File: [local] / src / sys / uvm / uvm_map.c (download)
Revision 1.6, Thu Sep 7 20:15:28 2000 UTC (23 years, 9 months ago) by art
Branch: MAIN
CVS Tags: OPENBSD_2_8_BASE, OPENBSD_2_8
Changes since 1.5: +3 -3 lines
Convert bzero to memset(X, 0..) and bcopy to memcpy.
This is to match (make diffs smaller) the code in NetBSD.
new gcc inlines those functions, so this could also be a performance win.
|
/* $NetBSD: uvm_map.c,v 1.53 1999/06/07 16:31:42 thorpej Exp $ */
/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Charles D. Cranor,
* Washington University, the University of California, Berkeley and
* its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)vm_map.c 8.3 (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
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mman.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#ifdef SYSVSHM
#include <sys/shm.h>
#endif
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_kern.h>
#define UVM_MAP
#include <uvm/uvm.h>
#ifdef DDB
#include <uvm/uvm_ddb.h>
#endif
struct uvm_cnt uvm_map_call, map_backmerge, map_forwmerge;
struct uvm_cnt uvm_mlk_call, uvm_mlk_hint;
/*
* pool for vmspace structures.
*/
struct pool uvm_vmspace_pool;
/*
* pool for dynamically-allocated map entries.
*/
struct pool uvm_map_entry_pool;
#ifdef PMAP_GROWKERNEL
/*
* 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;
#endif
/*
* macros
*/
/*
* uvm_map_entry_link: insert entry into a map
*
* => map must be locked
*/
#define uvm_map_entry_link(map, after_where, entry) do { \
(map)->nentries++; \
(entry)->prev = (after_where); \
(entry)->next = (after_where)->next; \
(entry)->prev->next = (entry); \
(entry)->next->prev = (entry); \
} while (0)
/*
* uvm_map_entry_unlink: remove entry from a map
*
* => map must be locked
*/
#define uvm_map_entry_unlink(map, entry) do { \
(map)->nentries--; \
(entry)->next->prev = (entry)->prev; \
(entry)->prev->next = (entry)->next; \
} while (0)
/*
* SAVE_HINT: saves the specified entry as the hint for future lookups.
*
* => map need not be locked (protected by hint_lock).
*/
#define SAVE_HINT(map,value) do { \
simple_lock(&(map)->hint_lock); \
(map)->hint = (value); \
simple_unlock(&(map)->hint_lock); \
} while (0)
/*
* VM_MAP_RANGE_CHECK: check and correct range
*
* => map must at least be read locked
*/
#define VM_MAP_RANGE_CHECK(map, start, end) do { \
if (start < vm_map_min(map)) \
start = vm_map_min(map); \
if (end > vm_map_max(map)) \
end = vm_map_max(map); \
if (start > end) \
start = end; \
} while (0)
/*
* local prototypes
*/
static vm_map_entry_t uvm_mapent_alloc __P((vm_map_t));
static void uvm_mapent_copy __P((vm_map_entry_t,vm_map_entry_t));
static void uvm_mapent_free __P((vm_map_entry_t));
static void uvm_map_entry_unwire __P((vm_map_t, vm_map_entry_t));
/*
* local inlines
*/
/* XXX Should not exist! */
#define vm_map_downgrade(map) \
(void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL, curproc)
/* XXX Should not exist! */
#ifdef DIAGNOSTIC
#define vm_map_upgrade(map) \
do { \
if (lockmgr(&(map)->lock, LK_UPGRADE, NULL, curproc) != 0) \
panic("vm_map_upgrade: failed to upgrade lock"); \
} while (0)
#else
#define vm_map_upgrade(map) \
(void) lockmgr(&(map)->lock, LK_UPGRADE, NULL, curproc)
#endif /* DIAGNOSTIC */
/*
* uvm_mapent_alloc: allocate a map entry
*
* => XXX: static pool for kernel map?
*/
static __inline vm_map_entry_t
uvm_mapent_alloc(map)
vm_map_t map;
{
vm_map_entry_t me;
int s;
UVMHIST_FUNC("uvm_mapent_alloc");
UVMHIST_CALLED(maphist);
if ((map->flags & VM_MAP_INTRSAFE) == 0 &&
map != kernel_map && kernel_map != NULL /* XXX */) {
me = pool_get(&uvm_map_entry_pool, PR_WAITOK);
me->flags = 0;
/* me can't be null, wait ok */
} else {
s = splimp(); /* protect kentry_free list with splimp */
simple_lock(&uvm.kentry_lock);
me = uvm.kentry_free;
if (me) uvm.kentry_free = me->next;
simple_unlock(&uvm.kentry_lock);
splx(s);
if (!me)
panic("mapent_alloc: out of static map entries, check MAX_KMAPENT");
me->flags = UVM_MAP_STATIC;
}
UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]",
me, ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map)
? TRUE : FALSE, 0, 0);
return(me);
}
/*
* uvm_mapent_free: free map entry
*
* => XXX: static pool for kernel map?
*/
static __inline void
uvm_mapent_free(me)
vm_map_entry_t me;
{
int s;
UVMHIST_FUNC("uvm_mapent_free");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]",
me, me->flags, 0, 0);
if ((me->flags & UVM_MAP_STATIC) == 0) {
pool_put(&uvm_map_entry_pool, me);
} else {
s = splimp(); /* protect kentry_free list with splimp */
simple_lock(&uvm.kentry_lock);
me->next = uvm.kentry_free;
uvm.kentry_free = me;
simple_unlock(&uvm.kentry_lock);
splx(s);
}
}
/*
* uvm_mapent_copy: copy a map entry, preserving flags
*/
static __inline void
uvm_mapent_copy(src, dst)
vm_map_entry_t src;
vm_map_entry_t dst;
{
memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) - ((char*)src));
}
/*
* uvm_map_entry_unwire: unwire a map entry
*
* => map should be locked by caller
*/
static __inline void
uvm_map_entry_unwire(map, entry)
vm_map_t map;
vm_map_entry_t entry;
{
uvm_fault_unwire(map, entry->start, entry->end);
entry->wired_count = 0;
}
/*
* uvm_map_init: init mapping system at boot time. note that we allocate
* and init the static pool of vm_map_entry_t's for the kernel here.
*/
void
uvm_map_init()
{
static struct vm_map_entry kernel_map_entry[MAX_KMAPENT];
#if defined(UVMHIST)
static struct uvm_history_ent maphistbuf[100];
static struct uvm_history_ent pdhistbuf[100];
#endif
int lcv;
/*
* first, init logging system.
