Re: [PATCH] watchdog: cpwd: fix build regression

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Oct 08, 2019 at 09:36:16AM +0200, Arnd Bergmann wrote:
> The compat_ptr_ioctl() infrastructure did not make it into
> linux-5.4, so cpwd now fails to build.
> 
> Fix it by using an open-coded version.
> 
> Fixes: 68f28b01fb9e ("watchdog: cpwd: use generic compat_ptr_ioctl")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Guenter

> ---
>  drivers/watchdog/cpwd.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/watchdog/cpwd.c b/drivers/watchdog/cpwd.c
> index 9393be584e72..808eeb4779e4 100644
> --- a/drivers/watchdog/cpwd.c
> +++ b/drivers/watchdog/cpwd.c
> @@ -26,6 +26,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/ioport.h>
>  #include <linux/timer.h>
> +#include <linux/compat.h>
>  #include <linux/slab.h>
>  #include <linux/mutex.h>
>  #include <linux/io.h>
> @@ -473,6 +474,11 @@ static long cpwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  	return 0;
>  }
>  
> +static long cpwd_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> +{
> +	return cpwd_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
> +}
> +
>  static ssize_t cpwd_write(struct file *file, const char __user *buf,
>  			  size_t count, loff_t *ppos)
>  {
> @@ -497,7 +503,7 @@ static ssize_t cpwd_read(struct file *file, char __user *buffer,
>  static const struct file_operations cpwd_fops = {
>  	.owner =		THIS_MODULE,
>  	.unlocked_ioctl =	cpwd_ioctl,
> -	.compat_ioctl =		compat_ptr_ioctl,
> +	.compat_ioctl =		cpwd_compat_ioctl,
>  	.open =			cpwd_open,
>  	.write =		cpwd_write,
>  	.read =			cpwd_read,
> -- 
> 2.20.0
>