Re: [PATCH] Beginnings of conpat 32 code cleanups

[torvalds@transmeta.com (Linus Torvalds)]

In article <20021123051628.GA3658@krispykreme>,
Anton Blanchard  <anton@samba.org> wrote:
>
>_t32 == 32 bit version, its not the size. eg

Oh, I realize that. What I do not see is the point of the typedefs AT
ALL. They must go. They are crap. They have no reason for their
existence.

>asm-ia64/ia32.h:		typedef unsigned short	__kernel_ipc_pid_t32;
>asm-mips64/posix_types.h:	typedef int		__kernel_ipc_pid_t32;
>asm-parisc/posix_types.h:	typedef unsigned short	__kernel_ipc_pid_t32;
>asm-ppc64/ppc32.h:		typedef unsigned short	__kernel_ipc_pid_t32;
>asm-sparc64/posix_types.h:	typedef unsigned short	__kernel_ipc_pid_t32;
>asm-x86_64/ia32.h:		typedef unsigned short	__kernel_ipc_pid_t32;
>
>Or do you mean we should use typedef u16 __kernel_ipc_pid_t32? Yeah,
>I can understand that.

That helps, by removing half of the reason why they are crap - the using
of types that are not architecture-safe in a generic ABI file. But the
other half of the reason is still there:

It doesn't remove the rest of the reason: that "__kernel_" prefix is
meaningless (since the type shouldn't be visible in a non-kernel
namespace ANYWAY, and that is the only reason for the prefix in the
first place). 

Basically, you have two cases:

 - you have types that are _truly_ generic 32-bit compatibility stuff,
   and are the same on all architectures that use this compatibility
   layer. 

   But if they are truly generic, they shouldn't need a new typedef AT
   ALL.  You should just realize that "loff_t" is always a "s64", and
   then just use s64 in the compatibility functions/structures. No need
   to make up some new typedef.

 - You have types (like the above) where the compatibility layer
   actually has _different_ types for different architectures. In which
   case they should be in an architecture-specific file, not in some
   generic file. And the name should not be "__kernel_xxxx_t32", but
   "compat32_xxxx_t" or something.

In _neither_ case is it valid to have a generic architecture-independent
file that makes up new types.  See? And THAT is why I thin kthe patch is
crud. 

		Linus