Received: by 2002:a25:1506:0:0:0:0:0 with SMTP id 6csp1556041ybv; Thu, 20 Feb 2020 23:08:23 -0800 (PST) X-Google-Smtp-Source: APXvYqyR/5txpltcxZoOU3GnnG1i/HoMFu7jWdHUfsAD9JpM50cbazOEoKoTmm1Z50d7QP79Tbrr X-Received: by 2002:a9d:7357:: with SMTP id l23mr25908968otk.10.1582268903631; Thu, 20 Feb 2020 23:08:23 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1582268903; cv=none; d=google.com; s=arc-20160816; b=RFNlwh0A+JCX8J8lijK3oVhPp2aNdslOgz//sYsAfXB9LhWBIQAAW8dNz38JbPmC6N iN3OB0kx1a9FoYXx85OVMI08I6j0nqojOivBWVdTA2jS86cqna/6p1cQUMQBL1XX1LXd XQzslq33BQcfMLSQVQKtESYtuT6qk382bh2a1IhKHfm3HtrkZ1e8dzgQ9MNMsmLwI8re ZAeFN57cuKQ/k+XSEk2cjTWQ0fitLXic8WzZLlQc4NEEm9EmV4CSXOVYeRRAfmw2IDuU q3/jxBrW7zdWkpf3XRmCyYENluaKgBM5vRXcpizmWFmT5a2JXTh3auLOHGgMTr5lh0nh cbPA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=+hQhtEiWxKt6OHXj/cguIUptl/TS/JhzBp9uSpYPPKM=; b=t/jAKH2HTbeeRZVeWZGdW5owMUPe5q76OTTVZ3OgdoaKhAbxFbnurL1P2ne86TMcFw hlgo1bAuQl8RBdLuFxDmJSerLcXKttaTGeWL/3KWCpl7y+h7l0TyxsKZ/rDYVoytEj0b WkAD5KN3tviJs1IStQ9y1A5/A2NK9Ff5Jzm2GTWornQUm/hN71E+c3ghKsjZe4KDgPsY E1lpDptcmuEgez1km6a+eYhLdz8UYbqTfmmfGXdX99i7/12IFRv2V8PKwpjVTwBHPjjW 3nhG8TWSKJWFLNtQdDEjxxEN2tSRLt+BG0PEOVcrl9wa2G2iVY06HdmCTvcWbuTQ5muf CmBg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id z22si1071731otq.94.2020.02.20.23.08.11; Thu, 20 Feb 2020 23:08:23 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727699AbgBUHHf (ORCPT + 99 others); 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