xref: /freebsd/sys/vm/vm_unix.c (revision 3eeb75112272ef9ef244a00bc73beef3a146856a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988 University of Utah.
5  * Copyright (c) 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * the Systems Programming Group of the University of Utah Computer
10  * Science Department.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
37  *
38  *	@(#)vm_unix.c	8.1 (Berkeley) 6/11/93
39  */
40 
41 /*
42  * Traditional sbrk/grow interface to VM
43  */
44 
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include <sys/param.h>
49 #include <sys/lock.h>
50 #include <sys/mutex.h>
51 #include <sys/proc.h>
52 #include <sys/racct.h>
53 #include <sys/resourcevar.h>
54 #include <sys/sysent.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 sys_obreak(struct thread *td, struct obreak_args *uap)
75 {
76 	struct vmspace *vm = td->td_proc->p_vmspace;
77 	vm_map_t map = &vm->vm_map;
78 	vm_offset_t new, old, base;
79 	rlim_t datalim, lmemlim, vmemlim;
80 	int prot, rv;
81 	int error = 0;
82 	boolean_t do_map_wirefuture;
83 
84 	datalim = lim_cur(td, RLIMIT_DATA);
85 	lmemlim = lim_cur(td, RLIMIT_MEMLOCK);
86 	vmemlim = lim_cur(td, RLIMIT_VMEM);
87 
88 	do_map_wirefuture = FALSE;
89 	new = round_page((vm_offset_t)uap->nsize);
90 	vm_map_lock(map);
91 
92 	base = round_page((vm_offset_t) vm->vm_daddr);
93 	old = base + ctob(vm->vm_dsize);
94 	if (new > base) {
95 		/*
96 		 * Check the resource limit, but allow a process to reduce
97 		 * its usage, even if it remains over the limit.
98 		 */
99 		if (new - base > datalim && new > old) {
100 			error = ENOMEM;
101 			goto done;
102 		}
103 		if (new > vm_map_max(map)) {
104 			error = ENOMEM;
105 			goto done;
106 		}
107 	} else if (new < base) {
108 		/*
109 		 * This is simply an invalid value.  If someone wants to
110 		 * do fancy address space manipulations, mmap and munmap
111 		 * can do most of what the user would want.
112 		 */
113 		error = EINVAL;
114 		goto done;
115 	}
116 	if (new > old) {
117 		if (!old_mlock && map->flags & MAP_WIREFUTURE) {
118 			if (ptoa(pmap_wired_count(map->pmap)) +
119 			    (new - old) > lmemlim) {
120 				error = ENOMEM;
121 				goto done;
122 			}
123 		}
124 		if (map->size + (new - old) > vmemlim) {
125 			error = ENOMEM;
126 			goto done;
127 		}
128 #ifdef RACCT
129 		if (racct_enable) {
130 			PROC_LOCK(td->td_proc);
131 			error = racct_set(td->td_proc, RACCT_DATA, new - base);
132 			if (error != 0) {
133 				PROC_UNLOCK(td->td_proc);
134 				error = ENOMEM;
135 				goto done;
136 			}
137 			error = racct_set(td->td_proc, RACCT_VMEM,
138 			    map->size + (new - old));
139 			if (error != 0) {
140 				racct_set_force(td->td_proc, RACCT_DATA,
141 				    old - base);
142 				PROC_UNLOCK(td->td_proc);
143 				error = ENOMEM;
144 				goto done;
145 			}
146 			if (!old_mlock && map->flags & MAP_WIREFUTURE) {
147 				error = racct_set(td->td_proc, RACCT_MEMLOCK,
148 				    ptoa(pmap_wired_count(map->pmap)) +
149 				    (new - old));
150 				if (error != 0) {
151 					racct_set_force(td->td_proc, RACCT_DATA,
152 					    old - base);
153 					racct_set_force(td->td_proc, RACCT_VMEM,
154 					    map->size);
155 					PROC_UNLOCK(td->td_proc);
156 					error = ENOMEM;
157 					goto done;
158 				}
159 			}
160 			PROC_UNLOCK(td->td_proc);
161 		}
162 #endif
163 		prot = VM_PROT_RW;
164 #ifdef COMPAT_FREEBSD32
165 #if defined(__amd64__)
166 		if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32))
167 			prot |= VM_PROT_EXECUTE;
168 #endif
169 #endif
170 		rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0);
171 		if (rv != KERN_SUCCESS) {
172 #ifdef RACCT
173 			if (racct_enable) {
174 				PROC_LOCK(td->td_proc);
175 				racct_set_force(td->td_proc,
176 				    RACCT_DATA, old - base);
177 				racct_set_force(td->td_proc,
178 				    RACCT_VMEM, map->size);
179 				if (!old_mlock && map->flags & MAP_WIREFUTURE) {
180 					racct_set_force(td->td_proc,
181 					    RACCT_MEMLOCK,
182 					    ptoa(pmap_wired_count(map->pmap)));
183 				}
184 				PROC_UNLOCK(td->td_proc);
185 			}
186 #endif
187 			error = ENOMEM;
188 			goto done;
189 		}
190 		vm->vm_dsize += btoc(new - old);
191 		/*
192 		 * Handle the MAP_WIREFUTURE case for legacy applications,
193 		 * by marking the newly mapped range of pages as wired.
194 		 * We are not required to perform a corresponding
195 		 * vm_map_unwire() before vm_map_delete() below, as
196 		 * it will forcibly unwire the pages in the range.
197 		 *
198 		 * XXX If the pages cannot be wired, no error is returned.
199 		 */
200 		if ((map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
201 			if (bootverbose)
202 				printf("obreak: MAP_WIREFUTURE set\n");
203 			do_map_wirefuture = TRUE;
204 		}
205 	} else if (new < old) {
206 		rv = vm_map_delete(map, new, old);
207 		if (rv != KERN_SUCCESS) {
208 			error = ENOMEM;
209 			goto done;
210 		}
211 		vm->vm_dsize -= btoc(old - new);
212 #ifdef RACCT
213 		if (racct_enable) {
214 			PROC_LOCK(td->td_proc);
215 			racct_set_force(td->td_proc, RACCT_DATA, new - base);
216 			racct_set_force(td->td_proc, RACCT_VMEM, map->size);
217 			if (!old_mlock && map->flags & MAP_WIREFUTURE) {
218 				racct_set_force(td->td_proc, RACCT_MEMLOCK,
219 				    ptoa(pmap_wired_count(map->pmap)));
220 			}
221 			PROC_UNLOCK(td->td_proc);
222 		}
223 #endif
224 	}
225 done:
226 	vm_map_unlock(map);
227 
228 	if (do_map_wirefuture)
229 		(void) vm_map_wire(map, old, new,
230 		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
231 
232 	return (error);
233 }
234 
235 #ifndef _SYS_SYSPROTO_H_
236 struct ovadvise_args {
237 	int anom;
238 };
239 #endif
240 
241 /*
242  * MPSAFE
243  */
244 /* ARGSUSED */
245 int
246 sys_ovadvise(struct thread *td, struct ovadvise_args *uap)
247 {
248 	/* START_GIANT_OPTIONAL */
249 	/* END_GIANT_OPTIONAL */
250 	return (EINVAL);
251 }
252