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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED 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 96DC9C11F69 for ; Thu, 1 Jul 2021 01:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B94D61469 for ; Thu, 1 Jul 2021 01:51:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238457AbhGABxf (ORCPT ); Wed, 30 Jun 2021 21:53:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:43110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238452AbhGABxf (ORCPT ); Wed, 30 Jun 2021 21:53:35 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 218E26105A; Thu, 1 Jul 2021 01:51:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1625104264; bh=f7LPnw86Ap+ikHRqhja7nyyAa3xRirXQNc40PynI9/A=; h=Date:From:To:Subject:In-Reply-To:From; b=Ceft8B61AbVjYWPqIyPSZePIbmEfDqGN29EQ4dhoOgipSHZL+NdByjfmbPKhD5pZ0 q5miDD9XTQBJHRjneGuOo7+vyvWJrVKXvT9s+oaS1DXo9Apz2Fhu9FOarVBGbncKc3 +22fPHTKWeEHDKbpJoqz+athUVVp9mpy2DASwLSE= Date: Wed, 30 Jun 2021 18:51:03 -0700 From: Andrew Morton To: aarcange@redhat.com, ak@linux.intel.com, akpm@linux-foundation.org, ben.widawsky@intel.com, dan.j.williams@intel.com, dave.hansen@intel.com, feng.tang@intel.com, linux-mm@kvack.org, mgorman@techsingularity.net, mhocko@suse.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, rdunlap@infradead.org, rientjes@google.com, torvalds@linux-foundation.org, vbabka@suse.cz, ying.huang@intel.com Subject: [patch 073/192] mm/mempolicy: unify the parameter sanity check for mbind and set_mempolicy Message-ID: <20210701015103.yXMghYrpe%akpm@linux-foundation.org> In-Reply-To: <20210630184624.9ca1937310b0dd5ce66b30e7@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Feng Tang Subject: mm/mempolicy: unify the parameter sanity check for mbind and set_mempolicy 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]. [feng.tang@intel.com: add comment] Link: https://lkml.kernel.org/r/1622560492-1294-4-git-send-email-feng.tang@intel.com Link: https://lkml.kernel.org/r/1622469956-82897-4-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang Acked-by: Michal Hocko Cc: David Rientjes Cc: Dave Hansen Cc: Ben Widawsky Cc: Andrea Arcangeli Cc: Mel Gorman Cc: Mike Kravetz Cc: Randy Dunlap Cc: Vlastimil Babka Cc: Andi Kleen Cc: Dan Williams Cc: Huang Ying Cc: Michal Hocko Signed-off-by: Andrew Morton --- mm/mempolicy.c | 48 +++++++++++++++++++++++++++++------------------ 1 file changed, 30 insertions(+), 18 deletions(-) --- a/mm/mempolicy.c~mm-mempolicy-unify-the-parameter-sanity-check-for-mbind-and-set_mempolicy +++ a/mm/mempolicy.c @@ -1441,26 +1441,38 @@ static int copy_nodes_to_user(unsigned l 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, @@ -1474,20 +1486,20 @@ SYSCALL_DEFINE6(mbind, unsigned long, st 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, _