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uvm_map.c
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uvm_map.c
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/* $OpenBSD: uvm_map.c,v 1.289 2022/03/11 19:24:19 kettenis Exp $ */
/* $NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $ */
/*
* Copyright (c) 2011 Ariane van der Steldt <ariane@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* 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.c 8.3 (Berkeley) 1/12/94
* from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp
*
*
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
* All rights reserved.
*
* 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.
*/
/*
* uvm_map.c: uvm map operations
*/
/* #define DEBUG */
/* #define VMMAP_DEBUG */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/acct.h>
#include <sys/mman.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/sysctl.h>
#include <sys/signalvar.h>
#include <sys/syslog.h>
#include <sys/user.h>
#include <sys/tracepoint.h>
#ifdef SYSVSHM
#include <sys/shm.h>
#endif
#include <uvm/uvm.h>
#ifdef DDB
#include <uvm/uvm_ddb.h>
#endif
#include <uvm/uvm_addr.h>
vsize_t uvmspace_dused(struct vm_map*, vaddr_t, vaddr_t);
int uvm_mapent_isjoinable(struct vm_map*,
struct vm_map_entry*, struct vm_map_entry*);
struct vm_map_entry *uvm_mapent_merge(struct vm_map*, struct vm_map_entry*,
struct vm_map_entry*, struct uvm_map_deadq*);
struct vm_map_entry *uvm_mapent_tryjoin(struct vm_map*,
struct vm_map_entry*, struct uvm_map_deadq*);
struct vm_map_entry *uvm_map_mkentry(struct vm_map*, struct vm_map_entry*,
struct vm_map_entry*, vaddr_t, vsize_t, int,
struct uvm_map_deadq*, struct vm_map_entry*);
struct vm_map_entry *uvm_mapent_alloc(struct vm_map*, int);
void uvm_mapent_free(struct vm_map_entry*);
void uvm_unmap_kill_entry(struct vm_map*,
struct vm_map_entry*);
void uvm_unmap_kill_entry_withlock(struct vm_map *,
struct vm_map_entry *, int);
void uvm_unmap_detach_intrsafe(struct uvm_map_deadq *);
void uvm_mapent_mkfree(struct vm_map*,
struct vm_map_entry*, struct vm_map_entry**,
struct uvm_map_deadq*, boolean_t);
void uvm_map_pageable_pgon(struct vm_map*,
struct vm_map_entry*, struct vm_map_entry*,
vaddr_t, vaddr_t);
int uvm_map_pageable_wire(struct vm_map*,
struct vm_map_entry*, struct vm_map_entry*,
vaddr_t, vaddr_t, int);
void uvm_map_setup_entries(struct vm_map*);
void uvm_map_setup_md(struct vm_map*);
void uvm_map_teardown(struct vm_map*);
void uvm_map_vmspace_update(struct vm_map*,
struct uvm_map_deadq*, int);
void uvm_map_kmem_grow(struct vm_map*,
struct uvm_map_deadq*, vsize_t, int);
void uvm_map_freelist_update_clear(struct vm_map*,
struct uvm_map_deadq*);
void uvm_map_freelist_update_refill(struct vm_map *, int);
void uvm_map_freelist_update(struct vm_map*,
struct uvm_map_deadq*, vaddr_t, vaddr_t,
vaddr_t, vaddr_t, int);
struct vm_map_entry *uvm_map_fix_space(struct vm_map*, struct vm_map_entry*,
vaddr_t, vaddr_t, int);
int uvm_map_sel_limits(vaddr_t*, vaddr_t*, vsize_t, int,
struct vm_map_entry*, vaddr_t, vaddr_t, vaddr_t,
int);
int uvm_map_findspace(struct vm_map*,
struct vm_map_entry**, struct vm_map_entry**,
vaddr_t*, vsize_t, vaddr_t, vaddr_t, vm_prot_t,
vaddr_t);
vsize_t uvm_map_addr_augment_get(struct vm_map_entry*);
void uvm_map_addr_augment(struct vm_map_entry*);
int uvm_map_inentry_recheck(u_long, vaddr_t,
struct p_inentry *);
boolean_t uvm_map_inentry_fix(struct proc *, struct p_inentry *,
vaddr_t, int (*)(vm_map_entry_t), u_long);
/*
* Tree management functions.
