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  * 3. All advertising materials mentioning features or use of this software
   19  *    must display the following acknowledgement:
   20  *      This product includes software developed by the University of
   21  *      California, Berkeley and its contributors.
   22  * 4. Neither the name of the University nor the names of its contributors
   23  *    may be used to endorse or promote products derived from this software
   24  *    without specific prior written permission.
   25  *
   26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   36  * SUCH DAMAGE.
   37  *
   38  * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
   39  *
   40  *      @(#)vm_mmap.c   8.4 (Berkeley) 1/12/94
   41  * $FreeBSD$
   42  */
   43 
   44 /*
   45  * Mapped file (mmap) interface to VM
   46  */
   47 
   48 #include "opt_compat.h"
   49 #include "opt_rlimit.h"
   50 
   51 #include <sys/param.h>
   52 #include <sys/systm.h>
   53 #include <sys/sysproto.h>
   54 #include <sys/filedesc.h>
   55 #include <sys/proc.h>
   56 #include <sys/vnode.h>
   57 #include <sys/fcntl.h>
   58 #include <sys/file.h>
   59 #include <sys/mman.h>
   60 #include <sys/conf.h>
   61 #include <sys/stat.h>
   62 #include <sys/vmmeter.h>
   63 
   64 #include <miscfs/specfs/specdev.h>
   65 
   66 #include <vm/vm.h>
   67 #include <vm/vm_param.h>
   68 #include <vm/vm_prot.h>
   69 #include <vm/vm_inherit.h>
   70 #include <sys/lock.h>
   71 #include <vm/pmap.h>
   72 #include <vm/vm_map.h>
   73 #include <vm/vm_object.h>
   74 #include <vm/vm_pager.h>
   75 #include <vm/vm_pageout.h>
   76 #include <vm/vm_extern.h>
   77 #include <vm/vm_page.h>
   78 
   79 #ifndef _SYS_SYSPROTO_H_
   80 struct sbrk_args {
   81         int incr;
   82 };
   83 #endif
   84 
   85 /* ARGSUSED */
   86 int
   87 sbrk(p, uap)
   88         struct proc *p;
   89         struct sbrk_args *uap;
   90 {
   91 
   92         /* Not yet implemented */
   93         return (EOPNOTSUPP);
   94 }
   95 
   96 #ifndef _SYS_SYSPROTO_H_
   97 struct sstk_args {
   98         int incr;
   99 };
  100 #endif
  101 
  102 /* ARGSUSED */
  103 int
  104 sstk(p, uap)
  105         struct proc *p;
  106         struct sstk_args *uap;
  107 {
  108 
  109         /* Not yet implemented */
  110         return (EOPNOTSUPP);
  111 }
  112 
  113 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
  114 #ifndef _SYS_SYSPROTO_H_
  115 struct getpagesize_args {
  116         int dummy;
  117 };
  118 #endif
  119 
  120 /* ARGSUSED */
  121 int
  122 ogetpagesize(p, uap)
  123         struct proc *p;
  124         struct getpagesize_args *uap;
  125 {
  126 
  127         p->p_retval[0] = PAGE_SIZE;
  128         return (0);
  129 }
  130 #endif                          /* COMPAT_43 || COMPAT_SUNOS */
  131 
  132 
  133 /* 
  134  * Memory Map (mmap) system call.  Note that the file offset
  135  * and address are allowed to be NOT page aligned, though if
  136  * the MAP_FIXED flag it set, both must have the same remainder
  137  * modulo the PAGE_SIZE (POSIX 1003.1b).  If the address is not
  138  * page-aligned, the actual mapping starts at trunc_page(addr)
  139  * and the return value is adjusted up by the page offset.
  140  */
  141 #ifndef _SYS_SYSPROTO_H_
  142 struct mmap_args {
  143         void *addr;
  144         size_t len;
  145         int prot;
  146         int flags;
  147         int fd;
  148         long pad;
  149         off_t pos;
  150 };
  151 #endif
  152 
  153 int
  154 mmap(p, uap)
  155         struct proc *p;
  156         register struct mmap_args *uap;
  157 {
  158         register struct filedesc *fdp = p->p_fd;
  159         register struct file *fp;
  160         struct vnode *vp;
  161         vm_offset_t addr;
  162         vm_size_t size, pageoff;
  163         vm_prot_t prot, maxprot;
  164         void *handle;
  165         int flags, error;
  166         int disablexworkaround;
  167         off_t pos;
  168 
  169         addr = (vm_offset_t) uap->addr;
  170         size = uap->len;
  171         prot = uap->prot & VM_PROT_ALL;
  172         flags = uap->flags;
  173         pos = uap->pos;
  174 
  175         /* make sure mapping fits into numeric range etc */
  176         if ((ssize_t) uap->len < 0 ||
  177             ((flags & MAP_ANON) && uap->fd != -1))
  178                 return (EINVAL);
  179 
  180         if (flags & MAP_STACK) {
  181 #ifdef VM_STACK
  182                 if ((uap->fd != -1) ||
  183                     ((prot & (PROT_READ | PROT_WRITE)) != (PROT_READ | PROT_WRITE)))
  184                         return (EINVAL);
  185                 flags |= MAP_ANON;
  186                 pos = 0;
  187 #else
  188                 return (EINVAL);
  189 #endif
  190         }
  191 
  192         /*
  193          * Align the file position to a page boundary,
  194          * and save its page offset component.
