From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757123AbcJXG0e (ORCPT ); Mon, 24 Oct 2016 02:26:34 -0400 Received: from shell.dhp.com ([199.4.150.5]:2136 "EHLO shell.dhp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437AbcJXG0c (ORCPT ); Mon, 24 Oct 2016 02:26:32 -0400 X-Greylist: delayed 1653 seconds by postgrey-1.27 at vger.kernel.org; Mon, 24 Oct 2016 02:26:32 EDT Date: Mon, 24 Oct 2016 05:58:58 +0000 (/etc/localtime) From: n@dhp.com To: linux-kernel@vger.kernel.org Subject: /dev/mem arch/x86 mm/pat.c break Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Unless I read C wrong, pat.c seems to break all non-strict devmem use. I discovered this while reversing a bunch of pci and other low-level stuff. Here is a link to the fix, http//users.dhp.com/~n/pubs/ the one starting with Linux-86...txt is the correct file, those kernel bugs in OpenBSD and that are just hilarious enough to keep around.. Oh, here is the full link: http://users.dhp.com/~n/Linux-x86-mmap-nonstrict-broken.txt This was first 'nonpromisc_devmem', probably dating back to that introduction of 1MB limits on mmap(2) way back in the day.. who knows. Alright, I confess as a kernel programmer Linux isn't my thing, I prefer Unix particularly BSD and SysV (SVR4 would be sort of both). Thats mostly because sys_call_table is sysent to me, as are tons of other symbols. But still, /usr/libexec/cpp seems to have broken /dev/mem mmap(2) functionality over the non-strict range of memory for.. a long time. If I'm wrong, then there is no problem, however I had to fix this to get things working. Thanks, I realize that #ifdef instead of #ifndef can cause strictness reversals.. good thing other portions of the kernel had this correct, or strict would be nonstrict, and vice-versa. Alright, enjoy.. Reply address: n@mod.net (please). -n