2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1991, 1993
6 * The Regents of the University of California. All rights reserved.
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
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.
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
36 * from: Utah $Hdr: vm_unix.c 1.1 89/11/07$
38 * @(#)vm_unix.c 8.1 (Berkeley) 6/11/93
42 * Traditional sbrk/grow interface to VM
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include <sys/param.h>
50 #include <sys/mutex.h>
52 #include <sys/racct.h>
53 #include <sys/resourcevar.h>
54 #include <sys/syscallsubr.h>
55 #include <sys/sysent.h>
56 #include <sys/sysproto.h>
57 #include <sys/systm.h>
60 #include <vm/vm_param.h>
62 #include <vm/vm_map.h>
64 #ifndef _SYS_SYSPROTO_H_
70 sys_break(struct thread *td, struct break_args *uap)
72 #if !defined(__aarch64__) && !defined(__riscv__)
76 addr = (uintptr_t)uap->nsize;
77 error = kern_break(td, &addr);
79 td->td_retval[0] = addr;
81 #else /* defined(__aarch64__) || defined(__riscv__) */
83 #endif /* defined(__aarch64__) || defined(__riscv__) */
87 kern_break(struct thread *td, uintptr_t *addr)
89 struct vmspace *vm = td->td_proc->p_vmspace;
90 vm_map_t map = &vm->vm_map;
91 vm_offset_t new, old, base;
92 rlim_t datalim, lmemlim, vmemlim;
95 boolean_t do_map_wirefuture;
97 datalim = lim_cur(td, RLIMIT_DATA);
98 lmemlim = lim_cur(td, RLIMIT_MEMLOCK);
99 vmemlim = lim_cur(td, RLIMIT_VMEM);
101 do_map_wirefuture = FALSE;
102 new = round_page(*addr);
105 base = round_page((vm_offset_t) vm->vm_daddr);
106 old = base + ctob(vm->vm_dsize);
109 * Check the resource limit, but allow a process to reduce
110 * its usage, even if it remains over the limit.
112 if (new - base > datalim && new > old) {
116 if (new > vm_map_max(map)) {
120 } else if (new < base) {
122 * Simply return the current break address without
123 * modifying any state. This is an ad-hoc interface
124 * used by libc to determine the initial break address,
125 * avoiding a dependency on magic features in the system
133 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
134 if (ptoa(pmap_wired_count(map->pmap)) +
135 (new - old) > lmemlim) {
140 if (map->size + (new - old) > vmemlim) {
146 PROC_LOCK(td->td_proc);
147 error = racct_set(td->td_proc, RACCT_DATA, new - base);
149 PROC_UNLOCK(td->td_proc);
153 error = racct_set(td->td_proc, RACCT_VMEM,
154 map->size + (new - old));
156 racct_set_force(td->td_proc, RACCT_DATA,
158 PROC_UNLOCK(td->td_proc);
162 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
163 error = racct_set(td->td_proc, RACCT_MEMLOCK,
164 ptoa(pmap_wired_count(map->pmap)) +
167 racct_set_force(td->td_proc, RACCT_DATA,
169 racct_set_force(td->td_proc, RACCT_VMEM,
171 PROC_UNLOCK(td->td_proc);
176 PROC_UNLOCK(td->td_proc);
180 #ifdef COMPAT_FREEBSD32
181 #if defined(__amd64__)
182 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32))
183 prot |= VM_PROT_EXECUTE;
186 rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0);
187 if (rv != KERN_SUCCESS) {
190 PROC_LOCK(td->td_proc);
191 racct_set_force(td->td_proc,
192 RACCT_DATA, old - base);
193 racct_set_force(td->td_proc,
194 RACCT_VMEM, map->size);
195 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
196 racct_set_force(td->td_proc,
198 ptoa(pmap_wired_count(map->pmap)));
200 PROC_UNLOCK(td->td_proc);
206 vm->vm_dsize += btoc(new - old);
208 * Handle the MAP_WIREFUTURE case for legacy applications,
209 * by marking the newly mapped range of pages as wired.
210 * We are not required to perform a corresponding
211 * vm_map_unwire() before vm_map_delete() below, as
212 * it will forcibly unwire the pages in the range.
214 * XXX If the pages cannot be wired, no error is returned.
216 if ((map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE)
217 do_map_wirefuture = TRUE;
218 } else if (new < old) {
219 rv = vm_map_delete(map, new, old);
220 if (rv != KERN_SUCCESS) {
224 vm->vm_dsize -= btoc(old - new);
227 PROC_LOCK(td->td_proc);
228 racct_set_force(td->td_proc, RACCT_DATA, new - base);
229 racct_set_force(td->td_proc, RACCT_VMEM, map->size);
230 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
231 racct_set_force(td->td_proc, RACCT_MEMLOCK,
232 ptoa(pmap_wired_count(map->pmap)));
234 PROC_UNLOCK(td->td_proc);
241 if (do_map_wirefuture)
242 (void) vm_map_wire(map, old, new,
243 VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
251 #ifdef COMPAT_FREEBSD11
253 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap)