From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755633AbbLGJ1k (ORCPT ); Mon, 7 Dec 2015 04:27:40 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:46211 "EHLO out4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755405AbbLGJ1U (ORCPT ); Mon, 7 Dec 2015 04:27:20 -0500 X-Sasl-enc: Nhit8gfI8H34Vu1nJwIRUCwqZMnq+6Oka11fMxtExAil 1449480436 Subject: Re: gigaset: freeing an active object To: Paul Bolle , Peter Hurley , Sasha Levin References: <56587467.8050102@oracle.com> <565B1A1B.8020503@imap.cc> <565B4256.6080101@hurleysoftware.com> <565B4844.9020600@imap.cc> <1448828800.2603.17.camel@tiscali.nl> <1448839396.2891.14.camel@tiscali.nl> <1448906497.3546.16.camel@tiscali.nl> <565F8341.7010704@hurleysoftware.com> <1449408690.2515.15.camel@tiscali.nl> <5664545C.90607@imap.cc> <1449432742.2515.20.camel@tiscali.nl> Cc: isdn@linux-pingi.de, davem@davemloft.net, gigaset307x-common@lists.sourceforge.net, LKML , "netdev@vger.kernel.org" , syzkaller From: Tilman Schmidt X-Enigmail-Draft-Status: N1110 Message-ID: <566550E7.80801@imap.cc> Date: Mon, 7 Dec 2015 10:27:03 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <1449432742.2515.20.camel@tiscali.nl> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="OpGCrtUvXV50QTd7W3AWj3WurUhMUAAJe" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --OpGCrtUvXV50QTd7W3AWj3WurUhMUAAJe Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Am 06.12.2015 um 21:12 schrieb Paul Bolle: > On zo, 2015-12-06 at 16:29 +0100, Tilman Schmidt wrote: >> So the solution might be as simple as moving the kfree() call from >> gigaset_freecshw() to gigaset_device_release(). Something like this: >> >> --- a/drivers/isdn/gigaset/ser-gigaset.c >> +++ b/drivers/isdn/gigaset/ser-gigaset.c >> @@ -370,19 +370,18 @@ static void gigaset_freecshw(struct cardstate >> *cs) >> tasklet_kill(&cs->write_tasklet); >> if (!cs->hw.ser) >> return; >> - dev_set_drvdata(&cs->hw.ser->dev.dev, NULL); >> platform_device_unregister(&cs->hw.ser->dev); >> - kfree(cs->hw.ser); >> - cs->hw.ser =3D NULL; >> } >> >> static void gigaset_device_release(struct device *dev) >> { >> - struct platform_device *pdev =3D to_platform_device(dev); >> + struct cardstate *cs =3D dev_get_drvdata(dev); >> >> - /* adapted from platform_device_release() in drivers/base/plat= form.c */ >> - kfree(dev->platform_data); >> - kfree(pdev->resource); >> + if (!cs) >> + return; >> + dev_set_drvdata(dev, NULL); >> + kfree(cs->hw.ser); >> + cs->hw.ser =3D NULL; >> } >=20 > This solution assumes that the struct platform_device is moved out of > the struct ser_cardstate, doesn't it? In other words, this is something= > to do on top of my (draft) patch. No, that wasn't my intention. I thought of that solution as an alternative, not an increment to your patch. > Otherwise we'd still be freeing memory > managed through reference counting. Now I#m confused. I thought by following Peter's suggestion to put the kfree() in the release method we'd avoid just that. Regards, Tilman --=20 Tilman Schmidt E-Mail: tilman@imap.cc Bonn, Germany Nous, on a des fleurs et des bougies pour nous prot=C3=A9ger. --OpGCrtUvXV50QTd7W3AWj3WurUhMUAAJe Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWZVD0AAoJEFPuqx0v+F+q1MYH/3mrcgm5tuDM9co1q79tjbmK X5K91JW+DScmPIvSri7JtNtTCyoQmLZkZPl/4d+vtULp50YrHslnHUXX/lZM8hfd dy2wnmo67UPExIO9R+BI60R90cNcAoigtK9Duuq3b4gxsTIXd9Ac9RCxpXWM7yMo 7BzoVFuPhbwLskHAZYfmz2obq+OWvg72UAgwltj0bOQy9OA2f9Bq2pfrxs9lLvx1 SwT4XgArIEIuSVaglisQ09+9jFQ93g6QXSeWbcBiURu+8ZmAJKK3yD5vMbsorVQD ZWxodML8+rE5zGbuRICJsjgrMKobcanyd5PBoxyYqHehrnct52/P52qHYfpKwic= =tYj3 -----END PGP SIGNATURE----- --OpGCrtUvXV50QTd7W3AWj3WurUhMUAAJe--