423521aa33
so add a WITNESS_WARN() to catch cases where it is called with a non-sleepable lock held. MFC after: 1 month Sponsored by: Sandvine Inc.
4282 lines
115 KiB
C
4282 lines
115 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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* 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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/*
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* Virtual memory mapping module.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/ktr.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/vmmeter.h>
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#include <sys/mman.h>
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#include <sys/vnode.h>
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#include <sys/racct.h>
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#include <sys/resourcevar.h>
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#include <sys/rwlock.h>
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#include <sys/file.h>
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#include <sys/sysctl.h>
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#include <sys/sysent.h>
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#include <sys/shm.h>
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#include <vm/vm.h>
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#include <vm/vm_param.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_pager.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#include <vm/vnode_pager.h>
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#include <vm/swap_pager.h>
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#include <vm/uma.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 self-adjusting binary search tree of these
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* entries is used to speed up lookups.
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*
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* Since portions of maps are specified by start/end addresses,
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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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*
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* As mentioned above, virtual copy operations are performed
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* by copying VM object references from one map to
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* another, and then marking both regions as copy-on-write.
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*/
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static struct mtx map_sleep_mtx;
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static uma_zone_t mapentzone;
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static uma_zone_t kmapentzone;
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static uma_zone_t mapzone;
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static uma_zone_t vmspace_zone;
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static int vmspace_zinit(void *mem, int size, int flags);
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static int vm_map_zinit(void *mem, int ize, int flags);
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static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min,
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vm_offset_t max);
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static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map);
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static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry);
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static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry);
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static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
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vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags);
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#ifdef INVARIANTS
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static void vm_map_zdtor(void *mem, int size, void *arg);
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static void vmspace_zdtor(void *mem, int size, void *arg);
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#endif
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static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos,
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vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max,
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int cow);
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static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
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vm_offset_t failed_addr);
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#define ENTRY_CHARGED(e) ((e)->cred != NULL || \
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((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \
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!((e)->eflags & MAP_ENTRY_NEEDS_COPY)))
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/*
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* PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type
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* stable.
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*/
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#define PROC_VMSPACE_LOCK(p) do { } while (0)
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#define PROC_VMSPACE_UNLOCK(p) do { } while (0)
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/*
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* VM_MAP_RANGE_CHECK: [ internal use only ]
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*
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* Asserts that the starting and ending region
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* addresses fall within the valid range of the map.
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*/
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#define VM_MAP_RANGE_CHECK(map, start, end) \
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{ \
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if (start < vm_map_min(map)) \
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start = vm_map_min(map); \
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if (end > vm_map_max(map)) \
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end = vm_map_max(map); \
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if (start > end) \
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start = end; \
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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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void
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vm_map_startup(void)
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{
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mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
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mapzone = uma_zcreate("MAP", sizeof(struct vm_map), NULL,
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#ifdef INVARIANTS
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vm_map_zdtor,
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#else
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NULL,
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#endif
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vm_map_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
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uma_prealloc(mapzone, MAX_KMAP);
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kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry),
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
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UMA_ZONE_MTXCLASS | UMA_ZONE_VM);
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mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry),
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
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vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL,
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#ifdef INVARIANTS
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vmspace_zdtor,
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#else
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NULL,
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#endif
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vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
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}
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static int
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vmspace_zinit(void *mem, int size, int flags)
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{
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struct vmspace *vm;
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vm = (struct vmspace *)mem;
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vm->vm_map.pmap = NULL;
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(void)vm_map_zinit(&vm->vm_map, sizeof(vm->vm_map), flags);
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PMAP_LOCK_INIT(vmspace_pmap(vm));
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return (0);
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}
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static int
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vm_map_zinit(void *mem, int size, int flags)
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{
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vm_map_t map;
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map = (vm_map_t)mem;
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memset(map, 0, sizeof(*map));
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mtx_init(&map->system_mtx, "vm map (system)", NULL, MTX_DEF | MTX_DUPOK);
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sx_init(&map->lock, "vm map (user)");
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return (0);
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}
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#ifdef INVARIANTS
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static void
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vmspace_zdtor(void *mem, int size, void *arg)
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{
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struct vmspace *vm;
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vm = (struct vmspace *)mem;
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vm_map_zdtor(&vm->vm_map, sizeof(vm->vm_map), arg);
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}
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static void
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vm_map_zdtor(void *mem, int size, void *arg)
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{
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vm_map_t map;
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map = (vm_map_t)mem;
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KASSERT(map->nentries == 0,
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("map %p nentries == %d on free.",
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map, map->nentries));
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KASSERT(map->size == 0,
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("map %p size == %lu on free.",
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map, (unsigned long)map->size));
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}
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#endif /* INVARIANTS */
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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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*
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* If 'pinit' is NULL then the embedded pmap is initialized via pmap_pinit().
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*/
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struct vmspace *
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vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit)
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{
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struct vmspace *vm;
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vm = uma_zalloc(vmspace_zone, M_WAITOK);
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KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL"));
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if (pinit == NULL)
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pinit = &pmap_pinit;
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if (!pinit(vmspace_pmap(vm))) {
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uma_zfree(vmspace_zone, vm);
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return (NULL);
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}
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CTR1(KTR_VM, "vmspace_alloc: %p", vm);
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_vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max);
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vm->vm_refcnt = 1;
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vm->vm_shm = NULL;
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vm->vm_swrss = 0;
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vm->vm_tsize = 0;
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vm->vm_dsize = 0;
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vm->vm_ssize = 0;
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vm->vm_taddr = 0;
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vm->vm_daddr = 0;
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vm->vm_maxsaddr = 0;
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return (vm);
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}
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static void
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vmspace_container_reset(struct proc *p)
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{
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#ifdef RACCT
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PROC_LOCK(p);
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racct_set(p, RACCT_DATA, 0);
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racct_set(p, RACCT_STACK, 0);
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racct_set(p, RACCT_RSS, 0);
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racct_set(p, RACCT_MEMLOCK, 0);
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racct_set(p, RACCT_VMEM, 0);
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PROC_UNLOCK(p);
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#endif
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}
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static inline void
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vmspace_dofree(struct vmspace *vm)
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{
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CTR1(KTR_VM, "vmspace_free: %p", vm);
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/*
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* Make sure any SysV shm is freed, it might not have been in
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* exit1().
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*/
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shmexit(vm);
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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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(void)vm_map_remove(&vm->vm_map, vm->vm_map.min_offset,
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vm->vm_map.max_offset);
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pmap_release(vmspace_pmap(vm));
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vm->vm_map.pmap = NULL;
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uma_zfree(vmspace_zone, vm);
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}
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void
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vmspace_free(struct vmspace *vm)
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{
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|
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WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
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"vmspace_free() called with non-sleepable lock held");
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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 (atomic_fetchadd_int(&vm->vm_refcnt, -1) == 1)
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vmspace_dofree(vm);
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}
|
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|
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void
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vmspace_exitfree(struct proc *p)
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{
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struct vmspace *vm;
|
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PROC_VMSPACE_LOCK(p);
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vm = p->p_vmspace;
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p->p_vmspace = NULL;
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PROC_VMSPACE_UNLOCK(p);
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KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace"));
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vmspace_free(vm);
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}
|
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|
|
void
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|
vmspace_exit(struct thread *td)
|
|
{
|
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int refcnt;
|
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struct vmspace *vm;
|
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struct proc *p;
|
|
|
|
/*
|
|
* Release user portion of address space.
|
|
* This releases references to vnodes,
|
|
* which could cause I/O if the file has been unlinked.
|
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* Need to do this early enough that we can still sleep.
|
|
*
|
|
* The last exiting process to reach this point releases as
|
|
* much of the environment as it can. vmspace_dofree() is the
|
|
* slower fallback in case another process had a temporary
|
|
* reference to the vmspace.
|
|
*/
|
|
|
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p = td->td_proc;
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vm = p->p_vmspace;
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atomic_add_int(&vmspace0.vm_refcnt, 1);
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do {
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refcnt = vm->vm_refcnt;
|
|
if (refcnt > 1 && p->p_vmspace != &vmspace0) {
|
|
/* Switch now since other proc might free vmspace */
|
|
PROC_VMSPACE_LOCK(p);
|
|
p->p_vmspace = &vmspace0;
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
pmap_activate(td);
|
|
}
|
|
} while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt - 1));
|
|
if (refcnt == 1) {
|
|
if (p->p_vmspace != vm) {
|
|
/* vmspace not yet freed, switch back */
|
|
PROC_VMSPACE_LOCK(p);
|
|
p->p_vmspace = vm;
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
pmap_activate(td);
|
|
}
|
|
pmap_remove_pages(vmspace_pmap(vm));
|
|
/* Switch now since this proc will free vmspace */
|
|
PROC_VMSPACE_LOCK(p);
|
|
p->p_vmspace = &vmspace0;
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
pmap_activate(td);
|
|
vmspace_dofree(vm);
|
|
}
|
|
vmspace_container_reset(p);
|
|
}
|
|
|
|
/* Acquire reference to vmspace owned by another process. */
|
|
|
|
struct vmspace *
|
|
vmspace_acquire_ref(struct proc *p)
|
|
{
|
|
struct vmspace *vm;
|
|
int refcnt;
|
|
|
|
PROC_VMSPACE_LOCK(p);
|
|
vm = p->p_vmspace;
|
|
if (vm == NULL) {
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
return (NULL);
|
|
}
|
|
do {
|
|
refcnt = vm->vm_refcnt;
|
|
if (refcnt <= 0) { /* Avoid 0->1 transition */
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
return (NULL);
|
|
}
|
|
} while (!atomic_cmpset_int(&vm->vm_refcnt, refcnt, refcnt + 1));
|
|
if (vm != p->p_vmspace) {
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
vmspace_free(vm);
|
|
return (NULL);
|
|
}
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
return (vm);
|
|
}
|
|
|
|
void
|
|
_vm_map_lock(vm_map_t map, const char *file, int line)
|
|
{
|
|
|
|
if (map->system_map)
|
|
mtx_lock_flags_(&map->system_mtx, 0, file, line);
|
|
else
|
|
sx_xlock_(&map->lock, file, line);
|
|
map->timestamp++;
|
|
}
|
|
|
|
static void
|
|
vm_map_process_deferred(void)
|
|
{
|
|
struct thread *td;
|
|
vm_map_entry_t entry, next;
|
|
vm_object_t object;
|
|
|
|
td = curthread;
|
|
entry = td->td_map_def_user;
|
|
td->td_map_def_user = NULL;
|
|
while (entry != NULL) {
|
|
next = entry->next;
|
|
if ((entry->eflags & MAP_ENTRY_VN_WRITECNT) != 0) {
|
|
/*
|
|
* Decrement the object's writemappings and
|
|
* possibly the vnode's v_writecount.
|
|
*/
|
|
KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
|
|
("Submap with writecount"));
|
|
object = entry->object.vm_object;
|
|
KASSERT(object != NULL, ("No object for writecount"));
|
|
vnode_pager_release_writecount(object, entry->start,
|
|
entry->end);
|
|
}
|
|
vm_map_entry_deallocate(entry, FALSE);
|
|
entry = next;
|
|
}
|
|
}
|
|
|
|
void
|
|
_vm_map_unlock(vm_map_t map, const char *file, int line)
|
|
{
|
|
|
|
if (map->system_map)
|
|
mtx_unlock_flags_(&map->system_mtx, 0, file, line);
|
|
else {
|
|
sx_xunlock_(&map->lock, file, line);
|
|
vm_map_process_deferred();
|
|
}
|
|
}
|
|
|
|
void
|
|
_vm_map_lock_read(vm_map_t map, const char *file, int line)
|
|
{
|
|
|
|
if (map->system_map)
|
|
mtx_lock_flags_(&map->system_mtx, 0, file, line);
|
|
else
|
|
sx_slock_(&map->lock, file, line);
|
|
}
|
|
|
|
void
|
|
_vm_map_unlock_read(vm_map_t map, const char *file, int line)
|
|
{
|
|
|
|
if (map->system_map)
|
|
mtx_unlock_flags_(&map->system_mtx, 0, file, line);
|
|
else {
|
|
sx_sunlock_(&map->lock, file, line);
|
|
vm_map_process_deferred();
|
|
}
|
|
}
|
|
|
|
int
|
|
_vm_map_trylock(vm_map_t map, const char *file, int line)
|
|
{
|
|
int error;
|
|
|
|
error = map->system_map ?
|
|
!mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
|
|
!sx_try_xlock_(&map->lock, file, line);
|
|
if (error == 0)
|
|
map->timestamp++;
|
|
return (error == 0);
|
|
}
|
|
|
|
int
|
|
_vm_map_trylock_read(vm_map_t map, const char *file, int line)
|
|
{
|
|
int error;
|
|
|
|
error = map->system_map ?
|
|
!mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
|
|
!sx_try_slock_(&map->lock, file, line);
|
|
return (error == 0);
|
|
}
|
|
|
|
/*
|
|
* _vm_map_lock_upgrade: [ internal use only ]
|
|
*
|
|
* Tries to upgrade a read (shared) lock on the specified map to a write
|
|
* (exclusive) lock. Returns the value "0" if the upgrade succeeds and a
|
|
* non-zero value if the upgrade fails. If the upgrade fails, the map is
|
|
* returned without a read or write lock held.
|
|
*
|
|
* Requires that the map be read locked.
|
|
*/
|
|
int
|
|
_vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
|
|
{
|
|
unsigned int last_timestamp;
|
|
|
|
if (map->system_map) {
|
|
mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
|
|
} else {
|
|
if (!sx_try_upgrade_(&map->lock, file, line)) {
|
|
last_timestamp = map->timestamp;
|
|
sx_sunlock_(&map->lock, file, line);
|
|
vm_map_process_deferred();
|
|
/*
|
|
* If the map's timestamp does not change while the
|
|
* map is unlocked, then the upgrade succeeds.
|
|
*/
|
|
sx_xlock_(&map->lock, file, line);
|
|
if (last_timestamp != map->timestamp) {
|
|
sx_xunlock_(&map->lock, file, line);
|
|
return (1);
|
|
}
|
|
}
|
|
}
|
|
map->timestamp++;
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
_vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
|
|
{
|
|
|
|
if (map->system_map) {
|
|
mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
|
|
} else
|
|
sx_downgrade_(&map->lock, file, line);
|
|
}
|
|
|
|
/*
|
|
* vm_map_locked:
|
|
*
|
|
* Returns a non-zero value if the caller holds a write (exclusive) lock
|
|
* on the specified map and the value "0" otherwise.
|
|
*/
|
|
int
|
|
vm_map_locked(vm_map_t map)
|
|
{
|
|
|
|
if (map->system_map)
|
|
return (mtx_owned(&map->system_mtx));
|
|
else
|
|
return (sx_xlocked(&map->lock));
|
|
}
|
|
|
|
#ifdef INVARIANTS
|
|
static void
|
|
_vm_map_assert_locked(vm_map_t map, const char *file, int line)
|
|
{
|
|
|
|
if (map->system_map)
|
|
mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
|
|
else
|
|
sx_assert_(&map->lock, SA_XLOCKED, file, line);
|
|
}
|
|
|
|
#define VM_MAP_ASSERT_LOCKED(map) \
|
|
_vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE)
|
|
#else
|
|
#define VM_MAP_ASSERT_LOCKED(map)
|
|
#endif
|
|
|
|
/*
|
|
* _vm_map_unlock_and_wait:
|
|
*
|
|
* Atomically releases the lock on the specified map and puts the calling
|
|
* thread to sleep. The calling thread will remain asleep until either
|
|
* vm_map_wakeup() is performed on the map or the specified timeout is
|
|
* exceeded.
|
|
*
|
|
* WARNING! This function does not perform deferred deallocations of
|
|
* objects and map entries. Therefore, the calling thread is expected to
|
|
* reacquire the map lock after reawakening and later perform an ordinary
|
|
* unlock operation, such as vm_map_unlock(), before completing its
|
|
* operation on the map.
