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=-6.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT 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 627C2C4363D for ; Fri, 25 Sep 2020 16:54:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1891220936 for ; Fri, 25 Sep 2020 16:54:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=codeweavers.com header.i=@codeweavers.com header.b="kIWREGw5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729529AbgIYQyR (ORCPT ); Fri, 25 Sep 2020 12:54:17 -0400 Received: from mail.codeweavers.com ([50.203.203.244]:49572 "EHLO mail.codeweavers.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727324AbgIYQyQ (ORCPT ); Fri, 25 Sep 2020 12:54:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=codeweavers.com; s=6377696661; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=28cqnasr75E8p2FpIR3JEwCn5rkK20DQw7UOa0lKlec=; b=kIWREGw57vyQX8Tx0wQRFgmCa9 hfl+tPhr/lyWTf1aW8IZkDCBlDpW9kUqT6Wxc3lVa2ILxHGXBNpTACZvbFFMLsJnt/xFDt7x1CBLB gzu3PY757TDV9dYb6PKnMSaxCCoBLymbGjsD0b1QamoGeLc3TKX7AVNFWajCnfiDwkek=; Received: from pool-72-73-20-93.clppva.fios.verizon.net ([72.73.20.93] helo=derek-personal-arch.fios-router.home) by mail.codeweavers.com with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kLqz6-00020E-7b; Fri, 25 Sep 2020 11:54:15 -0500 From: Derek Lesho To: linux-kernel@vger.kernel.org Cc: Derek Lesho Subject: Re: [RFC] mm: Allow 64-bit mmap syscalls to access higher addresses. Date: Fri, 25 Sep 2020 11:53:44 -0500 Message-Id: <20200925165343.292885-1-dlesho@codeweavers.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200925153703.288236-1-dlesho@codeweavers.com> References: <20200925153703.288236-1-dlesho@codeweavers.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For some reason, git send-email cut off the first paragprah in my first email, so I'm resending it now: Hello everyone, I am sending this mostly as a discussion starter/curiosity. I would like to be able to use the 48-bit address range while in long mode on an IA32 process. However, these two checks prevent mmap and munmap from dealing with addresses in that range. My question, is there any will to support something like this in the kernel, and if so, how would it be accomplished, generally. Maybe the TASK_SIZE macro could check for whether we are currently in the context of a x86-64 syscall? For those curious about my usecase, I'm working on running some windows 64-bit driver code in context of any given process. I accomplish this by mapping some of the fake kernel bits in the target process, and running the code in a dedicated thread. ---