From patchwork Wed Jan 27 23:01:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 12051155 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=-12.9 required=3.0 tests=BAYES_50, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 C4C4EC433DB for ; Wed, 27 Jan 2021 23:01:33 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AAD6264DD0 for ; Wed, 27 Jan 2021 23:01:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AAD6264DD0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kleine-koenig.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 13D5B100EB340; Wed, 27 Jan 2021 15:01:32 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=94.130.110.236; helo=antares.kleine-koenig.org; envelope-from=uwe@kleine-koenig.org; receiver= Received: from antares.kleine-koenig.org (antares.kleine-koenig.org [94.130.110.236]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C1065100EB33D for ; Wed, 27 Jan 2021 15:01:29 -0800 (PST) Received: by antares.kleine-koenig.org (Postfix, from userid 1000) id E2374AE0D2A; Thu, 28 Jan 2021 00:01:26 +0100 (CET) From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Dan Williams , Vishal Verma , Dave Jiang Subject: [PATCH 1/3] device-dax: Prevent registering drivers without probe or remove callback Date: Thu, 28 Jan 2021 00:01:22 +0100 Message-Id: <20210127230124.109522-1-uwe@kleine-koenig.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Message-ID-Hash: Z4AFUZPD2MDLHXBS6CLHMYFZ2Y4QN44O X-Message-ID-Hash: Z4AFUZPD2MDLHXBS6CLHMYFZ2Y4QN44O X-MailFrom: uwe@kleine-koenig.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: The bus probe and remove functions (dax_bus_probe and dax_bus_remove respectively) call these functions without checking them to be non-NULL. Add a check to prevent a NULL pointer exception. Signed-off-by: Uwe Kleine-König --- drivers/dax/bus.c | 8 ++++++++ 1 file changed, 8 insertions(+) base-commit: 5c8fe583cce542aa0b84adc939ce85293de36e5e diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 737b207c9e30..618d462975ba 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1392,6 +1392,14 @@ int __dax_driver_register(struct dax_device_driver *dax_drv, struct device_driver *drv = &dax_drv->drv; int rc = 0; + /* + * dax_bus_probe() calls dax_drv->probe() unconditionally and + * dax_bus_remove() calls dax_drv->remove() unconditionally. So better + * be safe than sorry and ensure these are provided. + */ + if (!dax_drv->probe || !dax_drv->remove) + return -EINVAL; + INIT_LIST_HEAD(&dax_drv->ids); drv->owner = module; drv->name = mod_name; From patchwork Wed Jan 27 23:01:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 12051157 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=-12.9 required=3.0 tests=BAYES_50, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 6585FC433E0 for ; Wed, 27 Jan 2021 23:01:34 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9A5A360C3D for ; Wed, 27 Jan 2021 23:01:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9A5A360C3D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kleine-koenig.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 3BEFF100EB343; Wed, 27 Jan 2021 15:01:33 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=94.130.110.236; helo=antares.kleine-koenig.org; envelope-from=uwe@kleine-koenig.org; receiver= Received: from antares.kleine-koenig.org (antares.kleine-koenig.org [94.130.110.236]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C1EFD100EB33F for ; Wed, 27 Jan 2021 15:01:29 -0800 (PST) Received: by antares.kleine-koenig.org (Postfix, from userid 1000) id 21E01AE0D2C; Thu, 28 Jan 2021 00:01:27 +0100 (CET) From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Dan Williams , Vishal Verma , Dave Jiang Subject: [PATCH 2/3] dax-device: Fix error path in dax_driver_register Date: Thu, 28 Jan 2021 00:01:23 +0100 Message-Id: <20210127230124.109522-2-uwe@kleine-koenig.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210127230124.109522-1-uwe@kleine-koenig.org> References: <20210127230124.109522-1-uwe@kleine-koenig.org> MIME-Version: 1.0 Message-ID-Hash: WMEDCSPGTV5FL6FT6WAJ2OIADNK3BJRW X-Message-ID-Hash: WMEDCSPGTV5FL6FT6WAJ2OIADNK3BJRW X-MailFrom: uwe@kleine-koenig.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: The static variable match_always_count is supposed to track if there is a driver registered that has .match_always set. If driver_register() fails, the previous increment must be undone. Signed-off-by: Uwe Kleine-König --- drivers/dax/bus.