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

[Mario.Limonciello]

> -----Original Message-----
> From: Greg KH [mailto:g...@kroah.com]
> Sent: Friday, October 20, 2017 8:23 AM
> To: Limonciello, Mario <mario_limoncie...@dell.com>
> Cc: dvh...@infradead.org; Andy Shevchenko <andy.shevche...@gmail.com>;
> LKML <linux-kernel@vger.kernel.org>; platform-driver-...@vger.kernel.org; Andy
> Lutomirski <l...@kernel.org>; quasi...@google.com; pali.ro...@gmail.com;
> r...@rjwysocki.net; mj...@google.com; h...@lst.de; Alan Cox
> <gno...@lxorguk.ukuu.org.uk>
> 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.