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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 2A8D7C3A5A7 for ; Mon, 2 Sep 2019 21:28:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0085B21881 for ; Mon, 2 Sep 2019 21:28:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="E7XWS51m" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727647AbfIBV2N (ORCPT ); Mon, 2 Sep 2019 17:28:13 -0400 Received: from mail-qk1-f196.google.com ([209.85.222.196]:36771 "EHLO mail-qk1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726964AbfIBV2N (ORCPT ); Mon, 2 Sep 2019 17:28:13 -0400 Received: by mail-qk1-f196.google.com with SMTP id s18so2666937qkj.3 for ; Mon, 02 Sep 2019 14:28:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=m5Tr8peCYLPTBLyG4jlj+OLhYRR0ev+4cBo1n2zucSI=; b=E7XWS51m3HrCCTEixm5DCt3mCnbxRvgSDNLcJNwLa+R4y1JIjfRngyCAtllxj7BiDV QXSvevY8BokCCfeECi4pWRDaupFZQ6gaOBdFwoHvyuMn3hh0ueJtchjxb+/pZ8fibZYY AYtVk6gogONa8YRAddmi9iNLn6SXWOFGuBgPDbLmI0UuopSdZgtT1FPRv+5bJUSzP9Ju Lp/778ylNxlmOoTesZOF75ZgMBtAvAZfz+aBqMBpvhIIT6JS2KUHJOA3k9DtmPGZktjy CxFywRTqNgyBJQfWJmuN4Cf3XFB/HBs9BONoBLBlwdhhpJYf+0HjHk7gWvjCEJnoo1qM zx8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=m5Tr8peCYLPTBLyG4jlj+OLhYRR0ev+4cBo1n2zucSI=; b=nwH+8qmzS199CHLje1AsBcdVNyqfU3tJ9FwSF2AlLNDGJaLLIK2IfEHbYhfyfU0Bek dWMpOKTvUE2x4tY3eiKklCFAkUSTy2PB84uPdc76UoCEn9zw+LCgfFJR+aKAfaqzgGqL JKLcF6PMUfrdQCG9iM/89/rKzW5UBvZeVQqdubaPQJYJniFcP4wPTKIH23SraI/llrXC 2pH8suMQ63KqaIiYVtwidB0bUV+CBftiJS/zXAFoqkB1K0TFMYrfVAdGbqsAbtIbGWa/ z751GTNfPxAqizQP/Hxkp6aSctwOHITNepj5ZdB1qyXWX1XW1ofF3P7Q/oIexmimn8rO qYsw== X-Gm-Message-State: APjAAAUZmJB40Fi0E2lhWVr4oH0mhn9ctK/X9i/GrPGnIwJnb4cEmQOC cDzRkwYhkbS58KhwOy8I3DHAbIIMaRAomVChd2g= X-Google-Smtp-Source: APXvYqySasX/x6fK/ZFBF4sNLvCdTUg5vYzZ0ptU0WC1DQqA7ozHIr8NeksPjbfjj3j9Z+i5q/D67EoDgzPair+kAjY= X-Received: by 2002:a37:8684:: with SMTP id i126mr18173762qkd.433.1567459692698; Mon, 02 Sep 2019 14:28:12 -0700 (PDT) MIME-Version: 1.0 References: <20190830035716.GA190684@LGEARND20B15> <20190830135007.8b5949bd57975d687ff0a3f8@linux-foundation.org> In-Reply-To: <20190830135007.8b5949bd57975d687ff0a3f8@linux-foundation.org> From: Austin Kim Date: Tue, 3 Sep 2019 06:28:08 +0900 Message-ID: Subject: Re: [PATCH] mm/vmalloc: move 'area->pages' after if statement To: Andrew Morton Cc: urezki@gmail.com, guro@fb.com, rpenyaev@suse.de, mhocko@suse.com, rick.p.edgecombe@intel.com, rppt@linux.ibm.com, aryabinin@virtuozzo.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2019=EB=85=84 8=EC=9B=94 31=EC=9D=BC (=ED=86=A0) =EC=98=A4=EC=A0=84 5:50, A= ndrew Morton =EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84= =B1: > > On Fri, 30 Aug 2019 12:57:16 +0900 Austin Kim wr= ote: > > > If !area->pages statement is true where memory allocation fails, > > area is freed. > > > > In this case 'area->pages =3D pages' should not executed. > > So move 'area->pages =3D pages' after if statement. > > > > ... > > > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -2416,13 +2416,15 @@ static void *__vmalloc_area_node(struct vm_stru= ct *area, gfp_t gfp_mask, > > } else { > > pages =3D kmalloc_node(array_size, nested_gfp, node); > > } > > - area->pages =3D pages; > > - if (!area->pages) { > > + > > + if (!pages) { > > remove_vm_area(area->addr); > > kfree(area); > > return NULL; > > } > > > > + area->pages =3D pages; > > + > > for (i =3D 0; i < area->nr_pages; i++) { > > struct page *page; > > > > Fair enough. But we can/should also do this? I agreed since it is the same treatment. Thanks for feedback. > > --- a/mm/vmalloc.c~mm-vmalloc-move-area-pages-after-if-statement-fix > +++ a/mm/vmalloc.c > @@ -2409,7 +2409,6 @@ static void *__vmalloc_area_node(struct > nr_pages =3D get_vm_area_size(area) >> PAGE_SHIFT; > array_size =3D (nr_pages * sizeof(struct page *)); > > - area->nr_pages =3D nr_pages; > /* Please note that the recursion is strictly bounded. */ > if (array_size > PAGE_SIZE) { > pages =3D __vmalloc_node(array_size, 1, nested_gfp|highme= m_mask, > @@ -2425,6 +2424,7 @@ static void *__vmalloc_area_node(struct > } > > area->pages =3D pages; > + area->nr_pages =3D nr_pages; > > for (i =3D 0; i < area->nr_pages; i++) { > struct page *page; > _ >