  195          */
  196         pageoff = (pos & PAGE_MASK);
  197         pos -= pageoff;
  198 
  199         /* Adjust size for rounding (on both ends). */
  200         size += pageoff;                        /* low end... */
  201         size = (vm_size_t) round_page(size);    /* hi end */
  202 
  203         /*
  204          * Check for illegal addresses.  Watch out for address wrap... Note
  205          * that VM_*_ADDRESS are not constants due to casts (argh).
  206          */
  207         if (flags & MAP_FIXED) {
  208                 /*
  209                  * The specified address must have the same remainder
  210                  * as the file offset taken modulo PAGE_SIZE, so it
  211                  * should be aligned after adjustment by pageoff.
  212                  */
  213                 addr -= pageoff;
  214                 if (addr & PAGE_MASK)
  215                         return (EINVAL);
  216                 /* Address range must be all in user VM space. */
  217                 if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
  218                         return (EINVAL);
  219 #ifndef i386
  220                 if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
  221                         return (EINVAL);
  222 #endif
  223                 if (addr + size < addr)
  224                         return (EINVAL);
  225         }
  226         /*
  227          * XXX for non-fixed mappings where no hint is provided or
  228          * the hint would fall in the potential heap space,
  229          * place it after the end of the largest possible heap.
  230          *
  231          * There should really be a pmap call to determine a reasonable
  232          * location.
  233          */
  234         else if (addr == 0 ||
  235             addr >= round_page((vm_offset_t)p->p_vmspace->vm_taddr) &&
  236             addr < round_page((vm_offset_t)p->p_vmspace->vm_daddr + MAXDSIZ))
  237                 addr = round_page((vm_offset_t)p->p_vmspace->vm_daddr + MAXDSIZ);
  238 
  239         if (flags & MAP_ANON) {
  240                 /*
  241                  * Mapping blank space is trivial.
  242                  */
  243                 handle = NULL;
  244                 maxprot = VM_PROT_ALL;
  245                 pos = 0;
  246         } else {
  247                 /*
  248                  * Mapping file, get fp for validation. Obtain vnode and make
  249                  * sure it is of appropriate type.
  250                  */
  251                 if (((unsigned) uap->fd) >= fdp->fd_nfiles ||
  252                     (fp = fdp->fd_ofiles[uap->fd]) == NULL)
  253                         return (EBADF);
  254                 if (fp->f_type != DTYPE_VNODE)
  255                         return (EINVAL);
  256                 vp = (struct vnode *) fp->f_data;
  257                 if (vp->v_type != VREG && vp->v_type != VCHR)
  258                         return (EINVAL);
  259                 /*
  260                  * XXX hack to handle use of /dev/zero to map anon memory (ala
  261                  * SunOS).
  262                  */
  263                 if (vp->v_type == VCHR && iszerodev(vp->v_rdev)) {
  264                         handle = NULL;
  265                         maxprot = VM_PROT_ALL;
  266                         flags |= MAP_ANON;
  267                         pos = 0;
  268                 } else {
  269                         /*
  270                          * cdevs does not provide private mappings of any kind.
  271                          */
  272                         /*
  273                          * However, for XIG X server to continue to work,
  274                          * we should allow the superuser to do it anyway.
  275                          * We only allow it at securelevel < 1.
  276                          * (Because the XIG X server writes directly to video
  277                          * memory via /dev/mem, it should never work at any
  278                          * other securelevel.
  279                          * XXX this will have to go
  280                          */
  281                         if (securelevel >= 1)
  282                                 disablexworkaround = 1;
  283                         else
  284                                 disablexworkaround = suser(p->p_ucred,
  285                                                            &p->p_acflag);
  286                         if (vp->v_type == VCHR && disablexworkaround &&
  287                                 (flags & (MAP_PRIVATE|MAP_COPY)))
  288                                  return (EINVAL);
  289                         /*
  290                          * Ensure that file and memory protections are
  291                          * compatible.  Note that we only worry about
  292                          * writability if mapping is shared; in this case,
  293                          * current and max prot are dictated by the open file.