*/
UVMHIST_FUNC("uvm_map_init");
UVMHIST_INIT_STATIC(maphist, maphistbuf);
UVMHIST_INIT_STATIC(pdhist, pdhistbuf);
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0);
UVMCNT_INIT(uvm_map_call, UVMCNT_CNT, 0,
"# uvm_map() successful calls", 0);
UVMCNT_INIT(map_backmerge, UVMCNT_CNT, 0, "# uvm_map() back merges", 0);
UVMCNT_INIT(map_forwmerge, UVMCNT_CNT, 0, "# uvm_map() missed forward",
0);
UVMCNT_INIT(uvm_mlk_call, UVMCNT_CNT, 0, "# map lookup calls", 0);
UVMCNT_INIT(uvm_mlk_hint, UVMCNT_CNT, 0, "# map lookup hint hits", 0);
/*
* now set up static pool of kernel map entrys ...
*/
simple_lock_init(&uvm.kentry_lock);
uvm.kentry_free = NULL;
for (lcv = 0 ; lcv < MAX_KMAPENT ; lcv++) {
kernel_map_entry[lcv].next = uvm.kentry_free;
uvm.kentry_free = &kernel_map_entry[lcv];
}
/*
* initialize the map-related pools.
*/
pool_init(&uvm_vmspace_pool, sizeof(struct vmspace),
0, 0, 0, "vmsppl", 0,
pool_page_alloc_nointr, pool_page_free_nointr, M_VMMAP);
pool_init(&uvm_map_entry_pool, sizeof(struct vm_map_entry),
0, 0, 0, "vmmpepl", 0,
pool_page_alloc_nointr, pool_page_free_nointr, M_VMMAP);
}
/*
* clippers
*/
/*
* uvm_map_clip_start: ensure that the entry begins at or after
* the starting address, if it doesn't we split the entry.
*
* => caller should use UVM_MAP_CLIP_START macro rather than calling
* this directly
* => map must be locked by caller
*/
void uvm_map_clip_start(map, entry, start)
vm_map_t map;
vm_map_entry_t entry;
vaddr_t start;
{
vm_map_entry_t new_entry;
vaddr_t new_adj;
/* uvm_map_simplify_entry(map, entry); */ /* XXX */
/*
* 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.
*/
new_entry = uvm_mapent_alloc(map);
uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
new_entry->end = start;
new_adj = start - new_entry->start;
if (entry->object.uvm_obj)
entry->offset += new_adj; /* shift start over */
entry->start = start;
if (new_entry->aref.ar_amap) {
amap_splitref(&new_entry->aref, &entry->aref, new_adj);
}
uvm_map_entry_link(map, entry->prev, new_entry);
if (UVM_ET_ISSUBMAP(entry)) {
/* ... unlikely to happen, but play it safe */
uvm_map_reference(new_entry->object.sub_map);
} else {
if (UVM_ET_ISOBJ(entry) &&
entry->object.uvm_obj->pgops &&
entry->object.uvm_obj->pgops->pgo_reference)
entry->object.uvm_obj->pgops->pgo_reference(
entry->object.uvm_obj);
}
}
/*
* uvm_map_clip_end: ensure that the entry ends at or before
* the ending address, if it does't we split the reference
*
* => caller should use UVM_MAP_CLIP_END macro rather than calling
* this directly
* => map must be locked by caller
*/
void
uvm_map_clip_end(map, entry, end)
vm_map_t map;
vm_map_entry_t entry;
vaddr_t end;
{
vm_map_entry_t new_entry;
vaddr_t new_adj; /* #bytes we move start forward */
/*
* Create a new entry and insert it
* AFTER the specified entry
*/
new_entry = uvm_mapent_alloc(map);
uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
new_entry->start = entry->end = end;
new_adj = end - entry->start;
if (new_entry->object.uvm_obj)
new_entry->offset += new_adj;
if (entry->aref.ar_amap)
amap_splitref(&entry->aref, &new_entry->aref, new_adj);
uvm_map_entry_link(map, entry, new_entry);
if (UVM_ET_ISSUBMAP(entry)) {
/* ... unlikely to happen, but play it safe */
uvm_map_reference(new_entry->object.sub_map);
} else {
if (UVM_ET_ISOBJ(entry) &&
entry->object.uvm_obj->pgops &&
entry->object.uvm_obj->pgops->pgo_reference)
entry->object.uvm_obj->pgops->pgo_reference(
entry->object.uvm_obj);
}
}
/*
* M A P - m a i n e n t r y p o i n t
*/
/*
* uvm_map: establish a valid mapping in a map
*
* => assume startp is page aligned.
* => assume size is a multiple of PAGE_SIZE.
* => assume sys_mmap provides enough of a "hint" to have us skip
* over text/data/bss area.
* => map must be unlocked (we will lock it)
* => <uobj,uoffset> value meanings (4 cases):
* [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER
* [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER
* [3] <uobj,uoffset> == normal mapping
* [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA
*
* case [4] is for kernel mappings where we don't know the offset until
* we've found a virtual address. note that kernel object offsets are
* always relative to vm_map_min(kernel_map).
* => XXXCDC: need way to map in external amap?
*/
int
uvm_map(map, startp, size, uobj, uoffset, flags)
vm_map_t map;
vaddr_t *startp; /* IN/OUT */
vsize_t size;
struct uvm_object *uobj;
vaddr_t uoffset;
uvm_flag_t flags;
{
vm_map_entry_t prev_entry, new_entry;
vm_prot_t prot = UVM_PROTECTION(flags), maxprot =
UVM_MAXPROTECTION(flags);
vm_inherit_t inherit = UVM_INHERIT(flags);
int advice = UVM_ADVICE(flags);
UVMHIST_FUNC("uvm_map");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, *startp=0x%x, size=%d, flags=0x%x)",
map, *startp, size, flags);
UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0);
/*
* step 0: sanity check of protection code
*/
if ((prot & maxprot) != prot) {
UVMHIST_LOG(maphist, "<- prot. failure: prot=0x%x, max=0x%x",
prot, maxprot,0,0);
return(KERN_PROTECTION_FAILURE);
}
/*
* step 1: figure out where to put new VM range
*/
if (vm_map_lock_try(map) == FALSE) {
if (flags & UVM_FLAG_TRYLOCK)
return(KERN_FAILURE);
vm_map_lock(map); /* could sleep here */
}
if ((prev_entry = uvm_map_findspace(map, *startp, size, startp,
uobj, uoffset, flags & UVM_FLAG_FIXED)) == NULL) {
UVMHIST_LOG(maphist,"<- uvm_map_findspace failed!",0,0,0,0);
vm_map_unlock(map);
return (KERN_NO_SPACE);
}
#ifdef PMAP_GROWKERNEL
{
/*
* If the kernel pmap can't map the requested space,
* then allocate more resources for it.
