The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/vm/vm_mmap.c

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    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_mac.h"
   49 
   50 #include <sys/param.h>
   51 #include <sys/systm.h>
   52 #include <sys/kernel.h>
   53 #include <sys/lock.h>
   54 #include <sys/mutex.h>
   55 #include <sys/sysproto.h>
   56 #include <sys/filedesc.h>
   57 #include <sys/priv.h>
   58 #include <sys/proc.h>
   59 #include <sys/resource.h>
   60 #include <sys/resourcevar.h>
   61 #include <sys/vnode.h>
   62 #include <sys/fcntl.h>
   63 #include <sys/file.h>
   64 #include <sys/mman.h>
   65 #include <sys/mount.h>
   66 #include <sys/conf.h>
   67 #include <sys/stat.h>
   68 #include <sys/vmmeter.h>
   69 #include <sys/sysctl.h>
   70 
   71 #include <security/mac/mac_framework.h>
   72 
   73 #include <vm/vm.h>
   74 #include <vm/vm_param.h>
   75 #include <vm/pmap.h>
   76 #include <vm/vm_map.h>
   77 #include <vm/vm_object.h>
   78 #include <vm/vm_page.h>
   79 #include <vm/vm_pager.h>
   80 #include <vm/vm_pageout.h>
   81 #include <vm/vm_extern.h>
   82 #include <vm/vm_page.h>
   83 #include <vm/vm_kern.h>
   84 
   85 #ifdef HWPMC_HOOKS
   86 #include <sys/pmckern.h>
   87 #endif
   88 
   89 #ifndef _SYS_SYSPROTO_H_
   90 struct sbrk_args {
   91         int incr;
   92 };
   93 #endif
   94 
   95 static int max_proc_mmap;
   96 SYSCTL_INT(_vm, OID_AUTO, max_proc_mmap, CTLFLAG_RW, &max_proc_mmap, 0, "");
   97 
   98 /*
   99  * Set the maximum number of vm_map_entry structures per process.  Roughly
  100  * speaking vm_map_entry structures are tiny, so allowing them to eat 1/100
  101  * of our KVM malloc space still results in generous limits.  We want a
  102  * default that is good enough to prevent the kernel running out of resources
  103  * if attacked from compromised user account but generous enough such that
  104  * multi-threaded processes are not unduly inconvenienced.
  105  */
  106 static void vmmapentry_rsrc_init(void *);
  107 SYSINIT(vmmersrc, SI_SUB_KVM_RSRC, SI_ORDER_FIRST, vmmapentry_rsrc_init, NULL)
  108 
  109 static void
  110 vmmapentry_rsrc_init(dummy)
  111         void *dummy;
  112 {
  113     max_proc_mmap = vm_kmem_size / sizeof(struct vm_map_entry);
  114     max_proc_mmap /= 100;
  115 }
  116 
  117 static int vm_mmap_vnode(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
  118     int *, struct vnode *, vm_ooffset_t, vm_object_t *);
  119 static int vm_mmap_cdev(struct thread *, vm_size_t, vm_prot_t, vm_prot_t *,
  120     int *, struct cdev *, vm_ooffset_t, vm_object_t *);
  121 
  122 /*
  123  * MPSAFE
  124  */
  125 /* ARGSUSED */
  126 int
  127 sbrk(td, uap)
  128         struct thread *td;
  129         struct sbrk_args *uap;
  130 {
  131         /* Not yet implemented */
  132         return (EOPNOTSUPP);
  133 }
  134 
  135 #ifndef _SYS_SYSPROTO_H_
  136 struct sstk_args {
  137         int incr;
  138 };
  139 #endif
  140 
  141 /*
  142  * MPSAFE
  143  */
  144 /* ARGSUSED */
  145 int
  146 sstk(td, uap)
  147         struct thread *td;
  148         struct sstk_args *uap;
  149 {
  150         /* Not yet implemented */
  151         return (EOPNOTSUPP);
  152 }
  153 
  154 #if defined(COMPAT_43)
  155 #ifndef _SYS_SYSPROTO_H_
  156 struct getpagesize_args {
  157         int dummy;
  158 };
  159 #endif
  160 
  161 /* ARGSUSED */
  162 int
  163 ogetpagesize(td, uap)
  164         struct thread *td;
  165         struct getpagesize_args *uap;
  166 {
  167         /* MP SAFE */
  168         td->td_retval[0] = PAGE_SIZE;
  169         return (0);
  170 }
  171 #endif                          /* COMPAT_43 */
  172 
  173 
  174 /*
  175  * Memory Map (mmap) system call.  Note that the file offset
  176  * and address are allowed to be NOT page aligned, though if
  177  * the MAP_FIXED flag it set, both must have the same remainder
  178  * modulo the PAGE_SIZE (POSIX 1003.1b).  If the address is not
  179  * page-aligned, the actual mapping starts at trunc_page(addr)
  180  * and the return value is adjusted up by the page offset.
  181  *
  182  * Generally speaking, only character devices which are themselves
  183  * memory-based, such as a video framebuffer, can be mmap'd.  Otherwise
  184  * there would be no cache coherency between a descriptor and a VM mapping
  185  * both to the same character device.
  186  *
  187  * Block devices can be mmap'd no matter what they represent.  Cache coherency
  188  * is maintained as long as you do not write directly to the underlying
  189  * character device.
  190  */
  191 #ifndef _SYS_SYSPROTO_H_
  192 struct mmap_args {
  193         void *addr;
  194         size_t len;
  195         int prot;
  196         int flags;
  197         int fd;
  198         long pad;
  199         off_t pos;
  200 };
  201 #endif
  202 
  203 /*
  204  * MPSAFE
  205  */
  206 int
  207 mmap(td, uap)
  208         struct thread *td;
  209         struct mmap_args *uap;
  210 {
  211 #ifdef HWPMC_HOOKS
  212         struct pmckern_map_in pkm;
  213 #endif
  214         struct file *fp;
  215         struct vnode *vp;
  216         vm_offset_t addr;
  217         vm_size_t size, pageoff;
  218         vm_prot_t prot, maxprot;
  219         void *handle;
  220         objtype_t handle_type;
  221         int flags, error;
  222         off_t pos;
  223         struct vmspace *vms = td->td_proc->p_vmspace;
  224 
  225         addr = (vm_offset_t) uap->addr;
  226         size = uap->len;
  227         prot = uap->prot & VM_PROT_ALL;
  228         flags = uap->flags;
  229         pos = uap->pos;
  230 
  231         fp = NULL;
  232         /* make sure mapping fits into numeric range etc */
  233         if ((ssize_t) uap->len < 0 ||
  234             ((flags & MAP_ANON) && uap->fd != -1))
  235                 return (EINVAL);
  236 
  237         if (flags & MAP_STACK) {
  238                 if ((uap->fd != -1) ||
  239                     ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
  240                         return (EINVAL);
  241                 flags |= MAP_ANON;
  242                 pos = 0;
  243         }
  244 
  245         /*
  246          * Align the file position to a page boundary,
  247          * and save its page offset component.
