2022-09-14 05:29:26

by Dongliang Mu

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

From: Dongliang Mu <[email protected]>

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 <[email protected]>
---
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);
--
2.35.1

2022-09-14 07:47:05

by Marc Zyngier

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

On Wed, 14 Sep 2022 06:18:42 +0100,
Dongliang Mu <[email protected]> wrote:
>
> From: Dongliang Mu <[email protected]>
>
> 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 <[email protected]>
> ---
> 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.

2022-09-15 06:19:05

by Dongliang Mu

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

On Wed, Sep 14, 2022 at 3:36 PM Marc Zyngier <[email protected]> wrote:
>
> On Wed, 14 Sep 2022 06:18:42 +0100,
> Dongliang Mu <[email protected]> wrote:
> >
> > From: Dongliang Mu <[email protected]>
> >
> > 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 <[email protected]>
> > ---
> > 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.

If irq_domain_set_pm_device has no dependency on
devm_gpiochip_add_data, we can directly move irq_domain_set_pm_device
to the if block.

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

2022-09-16 08:03:34

by Marc Zyngier

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

On Thu, 15 Sep 2022 07:08:10 +0100,
Dongliang Mu <[email protected]> wrote:
>
> On Wed, Sep 14, 2022 at 3:36 PM Marc Zyngier <[email protected]> wrote:
> >
> > On Wed, 14 Sep 2022 06:18:42 +0100,
> > Dongliang Mu <[email protected]> wrote:
> > >
> > > From: Dongliang Mu <[email protected]>
> > >
> > > 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 <[email protected]>
> > > ---
> > > 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.
>
> If irq_domain_set_pm_device has no dependency on
> devm_gpiochip_add_data, we can directly move irq_domain_set_pm_device
> to the if block.

There is no dependency there, and you can convince yourself by looking
at the (trivial) code.

M.

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