From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.7 required=3.0 tests=DATE_IN_PAST_03_06, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 644EFCA9EC0 for ; Mon, 28 Oct 2019 13:29:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 408A020862 for ; Mon, 28 Oct 2019 13:29:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727041AbfJ1N3x (ORCPT ); Mon, 28 Oct 2019 09:29:53 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:60228 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726691AbfJ1N3x (ORCPT ); Mon, 28 Oct 2019 09:29:53 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 3E0FFF9A41F616FE4F0C; Mon, 28 Oct 2019 21:29:49 +0800 (CST) Received: from HGHY4Z004218071.china.huawei.com (10.133.224.57) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.439.0; Mon, 28 Oct 2019 21:29:41 +0800 From: Xiang Zheng To: CC: , , , , , , , , , , , Subject: [PATCH] pci: lock the pci_cfg_wait queue for the consistency of data Date: Mon, 28 Oct 2019 17:18:09 +0800 Message-ID: <20191028091809.35212-1-zhengxiang9@huawei.com> X-Mailer: git-send-email 2.15.1.windows.2 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.133.224.57] X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Commit "7ea7e98fd8d0" suggests that the "pci_lock" is sufficient, and all the callers of pci_wait_cfg() are wrapped with the "pci_lock". However, since the commit "cdcb33f98244" merged, the accesses to the pci_cfg_wait queue are not safe anymore. A "pci_lock" is insufficient and we need to hold an additional queue lock while read/write the wait queue. So let's use the add_wait_queue()/remove_wait_queue() instead of __add_wait_queue()/__remove_wait_queue(). Signed-off-by: Xiang Zheng Cc: Heyi Guo Cc: Biaoxiang Ye Cc: Xiongfeng Wang --- drivers/pci/access.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 2fccb5762c76..247bf36e0047 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -207,14 +207,14 @@ static noinline void pci_wait_cfg(struct pci_dev *dev) { DECLARE_WAITQUEUE(wait, current); - __add_wait_queue(&pci_cfg_wait, &wait); + add_wait_queue(&pci_cfg_wait, &wait); do { set_current_state(TASK_UNINTERRUPTIBLE); raw_spin_unlock_irq(&pci_lock); schedule(); raw_spin_lock_irq(&pci_lock); } while (dev->block_cfg_access); - __remove_wait_queue(&pci_cfg_wait, &wait); + remove_wait_queue(&pci_cfg_wait, &wait); } /* Returns 0 on success, negative values indicate error. */ -- 2.19.1