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0209400cea
freebsd-skq/sys/vm/vm_map.h
Konstantin Belousov 0659df6fad vm_map_protect: allow to set prot and max_prot in one go. 
This prevents a situation where other thread modifies map entries
permissions between setting max_prot, then relocking, then setting prot,
confusing the operation outcome.  E.g. you can get an error that is not
possible if operation is performed atomic.

Also enable setting rwx for max_prot even if map does not allow to set
effective rwx protection.

Reviewed by:	brooks, markj (previous version)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D28117
2021-01-13 01:35:22 +02:00

536 lines
18 KiB
C
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/*-
* SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* The Mach Operating System project at Carnegie-Mellon University.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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 *left; /* left child or previous entry */
struct vm_map_entry *right; /* right child or next entry */
vm_offset_t start; /* start address */
vm_offset_t end; /* end address */
vm_offset_t next_read; /* vaddr of the next sequential read */
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 */
uint8_t read_ahead; /* pages in the read-ahead window */
int wired_count; /* can be paged if = 0 */
struct ucred *cred; /* tmp storage for creator ref */
struct thread *wiring_thread;
};
#define MAP_ENTRY_NOSYNC 0x00000001
#define MAP_ENTRY_IS_SUB_MAP 0x00000002
#define MAP_ENTRY_COW 0x00000004
#define MAP_ENTRY_NEEDS_COPY 0x00000008
#define MAP_ENTRY_NOFAULT 0x00000010
#define MAP_ENTRY_USER_WIRED 0x00000020
#define MAP_ENTRY_BEHAV_NORMAL 0x00000000 /* default behavior */
#define MAP_ENTRY_BEHAV_SEQUENTIAL 0x00000040 /* expect sequential
access */
#define MAP_ENTRY_BEHAV_RANDOM 0x00000080 /* expect random
access */
#define MAP_ENTRY_BEHAV_RESERVED 0x000000c0 /* future use */
#define MAP_ENTRY_BEHAV_MASK 0x000000c0
#define MAP_ENTRY_IN_TRANSITION 0x00000100 /* entry being
changed */
#define MAP_ENTRY_NEEDS_WAKEUP 0x00000200 /* waiters in
transition */
#define MAP_ENTRY_NOCOREDUMP 0x00000400 /* don't include in
a core */
#define MAP_ENTRY_VN_EXEC 0x00000800 /* text vnode mapping */
#define MAP_ENTRY_GROWS_DOWN 0x00001000 /* top-down stacks */
#define MAP_ENTRY_GROWS_UP 0x00002000 /* bottom-up stacks */
#define MAP_ENTRY_WIRE_SKIPPED 0x00004000
#define MAP_ENTRY_WRITECNT 0x00008000 /* tracked writeable
mapping */
#define MAP_ENTRY_GUARD 0x00010000
#define MAP_ENTRY_STACK_GAP_DN 0x00020000
#define MAP_ENTRY_STACK_GAP_UP 0x00040000
#define MAP_ENTRY_HEADER 0x00080000
#define MAP_ENTRY_SPLIT_BOUNDARY_MASK 0x00300000
#define MAP_ENTRY_SPLIT_BOUNDARY_SHIFT 20
#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 as a threaded binary search tree. Both structures
* are ordered based upon the start and end addresses contained
* within each map entry. The largest gap between an entry in a
* subtree and one of its neighbors is saved in the max_free
* field, and that field is updated when the tree is
* restructured.
*
* Sleator and Tarjan's top-down splay algorithm is employed to
* control height imbalance in the binary search tree.
*
* The map's min offset value is stored in map->header.end, and
* its max offset value is stored in map->header.start. These
* values act as sentinels for any forward or backward address
* scan of the list. The right and left fields of the map
* header point to the first and list map entries. The map
* header has a special value for the eflags field,
* MAP_ENTRY_HEADER, that is set initially, is never changed,
* and prevents an eflags match of the header with any other map
* entry.
*
* 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 */
vm_offset_t anon_loc;
int busy;
#ifdef DIAGNOSTIC
int nupdates;
#endif
};
/*
* vm_flags_t values
*/
#define MAP_WIREFUTURE 0x01 /* wire all future pages */
#define MAP_BUSY_WAKEUP 0x02
#define MAP_IS_SUB_MAP 0x04 /* has parent */
#define MAP_ASLR 0x08 /* enabled ASLR */
#define MAP_ASLR_IGNSTART 0x10
#define MAP_REPLENISH 0x20
#define MAP_WXORX 0x40 /* enforce W^X */
#ifdef _KERNEL
#if defined(KLD_MODULE) && !defined(KLD_TIED)
#define vm_map_max(map) vm_map_max_KBI((map))
#define vm_map_min(map) vm_map_min_KBI((map))
#define vm_map_pmap(map) vm_map_pmap_KBI((map))
#define vm_map_range_valid(map, start, end) \
vm_map_range_valid_KBI((map), (start), (end))
#else
static __inline vm_offset_t
vm_map_max(const struct vm_map *map)
{
return (map->header.start);
}
static __inline vm_offset_t
vm_map_min(const struct vm_map *map)
{
return (map->header.end);
}
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;
}
static inline bool
vm_map_range_valid(vm_map_t map, vm_offset_t start, vm_offset_t end)
{
if (end < start)
return (false);
if (start < vm_map_min(map) || end > vm_map_max(map))
return (false);
return (true);
}
#endif /* KLD_MODULE */
#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 */
u_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);
vm_offset_t vm_map_max_KBI(const struct vm_map *map);
vm_offset_t vm_map_min_KBI(const struct vm_map *map);
