Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753411AbbF3NsS (ORCPT ); Tue, 30 Jun 2015 09:48:18 -0400 Received: from mail-oi0-f41.google.com ([209.85.218.41]:36614 "EHLO mail-oi0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753715AbbF3NsL (ORCPT ); Tue, 30 Jun 2015 09:48:11 -0400 MIME-Version: 1.0 In-Reply-To: <1435253451-19817-1-git-send-email-grygorii.strashko@ti.com> References: <1435253451-19817-1-git-send-email-grygorii.strashko@ti.com> From: Alexandre Courbot Date: Tue, 30 Jun 2015 22:47:51 +0900 Message-ID: Subject: Re: [PATCH 1/2] gpiolib: irqchip: prevent driver unloading if gpio is used as irq only To: Grygorii Strashko Cc: Linus Walleij , Sekhar Nori , "linux-gpio@vger.kernel.org" , Linux Kernel Mailing List , Johan Hovold Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1864 Lines: 54 On Fri, Jun 26, 2015 at 2:30 AM, Grygorii Strashko wrote: > Now nothing prevents GPIO driver from being unloaded if its gpios > were requested as GPIO IRQs only (without calling gpio_request()). > > Hence, add calls of try_module_get()/module_put() into > gpiochip_irq_reqres/relres() to track such scenario properly. Bad things could happen indeed. Reviewed-by: Alexandre Courbot > > Cc: Johan Hovold > Signed-off-by: Grygorii Strashko > --- > drivers/gpio/gpiolib.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index be42ab3..9b1d247 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -522,10 +522,14 @@ static int gpiochip_irq_reqres(struct irq_data *d) > { > struct gpio_chip *chip = irq_data_get_irq_chip_data(d); > > + if (!try_module_get(chip->owner)) > + return -ENODEV; > + > if (gpiochip_lock_as_irq(chip, d->hwirq)) { > chip_err(chip, > "unable to lock HW IRQ %lu for IRQ\n", > d->hwirq); > + module_put(chip->owner); > return -EINVAL; > } > return 0; > @@ -536,6 +540,7 @@ static void gpiochip_irq_relres(struct irq_data *d) > struct gpio_chip *chip = irq_data_get_irq_chip_data(d); > > gpiochip_unlock_as_irq(chip, d->hwirq); > + module_put(chip->owner); > } > > static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) > -- > 2.4.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/