Commit bfcd70f7 authored by Paolo Abeni's avatar Paolo Abeni Committed by Geliang Tang
Browse files

mptcp: annotate lockless access for the tx path 

mainline inclusion
from mainline-v6.9-rc1
commit d440a4e27acdede686b974b62a6b2b2bd7914437
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9VYQ9
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=d440a4e27acdede686b974b62a6b2b2bd7914437



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

The mptcp-level TX path info (write_seq, bytes_sent, snd_nxt) are under
the msk socket lock protection, and are accessed lockless in a few spots.

Always mark the write operations with WRITE_ONCE, read operations
outside the lock with READ_ONCE and drop the annotation for read
under such lock.

To simplify the annotations move mptcp_pending_data_fin_ack() from
__mptcp_data_acked() to __mptcp_clean_una(), under the msk socket
lock, where such call would belong.

Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarMat Martineau <martineau@kernel.org>
Signed-off-by: default avatarMatthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Reviewed-by: default avatarJackie Liu <liuyun01@kylinos.cn>
Signed-off-by: default avatarGeliang Tang <tanggeliang@kylinos.cn>
parent 61b3cc32

net/mptcp/options.c

+1 −1
Original line number Diff line number Diff line
@@ -1061,7 +1061,7 @@ static void ack_update_msk(struct mptcp_sock *msk, 
		msk->wnd_end = new_wnd_end;



	/* this assumes mptcp_incoming_options() is invoked after tcp_ack() */

	if (after64(msk->wnd_end, READ_ONCE(msk->snd_nxt)))

	if (after64(msk->wnd_end, snd_nxt))

		__mptcp_check_push(sk, ssk);



	if (after64(new_snd_una, old_snd_una)) {

net/mptcp/protocol.c

+7 −8
Original line number Diff line number Diff line
@@ -1033,13 +1033,15 @@ static void __mptcp_clean_una(struct sock *sk) 
		msk->recovery = false;



out:

	if (snd_una == READ_ONCE(msk->snd_nxt) &&

	    snd_una == READ_ONCE(msk->write_seq)) {

	if (snd_una == msk->snd_nxt && snd_una == msk->write_seq) {

		if (mptcp_rtx_timer_pending(sk) && !mptcp_data_fin_enabled(msk))

			mptcp_stop_rtx_timer(sk);

	} else {

		mptcp_reset_rtx_timer(sk);

	}



	if (mptcp_pending_data_fin_ack(sk))

		mptcp_schedule_work(sk);

}



static void __mptcp_clean_una_wakeup(struct sock *sk)
@@ -1500,7 +1502,7 @@ static void mptcp_update_post_push(struct mptcp_sock *msk, 
	 */

	if (likely(after64(snd_nxt_new, msk->snd_nxt))) {

		msk->bytes_sent += snd_nxt_new - msk->snd_nxt;

		msk->snd_nxt = snd_nxt_new;

		WRITE_ONCE(msk->snd_nxt, snd_nxt_new);

	}

}
@@ -3257,8 +3259,8 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk, 
	if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD)

		WRITE_ONCE(msk->csum_enabled, true);



	msk->write_seq = subflow_req->idsn + 1;

	msk->snd_nxt = msk->write_seq;

	WRITE_ONCE(msk->write_seq, subflow_req->idsn + 1);

	WRITE_ONCE(msk->snd_nxt, msk->write_seq);

	msk->snd_una = msk->write_seq;

	msk->wnd_end = msk->snd_nxt + tcp_sk(ssk)->snd_wnd;

	msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
@@ -3363,9 +3365,6 @@ void __mptcp_data_acked(struct sock *sk) 
		__mptcp_clean_una(sk);

	else

		__set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags);



	if (mptcp_pending_data_fin_ack(sk))

		mptcp_schedule_work(sk);

}



void __mptcp_check_push(struct sock *sk, struct sock *ssk)

net/mptcp/protocol.h

+1 −1
Original line number Diff line number Diff line
@@ -402,7 +402,7 @@ static inline struct mptcp_data_frag *mptcp_rtx_head(struct sock *sk) 
{

	struct mptcp_sock *msk = mptcp_sk(sk);



	if (msk->snd_una == READ_ONCE(msk->snd_nxt))

	if (msk->snd_una == msk->snd_nxt)

		return NULL;



	return list_first_entry_or_null(&msk->rtx_queue, struct mptcp_data_frag, list);