*/
if (map == kernel_map && uvm_maxkaddr < (*startp + size))
uvm_maxkaddr = pmap_growkernel(*startp + size);
}
#endif
UVMCNT_INCR(uvm_map_call);
/*
* if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER
* [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in
* either case we want to zero it before storing it in the map entry
* (because it looks strange and confusing when debugging...)
*
* if uobj is not null
* if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping
* and we do not need to change uoffset.
* if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset
* now (based on the starting address of the map). this case is
* for kernel object mappings where we don't know the offset until
* the virtual address is found (with uvm_map_findspace). the
* offset is the distance we are from the start of the map.
*/
if (uobj == NULL) {
uoffset = 0;
} else {
if (uoffset == UVM_UNKNOWN_OFFSET) {
#ifdef DIAGNOSTIC
if (UVM_OBJ_IS_KERN_OBJECT(uobj) == 0)
panic("uvm_map: unknown offset with "
"non-kernel object");
#endif
uoffset = *startp - vm_map_min(kernel_map);
}
}
/*
* step 2: try and insert in map by extending previous entry, if
* possible
* XXX: we don't try and pull back the next entry. might be useful
* for a stack, but we are currently allocating our stack in advance.
*/
if ((flags & UVM_FLAG_NOMERGE) == 0 &&
prev_entry->end == *startp && prev_entry != &map->header &&
prev_entry->object.uvm_obj == uobj) {
if (uobj && prev_entry->offset +
(prev_entry->end - prev_entry->start) != uoffset)
goto step3;
if (UVM_ET_ISSUBMAP(prev_entry))
goto step3;
if (prev_entry->protection != prot ||
prev_entry->max_protection != maxprot)
goto step3;
if (prev_entry->inheritance != inherit ||
prev_entry->advice != advice)
goto step3;
/* wired_count's must match (new area is unwired) */
if (prev_entry->wired_count)
goto step3;
/*
* can't extend a shared amap. note: no need to lock amap to
* look at refs since we don't care about its exact value.
* if it is one (i.e. we have only reference) it will stay there
*/
if (prev_entry->aref.ar_amap &&
amap_refs(prev_entry->aref.ar_amap) != 1) {
goto step3;
}
/* got it! */
UVMCNT_INCR(map_backmerge);
UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0);
/*
* drop our reference to uobj since we are extending a reference
* that we already have (the ref count can not drop to zero).
*/
if (uobj && uobj->pgops->pgo_detach)
uobj->pgops->pgo_detach(uobj);
if (prev_entry->aref.ar_amap) {
amap_extend(prev_entry, size);
}
prev_entry->end += size;
map->size += size;
UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0);
vm_map_unlock(map);
return (KERN_SUCCESS);
}
step3:
UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0);
/*
* check for possible forward merge (which we don't do) and count
* the number of times we missed a *possible* chance to merge more
*/
if ((flags & UVM_FLAG_NOMERGE) == 0 &&
prev_entry->next != &map->header &&
prev_entry->next->start == (*startp + size))
UVMCNT_INCR(map_forwmerge);
/*
* step 3: allocate new entry and link it in
*/
new_entry = uvm_mapent_alloc(map);
new_entry->start = *startp;
new_entry->end = new_entry->start + size;
new_entry->object.uvm_obj = uobj;
new_entry->offset = uoffset;
if (uobj)
new_entry->etype = UVM_ET_OBJ;
else
new_entry->etype = 0;
if (flags & UVM_FLAG_COPYONW) {
new_entry->etype |= UVM_ET_COPYONWRITE;
if ((flags & UVM_FLAG_OVERLAY) == 0)
new_entry->etype |= UVM_ET_NEEDSCOPY;
}
new_entry->protection = prot;
new_entry->max_protection = maxprot;
new_entry->inheritance = inherit;
new_entry->wired_count = 0;
new_entry->advice = advice;
if (flags & UVM_FLAG_OVERLAY) {
/*
* to_add: for BSS we overallocate a little since we
* are likely to extend
*/
vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ?
UVM_AMAP_CHUNK << PAGE_SHIFT : 0;
struct vm_amap *amap = amap_alloc(size, to_add, M_WAITOK);
new_entry->aref.ar_pageoff = 0;
new_entry->aref.ar_amap = amap;
} else {
new_entry->aref.ar_amap = NULL;
}
uvm_map_entry_link(map, prev_entry, new_entry);
map->size += size;
/*
* Update the free space hint
*/
if ((map->first_free == prev_entry) &&
(prev_entry->end >= new_entry->start))
map->first_free = new_entry;
UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
vm_map_unlock(map);
return(KERN_SUCCESS);
}
/*
* uvm_map_lookup_entry: find map entry at or before an address
*
* => map must at least be read-locked by caller
* => entry is returned in "entry"
* => return value is true if address is in the returned entry
*/
boolean_t
uvm_map_lookup_entry(map, address, entry)
vm_map_t map;
vaddr_t address;
vm_map_entry_t *entry; /* OUT */
{
vm_map_entry_t cur;
vm_map_entry_t last;
UVMHIST_FUNC("uvm_map_lookup_entry");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,addr=0x%x,ent=0x%x)",
map, address, entry, 0);
/*
* start looking either from the head of the
* list, or from the hint.
*/
simple_lock(&map->hint_lock);
cur = map->hint;
simple_unlock(&map->hint_lock);
if (cur == &map->header)
cur = cur->next;
UVMCNT_INCR(uvm_mlk_call);
if (address >= cur->start) {
/*
* go from hint to end of list.
*
* but first, make a quick check to see if
* we are already looking at the entry we
* want (which is usually the case).
* note also that we don't need to save the hint
* here... it is the same hint (unless we are
* at the header, in which case the hint didn't
* buy us anything anyway).
*/
last = &map->header;
if ((cur != last) && (cur->end > address)) {
UVMCNT_INCR(uvm_mlk_hint);
*entry = cur;
UVMHIST_LOG(maphist,"<- got it via hint (0x%x)",
cur, 0, 0, 0);
return (TRUE);
}
} else {
/*
* go from start to hint, *inclusively*
*/
last = cur->next;
cur = map->header.next;
}
/*
* search linearly
*/
while (cur != last) {
if (cur->end > address) {
if (address >= cur->start) {
/*
* save this lookup for future
* hints, and return
*/
*entry = cur;
SAVE_HINT(map, cur);
UVMHIST_LOG(maphist,"<- search got it (0x%x)",
cur, 0, 0, 0);
return (TRUE);
}
break;
}
cur = cur->next;
}
*entry = cur->prev;
SAVE_HINT(map, *entry);
UVMHIST_LOG(maphist,"<- failed!",0,0,0,0);
return (FALSE);
}
/*
* uvm_map_findspace: find "length" sized space in "map".