  248          */
  249         pageoff = (pos & PAGE_MASK);
  250         pos -= pageoff;
  251 
  252         /* Adjust size for rounding (on both ends). */
  253         size += pageoff;                        /* low end... */
  254         size = (vm_size_t) round_page(size);    /* hi end */
  255 
  256         /*
  257          * Check for illegal addresses.  Watch out for address wrap... Note
  258          * that VM_*_ADDRESS are not constants due to casts (argh).
  259          */
  260         if (flags & MAP_FIXED) {
  261                 /*
  262                  * The specified address must have the same remainder
  263                  * as the file offset taken modulo PAGE_SIZE, so it
  264                  * should be aligned after adjustment by pageoff.
  265                  */
  266                 addr -= pageoff;
  267                 if (addr & PAGE_MASK)
  268                         return (EINVAL);
  269                 /* Address range must be all in user VM space. */
  270                 if (addr < vm_map_min(&vms->vm_map) ||
  271                     addr + size > vm_map_max(&vms->vm_map))
  272                         return (EINVAL);
  273                 if (addr + size < addr)
  274                         return (EINVAL);
  275         } else {
  276         /*
  277          * XXX for non-fixed mappings where no hint is provided or
  278          * the hint would fall in the potential heap space,
  279          * place it after the end of the largest possible heap.
  280          *
  281          * There should really be a pmap call to determine a reasonable
  282          * location.
  283          */
  284                 PROC_LOCK(td->td_proc);
  285                 if (addr == 0 ||
  286                     (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
  287                     addr < round_page((vm_offset_t)vms->vm_daddr +
  288                     lim_max(td->td_proc, RLIMIT_DATA))))
  289                         addr = round_page((vm_offset_t)vms->vm_daddr +
  290                             lim_max(td->td_proc, RLIMIT_DATA));
  291                 PROC_UNLOCK(td->td_proc);
  292         }
  293         if (flags & MAP_ANON) {
  294                 /*
  295                  * Mapping blank space is trivial.
  296                  */
  297                 handle = NULL;
  298                 handle_type = OBJT_DEFAULT;
  299                 maxprot = VM_PROT_ALL;
  300                 pos = 0;
  301         } else {
  302                 /*
  303                  * Mapping file, get fp for validation. Obtain vnode and make
  304                  * sure it is of appropriate type.
  305                  * don't let the descriptor disappear on us if we block
  306                  */
  307                 if ((error = fget(td, uap->fd, &fp)) != 0)
  308                         goto done;
  309                 if (fp->f_type != DTYPE_VNODE) {
  310                         error = ENODEV;
  311                         goto done;
  312                 }
  313                 /*
  314                  * POSIX shared-memory objects are defined to have
  315                  * kernel persistence, and are not defined to support
  316                  * read(2)/write(2) -- or even open(2).  Thus, we can
  317                  * use MAP_ASYNC to trade on-disk coherence for speed.
  318                  * The shm_open(3) library routine turns on the FPOSIXSHM
  319                  * flag to request this behavior.
  320                  */
  321                 if (fp->f_flag & FPOSIXSHM)
  322                         flags |= MAP_NOSYNC;
  323                 vp = fp->f_vnode;
  324                 /*
  325                  * Ensure that file and memory protections are
  326                  * compatible.  Note that we only worry about
  327                  * writability if mapping is shared; in this case,
  328                  * current and max prot are dictated by the open file.
  329                  * XXX use the vnode instead?  Problem is: what
  330                  * credentials do we use for determination? What if
  331                  * proc does a setuid?
  332                  */
  333                 if (vp->v_mount != NULL && vp->v_mount->mnt_flag & MNT_NOEXEC)
  334                         maxprot = VM_PROT_NONE;
  335                 else
  336                         maxprot = VM_PROT_EXECUTE;
  337                 if (fp->f_flag & FREAD) {
  338                         maxprot |= VM_PROT_READ;
  339                 } else if (prot & PROT_READ) {
  340                         error = EACCES;
  341                         goto done;
  342                 }
  343                 /*
  344                  * If we are sharing potential changes (either via
  345                  * MAP_SHARED or via the implicit sharing of character
  346                  * device mappings), and we are trying to get write
  347                  * permission although we opened it without asking
  348                  * for it, bail out.
  349                  */
  350                 if ((flags & MAP_SHARED) != 0) {
  351                         if ((fp->f_flag & FWRITE) != 0) {
  352                                 maxprot |= VM_PROT_WRITE;
  353                         } else if ((prot & PROT_WRITE) != 0) {
  354                                 error = EACCES;
  355                                 goto done;
  356                         }
  357                 } else if (vp->v_type != VCHR || (fp->f_flag & FWRITE) != 0) {
  358                         maxprot |= VM_PROT_WRITE;
  359                 }
  360                 handle = (void *)vp;
  361                 handle_type = OBJT_VNODE;
  362         }
  363 
  364         /*
  365          * Do not allow more then a certain number of vm_map_entry structures
  366          * per process.  Scale with the number of rforks sharing the map
  367          * to make the limit reasonable for threads.
