From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753391Ab2GQMfD (ORCPT ); Tue, 17 Jul 2012 08:35:03 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:41962 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753254Ab2GQMe4 (ORCPT ); Tue, 17 Jul 2012 08:34:56 -0400 From: Joonsoo Kim To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Joonsoo Kim , Sasha Levin , Christoph Lameter Subject: [PATCH 2/4 v2] mm: fix possible incorrect return value of migrate_pages() syscall Date: Tue, 17 Jul 2012 21:33:33 +0900 Message-Id: <1342528415-2291-2-git-send-email-js1304@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1342528415-2291-1-git-send-email-js1304@gmail.com> References: <1342528415-2291-1-git-send-email-js1304@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org do_migrate_pages() can return the number of pages not migrated. Because migrate_pages() syscall return this value directly, migrate_pages() syscall may return the number of pages not migrated. In fail case in migrate_pages() syscall, we should return error value. So change err to -EBUSY Additionally, Correct comment above do_migrate_pages() Signed-off-by: Joonsoo Kim Cc: Sasha Levin Cc: Christoph Lameter diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 1d771e4..0732729 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -948,7 +948,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest, * Move pages between the two nodesets so as to preserve the physical * layout as much as possible. * - * Returns the number of page that could not be moved. + * Returns error or the number of pages not migrated. */ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from, const nodemask_t *to, int flags) @@ -1382,6 +1382,8 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, err = do_migrate_pages(mm, old, new, capable(CAP_SYS_NICE) ? MPOL_MF_MOVE_ALL : MPOL_MF_MOVE); + if (err > 0) + err = -EBUSY; mmput(mm); out: -- 1.7.9.5