*/
static inline void uvm_mapent_copy(struct vm_map_entry*,
struct vm_map_entry*);
static inline int uvm_mapentry_addrcmp(const struct vm_map_entry*,
const struct vm_map_entry*);
void uvm_mapent_free_insert(struct vm_map*,
struct uvm_addr_state*, struct vm_map_entry*);
void uvm_mapent_free_remove(struct vm_map*,
struct uvm_addr_state*, struct vm_map_entry*);
void uvm_mapent_addr_insert(struct vm_map*,
struct vm_map_entry*);
void uvm_mapent_addr_remove(struct vm_map*,
struct vm_map_entry*);
void uvm_map_splitentry(struct vm_map*,
struct vm_map_entry*, struct vm_map_entry*,
vaddr_t);
vsize_t uvm_map_boundary(struct vm_map*, vaddr_t, vaddr_t);
/*
* uvm_vmspace_fork helper functions.
*/
struct vm_map_entry *uvm_mapent_clone(struct vm_map*, vaddr_t, vsize_t,
vsize_t, vm_prot_t, vm_prot_t,
struct vm_map_entry*, struct uvm_map_deadq*, int,
int);
struct vm_map_entry *uvm_mapent_share(struct vm_map*, vaddr_t, vsize_t,
vsize_t, vm_prot_t, vm_prot_t, struct vm_map*,
struct vm_map_entry*, struct uvm_map_deadq*);
struct vm_map_entry *uvm_mapent_forkshared(struct vmspace*, struct vm_map*,
struct vm_map*, struct vm_map_entry*,
struct uvm_map_deadq*);
struct vm_map_entry *uvm_mapent_forkcopy(struct vmspace*, struct vm_map*,
struct vm_map*, struct vm_map_entry*,
struct uvm_map_deadq*);
struct vm_map_entry *uvm_mapent_forkzero(struct vmspace*, struct vm_map*,
struct vm_map*, struct vm_map_entry*,
struct uvm_map_deadq*);
/*
* Tree validation.
*/
#ifdef VMMAP_DEBUG
void uvm_tree_assert(struct vm_map*, int, char*,
char*, int);
#define UVM_ASSERT(map, cond, file, line) \
uvm_tree_assert((map), (cond), #cond, (file), (line))
void uvm_tree_sanity(struct vm_map*, char*, int);
void uvm_tree_size_chk(struct vm_map*, char*, int);
void vmspace_validate(struct vm_map*);
#else
#define uvm_tree_sanity(_map, _file, _line) do {} while (0)
#define uvm_tree_size_chk(_map, _file, _line) do {} while (0)
#define vmspace_validate(_map) do {} while (0)
#endif
/*
* All architectures will have pmap_prefer.
*/
#ifndef PMAP_PREFER
#define PMAP_PREFER_ALIGN() (vaddr_t)PAGE_SIZE
#define PMAP_PREFER_OFFSET(off) 0
#define PMAP_PREFER(addr, off) (addr)
#endif
/*
* The kernel map will initially be VM_MAP_KSIZE_INIT bytes.
* Every time that gets cramped, we grow by at least VM_MAP_KSIZE_DELTA bytes.
*
* We attempt to grow by UVM_MAP_KSIZE_ALLOCMUL times the allocation size
* each time.
*/
#define VM_MAP_KSIZE_INIT (512 * (vaddr_t)PAGE_SIZE)
#define VM_MAP_KSIZE_DELTA (256 * (vaddr_t)PAGE_SIZE)
#define VM_MAP_KSIZE_ALLOCMUL 4
/*
* When selecting a random free-space block, look at most FSPACE_DELTA blocks
* ahead.
*/
#define FSPACE_DELTA 8
/*
* Put allocations adjecent to previous allocations when the free-space tree
* is larger than FSPACE_COMPACT entries.
*
* Alignment and PMAP_PREFER may still cause the entry to not be fully
* adjecent. Note that this strategy reduces memory fragmentation (by leaving
* a large space before or after the allocation).
