From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 1F1C5C5CFF1 for ; Tue, 12 Jun 2018 05:26:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C378A208B9 for ; Tue, 12 Jun 2018 05:26:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C378A208B9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932584AbeFLF0x (ORCPT ); Tue, 12 Jun 2018 01:26:53 -0400 Received: from mx2.suse.de ([195.135.220.15]:47453 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932281AbeFLF0x (ORCPT ); Tue, 12 Jun 2018 01:26:53 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext-too.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 9BD58AB43; Tue, 12 Jun 2018 05:26:51 +0000 (UTC) From: NeilBrown To: Zhouyang Jia Date: Tue, 12 Jun 2018 15:26:38 +1000 Cc: Zhouyang Jia , Oleg Drokin , Andreas Dilger , James Simmons , Greg Kroah-Hartman , Haneen Mohammed , Al Viro , "Gustavo A. R. Silva" , lustre-devel@lists.lustre.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] staging: lustre: add error handling for try_module_get In-Reply-To: <1528778968-42225-1-git-send-email-jiazhouyang09@gmail.com> References: <1528778968-42225-1-git-send-email-jiazhouyang09@gmail.com> Message-ID: <87y3fkinht.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, Jun 12 2018, Zhouyang Jia wrote: > When try_module_get fails, the lack of error-handling code may > cause unexpected results. > > This patch adds error-handling code after calling try_module_get. > > Signed-off-by: Zhouyang Jia > --- > drivers/staging/lustre/lnet/klnds/socklnd/socklnd.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.c b/driver= s/staging/lustre/lnet/klnds/socklnd/socklnd.c > index 7086678..72a42bd 100644 > --- a/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.c > +++ b/drivers/staging/lustre/lnet/klnds/socklnd/socklnd.c > @@ -2422,7 +2422,10 @@ ksocknal_base_startup(void) >=20=20 > /* flag lists/ptrs/locks initialised */ > ksocknal_data.ksnd_init =3D SOCKNAL_INIT_DATA; > - try_module_get(THIS_MODULE); > + if (!try_module_get(THIS_MODULE)) { > + CERROR("%s: cannot get module\n", __func__); > + goto failed; > + } >=20=20 > ksocknal_data.ksnd_sched_info =3D cfs_percpt_alloc(lnet_cpt_table(), > sizeof(*info)); Thanks for the patch.... I agree that this is probably a bug, but the code is still buggy after you patch, just in a different way. Try following through the code and see what happens when you 'goto failed'. NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAlsfWY8ACgkQOeye3VZi gblrxQ/+LaWJKrcgWws5nx3/4yrLdQiRrf/v4VTTxWb/54LKfpHAHMk7lVjujvrC 9ADyEsII3moabv8t/OQtyQZ0FGuH97x5WcwSLAMdfOjM//RzEJ0Iedwl9TxGjLnu Kqm/G+d+tuP6Izt2Qqhx52nBuWsbkrTw3Lhu3a+Ym7dDQzbbcOF0E1ZMKKXAJgyn zZwPqJlpz2fXvOVFuuRrgSi+mnwthPaW45ckgcO9zheV0qp11w21qHAR2akHpzdd 0aB91yJrrpeg2/OWqrQg0Pa28Vf8TPFcCzK8qqpjPPbsvmBr84yFeCIPXp5ySgH4 sWm5N+firleXsXc5dNCZ3a8uqCZ5vwxp1wNkLiBC0+lj0WFKvbUPqgJGfAxNHkrH zu55MMklp+A4p/tL1Z5KtfhMkQBBNaCmCYjk4wryjXuLJ19EL+UxbrsT9Fvbj6eA H6iy8lj99Pqo+DyjXvBtgff2wClyr63B0HtIl9/fg5wfDyULLuRFc85rUl4yEXHr PBn9QFd9cN9csBDS7PUICmV3FU/OO9RpBLR1PFV+w2Zs8opjx7eLu9cVQ1+QziuZ iUWCWsPglja6LlrxojdabcE5Szz4XRVkrdRwqNwMituSiQwSBr+LJPcErCFP6KFG FEtEqiX/qzRMvhOMhNByKjKma30zf9XAHMqmAta4QAWK8EOdILo= =2gRt -----END PGP SIGNATURE----- --=-=-=--