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=-8.9 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_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 D792CC00319 for ; Thu, 21 Feb 2019 04:01:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A6049214AF for ; Thu, 21 Feb 2019 04:01:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="slI1ohXT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727083AbfBUEB4 (ORCPT ); Wed, 20 Feb 2019 23:01:56 -0500 Received: from mail-pf1-f196.google.com ([209.85.210.196]:43405 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726172AbfBUEBy (ORCPT ); Wed, 20 Feb 2019 23:01:54 -0500 Received: by mail-pf1-f196.google.com with SMTP id q17so13061090pfh.10 for ; Wed, 20 Feb 2019 20:01:54 -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:in-reply-to:references; bh=auu7sPoqnYOjV0cCzT/qrL11WOBRgRd5ITVHRQ8h3zo=; b=slI1ohXTh/xsmYYMHV64QPy2RBdZPwCB45eg01Tz1FkJAN29lre1/lsTzcrkb92T65 +wN+B+xAtPBmjvKmPtn8RZnqjZU1Ue/17qeS9TE9kek7EevHqrfDe76Eb21R5bz5wUbq ie9/0tvopdsyVxM1i6bL4K2VIVg8nz2eEBuh0TlcMGrOeRPwtnTCmp4boIdLcZNkGUm1 j3Ssg+jLJv20L1pt61eLU00ewLRDe8uQVArMMd0nKuyX0jgDJdXye1k2XN4wXm5lJwAA ha4aLfpajRtPmDrt5dXHzBazCywIZ5Wln5bWPOnvu54k0mTNxoikfb557RYnFDEz0PTA Qc5A== 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:in-reply-to :references; bh=auu7sPoqnYOjV0cCzT/qrL11WOBRgRd5ITVHRQ8h3zo=; b=OrtMWOfUV3hTTJhehr/fJf+JzTXyG2stBR7VmthkwcoIvdydKCPTGk0VzJXSr9hNzV BnXN9obzxHD8lMzHxW8PZxXOsNTpnG8gwQ9cmvsXicW9WpAaGInclGp7apYFleAKsnrw I7zaYC2uk0HugXbusWVV06tn4a++o+u5BPvkx/4VFmMihzGtFc0xr8cJE+JpMUqLW2M4 7qMgLOaIa/WGBYV3x864kkaGYF0Bonwrsd+JChhgkh1WAfOtE1DmrvDkHA9KV74Iw1gu jnBMNxMpr8K09A8ElQbVuxbBcw8aCcq4VLReseRa0cljUrHLrxZVf0TE8CvONiBkj+Jo cIvg== X-Gm-Message-State: AHQUAuYtFQWI2yLnfAKVcX9QiyL9yJaP5301DTXRmSyprA6Frf/sXTQJ 4G8l6pfOGzmkrpe5bWY4Jls= X-Google-Smtp-Source: AHgI3IZ4AFFJXmbpIjIrZunHa4CkehfYlISghECHg2aZiI6bpwojNPXg4a6uU19VtC2ztipHnekhVA== X-Received: by 2002:a62:a9b:: with SMTP id 27mr38021830pfk.223.1550721714199; Wed, 20 Feb 2019 20:01:54 -0800 (PST) Received: from huyue2.ccdomain.com ([218.189.10.173]) by smtp.gmail.com with ESMTPSA id e9sm48836730pfb.52.2019.02.20.20.01.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Feb 2019 20:01:53 -0800 (PST) From: Yue Hu To: akpm@linux-foundation.org, mhocko@suse.com, rientjes@google.com, joe@perches.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, huyue2@yulong.com Subject: [PATCH] mm/cma_debug: Check for null tmp in cma_debugfs_add_one() Date: Thu, 21 Feb 2019 12:01:30 +0800 Message-Id: <20190221040130.8940-2-zbestahu@gmail.com> X-Mailer: git-send-email 2.17.1.windows.2 In-Reply-To: <20190221040130.8940-1-zbestahu@gmail.com> References: <20190221040130.8940-1-zbestahu@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yue Hu If debugfs_create_dir() failed, the following debugfs_create_file() will be meanless since it depends on non-NULL tmp dentry and it will only waste CPU resource. Signed-off-by: Yue Hu --- mm/cma_debug.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/cma_debug.c b/mm/cma_debug.c index 2c2c869..3e9d984 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -169,6 +169,8 @@ static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry) scnprintf(name, sizeof(name), "cma-%s", cma->name); tmp = debugfs_create_dir(name, root_dentry); + if (!tmp) + return; debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops); debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops); -- 1.9.1