From patchwork Wed Apr 11 10:24:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 897128 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="RXK9z3Q6"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40LgC50MnXz9s1r for ; Wed, 11 Apr 2018 20:24:49 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751961AbeDKKYh (ORCPT ); Wed, 11 Apr 2018 06:24:37 -0400 Received: from mail-pl0-f65.google.com ([209.85.160.65]:34159 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751729AbeDKKYf (ORCPT ); Wed, 11 Apr 2018 06:24:35 -0400 Received: by mail-pl0-f65.google.com with SMTP id y12-v6so1074449plt.1; Wed, 11 Apr 2018 03:24:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=7oBFXmVNOHJMYNmOaKS96qvWlszw2Mw/exHM21VtTwE=; b=RXK9z3Q62YUN7tD6Vw5EQb9ZpmPOnPaPEORE0EQFv2dr0QfQo3ik6GfMk7h/Y8VHg9 zeX0Cum0bDxUwhJOqzud5qvjX7AxsFwgl8TobMfEb00NZ8+cq8BYj4ehm/dhzA+rsmsl kRZhpNm57lJoqKP9jPx+bGznS833hHsIT4JcLlGjMd+oJYhxEtGEd8Ztrgv1CA45JMSO 0InKCprTFPhqOasY9YTkqYlJzutmWQED3J7EM3GDNlqQfBtqcMB16enr+7uNgx2PzcIz pzZ84eb48wko3KAYZoz8BaYiBs416FVU9MwKSx/JKuR5wzf1Odyfxd+ZhZpuQbCF1FKq d8cA== 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=7oBFXmVNOHJMYNmOaKS96qvWlszw2Mw/exHM21VtTwE=; b=k1bOeAHIrhZWYRYEw22W5R+7v2gSagbjYQASVmIthUHoPzTKAhq1KO1UmObXxsTW0h hwG6Q3/GMvJTbdq+sAkZJDvtfKS7y6c2BliX+0/04g01EgeQ75YXrX1e2PgdKHygup95 AsxL51i+7rodstxyZLrQXiL9fuy9Ovvj4T/ytpozILfuudZx8rJIuomQMHx45sRc0quw +CCvVvRFS4m4ClIBBKolx4SThktEu7ghbN3QOp8lW7I+oso1do/wR+nXfEKfXOqe/rRn /ve+PK/J6UyiMR2ET3ISwbsuxt+oBRHq4bfhaEvbGwSvrM4FnEHVWHvSd/fNUWWG35sj UG8Q== X-Gm-Message-State: ALQs6tDIXwN6JL8rUM1Bx00WxubYxQYDfCiTTq3dMzwquMitoNLOTKvf uKbhMkE14nt+FDsV3qhNSYk= X-Google-Smtp-Source: AIpwx4/qBRnGdDkPYDam4SZNRmCTRpbQAxNuNFkwh1KAMzJvXf60VUxJhkknxzq1WwLgi1M4BEegJQ== X-Received: by 2002:a17:902:5501:: with SMTP id f1-v6mr4396286pli.50.1523442275392; Wed, 11 Apr 2018 03:24:35 -0700 (PDT) Received: from oslab.tsinghua.edu.cn ([2402:f000:1:4413:edc8:c1dd:b0a8:461d]) by smtp.gmail.com with ESMTPSA id z16sm2341184pfn.101.2018.04.11.03.24.31 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 11 Apr 2018 03:24:34 -0700 (PDT) From: Jia-Ju Bai To: jon.maloy@ericsson.com, ying.xue@windriver.com, davem@davemloft.net Cc: netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH v3] net: tipc: Replace GFP_ATOMIC with GFP_KERNEL in tipc_mon_create Date: Wed, 11 Apr 2018 18:24:22 +0800 Message-Id: <1523442262-4823-1-git-send-email-baijiaju1990@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org tipc_mon_create() is never called in atomic context. The call chain ending up at tipc_mon_create() is: [1] tipc_mon_create() <- tipc_enable_bearer() <- tipc_nl_bearer_enable() tipc_nl_bearer_enable() calls rtnl_lock(), which indicates this function is not called in atomic context. Despite never getting called from atomic context, tipc_mon_create() calls kzalloc() with GFP_ATOMIC, which does not sleep for allocation. GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, which can sleep and improve the possibility of successful allocation. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai Acked-by: Ying Xue Acked-by: Jon Maloy --- v2: * Modify the description of GFP_ATOMIC in v1. Thank Eric for good advice. v3: * Modify wrong text in description in v2. Thank Ying for good advice. --- net/tipc/monitor.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c index 9e109bb..9714d80 100644 --- a/net/tipc/monitor.c +++ b/net/tipc/monitor.c @@ -604,9 +604,9 @@ int tipc_mon_create(struct net *net, int bearer_id) if (tn->monitors[bearer_id]) return 0; - mon = kzalloc(sizeof(*mon), GFP_ATOMIC); - self = kzalloc(sizeof(*self), GFP_ATOMIC); - dom = kzalloc(sizeof(*dom), GFP_ATOMIC); + mon = kzalloc(sizeof(*mon), GFP_KERNEL); + self = kzalloc(sizeof(*self), GFP_KERNEL); + dom = kzalloc(sizeof(*dom), GFP_KERNEL); if (!mon || !self || !dom) { kfree(mon); kfree(self);