*/
#define FSPACE_COMPACT 128
/*
* Make the address selection skip at most this many bytes from the start of
* the free space in which the allocation takes place.
*
* The main idea behind a randomized address space is that an attacker cannot
* know where to target his attack. Therefore, the location of objects must be
* as random as possible. However, the goal is not to create the most sparse
* map that is possible.
* FSPACE_MAXOFF pushes the considered range in bytes down to less insane
* sizes, thereby reducing the sparseness. The biggest randomization comes
* from fragmentation, i.e. FSPACE_COMPACT.
*/
#define FSPACE_MAXOFF ((vaddr_t)32 * 1024 * 1024)
/*
* Allow for small gaps in the overflow areas.
* Gap size is in bytes and does not have to be a multiple of page-size.
*/
#define FSPACE_BIASGAP ((vaddr_t)32 * 1024)
/* auto-allocate address lower bound */
#define VMMAP_MIN_ADDR PAGE_SIZE
#ifdef DEADBEEF0
#define UVMMAP_DEADBEEF ((unsigned long)DEADBEEF0)
#else
#define UVMMAP_DEADBEEF ((unsigned long)0xdeadd0d0)
#endif
#ifdef DEBUG
int uvm_map_printlocks = 0;
#define LPRINTF(_args) \
do { \
if (uvm_map_printlocks) \
printf _args; \
} while (0)
#else
#define LPRINTF(_args) do {} while (0)
#endif
static struct mutex uvm_kmapent_mtx;
static struct timeval uvm_kmapent_last_warn_time;
static struct timeval uvm_kmapent_warn_rate = { 10, 0 };
const char vmmapbsy[] = "vmmapbsy";
/*
* pool for vmspace structures.
*/
struct pool uvm_vmspace_pool;
/*
* pool for dynamically-allocated map entries.
*/
struct pool uvm_map_entry_pool;
struct pool uvm_map_entry_kmem_pool;
/*
* This global represents the end of the kernel virtual address
* space. If we want to exceed this, we must grow the kernel
* virtual address space dynamically.
*
* Note, this variable is locked by kernel_map's lock.
*/
vaddr_t uvm_maxkaddr;
/*
* Locking predicate.
*/
#define UVM_MAP_REQ_WRITE(_map) \
do { \
if ((_map)->ref_count > 0) { \
if (((_map)->flags & VM_MAP_INTRSAFE) == 0) \
rw_assert_wrlock(&(_map)->lock); \
else \
MUTEX_ASSERT_LOCKED(&(_map)->mtx); \
} \
} while (0)
#define vm_map_modflags(map, set, clear) \
do { \
mtx_enter(&(map)->flags_lock); \
(map)->flags = ((map)->flags | (set)) & ~(clear); \
mtx_leave(&(map)->flags_lock); \
} while (0)
/*
* Tree describing entries by address.
*
* Addresses are unique.
* Entries with start == end may only exist if they are the first entry
* (sorted by address) within a free-memory tree.
*/
static inline int
uvm_mapentry_addrcmp(const struct vm_map_entry *e1,
const struct vm_map_entry *e2)
{
return e1->start < e2->start ? -1 : e1->start > e2->start;
}
/*
* Copy mapentry.
*/
static inline void
uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst)
{
caddr_t csrc, cdst;
size_t sz;
csrc = (caddr_t)src;
cdst = (caddr_t)dst;
csrc += offsetof(struct vm_map_entry, uvm_map_entry_start_copy);
cdst += offsetof(struct vm_map_entry, uvm_map_entry_start_copy);
sz = offsetof(struct vm_map_entry, uvm_map_entry_stop_copy) -
offsetof(struct vm_map_entry, uvm_map_entry_start_copy);
memcpy(cdst, csrc, sz);
}
/*
* Handle free-list insertion.
*/
void
uvm_mapent_free_insert(struct vm_map *map, struct uvm_addr_state *uaddr,
struct vm_map_entry *entry)
{
const struct uvm_addr_functions *fun;
#ifdef VMMAP_DEBUG
vaddr_t min, max, bound;
#endif
#ifdef VMMAP_DEBUG
/*
* Boundary check.
