sys/vm/vm_mmap.c

   1 /*-
   2  * Copyright (c) 1988 University of Utah.
   3  * Copyright (c) 1991, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * the Systems Programming Group of the University of Utah Computer
   8  * Science Department.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 4. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
  35  *
  36  *      @(#)vm_mmap.c   8.4 (Berkeley) 1/12/94
  37  */
  38
  39 /*
  40  * Mapped file (mmap) interface to VM
  41  */
  42
  43 #include <sys/cdefs.h>
  44 __FBSDID("$FreeBSD$");
  45
  46 #include "opt_compat.h"
  47 #include "opt_hwpmc_hooks.h"
  48 #include "opt_vm.h"
  49
  50 #include <sys/param.h>
  51 #include <sys/systm.h>
  52 #include <sys/capsicum.h>
  53 #include <sys/kernel.h>
  54 #include <sys/lock.h>
  55 #include <sys/mutex.h>
  56 #include <sys/sysproto.h>
  57 #include <sys/filedesc.h>
  58 #include <sys/priv.h>
  59 #include <sys/proc.h>
  60 #include <sys/procctl.h>
  61 #include <sys/racct.h>
  62 #include <sys/resource.h>
  63 #include <sys/resourcevar.h>
  64 #include <sys/rwlock.h>
  65 #include <sys/sysctl.h>
  66 #include <sys/vnode.h>
  67 #include <sys/fcntl.h>
  68 #include <sys/file.h>
  69 #include <sys/mman.h>
  70 #include <sys/mount.h>
  71 #include <sys/conf.h>
  72 #include <sys/stat.h>
  73 #include <sys/syscallsubr.h>
  74 #include <sys/sysent.h>
  75 #include <sys/vmmeter.h>
  76
  77 #include <security/audit/audit.h>
  78 #include <security/mac/mac_framework.h>
  79
  80 #include <vm/vm.h>
  81 #include <vm/vm_param.h>
  82 #include <vm/pmap.h>
  83 #include <vm/vm_map.h>
  84 #include <vm/vm_object.h>
  85 #include <vm/vm_page.h>
  86 #include <vm/vm_pager.h>
  87 #include <vm/vm_pageout.h>
  88 #include <vm/vm_extern.h>
  89 #include <vm/vm_page.h>
  90 #include <vm/vnode_pager.h>
  91
  92 #ifdef HWPMC_HOOKS
  93 #include <sys/pmckern.h>
  94 #endif
  95
  96 int old_mlock = 0;
  97 SYSCTL_INT(_vm, OID_AUTO, old_mlock, CTLFLAG_RWTUN, &old_mlock, 0,
  98     "Do not apply RLIMIT_MEMLOCK on mlockall");
  99
 100 #ifdef MAP_32BIT
 101 #define MAP_32BIT_MAX_ADDR      ((vm_offset_t)1 << 31)
 102 #endif
 103
 104 #ifndef _SYS_SYSPROTO_H_
 105 struct sbrk_args {
 106         int incr;
 107 };
 108 #endif
 109
 110 /*
 111  * MPSAFE
 112  */
 113 /* ARGSUSED */
 114 int
 115 sys_sbrk(td, uap)
 116         struct thread *td;
 117         struct sbrk_args *uap;
 118 {
 119         /* Not yet implemented */
 120         return (EOPNOTSUPP);
 121 }
 122
 123 #ifndef _SYS_SYSPROTO_H_
 124 struct sstk_args {
 125         int incr;
 126 };
 127 #endif
 128
 129 /*
 130  * MPSAFE
 131  */
 132 /* ARGSUSED */
 133 int
 134 sys_sstk(td, uap)
 135         struct thread *td;
 136         struct sstk_args *uap;
 137 {
 138         /* Not yet implemented */
 139         return (EOPNOTSUPP);
 140 }
 141
 142 #if defined(COMPAT_43)
 143 #ifndef _SYS_SYSPROTO_H_
 144 struct getpagesize_args {
 145         int dummy;
 146 };
 147 #endif
 148
 149 int
 150 ogetpagesize(td, uap)
 151         struct thread *td;
 152         struct getpagesize_args *uap;
 153 {
 154         /* MP SAFE */
 155         td->td_retval[0] = PAGE_SIZE;
 156         return (0);
 157 }
 158 #endif                          /* COMPAT_43 */
 159
 160
 161 /*
 162  * Memory Map (mmap) system call.  Note that the file offset
 163  * and address are allowed to be NOT page aligned, though if
 164  * the MAP_FIXED flag it set, both must have the same remainder
 165  * modulo the PAGE_SIZE (POSIX 1003.1b).  If the address is not
 166  * page-aligned, the actual mapping starts at trunc_page(addr)
 167  * and the return value is adjusted up by the page offset.
 168  *
 169  * Generally speaking, only character devices which are themselves
 170  * memory-based, such as a video framebuffer, can be mmap'd.  Otherwise
 171  * there would be no cache coherency between a descriptor and a VM mapping
 172  * both to the same character device.
 173  */
 174 #ifndef _SYS_SYSPROTO_H_
 175 struct mmap_args {
 176         void *addr;
 177         size_t len;
 178         int prot;
 179         int flags;
 180         int fd;
 181         long pad;
 182         off_t pos;
 183 };
 184 #endif
 185
 186 /*
 187  * MPSAFE
 188  */
 189 int
 190 sys_mmap(td, uap)
 191         struct thread *td;
 192         struct mmap_args *uap;
 193 {
 194         struct file *fp;
 195         vm_offset_t addr;
 196         vm_size_t size, pageoff;
 197         vm_prot_t cap_maxprot;
 198         int align, error, flags, prot;
 199         off_t pos;
 200         struct vmspace *vms = td->td_proc->p_vmspace;
 201         cap_rights_t rights;
 202
 203         addr = (vm_offset_t) uap->addr;
 204         size = uap->len;
 205         prot = uap->prot;
 206         flags = uap->flags;
 207         pos = uap->pos;
 208
 209         fp = NULL;
 210         AUDIT_ARG_FD(uap->fd);
 211
 212         /*
 213          * Ignore old flags that used to be defined but did not do anything.
 214          */
 215         flags &= ~(MAP_RESERVED0020 | MAP_RESERVED0040);
 216
 217         /*
 218          * Enforce the constraints.
 219          * Mapping of length 0 is only allowed for old binaries.
 220          * Anonymous mapping shall specify -1 as filedescriptor and
 221          * zero position for new code. Be nice to ancient a.out
 222          * binaries and correct pos for anonymous mapping, since old
 223          * ld.so sometimes issues anonymous map requests with non-zero
 224          * pos.
