Re: [PATCH 20/24] compat_ioctl: move HDIO ioctl handling into drivers/ide

[Christoph Hellwig]

> +static int put_user_long(long val, unsigned long arg)
> +{
> +#ifdef CONFIG_COMPAT
> +	if (in_compat_syscall())
> +		return put_user(val, (compat_long_t __user *)compat_ptr(arg));
> +#endif
> +	return put_user(val, (long __user *)arg);
> +}

We had this

#ifdef CONFIG_COMPAT
	if (in_compat_syscall())
		...
	...
#endif

patter quite frequently.  Can we define a in_compat_syscall stub
and make sure compat_ptr and the compat_* types are available available
to clean this up a bit?

> -	if (NULL == (void *) arg) {
> +	if (NULL == argp) {

	if (!argp) {

?