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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 D05A3C2D0CE for ; Sun, 29 Dec 2019 18:07:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A423220722 for ; Sun, 29 Dec 2019 18:07:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577642858; bh=iFzkxAtH3OwBv3iylaBB43pFtsaqvu4jKMspbma5VbE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DUs25BGupxZ1oMDo62VWksJesGKac3OOewdN5DWhnVIUzPXH2WWesmN68XicFqzZx 60CGy+wIFaKfMW7Lk0pQJyZ28y+lYsmmxepAoB4IKpoDSuslnuGxb0p8MCpJX4D5m/ xRSduIT2Icpyr/PSiWLpSuY6WbiZUmx1XwR9FMis= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731415AbfL2RsO (ORCPT ); Sun, 29 Dec 2019 12:48:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:59318 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731411AbfL2RsM (ORCPT ); Sun, 29 Dec 2019 12:48:12 -0500 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 7CE95206DB; Sun, 29 Dec 2019 17:48:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577641691; bh=iFzkxAtH3OwBv3iylaBB43pFtsaqvu4jKMspbma5VbE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nnPdNjQmch9weTL7TDJGE7nvVhzfRqOuGaj/4aYd/BqDHSf2okfxCXwXiG9NRlqg6 b1BR3HfmTQO4B39Q3KK5/ycUYYs2ILlRbulbnIWWKWHZmEs5LpWALrNmcVQoKY+Qto WDDEmJe9vxbQpxMTMT58truR6cAonS4gezm+Yh44= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, tony camuso , Corey Minyard , Sasha Levin Subject: [PATCH 5.4 171/434] ipmi: Dont allow device module unload when in use Date: Sun, 29 Dec 2019 18:23:44 +0100 Message-Id: <20191229172713.162705197@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191229172702.393141737@linuxfoundation.org> References: <20191229172702.393141737@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Corey Minyard [ Upstream commit cbb79863fc3175ed5ac506465948b02a893a8235 ] If something has the IPMI driver open, don't allow the device module to be unloaded. Before it would unload and the user would get errors on use. This change is made on user request, and it makes it consistent with the I2C driver, which has the same behavior. It does change things a little bit with respect to kernel users. If the ACPI or IPMI watchdog (or any other kernel user) has created a user, then the device module cannot be unloaded. Before it could be unloaded, This does not affect hot-plug. If the device goes away (it's on something removable that is removed or is hot-removed via sysfs) then it still behaves as it did before. Reported-by: tony camuso Signed-off-by: Corey Minyard Tested-by: tony camuso Signed-off-by: Sasha Levin --- drivers/char/ipmi/ipmi_msghandler.c | 23 ++++++++++++++++------- include/linux/ipmi_smi.h | 12 ++++++++---- 2 files changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 2aab80e19ae0..3c8a559506e8 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -448,6 +448,8 @@ enum ipmi_stat_indexes { #define IPMI_IPMB_NUM_SEQ 64 struct ipmi_smi { + struct module *owner; + /* What interface number are we? */ int intf_num; @@ -1220,6 +1222,11 @@ int ipmi_create_user(unsigned int if_num, if (rv) goto out_kfree; + if (!try_module_get(intf->owner)) { + rv = -ENODEV; + goto out_kfree; + } + /* Note that each existing user holds a refcount to the interface. */ kref_get(&intf->refcount); @@ -1349,6 +1356,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user) } kref_put(&intf->refcount, intf_free); + module_put(intf->owner); } int ipmi_destroy_user(struct ipmi_user *user) @@ -2459,7 +2467,7 @@ static int __get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc) * been recently fetched, this will just use the cached data. Otherwise * it will run a new fetch. * - * Except for the first time this is called (in ipmi_register_smi()), + * Except for the first time this is called (in ipmi_add_smi()), * this will always return good data; */ static int __bmc_get_device_id(struct ipmi_smi *intf, struct bmc_device *bmc, @@ -3377,10 +3385,11 @@ static void redo_bmc_reg(struct work_struct *work) kref_put(&intf->refcount, intf_free); } -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers, - void *send_info, - struct device *si_dev, - unsigned char slave_addr) +int ipmi_add_smi(struct module *owner, + const struct ipmi_smi_handlers *handlers, + void *send_info, + struct device *si_dev, + unsigned char slave_addr) { int i, j; int rv; @@ -3406,7 +3415,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers, return rv; } - + intf->owner = owner; intf->bmc = &intf->tmp_bmc; INIT_LIST_HEAD(&intf->bmc->intfs); mutex_init(&intf->bmc->dyn_mutex); @@ -3514,7 +3523,7 @@ int ipmi_register_smi(const struct ipmi_smi_handlers *handlers, return rv; } -EXPORT_SYMBOL(ipmi_register_smi); +EXPORT_SYMBOL(ipmi_add_smi); static void deliver_smi_err_response(struct ipmi_smi *intf, struct ipmi_smi_msg *msg, diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h index 4dc66157d872..deec18b8944a 100644 --- a/include/linux/ipmi_smi.h +++ b/include/linux/ipmi_smi.h @@ -224,10 +224,14 @@ static inline int ipmi_demangle_device_id(uint8_t netfn, uint8_t cmd, * is called, and the lower layer must get the interface from that * call. */ -int ipmi_register_smi(const struct ipmi_smi_handlers *handlers, - void *send_info, - struct device *dev, - unsigned char slave_addr); +int ipmi_add_smi(struct module *owner, + const struct ipmi_smi_handlers *handlers, + void *send_info, + struct device *dev, + unsigned char slave_addr); + +#define ipmi_register_smi(handlers, send_info, dev, slave_addr) \ + ipmi_add_smi(THIS_MODULE, handlers, send_info, dev, slave_addr) /* * Remove a low-level interface from the IPMI driver. This will -- 2.20.1