  294                          * XXX use the vnode instead?  Problem is: what
  295                          * credentials do we use for determination? What if
  296                          * proc does a setuid?
  297                          */
  298                         maxprot = VM_PROT_EXECUTE;      /* ??? */
  299                         if (fp->f_flag & FREAD)
  300                                 maxprot |= VM_PROT_READ;
  301                         else if (prot & PROT_READ)
  302                                 return (EACCES);
  303                         /*
  304                          * If we are sharing potential changes (either via
  305                          * MAP_SHARED or via the implicit sharing of character
  306                          * device mappings), and we are trying to get write
  307                          * permission although we opened it without asking
  308                          * for it, bail out.  Check for superuser, only if
  309                          * we're at securelevel < 1, to allow the XIG X server
  310                          * to continue to work.
  311                          */
  312 
  313                         if ((flags & MAP_SHARED) != 0 ||
  314                             (vp->v_type == VCHR && disablexworkaround)) {
  315                                 if ((fp->f_flag & FWRITE) != 0) {
  316                                         struct vattr va;
  317                                         if ((error =
  318                                             VOP_GETATTR(vp, &va,
  319                                                         p->p_ucred, p)))
  320                                                 return (error);
  321                                         if ((va.va_flags &
  322                                             (IMMUTABLE|APPEND)) == 0)
  323                                                 maxprot |= VM_PROT_WRITE;
  324                                         else if (prot & PROT_WRITE)
  325                                                 return (EPERM);
  326                                 } else if ((prot & PROT_WRITE) != 0)
  327                                         return (EACCES);
  328                         } else
  329                                 maxprot |= VM_PROT_WRITE;
  330 
  331                         handle = (void *)vp;
  332                 }
  333         }
  334         error = vm_mmap(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
  335             flags, handle, pos);
  336         if (error == 0)
  337                 p->p_retval[0] = (register_t) (addr + pageoff);
  338         return (error);
  339 }
  340 
  341 #ifdef COMPAT_43
  342 #ifndef _SYS_SYSPROTO_H_
  343 struct ommap_args {
  344         caddr_t addr;
  345         int len;
  346         int prot;
  347         int flags;
  348         int fd;
  349         long pos;
  350 };
  351 #endif
  352 int
  353 ommap(p, uap)
  354         struct proc *p;
  355         register struct ommap_args *uap;
  356 {
  357         struct mmap_args nargs;
  358         static const char cvtbsdprot[8] = {
  359                 0,
  360                 PROT_EXEC,
  361                 PROT_WRITE,
  362                 PROT_EXEC | PROT_WRITE,
  363                 PROT_READ,
  364                 PROT_EXEC | PROT_READ,
  365                 PROT_WRITE | PROT_READ,
  366                 PROT_EXEC | PROT_WRITE | PROT_READ,
  367         };
  368 
  369 #define OMAP_ANON       0x0002
  370 #define OMAP_COPY       0x0020
  371 #define OMAP_SHARED     0x0010
  372 #define OMAP_FIXED      0x0100
  373 #define OMAP_INHERIT    0x0800
  374 
  375         nargs.addr = uap->addr;
  376         nargs.len = uap->len;
  377         nargs.prot = cvtbsdprot[uap->prot & 0x7];
  378         nargs.flags = 0;
  379         if (uap->flags & OMAP_ANON)
  380                 nargs.flags |= MAP_ANON;
  381         if (uap->flags & OMAP_COPY)
  382                 nargs.flags |= MAP_COPY;
  383         if (uap->flags & OMAP_SHARED)
  384                 nargs.flags |= MAP_SHARED;
  385         else
  386                 nargs.flags |= MAP_PRIVATE;
  387         if (uap->flags & OMAP_FIXED)
  388                 nargs.flags |= MAP_FIXED;
  389         if (uap->flags & OMAP_INHERIT)
  390                 nargs.flags |= MAP_INHERIT;
  391         nargs.fd = uap->fd;
  392         nargs.pos = uap->pos;
  393         return (mmap(p, &nargs));
  394 }
  395 #endif                          /* COMPAT_43 */
  396 
  397 
  398 #ifndef _SYS_SYSPROTO_H_
  399 struct msync_args {
  400         void *addr;
  401         int len;
  402         int flags;
  403 };
  404 #endif
  405 int
  406 msync(p, uap)
  407         struct proc *p;
  408         struct msync_args *uap;
  409 {
  410         vm_offset_t addr;
  411         vm_size_t size, pageoff;
  412         int flags;
  413         vm_map_t map;
  414         int rv;
  415 
  416         addr = (vm_offset_t) uap->addr;
  417         size = uap->len;
  418         flags = uap->flags;
  419 
  420         pageoff = (addr & PAGE_MASK);
  421         addr -= pageoff;
  422         size += pageoff;
  423         size = (vm_size_t) round_page(size);
  424         if (addr + size < addr)
  425                 return(EINVAL);
  426 
  427         if ((flags & (MS_ASYNC|MS_INVALIDATE)) == (MS_ASYNC|MS_INVALIDATE))
  428                 return (EINVAL);
  429 
  430         map = &p->p_vmspace->vm_map;
  431 
  432         /*
  433          * XXX Gak!  If size is zero we are supposed to sync "all modified
  434          * pages with the region containing addr".  Unfortunately, we don't
  435          * really keep track of individual mmaps so we approximate by flushing
  436          * the range of the map entry containing addr. This can be incorrect
  437          * if the region splits or is coalesced with a neighbor.
