From: Jakub Sitnicki <jakub@cloudflare.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
Cong Wang <cong.wang@bytedance.com>,
Jiang Wang <jiang.wang@bytedance.com>,
Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Lorenz Bauer <lmb@cloudflare.com>
Subject: Re: [Patch bpf] skmsg: check sk_rcvbuf limit before queuing to ingress_skb
Date: Wed, 30 Jun 2021 11:21:25 +0200 [thread overview]
Message-ID: <878s2rso6i.fsf@cloudflare.com> (raw)
In-Reply-To: <20210629062029.13684-1-xiyou.wangcong@gmail.com>
On Tue, Jun 29, 2021 at 08:20 AM CEST, Cong Wang wrote:
[...]
> @@ -854,7 +854,8 @@ static int sk_psock_skb_redirect(struct sk_psock *from, struct sk_buff *skb)
> return -EIO;
> }
> spin_lock_bh(&psock_other->ingress_lock);
> - if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) {
> + if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED) ||
> + atomic_read(&sk_other->sk_rmem_alloc) > sk_other->sk_rcvbuf) {
> spin_unlock_bh(&psock_other->ingress_lock);
> skb_bpf_redirect_clear(skb);
> sock_drop(from->sk, skb);
> @@ -930,7 +931,8 @@ static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb,
> }
> if (err < 0) {
> spin_lock_bh(&psock->ingress_lock);
> - if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
> + if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED) &&
> + atomic_read(&sk_other->sk_rmem_alloc) <= sk_other->sk_rcvbuf) {
> skb_queue_tail(&psock->ingress_skb, skb);
> schedule_work(&psock->work);
> err = 0;
I belive access to sk_rcvbuf should be annotated with READ_ONCE (for
KCSAN's sake) as we don't lock the egress socket. See 8265792bf887 [1]
("net: silence KCSAN warnings around sk_add_backlog() calls") for
guidance.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=8265792bf8871acc2d00fd03883d830e2249d395
prev parent reply other threads:[~2021-06-30 9:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-29 6:20 [Patch bpf] skmsg: check sk_rcvbuf limit before queuing to ingress_skb Cong Wang
2021-06-30 9:21 ` Jakub Sitnicki [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=878s2rso6i.fsf@cloudflare.com \
--to=jakub@cloudflare.com \
--cc=bpf@vger.kernel.org \
--cc=cong.wang@bytedance.com \
--cc=daniel@iogearbox.net \
--cc=jiang.wang@bytedance.com \
--cc=john.fastabend@gmail.com \
--cc=lmb@cloudflare.com \
--cc=netdev@vger.kernel.org \
--cc=xiyou.wangcong@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.