 225          */
 226         if (!SV_CURPROC_FLAG(SV_AOUT)) {
 227                 if ((uap->len == 0 && curproc->p_osrel >= P_OSREL_MAP_ANON) ||
 228                     ((flags & MAP_ANON) != 0 && (uap->fd != -1 || pos != 0)))
 229                         return (EINVAL);
 230         } else {
 231                 if ((flags & MAP_ANON) != 0)
 232                         pos = 0;
 233         }
 234
 235         if (flags & MAP_STACK) {
 236                 if ((uap->fd != -1) ||
 237                     ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
 238                         return (EINVAL);
 239                 flags |= MAP_ANON;
 240                 pos = 0;
 241         }
 242         if ((flags & ~(MAP_SHARED | MAP_PRIVATE | MAP_FIXED | MAP_HASSEMAPHORE |
 243             MAP_STACK | MAP_NOSYNC | MAP_ANON | MAP_EXCL | MAP_NOCORE |
 244             MAP_PREFAULT_READ |
 245 #ifdef MAP_32BIT
 246             MAP_32BIT |
 247 #endif
 248             MAP_ALIGNMENT_MASK)) != 0)
 249                 return (EINVAL);
 250         if ((flags & (MAP_EXCL | MAP_FIXED)) == MAP_EXCL)
 251                 return (EINVAL);
 252         if ((flags & (MAP_SHARED | MAP_PRIVATE)) == (MAP_SHARED | MAP_PRIVATE))
 253                 return (EINVAL);
 254         if (prot != PROT_NONE &&
 255             (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) != 0)
 256                 return (EINVAL);
 257
 258         /*
 259          * Align the file position to a page boundary,
 260          * and save its page offset component.
 261          */
 262         pageoff = (pos & PAGE_MASK);
 263         pos -= pageoff;
 264
 265         /* Adjust size for rounding (on both ends). */
 266         size += pageoff;                        /* low end... */
 267         size = (vm_size_t) round_page(size);    /* hi end */
 268
 269         /* Ensure alignment is at least a page and fits in a pointer. */
 270         align = flags & MAP_ALIGNMENT_MASK;
 271         if (align != 0 && align != MAP_ALIGNED_SUPER &&
 272             (align >> MAP_ALIGNMENT_SHIFT >= sizeof(void *) * NBBY ||
 273             align >> MAP_ALIGNMENT_SHIFT < PAGE_SHIFT))
 274                 return (EINVAL);
 275
 276         /*
 277          * Check for illegal addresses.  Watch out for address wrap... Note
 278          * that VM_*_ADDRESS are not constants due to casts (argh).
 279          */
 280         if (flags & MAP_FIXED) {
 281                 /*
 282                  * The specified address must have the same remainder
 283                  * as the file offset taken modulo PAGE_SIZE, so it
 284                  * should be aligned after adjustment by pageoff.
 285                  */
 286                 addr -= pageoff;
 287                 if (addr & PAGE_MASK)
 288                         return (EINVAL);
 289
 290                 /* Address range must be all in user VM space. */
 291                 if (addr < vm_map_min(&vms->vm_map) ||
 292                     addr + size > vm_map_max(&vms->vm_map))
 293                         return (EINVAL);
 294                 if (addr + size < addr)
 295                         return (EINVAL);
 296 #ifdef MAP_32BIT
 297                 if (flags & MAP_32BIT && addr + size > MAP_32BIT_MAX_ADDR)
 298                         return (EINVAL);
 299         } else if (flags & MAP_32BIT) {
 300                 /*
 301                  * For MAP_32BIT, override the hint if it is too high and
 302                  * do not bother moving the mapping past the heap (since
 303                  * the heap is usually above 2GB).
 304                  */
 305                 if (addr + size > MAP_32BIT_MAX_ADDR)
 306                         addr = 0;
 307 #endif
 308         } else {
 309                 /*
 310                  * XXX for non-fixed mappings where no hint is provided or
 311                  * the hint would fall in the potential heap space,
 312                  * place it after the end of the largest possible heap.
 313                  *
 314                  * There should really be a pmap call to determine a reasonable
 315                  * location.
 316                  */
 317                 if (addr == 0 ||
 318                     (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
 319                     addr < round_page((vm_offset_t)vms->vm_daddr +
 320                     lim_max(td, RLIMIT_DATA))))
 321                         addr = round_page((vm_offset_t)vms->vm_daddr +
 322                             lim_max(td, RLIMIT_DATA));
 323         }
 324         if (size == 0) {
 325                 /*
 326                  * Return success without mapping anything for old
 327                  * binaries that request a page-aligned mapping of
 328                  * length 0.  For modern binaries, this function
 329                  * returns an error earlier.
 330                  */
 331                 error = 0;
 332         } else if (flags & MAP_ANON) {
 333                 /*
 334                  * Mapping blank space is trivial.
 335                  *
 336                  * This relies on VM_PROT_* matching PROT_*.
 337                  */
 338                 error = vm_mmap_object(&vms->vm_map, &addr, size, prot,
 339                     VM_PROT_ALL, flags, NULL, pos, FALSE, td);
 340         } else {
 341                 /*
 342                  * Mapping file, get fp for validation and don't let the
 343                  * descriptor disappear on us if we block. Check capability
 344                  * rights, but also return the maximum rights to be combined
 345                  * with maxprot later.
 346                  */
 347                 cap_rights_init(&rights, CAP_MMAP);
 348                 if (prot & PROT_READ)
 349                         cap_rights_set(&rights, CAP_MMAP_R);
 350                 if ((flags & MAP_SHARED) != 0) {
 351                         if (prot & PROT_WRITE)
 352                                 cap_rights_set(&rights, CAP_MMAP_W);
 353                 }
 354                 if (prot & PROT_EXEC)
