From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9740559B71; Fri, 3 Jan 2025 16:44:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735922690; cv=none; b=F2iUG2OSpm1atS4PL3/SsRZnYkHHRqTKfSW0iv+lKd8emwk+mPndTaIoWkB87jc6pB/+6yOXbM+pEAt7pWqpCOZT6hOeA6qjM5/b3l7aVb+si8MrOCjpJ4dH/DEQ7el1Ruwj5A/zg1JVvGqpFUHkCSKw4ujtlPYWAqCV0XCB97c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735922690; c=relaxed/simple; bh=mM6M2n/XvzJx+DelvfRYyLa7H4UKjUM+Ow/bdnD/UpQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=GvyDuOzpHj9HELxTNpqV1w2xJR43jI0NAIVflNOJetaep0sryr3BjsB9BCFTbxb4C4VGpXjQYst3yOidxOw9Tr91S00m9SNSSn30wi6YO0a6CrqfZHEbFN+7chdIRKXMyTArG+14dAbdZEtlUyTuYZS1//foJ3iZ+0ojQy35c4U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=feHq1LXz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="feHq1LXz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24BE3C4CECE; Fri, 3 Jan 2025 16:44:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1735922690; bh=mM6M2n/XvzJx+DelvfRYyLa7H4UKjUM+Ow/bdnD/UpQ=; h=From:To:Cc:Subject:Date:From; b=feHq1LXzvjzudiKX7L1G/scZWIXBqS6Hx+x3CGtZ6qe5Nhp3N4qAuo3BnDS6vn3AG /D3D5T8EDXa1ovdnoM090EooMlQQaCNbTHmM77FRWqBbhC3k2sjr694uDt+CTqCU7P k4i4SNE+1qeUokQbu65CG8igVpF2RoSEyDTkOu+Q4tGBKl6y431tH/lMbuWAWBAmWE 2c8I+gdzeqXQA174aS0+gPOwXcfDh0s7CBR0FTFdoyabHx4wZyEGtA6OOKb1KVFdcT UEQDlDu/CRA7MXo6RK4/kqRgLRydwGbrkqTNhEG1P4IGHLc3S5Pn/99NTUOg2roike cq5MuOxknh27A== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu Cc: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, Danilo Krummrich Subject: [PATCH 1/2] devres: add devm_remove_action_nowarn() Date: Fri, 3 Jan 2025 17:44:30 +0100 Message-ID: <20250103164436.96449-1-dakr@kernel.org> X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit devm_remove_action() warns if the action to remove does not exist (anymore). The Rust devres abstraction, however, has a use-case to call devm_remove_action() at a point where it can't be guaranteed that the corresponding action hasn't been released yet. In particular, an instance of `Devres` may be dropped after the action has been released. So far, `Devres` worked around this by keeping the inner type alive. Hence, add devm_remove_action_nowarn(), which returns an error code if the action has been removed already. A subsequent patch uses devm_remove_action_nowarn() to remove the action when `Devres` is dropped. Signed-off-by: Danilo Krummrich --- drivers/base/devres.c | 17 ++++++++++++----- include/linux/device.h | 18 +++++++++++++++++- 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 2152eec0c135..d59b8078fc33 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -750,25 +750,32 @@ int __devm_add_action(struct device *dev, void (*action)(void *), void *data, co EXPORT_SYMBOL_GPL(__devm_add_action); /** - * devm_remove_action() - removes previously added custom action + * devm_remove_action_nowarn() - removes previously added custom action * @dev: Device that owns the action * @action: Function implementing the action * @data: Pointer to data passed to @action implementation * * Removes instance of @action previously added by devm_add_action(). * Both action and data should match one of the existing entries. + * + * In contrast to devm_remove_action(), this function does not WARN() if no + * entry could have been found. + * + * Returns: 0 on success, -ENOENT if no entry could have been found. */ -void devm_remove_action(struct device *dev, void (*action)(void *), void *data) +int devm_remove_action_nowarn(struct device *dev, + void (*action)(void *), + void *data) { struct action_devres devres = { .data = data, .action = action, }; - WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match, - &devres)); + return devres_destroy(dev, devm_action_release, devm_action_match, + &devres); } -EXPORT_SYMBOL_GPL(devm_remove_action); +EXPORT_SYMBOL_GPL(devm_remove_action_nowarn); /** * devm_release_action() - release previously added custom action diff --git a/include/linux/device.h b/include/linux/device.h index 667cb6db9019..6879d5e8ac3d 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -399,7 +399,23 @@ void __iomem *devm_of_iomap(struct device *dev, #endif /* allows to add/remove a custom action to devres stack */ -void devm_remove_action(struct device *dev, void (*action)(void *), void *data); +int devm_remove_action_nowarn(struct device *dev, void (*action)(void *), void *data); + +/** + * devm_remove_action() - removes previously added custom action + * @dev: Device that owns the action + * @action: Function implementing the action + * @data: Pointer to data passed to @action implementation + * + * Removes instance of @action previously added by devm_add_action(). + * Both action and data should match one of the existing entries. + */ +static inline +void devm_remove_action(struct device *dev, void (*action)(void *), void *data) +{ + WARN_ON(devm_remove_action_nowarn(dev, action, data)); +} + void devm_release_action(struct device *dev, void (*action)(void *), void *data); int __devm_add_action(struct device *dev, void (*action)(void *), void *data, const char *name); base-commit: 06e843bbbf2107463249ea6f6b1a736f5647e24a -- 2.47.1