vm.zip_open

/* * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * The Mach Operating System project at Carnegie-Mellon University. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vm_map.c 8.9 (Berkeley) 5/17/95 * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * Authors: Avadis Tevanian, Jr., Michael Wayne Young * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or [email protected] * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * Virtual memory mapping module. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/malloc.h> #include <vm/vm.h> #include <vm/vm_page.h> /* * Virtual memory maps provide for the mapping, protection, * and sharing of virtual memory objects. In addition, * this module provides for an efficient virtual copy of * memory from one map to another. * * Synchronization is required prior to most operations. * * Maps consist of an ordered doubly-linked list of simple * entries; a single hint is used to speed up lookups. * * In order to properly represent the sharing of virtual * memory regions among maps, the map structure is bi-level. * Top-level ("address") maps refer to regions of sharable * virtual memory. These regions are implemented as * ("sharing") maps, which then refer to the actual virtual * memory objects. When two address maps "share" memory, * their top-level maps both have references to the same * sharing map. When memory is virtual-copied from one * address map to another, the references in the sharing * maps are actually copied -- no copying occurs at the * virtual memory object level. * * Since portions of maps are specified by start/end addreses, * which may not align with existing map entries, all * routines merely "clip" entries to these start/end values. * [That is, an entry is split into two, bordering at a * start or end value.] Note that these clippings may not * always be necessary (as the two resulting entries are then * not changed); however, the clipping is done for convenience. * No attempt is currently made to "glue back together" two * abutting entries. * * As mentioned above, virtual copy operations are performed * by copying VM object references from one sharing map to * another, and then marking both regions as copy-on-write. * It is important to note that only one writeable reference * to a VM object region exists in any map -- this means that * shadow object creation can be delayed until a write operation * occurs. */ /* * vm_map_startup: * * Initialize the vm_map module. Must be called before * any other vm_map routines. * * Map and entry structures are allocated from the general * purpose memory pool with some exceptions: * * - The kernel map and kmem submap are allocated statically. * - Kernel map entries are allocated out of a static pool. * * These restrictions are necessary since malloc() uses the * maps and requires map entries. */ vm_offset_t kentry_data; vm_size_t kentry_data_size; vm_map_entry_t kentry_free; vm_map_t kmap_free; static void _vm_map_clip_end __P((vm_map_t, vm_map_entry_t, vm_offset_t)); static void _vm_map_clip_start __P((vm_map_t, vm_map_entry_t, vm_offset_t)); void vm_map_startup() { register int i; register vm_map_entry_t mep; vm_map_t mp; /* * Static map structures for allocation before initialization of * kernel map or kmem map. vm_map_create knows how to deal with them. */ kmap_free = mp = (vm_map_t) kentry_data; i = MAX_KMAP; while (--i > 0) { mp->header.next = (vm_map_entry_t) (mp + 1); mp++; } mp++->header.next = NULL; /* * Form a free list of statically allocated kernel map entries * with the rest. */ kentry_free = mep = (vm_map_entry_t) mp; i = (kentry_data_size - MAX_KMAP * sizeof *mp) / sizeof *mep; while (--i > 0) { mep->next = mep + 1; mep++; } mep->next = NULL; } /* * Allocate a vmspace structure, including a vm_map and pmap, * and initialize those structures. The refcnt is set to 1. * The remaining fields must be initialized by the caller. */ struct vmspace * vmspace_alloc(min, max, pageable) vm_offset_t min, max; int pageable; { register struct vmspace *vm; MALLOC(vm, struct vmspace *, sizeof(struct vmspace), M_VMMAP, M_WAITOK); bzero(vm, (caddr_t) &vm->vm_startcopy - (caddr_t) vm); vm_map_init(&vm->vm_map, min, max, pageable); pmap_pinit(&vm->vm_pmap); vm->vm_map.pmap = &vm->vm_pmap; /* XXX */ vm->vm_refcnt = 1; return (vm); } void vmspace_free(vm) register struct vmspace *vm; { if (--vm->vm_refcnt == 0) { /* * Lock the map, to wait out all other references to it. * Delete all of the mappings and pages they hold, * then call the pmap module to reclaim anything left. */ vm_map_lock(&vm->vm_map); (void) vm_map_delete(&vm->vm_map, vm->vm_map.min_offset, vm->vm_map.max_offset); pmap_release(&vm->vm_pmap); FREE(vm, M_VMMAP); } } /* * vm_map_create: * * Creates and returns a new empty VM map with * the given physical map structure, and having * the given lower and upper address bounds. */ vm_map_t vm_map_create(pmap, min, max, pageable) pmap_t pmap; vm_offset_t min, max; boolean_t pageable; { register vm_map_t result; extern vm_map_t kmem_map; if (kmem_map == NULL) { result = kmap_free; if (result == NULL) panic("vm_map_create: out of maps"); kmap_free = (vm_map_t) result->header.next