On Tue, Dec 06, 2022 at 02:10:52AM +0100, Samuel Thibault wrote:
Hello Flavio,
What do you think of that?
I think we could just define vm_size_t as typedef of __mach_uintptr_t
then it will be unsigned int on 32 bits and unsigned long on 64 bits.
Regarding mach_msg_type_number_t, do you know if there is a need to copy
more than 4GB using RPCs? I guess it could be useful, but servers can just
paginate the data. For now, we could just change some of the signatures to
use mach_msg_type_number_t instead of vm_size_t to make the interface
explicit about the limits. If we think there is a need to go beyond 4GB
we can make mach_msg_type_number_t an unsigned long on pure 64 bits.
Samuel
Samuel Thibault, le lun. 29 août 2022 01:21:23 +0200, a ecrit:
Hello,
Luca Dariz, le dim. 03 avril 2022 16:59:55 +0200, a ecrit:
> @@ -88,13 +94,36 @@ typedef unsigned long long rpc_phys_addr_t;
> * expressing the difference between two
> * vm_offset_t entities.
> */
> -#ifdef __x86_64__
> typedef unsigned long vm_size_t;
> -#else
> -typedef natural_t vm_size_t;
> -#endif
> typedef vm_size_t * vm_size_array_t;
Mmm, this has triggered a lot of warnings & errors about mismatches
between vm_size_t and mach_msg_type_number_t in userland hurd&glibc.
While a lot of them are real mistakes (passing mach_msg_type_number_t*
for a vm_size_t* parameter), others are questioning, for instance:
routine io_read (
io_object: io_t;
RPT
out data: data_t, dealloc;
offset: loff_t;
amount: vm_size_t);
amount is a vm_size_t, thus unsigned long, but the data_t array will
have a mach_msg_type_number_t size. On a 64bit userland, vm_size_t being
64bit would be useless if mach_msg_type_number_t is 32bit. Perhaps we
want to make mach_msg_type_number_t long? Or use another type for
the size of data_t?
That's tricky questions ahead. Perhaps we can for now use
#if defined(KERNEL) || defined(__x86_64__)
typedef unsigned long vm_size_t;
#else
typedef natural_t vm_size_t;
#endif
to avoid exposing the new type to userland for now, so as to have the
time to fix such questions before exposing the switch?
Samuel
