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fed9a9032e
was in the VM_INHERIT_SHARE case of vmspace_fork, and also in vm_map_madvise. Submitted by: Alan Cox <alc@cs.rice.edu>
2540 lines
63 KiB
C
2540 lines
63 KiB
C
/*
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* The Mach Operating System project at Carnegie-Mellon University.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)vm_map.c 8.3 (Berkeley) 1/12/94
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*
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*
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* Copyright (c) 1987, 1990 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Authors: Avadis Tevanian, Jr., Michael Wayne Young
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*
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* $FreeBSD$
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*/
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/*
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* Virtual memory mapping module.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/queue.h>
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#include <sys/vmmeter.h>
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#include <sys/mman.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_prot.h>
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#include <vm/vm_inherit.h>
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#include <vm/lock.h>
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <vm/vm_page.h>
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#include <vm/vm_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_pager.h>
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#include <vm/vm_extern.h>
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#include <vm/default_pager.h>
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/*
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* Virtual memory maps provide for the mapping, protection,
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* and sharing of virtual memory objects. In addition,
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* this module provides for an efficient virtual copy of
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* memory from one map to another.
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*
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* Synchronization is required prior to most operations.
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*
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* Maps consist of an ordered doubly-linked list of simple
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* entries; a single hint is used to speed up lookups.
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*
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* In order to properly represent the sharing of virtual
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* memory regions among maps, the map structure is bi-level.
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* Top-level ("address") maps refer to regions of sharable
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* virtual memory. These regions are implemented as
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* ("sharing") maps, which then refer to the actual virtual
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* memory objects. When two address maps "share" memory,
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* their top-level maps both have references to the same
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* sharing map. When memory is virtual-copied from one
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* address map to another, the references in the sharing
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* maps are actually copied -- no copying occurs at the
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* virtual memory object level.
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*
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* Since portions of maps are specified by start/end addreses,
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* which may not align with existing map entries, all
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* routines merely "clip" entries to these start/end values.
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* [That is, an entry is split into two, bordering at a
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* start or end value.] Note that these clippings may not
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* always be necessary (as the two resulting entries are then
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* not changed); however, the clipping is done for convenience.
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* No attempt is currently made to "glue back together" two
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* abutting entries.
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*
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* As mentioned above, virtual copy operations are performed
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* by copying VM object references from one sharing map to
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* another, and then marking both regions as copy-on-write.
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* It is important to note that only one writeable reference
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* to a VM object region exists in any map -- this means that
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* shadow object creation can be delayed until a write operation
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* occurs.
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*/
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/*
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* vm_map_startup:
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*
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* Initialize the vm_map module. Must be called before
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* any other vm_map routines.
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*
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* Map and entry structures are allocated from the general
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* purpose memory pool with some exceptions:
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*
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* - The kernel map and kmem submap are allocated statically.
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* - Kernel map entries are allocated out of a static pool.
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*
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* These restrictions are necessary since malloc() uses the
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* maps and requires map entries.
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*/
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vm_offset_t kentry_data;
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vm_size_t kentry_data_size;
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static vm_map_entry_t kentry_free;
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static vm_map_t kmap_free;
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extern char kstack[];
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extern int inmprotect;
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static int kentry_count;
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static vm_offset_t mapvm_start, mapvm, mapvmmax;
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static int mapvmpgcnt;
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static struct vm_map_entry *mappool;
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static int mappoolcnt;
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#define KENTRY_LOW_WATER 128
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static void _vm_map_clip_end __P((vm_map_t, vm_map_entry_t, vm_offset_t));
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static void _vm_map_clip_start __P((vm_map_t, vm_map_entry_t, vm_offset_t));
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static vm_map_entry_t vm_map_entry_create __P((vm_map_t));
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static void vm_map_entry_delete __P((vm_map_t, vm_map_entry_t));
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static void vm_map_entry_dispose __P((vm_map_t, vm_map_entry_t));
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static void vm_map_entry_unwire __P((vm_map_t, vm_map_entry_t));
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static void vm_map_copy_entry __P((vm_map_t, vm_map_t, vm_map_entry_t,
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vm_map_entry_t));
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void
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vm_map_startup()
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{
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register int i;
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register vm_map_entry_t mep;
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vm_map_t mp;
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/*
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* Static map structures for allocation before initialization of
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* kernel map or kmem map. vm_map_create knows how to deal with them.
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*/
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kmap_free = mp = (vm_map_t) kentry_data;
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i = MAX_KMAP;
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while (--i > 0) {
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mp->header.next = (vm_map_entry_t) (mp + 1);
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mp++;
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}
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mp++->header.next = NULL;
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/*
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* Form a free list of statically allocated kernel map entries with
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* the rest.
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*/
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kentry_free = mep = (vm_map_entry_t) mp;
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kentry_count = i = (kentry_data_size - MAX_KMAP * sizeof *mp) / sizeof *mep;
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while (--i > 0) {
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mep->next = mep + 1;
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mep++;
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}
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mep->next = NULL;
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}
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/*
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* Allocate a vmspace structure, including a vm_map and pmap,
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* and initialize those structures. The refcnt is set to 1.
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* The remaining fields must be initialized by the caller.
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*/
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struct vmspace *
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vmspace_alloc(min, max, pageable)
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vm_offset_t min, max;
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int pageable;
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{
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register struct vmspace *vm;
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if (mapvmpgcnt == 0 && mapvm == 0) {
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mapvmpgcnt = (cnt.v_page_count * sizeof(struct vm_map_entry) + PAGE_SIZE - 1) / PAGE_SIZE;
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mapvm_start = mapvm = kmem_alloc_pageable(kernel_map,
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mapvmpgcnt * PAGE_SIZE);
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mapvmmax = mapvm_start + mapvmpgcnt * PAGE_SIZE;
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if (!mapvm)
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mapvmpgcnt = 0;
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}
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MALLOC(vm, struct vmspace *, sizeof(struct vmspace), M_VMMAP, M_WAITOK);
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bzero(vm, (caddr_t) &vm->vm_startcopy - (caddr_t) vm);
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vm_map_init(&vm->vm_map, min, max, pageable);
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pmap_pinit(&vm->vm_pmap);
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vm->vm_map.pmap = &vm->vm_pmap; /* XXX */
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vm->vm_refcnt = 1;
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return (vm);
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}
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void
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vmspace_free(vm)
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register struct vmspace *vm;
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{
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if (vm->vm_refcnt == 0)
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panic("vmspace_free: attempt to free already freed vmspace");
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if (--vm->vm_refcnt == 0) {
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/*
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* Lock the map, to wait out all other references to it.
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* Delete all of the mappings and pages they hold, then call
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* the pmap module to reclaim anything left.
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*/
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vm_map_lock(&vm->vm_map);
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(void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
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vm->vm_map.max_offset);
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vm_map_unlock(&vm->vm_map);
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while( vm->vm_map.ref_count != 1)
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tsleep(&vm->vm_map.ref_count, PVM, "vmsfre", 0);
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--vm->vm_map.ref_count;
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vm_object_pmap_remove(vm->vm_upages_obj,
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0, vm->vm_upages_obj->size);
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vm_object_deallocate(vm->vm_upages_obj);
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pmap_release(&vm->vm_pmap);
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FREE(vm, M_VMMAP);
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} else {
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wakeup(&vm->vm_map.ref_count);
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}
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}
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/*
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* vm_map_create:
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*
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* Creates and returns a new empty VM map with
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* the given physical map structure, and having
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* the given lower and upper address bounds.
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*/
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vm_map_t
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vm_map_create(pmap, min, max, pageable)
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pmap_t pmap;
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vm_offset_t min, max;
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boolean_t pageable;
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{
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register vm_map_t result;
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if (kmem_map == NULL) {
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result = kmap_free;
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kmap_free = (vm_map_t) result->header.next;
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if (result == NULL)
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panic("vm_map_create: out of maps");
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} else
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MALLOC(result, vm_map_t, sizeof(struct vm_map),
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M_VMMAP, M_WAITOK);
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vm_map_init(result, min, max, pageable);
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result->pmap = pmap;
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return (result);
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}
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/*
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* Initialize an existing vm_map structure
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* such as that in the vmspace structure.
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* The pmap is set elsewhere.
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*/
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void
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vm_map_init(map, min, max, pageable)
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register struct vm_map *map;
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vm_offset_t min, max;
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boolean_t pageable;
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{
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map->header.next = map->header.prev = &map->header;
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map->nentries = 0;
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map->size = 0;
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map->ref_count = 1;
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map->is_main_map = TRUE;
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map->min_offset = min;
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map->max_offset = max;
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map->entries_pageable = pageable;
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map->first_free = &map->header;
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map->hint = &map->header;
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map->timestamp = 0;
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lock_init(&map->lock, TRUE);
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}
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/*
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* vm_map_entry_dispose: [ internal use only ]
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*
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* Inverse of vm_map_entry_create.
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*/
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static void
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vm_map_entry_dispose(map, entry)
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vm_map_t map;
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vm_map_entry_t entry;
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{
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int s;
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if (map == kernel_map || map == kmem_map ||
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map == mb_map || map == pager_map) {
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s = splvm();
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entry->next = kentry_free;
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kentry_free = entry;
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++kentry_count;
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splx(s);
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} else {
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entry->next = mappool;
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mappool = entry;
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++mappoolcnt;
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}
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}
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/*
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* vm_map_entry_create: [ internal use only ]
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*
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* Allocates a VM map entry for insertion.
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* No entry fields are filled in. This routine is
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*/
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static vm_map_entry_t
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vm_map_entry_create(map)
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vm_map_t map;
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{
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vm_map_entry_t entry;
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int i;
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int s;
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/*
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* This is a *very* nasty (and sort of incomplete) hack!!!!