  368          */
  369         if (max_proc_mmap &&
  370             vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) {
  371                 error = ENOMEM;
  372                 goto done;
  373         }
  374 
  375         error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
  376             flags, handle_type, handle, pos);
  377 #ifdef HWPMC_HOOKS
  378         /* inform hwpmc(4) if an executable is being mapped */
  379         if (error == 0 && handle_type == OBJT_VNODE &&
  380             (prot & PROT_EXEC)) {
  381                 pkm.pm_file = handle;
  382                 pkm.pm_address = (uintptr_t) addr;
  383                 PMC_CALL_HOOK(td, PMC_FN_MMAP, (void *) &pkm);
  384         }
  385 #endif
  386         if (error == 0)
  387                 td->td_retval[0] = (register_t) (addr + pageoff);
  388 done:
  389         if (fp)
  390                 fdrop(fp, td);
  391 
  392         return (error);
  393 }
  394 
  395 int
  396 freebsd6_mmap(struct thread *td, struct freebsd6_mmap_args *uap)
  397 {
  398         struct mmap_args oargs;
  399 
  400         oargs.addr = uap->addr;
  401         oargs.len = uap->len;
  402         oargs.prot = uap->prot;
  403         oargs.flags = uap->flags;
  404         oargs.fd = uap->fd;
  405         oargs.pos = uap->pos;
  406         return (mmap(td, &oargs));
  407 }
  408 
  409 #ifdef COMPAT_43
  410 #ifndef _SYS_SYSPROTO_H_
  411 struct ommap_args {
  412         caddr_t addr;
  413         int len;
  414         int prot;
  415         int flags;
  416         int fd;
  417         long pos;
  418 };
  419 #endif
  420 int
  421 ommap(td, uap)
  422         struct thread *td;
  423         struct ommap_args *uap;
  424 {
  425         struct mmap_args nargs;
  426         static const char cvtbsdprot[8] = {
  427                 0,
  428                 PROT_EXEC,
  429                 PROT_WRITE,
  430                 PROT_EXEC | PROT_WRITE,
  431                 PROT_READ,
  432                 PROT_EXEC | PROT_READ,
  433                 PROT_WRITE | PROT_READ,
  434                 PROT_EXEC | PROT_WRITE | PROT_READ,
  435         };
  436 
  437 #define OMAP_ANON       0x0002
  438 #define OMAP_COPY       0x0020
  439 #define OMAP_SHARED     0x0010
  440 #define OMAP_FIXED      0x0100
  441 
  442         nargs.addr = uap->addr;
  443         nargs.len = uap->len;
  444         nargs.prot = cvtbsdprot[uap->prot & 0x7];
  445         nargs.flags = 0;
  446         if (uap->flags & OMAP_ANON)
  447                 nargs.flags |= MAP_ANON;
  448         if (uap->flags & OMAP_COPY)
  449                 nargs.flags |= MAP_COPY;
  450         if (uap->flags & OMAP_SHARED)
  451                 nargs.flags |= MAP_SHARED;
  452         else
  453                 nargs.flags |= MAP_PRIVATE;
  454         if (uap->flags & OMAP_FIXED)
  455                 nargs.flags |= MAP_FIXED;
  456         nargs.fd = uap->fd;
  457         nargs.pos = uap->pos;
  458         return (mmap(td, &nargs));
  459 }
  460 #endif                          /* COMPAT_43 */
  461 
  462 
  463 #ifndef _SYS_SYSPROTO_H_
  464 struct msync_args {
  465         void *addr;
  466         int len;
  467         int flags;
  468 };
  469 #endif
  470 /*
  471  * MPSAFE
  472  */
  473 int
  474 msync(td, uap)
  475         struct thread *td;
  476         struct msync_args *uap;
  477 {
  478         vm_offset_t addr;
  479         vm_size_t size, pageoff;
  480         int flags;
  481         vm_map_t map;
  482         int rv;
  483 
  484         addr = (vm_offset_t) uap->addr;
  485         size = uap->len;
  486         flags = uap->flags;
  487 
  488         pageoff = (addr & PAGE_MASK);
  489         addr -= pageoff;
  490         size += pageoff;
  491         size = (vm_size_t) round_page(size);
  492         if (addr + size < addr)
  493                 return (EINVAL);
  494 
  495         if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
  496                 return (EINVAL);
  497 
  498         map = &td->td_proc->p_vmspace->vm_map;
  499 
  500         /*
  501          * Clean the pages and interpret the return value.
  502          */
  503         rv = vm_map_sync(map, addr, addr + size, (flags & MS_ASYNC) == 0,
  504             (flags & MS_INVALIDATE) != 0);
  505         switch (rv) {
  506         case KERN_SUCCESS:
  507                 return (0);
  508         case KERN_INVALID_ADDRESS:
  509                 return (EINVAL);        /* Sun returns ENOMEM? */
  510         case KERN_INVALID_ARGUMENT:
  511                 return (EBUSY);
  512         default:
  513                 return (EINVAL);
  514         }
  515 }
  516 
  517 #ifndef _SYS_SYSPROTO_H_
  518 struct munmap_args {
  519         void *addr;
  520         size_t len;
  521 };
  522 #endif
  523 /*
  524  * MPSAFE
  525  */
  526 int
  527 munmap(td, uap)
  528         struct thread *td;
  529         struct munmap_args *uap;
  530 {
  531 #ifdef HWPMC_HOOKS
  532         struct pmckern_map_out pkm;
  533         vm_map_entry_t entry;
  534 #endif
  535         vm_offset_t addr;
  536         vm_size_t size, pageoff;
  537         vm_map_t map;
  538 
  539         addr = (vm_offset_t) uap->addr;
  540         size = uap->len;
  541         if (size == 0)
  542                 return (EINVAL);
  543 
  544         pageoff = (addr & PAGE_MASK);
  545         addr -= pageoff;
  546         size += pageoff;
  547         size = (vm_size_t) round_page(size);
  548         if (addr + size < addr)
  549                 return (EINVAL);
  550 
  551         /*
  552          * Check for illegal addresses.  Watch out for address wrap...
  553          */
  554         map = &td->td_proc->p_vmspace->vm_map;
  555         if (addr < vm_map_min(map) || addr + size > vm_map_max(map))
  556                 return (EINVAL);
  557         vm_map_lock(map);
  558         /*
  559          * Make sure entire range is allocated.
  560          */
  561         if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE)) {
  562                 vm_map_unlock(map);
  563                 return (EINVAL);
  564         }
  565 #ifdef HWPMC_HOOKS
  566         /*
  567          * Inform hwpmc if the address range being unmapped contains
  568          * an executable region.
