From nobody Sun Mar 22 10:05:15 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 64AB3379999 for ; Thu, 19 Mar 2026 10:09:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773914947; cv=none; b=jBIWqlcg7ZwnVOXFIDwo+k7RToVikVwbKLC55NgixKMcNE28lggo+/L7mRPZYpx9RsV0gNepVqBzD7Ua8Q7hnk/THDISKzcR7W2Yw1DtrkFZmUcE6gHaHL4FswbUDoIy8rmXnWJpkot3cE0psLJtPuZv3Tfjx+tYhmj/r1uKPPU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773914947; c=relaxed/simple; bh=g0QtebIG9KnPGBWOJY5HMZ/sRaDgRN7bFJpZ1zwo4H8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pJpbC+qnCknbXE7sgB+aYV73MwzF+EyMW7tiYaCPZTmfhFTN8PJyIZzmnZYZ4rmRm91Ak9JD1T2ioM7Qq64IbyHEwCKOXQZGys+GvVyfGVkp/KOKHFTpJioeT0r7bJGgNsxSzhsJekM2Zh9C7Tsvve45fZnKqCg6YXOw3bhutOs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iKIrJyXa; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iKIrJyXa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C2ECC2BC87; Thu, 19 Mar 2026 10:09:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773914947; bh=g0QtebIG9KnPGBWOJY5HMZ/sRaDgRN7bFJpZ1zwo4H8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iKIrJyXaza988hBpj5Fhsb9DMi9RxFnIb4v5QrdWDxn8RnOTIBiHk5hOZqoibQ755 at4Ta1UmitSa6UV17e7HZLvF6ExCQnheJlRByaHJYFh9EWWxfwlfv+d37JnXgB3/mO MuY2/rYUdkd9RHVc9x2n3eRNR+Rl6OQO4HWLmbwVNRq4eKfrKgyzHQ33Afv64frWPF +GtTvGK0dh+O0umsuDv2/vX8bD6XVAGFE3o//x03uAMY5rEjLBgJapRq920ZdK7Ioy 4hzDmpU813588Uz7zyAZGr9d6yO5ogLo0q7b3wla2+GpWwm/e/psHNn3s+c0TjLWEc H43F3cwN2fflQ== From: Geliang Tang To: mptcp@lists.linux.dev Cc: Geliang Tang , Gang Yan Subject: [RFC mptcp-next v11 05/15] mptcp: avoid sleeping in read_sock path under softirq Date: Thu, 19 Mar 2026 18:08:38 +0800 Message-ID: X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Geliang Tang When mptcp_read_sock() is called from softirq context via TLS read_sock, lock_sock_fast() in mptcp_rcv_space_adjust() and mptcp_cleanup_rbuf() may trigger might_sleep() warnings or illegal sleeps, as softirq context cannot block. Replace lock_sock_fast() with spin_trylock_bh() to make locking non-blocking and context-safe. Skip operations if the lock cannot be acquired. Co-developed-by: Gang Yan Signed-off-by: Gang Yan Signed-off-by: Geliang Tang --- net/mptcp/protocol.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5585f43cf879..e9e40dfab5ea 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -561,12 +561,11 @@ static void mptcp_send_ack(struct mptcp_sock *msk) =20 static void mptcp_subflow_cleanup_rbuf(struct sock *ssk, int copied) { - bool slow; - - slow =3D lock_sock_fast(ssk); - if (tcp_can_send_ack(ssk)) + if (!spin_trylock_bh(&ssk->sk_lock.slock)) + return; + if (!sock_owned_by_user(ssk) && tcp_can_send_ack(ssk)) tcp_cleanup_rbuf(ssk, copied); - unlock_sock_fast(ssk, slow); + spin_unlock_bh(&ssk->sk_lock.slock); } =20 static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_em= pty) @@ -2194,14 +2193,15 @@ static void mptcp_rcv_space_adjust(struct mptcp_soc= k *msk, int copied) */ mptcp_for_each_subflow(msk, subflow) { struct sock *ssk; - bool slow; =20 ssk =3D mptcp_subflow_tcp_sock(subflow); - slow =3D lock_sock_fast(ssk); + if (!spin_trylock_bh(&ssk->sk_lock.slock)) + continue; /* subflows can be added before tcp_init_transfer() */ - if (tcp_sk(ssk)->rcvq_space.space) + if (!sock_owned_by_user(ssk) && + tcp_sk(ssk)->rcvq_space.space) tcp_rcvbuf_grow(ssk, copied); - unlock_sock_fast(ssk, slow); + spin_unlock_bh(&ssk->sk_lock.slock); } } =20 --=20 2.53.0