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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DF462C35641 for ; Fri, 21 Feb 2020 07:07:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB1D92073A for ; Fri, 21 Feb 2020 07:07:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727734AbgBUHHf (ORCPT ); Fri, 21 Feb 2020 02:07:35 -0500 Received: from isilmar-4.linta.de ([136.243.71.142]:34436 "EHLO isilmar-4.linta.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727213AbgBUHH1 (ORCPT ); Fri, 21 Feb 2020 02:07:27 -0500 X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES X-isilmar-external: YES Received: from light.dominikbrodowski.net (brodo.linta [10.1.0.102]) by isilmar-4.linta.de (Postfix) with ESMTPSA id 7A7292006FB; Fri, 21 Feb 2020 07:07:25 +0000 (UTC) Received: by light.dominikbrodowski.net (Postfix, from userid 1000) id 493CF20AA1; Fri, 21 Feb 2020 07:07:56 +0100 (CET) Date: Fri, 21 Feb 2020 07:07:56 +0100 From: Dominik Brodowski To: Brian Gerst Cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Andy Lutomirski Subject: Re: [PATCH 0/5] Enable pt_regs based syscalls for x86-32 native Message-ID: <20200221060756.GA3368@light.dominikbrodowski.net> References: <20200221050934.719152-1-brgerst@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200221050934.719152-1-brgerst@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Brian, On Fri, Feb 21, 2020 at 12:09:29AM -0500, Brian Gerst wrote: > This patch series cleans up the x86 syscall wrapper code and converts > the 32-bit native kernel over to pt_regs based syscalls. thanks for your patchset. Could you explain a bit more what the rationale is. Due to asmlinkage, it doesn't leak "random user-provided register content down the call chain" (as was the case for x86-64). But it may be cleaner, and you mention in patch 5/5 that the new way is "a bit more efficient" -- do you have numbers? Thanks, Dominik