vm_unix.c revision 90702 
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 * $FreeBSD: head/sys/vm/vm_unix.c 90702 2002-02-15 13:16:11Z bde $
42 */
43
44/*
45 * Traditional sbrk/grow interface to VM
46 */
47
48#include <sys/param.h>
49#include <sys/lock.h>
50#include <sys/mutex.h>
51#include <sys/proc.h>
52#include <sys/resourcevar.h>
53#include <sys/sysproto.h>
54#include <sys/systm.h>
55
56#include <vm/vm.h>
57#include <vm/vm_param.h>
58#include <vm/pmap.h>
59#include <vm/vm_map.h>
60
61#ifndef _SYS_SYSPROTO_H_
62struct obreak_args {
63	char *nsize;
64};
65#endif
66
67/*
68 * MPSAFE
69 */
70/* ARGSUSED */
71int
72obreak(td, uap)
73	struct thread *td;
74	struct obreak_args *uap;
75{
76	struct vmspace *vm = td->td_proc->p_vmspace;
77	vm_offset_t new, old, base;
78	int rv;
79	int error = 0;
80
81	mtx_lock(&Giant);	/* syscall marked mp-safe but isn't */
82
83	base = round_page((vm_offset_t) vm->vm_daddr);
84	new = round_page((vm_offset_t)uap->nsize);
85	old = base + ctob(vm->vm_dsize);
86	if (new > base) {
87		/*
88		 * We check resource limits here, but alow processes to
89		 * reduce their usage, even if they remain over the limit.
90		 */
91		if (new > old &&
92		    (new - base) > (unsigned) td->td_proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
93			error = ENOMEM;
94			goto done;
95		}
96		if (new >= VM_MAXUSER_ADDRESS) {
97			error = ENOMEM;
98			goto done;
99		}
100	} else if (new < base) {
101		/*
102		 * This is simply an invalid value.  If someone wants to
103		 * do fancy address space manipulations, mmap and munmap
104		 * can do most of what the user would want.
105		 */
106		error = EINVAL;
107		goto done;
108	}
109
110	if (new > old) {
111		vm_size_t diff;
112
113		diff = new - old;
114		rv = vm_map_find(&vm->vm_map, NULL, 0, &old, diff, FALSE,
115			VM_PROT_ALL, VM_PROT_ALL, 0);
116		if (rv != KERN_SUCCESS) {
117			error = ENOMEM;
118			goto done;
119		}
120		vm->vm_dsize += btoc(diff);
121	} else if (new < old) {
122		rv = vm_map_remove(&vm->vm_map, new, old);
123		if (rv != KERN_SUCCESS) {
124			error = ENOMEM;
125			goto done;
126		}
127		vm->vm_dsize -= btoc(old - new);
128	}
129done:
130	mtx_unlock(&Giant);
131	return (error);
132}
133
134#ifndef _SYS_SYSPROTO_H_
135struct ovadvise_args {
136	int anom;
137};
138#endif
139
140/*
141 * MPSAFE
142 */
143/* ARGSUSED */
144int
145ovadvise(td, uap)
146	struct thread *td;
147	struct ovadvise_args *uap;
148{
149	/* START_GIANT_OPTIONAL */
150	/* END_GIANT_OPTIONAL */
151	return (EINVAL);
152}
153