|
|
*/
|
|
int
|
|
_vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line)
|
|
{
|
|
|
|
mtx_lock(&map_sleep_mtx);
|
|
if (map->system_map)
|
|
mtx_unlock_flags_(&map->system_mtx, 0, file, line);
|
|
else
|
|
sx_xunlock_(&map->lock, file, line);
|
|
return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps",
|
|
timo));
|
|
}
|
|
|
|
/*
|
|
* vm_map_wakeup:
|
|
*
|
|
* Awaken any threads that have slept on the map using
|
|
* vm_map_unlock_and_wait().
|
|
*/
|
|
void
|
|
vm_map_wakeup(vm_map_t map)
|
|
{
|
|
|
|
/*
|
|
* Acquire and release map_sleep_mtx to prevent a wakeup()
|
|
* from being performed (and lost) between the map unlock
|
|
* and the msleep() in _vm_map_unlock_and_wait().
|
|
*/
|
|
mtx_lock(&map_sleep_mtx);
|
|
mtx_unlock(&map_sleep_mtx);
|
|
wakeup(&map->root);
|
|
}
|
|
|
|
void
|
|
vm_map_busy(vm_map_t map)
|
|
{
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
map->busy++;
|
|
}
|
|
|
|
void
|
|
vm_map_unbusy(vm_map_t map)
|
|
{
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
KASSERT(map->busy, ("vm_map_unbusy: not busy"));
|
|
if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) {
|
|
vm_map_modflags(map, 0, MAP_BUSY_WAKEUP);
|
|
wakeup(&map->busy);
|
|
}
|
|
}
|
|
|
|
void
|
|
vm_map_wait_busy(vm_map_t map)
|
|
{
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
while (map->busy) {
|
|
vm_map_modflags(map, MAP_BUSY_WAKEUP, 0);
|
|
if (map->system_map)
|
|
msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0);
|
|
else
|
|
sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0);
|
|
}
|
|
map->timestamp++;
|
|
}
|
|
|
|
long
|
|
vmspace_resident_count(struct vmspace *vmspace)
|
|
{
|
|
return pmap_resident_count(vmspace_pmap(vmspace));
|
|
}
|
|
|
|
/*
|
|
* 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_t pmap, vm_offset_t min, vm_offset_t max)
|
|
{
|
|
vm_map_t result;
|
|
|
|
result = uma_zalloc(mapzone, M_WAITOK);
|
|
CTR1(KTR_VM, "vm_map_create: %p", result);
|
|
_vm_map_init(result, pmap, min, max);
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* Initialize an existing vm_map structure
|
|
* such as that in the vmspace structure.
|
|
*/
|
|
static void
|
|
_vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
|
|
{
|
|
|
|
map->header.next = map->header.prev = &map->header;
|
|
map->needs_wakeup = FALSE;
|
|
map->system_map = 0;
|
|
map->pmap = pmap;
|
|
map->min_offset = min;
|
|
map->max_offset = max;
|
|
map->flags = 0;
|
|
map->root = NULL;
|
|
map->timestamp = 0;
|
|
map->busy = 0;
|
|
}
|
|
|
|
void
|
|
vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
|
|
{
|
|
|
|
_vm_map_init(map, pmap, min, max);
|
|
mtx_init(&map->system_mtx, "system map", NULL, MTX_DEF | MTX_DUPOK);
|
|
sx_init(&map->lock, "user map");
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_dispose: [ internal use only ]
|
|
*
|
|
* Inverse of vm_map_entry_create.
|
|
*/
|
|
static void
|
|
vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry)
|
|
{
|
|
uma_zfree(map->system_map ? kmapentzone : mapentzone, entry);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_create: [ internal use only ]
|
|
*
|
|
* Allocates a VM map entry for insertion.
|
|
* No entry fields are filled in.
|
|
*/
|
|
static vm_map_entry_t
|
|
vm_map_entry_create(vm_map_t map)
|
|
{
|
|
vm_map_entry_t new_entry;
|
|
|
|
if (map->system_map)
|
|
new_entry = uma_zalloc(kmapentzone, M_NOWAIT);
|
|
else
|
|
new_entry = uma_zalloc(mapentzone, M_WAITOK);
|
|
if (new_entry == NULL)
|
|
panic("vm_map_entry_create: kernel resources exhausted");
|
|
return (new_entry);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_set_behavior:
|
|
*
|
|
* Set the expected access behavior, either normal, random, or
|
|
* sequential.
|
|
*/
|
|
static inline void
|
|
vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior)
|
|
{
|
|
entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) |
|
|
(behavior & MAP_ENTRY_BEHAV_MASK);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_set_max_free:
|
|
*
|
|
* Set the max_free field in a vm_map_entry.
|
|
*/
|
|
static inline void
|
|
vm_map_entry_set_max_free(vm_map_entry_t entry)
|
|
{
|
|
|
|
entry->max_free = entry->adj_free;
|
|
if (entry->left != NULL && entry->left->max_free > entry->max_free)
|
|
entry->max_free = entry->left->max_free;
|
|
if (entry->right != NULL && entry->right->max_free > entry->max_free)
|
|
entry->max_free = entry->right->max_free;
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_splay:
|
|
*
|
|
* The Sleator and Tarjan top-down splay algorithm with the
|
|
* following variation. Max_free must be computed bottom-up, so
|
|
* on the downward pass, maintain the left and right spines in
|
|
* reverse order. Then, make a second pass up each side to fix
|
|
* the pointers and compute max_free. The time bound is O(log n)
|
|
* amortized.
|
|
*
|
|
* The new root is the vm_map_entry containing "addr", or else an
|
|
* adjacent entry (lower or higher) if addr is not in the tree.
|
|
*
|
|
* The map must be locked, and leaves it so.
|
|
*
|
|
* Returns: the new root.
|
|
*/
|
|
static vm_map_entry_t
|
|
vm_map_entry_splay(vm_offset_t addr, vm_map_entry_t root)
|
|
{
|
|
vm_map_entry_t llist, rlist;
|
|
vm_map_entry_t ltree, rtree;
|
|
vm_map_entry_t y;
|
|
|
|
/* Special case of empty tree. */
|
|
if (root == NULL)
|
|
return (root);
|
|
|
|
/*
|
|
* Pass One: Splay down the tree until we find addr or a NULL
|
|
* pointer where addr would go. llist and rlist are the two
|
|
* sides in reverse order (bottom-up), with llist linked by
|
|
* the right pointer and rlist linked by the left pointer in
|
|
* the vm_map_entry. Wait until Pass Two to set max_free on
|
|
* the two spines.
|
|
*/
|
|
llist = NULL;
|
|
rlist = NULL;
|
|
for (;;) {
|
|
/* root is never NULL in here. */
|
|
if (addr < root->start) {
|
|
y = root->left;
|
|
if (y == NULL)
|
|
break;
|
|
if (addr < y->start && y->left != NULL) {
|
|
/* Rotate right and put y on rlist. */
|
|
root->left = y->right;
|
|
y->right = root;
|
|
vm_map_entry_set_max_free(root);
|
|
root = y->left;
|
|
y->left = rlist;
|
|
rlist = y;
|
|
} else {
|
|
/* Put root on rlist. */
|
|
root->left = rlist;
|
|
rlist = root;
|
|
root = y;
|
|
}
|
|
} else if (addr >= root->end) {
|
|
y = root->right;
|
|
if (y == NULL)
|
|
break;
|
|
if (addr >= y->end && y->right != NULL) {
|
|
/* Rotate left and put y on llist. */
|
|
root->right = y->left;
|
|
y->left = root;
|
|
vm_map_entry_set_max_free(root);
|
|
root = y->right;
|
|
y->right = llist;
|
|
llist = y;
|
|
} else {
|
|
/* Put root on llist. */
|
|
root->right = llist;
|
|
llist = root;
|
|
root = y;
|
|
}
|
|
} else
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Pass Two: Walk back up the two spines, flip the pointers
|
|
* and set max_free. The subtrees of the root go at the
|
|
* bottom of llist and rlist.
|
|
*/
|
|
ltree = root->left;
|
|
while (llist != NULL) {
|
|
y = llist->right;
|
|
llist->right = ltree;
|
|
vm_map_entry_set_max_free(llist);
|
|
ltree = llist;
|
|
llist = y;
|
|
}
|
|
rtree = root->right;
|
|
while (rlist != NULL) {
|
|
y = rlist->left;
|
|
rlist->left = rtree;
|
|
vm_map_entry_set_max_free(rlist);
|
|
rtree = rlist;
|
|
rlist = y;
|
|
}
|
|
|
|
/*
|
|
* Final assembly: add ltree and rtree as subtrees of root.
|
|
*/
|
|
root->left = ltree;
|
|
root->right = rtree;
|
|
vm_map_entry_set_max_free(root);
|
|
|
|
return (root);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_{un,}link:
|
|
*
|
|
* Insert/remove entries from maps.
|
|
*/
|
|
static void
|
|
vm_map_entry_link(vm_map_t map,
|
|
vm_map_entry_t after_where,
|
|
vm_map_entry_t entry)
|
|
{
|
|
|
|
CTR4(KTR_VM,
|
|
"vm_map_entry_link: map %p, nentries %d, entry %p, after %p", map,
|
|
map->nentries, entry, after_where);
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
KASSERT(after_where == &map->header ||
|
|
after_where->end <= entry->start,
|
|
("vm_map_entry_link: prev end %jx new start %jx overlap",
|
|
(uintmax_t)after_where->end, (uintmax_t)entry->start));
|
|
KASSERT(after_where->next == &map->header ||
|
|
entry->end <= after_where->next->start,
|
|
("vm_map_entry_link: new end %jx next start %jx overlap",
|
|
(uintmax_t)entry->end, (uintmax_t)after_where->next->start));
|
|
|
|
map->nentries++;
|
|
entry->prev = after_where;
|
|
entry->next = after_where->next;
|
|
entry->next->prev = entry;
|
|
after_where->next = entry;
|
|
|
|
if (after_where != &map->header) {
|
|
if (after_where != map->root)
|
|
vm_map_entry_splay(after_where->start, map->root);
|
|
entry->right = after_where->right;
|
|
entry->left = after_where;
|
|
after_where->right = NULL;
|
|
after_where->adj_free = entry->start - after_where->end;
|
|
vm_map_entry_set_max_free(after_where);
|
|
} else {
|
|
entry->right = map->root;
|
|
entry->left = NULL;
|
|
}
|
|
entry->adj_free = (entry->next == &map->header ? map->max_offset :
|
|
entry->next->start) - entry->end;
|
|
vm_map_entry_set_max_free(entry);
|
|
map->root = entry;
|
|
}
|
|
|
|
static void
|
|
vm_map_entry_unlink(vm_map_t map,
|
|
vm_map_entry_t entry)
|
|
{
|
|
vm_map_entry_t next, prev, root;
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
if (entry != map->root)
|
|
vm_map_entry_splay(entry->start, map->root);
|
|
if (entry->left == NULL)
|
|
root = entry->right;
|
|
else {
|
|
root = vm_map_entry_splay(entry->start, entry->left);
|
|
root->right = entry->right;
|
|
root->adj_free = (entry->next == &map->header ? map->max_offset :
|
|
entry->next->start) - root->end;
|
|
vm_map_entry_set_max_free(root);
|
|
}
|
|
map->root = root;
|
|
|
|
prev = entry->prev;
|
|
next = entry->next;
|
|
next->prev = prev;
|
|
prev->next = next;
|
|
map->nentries--;
|
|
CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
|
|
map->nentries, entry);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_resize_free:
|
|
*
|
|
* Recompute the amount of free space following a vm_map_entry
|
|
* and propagate that value up the tree. Call this function after
|
|
* resizing a map entry in-place, that is, without a call to
|
|
* vm_map_entry_link() or _unlink().
|
|
*
|
|
* The map must be locked, and leaves it so.
|
|
*/
|
|
static void
|
|
vm_map_entry_resize_free(vm_map_t map, vm_map_entry_t entry)
|
|
{
|
|
|
|
/*
|
|
* Using splay trees without parent pointers, propagating
|
|
* max_free up the tree is done by moving the entry to the
|
|
* root and making the change there.
|
|
*/
|
|
if (entry != map->root)
|
|
map->root = vm_map_entry_splay(entry->start, map->root);
|
|
|
|
entry->adj_free = (entry->next == &map->header ? map->max_offset :
|
|
entry->next->start) - entry->end;
|
|
vm_map_entry_set_max_free(entry);
|
|
}
|
|
|
|
/*
|
|
* 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(
|
|
vm_map_t map,
|
|
vm_offset_t address,
|
|
vm_map_entry_t *entry) /* OUT */
|
|
{
|
|
vm_map_entry_t cur;
|
|
boolean_t locked;
|
|
|
|
/*
|
|
* If the map is empty, then the map entry immediately preceding
|
|
* "address" is the map's header.
|
|
*/
|
|
cur = map->root;
|
|
if (cur == NULL)
|
|
*entry = &map->header;
|
|
else if (address >= cur->start && cur->end > address) {
|
|
*entry = cur;
|
|
return (TRUE);
|
|
} else if ((locked = vm_map_locked(map)) ||
|
|
sx_try_upgrade(&map->lock)) {
|
|
/*
|
|
* Splay requires a write lock on the map. However, it only
|
|
* restructures the binary search tree; it does not otherwise
|
|
* change the map. Thus, the map's timestamp need not change
|
|
* on a temporary upgrade.
|
|
*/
|
|
map->root = cur = vm_map_entry_splay(address, cur);
|
|
if (!locked)
|
|
sx_downgrade(&map->lock);
|
|
|
|
/*
|
|
* If "address" is contained within a map entry, the new root
|
|
* is that map entry. Otherwise, the new root is a map entry
|
|
* immediately before or after "address".
|
|
*/
|
|
if (address >= cur->start) {
|
|
*entry = cur;
|
|
if (cur->end > address)
|
|
return (TRUE);
|
|
} else
|
|
*entry = cur->prev;
|
|
} else
|
|
/*
|
|
* Since the map is only locked for read access, perform a
|
|
* standard binary search tree lookup for "address".
|
|
*/
|
|
for (;;) {
|
|
if (address < cur->start) {
|
|
if (cur->left == NULL) {
|
|
*entry = cur->prev;
|
|
break;
|
|
}
|
|
cur = cur->left;
|
|
} else if (cur->end > address) {
|
|
*entry = cur;
|
|
return (TRUE);
|
|
} else {
|
|
if (cur->right == NULL) {
|
|
*entry = cur;
|
|
break;
|
|
}
|
|
cur = cur->right;
|
|
}
|
|
}
|
|
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.
|
|
*
|
|
* If object is non-NULL, ref count must be bumped by caller
|
|
* prior to making call to account for the new entry.
