From 1f65905c9f926f0bf7a98cb7f51ded3a6c2d0a8a Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 6 May 2020 15:33:04 -0600 Subject: wireguard: send/receive: cond_resched() when processing worker ringbuffers Users with pathological hardware reported CPU stalls on CONFIG_ PREEMPT_VOLUNTARY=y, because the ringbuffers would stay full, meaning these workers would never terminate. That turned out not to be okay on systems without forced preemption, which Sultan observed. This commit adds a cond_resched() to the bottom of each loop iteration, so that these workers don't hog the core. Note that we don't need this on the napi poll worker, since that terminates after its budget is expended. Suggested-by: Sultan Alsawaf Reported-by: Wang Jian Fixes: a8f1bc7bdea3 ("net: WireGuard secure network tunnel") Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- drivers/net/wireguard/receive.c | 2 ++ drivers/net/wireguard/send.c | 4 ++++ 2 files changed, 6 insertions(+) (limited to 'drivers') diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index 267f202..2566e13 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -516,6 +516,8 @@ void wg_packet_decrypt_worker(struct work_struct *work) &PACKET_CB(skb)->keypair->receiving)) ? PACKET_STATE_CRYPTED : PACKET_STATE_DEAD; wg_queue_enqueue_per_peer_napi(skb, state); + if (need_resched()) + cond_resched(); } } diff --git a/drivers/net/wireguard/send.c b/drivers/net/wireguard/send.c index 3e030d6..dc3079e 100644 --- a/drivers/net/wireguard/send.c +++ b/drivers/net/wireguard/send.c @@ -281,6 +281,8 @@ void wg_packet_tx_worker(struct work_struct *work) wg_noise_keypair_put(keypair, false); wg_peer_put(peer); + if (need_resched()) + cond_resched(); } } @@ -304,6 +306,8 @@ void wg_packet_encrypt_worker(struct work_struct *work) } wg_queue_enqueue_per_peer(&PACKET_PEER(first)->tx_queue, first, state); + if (need_resched()) + cond_resched(); } } -- cgit v1.2.3