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_BLOCKED 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 D3247C433E0 for ; Wed, 13 Jan 2021 00:56:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A07222312E for ; Wed, 13 Jan 2021 00:56:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388839AbhAMAms (ORCPT ); Tue, 12 Jan 2021 19:42:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:46106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391950AbhALXuC (ORCPT ); Tue, 12 Jan 2021 18:50:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9EF8023138; Tue, 12 Jan 2021 23:49:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1610495362; bh=RDcIaqC9EWRiTftuo/Tl8jcOF/9zYknnO+03Bno0x6k=; h=Date:From:To:Subject:In-Reply-To:From; b=1uxqsSYK14GsNc3bX09iPRCjufcccpG+YCV/kEQZNVQtqumA6rvz45/il3XQMk9S+ tbQSBJhIedltUXaElDzQQFsZhAXd8BUpidvdzS6TbqkH/9BquhNaOVHMzJP1btxbML siW2IqHgjKrMxnoHgwWg3jGgskgRbVG+I9sIy+ns= Date: Tue, 12 Jan 2021 15:49:21 -0800 From: Andrew Morton To: akpm@linux-foundation.org, jack@suse.cz, jstancek@redhat.com, linux-mm@kvack.org, mgorman@suse.de, mhocko@suse.com, mm-commits@vger.kernel.org, shy828301@gmail.com, songliubraving@fb.com, torvalds@linux-foundation.org, willy@infradead.org, ziy@nvidia.com Subject: [patch 06/10] mm: migrate: initialize err in do_migrate_pages Message-ID: <20210112234921.ydOmosyOp%akpm@linux-foundation.org> In-Reply-To: <20210112154839.abeb6e57de79480059fd9b0e@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: Jan Stancek Subject: mm: migrate: initialize err in do_migrate_pages After commit 236c32eb1096 ("mm: migrate: clean up migrate_prep{_local}")', do_migrate_pages can return uninitialized variable 'err' (which is propagated to user-space as error) when 'from' and 'to' nodesets are identical. This can be reproduced with LTP migrate_pages01, which calls migrate_pages() with same set for both old/new_nodes. Add 'err' initialization back. Link: https://lkml.kernel.org/r/456a021c7ef3636d7668cec9dcb4a446a4244812.1609855564.git.jstancek@redhat.com Fixes: 236c32eb1096 ("mm: migrate: clean up migrate_prep{_local}") Signed-off-by: Jan Stancek Acked-by: Michal Hocko Acked-by: Yang Shi Cc: Zi Yan Cc: Jan Kara Cc: Matthew Wilcox Cc: Mel Gorman Cc: Song Liu Signed-off-by: Andrew Morton --- mm/mempolicy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/mempolicy.c~mm-migrate-initialize-err-in-do_migrate_pages +++ a/mm/mempolicy.c @@ -1111,7 +1111,7 @@ int do_migrate_pages(struct mm_struct *m const nodemask_t *to, int flags) { int busy = 0; - int err; + int err = 0; nodemask_t tmp; migrate_prep(); _