Re: new architectures, time_t __kernel_long_t

[H. Peter Anvin]

On 12/20/2012 09:02 PM, Al Viro wrote:
> On Thu, Dec 20, 2012 at 09:00:27PM -0800, H. Peter Anvin wrote:
> > On 12/20/2012 08:57 PM, Al Viro wrote:
> > > On Wed, Nov 14, 2012 at 12:18:01PM +0000, Arnd Bergmann wrote:
> > >
> > > > The other types that are used as 64 bit on x32 are ino_t, nlink_t,
> > > > size_t, ssize_t, ptrdiff_t, and off_t.
> > >
> > > *Kernel-side* we should not give a damn about the userland nlink_t, period.
> > > Making it architecture-dependent had been a bad mistake that essentially
> > > made nlink_t useless for the kernel.  That mistake had been fixed; please,
> > > do not bring it back.  If some userland structure needs to include a field
> > > encoding nlink_t values, please use an explicitly-sized type when refering
> > > to it kernel-side.
> >
> > We should never use userland types per se.  We can use __kernel_*_t
> > typedefs to make the kernel headers neater if it makes sense, but that
> > is often not even necessary.
>
> ... as long as we do not have typedef __kernel_foo_t foo_t in linux/types.h.

In the case of things like nlink_t and dev_t I would suggest we 
explicitly call out the types as kernel and user.  I would suggest 
knlink_t and unlink_t but the latter made me want to stab my eyes out 
due to its confusion potential, so I wonder if we should establish a new 
convention with _kt (kernel type) and _ut (user type) suffixes, so 
nlink_kt and nlink_ut, alternatively one could consider k_nlink_t and 
u_nlink_t.

	-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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