From: Yafang Shao <laoar.s...@gmail.com> Date: Tue, 7 Nov 2017 18:36:28 +0800
> When I hooked the function tcp_set_state with kprobe to track the ipv4/tcp > state transistion, I found state transition from TCP_LISTEN to TCP_SYN_RECV > is missed. > > I think it is better to use the helper to do state transition instead of > assigning the state to sk_state directly. > Then we can monitor the whole tcp lifespans with kprobe or ftrace easily. > > Signed-off-by: Yafang Shao <laoar.s...@gmail.com> This is really heavy handed and excessive for these cases. They don't have to handle any of the issues dealt with in tcp_set_state(). I would prefer if you made a special helper to net/tcp.h which did: static inline void __tcp_set_state(struct sock *sk, int state) { trace_tcp_set_state(sk, sk->sk_state, state); sk->sk_state = state; }