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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 E3710C47093 for ; Tue, 1 Jun 2021 15:15:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9033861375 for ; Tue, 1 Jun 2021 15:15:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9033861375 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 283156B0073; Tue, 1 Jun 2021 11:15:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 259766B0074; Tue, 1 Jun 2021 11:15:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0FA7E6B0075; Tue, 1 Jun 2021 11:15:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0134.hostedemail.com [216.40.44.134]) by kanga.kvack.org (Postfix) with ESMTP id D01456B0073 for ; Tue, 1 Jun 2021 11:15:09 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 63E58180AD811 for ; Tue, 1 Jun 2021 15:15:09 +0000 (UTC) X-FDA: 78205503138.12.3ADAA0A Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf30.hostedemail.com (Postfix) with ESMTP id 70B7CE00026B for ; Tue, 1 Jun 2021 15:14:59 +0000 (UTC) IronPort-SDR: XuaueSrWUaI5mWXuRlBv40IM8wdcfqyoJNLAuU5SCmCtZREoVl7FYQdcbwIa8JdDzrSYebI1bJ RE0tunJlfVmQ== X-IronPort-AV: E=McAfee;i="6200,9189,10002"; a="183926966" X-IronPort-AV: E=Sophos;i="5.83,240,1616482800"; d="scan'208";a="183926966" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jun 2021 08:15:08 -0700 IronPort-SDR: POLDI6p1uxAdB0Urxy1YA0R7vC1Ud3T53dZx8PxoyXnLVQepT3KmU5iDtgO4FOtT4jNPKLKNtE l4J9bNaMP77w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,240,1616482800"; d="scan'208";a="482522223" Received: from shbuild999.sh.intel.com ([10.239.147.94]) by fmsmga002.fm.intel.com with ESMTP; 01 Jun 2021 08:15:05 -0700 From: Feng Tang To: linux-mm@kvack.org, Andrew Morton , Michal Hocko , David Rientjes , Dave Hansen , Ben Widawsky Cc: Andrea Arcangeli , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Andi Kleen , Dan Williams , ying.huang@intel.com, Feng Tang Subject: [v4 PATCH 3/3] mm/mempolicy: unify the parameter sanity check for mbind and set_mempolicy Date: Tue, 1 Jun 2021 23:14:52 +0800 Message-Id: <1622560492-1294-4-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1622560492-1294-1-git-send-email-feng.tang@intel.com> References: <1622560492-1294-1-git-send-email-feng.tang@intel.com> X-Rspamd-Queue-Id: 70B7CE00026B Authentication-Results: imf30.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf30.hostedemail.com: domain of feng.tang@intel.com has no SPF policy when checking 192.55.52.151) smtp.mailfrom=feng.tang@intel.com X-Rspamd-Server: rspam04 X-Stat-Signature: znrtk33m3j9s4d7d3a76anysj83opw3p X-HE-Tag: 1622560499-650732 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Currently the kernel_mbind() and kernel_set_mempolicy() do almost the same operation for parameter sanity check. Add a helper function to unify the code to reduce the redundancy, and make it easier for changing the sanity check code in future. [thanks to David Rientjes for suggesting using helper function instead of macro] Signed-off-by: Feng Tang Acked-by: Michal Hocko --- mm/mempolicy.c | 48 ++++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 9805291..32ca8fc 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1440,26 +1440,38 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0; } +/* Basic parameter sanity check used by both mbind() and set_mempolicy() */ +static inline int sanitize_mpol_flags(int *mode, unsigned short *flags) +{ + *flags = *mode & MPOL_MODE_FLAGS; + *mode &= ~MPOL_MODE_FLAGS; + if ((unsigned int)(*mode) >= MPOL_MAX) + return -EINVAL; + if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES)) + return -EINVAL; + + return 0; +} + static long kernel_mbind(unsigned long start, unsigned long len, unsigned long mode, const unsigned long __user *nmask, unsigned long maxnode, unsigned int flags) { + unsigned short mode_flags; nodemask_t nodes; + int lmode = mode; int err; - unsigned short mode_flags; start = untagged_addr(start); - mode_flags = mode & MPOL_MODE_FLAGS; - mode &= ~MPOL_MODE_FLAGS; - if (mode >= MPOL_MAX) - return -EINVAL; - if ((mode_flags & MPOL_F_STATIC_NODES) && - (mode_flags & MPOL_F_RELATIVE_NODES)) - return -EINVAL; + err = sanitize_mpol_flags(&lmode, &mode_flags); + if (err) + return err; + err = get_nodes(&nodes, nmask, maxnode); if (err) return err; - return do_mbind(start, len, mode, mode_flags, &nodes, flags); + + return do_mbind(start, len, lmode, mode_flags, &nodes, flags); } SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, @@ -1473,20 +1485,20 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len, static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask, unsigned long maxnode) { - int err; + unsigned short mode_flags; nodemask_t nodes; - unsigned short flags; + int lmode = mode; + int err; + + err = sanitize_mpol_flags(&lmode, &mode_flags); + if (err) + return err; - flags = mode & MPOL_MODE_FLAGS; - mode &= ~MPOL_MODE_FLAGS; - if ((unsigned int)mode >= MPOL_MAX) - return -EINVAL; - if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES)) - return -EINVAL; err = get_nodes(&nodes, nmask, maxnode); if (err) return err; - return do_set_mempolicy(mode, flags, &nodes); + + return do_set_mempolicy(lmode, mode_flags, &nodes); } SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask, -- 2.7.4