From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f71.google.com (mail-pg0-f71.google.com [74.125.83.71]) by kanga.kvack.org (Postfix) with ESMTP id 933C26B02D4 for ; Mon, 11 Sep 2017 11:03:46 -0400 (EDT) Received: by mail-pg0-f71.google.com with SMTP id m30so9721808pgn.2 for ; Mon, 11 Sep 2017 08:03:46 -0700 (PDT) Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41]) by mx.google.com with SMTPS id h8sor3632956pgq.67.2017.09.11.08.03.45 for (Google Transport Security); Mon, 11 Sep 2017 08:03:45 -0700 (PDT) Date: Mon, 11 Sep 2017 08:03:42 -0700 From: Tycho Andersen Subject: Re: [PATCH v6 03/11] mm, x86: Add support for eXclusive Page Frame Ownership (XPFO) Message-ID: <20170911150342.kf6n5ce4aldqy27a@docker> References: <20170907173609.22696-1-tycho@docker.com> <20170907173609.22696-4-tycho@docker.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Laura Abbott Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com, Marco Benatto , Juerg Haefliger , x86@kernel.org On Sat, Sep 09, 2017 at 08:35:17AM -0700, Laura Abbott wrote: > On 09/07/2017 10:36 AM, Tycho Andersen wrote: > > +static inline struct xpfo *lookup_xpfo(struct page *page) > > +{ > > + struct page_ext *page_ext = lookup_page_ext(page); > > + > > + if (unlikely(!page_ext)) { > > + WARN(1, "xpfo: failed to get page ext"); > > + return NULL; > > + } > > + > > + return (void *)page_ext + page_xpfo_ops.offset; > > +} > > + > > Just drop the WARN. On my arm64 UEFI machine this spews warnings > under most normal operation. This should be normal for some > situations but I haven't had the time to dig into why this > is so pronounced on arm64. Will do, thanks! If you figure out under what conditions it's normal, I'd be curious :) Tycho -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org