* Boundaries are folded if they go on the same free list.
*/
min = VMMAP_FREE_START(entry);
max = VMMAP_FREE_END(entry);
while (min < max) {
bound = uvm_map_boundary(map, min, max);
KASSERT(uvm_map_uaddr(map, min) == uaddr);
min = bound;
}
#endif
KDASSERT((entry->fspace & (vaddr_t)PAGE_MASK) == 0);
KASSERT((entry->etype & UVM_ET_FREEMAPPED) == 0);
UVM_MAP_REQ_WRITE(map);
/* Actual insert: forward to uaddr pointer. */
if (uaddr != NULL) {
fun = uaddr->uaddr_functions;
KDASSERT(fun != NULL);
if (fun->uaddr_free_insert != NULL)
(*fun->uaddr_free_insert)(map, uaddr, entry);
entry->etype |= UVM_ET_FREEMAPPED;
}
/* Update fspace augmentation. */
uvm_map_addr_augment(entry);
}
/*
* Handle free-list removal.
*/
void
uvm_mapent_free_remove(struct vm_map *map, struct uvm_addr_state *uaddr,
struct vm_map_entry *entry)
{
const struct uvm_addr_functions *fun;
KASSERT((entry->etype & UVM_ET_FREEMAPPED) != 0 || uaddr == NULL);
KASSERT(uvm_map_uaddr_e(map, entry) == uaddr);
UVM_MAP_REQ_WRITE(map);
if (uaddr != NULL) {
fun = uaddr->uaddr_functions;
if (fun->uaddr_free_remove != NULL)
(*fun->uaddr_free_remove)(map, uaddr, entry);
entry->etype &= ~UVM_ET_FREEMAPPED;
}
}
/*
* Handle address tree insertion.
*/
void
uvm_mapent_addr_insert(struct vm_map *map, struct vm_map_entry *entry)
{
struct vm_map_entry *res;
if (!RBT_CHECK(uvm_map_addr, entry, UVMMAP_DEADBEEF))
panic("uvm_mapent_addr_insert: entry still in addr list");
KDASSERT(entry->start <= entry->end);
KDASSERT((entry->start & (vaddr_t)PAGE_MASK) == 0 &&
(entry->end & (vaddr_t)PAGE_MASK) == 0);
TRACEPOINT(uvm, map_insert,
entry->start, entry->end, entry->protection, NULL);
UVM_MAP_REQ_WRITE(map);
res = RBT_INSERT(uvm_map_addr, &map->addr, entry);
if (res != NULL) {
panic("uvm_mapent_addr_insert: map %p entry %p "
"(0x%lx-0x%lx G=0x%lx F=0x%lx) insert collision "
"with entry %p (0x%lx-0x%lx G=0x%lx F=0x%lx)",
map, entry,
entry->start, entry->end, entry->guard, entry->fspace,
res, res->start, res->end, res->guard, res->fspace);
}
}
/*
* Handle address tree removal.
*/
void
uvm_mapent_addr_remove(struct vm_map *map, struct vm_map_entry *entry)
{
struct vm_map_entry *res;
TRACEPOINT(uvm, map_remove,
entry->start, entry->end, entry->protection, NULL);
UVM_MAP_REQ_WRITE(map);
res = RBT_REMOVE(uvm_map_addr, &map->addr, entry);
if (res != entry)
panic("uvm_mapent_addr_remove");
RBT_POISON(uvm_map_addr, entry, UVMMAP_DEADBEEF);
}
/*
* uvm_map_reference: add reference to a map
*
* => map need not be locked
*/
void
uvm_map_reference(struct vm_map *map)
{
atomic_inc_int(&map->ref_count);
}
void
uvm_map_lock_entry(struct vm_map_entry *entry)
{
if (entry->aref.ar_amap != NULL) {
amap_lock(entry->aref.ar_amap);
}
if (UVM_ET_ISOBJ(entry)) {
rw_enter(entry->object.uvm_obj->vmobjlock, RW_WRITE);
}
}
void
uvm_map_unlock_entry(struct vm_map_entry *entry)
{
if (UVM_ET_ISOBJ(entry)) {
rw_exit(entry->object.uvm_obj->vmobjlock);
}
if (entry->aref.ar_amap != NULL) {
amap_unlock(entry->aref.ar_amap);
}
}
/*
* Calculate the dused delta.