*
* => "hint" is a hint about where we want it, unless fixed is true
* (in which case we insist on using "hint").
* => "result" is VA returned
* => uobj/uoffset are to be used to handle VAC alignment, if required
* => caller must at least have read-locked map
* => returns NULL on failure, or pointer to prev. map entry if success
* => note this is a cross between the old vm_map_findspace and vm_map_find
*/
vm_map_entry_t
uvm_map_findspace(map, hint, length, result, uobj, uoffset, fixed)
vm_map_t map;
vaddr_t hint;
vsize_t length;
vaddr_t *result; /* OUT */
struct uvm_object *uobj;
vaddr_t uoffset;
boolean_t fixed;
{
vm_map_entry_t entry, next, tmp;
vaddr_t end;
UVMHIST_FUNC("uvm_map_findspace");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, fixed=%d)",
map, hint, length, fixed);
if (hint < map->min_offset) { /* check ranges ... */
if (fixed) {
UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0);
return(NULL);
}
hint = map->min_offset;
}
if (hint > map->max_offset) {
UVMHIST_LOG(maphist,"<- VA 0x%x > range [0x%x->0x%x]",
hint, map->min_offset, map->max_offset, 0);
return(NULL);
}
/*
* Look for the first possible address; if there's already
* something at this address, we have to start after it.
*/
if (!fixed && hint == map->min_offset) {
if ((entry = map->first_free) != &map->header)
hint = entry->end;
} else {
if (uvm_map_lookup_entry(map, hint, &tmp)) {
/* "hint" address already in use ... */
if (fixed) {
UVMHIST_LOG(maphist,"<- fixed & VA in use",
0, 0, 0, 0);
return(NULL);
}
hint = tmp->end;
}
entry = tmp;
}
/*
* Look through the rest of the map, trying to fit a new region in
* the gap between existing regions, or after the very last region.
* note: entry->end = base VA of current gap,
* next->start = VA of end of current gap
*/
for (;; hint = (entry = next)->end) {
/*
* Find the end of the proposed new region. Be sure we didn't
* go beyond the end of the map, or wrap around the address;
* if so, we lose. Otherwise, if this is the last entry, or
* if the proposed new region fits before the next entry, we
* win.
*/
#ifdef PMAP_PREFER
/*
* push hint forward as needed to avoid VAC alias problems.
* we only do this if a valid offset is specified.
*/
if (!fixed && uoffset != UVM_UNKNOWN_OFFSET)
PMAP_PREFER(uoffset, &hint);
#endif
end = hint + length;
if (end > map->max_offset || end < hint) {
UVMHIST_LOG(maphist,"<- failed (off end)", 0,0,0,0);
return (NULL);
}
next = entry->next;
if (next == &map->header || next->start >= end)
break;
if (fixed) {
UVMHIST_LOG(maphist,"<- fixed mapping failed", 0,0,0,0);
return(NULL); /* only one shot at it ... */
}
}
SAVE_HINT(map, entry);
*result = hint;
UVMHIST_LOG(maphist,"<- got it! (result=0x%x)", hint, 0,0,0);
return (entry);
}
/*
* U N M A P - m a i n h e l p e r f u n c t i o n s
*/
/*
* uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop")
*
* => caller must check alignment and size
* => map must be locked by caller
* => we return a list of map entries that we've remove from the map
* in "entry_list"
*/
int
uvm_unmap_remove(map, start, end, entry_list)
vm_map_t map;
vaddr_t start,end;
vm_map_entry_t *entry_list; /* OUT */
{
vm_map_entry_t entry, first_entry, next;
vaddr_t len;
UVMHIST_FUNC("uvm_unmap_remove");
UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x, start=0x%x, end=0x%x)",
map, start, end, 0);
VM_MAP_RANGE_CHECK(map, start, end);
/*
* find first entry
*/
if (uvm_map_lookup_entry(map, start, &first_entry) == TRUE) {
/* clip and go... */
entry = first_entry;
UVM_MAP_CLIP_START(map, entry, start);
/* critical! prevents stale hint */
SAVE_HINT(map, entry->prev);
} else {
entry = first_entry->next;
}
/*
* Save the free space hint
*/
if (map->first_free->start >= start)
map->first_free = entry->prev;
/*
* note: we now re-use first_entry for a different task. we remove
* a number of map entries from the map and save them in a linked
* list headed by "first_entry". once we remove them from the map
* the caller should unlock the map and drop the references to the
* backing objects [c.f. uvm_unmap_detach]. the object is to
* seperate unmapping from reference dropping. why?
* [1] the map has to be locked for unmapping
* [2] the map need not be locked for reference dropping
* [3] dropping references may trigger pager I/O, and if we hit
* a pager that does synchronous I/O we may have to wait for it.
* [4] we would like all waiting for I/O to occur with maps unlocked
* so that we don't block other threads.
*/
first_entry = NULL;
*entry_list = NULL; /* to be safe */
/*
* break up the area into map entry sized regions and unmap. note
* that all mappings have to be removed before we can even consider
* dropping references to amaps or VM objects (otherwise we could end
* up with a mapping to a page on the free list which would be very bad)
*/
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end);
next = entry->next;
len = entry->end - entry->start;
/*
* unwire before removing addresses from the pmap; otherwise
* unwiring will put the entries back into the pmap (XXX).
*/
if (entry->wired_count)
uvm_map_entry_unwire(map, entry);
/*
* special case: handle mappings to anonymous kernel objects.
* we want to free these pages right away...
*/
if (UVM_ET_ISOBJ(entry) &&
UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) {
#ifdef DIAGNOSTIC
if (vm_map_pmap(map) != pmap_kernel())
panic("uvm_unmap_remove: kernel object "
"mapped by non-kernel map");
#endif
/*
* note: kernel object mappings are currently used in
* two ways:
* [1] "normal" mappings of pages in the kernel object
* [2] uvm_km_valloc'd allocations in which we
* pmap_enter in some non-kernel-object page
* (e.g. vmapbuf).
*
* for case [1], we need to remove the mapping from
* the pmap and then remove the page from the kernel
* object (because, once pages in a kernel object are
* unmapped they are no longer needed, unlike, say,
* a vnode where you might want the data to persist
* until flushed out of a queue).
*
* for case [2], we need to remove the mapping from
* the pmap. there shouldn't be any pages at the
* specified offset in the kernel object [but it
* doesn't hurt to call uvm_km_pgremove just to be
* safe?]