 355                         cap_rights_set(&rights, CAP_MMAP_X);
 356                 error = fget_mmap(td, uap->fd, &rights, &cap_maxprot, &fp);
 357                 if (error != 0)
 358                         goto done;
 359                 if ((flags & (MAP_SHARED | MAP_PRIVATE)) == 0 &&
 360                     td->td_proc->p_osrel >= P_OSREL_MAP_FSTRICT) {
 361                         error = EINVAL;
 362                         goto done;
 363                 }
 364
 365                 /* This relies on VM_PROT_* matching PROT_*. */
 366                 error = fo_mmap(fp, &vms->vm_map, &addr, size, prot,
 367                     cap_maxprot, flags, pos, td);
 368         }
 369
 370         if (error == 0)
 371                 td->td_retval[0] = (register_t) (addr + pageoff);
 372 done:
 373         if (fp)
 374                 fdrop(fp, td);
 375
 376         return (error);
 377 }
 378
 379 #if defined(COMPAT_FREEBSD6)
 380 int
 381 freebsd6_mmap(struct thread *td, struct freebsd6_mmap_args *uap)
 382 {
 383         struct mmap_args oargs;
 384
 385         oargs.addr = uap->addr;
 386         oargs.len = uap->len;
 387         oargs.prot = uap->prot;
 388         oargs.flags = uap->flags;
 389         oargs.fd = uap->fd;
 390         oargs.pos = uap->pos;
 391         return (sys_mmap(td, &oargs));
 392 }
 393 #endif
 394
 395 #ifdef COMPAT_43
 396 #ifndef _SYS_SYSPROTO_H_
 397 struct ommap_args {
 398         caddr_t addr;
 399         int len;
 400         int prot;
 401         int flags;
 402         int fd;
 403         long pos;
 404 };
 405 #endif
 406 int
 407 ommap(td, uap)
 408         struct thread *td;
 409         struct ommap_args *uap;
 410 {
 411         struct mmap_args nargs;
 412         static const char cvtbsdprot[8] = {
 413                 0,
 414                 PROT_EXEC,
 415                 PROT_WRITE,
 416                 PROT_EXEC | PROT_WRITE,
 417                 PROT_READ,
 418                 PROT_EXEC | PROT_READ,
 419                 PROT_WRITE | PROT_READ,
 420                 PROT_EXEC | PROT_WRITE | PROT_READ,
 421         };
 422
 423 #define OMAP_ANON       0x0002
 424 #define OMAP_COPY       0x0020
 425 #define OMAP_SHARED     0x0010
 426 #define OMAP_FIXED      0x0100
 427
 428         nargs.addr = uap->addr;
 429         nargs.len = uap->len;
 430         nargs.prot = cvtbsdprot[uap->prot & 0x7];
 431 #ifdef COMPAT_FREEBSD32
 432 #if defined(__amd64__)
 433         if (i386_read_exec && SV_PROC_FLAG(td->td_proc, SV_ILP32) &&
 434             nargs.prot != 0)
 435                 nargs.prot |= PROT_EXEC;
 436 #endif
 437 #endif
 438         nargs.flags = 0;
 439         if (uap->flags & OMAP_ANON)
 440                 nargs.flags |= MAP_ANON;
 441         if (uap->flags & OMAP_COPY)
 442                 nargs.flags |= MAP_COPY;
 443         if (uap->flags & OMAP_SHARED)
 444                 nargs.flags |= MAP_SHARED;
 445         else
 446                 nargs.flags |= MAP_PRIVATE;
 447         if (uap->flags & OMAP_FIXED)
 448                 nargs.flags |= MAP_FIXED;
 449         nargs.fd = uap->fd;
 450         nargs.pos = uap->pos;
 451         return (sys_mmap(td, &nargs));
 452 }
 453 #endif                          /* COMPAT_43 */
 454
 455
 456 #ifndef _SYS_SYSPROTO_H_
 457 struct msync_args {
 458         void *addr;
 459         size_t len;
 460         int flags;
 461 };
 462 #endif
 463 /*
 464  * MPSAFE
 465  */
 466 int
 467 sys_msync(td, uap)
 468         struct thread *td;
 469         struct msync_args *uap;
 470 {
 471         vm_offset_t addr;
 472         vm_size_t size, pageoff;
 473         int flags;
 474         vm_map_t map;
 475         int rv;
 476
 477         addr = (vm_offset_t) uap->addr;
 478         size = uap->len;
 479         flags = uap->flags;
 480
 481         pageoff = (addr & PAGE_MASK);
 482         addr -= pageoff;
 483         size += pageoff;
 484         size = (vm_size_t) round_page(size);
 485         if (addr + size < addr)
 486                 return (EINVAL);
 487
 488         if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
 489                 return (EINVAL);
 490
 491         map = &td->td_proc->p_vmspace->vm_map;
 492
 493         /*
 494          * Clean the pages and interpret the return value.
 495          */
 496         rv = vm_map_sync(map, addr, addr + size, (flags & MS_ASYNC) == 0,
 497             (flags & MS_INVALIDATE) != 0);
 498         switch (rv) {
 499         case KERN_SUCCESS:
 500                 return (0);
 501         case KERN_INVALID_ADDRESS:
 502                 return (ENOMEM);
 503         case KERN_INVALID_ARGUMENT:
 504                 return (EBUSY);
 505         case KERN_FAILURE:
 506                 return (EIO);
 507         default:
 508                 return (EINVAL);
 509         }
 510 }
 511
 512 #ifndef _SYS_SYSPROTO_H_
 513 struct munmap_args {
 514         void *addr;
 515         size_t len;
 516 };
 517 #endif
 518 /*
 519  * MPSAFE
 520  */
 521 int
 522 sys_munmap(td, uap)
 523         struct thread *td;
 524         struct munmap_args *uap;
 525 {
 526 #ifdef HWPMC_HOOKS
 527         struct pmckern_map_out pkm;
 528         vm_map_entry_t entry;
 529 #endif
 530         vm_offset_t addr;
 531         vm_size_t size, pageoff;
 532         vm_map_t map;
 533
 534         addr = (vm_offset_t) uap->addr;
 535         size = uap->len;
 536         if (size == 0)
 537                 return (EINVAL);
 538
 539         pageoff = (addr & PAGE_MASK);
 540         addr -= pageoff;
 541         size += pageoff;
 542         size = (vm_size_t) round_page(size);
 543         if (addr + size < addr)
 544                 return (EINVAL);
 545
 546         /*
 547          * Check for illegal addresses.  Watch out for address wrap...
 548          */
 549         map = &td->td_proc->p_vmspace->vm_map;
 550         if (addr < vm_map_min(map) || addr + size > vm_map_max(map))
 551                 return (EINVAL);
 552         vm_map_lock(map);
 553 #ifdef HWPMC_HOOKS
 554         /*
 555          * Inform hwpmc if the address range being unmapped contains
 556          * an executable region.
