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freebsd-skq/sys/vm/vm_map.h
kib dacbfe950a Close a race due to dropping of the map lock between creating map entry 
for a shared mapping and marking the entry for inheritance.
Other thread might execute vmspace_fork() in between (e.g. by fork(2)),
resulting in the mapping becoming private.

Noted and reviewed by:	alc
MFC after:	1 week
2012-02-11 17:29:07 +00:00

388 lines
14 KiB
C
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/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vm_map.h 8.9 (Berkeley) 5/17/95
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $FreeBSD$
*/
/*
* Virtual memory map module definitions.
*/
#ifndef _VM_MAP_
#define _VM_MAP_
#include <sys/lock.h>
#include <sys/sx.h>
#include <sys/_mutex.h>
/*
* Types defined:
*
* vm_map_t the high-level address map data structure.
* vm_map_entry_t an entry in an address map.
*/
typedef u_char vm_flags_t;
typedef u_int vm_eflags_t;
/*
* Objects which live in maps may be either VM objects, or
* another map (called a "sharing map") which denotes read-write
* sharing with other maps.
*/
union vm_map_object {
struct vm_object *vm_object; /* object object */
struct vm_map *sub_map; /* belongs to another map */
};
/*
* Address map entries consist of start and end addresses,
* a VM object (or sharing map) and offset into that object,
* and user-exported inheritance and protection information.
* Also included is control information for virtual copy operations.
*/
struct vm_map_entry {
struct vm_map_entry *prev; /* previous entry */
struct vm_map_entry *next; /* next entry */
struct vm_map_entry *left; /* left child in binary search tree */
struct vm_map_entry *right; /* right child in binary search tree */
vm_offset_t start; /* start address */
vm_offset_t end; /* end address */
vm_offset_t avail_ssize; /* amt can grow if this is a stack */
vm_size_t adj_free; /* amount of adjacent free space */
vm_size_t max_free; /* max free space in subtree */
union vm_map_object object; /* object I point to */
vm_ooffset_t offset; /* offset into object */
vm_eflags_t eflags; /* map entry flags */
vm_prot_t protection; /* protection code */
vm_prot_t max_protection; /* maximum protection */
vm_inherit_t inheritance; /* inheritance */
int wired_count; /* can be paged if = 0 */
vm_pindex_t lastr; /* last read */
struct ucred *cred; /* tmp storage for creator ref */
};
#define MAP_ENTRY_NOSYNC 0x0001
#define MAP_ENTRY_IS_SUB_MAP 0x0002
#define MAP_ENTRY_COW 0x0004
#define MAP_ENTRY_NEEDS_COPY 0x0008
#define MAP_ENTRY_NOFAULT 0x0010
#define MAP_ENTRY_USER_WIRED 0x0020
#define MAP_ENTRY_BEHAV_NORMAL 0x0000 /* default behavior */
#define MAP_ENTRY_BEHAV_SEQUENTIAL 0x0040 /* expect sequential access */
#define MAP_ENTRY_BEHAV_RANDOM 0x0080 /* expect random access */
#define MAP_ENTRY_BEHAV_RESERVED 0x00C0 /* future use */
#define MAP_ENTRY_BEHAV_MASK 0x00C0
#define MAP_ENTRY_IN_TRANSITION 0x0100 /* entry being changed */
#define MAP_ENTRY_NEEDS_WAKEUP 0x0200 /* waiters in transition */
#define MAP_ENTRY_NOCOREDUMP 0x0400 /* don't include in a core */
#define MAP_ENTRY_GROWS_DOWN 0x1000 /* Top-down stacks */
#define MAP_ENTRY_GROWS_UP 0x2000 /* Bottom-up stacks */
#define MAP_ENTRY_WIRE_SKIPPED 0x4000
#ifdef _KERNEL
static __inline u_char
vm_map_entry_behavior(vm_map_entry_t entry)
{
return (entry->eflags & MAP_ENTRY_BEHAV_MASK);
}
static __inline int
vm_map_entry_user_wired_count(vm_map_entry_t entry)
{
if (entry->eflags & MAP_ENTRY_USER_WIRED)
return (1);
return (0);
}
static __inline int
vm_map_entry_system_wired_count(vm_map_entry_t entry)
{
return (entry->wired_count - vm_map_entry_user_wired_count(entry));
}
#endif /* _KERNEL */
/*
* A map is a set of map entries. These map entries are
* organized both as a binary search tree and as a doubly-linked
* list. Both structures are ordered based upon the start and
* end addresses contained within each map entry. Sleator and
* Tarjan's top-down splay algorithm is employed to control
* height imbalance in the binary search tree.