*
* uvm_km_pgremove currently does the following:
* for pages in the kernel object in range:
* - drops the swap slot
* - uvm_pagefree the page
*
* note there is version of uvm_km_pgremove() that
* is used for "intrsafe" objects.
*/
/*
* remove mappings from pmap and drop the pages
* from the object. offsets are always relative
* to vm_map_min(kernel_map).
*/
if (UVM_OBJ_IS_INTRSAFE_OBJECT(entry->object.uvm_obj)) {
#if defined(PMAP_NEW)
pmap_kremove(entry->start, len);
#else
pmap_remove(pmap_kernel(), entry->start,
entry->start + len);
#endif
uvm_km_pgremove_intrsafe(entry->object.uvm_obj,
entry->start - vm_map_min(kernel_map),
entry->end - vm_map_min(kernel_map));
} else {
pmap_remove(pmap_kernel(), entry->start,
entry->start + len);
uvm_km_pgremove(entry->object.uvm_obj,
entry->start - vm_map_min(kernel_map),
entry->end - vm_map_min(kernel_map));
}
/*
* null out kernel_object reference, we've just
* dropped it
*/
entry->etype &= ~UVM_ET_OBJ;
entry->object.uvm_obj = NULL; /* to be safe */
} else {
/*
* remove mappings the standard way.
*/
pmap_remove(map->pmap, entry->start, entry->end);
}
/*
* remove entry from map and put it on our list of entries
* that we've nuked. then go do next entry.
*/
UVMHIST_LOG(maphist, " removed map entry 0x%x", entry, 0, 0,0);
uvm_map_entry_unlink(map, entry);
map->size -= len;
entry->next = first_entry;
first_entry = entry;
entry = next; /* next entry, please */
}
/*
* now we've cleaned up the map and are ready for the caller to drop
* references to the mapped objects.
*/
*entry_list = first_entry;
UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
return(KERN_SUCCESS);
}
/*
* uvm_unmap_detach: drop references in a chain of map entries
*
* => we will free the map entries as we traverse the list.
*/
void
uvm_unmap_detach(first_entry, amap_unref_flags)
vm_map_entry_t first_entry;
int amap_unref_flags;
{
vm_map_entry_t next_entry;
UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist);
while (first_entry) {
#ifdef DIAGNOSTIC
/*
* sanity check
*/
/* was part of vm_map_entry_delete() */
if (first_entry->wired_count)
panic("unmap: still wired!");
#endif
UVMHIST_LOG(maphist,
" detach 0x%x: amap=0x%x, obj=0x%x, submap?=%d",
first_entry, first_entry->aref.ar_amap,
first_entry->object.uvm_obj,
UVM_ET_ISSUBMAP(first_entry));
/*
* drop reference to amap, if we've got one
*/
if (first_entry->aref.ar_amap)
amap_unref(first_entry, amap_unref_flags);
/*
* drop reference to our backing object, if we've got one
*/
if (UVM_ET_ISSUBMAP(first_entry)) {
/* ... unlikely to happen, but play it safe */
uvm_map_deallocate(first_entry->object.sub_map);
} else {
if (UVM_ET_ISOBJ(first_entry) &&
first_entry->object.uvm_obj->pgops->pgo_detach)
first_entry->object.uvm_obj->pgops->
pgo_detach(first_entry->object.uvm_obj);
}
/*
* next entry
*/
next_entry = first_entry->next;
uvm_mapent_free(first_entry);
first_entry = next_entry;
}
/*
* done!
*/
UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
return;
}
/*
* E X T R A C T I O N F U N C T I O N S
*/
/*
* uvm_map_reserve: reserve space in a vm_map for future use.
*
* => we reserve space in a map by putting a dummy map entry in the
* map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE)
* => map should be unlocked (we will write lock it)
* => we return true if we were able to reserve space
* => XXXCDC: should be inline?
*/
int
uvm_map_reserve(map, size, offset, raddr)
vm_map_t map;
vsize_t size;
vaddr_t offset; /* hint for pmap_prefer */
vaddr_t *raddr; /* OUT: reserved VA */
{
UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x, offset=0x%x,addr=0x%x)",
map,size,offset,raddr);
size = round_page(size);
if (*raddr < vm_map_min(map))
*raddr = vm_map_min(map); /* hint */
/*
* reserve some virtual space.
*/
if (uvm_map(map, raddr, size, NULL, offset,
UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
UVM_ADV_RANDOM, UVM_FLAG_NOMERGE)) != KERN_SUCCESS) {
UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
return (FALSE);
}
UVMHIST_LOG(maphist, "<- done (*raddr=0x%x)", *raddr,0,0,0);
return (TRUE);
}
/*
* uvm_map_replace: replace a reserved (blank) area of memory with
* real mappings.
*
* => caller must WRITE-LOCK the map
* => we return TRUE if replacement was a success
* => we expect the newents chain to have nnewents entrys on it and
* we expect newents->prev to point to the last entry on the list
* => note newents is allowed to be NULL
*/
int
uvm_map_replace(map, start, end, newents, nnewents)
struct vm_map *map;
vaddr_t start, end;
vm_map_entry_t newents;
int nnewents;
{
vm_map_entry_t oldent, last;
UVMHIST_FUNC("uvm_map_replace");
UVMHIST_CALLED(maphist);
/*
* first find the blank map entry at the specified address
*/
if (!uvm_map_lookup_entry(map, start, &oldent)) {
return(FALSE);
}
/*
* check to make sure we have a proper blank entry
*/
if (oldent->start != start || oldent->end != end ||
oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) {
return (FALSE);
}
#ifdef DIAGNOSTIC
/*
* sanity check the newents chain
*/
{
vm_map_entry_t tmpent = newents;
int nent = 0;
vaddr_t cur = start;
while (tmpent) {
nent++;
if (tmpent->start < cur)
panic("uvm_map_replace1");
if (tmpent->start > tmpent->end || tmpent->end > end) {
printf("tmpent->start=0x%lx, tmpent->end=0x%lx, end=0x%lx\n",
tmpent->start, tmpent->end, end);
panic("uvm_map_replace2");
}
cur = tmpent->end;
if (tmpent->next) {
if (tmpent->next->prev != tmpent)
panic("uvm_map_replace3");
} else {
if (newents->prev != tmpent)
panic("uvm_map_replace4");
}
tmpent = tmpent->next;
}
if (nent != nnewents)
panic("uvm_map_replace5");
}
#endif
/*
* map entry is a valid blank! replace it. (this does all the
* work of map entry link/unlink...).