|
|
*/
|
|
int
|
|
vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
|
|
vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow)
|
|
{
|
|
vm_map_entry_t new_entry, prev_entry, temp_entry;
|
|
vm_eflags_t protoeflags;
|
|
struct ucred *cred;
|
|
vm_inherit_t inheritance;
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
KASSERT((object != kmem_object && object != kernel_object) ||
|
|
(cow & MAP_COPY_ON_WRITE) == 0,
|
|
("vm_map_insert: kmem or kernel object and COW"));
|
|
KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0,
|
|
("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_ON_WRITE)
|
|
protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY;
|
|
if (cow & MAP_NOFAULT)
|
|
protoeflags |= MAP_ENTRY_NOFAULT;
|
|
if (cow & MAP_DISABLE_SYNCER)
|
|
protoeflags |= MAP_ENTRY_NOSYNC;
|
|
if (cow & MAP_DISABLE_COREDUMP)
|
|
protoeflags |= MAP_ENTRY_NOCOREDUMP;
|
|
if (cow & MAP_STACK_GROWS_DOWN)
|
|
protoeflags |= MAP_ENTRY_GROWS_DOWN;
|
|
if (cow & MAP_STACK_GROWS_UP)
|
|
protoeflags |= MAP_ENTRY_GROWS_UP;
|
|
if (cow & MAP_VN_WRITECOUNT)
|
|
protoeflags |= MAP_ENTRY_VN_WRITECNT;
|
|
if (cow & MAP_INHERIT_SHARE)
|
|
inheritance = VM_INHERIT_SHARE;
|
|
else
|
|
inheritance = VM_INHERIT_DEFAULT;
|
|
|
|
cred = NULL;
|
|
if (cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT))
|
|
goto charged;
|
|
if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) &&
|
|
((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) {
|
|
if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start))
|
|
return (KERN_RESOURCE_SHORTAGE);
|
|
KASSERT(object == NULL || (protoeflags & MAP_ENTRY_NEEDS_COPY) ||
|
|
object->cred == NULL,
|
|
("OVERCOMMIT: vm_map_insert o %p", object));
|
|
cred = curthread->td_ucred;
|
|
}
|
|
|
|
charged:
|
|
/* Expand the kernel pmap, if necessary. */
|
|
if (map == kernel_map && end > kernel_vm_end)
|
|
pmap_growkernel(end);
|
|
if (object != NULL) {
|
|
/*
|
|
* OBJ_ONEMAPPING must be cleared unless this mapping
|
|
* is trivially proven to be the only mapping for any
|
|
* of the object's pages. (Object granularity
|
|
* reference counting is insufficient to recognize
|
|
* aliases with precision.)
|
|
*/
|
|
VM_OBJECT_WLOCK(object);
|
|
if (object->ref_count > 1 || object->shadow_count != 0)
|
|
vm_object_clear_flag(object, OBJ_ONEMAPPING);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
}
|
|
else if ((prev_entry != &map->header) &&
|
|
(prev_entry->eflags == protoeflags) &&
|
|
(cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 &&
|
|
(prev_entry->end == start) &&
|
|
(prev_entry->wired_count == 0) &&
|
|
(prev_entry->cred == cred ||
|
|
(prev_entry->object.vm_object != NULL &&
|
|
(prev_entry->object.vm_object->cred == cred))) &&
|
|
vm_object_coalesce(prev_entry->object.vm_object,
|
|
prev_entry->offset,
|
|
(vm_size_t)(prev_entry->end - prev_entry->start),
|
|
(vm_size_t)(end - prev_entry->end), cred != NULL &&
|
|
(protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) {
|
|
/*
|
|
* We were able to extend the object. Determine if we
|
|
* can extend the previous map entry to include the
|
|
* new range as well.
|
|
*/
|
|
if ((prev_entry->inheritance == inheritance) &&
|
|
(prev_entry->protection == prot) &&
|
|
(prev_entry->max_protection == max)) {
|
|
map->size += (end - prev_entry->end);
|
|
prev_entry->end = end;
|
|
vm_map_entry_resize_free(map, prev_entry);
|
|
vm_map_simplify_entry(map, prev_entry);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* If we can extend the object but cannot extend the
|
|
* map entry, we have to create a new map entry. We
|
|
* must bump the ref count on the extended object to
|
|
* account for it. object may be NULL.
|
|
*/
|
|
object = prev_entry->object.vm_object;
|
|
offset = prev_entry->offset +
|
|
(prev_entry->end - prev_entry->start);
|
|
vm_object_reference(object);
|
|
if (cred != NULL && object != NULL && object->cred != NULL &&
|
|
!(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
|
|
/* Object already accounts for this uid. */
|
|
cred = NULL;
|
|
}
|
|
}
|
|
if (cred != NULL)
|
|
crhold(cred);
|
|
|
|
/*
|
|
* Create a new entry
|
|
*/
|
|
new_entry = vm_map_entry_create(map);
|
|
new_entry->start = start;
|
|
new_entry->end = end;
|
|
new_entry->cred = NULL;
|
|
|
|
new_entry->eflags = protoeflags;
|
|
new_entry->object.vm_object = object;
|
|
new_entry->offset = offset;
|
|
new_entry->avail_ssize = 0;
|
|
|
|
new_entry->inheritance = inheritance;
|
|
new_entry->protection = prot;
|
|
new_entry->max_protection = max;
|
|
new_entry->wired_count = 0;
|
|
new_entry->wiring_thread = NULL;
|
|
new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT;
|
|
new_entry->next_read = OFF_TO_IDX(offset);
|
|
|
|
KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry),
|
|
("OVERCOMMIT: vm_map_insert leaks vm_map %p", new_entry));
|
|
new_entry->cred = cred;
|
|
|
|
/*
|
|
* Insert the new entry into the list
|
|
*/
|
|
vm_map_entry_link(map, prev_entry, new_entry);
|
|
map->size += new_entry->end - new_entry->start;
|
|
|
|
/*
|
|
* Try to coalesce the new entry with both the previous and next
|
|
* entries in the list. Previously, we only attempted to coalesce
|
|
* with the previous entry when object is NULL. Here, we handle the
|
|
* other cases, which are less common.
|
|
*/
|
|
vm_map_simplify_entry(map, new_entry);
|
|
|
|
if (cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) {
|
|
vm_map_pmap_enter(map, start, prot,
|
|
object, OFF_TO_IDX(offset), end - start,
|
|
cow & MAP_PREFAULT_PARTIAL);
|
|
}
|
|
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_findspace:
|
|
*
|
|
* Find the first fit (lowest VM address) for "length" free bytes
|
|
* beginning at address >= start in the given map.
|
|
*
|
|
* In a vm_map_entry, "adj_free" is the amount of free space
|
|
* adjacent (higher address) to this entry, and "max_free" is the
|
|
* maximum amount of contiguous free space in its subtree. This
|
|
* allows finding a free region in one path down the tree, so
|
|
* O(log n) amortized with splay trees.
|
|
*
|
|
* The map must be locked, and leaves it so.
|
|
*
|
|
* Returns: 0 on success, and starting address in *addr,
|
|
* 1 if insufficient space.
|
|
*/
|
|
int
|
|
vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
|
|
vm_offset_t *addr) /* OUT */
|
|
{
|
|
vm_map_entry_t entry;
|
|
vm_offset_t st;
|
|
|
|
/*
|
|
* Request must fit within min/max VM address and must avoid
|
|
* address wrap.
|
|
*/
|
|
if (start < map->min_offset)
|
|
start = map->min_offset;
|
|
if (start + length > map->max_offset || start + length < start)
|
|
return (1);
|
|
|
|
/* Empty tree means wide open address space. */
|
|
if (map->root == NULL) {
|
|
*addr = start;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* After splay, if start comes before root node, then there
|
|
* must be a gap from start to the root.
|
|
*/
|
|
map->root = vm_map_entry_splay(start, map->root);
|
|
if (start + length <= map->root->start) {
|
|
*addr = start;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Root is the last node that might begin its gap before
|
|
* start, and this is the last comparison where address
|
|
* wrap might be a problem.
|
|
*/
|
|
st = (start > map->root->end) ? start : map->root->end;
|
|
if (length <= map->root->end + map->root->adj_free - st) {
|
|
*addr = st;
|
|
return (0);
|
|
}
|
|
|
|
/* With max_free, can immediately tell if no solution. */
|
|
entry = map->root->right;
|
|
if (entry == NULL || length > entry->max_free)
|
|
return (1);
|
|
|
|
/*
|
|
* Search the right subtree in the order: left subtree, root,
|
|
* right subtree (first fit). The previous splay implies that
|
|
* all regions in the right subtree have addresses > start.
|
|
*/
|
|
while (entry != NULL) {
|
|
if (entry->left != NULL && entry->left->max_free >= length)
|
|
entry = entry->left;
|
|
else if (entry->adj_free >= length) {
|
|
*addr = entry->end;
|
|
return (0);
|
|
} else
|
|
entry = entry->right;
|
|
}
|
|
|
|
/* Can't get here, so panic if we do. */
|
|
panic("vm_map_findspace: max_free corrupt");
|
|
}
|
|
|
|
int
|
|
vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
|
|
vm_offset_t start, vm_size_t length, vm_prot_t prot,
|
|
vm_prot_t max, int cow)
|
|
{
|
|
vm_offset_t end;
|
|
int result;
|
|
|
|
end = start + length;
|
|
KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
|
|
object == NULL,
|
|
("vm_map_fixed: non-NULL backing object for stack"));
|
|
vm_map_lock(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
if ((cow & MAP_CHECK_EXCL) == 0)
|
|
vm_map_delete(map, start, end);
|
|
if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
|
|
result = vm_map_stack_locked(map, start, length, sgrowsiz,
|
|
prot, max, cow);
|
|
} else {
|
|
result = vm_map_insert(map, object, offset, start, end,
|
|
prot, max, cow);
|
|
}
|
|
vm_map_unlock(map);
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* If object is non-NULL, ref count must be bumped by caller
|
|
* prior to making call to account for the new entry.
|
|
*/
|
|
int
|
|
vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
|
|
vm_offset_t *addr, /* IN/OUT */
|
|
vm_size_t length, vm_offset_t max_addr, int find_space,
|
|
vm_prot_t prot, vm_prot_t max, int cow)
|
|
{
|
|
vm_offset_t alignment, initial_addr, start;
|
|
int result;
|
|
|
|
KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
|
|
object == NULL,
|
|
("vm_map_find: non-NULL backing object for stack"));
|
|
if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
|
|
(object->flags & OBJ_COLORED) == 0))
|
|
find_space = VMFS_ANY_SPACE;
|
|
if (find_space >> 8 != 0) {
|
|
KASSERT((find_space & 0xff) == 0, ("bad VMFS flags"));
|
|
alignment = (vm_offset_t)1 << (find_space >> 8);
|
|
} else
|
|
alignment = 0;
|
|
initial_addr = *addr;
|
|
again:
|
|
start = initial_addr;
|
|
vm_map_lock(map);
|
|
do {
|
|
if (find_space != VMFS_NO_SPACE) {
|
|
if (vm_map_findspace(map, start, length, addr) ||
|
|
(max_addr != 0 && *addr + length > max_addr)) {
|
|
vm_map_unlock(map);
|
|
if (find_space == VMFS_OPTIMAL_SPACE) {
|
|
find_space = VMFS_ANY_SPACE;
|
|
goto again;
|
|
}
|
|
return (KERN_NO_SPACE);
|
|
}
|
|
switch (find_space) {
|
|
case VMFS_SUPER_SPACE:
|
|
case VMFS_OPTIMAL_SPACE:
|
|
pmap_align_superpage(object, offset, addr,
|
|
length);
|
|
break;
|
|
case VMFS_ANY_SPACE:
|
|
break;
|
|
default:
|
|
if ((*addr & (alignment - 1)) != 0) {
|
|
*addr &= ~(alignment - 1);
|
|
*addr += alignment;
|
|
}
|
|
break;
|
|
}
|
|
|
|
start = *addr;
|
|
}
|
|
if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
|
|
result = vm_map_stack_locked(map, start, length,
|
|
sgrowsiz, prot, max, cow);
|
|
} else {
|
|
result = vm_map_insert(map, object, offset, start,
|
|
start + length, prot, max, cow);
|
|
}
|
|
} while (result == KERN_NO_SPACE && find_space != VMFS_NO_SPACE &&
|
|
find_space != VMFS_ANY_SPACE);
|
|
vm_map_unlock(map);
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* vm_map_simplify_entry:
|
|
*
|
|
* Simplify the given map entry by merging with either neighbor. This
|
|
* routine also has the ability to merge with both neighbors.
|
|
*
|
|
* The map must be locked.
|
|
*
|
|
* This routine guarentees that the passed entry remains valid (though
|
|
* possibly extended). When merging, this routine may delete one or
|
|
* both neighbors.
|
|
*/
|
|
void
|
|
vm_map_simplify_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_GROWS_DOWN | MAP_ENTRY_GROWS_UP |
|
|
MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP)) != 0)
|
|
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->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) &&
|
|
(prev->cred == entry->cred)) {
|
|
vm_map_entry_unlink(map, prev);
|
|
entry->start = prev->start;
|
|
entry->offset = prev->offset;
|
|
if (entry->prev != &map->header)
|
|
vm_map_entry_resize_free(map, entry->prev);
|
|
|
|
/*
|
|
* If the backing object is a vnode object,
|
|
* vm_object_deallocate() calls vrele().
|
|
* However, vrele() does not lock the vnode
|
|
* because the vnode has additional
|
|
* references. Thus, the map lock can be kept
|
|
* without causing a lock-order reversal with
|
|
* the vnode lock.
|
|
*
|
|
* Since we count the number of virtual page
|
|
* mappings in object->un_pager.vnp.writemappings,
|
|
* the writemappings value should not be adjusted
|
|
* when the entry is disposed of.
|
|
*/
|
|
if (prev->object.vm_object)
|
|
vm_object_deallocate(prev->object.vm_object);
|
|
if (prev->cred != NULL)
|
|
crfree(prev->cred);
|
|
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) &&
|
|
(!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) &&
|
|
(next->cred == entry->cred)) {
|
|
vm_map_entry_unlink(map, next);
|
|
entry->end = next->end;
|
|
vm_map_entry_resize_free(map, entry);
|
|
|
|
/*
|
|
* See comment above.
|
|
*/
|
|
if (next->object.vm_object)
|
|
vm_object_deallocate(next->object.vm_object);
|
|
if (next->cred != NULL)
|
|
crfree(next->cred);
|
|
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(vm_map_t map, vm_map_entry_t entry, vm_offset_t start)
|
|
{
|
|
vm_map_entry_t new_entry;
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* If there is no object backing this entry, we might as well create
|
|
* one now. If we defer it, an object can get created after the map
|
|
* is clipped, and individual objects will be created for the split-up
|
|
* map. This is a bit of a hack, but is also about the best place to
|
|
* put this improvement.
|
|
*/
|
|
if (entry->object.vm_object == NULL && !map->system_map) {
|
|
vm_object_t object;
|
|
object = vm_object_allocate(OBJT_DEFAULT,
|
|
atop(entry->end - entry->start));
|
|
entry->object.vm_object = object;
|
|
entry->offset = 0;
|
|
if (entry->cred != NULL) {
|
|
object->cred = entry->cred;
|
|
object->charge = entry->end - entry->start;
|
|
entry->cred = NULL;
|
|
}
|
|
} else if (entry->object.vm_object != NULL &&
|
|
((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
|
|
entry->cred != NULL) {
|
|
VM_OBJECT_WLOCK(entry->object.vm_object);
|
|
KASSERT(entry->object.vm_object->cred == NULL,
|
|
("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry));
|
|
entry->object.vm_object->cred = entry->cred;
|
|
entry->object.vm_object->charge = entry->end - entry->start;
|
|
VM_OBJECT_WUNLOCK(entry->object.vm_object);
|
|
entry->cred = NULL;
|
|
}
|
|
|
|
new_entry = vm_map_entry_create(map);
|
|
*new_entry = *entry;
|
|
|
|
new_entry->end = start;
|
|
entry->offset += (start - entry->start);
|
|
entry->start = start;
|
|
if (new_entry->cred != NULL)
|
|
crhold(entry->cred);
|
|
|
|
vm_map_entry_link(map, entry->prev, new_entry);
|
|
|
|
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
|
|
vm_object_reference(new_entry->object.vm_object);
|
|
/*
|
|
* The object->un_pager.vnp.writemappings for the
|
|
* object of MAP_ENTRY_VN_WRITECNT type entry shall be
|
|
* kept as is here. The virtual pages are
|
|
* re-distributed among the clipped entries, so the sum is
|
|
* left the same.
|
|
*/
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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(vm_map_t map, vm_map_entry_t entry, vm_offset_t end)
|
|
{
|
|
vm_map_entry_t new_entry;
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
|
|
/*
|
|
* If there is no object backing this entry, we might as well create
|
|
* one now. If we defer it, an object can get created after the map
|
|
* is clipped, and individual objects will be created for the split-up
|
|
* map. This is a bit of a hack, but is also about the best place to
|
|
* put this improvement.
