Re: 64bit GNU Mach

[Samuel Thibault]

Richard Braun, le Mon 02 Apr 2012 14:58:55 +0200, a écrit :
> On Mon, Apr 02, 2012 at 02:54:17PM +0200, Samuel Thibault wrote:
> > > I believe we're thinking of two different things here. My current idea
> > > of the solution is to directly convert names (32-bits) to ports or other
> > > IPC objects (e.g. port sets, 64-bits).
> > 
> > That's what I'm suggesting from the beginning. That needs two differents
> > types (64bit mach_port_t and 32bit mach_port_name_t), where there is
> > currently just one (vm_offset_t mach_port_t).
> 
> Then I don't see why you want two different types. There would be one
> 32-bits mach_port_t, and no mach_port_name_t.

Because there is code in GNU Mach that uses mach_port_t as a pointer,
see e.g. kdportdeath(), which just casts mach_port_t into ipc_port_t, or
ipc_kmsg_copyin_header which casts back the just-resolved object into
mach_port_t. Such code might have to simply use the ipc_port_t type
instead, I don't know. What I know for sure, however, is that xnu does
typedef ipc_port_t mach_port_t, which makes me tend to think that in the
kernel, mach_port_t is supposed to be a pointer, while mach_port_name_t
is for the port names.

Samuel