*/
vsize_t
uvmspace_dused(struct vm_map *map, vaddr_t min, vaddr_t max)
{
struct vmspace *vm;
vsize_t sz;
vaddr_t lmax;
vaddr_t stack_begin, stack_end; /* Position of stack. */
KASSERT(map->flags & VM_MAP_ISVMSPACE);
vm = (struct vmspace *)map;
stack_begin = MIN((vaddr_t)vm->vm_maxsaddr, (vaddr_t)vm->vm_minsaddr);
stack_end = MAX((vaddr_t)vm->vm_maxsaddr, (vaddr_t)vm->vm_minsaddr);
sz = 0;
while (min != max) {
lmax = max;
if (min < stack_begin && lmax > stack_begin)
lmax = stack_begin;
else if (min < stack_end && lmax > stack_end)
lmax = stack_end;
if (min >= stack_begin && min < stack_end) {
/* nothing */
} else
sz += lmax - min;
min = lmax;
}
return sz >> PAGE_SHIFT;
}
/*
* Find the entry describing the given address.
*/
struct vm_map_entry*
uvm_map_entrybyaddr(struct uvm_map_addr *atree, vaddr_t addr)
{
struct vm_map_entry *iter;
iter = RBT_ROOT(uvm_map_addr, atree);
while (iter != NULL) {
if (iter->start > addr)
iter = RBT_LEFT(uvm_map_addr, iter);
else if (VMMAP_FREE_END(iter) <= addr)
iter = RBT_RIGHT(uvm_map_addr, iter);
else
return iter;
}
return NULL;
}
/*
* DEAD_ENTRY_PUSH(struct vm_map_deadq *deadq, struct vm_map_entry *entry)
*
* Push dead entries into a linked list.
* Since the linked list abuses the address tree for storage, the entry
* may not be linked in a map.
*
* *head must be initialized to NULL before the first call to this macro.
* uvm_unmap_detach(*head, 0) will remove dead entries.
*/
static inline void
dead_entry_push(struct uvm_map_deadq *deadq, struct vm_map_entry *entry)
{
TAILQ_INSERT_TAIL(deadq, entry, dfree.deadq);
}
#define DEAD_ENTRY_PUSH(_headptr, _entry) \
dead_entry_push((_headptr), (_entry))
/*
* Helper function for uvm_map_findspace_tree.
*
* Given allocation constraints and pmap constraints, finds the
* lowest and highest address in a range that can be used for the
* allocation.
*
* pmap_align and pmap_off are ignored on non-PMAP_PREFER archs.
*
*
* Big chunk of math with a seasoning of dragons.
*/
int
uvm_map_sel_limits(vaddr_t *min, vaddr_t *max, vsize_t sz, int guardpg,
struct vm_map_entry *sel, vaddr_t align,
vaddr_t pmap_align, vaddr_t pmap_off, int bias)
{
vaddr_t sel_min, sel_max;
#ifdef PMAP_PREFER
vaddr_t pmap_min, pmap_max;
#endif /* PMAP_PREFER */
#ifdef DIAGNOSTIC
int bad;
#endif /* DIAGNOSTIC */
sel_min = VMMAP_FREE_START(sel);
sel_max = VMMAP_FREE_END(sel) - sz - (guardpg ? PAGE_SIZE : 0);
#ifdef PMAP_PREFER
/*
* There are two special cases, in which we can satisfy the align
* requirement and the pmap_prefer requirement.
* - when pmap_off == 0, we always select the largest of the two
* - when pmap_off % align == 0 and pmap_align > align, we simply
* satisfy the pmap_align requirement and automatically
* satisfy the align requirement.
*/
if (align > PAGE_SIZE &&
!(pmap_align > align && (pmap_off & (align - 1)) == 0)) {
/*
* Simple case: only use align.