|
|
*/
|
|
if (entry->object.vm_object == NULL && !map->system_map) {
|
|
vm_object_t object;
|
|
object = vm_object_allocate(OBJT_DEFAULT,
|
|
atop(entry->end - entry->start));
|
|
entry->object.vm_object = object;
|
|
entry->offset = 0;
|
|
if (entry->cred != NULL) {
|
|
object->cred = entry->cred;
|
|
object->charge = entry->end - entry->start;
|
|
entry->cred = NULL;
|
|
}
|
|
} else if (entry->object.vm_object != NULL &&
|
|
((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
|
|
entry->cred != NULL) {
|
|
VM_OBJECT_WLOCK(entry->object.vm_object);
|
|
KASSERT(entry->object.vm_object->cred == NULL,
|
|
("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry));
|
|
entry->object.vm_object->cred = entry->cred;
|
|
entry->object.vm_object->charge = entry->end - entry->start;
|
|
VM_OBJECT_WUNLOCK(entry->object.vm_object);
|
|
entry->cred = NULL;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
if (new_entry->cred != NULL)
|
|
crhold(entry->cred);
|
|
|
|
vm_map_entry_link(map, entry, new_entry);
|
|
|
|
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
|
|
vm_object_reference(new_entry->object.vm_object);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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(
|
|
vm_map_t map,
|
|
vm_offset_t start,
|
|
vm_offset_t end,
|
|
vm_map_t submap)
|
|
{
|
|
vm_map_entry_t entry;
|
|
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_COW) == 0) &&
|
|
(entry->object.vm_object == NULL)) {
|
|
entry->object.sub_map = submap;
|
|
entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
|
|
result = KERN_SUCCESS;
|
|
}
|
|
vm_map_unlock(map);
|
|
|
|
return (result);
|
|
}
|
|
|
|
/*
|
|
* The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified
|
|
*/
|
|
#define MAX_INIT_PT 96
|
|
|
|
/*
|
|
* vm_map_pmap_enter:
|
|
*
|
|
* Preload the specified map's pmap with mappings to the specified
|
|
* object's memory-resident pages. No further physical pages are
|
|
* allocated, and no further virtual pages are retrieved from secondary
|
|
* storage. If the specified flags include MAP_PREFAULT_PARTIAL, then a
|
|
* limited number of page mappings are created at the low-end of the
|
|
* specified address range. (For this purpose, a superpage mapping
|
|
* counts as one page mapping.) Otherwise, all resident pages within
|
|
* the specified address range are mapped. Because these mappings are
|
|
* being created speculatively, cached pages are not reactivated and
|
|
* mapped.
|
|
*/
|
|
static void
|
|
vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
|
|
vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags)
|
|
{
|
|
vm_offset_t start;
|
|
vm_page_t p, p_start;
|
|
vm_pindex_t mask, psize, threshold, tmpidx;
|
|
|
|
if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL)
|
|
return;
|
|
VM_OBJECT_RLOCK(object);
|
|
if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
|
|
VM_OBJECT_RUNLOCK(object);
|
|
VM_OBJECT_WLOCK(object);
|
|
if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
|
|
pmap_object_init_pt(map->pmap, addr, object, pindex,
|
|
size);
|
|
VM_OBJECT_WUNLOCK(object);
|
|
return;
|
|
}
|
|
VM_OBJECT_LOCK_DOWNGRADE(object);
|
|
}
|
|
|
|
psize = atop(size);
|
|
if (psize + pindex > object->size) {
|
|
if (object->size < pindex) {
|
|
VM_OBJECT_RUNLOCK(object);
|
|
return;
|
|
}
|
|
psize = object->size - pindex;
|
|
}
|
|
|
|
start = 0;
|
|
p_start = NULL;
|
|
threshold = MAX_INIT_PT;
|
|
|
|
p = vm_page_find_least(object, pindex);
|
|
/*
|
|
* Assert: the variable p is either (1) the page with the
|
|
* least pindex greater than or equal to the parameter pindex
|
|
* or (2) NULL.
|
|
*/
|
|
for (;
|
|
p != NULL && (tmpidx = p->pindex - pindex) < psize;
|
|
p = TAILQ_NEXT(p, listq)) {
|
|
/*
|
|
* don't allow an madvise to blow away our really
|
|
* free pages allocating pv entries.
|
|
*/
|
|
if (((flags & MAP_PREFAULT_MADVISE) != 0 &&
|
|
vm_cnt.v_free_count < vm_cnt.v_free_reserved) ||
|
|
((flags & MAP_PREFAULT_PARTIAL) != 0 &&
|
|
tmpidx >= threshold)) {
|
|
psize = tmpidx;
|
|
break;
|
|
}
|
|
if (p->valid == VM_PAGE_BITS_ALL) {
|
|
if (p_start == NULL) {
|
|
start = addr + ptoa(tmpidx);
|
|
p_start = p;
|
|
}
|
|
/* Jump ahead if a superpage mapping is possible. */
|
|
if (p->psind > 0 && ((addr + ptoa(tmpidx)) &
|
|
(pagesizes[p->psind] - 1)) == 0) {
|
|
mask = atop(pagesizes[p->psind]) - 1;
|
|
if (tmpidx + mask < psize &&
|
|
vm_page_ps_is_valid(p)) {
|
|
p += mask;
|
|
threshold += mask;
|
|
}
|
|
}
|
|
} else if (p_start != NULL) {
|
|
pmap_enter_object(map->pmap, start, addr +
|
|
ptoa(tmpidx), p_start, prot);
|
|
p_start = NULL;
|
|
}
|
|
}
|
|
if (p_start != NULL)
|
|
pmap_enter_object(map->pmap, start, addr + ptoa(psize),
|
|
p_start, prot);
|
|
VM_OBJECT_RUNLOCK(object);
|
|
}
|
|
|
|
/*
|
|
* 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(vm_map_t map, vm_offset_t start, vm_offset_t end,
|
|
vm_prot_t new_prot, boolean_t set_max)
|
|
{
|
|
vm_map_entry_t current, entry;
|
|
vm_object_t obj;
|
|
struct ucred *cred;
|
|
vm_prot_t old_prot;
|
|
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
/*
|
|
* Do an accounting pass for private read-only mappings that
|
|
* now will do cow due to allowed write (e.g. debugger sets
|
|
* breakpoint on text segment)
|
|
*/
|
|
for (current = entry; (current != &map->header) &&
|
|
(current->start < end); current = current->next) {
|
|
|
|
vm_map_clip_end(map, current, end);
|
|
|
|
if (set_max ||
|
|
((new_prot & ~(current->protection)) & VM_PROT_WRITE) == 0 ||
|
|
ENTRY_CHARGED(current)) {
|
|
continue;
|
|
}
|
|
|
|
cred = curthread->td_ucred;
|
|
obj = current->object.vm_object;
|
|
|
|
if (obj == NULL || (current->eflags & MAP_ENTRY_NEEDS_COPY)) {
|
|
if (!swap_reserve(current->end - current->start)) {
|
|
vm_map_unlock(map);
|
|
return (KERN_RESOURCE_SHORTAGE);
|
|
}
|
|
crhold(cred);
|
|
current->cred = cred;
|
|
continue;
|
|
}
|
|
|
|
VM_OBJECT_WLOCK(obj);
|
|
if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Charge for the whole object allocation now, since
|
|
* we cannot distinguish between non-charged and
|
|
* charged clipped mapping of the same object later.
|
|
*/
|
|
KASSERT(obj->charge == 0,
|
|
("vm_map_protect: object %p overcharged (entry %p)",
|
|
obj, current));
|
|
if (!swap_reserve(ptoa(obj->size))) {
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
vm_map_unlock(map);
|
|
return (KERN_RESOURCE_SHORTAGE);
|
|
}
|
|
|
|
crhold(cred);
|
|
obj->cred = cred;
|
|
obj->charge = ptoa(obj->size);
|
|
VM_OBJECT_WUNLOCK(obj);
|
|
}
|
|
|
|
/*
|
|
* Go back and fix up protections. [Note that clipping is not
|
|
* necessary the second time.]
|
|
*/
|
|
current = entry;
|
|
while ((current != &map->header) && (current->start < end)) {
|
|
old_prot = current->protection;
|
|
|
|
if (set_max)
|
|
current->protection =
|
|
(current->max_protection = new_prot) &
|
|
old_prot;
|
|
else
|
|
current->protection = new_prot;
|
|
|
|
/*
|
|
* For user wired map entries, the normal lazy evaluation of
|
|
* write access upgrades through soft page faults is
|
|
* undesirable. Instead, immediately copy any pages that are
|
|
* copy-on-write and enable write access in the physical map.
|
|
*/
|
|
if ((current->eflags & MAP_ENTRY_USER_WIRED) != 0 &&
|
|
(current->protection & VM_PROT_WRITE) != 0 &&
|
|
(old_prot & VM_PROT_WRITE) == 0)
|
|
vm_fault_copy_entry(map, map, current, current, NULL);
|
|
|
|
/*
|
|
* When restricting access, update the physical map. Worry
|
|
* about copy-on-write here.
|
|
*/
|
|
if ((old_prot & ~current->protection) != 0) {
|
|
#define MASK(entry) (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
|
|
VM_PROT_ALL)
|
|
pmap_protect(map->pmap, current->start,
|
|
current->end,
|
|
current->protection & MASK(current));
|
|
#undef MASK
|
|
}
|
|
vm_map_simplify_entry(map, current);
|
|
current = current->next;
|
|
}
|
|
vm_map_unlock(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_madvise:
|
|
*
|
|
* This routine traverses a processes map handling the madvise
|
|
* system call. Advisories are classified as either those effecting
|
|
* the vm_map_entry structure, or those effecting the underlying
|
|
* objects.
|
|
*/
|
|
int
|
|
vm_map_madvise(
|
|
vm_map_t map,
|
|
vm_offset_t start,
|
|
vm_offset_t end,
|
|
int behav)
|
|
{
|
|
vm_map_entry_t current, entry;
|
|
int modify_map = 0;
|
|
|
|
/*
|
|
* Some madvise calls directly modify the vm_map_entry, in which case
|
|
* we need to use an exclusive lock on the map and we need to perform
|
|
* various clipping operations. Otherwise we only need a read-lock
|
|
* on the map.
|
|
*/
|
|
switch(behav) {
|
|
case MADV_NORMAL:
|
|
case MADV_SEQUENTIAL:
|
|
case MADV_RANDOM:
|
|
case MADV_NOSYNC:
|
|
case MADV_AUTOSYNC:
|
|
case MADV_NOCORE:
|
|
case MADV_CORE:
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
modify_map = 1;
|
|
vm_map_lock(map);
|
|
break;
|
|
case MADV_WILLNEED:
|
|
case MADV_DONTNEED:
|
|
case MADV_FREE:
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
vm_map_lock_read(map);
|
|
break;
|
|
default:
|
|
return (KERN_INVALID_ARGUMENT);
|
|
}
|
|
|
|
/*
|
|
* Locate starting entry and clip if necessary.
|
|
*/
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
|
|
if (vm_map_lookup_entry(map, start, &entry)) {
|
|
if (modify_map)
|
|
vm_map_clip_start(map, entry, start);
|
|
} else {
|
|
entry = entry->next;
|
|
}
|
|
|
|
if (modify_map) {
|
|
/*
|
|
* madvise behaviors that are implemented in the vm_map_entry.
|
|
*
|
|
* We clip the vm_map_entry so that behavioral changes are
|
|
* limited to the specified address range.
|
|
*/
|
|
for (current = entry;
|
|
(current != &map->header) && (current->start < end);
|
|
current = current->next
|
|
) {
|
|
if (current->eflags & MAP_ENTRY_IS_SUB_MAP)
|
|
continue;
|
|
|
|
vm_map_clip_end(map, current, end);
|
|
|
|
switch (behav) {
|
|
case MADV_NORMAL:
|
|
vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
|
|
break;
|
|
case MADV_SEQUENTIAL:
|
|
vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
|
|
break;
|
|
case MADV_RANDOM:
|
|
vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
|
|
break;
|
|
case MADV_NOSYNC:
|
|
current->eflags |= MAP_ENTRY_NOSYNC;
|
|
break;
|
|
case MADV_AUTOSYNC:
|
|
current->eflags &= ~MAP_ENTRY_NOSYNC;
|
|
break;
|
|
case MADV_NOCORE:
|
|
current->eflags |= MAP_ENTRY_NOCOREDUMP;
|
|
break;
|
|
case MADV_CORE:
|
|
current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
vm_map_simplify_entry(map, current);
|
|
}
|
|
vm_map_unlock(map);
|
|
} else {
|
|
vm_pindex_t pstart, pend;
|
|
|
|
/*
|
|
* madvise behaviors that are implemented in the underlying
|
|
* vm_object.
|
|
*
|
|
* Since we don't clip the vm_map_entry, we have to clip
|
|
* the vm_object pindex and count.
|
|
*/
|
|
for (current = entry;
|
|
(current != &map->header) && (current->start < end);
|
|
current = current->next
|
|
) {
|
|
vm_offset_t useEnd, useStart;
|
|
|
|
if (current->eflags & MAP_ENTRY_IS_SUB_MAP)
|
|
continue;
|
|
|
|
pstart = OFF_TO_IDX(current->offset);
|
|
pend = pstart + atop(current->end - current->start);
|
|
useStart = current->start;
|
|
useEnd = current->end;
|
|
|
|
if (current->start < start) {
|
|
pstart += atop(start - current->start);
|
|
useStart = start;
|
|
}
|
|
if (current->end > end) {
|
|
pend -= atop(current->end - end);
|
|
useEnd = end;
|
|
}
|
|
|
|
if (pstart >= pend)
|
|
continue;
|
|
|
|
/*
|
|
* Perform the pmap_advise() before clearing
|
|
* PGA_REFERENCED in vm_page_advise(). Otherwise, a
|
|
* concurrent pmap operation, such as pmap_remove(),
|
|
* could clear a reference in the pmap and set
|
|
* PGA_REFERENCED on the page before the pmap_advise()
|
|
* had completed. Consequently, the page would appear
|
|
* referenced based upon an old reference that
|
|
* occurred before this pmap_advise() ran.
|
|
*/
|
|
if (behav == MADV_DONTNEED || behav == MADV_FREE)
|
|
pmap_advise(map->pmap, useStart, useEnd,
|
|
behav);
|
|
|
|
vm_object_madvise(current->object.vm_object, pstart,
|
|
pend, behav);
|
|
|
|
/*
|
|
* Pre-populate paging structures in the
|
|
* WILLNEED case. For wired entries, the
|
|
* paging structures are already populated.
|
|
*/
|
|
if (behav == MADV_WILLNEED &&
|
|
current->wired_count == 0) {
|
|
vm_map_pmap_enter(map,
|
|
useStart,
|
|
current->protection,
|
|
current->object.vm_object,
|
|
pstart,
|
|
ptoa(pend - pstart),
|
|
MAP_PREFAULT_MADVISE
|
|
);
|
|
}
|
|
}
|
|
vm_map_unlock_read(map);
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
|
|
/*
|
|
* 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 vmspace_fork.
|
|
*/
|
|
int
|
|
vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
|
|
vm_inherit_t new_inheritance)
|
|
{
|
|
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);
|
|
}
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
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;
|
|
vm_map_simplify_entry(map, entry);
|
|
entry = entry->next;
|
|
}
|
|
vm_map_unlock(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_unwire:
|
|
*
|
|
* Implements both kernel and user unwiring.
|
|
*/
|
|
int
|
|
vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
|
|
int flags)
|
|
{
|
|
vm_map_entry_t entry, first_entry, tmp_entry;
|
|
vm_offset_t saved_start;
|
|
unsigned int last_timestamp;
|
|
int rv;
|
|
boolean_t need_wakeup, result, user_unwire;
|
|
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
user_unwire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE;
|
|
vm_map_lock(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
if (!vm_map_lookup_entry(map, start, &first_entry)) {
|
|
if (flags & VM_MAP_WIRE_HOLESOK)
|
|
first_entry = first_entry->next;
|
|
else {
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
}
|
|
last_timestamp = map->timestamp;
|
|
entry = first_entry;
|
|
while (entry != &map->header && entry->start < end) {
|
|
if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
|
|
/*
|
|
* We have not yet clipped the entry.
