xref: /freebsd/sys/vm/vm_unix.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
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  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * 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("$FreeBSD$");
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_
60 struct obreak_args {
61 	char *nsize;
62 };
63 #endif
64 
65 /*
66  * MPSAFE
67  */
68 /* ARGSUSED */
69 int
70 obreak(td, uap)
71 	struct thread *td;
72 	struct obreak_args *uap;
73 {
74 	struct vmspace *vm = td->td_proc->p_vmspace;
75 	vm_offset_t new, old, base;
76 	rlim_t datalim, vmemlim;
77 	int rv;
78 	int error = 0;
79 	boolean_t do_map_wirefuture;
80 
81 	PROC_LOCK(td->td_proc);
82 	datalim = lim_cur(td->td_proc, RLIMIT_DATA);
83 	vmemlim = lim_cur(td->td_proc, RLIMIT_VMEM);
84 	PROC_UNLOCK(td->td_proc);
85 
86 	do_map_wirefuture = FALSE;
87 	new = round_page((vm_offset_t)uap->nsize);
88 	vm_map_lock(&vm->vm_map);
89 
90 	base = round_page((vm_offset_t) vm->vm_daddr);
91 	old = base + ctob(vm->vm_dsize);
92 	if (new > base) {
93 		/*
94 		 * Check the resource limit, but allow a process to reduce
95 		 * its usage, even if it remains over the limit.
96 		 */
97 		if (new - base > datalim && new > old) {
98 			error = ENOMEM;
99 			goto done;
100 		}
101 		if (new > vm_map_max(&vm->vm_map)) {
102 			error = ENOMEM;
103 			goto done;
104 		}
105 	} else if (new < base) {
106 		/*
107 		 * This is simply an invalid value.  If someone wants to
108 		 * do fancy address space manipulations, mmap and munmap
109 		 * can do most of what the user would want.
110 		 */
111 		error = EINVAL;
112 		goto done;
113 	}
114 	if (new > old) {
115 		if (vm->vm_map.size + (new - old) > vmemlim) {
116 			error = ENOMEM;
117 			goto done;
118 		}
119 		rv = vm_map_insert(&vm->vm_map, NULL, 0, old, new,
120 		    VM_PROT_RW, VM_PROT_ALL, 0);
121 		if (rv != KERN_SUCCESS) {
122 			error = ENOMEM;
123 			goto done;
124 		}
125 		vm->vm_dsize += btoc(new - old);
126 		/*
127 		 * Handle the MAP_WIREFUTURE case for legacy applications,
128 		 * by marking the newly mapped range of pages as wired.
129 		 * We are not required to perform a corresponding
130 		 * vm_map_unwire() before vm_map_delete() below, as
131 		 * it will forcibly unwire the pages in the range.
132 		 *
133 		 * XXX If the pages cannot be wired, no error is returned.
134 		 */
135 		if ((vm->vm_map.flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
136 			if (bootverbose)
137 				printf("obreak: MAP_WIREFUTURE set\n");
138 			do_map_wirefuture = TRUE;
139 		}
140 	} else if (new < old) {
141 		rv = vm_map_delete(&vm->vm_map, new, old);
142 		if (rv != KERN_SUCCESS) {
143 			error = ENOMEM;
144 			goto done;
145 		}
146 		vm->vm_dsize -= btoc(old - new);
147 	}
148 done:
149 	vm_map_unlock(&vm->vm_map);
150 
151 	if (do_map_wirefuture)
152 		(void) vm_map_wire(&vm->vm_map, old, new,
153 		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
154 
155 	return (error);
156 }
157 
158 #ifndef _SYS_SYSPROTO_H_
159 struct ovadvise_args {
160 	int anom;
161 };
162 #endif
163 
164 /*
165  * MPSAFE
166  */
167 /* ARGSUSED */
168 int
169 ovadvise(td, uap)
170 	struct thread *td;
171 	struct ovadvise_args *uap;
172 {
173 	/* START_GIANT_OPTIONAL */
174 	/* END_GIANT_OPTIONAL */
175 	return (EINVAL);
176 }
177