From patchwork Wed Oct 13 16:04:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 12556277 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87D24C43217 for ; Wed, 13 Oct 2021 16:04:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6549E611AE for ; Wed, 13 Oct 2021 16:04:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236136AbhJMQGR (ORCPT ); Wed, 13 Oct 2021 12:06:17 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:55576 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbhJMQGR (ORCPT ); Wed, 13 Oct 2021 12:06:17 -0400 Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 3.0.0) id 5610ad909f428166; Wed, 13 Oct 2021 18:04:11 +0200 Received: from kreacher.localnet (unknown [213.134.161.244]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by v370.home.net.pl (Postfix) with ESMTPSA id E1E2166A871; Wed, 13 Oct 2021 18:04:10 +0200 (CEST) From: "Rafael J. Wysocki" To: Linux ACPI Cc: linux-hwmon@vger.kernel.org, LKML , Jean Delvare , Guenter Roeck , Andy Shevchenko Subject: [PATCH v2] hwmon: acpi_power_meter: Use acpi_bus_get_acpi_device() Date: Wed, 13 Oct 2021 18:04:09 +0200 Message-ID: <11871063.O9o76ZdvQC@kreacher> In-Reply-To: <11864888.O9o76ZdvQC@kreacher> References: <11864888.O9o76ZdvQC@kreacher> MIME-Version: 1.0 X-CLIENT-IP: 213.134.161.244 X-CLIENT-HOSTNAME: 213.134.161.244 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvtddrvddutddgleegucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvffufffkjghfggfgtgesthfuredttddtjeenucfhrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqeenucggtffrrghtthgvrhhnpedvjeelgffhiedukedtleekkedvudfggefhgfegjefgueekjeelvefggfdvledutdenucfkphepvddufedrudefgedrudeiuddrvdeggeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedvudefrddufeegrdduiedurddvgeegpdhhvghlohepkhhrvggrtghhvghrrdhlohgtrghlnhgvthdpmhgrihhlfhhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqpdhrtghpthhtoheplhhinhhugidqrggtphhisehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqhhifmhhonhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehjuggvlhhvrghrvgesshhushgvrdgtohhmpdhrtghpthhtoheplhhinhhugiesrhhovggt khdquhhsrdhnvghtpdhrtghpthhtoheprghnughrihihrdhshhgvvhgthhgvnhhkoheslhhinhhugidrihhnthgvlhdrtghomh X-DCC--Metrics: v370.home.net.pl 1024; Body=6 Fuz1=6 Fuz2=6 Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org From: Rafael J. Wysocki In read_domain_devices(), acpi_bus_get_device() is called to obtain the ACPI device object attached to the given ACPI handle and subsequently that object is passed to get_device() for reference counting, but there is a window between the acpi_bus_get_device() and get_device() calls in which the ACPI device object in question may go away. To address this issue, make read_domain_devices() use acpi_bus_get_acpi_device() to reference count and return the given ACPI device object in one go and export that function to modules. While at it, also make read_domain_devices() and remove_domain_devices() use acpi_dev_put() instead of calling put_device() directly on the ACPI device objects returned by acpi_bus_get_acpi_device(). Signed-off-by: Rafael J. Wysocki Reviewed-by: Andy Shevchenko --- -> v2: Resend with a different From and S-o-b address and with R-by from Andy. No other changes. --- drivers/acpi/scan.c | 1 + drivers/hwmon/acpi_power_meter.c | 13 +++++-------- 2 files changed, 6 insertions(+), 8 deletions(-) Index: linux-pm/drivers/hwmon/acpi_power_meter.c =================================================================== --- linux-pm.orig/drivers/hwmon/acpi_power_meter.c +++ linux-pm/drivers/hwmon/acpi_power_meter.c @@ -535,7 +535,7 @@ static void remove_domain_devices(struct sysfs_remove_link(resource->holders_dir, kobject_name(&obj->dev.kobj)); - put_device(&obj->dev); + acpi_dev_put(obj); } kfree(resource->domain_devices); @@ -597,18 +597,15 @@ static int read_domain_devices(struct ac continue; /* Create a symlink to domain objects */ - resource->domain_devices[i] = NULL; - if (acpi_bus_get_device(element->reference.handle, - &resource->domain_devices[i])) + obj = acpi_bus_get_acpi_device(element->reference.handle); + resource->domain_devices[i] = obj; + if (!obj) continue; - obj = resource->domain_devices[i]; - get_device(&obj->dev); - res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj, kobject_name(&obj->dev.kobj)); if (res) { - put_device(&obj->dev); + acpi_dev_put(obj); resource->domain_devices[i] = NULL; } } Index: linux-pm/drivers/acpi/scan.c =================================================================== --- linux-pm.orig/drivers/acpi/scan.c +++ linux-pm/drivers/acpi/scan.c @@ -608,6 +608,7 @@ struct acpi_device *acpi_bus_get_acpi_de { return handle_to_device(handle, get_acpi_device); } +EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device); static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) {