|
|
*/
|
|
saved_start = (start >= entry->start) ? start :
|
|
entry->start;
|
|
entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
|
|
if (vm_map_unlock_and_wait(map, 0)) {
|
|
/*
|
|
* Allow interruption of user unwiring?
|
|
*/
|
|
}
|
|
vm_map_lock(map);
|
|
if (last_timestamp+1 != map->timestamp) {
|
|
/*
|
|
* Look again for the entry because the map was
|
|
* modified while it was unlocked.
|
|
* Specifically, the entry may have been
|
|
* clipped, merged, or deleted.
|
|
*/
|
|
if (!vm_map_lookup_entry(map, saved_start,
|
|
&tmp_entry)) {
|
|
if (flags & VM_MAP_WIRE_HOLESOK)
|
|
tmp_entry = tmp_entry->next;
|
|
else {
|
|
if (saved_start == start) {
|
|
/*
|
|
* First_entry has been deleted.
|
|
*/
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
end = saved_start;
|
|
rv = KERN_INVALID_ADDRESS;
|
|
goto done;
|
|
}
|
|
}
|
|
if (entry == first_entry)
|
|
first_entry = tmp_entry;
|
|
else
|
|
first_entry = NULL;
|
|
entry = tmp_entry;
|
|
}
|
|
last_timestamp = map->timestamp;
|
|
continue;
|
|
}
|
|
vm_map_clip_start(map, entry, start);
|
|
vm_map_clip_end(map, entry, end);
|
|
/*
|
|
* Mark the entry in case the map lock is released. (See
|
|
* above.)
|
|
*/
|
|
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
|
|
entry->wiring_thread == NULL,
|
|
("owned map entry %p", entry));
|
|
entry->eflags |= MAP_ENTRY_IN_TRANSITION;
|
|
entry->wiring_thread = curthread;
|
|
/*
|
|
* Check the map for holes in the specified region.
|
|
* If VM_MAP_WIRE_HOLESOK was specified, skip this check.
|
|
*/
|
|
if (((flags & VM_MAP_WIRE_HOLESOK) == 0) &&
|
|
(entry->end < end && (entry->next == &map->header ||
|
|
entry->next->start > entry->end))) {
|
|
end = entry->end;
|
|
rv = KERN_INVALID_ADDRESS;
|
|
goto done;
|
|
}
|
|
/*
|
|
* If system unwiring, require that the entry is system wired.
|
|
*/
|
|
if (!user_unwire &&
|
|
vm_map_entry_system_wired_count(entry) == 0) {
|
|
end = entry->end;
|
|
rv = KERN_INVALID_ARGUMENT;
|
|
goto done;
|
|
}
|
|
entry = entry->next;
|
|
}
|
|
rv = KERN_SUCCESS;
|
|
done:
|
|
need_wakeup = FALSE;
|
|
if (first_entry == NULL) {
|
|
result = vm_map_lookup_entry(map, start, &first_entry);
|
|
if (!result && (flags & VM_MAP_WIRE_HOLESOK))
|
|
first_entry = first_entry->next;
|
|
else
|
|
KASSERT(result, ("vm_map_unwire: lookup failed"));
|
|
}
|
|
for (entry = first_entry; entry != &map->header && entry->start < end;
|
|
entry = entry->next) {
|
|
/*
|
|
* If VM_MAP_WIRE_HOLESOK was specified, an empty
|
|
* space in the unwired region could have been mapped
|
|
* while the map lock was dropped for draining
|
|
* MAP_ENTRY_IN_TRANSITION. Moreover, another thread
|
|
* could be simultaneously wiring this new mapping
|
|
* entry. Detect these cases and skip any entries
|
|
* marked as in transition by us.
|
|
*/
|
|
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
|
|
entry->wiring_thread != curthread) {
|
|
KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0,
|
|
("vm_map_unwire: !HOLESOK and new/changed entry"));
|
|
continue;
|
|
}
|
|
|
|
if (rv == KERN_SUCCESS && (!user_unwire ||
|
|
(entry->eflags & MAP_ENTRY_USER_WIRED))) {
|
|
if (user_unwire)
|
|
entry->eflags &= ~MAP_ENTRY_USER_WIRED;
|
|
if (entry->wired_count == 1)
|
|
vm_map_entry_unwire(map, entry);
|
|
else
|
|
entry->wired_count--;
|
|
}
|
|
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
|
|
("vm_map_unwire: in-transition flag missing %p", entry));
|
|
KASSERT(entry->wiring_thread == curthread,
|
|
("vm_map_unwire: alien wire %p", entry));
|
|
entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
|
|
entry->wiring_thread = NULL;
|
|
if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
|
|
entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
|
|
need_wakeup = TRUE;
|
|
}
|
|
vm_map_simplify_entry(map, entry);
|
|
}
|
|
vm_map_unlock(map);
|
|
if (need_wakeup)
|
|
vm_map_wakeup(map);
|
|
return (rv);
|
|
}
|
|
|
|
/*
|
|
* vm_map_wire_entry_failure:
|
|
*
|
|
* Handle a wiring failure on the given entry.
|
|
*
|
|
* The map should be locked.
|
|
*/
|
|
static void
|
|
vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
|
|
vm_offset_t failed_addr)
|
|
{
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
|
|
entry->wired_count == 1,
|
|
("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
|
|
KASSERT(failed_addr < entry->end,
|
|
("vm_map_wire_entry_failure: entry %p was fully wired", entry));
|
|
|
|
/*
|
|
* If any pages at the start of this entry were successfully wired,
|
|
* then unwire them.
|
|
*/
|
|
if (failed_addr > entry->start) {
|
|
pmap_unwire(map->pmap, entry->start, failed_addr);
|
|
vm_object_unwire(entry->object.vm_object, entry->offset,
|
|
failed_addr - entry->start, PQ_ACTIVE);
|
|
}
|
|
|
|
/*
|
|
* Assign an out-of-range value to represent the failure to wire this
|
|
* entry.
|
|
*/
|
|
entry->wired_count = -1;
|
|
}
|
|
|
|
/*
|
|
* vm_map_wire:
|
|
*
|
|
* Implements both kernel and user wiring.
|
|
*/
|
|
int
|
|
vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
|
|
int flags)
|
|
{
|
|
vm_map_entry_t entry, first_entry, tmp_entry;
|
|
vm_offset_t faddr, saved_end, saved_start;
|
|
unsigned int last_timestamp;
|
|
int rv;
|
|
boolean_t need_wakeup, result, user_wire;
|
|
vm_prot_t prot;
|
|
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
prot = 0;
|
|
if (flags & VM_MAP_WIRE_WRITE)
|
|
prot |= VM_PROT_WRITE;
|
|
user_wire = (flags & VM_MAP_WIRE_USER) ? TRUE : FALSE;
|
|
vm_map_lock(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
if (!vm_map_lookup_entry(map, start, &first_entry)) {
|
|
if (flags & VM_MAP_WIRE_HOLESOK)
|
|
first_entry = first_entry->next;
|
|
else {
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
}
|
|
last_timestamp = map->timestamp;
|
|
entry = first_entry;
|
|
while (entry != &map->header && entry->start < end) {
|
|
if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
|
|
/*
|
|
* We have not yet clipped the entry.
|
|
*/
|
|
saved_start = (start >= entry->start) ? start :
|
|
entry->start;
|
|
entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
|
|
if (vm_map_unlock_and_wait(map, 0)) {
|
|
/*
|
|
* Allow interruption of user wiring?
|
|
*/
|
|
}
|
|
vm_map_lock(map);
|
|
if (last_timestamp + 1 != map->timestamp) {
|
|
/*
|
|
* Look again for the entry because the map was
|
|
* modified while it was unlocked.
|
|
* Specifically, the entry may have been
|
|
* clipped, merged, or deleted.
|
|
*/
|
|
if (!vm_map_lookup_entry(map, saved_start,
|
|
&tmp_entry)) {
|
|
if (flags & VM_MAP_WIRE_HOLESOK)
|
|
tmp_entry = tmp_entry->next;
|
|
else {
|
|
if (saved_start == start) {
|
|
/*
|
|
* first_entry has been deleted.
|
|
*/
|
|
vm_map_unlock(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
end = saved_start;
|
|
rv = KERN_INVALID_ADDRESS;
|
|
goto done;
|
|
}
|
|
}
|
|
if (entry == first_entry)
|
|
first_entry = tmp_entry;
|
|
else
|
|
first_entry = NULL;
|
|
entry = tmp_entry;
|
|
}
|
|
last_timestamp = map->timestamp;
|
|
continue;
|
|
}
|
|
vm_map_clip_start(map, entry, start);
|
|
vm_map_clip_end(map, entry, end);
|
|
/*
|
|
* Mark the entry in case the map lock is released. (See
|
|
* above.)
|
|
*/
|
|
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
|
|
entry->wiring_thread == NULL,
|
|
("owned map entry %p", entry));
|
|
entry->eflags |= MAP_ENTRY_IN_TRANSITION;
|
|
entry->wiring_thread = curthread;
|
|
if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0
|
|
|| (entry->protection & prot) != prot) {
|
|
entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
|
|
if ((flags & VM_MAP_WIRE_HOLESOK) == 0) {
|
|
end = entry->end;
|
|
rv = KERN_INVALID_ADDRESS;
|
|
goto done;
|
|
}
|
|
goto next_entry;
|
|
}
|
|
if (entry->wired_count == 0) {
|
|
entry->wired_count++;
|
|
saved_start = entry->start;
|
|
saved_end = entry->end;
|
|
|
|
/*
|
|
* Release the map lock, relying on the in-transition
|
|
* mark. Mark the map busy for fork.
|
|
*/
|
|
vm_map_busy(map);
|
|
vm_map_unlock(map);
|
|
|
|
faddr = saved_start;
|
|
do {
|
|
/*
|
|
* Simulate a fault to get the page and enter
|
|
* it into the physical map.
|
|
*/
|
|
if ((rv = vm_fault(map, faddr, VM_PROT_NONE,
|
|
VM_FAULT_CHANGE_WIRING)) != KERN_SUCCESS)
|
|
break;
|
|
} while ((faddr += PAGE_SIZE) < saved_end);
|
|
vm_map_lock(map);
|
|
vm_map_unbusy(map);
|
|
if (last_timestamp + 1 != map->timestamp) {
|
|
/*
|
|
* Look again for the entry because the map was
|
|
* modified while it was unlocked. The entry
|
|
* may have been clipped, but NOT merged or
|
|
* deleted.
|
|
*/
|
|
result = vm_map_lookup_entry(map, saved_start,
|
|
&tmp_entry);
|
|
KASSERT(result, ("vm_map_wire: lookup failed"));
|
|
if (entry == first_entry)
|
|
first_entry = tmp_entry;
|
|
else
|
|
first_entry = NULL;
|
|
entry = tmp_entry;
|
|
while (entry->end < saved_end) {
|
|
/*
|
|
* In case of failure, handle entries
|
|
* that were not fully wired here;
|
|
* fully wired entries are handled
|
|
* later.
|
|
*/
|
|
if (rv != KERN_SUCCESS &&
|
|
faddr < entry->end)
|
|
vm_map_wire_entry_failure(map,
|
|
entry, faddr);
|
|
entry = entry->next;
|
|
}
|
|
}
|
|
last_timestamp = map->timestamp;
|
|
if (rv != KERN_SUCCESS) {
|
|
vm_map_wire_entry_failure(map, entry, faddr);
|
|
end = entry->end;
|
|
goto done;
|
|
}
|
|
} else if (!user_wire ||
|
|
(entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
|
|
entry->wired_count++;
|
|
}
|
|
/*
|
|
* Check the map for holes in the specified region.
|
|
* If VM_MAP_WIRE_HOLESOK was specified, skip this check.
|
|
*/
|
|
next_entry:
|
|
if (((flags & VM_MAP_WIRE_HOLESOK) == 0) &&
|
|
(entry->end < end && (entry->next == &map->header ||
|
|
entry->next->start > entry->end))) {
|
|
end = entry->end;
|
|
rv = KERN_INVALID_ADDRESS;
|
|
goto done;
|
|
}
|
|
entry = entry->next;
|
|
}
|
|
rv = KERN_SUCCESS;
|
|
done:
|
|
need_wakeup = FALSE;
|
|
if (first_entry == NULL) {
|
|
result = vm_map_lookup_entry(map, start, &first_entry);
|
|
if (!result && (flags & VM_MAP_WIRE_HOLESOK))
|
|
first_entry = first_entry->next;
|
|
else
|
|
KASSERT(result, ("vm_map_wire: lookup failed"));
|
|
}
|
|
for (entry = first_entry; entry != &map->header && entry->start < end;
|
|
entry = entry->next) {
|
|
if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0)
|
|
goto next_entry_done;
|
|
|
|
/*
|
|
* If VM_MAP_WIRE_HOLESOK was specified, an empty
|
|
* space in the unwired region could have been mapped
|
|
* while the map lock was dropped for faulting in the
|
|
* pages or draining MAP_ENTRY_IN_TRANSITION.
|
|
* Moreover, another thread could be simultaneously
|
|
* wiring this new mapping entry. Detect these cases
|
|
* and skip any entries marked as in transition by us.
|
|
*/
|
|
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
|
|
entry->wiring_thread != curthread) {
|
|
KASSERT((flags & VM_MAP_WIRE_HOLESOK) != 0,
|
|
("vm_map_wire: !HOLESOK and new/changed entry"));
|
|
continue;
|
|
}
|
|
|
|
if (rv == KERN_SUCCESS) {
|
|
if (user_wire)
|
|
entry->eflags |= MAP_ENTRY_USER_WIRED;
|
|
} else if (entry->wired_count == -1) {
|
|
/*
|
|
* Wiring failed on this entry. Thus, unwiring is
|
|
* unnecessary.
|
|
*/
|
|
entry->wired_count = 0;
|
|
} else if (!user_wire ||
|
|
(entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
|
|
/*
|
|
* Undo the wiring. Wiring succeeded on this entry
|
|
* but failed on a later entry.
|
|
*/
|
|
if (entry->wired_count == 1)
|
|
vm_map_entry_unwire(map, entry);
|
|
else
|
|
entry->wired_count--;
|
|
}
|
|
next_entry_done:
|
|
KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
|
|
("vm_map_wire: in-transition flag missing %p", entry));
|
|
KASSERT(entry->wiring_thread == curthread,
|
|
("vm_map_wire: alien wire %p", entry));
|
|
entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION |
|
|
MAP_ENTRY_WIRE_SKIPPED);
|
|
entry->wiring_thread = NULL;
|
|
if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
|
|
entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
|
|
need_wakeup = TRUE;
|
|
}
|
|
vm_map_simplify_entry(map, entry);
|
|
}
|
|
vm_map_unlock(map);
|
|
if (need_wakeup)
|
|
vm_map_wakeup(map);
|
|
return (rv);
|
|
}
|
|
|
|
/*
|
|
* vm_map_sync
|
|
*
|
|
* 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.
|
|
*
|
|
* If the size of the region from start to end is zero, we are
|
|
* supposed to flush all modified pages within the region containing
|
|
* start. Unfortunately, a region can be split or coalesced with
|
|
* neighboring regions, making it difficult to determine what the
|
|
* original region was. Therefore, we approximate this requirement by
|
|
* flushing the current region containing start.
|
|
*
|
|
* Returns an error if any part of the specified range is not mapped.
|
|
*/
|
|
int
|
|
vm_map_sync(
|
|
vm_map_t map,
|
|
vm_offset_t start,
|
|
vm_offset_t end,
|
|
boolean_t syncio,
|
|
boolean_t invalidate)
|
|
{
|
|
vm_map_entry_t current;
|
|
vm_map_entry_t entry;
|
|
vm_size_t size;
|
|
vm_object_t object;
|
|
vm_ooffset_t offset;
|
|
unsigned int last_timestamp;
|
|
boolean_t failed;
|
|
|
|
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);
|
|
} else if (start == end) {
|
|
start = entry->start;
|
|
end = entry->end;
|
|
}
|
|
/*
|
|
* Make a first pass to check for user-wired memory and holes.