*/
if (newents) {
last = newents->prev; /* we expect this */
/* critical: flush stale hints out of map */
SAVE_HINT(map, newents);
if (map->first_free == oldent)
map->first_free = last;
last->next = oldent->next;
last->next->prev = last;
newents->prev = oldent->prev;
newents->prev->next = newents;
map->nentries = map->nentries + (nnewents - 1);
} else {
/* critical: flush stale hints out of map */
SAVE_HINT(map, oldent->prev);
if (map->first_free == oldent)
map->first_free = oldent->prev;
/* NULL list of new entries: just remove the old one */
uvm_map_entry_unlink(map, oldent);
}
/*
* now we can free the old blank entry, unlock the map and return.
*/
uvm_mapent_free(oldent);
return(TRUE);
}
/*
* uvm_map_extract: extract a mapping from a map and put it somewhere
* (maybe removing the old mapping)
*
* => maps should be unlocked (we will write lock them)
* => returns 0 on success, error code otherwise
* => start must be page aligned
* => len must be page sized
* => flags:
* UVM_EXTRACT_REMOVE: remove mappings from srcmap
* UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only)
* UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs
* UVM_EXTRACT_FIXPROT: set prot to maxprot as we go
* >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<<
* >>>NOTE: QREF's must be unmapped via the QREF path, thus should only
* be used from within the kernel in a kernel level map <<<
*/
int
uvm_map_extract(srcmap, start, len, dstmap, dstaddrp, flags)
vm_map_t srcmap, dstmap;
vaddr_t start, *dstaddrp;
vsize_t len;
int flags;
{
vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge,
oldstart;
vm_map_entry_t chain, endchain, entry, orig_entry, newentry, deadentry;
vm_map_entry_t oldentry;
vsize_t elen;
int nchain, error, copy_ok;
UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(srcmap=0x%x,start=0x%x, len=0x%x", srcmap, start,
len,0);
UVMHIST_LOG(maphist," ...,dstmap=0x%x, flags=0x%x)", dstmap,flags,0,0);
#ifdef DIAGNOSTIC
/*
* step 0: sanity check: start must be on a page boundary, length
* must be page sized. can't ask for CONTIG/QREF if you asked for
* REMOVE.
*/
if ((start & PAGE_MASK) || (len & PAGE_MASK))
panic("uvm_map_extract1");
if (flags & UVM_EXTRACT_REMOVE)
if (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF))
panic("uvm_map_extract2");
#endif
/*
* step 1: reserve space in the target map for the extracted area
*/
dstaddr = *dstaddrp;
if (uvm_map_reserve(dstmap, len, start, &dstaddr) == FALSE)
return(ENOMEM);
*dstaddrp = dstaddr; /* pass address back to caller */
UVMHIST_LOG(maphist, " dstaddr=0x%x", dstaddr,0,0,0);
/*
* step 2: setup for the extraction process loop by init'ing the
* map entry chain, locking src map, and looking up the first useful
* entry in the map.
*/
end = start + len;
newend = dstaddr + len;
chain = endchain = NULL;
nchain = 0;
vm_map_lock(srcmap);
if (uvm_map_lookup_entry(srcmap, start, &entry)) {
/* "start" is within an entry */
if (flags & UVM_EXTRACT_QREF) {
/*
* for quick references we don't clip the entry, so
* the entry may map space "before" the starting
* virtual address... this is the "fudge" factor
* (which can be non-zero only the first time
* through the "while" loop in step 3).
*/
fudge = start - entry->start;
} else {
/*
* normal reference: we clip the map to fit (thus
* fudge is zero)
*/
UVM_MAP_CLIP_START(srcmap, entry, start);
SAVE_HINT(srcmap, entry->prev);
fudge = 0;
}
} else {
/* "start" is not within an entry ... skip to next entry */
if (flags & UVM_EXTRACT_CONTIG) {
error = EINVAL;
goto bad; /* definite hole here ... */
}
entry = entry->next;
fudge = 0;
}
/* save values from srcmap for step 6 */
orig_entry = entry;
orig_fudge = fudge;
/*
* step 3: now start looping through the map entries, extracting
* as we go.
*/
while (entry->start < end && entry != &srcmap->header) {
/* if we are not doing a quick reference, clip it */
if ((flags & UVM_EXTRACT_QREF) == 0)
UVM_MAP_CLIP_END(srcmap, entry, end);
/* clear needs_copy (allow chunking) */
if (UVM_ET_ISNEEDSCOPY(entry)) {
if (fudge)
oldstart = entry->start;
else
oldstart = 0; /* XXX: gcc */
amap_copy(srcmap, entry, M_NOWAIT, TRUE, start, end);
if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */
error = ENOMEM;
goto bad;
}
/* amap_copy could clip (during chunk)! update fudge */
if (fudge) {
fudge = fudge - (entry->start - oldstart);
orig_fudge = fudge;
}
}
/* calculate the offset of this from "start" */
oldoffset = (entry->start + fudge) - start;
/* allocate a new map entry */
newentry = uvm_mapent_alloc(dstmap);
if (newentry == NULL) {
error = ENOMEM;
goto bad;
}
/* set up new map entry */
newentry->next = NULL;
newentry->prev = endchain;
newentry->start = dstaddr + oldoffset;
newentry->end =
newentry->start + (entry->end - (entry->start + fudge));
if (newentry->end > newend || newentry->end < newentry->start)
newentry->end = newend;
newentry->object.uvm_obj = entry->object.uvm_obj;
if (newentry->object.uvm_obj) {
if (newentry->object.uvm_obj->pgops->pgo_reference)
newentry->object.uvm_obj->pgops->
pgo_reference(newentry->object.uvm_obj);
newentry->offset = entry->offset + fudge;
} else {
newentry->offset = 0;
}
newentry->etype = entry->etype;
newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ?
entry->max_protection : entry->protection;
newentry->max_protection = entry->max_protection;
newentry->inheritance = entry->inheritance;
newentry->wired_count = 0;
newentry->aref.ar_amap = entry->aref.ar_amap;
if (newentry->aref.ar_amap) {
newentry->aref.ar_pageoff =
entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT);
amap_ref(newentry, AMAP_SHARED |
((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0));
} else {
newentry->aref.ar_pageoff = 0;
}
newentry->advice = entry->advice;
/* now link it on the chain */
nchain++;
if (endchain == NULL) {
chain = endchain = newentry;
} else {
endchain->next = newentry;
endchain = newentry;
}
/* end of 'while' loop! */
if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end &&
(entry->next == &srcmap->header ||
entry->next->start != entry->end)) {
error = EINVAL;
goto bad;
}
entry = entry->next;
fudge = 0;
}
/*
* step 4: close off chain (in format expected by uvm_map_replace)
*/
if (chain)
chain->prev = endchain;
/*
* step 5: attempt to lock the dest map so we can pmap_copy.
