Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752049AbeADCAl (ORCPT + 1 other); Wed, 3 Jan 2018 21:00:41 -0500 Received: from twin.jikos.cz ([91.219.245.39]:41904 "EHLO twin.jikos.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751842AbeADCAi (ORCPT ); Wed, 3 Jan 2018 21:00:38 -0500 X-Greylist: delayed 1864 seconds by postgrey-1.27 at vger.kernel.org; Wed, 03 Jan 2018 21:00:37 EST Date: Thu, 4 Jan 2018 02:59:47 +0100 (CET) From: Jiri Kosina To: Dan Williams cc: Jiri Kosina , Alan Cox , Linus Torvalds , Linux Kernel Mailing List , Mark Rutland , linux-arch@vger.kernel.org, Peter Zijlstra , Greg KH , Thomas Gleixner , Elena Reshetova , Alan Cox Subject: Re: [RFC PATCH] asm/generic: introduce if_nospec and nospec_barrier In-Reply-To: Message-ID: References: <20180103223827.39601-1-mark.rutland@arm.com> <151502463248.33513.5960736946233335087.stgit@dwillia2-desk3.amr.corp.intel.com> <20180104010754.22ca6a74@alans-desktop> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) 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 Return-Path: On Wed, 3 Jan 2018, Dan Williams wrote: > Speaking from a purely Linux kernel maintenance process perspective we > play wack-a-mole with missed endian conversions and other bugs that > coccinelle, sparse, etc help us catch. Fully agreed. > So this is in that same category, but yes, it's inconvenient. Disagreed, violently. CPU has to execute the instructions I ask it to execute, and if it executes *anything* else that reveals any information about the instructions that have *not* been executed, it's flawed. > Elena has done the work of auditing static analysis reports to a dozen > or so locations that need some 'nospec' handling. How exactly is that related (especially in longer-term support terms) to BPF anyway? Thanks, -- Jiri Kosina SUSE Labs