xref: /freebsd/sys/vm/vm_unix.c (revision e858faa9bb929e040dfa2ee6f9e4806cec4d685d)
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 	rlim_t datalim, vmemlim;
81 	int rv;
82 	int error = 0;
83 	boolean_t do_map_wirefuture;
84 
85 	PROC_LOCK(td->td_proc);
86 	datalim = lim_cur(td->td_proc, RLIMIT_DATA);
87 	vmemlim = lim_cur(td->td_proc, RLIMIT_VMEM);
88 	PROC_UNLOCK(td->td_proc);
89 
90 	do_map_wirefuture = FALSE;
91 	new = round_page((vm_offset_t)uap->nsize);
92 	vm_map_lock(&vm->vm_map);
93 
94 	base = round_page((vm_offset_t) vm->vm_daddr);
95 	old = base + ctob(vm->vm_dsize);
96 	if (new > base) {
97 		/*
98 		 * Check the resource limit, but allow a process to reduce
99 		 * its usage, even if it remains over the limit.
100 		 */
101 		if (new - base > datalim && new > old) {
102 			error = ENOMEM;
103 			goto done;
104 		}
105 		if (new > vm_map_max(&vm->vm_map)) {
106 			error = ENOMEM;
107 			goto done;
108 		}
109 	} else if (new < base) {
110 		/*
111 		 * This is simply an invalid value.  If someone wants to
112 		 * do fancy address space manipulations, mmap and munmap
113 		 * can do most of what the user would want.
114 		 */
115 		error = EINVAL;
116 		goto done;
117 	}
118 	if (new > old) {
119 		if (vm->vm_map.size + (new - old) > vmemlim) {
120 			error = ENOMEM;
121 			goto done;
122 		}
123 		rv = vm_map_insert(&vm->vm_map, NULL, 0, old, new,
124 		    VM_PROT_ALL, VM_PROT_ALL, 0);
125 		if (rv != KERN_SUCCESS) {
126 			error = ENOMEM;
127 			goto done;
128 		}
129 		vm->vm_dsize += btoc(new - old);
130 		/*
131 		 * Handle the MAP_WIREFUTURE case for legacy applications,
132 		 * by marking the newly mapped range of pages as wired.
133 		 * We are not required to perform a corresponding
134 		 * vm_map_unwire() before vm_map_delete() below, as
135 		 * it will forcibly unwire the pages in the range.
136 		 *
137 		 * XXX If the pages cannot be wired, no error is returned.
138 		 */
139 		if ((vm->vm_map.flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
140 			if (bootverbose)
141 				printf("obreak: MAP_WIREFUTURE set\n");
142 			do_map_wirefuture = TRUE;
143 		}
144 	} else if (new < old) {
145 		rv = vm_map_delete(&vm->vm_map, new, old);
146 		if (rv != KERN_SUCCESS) {
147 			error = ENOMEM;
148 			goto done;
149 		}
150 		vm->vm_dsize -= btoc(old - new);
151 	}
152 done:
153 	vm_map_unlock(&vm->vm_map);
154 
155 	if (do_map_wirefuture)
156 		(void) vm_map_wire(&vm->vm_map, old, new,
157 		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
158 
159 	return (error);
160 }
161 
162 #ifndef _SYS_SYSPROTO_H_
163 struct ovadvise_args {
164 	int anom;
165 };
166 #endif
167 
168 /*
169  * MPSAFE
170  */
171 /* ARGSUSED */
172 int
173 ovadvise(td, uap)
174 	struct thread *td;
175 	struct ovadvise_args *uap;
176 {
177 	/* START_GIANT_OPTIONAL */
178 	/* END_GIANT_OPTIONAL */
179 	return (EINVAL);
180 }
181