*
* List of locks
* (c) const until freed
*/
struct vm_map {
struct vm_map_entry header; /* List of entries */
struct sx lock; /* Lock for map data */
struct mtx system_mtx;
int nentries; /* Number of entries */
vm_size_t size; /* virtual size */
u_int timestamp; /* Version number */
u_char needs_wakeup;
u_char system_map; /* (c) Am I a system map? */
vm_flags_t flags; /* flags for this vm_map */
vm_map_entry_t root; /* Root of a binary search tree */
pmap_t pmap; /* (c) Physical map */
#define min_offset header.start /* (c) */
#define max_offset header.end /* (c) */
int busy;
};
/*
* vm_flags_t values
*/
#define MAP_WIREFUTURE 0x01 /* wire all future pages */
#define MAP_BUSY_WAKEUP 0x02
#ifdef _KERNEL
static __inline vm_offset_t
vm_map_max(vm_map_t map)
{
return (map->max_offset);
}
static __inline vm_offset_t
vm_map_min(vm_map_t map)
{
return (map->min_offset);
}
static __inline pmap_t
vm_map_pmap(vm_map_t map)
{
return (map->pmap);
}
static __inline void
vm_map_modflags(vm_map_t map, vm_flags_t set, vm_flags_t clear)
{
map->flags = (map->flags | set) & ~clear;
}
#endif /* _KERNEL */
/*
* Shareable process virtual address space.
*
* List of locks
* (c) const until freed
*/
struct vmspace {
struct vm_map vm_map; /* VM address map */
struct shmmap_state *vm_shm; /* SYS5 shared memory private data XXX */
segsz_t vm_swrss; /* resident set size before last swap */
segsz_t vm_tsize; /* text size (pages) XXX */
segsz_t vm_dsize; /* data size (pages) XXX */
segsz_t vm_ssize; /* stack size (pages) */
caddr_t vm_taddr; /* (c) user virtual address of text */
caddr_t vm_daddr; /* (c) user virtual address of data */
caddr_t vm_maxsaddr; /* user VA at max stack growth */
volatile int vm_refcnt; /* number of references */
/*
* Keep the PMAP last, so that CPU-specific variations of that
* structure on a single architecture don't result in offset
* variations of the machine-independent fields in the vmspace.
*/
struct pmap vm_pmap; /* private physical map */
};
#ifdef _KERNEL
static __inline pmap_t
vmspace_pmap(struct vmspace *vmspace)
{
return &vmspace->vm_pmap;
}
#endif /* _KERNEL */
#ifdef _KERNEL
/*
* Macros: vm_map_lock, etc.
* Function:
* Perform locking on the data portion of a map. Note that
* these macros mimic procedure calls returning void. The
* semicolon is supplied by the user of these macros, not
* by the macros themselves. The macros can safely be used
* as unbraced elements in a higher level statement.
*/
void _vm_map_lock(vm_map_t map, const char *file, int line);
void _vm_map_unlock(vm_map_t map, const char *file, int line);
int _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line);
void _vm_map_lock_read(vm_map_t map, const char *file, int line);
void _vm_map_unlock_read(vm_map_t map, const char *file, int line);
int _vm_map_trylock(vm_map_t map, const char *file, int line);
int _vm_map_trylock_read(vm_map_t map, const char *file, int line);
int _vm_map_lock_upgrade(vm_map_t map, const char *file, int line);
void _vm_map_lock_downgrade(vm_map_t map, const char *file, int line);
int vm_map_locked(vm_map_t map);
void vm_map_wakeup(vm_map_t map);
void vm_map_busy(vm_map_t map);
void vm_map_unbusy(vm_map_t map);
void vm_map_wait_busy(vm_map_t map);
#define vm_map_lock(map) _vm_map_lock(map, LOCK_FILE, LOCK_LINE)
#define vm_map_unlock(map) _vm_map_unlock(map, LOCK_FILE, LOCK_LINE)
#define vm_map_unlock_and_wait(map, timo) \
_vm_map_unlock_and_wait(map, timo, LOCK_FILE, LOCK_LINE)
#define vm_map_lock_read(map) _vm_map_lock_read(map, LOCK_FILE, LOCK_LINE)
#define vm_map_unlock_read(map) _vm_map_unlock_read(map, LOCK_FILE, LOCK_LINE)
#define vm_map_trylock(map) _vm_map_trylock(map, LOCK_FILE, LOCK_LINE)
#define vm_map_trylock_read(map) \
_vm_map_trylock_read(map, LOCK_FILE, LOCK_LINE)
#define vm_map_lock_upgrade(map) \
_vm_map_lock_upgrade(map, LOCK_FILE, LOCK_LINE)
