From: Geliang Tang tanggeliang@kylinos.cn
The 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 tanggeliang@kylinos.cn Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/bpf.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c index e39f0e4fb683c1aa31ee075281daee218dac5878..d50bd1ea7f6d0ff1abff32deef9a98b98ee8f42c 100644 --- a/net/mptcp/bpf.c +++ b/net/mptcp/bpf.c @@ -97,6 +97,23 @@ bpf_iter_mptcp_subflow_destroy(struct bpf_iter_mptcp_subflow *it) { }
+__bpf_kfunc static 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 static 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_end_defs();
BTF_KFUNCS_START(bpf_mptcp_common_kfunc_ids) @@ -104,6 +121,8 @@ BTF_ID_FLAGS(func, bpf_mptcp_subflow_ctx, KF_RET_NULL) 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 = {