From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752290AbaEETgg (ORCPT ); Mon, 5 May 2014 15:36:36 -0400 Received: from casper.infradead.org ([85.118.1.10]:56968 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740AbaEETge (ORCPT ); Mon, 5 May 2014 15:36:34 -0400 Date: Mon, 5 May 2014 21:36:29 +0200 From: Peter Zijlstra To: Vince Weaver Cc: Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, Steven Rostedt Subject: Re: [perf] more perf_fuzzer memory corruption Message-ID: <20140505193629.GB11096@twins.programming.kicks-ass.net> References: <20140505093124.GN17778@laptop.programming.kicks-ass.net> <20140505171428.GU26782@laptop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="jIYo0VRlfdMI9fLa" Content-Disposition: inline In-Reply-To: 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 --jIYo0VRlfdMI9fLa Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 05, 2014 at 02:47:32PM -0400, Vince Weaver wrote: > On Mon, 5 May 2014, Peter Zijlstra wrote: >=20 > > Cute.. does the below cure? > >=20 > >=20 > > --- > > Subject: perf: Fix perf_event_init_context() > > From: Peter Zijlstra > > Date: Mon May 5 19:12:20 CEST 2014 > >=20 > > perf_pin_task_context() can return NULL but perf_event_init_context() > > assumes it will not, correct this. >=20 > It makes the oops go away, but it does make the fuzzer become unkillable= =20 > while using 100% CPU. Ooh, I know that one. Its what my WSM-EP favours. I'll try and have a look. > It looks like it is stuck repeating this forever: > perf_fuzzer-5256 [000] 275.943049: kmalloc: (T.1262+0xe)= call_site=3Dffffffff810d022f ptr=3D0xffff8800cb028400 bytes_req=3D216 byte= s_alloc=3D256 gfp_flags=3DGFP_KERNEL|GFP_ZERO > perf_fuzzer-5256 [000] 275.943057: function: perf_lock_ta= sk_context > perf_fuzzer-5256 [000] 275.943057: function: alloc_perf_c= ontext > and memory is slowly leaking away. Oh, usually when my WSM gets funny like this and I enable the tracer it just stops being a computer and starts being a brick. Might be a nice clue though. --jIYo0VRlfdMI9fLa Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJTZ+gwAAoJEHZH4aRLwOS6k0AP/i7izbXXiDP132lVJcPxaYUV AkDzxF6tWPw2hvEDabjvF1PYe/J2iGSZre9rMJh8EHWyW1cSmP/vIYxJvxm7rLjQ 9L3Dc7z6raK5ZxPAZcngmGokXqV3FDRpPty98ZkV9aBapvcd5rM3JTtJwyJUPsDp bbqqiVO0ROAju27APz+9L7hX6UvAorLFD5EXFuVUr5lrbGo+hiepkBTlTivN6xry M7UyuzX87OzWUuOgW8ISukUhZmTQac1P+i0meUzDyFsS3ZtwTbGiLl2XLOE3N6/X ATlEzLB/oA5BL2gs5GtnK7FHykhsuEKPX9+aTumTZsXe2Cg6hLZ+48Q2Bp2MNiBQ 0jqnIOyuuVzYdzw7B3Dqd0pcwscwcdpDqRyNwhNLVYCyZadNwY8E0XwiKl0yWLXV NSQ1jMfXwSJosAc+F+awI5qkVwqeo/1XGm0a0CHo5F1gFiDFSzKMMLO9kkRMBg7v v9JBIVSPIcQJBW5VE8TlJCBwcrvDuxT0PJ1Zx/ZbOYelNvmmwI3SUCjFNwBFtl11 Feb1MBqF24Tp1qJh9qqwxS7MIVuhG3v8TXORqwCQLXRpr9w0X/2Wjv1xqNeXOHST JPFFFwvdS4tt9yo+RrfaeyXn9u7czgV51VvIVWSAgH2QEsIXV5IEeaIuEIOoO4gs 369NWpucEw1Q2vVODinO =ZIra -----END PGP SIGNATURE----- --jIYo0VRlfdMI9fLa--