Call __remap to remap 64-bit addresses into 32-bit addresses.
#include <sys/types.h> #include <sys/errno.h> #include <sys/remap.h>
REMAP(nparms) int nparms;
REMAP_VOID(nparms) int nparms;
The REMAP macro calls the __remap subroutine to remap 64-bit addresses into 32-bit addresses suitable for passing to the kernel. This macro should be used in conjunction with the REMAP_DCL(), REMAP_SETUP(), REMAPPED(), and REMAP_HANDLEx macros. The macro is dependent on structures declared by REMAP_DCL and initialized by REMAP_SETUP.
Here is an example of the usage of REMAP:
int
naccept (int s,
struct sockaddr * name,
int * anamelan)
{
REMAP_DCL (2); <--2 addrs to remap
int rc;
REMAP_SETUP_WITH_LEN(0, name, *anamelan); <--1st addr, explicit len
REMAP_SETUP (1, anamelen); <--2nd addr, implied len
REMAP (3); <-------+------------------3 parameters to pass
V
rc = __naccept (REMAP_HANDLE3, s, REMAPPED(0), REMAPPED(1));
return rc; ^ ^
} | |
1st remapped addr 2nd remapped addr
In the example shown, there are 2 addresses to be remapped (name and anamelen). REMAP_DCL(2) is used to declare the structures necessary for the remapping of 2 addresses. The first address range to be remapped (name) is defined to be of length *anamelen. Therefore REMAP_SETUP_WITH_LEN is called to set up the first remapping (remapping #0) so the length can be specified. The length of the 2nd range (remapping #1) is implied by the type (int), so REMAP_SETUP is used.
REMAP is then called, and nparms is 3 since there are a total of 3 parameters for the naccept system call. Finally, the 32-bit system call is called passing the remap_handle structure followed by the parameters, including the remapped addresses. The REMAP_HANDLE3 macro is used to pass the remap_handle structure appropriate for a system call with 3 parameters. The REMAPPED macros are used to pass remapped address #0 (name) and remapped address #1 (anamelen).
This service may only be called from a 64-bit user process.
| nparms | the number of (32-bit) parameters to be passed on this system call. |
On error, the errno value has been set by __remap and the REMAP macro calls return to return -1 to the caller of the system call. If the system call is a void, the REMAP_VOID macro should be used (same syntax). In this case, if there is an error the REMAP_VOID macro simply calls return with no value.
| 0 | Successful completion. |
| -1 | Unable to complete the remapping due to insufficient resources. In this case ERRNO is set to EINVAL. |
The __remap subroutine is part of Base Operating System (BOS) Runtime. The REMAP macro is defined in sys/remap.h.
The REMAP_IDENTITY macro, REMAP_DCL macro, REMAP_SETUP macro, __remap subroutine, remap_64 kernel service, the as_remap64 kernel service, the as_unremap64 kernel service.
Memory Kernel Services and Understanding Virtual Memory Manager Interfaces in AIX Version 4 Kernel Extensions and Device Support Programming Concepts.