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 break_args { 65 char *nsize; 66 }; 67 #endif 68 int 69 sys_break(struct thread *td, struct break_args *uap) 70 { 71 #if !defined(__aarch64__) && !defined(__riscv__) 72 struct vmspace *vm = td->td_proc->p_vmspace; 73 vm_map_t map = &vm->vm_map; 74 vm_offset_t new, old, base; 75 rlim_t datalim, lmemlim, vmemlim; 76 int prot, rv; 77 int error = 0; 78 boolean_t do_map_wirefuture; 79 80 datalim = lim_cur(td, RLIMIT_DATA); 81 lmemlim = lim_cur(td, RLIMIT_MEMLOCK); 82 vmemlim = lim_cur(td, RLIMIT_VMEM); 83 84 do_map_wirefuture = FALSE; 85 new = round_page((vm_offset_t)uap->nsize); 86 vm_map_lock(map); 87 88 base = round_page((vm_offset_t) vm->vm_daddr); 89 old = base + ctob(vm->vm_dsize); 90 if (new > base) { 91 /* 92 * Check the resource limit, but allow a process to reduce 93 * its usage, even if it remains over the limit. 94 */ 95 if (new - base > datalim && new > old) { 96 error = ENOMEM; 97 goto done; 98 } 99 if (new > vm_map_max(map)) { 100 error = ENOMEM; 101 goto done; 102 } 103 } else if (new < base) { 104 /* 105 * Simply return the current break address without 106 * modifying any state. This is an ad-hoc interface 107 * used by libc to determine the initial break address, 108 * avoiding a dependency on magic features in the system 109 * linker. 110 */ 111 new = old; 112 goto done; 113 } 114 115 if (new > old) { 116 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 117 if (ptoa(pmap_wired_count(map->pmap)) + 118 (new - old) > lmemlim) { 119 error = ENOMEM; 120 goto done; 121 } 122 } 123 if (map->size + (new - old) > vmemlim) { 124 error = ENOMEM; 125 goto done; 126 } 127 #ifdef RACCT 128 if (racct_enable) { 129 PROC_LOCK(td->td_proc); 130 error = racct_set(td->td_proc, RACCT_DATA, new - base); 131 if (error != 0) { 132 PROC_UNLOCK(td->td_proc); 133 error = ENOMEM; 134 goto done; 135 } 136 error = racct_set(td->td_proc, RACCT_VMEM, 137 map->size + (new - old)); 138 if (error != 0) { 139 racct_set_force(td->td_proc, RACCT_DATA, 140 old - base); 141 PROC_UNLOCK(td->td_proc); 142 error = ENOMEM; 143 goto done; 144 } 145 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 146 error = racct_set(td->td_proc, RACCT_MEMLOCK, 147 ptoa(pmap_wired_count(map->pmap)) + 148 (new - old)); 149 if (error != 0) { 150 racct_set_force(td->td_proc, RACCT_DATA, 151 old - base); 152 racct_set_force(td->td_proc, RACCT_VMEM, 153 map->size); 154 PROC_UNLOCK(td->td_proc); 155 error = ENOMEM; 156 goto done; 157 } 158 } 159 PROC_UNLOCK(td->td_proc); 160 } 161 #endif 162 prot = VM_PROT_RW; 163 #ifdef COMPAT_FREEBSD32 164 #if defined(__amd64__) 165 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32)) 166 prot |= VM_PROT_EXECUTE; 167 #endif 168 #endif 169 rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0); 170 if (rv != KERN_SUCCESS) { 171 #ifdef RACCT 172 if (racct_enable) { 173 PROC_LOCK(td->td_proc); 174 racct_set_force(td->td_proc, 175 RACCT_DATA, old - base); 176 racct_set_force(td->td_proc, 177 RACCT_VMEM, map->size); 178 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 179 racct_set_force(td->td_proc, 180 RACCT_MEMLOCK, 181 ptoa(pmap_wired_count(map->pmap))); 182 } 183 PROC_UNLOCK(td->td_proc); 184 } 185 #endif 186 error = ENOMEM; 187 goto done; 188 } 189 vm->vm_dsize += btoc(new - old); 190 /* 191 * Handle the MAP_WIREFUTURE case for legacy applications, 192 * by marking the newly mapped range of pages as wired. 193 * We are not required to perform a corresponding 194 * vm_map_unwire() before vm_map_delete() below, as 195 * it will forcibly unwire the pages in the range. 196 * 197 * XXX If the pages cannot be wired, no error is returned. 198 */ 199 if ((map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) 200 do_map_wirefuture = TRUE; 201 } else if (new < old) { 202 rv = vm_map_delete(map, new, old); 203 if (rv != KERN_SUCCESS) { 204 error = ENOMEM; 205 goto done; 206 } 207 vm->vm_dsize -= btoc(old - new); 208 #ifdef RACCT 209 if (racct_enable) { 210 PROC_LOCK(td->td_proc); 211 racct_set_force(td->td_proc, RACCT_DATA, new - base); 212 racct_set_force(td->td_proc, RACCT_VMEM, map->size); 213 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 214 racct_set_force(td->td_proc, RACCT_MEMLOCK, 215 ptoa(pmap_wired_count(map->pmap))); 216 } 217 PROC_UNLOCK(td->td_proc); 218 } 219 #endif 220 } 221 done: 222 vm_map_unlock(map); 223 224 if (do_map_wirefuture) 225 (void) vm_map_wire(map, old, new, 226 VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 227 228 if (error == 0) 229 td->td_retval[0] = new; 230 231 return (error); 232 #else /* defined(__aarch64__) || defined(__riscv__) */ 233 return (ENOSYS); 234 #endif /* defined(__aarch64__) || defined(__riscv__) */ 235 } 236 237 #ifdef COMPAT_FREEBSD11 238 int 239 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap) 240 { 241 242 return (EINVAL); 243 } 244 #endif 245