vm_unix.c revision 1541 
1/*
2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1991, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
39 *
40 *	@(#)vm_unix.c	8.1 (Berkeley) 6/11/93
41 */
42
43/*
44 * Traditional sbrk/grow interface to VM
45 */
46#include <sys/param.h>
47#include <sys/systm.h>
48#include <sys/proc.h>
49#include <sys/resourcevar.h>
50
51#include <vm/vm.h>
52
53struct obreak_args {
54	char	*nsiz;
55};
56/* ARGSUSED */
57int
58obreak(p, uap, retval)
59	struct proc *p;
60	struct obreak_args *uap;
61	int *retval;
62{
63	register struct vmspace *vm = p->p_vmspace;
64	vm_offset_t new, old;
65	int rv;
66	register int diff;
67
68	old = (vm_offset_t)vm->vm_daddr;
69	new = round_page(uap->nsiz);
70	if ((int)(new - old) > p->p_rlimit[RLIMIT_DATA].rlim_cur)
71		return(ENOMEM);
72	old = round_page(old + ctob(vm->vm_dsize));
73	diff = new - old;
74	if (diff > 0) {
75		rv = vm_allocate(&vm->vm_map, &old, diff, FALSE);
76		if (rv != KERN_SUCCESS) {
77			uprintf("sbrk: grow failed, return = %d\n", rv);
78			return(ENOMEM);
79		}
80		vm->vm_dsize += btoc(diff);
81	} else if (diff < 0) {
82		diff = -diff;
83		rv = vm_deallocate(&vm->vm_map, new, diff);
84		if (rv != KERN_SUCCESS) {
85			uprintf("sbrk: shrink failed, return = %d\n", rv);
86			return(ENOMEM);
87		}
88		vm->vm_dsize -= btoc(diff);
89	}
90	return(0);
91}
92
93/*
94 * Enlarge the "stack segment" to include the specified
95 * stack pointer for the process.
96 */
97int
98grow(p, sp)
99	struct proc *p;
100	unsigned sp;
101{
102	register struct vmspace *vm = p->p_vmspace;
103	register int si;
104
105	/*
106	 * For user defined stacks (from sendsig).
107	 */
108	if (sp < (unsigned)vm->vm_maxsaddr)
109		return (0);
110	/*
111	 * For common case of already allocated (from trap).
112	 */
113	if (sp >= USRSTACK - ctob(vm->vm_ssize))
114		return (1);
115	/*
116	 * Really need to check vs limit and increment stack size if ok.
117	 */
118	si = clrnd(btoc(USRSTACK-sp) - vm->vm_ssize);
119	if (vm->vm_ssize + si > btoc(p->p_rlimit[RLIMIT_STACK].rlim_cur))
120		return (0);
121	vm->vm_ssize += si;
122	return (1);
123}
124
125struct ovadvise_args {
126	int	anom;
127};
128/* ARGSUSED */
129int
130ovadvise(p, uap, retval)
131	struct proc *p;
132	struct ovadvise_args *uap;
133	int *retval;
134{
135
136	return (EINVAL);
137}
138