vm_unix.c revision 190949 
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 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
35 *
36 *	@(#)vm_unix.c	8.1 (Berkeley) 6/11/93
37 */
38
39/*
40 * Traditional sbrk/grow interface to VM
41 */
42
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD: head/sys/vm/vm_unix.c 190949 2009-04-11 22:34:08Z alc $");
45
46#include <sys/param.h>
47#include <sys/lock.h>
48#include <sys/mutex.h>
49#include <sys/proc.h>
50#include <sys/resourcevar.h>
51#include <sys/sysproto.h>
52#include <sys/systm.h>
53
54#include <vm/vm.h>
55#include <vm/vm_param.h>
56#include <vm/pmap.h>
57#include <vm/vm_map.h>
58
59#ifndef _SYS_SYSPROTO_H_
60struct obreak_args {
61	char *nsize;
62};
63#endif
64
65/*
66 * MPSAFE
67 */
68/* ARGSUSED */
69int
70obreak(td, uap)
71	struct thread *td;
72	struct obreak_args *uap;
73{
74	struct vmspace *vm = td->td_proc->p_vmspace;
75	vm_offset_t new, old, base;
76	rlim_t datalim, vmemlim;
77	int rv;
78	int error = 0;
79	boolean_t do_map_wirefuture;
80
81	PROC_LOCK(td->td_proc);
82	datalim = lim_cur(td->td_proc, RLIMIT_DATA);
83	vmemlim = lim_cur(td->td_proc, RLIMIT_VMEM);
84	PROC_UNLOCK(td->td_proc);
85
86	do_map_wirefuture = FALSE;
87	new = round_page((vm_offset_t)uap->nsize);
88	vm_map_lock(&vm->vm_map);
89
90	base = round_page((vm_offset_t) vm->vm_daddr);
91	old = base + ctob(vm->vm_dsize);
92	if (new > base) {
93		/*
94		 * Check the resource limit, but allow a process to reduce
95		 * its usage, even if it remains over the limit.
96		 */
97		if (new - base > datalim && new > old) {
98			error = ENOMEM;
99			goto done;
100		}
101		if (new > vm_map_max(&vm->vm_map)) {
102			error = ENOMEM;
103			goto done;
104		}
105	} else if (new < base) {
106		/*
107		 * This is simply an invalid value.  If someone wants to
108		 * do fancy address space manipulations, mmap and munmap
109		 * can do most of what the user would want.
110		 */
111		error = EINVAL;
112		goto done;
113	}
114	if (new > old) {
115		if (vm->vm_map.size + (new - old) > vmemlim) {
116			error = ENOMEM;
117			goto done;
118		}
119		rv = vm_map_insert(&vm->vm_map, NULL, 0, old, new,
120		    VM_PROT_RW, VM_PROT_ALL, 0);
121		if (rv != KERN_SUCCESS) {
122			error = ENOMEM;
123			goto done;
124		}
125		vm->vm_dsize += btoc(new - old);
126		/*
127		 * Handle the MAP_WIREFUTURE case for legacy applications,
128		 * by marking the newly mapped range of pages as wired.
129		 * We are not required to perform a corresponding
130		 * vm_map_unwire() before vm_map_delete() below, as
131		 * it will forcibly unwire the pages in the range.
132		 *
133		 * XXX If the pages cannot be wired, no error is returned.
134		 */
135		if ((vm->vm_map.flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
136			if (bootverbose)
137				printf("obreak: MAP_WIREFUTURE set\n");
138			do_map_wirefuture = TRUE;
139		}
140	} else if (new < old) {
141		rv = vm_map_delete(&vm->vm_map, new, old);
142		if (rv != KERN_SUCCESS) {
143			error = ENOMEM;
144			goto done;
145		}
146		vm->vm_dsize -= btoc(old - new);
147	}
148done:
149	vm_map_unlock(&vm->vm_map);
150
151	if (do_map_wirefuture)
152		(void) vm_map_wire(&vm->vm_map, old, new,
153		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
154
155	return (error);
156}
157
158#ifndef _SYS_SYSPROTO_H_
159struct ovadvise_args {
160	int anom;
161};
162#endif
163
164/*
165 * MPSAFE
166 */
167/* ARGSUSED */
168int
169ovadvise(td, uap)
170	struct thread *td;
171	struct ovadvise_args *uap;
172{
173	/* START_GIANT_OPTIONAL */
174	/* END_GIANT_OPTIONAL */
175	return (EINVAL);
176}
177