diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-05-12 11:27:33 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-05-15 15:23:31 +0200 |
| commit | 82d9e6b9a0a164719a8df7584d9f7e42de443698 (patch) | |
| tree | 083e88e6deeaba64ed170c5f8227f5ba332cdab0 | |
| parent | 20d677d389e7df6963ca9a41cd0f88954a65ba7b (diff) | |
mptcp: Use nested-BH locking for hmac_storage
mptcp_delegated_actions is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this data
structure requires explicit locking.
Add a local_lock_t to the data structure and use local_lock_nested_bh() for
locking. This change adds only lockdep coverage and does not alter the
functional behaviour for !PREEMPT_RT.
Cc: Matthieu Baerts <matttbe@kernel.org>
Cc: Mat Martineau <martineau@kernel.org>
Cc: Geliang Tang <geliang@kernel.org>
Cc: mptcp@lists.linux.dev
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-13-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/mptcp/protocol.c | 4 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 9 |
2 files changed, 11 insertions, 2 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index c4fd558307f2..0749733ea897 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -46,7 +46,9 @@ static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_sm static void __mptcp_destroy_sock(struct sock *sk); static void mptcp_check_send_data_fin(struct sock *sk); -DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); +DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions) = { + .bh_lock = INIT_LOCAL_LOCK(bh_lock), +}; static struct net_device *mptcp_napi_dev; /* Returns end sequence number of the receiver's advertised window */ diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 7aa38d74fef6..3dd11dd3ba16 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -479,6 +479,7 @@ mptcp_subflow_rsk(const struct request_sock *rsk) struct mptcp_delegated_action { struct napi_struct napi; + local_lock_t bh_lock; struct list_head head; }; @@ -670,9 +671,11 @@ static inline void mptcp_subflow_delegate(struct mptcp_subflow_context *subflow, if (WARN_ON_ONCE(!list_empty(&subflow->delegated_node))) return; + local_lock_nested_bh(&mptcp_delegated_actions.bh_lock); delegated = this_cpu_ptr(&mptcp_delegated_actions); schedule = list_empty(&delegated->head); list_add_tail(&subflow->delegated_node, &delegated->head); + local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock); sock_hold(mptcp_subflow_tcp_sock(subflow)); if (schedule) napi_schedule(&delegated->napi); @@ -684,11 +687,15 @@ mptcp_subflow_delegated_next(struct mptcp_delegated_action *delegated) { struct mptcp_subflow_context *ret; - if (list_empty(&delegated->head)) + local_lock_nested_bh(&mptcp_delegated_actions.bh_lock); + if (list_empty(&delegated->head)) { + local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock); return NULL; + } ret = list_first_entry(&delegated->head, struct mptcp_subflow_context, delegated_node); list_del_init(&ret->delegated_node); + local_unlock_nested_bh(&mptcp_delegated_actions.bh_lock); return ret; } |