From 0ec1195f913ac4cfca055822df2290b8a99fcdd4 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Wed, 9 Oct 2024 17:45:45 +0800 Subject: [PATCH] bpf: Add mptcp_sock acquire and release helpers KF_TRUSTED_ARGS flag is used for bpf_iter_mptcp_subflow_new, it indicates that the all pointer arguments are valid. It's necessary to add a KF_ACQUIRE helper to get valid "msk". This patch adds bpf_mptcp_sock_acquire() and bpf_mptcp_sock_release() helpers for this. Increase sk->sk_refcnt in _acquire() and decrease it in _release(). Register them with KF_ACQUIRE flag and KF_RELEASE flag. Signed-off-by: Geliang Tang --- net/mptcp/bpf.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index fe2ee03ff1ee33..9b87eee13955ce 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -255,6 +255,22 @@ __bpf_kfunc void bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *i { } +__bpf_kfunc struct mptcp_sock *bpf_mptcp_sock_acquire(struct mptcp_sock *msk) +{ + struct sock *sk = (struct sock *)msk; + + if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) + return msk; + return NULL; +} + +__bpf_kfunc void bpf_mptcp_sock_release(struct mptcp_sock *msk) +{ + struct sock *sk = (struct sock *)msk; + + WARN_ON_ONCE(!sk || !refcount_dec_not_one(&sk->sk_refcnt)); +} + __bpf_kfunc struct mptcp_subflow_context * bpf_mptcp_subflow_ctx_by_pos(const struct mptcp_sched_data *data, unsigned int pos) { @@ -278,6 +294,8 @@ BTF_ID_FLAGS(func, mptcp_subflow_active) BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_new, KF_ITER_NEW | KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_mptcp_subflow_destroy, KF_ITER_DESTROY) +BTF_ID_FLAGS(func, bpf_mptcp_sock_acquire, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_mptcp_sock_release, KF_RELEASE) BTF_KFUNCS_END(bpf_mptcp_common_kfunc_ids) static const struct btf_kfunc_id_set bpf_mptcp_common_kfunc_set = {