From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15401 invoked by alias); 17 Jan 2012 21:55:13 -0000 Received: (qmail 15394 invoked by uid 22791); 17 Jan 2012 21:55:12 -0000 X-SWARE-Spam-Status: No, hits=-2.4 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from smtp-3.hut.fi (HELO smtp-3.hut.fi) (130.233.228.93) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 17 Jan 2012 21:54:58 +0000 Received: from localhost (katosiko.hut.fi [130.233.228.115]) by smtp-3.hut.fi (8.13.6/8.12.10) with ESMTP id q0HLsuT5021352 for ; Tue, 17 Jan 2012 23:54:56 +0200 Received: from smtp-3.hut.fi ([130.233.228.93]) by localhost (katosiko.hut.fi [130.233.228.115]) (amavisd-new, port 10024) with LMTP id 01047-1030 for ; Tue, 17 Jan 2012 23:54:56 +0200 (EET) Received: from kosh.localdomain (kosh.hut.fi [130.233.228.12]) by smtp-3.hut.fi (8.13.6/8.12.10) with ESMTP id q0HLsloM021336 for ; Tue, 17 Jan 2012 23:54:52 +0200 Received: by kosh.localdomain (Postfix, from userid 43888) id A836BEC8; Tue, 17 Jan 2012 23:54:47 +0200 (EET) Date: Tue, 17 Jan 2012 21:55:00 -0000 From: Sami Liedes To: systemtap@sourceware.org Subject: Re: automated way to find functions that we might want to blacklist Message-ID: <20120117215447.GA26534@sli.dy.fi> Mail-Followup-To: systemtap@sourceware.org References: <84bor03ij9.fsf@sauna.l.org> <20111223211030.GA23631@sli.dy.fi> <20120115214402.GG6309@sli.dy.fi> <4F15D792.2050408@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="bp/iNruPH9dso1Pn" Content-Disposition: inline In-Reply-To: <4F15D792.2050408@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TKK-Virus-Scanned: by amavisd-new-2.1.2-hutcc at katosiko.hut.fi X-IsSubscribed: yes Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org X-SW-Source: 2012-q1/txt/msg00021.txt.bz2 --bp/iNruPH9dso1Pn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-length: 1057 On Tue, Jan 17, 2012 at 02:18:26PM -0600, David Smith wrote: > There is nothing that those 2 functions do that can crash the kernel. > Those functions (should be) always inlined. I'd guess the problem isn't > those two functions, but the function that is calling them. Yes, I've figured as much that the crashes come from places where these are inlined. But I had't thought about using .call; will do that. > Another problem I see with your testing methodology is that you are > using xen. I don't think we've used xen in a while, but the xen kernel > always gave us different results than a regular kernel. I'd test on > bare metal or in a kvm instance. Timo uses Xen, but I'm running the tests in KVM. > I'll make one final comment here. In my mind the blacklist is a > semi-temporary thing (although we don't typically remove functions from > it). The real fix here is to get the crashing functions marked with > '__kprobes' in the upstream kernel. This fixes the problem for all > kprobes users, not just systemtap. Makes sense to me. Sami --bp/iNruPH9dso1Pn Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-length: 836 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAEBCgAGBQJPFe4nAAoJEKLT589SE0a01ecQAKhhunHBJ7RGSmMovoFNMbZF kkr7+etgC7n39TrxVL1pDkaTOoD2mH5i2THnA1uLwGmJyDJpsjYDscoRgsVwQJKB hhbOipfC2zsQ4bdlLnhBiaztWCXn/kye36ktn4tbwBHGnHSV9Db3c9cRJxRMnnz8 AktbrPTPAivIUy800l7s255ajvq2UMGIxqE/HwSPoc/gmRsGMVt1e6s07uVnUDQo kKfCGaJLD9GU+vPKHTdSha9bAY9caniUUQwwpK3AHLSHFC1elTLXPJcT4K7rrdsY b1852zJE8DXVp7WS44eojocIap1Ys1VcoXHUm1yJg4WjZc4joFIiv19aCSJUtXC1 i2QzG7vs3GUPWMv0+AyYJfrBB7HYKJDm5JGu+OtnUhvqfhtYWezFr/MFNYPC5y3r 46Zi8bJnmQRGlhVvJizu8U2mqGHnaob73+ARL7E1haoyA9sZpzuTITxPe0ODphoW UrxVoRfkkPY67+1hH2h4MKBpjX5by7/YysuTmQGNzNPMiO5lg6MpaGXXzEzMXSUK /UB5MtWInm9yh8xe3z+38BsHJIFhCSITYqVdoA5OcvmFHmzmzVpfxy9b4P2E59zw zHr9kKm9rEJTswhr+Sz69gzocvrDMUGIruFopsFsxU0aSS7AFHLuSeCspxsn6Iab KurbVkmMzGXgSB82lqpg =4Fi8 -----END PGP SIGNATURE----- --bp/iNruPH9dso1Pn--