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 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 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 239 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap) 240 { 241 242 return (EINVAL); 243 } 244 #endif 245