#define vm_map_lock_downgrade(map) \
_vm_map_lock_downgrade(map, LOCK_FILE, LOCK_LINE)
long vmspace_resident_count(struct vmspace *vmspace);
long vmspace_wired_count(struct vmspace *vmspace);
#endif /* _KERNEL */
/* XXX: number of kernel maps and entries to statically allocate */
#define MAX_KMAP 10
#define MAX_KMAPENT 128
/*
* Copy-on-write flags for vm_map operations
*/
#define MAP_INHERIT_SHARE 0x0001
#define MAP_COPY_ON_WRITE 0x0002
#define MAP_NOFAULT 0x0004
#define MAP_PREFAULT 0x0008
#define MAP_PREFAULT_PARTIAL 0x0010
#define MAP_DISABLE_SYNCER 0x0020
#define MAP_DISABLE_COREDUMP 0x0100
#define MAP_PREFAULT_MADVISE 0x0200 /* from (user) madvise request */
#define MAP_STACK_GROWS_DOWN 0x1000
#define MAP_STACK_GROWS_UP 0x2000
#define MAP_ACC_CHARGED 0x4000
#define MAP_ACC_NO_CHARGE 0x8000
/*
* vm_fault option flags
*/
#define VM_FAULT_NORMAL 0 /* Nothing special */
#define VM_FAULT_CHANGE_WIRING 1 /* Change the wiring as appropriate */
#define VM_FAULT_DIRTY 2 /* Dirty the page; use w/VM_PROT_COPY */
/*
* The following "find_space" options are supported by vm_map_find()
*/
#define VMFS_NO_SPACE 0 /* don't find; use the given range */
#define VMFS_ANY_SPACE 1 /* find a range with any alignment */
#define VMFS_ALIGNED_SPACE 2 /* find a superpage-aligned range */
#if defined(__mips__)
#define VMFS_TLB_ALIGNED_SPACE 3 /* find a TLB entry aligned range */
#endif
/*
* vm_map_wire and vm_map_unwire option flags
*/
#define VM_MAP_WIRE_SYSTEM 0 /* wiring in a kernel map */
#define VM_MAP_WIRE_USER 1 /* wiring in a user map */
#define VM_MAP_WIRE_NOHOLES 0 /* region must not have holes */
#define VM_MAP_WIRE_HOLESOK 2 /* region may have holes */
#define VM_MAP_WIRE_WRITE 4 /* Validate writable. */
#ifdef _KERNEL
boolean_t vm_map_check_protection (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t);
vm_map_t vm_map_create(pmap_t, vm_offset_t, vm_offset_t);
int vm_map_delete(vm_map_t, vm_offset_t, vm_offset_t);
int vm_map_find(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *, vm_size_t,
int, vm_prot_t, vm_prot_t, int);
int vm_map_fixed(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t, vm_size_t,
vm_prot_t, vm_prot_t, int);
int vm_map_findspace (vm_map_t, vm_offset_t, vm_size_t, vm_offset_t *);
int vm_map_inherit (vm_map_t, vm_offset_t, vm_offset_t, vm_inherit_t);
void vm_map_init(vm_map_t, pmap_t, vm_offset_t, vm_offset_t);
int vm_map_insert (vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t, vm_offset_t, vm_prot_t, vm_prot_t, int);
int vm_map_lookup (vm_map_t *, vm_offset_t, vm_prot_t, vm_map_entry_t *, vm_object_t *,
vm_pindex_t *, vm_prot_t *, boolean_t *);
int vm_map_lookup_locked(vm_map_t *, vm_offset_t, vm_prot_t, vm_map_entry_t *, vm_object_t *,
vm_pindex_t *, vm_prot_t *, boolean_t *);
void vm_map_lookup_done (vm_map_t, vm_map_entry_t);
boolean_t vm_map_lookup_entry (vm_map_t, vm_offset_t, vm_map_entry_t *);
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);
int vm_map_protect (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t, boolean_t);
int vm_map_remove (vm_map_t, vm_offset_t, vm_offset_t);
void vm_map_startup (void);
int vm_map_submap (vm_map_t, vm_offset_t, vm_offset_t, vm_map_t);
int vm_map_sync(vm_map_t, vm_offset_t, vm_offset_t, boolean_t, boolean_t);
int vm_map_madvise (vm_map_t, vm_offset_t, vm_offset_t, int);
void vm_map_simplify_entry (vm_map_t, vm_map_entry_t);
void vm_init2 (void);
int vm_map_stack (vm_map_t, vm_offset_t, vm_size_t, vm_prot_t, vm_prot_t, int);
int vm_map_growstack (struct proc *p, vm_offset_t addr);
int vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
int flags);
int vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
int flags);
long vmspace_swap_count(struct vmspace *vmspace);
#endif /* _KERNEL */
#endif /* _VM_MAP_ */
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