From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754834AbcHCNih (ORCPT ); Wed, 3 Aug 2016 09:38:37 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:40396 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751535AbcHCNif (ORCPT ); Wed, 3 Aug 2016 09:38:35 -0400 Date: Wed, 3 Aug 2016 15:36:10 +0200 From: Peter Zijlstra To: Daniel Micay Cc: kernel-hardening@lists.openwall.com, Kees Cook , Jeff Vander Stoep , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , "linux-doc@vger.kernel.org" , LKML , Jonathan Corbet , "Eric W. Biederman" Subject: Re: [kernel-hardening] Re: [PATCH 1/2] security, perf: allow further restriction of perf_event_open Message-ID: <20160803133610.GF6879@twins.programming.kicks-ass.net> References: <1469630746-32279-1-git-send-email-jeffv@google.com> <20160802095243.GD6862@twins.programming.kicks-ass.net> <20160802203037.GC6879@twins.programming.kicks-ass.net> <20160803082830.GA3163@gmail.com> <1470227290.19955.30.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1470227290.19955.30.camel@gmail.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 03, 2016 at 08:28:10AM -0400, Daniel Micay wrote: > I don't think there are runtimes using this for JIT tracing. Perhaps it > doesn't actually suit their needs. It's a theoretical use case. I know there are compiler teams using perf for FDO, see for example: https://gcc.gnu.org/wiki/AutoFDO/Tutorial LLVM also has AutoFDO support AFAIU. There is no reason JITs could not also do this, and IIRC there's JITs build on top of LLVM, so it shouldn't be too hard to imagine an AutoFDO enabled JIT.