sys/vm/vm_unix.c

   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