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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 67CF4C43603 for ; Wed, 18 Dec 2019 14:01:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3AD3E227BF for ; Wed, 18 Dec 2019 14:01:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="B20ej4mZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727121AbfLROBN (ORCPT ); Wed, 18 Dec 2019 09:01:13 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:40261 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726825AbfLROBN (ORCPT ); Wed, 18 Dec 2019 09:01:13 -0500 Received: by mail-pf1-f194.google.com with SMTP id q8so1261761pfh.7; Wed, 18 Dec 2019 06:01:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=DFCnoBm3aJ4yBdlgfovQA6oA3BnQmF1k6xZZgru1lck=; b=B20ej4mZOi5gLgjfFgNoUVSHyV8P35/33fTDKxA5YmemAVZk5Qdmcm92RshrqEa7Sk sTPnUSpSauLGWD+Db556aQJmSwl0ZAZ14YM4lgRYuQ1Gvtj6cShj2I8Ne/m54goqNaDO 1XqsfwezGHEcyMpJa0LKFjQEF4hdhCMxigdl/fkJpryRTTJnnQgQspoiqRFi7XrQ4BYc GxZyTHeT2leu91F8pvWyhan6TqK6iFXvvbp8iN90NZnvuuyO3lzgT6oRVtrkh89GPjHc Zp2V223j0Y/xLuREkjMRGB6ekUZsas8uA4Qc3E7eknGZyE19voXRGGhsRb0kgNn8nECy hLmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=DFCnoBm3aJ4yBdlgfovQA6oA3BnQmF1k6xZZgru1lck=; b=Yrab/qHk32of2WpUg1PEn4tiQ5p7i6sZqrXnwlz8Ht+NcCb7mH7EfMxnM9RZ0yI3qh T5zfmOBEKhg+cyfuvVIIbnUgOSLbxzHOXuSIeiBs9IoeLj5t/PtlZ5DrTTMiw1oAuvBg wttxJpHqFgtAfrBJrPySatLsHT3ZB4xXH69WcV06ZLW+Mu8mevuSnjMrEf7ouVyOsE5c +eOqDGHvVlscallU0VbguSKQMCnlfa6lTxMw3zx0nQefeejo0gdj/ooE1OSmPi5qnEpL JSC9jVhc75o4ywNkvgpO15OTdNWKKrvOjZFJi/K4DgSAKZm/3XNm4aS4ZHkg1eJS9MJv ZVXA== X-Gm-Message-State: APjAAAUpfO2ovUVpj+Rg0xuv0BBZYZZIO2Xo0rIvc6wvaY9b0FdZrJbw NN35gAkwlV8AFtDRoN+NIFk= X-Google-Smtp-Source: APXvYqwxjCJcdPd2xsTBHgah7u883gmPlr5xfXoWL1tYk7k1Gb2MINKxCgQnpEygPSN6qgrhCUOh/w== X-Received: by 2002:a63:f455:: with SMTP id p21mr3198893pgk.436.1576677672115; Wed, 18 Dec 2019 06:01:12 -0800 (PST) Received: from oslab.tsinghua.edu.cn ([166.111.139.172]) by smtp.gmail.com with ESMTPSA id l66sm3486691pga.30.2019.12.18.06.01.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2019 06:01:11 -0800 (PST) From: Jia-Ju Bai To: thomas.lendacky@amd.com, davem@davemloft.net Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] net: amd: xgbe: fix possible sleep-in-atomic-context bugs in xgbe_powerdown() Date: Wed, 18 Dec 2019 22:01:02 +0800 Message-Id: <20191218140102.11579-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The driver may sleep while holding a spinlock. The function call path (from bottom to top) in Linux 4.19 is: drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1261: flush_workqueue in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1253: _raw_spin_lock_irqsave in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1055: napi_disable in xgbe_napi_disable drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1266: xgbe_napi_disable in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1253: _raw_spin_lock_irqsave in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1049: napi_disable in xgbe_napi_disable drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1266: xgbe_napi_disable in xgbe_powerdown drivers/net/ethernet/amd/xgbe/xgbe-drv.c, 1253: _raw_spin_lock_irqsave in xgbe_powerdown flush_workqueue() and napi_disable() can sleep at runtime. To fix these bugs, flush_workqueue() and xgbe_napi_disable() are called without holding the spinlock. These bugs are found by a static analysis tool STCheck written by myself. Signed-off-by: Jia-Ju Bai --- drivers/net/ethernet/amd/xgbe/xgbe-drv.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c index 98f8f2033154..328361d0e190 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c @@ -1257,17 +1257,18 @@ int xgbe_powerdown(struct net_device *netdev, unsigned int caller) netif_tx_stop_all_queues(netdev); xgbe_stop_timers(pdata); - flush_workqueue(pdata->dev_workqueue); hw_if->powerdown_tx(pdata); hw_if->powerdown_rx(pdata); - xgbe_napi_disable(pdata, 0); - pdata->power_down = 1; spin_unlock_irqrestore(&pdata->lock, flags); + flush_workqueue(pdata->dev_workqueue); + + xgbe_napi_disable(pdata, 0); + DBGPR("<--xgbe_powerdown\n"); return 0; -- 2.17.1