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*/
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if (kentry_count < KENTRY_LOW_WATER) {
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s = splvm();
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if (mapvmpgcnt && mapvm) {
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vm_page_t m;
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m = vm_page_alloc(kernel_object,
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OFF_TO_IDX(mapvm - VM_MIN_KERNEL_ADDRESS),
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(map == kmem_map || map == mb_map) ? VM_ALLOC_INTERRUPT : VM_ALLOC_NORMAL);
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if (m) {
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int newentries;
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newentries = (PAGE_SIZE / sizeof(struct vm_map_entry));
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vm_page_wire(m);
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PAGE_WAKEUP(m);
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m->valid = VM_PAGE_BITS_ALL;
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pmap_kenter(mapvm, VM_PAGE_TO_PHYS(m));
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m->flags |= PG_WRITEABLE;
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entry = (vm_map_entry_t) mapvm;
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mapvm += PAGE_SIZE;
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--mapvmpgcnt;
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for (i = 0; i < newentries; i++) {
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vm_map_entry_dispose(kernel_map, entry);
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entry++;
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}
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}
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}
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splx(s);
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}
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if (map == kernel_map || map == kmem_map ||
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map == mb_map || map == pager_map) {
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s = splvm();
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entry = kentry_free;
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if (entry) {
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kentry_free = entry->next;
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--kentry_count;
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} else {
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panic("vm_map_entry_create: out of map entries for kernel");
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}
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splx(s);
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} else {
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entry = mappool;
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if (entry) {
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mappool = entry->next;
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--mappoolcnt;
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} else {
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MALLOC(entry, vm_map_entry_t, sizeof(struct vm_map_entry),
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M_VMMAPENT, M_WAITOK);
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}
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}
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return (entry);
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}
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/*
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* vm_map_entry_{un,}link:
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*
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* Insert/remove entries from maps.
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*/
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#define vm_map_entry_link(map, after_where, entry) \
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{ \
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(map)->nentries++; \
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(entry)->prev = (after_where); \
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(entry)->next = (after_where)->next; \
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(entry)->prev->next = (entry); \
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(entry)->next->prev = (entry); \
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}
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#define vm_map_entry_unlink(map, entry) \
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{ \
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(map)->nentries--; \
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(entry)->next->prev = (entry)->prev; \
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(entry)->prev->next = (entry)->next; \
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}
|
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|
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/*
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* vm_map_reference:
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*
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* Creates another valid reference to the given map.
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*
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*/
|
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void
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vm_map_reference(map)
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register vm_map_t map;
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{
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if (map == NULL)
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return;
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map->ref_count++;
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}
|
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|
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/*
|
|
* vm_map_deallocate:
|
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*
|
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* Removes a reference from the specified map,
|
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* destroying it if no references remain.
|
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* The map should not be locked.
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|
*/
|
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void
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vm_map_deallocate(map)
|
|
register vm_map_t map;
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{
|
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register int c;
|
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if (map == NULL)
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return;
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c = map->ref_count;
|
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|
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if (c == 0)
|
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panic("vm_map_deallocate: deallocating already freed map");
|
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|
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if (c != 1) {
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--map->ref_count;
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wakeup(&map->ref_count);
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return;
|
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}
|
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/*
|
|
* Lock the map, to wait out all other references to it.
|
|
*/
|
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|
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vm_map_lock(map);
|
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(void) vm_map_delete(map, map->min_offset, map->max_offset);
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--map->ref_count;
|
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if( map->ref_count != 0) {
|
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vm_map_unlock(map);
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return;
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}
|
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|
|
pmap_destroy(map->pmap);
|
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FREE(map, M_VMMAP);
|
|
}
|
|
|
|
/*
|
|
* SAVE_HINT:
|
|
*
|
|
* Saves the specified entry as the hint for
|
|
* future lookups.
|
|
*/
|
|
#define SAVE_HINT(map,value) \
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|
(map)->hint = (value);
|
|
|
|
/*
|
|
* vm_map_lookup_entry: [ internal use only ]
|
|
*
|
|
* Finds the map entry containing (or
|
|
* immediately preceding) the specified address
|
|
* in the given map; the entry is returned
|
|
* in the "entry" parameter. The boolean
|
|
* result indicates whether the address is
|
|
* actually contained in the map.
|
|
*/
|
|
boolean_t
|
|
vm_map_lookup_entry(map, address, entry)
|
|
register vm_map_t map;
|
|
register vm_offset_t address;
|
|
vm_map_entry_t *entry; /* OUT */
|
|
{
|
|
register vm_map_entry_t cur;
|
|
register vm_map_entry_t last;
|
|
|
|
/*
|
|
* Start looking either from the head of the list, or from the hint.
|
|
*/
|
|
|
|
cur = map->hint;
|
|
|
|
if (cur == &map->header)
|
|
cur = cur->next;
|
|
|
|
if (address >= cur->start) {
|
|
/*
|
|
* Go from hint to end of list.
|
|
*
|
|
* But first, make a quick check to see if we are already looking
|
|
* at the entry we want (which is usually the case). Note also
|
|
* that we don't need to save the hint here... it is the same
|
|
* hint (unless we are at the header, in which case the hint
|
|
* didn't buy us anything anyway).
|
|
*/
|
|
last = &map->header;
|
|
if ((cur != last) && (cur->end > address)) {
|
|
*entry = cur;
|
|
return (TRUE);
|
|
}
|
|
} else {
|
|
/*
|
|
* Go from start to hint, *inclusively*
|
|
*/
|
|
last = cur->next;
|
|
cur = map->header.next;
|
|
}
|
|
|
|
/*
|
|
* Search linearly
|
|
*/
|
|
|
|
while (cur != last) {
|
|
if (cur->end > address) {
|
|
if (address >= cur->start) {
|
|
/*
|
|
* Save this lookup for future hints, and
|
|
* return
|
|
*/
|
|
|
|
*entry = cur;
|
|
SAVE_HINT(map, cur);
|
|
return (TRUE);
|
|
}
|
|
break;
|
|
}
|
|
cur = cur->next;
|
|
}
|
|
*entry = cur->prev;
|
|
SAVE_HINT(map, *entry);
|
|
return (FALSE);
|
|
}
|
|
|
|
/*
|
|
* vm_map_insert:
|
|
*
|
|
* Inserts the given whole VM object into the target
|
|
* map at the specified address range. The object's
|
|
* size should match that of the address range.
|
|
*
|
|
* Requires that the map be locked, and leaves it so.
|
|
*/
|
|
int
|
|
vm_map_insert(map, object, offset, start, end, prot, max, cow)
|
|
vm_map_t map;
|
|
vm_object_t object;
|
|
vm_ooffset_t offset;
|
|
vm_offset_t start;
|
|
vm_offset_t end;
|
|
vm_prot_t prot, max;
|
|
int cow;
|
|
{
|
|
register vm_map_entry_t new_entry;
|
|
register vm_map_entry_t prev_entry;
|
|
vm_map_entry_t temp_entry;
|
|
vm_object_t prev_object;
|
|
u_char protoeflags;
|
|
|
|
if ((object != NULL) && (cow & MAP_NOFAULT)) {
|
|
panic("vm_map_insert: paradoxical MAP_NOFAULT request");
|
|
}
|
|
|
|
/*
|
|
* Check that the start and end points are not bogus.
|
|
*/
|
|
|
|
if ((start < map->min_offset) || (end > map->max_offset) ||
|
|
(start >= end))
|
|
return (KERN_INVALID_ADDRESS);
|
|
|
|
/*
|
|
* Find the entry prior to the proposed starting address; if it's part
|
|
* of an existing entry, this range is bogus.
|
|
*/
|
|
|
|
if (vm_map_lookup_entry(map, start, &temp_entry))
|
|
return (KERN_NO_SPACE);
|
|
|
|
prev_entry = temp_entry;
|
|
|
|
/*
|
|
* Assert that the next entry doesn't overlap the end point.
|
|
*/
|
|
|
|
if ((prev_entry->next != &map->header) &&
|
|
(prev_entry->next->start < end))
|
|
return (KERN_NO_SPACE);
|
|
|
|
protoeflags = 0;
|
|
if (cow & MAP_COPY_NEEDED)
|
|
protoeflags |= MAP_ENTRY_NEEDS_COPY;
|
|
|
|
if (cow & MAP_COPY_ON_WRITE)
|
|
protoeflags |= MAP_ENTRY_COW;
|
|
|
|
if (cow & MAP_NOFAULT)
|
|
protoeflags |= MAP_ENTRY_NOFAULT;
|
|
|
|
/*
|
|
* See if we can avoid creating a new entry by extending one of our
|
|
* neighbors. Or at least extend the object.
|
|
*/
|
|
|
|
if ((object == NULL) &&
|
|
(prev_entry != &map->header) &&
|
|
(( prev_entry->eflags & (MAP_ENTRY_IS_A_MAP | MAP_ENTRY_IS_SUB_MAP)) == 0) &&
|
|
(prev_entry->end == start) &&
|
|
(prev_entry->wired_count == 0)) {
|
|
|
|
|
|
if ((protoeflags == prev_entry->eflags) &&
|
|
((cow & MAP_NOFAULT) ||
|
|
vm_object_coalesce(prev_entry->object.vm_object,
|
|
OFF_TO_IDX(prev_entry->offset),
|
|
(vm_size_t) (prev_entry->end - prev_entry->start),
|
|
(vm_size_t) (end - prev_entry->end)))) {
|
|
|
|
/*
|
|
* Coalesced the two objects. Can we extend the
|
|
* previous map entry to include the new range?
