vm_att Kernel Service

AIX Version 4.3 Kernel and Subsystems Technical Reference, Volume 1

Maps a specified virtual memory object to a region in the current address space.

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/vmuser.h>

caddr_t vm_att (vmhandle, offset)
vmhandle_t  vmhandle;
caddr_t offset;

vmhandle	Specifies the handle for the virtual memory object to be mapped.
offset	Specifies the offset in the virtual memory object and region.

The vm_att kernel service performs the following tasks:

Selects an unallocated region in the current address space and allocates it.
Maps the virtual memory object specified by the vmhandle parameter with the access permission specified in the handle.
Constructs the address in the current address space corresponding to the offset in the virtual memory object and region.

The vm_att kernel service assumes an address space model of fixed-size virtual memory objects and address space regions.

Attention: If there are no more free regions, this call cannot complete and calls the panic kernel service.

The vm_att kernel service can be called from either the process or interrupt environment.

The vm_att kernel service returns the address that corresponds to the offset parameter in the address space.

The vm_att kernel service is part of Base Operating System (BOS) Runtime.

The as_geth kernel service, as_getsrval kernel service, as_puth kernel service, vm_det kernel service.

Memory Kernel Services and Understanding Virtual Memory Manager Interfaces in AIX Kernel Extensions and Device Support Programming Concepts.