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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B82DC32792 for ; Thu, 3 Oct 2019 16:22:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E1A620867 for ; Thu, 3 Oct 2019 16:22:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570119726; bh=zrdNoSnOeNZj5QJjLU3IpZ0WHzz72+SQAhpLfEHBe8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=omGY6nT1JglbBLEaZmlxzR+OmhX2pYA6N3o41nfCYZc4YBr8VCyRKXjMmh/msRG4I 4O8on/9pMUKvoeLGTx+apWrTJEPl/6c2DgD9lF0UeuARikm6Y3ZWIC7dCP7ajFkf+C 6r0P6Sd/hhCeeRSZbvfpECQG2VF5aPO1etBmtW14= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390242AbfJCQWE (ORCPT ); Thu, 3 Oct 2019 12:22:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:50528 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390229AbfJCQWB (ORCPT ); Thu, 3 Oct 2019 12:22:01 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BCAF120865; Thu, 3 Oct 2019 16:21:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570119720; bh=zrdNoSnOeNZj5QJjLU3IpZ0WHzz72+SQAhpLfEHBe8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=md8OdiptVzGPkWvj9vlzb7RLUcXHabwCg0MIB706oF+JaM0pfXnQE5G1z/QOB3G9L C/IgPZLbBgzofazObLIroBYDrLbXq2Znswk3d6OuIQjB1VyCHYrW4ia8jcIgjcrzW3 387I1WreIaZ+EGPWmjZ3hxgSOp8SECsulKMxP7xI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Max Kellermann , Wolfgang Rohdewald , Arnd Bergmann , Sean Young , Mauro Carvalho Chehab Subject: [PATCH 4.19 169/211] media: dont drop front-end reference count for ->detach Date: Thu, 3 Oct 2019 17:53:55 +0200 Message-Id: <20191003154526.075951948@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154447.010950442@linuxfoundation.org> References: <20191003154447.010950442@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann commit 14e3cdbb00a885eedc95c0cf8eda8fe28d26d6b4 upstream. A bugfix introduce a link failure in configurations without CONFIG_MODULES: In file included from drivers/media/usb/dvb-usb/pctv452e.c:20:0: drivers/media/usb/dvb-usb/pctv452e.c: In function 'pctv452e_frontend_attach': drivers/media/dvb-frontends/stb0899_drv.h:151:36: error: weak declaration of 'stb0899_attach' being applied to a already existing, static definition The problem is that the !IS_REACHABLE() declaration of stb0899_attach() is a 'static inline' definition that clashes with the weak definition. I further observed that the bugfix was only done for one of the five users of stb0899_attach(), the other four still have the problem. This reverts the bugfix and instead addresses the problem by not dropping the reference count when calling '->detach()', instead we call this function directly in dvb_frontend_put() before dropping the kref on the front-end. I first submitted this in early 2018, and after some discussion it was apparently discarded. While there is a long-term plan in place, that plan is obviously not nearing completion yet, and the current kernel is still broken unless this patch is applied. Link: https://patchwork.kernel.org/patch/10140175/ Link: https://patchwork.linuxtv.org/patch/54831/ Cc: Max Kellermann Cc: Wolfgang Rohdewald Cc: stable@vger.kernel.org Fixes: f686c14364ad ("[media] stb0899: move code to "detach" callback") Fixes: 6cdeaed3b142 ("media: dvb_usb_pctv452e: module refcount changes were unbalanced") Signed-off-by: Arnd Bergmann Signed-off-by: Sean Young Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/dvb-core/dvb_frontend.c | 4 +++- drivers/media/usb/dvb-usb/pctv452e.c | 8 -------- 2 files changed, 3 insertions(+), 9 deletions(-) --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -164,6 +164,9 @@ static void dvb_frontend_free(struct kre static void dvb_frontend_put(struct dvb_frontend *fe) { + /* call detach before dropping the reference count */ + if (fe->ops.detach) + fe->ops.detach(fe); /* * Check if the frontend was registered, as otherwise * kref was not initialized yet. @@ -3035,7 +3038,6 @@ void dvb_frontend_detach(struct dvb_fron dvb_frontend_invoke_release(fe, fe->ops.release_sec); dvb_frontend_invoke_release(fe, fe->ops.tuner_ops.release); dvb_frontend_invoke_release(fe, fe->ops.analog_ops.release); - dvb_frontend_invoke_release(fe, fe->ops.detach); dvb_frontend_put(fe); } EXPORT_SYMBOL(dvb_frontend_detach); --- a/drivers/media/usb/dvb-usb/pctv452e.c +++ b/drivers/media/usb/dvb-usb/pctv452e.c @@ -913,14 +913,6 @@ static int pctv452e_frontend_attach(stru &a->dev->i2c_adap); if (!a->fe_adap[0].fe) return -ENODEV; - - /* - * dvb_frontend will call dvb_detach for both stb0899_detach - * and stb0899_release but we only do dvb_attach(stb0899_attach). - * Increment the module refcount instead. - */ - symbol_get(stb0899_attach); - if ((dvb_attach(lnbp22_attach, a->fe_adap[0].fe, &a->dev->i2c_adap)) == NULL) err("Cannot attach lnbp22\n");