xref: /freebsd/sys/vm/vm_unix.c (revision b52f49a9a0f22207ad5130ad8faba08de3ed23d8)
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  */
42 
43 /*
44  * Traditional sbrk/grow interface to VM
45  */
46 
47 #include <sys/cdefs.h>
48 __FBSDID("$FreeBSD$");
49 
50 #include <sys/param.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/proc.h>
54 #include <sys/resourcevar.h>
55 #include <sys/sysproto.h>
56 #include <sys/systm.h>
57 
58 #include <vm/vm.h>
59 #include <vm/vm_param.h>
60 #include <vm/pmap.h>
61 #include <vm/vm_map.h>
62 
63 #ifndef _SYS_SYSPROTO_H_
64 struct obreak_args {
65 	char *nsize;
66 };
67 #endif
68 
69 /*
70  * MPSAFE
71  */
72 /* ARGSUSED */
73 int
74 obreak(td, uap)
75 	struct thread *td;
76 	struct obreak_args *uap;
77 {
78 	struct vmspace *vm = td->td_proc->p_vmspace;
79 	vm_offset_t new, old, base;
80 	int rv;
81 	int error = 0;
82 
83 	new = round_page((vm_offset_t)uap->nsize);
84 	vm_map_lock(&vm->vm_map);
85 
86 	base = round_page((vm_offset_t) vm->vm_daddr);
87 	old = base + ctob(vm->vm_dsize);
88 	if (new > base) {
89 		/*
90 		 * Check the resource limit, but allow a process to reduce
91 		 * its usage, even if it remains over the limit.
92 		 */
93 		if (new - base > td->td_proc->p_rlimit[RLIMIT_DATA].rlim_cur &&
94 		    new > old) {
95 			error = ENOMEM;
96 			goto done;
97 		}
98 		if (new > vm_map_max(&vm->vm_map)) {
99 			error = ENOMEM;
100 			goto done;
101 		}
102 	} else if (new < base) {
103 		/*
104 		 * This is simply an invalid value.  If someone wants to
105 		 * do fancy address space manipulations, mmap and munmap
106 		 * can do most of what the user would want.
107 		 */
108 		error = EINVAL;
109 		goto done;
110 	}
111 	if (new > old) {
112 		if (vm->vm_map.size + (new - old) >
113 		    td->td_proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
114 			error = ENOMEM;
115 			goto done;
116 		}
117 		rv = vm_map_insert(&vm->vm_map, NULL, 0, old, new,
118 		    VM_PROT_ALL, VM_PROT_ALL, 0);
119 		if (rv != KERN_SUCCESS) {
120 			error = ENOMEM;
121 			goto done;
122 		}
123 		vm->vm_dsize += btoc(new - old);
124 	} else if (new < old) {
125 		rv = vm_map_delete(&vm->vm_map, new, old);
126 		if (rv != KERN_SUCCESS) {
127 			error = ENOMEM;
128 			goto done;
129 		}
130 		vm->vm_dsize -= btoc(old - new);
131 	}
132 done:
133 	vm_map_unlock(&vm->vm_map);
134 	return (error);
135 }
136 
137 #ifndef _SYS_SYSPROTO_H_
138 struct ovadvise_args {
139 	int anom;
140 };
141 #endif
142 
143 /*
144  * MPSAFE
145  */
146 /* ARGSUSED */
147 int
148 ovadvise(td, uap)
149 	struct thread *td;
150 	struct ovadvise_args *uap;
151 {
152 	/* START_GIANT_OPTIONAL */
153 	/* END_GIANT_OPTIONAL */
154 	return (EINVAL);
155 }
156