Commit 8818e269 authored by Wang Yufen's avatar Wang Yufen Committed by Zheng Zengkai
Browse files

bpf, sockmap: Add sk_rmem_alloc check for sockmap 

hulk inclusion
category: feature
bugzilla: 186640, https://gitee.com/openeuler/kernel/issues/I545NW



--------------------------------

A tcp socket in a sockmap. If the packets transmission rate is very fast
and the packets receiving rate is very slow, a large number of packets
are stacked in the ingress queue on the packets receiving side. As a
result the memory is exhausted and the system ooms.

To fix, we add sk_rmem_alloc while sk_msg queued in the ingress queue
and subtract sk_rmem_alloc while sk_msg dequeued from the ingress queue
and check sk_rmem_alloc at the beginning of bpf_tcp_ingress().

Signed-off-by: default avatarWang Yufen <wangyufen@huawei.com>
Reviewed-by: default avatarLiu Jian <liujian56@huawei.com>
Reviewed-by: default avatarWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: default avatarYue Haibing <yuehaibing@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 8207c85b

net/core/skmsg.c

+1 −0
Original line number Diff line number Diff line
@@ -659,6 +659,7 @@ void __sk_psock_purge_ingress_msg(struct sk_psock *psock) 


	list_for_each_entry_safe(msg, tmp, &psock->ingress_msg, list) {

		list_del(&msg->list);

		atomic_sub(msg->sg.size, &psock->sk->sk_rmem_alloc);

		sk_msg_free(psock->sk, msg);

		kfree(msg);

	}

net/ipv4/tcp_bpf.c

+9 −1
Original line number Diff line number Diff line
@@ -43,8 +43,10 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, 
			if (likely(!peek)) {

				sge->offset += copy;

				sge->length -= copy;

				if (!msg_rx->skb)

				if (!msg_rx->skb) {

					atomic_sub(copy, &sk->sk_rmem_alloc);

					sk_mem_uncharge(sk, copy);

				}

				msg_rx->sg.size -= copy;



				if (!sge->length) {
@@ -98,6 +100,11 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock, 
		return -ENOMEM;



	lock_sock(sk);

	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {

		kfree(tmp);

		release_sock(sk);

		return -EAGAIN;

	}

	tmp->sg.start = msg->sg.start;

	i = msg->sg.start;

	do {
@@ -127,6 +134,7 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock, 
	if (!ret) {

		msg->sg.start = i;

		sk_psock_queue_msg(psock, tmp);

		atomic_add(tmp->sg.size, &sk->sk_rmem_alloc);

		sk_psock_data_ready(sk, psock);

	} else {

		sk_msg_free(sk, tmp);