386BSD 0.0 development

[unix-history] / usr / src / sys.386bsd / vm / vm_unix.c

/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1991 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.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
*
*      @(#)vm_unix.c   7.2 (Berkeley) 4/20/91
*/

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

#include "vm.h"

/* ARGSUSED */
obreak(p, uap, retval)
       struct proc *p;
       struct args {
               char    *nsiz;
       } *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.
*/
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);
}

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

       return (EINVAL);
}