RE: [PATCH v10 13/15] platform/x86: wmi: create userspace interface for drivers

[Mario.Limonciello]

> -----Original Message-----
> From: Greg KH [mailto:greg@xxxxxxxxx]
> Sent: Friday, October 20, 2017 8:23 AM
> To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx>
> Cc: dvhart@xxxxxxxxxxxxx; Andy Shevchenko <andy.shevchenko@xxxxxxxxx>;
> LKML <linux-kernel@xxxxxxxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; Andy
> Lutomirski <luto@xxxxxxxxxx>; quasisec@xxxxxxxxxx; pali.rohar@xxxxxxxxx;
> rjw@xxxxxxxxxxxxx; mjg59@xxxxxxxxxx; hch@xxxxxx; Alan Cox
> <gnomes@xxxxxxxxxxxxxxxxxxx>
> Subject: Re: [PATCH v10 13/15] platform/x86: wmi: create userspace interface for
> drivers
> 
> On Thu, Oct 19, 2017 at 12:50:16PM -0500, Mario Limonciello wrote:
> > +static ssize_t wmi_char_read(struct file *filp, char __user *buffer,
> > +	size_t length, loff_t *offset)
> > +{
> > +	struct wmi_block *wblock = filp->private_data;
> > +	size_t count;
> > +
> > +	if (*offset != 0)
> > +		return 0;
> > +
> > +	count = sizeof(wblock->req_buf_size);
> > +	count = length < count ? length : count;
> > +
> > +	if (copy_to_user(buffer, &wblock->req_buf_size, count))
> > +		return -EFAULT;
> > +
> > +	*offset = count;
> > +	return count;
> 
> simple_read_from_buffer()?  Library functions are your friend :)
> 
Thanks, wasn't aware of it.