usr/src/sys/vm/vm_unix.c

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * %sccs.include.redist.c%
 *
 * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
 *
 *      @(#)vm_unix.c   8.1 (Berkeley) %G%
 */

/*
 * Traditional sbrk/grow interface to VM
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>

#include <vm/vm.h>

struct obreak_args {
        char    *nsiz;
};
/* ARGSUSED */
int
obreak(p, uap, retval)
        struct proc *p;
        struct obreak_args *uap;
        int *retval;
{
        register struct vmspace *vm = p->p_vmspace;
        vm_offset_t new, old;
        int rv;
        register int diff;

        old = (vm_offset_t)vm->vm_daddr;
        new = round_page(uap->nsiz);
        if ((int)(new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
                return(ENOMEM);
        old = round_page(old + ctob(vm->vm_dsize));
        diff = new - old;
        if (diff > 0) {
                rv = vm_allocate(&vm->vm_map, &old, diff, FALSE);
                if (rv != KERN_SUCCESS) {
                        uprintf("sbrk: grow failed, return = %d\n", rv);
                        return(ENOMEM);
                }
                vm->vm_dsize += btoc(diff);
        } else if (diff < 0) {
                diff = -diff;
                rv = vm_deallocate(&vm->vm_map, new, diff);
                if (rv != KERN_SUCCESS) {
                        uprintf("sbrk: shrink failed, return = %d\n", rv);
                        return(ENOMEM);
                }
                vm->vm_dsize -= btoc(diff);
        }
        return(0);
}

/*
 * Enlarge the "stack segment" to include the specified
 * stack pointer for the process.
 */
int
grow(p, sp)
        struct proc *p;
        unsigned sp;
{
        register struct vmspace *vm = p->p_vmspace;
        register int si;

        /*
         * For user defined stacks (from sendsig).
         */
        if (sp < (unsigned)vm->vm_maxsaddr)
                return (0);
        /*
         * For common case of already allocated (from trap).
         */
        if (sp >= USRSTACK - ctob(vm->vm_ssize))
                return (1);
        /*
         * Really need to check vs limit and increment stack size if ok.
         */
        si = clrnd(btoc(USRSTACK-sp) - vm->vm_ssize);
        if (vm->vm_ssize + si > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
                return (0);
        vm->vm_ssize += si;
        return (1);
}

struct ovadvise_args {
        int     anom;
};
/* ARGSUSED */
int
ovadvise(p, uap, retval)
        struct proc *p;
        struct ovadvise_args *uap;
        int *retval;
{

        return (EINVAL);
}