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=-3.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 71219C41518 for ; Tue, 22 Jan 2019 06:58:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B01220854 for ; Tue, 22 Jan 2019 06:58:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548140304; bh=SpD9MLuRuZrYRFGlhQ0SQ1DyF5BUfOzvZsNEMS7parw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1/Vpr07eHRljHmDGavp4M8aLoTVq6QzAD8F1ivMYaixuZWouhWNENe52O4Fu0ZqE4 rkGeNy2dy3lovznpSXZKBYe7eEC44/gB/CeSuVtbHm4pPIDaHTGEebHHqlYuvD3STW H6Tq117YLJJLDxcRj5RDmifQgHYEsiVz+i4pIuhU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727146AbfAVG6W (ORCPT ); Tue, 22 Jan 2019 01:58:22 -0500 Received: from mx2.suse.de ([195.135.220.15]:40780 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725862AbfAVG6W (ORCPT ); Tue, 22 Jan 2019 01:58:22 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 9DFD8ACC0; Tue, 22 Jan 2019 06:58:20 +0000 (UTC) Date: Tue, 22 Jan 2019 07:58:18 +0100 From: Michal Hocko To: Qian Cai Cc: akpm@linux-foundation.org, osalvador@suse.de, catalin.marinas@arm.com, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mm/hotplug: invalid PFNs from pfn_to_online_page() Message-ID: <20190122065818.GA4087@dhcp22.suse.cz> References: <20190121212747.23029-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190121212747.23029-1-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 Mon 21-01-19 16:27:47, Qian Cai wrote: [...] Sorry to miss this before but you want to > +#define pfn_to_online_page(pfn) \ > +({ \ > + struct page *___page = NULL; \ unsigned long ___pfn = pfn; > + unsigned long ___nr = pfn_to_section_nr(pfn); \ pfn_to_section_nr(___pfn); > + \ > + if (___nr < NR_MEM_SECTIONS && online_section_nr(___nr) && \ > + pfn_valid_within(pfn)) \ pfn_valid_within(___pfn)) > + ___page = pfn_to_page(pfn); \ > + ___page; \ > }) to prevent from issues when pfn expression has side effects. -- Michal Hocko SUSE Labs