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 boolean_t do_map_wirefuture; 99 100 datalim = lim_cur(td, RLIMIT_DATA); 101 lmemlim = lim_cur(td, RLIMIT_MEMLOCK); 102 vmemlim = lim_cur(td, RLIMIT_VMEM); 103 104 do_map_wirefuture = FALSE; 105 new = round_page(*addr); 106 vm_map_lock(map); 107 108 base = round_page((vm_offset_t) vm->vm_daddr); 109 old = base + ctob(vm->vm_dsize); 110 if (new > base) { 111 /* 112 * Check the resource limit, but allow a process to reduce 113 * its usage, even if it remains over the limit. 114 */ 115 if (new - base > datalim && new > old) { 116 error = ENOMEM; 117 goto done; 118 } 119 if (new > vm_map_max(map)) { 120 error = ENOMEM; 121 goto done; 122 } 123 } else if (new < base) { 124 /* 125 * Simply return the current break address without 126 * modifying any state. This is an ad-hoc interface 127 * used by libc to determine the initial break address, 128 * avoiding a dependency on magic features in the system 129 * linker. 130 */ 131 new = old; 132 goto done; 133 } 134 135 if (new > old) { 136 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 137 if (ptoa(pmap_wired_count(map->pmap)) + 138 (new - old) > lmemlim) { 139 error = ENOMEM; 140 goto done; 141 } 142 } 143 if (map->size + (new - old) > vmemlim) { 144 error = ENOMEM; 145 goto done; 146 } 147 #ifdef RACCT 148 if (racct_enable) { 149 PROC_LOCK(td->td_proc); 150 error = racct_set(td->td_proc, RACCT_DATA, new - base); 151 if (error != 0) { 152 PROC_UNLOCK(td->td_proc); 153 error = ENOMEM; 154 goto done; 155 } 156 error = racct_set(td->td_proc, RACCT_VMEM, 157 map->size + (new - old)); 158 if (error != 0) { 159 racct_set_force(td->td_proc, RACCT_DATA, 160 old - base); 161 PROC_UNLOCK(td->td_proc); 162 error = ENOMEM; 163 goto done; 164 } 165 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 166 error = racct_set(td->td_proc, RACCT_MEMLOCK, 167 ptoa(pmap_wired_count(map->pmap)) + 168 (new - old)); 169 if (error != 0) { 170 racct_set_force(td->td_proc, RACCT_DATA, 171 old - base); 172 racct_set_force(td->td_proc, RACCT_VMEM, 173 map->size); 174 PROC_UNLOCK(td->td_proc); 175 error = ENOMEM; 176 goto done; 177 } 178 } 179 PROC_UNLOCK(td->td_proc); 180 } 181 #endif 182 prot = VM_PROT_RW; 183 #if (defined(COMPAT_FREEBSD32) && defined(__amd64__)) || defined(__i386__) 184 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32)) 185 prot |= VM_PROT_EXECUTE; 186 #endif 187 rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0); 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 /* 209 * Handle the MAP_WIREFUTURE case for legacy applications, 210 * by marking the newly mapped range of pages as wired. 211 * We are not required to perform a corresponding 212 * vm_map_unwire() before vm_map_delete() below, as 213 * it will forcibly unwire the pages in the range. 214 * 215 * XXX If the pages cannot be wired, no error is returned. 216 */ 217 if ((map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE) 218 do_map_wirefuture = TRUE; 219 } else if (new < old) { 220 rv = vm_map_delete(map, new, old); 221 if (rv != KERN_SUCCESS) { 222 error = ENOMEM; 223 goto done; 224 } 225 vm->vm_dsize -= btoc(old - new); 226 #ifdef RACCT 227 if (racct_enable) { 228 PROC_LOCK(td->td_proc); 229 racct_set_force(td->td_proc, RACCT_DATA, new - base); 230 racct_set_force(td->td_proc, RACCT_VMEM, map->size); 231 if (!old_mlock && map->flags & MAP_WIREFUTURE) { 232 racct_set_force(td->td_proc, RACCT_MEMLOCK, 233 ptoa(pmap_wired_count(map->pmap))); 234 } 235 PROC_UNLOCK(td->td_proc); 236 } 237 #endif 238 } 239 done: 240 vm_map_unlock(map); 241 242 if (do_map_wirefuture) 243 (void) vm_map_wire(map, old, new, 244 VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES); 245 246 if (error == 0) 247 *addr = new; 248 249 return (error); 250 } 251 252 #ifdef COMPAT_FREEBSD11 253 int 254 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap) 255 { 256 257 return (EINVAL); 258 } 259 #endif 260