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=-1.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 63E96C43610 for ; Thu, 29 Nov 2018 17:35:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33E502145D for ; Thu, 29 Nov 2018 17:35:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 33E502145D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730542AbeK3Elj (ORCPT ); Thu, 29 Nov 2018 23:41:39 -0500 Received: from mx2.suse.de ([195.135.220.15]:45924 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730407AbeK3Elj (ORCPT ); Thu, 29 Nov 2018 23:41:39 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D166BABCE; Thu, 29 Nov 2018 17:35:29 +0000 (UTC) Date: Thu, 29 Nov 2018 18:35:26 +0100 (CET) From: Jiri Kosina To: Andy Lutomirski cc: Peter Zijlstra , Linus Torvalds , Josh Poimboeuf , Andrew Lutomirski , the arch/x86 maintainers , Linux List Kernel Mailing , Ard Biesheuvel , Steven Rostedt , Ingo Molnar , Thomas Gleixner , mhiramat@kernel.org, jbaron@akamai.com, David.Laight@aculab.com, bp@alien8.de, julia@ni.com, jeyu@kernel.org, Peter Anvin Subject: Re: [PATCH v2 4/4] x86/static_call: Add inline static call implementation for x86-64 In-Reply-To: <6C359EF7-B2B6-4FED-96EB-CB7C91918763@amacapital.net> Message-ID: References: <20181126200801.GW2113@hirez.programming.kicks-ass.net> <20181126212628.4apztfazichxnt7r@treble> <20181127084330.GX2113@hirez.programming.kicks-ass.net> <20181129094210.GC2131@hirez.programming.kicks-ass.net> <20181129143853.GO2131@hirez.programming.kicks-ass.net> <20181129163342.tp5wlfcyiazwwyoh@treble> <0A629D30-ADCF-4159-9443-E5727146F65F@amacapital.net> <20181129170742.GC9027@hirez.programming.kicks-ass.net> <6C359EF7-B2B6-4FED-96EB-CB7C91918763@amacapital.net> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 29 Nov 2018, Andy Lutomirski wrote: > Does anyone know what the actual hardware semantics are? The SDM is not > particularly informative unless I looked at the wrong section. I don't think SDM answers all the questions there, unfortunately. I vaguely remember that back then when I was preparing the original text_poke_bp() implementation, hpa had to provide some answers directly from inner depths of Intel ... see fd4363fff3 ("x86: Introduce int3 (breakpoint)-based instruction patching") for reference. -- Jiri Kosina SUSE Labs