pmap_t vm_map_pmap_KBI(vm_map_t map);
bool vm_map_range_valid_KBI(vm_map_t map, vm_offset_t start, vm_offset_t end);
#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);
#endif /* _KERNEL */
/*
* Copy-on-write flags for vm_map operations
*/
#define MAP_INHERIT_SHARE 0x00000001
#define MAP_COPY_ON_WRITE 0x00000002
#define MAP_NOFAULT 0x00000004
#define MAP_PREFAULT 0x00000008
#define MAP_PREFAULT_PARTIAL 0x00000010
#define MAP_DISABLE_SYNCER 0x00000020
#define MAP_CHECK_EXCL 0x00000040
#define MAP_CREATE_GUARD 0x00000080
#define MAP_DISABLE_COREDUMP 0x00000100
#define MAP_PREFAULT_MADVISE 0x00000200 /* from (user) madvise request */
#define MAP_WRITECOUNT 0x00000400
#define MAP_REMAP 0x00000800
#define MAP_STACK_GROWS_DOWN 0x00001000
#define MAP_STACK_GROWS_UP 0x00002000
#define MAP_ACC_CHARGED 0x00004000
#define MAP_ACC_NO_CHARGE 0x00008000
#define MAP_CREATE_STACK_GAP_UP 0x00010000
#define MAP_CREATE_STACK_GAP_DN 0x00020000
#define MAP_VN_EXEC 0x00040000
#define MAP_SPLIT_BOUNDARY_MASK 0x00180000
#define MAP_SPLIT_BOUNDARY_SHIFT 19
/*
* vm_fault option flags
*/
#define VM_FAULT_NORMAL 0x00 /* Nothing special */
#define VM_FAULT_WIRE 0x01 /* Wire the mapped page */
#define VM_FAULT_DIRTY 0x02 /* Dirty the page; use w/VM_PROT_COPY */
#define VM_FAULT_NOFILL 0x04 /* Fail if the pager doesn't have a copy */
/*
* Initially, mappings are slightly sequential. The maximum window size must
* account for the map entry's "read_ahead" field being defined as an uint8_t.
*/
#define VM_FAULT_READ_AHEAD_MIN 7
#define VM_FAULT_READ_AHEAD_INIT 15
#define VM_FAULT_READ_AHEAD_MAX min(atop(maxphys) - 1, UINT8_MAX)
/*
* The following "find_space" options are supported by vm_map_find().
*
* For VMFS_ALIGNED_SPACE, the desired alignment is specified to
* the macro argument as log base 2 of the desired alignment.
*/
#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_OPTIMAL_SPACE 2 /* find a range with optimal alignment*/
#define VMFS_SUPER_SPACE 3 /* find a superpage-aligned range */
#define VMFS_ALIGNED_SPACE(x) ((x) << 8) /* find a range with fixed alignment */
/*
* 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. */
typedef int vm_map_entry_reader(void *token, vm_map_entry_t addr,
vm_map_entry_t dest);
#ifndef _KERNEL
/*
* Find the successor of a map_entry, using a reader to dereference pointers.
* '*clone' is a copy of a vm_map entry. 'reader' is used to copy a map entry
* at some address into '*clone'. Change *clone to a copy of the next map
* entry, and return the address of that entry, or NULL if copying has failed.
*
* This function is made available to user-space code that needs to traverse
* map entries.
*/
static inline vm_map_entry_t
vm_map_entry_read_succ(void *token, struct vm_map_entry *const clone,
vm_map_entry_reader reader)
{
vm_map_entry_t after, backup;
vm_offset_t start;
after = clone->right;
start = clone->start;
if (!reader(token, after, clone))
return (NULL);
backup = clone->left;
if (!reader(token, backup, clone))
return (NULL);
if (clone->start > start) {
do {
after = backup;
backup = clone->left;
if (!reader(token, backup, clone))
return (NULL);
} while (clone->start != start);
}
if (!reader(token, after, clone))
return (NULL);
return (after);
}
#endif /* ! _KERNEL */
#ifdef _KERNEL
boolean_t vm_map_check_protection (vm_map_t, vm_offset_t, vm_offset_t, vm_prot_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,
vm_offset_t, int, vm_prot_t, vm_prot_t, int);
int vm_map_find_min(vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *,
vm_size_t, vm_offset_t, vm_offset_t, int, vm_prot_t, vm_prot_t, int);
int vm_map_find_aligned(vm_map_t map, vm_offset_t *addr, vm_size_t length,
vm_offset_t max_addr, vm_offset_t alignment);
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);
vm_offset_t vm_map_findspace(vm_map_t, vm_offset_t, vm_size_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 *);
static inline vm_map_entry_t
vm_map_entry_first(vm_map_t map)
{
return (map->header.right);
}
static inline vm_map_entry_t
vm_map_entry_succ(vm_map_entry_t entry)
{
vm_map_entry_t after;
after = entry->right;
if (after->left->start > entry->start) {
do
after = after->left;
while (after->left != entry);
}
return (after);
}
#define VM_MAP_ENTRY_FOREACH(it, map) \
for ((it) = vm_map_entry_first(map); \
(it) != &(map)->header; \
(it) = vm_map_entry_succ(it))
#define VM_MAP_PROTECT_SET_PROT 0x0001
#define VM_MAP_PROTECT_SET_MAXPROT 0x0002
int vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
vm_prot_t new_prot, vm_prot_t new_maxprot, int flags);
int vm_map_remove (vm_map_t, vm_offset_t, vm_offset_t);
void vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev,
vm_map_entry_t entry);
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);
int vm_map_stack (vm_map_t, vm_offset_t, vm_size_t, vm_prot_t, vm_prot_t, int);
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);
int vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end,
int flags);
long vmspace_swap_count(struct vmspace *vmspace);
void vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add);
#endif /* _KERNEL */
#endif /* _VM_MAP_ */
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