|
|
*/
|
|
if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
|
|
(prev_entry->protection == prot) &&
|
|
(prev_entry->max_protection == max)) {
|
|
|
|
map->size += (end - prev_entry->end);
|
|
prev_entry->end = end;
|
|
if ((cow & MAP_NOFAULT) == 0) {
|
|
prev_object = prev_entry->object.vm_object;
|
|
default_pager_convert_to_swapq(prev_object);
|
|
}
|
|
return (KERN_SUCCESS);
|
|
}
|
|
else {
|
|
object = prev_entry->object.vm_object;
|
|
offset = prev_entry->offset + (prev_entry->end -
|
|
prev_entry->start);
|
|
|
|
vm_object_reference(object);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create a new entry
|
|
*/
|
|
|
|
new_entry = vm_map_entry_create(map);
|
|
new_entry->start = start;
|
|
new_entry->end = end;
|
|
|
|
new_entry->eflags = protoeflags;
|
|
new_entry->object.vm_object = object;
|
|
new_entry->offset = offset;
|
|
|
|
if (map->is_main_map) {
|
|
new_entry->inheritance = VM_INHERIT_DEFAULT;
|
|
new_entry->protection = prot;
|
|
new_entry->max_protection = max;
|
|
new_entry->wired_count = 0;
|
|
}
|
|
/*
|
|
* Insert the new entry into the list
|
|
*/
|
|
|
|
vm_map_entry_link(map, prev_entry, new_entry);
|
|
map->size += new_entry->end - new_entry->start;
|
|
|
|
/*
|
|
* Update the free space hint
|
|
*/
|
|
if ((map->first_free == prev_entry) &&
|
|
(prev_entry->end >= new_entry->start))
|
|
map->first_free = new_entry;
|
|
|
|
default_pager_convert_to_swapq(object);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* Find sufficient space for `length' bytes in the given map, starting at
|
|
* `start'. The map must be locked. Returns 0 on success, 1 on no space.
|
|
*/
|
|
int
|
|
vm_map_findspace(map, start, length, addr)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
vm_size_t length;
|
|
vm_offset_t *addr;
|
|
{
|
|
register vm_map_entry_t entry, next;
|
|
register vm_offset_t end;
|
|
|
|
if (start < map->min_offset)
|
|
start = map->min_offset;
|
|
if (start > map->max_offset)
|
|
return (1);
|
|
|
|
/*
|
|
* Look for the first possible address; if there's already something
|
|
* at this address, we have to start after it.
|
|
*/
|
|
if (start == map->min_offset) {
|
|
if ((entry = map->first_free) != &map->header)
|
|
start = entry->end;
|
|
} else {
|
|
vm_map_entry_t tmp;
|
|
|
|
if (vm_map_lookup_entry(map, start, &tmp))
|
|
start = tmp->end;
|
|
entry = tmp;
|
|
}
|
|
|
|
/*
|
|
* Look through the rest of the map, trying to fit a new region in the
|
|
* gap between existing regions, or after the very last region.
|
|
*/
|
|
for (;; start = (entry = next)->end) {
|
|
/*
|
|
* Find the end of the proposed new region. Be sure we didn't
|
|
* go beyond the end of the map, or wrap around the address;
|
|
* if so, we lose. Otherwise, if this is the last entry, or
|
|
* if the proposed new region fits before the next entry, we
|
|
* win.
|
|
*/
|
|
end = start + length;
|
|
if (end > map->max_offset || end < start)
|
|
return (1);
|
|
next = entry->next;
|
|
if (next == &map->header || next->start >= end)
|
|
break;
|
|
}
|
|
SAVE_HINT(map, entry);
|
|
*addr = start;
|
|
if (map == kernel_map && round_page(start + length) > kernel_vm_end)
|
|
pmap_growkernel(round_page(start + length));
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* vm_map_find finds an unallocated region in the target address
|
|
* map with the given length. The search is defined to be
|
|
* first-fit from the specified address; the region found is
|
|
* returned in the same parameter.
|
|
*
|
|
*/
|
|
int
|
|
vm_map_find(map, object, offset, addr, length, find_space, prot, max, cow)
|
|
vm_map_t map;
|
|
vm_object_t object;
|
|
vm_ooffset_t offset;
|
|
vm_offset_t *addr; /* IN/OUT */
|
|
vm_size_t length;
|
|
boolean_t find_space;
|
|
vm_prot_t prot, max;
|
|
int cow;
|
|
{
|
|
register vm_offset_t start;
|
|
int result, s = 0;
|
|
|
|
start = *addr;
|
|
|
|
if (map == kmem_map || map == mb_map)
|
|
s = splvm();
|
|
|
|
vm_map_lock(map);
|
|
if (find_space) {
|
|
if (vm_map_findspace(map, start, length, addr)) {
|
|
vm_map_unlock(map);
|
|
if (map == kmem_map || map == mb_map)
|
|
splx(s);
|
|
return (KERN_NO_SPACE);
|
|
}
|
|
start = *addr;
|
|
}
|
|
result = vm_map_insert(map, object, offset,
|
|
start, start + length, prot, max, cow);
|
|
vm_map_unlock(map);
|
|
|
|
if (map == kmem_map || map == mb_map)
|
|
splx(s);
|
|
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* vm_map_simplify_entry:
|
|
*
|
|
* Simplify the given map entry by merging with either neighbor.
|
|
*/
|
|
void
|
|
vm_map_simplify_entry(map, entry)
|
|
vm_map_t map;
|
|
vm_map_entry_t entry;
|
|
{
|
|
vm_map_entry_t next, prev;
|
|
vm_size_t prevsize, esize;
|
|
|
|
if (entry->eflags & (MAP_ENTRY_IS_SUB_MAP|MAP_ENTRY_IS_A_MAP))
|
|
return;
|
|
|
|
prev = entry->prev;
|
|
if (prev != &map->header) {
|
|
prevsize = prev->end - prev->start;
|
|
if ( (prev->end == entry->start) &&
|
|
(prev->object.vm_object == entry->object.vm_object) &&
|
|
(!prev->object.vm_object || (prev->object.vm_object->behavior == entry->object.vm_object->behavior)) &&
|
|
(!prev->object.vm_object ||
|
|
(prev->offset + prevsize == entry->offset)) &&
|
|
(prev->eflags == entry->eflags) &&
|
|
(prev->protection == entry->protection) &&
|
|
(prev->max_protection == entry->max_protection) &&
|
|
(prev->inheritance == entry->inheritance) &&
|
|
(prev->wired_count == entry->wired_count)) {
|
|
if (map->first_free == prev)
|
|
map->first_free = entry;
|
|
if (map->hint == prev)
|
|
map->hint = entry;
|
|
vm_map_entry_unlink(map, prev);
|
|
entry->start = prev->start;
|
|
entry->offset = prev->offset;
|
|
if (prev->object.vm_object)
|
|
vm_object_deallocate(prev->object.vm_object);
|
|
vm_map_entry_dispose(map, prev);
|
|
}
|
|
}
|
|
|
|
next = entry->next;
|
|
if (next != &map->header) {
|
|
esize = entry->end - entry->start;
|
|
if ((entry->end == next->start) &&
|
|
(next->object.vm_object == entry->object.vm_object) &&
|
|
(!next->object.vm_object || (next->object.vm_object->behavior == entry->object.vm_object->behavior)) &&
|
|
(!entry->object.vm_object ||
|
|
(entry->offset + esize == next->offset)) &&
|
|
(next->eflags == entry->eflags) &&
|
|
(next->protection == entry->protection) &&
|
|
(next->max_protection == entry->max_protection) &&
|
|
(next->inheritance == entry->inheritance) &&
|
|
(next->wired_count == entry->wired_count)) {
|
|
if (map->first_free == next)
|
|
map->first_free = entry;
|
|
if (map->hint == next)
|
|
map->hint = entry;
|
|
vm_map_entry_unlink(map, next);
|
|
entry->end = next->end;
|
|
if (next->object.vm_object)
|
|
vm_object_deallocate(next->object.vm_object);
|
|
vm_map_entry_dispose(map, next);
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* vm_map_clip_start: [ internal use only ]
|
|
*
|
|
* Asserts that the given entry begins at or after
|
|
* the specified address; if necessary,
|
|
* it splits the entry into two.
|
|
*/
|
|
#define vm_map_clip_start(map, entry, startaddr) \
|
|
{ \
|
|
if (startaddr > entry->start) \
|
|
_vm_map_clip_start(map, entry, startaddr); \
|
|
}
|
|
|
|
/*
|
|
* This routine is called only when it is known that
|
|
* the entry must be split.
|
|
*/
|
|
static void
|
|
_vm_map_clip_start(map, entry, start)
|
|
register vm_map_t map;
|
|
register vm_map_entry_t entry;
|
|
register vm_offset_t start;
|
|
{
|
|
register vm_map_entry_t new_entry;
|
|
|
|
/*
|
|
* Split off the front portion -- note that we must insert the new
|
|
* entry BEFORE this one, so that this entry has the specified
|
|
* starting address.
|
|
*/
|
|
|
|
vm_map_simplify_entry(map, entry);
|
|
|
|
new_entry = vm_map_entry_create(map);
|
|
*new_entry = *entry;
|
|
|
|
new_entry->end = start;
|
|
entry->offset += (start - entry->start);
|
|
entry->start = start;
|
|
|
|
vm_map_entry_link(map, entry->prev, new_entry);
|
|
|
|
if (entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP))
|
|
vm_map_reference(new_entry->object.share_map);
|
|
else
|
|
vm_object_reference(new_entry->object.vm_object);
|
|
}
|
|
|
|
/*
|
|
* vm_map_clip_end: [ internal use only ]
|
|
*
|
|
* Asserts that the given entry ends at or before
|
|
* the specified address; if necessary,
|
|
* it splits the entry into two.
|
|
*/
|
|
|
|
#define vm_map_clip_end(map, entry, endaddr) \
|
|
{ \
|
|
if (endaddr < entry->end) \
|
|
_vm_map_clip_end(map, entry, endaddr); \
|
|
}
|
|
|
|
/*
|
|
* This routine is called only when it is known that
|
|
* the entry must be split.