  438          */
  439         if (size == 0) {
  440                 vm_map_entry_t entry;
  441 
  442                 vm_map_lock_read(map);
  443                 rv = vm_map_lookup_entry(map, addr, &entry);
  444                 vm_map_unlock_read(map);
  445                 if (rv == FALSE)
  446                         return (EINVAL);
  447                 addr = entry->start;
  448                 size = entry->end - entry->start;
  449         }
  450 
  451         /*
  452          * Clean the pages and interpret the return value.
  453          */
  454         rv = vm_map_clean(map, addr, addr + size, (flags & MS_ASYNC) == 0,
  455             (flags & MS_INVALIDATE) != 0);
  456 
  457         switch (rv) {
  458         case KERN_SUCCESS:
  459                 break;
  460         case KERN_INVALID_ADDRESS:
  461                 return (EINVAL);        /* Sun returns ENOMEM? */
  462         case KERN_FAILURE:
  463                 return (EIO);
  464         default:
  465                 return (EINVAL);
  466         }
  467 
  468         return (0);
  469 }
  470 
  471 #ifndef _SYS_SYSPROTO_H_
  472 struct munmap_args {
  473         void *addr;
  474         size_t len;
  475 };
  476 #endif
  477 int
  478 munmap(p, uap)
  479         register struct proc *p;
  480         register struct munmap_args *uap;
  481 {
  482         vm_offset_t addr;
  483         vm_size_t size, pageoff;
  484         vm_map_t map;
  485 
  486         addr = (vm_offset_t) uap->addr;
  487         size = uap->len;
  488 
  489         pageoff = (addr & PAGE_MASK);
  490         addr -= pageoff;
  491         size += pageoff;
  492         size = (vm_size_t) round_page(size);
  493         if (addr + size < addr)
  494                 return(EINVAL);
  495 
  496         if (size == 0)
  497                 return (0);
  498 
  499         /*
  500          * Check for illegal addresses.  Watch out for address wrap... Note
  501          * that VM_*_ADDRESS are not constants due to casts (argh).
  502          */
  503         if (VM_MAXUSER_ADDRESS > 0 && addr + size > VM_MAXUSER_ADDRESS)
  504                 return (EINVAL);
  505 #ifndef i386
  506         if (VM_MIN_ADDRESS > 0 && addr < VM_MIN_ADDRESS)
  507                 return (EINVAL);
  508 #endif
  509         map = &p->p_vmspace->vm_map;
  510         /*
  511          * Make sure entire range is allocated.