* note usage of copy_ok:
* 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5)
* 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7
*/
if (srcmap == dstmap || vm_map_lock_try(dstmap) == TRUE) {
copy_ok = 1;
if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
nchain)) {
if (srcmap != dstmap)
vm_map_unlock(dstmap);
error = EIO;
goto bad;
}
} else {
copy_ok = 0;
/* replace defered until step 7 */
}
/*
* step 6: traverse the srcmap a second time to do the following:
* - if we got a lock on the dstmap do pmap_copy
* - if UVM_EXTRACT_REMOVE remove the entries
* we make use of orig_entry and orig_fudge (saved in step 2)
*/
if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) {
/* purge possible stale hints from srcmap */
if (flags & UVM_EXTRACT_REMOVE) {
SAVE_HINT(srcmap, orig_entry->prev);
if (srcmap->first_free->start >= start)
srcmap->first_free = orig_entry->prev;
}
entry = orig_entry;
fudge = orig_fudge;
deadentry = NULL; /* for UVM_EXTRACT_REMOVE */
while (entry->start < end && entry != &srcmap->header) {
if (copy_ok) {
oldoffset = (entry->start + fudge) - start;
elen = min(end, entry->end) - (entry->start + fudge);
pmap_copy(dstmap->pmap, srcmap->pmap, dstaddr + oldoffset,
elen, entry->start + fudge);
}
/* we advance "entry" in the following if statement */
if (flags & UVM_EXTRACT_REMOVE) {
pmap_remove(srcmap->pmap, entry->start,
entry->end);
oldentry = entry; /* save entry */
entry = entry->next; /* advance */
uvm_map_entry_unlink(srcmap, oldentry);
/* add to dead list */
oldentry->next = deadentry;
deadentry = oldentry;
} else {
entry = entry->next; /* advance */
}
/* end of 'while' loop */
fudge = 0;
}
/*
* unlock dstmap. we will dispose of deadentry in
* step 7 if needed
*/
if (copy_ok && srcmap != dstmap)
vm_map_unlock(dstmap);
}
else
deadentry = NULL; /* XXX: gcc */
/*
* step 7: we are done with the source map, unlock. if copy_ok
* is 0 then we have not replaced the dummy mapping in dstmap yet
* and we need to do so now.
*/
vm_map_unlock(srcmap);
if ((flags & UVM_EXTRACT_REMOVE) && deadentry)
uvm_unmap_detach(deadentry, 0); /* dispose of old entries */
/* now do the replacement if we didn't do it in step 5 */
if (copy_ok == 0) {
vm_map_lock(dstmap);
error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
nchain);
vm_map_unlock(dstmap);
if (error == FALSE) {
error = EIO;
goto bad2;
}
}
/*
* done!
*/
return(0);
/*
* bad: failure recovery
*/
bad:
vm_map_unlock(srcmap);
bad2: /* src already unlocked */
if (chain)
uvm_unmap_detach(chain,
(flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0);
uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */
return(error);
}
/* end of extraction functions */
/*
* uvm_map_submap: punch down part of a map into a submap
*
* => only the kernel_map is allowed to be submapped
* => the purpose of submapping is to break up the locking granularity
* of a larger map
* => the range specified must have been mapped previously with a uvm_map()
* call [with uobj==NULL] to create a blank map entry in the main map.
* [And it had better still be blank!]
* => maps which contain submaps should never be copied or forked.
* => to remove a submap, use uvm_unmap() on the main map
* and then uvm_map_deallocate() the submap.
* => main map must be unlocked.
* => submap must have been init'd and have a zero reference count.
* [need not be locked as we don't actually reference it]
*/
int
uvm_map_submap(map, start, end, submap)
vm_map_t map, submap;
vaddr_t start, end;
{
vm_map_entry_t entry;
int result;
UVMHIST_FUNC("uvm_map_submap"); UVMHIST_CALLED(maphist);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &entry)) {
UVM_MAP_CLIP_START(map, entry, start);
UVM_MAP_CLIP_END(map, entry, end); /* to be safe */
}
else {
entry = NULL;
}
if (entry != NULL &&
entry->start == start && entry->end == end &&
entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL &&
!UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) {
/*
* doit!
*/
entry->etype |= UVM_ET_SUBMAP;
entry->object.sub_map = submap;
entry->offset = 0;
uvm_map_reference(submap);
result = KERN_SUCCESS;
} else {
result = KERN_INVALID_ARGUMENT;
}
vm_map_unlock(map);
return(result);
}
/*
* uvm_map_protect: change map protection
*
* => set_max means set max_protection.
* => map must be unlocked.
*/
#define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \
~VM_PROT_WRITE : VM_PROT_ALL)
#define max(a,b) ((a) > (b) ? (a) : (b))
int
uvm_map_protect(map, start, end, new_prot, set_max)
vm_map_t map;
vaddr_t start, end;
vm_prot_t new_prot;
boolean_t set_max;
{
vm_map_entry_t current, entry;
UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)",
map, start, end, new_prot);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &entry)) {
UVM_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 (UVM_ET_ISSUBMAP(current))
return (KERN_INVALID_ARGUMENT);
if ((new_prot & current->max_protection) != new_prot) {
vm_map_unlock(map);
return (KERN_PROTECTION_FAILURE);
}
current = current->next;
}
/* go back and fix up protections (no need to clip this time). */
current = entry;
while ((current != &map->header) && (current->start < end)) {
vm_prot_t old_prot;
UVM_MAP_CLIP_END(map, current, end);
old_prot = current->protection;
if (set_max)
current->protection =
(current->max_protection = new_prot) & old_prot;
else
current->protection = new_prot;
/*
* update physical map if necessary. worry about copy-on-write
* here -- CHECK THIS XXX
*/
if (current->protection != old_prot) {
/* update pmap! */
pmap_protect(map->pmap, current->start, current->end,
current->protection & MASK(entry));
}
current = current->next;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist, "<- done",0,0,0,0);
return(KERN_SUCCESS);
}
#undef max
#undef MASK
/*
* uvm_map_inherit: set inheritance code for range of addrs in map.
*
* => map must be unlocked
* => note that the inherit code is used during a "fork". see fork
* code for details.
