xref: /freebsd/sys/vm/vm_unix.c (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
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 #include "opt_compat.h"
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/racct.h>
55 #include <sys/resourcevar.h>
56 #include <sys/sysent.h>
57 #include <sys/sysproto.h>
58 #include <sys/systm.h>
59 
60 #include <vm/vm.h>
61 #include <vm/vm_param.h>
62 #include <vm/pmap.h>
63 #include <vm/vm_map.h>
64 
65 #ifndef _SYS_SYSPROTO_H_
66 struct obreak_args {
67 	char *nsize;
68 };
69 #endif
70 
71 /*
72  * MPSAFE
73  */
74 /* ARGSUSED */
75 int
76 sys_obreak(td, uap)
77 	struct thread *td;
78 	struct obreak_args *uap;
79 {
80 	struct vmspace *vm = td->td_proc->p_vmspace;
81 	vm_map_t map = &vm->vm_map;
82 	vm_offset_t new, old, base;
83 	rlim_t datalim, lmemlim, vmemlim;
84 	int prot, rv;
85 	int error = 0;
86 	boolean_t do_map_wirefuture;
87 
88 	datalim = lim_cur(td, RLIMIT_DATA);
89 	lmemlim = lim_cur(td, RLIMIT_MEMLOCK);
90 	vmemlim = lim_cur(td, RLIMIT_VMEM);
91 
92 	do_map_wirefuture = FALSE;
93 	new = round_page((vm_offset_t)uap->nsize);
94 	vm_map_lock(map);
95 
96 	base = round_page((vm_offset_t) vm->vm_daddr);
97 	old = base + ctob(vm->vm_dsize);
98 	if (new > base) {
99 		/*
100 		 * Check the resource limit, but allow a process to reduce
101 		 * its usage, even if it remains over the limit.
102 		 */
103 		if (new - base > datalim && new > old) {
104 			error = ENOMEM;
105 			goto done;
106 		}
107 		if (new > vm_map_max(map)) {
108 			error = ENOMEM;
109 			goto done;
110 		}
111 	} else if (new < base) {
112 		/*
113 		 * This is simply an invalid value.  If someone wants to
114 		 * do fancy address space manipulations, mmap and munmap
115 		 * can do most of what the user would want.
116 		 */
117 		error = EINVAL;
118 		goto done;
119 	}
120 	if (new > old) {
121 		if (!old_mlock && map->flags & MAP_WIREFUTURE) {
122 			if (ptoa(pmap_wired_count(map->pmap)) +
123 			    (new - old) > lmemlim) {
124 				error = ENOMEM;
125 				goto done;
126 			}
127 		}
128 		if (map->size + (new - old) > vmemlim) {
129 			error = ENOMEM;
130 			goto done;
131 		}
132 #ifdef RACCT
133 		if (racct_enable) {
134 			PROC_LOCK(td->td_proc);
135 			error = racct_set(td->td_proc, RACCT_DATA, new - base);
136 			if (error != 0) {
137 				PROC_UNLOCK(td->td_proc);
138 				error = ENOMEM;
139 				goto done;
140 			}
141 			error = racct_set(td->td_proc, RACCT_VMEM,
142 			    map->size + (new - old));
143 			if (error != 0) {
144 				racct_set_force(td->td_proc, RACCT_DATA,
145 				    old - base);
146 				PROC_UNLOCK(td->td_proc);
147 				error = ENOMEM;
148 				goto done;
149 			}
150 			if (!old_mlock && map->flags & MAP_WIREFUTURE) {
151 				error = racct_set(td->td_proc, RACCT_MEMLOCK,
152 				    ptoa(pmap_wired_count(map->pmap)) +
153 				    (new - old));
154 				if (error != 0) {
155 					racct_set_force(td->td_proc, RACCT_DATA,
156 					    old - base);
157 					racct_set_force(td->td_proc, RACCT_VMEM,
158 					    map->size);
159 					PROC_UNLOCK(td->td_proc);
160 					error = ENOMEM;
161 					goto done;
162 				}
163 			}
164 			PROC_UNLOCK(td->td_proc);
165 		}
166 #endif
167 		prot = VM_PROT_RW;
168 #ifdef COMPAT_FREEBSD32
169 #if defined(__amd64__)
170 		if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32))
171 			prot |= VM_PROT_EXECUTE;
172 #endif
173 #endif
174 		rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0);
175 		if (rv != KERN_SUCCESS) {
176 #ifdef RACCT
177 			if (racct_enable) {
178 				PROC_LOCK(td->td_proc);
179 				racct_set_force(td->td_proc,
180 				    RACCT_DATA, old - base);
181 				racct_set_force(td->td_proc,
182 				    RACCT_VMEM, map->size);
183 				if (!old_mlock && map->flags & MAP_WIREFUTURE) {
184 					racct_set_force(td->td_proc,
185 					    RACCT_MEMLOCK,
186 					    ptoa(pmap_wired_count(map->pmap)));
187 				}
188 				PROC_UNLOCK(td->td_proc);
189 			}
190 #endif
191 			error = ENOMEM;
192 			goto done;
193 		}
194 		vm->vm_dsize += btoc(new - old);
195 		/*
196 		 * Handle the MAP_WIREFUTURE case for legacy applications,
197 		 * by marking the newly mapped range of pages as wired.
198 		 * We are not required to perform a corresponding
199 		 * vm_map_unwire() before vm_map_delete() below, as
200 		 * it will forcibly unwire the pages in the range.
201 		 *
202 		 * XXX If the pages cannot be wired, no error is returned.
203 		 */
204 		if ((map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) {
205 			if (bootverbose)
206 				printf("obreak: MAP_WIREFUTURE set\n");
207 			do_map_wirefuture = TRUE;
208 		}
209 	} else if (new < old) {
210 		rv = vm_map_delete(map, new, old);
211 		if (rv != KERN_SUCCESS) {
212 			error = ENOMEM;
213 			goto done;
214 		}
215 		vm->vm_dsize -= btoc(old - new);
216 #ifdef RACCT
217 		if (racct_enable) {
218 			PROC_LOCK(td->td_proc);
219 			racct_set_force(td->td_proc, RACCT_DATA, new - base);
220 			racct_set_force(td->td_proc, RACCT_VMEM, map->size);
221 			if (!old_mlock && map->flags & MAP_WIREFUTURE) {
222 				racct_set_force(td->td_proc, RACCT_MEMLOCK,
223 				    ptoa(pmap_wired_count(map->pmap)));
224 			}
225 			PROC_UNLOCK(td->td_proc);
226 		}
227 #endif
228 	}
229 done:
230 	vm_map_unlock(map);
231 
232 	if (do_map_wirefuture)
233 		(void) vm_map_wire(map, old, new,
234 		    VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
235 
236 	return (error);
237 }
238 
239 #ifndef _SYS_SYSPROTO_H_
240 struct ovadvise_args {
241 	int anom;
242 };
243 #endif
244 
245 /*
246  * MPSAFE
247  */
248 /* ARGSUSED */
249 int
250 sys_ovadvise(td, uap)
251 	struct thread *td;
252 	struct ovadvise_args *uap;
253 {
254 	/* START_GIANT_OPTIONAL */
255 	/* END_GIANT_OPTIONAL */
256 	return (EINVAL);
257 }
258