  512          */
  513         if (!vm_map_check_protection(map, addr, addr + size, VM_PROT_NONE))
  514                 return (EINVAL);
  515         /* returns nothing but KERN_SUCCESS anyway */
  516         (void) vm_map_remove(map, addr, addr + size);
  517         return (0);
  518 }
  519 
  520 void
  521 munmapfd(p, fd)
  522         struct proc *p;
  523         int fd;
  524 {
  525         /*
  526          * XXX should unmap any regions mapped to this file
  527          */
  528         p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED;
  529 }
  530 
  531 #ifndef _SYS_SYSPROTO_H_
  532 struct mprotect_args {
  533         const void *addr;
  534         size_t len;
  535         int prot;
  536 };
  537 #endif
  538 int
  539 mprotect(p, uap)
  540         struct proc *p;
  541         struct mprotect_args *uap;
  542 {
  543         vm_offset_t addr;
  544         vm_size_t size, pageoff;
  545         register vm_prot_t prot;
  546 
  547         addr = (vm_offset_t) uap->addr;
  548         size = uap->len;
  549         prot = uap->prot & VM_PROT_ALL;
  550 #if defined(VM_PROT_READ_IS_EXEC)
  551         if (prot & VM_PROT_READ)
  552                 prot |= VM_PROT_EXECUTE;
  553 #endif
  554 
  555         pageoff = (addr & PAGE_MASK);
  556         addr -= pageoff;
  557         size += pageoff;
  558         size = (vm_size_t) round_page(size);
  559         if (addr + size < addr)
  560                 return(EINVAL);
  561 
  562         switch (vm_map_protect(&p->p_vmspace->vm_map, addr, addr + size, prot,
  563                 FALSE)) {
  564         case KERN_SUCCESS:
  565                 return (0);
  566         case KERN_PROTECTION_FAILURE:
  567                 return (EACCES);
  568         }
  569         return (EINVAL);
  570 }
  571 
  572 #ifndef _SYS_SYSPROTO_H_
  573 struct minherit_args {
  574         void *addr;
  575         size_t len;
  576         int inherit;
  577 };
  578 #endif
  579 int
  580 minherit(p, uap)
  581         struct proc *p;
  582         struct minherit_args *uap;
  583 {
  584         vm_offset_t addr;
  585         vm_size_t size, pageoff;
  586         register vm_inherit_t inherit;
  587 
  588         addr = (vm_offset_t)uap->addr;
  589         size = uap->len;
  590         inherit = uap->inherit;
  591 
  592         pageoff = (addr & PAGE_MASK);
  593         addr -= pageoff;
  594         size += pageoff;
  595         size = (vm_size_t) round_page(size);
  596         if (addr + size < addr)
  597                 return(EINVAL);
  598 
  599         switch (vm_map_inherit(&p->p_vmspace->vm_map, addr, addr+size,
  600             inherit)) {
  601         case KERN_SUCCESS:
  602                 return (0);
  603         case KERN_PROTECTION_FAILURE:
  604                 return (EACCES);
  605         }
  606         return (EINVAL);
  607 }
  608 
  609 #ifndef _SYS_SYSPROTO_H_
  610 struct madvise_args {
  611         void *addr;
  612         size_t len;
  613         int behav;
  614 };
  615 #endif
  616 
  617 /* ARGSUSED */
  618 int
  619 madvise(p, uap)
  620         struct proc *p;
  621         struct madvise_args *uap;
  622 {
  623         vm_map_t map;
  624         pmap_t pmap;
  625         vm_offset_t start, end;
  626         /*
  627          * Check for illegal addresses.  Watch out for address wrap... Note
  628          * that VM_*_ADDRESS are not constants due to casts (argh).
  629          */
  630         if (VM_MAXUSER_ADDRESS > 0 &&
  631                 ((vm_offset_t) uap->addr + uap->len) > VM_MAXUSER_ADDRESS)
  632                 return (EINVAL);
  633 #ifndef i386
  634         if (VM_MIN_ADDRESS > 0 && uap->addr < VM_MIN_ADDRESS)
  635                 return (EINVAL);
  636 #endif
  637         if (((vm_offset_t) uap->addr + uap->len) < (vm_offset_t) uap->addr)
  638                 return (EINVAL);
  639 
  640         /*
  641          * Since this routine is only advisory, we default to conservative
  642          * behavior.
  643          */
  644         start = trunc_page((vm_offset_t) uap->addr);
  645         end = round_page((vm_offset_t) uap->addr + uap->len);
  646         
  647         map = &p->p_vmspace->vm_map;
  648         pmap = &p->p_vmspace->vm_pmap;
  649 
  650         vm_map_madvise(map, pmap, start, end, uap->behav);
  651 
  652         return (0);
  653 }
  654 
  655 #ifndef _SYS_SYSPROTO_H_
  656 struct mincore_args {
  657         const void *addr;
  658         size_t len;
  659         char *vec;
  660 };
  661 #endif
  662 
  663 /* ARGSUSED */
  664 int
  665 mincore(p, uap)
  666         struct proc *p;
  667         struct mincore_args *uap;
  668 {
  669         vm_offset_t addr, first_addr;
  670         vm_offset_t end, cend;
  671         pmap_t pmap;
  672         vm_map_t map;
  673         char *vec;
  674         int error;
  675         int vecindex, lastvecindex;
  676         register vm_map_entry_t current;
  677         vm_map_entry_t entry;
  678         int mincoreinfo;
  679 
  680         /*
  681          * Make sure that the addresses presented are valid for user
  682          * mode.
