Re: [PATCH] gpio: tpmx86: fix uninitialized variable girq

Marc Zyngier
2022-09-14T07:36:18Z

On Wed, 14 Sep 2022 06:18:42 +0100,
Dongliang Mu <dzm91@hust.edu.cn> wrote:
>
> From: Dongliang Mu <mudongliangabcd@gmail.com>
>
> The commit 924610607f19 ("gpio: tpmx86: Move PM device over to
> irq domain") adds a dereference of girq that may be uninitialized.
>
> Fix this by initializing girq and checking irq before invoking
> irq_domain_set_pm_device.
>
> Fixes: 924610607f19 ("gpio: tpmx86: Move PM device over to irq domain")
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
> drivers/gpio/gpio-tqmx86.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpio-tqmx86.c b/drivers/gpio/gpio-tqmx86.c
> index fa4bc7481f9a..bdef182c11c2 100644
> --- a/drivers/gpio/gpio-tqmx86.c
> +++ b/drivers/gpio/gpio-tqmx86.c
> @@ -231,7 +231,7 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
> struct device *dev = &pdev->dev;
> struct tqmx86_gpio_data *gpio;
> struct gpio_chip *chip;
> - struct gpio_irq_chip *girq;
> + struct gpio_irq_chip *girq = NULL;
> void __iomem *io_base;
> struct resource *res;
> int ret, irq;
> @@ -315,7 +315,9 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
> goto out_pm_dis;
> }
>
> - irq_domain_set_pm_device(girq->domain, dev);
> + if (girq) {
> + irq_domain_set_pm_device(girq->domain, dev);
> + }
>
> dev_info(dev, "GPIO functionality initialized with %d pins\n",
> chip->ngpio);

I wonder if a better fix wouldn't be to directly hoist the
irq_domain_set_pm_device() call into the 'if (irq > 0)' block.

Thanks,

M.

--
Without deviation from the norm, progress is not possible.