|
|
*/
|
|
for (current = entry; current != &map->header && current->start < end;
|
|
current = current->next) {
|
|
if (invalidate && (current->eflags & MAP_ENTRY_USER_WIRED)) {
|
|
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);
|
|
}
|
|
}
|
|
|
|
if (invalidate)
|
|
pmap_remove(map->pmap, start, end);
|
|
failed = FALSE;
|
|
|
|
/*
|
|
* Make a second pass, cleaning/uncaching pages from the indicated
|
|
* objects as we go.
|
|
*/
|
|
for (current = entry; current != &map->header && current->start < end;) {
|
|
offset = current->offset + (start - current->start);
|
|
size = (end <= current->end ? end : current->end) - start;
|
|
if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
|
|
vm_map_t smap;
|
|
vm_map_entry_t tentry;
|
|
vm_size_t tsize;
|
|
|
|
smap = current->object.sub_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;
|
|
}
|
|
vm_object_reference(object);
|
|
last_timestamp = map->timestamp;
|
|
vm_map_unlock_read(map);
|
|
if (!vm_object_sync(object, offset, size, syncio, invalidate))
|
|
failed = TRUE;
|
|
start += size;
|
|
vm_object_deallocate(object);
|
|
vm_map_lock_read(map);
|
|
if (last_timestamp == map->timestamp ||
|
|
!vm_map_lookup_entry(map, start, ¤t))
|
|
current = current->next;
|
|
}
|
|
|
|
vm_map_unlock_read(map);
|
|
return (failed ? KERN_FAILURE : 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(vm_map_t map, vm_map_entry_t entry)
|
|
{
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
KASSERT(entry->wired_count > 0,
|
|
("vm_map_entry_unwire: entry %p isn't wired", entry));
|
|
pmap_unwire(map->pmap, entry->start, entry->end);
|
|
vm_object_unwire(entry->object.vm_object, entry->offset, entry->end -
|
|
entry->start, PQ_ACTIVE);
|
|
entry->wired_count = 0;
|
|
}
|
|
|
|
static void
|
|
vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map)
|
|
{
|
|
|
|
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
|
|
vm_object_deallocate(entry->object.vm_object);
|
|
uma_zfree(system_map ? kmapentzone : mapentzone, entry);
|
|
}
|
|
|
|
/*
|
|
* vm_map_entry_delete: [ internal use only ]
|
|
*
|
|
* Deallocate the given entry from the target map.
|
|
*/
|
|
static void
|
|
vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
|
|
{
|
|
vm_object_t object;
|
|
vm_pindex_t offidxstart, offidxend, count, size1;
|
|
vm_ooffset_t size;
|
|
|
|
vm_map_entry_unlink(map, entry);
|
|
object = entry->object.vm_object;
|
|
size = entry->end - entry->start;
|
|
map->size -= size;
|
|
|
|
if (entry->cred != NULL) {
|
|
swap_release_by_cred(size, entry->cred);
|
|
crfree(entry->cred);
|
|
}
|
|
|
|
if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0 &&
|
|
(object != NULL)) {
|
|
KASSERT(entry->cred == NULL || object->cred == NULL ||
|
|
(entry->eflags & MAP_ENTRY_NEEDS_COPY),
|
|
("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
|
|
count = OFF_TO_IDX(size);
|
|
offidxstart = OFF_TO_IDX(entry->offset);
|
|
offidxend = offidxstart + count;
|
|
VM_OBJECT_WLOCK(object);
|
|
if (object->ref_count != 1 &&
|
|
((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING ||
|
|
object == kernel_object || object == kmem_object)) {
|
|
vm_object_collapse(object);
|
|
|
|
/*
|
|
* The option OBJPR_NOTMAPPED can be passed here
|
|
* because vm_map_delete() already performed
|
|
* pmap_remove() on the only mapping to this range
|
|
* of pages.
|
|
*/
|
|
vm_object_page_remove(object, offidxstart, offidxend,
|
|
OBJPR_NOTMAPPED);
|
|
if (object->type == OBJT_SWAP)
|
|
swap_pager_freespace(object, offidxstart, count);
|
|
if (offidxend >= object->size &&
|
|
offidxstart < object->size) {
|
|
size1 = object->size;
|
|
object->size = offidxstart;
|
|
if (object->cred != NULL) {
|
|
size1 -= object->size;
|
|
KASSERT(object->charge >= ptoa(size1),
|
|
("vm_map_entry_delete: object->charge < 0"));
|
|
swap_release_by_cred(ptoa(size1), object->cred);
|
|
object->charge -= ptoa(size1);
|
|
}
|
|
}
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
} else
|
|
entry->object.vm_object = NULL;
|
|
if (map->system_map)
|
|
vm_map_entry_deallocate(entry, TRUE);
|
|
else {
|
|
entry->next = curthread->td_map_def_user;
|
|
curthread->td_map_def_user = entry;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vm_map_delete: [ internal use only ]
|
|
*
|
|
* Deallocates the given address range from the target
|
|
* map.
|
|
*/
|
|
int
|
|
vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
|
|
{
|
|
vm_map_entry_t entry;
|
|
vm_map_entry_t first_entry;
|
|
|
|
VM_MAP_ASSERT_LOCKED(map);
|
|
if (start == end)
|
|
return (KERN_SUCCESS);
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
/*
|
|
* Step through all entries in this region
|
|
*/
|
|
while ((entry != &map->header) && (entry->start < end)) {
|
|
vm_map_entry_t next;
|
|
|
|
/*
|
|
* Wait for wiring or unwiring of an entry to complete.
|
|
* Also wait for any system wirings to disappear on
|
|
* user maps.
|
|
*/
|
|
if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
|
|
(vm_map_pmap(map) != kernel_pmap &&
|
|
vm_map_entry_system_wired_count(entry) != 0)) {
|
|
unsigned int last_timestamp;
|
|
vm_offset_t saved_start;
|
|
vm_map_entry_t tmp_entry;
|
|
|
|
saved_start = entry->start;
|
|
entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
|
|
last_timestamp = map->timestamp;
|
|
(void) vm_map_unlock_and_wait(map, 0);
|
|
vm_map_lock(map);
|
|
if (last_timestamp + 1 != map->timestamp) {
|
|
/*
|
|
* Look again for the entry because the map was
|
|
* modified while it was unlocked.
|
|
* Specifically, the entry may have been
|
|
* clipped, merged, or deleted.
|
|
*/
|
|
if (!vm_map_lookup_entry(map, saved_start,
|
|
&tmp_entry))
|
|
entry = tmp_entry->next;
|
|
else {
|
|
entry = tmp_entry;
|
|
vm_map_clip_start(map, entry,
|
|
saved_start);
|
|
}
|
|
}
|
|
continue;
|
|
}
|
|
vm_map_clip_end(map, entry, end);
|
|
|
|
next = entry->next;
|
|
|
|
/*
|
|
* Unwire before removing addresses from the pmap; otherwise,
|
|
* unwiring will put the entries back in the pmap.
|
|
*/
|
|
if (entry->wired_count != 0) {
|
|
vm_map_entry_unwire(map, entry);
|
|
}
|
|
|
|
pmap_remove(map->pmap, entry->start, entry->end);
|
|
|
|
/*
|
|
* Delete the entry 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(vm_map_t map, vm_offset_t start, vm_offset_t end)
|
|
{
|
|
int result;
|
|
|
|
vm_map_lock(map);
|
|
VM_MAP_RANGE_CHECK(map, start, end);
|
|
result = vm_map_delete(map, start, end);
|
|
vm_map_unlock(map);
|
|
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.
|
|
*
|
|
* WARNING! This code does not and should not check whether the
|
|
* contents of the region is accessible. For example a smaller file
|
|
* might be mapped into a larger address space.
|
|
*
|
|
* NOTE! This code is also called by munmap().
|
|
*
|
|
* The map must be locked. A read lock is sufficient.
|
|
*/
|
|
boolean_t
|
|
vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
|
|
vm_prot_t protection)
|
|
{
|
|
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(
|
|
vm_map_t src_map,
|
|
vm_map_t dst_map,
|
|
vm_map_entry_t src_entry,
|
|
vm_map_entry_t dst_entry,
|
|
vm_ooffset_t *fork_charge)
|
|
{
|
|
vm_object_t src_object;
|
|
vm_map_entry_t fake_entry;
|
|
vm_offset_t size;
|
|
struct ucred *cred;
|
|
int charged;
|
|
|
|
VM_MAP_ASSERT_LOCKED(dst_map);
|
|
|
|
if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
|
|
return;
|
|
|
|
if (src_entry->wired_count == 0 ||
|
|
(src_entry->protection & VM_PROT_WRITE) == 0) {
|
|
/*
|
|
* If the source entry is marked needs_copy, it is already
|
|
* write-protected.
|
|
*/
|
|
if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 &&
|
|
(src_entry->protection & VM_PROT_WRITE) != 0) {
|
|
pmap_protect(src_map->pmap,
|
|
src_entry->start,
|
|
src_entry->end,
|
|
src_entry->protection & ~VM_PROT_WRITE);
|
|
}
|
|
|
|
/*
|
|
* Make a copy of the object.
|
|
*/
|
|
size = src_entry->end - src_entry->start;
|
|
if ((src_object = src_entry->object.vm_object) != NULL) {
|
|
VM_OBJECT_WLOCK(src_object);
|
|
charged = ENTRY_CHARGED(src_entry);
|
|
if ((src_object->handle == NULL) &&
|
|
(src_object->type == OBJT_DEFAULT ||
|
|
src_object->type == OBJT_SWAP)) {
|
|
vm_object_collapse(src_object);
|
|
if ((src_object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING) {
|
|
vm_object_split(src_entry);
|
|
src_object = src_entry->object.vm_object;
|
|
}
|
|
}
|
|
vm_object_reference_locked(src_object);
|
|
vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
|
|
if (src_entry->cred != NULL &&
|
|
!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
|
|
KASSERT(src_object->cred == NULL,
|
|
("OVERCOMMIT: vm_map_copy_entry: cred %p",
|
|
src_object));
|
|
src_object->cred = src_entry->cred;
|
|
src_object->charge = size;
|
|
}
|
|
VM_OBJECT_WUNLOCK(src_object);
|
|
dst_entry->object.vm_object = src_object;
|
|
if (charged) {
|
|
cred = curthread->td_ucred;
|
|
crhold(cred);
|
|
dst_entry->cred = cred;
|
|
*fork_charge += size;
|
|
if (!(src_entry->eflags &
|
|
MAP_ENTRY_NEEDS_COPY)) {
|
|
crhold(cred);
|
|
src_entry->cred = cred;
|
|
*fork_charge += size;
|
|
}
|
|
}
|
|
src_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
|
|
dst_entry->eflags |= (MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY);
|
|
dst_entry->offset = src_entry->offset;
|
|
if (src_entry->eflags & MAP_ENTRY_VN_WRITECNT) {
|
|
/*
|
|
* MAP_ENTRY_VN_WRITECNT cannot
|
|
* indicate write reference from
|
|
* src_entry, since the entry is
|
|
* marked as needs copy. Allocate a
|
|
* fake entry that is used to
|
|
* decrement object->un_pager.vnp.writecount
|
|
* at the appropriate time. Attach
|
|
* fake_entry to the deferred list.
|
|
*/
|
|
fake_entry = vm_map_entry_create(dst_map);
|
|
fake_entry->eflags = MAP_ENTRY_VN_WRITECNT;
|
|
src_entry->eflags &= ~MAP_ENTRY_VN_WRITECNT;
|
|
vm_object_reference(src_object);
|
|
fake_entry->object.vm_object = src_object;
|
|
fake_entry->start = src_entry->start;
|
|
fake_entry->end = src_entry->end;
|
|
fake_entry->next = curthread->td_map_def_user;
|
|
curthread->td_map_def_user = fake_entry;
|
|
}
|
|
} else {
|
|
dst_entry->object.vm_object = NULL;
|
|
dst_entry->offset = 0;
|
|
if (src_entry->cred != NULL) {
|
|
dst_entry->cred = curthread->td_ucred;
|
|
crhold(dst_entry->cred);
|
|
*fork_charge += size;
|
|
}
|
|
}
|
|
|
|
pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
|
|
dst_entry->end - dst_entry->start, src_entry->start);
|
|
} else {
|
|
/*
|
|
* We don't want to make writeable wired pages copy-on-write.
|
|
* Immediately copy these pages into the new map by simulating
|
|
* page faults. The new pages are pageable.
|
|
*/
|
|
vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry,
|
|
fork_charge);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* vmspace_map_entry_forked:
|
|
* Update the newly-forked vmspace each time a map entry is inherited
|
|
* or copied. The values for vm_dsize and vm_tsize are approximate
|
|
* (and mostly-obsolete ideas in the face of mmap(2) et al.)
|
|
*/
|
|
static void
|
|
vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2,
|
|
vm_map_entry_t entry)
|
|
{
|
|
vm_size_t entrysize;
|
|
vm_offset_t newend;
|
|
|
|
entrysize = entry->end - entry->start;
|
|
vm2->vm_map.size += entrysize;
|
|
if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) {
|
|
vm2->vm_ssize += btoc(entrysize);
|
|
} else if (entry->start >= (vm_offset_t)vm1->vm_daddr &&
|
|
entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) {
|
|
newend = MIN(entry->end,
|
|
(vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize));
|
|
vm2->vm_dsize += btoc(newend - entry->start);
|
|
} else if (entry->start >= (vm_offset_t)vm1->vm_taddr &&
|
|
entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) {
|
|
newend = MIN(entry->end,
|
|
(vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize));
|
|
vm2->vm_tsize += btoc(newend - entry->start);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*
|
|
* XXX It might be worth coalescing the entries added to the new vmspace.
|
|
*
|
|
* The source map must not be locked.
|
|
*/
|
|
struct vmspace *
|
|
vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
|
|
{
|
|
struct vmspace *vm2;
|
|
vm_map_t new_map, old_map;
|
|
vm_map_entry_t new_entry, old_entry;
|
|
vm_object_t object;
|
|
int locked;
|
|
|
|
old_map = &vm1->vm_map;
|
|
/* Copy immutable fields of vm1 to vm2. */
|
|
vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset, NULL);
|
|
if (vm2 == NULL)
|
|
return (NULL);
|
|
vm2->vm_taddr = vm1->vm_taddr;
|
|
vm2->vm_daddr = vm1->vm_daddr;
|
|
vm2->vm_maxsaddr = vm1->vm_maxsaddr;
|
|
vm_map_lock(old_map);
|
|
if (old_map->busy)
|
|
vm_map_wait_busy(old_map);
|
|
new_map = &vm2->vm_map;
|
|
locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
|
|
KASSERT(locked, ("vmspace_fork: lock failed"));
|
|
|
|
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,
|
|
atop(old_entry->end - old_entry->start));
|
|
old_entry->object.vm_object = object;
|
|
old_entry->offset = 0;
|
|
if (old_entry->cred != NULL) {
|
|
object->cred = old_entry->cred;
|
|
object->charge = old_entry->end -
|
|
old_entry->start;
|
|
old_entry->cred = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Add the reference before calling vm_object_shadow
|
|
* to insure that a shadow object is created.
|
|
*/
|
|
vm_object_reference(object);
|
|
if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
|
|
vm_object_shadow(&old_entry->object.vm_object,
|
|
&old_entry->offset,
|
|
old_entry->end - old_entry->start);
|
|
old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
|
|
/* Transfer the second reference too. */
|
|
vm_object_reference(
|
|
old_entry->object.vm_object);
|
|
|
|
/*
|
|
* As in vm_map_simplify_entry(), the
|
|
* vnode lock will not be acquired in
|
|
* this call to vm_object_deallocate().