|
|
*/
|
|
static void
|
|
_vm_map_clip_end(map, entry, end)
|
|
register vm_map_t map;
|
|
register vm_map_entry_t entry;
|
|
register vm_offset_t end;
|
|
{
|
|
register vm_map_entry_t new_entry;
|
|
|
|
/*
|
|
* Create a new entry and insert it AFTER the specified entry
|
|
*/
|
|
|
|
new_entry = vm_map_entry_create(map);
|
|
*new_entry = *entry;
|
|
|
|
new_entry->start = entry->end = end;
|
|
new_entry->offset += (end - entry->start);
|
|
|
|
vm_map_entry_link(map, entry, new_entry);
|
|
|
|
if (entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP))
|
|
vm_map_reference(new_entry->object.share_map);
|
|
else
|
|
vm_object_reference(new_entry->object.vm_object);
|
|
}
|
|
|
|
/*
|
|
* VM_MAP_RANGE_CHECK: [ internal use only ]
|
|
*
|
|
* Asserts that the starting and ending region
|
|
* addresses fall within the valid range of the map.
|
|
*/
|
|
#define VM_MAP_RANGE_CHECK(map, start, end) \
|
|
{ \
|
|
if (start < vm_map_min(map)) \
|
|
start = vm_map_min(map); \
|
|
if (end > vm_map_max(map)) \
|
|
end = vm_map_max(map); \
|
|
if (start > end) \
|
|
start = end; \
|
|
}
|
|
|
|
/*
|
|
* vm_map_submap: [ kernel use only ]
|
|
*
|
|
* Mark the given range as handled by a subordinate map.
|
|
*
|
|
* This range must have been created with vm_map_find,
|
|
* and no other operations may have been performed on this
|
|
* range prior to calling vm_map_submap.
|
|
*
|
|
* Only a limited number of operations can be performed
|
|
* within this rage after calling vm_map_submap:
|
|
* vm_fault
|
|
* [Don't try vm_map_copy!]
|
|
*
|
|
* To remove a submapping, one must first remove the
|
|
* range from the superior map, and then destroy the
|
|
* submap (if desired). [Better yet, don't try it.]
|
|
*/
|
|
int
|
|
vm_map_submap(map, start, end, submap)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
vm_map_t submap;
|
|
{
|
|
vm_map_entry_t entry;
|
|
register int result = KERN_INVALID_ARGUMENT;
|
|
|
|
vm_map_lock(map);
|
|
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
if (vm_map_lookup_entry(map, start, &entry)) {
|
|
vm_map_clip_start(map, entry, start);
|
|
} else
|
|
entry = entry->next;
|
|
|
|
vm_map_clip_end(map, entry, end);
|
|
|
|
if ((entry->start == start) && (entry->end == end) &&
|
|
((entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_COW)) == 0) &&
|
|
(entry->object.vm_object == NULL)) {
|
|
entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
|
|
vm_map_reference(entry->object.sub_map = submap);
|
|
result = KERN_SUCCESS;
|
|
}
|
|
vm_map_unlock(map);
|
|
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* vm_map_protect:
|
|
*
|
|
* Sets the protection of the specified address
|
|
* region in the target map. If "set_max" is
|
|
* specified, the maximum protection is to be set;
|
|
* otherwise, only the current protection is affected.
|
|
*/
|
|
int
|
|
vm_map_protect(map, start, end, new_prot, set_max)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
register vm_prot_t new_prot;
|
|
register boolean_t set_max;
|
|
{
|
|
register vm_map_entry_t current;
|
|
vm_map_entry_t entry;
|
|
|
|
vm_map_lock(map);
|
|
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
if (vm_map_lookup_entry(map, start, &entry)) {
|
|
vm_map_clip_start(map, entry, start);
|
|
} else {
|
|
entry = entry->next;
|
|
}
|
|
|
|
/*
|
|
* Make a first pass to check for protection violations.
|
|
*/
|
|
|
|
current = entry;
|
|
while ((current != &map->header) && (current->start < end)) {
|
|
if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ARGUMENT);
|
|
}
|
|
if ((new_prot & current->max_protection) != new_prot) {
|
|
vm_map_unlock(map);
|
|
return (KERN_PROTECTION_FAILURE);
|
|
}
|
|
current = current->next;
|
|
}
|
|
|
|
/*
|
|
* Go back and fix up protections. [Note that clipping is not
|
|
* necessary the second time.]
|
|
*/
|
|
|
|
current = entry;
|
|
|
|
while ((current != &map->header) && (current->start < end)) {
|
|
vm_prot_t old_prot;
|
|
|
|
vm_map_clip_end(map, current, end);
|
|
|
|
old_prot = current->protection;
|
|
if (set_max)
|
|
current->protection =
|
|
(current->max_protection = new_prot) &
|
|
old_prot;
|
|
else
|
|
current->protection = new_prot;
|
|
|
|
/*
|
|
* Update physical map if necessary. Worry about copy-on-write
|
|
* here -- CHECK THIS XXX
|
|
*/
|
|
|
|
if (current->protection != old_prot) {
|
|
#define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
|
|
VM_PROT_ALL)
|
|
#define max(a,b) ((a) > (b) ? (a) : (b))
|
|
|
|
if (current->eflags & MAP_ENTRY_IS_A_MAP) {
|
|
vm_map_entry_t share_entry;
|
|
vm_offset_t share_end;
|
|
|
|
vm_map_lock(current->object.share_map);
|
|
(void) vm_map_lookup_entry(
|
|
current->object.share_map,
|
|
current->offset,
|
|
&share_entry);
|
|
share_end = current->offset +
|
|
(current->end - current->start);
|
|
while ((share_entry !=
|
|
¤t->object.share_map->header) &&
|
|
(share_entry->start < share_end)) {
|
|
|
|
pmap_protect(map->pmap,
|
|
(max(share_entry->start,
|
|
current->offset) -
|
|
current->offset +
|
|
current->start),
|
|
min(share_entry->end,
|
|
share_end) -
|
|
current->offset +
|
|
current->start,
|
|
current->protection &
|
|
MASK(share_entry));
|
|
|
|
share_entry = share_entry->next;
|
|
}
|
|
vm_map_unlock(current->object.share_map);
|
|
} else
|
|
pmap_protect(map->pmap, current->start,
|
|
current->end,
|
|
current->protection & MASK(entry));
|
|
#undef max
|
|
#undef MASK
|
|
}
|
|
current = current->next;
|
|
}
|
|
|
|
vm_map_simplify_entry(map, entry);
|
|
vm_map_unlock(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_madvise:
|
|
*
|
|
* This routine traverses a processes map handling the madvise
|
|
* system call.
|
|
*/
|
|
void
|
|
vm_map_madvise(map, pmap, start, end, advise)
|
|
vm_map_t map;
|
|
pmap_t pmap;
|
|
vm_offset_t start, end;
|
|
int advise;
|
|
{
|
|
register vm_map_entry_t current;
|
|
vm_map_entry_t entry;
|
|
|
|
vm_map_lock(map);
|
|
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
if (vm_map_lookup_entry(map, start, &entry)) {
|
|
vm_map_clip_start(map, entry, start);
|
|
} else
|
|
entry = entry->next;
|
|
|
|
for(current = entry;
|
|
(current != &map->header) && (current->start < end);
|
|
current = current->next) {
|
|
vm_size_t size = current->end - current->start;
|
|
|
|
if (current->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) {
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Create an object if needed
|
|
*/
|
|
if (current->object.vm_object == NULL) {
|
|
vm_object_t object;
|
|
object = vm_object_allocate(OBJT_DEFAULT, OFF_TO_IDX(size));
|
|
current->object.vm_object = object;
|
|
current->offset = 0;
|
|
}
|
|
|
|
vm_map_clip_end(map, current, end);
|
|
switch (advise) {
|
|
case MADV_NORMAL:
|
|
current->object.vm_object->behavior = OBJ_NORMAL;
|
|
break;
|
|
case MADV_SEQUENTIAL:
|
|
current->object.vm_object->behavior = OBJ_SEQUENTIAL;
|
|
break;
|
|
case MADV_RANDOM:
|
|
current->object.vm_object->behavior = OBJ_RANDOM;
|
|
break;
|
|
/*
|
|
* Right now, we could handle DONTNEED and WILLNEED with common code.
|
|
* They are mostly the same, except for the potential async reads (NYI).
|
|
*/
|
|
case MADV_FREE:
|
|
case MADV_DONTNEED:
|
|
{
|
|
vm_pindex_t pindex;
|
|
int count;
|
|
size = current->end - current->start;
|
|
pindex = OFF_TO_IDX(entry->offset);
|
|
count = OFF_TO_IDX(size);
|
|
/*
|
|
* MADV_DONTNEED removes the page from all
|
|
* pmaps, so pmap_remove is not necessary.
|
|
*/
|
|
vm_object_madvise(current->object.vm_object,
|
|
pindex, count, advise);
|
|
}
|
|
break;
|
|
|
|
case MADV_WILLNEED:
|
|
{
|
|
vm_pindex_t pindex;
|
|
int count;
|
|
size = current->end - current->start;
|
|
pindex = OFF_TO_IDX(current->offset);
|
|
count = OFF_TO_IDX(size);
|
|
vm_object_madvise(current->object.vm_object,
|
|
pindex, count, advise);
|
|
pmap_object_init_pt(pmap, current->start,
|
|
current->object.vm_object, pindex,
|
|
(count << PAGE_SHIFT), 0);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
vm_map_simplify_entry(map, entry);
|
|
vm_map_unlock(map);
|
|
return;
|
|
}
|
|
|
|
|
|
/*
|
|
* vm_map_inherit:
|
|
*
|
|
* Sets the inheritance of the specified address
|
|
* range in the target map. Inheritance
|
|
* affects how the map will be shared with
|
|
* child maps at the time of vm_map_fork.