  569          */
  570         if (vm_map_lookup_entry(map, addr, &entry)) {
  571                 for (;
  572                      entry != &map->header && entry->start < addr + size;
  573                      entry = entry->next) {
  574                         if (vm_map_check_protection(map, entry->start,
  575                                 entry->end, VM_PROT_EXECUTE) == TRUE) {
  576                                 pkm.pm_address = (uintptr_t) addr;
  577                                 pkm.pm_size = (size_t) size;
  578                                 PMC_CALL_HOOK(td, PMC_FN_MUNMAP,
  579                                     (void *) &pkm);
  580                                 break;
  581                         }
  582                 }
  583         }
  584 #endif
  585         /* returns nothing but KERN_SUCCESS anyway */
  586         vm_map_delete(map, addr, addr + size);
  587         vm_map_unlock(map);
  588         return (0);
  589 }
  590 
  591 #ifndef _SYS_SYSPROTO_H_
  592 struct mprotect_args {
  593         const void *addr;
  594         size_t len;
  595         int prot;
  596 };
  597 #endif
  598 /*
  599  * MPSAFE
  600  */
  601 int
  602 mprotect(td, uap)
  603         struct thread *td;
  604         struct mprotect_args *uap;
  605 {
  606         vm_offset_t addr;
  607         vm_size_t size, pageoff;
  608         vm_prot_t prot;
  609 
  610         addr = (vm_offset_t) uap->addr;
  611         size = uap->len;
  612         prot = uap->prot & VM_PROT_ALL;
  613 #if defined(VM_PROT_READ_IS_EXEC)
  614         if (prot & VM_PROT_READ)
  615                 prot |= VM_PROT_EXECUTE;
  616 #endif
  617 
  618         pageoff = (addr & PAGE_MASK);
  619         addr -= pageoff;
  620         size += pageoff;
  621         size = (vm_size_t) round_page(size);
  622         if (addr + size < addr)
  623                 return (EINVAL);
  624 
  625         switch (vm_map_protect(&td->td_proc->p_vmspace->vm_map, addr,
  626             addr + size, prot, FALSE)) {
  627         case KERN_SUCCESS:
  628                 return (0);
  629         case KERN_PROTECTION_FAILURE:
  630                 return (EACCES);
  631         }
  632         return (EINVAL);
  633 }
  634 
  635 #ifndef _SYS_SYSPROTO_H_
  636 struct minherit_args {
  637         void *addr;
  638         size_t len;
  639         int inherit;
  640 };
  641 #endif
  642 /*
  643  * MPSAFE
  644  */
  645 int
  646 minherit(td, uap)
  647         struct thread *td;
  648         struct minherit_args *uap;
  649 {
  650         vm_offset_t addr;
  651         vm_size_t size, pageoff;
  652         vm_inherit_t inherit;
  653 
  654         addr = (vm_offset_t)uap->addr;
  655         size = uap->len;
  656         inherit = uap->inherit;
  657 
  658         pageoff = (addr & PAGE_MASK);
  659         addr -= pageoff;
  660         size += pageoff;
  661         size = (vm_size_t) round_page(size);
  662         if (addr + size < addr)
  663                 return (EINVAL);
  664 
  665         switch (vm_map_inherit(&td->td_proc->p_vmspace->vm_map, addr,
  666             addr + size, inherit)) {
  667         case KERN_SUCCESS:
  668                 return (0);
  669         case KERN_PROTECTION_FAILURE:
  670                 return (EACCES);
  671         }
  672         return (EINVAL);
  673 }
  674 
  675 #ifndef _SYS_SYSPROTO_H_
  676 struct madvise_args {
  677         void *addr;
  678         size_t len;
  679         int behav;
  680 };
  681 #endif
  682 
  683 /*
  684  * MPSAFE
  685  */
  686 /* ARGSUSED */
  687 int
  688 madvise(td, uap)
  689         struct thread *td;
  690         struct madvise_args *uap;
  691 {
  692         vm_offset_t start, end;
  693         vm_map_t map;
  694         struct proc *p;
  695         int error;
  696 
  697         /*
  698          * Check for our special case, advising the swap pager we are
  699          * "immortal."
  700          */
  701         if (uap->behav == MADV_PROTECT) {
  702                 error = priv_check(td, PRIV_VM_MADV_PROTECT);
  703                 if (error == 0) {
  704                         p = td->td_proc;
  705                         PROC_LOCK(p);
  706                         p->p_flag |= P_PROTECTED;
  707                         PROC_UNLOCK(p);
  708                 }
  709                 return (error);
  710         }
  711         /*
  712          * Check for illegal behavior
  713          */
  714         if (uap->behav < 0 || uap->behav > MADV_CORE)
  715                 return (EINVAL);
  716         /*
  717          * Check for illegal addresses.  Watch out for address wrap... Note
  718          * that VM_*_ADDRESS are not constants due to casts (argh).
  719          */
  720         map = &td->td_proc->p_vmspace->vm_map;
  721         if ((vm_offset_t)uap->addr < vm_map_min(map) ||
  722             (vm_offset_t)uap->addr + uap->len > vm_map_max(map))
  723                 return (EINVAL);
  724         if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
  725                 return (EINVAL);
  726 
  727         /*
  728          * Since this routine is only advisory, we default to conservative
  729          * behavior.
  730          */
  731         start = trunc_page((vm_offset_t) uap->addr);
  732         end = round_page((vm_offset_t) uap->addr + uap->len);
  733 
  734         if (vm_map_madvise(map, start, end, uap->behav))
  735                 return (EINVAL);
  736         return (0);
  737 }
  738 
  739 #ifndef _SYS_SYSPROTO_H_
  740 struct mincore_args {
  741         const void *addr;
  742         size_t len;
  743         char *vec;
  744 };
  745 #endif
  746 
  747 /*
  748  * MPSAFE
  749  */
  750 /* ARGSUSED */
  751 int
  752 mincore(td, uap)
  753         struct thread *td;
  754         struct mincore_args *uap;
  755 {
  756         vm_offset_t addr, first_addr;
  757         vm_offset_t end, cend;
  758         pmap_t pmap;
  759         vm_map_t map;
  760         char *vec;
  761         int error = 0;
  762         int vecindex, lastvecindex;
  763         vm_map_entry_t current;
  764         vm_map_entry_t entry;
  765         int mincoreinfo;
  766         unsigned int timestamp;
  767 
  768         /*
  769          * Make sure that the addresses presented are valid for user
  770          * mode.
