From patchwork Tue Feb 25 19:54:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dennis Dalessandro X-Patchwork-Id: 11404503 X-Patchwork-Delegate: jgg@ziepe.ca Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D3A79138D for ; Tue, 25 Feb 2020 19:54:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC0372082F for ; Tue, 25 Feb 2020 19:54:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728383AbgBYTyw (ORCPT ); Tue, 25 Feb 2020 14:54:52 -0500 Received: from mga02.intel.com ([134.134.136.20]:14778 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728051AbgBYTyv (ORCPT ); Tue, 25 Feb 2020 14:54:51 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Feb 2020 11:54:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,485,1574150400"; d="scan'208";a="438177007" Received: from sedona.ch.intel.com ([10.2.136.157]) by fmsmga006.fm.intel.com with ESMTP; 25 Feb 2020 11:54:50 -0800 Received: from awfm-01.aw.intel.com (awfm-01.aw.intel.com [10.228.212.213]) by sedona.ch.intel.com (8.14.3/8.14.3/Standard MailSET/Hub) with ESMTP id 01PJsmrv003071; Tue, 25 Feb 2020 12:54:48 -0700 Received: from awfm-01.aw.intel.com (localhost [127.0.0.1]) by awfm-01.aw.intel.com (8.14.7/8.14.7) with ESMTP id 01PJsjnX140918; Tue, 25 Feb 2020 14:54:46 -0500 Subject: [PATCH for-rc] IB/hfi1, qib: Ensure RCU is locked when accessing list From: Dennis Dalessandro To: jgg@ziepe.ca, dledford@redhat.com Cc: linux-rdma@vger.kernel.org, Mike Marciniszyn , Madhuparna Bhowmik Date: Tue, 25 Feb 2020 14:54:45 -0500 Message-ID: <20200225195445.140896.41873.stgit@awfm-01.aw.intel.com> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org The packet handling function, specifically the iteration of the qp list for mad packet processing misses locking RCU before running through the list. Not only is this incorrect, but the list_for_each_entry_rcu() call can not be called with a conditional check for lock dependency. Remedy this by invoking the rcu lock and unlock around the critical section. This brings MAD packet processing in line with what is done for non-MAD packets. Cc: Madhuparna Bhowmik Reviewed-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro --- drivers/infiniband/hw/hfi1/verbs.c | 4 +++- drivers/infiniband/hw/qib/qib_verbs.c | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/hfi1/verbs.c b/drivers/infiniband/hw/hfi1/verbs.c index 089e201..2f6323a 100644 --- a/drivers/infiniband/hw/hfi1/verbs.c +++ b/drivers/infiniband/hw/hfi1/verbs.c @@ -515,10 +515,11 @@ static inline void hfi1_handle_packet(struct hfi1_packet *packet, opa_get_lid(packet->dlid, 9B)); if (!mcast) goto drop; + rcu_read_lock(); list_for_each_entry_rcu(p, &mcast->qp_list, list) { packet->qp = p->qp; if (hfi1_do_pkey_check(packet)) - goto drop; + goto unlock_drop; spin_lock_irqsave(&packet->qp->r_lock, flags); packet_handler = qp_ok(packet); if (likely(packet_handler)) @@ -527,6 +528,7 @@ static inline void hfi1_handle_packet(struct hfi1_packet *packet, ibp->rvp.n_pkt_drops++; spin_unlock_irqrestore(&packet->qp->r_lock, flags); } + rcu_read_unlock(); /* * Notify rvt_multicast_detach() if it is waiting for us * to finish. diff --git a/drivers/infiniband/hw/qib/qib_verbs.c b/drivers/infiniband/hw/qib/qib_verbs.c index 33778d4..5ef93f8 100644 --- a/drivers/infiniband/hw/qib/qib_verbs.c +++ b/drivers/infiniband/hw/qib/qib_verbs.c @@ -329,8 +329,10 @@ void qib_ib_rcv(struct qib_ctxtdata *rcd, void *rhdr, void *data, u32 tlen) if (mcast == NULL) goto drop; this_cpu_inc(ibp->pmastats->n_multicast_rcv); + rcu_read_lock(); list_for_each_entry_rcu(p, &mcast->qp_list, list) qib_qp_rcv(rcd, hdr, 1, data, tlen, p->qp); + rcu_read_unlock(); /* * Notify rvt_multicast_detach() if it is waiting for us * to finish.