From patchwork Wed Jan 8 17:22:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yishai Hadas X-Patchwork-Id: 11324163 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 6DE341871 for ; Wed, 8 Jan 2020 17:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4CA87205F4 for ; Wed, 8 Jan 2020 17:22:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729516AbgAHRWh (ORCPT ); Wed, 8 Jan 2020 12:22:37 -0500 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:41810 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729767AbgAHRWh (ORCPT ); Wed, 8 Jan 2020 12:22:37 -0500 Received: from Internal Mail-Server by MTLPINE1 (envelope-from yishaih@mellanox.com) with ESMTPS (AES256-SHA encrypted); 8 Jan 2020 19:22:32 +0200 Received: from vnc17.mtl.labs.mlnx (vnc17.mtl.labs.mlnx [10.7.2.17]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id 008HMW8S009631; Wed, 8 Jan 2020 19:22:32 +0200 Received: from vnc17.mtl.labs.mlnx (vnc17.mtl.labs.mlnx [127.0.0.1]) by vnc17.mtl.labs.mlnx (8.13.8/8.13.8) with ESMTP id 008HMWl3009571; Wed, 8 Jan 2020 19:22:32 +0200 Received: (from yishaih@localhost) by vnc17.mtl.labs.mlnx (8.13.8/8.13.8/Submit) id 008HMWwB009570; Wed, 8 Jan 2020 19:22:32 +0200 From: Yishai Hadas To: linux-rdma@vger.kernel.org, jgg@mellanox.com, dledford@redhat.com Cc: yishaih@mellanox.com, maorg@mellanox.com, michaelgur@mellanox.com Subject: [PATCH rdma-next 11/14] RDMA/core: Fix locking in ib_uverbs_event_read Date: Wed, 8 Jan 2020 19:22:03 +0200 Message-Id: <1578504126-9400-12-git-send-email-yishaih@mellanox.com> X-Mailer: git-send-email 1.8.2.3 In-Reply-To: <1578504126-9400-1-git-send-email-yishaih@mellanox.com> References: <1578504126-9400-1-git-send-email-yishaih@mellanox.com> Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Jason Gunthorpe This should not be using ib_dev to test for disassociation, during disassociation is_closed is set under lock and the waitq is triggered. Instead check is_closed and be sure to re-obtain the lock to test the value after the wait_event returns. Fixes: 036b10635739 ("IB/uverbs: Enable device removal when there are active user space applications") Signed-off-by: Yishai Hadas Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/uverbs_main.c | 32 ++++++++++++++------------------ 1 file changed, 14 insertions(+), 18 deletions(-) diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 85dbd81..97770e7 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -215,7 +215,6 @@ void ib_uverbs_release_file(struct kref *ref) } static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue, - struct ib_uverbs_file *uverbs_file, struct file *filp, char __user *buf, size_t count, loff_t *pos, size_t eventsz) @@ -233,19 +232,16 @@ static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue, if (wait_event_interruptible(ev_queue->poll_wait, (!list_empty(&ev_queue->event_list) || - /* The barriers built into wait_event_interruptible() - * and wake_up() guarentee this will see the null set - * without using RCU - */ - !uverbs_file->device->ib_dev))) + ev_queue->is_closed))) return -ERESTARTSYS; + spin_lock_irq(&ev_queue->lock); + /* If device was disassociated and no event exists set an error */ - if (list_empty(&ev_queue->event_list) && - !uverbs_file->device->ib_dev) + if (list_empty(&ev_queue->event_list) && ev_queue->is_closed) { + spin_unlock_irq(&ev_queue->lock); return -EIO; - - spin_lock_irq(&ev_queue->lock); + } } event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list); @@ -280,8 +276,7 @@ static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf, { struct ib_uverbs_async_event_file *file = filp->private_data; - return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp, - buf, count, pos, + return ib_uverbs_event_read(&file->ev_queue, filp, buf, count, pos, sizeof(struct ib_uverbs_async_event_desc)); } @@ -291,9 +286,8 @@ static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf, struct ib_uverbs_completion_event_file *comp_ev_file = filp->private_data; - return ib_uverbs_event_read(&comp_ev_file->ev_queue, - comp_ev_file->uobj.ufile, filp, - buf, count, pos, + return ib_uverbs_event_read(&comp_ev_file->ev_queue, filp, buf, count, + pos, sizeof(struct ib_uverbs_comp_event_desc)); } @@ -316,7 +310,9 @@ static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue, static __poll_t ib_uverbs_async_event_poll(struct file *filp, struct poll_table_struct *wait) { - return ib_uverbs_event_poll(filp->private_data, filp, wait); + struct ib_uverbs_async_event_file *file = filp->private_data; + + return ib_uverbs_event_poll(&file->ev_queue, filp, wait); } static __poll_t ib_uverbs_comp_event_poll(struct file *filp, @@ -330,9 +326,9 @@ static __poll_t ib_uverbs_comp_event_poll(struct file *filp, static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on) { - struct ib_uverbs_event_queue *ev_queue = filp->private_data; + struct ib_uverbs_async_event_file *file = filp->private_data; - return fasync_helper(fd, filp, on, &ev_queue->async_queue); + return fasync_helper(fd, filp, on, &file->ev_queue.async_queue); } static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)