Subject: Re: [PATCH 2/3] Create compat_sys_migrate_pages

From: Benjamin Herrenschmidt <[email-masked]>
Date: Mon, 30 Oct 2006 16:29:09 +1100

On Fri, 2006-10-27 at 06:24 -0700, Christoph Lameter wrote:
> On Fri, 27 Oct 2006, Stephen Rothwell wrote:
> 
> > No they aren't because they have compat routines that convert the bitmaps
> > before calling the "normal" syscall.  They, importantly, only use
> > compat_alloc_user_space once each.
> 
> Ah...
> 
> > > Fixing get_nodes() to do the proper thing would fix all of these
> > > without having to touch sys_migrate_pages or creating a compat_ function
> > > (which usually is placed in kernel/compat.c)
> > 
> > You need the compat_ version of the syscalls to know if you were called
> > from a 32bit application in order to know if you may need to fixup the
> > bitmaps that are passed from/to user mode.
> 
> The compat functions should be placed in kernel/compat.c next to 
> compat_sys_move_pages.

I disagree.. it's really annoying when they are away from their
respective "non-compat" function, especially when they are more than
just wrappers copying/converting arguments...

Now, if only we had done a sane ABI in the first place...
 
Ben.