 557          */
 558         pkm.pm_address = (uintptr_t) NULL;
 559         if (vm_map_lookup_entry(map, addr, &entry)) {
 560                 for (;
 561                      entry != &map->header && entry->start < addr + size;
 562                      entry = entry->next) {
 563                         if (vm_map_check_protection(map, entry->start,
 564                                 entry->end, VM_PROT_EXECUTE) == TRUE) {
 565                                 pkm.pm_address = (uintptr_t) addr;
 566                                 pkm.pm_size = (size_t) size;
 567                                 break;
 568                         }
 569                 }
 570         }
 571 #endif
 572         vm_map_delete(map, addr, addr + size);
 573
 574 #ifdef HWPMC_HOOKS
 575         /* downgrade the lock to prevent a LOR with the pmc-sx lock */
 576         vm_map_lock_downgrade(map);
 577         if (pkm.pm_address != (uintptr_t) NULL)
 578                 PMC_CALL_HOOK(td, PMC_FN_MUNMAP, (void *) &pkm);
 579         vm_map_unlock_read(map);
 580 #else
 581         vm_map_unlock(map);
 582 #endif
 583         /* vm_map_delete returns nothing but KERN_SUCCESS anyway */
 584         return (0);
 585 }
 586
 587 #ifndef _SYS_SYSPROTO_H_
 588 struct mprotect_args {
 589         const void *addr;
 590         size_t len;
 591         int prot;
 592 };
 593 #endif
 594 /*
 595  * MPSAFE
 596  */
 597 int
 598 sys_mprotect(td, uap)
 599         struct thread *td;
 600         struct mprotect_args *uap;
 601 {
 602         vm_offset_t addr;
 603         vm_size_t size, pageoff;
 604         vm_prot_t prot;
 605
 606         addr = (vm_offset_t) uap->addr;
 607         size = uap->len;
 608         prot = uap->prot & VM_PROT_ALL;
 609
 610         pageoff = (addr & PAGE_MASK);
 611         addr -= pageoff;
 612         size += pageoff;
 613         size = (vm_size_t) round_page(size);
 614         if (addr + size < addr)
 615                 return (EINVAL);
 616
 617         switch (vm_map_protect(&td->td_proc->p_vmspace->vm_map, addr,
 618             addr + size, prot, FALSE)) {
 619         case KERN_SUCCESS:
 620                 return (0);
 621         case KERN_PROTECTION_FAILURE:
 622                 return (EACCES);
 623         case KERN_RESOURCE_SHORTAGE:
 624                 return (ENOMEM);
 625         }
 626         return (EINVAL);
 627 }
 628
 629 #ifndef _SYS_SYSPROTO_H_
 630 struct minherit_args {
 631         void *addr;
 632         size_t len;
 633         int inherit;
 634 };
 635 #endif
 636 /*
 637  * MPSAFE
 638  */
 639 int
 640 sys_minherit(td, uap)
 641         struct thread *td;
 642         struct minherit_args *uap;
 643 {
 644         vm_offset_t addr;
 645         vm_size_t size, pageoff;
 646         vm_inherit_t inherit;
 647
 648         addr = (vm_offset_t)uap->addr;
 649         size = uap->len;
 650         inherit = uap->inherit;
 651
 652         pageoff = (addr & PAGE_MASK);
 653         addr -= pageoff;
 654         size += pageoff;
 655         size = (vm_size_t) round_page(size);
 656         if (addr + size < addr)
 657                 return (EINVAL);
 658
 659         switch (vm_map_inherit(&td->td_proc->p_vmspace->vm_map, addr,
 660             addr + size, inherit)) {
 661         case KERN_SUCCESS:
 662                 return (0);
 663         case KERN_PROTECTION_FAILURE:
 664                 return (EACCES);
 665         }
 666         return (EINVAL);
 667 }
 668
 669 #ifndef _SYS_SYSPROTO_H_
 670 struct madvise_args {
 671         void *addr;
 672         size_t len;
 673         int behav;
 674 };
 675 #endif
 676
 677 /*
 678  * MPSAFE
 679  */
 680 int
 681 sys_madvise(td, uap)
 682         struct thread *td;
 683         struct madvise_args *uap;
 684 {
 685         vm_offset_t start, end;
 686         vm_map_t map;
 687         int flags;
 688
 689         /*
 690          * Check for our special case, advising the swap pager we are
 691          * "immortal."
 692          */
 693         if (uap->behav == MADV_PROTECT) {
 694                 flags = PPROT_SET;
 695                 return (kern_procctl(td, P_PID, td->td_proc->p_pid,
 696                     PROC_SPROTECT, &flags));
 697         }
 698
 699         /*
 700          * Check for illegal behavior
 701          */
 702         if (uap->behav < 0 || uap->behav > MADV_CORE)
 703                 return (EINVAL);
 704         /*
 705          * Check for illegal addresses.  Watch out for address wrap... Note
 706          * that VM_*_ADDRESS are not constants due to casts (argh).
 707          */
 708         map = &td->td_proc->p_vmspace->vm_map;
 709         if ((vm_offset_t)uap->addr < vm_map_min(map) ||
 710             (vm_offset_t)uap->addr + uap->len > vm_map_max(map))
 711                 return (EINVAL);
 712         if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
 713                 return (EINVAL);
 714
 715         /*
 716          * Since this routine is only advisory, we default to conservative
 717          * behavior.
 718          */
 719         start = trunc_page((vm_offset_t) uap->addr);
 720         end = round_page((vm_offset_t) uap->addr + uap->len);
 721
 722         if (vm_map_madvise(map, start, end, uap->behav))
 723                 return (EINVAL);
 724         return (0);
 725 }
 726
 727 #ifndef _SYS_SYSPROTO_H_
 728 struct mincore_args {
 729         const void *addr;
 730         size_t len;
 731         char *vec;
 732 };
 733 #endif
 734
 735 /*
 736  * MPSAFE
 737  */
 738 int
 739 sys_mincore(td, uap)
 740         struct thread *td;
 741         struct mincore_args *uap;
 742 {
 743         vm_offset_t addr, first_addr;
 744         vm_offset_t end, cend;
 745         pmap_t pmap;
 746         vm_map_t map;
 747         char *vec;
 748         int error = 0;
 749         int vecindex, lastvecindex;
 750         vm_map_entry_t current;
 751         vm_map_entry_t entry;
 752         vm_object_t object;
 753         vm_paddr_t locked_pa;
 754         vm_page_t m;
 755         vm_pindex_t pindex;
 756         int mincoreinfo;
 757         unsigned int timestamp;
 758         boolean_t locked;
 759
 760         /*
 761          * Make sure that the addresses presented are valid for user
 762          * mode.
 763          */
 764         first_addr = addr = trunc_page((vm_offset_t) uap->addr);
 765         end = addr + (vm_size_t)round_page(uap->len);
 766         map = &td->td_proc->p_vmspace->vm_map;
 767         if (end > vm_map_max(map) || end < addr)
 768                 return (ENOMEM);
 769
 770         /*
 771          * Address of byte vector
 772          */
 773         vec = uap->vec;
 774
 775         pmap = vmspace_pmap(td->td_proc->p_vmspace);
 776
 777         vm_map_lock_read(map);
 778 RestartScan:
 779         timestamp = map->timestamp;
 780
 781         if (!vm_map_lookup_entry(map, addr, &entry)) {
 782                 vm_map_unlock_read(map);
 783                 return (ENOMEM);
 784         }
 785
 786         /*
 787          * Do this on a map entry basis so that if the pages are not
 788          * in the current processes address space, we can easily look
 789          * up the pages elsewhere.
 790          */
 791         lastvecindex = -1;
 792         for (current = entry;
 793             (current != &map->header) && (current->start < end);
 794             current = current->next) {
 795
 796                 /*
 797                  * check for contiguity
 798                  */
 799                 if (current->end < end &&
 800                     (entry->next == &map->header ||
 801                      current->next->start > current->end)) {
 802                         vm_map_unlock_read(map);
 803                         return (ENOMEM);
 804                 }
 805
 806                 /*
 807                  * ignore submaps (for now) or null objects
 808                  */
 809                 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
 810                         current->object.vm_object == NULL)
 811                         continue;
 812
 813                 /*
 814                  * limit this scan to the current map entry and the
 815                  * limits for the mincore call
 816                  */
 817                 if (addr < current->start)
 818                         addr = current->start;
 819                 cend = current->end;
 820                 if (cend > end)
 821                         cend = end;
 822
 823                 /*
 824                  * scan this entry one page at a time
 825                  */
 826                 while (addr < cend) {
 827                         /*
 828                          * Check pmap first, it is likely faster, also
 829                          * it can provide info as to whether we are the
 830                          * one referencing or modifying the page.
 831                          */
 832                         object = NULL;
 833                         locked_pa = 0;
 834                 retry:
 835                         m = NULL;
 836                         mincoreinfo = pmap_mincore(pmap, addr, &locked_pa);
 837                         if (locked_pa != 0) {
 838                                 /*
 839                                  * The page is mapped by this process but not
 840                                  * both accessed and modified.  It is also
 841                                  * managed.  Acquire the object lock so that
 842                                  * other mappings might be examined.
