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 __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
  59 #include <vm/vm.h>
  60 #include <vm/vm_param.h>
  61 #include <vm/pmap.h>
  62 #include <vm/vm_map.h>
  63
  64 #ifndef _SYS_SYSPROTO_H_
  65 struct break_args {
  66         char *nsize;
  67 };
  68 #endif
  69 int
  70 sys_break(struct thread *td, struct break_args *uap)
  71 {
  72 #if !defined(__aarch64__) && !defined(__riscv)
  73         uintptr_t addr;
  74         int error;
  75
  76         addr = (uintptr_t)uap->nsize;
  77         error = kern_break(td, &addr);
  78         if (error == 0)
  79                 td->td_retval[0] = addr;
  80         return (error);
  81 #else /* defined(__aarch64__) || defined(__riscv) */
  82         return (ENOSYS);
  83 #endif /* defined(__aarch64__) || defined(__riscv) */
  84 }
  85
  86 int
  87 kern_break(struct thread *td, uintptr_t *addr)
  88 {
  89         struct vmspace *vm = td->td_proc->p_vmspace;
  90         vm_map_t map = &vm->vm_map;
  91         vm_offset_t new, old, base;
  92         rlim_t datalim, lmemlim, vmemlim;
  93         int prot, rv;
  94         int error = 0;
  95         boolean_t do_map_wirefuture;
  96
  97         datalim = lim_cur(td, RLIMIT_DATA);
  98         lmemlim = lim_cur(td, RLIMIT_MEMLOCK);
  99         vmemlim = lim_cur(td, RLIMIT_VMEM);
 100
 101         do_map_wirefuture = FALSE;
 102         new = round_page(*addr);
 103         vm_map_lock(map);
 104
 105         base = round_page((vm_offset_t) vm->vm_daddr);
 106         old = base + ctob(vm->vm_dsize);
 107         if (new > base) {
 108                 /*
 109                  * Check the resource limit, but allow a process to reduce
 110                  * its usage, even if it remains over the limit.
 111                  */
 112                 if (new - base > datalim && new > old) {
 113                         error = ENOMEM;
 114                         goto done;
 115                 }
 116                 if (new > vm_map_max(map)) {
 117                         error = ENOMEM;
 118                         goto done;
 119                 }
 120         } else if (new < base) {
 121                 /*
 122                  * Simply return the current break address without
 123                  * modifying any state.  This is an ad-hoc interface
 124                  * used by libc to determine the initial break address,
 125                  * avoiding a dependency on magic features in the system
 126                  * linker.
 127                  */
 128                 new = old;
 129                 goto done;
 130         }
 131
 132         if (new > old) {
 133                 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
 134                         if (ptoa(pmap_wired_count(map->pmap)) +
 135                             (new - old) > lmemlim) {
 136                                 error = ENOMEM;
 137                                 goto done;
 138                         }
 139                 }
 140                 if (map->size + (new - old) > vmemlim) {
 141                         error = ENOMEM;
 142                         goto done;
 143                 }
 144 #ifdef RACCT
 145                 if (racct_enable) {
 146                         PROC_LOCK(td->td_proc);
 147                         error = racct_set(td->td_proc, RACCT_DATA, new - base);
 148                         if (error != 0) {
 149                                 PROC_UNLOCK(td->td_proc);
 150                                 error = ENOMEM;
 151                                 goto done;
 152                         }
 153                         error = racct_set(td->td_proc, RACCT_VMEM,
 154                             map->size + (new - old));
 155                         if (error != 0) {
 156                                 racct_set_force(td->td_proc, RACCT_DATA,
 157                                     old - base);
 158                                 PROC_UNLOCK(td->td_proc);
 159                                 error = ENOMEM;
 160                                 goto done;
 161                         }
 162                         if (!old_mlock && map->flags & MAP_WIREFUTURE) {
 163                                 error = racct_set(td->td_proc, RACCT_MEMLOCK,
 164                                     ptoa(pmap_wired_count(map->pmap)) +
 165                                     (new - old));
 166                                 if (error != 0) {
 167                                         racct_set_force(td->td_proc, RACCT_DATA,
 168                                             old - base);
 169                                         racct_set_force(td->td_proc, RACCT_VMEM,
 170                                             map->size);
 171                                         PROC_UNLOCK(td->td_proc);
 172                                         error = ENOMEM;
 173                                         goto done;
 174                                 }
 175                         }
 176                         PROC_UNLOCK(td->td_proc);
 177                 }
 178 #endif
 179                 prot = VM_PROT_RW;
 180 #ifdef COMPAT_FREEBSD32
 181 #if defined(__amd64__)
 182                 if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32))
 183                         prot |= VM_PROT_EXECUTE;
 184 #endif
 185 #endif
 186                 rv = vm_map_insert(map, NULL, 0, old, new, prot, VM_PROT_ALL, 0);
 187                 if (rv != KERN_SUCCESS) {
 188 #ifdef RACCT
 189                         if (racct_enable) {
 190                                 PROC_LOCK(td->td_proc);
 191                                 racct_set_force(td->td_proc,
 192                                     RACCT_DATA, old - base);
 193                                 racct_set_force(td->td_proc,
 194                                     RACCT_VMEM, map->size);
 195                                 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
 196                                         racct_set_force(td->td_proc,
 197                                             RACCT_MEMLOCK,
 198                                             ptoa(pmap_wired_count(map->pmap)));
 199                                 }
 200                                 PROC_UNLOCK(td->td_proc);
 201                         }
 202 #endif
 203                         error = ENOMEM;
 204                         goto done;
 205                 }
 206                 vm->vm_dsize += btoc(new - old);
 207                 /*
 208                  * Handle the MAP_WIREFUTURE case for legacy applications,
 209                  * by marking the newly mapped range of pages as wired.
 210                  * We are not required to perform a corresponding
 211                  * vm_map_unwire() before vm_map_delete() below, as
 212                  * it will forcibly unwire the pages in the range.
 213                  *
 214                  * XXX If the pages cannot be wired, no error is returned.
 215                  */
 216                 if ((map->flags & MAP_WIREFUTURE) == MAP_WIREFUTURE)
 217                         do_map_wirefuture = TRUE;
 218         } else if (new < old) {
 219                 rv = vm_map_delete(map, new, old);
 220                 if (rv != KERN_SUCCESS) {
 221                         error = ENOMEM;
 222                         goto done;
 223                 }
 224                 vm->vm_dsize -= btoc(old - new);
 225 #ifdef RACCT
 226                 if (racct_enable) {
 227                         PROC_LOCK(td->td_proc);
 228                         racct_set_force(td->td_proc, RACCT_DATA, new - base);
 229                         racct_set_force(td->td_proc, RACCT_VMEM, map->size);
 230                         if (!old_mlock && map->flags & MAP_WIREFUTURE) {
 231                                 racct_set_force(td->td_proc, RACCT_MEMLOCK,
 232                                     ptoa(pmap_wired_count(map->pmap)));
 233                         }
 234                         PROC_UNLOCK(td->td_proc);
 235                 }
 236 #endif
 237         }
 238 done:
 239         vm_map_unlock(map);
 240
 241         if (do_map_wirefuture)
 242                 (void) vm_map_wire(map, old, new,
 243                     VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
 244
 245         if (error == 0)
 246                 *addr = new;
 247
 248         return (error);
 249 }
 250
 251 #ifdef COMPAT_FREEBSD11
 252 int
 253 freebsd11_vadvise(struct thread *td, struct freebsd11_vadvise_args *uap)
 254 {
 255
 256         return (EINVAL);
 257 }
 258 #endif