  683          */
  684         first_addr = addr = trunc_page((vm_offset_t) uap->addr);
  685         end = addr + (vm_size_t)round_page(uap->len);
  686         if (VM_MAXUSER_ADDRESS > 0 && end > VM_MAXUSER_ADDRESS)
  687                 return (EINVAL);
  688         if (end < addr)
  689                 return (EINVAL);
  690 
  691         /*
  692          * Address of byte vector
  693          */
  694         vec = uap->vec;
  695 
  696         map = &p->p_vmspace->vm_map;
  697         pmap = &p->p_vmspace->vm_pmap;
  698 
  699         vm_map_lock(map);
  700 
  701         if (!vm_map_lookup_entry(map, addr, &entry))
  702                 entry = entry->next;
  703 
  704         /*
  705          * Do this on a map entry basis so that if the pages are not
  706          * in the current processes address space, we can easily look
  707          * up the pages elsewhere.
  708          */
  709         lastvecindex = -1;
  710         for(current = entry;
  711                 (current != &map->header) && (current->start < end);
  712                 current = current->next) {
  713 
  714                 /*
  715                  * ignore submaps (for now) or null objects
  716                  */
  717                 if ((current->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) ||
  718                         current->object.vm_object == NULL)
  719                         continue;
  720                 
  721                 /*
  722                  * limit this scan to the current map entry and the
  723                  * limits for the mincore call
  724                  */
  725                 if (addr < current->start)
  726                         addr = current->start;
  727                 cend = current->end;
  728                 if (cend > end)
  729                         cend = end;
  730 
  731                 /*
  732                  * scan this entry one page at a time
  733                  */
  734                 while(addr < cend) {
  735                         /*
  736                          * Check pmap first, it is likely faster, also
  737                          * it can provide info as to whether we are the
  738                          * one referencing or modifying the page.
  739                          */
  740                         mincoreinfo = pmap_mincore(pmap, addr);
  741                         if (!mincoreinfo) {
  742                                 vm_pindex_t pindex;
  743                                 vm_ooffset_t offset;
  744                                 vm_page_t m;
  745                                 /*
  746                                  * calculate the page index into the object
  747                                  */
  748                                 offset = current->offset + (addr - current->start);
  749                                 pindex = OFF_TO_IDX(offset);
  750                                 m = vm_page_lookup(current->object.vm_object,
  751                                         pindex);
  752                                 /*
  753                                  * if the page is resident, then gather information about
  754                                  * it.
  755                                  */
  756                                 if (m) {
  757                                         mincoreinfo = MINCORE_INCORE;
  758                                         if (m->dirty ||
  759                                                 pmap_is_modified(VM_PAGE_TO_PHYS(m)))
  760                                                 mincoreinfo |= MINCORE_MODIFIED_OTHER;
  761                                         if ((m->flags & PG_REFERENCED) ||
  762                                                 pmap_ts_referenced(VM_PAGE_TO_PHYS(m))) {
  763                                                 vm_page_flag_set(m, PG_REFERENCED);
  764                                                 mincoreinfo |= MINCORE_REFERENCED_OTHER;
  765                                         }
  766                                 }
  767                         }
  768 
  769                         /*
  770                          * calculate index into user supplied byte vector
  771                          */
  772                         vecindex = OFF_TO_IDX(addr - first_addr);
  773 
  774                         /*
  775                          * If we have skipped map entries, we need to make sure that
  776                          * the byte vector is zeroed for those skipped entries.
  777                          */
  778                         while((lastvecindex + 1) < vecindex) {
  779                                 error = subyte( vec + lastvecindex, 0);
  780                                 if (error) {
  781                                         vm_map_unlock(map);
  782                                         return (EFAULT);
  783                                 }
  784                                 ++lastvecindex;
  785                         }
  786 
  787                         /*
  788                          * Pass the page information to the user
  789                          */
  790                         error = subyte( vec + vecindex, mincoreinfo);
  791                         if (error) {
  792                                 vm_map_unlock(map);
  793                                 return (EFAULT);
  794                         }
  795                         lastvecindex = vecindex;
  796                         addr += PAGE_SIZE;
  797                 }
  798         }
  799 
  800         /*
  801          * Zero the last entries in the byte vector.
