From nobody Fri Oct 24 20:33:56 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 31C71C00140 for ; Mon, 15 Aug 2022 21:53:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349810AbiHOVxN (ORCPT ); Mon, 15 Aug 2022 17:53:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60594 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349876AbiHOVsz (ORCPT ); Mon, 15 Aug 2022 17:48:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 119FF606B8; Mon, 15 Aug 2022 12:32:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2640461133; Mon, 15 Aug 2022 19:32:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11D65C433C1; Mon, 15 Aug 2022 19:32:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660591926; bh=cRcGwfrIuzA+tBZlDTT6JWtbArYGci7x41RI+xWkygM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f3+KWOYgzLfiZ2g/LTKQPdRQkL3Y5OJI5A5HJnSLYpwgVc8R+dtwBBUzKkglzJm88 efI7MXD9O2isrfneKHtJh+RlqyfXx/gJnpfmDsnl7zqpA5xy7zmGVtQT/QRGGXxy25 x4Qy+c6d07530W1zioSRaTsNIosCnsikon3/i+dc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jenny Hack , Bob Pearson , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.18 0705/1095] RDMA/rxe: Fix deadlock in rxe_do_local_ops() Date: Mon, 15 Aug 2022 20:01:44 +0200 Message-Id: <20220815180458.543648823@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180429.240518113@linuxfoundation.org> References: <20220815180429.240518113@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Bob Pearson [ Upstream commit 7cb33d1bc1ac8e51fd88928f96674d392f8e07c4 ] When a local operation (invalidate mr, reg mr, bind mw) is finished there will be no ack packet coming from a responder to cause the wqe to be completed. This may happen anyway if a subsequent wqe performs IO. Currently if the wqe is signalled the completer tasklet is scheduled immediately but not otherwise. This leads to a deadlock if the next wqe has the fence bit set in send flags and the operation is not signalled. This patch removes the condition that the wqe must be signalled in order to schedule the completer tasklet which is the simplest fix for this deadlock and is fairly low cost. This is the analog for local operations of always setting the ackreq bit in all last or only request packets even if the operation is not signalled. Link: https://lore.kernel.org/r/20220523223251.15350-1-rpearsonhpe@gmail.com Reported-by: Jenny Hack Fixes: c1a411268a4b ("RDMA/rxe: Move local ops to subroutine") Signed-off-by: Bob Pearson Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rxe/rxe_req.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rx= e/rxe_req.c index 8a1cff80a68e..d574c47099b8 100644 --- a/drivers/infiniband/sw/rxe/rxe_req.c +++ b/drivers/infiniband/sw/rxe/rxe_req.c @@ -586,9 +586,11 @@ static int rxe_do_local_ops(struct rxe_qp *qp, struct = rxe_send_wqe *wqe) wqe->status =3D IB_WC_SUCCESS; qp->req.wqe_index =3D queue_next_index(qp->sq.queue, qp->req.wqe_index); =20 - if ((wqe->wr.send_flags & IB_SEND_SIGNALED) || - qp->sq_sig_type =3D=3D IB_SIGNAL_ALL_WR) - rxe_run_task(&qp->comp.task, 1); + /* There is no ack coming for local work requests + * which can lead to a deadlock. So go ahead and complete + * it now. + */ + rxe_run_task(&qp->comp.task, 1); =20 return 0; } --=20 2.35.1