*/
sel_min = roundup(sel_min, align);
sel_max &= ~(align - 1);
if (sel_min > sel_max)
return ENOMEM;
/* Correct for bias. */
if (sel_max - sel_min > FSPACE_BIASGAP) {
if (bias > 0) {
sel_min = sel_max - FSPACE_BIASGAP;
sel_min = roundup(sel_min, align);
} else if (bias < 0) {
sel_max = sel_min + FSPACE_BIASGAP;
sel_max &= ~(align - 1);
}
}
} else if (pmap_align != 0) {
/*
* Special case: satisfy both pmap_prefer and
* align argument.
*/
pmap_max = sel_max & ~(pmap_align - 1);
pmap_min = sel_min;
if (pmap_max < sel_min)
return ENOMEM;
/* Adjust pmap_min for BIASGAP for top-addr bias. */
if (bias > 0 && pmap_max - pmap_min > FSPACE_BIASGAP)
pmap_min = pmap_max - FSPACE_BIASGAP;
/* Align pmap_min. */
pmap_min &= ~(pmap_align - 1);
if (pmap_min < sel_min)
pmap_min += pmap_align;
if (pmap_min > pmap_max)
return ENOMEM;
/* Adjust pmap_max for BIASGAP for bottom-addr bias. */
if (bias < 0 && pmap_max - pmap_min > FSPACE_BIASGAP) {
pmap_max = (pmap_min + FSPACE_BIASGAP) &
~(pmap_align - 1);
}
if (pmap_min > pmap_max)
return ENOMEM;
/* Apply pmap prefer offset. */
pmap_max |= pmap_off;
if (pmap_max > sel_max)
pmap_max -= pmap_align;
pmap_min |= pmap_off;
if (pmap_min < sel_min)
pmap_min += pmap_align;
/*
* Fixup: it's possible that pmap_min and pmap_max
* cross each other. In this case, try to find one
* address that is allowed.
* (This usually happens in biased case.)
*/
if (pmap_min > pmap_max) {
if (pmap_min < sel_max)
pmap_max = pmap_min;
else if (pmap_max > sel_min)
pmap_min = pmap_max;
else
return ENOMEM;
}
/* Internal validation. */
KDASSERT(pmap_min <= pmap_max);
sel_min = pmap_min;
sel_max = pmap_max;
} else if (bias > 0 && sel_max - sel_min > FSPACE_BIASGAP)
sel_min = sel_max - FSPACE_BIASGAP;
else if (bias < 0 && sel_max - sel_min > FSPACE_BIASGAP)
sel_max = sel_min + FSPACE_BIASGAP;
#else
if (align > PAGE_SIZE) {
sel_min = roundup(sel_min, align);
sel_max &= ~(align - 1);
if (sel_min > sel_max)
return ENOMEM;
if (bias != 0 && sel_max - sel_min > FSPACE_BIASGAP) {
if (bias > 0) {
sel_min = roundup(sel_max - FSPACE_BIASGAP,
align);
} else {
sel_max = (sel_min + FSPACE_BIASGAP) &
~(align - 1);
}
}
} else if (bias > 0 && sel_max - sel_min > FSPACE_BIASGAP)
sel_min = sel_max - FSPACE_BIASGAP;
else if (bias < 0 && sel_max - sel_min > FSPACE_BIASGAP)
sel_max = sel_min + FSPACE_BIASGAP;
#endif
if (sel_min > sel_max)
return ENOMEM;
#ifdef DIAGNOSTIC
bad = 0;
/* Lower boundary check. */
if (sel_min < VMMAP_FREE_START(sel)) {
printf("sel_min: 0x%lx, but should be at least 0x%lx\n",
sel_min, VMMAP_FREE_START(sel));
bad++;
}
/* Upper boundary check. */
if (sel_max > VMMAP_FREE_END(sel) - sz - (guardpg ? PAGE_SIZE : 0)) {
printf("sel_max: 0x%lx, but should be at most 0x%lx\n",
sel_max,
VMMAP_FREE_END(sel) - sz - (guardpg ? PAGE_SIZE : 0));
bad++;
}
/* Lower boundary alignment. */
if (align != 0 && (sel_min & (align - 1)) != 0) {
