From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga06.intel.com ([134.134.136.31]:4805 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725903AbeKUL0e (ORCPT ); Wed, 21 Nov 2018 06:26:34 -0500 Subject: Re: [Patch v6 12/16] x86/speculation: Add 'seccomp' Spectre v2 app to app protection mode To: Jiri Kosina Cc: Thomas Gleixner , Linus Torvalds , Tom Lendacky , Ingo Molnar , Peter Zijlstra , Josh Poimboeuf , Andrea Arcangeli , David Woodhouse , Andi Kleen , Dave Hansen , Casey Schaufler , Asit Mallick , Arjan van de Ven , Jon Masters , Waiman Long , Greg KH , Dave Stewart , linux-kernel@vger.kernel.org, x86@kernel.org, stable@vger.kernel.org References: From: Tim Chen Message-ID: <79be3a64-9f25-a1e2-6926-baea677ccdb6@linux.intel.com> Date: Tue, 20 Nov 2018 16:54:32 -0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On 11/20/2018 04:44 PM, Jiri Kosina wrote: > On Tue, 20 Nov 2018, Tim Chen wrote: > >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt >> index d2255f7..89b193c 100644 >> --- a/Documentation/admin-guide/kernel-parameters.txt >> +++ b/Documentation/admin-guide/kernel-parameters.txt >> @@ -4227,12 +4227,17 @@ >> and STIBP mitigations against Spectre V2 attacks. >> If the CPU is not vulnerable, "off" is selected. >> If the CPU is vulnerable, the default mitigation >> - is "prctl". >> + is architecture and Kconfig dependent. See below. >> prctl - Enable mitigations per thread by restricting >> indirect branch speculation via prctl. >> Mitigation for a thread is not enabled by default to >> avoid mitigation overhead. The state of >> of the control is inherited on fork. >> + seccomp - Same as "prctl" above, but all seccomp threads >> + will disable SSB unless they explicitly opt out. > > As Dave already pointed out elsewhere -- the "SSB" here is probably a > copy/paste error. It should read something along the lines of "... will > restrict indirect branch speculation ..." > Thanks. Should have caught it. Tim