  771          */
  772         first_addr = addr = trunc_page((vm_offset_t) uap->addr);
  773         end = addr + (vm_size_t)round_page(uap->len);
  774         map = &td->td_proc->p_vmspace->vm_map;
  775         if (end > vm_map_max(map) || end < addr)
  776                 return (ENOMEM);
  777 
  778         /*
  779          * Address of byte vector
  780          */
  781         vec = uap->vec;
  782 
  783         pmap = vmspace_pmap(td->td_proc->p_vmspace);
  784 
  785         vm_map_lock_read(map);
  786 RestartScan:
  787         timestamp = map->timestamp;
  788 
  789         if (!vm_map_lookup_entry(map, addr, &entry)) {
  790                 vm_map_unlock_read(map);
  791                 return (ENOMEM);
  792         }
  793 
  794         /*
  795          * Do this on a map entry basis so that if the pages are not
  796          * in the current processes address space, we can easily look
  797          * up the pages elsewhere.
  798          */
  799         lastvecindex = -1;
  800         for (current = entry;
  801             (current != &map->header) && (current->start < end);
  802             current = current->next) {
  803 
  804                 /*
  805                  * check for contiguity
  806                  */
  807                 if (current->end < end &&
  808                     (entry->next == &map->header ||
  809                      current->next->start > current->end)) {
  810                         vm_map_unlock_read(map);
  811                         return (ENOMEM);
  812                 }
  813 
  814                 /*
  815                  * ignore submaps (for now) or null objects
  816                  */
  817                 if ((current->eflags & MAP_ENTRY_IS_SUB_MAP) ||
  818                         current->object.vm_object == NULL)
  819                         continue;
  820 
  821                 /*
  822                  * limit this scan to the current map entry and the
  823                  * limits for the mincore call
  824                  */
  825                 if (addr < current->start)
  826                         addr = current->start;
  827                 cend = current->end;
  828                 if (cend > end)
  829                         cend = end;
  830 
  831                 /*
  832                  * scan this entry one page at a time
  833                  */
  834                 while (addr < cend) {
  835                         /*
  836                          * Check pmap first, it is likely faster, also
  837                          * it can provide info as to whether we are the
  838                          * one referencing or modifying the page.
  839                          */
  840                         mincoreinfo = pmap_mincore(pmap, addr);
  841                         if (!mincoreinfo) {
  842                                 vm_pindex_t pindex;
  843                                 vm_ooffset_t offset;
  844                                 vm_page_t m;
  845                                 /*
  846                                  * calculate the page index into the object
  847                                  */
  848                                 offset = current->offset + (addr - current->start);
  849                                 pindex = OFF_TO_IDX(offset);
  850                                 VM_OBJECT_LOCK(current->object.vm_object);
  851                                 m = vm_page_lookup(current->object.vm_object,
  852                                         pindex);
  853                                 /*
  854                                  * if the page is resident, then gather information about
  855                                  * it.
  856                                  */
  857                                 if (m != NULL && m->valid != 0) {
  858                                         mincoreinfo = MINCORE_INCORE;
  859                                         vm_page_lock_queues();
  860                                         if (m->dirty ||
  861                                                 pmap_is_modified(m))
  862                                                 mincoreinfo |= MINCORE_MODIFIED_OTHER;
  863                                         if ((m->flags & PG_REFERENCED) ||
  864                                                 pmap_ts_referenced(m)) {
  865                                                 vm_page_flag_set(m, PG_REFERENCED);
  866                                                 mincoreinfo |= MINCORE_REFERENCED_OTHER;
  867                                         }
  868                                         vm_page_unlock_queues();
  869                                 }
  870                                 VM_OBJECT_UNLOCK(current->object.vm_object);
  871                         }
  872 
  873                         /*
  874                          * subyte may page fault.  In case it needs to modify
  875                          * the map, we release the lock.
  876                          */
  877                         vm_map_unlock_read(map);
  878 
  879                         /*
  880                          * calculate index into user supplied byte vector
  881                          */
  882                         vecindex = OFF_TO_IDX(addr - first_addr);
  883 
  884                         /*
  885                          * If we have skipped map entries, we need to make sure that
  886                          * the byte vector is zeroed for those skipped entries.
  887                          */
  888                         while ((lastvecindex + 1) < vecindex) {
  889                                 error = subyte(vec + lastvecindex, 0);
  890                                 if (error) {
  891                                         error = EFAULT;
  892                                         goto done2;
  893                                 }
  894                                 ++lastvecindex;
  895                         }
  896 
  897                         /*
  898                          * Pass the page information to the user
  899                          */
  900                         error = subyte(vec + vecindex, mincoreinfo);
  901                         if (error) {
  902                                 error = EFAULT;
  903                                 goto done2;
  904                         }
  905 
  906                         /*
  907                          * If the map has changed, due to the subyte, the previous
  908                          * output may be invalid.
  909                          */
  910                         vm_map_lock_read(map);
  911                         if (timestamp != map->timestamp)
  912                                 goto RestartScan;
  913 
  914                         lastvecindex = vecindex;
  915                         addr += PAGE_SIZE;
  916                 }
  917         }
  918 
  919         /*
  920          * subyte may page fault.  In case it needs to modify
  921          * the map, we release the lock.
  922          */
  923         vm_map_unlock_read(map);
  924 
  925         /*
  926          * Zero the last entries in the byte vector.
  927          */
  928         vecindex = OFF_TO_IDX(end - first_addr);
  929         while ((lastvecindex + 1) < vecindex) {
  930                 error = subyte(vec + lastvecindex, 0);
  931                 if (error) {
  932                         error = EFAULT;
  933                         goto done2;
  934                 }
  935                 ++lastvecindex;
  936         }
  937 
  938         /*
  939          * If the map has changed, due to the subyte, the previous
  940          * output may be invalid.
