xref: /freebsd/sys/vm/vm_unix.c (revision eacee0ff7ec955b32e09515246bd97b6edcd2b0f)
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 
48 #include <sys/param.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/proc.h>
52 #include <sys/resourcevar.h>
53 #include <sys/sysproto.h>
54 #include <sys/systm.h>
55 
56 #include <vm/vm.h>
57 #include <vm/vm_param.h>
58 #include <vm/pmap.h>
59 #include <vm/vm_map.h>
60 
61 #ifndef _SYS_SYSPROTO_H_
62 struct obreak_args {
63 	char *nsize;
64 };
65 #endif
66 
67 /*
68  * MPSAFE
69  */
70 /* ARGSUSED */
71 int
72 obreak(td, uap)
73 	struct thread *td;
74 	struct obreak_args *uap;
75 {
76 	struct vmspace *vm = td->td_proc->p_vmspace;
77 	vm_offset_t new, old, base;
78 	int rv;
79 	int error = 0;
80 
81 	mtx_lock(&Giant);	/* syscall marked mp-safe but isn't */
82 
83 	base = round_page((vm_offset_t) vm->vm_daddr);
84 	new = round_page((vm_offset_t)uap->nsize);
85 	old = base + ctob(vm->vm_dsize);
86 	if (new > base) {
87 		/*
88 		 * We check resource limits here, but alow processes to
89 		 * reduce their usage, even if they remain over the limit.
90 		 */
91 		if (new > old &&
92 		    (new - base) > (unsigned) td->td_proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
93 			error = ENOMEM;
94 			goto done;
95 		}
96 		if (new >= VM_MAXUSER_ADDRESS) {
97 			error = ENOMEM;
98 			goto done;
99 		}
100 	} else if (new < base) {
101 		/*
102 		 * This is simply an invalid value.  If someone wants to
103 		 * do fancy address space manipulations, mmap and munmap
104 		 * can do most of what the user would want.
105 		 */
106 		error = EINVAL;
107 		goto done;
108 	}
109 
110 	if (new > old) {
111 		vm_size_t diff;
112 
113 		diff = new - old;
114 		rv = vm_map_find(&vm->vm_map, NULL, 0, &old, diff, FALSE,
115 			VM_PROT_ALL, VM_PROT_ALL, 0);
116 		if (rv != KERN_SUCCESS) {
117 			error = ENOMEM;
118 			goto done;
119 		}
120 		vm->vm_dsize += btoc(diff);
121 	} else if (new < old) {
122 		rv = vm_map_remove(&vm->vm_map, new, old);
123 		if (rv != KERN_SUCCESS) {
124 			error = ENOMEM;
125 			goto done;
126 		}
127 		vm->vm_dsize -= btoc(old - new);
128 	}
129 done:
130 	mtx_unlock(&Giant);
131 	return (error);
132 }
133 
134 #ifndef _SYS_SYSPROTO_H_
135 struct ovadvise_args {
136 	int anom;
137 };
138 #endif
139 
140 /*
141  * MPSAFE
142  */
143 /* ARGSUSED */
144 int
145 ovadvise(td, uap)
146 	struct thread *td;
147 	struct ovadvise_args *uap;
148 {
149 	/* START_GIANT_OPTIONAL */
150 	/* END_GIANT_OPTIONAL */
151 	return (EINVAL);
152 }
153