|
|
*/
|
|
int
|
|
vm_map_inherit(map, start, end, new_inheritance)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
register vm_inherit_t new_inheritance;
|
|
{
|
|
register vm_map_entry_t entry;
|
|
vm_map_entry_t temp_entry;
|
|
|
|
switch (new_inheritance) {
|
|
case VM_INHERIT_NONE:
|
|
case VM_INHERIT_COPY:
|
|
case VM_INHERIT_SHARE:
|
|
break;
|
|
default:
|
|
return (KERN_INVALID_ARGUMENT);
|
|
}
|
|
|
|
vm_map_lock(map);
|
|
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
if (vm_map_lookup_entry(map, start, &temp_entry)) {
|
|
entry = temp_entry;
|
|
vm_map_clip_start(map, entry, start);
|
|
} else
|
|
entry = temp_entry->next;
|
|
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
vm_map_clip_end(map, entry, end);
|
|
|
|
entry->inheritance = new_inheritance;
|
|
|
|
entry = entry->next;
|
|
}
|
|
|
|
vm_map_simplify_entry(map, temp_entry);
|
|
vm_map_unlock(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* Implement the semantics of mlock
|
|
*/
|
|
int
|
|
vm_map_user_pageable(map, start, end, new_pageable)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
register boolean_t new_pageable;
|
|
{
|
|
register vm_map_entry_t entry;
|
|
vm_map_entry_t start_entry;
|
|
register vm_offset_t failed = 0;
|
|
int rv;
|
|
|
|
vm_map_lock(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) {
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
|
|
if (new_pageable) {
|
|
|
|
entry = start_entry;
|
|
vm_map_clip_start(map, entry, start);
|
|
|
|
/*
|
|
* Now decrement the wiring count for each region. If a region
|
|
* becomes completely unwired, unwire its physical pages and
|
|
* mappings.
|
|
*/
|
|
lock_set_recursive(&map->lock);
|
|
|
|
entry = start_entry;
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
if (entry->eflags & MAP_ENTRY_USER_WIRED) {
|
|
vm_map_clip_end(map, entry, end);
|
|
entry->eflags &= ~MAP_ENTRY_USER_WIRED;
|
|
entry->wired_count--;
|
|
if (entry->wired_count == 0)
|
|
vm_fault_unwire(map, entry->start, entry->end);
|
|
}
|
|
entry = entry->next;
|
|
}
|
|
vm_map_simplify_entry(map, start_entry);
|
|
lock_clear_recursive(&map->lock);
|
|
} else {
|
|
|
|
/*
|
|
* Because of the possiblity of blocking, etc. We restart
|
|
* through the process's map entries from beginning so that
|
|
* we don't end up depending on a map entry that could have
|
|
* changed.
|
|
*/
|
|
rescan:
|
|
|
|
entry = start_entry;
|
|
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
|
|
if (entry->eflags & MAP_ENTRY_USER_WIRED) {
|
|
entry = entry->next;
|
|
continue;
|
|
}
|
|
|
|
if (entry->wired_count != 0) {
|
|
entry->wired_count++;
|
|
entry->eflags |= MAP_ENTRY_USER_WIRED;
|
|
entry = entry->next;
|
|
continue;
|
|
}
|
|
|
|
/* Here on entry being newly wired */
|
|
|
|
if ((entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) == 0) {
|
|
int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY;
|
|
if (copyflag && ((entry->protection & VM_PROT_WRITE) != 0)) {
|
|
|
|
vm_object_shadow(&entry->object.vm_object,
|
|
&entry->offset,
|
|
OFF_TO_IDX(entry->end
|
|
- entry->start));
|
|
entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
|
|
|
|
} else if (entry->object.vm_object == NULL) {
|
|
|
|
entry->object.vm_object =
|
|
vm_object_allocate(OBJT_DEFAULT,
|
|
OFF_TO_IDX(entry->end - entry->start));
|
|
entry->offset = (vm_offset_t) 0;
|
|
|
|
}
|
|
default_pager_convert_to_swapq(entry->object.vm_object);
|
|
}
|
|
|
|
vm_map_clip_start(map, entry, start);
|
|
vm_map_clip_end(map, entry, end);
|
|
|
|
entry->wired_count++;
|
|
entry->eflags |= MAP_ENTRY_USER_WIRED;
|
|
|
|
/* First we need to allow map modifications */
|
|
lock_set_recursive(&map->lock);
|
|
lock_write_to_read(&map->lock);
|
|
|
|
rv = vm_fault_user_wire(map, entry->start, entry->end);
|
|
if (rv) {
|
|
|
|
entry->wired_count--;
|
|
entry->eflags &= ~MAP_ENTRY_USER_WIRED;
|
|
|
|
lock_clear_recursive(&map->lock);
|
|
vm_map_unlock(map);
|
|
|
|
(void) vm_map_user_pageable(map, start, entry->start, TRUE);
|
|
return rv;
|
|
}
|
|
|
|
lock_clear_recursive(&map->lock);
|
|
vm_map_unlock(map);
|
|
vm_map_lock(map);
|
|
|
|
goto rescan;
|
|
}
|
|
}
|
|
vm_map_unlock(map);
|
|
return KERN_SUCCESS;
|
|
}
|
|
|
|
/*
|
|
* vm_map_pageable:
|
|
*
|
|
* Sets the pageability of the specified address
|
|
* range in the target map. Regions specified
|
|
* as not pageable require locked-down physical
|
|
* memory and physical page maps.
|
|
*
|
|
* The map must not be locked, but a reference
|
|
* must remain to the map throughout the call.
|
|
*/
|
|
int
|
|
vm_map_pageable(map, start, end, new_pageable)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
register boolean_t new_pageable;
|
|
{
|
|
register vm_map_entry_t entry;
|
|
vm_map_entry_t start_entry;
|
|
register vm_offset_t failed = 0;
|
|
int rv;
|
|
|
|
vm_map_lock(map);
|
|
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
/*
|
|
* Only one pageability change may take place at one time, since
|
|
* vm_fault assumes it will be called only once for each
|
|
* wiring/unwiring. Therefore, we have to make sure we're actually
|
|
* changing the pageability for the entire region. We do so before
|
|
* making any changes.
|
|
*/
|
|
|
|
if (vm_map_lookup_entry(map, start, &start_entry) == FALSE) {
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
entry = start_entry;
|
|
|
|
/*
|
|
* Actions are rather different for wiring and unwiring, so we have
|
|
* two separate cases.
|
|
*/
|
|
|
|
if (new_pageable) {
|
|
|
|
vm_map_clip_start(map, entry, start);
|
|
|
|
/*
|
|
* Unwiring. First ensure that the range to be unwired is
|
|
* really wired down and that there are no holes.
|
|
*/
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
|
|
if (entry->wired_count == 0 ||
|
|
(entry->end < end &&
|
|
(entry->next == &map->header ||
|
|
entry->next->start > entry->end))) {
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ARGUMENT);
|
|
}
|
|
entry = entry->next;
|
|
}
|
|
|
|
/*
|
|
* Now decrement the wiring count for each region. If a region
|
|
* becomes completely unwired, unwire its physical pages and
|
|
* mappings.
|
|
*/
|
|
lock_set_recursive(&map->lock);
|
|
|
|
entry = start_entry;
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
vm_map_clip_end(map, entry, end);
|
|
|
|
entry->wired_count--;
|
|
if (entry->wired_count == 0)
|
|
vm_fault_unwire(map, entry->start, entry->end);
|
|
|
|
entry = entry->next;
|
|
}
|
|
vm_map_simplify_entry(map, start_entry);
|
|
lock_clear_recursive(&map->lock);
|
|
} else {
|
|
/*
|
|
* Wiring. We must do this in two passes:
|
|
*
|
|
* 1. Holding the write lock, we create any shadow or zero-fill
|
|
* objects that need to be created. Then we clip each map
|
|
* entry to the region to be wired and increment its wiring
|
|
* count. We create objects before clipping the map entries
|
|
* to avoid object proliferation.
|
|
*
|
|
* 2. We downgrade to a read lock, and call vm_fault_wire to
|
|
* fault in the pages for any newly wired area (wired_count is
|
|
* 1).
|
|
*
|
|
* Downgrading to a read lock for vm_fault_wire avoids a possible
|
|
* deadlock with another process that may have faulted on one
|
|
* of the pages to be wired (it would mark the page busy,
|
|
* blocking us, then in turn block on the map lock that we
|
|
* hold). Because of problems in the recursive lock package,
|
|
* we cannot upgrade to a write lock in vm_map_lookup. Thus,
|
|
* any actions that require the write lock must be done
|
|
* beforehand. Because we keep the read lock on the map, the
|
|
* copy-on-write status of the entries we modify here cannot
|
|
* change.
|
|
*/
|
|
|
|
/*
|
|
* Pass 1.
|
|
*/
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
if (entry->wired_count == 0) {
|
|
|
|
/*
|
|
* Perform actions of vm_map_lookup that need
|
|
* the write lock on the map: create a shadow
|
|
* object for a copy-on-write region, or an
|
|
* object for a zero-fill region.
|
|
*
|
|
* We don't have to do this for entries that
|
|
* point to sharing maps, because we won't
|
|
* hold the lock on the sharing map.
|
|
*/
|
|
if ((entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) == 0) {
|
|
int copyflag = entry->eflags & MAP_ENTRY_NEEDS_COPY;
|
|
if (copyflag &&
|
|
((entry->protection & VM_PROT_WRITE) != 0)) {
|
|
|
|
vm_object_shadow(&entry->object.vm_object,
|
|
&entry->offset,
|
|
OFF_TO_IDX(entry->end
|
|
- entry->start));
|
|
entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
|
|
} else if (entry->object.vm_object == NULL) {
|
|
entry->object.vm_object =
|
|
vm_object_allocate(OBJT_DEFAULT,
|
|
OFF_TO_IDX(entry->end - entry->start));
|
|
entry->offset = (vm_offset_t) 0;
|
|
}
|
|
default_pager_convert_to_swapq(entry->object.vm_object);
|
|
}
|
|
}
|
|
vm_map_clip_start(map, entry, start);
|
|
vm_map_clip_end(map, entry, end);
|
|
entry->wired_count++;
|
|
|
|
/*
|
|
* Check for holes
|
|
*/
|
|
if (entry->end < end &&
|
|
(entry->next == &map->header ||
|
|
entry->next->start > entry->end)) {
|
|
/*
|
|
* Found one. Object creation actions do not
|
|
* need to be undone, but the wired counts
|
|
* need to be restored.
