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[209.132.180.67]) by mx.google.com with ESMTP id h132si667268pfe.52.2018.04.11.03.30.37; Wed, 11 Apr 2018 03:31:15 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=RXK9z3Q6; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752178AbeDKKYh (ORCPT + 99 others); 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-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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 --- 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); -- 1.9.1