 843                                  */
 844                                 m = PHYS_TO_VM_PAGE(locked_pa);
 845                                 if (m->object != object) {
 846                                         if (object != NULL)
 847                                                 VM_OBJECT_WUNLOCK(object);
 848                                         object = m->object;
 849                                         locked = VM_OBJECT_TRYWLOCK(object);
 850                                         vm_page_unlock(m);
 851                                         if (!locked) {
 852                                                 VM_OBJECT_WLOCK(object);
 853                                                 vm_page_lock(m);
 854                                                 goto retry;
 855                                         }
 856                                 } else
 857                                         vm_page_unlock(m);
 858                                 KASSERT(m->valid == VM_PAGE_BITS_ALL,
 859                                     ("mincore: page %p is mapped but invalid",
 860                                     m));
 861                         } else if (mincoreinfo == 0) {
 862                                 /*
 863                                  * The page is not mapped by this process.  If
 864                                  * the object implements managed pages, then
 865                                  * determine if the page is resident so that
 866                                  * the mappings might be examined.
 867                                  */
 868                                 if (current->object.vm_object != object) {
 869                                         if (object != NULL)
 870                                                 VM_OBJECT_WUNLOCK(object);
 871                                         object = current->object.vm_object;
 872                                         VM_OBJECT_WLOCK(object);
 873                                 }
 874                                 if (object->type == OBJT_DEFAULT ||
 875                                     object->type == OBJT_SWAP ||
 876                                     object->type == OBJT_VNODE) {
 877                                         pindex = OFF_TO_IDX(current->offset +
 878                                             (addr - current->start));
 879                                         m = vm_page_lookup(object, pindex);
 880                                         if (m == NULL &&
 881                                             vm_page_is_cached(object, pindex))
 882                                                 mincoreinfo = MINCORE_INCORE;
 883                                         if (m != NULL && m->valid == 0)
 884                                                 m = NULL;
 885                                         if (m != NULL)
 886                                                 mincoreinfo = MINCORE_INCORE;
 887                                 }
 888                         }
 889                         if (m != NULL) {
 890                                 /* Examine other mappings to the page. */
 891                                 if (m->dirty == 0 && pmap_is_modified(m))
 892                                         vm_page_dirty(m);
 893                                 if (m->dirty != 0)
 894                                         mincoreinfo |= MINCORE_MODIFIED_OTHER;
 895                                 /*
 896                                  * The first test for PGA_REFERENCED is an
 897                                  * optimization.  The second test is
 898                                  * required because a concurrent pmap
 899                                  * operation could clear the last reference
 900                                  * and set PGA_REFERENCED before the call to
 901                                  * pmap_is_referenced().
 902                                  */
 903                                 if ((m->aflags & PGA_REFERENCED) != 0 ||
 904                                     pmap_is_referenced(m) ||
 905                                     (m->aflags & PGA_REFERENCED) != 0)
 906                                         mincoreinfo |= MINCORE_REFERENCED_OTHER;
 907                         }
 908                         if (object != NULL)
 909                                 VM_OBJECT_WUNLOCK(object);
 910
 911                         /*
 912                          * subyte may page fault.  In case it needs to modify
 913                          * the map, we release the lock.
 914                          */
 915                         vm_map_unlock_read(map);
 916
 917                         /*
 918                          * calculate index into user supplied byte vector
 919                          */
 920                         vecindex = OFF_TO_IDX(addr - first_addr);
 921
 922                         /*
 923                          * If we have skipped map entries, we need to make sure that
 924                          * the byte vector is zeroed for those skipped entries.
 925                          */
 926                         while ((lastvecindex + 1) < vecindex) {
 927                                 ++lastvecindex;
 928                                 error = subyte(vec + lastvecindex, 0);
 929                                 if (error) {
 930                                         error = EFAULT;
 931                                         goto done2;
 932                                 }
 933                         }
 934
 935                         /*
 936                          * Pass the page information to the user
 937                          */
 938                         error = subyte(vec + vecindex, mincoreinfo);
 939                         if (error) {
 940                                 error = EFAULT;
 941                                 goto done2;
 942                         }
 943
 944                         /*
 945                          * If the map has changed, due to the subyte, the previous
 946                          * output may be invalid.
 947                          */
 948                         vm_map_lock_read(map);
 949                         if (timestamp != map->timestamp)
 950                                 goto RestartScan;
 951
 952                         lastvecindex = vecindex;
 953                         addr += PAGE_SIZE;
 954                 }
 955         }
 956
 957         /*
 958          * subyte may page fault.  In case it needs to modify
 959          * the map, we release the lock.
 960          */
 961         vm_map_unlock_read(map);
 962
 963         /*
 964          * Zero the last entries in the byte vector.
 965          */
 966         vecindex = OFF_TO_IDX(end - first_addr);
 967         while ((lastvecindex + 1) < vecindex) {
 968                 ++lastvecindex;
 969                 error = subyte(vec + lastvecindex, 0);
 970                 if (error) {
 971                         error = EFAULT;
 972                         goto done2;
 973                 }
 974         }
 975
 976         /*
 977          * If the map has changed, due to the subyte, the previous
 978          * output may be invalid.
