From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id 651F26B0253 for ; Thu, 16 Nov 2017 20:49:40 -0500 (EST) Received: by mail-it0-f71.google.com with SMTP id b5so1720768itc.7 for ; Thu, 16 Nov 2017 17:49:40 -0800 (PST) Received: from szxga05-in.huawei.com (szxga05-in.huawei.com. [45.249.212.191]) by mx.google.com with ESMTPS id w33si1878629ioe.106.2017.11.16.17.49.36 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 16 Nov 2017 17:49:39 -0800 (PST) From: Yisheng Xie Subject: [PATCH v3 3/3] mm/mempolicy: add nodes_empty check in SYSC_migrate_pages Date: Fri, 17 Nov 2017 09:37:04 +0800 Message-ID: <1510882624-44342-4-git-send-email-xieyisheng1@huawei.com> In-Reply-To: <1510882624-44342-1-git-send-email-xieyisheng1@huawei.com> References: <1510882624-44342-1-git-send-email-xieyisheng1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, vbabka@suse.cz, mhocko@suse.com, mingo@kernel.org, rientjes@google.com, n-horiguchi@ah.jp.nec.com, salls@cs.ucsb.edu, ak@linux.intel.com, cl@linux.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, tanxiaojun@huawei.com As manpage of migrate_pages, the errno should be set to EINVAL when none of the node IDs specified by new_nodes are on-line and allowed by the process's current cpuset context, or none of the specified nodes contain memory. However, when test by following case: new_nodes = 0; old_nodes = 0xf; ret = migrate_pages(pid, old_nodes, new_nodes, MAX); The ret will be 0 and no errno is set. As the new_nodes is empty, we should expect EINVAL as documented. To fix the case like above, this patch check whether target nodes AND current task_nodes is empty, and then check whether AND node_states[N_MEMORY] is empty. Signed-off-by: Yisheng Xie --- mm/mempolicy.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 65df28d..f604b22 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1433,10 +1433,14 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode, goto out_put; } - if (!nodes_subset(*new, node_states[N_MEMORY])) { - err = -EINVAL; + task_nodes = cpuset_mems_allowed(current); + nodes_and(*new, *new, task_nodes); + if (nodes_empty(*new)) + goto out_put; + + nodes_and(*new, *new, node_states[N_MEMORY]); + if (nodes_empty(*new)) goto out_put; - } err = security_task_movememory(task); if (err) -- 1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org