From mboxrd@z Thu Jan 1 00:00:00 1970 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 CD48E60DE3; Tue, 23 Jan 2024 00:49:20 +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=1705970960; cv=none; b=ceQS5js71VuI6ABAsU49a/zmLb3gdMujEgIj6Onu6/fwp031Yh42ceU66rYYbVvNs+8GnT2CWfAtmhCLfHoUfL7uob/V3V79hj227c5Zua7lg4e+NgcOpgx1tQkBrGpi+/KL1iMjHCozMouCC7KJpIxlhjM5y1Jmm7p10WUlszM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705970960; c=relaxed/simple; bh=BJvDOAzy8/BWztnV6Axb40uBFEUW+MwP550UfFhGtPA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ft+6OWtZdIQe2rIkQUIdcEbiFNbVDV2QMt8i6aBcWnPVQCYhY2zPO/tmBnS9F8O4JLDGi0eXfZ6iCnVD+J2dMWNbzt4xwvyH05HfotKEn6iG19E/5wf4om8+6J5d8q2+8mXgwEKQ2QkNr1zWKWpUIfDORWvZchlcqIJ4zZRFD9w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LZPLnofK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LZPLnofK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D75FC433C7; Tue, 23 Jan 2024 00:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705970960; bh=BJvDOAzy8/BWztnV6Axb40uBFEUW+MwP550UfFhGtPA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LZPLnofK1JHD4q8j03QpscoOgxAbin4dsWPw5UpS/c08WfVMSu+5p4MWc5Y1KCkMT GZlKeuCv85PAx4Q+ki6mD8RPjpSi9Z8yB9myyfFIJ4Eyi4SMm+ElfVok85YSCkH4xd HS2vLUNsa/20/XEBdNEIiBNjnTzVc9jTJQ3187Fs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jacob Moroni , Eric Dumazet , Marcelo Ricardo Leitner , Xin Long , "David S. Miller" , Sasha Levin Subject: [PATCH 6.1 150/417] sctp: fix busy polling Date: Mon, 22 Jan 2024 15:55:18 -0800 Message-ID: <20240122235757.025379683@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235751.480367507@linuxfoundation.org> References: <20240122235751.480367507@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit a562c0a2d651e040681b0bfce9b4d229ac3b0b8c ] Busy polling while holding the socket lock makes litle sense, because incoming packets wont reach our receive queue. Fixes: 8465a5fcd1ce ("sctp: add support for busy polling to sctp protocol") Reported-by: Jacob Moroni Signed-off-by: Eric Dumazet Cc: Marcelo Ricardo Leitner Cc: Xin Long Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sctp/socket.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index da56832179f0..237a6b04adf6 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2101,6 +2101,10 @@ static int sctp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (unlikely(flags & MSG_ERRQUEUE)) return inet_recv_error(sk, msg, len, addr_len); + if (sk_can_busy_loop(sk) && + skb_queue_empty_lockless(&sk->sk_receive_queue)) + sk_busy_loop(sk, flags & MSG_DONTWAIT); + lock_sock(sk); if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED) && @@ -9041,12 +9045,6 @@ struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags, int *err) if (sk->sk_shutdown & RCV_SHUTDOWN) break; - if (sk_can_busy_loop(sk)) { - sk_busy_loop(sk, flags & MSG_DONTWAIT); - - if (!skb_queue_empty_lockless(&sk->sk_receive_queue)) - continue; - } /* User doesn't want to wait. */ error = -EAGAIN; -- 2.43.0