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