drivers: char: scx200_gpio: check return value of cdev_add()

[PATCH] drivers: char: scx200_gpio: check return value of cdev_add()

Posted by Salah Triki 10 months ago

Check return value of cdev_add() and in case of error unregister the
range of device numbers.

Signed-off-by: Salah Triki <salah.triki@gmail.com>
---
 drivers/char/scx200_gpio.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
index 700e6affea6f..36efcc828e8e 100644
--- a/drivers/char/scx200_gpio.c
+++ b/drivers/char/scx200_gpio.c
@@ -107,10 +107,14 @@ static int __init scx200_gpio_init(void)
 	}
 
 	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
-	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
+	rc = cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
+	if (rc)
+		goto unregister_chrdev_region;
 
 	return 0; /* succeed */
 
+unregister_chrdev_region:
+	unregister_chrdev_region(devid, MAX_PINS);
 undo_platform_device_add:
 	platform_device_del(pdev);
 undo_malloc:
-- 
2.43.0

Re: [PATCH] drivers: char: scx200_gpio: check return value of cdev_add()

Posted by Greg Kroah-Hartman 9 months, 4 weeks ago

On Mon, Apr 07, 2025 at 05:56:14PM +0100, Salah Triki wrote:
> Check return value of cdev_add() and in case of error unregister the
> range of device numbers.
> 
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> ---
>  drivers/char/scx200_gpio.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
> index 700e6affea6f..36efcc828e8e 100644
> --- a/drivers/char/scx200_gpio.c
> +++ b/drivers/char/scx200_gpio.c
> @@ -107,10 +107,14 @@ static int __init scx200_gpio_init(void)
>  	}
>  
>  	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
> -	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> +	rc = cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> +	if (rc)
> +		goto unregister_chrdev_region;
>  
>  	return 0; /* succeed */
>  
> +unregister_chrdev_region:
> +	unregister_chrdev_region(devid, MAX_PINS);
>  undo_platform_device_add:
>  	platform_device_del(pdev);
>  undo_malloc:
> -- 
> 2.43.0
> 

How was this tested?

thanks,

greg k-h

Re: [PATCH] drivers: char: scx200_gpio: check return value of cdev_add()

Posted by Salah Triki 9 months, 4 weeks ago

On Tue, Apr 15, 2025 at 04:54:38PM +0200, Greg Kroah-Hartman wrote:
> On Mon, Apr 07, 2025 at 05:56:14PM +0100, Salah Triki wrote:
> > Check return value of cdev_add() and in case of error unregister the
> > range of device numbers.
> > 
> > Signed-off-by: Salah Triki <salah.triki@gmail.com>
> > ---
> >  drivers/char/scx200_gpio.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
> > index 700e6affea6f..36efcc828e8e 100644
> > --- a/drivers/char/scx200_gpio.c
> > +++ b/drivers/char/scx200_gpio.c
> > @@ -107,10 +107,14 @@ static int __init scx200_gpio_init(void)
> >  	}
> >  
> >  	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
> > -	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> > +	rc = cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> > +	if (rc)
> > +		goto unregister_chrdev_region;
> >  
> >  	return 0; /* succeed */
> >  
> > +unregister_chrdev_region:
> > +	unregister_chrdev_region(devid, MAX_PINS);
> >  undo_platform_device_add:
> >  	platform_device_del(pdev);
> >  undo_malloc:
> > -- 
> > 2.43.0
> > 
> 
> How was this tested?
> 

I only compiled it.

ST 

> thanks,
> 
> greg k-h

Re: [PATCH] drivers: char: scx200_gpio: check return value of cdev_add()

Posted by Greg Kroah-Hartman 9 months, 4 weeks ago

On Tue, Apr 15, 2025 at 04:30:08PM +0100, Salah Triki wrote:
> On Tue, Apr 15, 2025 at 04:54:38PM +0200, Greg Kroah-Hartman wrote:
> > On Mon, Apr 07, 2025 at 05:56:14PM +0100, Salah Triki wrote:
> > > Check return value of cdev_add() and in case of error unregister the
> > > range of device numbers.
> > > 
> > > Signed-off-by: Salah Triki <salah.triki@gmail.com>
> > > ---
> > >  drivers/char/scx200_gpio.c | 6 +++++-
> > >  1 file changed, 5 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
> > > index 700e6affea6f..36efcc828e8e 100644
> > > --- a/drivers/char/scx200_gpio.c
> > > +++ b/drivers/char/scx200_gpio.c
> > > @@ -107,10 +107,14 @@ static int __init scx200_gpio_init(void)
> > >  	}
> > >  
> > >  	cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops);
> > > -	cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> > > +	rc = cdev_add(&scx200_gpio_cdev, devid, MAX_PINS);
> > > +	if (rc)
> > > +		goto unregister_chrdev_region;
> > >  
> > >  	return 0; /* succeed */
> > >  
> > > +unregister_chrdev_region:
> > > +	unregister_chrdev_region(devid, MAX_PINS);
> > >  undo_platform_device_add:
> > >  	platform_device_del(pdev);
> > >  undo_malloc:
> > > -- 
> > > 2.43.0
> > > 
> > 
> > How was this tested?
> > 
> 
> I only compiled it.

Please properly test it.