From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: Re: [PATCH] drm/sysfs: Do not drop device reference twice Date: Wed, 30 Oct 2013 22:18:15 +0100 Message-ID: <20131030211814.GC7686@mithrandir> References: <1383130745-32165-1-git-send-email-treding@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1086177436==" Return-path: Received: from mail-bk0-f52.google.com (mail-bk0-f52.google.com [209.85.214.52]) by gabe.freedesktop.org (Postfix) with ESMTP id 4A178EF013 for ; Wed, 30 Oct 2013 14:18:18 -0700 (PDT) Received: by mail-bk0-f52.google.com with SMTP id u14so333231bkz.39 for ; Wed, 30 Oct 2013 14:18:17 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org To: Paulo Zanoni Cc: "linux-kernel@vger.kernel.org" , DRI Development List-Id: dri-devel@lists.freedesktop.org --===============1086177436== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="L6iaP+gRLNZHKoI4" Content-Disposition: inline --L6iaP+gRLNZHKoI4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 30, 2013 at 02:05:02PM -0200, Paulo Zanoni wrote: > 2013/10/30 Thierry Reding : > > device_unregister() already drops its reference to the struct device, so > > explicitly calling put_device() before device_unregister() can cause the > > device to have been freed before it can be unregistered. > > > > Signed-off-by: Thierry Reding >=20 > I started investigating this problem yesterday and reached the same > conclusion. The connector path can be easily reproduced on i915.ko: > get a machine that has an eDP panel, physically disconnect the panel, > boot the machine, "modprobe i915" and watch the segfault. >=20 > Reviewed-by: Paulo Zanoni > Tested-by: Paulo Zanoni >=20 > I didn't really bisect, but I believe this is probably a regression > from "drm/sysfs: sort out minor and connector device object > lifetimes". Yes, I think that's the one that broke it. Thierry --L6iaP+gRLNZHKoI4 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAEBAgAGBQJScXeVAAoJEN0jrNd/PrOhTLsP/1jSA43Ie5nwnqy51Zr+fL63 /3bCepldqSDmi3/a24pOPkO5EYwKw03MzC/47HdkrkzM2JVpOBaY6LTVZW7sJ9G+ 59WSJiPVjArvmiUKAY0en3Y3QKT6KGIdaYDlzHOUe/o8IGAhMNNpYQDJK8eadgGP zhtr5wujfxVUL4wT4dmygWp12WsqztVEY/vipPGNzQROiFJuhB4LTtwytA08FESU imRBmJIIWG4Bjn6fpvRImTZz7sNwnNHr4MXGtUS0ZwoNr7dYSWDH/jioiyuCVCb2 KsX8HmVUvW98GnxfKbF3RH15totmEYsj/ijQLlCEe972adMxg3P57FlO5271yu1U U/e2EKrLTLVQwGFx+hlPTHxRf9ihsh8QCY9Kr6QwQDJf5n/6JAQ+5EJkTcFhuqkY fPwAYVuOkCJQMxX0GCHJUfO3oNHHb+AHq3bsPh0AikAcymtAWpICYUmMXzSgon18 /6eTa822k0zPzZ1iN49PL1xyKZmuDTew+Os4SK8kZgBFeTez9YGwIQ1kIS7DuQXv RNwlVFR2KW8orErHyf75kYZHjP9IAamvE7ZZkyHc5SKRAQb6kVnPswZt+I7NVK/y EueKuKCqnOOXQubi5nD1YmiHxEIU3Nft0ofNoUQk0UdW1+yRMy/qAlONAtB1Uhrm l285mn8jFJrniYRZwPCF =7zvV -----END PGP SIGNATURE----- --L6iaP+gRLNZHKoI4-- --===============1086177436== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel --===============1086177436==--