Commit 4005f5c3 authored by Jason A. Donenfeld's avatar Jason A. Donenfeld Committed by David S. Miller

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: default avatarSultan Alsawaf <sultan@kerneltoast.com>
Reported-by: default avatarWang Jian <larkwang@gmail.com>
Fixes: e7096c13 ("net: WireGuard secure network tunnel")
Signed-off-by: default avatarJason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b673e24a
...@@ -516,6 +516,8 @@ void wg_packet_decrypt_worker(struct work_struct *work) ...@@ -516,6 +516,8 @@ void wg_packet_decrypt_worker(struct work_struct *work)
&PACKET_CB(skb)->keypair->receiving)) ? &PACKET_CB(skb)->keypair->receiving)) ?
PACKET_STATE_CRYPTED : PACKET_STATE_DEAD; PACKET_STATE_CRYPTED : PACKET_STATE_DEAD;
wg_queue_enqueue_per_peer_napi(skb, state); wg_queue_enqueue_per_peer_napi(skb, state);
if (need_resched())
cond_resched();
} }
} }
......
...@@ -281,6 +281,8 @@ void wg_packet_tx_worker(struct work_struct *work) ...@@ -281,6 +281,8 @@ void wg_packet_tx_worker(struct work_struct *work)
wg_noise_keypair_put(keypair, false); wg_noise_keypair_put(keypair, false);
wg_peer_put(peer); wg_peer_put(peer);
if (need_resched())
cond_resched();
} }
} }
...@@ -304,6 +306,8 @@ void wg_packet_encrypt_worker(struct work_struct *work) ...@@ -304,6 +306,8 @@ void wg_packet_encrypt_worker(struct work_struct *work)
} }
wg_queue_enqueue_per_peer(&PACKET_PEER(first)->tx_queue, first, wg_queue_enqueue_per_peer(&PACKET_PEER(first)->tx_queue, first,
state); state);
if (need_resched())
cond_resched();
} }
} }
......
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