From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751716AbaG1G64 (ORCPT ); Mon, 28 Jul 2014 02:58:56 -0400 Received: from casper.infradead.org ([85.118.1.10]:57468 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751083AbaG1G6z (ORCPT ); Mon, 28 Jul 2014 02:58:55 -0400 Date: Mon, 28 Jul 2014 08:58:44 +0200 From: Peter Zijlstra To: Arnaldo Carvalho de Melo Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Adrian Hunter , David Ahern , Frederic Weisbecker , Jiri Olsa , Namhyung Kim , Paul Mackerras , Stephane Eranian , Arnaldo Carvalho de Melo Subject: Re: [PATCH 02/27] perf tools: Fix jump label always changing during tracing Message-ID: <20140728065844.GK6758@twins.programming.kicks-ass.net> References: <1406302629-11790-1-git-send-email-acme@kernel.org> <1406302629-11790-3-git-send-email-acme@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Ngz69hoXASxZo3zU" Content-Disposition: inline In-Reply-To: <1406302629-11790-3-git-send-email-acme@kernel.org> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Ngz69hoXASxZo3zU Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jul 25, 2014 at 12:36:44PM -0300, Arnaldo Carvalho de Melo wrote: > From: Adrian Hunter >=20 > Intel PT decoding walks the object code to reconstruct the trace. A > jump label change during tracing causes decoding errors. >=20 > The "Enable close-on-exec flag on perf file descriptor" patch caused > there to be always a jump label change. >=20 > It was found that using a per-cpu context instead of a per-thread > context for the probe of the close-on-exec feature, made the problem go > away. per-cpu events are privileged, wouldn't this change make CLOEXEC always undetected for normal users? Also, the $subject doesn't related to CLOEXEC at all. --Ngz69hoXASxZo3zU Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJT1fSkAAoJEHZH4aRLwOS68aQP/1y/4SAKHxcPfZWFCPytxifv 4KY1rjaa3lEWRDT6s1ePmSWnTqsRokguGBaQWuddwqlfdIVmo/Un4aQVJCkq9Y7g dUl/2HHA+k3cKq7wBBj/mKmyvBVcQIciDbc8xMQGBbSyWfP/cx8j43IAYbf7fqb/ 7DksYPg/9nQMhWpHX7CHpS2Z/4MRQzftabAov4TVdXqt/hlzBLylA2xLIG78XNWf MpEhB/hXKaYwN1z1jDL2deMl0+X7pIkNyKSygOSh0DpJnOp2sw4FKKHv7ZfqW9gr tBU5Gp98Kdg9jlMaEF+QAaMEsWSL/QJmS3QebOxUOvJcTmdOm0cl39Lq+AwMwrlY BRs3sQrU3KPmx3VSDBDEh73M+OXbd3+sCmjAgSitwxBhd1zgTLIXAL3avFIu8YFB EG2NjlQyQvN/9VgNOEBhWmRN5c8SMhPDuiUgyKLteSBZiUrZMStrZ9yysEUzCCB/ sotR4cAOS050hPswYptMRfWUdJRtGXEe/WYUpYTJVsQ4XQC6l9jTCWgBcVZ+aRic pf1nmvp5vitpyvZlA/eArchAcWoxJQsk82MuK2fn966yhwn6kXkaL9bsgl4ctx2r 93GPM5e6XB9Kvv+utbr/E9mdKjr1UkC/9zWBpoTi9SKBfDAsbJ5EM2FHp2x3LK7O tw+4HNofCDUWeYK5P5h+ =rlsd -----END PGP SIGNATURE----- --Ngz69hoXASxZo3zU--