Re: [PATCH v9 2/3] kernel.h: add to_user_ptr()

[Gustavo Padovan <gustavo@padovan.org>]

2016-03-17 Joe Perches <joe@perches.com>:

> On Thu, 2016-03-17 at 18:19 -0300, Gustavo Padovan wrote:
> > 2016-03-17 Joe Perches <joe@perches.com>:
> > > On Thu, 2016-03-17 at 16:50 -0400, Rob Clark wrote:
> > > > On Thu, Mar 17, 2016 at 4:40 PM, Joe Perches <joe@perches.com> wrot=
e:
> > > []
> > > > > It's a name that seems like it should be a straightforward
> > > > > cast of a kernel pointer to a __user pointer like:
> > > > >=20
> > > > > static inline void __user *to_user_ptr(void *p)
> > > > > {
> > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0return (void __us=
er *)p;
> > > > > }
> > > > ahh, ok.=C2=A0=C2=A0I guess I was used to using it in the context o=
f ioctl
> > > > structs..=C2=A0=C2=A0in that context u64 -> (void __user *) made mo=
re sense.
> > > >=20
> > > > Maybe uapi_to_ptr()?=C2=A0=C2=A0(ok, not super-creative.. maybe som=
eone has a
> > > > better idea)
> > > Maybe u64_to_user_ptr?
> > That is a good name. If everyone agrees I can resend this patch
> > changing it to u64_to_user_ptr. Then should we still keep it on
> > kernel.h?
>=20
> I've no particular opinion about location,
> but maybe compat.h might be appropriate.

I don't think this is really related to compat. I'd keep kernel.h.

The problem I'm trying to solve here is:

CC      drivers/dma-buf/sync_file.o
drivers/dma-buf/sync_file.c: In function =E2=80=98sync_file_ioctl_fence_inf=
o=E2=80=99:
drivers/dma-buf/sync_file.c:341:19: warning: cast to pointer from
integer of different size [-Wint-to-pointer-cast]
  if (copy_to_user((void __user *)info.sync_fence_info, fence_info,

where info.sync_fence_info is __u64.

	Gustavo