DragonFly On-Line Manual Pages

KERNACC(9)            DragonFly Kernel Developer's Manual           KERNACC(9)

NAME
     kernacc, useracc -- check memory regions for accessibility

SYNOPSIS
     #include <sys/types.h>
     #include <vm/vm.h>
     #include <vm/vm_extern.h>

     int
     kernacc(c_caddr_t addr, int len, int rw);

     int
     useracc(c_caddr_t addr, int len, int rw);

DESCRIPTION
     The kernacc() and useracc() functions check whether operations of the
     type specified in rw are permitted in the range of virtual addresses
     given by addr and len.  The possible values of rw are any bitwise combi-
     nation of VM_PROT_READ, VM_PROT_WRITE and VM_PROT_EXECUTE.  kernacc()
     checks addresses in the kernel address space, while useracc() considers
     addr to represent an user space address.  The process context to use for
     this operation is taken from the global variable curproc.

RETURN VALUES
     Both functions return boolean true if the type of access specified by rw
     is permitted.  Otherwise boolean false is returned.

BUGS
     The process pointer should be passed in as an argument to useracc().

DragonFly 3.5                    June 16, 1996                   DragonFly 3.5