 979          */
 980         vm_map_lock_read(map);
 981         if (timestamp != map->timestamp)
 982                 goto RestartScan;
 983         vm_map_unlock_read(map);
 984 done2:
 985         return (error);
 986 }
 987
 988 #ifndef _SYS_SYSPROTO_H_
 989 struct mlock_args {
 990         const void *addr;
 991         size_t len;
 992 };
 993 #endif
 994 /*
 995  * MPSAFE
 996  */
 997 int
 998 sys_mlock(td, uap)
 999         struct thread *td;
1000         struct mlock_args *uap;
1001 {
1002
1003         return (vm_mlock(td->td_proc, td->td_ucred, uap->addr, uap->len));
1004 }
1005
1006 int
1007 vm_mlock(struct proc *proc, struct ucred *cred, const void *addr0, size_t len)
1008 {
1009         vm_offset_t addr, end, last, start;
1010         vm_size_t npages, size;
1011         vm_map_t map;
1012         unsigned long nsize;
1013         int error;
1014
1015         error = priv_check_cred(cred, PRIV_VM_MLOCK, 0);
1016         if (error)
1017                 return (error);
1018         addr = (vm_offset_t)addr0;
1019         size = len;
1020         last = addr + size;
1021         start = trunc_page(addr);
1022         end = round_page(last);
1023         if (last < addr || end < addr)
1024                 return (EINVAL);
1025         npages = atop(end - start);
1026         if (npages > vm_page_max_wired)
1027                 return (ENOMEM);
1028         map = &proc->p_vmspace->vm_map;
1029         PROC_LOCK(proc);
1030         nsize = ptoa(npages + pmap_wired_count(map->pmap));
1031         if (nsize > lim_cur_proc(proc, RLIMIT_MEMLOCK)) {
1032                 PROC_UNLOCK(proc);
1033                 return (ENOMEM);
1034         }
1035         PROC_UNLOCK(proc);
1036         if (npages + vm_cnt.v_wire_count > vm_page_max_wired)
1037                 return (EAGAIN);
1038 #ifdef RACCT
1039         if (racct_enable) {
1040                 PROC_LOCK(proc);
1041                 error = racct_set(proc, RACCT_MEMLOCK, nsize);
1042                 PROC_UNLOCK(proc);
1043                 if (error != 0)
1044                         return (ENOMEM);
1045         }
1046 #endif
1047         error = vm_map_wire(map, start, end,
1048             VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
1049 #ifdef RACCT
1050         if (racct_enable && error != KERN_SUCCESS) {
1051                 PROC_LOCK(proc);
1052                 racct_set(proc, RACCT_MEMLOCK,
1053                     ptoa(pmap_wired_count(map->pmap)));
1054                 PROC_UNLOCK(proc);
1055         }
1056 #endif
1057         return (error == KERN_SUCCESS ? 0 : ENOMEM);
1058 }
1059
1060 #ifndef _SYS_SYSPROTO_H_
1061 struct mlockall_args {
1062         int     how;
1063 };
1064 #endif
1065
1066 /*
1067  * MPSAFE
1068  */
1069 int
1070 sys_mlockall(td, uap)
1071         struct thread *td;
1072         struct mlockall_args *uap;
1073 {
1074         vm_map_t map;
1075         int error;
1076
1077         map = &td->td_proc->p_vmspace->vm_map;
1078         error = priv_check(td, PRIV_VM_MLOCK);
1079         if (error)
1080                 return (error);
1081
1082         if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0))
1083                 return (EINVAL);
1084
1085         /*
1086          * If wiring all pages in the process would cause it to exceed
1087          * a hard resource limit, return ENOMEM.
1088          */
1089         if (!old_mlock && uap->how & MCL_CURRENT) {
1090                 PROC_LOCK(td->td_proc);
1091                 if (map->size > lim_cur(td, RLIMIT_MEMLOCK)) {
1092                         PROC_UNLOCK(td->td_proc);
1093                         return (ENOMEM);
1094                 }
1095                 PROC_UNLOCK(td->td_proc);
1096         }
1097 #ifdef RACCT
1098         if (racct_enable) {
1099                 PROC_LOCK(td->td_proc);
1100                 error = racct_set(td->td_proc, RACCT_MEMLOCK, map->size);
1101                 PROC_UNLOCK(td->td_proc);
1102                 if (error != 0)
1103                         return (ENOMEM);
1104         }
1105 #endif
1106
1107         if (uap->how & MCL_FUTURE) {
1108                 vm_map_lock(map);
1109                 vm_map_modflags(map, MAP_WIREFUTURE, 0);
1110                 vm_map_unlock(map);
1111                 error = 0;
1112         }
1113
1114         if (uap->how & MCL_CURRENT) {
1115                 /*
1116                  * P1003.1-2001 mandates that all currently mapped pages
1117                  * will be memory resident and locked (wired) upon return
1118                  * from mlockall(). vm_map_wire() will wire pages, by
1119                  * calling vm_fault_wire() for each page in the region.
1120                  */
1121                 error = vm_map_wire(map, vm_map_min(map), vm_map_max(map),
1122                     VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
1123                 error = (error == KERN_SUCCESS ? 0 : EAGAIN);
1124         }
1125 #ifdef RACCT
1126         if (racct_enable && error != KERN_SUCCESS) {
1127                 PROC_LOCK(td->td_proc);
1128                 racct_set(td->td_proc, RACCT_MEMLOCK,
1129                     ptoa(pmap_wired_count(map->pmap)));
1130                 PROC_UNLOCK(td->td_proc);
1131         }
1132 #endif
1133
1134         return (error);
1135 }
1136
1137 #ifndef _SYS_SYSPROTO_H_
1138 struct munlockall_args {
1139         register_t dummy;
1140 };
1141 #endif
1142
1143 /*
1144  * MPSAFE
1145  */
1146 int
1147 sys_munlockall(td, uap)
1148         struct thread *td;
1149         struct munlockall_args *uap;
1150 {
1151         vm_map_t map;
1152         int error;
1153
1154         map = &td->td_proc->p_vmspace->vm_map;
1155         error = priv_check(td, PRIV_VM_MUNLOCK);
1156         if (error)
1157                 return (error);
1158
1159         /* Clear the MAP_WIREFUTURE flag from this vm_map. */
1160         vm_map_lock(map);
1161         vm_map_modflags(map, 0, MAP_WIREFUTURE);
1162         vm_map_unlock(map);
1163
1164         /* Forcibly unwire all pages. */
1165         error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map),
1166             VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
1167 #ifdef RACCT
1168         if (racct_enable && error == KERN_SUCCESS) {
1169                 PROC_LOCK(td->td_proc);
1170                 racct_set(td->td_proc, RACCT_MEMLOCK, 0);
1171                 PROC_UNLOCK(td->td_proc);
1172         }
1173 #endif
1174
1175         return (error);
1176 }
1177
1178 #ifndef _SYS_SYSPROTO_H_
1179 struct munlock_args {
1180         const void *addr;
1181         size_t len;
1182 };
1183 #endif
1184 /*
1185  * MPSAFE
1186  */
1187 int
1188 sys_munlock(td, uap)
1189         struct thread *td;
1190         struct munlock_args *uap;
1191 {
1192         vm_offset_t addr, end, last, start;
1193         vm_size_t size;
1194 #ifdef RACCT
1195         vm_map_t map;
1196 #endif
1197         int error;
1198
1199         error = priv_check(td, PRIV_VM_MUNLOCK);
1200         if (error)
1201                 return (error);
1202         addr = (vm_offset_t)uap->addr;
1203         size = uap->len;
1204         last = addr + size;
1205         start = trunc_page(addr);
1206         end = round_page(last);
1207         if (last < addr || end < addr)
1208                 return (EINVAL);
1209         error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, start, end,
1210             VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
1211 #ifdef RACCT
1212         if (racct_enable && error == KERN_SUCCESS) {
1213                 PROC_LOCK(td->td_proc);
1214                 map = &td->td_proc->p_vmspace->vm_map;
1215                 racct_set(td->td_proc, RACCT_MEMLOCK,
1216                     ptoa(pmap_wired_count(map->pmap)));
1217                 PROC_UNLOCK(td->td_proc);
1218         }
1219 #endif
1220         return (error == KERN_SUCCESS ? 0 : ENOMEM);
1221 }
1222
1223 /*
1224  * vm_mmap_vnode()
1225  *
1226  * Helper function for vm_mmap.  Perform sanity check specific for mmap
1227  * operations on vnodes.
