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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 42E38C43381 for ; Wed, 27 Feb 2019 17:26:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19E202186A for ; Wed, 27 Feb 2019 17:26:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730071AbfB0R0t (ORCPT ); Wed, 27 Feb 2019 12:26:49 -0500 Received: from foss.arm.com ([217.140.101.70]:37484 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726397AbfB0R0s (ORCPT ); Wed, 27 Feb 2019 12:26:48 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6A6981688; Wed, 27 Feb 2019 09:26:48 -0800 (PST) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7EC223F703; Wed, 27 Feb 2019 09:26:47 -0800 (PST) Date: Wed, 27 Feb 2019 17:26:45 +0000 From: Catalin Marinas To: Qian Cai Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm/page_ext: fix an imbalance with kmemleak Message-ID: <20190227172644.GF125513@arrakis.emea.arm.com> References: <20190227172445.75553-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190227172445.75553-1-cai@lca.pw> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 27, 2019 at 12:24:45PM -0500, Qian Cai wrote: > After offlined a memory block, kmemleak scan will trigger a crash, as it > encounters a page ext address that has already been freed during memory > offlining. At the beginning in alloc_page_ext(), it calls > kmemleak_alloc(), but it does not call kmemleak_free() in > free_page_ext(). [...] > diff --git a/mm/page_ext.c b/mm/page_ext.c > index 8c78b8d45117..0b6637d7bae9 100644 > --- a/mm/page_ext.c > +++ b/mm/page_ext.c > @@ -274,6 +274,7 @@ static void free_page_ext(void *addr) > > BUG_ON(PageReserved(page)); > free_pages_exact(addr, table_size); > + kmemleak_free(addr); Same comment as for v1, call kmemleak_free() before free_pages_exact(). With that: Reviewed-by: Catalin Marinas