From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3265A4FD7A7; Tue, 13 Oct 2026 12:10:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791893434; cv=none; b=j6R1kfyAqggsGxKWClx8gUrk4Nw+Dkc0W3E/2gdNf7OiIrvYsImAARK+2HkG9Ka2bcIaq5/56b2mpcPKoUS7ndevg9ggGpRbi9VsM1o3kHNpHZhTWKLR/NjpxjaAv+VBhGeJs1XEt29lM7i2lilMB6a6GjlWeAIGnGC+vXwqnWg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791893434; c=relaxed/simple; bh=sjkUf1TGI0N4osin+AmcVCC272eZxi9UOPjTVEL6MI8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PJh9WGR1CNiQ0jkgkmZU4tBQC9S1A3VjVjT27fswd5iuWZHixxRv4fNUvkH9ixFqwSVvRACQNnCiZwBANiw4JfAWjitdKljHFpgGP1L4ysta/WxjbS5ZF0IfyWCTSoyVzh/c84+E031lWtRfI9kcnmnmZVmlD6EiONID5krz7no= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=f+OggJBQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="f+OggJBQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 548B61F000FF; Tue, 13 Oct 2026 12:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791893432; bh=kccGkG4iJNQz+WzLuTOQsHkhtwtudFDcOMmPeyL2LYM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=f+OggJBQU7rQqc01OfFfPkRyjCF9E70g9lrPsTA9LodGja1UWSGkHml8GyFpqEh/9 LRXFwsXi+yMGFxXPwg8W3tH6cRc9K6FFQ8Fn+4wOyUYaiQee8RfXPhKucd7SwX1rTu NXfccM6f5hxqC9p0ikEi9CedxI/EWrhX24Ye+U8I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Krzysztof Kozlowski , Tejun Heo , Andy Shevchenko , Sasha Levin Subject: [PATCH 6.18 224/621] workqueue: devres: Add device-managed allocate workqueue Date: Tue, 13 Oct 2026 13:33:39 +0200 Message-ID: <20261013112926.173592986@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Krzysztof Kozlowski [ Upstream commit 1dfc9d60a69ec148e1cb709256617d86e5f0e8f8 ] Add a Resource-managed version of alloc_workqueue() to fix common problem of drivers mixing devm() calls with destroy_workqueue. Such naive and discouraged driver approach leads to difficult to debug bugs when the driver: 1. Allocates workqueue in standard way and destroys it in driver remove() callback, 2. Sets work struct with devm_work_autocancel(), 3. Registers interrupt handler with devm_request_threaded_irq(). Which leads to following unbind/removal path: 1. destroy_workqueue() via driver remove(), Any interrupt coming now would still execute the interrupt handler, which queues work on destroyed workqueue. 2. devm_irq_release(), 3. devm_work_drop() -> cancel_work_sync() on destroyed workqueue. devm_alloc_workqueue() has two benefits: 1. Solves above problem of mix-and-match devres and non-devres code in driver, 2. Simplify any sane drivers which were correctly using alloc_workqueue() + devm_add_action_or_reset(). Signed-off-by: Krzysztof Kozlowski Acked-by: Tejun Heo Reviewed-by: Andy Shevchenko Signed-off-by: Tejun Heo Stable-dep-of: 1e668baadefb ("power: supply: max77705: Free allocated workqueue and fix removal order") Signed-off-by: Sasha Levin --- .../driver-api/driver-model/devres.rst | 4 +++ include/linux/workqueue.h | 22 +++++++++++++++ kernel/workqueue.c | 28 +++++++++++++++++++ 3 files changed, 54 insertions(+) diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index 2b36ebde9cece..012f42a48f855 100644 --- a/Documentation/driver-api/driver-model/devres.rst +++ b/Documentation/driver-api/driver-model/devres.rst @@ -466,3 +466,7 @@ SPI WATCHDOG devm_watchdog_register_device() + +WORKQUEUE + devm_alloc_workqueue() + devm_alloc_ordered_workqueue() diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index dabc351cc127d..30fd0cb3229c1 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -512,6 +512,26 @@ __printf(1, 4) struct workqueue_struct * alloc_workqueue_noprof(const char *fmt, unsigned int flags, int max_active, ...); #define alloc_workqueue(...) alloc_hooks(alloc_workqueue_noprof(__VA_ARGS__)) +/** + * devm_alloc_workqueue - Resource-managed allocate a workqueue + * @dev: Device to allocate workqueue for + * @fmt: printf format for the name of the workqueue + * @flags: WQ_* flags + * @max_active: max in-flight work items, 0 for default + * @...: args for @fmt + * + * Resource managed workqueue, see alloc_workqueue() for details. + * + * The workqueue will be automatically destroyed on driver detach. Typically + * this should be used in drivers already relying on devm interafaces. + * + * RETURNS: + * Pointer to the allocated workqueue on success, %NULL on failure. + */ +__printf(2, 5) struct workqueue_struct * +devm_alloc_workqueue(struct device *dev, const char *fmt, unsigned int flags, + int max_active, ...); + #ifdef CONFIG_LOCKDEP /** * alloc_workqueue_lockdep_map - allocate a workqueue with user-defined lockdep_map @@ -568,6 +588,8 @@ alloc_workqueue_lockdep_map(const char *fmt, unsigned int flags, int max_active, */ #define alloc_ordered_workqueue(fmt, flags, args...) \ alloc_workqueue(fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args) +#define devm_alloc_ordered_workqueue(dev, fmt, flags, args...) \ + devm_alloc_workqueue(dev, fmt, WQ_UNBOUND | __WQ_ORDERED | (flags), 1, ##args) #define create_workqueue(name) \ alloc_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_PERCPU, 1, (name)) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 308299b48c96f..2c78034eca12b 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -41,6 +41,7 @@ #include #include #include +#include #include #include #include @@ -5894,6 +5895,33 @@ struct workqueue_struct *alloc_workqueue_noprof(const char *fmt, } EXPORT_SYMBOL_GPL(alloc_workqueue_noprof); +static void devm_workqueue_release(void *res) +{ + destroy_workqueue(res); +} + +__printf(2, 5) struct workqueue_struct * +devm_alloc_workqueue(struct device *dev, const char *fmt, unsigned int flags, + int max_active, ...) +{ + struct workqueue_struct *wq; + va_list args; + int ret; + + va_start(args, max_active); + wq = alloc_workqueue(fmt, flags, max_active, args); + va_end(args); + if (!wq) + return NULL; + + ret = devm_add_action_or_reset(dev, devm_workqueue_release, wq); + if (ret) + return NULL; + + return wq; +} +EXPORT_SYMBOL_GPL(devm_alloc_workqueue); + #ifdef CONFIG_LOCKDEP __printf(1, 5) struct workqueue_struct * -- 2.53.0