|
|
*/
|
|
while (entry != &map->header && entry->end > start) {
|
|
entry->wired_count--;
|
|
entry = entry->prev;
|
|
}
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ARGUMENT);
|
|
}
|
|
entry = entry->next;
|
|
}
|
|
|
|
/*
|
|
* Pass 2.
|
|
*/
|
|
|
|
/*
|
|
* HACK HACK HACK HACK
|
|
*
|
|
* If we are wiring in the kernel map or a submap of it,
|
|
* unlock the map to avoid deadlocks. We trust that the
|
|
* kernel is well-behaved, and therefore will not do
|
|
* anything destructive to this region of the map while
|
|
* we have it unlocked. We cannot trust user processes
|
|
* to do the same.
|
|
*
|
|
* HACK HACK HACK HACK
|
|
*/
|
|
if (vm_map_pmap(map) == kernel_pmap) {
|
|
vm_map_unlock(map); /* trust me ... */
|
|
} else {
|
|
lock_set_recursive(&map->lock);
|
|
lock_write_to_read(&map->lock);
|
|
}
|
|
|
|
rv = 0;
|
|
entry = start_entry;
|
|
while (entry != &map->header && entry->start < end) {
|
|
/*
|
|
* If vm_fault_wire fails for any page we need to undo
|
|
* what has been done. We decrement the wiring count
|
|
* for those pages which have not yet been wired (now)
|
|
* and unwire those that have (later).
|
|
*
|
|
* XXX this violates the locking protocol on the map,
|
|
* needs to be fixed.
|
|
*/
|
|
if (rv)
|
|
entry->wired_count--;
|
|
else if (entry->wired_count == 1) {
|
|
rv = vm_fault_wire(map, entry->start, entry->end);
|
|
if (rv) {
|
|
failed = entry->start;
|
|
entry->wired_count--;
|
|
}
|
|
}
|
|
entry = entry->next;
|
|
}
|
|
|
|
if (vm_map_pmap(map) == kernel_pmap) {
|
|
vm_map_lock(map);
|
|
} else {
|
|
lock_clear_recursive(&map->lock);
|
|
}
|
|
if (rv) {
|
|
vm_map_unlock(map);
|
|
(void) vm_map_pageable(map, start, failed, TRUE);
|
|
return (rv);
|
|
}
|
|
vm_map_simplify_entry(map, start_entry);
|
|
}
|
|
|
|
vm_map_unlock(map);
|
|
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_clean
|
|
*
|
|
* Push any dirty cached pages in the address range to their pager.
|
|
* If syncio is TRUE, dirty pages are written synchronously.
|
|
* If invalidate is TRUE, any cached pages are freed as well.
|
|
*
|
|
* Returns an error if any part of the specified range is not mapped.
|
|
*/
|
|
int
|
|
vm_map_clean(map, start, end, syncio, invalidate)
|
|
vm_map_t map;
|
|
vm_offset_t start;
|
|
vm_offset_t end;
|
|
boolean_t syncio;
|
|
boolean_t invalidate;
|
|
{
|
|
register vm_map_entry_t current;
|
|
vm_map_entry_t entry;
|
|
vm_size_t size;
|
|
vm_object_t object;
|
|
vm_ooffset_t offset;
|
|
|
|
vm_map_lock_read(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
if (!vm_map_lookup_entry(map, start, &entry)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
/*
|
|
* Make a first pass to check for holes.
|
|
*/
|
|
for (current = entry; current->start < end; current = current->next) {
|
|
if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_INVALID_ARGUMENT);
|
|
}
|
|
if (end > current->end &&
|
|
(current->next == &map->header ||
|
|
current->end != current->next->start)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make a second pass, cleaning/uncaching pages from the indicated
|
|
* objects as we go.
|
|
*/
|
|
for (current = entry; current->start < end; current = current->next) {
|
|
offset = current->offset + (start - current->start);
|
|
size = (end <= current->end ? end : current->end) - start;
|
|
if (current->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) {
|
|
register vm_map_t smap;
|
|
vm_map_entry_t tentry;
|
|
vm_size_t tsize;
|
|
|
|
smap = current->object.share_map;
|
|
vm_map_lock_read(smap);
|
|
(void) vm_map_lookup_entry(smap, offset, &tentry);
|
|
tsize = tentry->end - offset;
|
|
if (tsize < size)
|
|
size = tsize;
|
|
object = tentry->object.vm_object;
|
|
offset = tentry->offset + (offset - tentry->start);
|
|
vm_map_unlock_read(smap);
|
|
} else {
|
|
object = current->object.vm_object;
|
|
}
|
|
/*
|
|
* Note that there is absolutely no sense in writing out
|
|
* anonymous objects, so we track down the vnode object
|
|
* to write out.
|
|
* We invalidate (remove) all pages from the address space
|
|
* anyway, for semantic correctness.
|
|
*/
|
|
while (object->backing_object) {
|
|
object = object->backing_object;
|
|
offset += object->backing_object_offset;
|
|
if (object->size < OFF_TO_IDX( offset + size))
|
|
size = IDX_TO_OFF(object->size) - offset;
|
|
}
|
|
if (invalidate)
|
|
pmap_remove(vm_map_pmap(map), current->start,
|
|
current->start + size);
|
|
if (object && (object->type == OBJT_VNODE)) {
|
|
/*
|
|
* Flush pages if writing is allowed. XXX should we continue
|
|
* on an error?
|
|
*
|
|
* XXX Doing async I/O and then removing all the pages from
|
|
* the object before it completes is probably a very bad
|
|
* idea.
|
|
*/
|
|
if (current->protection & VM_PROT_WRITE) {
|
|
vm_object_page_clean(object,
|
|
OFF_TO_IDX(offset),
|
|
OFF_TO_IDX(offset + size),
|
|
(syncio||invalidate)?1:0, TRUE);
|
|
if (invalidate)
|
|
vm_object_page_remove(object,
|
|
OFF_TO_IDX(offset),
|
|
OFF_TO_IDX(offset + size),
|
|
FALSE);
|
|
}
|
|
}
|
|
start += size;
|
|
}
|
|
|
|
vm_map_unlock_read(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_unwire: [ internal use only ]
|
|
*
|
|
* Make the region specified by this entry pageable.
|
|
*
|
|
* The map in question should be locked.
|
|
* [This is the reason for this routine's existence.]
|
|
*/
|
|
static void
|
|
vm_map_entry_unwire(map, entry)
|
|
vm_map_t map;
|
|
register vm_map_entry_t entry;
|
|
{
|
|
vm_fault_unwire(map, entry->start, entry->end);
|
|
entry->wired_count = 0;
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_delete: [ internal use only ]
|
|
*
|
|
* Deallocate the given entry from the target map.
|
|
*/
|
|
static void
|
|
vm_map_entry_delete(map, entry)
|
|
register vm_map_t map;
|
|
register vm_map_entry_t entry;
|
|
{
|
|
vm_map_entry_unlink(map, entry);
|
|
map->size -= entry->end - entry->start;
|
|
|
|
if (entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) {
|
|
vm_map_deallocate(entry->object.share_map);
|
|
} else {
|
|
vm_object_deallocate(entry->object.vm_object);
|
|
}
|
|
|
|
vm_map_entry_dispose(map, entry);
|
|
}
|
|
|
|
/*
|
|
* vm_map_delete: [ internal use only ]
|
|
*
|
|
* Deallocates the given address range from the target
|
|
* map.
|
|
*
|
|
* When called with a sharing map, removes pages from
|
|
* that region from all physical maps.
|
|
*/
|
|
int
|
|
vm_map_delete(map, start, end)
|
|
register vm_map_t map;
|
|
vm_offset_t start;
|
|
register vm_offset_t end;
|
|
{
|
|
register vm_map_entry_t entry;
|
|
vm_map_entry_t first_entry;
|
|
|
|
/*
|
|
* Find the start of the region, and clip it
|
|
*/
|
|
|
|
if (!vm_map_lookup_entry(map, start, &first_entry))
|
|
entry = first_entry->next;
|
|
else {
|
|
entry = first_entry;
|
|
vm_map_clip_start(map, entry, start);
|
|
|
|
/*
|
|
* Fix the lookup hint now, rather than each time though the
|
|
* loop.
|
|
*/
|
|
|
|
SAVE_HINT(map, entry->prev);
|
|
}
|
|
|
|
/*
|
|
* Save the free space hint
|
|
*/
|
|
|
|
if (entry == &map->header) {
|
|
map->first_free = &map->header;
|
|
} else if (map->first_free->start >= start)
|
|
map->first_free = entry->prev;
|
|
|
|
/*
|
|
* Step through all entries in this region
|
|
*/
|
|
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
vm_map_entry_t next;
|
|
vm_offset_t s, e;
|
|
vm_object_t object;
|
|
vm_ooffset_t offset;
|
|
|
|
vm_map_clip_end(map, entry, end);
|
|
|
|
next = entry->next;
|
|
s = entry->start;
|
|
e = entry->end;
|
|
offset = entry->offset;
|
|
|
|
/*
|
|
* Unwire before removing addresses from the pmap; otherwise,
|
|
* unwiring will put the entries back in the pmap.
|
|
*/
|
|
|
|
object = entry->object.vm_object;
|
|
if (entry->wired_count != 0)
|
|
vm_map_entry_unwire(map, entry);
|
|
|
|
/*
|
|
* If this is a sharing map, we must remove *all* references
|
|
* to this data, since we can't find all of the physical maps
|
|
* which are sharing it.
|
|
*/
|
|
|
|
if (object == kernel_object || object == kmem_object) {
|
|
vm_object_page_remove(object, OFF_TO_IDX(offset),
|
|
OFF_TO_IDX(offset + (e - s)), FALSE);
|
|
} else if (!map->is_main_map) {
|
|
vm_object_pmap_remove(object,
|
|
OFF_TO_IDX(offset),
|
|
OFF_TO_IDX(offset + (e - s)));
|
|
} else {
|
|
pmap_remove(map->pmap, s, e);
|
|
}
|
|
|
|
/*
|
|
* Delete the entry (which may delete the object) only after
|
|
* removing all pmap entries pointing to its pages.
