vm_unix.c revision 188334 
169626Sru/*-
218099Spst * Copyright (c) 1988 University of Utah.
318099Spst * Copyright (c) 1991, 1993
418099Spst *	The Regents of the University of California.  All rights reserved.
518099Spst *
618099Spst * This code is derived from software contributed to Berkeley by
718099Spst * the Systems Programming Group of the University of Utah Computer
818099Spst * Science Department.
918099Spst *
1018099Spst * Redistribution and use in source and binary forms, with or without
1118099Spst * modification, are permitted provided that the following conditions
1218099Spst * are met:
1318099Spst * 1. Redistributions of source code must retain the above copyright
1418099Spst *    notice, this list of conditions and the following disclaimer.
1518099Spst * 2. Redistributions in binary form must reproduce the above copyright
1618099Spst *    notice, this list of conditions and the following disclaimer in the
1718099Spst *    documentation and/or other materials provided with the distribution.
18151497Sru * 4. Neither the name of the University nor the names of its contributors
1918099Spst *    may be used to endorse or promote products derived from this software
2018099Spst *    without specific prior written permission.
2118099Spst *
2218099Spst * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
2318099Spst * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2418099Spst * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2518099Spst * 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 188334 2009-02-08 20:39:17Z kib $");
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_map_entry_t freelist;
76	vm_offset_t new, old, base;
77	rlim_t datalim, vmemlim;
78	int rv;
79	int error = 0;
80	boolean_t do_map_wirefuture;
81
82	PROC_LOCK(td->td_proc);
83	datalim = lim_cur(td->td_proc, RLIMIT_DATA);
84	vmemlim = lim_cur(td->td_proc, RLIMIT_VMEM);
85	PROC_UNLOCK(td->td_proc);
86
87	do_map_wirefuture = FALSE;
88	new = round_page((vm_offset_t)uap->nsize);
89	freelist = NULL;
90	vm_map_lock(&vm->vm_map);
91
92	base = round_page((vm_offset_t) vm->vm_daddr);
93	old = base + ctob(vm->vm_dsize);
94	if (new > base) {
95		/*
96		 * Check the resource limit, but allow a process to reduce
97		 * its usage, even if it remains over the limit.
98		 */
99		if (new - base > datalim && new > old) {
100			error = ENOMEM;
101			goto done;
102		}
103		if (new > vm_map_max(&vm->vm_map)) {
104			error = ENOMEM;
105			goto done;
106		}
107	} else if (new < base) {
108		/*
109		 * This is simply an invalid value.  If someone wants to
110		 * do fancy address space manipulations, mmap and munmap
111		 * can do most of what the user would want.
112		 */
113		error = EINVAL;
114		goto done;
115	}
116	if (new > old) {
117		if (vm->vm_map.size + (new - old) > vmemlim) {
118			error = ENOMEM;
119			goto done;
120		}
121		rv = vm_map_insert(&vm->vm_map, NULL, 0, old, new,
122		    VM_PROT_ALL, VM_PROT_ALL, 0);
123		if (rv != KERN_SUCCESS) {
124			error = ENOMEM;
125			goto done;
126		}
127		vm->vm_dsize += btoc(new - old);
128		/*
129		 * Handle the MAP_WIREFUTURE case for legacy applications,
130		 * by marking the newly mapped range of pages as wired.
131		 * We are not required to perform a corresponding
132		 * vm_map_unwire() before vm_map_delete() below, as
133		 * it will forcibly unwire the pages in the range.
134		 *
135		 * XXX If the pages cannot be wired, no error is returned.
136		 */
137		if ((vm->vm_map.flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
138			if (bootverbose)
139				printf("obreak: MAP_WIREFUTURE set\n");
140			do_map_wirefuture = TRUE;
141		}
142	} else if (new < old) {
143		rv = vm_map_delete(&vm->vm_map, new, old, &freelist);
144		if (rv != KERN_SUCCESS) {
145			error = ENOMEM;
146			goto done;
147		}
148		vm->vm_dsize -= btoc(old - new);
149	}
150done:
151	vm_map_unlock(&vm->vm_map);
152	vm_map_entry_free_freelist(&vm->vm_map, freelist);
153
154	if (do_map_wirefuture)
155		(void) vm_map_wire(&vm->vm_map, old, new,
156		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
157
158	return (error);
159}
160
161#ifndef _SYS_SYSPROTO_H_
162struct ovadvise_args {
163	int anom;
164};
165#endif
166
167/*
168 * MPSAFE
169 */
170/* ARGSUSED */
171int
172ovadvise(td, uap)
173	struct thread *td;
174	struct ovadvise_args *uap;
175{
176	/* START_GIANT_OPTIONAL */
177	/* END_GIANT_OPTIONAL */
178	return (EINVAL);
179}
180