vm_unix.c revision 83366 
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 83366 2001-09-12 08:38:13Z julian $
42 */
43
44/*
45 * Traditional sbrk/grow interface to VM
46 */
47#include "opt_bleed.h"
48
49#include <sys/param.h>
50#include <sys/lock.h>
51#include <sys/mutex.h>
52#include <sys/proc.h>
53#include <sys/resourcevar.h>
54#include <sys/sysproto.h>
55#include <sys/systm.h>
56
57#include <vm/vm.h>
58#include <vm/vm_param.h>
59#include <vm/pmap.h>
60#include <vm/vm_map.h>
61
62#ifndef _SYS_SYSPROTO_H_
63struct obreak_args {
64	char *nsize;
65};
66#endif
67
68/*
69 * MPSAFE
70 */
71/* ARGSUSED */
72int
73obreak(td, uap)
74	struct thread *td;
75	struct obreak_args *uap;
76{
77	struct vmspace *vm = td->td_proc->p_vmspace;
78	vm_offset_t new, old, base;
79	int rv;
80	int error = 0;
81
82	mtx_lock(&Giant);	/* syscall marked mp-safe but isn't */
83
84	base = round_page((vm_offset_t) vm->vm_daddr);
85	new = round_page((vm_offset_t)uap->nsize);
86	old = base + ctob(vm->vm_dsize);
87	if (new > base) {
88		/*
89		 * We check resource limits here, but alow processes to
90		 * reduce their usage, even if they remain over the limit.
91		 */
92		if (new > old &&
93		    (new - base) > (unsigned) td->td_proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
94			error = ENOMEM;
95			goto done;
96		}
97		if (new >= VM_MAXUSER_ADDRESS) {
98			error = ENOMEM;
99			goto done;
100		}
101	} else if (new < base) {
102		/*
103		 * This is simply an invalid value.  If someone wants to
104		 * do fancy address space manipulations, mmap and munmap
105		 * can do most of what the user would want.
106		 */
107		error = EINVAL;
108		goto done;
109	}
110
111	if (new > old) {
112		vm_size_t diff;
113
114		diff = new - old;
115		rv = vm_map_find(&vm->vm_map, NULL, 0, &old, diff, FALSE,
116			VM_PROT_ALL, VM_PROT_ALL, 0);
117		if (rv != KERN_SUCCESS) {
118			error = ENOMEM;
119			goto done;
120		}
121		vm->vm_dsize += btoc(diff);
122	} else if (new < old) {
123		rv = vm_map_remove(&vm->vm_map, new, old);
124		if (rv != KERN_SUCCESS) {
125			error = ENOMEM;
126			goto done;
127		}
128		vm->vm_dsize -= btoc(old - new);
129	}
130done:
131	mtx_unlock(&Giant);
132	return (error);
133}
134
135#ifndef _SYS_SYSPROTO_H_
136struct ovadvise_args {
137	int anom;
138};
139#endif
140
141/*
142 * MPSAFE
143 */
144/* ARGSUSED */
145int
146ovadvise(td, uap)
147	struct thread *td;
148	struct ovadvise_args *uap;
149{
150	/* START_GIANT_OPTIONAL */
151	/* END_GIANT_OPTIONAL */
152	return (EINVAL);
153}
154