printf("sel_min: 0x%lx, not aligned to 0x%lx\n",
sel_min, align);
bad++;
}
/* Upper boundary alignment. */
if (align != 0 && (sel_max & (align - 1)) != 0) {
printf("sel_max: 0x%lx, not aligned to 0x%lx\n",
sel_max, align);
bad++;
}
/* Lower boundary PMAP_PREFER check. */
if (pmap_align != 0 && align == 0 &&
(sel_min & (pmap_align - 1)) != pmap_off) {
printf("sel_min: 0x%lx, aligned to 0x%lx, expected 0x%lx\n",
sel_min, sel_min & (pmap_align - 1), pmap_off);
bad++;
}
/* Upper boundary PMAP_PREFER check. */
if (pmap_align != 0 && align == 0 &&
(sel_max & (pmap_align - 1)) != pmap_off) {
printf("sel_max: 0x%lx, aligned to 0x%lx, expected 0x%lx\n",
sel_max, sel_max & (pmap_align - 1), pmap_off);
bad++;
}
if (bad) {
panic("uvm_map_sel_limits(sz = %lu, guardpg = %c, "
"align = 0x%lx, pmap_align = 0x%lx, pmap_off = 0x%lx, "
"bias = %d, "
"FREE_START(sel) = 0x%lx, FREE_END(sel) = 0x%lx)",
sz, (guardpg ? 'T' : 'F'), align, pmap_align, pmap_off,
bias, VMMAP_FREE_START(sel), VMMAP_FREE_END(sel));
}
#endif /* DIAGNOSTIC */
*min = sel_min;
*max = sel_max;
return 0;
}
/*
* Test if memory starting at addr with sz bytes is free.
*
* Fills in *start_ptr and *end_ptr to be the first and last entry describing
* the space.
* If called with prefilled *start_ptr and *end_ptr, they are to be correct.
*/
int
uvm_map_isavail(struct vm_map *map, struct uvm_addr_state *uaddr,
struct vm_map_entry **start_ptr, struct vm_map_entry **end_ptr,
vaddr_t addr, vsize_t sz)
{
struct uvm_addr_state *free;
struct uvm_map_addr *atree;
struct vm_map_entry *i, *i_end;
if (addr + sz < addr)
return 0;
/*
* Kernel memory above uvm_maxkaddr is considered unavailable.
*/
if ((map->flags & VM_MAP_ISVMSPACE) == 0) {
if (addr + sz > uvm_maxkaddr)
return 0;
}
atree = &map->addr;
/*
* Fill in first, last, so they point at the entries containing the
* first and last address of the range.
* Note that if they are not NULL, we don't perform the lookup.
*/
KDASSERT(atree != NULL && start_ptr != NULL && end_ptr != NULL);
if (*start_ptr == NULL) {
*start_ptr = uvm_map_entrybyaddr(atree, addr);
if (*start_ptr == NULL)
return 0;
} else
KASSERT(*start_ptr == uvm_map_entrybyaddr(atree, addr));
if (*end_ptr == NULL) {
if (VMMAP_FREE_END(*start_ptr) >= addr + sz)
*end_ptr = *start_ptr;
else {
*end_ptr = uvm_map_entrybyaddr(atree, addr + sz - 1);
if (*end_ptr == NULL)
return 0;
}
} else
KASSERT(*end_ptr == uvm_map_entrybyaddr(atree, addr + sz - 1));
/* Validation. */
KDASSERT(*start_ptr != NULL && *end_ptr != NULL);
KDASSERT((*start_ptr)->start <= addr &&
VMMAP_FREE_END(*start_ptr) > addr &&
(*end_ptr)->start < addr + sz &&
VMMAP_FREE_END(*end_ptr) >= addr + sz);
/*
* Check the none of the entries intersects with <addr, addr+sz>.
* Also, if the entry belong to uaddr_exe or uaddr_brk_stack, it is
* considered unavailable unless called by those allocators.