|
|
*/
|
|
vm_object_deallocate(object);
|
|
object = old_entry->object.vm_object;
|
|
}
|
|
VM_OBJECT_WLOCK(object);
|
|
vm_object_clear_flag(object, OBJ_ONEMAPPING);
|
|
if (old_entry->cred != NULL) {
|
|
KASSERT(object->cred == NULL, ("vmspace_fork both cred"));
|
|
object->cred = old_entry->cred;
|
|
object->charge = old_entry->end - old_entry->start;
|
|
old_entry->cred = NULL;
|
|
}
|
|
|
|
/*
|
|
* Assert the correct state of the vnode
|
|
* v_writecount while the object is locked, to
|
|
* not relock it later for the assertion
|
|
* correctness.
|
|
*/
|
|
if (old_entry->eflags & MAP_ENTRY_VN_WRITECNT &&
|
|
object->type == OBJT_VNODE) {
|
|
KASSERT(((struct vnode *)object->handle)->
|
|
v_writecount > 0,
|
|
("vmspace_fork: v_writecount %p", object));
|
|
KASSERT(object->un_pager.vnp.writemappings > 0,
|
|
("vmspace_fork: vnp.writecount %p",
|
|
object));
|
|
}
|
|
VM_OBJECT_WUNLOCK(object);
|
|
|
|
/*
|
|
* Clone the entry, referencing the shared object.
|
|
*/
|
|
new_entry = vm_map_entry_create(new_map);
|
|
*new_entry = *old_entry;
|
|
new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
|
|
MAP_ENTRY_IN_TRANSITION);
|
|
new_entry->wiring_thread = NULL;
|
|
new_entry->wired_count = 0;
|
|
if (new_entry->eflags & MAP_ENTRY_VN_WRITECNT) {
|
|
vnode_pager_update_writecount(object,
|
|
new_entry->start, new_entry->end);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
vmspace_map_entry_forked(vm1, vm2, 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;
|
|
/*
|
|
* Copied entry is COW over the old object.
|
|
*/
|
|
new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
|
|
MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_VN_WRITECNT);
|
|
new_entry->wiring_thread = NULL;
|
|
new_entry->wired_count = 0;
|
|
new_entry->object.vm_object = NULL;
|
|
new_entry->cred = NULL;
|
|
vm_map_entry_link(new_map, new_map->header.prev,
|
|
new_entry);
|
|
vmspace_map_entry_forked(vm1, vm2, new_entry);
|
|
vm_map_copy_entry(old_map, new_map, old_entry,
|
|
new_entry, fork_charge);
|
|
break;
|
|
}
|
|
old_entry = old_entry->next;
|
|
}
|
|
/*
|
|
* Use inlined vm_map_unlock() to postpone handling the deferred
|
|
* map entries, which cannot be done until both old_map and
|
|
* new_map locks are released.
|
|
*/
|
|
sx_xunlock(&old_map->lock);
|
|
sx_xunlock(&new_map->lock);
|
|
vm_map_process_deferred();
|
|
|
|
return (vm2);
|
|
}
|
|
|
|
int
|
|
vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
|
|
vm_prot_t prot, vm_prot_t max, int cow)
|
|
{
|
|
vm_size_t growsize, init_ssize;
|
|
rlim_t lmemlim, vmemlim;
|
|
int rv;
|
|
|
|
growsize = sgrowsiz;
|
|
init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
|
|
vm_map_lock(map);
|
|
PROC_LOCK(curproc);
|
|
lmemlim = lim_cur(curproc, RLIMIT_MEMLOCK);
|
|
vmemlim = lim_cur(curproc, RLIMIT_VMEM);
|
|
PROC_UNLOCK(curproc);
|
|
if (!old_mlock && map->flags & MAP_WIREFUTURE) {
|
|
if (ptoa(pmap_wired_count(map->pmap)) + init_ssize > lmemlim) {
|
|
rv = KERN_NO_SPACE;
|
|
goto out;
|
|
}
|
|
}
|
|
/* If we would blow our VMEM resource limit, no go */
|
|
if (map->size + init_ssize > vmemlim) {
|
|
rv = KERN_NO_SPACE;
|
|
goto out;
|
|
}
|
|
rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot,
|
|
max, cow);
|
|
out:
|
|
vm_map_unlock(map);
|
|
return (rv);
|
|
}
|
|
|
|
static int
|
|
vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
|
|
vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow)
|
|
{
|
|
vm_map_entry_t new_entry, prev_entry;
|
|
vm_offset_t bot, top;
|
|
vm_size_t init_ssize;
|
|
int orient, rv;
|
|
|
|
/*
|
|
* The stack orientation is piggybacked with the cow argument.
|
|
* Extract it into orient and mask the cow argument so that we
|
|
* don't pass it around further.
|
|
* NOTE: We explicitly allow bi-directional stacks.
|
|
*/
|
|
orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP);
|
|
KASSERT(orient != 0, ("No stack grow direction"));
|
|
|
|
if (addrbos < vm_map_min(map) ||
|
|
addrbos > vm_map_max(map) ||
|
|
addrbos + max_ssize < addrbos)
|
|
return (KERN_NO_SPACE);
|
|
|
|
init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
|
|
|
|
/* If addr is already mapped, no go */
|
|
if (vm_map_lookup_entry(map, addrbos, &prev_entry))
|
|
return (KERN_NO_SPACE);
|
|
|
|
/*
|
|
* If we can't accomodate max_ssize in the current mapping, no go.
|
|
* However, we need to be aware that subsequent user mappings might
|
|
* map into the space we have reserved for stack, and currently this
|
|
* space is not protected.
|
|
*
|
|
* Hopefully we will at least detect this condition when we try to
|
|
* grow the stack.
|
|
*/
|
|
if ((prev_entry->next != &map->header) &&
|
|
(prev_entry->next->start < addrbos + max_ssize))
|
|
return (KERN_NO_SPACE);
|
|
|
|
/*
|
|
* We initially map a stack of only init_ssize. We will grow as
|
|
* needed later. Depending on the orientation of the stack (i.e.
|
|
* the grow direction) we either map at the top of the range, the
|
|
* bottom of the range or in the middle.
|
|
*
|
|
* Note: we would normally expect prot and max to be VM_PROT_ALL,
|
|
* and cow to be 0. Possibly we should eliminate these as input
|
|
* parameters, and just pass these values here in the insert call.
|
|
*/
|
|
if (orient == MAP_STACK_GROWS_DOWN)
|
|
bot = addrbos + max_ssize - init_ssize;
|
|
else if (orient == MAP_STACK_GROWS_UP)
|
|
bot = addrbos;
|
|
else
|
|
bot = round_page(addrbos + max_ssize/2 - init_ssize/2);
|
|
top = bot + init_ssize;
|
|
rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow);
|
|
|
|
/* Now set the avail_ssize amount. */
|
|
if (rv == KERN_SUCCESS) {
|
|
new_entry = prev_entry->next;
|
|
if (new_entry->end != top || new_entry->start != bot)
|
|
panic("Bad entry start/end for new stack entry");
|
|
|
|
new_entry->avail_ssize = max_ssize - init_ssize;
|
|
KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
|
|
(new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
|
|
("new entry lacks MAP_ENTRY_GROWS_DOWN"));
|
|
KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
|
|
(new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
|
|
("new entry lacks MAP_ENTRY_GROWS_UP"));
|
|
}
|
|
|
|
return (rv);
|
|
}
|
|
|
|
static int stack_guard_page = 0;
|
|
SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN,
|
|
&stack_guard_page, 0,
|
|
"Insert stack guard page ahead of the growable segments.");
|
|
|
|
/* Attempts to grow a vm stack entry. Returns KERN_SUCCESS if the
|
|
* desired address is already mapped, or if we successfully grow
|
|
* the stack. Also returns KERN_SUCCESS if addr is outside the
|
|
* stack range (this is strange, but preserves compatibility with
|
|
* the grow function in vm_machdep.c).
|
|
*/
|
|
int
|
|
vm_map_growstack(struct proc *p, vm_offset_t addr)
|
|
{
|
|
vm_map_entry_t next_entry, prev_entry;
|
|
vm_map_entry_t new_entry, stack_entry;
|
|
struct vmspace *vm = p->p_vmspace;
|
|
vm_map_t map = &vm->vm_map;
|
|
vm_offset_t end;
|
|
vm_size_t growsize;
|
|
size_t grow_amount, max_grow;
|
|
rlim_t lmemlim, stacklim, vmemlim;
|
|
int is_procstack, rv;
|
|
struct ucred *cred;
|
|
#ifdef notyet
|
|
uint64_t limit;
|
|
#endif
|
|
#ifdef RACCT
|
|
int error;
|
|
#endif
|
|
|
|
Retry:
|
|
PROC_LOCK(p);
|
|
lmemlim = lim_cur(p, RLIMIT_MEMLOCK);
|
|
stacklim = lim_cur(p, RLIMIT_STACK);
|
|
vmemlim = lim_cur(p, RLIMIT_VMEM);
|
|
PROC_UNLOCK(p);
|
|
|
|
vm_map_lock_read(map);
|
|
|
|
/* If addr is already in the entry range, no need to grow.*/
|
|
if (vm_map_lookup_entry(map, addr, &prev_entry)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
next_entry = prev_entry->next;
|
|
if (!(prev_entry->eflags & MAP_ENTRY_GROWS_UP)) {
|
|
/*
|
|
* This entry does not grow upwards. Since the address lies
|
|
* beyond this entry, the next entry (if one exists) has to
|
|
* be a downward growable entry. The entry list header is
|
|
* never a growable entry, so it suffices to check the flags.
|
|
*/
|
|
if (!(next_entry->eflags & MAP_ENTRY_GROWS_DOWN)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_SUCCESS);
|
|
}
|
|
stack_entry = next_entry;
|
|
} else {
|
|
/*
|
|
* This entry grows upward. If the next entry does not at
|
|
* least grow downwards, this is the entry we need to grow.
|
|
* otherwise we have two possible choices and we have to
|
|
* select one.
|
|
*/
|
|
if (next_entry->eflags & MAP_ENTRY_GROWS_DOWN) {
|
|
/*
|
|
* We have two choices; grow the entry closest to
|
|
* the address to minimize the amount of growth.
|
|
*/
|
|
if (addr - prev_entry->end <= next_entry->start - addr)
|
|
stack_entry = prev_entry;
|
|
else
|
|
stack_entry = next_entry;
|
|
} else
|
|
stack_entry = prev_entry;
|
|
}
|
|
|
|
if (stack_entry == next_entry) {
|
|
KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_DOWN, ("foo"));
|
|
KASSERT(addr < stack_entry->start, ("foo"));
|
|
end = (prev_entry != &map->header) ? prev_entry->end :
|
|
stack_entry->start - stack_entry->avail_ssize;
|
|
grow_amount = roundup(stack_entry->start - addr, PAGE_SIZE);
|
|
max_grow = stack_entry->start - end;
|
|
} else {
|
|
KASSERT(stack_entry->eflags & MAP_ENTRY_GROWS_UP, ("foo"));
|
|
KASSERT(addr >= stack_entry->end, ("foo"));
|
|
end = (next_entry != &map->header) ? next_entry->start :
|
|
stack_entry->end + stack_entry->avail_ssize;
|
|
grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE);
|
|
max_grow = end - stack_entry->end;
|
|
}
|
|
|
|
if (grow_amount > stack_entry->avail_ssize) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_NO_SPACE);
|
|
}
|
|
|
|
/*
|
|
* If there is no longer enough space between the entries nogo, and
|
|
* adjust the available space. Note: this should only happen if the
|
|
* user has mapped into the stack area after the stack was created,
|
|
* and is probably an error.
|
|
*
|
|
* This also effectively destroys any guard page the user might have
|
|
* intended by limiting the stack size.
|
|
*/
|
|
if (grow_amount + (stack_guard_page ? PAGE_SIZE : 0) > max_grow) {
|
|
if (vm_map_lock_upgrade(map))
|
|
goto Retry;
|
|
|
|
stack_entry->avail_ssize = max_grow;
|
|
|
|
vm_map_unlock(map);
|
|
return (KERN_NO_SPACE);
|
|
}
|
|
|
|
is_procstack = (addr >= (vm_offset_t)vm->vm_maxsaddr) ? 1 : 0;
|
|
|
|
/*
|
|
* If this is the main process stack, see if we're over the stack
|
|
* limit.
|
|
*/
|
|
if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_NO_SPACE);
|
|
}
|
|
#ifdef RACCT
|
|
PROC_LOCK(p);
|
|
if (is_procstack &&
|
|
racct_set(p, RACCT_STACK, ctob(vm->vm_ssize) + grow_amount)) {
|
|
PROC_UNLOCK(p);
|
|
vm_map_unlock_read(map);
|
|
return (KERN_NO_SPACE);
|
|
}
|
|
PROC_UNLOCK(p);
|
|
#endif
|
|
|
|
/* Round up the grow amount modulo sgrowsiz */
|
|
growsize = sgrowsiz;
|
|
grow_amount = roundup(grow_amount, growsize);
|
|
if (grow_amount > stack_entry->avail_ssize)
|
|
grow_amount = stack_entry->avail_ssize;
|
|
if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
|
|
grow_amount = trunc_page((vm_size_t)stacklim) -
|
|
ctob(vm->vm_ssize);
|
|
}
|
|
#ifdef notyet
|
|
PROC_LOCK(p);
|
|
limit = racct_get_available(p, RACCT_STACK);
|
|
PROC_UNLOCK(p);
|
|
if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit))
|
|
grow_amount = limit - ctob(vm->vm_ssize);
|
|
#endif
|
|
if (!old_mlock && map->flags & MAP_WIREFUTURE) {
|
|
if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) {
|
|
vm_map_unlock_read(map);
|
|
rv = KERN_NO_SPACE;
|
|
goto out;
|
|
}
|
|
#ifdef RACCT
|
|
PROC_LOCK(p);
|
|
if (racct_set(p, RACCT_MEMLOCK,
|
|
ptoa(pmap_wired_count(map->pmap)) + grow_amount)) {
|
|
PROC_UNLOCK(p);
|
|
vm_map_unlock_read(map);
|
|
rv = KERN_NO_SPACE;
|
|
goto out;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
#endif
|
|
}
|
|
/* If we would blow our VMEM resource limit, no go */
|
|
if (map->size + grow_amount > vmemlim) {
|
|
vm_map_unlock_read(map);
|
|
rv = KERN_NO_SPACE;
|
|
goto out;
|
|
}
|
|
#ifdef RACCT
|
|
PROC_LOCK(p);
|
|
if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) {
|
|
PROC_UNLOCK(p);
|
|
vm_map_unlock_read(map);
|
|
rv = KERN_NO_SPACE;
|
|
goto out;
|
|
}
|
|
PROC_UNLOCK(p);
|
|
#endif
|
|
|
|
if (vm_map_lock_upgrade(map))
|
|
goto Retry;
|
|
|
|
if (stack_entry == next_entry) {
|
|
/*
|
|
* Growing downward.
|
|
*/
|
|
/* Get the preliminary new entry start value */
|
|
addr = stack_entry->start - grow_amount;
|
|
|
|
/*
|
|
* If this puts us into the previous entry, cut back our
|
|
* growth to the available space. Also, see the note above.
|
|
*/
|
|
if (addr < end) {
|
|
stack_entry->avail_ssize = max_grow;
|
|
addr = end;
|
|
if (stack_guard_page)
|
|
addr += PAGE_SIZE;
|
|
}
|
|
|
|
rv = vm_map_insert(map, NULL, 0, addr, stack_entry->start,
|
|
next_entry->protection, next_entry->max_protection,
|
|
MAP_STACK_GROWS_DOWN);
|
|
|
|
/* Adjust the available stack space by the amount we grew. */
|
|
if (rv == KERN_SUCCESS) {
|
|
new_entry = prev_entry->next;
|
|
KASSERT(new_entry == stack_entry->prev, ("foo"));
|
|
KASSERT(new_entry->end == stack_entry->start, ("foo"));
|
|
KASSERT(new_entry->start == addr, ("foo"));
|
|
KASSERT((new_entry->eflags & MAP_ENTRY_GROWS_DOWN) !=
|
|
0, ("new entry lacks MAP_ENTRY_GROWS_DOWN"));
|
|
grow_amount = new_entry->end - new_entry->start;
|
|
new_entry->avail_ssize = stack_entry->avail_ssize -
|
|
grow_amount;
|
|
stack_entry->eflags &= ~MAP_ENTRY_GROWS_DOWN;
|
|
}
|
|
} else {
|
|
/*
|
|
* Growing upward.
