Re: [PATCH v2 5/5] Input: evdev - Switch to bitmap_zalloc()

[Joe Perches]

On Sat, 2018-06-16 at 21:45 +0300, Andy Shevchenko wrote:
> On Sat, Jun 16, 2018 at 12:46 AM Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> wrote:
> > On Fri, Jun 15, 2018 at 04:20:17PM +0300, Andy Shevchenko wrote:
> > > Switch to bitmap_zalloc() to show clearly what we are allocating.
> > > Besides that it returns pointer of bitmap type instead of opaque void *.
> 
> 
> > > +       mem = bitmap_alloc(maxbit, GFP_KERNEL);
> > >         if (!mem)
> > >                 return -ENOMEM;
> > 
> > But in commit message you say you switch to bitmap_zalloc(). IIUC
> > bitmap_alloc() is OK here. But could you please update comment to
> > avoid confusing.
> 
> There are two places, one with alloc, another with zalloc.
> I will clarify this in commit message of next version.
> 
> > > +       mask = bitmap_zalloc(cnt, GFP_KERNEL);
> > >         if (!mask)
> > >                 return -ENOMEM;
> > > 
> > >         error = bits_from_user(mask, cnt - 1, codes_size, codes, compat);
> > 
> > If my understanding of bits_from_user() correct, here you can also use
> > bitmap_alloc(), true?

Also it might be useful to have a separate bitmap_from_user
to alloc and copy.