  802          */
  803         vecindex = OFF_TO_IDX(end - first_addr);
  804         while((lastvecindex + 1) < vecindex) {
  805                 error = subyte( vec + lastvecindex, 0);
  806                 if (error) {
  807                         vm_map_unlock(map);
  808                         return (EFAULT);
  809                 }
  810                 ++lastvecindex;
  811         }
  812         
  813         vm_map_unlock(map);
  814         return (0);
  815 }
  816 
  817 #ifndef _SYS_SYSPROTO_H_
  818 struct mlock_args {
  819         const void *addr;
  820         size_t len;
  821 };
  822 #endif
  823 int
  824 mlock(p, uap)
  825         struct proc *p;
  826         struct mlock_args *uap;
  827 {
  828         vm_offset_t addr;
  829         vm_size_t size, pageoff;
  830         int error;
  831 
  832         addr = (vm_offset_t) uap->addr;
  833         size = uap->len;
  834 
  835         pageoff = (addr & PAGE_MASK);
  836         addr -= pageoff;
  837         size += pageoff;
  838         size = (vm_size_t) round_page(size);
  839 
  840         /* disable wrap around */
  841         if (addr + size < addr)
  842                 return (EINVAL);
  843 
  844         if (atop(size) + cnt.v_wire_count > vm_page_max_wired)
  845                 return (EAGAIN);
  846 
  847 #ifdef pmap_wired_count
  848         if (size + ptoa(pmap_wired_count(vm_map_pmap(&p->p_vmspace->vm_map))) >
  849             p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur)
  850                 return (ENOMEM);
  851 #else
  852         error = suser(p->p_ucred, &p->p_acflag);
  853         if (error)
  854                 return (error);
  855 #endif
  856 
  857         error = vm_map_user_pageable(&p->p_vmspace->vm_map, addr, addr + size, FALSE);
  858         return (error == KERN_SUCCESS ? 0 : ENOMEM);
  859 }
  860 
  861 #ifndef _SYS_SYSPROTO_H_
  862 struct mlockall_args {
  863         int     how;
  864 };
  865 #endif
  866 
  867 int
  868 mlockall(p, uap)
  869         struct proc *p;
  870         struct mlockall_args *uap;
  871 {
  872         return 0;
  873 }
  874 
  875 #ifndef _SYS_SYSPROTO_H_
  876 struct mlockall_args {
  877         int     how;
  878 };
  879 #endif
  880 
  881 int
  882 munlockall(p, uap)
  883         struct proc *p;
  884         struct munlockall_args *uap;
  885 {
  886         return 0;
  887 }
  888 
  889 #ifndef _SYS_SYSPROTO_H_
  890 struct munlock_args {
  891         const void *addr;
  892         size_t len;
  893 };
  894 #endif
  895 int
  896 munlock(p, uap)
  897         struct proc *p;
  898         struct munlock_args *uap;
  899 {
  900         vm_offset_t addr;
  901         vm_size_t size, pageoff;
  902         int error;
  903 
  904         addr = (vm_offset_t) uap->addr;
  905         size = uap->len;
  906 
  907         pageoff = (addr & PAGE_MASK);
  908         addr -= pageoff;
  909         size += pageoff;
  910         size = (vm_size_t) round_page(size);
  911 
  912         /* disable wrap around */
  913         if (addr + size < addr)
  914                 return (EINVAL);
  915 
  916 #ifndef pmap_wired_count
  917         error = suser(p->p_ucred, &p->p_acflag);
  918         if (error)
  919                 return (error);
  920 #endif
  921 
  922         error = vm_map_user_pageable(&p->p_vmspace->vm_map, addr, addr + size, TRUE);
  923         return (error == KERN_SUCCESS ? 0 : ENOMEM);
  924 }
  925 
  926 /*
  927  * Internal version of mmap.
  928  * Currently used by mmap, exec, and sys5 shared memory.
  929  * Handle is either a vnode pointer or NULL for MAP_ANON.
  930  */
  931 int
  932 vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
  933         vm_prot_t maxprot, int flags,
  934         void *handle,
  935         vm_ooffset_t foff)
  936 {
  937         boolean_t fitit;
  938         vm_object_t object;
  939         struct vnode *vp = NULL;
  940         objtype_t type;
  941         int rv = KERN_SUCCESS;
  942         vm_ooffset_t objsize;
  943         int docow;
  944         struct proc *p = curproc;
  945 
  946         if (size == 0)
  947                 return (0);
  948 
  949         objsize = size = round_page(size);
  950 
  951         /*
  952          * We currently can only deal with page aligned file offsets.
  953          * The check is here rather than in the syscall because the
  954          * kernel calls this function internally for other mmaping
  955          * operations (such as in exec) and non-aligned offsets will
  956          * cause pmap inconsistencies...so we want to be sure to
  957          * disallow this in all cases.