|
|
* (Otherwise, its page frames may be reallocated, and any
|
|
* modify bits will be set in the wrong object!)
|
|
*/
|
|
|
|
vm_map_entry_delete(map, entry);
|
|
entry = next;
|
|
}
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_remove:
|
|
*
|
|
* Remove the given address range from the target map.
|
|
* This is the exported form of vm_map_delete.
|
|
*/
|
|
int
|
|
vm_map_remove(map, start, end)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
{
|
|
register int result, s = 0;
|
|
|
|
if (map == kmem_map || map == mb_map)
|
|
s = splvm();
|
|
|
|
vm_map_lock(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
result = vm_map_delete(map, start, end);
|
|
vm_map_unlock(map);
|
|
|
|
if (map == kmem_map || map == mb_map)
|
|
splx(s);
|
|
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* vm_map_check_protection:
|
|
*
|
|
* Assert that the target map allows the specified
|
|
* privilege on the entire address region given.
|
|
* The entire region must be allocated.
|
|
*/
|
|
boolean_t
|
|
vm_map_check_protection(map, start, end, protection)
|
|
register vm_map_t map;
|
|
register vm_offset_t start;
|
|
register vm_offset_t end;
|
|
register vm_prot_t protection;
|
|
{
|
|
register vm_map_entry_t entry;
|
|
vm_map_entry_t tmp_entry;
|
|
|
|
if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
|
|
return (FALSE);
|
|
}
|
|
entry = tmp_entry;
|
|
|
|
while (start < end) {
|
|
if (entry == &map->header) {
|
|
return (FALSE);
|
|
}
|
|
/*
|
|
* No holes allowed!
|
|
*/
|
|
|
|
if (start < entry->start) {
|
|
return (FALSE);
|
|
}
|
|
/*
|
|
* Check protection associated with entry.
|
|
*/
|
|
|
|
if ((entry->protection & protection) != protection) {
|
|
return (FALSE);
|
|
}
|
|
/* go to next entry */
|
|
|
|
start = entry->end;
|
|
entry = entry->next;
|
|
}
|
|
return (TRUE);
|
|
}
|
|
|
|
/*
|
|
* vm_map_copy_entry:
|
|
*
|
|
* Copies the contents of the source entry to the destination
|
|
* entry. The entries *must* be aligned properly.
|
|
*/
|
|
static void
|
|
vm_map_copy_entry(src_map, dst_map, src_entry, dst_entry)
|
|
vm_map_t src_map, dst_map;
|
|
register vm_map_entry_t src_entry, dst_entry;
|
|
{
|
|
if ((dst_entry->eflags|src_entry->eflags) &
|
|
(MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP))
|
|
return;
|
|
|
|
if (src_entry->wired_count == 0) {
|
|
|
|
/*
|
|
* If the source entry is marked needs_copy, it is already
|
|
* write-protected.
|
|
*/
|
|
if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
|
|
|
|
boolean_t su;
|
|
|
|
/*
|
|
* If the source entry has only one mapping, we can
|
|
* just protect the virtual address range.
|
|
*/
|
|
if (!(su = src_map->is_main_map)) {
|
|
su = (src_map->ref_count == 1);
|
|
}
|
|
if (su) {
|
|
pmap_protect(src_map->pmap,
|
|
src_entry->start,
|
|
src_entry->end,
|
|
src_entry->protection & ~VM_PROT_WRITE);
|
|
} else {
|
|
vm_object_pmap_copy(src_entry->object.vm_object,
|
|
OFF_TO_IDX(src_entry->offset),
|
|
OFF_TO_IDX(src_entry->offset + (src_entry->end
|
|
- src_entry->start)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Make a copy of the object.
|
|
*/
|
|
if (src_entry->object.vm_object) {
|
|
if ((src_entry->object.vm_object->handle == NULL) &&
|
|
(src_entry->object.vm_object->type == OBJT_DEFAULT ||
|
|
src_entry->object.vm_object->type == OBJT_SWAP))
|
|
vm_object_collapse(src_entry->object.vm_object);
|
|
++src_entry->object.vm_object->ref_count;
|
|
src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
|
|
dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
|
|
dst_entry->object.vm_object =
|
|
src_entry->object.vm_object;
|
|
dst_entry->offset = src_entry->offset;
|
|
} else {
|
|
dst_entry->object.vm_object = NULL;
|
|
dst_entry->offset = 0;
|
|
}
|
|
|
|
pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
|
|
dst_entry->end - dst_entry->start, src_entry->start);
|
|
} else {
|
|
/*
|
|
* Of course, wired down pages can't be set copy-on-write.
|
|
* Cause wired pages to be copied into the new map by
|
|
* simulating faults (the new pages are pageable)
|
|
*/
|
|
vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vmspace_fork:
|
|
* Create a new process vmspace structure and vm_map
|
|
* based on those of an existing process. The new map
|
|
* is based on the old map, according to the inheritance
|
|
* values on the regions in that map.
|
|
*
|
|
* The source map must not be locked.
|
|
*/
|
|
struct vmspace *
|
|
vmspace_fork(vm1)
|
|
register struct vmspace *vm1;
|
|
{
|
|
register struct vmspace *vm2;
|
|
vm_map_t old_map = &vm1->vm_map;
|
|
vm_map_t new_map;
|
|
vm_map_entry_t old_entry;
|
|
vm_map_entry_t new_entry;
|
|
pmap_t new_pmap;
|
|
vm_object_t object;
|
|
|
|
vm_map_lock(old_map);
|
|
|
|
vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset,
|
|
old_map->entries_pageable);
|
|
bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
|
|
(caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy);
|
|
new_pmap = &vm2->vm_pmap; /* XXX */
|
|
new_map = &vm2->vm_map; /* XXX */
|
|
|
|
old_entry = old_map->header.next;
|
|
|
|
while (old_entry != &old_map->header) {
|
|
if (old_entry->eflags & MAP_ENTRY_IS_SUB_MAP)
|
|
panic("vm_map_fork: encountered a submap");
|
|
|
|
switch (old_entry->inheritance) {
|
|
case VM_INHERIT_NONE:
|
|
break;
|
|
|
|
case VM_INHERIT_SHARE:
|
|
/*
|
|
* Clone the entry, creating the shared object if necessary.
|
|
*/
|
|
object = old_entry->object.vm_object;
|
|
if (object == NULL) {
|
|
object = vm_object_allocate(OBJT_DEFAULT,
|
|
OFF_TO_IDX(old_entry->end -
|
|
old_entry->start));
|
|
old_entry->object.vm_object = object;
|
|
old_entry->offset = (vm_offset_t) 0;
|
|
}
|
|
|
|
/*
|
|
* Clone the entry, referencing the sharing map.
|
|
*/
|
|
new_entry = vm_map_entry_create(new_map);
|
|
*new_entry = *old_entry;
|
|
new_entry->wired_count = 0;
|
|
++object->ref_count;
|
|
|
|
/*
|
|
* Insert the entry into the new map -- we know we're
|
|
* inserting at the end of the new map.
|
|
*/
|
|
|
|
vm_map_entry_link(new_map, new_map->header.prev,
|
|
new_entry);
|
|
|
|
/*
|
|
* Update the physical map
|
|
*/
|
|
|
|
pmap_copy(new_map->pmap, old_map->pmap,
|
|
new_entry->start,
|
|
(old_entry->end - old_entry->start),
|
|
old_entry->start);
|
|
break;
|
|
|
|
case VM_INHERIT_COPY:
|
|
/*
|
|
* Clone the entry and link into the map.
|
|
*/
|
|
new_entry = vm_map_entry_create(new_map);
|
|
*new_entry = *old_entry;
|
|
new_entry->wired_count = 0;
|
|
new_entry->object.vm_object = NULL;
|
|
new_entry->eflags &= ~MAP_ENTRY_IS_A_MAP;
|
|
vm_map_entry_link(new_map, new_map->header.prev,
|
|
new_entry);
|
|
vm_map_copy_entry(old_map, new_map, old_entry,
|
|
new_entry);
|
|
break;
|
|
}
|
|
old_entry = old_entry->next;
|
|
}
|
|
|
|
new_map->size = old_map->size;
|
|
vm_map_unlock(old_map);
|
|
|
|
return (vm2);
|
|
}
|
|
|
|
/*
|
|
* vm_map_lookup:
|
|
*
|
|
* Finds the VM object, offset, and
|
|
* protection for a given virtual address in the
|
|
* specified map, assuming a page fault of the
|
|
* type specified.
|
|
*
|
|
* Leaves the map in question locked for read; return
|
|
* values are guaranteed until a vm_map_lookup_done
|
|
* call is performed. Note that the map argument
|
|
* is in/out; the returned map must be used in
|
|
* the call to vm_map_lookup_done.
|
|
*
|
|
* A handle (out_entry) is returned for use in
|
|
* vm_map_lookup_done, to make that fast.
|
|
*
|
|
* If a lookup is requested with "write protection"
|
|
* specified, the map may be changed to perform virtual
|
|
* copying operations, although the data referenced will
|
|
* remain the same.
|
|
*/
|
|
int
|
|
vm_map_lookup(var_map, vaddr, fault_type, out_entry,
|
|
object, pindex, out_prot, wired, single_use)
|
|
vm_map_t *var_map; /* IN/OUT */
|
|
register vm_offset_t vaddr;
|
|
register vm_prot_t fault_type;
|
|
|
|
vm_map_entry_t *out_entry; /* OUT */
|
|
vm_object_t *object; /* OUT */
|
|
vm_pindex_t *pindex; /* OUT */
|
|
vm_prot_t *out_prot; /* OUT */
|
|
boolean_t *wired; /* OUT */
|
|
boolean_t *single_use; /* OUT */
|
|
{
|
|
vm_map_t share_map;
|
|
vm_offset_t share_offset;
|
|
register vm_map_entry_t entry;
|
|
register vm_map_t map = *var_map;
|
|
register vm_prot_t prot;
|
|
register boolean_t su;
|
|
|
|
RetryLookup:;
|
|
|
|
/*
|
|
* Lookup the faulting address.