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 618d462975ba..498c60333d60 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -1417,7 +1417,15 @@ int __dax_driver_register(struct dax_device_driver *dax_drv, mutex_unlock(&dax_bus_lock); if (rc) return rc; - return driver_register(drv); + + rc = driver_register(drv); + if (rc && dax_drv->match_always) { + mutex_lock(&dax_bus_lock); + match_always_count -= dax_drv->match_always; + mutex_unlock(&dax_bus_lock); + } + + return rc; } EXPORT_SYMBOL_GPL(__dax_driver_register); From patchwork Wed Jan 27 23:01:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 12051159 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 3B6B2C433E6 for ; Wed, 27 Jan 2021 23:01:35 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BF66460C3D for ; Wed, 27 Jan 2021 23:01:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BF66460C3D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kleine-koenig.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 4E4D4100EB347; Wed, 27 Jan 2021 15:01:34 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2a01:4f8:c0c:3a97::2; helo=antares.kleine-koenig.org; envelope-from=uwe@kleine-koenig.org; receiver= Received: from antares.kleine-koenig.org (antares.kleine-koenig.org [IPv6:2a01:4f8:c0c:3a97::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 05A8C100EB340 for ; Wed, 27 Jan 2021 15:01:29 -0800 (PST) Received: by antares.kleine-koenig.org (Postfix, from userid 1000) id 5DB05AE0D2E; Thu, 28 Jan 2021 00:01:27 +0100 (CET) From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Dan Williams , Vishal Verma , Dave Jiang Subject: [PATCH 3/3] dax-device: Make remove callback return void Date: Thu, 28 Jan 2021 00:01:24 +0100 Message-Id: <20210127230124.109522-3-uwe@kleine-koenig.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210127230124.109522-1-uwe@kleine-koenig.org> References: <20210127230124.109522-1-uwe@kleine-koenig.org> MIME-Version: 1.0 Message-ID-Hash: 2XQEKAUSREFUGXN2VKZIOSCEMLHX3DCN X-Message-ID-Hash: 2XQEKAUSREFUGXN2VKZIOSCEMLHX3DCN X-MailFrom: uwe@kleine-koenig.org X-Mailman-Rule-Hits: nonmember-moderation X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation CC: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: The driver core ignores the return value of struct bus_type::remove() because there is only little that can be done. To simplify the quest to make this function return void, let struct dax_device_driver::remove() return void, too. All users already unconditionally return 0, this commit makes it obvious that returning an error code is a bad idea and makes it obvious for future driver authors that returning an error code isn't intended. Signed-off-by: Uwe Kleine-König --- drivers/dax/bus.c | 4 +++- drivers/dax/bus.h | 2 +- drivers/dax/device.c | 3 +-- drivers/dax/kmem.c | 7 ++----- 4 files changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c index 498c60333d60..253f37a61371 100644 --- a/drivers/dax/bus.c +++ b/drivers/dax/bus.c @@ -179,7 +179,9 @@ static int dax_bus_remove(struct device *dev) struct dax_device_driver *dax_drv = to_dax_drv(dev->driver); struct dev_dax *dev_dax = to_dev_dax(dev); - return dax_drv->remove(dev_dax); + dax_drv->remove(dev_dax); + + return 0; } static struct bus_type dax_bus_type = { diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h index 72b92f95509f..1e946ad7780a 100644 --- a/drivers/dax/bus.h +++ b/drivers/dax/bus.h @@ -39,7 +39,7 @@ struct dax_device_driver { struct list_head ids; int match_always; int (*probe)(struct dev_dax *dev); - int (*remove)(struct dev_dax *dev); + void (*remove)(struct dev_dax *dev); }; int __dax_driver_register(struct dax_device_driver *dax_drv, diff --git a/drivers/dax/device.c b/drivers/dax/device.c index 5da2980bb16b..d532c885f574 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -452,10 +452,9 @@ int dev_dax_probe(struct dev_dax *dev_dax) } EXPORT_SYMBOL_GPL(dev_dax_probe); -static int dev_dax_remove(struct dev_dax *dev_dax) +static void dev_dax_remove(struct dev_dax *dev_dax) { /* all probe actions are unwound by devm */ - return 0; } static struct dax_device_driver device_dax_driver = { diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 403ec42472d1..ac231cc36359 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -136,7 +136,7 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax) } #ifdef CONFIG_MEMORY_HOTREMOVE -static int dev_dax_kmem_remove(struct dev_dax *dev_dax) +static void dev_dax_kmem_remove(struct dev_dax *dev_dax) { int i, success = 0; struct device *dev = &dev_dax->dev; @@ -176,11 +176,9 @@ static int dev_dax_kmem_remove(struct dev_dax *dev_dax) kfree(data); dev_set_drvdata(dev, NULL); } - - return 0; } #else -static int dev_dax_kmem_remove(struct dev_dax *dev_dax) +static void dev_dax_kmem_remove(struct dev_dax *dev_dax) { /* * Without hotremove purposely leak the request_mem_region() for the @@ -190,7 +188,6 @@ static int dev_dax_kmem_remove(struct dev_dax *dev_dax) * request_mem_region(). */ any_hotremove_failed = true; - return 0; } #endif /* CONFIG_MEMORY_HOTREMOVE */