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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 0C3CBC4360F for ; Mon, 25 Feb 2019 21:28:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C45792087C for ; Mon, 25 Feb 2019 21:28:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130108; bh=c6KQmrDNRwsQUDsGEemvSKAPQAUUuekAxscjYFteMJM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VE9rU29tj/ADPUa55ivwzR71qcYKHNxBn3FY7gIwtSDbPTAqb5WHCd347acChzi6A ESJsVUIPJRE9YDOu7I0/XaijFv9f82vho/LNwFNTxcegvYL9xTPCo/OdIjDq/0+UQb pPQjyCPz0Nl3n67cy8S/+BaueJwgZIJ0WJgsLots= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731847AbfBYV2W (ORCPT ); Mon, 25 Feb 2019 16:28:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:34098 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731061AbfBYV2T (ORCPT ); Mon, 25 Feb 2019 16:28:19 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E58E420C01; Mon, 25 Feb 2019 21:28:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551130098; bh=c6KQmrDNRwsQUDsGEemvSKAPQAUUuekAxscjYFteMJM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ggz+khcGypxBTKCCTZY2TF5WW/wLYv62FF7SwvFGY+WtquqtpAWwmJs9E19Vw4VDx jcXz4CCB5Ju7JYsqsBkQyUAgGRVB3BqhEuf4L2D9OvC6usnZy0Us9X3gaYV4jAa/8S 7g3r+YLVzP3RbGY35cYnzABcP1qblz594cos6yRI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ralph Campbell , Alexander Duyck , Waiman Long , Andrew Morton , Linus Torvalds Subject: [PATCH 4.20 014/183] numa: change get_mempolicy() to use nr_node_ids instead of MAX_NUMNODES Date: Mon, 25 Feb 2019 22:09:47 +0100 Message-Id: <20190225195057.081690382@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190225195054.748060397@linuxfoundation.org> References: <20190225195054.748060397@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ralph Campbell commit 050c17f239fd53adb55aa768d4f41bc76c0fe045 upstream. The system call, get_mempolicy() [1], passes an unsigned long *nodemask pointer and an unsigned long maxnode argument which specifies the length of the user's nodemask array in bits (which is rounded up). The manual page says that if the maxnode value is too small, get_mempolicy will return EINVAL but there is no system call to return this minimum value. To determine this value, some programs search /proc//status for a line starting with "Mems_allowed:" and use the number of digits in the mask to determine the minimum value. A recent change to the way this line is formatted [2] causes these programs to compute a value less than MAX_NUMNODES so get_mempolicy() returns EINVAL. Change get_mempolicy(), the older compat version of get_mempolicy(), and the copy_nodes_to_user() function to use nr_node_ids instead of MAX_NUMNODES, thus preserving the defacto method of computing the minimum size for the nodemask array and the maxnode argument. [1] http://man7.org/linux/man-pages/man2/get_mempolicy.2.html [2] https://lore.kernel.org/lkml/1545405631-6808-1-git-send-email-longman@redhat.com Link: http://lkml.kernel.org/r/20190211180245.22295-1-rcampbell@nvidia.com Fixes: 4fb8e5b89bcbbbb ("include/linux/nodemask.h: use nr_node_ids (not MAX_NUMNODES) in __nodemask_pr_numnodes()") Signed-off-by: Ralph Campbell Suggested-by: Alexander Duyck Cc: Waiman Long Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mempolicy.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1314,7 +1314,7 @@ static int copy_nodes_to_user(unsigned l nodemask_t *nodes) { unsigned long copy = ALIGN(maxnode-1, 64) / 8; - const int nbytes = BITS_TO_LONGS(MAX_NUMNODES) * sizeof(long); + unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long); if (copy > nbytes) { if (copy > PAGE_SIZE) @@ -1491,7 +1491,7 @@ static int kernel_get_mempolicy(int __us int uninitialized_var(pval); nodemask_t nodes; - if (nmask != NULL && maxnode < MAX_NUMNODES) + if (nmask != NULL && maxnode < nr_node_ids) return -EINVAL; err = do_get_mempolicy(&pval, &nodes, addr, flags); @@ -1527,7 +1527,7 @@ COMPAT_SYSCALL_DEFINE5(get_mempolicy, in unsigned long nr_bits, alloc_size; DECLARE_BITMAP(bm, MAX_NUMNODES); - nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES); + nr_bits = min_t(unsigned long, maxnode-1, nr_node_ids); alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8; if (nmask)