*/
i = *start_ptr;
i_end = RBT_NEXT(uvm_map_addr, *end_ptr);
for (; i != i_end;
i = RBT_NEXT(uvm_map_addr, i)) {
if (i->start != i->end && i->end > addr)
return 0;
/*
* uaddr_exe and uaddr_brk_stack may only be used
* by these allocators and the NULL uaddr (i.e. no
* uaddr).
* Reject if this requirement is not met.
*/
if (uaddr != NULL) {
free = uvm_map_uaddr_e(map, i);
if (uaddr != free && free != NULL &&
(free == map->uaddr_exe ||
free == map->uaddr_brk_stack))
return 0;
}
}
return -1;
}
/*
* Invoke each address selector until an address is found.
* Will not invoke uaddr_exe.
*/
int
uvm_map_findspace(struct vm_map *map, struct vm_map_entry**first,
struct vm_map_entry**last, vaddr_t *addr, vsize_t sz,
vaddr_t pmap_align, vaddr_t pmap_offset, vm_prot_t prot, vaddr_t hint)
{
struct uvm_addr_state *uaddr;
int i;
/*
* Allocation for sz bytes at any address,
* using the addr selectors in order.
*/
for (i = 0; i < nitems(map->uaddr_any); i++) {
uaddr = map->uaddr_any[i];
if (uvm_addr_invoke(map, uaddr, first, last,
addr, sz, pmap_align, pmap_offset, prot, hint) == 0)
return 0;
}
/* Fall back to brk() and stack() address selectors. */
uaddr = map->uaddr_brk_stack;
if (uvm_addr_invoke(map, uaddr, first, last,
addr, sz, pmap_align, pmap_offset, prot, hint) == 0)
return 0;
return ENOMEM;
}
/* Calculate entry augmentation value. */
vsize_t
uvm_map_addr_augment_get(struct vm_map_entry *entry)
{
vsize_t augment;
struct vm_map_entry *left, *right;
augment = entry->fspace;
if ((left = RBT_LEFT(uvm_map_addr, entry)) != NULL)
augment = MAX(augment, left->fspace_augment);
if ((right = RBT_RIGHT(uvm_map_addr, entry)) != NULL)
augment = MAX(augment, right->fspace_augment);
return augment;
}
/*
* Update augmentation data in entry.
*/
void
uvm_map_addr_augment(struct vm_map_entry *entry)
{
vsize_t augment;
while (entry != NULL) {
/* Calculate value for augmentation. */
augment = uvm_map_addr_augment_get(entry);
/*
* Descend update.
* Once we find an entry that already has the correct value,
* stop, since it means all its parents will use the correct
* value too.
*/
if (entry->fspace_augment == augment)
return;
entry->fspace_augment = augment;
entry = RBT_PARENT(uvm_map_addr, entry);
}
}
/*
* uvm_mapanon: establish a valid mapping in map for an anon
*
* => *addr and sz must be a multiple of PAGE_SIZE.
* => *addr is ignored, except if flags contains UVM_FLAG_FIXED.
* => map must be unlocked.
*
* => align: align vaddr, must be a power-of-2.
* Align is only a hint and will be ignored if the alignment fails.
*/
int
uvm_mapanon(struct vm_map *map, vaddr_t *addr, vsize_t sz,
vsize_t align, unsigned int flags)
{
struct vm_map_entry *first, *last, *entry, *new;
struct uvm_map_deadq dead;
vm_prot_t prot;
vm_prot_t maxprot;
vm_inherit_t inherit;
int advice;
int error;
vaddr_t pmap_align, pmap_offset;
vaddr_t hint;
KASSERT((map->flags & VM_MAP_ISVMSPACE) == VM_MAP_ISVMSPACE);
KASSERT(map != kernel_map);
KASSERT((map->flags & UVM_FLAG_HOLE) == 0);
KASSERT((map->flags & VM_MAP_INTRSAFE) == 0);
splassert(IPL_NONE);
KASSERT((flags & UVM_FLAG_TRYLOCK) == 0);
/*
* We use pmap_align and pmap_offset as alignment and offset variables.
*
* Because the align parameter takes precedence over pmap prefer,
* the pmap_align will need to be set to align, with pmap_offset = 0,