  941          */
  942         vm_map_lock_read(map);
  943         if (timestamp != map->timestamp)
  944                 goto RestartScan;
  945         vm_map_unlock_read(map);
  946 done2:
  947         return (error);
  948 }
  949 
  950 #ifndef _SYS_SYSPROTO_H_
  951 struct mlock_args {
  952         const void *addr;
  953         size_t len;
  954 };
  955 #endif
  956 /*
  957  * MPSAFE
  958  */
  959 int
  960 mlock(td, uap)
  961         struct thread *td;
  962         struct mlock_args *uap;
  963 {
  964         struct proc *proc;
  965         vm_offset_t addr, end, last, start;
  966         vm_size_t npages, size;
  967         int error;
  968 
  969         error = priv_check(td, PRIV_VM_MLOCK);
  970         if (error)
  971                 return (error);
  972         addr = (vm_offset_t)uap->addr;
  973         size = uap->len;
  974         last = addr + size;
  975         start = trunc_page(addr);
  976         end = round_page(last);
  977         if (last < addr || end < addr)
  978                 return (EINVAL);
  979         npages = atop(end - start);
  980         if (npages > vm_page_max_wired)
  981                 return (ENOMEM);
  982         proc = td->td_proc;
  983         PROC_LOCK(proc);
  984         if (ptoa(npages +
  985             pmap_wired_count(vm_map_pmap(&proc->p_vmspace->vm_map))) >
  986             lim_cur(proc, RLIMIT_MEMLOCK)) {
  987                 PROC_UNLOCK(proc);
  988                 return (ENOMEM);
  989         }
  990         PROC_UNLOCK(proc);
  991         if (npages + cnt.v_wire_count > vm_page_max_wired)
  992                 return (EAGAIN);
  993         error = vm_map_wire(&proc->p_vmspace->vm_map, start, end,
  994             VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
  995         return (error == KERN_SUCCESS ? 0 : ENOMEM);
  996 }
  997 
  998 #ifndef _SYS_SYSPROTO_H_
  999 struct mlockall_args {
 1000         int     how;
 1001 };
 1002 #endif
 1003 
 1004 /*
 1005  * MPSAFE
 1006  */
 1007 int
 1008 mlockall(td, uap)
 1009         struct thread *td;
 1010         struct mlockall_args *uap;
 1011 {
 1012         vm_map_t map;
 1013         int error;
 1014 
 1015         map = &td->td_proc->p_vmspace->vm_map;
 1016         error = 0;
 1017 
 1018         if ((uap->how == 0) || ((uap->how & ~(MCL_CURRENT|MCL_FUTURE)) != 0))
 1019                 return (EINVAL);
 1020 
 1021 #if 0
 1022         /*
 1023          * If wiring all pages in the process would cause it to exceed
 1024          * a hard resource limit, return ENOMEM.
 1025          */
 1026         PROC_LOCK(td->td_proc);
 1027         if (map->size - ptoa(pmap_wired_count(vm_map_pmap(map)) >
 1028                 lim_cur(td->td_proc, RLIMIT_MEMLOCK))) {
 1029                 PROC_UNLOCK(td->td_proc);
 1030                 return (ENOMEM);
 1031         }
 1032         PROC_UNLOCK(td->td_proc);
 1033 #else
 1034         error = priv_check(td, PRIV_VM_MLOCK);
 1035         if (error)
 1036                 return (error);
 1037 #endif
 1038 
 1039         if (uap->how & MCL_FUTURE) {
 1040                 vm_map_lock(map);
 1041                 vm_map_modflags(map, MAP_WIREFUTURE, 0);
 1042                 vm_map_unlock(map);
 1043                 error = 0;
 1044         }
 1045 
 1046         if (uap->how & MCL_CURRENT) {
 1047                 /*
 1048                  * P1003.1-2001 mandates that all currently mapped pages
 1049                  * will be memory resident and locked (wired) upon return
 1050                  * from mlockall(). vm_map_wire() will wire pages, by
 1051                  * calling vm_fault_wire() for each page in the region.
 1052                  */
 1053                 error = vm_map_wire(map, vm_map_min(map), vm_map_max(map),
 1054                     VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
 1055                 error = (error == KERN_SUCCESS ? 0 : EAGAIN);
 1056         }
 1057 
 1058         return (error);
 1059 }
 1060 
 1061 #ifndef _SYS_SYSPROTO_H_
 1062 struct munlockall_args {
 1063         register_t dummy;
 1064 };
 1065 #endif
 1066 
 1067 /*
 1068  * MPSAFE
 1069  */
 1070 int
 1071 munlockall(td, uap)
 1072         struct thread *td;
 1073         struct munlockall_args *uap;
 1074 {
 1075         vm_map_t map;
 1076         int error;
 1077 
 1078         map = &td->td_proc->p_vmspace->vm_map;
 1079         error = priv_check(td, PRIV_VM_MUNLOCK);
 1080         if (error)
 1081                 return (error);
 1082 
 1083         /* Clear the MAP_WIREFUTURE flag from this vm_map. */
 1084         vm_map_lock(map);
 1085         vm_map_modflags(map, 0, MAP_WIREFUTURE);
 1086         vm_map_unlock(map);
 1087 
 1088         /* Forcibly unwire all pages. */
 1089         error = vm_map_unwire(map, vm_map_min(map), vm_map_max(map),
 1090             VM_MAP_WIRE_USER|VM_MAP_WIRE_HOLESOK);
 1091 
 1092         return (error);
 1093 }
 1094 
 1095 #ifndef _SYS_SYSPROTO_H_
 1096 struct munlock_args {
 1097         const void *addr;
 1098         size_t len;
 1099 };
 1100 #endif
 1101 /*
 1102  * MPSAFE
 1103  */
 1104 int
 1105 munlock(td, uap)
 1106         struct thread *td;
 1107         struct munlock_args *uap;
 1108 {
 1109         vm_offset_t addr, end, last, start;
 1110         vm_size_t size;
 1111         int error;
 1112 
 1113         error = priv_check(td, PRIV_VM_MUNLOCK);
 1114         if (error)
 1115                 return (error);
 1116         addr = (vm_offset_t)uap->addr;
 1117         size = uap->len;
 1118         last = addr + size;
 1119         start = trunc_page(addr);
 1120         end = round_page(last);
 1121         if (last < addr || end < addr)
 1122                 return (EINVAL);
 1123         error = vm_map_unwire(&td->td_proc->p_vmspace->vm_map, start, end,
 1124             VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
 1125         return (error == KERN_SUCCESS ? 0 : ENOMEM);
 1126 }
 1127 
 1128 /*
 1129  * vm_mmap_vnode()
 1130  *
 1131  * MPSAFE
 1132  *
 1133  * Helper function for vm_mmap.  Perform sanity check specific for mmap
 1134  * operations on vnodes.
