
> > > if (inet6_test_bit(REPFLOW, sk))
> > > label = ip6_flowlabel(ipv6h);
> > > priority = READ_ONCE(sk->sk_priority); @@
> > > -1129,6 +1128,8 @@ static void tcp_v6_send_reset(const struct sock *sk,
> struct sk_buff *skb)
> > > label = ip6_flowlabel(ipv6h);
> > > }
> > >
> > > + trace_tcp_send_reset(sk, skb);
> > > +
> > > tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1,
> > > ipv6_get_dsfield(ipv6h), label, priority,
> > > txhash,
> > > &key);
> > > --
> > > 2.37.3
> > >
