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/syscallsubr.h> 55 #include <sys/sysent.h> 56 #include <sys/sysproto.h> 57 #include <sys/systm.h> 58 #if defined(__amd64__) || defined(__i386__) /* for i386_read_exec */ 59 #include <machine/md_var.h> 60 #endif 61 62 #include <vm/vm.h> 63 #include <vm/vm_param.h> 64 #include <vm/pmap.h> 65 #include <vm/vm_map.h> 66 67 #ifndef _SYS_SYSPROTO_H_ 68 struct break_args { 69 char *nsize; 70 }; 71 #endif 72 int 73 sys_break(struct thread *td, struct break_args *uap) 74 { 75 #if !defined(__aarch64__) && !defined(__riscv) 76 uintptr_t addr; 77 int error; 78 79 addr = (uintptr_t)uap->nsize; 80 error = kern_break(td, &addr); 81 if (error == 0) 82 td->td_retval[0] = addr; 83 return (error); 84 #else /* defined(__aarch64__) || defined(__riscv) */ 85 return (ENOSYS); 86 #endif /* defined(__aarch64__) || defined(__riscv) */ 87 } 88 89 int 90 kern_break(struct thread *td, uintptr_t *addr) 91 { 92 struct vmspace *vm = td->td_proc->p_vmspace; 93 vm_map_t map = &vm->vm_map; 94 vm_offset_t new, old, base; 95 rlim_t datalim, lmemlim, vmemlim; 96 int prot, rv; 97 int error = 0; 98 99 datalim = lim_cur(td, RLIMIT_DATA); 100 lmemlim = lim_cur(td, RLIMIT_MEMLOCK); 101 vmemlim = lim_cur(td, RLIMIT_VMEM); 102 103 new = round_page(*addr); 104 vm_map_lock(map); 105 106 base = round_page((vm_offset_t) vm->vm_daddr); 107 old = base + ctob(vm->vm_dsize); 108 if (new > base) { 109 /* 110 * Check the resource limit, but allow a process to reduce 111 * its usage, even if it remains over the limit. 112 */ 113 if (new - base > datalim && new > old) { 114 error = ENOMEM; 115 goto done; 116 } 117 if (new > vm_map_max(map)) { 118 error = ENOMEM; 119 goto done; 120 } 121 } else if (new < base) { 122 /* 123 * Simply return the current break address without 124 * modifying any state. This is an ad-hoc interface 125 * used by libc to determine the initial break address, 126 * avoiding a dependency on magic features in the system 127 * linker. 128 */ 129 new = old; 130 goto done; 131 } 132 133 if (new > old) { 134 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 135 if (ptoa(pmap_wired_count(map->pmap)) + 136 (new - old) > lmemlim) { 137 error = ENOMEM; 138 goto done; 139 } 140 } 141 if (map->size + (new - old) > vmemlim) { 142 error = ENOMEM; 143 goto done; 144 } 145 #ifdef RACCT 146 if (racct_enable) { 147 PROC_LOCK(td->td_proc); 148 error = racct_set(td->td_proc, RACCT_DATA, new - base); 149 if (error != 0) { 150 PROC_UNLOCK(td->td_proc); 151 error = ENOMEM; 152 goto done; 153 } 154 error = racct_set(td->td_proc, RACCT_VMEM, 155 map->size + (new - old)); 156 if (error != 0) { 157 racct_set_force(td->td_proc, RACCT_DATA, 158 old - base); 159 PROC_UNLOCK(td->td_proc); 160 error = ENOMEM; 161 goto done; 162 } 163 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 164 error = racct_set(td->td_proc, RACCT_MEMLOCK, 165 ptoa(pmap_wired_count(map->pmap)) + 166 (new - old)); 167 if (error != 0) { 168 racct_set_force(td->td_proc, RACCT_DATA, 169 old - base); 170 racct_set_force(td->td_proc, RACCT_VMEM, 171 map->size); 172 PROC_UNLOCK(td->td_proc); 173 error = ENOMEM; 174 goto done; 175 } 176 } 177 PROC_UNLOCK(td->td_proc); 178 } 179 #endif 180 prot = VM_PROT_RW; 181 #if (defined(COMPAT_FREEBSD32) && defined(__amd64__)) || defined(__i386__) 182 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32)) 183 prot |= VM_PROT_EXECUTE; 184 #endif 185 rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 186 0); 187 if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) { 188 rv = vm_map_wire_locked(map, old, new, 189 VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES); 190 if (rv != KERN_SUCCESS) 191 (void)vm_map_delete(map, old, new); 192 } 193 if (rv != KERN_SUCCESS) { 194 #ifdef RACCT 195 if (racct_enable) { 196 PROC_LOCK(td->td_proc); 197 racct_set_force(td->td_proc, 198 RACCT_DATA, old - base); 199 racct_set_force(td->td_proc, 200 RACCT_VMEM, map->size); 201 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 202 racct_set_force(td->td_proc, 203 RACCT_MEMLOCK, 204 ptoa(pmap_wired_count(map->pmap))); 205 } 206 PROC_UNLOCK(td->td_proc); 207 } 208 #endif 209 error = ENOMEM; 210 goto done; 211 } 212 vm->vm_dsize += btoc(new - old); 213 } else if (new < old) { 214 rv = vm_map_delete(map, new, old); 215 if (rv != KERN_SUCCESS) { 216 error = ENOMEM; 217 goto done; 218 } 219 vm->vm_dsize -= btoc(old - new); 220 #ifdef RACCT 221 if (racct_enable) { 222 PROC_LOCK(td->td_proc); 223 racct_set_force(td->td_proc, RACCT_DATA, new - base); 224 racct_set_force(td->td_proc, RACCT_VMEM, map->size); 225 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 226 racct_set_force(td->td_proc, RACCT_MEMLOCK, 227 ptoa(pmap_wired_count(map->pmap))); 228 } 229 PROC_UNLOCK(td->td_proc); 230 } 231 #endif 232 } 233 done: 234 vm_map_unlock(map); 235 236 if (error == 0) 237 *addr = new; 238 239 return (error); 240 } 241 242 #ifdef COMPAT_FREEBSD11 243 int 244 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap) 245 { 246 247 return (EINVAL); 248 } 249 #endif 250