1228  */
1229 int
1230 vm_mmap_vnode(struct thread *td, vm_size_t objsize,
1231     vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
1232     struct vnode *vp, vm_ooffset_t *foffp, vm_object_t *objp,
1233     boolean_t *writecounted)
1234 {
1235         struct vattr va;
1236         vm_object_t obj;
1237         vm_offset_t foff;
1238         struct ucred *cred;
1239         int error, flags, locktype;
1240
1241         cred = td->td_ucred;
1242         if ((*maxprotp & VM_PROT_WRITE) && (*flagsp & MAP_SHARED))
1243                 locktype = LK_EXCLUSIVE;
1244         else
1245                 locktype = LK_SHARED;
1246         if ((error = vget(vp, locktype, td)) != 0)
1247                 return (error);
1248         AUDIT_ARG_VNODE1(vp);
1249         foff = *foffp;
1250         flags = *flagsp;
1251         obj = vp->v_object;
1252         if (vp->v_type == VREG) {
1253                 /*
1254                  * Get the proper underlying object
1255                  */
1256                 if (obj == NULL) {
1257                         error = EINVAL;
1258                         goto done;
1259                 }
1260                 if (obj->type == OBJT_VNODE && obj->handle != vp) {
1261                         vput(vp);
1262                         vp = (struct vnode *)obj->handle;
1263                         /*
1264                          * Bypass filesystems obey the mpsafety of the
1265                          * underlying fs.  Tmpfs never bypasses.
1266                          */
1267                         error = vget(vp, locktype, td);
1268                         if (error != 0)
1269                                 return (error);
1270                 }
1271                 if (locktype == LK_EXCLUSIVE) {
1272                         *writecounted = TRUE;
1273                         vnode_pager_update_writecount(obj, 0, objsize);
1274                 }
1275         } else {
1276                 error = EINVAL;
1277                 goto done;
1278         }
1279         if ((error = VOP_GETATTR(vp, &va, cred)))
1280                 goto done;
1281 #ifdef MAC
1282         /* This relies on VM_PROT_* matching PROT_*. */
1283         error = mac_vnode_check_mmap(cred, vp, (int)prot, flags);
1284         if (error != 0)
1285                 goto done;
1286 #endif
1287         if ((flags & MAP_SHARED) != 0) {
1288                 if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) {
1289                         if (prot & VM_PROT_WRITE) {
1290                                 error = EPERM;
1291                                 goto done;
1292                         }
1293                         *maxprotp &= ~VM_PROT_WRITE;
1294                 }
1295         }
1296         /*
1297          * If it is a regular file without any references
1298          * we do not need to sync it.
1299          * Adjust object size to be the size of actual file.
1300          */
1301         objsize = round_page(va.va_size);
1302         if (va.va_nlink == 0)
1303                 flags |= MAP_NOSYNC;
1304         if (obj->type == OBJT_VNODE) {
1305                 obj = vm_pager_allocate(OBJT_VNODE, vp, objsize, prot, foff,
1306                     cred);
1307                 if (obj == NULL) {
1308                         error = ENOMEM;
1309                         goto done;
1310                 }
1311         } else {
1312                 KASSERT(obj->type == OBJT_DEFAULT || obj->type == OBJT_SWAP,
1313                     ("wrong object type"));
1314                 VM_OBJECT_WLOCK(obj);
1315                 vm_object_reference_locked(obj);
1316 #if VM_NRESERVLEVEL > 0
1317                 vm_object_color(obj, 0);
1318 #endif
1319                 VM_OBJECT_WUNLOCK(obj);
1320         }
1321         *objp = obj;
1322         *flagsp = flags;
1323
1324         vfs_mark_atime(vp, cred);
1325
1326 done:
1327         if (error != 0 && *writecounted) {
1328                 *writecounted = FALSE;
1329                 vnode_pager_update_writecount(obj, objsize, 0);
1330         }
1331         vput(vp);
1332         return (error);
1333 }
1334
1335 /*
1336  * vm_mmap_cdev()
1337  *
1338  * MPSAFE
1339  *
1340  * Helper function for vm_mmap.  Perform sanity check specific for mmap
1341  * operations on cdevs.
1342  */
1343 int
1344 vm_mmap_cdev(struct thread *td, vm_size_t objsize, vm_prot_t prot,
1345     vm_prot_t *maxprotp, int *flagsp, struct cdev *cdev, struct cdevsw *dsw,
1346     vm_ooffset_t *foff, vm_object_t *objp)
1347 {
1348         vm_object_t obj;
1349         int error, flags;
1350
1351         flags = *flagsp;
1352
1353         if (dsw->d_flags & D_MMAP_ANON) {
1354                 *objp = NULL;
1355                 *foff = 0;
1356                 *maxprotp = VM_PROT_ALL;
1357                 *flagsp |= MAP_ANON;
1358                 return (0);
1359         }
1360         /*
1361          * cdevs do not provide private mappings of any kind.
1362          */
1363         if ((*maxprotp & VM_PROT_WRITE) == 0 &&
1364             (prot & VM_PROT_WRITE) != 0)
1365                 return (EACCES);
1366         if (flags & (MAP_PRIVATE|MAP_COPY))
1367                 return (EINVAL);
1368         /*
1369          * Force device mappings to be shared.
1370          */
1371         flags |= MAP_SHARED;
1372 #ifdef MAC_XXX
1373         error = mac_cdev_check_mmap(td->td_ucred, cdev, (int)prot);
1374         if (error != 0)
1375                 return (error);
1376 #endif
1377         /*
1378          * First, try d_mmap_single().  If that is not implemented
1379          * (returns ENODEV), fall back to using the device pager.
1380          * Note that d_mmap_single() must return a reference to the
1381          * object (it needs to bump the reference count of the object
1382          * it returns somehow).
1383          *
1384          * XXX assumes VM_PROT_* == PROT_*
1385          */
1386         error = dsw->d_mmap_single(cdev, foff, objsize, objp, (int)prot);
1387         if (error != ENODEV)
1388                 return (error);
1389         obj = vm_pager_allocate(OBJT_DEVICE, cdev, objsize, prot, *foff,
1390             td->td_ucred);
1391         if (obj == NULL)
1392                 return (EINVAL);
1393         *objp = obj;
1394         *flagsp = flags;
1395         return (0);
1396 }
1397
1398 /*
1399  * vm_mmap()
1400  *
1401  * Internal version of mmap used by exec, sys5 shared memory, and
1402  * various device drivers.  Handle is either a vnode pointer, a
1403  * character device, or NULL for MAP_ANON.
1404  */
1405 int
1406 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
1407         vm_prot_t maxprot, int flags,
1408         objtype_t handle_type, void *handle,
1409         vm_ooffset_t foff)
1410 {
1411         vm_object_t object;
1412         struct thread *td = curthread;
1413         int error;
1414         boolean_t writecounted;
1415
1416         if (size == 0)
1417                 return (EINVAL);
1418
1419         size = round_page(size);
1420         object = NULL;
1421         writecounted = FALSE;
1422
1423         /*
1424          * Lookup/allocate object.