|
|
*/
|
|
|
|
vm_map_lock_read(map);
|
|
|
|
#define RETURN(why) \
|
|
{ \
|
|
vm_map_unlock_read(map); \
|
|
return(why); \
|
|
}
|
|
|
|
/*
|
|
* If the map has an interesting hint, try it before calling full
|
|
* blown lookup routine.
|
|
*/
|
|
|
|
entry = map->hint;
|
|
|
|
*out_entry = entry;
|
|
|
|
if ((entry == &map->header) ||
|
|
(vaddr < entry->start) || (vaddr >= entry->end)) {
|
|
vm_map_entry_t tmp_entry;
|
|
|
|
/*
|
|
* Entry was either not a valid hint, or the vaddr was not
|
|
* contained in the entry, so do a full lookup.
|
|
*/
|
|
if (!vm_map_lookup_entry(map, vaddr, &tmp_entry))
|
|
RETURN(KERN_INVALID_ADDRESS);
|
|
|
|
entry = tmp_entry;
|
|
*out_entry = entry;
|
|
}
|
|
|
|
/*
|
|
* Handle submaps.
|
|
*/
|
|
|
|
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
|
|
vm_map_t old_map = map;
|
|
|
|
*var_map = map = entry->object.sub_map;
|
|
vm_map_unlock_read(old_map);
|
|
goto RetryLookup;
|
|
}
|
|
/*
|
|
* Check whether this task is allowed to have this page.
|
|
*/
|
|
|
|
prot = entry->protection;
|
|
if ((fault_type & (prot)) != fault_type)
|
|
RETURN(KERN_PROTECTION_FAILURE);
|
|
|
|
/*
|
|
* If this page is not pageable, we have to get it for all possible
|
|
* accesses.
|
|
*/
|
|
|
|
*wired = (entry->wired_count != 0);
|
|
if (*wired)
|
|
prot = fault_type = entry->protection;
|
|
|
|
/*
|
|
* If we don't already have a VM object, track it down.
|
|
*/
|
|
|
|
su = (entry->eflags & MAP_ENTRY_IS_A_MAP) == 0;
|
|
if (su) {
|
|
share_map = map;
|
|
share_offset = vaddr;
|
|
} else {
|
|
vm_map_entry_t share_entry;
|
|
|
|
/*
|
|
* Compute the sharing map, and offset into it.
|
|
*/
|
|
|
|
share_map = entry->object.share_map;
|
|
share_offset = (vaddr - entry->start) + entry->offset;
|
|
|
|
/*
|
|
* Look for the backing store object and offset
|
|
*/
|
|
|
|
vm_map_lock_read(share_map);
|
|
|
|
if (!vm_map_lookup_entry(share_map, share_offset,
|
|
&share_entry)) {
|
|
vm_map_unlock_read(share_map);
|
|
RETURN(KERN_INVALID_ADDRESS);
|
|
}
|
|
entry = share_entry;
|
|
}
|
|
|
|
/*
|
|
* If the entry was copy-on-write, we either ...
|
|
*/
|
|
|
|
if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
|
|
/*
|
|
* If we want to write the page, we may as well handle that
|
|
* now since we've got the sharing map locked.
|
|
*
|
|
* If we don't need to write the page, we just demote the
|
|
* permissions allowed.
|
|
*/
|
|
|
|
if (fault_type & VM_PROT_WRITE) {
|
|
/*
|
|
* Make a new object, and place it in the object
|
|
* chain. Note that no new references have appeared
|
|
* -- one just moved from the share map to the new
|
|
* object.
|
|
*/
|
|
|
|
if (lock_read_to_write(&share_map->lock)) {
|
|
if (share_map != map)
|
|
vm_map_unlock_read(map);
|
|
goto RetryLookup;
|
|
}
|
|
vm_object_shadow(
|
|
&entry->object.vm_object,
|
|
&entry->offset,
|
|
OFF_TO_IDX(entry->end - entry->start));
|
|
|
|
entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
|
|
|
|
lock_write_to_read(&share_map->lock);
|
|
} else {
|
|
/*
|
|
* We're attempting to read a copy-on-write page --
|
|
* don't allow writes.
|
|
*/
|
|
|
|
prot &= (~VM_PROT_WRITE);
|
|
}
|
|
}
|
|
/*
|
|
* Create an object if necessary.
|
|
*/
|
|
if (entry->object.vm_object == NULL) {
|
|
|
|
if (lock_read_to_write(&share_map->lock)) {
|
|
if (share_map != map)
|
|
vm_map_unlock_read(map);
|
|
goto RetryLookup;
|
|
}
|
|
entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT,
|
|
OFF_TO_IDX(entry->end - entry->start));
|
|
entry->offset = 0;
|
|
lock_write_to_read(&share_map->lock);
|
|
}
|
|
|
|
if (entry->object.vm_object != NULL)
|
|
default_pager_convert_to_swapq(entry->object.vm_object);
|
|
/*
|
|
* Return the object/offset from this entry. If the entry was
|
|
* copy-on-write or empty, it has been fixed up.
|
|
*/
|
|
|
|
*pindex = OFF_TO_IDX((share_offset - entry->start) + entry->offset);
|
|
*object = entry->object.vm_object;
|
|
|
|
/*
|
|
* Return whether this is the only map sharing this data.
|
|
*/
|
|
|
|
if (!su) {
|
|
su = (share_map->ref_count == 1);
|
|
}
|
|
*out_prot = prot;
|
|
*single_use = su;
|
|
|
|
return (KERN_SUCCESS);
|
|
|
|
#undef RETURN
|
|
}
|
|
|
|
/*
|
|
* vm_map_lookup_done:
|
|
*
|
|
* Releases locks acquired by a vm_map_lookup
|
|
* (according to the handle returned by that lookup).
|
|
*/
|
|
|
|
void
|
|
vm_map_lookup_done(map, entry)
|
|
register vm_map_t map;
|
|
vm_map_entry_t entry;
|
|
{
|
|
/*
|
|
* If this entry references a map, unlock it first.
|
|
*/
|
|
|
|
if (entry->eflags & MAP_ENTRY_IS_A_MAP)
|
|
vm_map_unlock_read(entry->object.share_map);
|
|
|
|
/*
|
|
* Unlock the main-level map
|
|
*/
|
|
|
|
vm_map_unlock_read(map);
|
|
}
|
|
|
|
#include "opt_ddb.h"
|
|
#ifdef DDB
|
|
#include <sys/kernel.h>
|
|
|
|
#include <ddb/ddb.h>
|
|
|
|
/*
|
|
* vm_map_print: [ debug ]
|
|
*/
|
|
DB_SHOW_COMMAND(map, vm_map_print)
|
|
{
|
|
/* XXX convert args. */
|
|
register vm_map_t map = (vm_map_t)addr;
|
|
boolean_t full = have_addr;
|
|
|
|
register vm_map_entry_t entry;
|
|
|
|
db_iprintf("%s map 0x%x: pmap=0x%x,ref=%d,nentries=%d,version=%d\n",
|
|
(map->is_main_map ? "Task" : "Share"),
|
|
(int) map, (int) (map->pmap), map->ref_count, map->nentries,
|
|
map->timestamp);
|
|
|
|
if (!full && db_indent)
|
|
return;
|
|
|
|
db_indent += 2;
|
|
for (entry = map->header.next; entry != &map->header;
|
|
entry = entry->next) {
|
|
db_iprintf("map entry 0x%x: start=0x%x, end=0x%x, ",
|
|
(int) entry, (int) entry->start, (int) entry->end);
|
|
if (map->is_main_map) {
|
|
static char *inheritance_name[4] =
|
|
{"share", "copy", "none", "donate_copy"};
|
|
|
|
db_printf("prot=%x/%x/%s, ",
|
|
entry->protection,
|
|
entry->max_protection,
|
|
inheritance_name[entry->inheritance]);
|
|
if (entry->wired_count != 0)
|
|
db_printf("wired, ");
|
|
}
|
|
if (entry->eflags & (MAP_ENTRY_IS_A_MAP|MAP_ENTRY_IS_SUB_MAP)) {
|
|
db_printf("share=0x%x, offset=0x%x\n",
|
|
(int) entry->object.share_map,
|
|
(int) entry->offset);
|
|
if ((entry->prev == &map->header) ||
|
|
((entry->prev->eflags & MAP_ENTRY_IS_A_MAP) == 0) ||
|
|
(entry->prev->object.share_map !=
|
|
entry->object.share_map)) {
|
|
db_indent += 2;
|
|
vm_map_print((int)entry->object.share_map,
|
|
full, 0, (char *)0);
|
|
db_indent -= 2;
|
|
}
|
|
} else {
|
|
db_printf("object=0x%x, offset=0x%x",
|
|
(int) entry->object.vm_object,
|
|
(int) entry->offset);
|
|
if (entry->eflags & MAP_ENTRY_COW)
|
|
db_printf(", copy (%s)",
|
|
(entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
|
|
db_printf("\n");
|
|
|
|
if ((entry->prev == &map->header) ||
|
|
(entry->prev->eflags & MAP_ENTRY_IS_A_MAP) ||
|
|
(entry->prev->object.vm_object !=
|
|
entry->object.vm_object)) {
|
|
db_indent += 2;
|
|
vm_object_print((int)entry->object.vm_object,
|
|
full, 0, (char *)0);
|
|
db_indent -= 2;
|
|
}
|
|
}
|
|
}
|
|
db_indent -= 2;
|
|
}
|
|
#endif /* DDB */
|