|
|
*/
|
|
addr = stack_entry->end + grow_amount;
|
|
|
|
/*
|
|
* If this puts us into the next entry, cut back our growth
|
|
* to the available space. Also, see the note above.
|
|
*/
|
|
if (addr > end) {
|
|
stack_entry->avail_ssize = end - stack_entry->end;
|
|
addr = end;
|
|
if (stack_guard_page)
|
|
addr -= PAGE_SIZE;
|
|
}
|
|
|
|
grow_amount = addr - stack_entry->end;
|
|
cred = stack_entry->cred;
|
|
if (cred == NULL && stack_entry->object.vm_object != NULL)
|
|
cred = stack_entry->object.vm_object->cred;
|
|
if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred))
|
|
rv = KERN_NO_SPACE;
|
|
/* Grow the underlying object if applicable. */
|
|
else if (stack_entry->object.vm_object == NULL ||
|
|
vm_object_coalesce(stack_entry->object.vm_object,
|
|
stack_entry->offset,
|
|
(vm_size_t)(stack_entry->end - stack_entry->start),
|
|
(vm_size_t)grow_amount, cred != NULL)) {
|
|
map->size += (addr - stack_entry->end);
|
|
/* Update the current entry. */
|
|
stack_entry->end = addr;
|
|
stack_entry->avail_ssize -= grow_amount;
|
|
vm_map_entry_resize_free(map, stack_entry);
|
|
rv = KERN_SUCCESS;
|
|
} else
|
|
rv = KERN_FAILURE;
|
|
}
|
|
|
|
if (rv == KERN_SUCCESS && is_procstack)
|
|
vm->vm_ssize += btoc(grow_amount);
|
|
|
|
vm_map_unlock(map);
|
|
|
|
/*
|
|
* Heed the MAP_WIREFUTURE flag if it was set for this process.
|
|
*/
|
|
if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE)) {
|
|
vm_map_wire(map,
|
|
(stack_entry == next_entry) ? addr : addr - grow_amount,
|
|
(stack_entry == next_entry) ? stack_entry->start : addr,
|
|
(p->p_flag & P_SYSTEM)
|
|
? VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES
|
|
: VM_MAP_WIRE_USER|VM_MAP_WIRE_NOHOLES);
|
|
}
|
|
|
|
out:
|
|
#ifdef RACCT
|
|
if (rv != KERN_SUCCESS) {
|
|
PROC_LOCK(p);
|
|
error = racct_set(p, RACCT_VMEM, map->size);
|
|
KASSERT(error == 0, ("decreasing RACCT_VMEM failed"));
|
|
if (!old_mlock) {
|
|
error = racct_set(p, RACCT_MEMLOCK,
|
|
ptoa(pmap_wired_count(map->pmap)));
|
|
KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed"));
|
|
}
|
|
error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize));
|
|
KASSERT(error == 0, ("decreasing RACCT_STACK failed"));
|
|
PROC_UNLOCK(p);
|
|
}
|
|
#endif
|
|
|
|
return (rv);
|
|
}
|
|
|
|
/*
|
|
* Unshare the specified VM space for exec. If other processes are
|
|
* mapped to it, then create a new one. The new vmspace is null.
|
|
*/
|
|
int
|
|
vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser)
|
|
{
|
|
struct vmspace *oldvmspace = p->p_vmspace;
|
|
struct vmspace *newvmspace;
|
|
|
|
KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0,
|
|
("vmspace_exec recursed"));
|
|
newvmspace = vmspace_alloc(minuser, maxuser, NULL);
|
|
if (newvmspace == NULL)
|
|
return (ENOMEM);
|
|
newvmspace->vm_swrss = oldvmspace->vm_swrss;
|
|
/*
|
|
* This code is written like this for prototype purposes. The
|
|
* goal is to avoid running down the vmspace here, but let the
|
|
* other process's that are still using the vmspace to finally
|
|
* run it down. Even though there is little or no chance of blocking
|
|
* here, it is a good idea to keep this form for future mods.
|
|
*/
|
|
PROC_VMSPACE_LOCK(p);
|
|
p->p_vmspace = newvmspace;
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
if (p == curthread->td_proc)
|
|
pmap_activate(curthread);
|
|
curthread->td_pflags |= TDP_EXECVMSPC;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Unshare the specified VM space for forcing COW. This
|
|
* is called by rfork, for the (RFMEM|RFPROC) == 0 case.
|
|
*/
|
|
int
|
|
vmspace_unshare(struct proc *p)
|
|
{
|
|
struct vmspace *oldvmspace = p->p_vmspace;
|
|
struct vmspace *newvmspace;
|
|
vm_ooffset_t fork_charge;
|
|
|
|
if (oldvmspace->vm_refcnt == 1)
|
|
return (0);
|
|
fork_charge = 0;
|
|
newvmspace = vmspace_fork(oldvmspace, &fork_charge);
|
|
if (newvmspace == NULL)
|
|
return (ENOMEM);
|
|
if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) {
|
|
vmspace_free(newvmspace);
|
|
return (ENOMEM);
|
|
}
|
|
PROC_VMSPACE_LOCK(p);
|
|
p->p_vmspace = newvmspace;
|
|
PROC_VMSPACE_UNLOCK(p);
|
|
if (p == curthread->td_proc)
|
|
pmap_activate(curthread);
|
|
vmspace_free(oldvmspace);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* 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(vm_map_t *var_map, /* IN/OUT */
|
|
vm_offset_t vaddr,
|
|
vm_prot_t fault_typea,
|
|
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 */
|
|
{
|
|
vm_map_entry_t entry;
|
|
vm_map_t map = *var_map;
|
|
vm_prot_t prot;
|
|
vm_prot_t fault_type = fault_typea;
|
|
vm_object_t eobject;
|
|
vm_size_t size;
|
|
struct ucred *cred;
|
|
|
|
RetryLookup:;
|
|
|
|
vm_map_lock_read(map);
|
|
|
|
/*
|
|
* Lookup the faulting address.
|
|
*/
|
|
if (!vm_map_lookup_entry(map, vaddr, out_entry)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_INVALID_ADDRESS);
|
|
}
|
|
|
|
entry = *out_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;
|
|
fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
|
|
if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_PROTECTION_FAILURE);
|
|
}
|
|
if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
|
|
(entry->eflags & MAP_ENTRY_COW) &&
|
|
(fault_type & VM_PROT_WRITE)) {
|
|
vm_map_unlock_read(map);
|
|
return (KERN_PROTECTION_FAILURE);
|
|
}
|
|
if ((fault_typea & VM_PROT_COPY) != 0 &&
|
|
(entry->max_protection & VM_PROT_WRITE) == 0 &&
|
|
(entry->eflags & MAP_ENTRY_COW) == 0) {
|
|
vm_map_unlock_read(map);
|
|
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)
|
|
fault_type = entry->protection;
|
|
size = entry->end - entry->start;
|
|
/*
|
|
* 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 map locked.
|
|
*
|
|
* If we don't need to write the page, we just demote the
|
|
* permissions allowed.
|
|
*/
|
|
if ((fault_type & VM_PROT_WRITE) != 0 ||
|
|
(fault_typea & VM_PROT_COPY) != 0) {
|
|
/*
|
|
* Make a new object, and place it in the object
|
|
* chain. Note that no new references have appeared
|
|
* -- one just moved from the map to the new
|
|
* object.
|
|
*/
|
|
if (vm_map_lock_upgrade(map))
|
|
goto RetryLookup;
|
|
|
|
if (entry->cred == NULL) {
|
|
/*
|
|
* The debugger owner is charged for
|
|
* the memory.
|
|
*/
|
|
cred = curthread->td_ucred;
|
|
crhold(cred);
|
|
if (!swap_reserve_by_cred(size, cred)) {
|
|
crfree(cred);
|
|
vm_map_unlock(map);
|
|
return (KERN_RESOURCE_SHORTAGE);
|
|
}
|
|
entry->cred = cred;
|
|
}
|
|
vm_object_shadow(&entry->object.vm_object,
|
|
&entry->offset, size);
|
|
entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
|
|
eobject = entry->object.vm_object;
|
|
if (eobject->cred != NULL) {
|
|
/*
|
|
* The object was not shadowed.
|
|
*/
|
|
swap_release_by_cred(size, entry->cred);
|
|
crfree(entry->cred);
|
|
entry->cred = NULL;
|
|
} else if (entry->cred != NULL) {
|
|
VM_OBJECT_WLOCK(eobject);
|
|
eobject->cred = entry->cred;
|
|
eobject->charge = size;
|
|
VM_OBJECT_WUNLOCK(eobject);
|
|
entry->cred = NULL;
|
|
}
|
|
|
|
vm_map_lock_downgrade(map);
|
|
} 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 &&
|
|
!map->system_map) {
|
|
if (vm_map_lock_upgrade(map))
|
|
goto RetryLookup;
|
|
entry->object.vm_object = vm_object_allocate(OBJT_DEFAULT,
|
|
atop(size));
|
|
entry->offset = 0;
|
|
if (entry->cred != NULL) {
|
|
VM_OBJECT_WLOCK(entry->object.vm_object);
|
|
entry->object.vm_object->cred = entry->cred;
|
|
entry->object.vm_object->charge = size;
|
|
VM_OBJECT_WUNLOCK(entry->object.vm_object);
|
|
entry->cred = NULL;
|
|
}
|
|
vm_map_lock_downgrade(map);
|
|
}
|
|
|
|
/*
|
|
* 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((vaddr - entry->start) + entry->offset);
|
|
*object = entry->object.vm_object;
|
|
|
|
*out_prot = prot;
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* vm_map_lookup_locked:
|
|
*
|
|
* Lookup the faulting address. A version of vm_map_lookup that returns
|
|
* KERN_FAILURE instead of blocking on map lock or memory allocation.
|
|
*/
|
|
int
|
|
vm_map_lookup_locked(vm_map_t *var_map, /* IN/OUT */
|
|
vm_offset_t vaddr,
|
|
vm_prot_t fault_typea,
|
|
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 */
|
|
{
|
|
vm_map_entry_t entry;
|
|
vm_map_t map = *var_map;
|
|
vm_prot_t prot;
|
|
vm_prot_t fault_type = fault_typea;
|
|
|
|
/*
|
|
* Lookup the faulting address.
|
|
*/
|
|
if (!vm_map_lookup_entry(map, vaddr, out_entry))
|
|
return (KERN_INVALID_ADDRESS);
|
|
|
|
entry = *out_entry;
|
|
|
|
/*
|
|
* Fail if the entry refers to a submap.
|
|
*/
|
|
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
|
|
return (KERN_FAILURE);
|
|
|
|
/*
|
|
* Check whether this task is allowed to have this page.
|
|
*/
|
|
prot = entry->protection;
|
|
fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
|
|
if ((fault_type & prot) != fault_type)
|
|
return (KERN_PROTECTION_FAILURE);
|
|
if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
|
|
(entry->eflags & MAP_ENTRY_COW) &&
|
|
(fault_type & VM_PROT_WRITE))
|
|
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)
|
|
fault_type = entry->protection;
|
|
|
|
if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
|
|
/*
|
|
* Fail if the entry was copy-on-write for a write fault.
|
|
*/
|
|
if (fault_type & VM_PROT_WRITE)
|
|
return (KERN_FAILURE);
|
|
/*
|
|
* We're attempting to read a copy-on-write page --
|
|
* don't allow writes.
|
|
*/
|
|
prot &= ~VM_PROT_WRITE;
|
|
}
|
|
|
|
/*
|
|
* Fail if an object should be created.
|
|
*/
|
|
if (entry->object.vm_object == NULL && !map->system_map)
|
|
return (KERN_FAILURE);
|
|
|
|
/*
|
|
* 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((vaddr - entry->start) + entry->offset);
|
|
*object = entry->object.vm_object;
|
|
|
|
*out_prot = prot;
|
|
return (KERN_SUCCESS);
|
|
}
|
|
|
|
/*
|
|
* 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(vm_map_t map, vm_map_entry_t entry)
|
|
{
|
|
/*
|
|
* Unlock the main-level map
|
|
*/
|
|
vm_map_unlock_read(map);
|
|
}
|
|
|
|
#include "opt_ddb.h"
|
|
#ifdef DDB
|
|
#include <sys/kernel.h>
|
|
|
|
#include <ddb/ddb.h>
|
|
|
|
static void
|
|
vm_map_print(vm_map_t map)
|
|
{
|
|
vm_map_entry_t entry;
|
|
|
|
db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
|
|
(void *)map,
|
|
(void *)map->pmap, map->nentries, map->timestamp);
|
|
|
|
db_indent += 2;
|
|
for (entry = map->header.next; entry != &map->header;
|
|
entry = entry->next) {
|
|
db_iprintf("map entry %p: start=%p, end=%p\n",
|
|
(void *)entry, (void *)entry->start, (void *)entry->end);
|
|
{
|
|
static char *inheritance_name[4] =
|
|
{"share", "copy", "none", "donate_copy"};
|
|
|
|
db_iprintf(" prot=%x/%x/%s",
|
|
entry->protection,
|
|
entry->max_protection,
|
|
inheritance_name[(int)(unsigned char)entry->inheritance]);
|
|
if (entry->wired_count != 0)
|
|
db_printf(", wired");
|
|
}
|
|
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
|
|
db_printf(", share=%p, offset=0x%jx\n",
|
|
(void *)entry->object.sub_map,
|
|
(uintmax_t)entry->offset);
|
|
if ((entry->prev == &map->header) ||
|
|
(entry->prev->object.sub_map !=
|
|
entry->object.sub_map)) {
|
|
db_indent += 2;
|
|
vm_map_print((vm_map_t)entry->object.sub_map);
|
|
db_indent -= 2;
|
|
}
|
|
} else {
|
|
if (entry->cred != NULL)
|
|
db_printf(", ruid %d", entry->cred->cr_ruid);
|
|
db_printf(", object=%p, offset=0x%jx",
|
|
(void *)entry->object.vm_object,
|
|
(uintmax_t)entry->offset);
|
|
if (entry->object.vm_object && entry->object.vm_object->cred)
|
|
db_printf(", obj ruid %d charge %jx",
|
|
entry->object.vm_object->cred->cr_ruid,
|
|
(uintmax_t)entry->object.vm_object->charge);
|
|
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->object.vm_object !=
|
|
entry->object.vm_object)) {
|
|
db_indent += 2;
|
|
vm_object_print((db_expr_t)(intptr_t)
|
|
entry->object.vm_object,
|
|
0, 0, (char *)0);
|
|
db_indent -= 2;
|
|
}
|
|
}
|
|
}
|
|
db_indent -= 2;
|
|
}
|
|
|
|
DB_SHOW_COMMAND(map, map)
|
|
{
|
|
|
|
if (!have_addr) {
|
|
db_printf("usage: show map <addr>\n");
|
|
return;
|
|
}
|
|
vm_map_print((vm_map_t)addr);
|
|
}
|
|
|
|
DB_SHOW_COMMAND(procvm, procvm)
|
|
{
|
|
struct proc *p;
|
|
|
|
if (have_addr) {
|
|
p = (struct proc *) addr;
|
|
} else {
|
|
p = curproc;
|
|
}
|
|
|
|
db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
|
|
(void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
|
|
(void *)vmspace_pmap(p->p_vmspace));
|
|
|
|
vm_map_print((vm_map_t)&p->p_vmspace->vm_map);
|
|
}
|
|
|
|
#endif /* DDB */
|