From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx-out1.startmail.com (mx-out1.startmail.com [145.131.90.139]) (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 9776E1946AA; Wed, 1 Oct 2025 20:51:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=145.131.90.139 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759351892; cv=none; b=j66Z7VWqmu2KBsSFFNvXdxO7qNGQQS2/sByXtMPwJr3yIzXyZXMF1+AV6asRI6Kv6Gm6oYu9f2WOUJPQ3CJIgnmGJ6hZKJuh0IJgtwAcYSvBPAjBTcQ3LawZ11fXhrBmZ0lfcES1cwcuHxKzw5hwKb29P0sYre/QeJrkeEl/pE0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759351892; c=relaxed/simple; bh=VPaXP4qHSspQ17XY5CPQB+lhfh+9TEuQQnadpD+XA7s=; h=Date:From:To:Cc:Subject:Message-ID:References:Mime-Version: Content-Type:Content-Disposition:In-Reply-To; b=KJ6JA/VhrdqQHadV0EYCrzA9Iwuqwp30mUzsqq0sIuIXqhoyyfG5zRYASwCYL9zRrPFzGJD/wiDv1T/6AunVdt/8Mva7GYhBf1iucJ771/ZuhBl2dd1PQafHprH+LGnqz6sxfsrR79CVGMEaIHtZQAZOnEjWrob1/u4XTyCjqK0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weathered-steel.dev; spf=pass smtp.mailfrom=weathered-steel.dev; dkim=pass (2048-bit key) header.d=weathered-steel.dev header.i=@weathered-steel.dev header.b=ImUQ+auC; arc=none smtp.client-ip=145.131.90.139 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=weathered-steel.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=weathered-steel.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=weathered-steel.dev header.i=@weathered-steel.dev header.b="ImUQ+auC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=weathered-steel.dev; s=startmail1; t=1759351881; bh=QbcGgb5EQSRVJLoUkXO4xyhEsG9J13OKh/OXOofe7G8=; h=Date:From:To:Subject:Message-ID:References:Mime-Version: Content-Type:Content-Disposition:In-Reply-To:From:Subject:To:Date: Sender:Content-Type:Content-Transfer-Encoding:Content-Disposition: Mime-Version:Reply-To:In-Reply-To:References:Message-Id: List-Unsubscribe:List-Unsubscribe-Post:Autocrypt; b=ImUQ+auCIzrbzgelzjZy/hT/6tYbxImGUQmh64wCOdKDUl20Co1kP7cTJ9lhFDrbR qQ4QZlSxRPKLJxwjRAbiuePe78ERBtTjj3yUHwpj56F9g4Lcw7rD1f4TPANFVG6jzA F8rvWj2+w96g7boCQZFbxZUGtuIibAjiT8peB42+PcniofccflsEr6bINEsaBUNBqe +VCQyDAPoOkVF6bO0L4BKQEtA7NcZZXU1+GXhmBxJrgTAIP/l2WYOWAw2drtpyeLBx ZsINN8ZnA3JZrn9ueU0l92T0EVFjY1yF5FNaIT+VMSk6FtfjKRBYPfKM8y5CggJ8Dg fI1MewDrYAc9w== Date: Wed, 1 Oct 2025 20:51:16 +0000 From: Elle Rhumsaa To: Michal Wilczynski Cc: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Guo Ren , Fu Wei , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Marek Szyprowski , Benno Lossin , Michael Turquette , Drew Fustini , Daniel Almeida , linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org Subject: Re: [PATCH v15 1/7] pwm: Export `pwmchip_release` for external use Message-ID: References: <20250930-rust-next-pwm-working-fan-for-sending-v15-0-5661c3090877@samsung.com> <20250930-rust-next-pwm-working-fan-for-sending-v15-1-5661c3090877@samsung.com> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250930-rust-next-pwm-working-fan-for-sending-v15-1-5661c3090877@samsung.com> On Tue, Sep 30, 2025 at 02:20:32PM +0200, Michal Wilczynski wrote: > The upcoming Rust abstraction layer for the PWM subsystem uses a custom > `dev->release` handler to safely manage the lifetime of its driver > data. > > To prevent leaking the memory of the `struct pwm_chip` (allocated by > `pwmchip_alloc`), this custom handler must also call the original > `pwmchip_release` function to complete the cleanup. > > Make `pwmchip_release` a global, exported function so that it can be > called from the Rust FFI bridge. This involves removing the `static` > keyword, adding a prototype to the public header, and exporting the > symbol. > > Reviewed-by: Elle Rhumsaa > Signed-off-by: Michal Wilczynski > --- > drivers/pwm/core.c | 3 ++- > include/linux/pwm.h | 6 ++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c > index 0d66376a83ec350e0c3718959f4d794efd71595a..a33da3dff608fdff91251e5fd07b0dbd295be022 100644 > --- a/drivers/pwm/core.c > +++ b/drivers/pwm/core.c > @@ -1600,12 +1600,13 @@ void pwmchip_put(struct pwm_chip *chip) > } > EXPORT_SYMBOL_GPL(pwmchip_put); > > -static void pwmchip_release(struct device *pwmchip_dev) > +void pwmchip_release(struct device *pwmchip_dev) > { > struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev); > > kfree(chip); > } > +EXPORT_SYMBOL_GPL(pwmchip_release); > > struct pwm_chip *pwmchip_alloc(struct device *parent, unsigned int npwm, size_t sizeof_priv) > { > diff --git a/include/linux/pwm.h b/include/linux/pwm.h > index 8cafc483db53addf95591d1ac74287532c0fa0ee..d86061024b52172edf3845bf9252a966f120e365 100644 > --- a/include/linux/pwm.h > +++ b/include/linux/pwm.h > @@ -485,6 +485,12 @@ int __pwmchip_add(struct pwm_chip *chip, struct module *owner); > #define pwmchip_add(chip) __pwmchip_add(chip, THIS_MODULE) > void pwmchip_remove(struct pwm_chip *chip); > > +/* > + * For FFI wrapper use only: > + * The Rust PWM abstraction needs this to properly free the pwm_chip. > + */ > +void pwmchip_release(struct device *dev); > + > int __devm_pwmchip_add(struct device *dev, struct pwm_chip *chip, struct module *owner); > #define devm_pwmchip_add(dev, chip) __devm_pwmchip_add(dev, chip, THIS_MODULE) > > > -- > 2.34.1 > Reviewed-by: Elle Rhumsaa