xref: /freebsd/sys/vm/vm_unix.c (revision 1b6c76a2fe091c74f08427e6c870851025a9cf67)
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  * $FreeBSD$
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_
63 struct obreak_args {
64 	char *nsize;
65 };
66 #endif
67 
68 /* ARGSUSED */
69 int
70 obreak(p, uap)
71 	struct proc *p;
72 	struct obreak_args *uap;
73 {
74 	register struct vmspace *vm = p->p_vmspace;
75 	vm_offset_t new, old, base;
76 	int rv;
77 
78 	base = round_page((vm_offset_t) vm->vm_daddr);
79 	new = round_page((vm_offset_t)uap->nsize);
80 	old = base + ctob(vm->vm_dsize);
81 	if (new > base) {
82 		/*
83 		 * We check resource limits here, but alow processes to
84 		 * reduce their usage, even if they remain over the limit.
85 		 */
86 		if (new > old &&
87 		    (new - base) > (unsigned) p->p_rlimit[RLIMIT_DATA].rlim_cur)
88 			return ENOMEM;
89 		if (new >= VM_MAXUSER_ADDRESS)
90 			return (ENOMEM);
91 	} else if (new < base) {
92 		/*
93 		 * This is simply an invalid value.  If someone wants to
94 		 * do fancy address space manipulations, mmap and munmap
95 		 * can do most of what the user would want.
96 		 */
97 		return EINVAL;
98 	}
99 
100 	if (new > old) {
101 		vm_size_t diff;
102 
103 		diff = new - old;
104 #ifndef BLEED
105 		mtx_lock(&Giant);
106 #endif
107 		mtx_lock(&vm_mtx);
108 		rv = vm_map_find(&vm->vm_map, NULL, 0, &old, diff, FALSE,
109 			VM_PROT_ALL, VM_PROT_ALL, 0);
110 		if (rv != KERN_SUCCESS) {
111 			mtx_unlock(&vm_mtx);
112 			return (ENOMEM);
113 		}
114 		vm->vm_dsize += btoc(diff);
115 		mtx_unlock(&vm_mtx);
116 #ifndef BLEED
117 		mtx_unlock(&Giant);
118 #endif
119 	} else if (new < old) {
120 		mtx_lock(&Giant);
121 		mtx_lock(&vm_mtx);
122 		rv = vm_map_remove(&vm->vm_map, new, old);
123 		if (rv != KERN_SUCCESS) {
124 			mtx_unlock(&vm_mtx);
125 			mtx_unlock(&Giant);
126 			return (ENOMEM);
127 		}
128 		vm->vm_dsize -= btoc(old - new);
129 		mtx_unlock(&vm_mtx);
130 		mtx_unlock(&Giant);
131 	}
132 	return (0);
133 }
134 
135 #ifndef _SYS_SYSPROTO_H_
136 struct ovadvise_args {
137 	int anom;
138 };
139 #endif
140 
141 /* ARGSUSED */
142 int
143 ovadvise(p, uap)
144 	struct proc *p;
145 	struct ovadvise_args *uap;
146 {
147 
148 	return (EINVAL);
149 }
150