 1135  */
 1136 int
 1137 vm_mmap_vnode(struct thread *td, vm_size_t objsize,
 1138     vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
 1139     struct vnode *vp, vm_ooffset_t foff, vm_object_t *objp)
 1140 {
 1141         struct vattr va;
 1142         void *handle;
 1143         vm_object_t obj;
 1144         struct mount *mp;
 1145         int error, flags, type;
 1146         int vfslocked;
 1147 
 1148         mp = vp->v_mount;
 1149         vfslocked = VFS_LOCK_GIANT(mp);
 1150         if ((error = vget(vp, LK_EXCLUSIVE, td)) != 0) {
 1151                 VFS_UNLOCK_GIANT(vfslocked);
 1152                 return (error);
 1153         }
 1154         flags = *flagsp;
 1155         obj = vp->v_object;
 1156         if (vp->v_type == VREG) {
 1157                 /*
 1158                  * Get the proper underlying object
 1159                  */
 1160                 if (obj == NULL) {
 1161                         error = EINVAL;
 1162                         goto done;
 1163                 }
 1164                 if (obj->handle != vp) {
 1165                         vput(vp);
 1166                         vp = (struct vnode*)obj->handle;
 1167                         vget(vp, LK_EXCLUSIVE, td);
 1168                 }
 1169                 type = OBJT_VNODE;
 1170                 handle = vp;
 1171         } else if (vp->v_type == VCHR) {
 1172                 type = OBJT_DEVICE;
 1173                 handle = vp->v_rdev;
 1174 
 1175                 /* XXX: lack thredref on device */
 1176                 if(vp->v_rdev->si_devsw->d_flags & D_MMAP_ANON) {
 1177                         *maxprotp = VM_PROT_ALL;
 1178                         *flagsp |= MAP_ANON;
 1179                         error = 0;
 1180                         goto done;
 1181                 }
 1182                 /*
 1183                  * cdevs does not provide private mappings of any kind.
 1184                  */
 1185                 if ((*maxprotp & VM_PROT_WRITE) == 0 &&
 1186                     (prot & PROT_WRITE) != 0) {
 1187                         error = EACCES;
 1188                         goto done;
 1189                 }
 1190                 if (flags & (MAP_PRIVATE|MAP_COPY)) {
 1191                         error = EINVAL;
 1192                         goto done;
 1193                 }
 1194                 /*
 1195                  * Force device mappings to be shared.
 1196                  */
 1197                 flags |= MAP_SHARED;
 1198         } else {
 1199                 error = EINVAL;
 1200                 goto done;
 1201         }
 1202         if ((error = VOP_GETATTR(vp, &va, td->td_ucred, td))) {
 1203                 goto done;
 1204         }
 1205 #ifdef MAC
 1206         error = mac_check_vnode_mmap(td->td_ucred, vp, prot, flags);
 1207         if (error != 0)
 1208                 goto done;
 1209 #endif
 1210         if ((flags & MAP_SHARED) != 0) {
 1211                 if ((va.va_flags & (SF_SNAPSHOT|IMMUTABLE|APPEND)) != 0) {
 1212                         if (prot & PROT_WRITE) {
 1213                                 error = EPERM;
 1214                                 goto done;
 1215                         }
 1216                         *maxprotp &= ~VM_PROT_WRITE;
 1217                 }
 1218         }
 1219         /*
 1220          * If it is a regular file without any references
 1221          * we do not need to sync it.
 1222          * Adjust object size to be the size of actual file.
 1223          */
 1224         if (vp->v_type == VREG) {
 1225                 objsize = round_page(va.va_size);
 1226                 if (va.va_nlink == 0)
 1227                         flags |= MAP_NOSYNC;
 1228         }
 1229         obj = vm_pager_allocate(type, handle, objsize, prot, foff);
 1230         if (obj == NULL) {
 1231                 error = (type == OBJT_DEVICE ? EINVAL : ENOMEM);
 1232                 goto done;
 1233         }
 1234         *objp = obj;
 1235         *flagsp = flags;
 1236         vfs_mark_atime(vp, td);
 1237 
 1238 done:
 1239         vput(vp);
 1240         VFS_UNLOCK_GIANT(vfslocked);
 1241         return (error);
 1242 }
 1243 
 1244 /*
 1245  * vm_mmap_cdev()
 1246  *
 1247  * MPSAFE
 1248  *
 1249  * Helper function for vm_mmap.  Perform sanity check specific for mmap
 1250  * operations on cdevs.
 1251  */
 1252 int
 1253 vm_mmap_cdev(struct thread *td, vm_size_t objsize,
 1254     vm_prot_t prot, vm_prot_t *maxprotp, int *flagsp,
 1255     struct cdev *cdev, vm_ooffset_t foff, vm_object_t *objp)
 1256 {
 1257         vm_object_t obj;
 1258         int flags;
 1259 
 1260         flags = *flagsp;
 1261 
 1262         /* XXX: lack thredref on device */
 1263         if (cdev->si_devsw->d_flags & D_MMAP_ANON) {
 1264                 *maxprotp = VM_PROT_ALL;
 1265                 *flagsp |= MAP_ANON;
 1266                 return (0);
 1267         }
 1268         /*
 1269          * cdevs does not provide private mappings of any kind.
 1270          */
 1271         if ((*maxprotp & VM_PROT_WRITE) == 0 &&
 1272             (prot & PROT_WRITE) != 0)
 1273                 return (EACCES);
 1274         if (flags & (MAP_PRIVATE|MAP_COPY))
 1275                 return (EINVAL);
 1276         /*
 1277          * Force device mappings to be shared.