1425          */
1426         switch (handle_type) {
1427         case OBJT_DEVICE: {
1428                 struct cdevsw *dsw;
1429                 struct cdev *cdev;
1430                 int ref;
1431
1432                 cdev = handle;
1433                 dsw = dev_refthread(cdev, &ref);
1434                 if (dsw == NULL)
1435                         return (ENXIO);
1436                 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags, cdev,
1437                     dsw, &foff, &object);
1438                 dev_relthread(cdev, ref);
1439                 break;
1440         }
1441         case OBJT_VNODE:
1442                 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags,
1443                     handle, &foff, &object, &writecounted);
1444                 break;
1445         case OBJT_DEFAULT:
1446                 if (handle == NULL) {
1447                         error = 0;
1448                         break;
1449                 }
1450                 /* FALLTHROUGH */
1451         default:
1452                 error = EINVAL;
1453                 break;
1454         }
1455         if (error)
1456                 return (error);
1457
1458         error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
1459             foff, writecounted, td);
1460         if (error != 0 && object != NULL) {
1461                 /*
1462                  * If this mapping was accounted for in the vnode's
1463                  * writecount, then undo that now.
1464                  */
1465                 if (writecounted)
1466                         vnode_pager_release_writecount(object, 0, size);
1467                 vm_object_deallocate(object);
1468         }
1469         return (error);
1470 }
1471
1472 /*
1473  * Internal version of mmap that maps a specific VM object into an
1474  * map.  Called by mmap for MAP_ANON, vm_mmap, shm_mmap, and vn_mmap.
1475  */
1476 int
1477 vm_mmap_object(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
1478     vm_prot_t maxprot, int flags, vm_object_t object, vm_ooffset_t foff,
1479     boolean_t writecounted, struct thread *td)
1480 {
1481         boolean_t fitit;
1482         int docow, error, findspace, rv;
1483
1484         if (map == &td->td_proc->p_vmspace->vm_map) {
1485                 PROC_LOCK(td->td_proc);
1486                 if (map->size + size > lim_cur_proc(td->td_proc, RLIMIT_VMEM)) {
1487                         PROC_UNLOCK(td->td_proc);
1488                         return (ENOMEM);
1489                 }
1490                 if (racct_set(td->td_proc, RACCT_VMEM, map->size + size)) {
1491                         PROC_UNLOCK(td->td_proc);
1492                         return (ENOMEM);
1493                 }
1494                 if (!old_mlock && map->flags & MAP_WIREFUTURE) {
1495                         if (ptoa(pmap_wired_count(map->pmap)) + size >
1496                             lim_cur_proc(td->td_proc, RLIMIT_MEMLOCK)) {
1497                                 racct_set_force(td->td_proc, RACCT_VMEM,
1498                                     map->size);
1499                                 PROC_UNLOCK(td->td_proc);
1500                                 return (ENOMEM);
1501                         }
1502                         error = racct_set(td->td_proc, RACCT_MEMLOCK,
1503                             ptoa(pmap_wired_count(map->pmap)) + size);
1504                         if (error != 0) {
1505                                 racct_set_force(td->td_proc, RACCT_VMEM,
1506                                     map->size);
1507                                 PROC_UNLOCK(td->td_proc);
1508                                 return (error);
1509                         }
1510                 }
1511                 PROC_UNLOCK(td->td_proc);
1512         }
1513
1514         /*
1515          * We currently can only deal with page aligned file offsets.
1516          * The mmap() system call already enforces this by subtracting
1517          * the page offset from the file offset, but checking here
1518          * catches errors in device drivers (e.g. d_single_mmap()
1519          * callbacks) and other internal mapping requests (such as in
1520          * exec).
1521          */
1522         if (foff & PAGE_MASK)
1523                 return (EINVAL);
1524
1525         if ((flags & MAP_FIXED) == 0) {
1526                 fitit = TRUE;
1527                 *addr = round_page(*addr);
1528         } else {
1529                 if (*addr != trunc_page(*addr))
1530                         return (EINVAL);
1531                 fitit = FALSE;
1532         }
1533
1534         if (flags & MAP_ANON) {
1535                 if (object != NULL || foff != 0)
1536                         return (EINVAL);
1537                 docow = 0;
1538         } else if (flags & MAP_PREFAULT_READ)
1539                 docow = MAP_PREFAULT;
1540         else
1541                 docow = MAP_PREFAULT_PARTIAL;
1542
1543         if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
1544                 docow |= MAP_COPY_ON_WRITE;
1545         if (flags & MAP_NOSYNC)
1546                 docow |= MAP_DISABLE_SYNCER;
1547         if (flags & MAP_NOCORE)
1548                 docow |= MAP_DISABLE_COREDUMP;
1549         /* Shared memory is also shared with children. */
1550         if (flags & MAP_SHARED)
1551                 docow |= MAP_INHERIT_SHARE;
1552         if (writecounted)
1553                 docow |= MAP_VN_WRITECOUNT;
1554         if (flags & MAP_STACK) {
1555                 if (object != NULL)
1556                         return (EINVAL);
1557                 docow |= MAP_STACK_GROWS_DOWN;
1558         }
1559         if ((flags & MAP_EXCL) != 0)
1560                 docow |= MAP_CHECK_EXCL;
1561
1562         if (fitit) {
1563                 if ((flags & MAP_ALIGNMENT_MASK) == MAP_ALIGNED_SUPER)
1564                         findspace = VMFS_SUPER_SPACE;
1565                 else if ((flags & MAP_ALIGNMENT_MASK) != 0)
1566                         findspace = VMFS_ALIGNED_SPACE(flags >>
1567                             MAP_ALIGNMENT_SHIFT);
1568                 else
1569                         findspace = VMFS_OPTIMAL_SPACE;
1570                 rv = vm_map_find(map, object, foff, addr, size,
1571 #ifdef MAP_32BIT
1572                     flags & MAP_32BIT ? MAP_32BIT_MAX_ADDR :
1573 #endif
1574                     0, findspace, prot, maxprot, docow);
1575         } else {
1576                 rv = vm_map_fixed(map, object, foff, *addr, size,
1577                     prot, maxprot, docow);
1578         }
1579
1580         if (rv == KERN_SUCCESS) {
1581                 /*
1582                  * If the process has requested that all future mappings
1583                  * be wired, then heed this.
1584                  */
1585                 if (map->flags & MAP_WIREFUTURE) {
1586                         vm_map_wire(map, *addr, *addr + size,
1587                             VM_MAP_WIRE_USER | ((flags & MAP_STACK) ?
1588                             VM_MAP_WIRE_HOLESOK : VM_MAP_WIRE_NOHOLES));
1589                 }
1590         }
1591         return (vm_mmap_to_errno(rv));
1592 }
1593
1594 /*
1595  * Translate a Mach VM return code to zero on success or the appropriate errno
1596  * on failure.
1597  */
1598 int
1599 vm_mmap_to_errno(int rv)
1600 {
1601
1602         switch (rv) {
1603         case KERN_SUCCESS:
1604                 return (0);
1605         case KERN_INVALID_ADDRESS:
1606         case KERN_NO_SPACE:
1607                 return (ENOMEM);
1608         case KERN_PROTECTION_FAILURE:
1609                 return (EACCES);
1610         default:
1611                 return (EINVAL);
1612         }
1613 }