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
39 /*
40 * Traditional sbrk/grow interface to VM
41 */
42
43 #include <sys/param.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/proc.h>
47 #include <sys/racct.h>
48 #include <sys/resourcevar.h>
49 #include <sys/syscallsubr.h>
50 #include <sys/sysent.h>
51 #include <sys/sysproto.h>
52 #include <sys/systm.h>
53 #if defined(__amd64__) || defined(__i386__) /* for i386_read_exec */
54 #include <machine/md_var.h>
55 #endif
56
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 #include <vm/pmap.h>
60 #include <vm/vm_map.h>
61
62 #ifndef _SYS_SYSPROTO_H_
63 struct break_args {
64 char *nsize;
65 };
66 #endif
67 int
sys_break(struct thread * td,struct break_args * uap)68 sys_break(struct thread *td, struct break_args *uap)
69 {
70 #if !defined(__aarch64__) && !defined(__riscv)
71 uintptr_t addr;
72 int error;
73
74 addr = (uintptr_t)uap->nsize;
75 error = kern_break(td, &addr);
76 if (error == 0)
77 td->td_retval[0] = addr;
78 return (error);
79 #else /* defined(__aarch64__) || defined(__riscv) */
80 return (ENOSYS);
81 #endif /* defined(__aarch64__) || defined(__riscv) */
82 }
83
84 int
kern_break(struct thread * td,uintptr_t * addr)85 kern_break(struct thread *td, uintptr_t *addr)
86 {
87 struct vmspace *vm = td->td_proc->p_vmspace;
88 vm_map_t map = &vm->vm_map;
89 vm_offset_t new, old, base;
90 rlim_t datalim, lmemlim, vmemlim;
91 int prot, rv;
92 int error = 0;
93
94 datalim = lim_cur(td, RLIMIT_DATA);
95 lmemlim = lim_cur(td, RLIMIT_MEMLOCK);
96 vmemlim = lim_cur(td, RLIMIT_VMEM);
97
98 new = round_page(*addr);
99 vm_map_lock(map);
100
101 base = round_page((vm_offset_t) vm->vm_daddr);
102 old = base + ctob(vm->vm_dsize);
103 if (new > base) {
104 /*
105 * Check the resource limit, but allow a process to reduce
106 * its usage, even if it remains over the limit.
107 */
108 if (new - base > datalim && new > old) {
109 error = ENOMEM;
110 goto done;
111 }
112 if (new > vm_map_max(map)) {
113 error = ENOMEM;
114 goto done;
115 }
116 } else if (new < base) {
117 /*
118 * Simply return the current break address without
119 * modifying any state. This is an ad-hoc interface
120 * used by libc to determine the initial break address,
121 * avoiding a dependency on magic features in the system
122 * linker.
123 */
124 new = old;
125 goto done;
126 }
127
128 if (new > old) {
129 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
130 if (ptoa(pmap_wired_count(map->pmap)) +
131 (new - old) > lmemlim) {
132 error = ENOMEM;
133 goto done;
134 }
135 }
136 if (map->size + (new - old) > vmemlim) {
137 error = ENOMEM;
138 goto done;
139 }
140 #ifdef RACCT
141 if (racct_enable) {
142 PROC_LOCK(td->td_proc);
143 error = racct_set(td->td_proc, RACCT_DATA, new - base);
144 if (error != 0) {
145 PROC_UNLOCK(td->td_proc);
146 error = ENOMEM;
147 goto done;
148 }
149 error = racct_set(td->td_proc, RACCT_VMEM,
150 map->size + (new - old));
151 if (error != 0) {
152 racct_set_force(td->td_proc, RACCT_DATA,
153 old - base);
154 PROC_UNLOCK(td->td_proc);
155 error = ENOMEM;
156 goto done;
157 }
158 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
159 error = racct_set(td->td_proc, RACCT_MEMLOCK,
160 ptoa(pmap_wired_count(map->pmap)) +
161 (new - old));
162 if (error != 0) {
163 racct_set_force(td->td_proc, RACCT_DATA,
164 old - base);
165 racct_set_force(td->td_proc, RACCT_VMEM,
166 map->size);
167 PROC_UNLOCK(td->td_proc);
168 error = ENOMEM;
169 goto done;
170 }
171 }
172 PROC_UNLOCK(td->td_proc);
173 }
174 #endif
175 prot = VM_PROT_RW;
176 #if (defined(COMPAT_FREEBSD32) && defined(__amd64__)) || defined(__i386__)
177 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32))
178 prot |= VM_PROT_EXECUTE;
179 #endif
180 rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL,
181 0);
182 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) {
183 rv = vm_map_wire_locked(map, old, new,
184 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
185 if (rv != KERN_SUCCESS)
186 (void)vm_map_delete(map, old, new);
187 }
188 if (rv != KERN_SUCCESS) {
189 #ifdef RACCT
190 if (racct_enable) {
191 PROC_LOCK(td->td_proc);
192 racct_set_force(td->td_proc,
193 RACCT_DATA, old - base);
194 racct_set_force(td->td_proc,
195 RACCT_VMEM, map->size);
196 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
197 racct_set_force(td->td_proc,
198 RACCT_MEMLOCK,
199 ptoa(pmap_wired_count(map->pmap)));
200 }
201 PROC_UNLOCK(td->td_proc);
202 }
203 #endif
204 error = ENOMEM;
205 goto done;
206 }
207 vm->vm_dsize += btoc(new - old);
208 } else if (new < old) {
209 rv = vm_map_delete(map, new, old);
210 if (rv != KERN_SUCCESS) {
211 error = ENOMEM;
212 goto done;
213 }
214 vm->vm_dsize -= btoc(old - new);
215 #ifdef RACCT
216 if (racct_enable) {
217 PROC_LOCK(td->td_proc);
218 racct_set_force(td->td_proc, RACCT_DATA, new - base);
219 racct_set_force(td->td_proc, RACCT_VMEM, map->size);
220 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
221 racct_set_force(td->td_proc, RACCT_MEMLOCK,
222 ptoa(pmap_wired_count(map->pmap)));
223 }
224 PROC_UNLOCK(td->td_proc);
225 }
226 #endif
227 }
228 done:
229 vm_map_unlock(map);
230
231 if (error == 0)
232 *addr = new;
233
234 return (error);
235 }
236
237 #ifdef COMPAT_FREEBSD11
238 int
freebsd11_vadvise(struct thread * td,struct freebsd11_vadvise_args * uap)239 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap)
240 {
241
242 return (EINVAL);
243 }
244 #endif
245