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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 DD768C3566F for ; Fri, 21 Feb 2020 22:15:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4939207FD for ; Fri, 21 Feb 2020 22:15:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Gc7qTHn7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728967AbgBUWPg (ORCPT ); Fri, 21 Feb 2020 17:15:36 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:34306 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726725AbgBUWPg (ORCPT ); Fri, 21 Feb 2020 17:15:36 -0500 Received: by mail-pg1-f194.google.com with SMTP id j4so1698976pgi.1 for ; Fri, 21 Feb 2020 14:15:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=kXLJzM+fudX+dk2vxGD8qXAlS6NHJlq4l43rKFobmIY=; b=Gc7qTHn74XmNFUGT18DRPr/JsTZZEH/R8iCK7yOVNokNvtxMq24mQGS/A3UBa734Oe ok5JEGXxkAGI5niBWfu8iTF3dy3cbSvEQOUiHM5bk8+K/i1B54Ha/ZTIyDMIPNepANzS 2JlhVJ9Y4Q5Jos3/06GoKWW6fEoxhqP/wI0ck= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=kXLJzM+fudX+dk2vxGD8qXAlS6NHJlq4l43rKFobmIY=; b=Xs5SqQvk3FGCLPBzxuTr9Z1Q0E9eOGfy+U22daajuoDHAB/RdC5KXZr9nNRkcfKn6A mPztvwakHl49qr31Iq8QzqSUkhyn6UkX1dkitvJYcpkyP1+2rCnL1TsZnJ69qKCbfqK+ VtD51lOJKcHHqwxOWgtXBgQUq0YWfP7oTlR9gKGqN7OTP2iu9QAbsgpKV85uqMPYkJrt AvE7lU9tUygDuAVZBfIvQmgSlb+8y0dG0NXcA+HLUmdCEl0fFN54KxA7cmjfBYbSSQsi f7LlWkWU2YXLi9UE9YK2dVHMVy2g6xwUK3YMotKw0YGLex7BLyfM95rPAHmY7jCzjyJ/ HPLw== X-Gm-Message-State: APjAAAU4wcODXoYmXcdDrqKydX9bNhNDVdsYO+52wfRzx7kIXJO7BrMb EqJRxLWsi/bgGrn516x2dhwsmQ== X-Google-Smtp-Source: APXvYqw/4KMFiZHKgqWkcx8RiqfqgaEMBsI7aB5y+dpe0h7yWzHYitbJTEbwREjD5aqSPClkV4sogw== X-Received: by 2002:a62:36c2:: with SMTP id d185mr41244236pfa.203.1582323334247; Fri, 21 Feb 2020 14:15:34 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id k2sm3477608pgk.84.2020.02.21.14.15.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Feb 2020 14:15:33 -0800 (PST) Date: Fri, 21 Feb 2020 14:15:32 -0800 From: Kees Cook To: Thomas Gleixner Cc: Vinicius Costa Gomes , LKML , David Miller , bpf@vger.kernel.org, netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Sebastian Sewior , Peter Zijlstra , Clark Williams , Steven Rostedt , Juri Lelli , Ingo Molnar , Will Drewry , Andy Lutomirski Subject: Re: [RFC patch 09/19] bpf: Use BPF_PROG_RUN_PIN_ON_CPU() at simple call sites. Message-ID: <202002211415.4111F356A@keescook> References: <20200214133917.304937432@linutronix.de> <20200214161503.804093748@linutronix.de> <87a75ftkwu.fsf@linux.intel.com> <875zg3q7cn.fsf@nanos.tec.linutronix.de> <202002201616.21FA55E@keescook> <87lfownip5.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87lfownip5.fsf@nanos.tec.linutronix.de> Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Feb 21, 2020 at 03:00:54PM +0100, Thomas Gleixner wrote: > Kees Cook writes: > > They're technically independent, but they are related to each > > other. (i.e. order matters, process hierarchy matters, etc). There's no > > reason I can see that we can't switch CPUs between running them, though. > > (AIUI, nothing here would suddenly make these run in parallel, right?) > > Of course not. If we'd run the same thread on multiple CPUs in parallel > the ordering of your BPF programs would be the least of your worries. Right, okay, good. I just wanted to be extra sure. :) -- Kees Cook