  958          */
  959         if (foff & PAGE_MASK)
  960                 return (EINVAL);
  961 
  962         if ((flags & MAP_FIXED) == 0) {
  963                 fitit = TRUE;
  964                 *addr = round_page(*addr);
  965         } else {
  966                 if (*addr != trunc_page(*addr))
  967                         return (EINVAL);
  968                 fitit = FALSE;
  969                 (void) vm_map_remove(map, *addr, *addr + size);
  970         }
  971 
  972         /*
  973          * Lookup/allocate object.
  974          */
  975         if (flags & MAP_ANON) {
  976                 type = OBJT_DEFAULT;
  977                 /*
  978                  * Unnamed anonymous regions always start at 0.
  979                  */
  980                 if (handle == 0)
  981                         foff = 0;
  982         } else {
  983                 vp = (struct vnode *) handle;
  984                 if (vp->v_type == VCHR) {
  985                         type = OBJT_DEVICE;
  986                         handle = (void *)(intptr_t)vp->v_rdev;
  987                 } else {
  988                         struct vattr vat;
  989                         int error;
  990 
  991                         error = VOP_GETATTR(vp, &vat, p->p_ucred, p);
  992                         if (error)
  993                                 return (error);
  994                         objsize = round_page(vat.va_size);
  995                         type = OBJT_VNODE;
  996                 }
  997         }
  998 
  999         if (handle == NULL) {
 1000                 object = NULL;
 1001         } else {
 1002                 object = vm_pager_allocate(type,
 1003                         handle, objsize, prot, foff);
 1004                 if (object == NULL)
 1005                         return (type == OBJT_DEVICE ? EINVAL : ENOMEM);
 1006         }
 1007 
 1008         /*
 1009          * Force device mappings to be shared.
 1010          */
 1011         if (type == OBJT_DEVICE) {
 1012                 flags &= ~(MAP_PRIVATE|MAP_COPY);
 1013                 flags |= MAP_SHARED;
 1014         }
 1015 
 1016         docow = 0;
 1017         if ((flags & (MAP_ANON|MAP_SHARED)) == 0) {
 1018                 docow = MAP_COPY_ON_WRITE | MAP_COPY_NEEDED;
 1019         }
 1020 
 1021 #if defined(VM_PROT_READ_IS_EXEC)
 1022         if (prot & VM_PROT_READ)
 1023                 prot |= VM_PROT_EXECUTE;
 1024 
 1025         if (maxprot & VM_PROT_READ)
 1026                 maxprot |= VM_PROT_EXECUTE;
 1027 #endif
 1028 
 1029         if (fitit) {
 1030                 *addr = pmap_addr_hint(object, *addr, size);
 1031         }
 1032 
 1033 #ifdef VM_STACK
 1034         if (flags & MAP_STACK)
 1035                 rv = vm_map_stack (map, *addr, size, prot,
 1036                                    maxprot, docow);
 1037         else
 1038 #endif
 1039         rv = vm_map_find(map, object, foff, addr, size, fitit,
 1040                         prot, maxprot, docow);
 1041 
 1042         if (rv != KERN_SUCCESS) {
 1043                 /*
 1044                  * Lose the object reference. Will destroy the
 1045                  * object if it's an unnamed anonymous mapping
 1046                  * or named anonymous without other references.
 1047                  */
 1048                 vm_object_deallocate(object);
 1049                 goto out;
 1050         }
 1051 
 1052         /*
 1053          * "Pre-fault" resident pages.
 1054          */
 1055         if ((map->pmap != NULL) && (object != NULL)) {
 1056                 pmap_object_init_pt(map->pmap, *addr,
 1057                         object, (vm_pindex_t) OFF_TO_IDX(foff), size, 1);
 1058         }
 1059 
 1060         /*
 1061          * Shared memory is also shared with children.
 1062          */
 1063         if (flags & (MAP_SHARED|MAP_INHERIT)) {
 1064                 rv = vm_map_inherit(map, *addr, *addr + size, VM_INHERIT_SHARE);
 1065                 if (rv != KERN_SUCCESS) {
 1066                         (void) vm_map_remove(map, *addr, *addr + size);
 1067                         goto out;
 1068                 }
 1069         }
 1070 out:
 1071         switch (rv) {
 1072         case KERN_SUCCESS:
 1073                 return (0);
 1074         case KERN_INVALID_ADDRESS:
 1075         case KERN_NO_SPACE:
 1076                 return (ENOMEM);
 1077         case KERN_PROTECTION_FAILURE:
 1078                 return (EACCES);
 1079         default:
 1080                 return (EINVAL);
 1081         }
 1082 }

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