 1278          */
 1279         flags |= MAP_SHARED;
 1280 #ifdef MAC_XXX
 1281         error = mac_check_cdev_mmap(td->td_ucred, cdev, prot);
 1282         if (error != 0)
 1283                 return (error);
 1284 #endif
 1285         obj = vm_pager_allocate(OBJT_DEVICE, cdev, objsize, prot, foff);
 1286         if (obj == NULL)
 1287                 return (EINVAL);
 1288         *objp = obj;
 1289         *flagsp = flags;
 1290         return (0);
 1291 }
 1292 
 1293 /*
 1294  * vm_mmap()
 1295  *
 1296  * MPSAFE
 1297  *
 1298  * Internal version of mmap.  Currently used by mmap, exec, and sys5
 1299  * shared memory.  Handle is either a vnode pointer or NULL for MAP_ANON.
 1300  */
 1301 int
 1302 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
 1303         vm_prot_t maxprot, int flags,
 1304         objtype_t handle_type, void *handle,
 1305         vm_ooffset_t foff)
 1306 {
 1307         boolean_t fitit;
 1308         vm_object_t object = NULL;
 1309         int rv = KERN_SUCCESS;
 1310         int docow, error;
 1311         struct thread *td = curthread;
 1312 
 1313         if (size == 0)
 1314                 return (0);
 1315 
 1316         size = round_page(size);
 1317 
 1318         PROC_LOCK(td->td_proc);
 1319         if (td->td_proc->p_vmspace->vm_map.size + size >
 1320             lim_cur(td->td_proc, RLIMIT_VMEM)) {
 1321                 PROC_UNLOCK(td->td_proc);
 1322                 return(ENOMEM);
 1323         }
 1324         PROC_UNLOCK(td->td_proc);
 1325 
 1326         /*
 1327          * We currently can only deal with page aligned file offsets.
 1328          * The check is here rather than in the syscall because the
 1329          * kernel calls this function internally for other mmaping
 1330          * operations (such as in exec) and non-aligned offsets will
 1331          * cause pmap inconsistencies...so we want to be sure to
 1332          * disallow this in all cases.
 1333          */
 1334         if (foff & PAGE_MASK)
 1335                 return (EINVAL);
 1336 
 1337         if ((flags & MAP_FIXED) == 0) {
 1338                 fitit = TRUE;
 1339                 *addr = round_page(*addr);
 1340         } else {
 1341                 if (*addr != trunc_page(*addr))
 1342                         return (EINVAL);
 1343                 fitit = FALSE;
 1344         }
 1345         /*
 1346          * Lookup/allocate object.
 1347          */
 1348         switch (handle_type) {
 1349         case OBJT_DEVICE:
 1350                 error = vm_mmap_cdev(td, size, prot, &maxprot, &flags,
 1351                     handle, foff, &object);
 1352                 break;
 1353         case OBJT_VNODE:
 1354                 error = vm_mmap_vnode(td, size, prot, &maxprot, &flags,
 1355                     handle, foff, &object);
 1356                 break;
 1357         case OBJT_DEFAULT:
 1358                 if (handle == NULL) {
 1359                         error = 0;
 1360                         break;
 1361                 }
 1362                 /* FALLTHROUGH */
 1363         default:
 1364                 error = EINVAL;
 1365                 break;
 1366         }
 1367         if (error)
 1368                 return (error);
 1369         if (flags & MAP_ANON) {
 1370                 object = NULL;
 1371                 docow = 0;
 1372                 /*
 1373                  * Unnamed anonymous regions always start at 0.
 1374                  */
 1375                 if (handle == 0)
 1376                         foff = 0;
 1377         } else {
 1378                 docow = MAP_PREFAULT_PARTIAL;
 1379         }
 1380 
 1381         if ((flags & (MAP_ANON|MAP_SHARED)) == 0)
 1382                 docow |= MAP_COPY_ON_WRITE;
 1383         if (flags & MAP_NOSYNC)
 1384                 docow |= MAP_DISABLE_SYNCER;
 1385         if (flags & MAP_NOCORE)
 1386                 docow |= MAP_DISABLE_COREDUMP;
 1387 
 1388 #if defined(VM_PROT_READ_IS_EXEC)
 1389         if (prot & VM_PROT_READ)
 1390                 prot |= VM_PROT_EXECUTE;
 1391 
 1392         if (maxprot & VM_PROT_READ)
 1393                 maxprot |= VM_PROT_EXECUTE;
 1394 #endif
 1395 
 1396         if (fitit)
 1397                 *addr = pmap_addr_hint(object, *addr, size);
 1398 
 1399         if (flags & MAP_STACK)
 1400                 rv = vm_map_stack(map, *addr, size, prot, maxprot,
 1401                     docow | MAP_STACK_GROWS_DOWN);
 1402         else if (fitit)
 1403                 rv = vm_map_find(map, object, foff, addr, size, TRUE,
 1404                                  prot, maxprot, docow);
 1405         else
 1406                 rv = vm_map_fixed(map, object, foff, addr, size,
 1407                                  prot, maxprot, docow);
 1408 
 1409         if (rv != KERN_SUCCESS) {
 1410                 /*
 1411                  * Lose the object reference. Will destroy the
 1412                  * object if it's an unnamed anonymous mapping
 1413                  * or named anonymous without other references.
 1414                  */
 1415                 vm_object_deallocate(object);
 1416         } else if (flags & MAP_SHARED) {
 1417                 /*
 1418                  * Shared memory is also shared with children.
 1419                  */
 1420                 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
 1421                 if (rv != KERN_SUCCESS)
 1422                         (void) vm_map_remove(map, *addr, *addr + size);
 1423         }
 1424 
 1425         /*
 1426          * If the process has requested that all future mappings
 1427          * be wired, then heed this.
 1428          */
 1429         if ((rv == KERN_SUCCESS) && (map->flags & MAP_WIREFUTURE))
 1430                 vm_map_wire(map, *addr, *addr + size,
 1431                     VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
 1432 
 1433         switch (rv) {
 1434         case KERN_SUCCESS:
 1435                 return (0);
 1436         case KERN_INVALID_ADDRESS:
 1437         case KERN_NO_SPACE:
 1438                 return (ENOMEM);
 1439         case KERN_PROTECTION_FAILURE:
 1440                 return (EACCES);
 1441         default:
 1442                 return (EINVAL);
 1443         }
 1444 }

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