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 #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