*/
int
uvm_map_inherit(map, start, end, new_inheritance)
vm_map_t map;
vaddr_t start;
vaddr_t end;
vm_inherit_t new_inheritance;
{
vm_map_entry_t entry, temp_entry;
UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_inh=0x%x)",
map, start, end, new_inheritance);
switch (new_inheritance) {
case VM_INHERIT_NONE:
case VM_INHERIT_COPY:
case VM_INHERIT_SHARE:
break;
default:
UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
return (KERN_INVALID_ARGUMENT);
}
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &temp_entry)) {
entry = temp_entry;
UVM_MAP_CLIP_START(map, entry, start);
} else {
entry = temp_entry->next;
}
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end);
entry->inheritance = new_inheritance;
entry = entry->next;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
return(KERN_SUCCESS);
}
/*
* uvm_map_advice: set advice code for range of addrs in map.
*
* => map must be unlocked
*/
int
uvm_map_advice(map, start, end, new_advice)
vm_map_t map;
vaddr_t start;
vaddr_t end;
int new_advice;
{
vm_map_entry_t entry, temp_entry;
UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_adv=0x%x)",
map, start, end, new_advice);
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (uvm_map_lookup_entry(map, start, &temp_entry)) {
entry = temp_entry;
UVM_MAP_CLIP_START(map, entry, start);
} else {
entry = temp_entry->next;
}
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end);
switch (new_advice) {
case MADV_NORMAL:
case MADV_RANDOM:
case MADV_SEQUENTIAL:
/* nothing special here */
break;
#if 0
case MADV_WILLNEED:
/* activate all these pages */
/* XXX */
/*
* should invent a "weak" mode for uvm_fault()
* which would only do the PGO_LOCKED pgo_get().
*/
break;
case MADV_DONTNEED:
/* deactivate this page */
/* XXX */
/*
* vm_page_t p;
* uvm_lock_pageq();
* for (p in each page)
* if (not_wired)
* uvm_pagedeactivate(p);
* uvm_unlock_pageq();
*/
break;
case MADV_SPACEAVAIL:
/*
* XXXMRG
* what is this? i think: "ensure that we have
* allocated backing-store for these pages". this
* is going to require changes in the page daemon,
* as it will free swap space allocated to pages in
* core. there's also what to do for
* device/file/anonymous memory..
*/
break;
case MADV_GARBAGE:
/* pages are `empty' and can be garbage collected */
/* XXX */
/*
* (perhaps MADV_FREE? check freebsd's MADV_FREE).
*
* need to do this:
* - clear all the referenced and modified bits on
* the pages,
* - delete any backing store,
* - mark the page as `recycable'.
*
* So, if you start paging, the pages would be thrown out
* and then zero-filled the next time they're used.
* Otherwise you'd just reuse them directly. Once the
* page has been modified again, it would no longer be
* recyclable. That way, malloc() can just tell the
* system when pages are `empty'; if memory is needed,
* they'll be tossed; if memory is not needed, there
* will be no additional overhead.
*/
break;
#endif
default:
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
return (KERN_INVALID_ARGUMENT);
}
entry->advice = new_advice;
entry = entry->next;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
return (KERN_SUCCESS);
}
/*
* uvm_map_pageable: sets the pageability of a range in a map.
*
* => regions sepcified as not pageable require lock-down (wired) memory
* and page tables.
* => map must not be locked.
* => XXXCDC: check this and try and clean it up.
*/
int
uvm_map_pageable(map, start, end, new_pageable)
vm_map_t map;
vaddr_t start, end;
boolean_t new_pageable;
{
vm_map_entry_t entry, start_entry;
vaddr_t failed = 0;
int rv;
UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_pageable=0x%x)",
map, start, end, new_pageable);
#ifdef DIAGNOSTIC
if ((map->flags & VM_MAP_PAGEABLE) == 0)
panic("uvm_map_pageable: map %p not pageable", map);
#endif
vm_map_lock(map);
VM_MAP_RANGE_CHECK(map, start, end);
/*
* only one pageability change may take place at one time, since
* uvm_fault_wire assumes it will be called only once for each
* wiring/unwiring. therefore, we have to make sure we're actually
* changing the pageability for the entire region. we do so before
* making any changes.
*/
if (uvm_map_lookup_entry(map, start, &start_entry) == FALSE) {
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
return (KERN_INVALID_ADDRESS);
}
entry = start_entry;
/*
* handle wiring and unwiring seperately.
*/
if (new_pageable) { /* unwire */
UVM_MAP_CLIP_START(map, entry, start);
/*
* unwiring. first ensure that the range to be unwired is
* really wired down and that there are no holes.
*/
while ((entry != &map->header) && (entry->start < end)) {
if (entry->wired_count == 0 ||
(entry->end < end &&
(entry->next == &map->header ||
entry->next->start > entry->end))) {
vm_map_unlock(map);
UVMHIST_LOG(maphist,
"<- done (INVALID UNWIRE ARG)",0,0,0,0);
return (KERN_INVALID_ARGUMENT);
}
entry = entry->next;
}
/*
* now decrement the wiring count for each region. if a region
* becomes completely unwired, unwire its physical pages and
* mappings.
*
* Note, uvm_fault_unwire() (called via uvm_map_entry_unwire())
* does not lock the map, so we don't have to do anything
* special regarding locking here.
*/
entry = start_entry;
while ((entry != &map->header) && (entry->start < end)) {
UVM_MAP_CLIP_END(map, entry, end);
entry->wired_count--;
if (entry->wired_count == 0)
uvm_map_entry_unwire(map, entry);
entry = entry->next;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
return(KERN_SUCCESS);
/*
* end of unwire case!
*/
}
/*
* wire case: in two passes [XXXCDC: ugly block of code here]
*
* 1: holding the write lock, we create any anonymous maps that need
* to be created. then we clip each map entry to the region to
* be wired and increment its wiring count.
*
* 2: we downgrade to a read lock, and call uvm_fault_wire to fault
* in the pages for any newly wired area (wired_count is 1).
*
* downgrading to a read lock for uvm_fault_wire avoids a possible
* deadlock with another thread that may have faulted on one of
* the pages to be wired (it would mark the page busy, blocking
* us, then in turn block on the map lock that we hold). because
* of problems in the recursive lock package, we cannot upgrade
* to a write lock in vm_map_lookup. thus, any actions that
* require the write lock must be done beforehand. because we
* keep the read lock on the map, the copy-on-write status of the
* entries we modify here cannot change.
*/
while ((entry != &map->header) && (entry->start < end)) {
if (entry->wired_count == 0) { /* not already wired? */
/*
* perform actions of vm_map_lookup that need the
* write lock on the map: create an anonymous map
* for a copy-on-write region, or an anonymous map
* for a zero-fill region. (XXXCDC: submap case
* ok?)
*/
if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
/*
* XXXCDC: protection vs. max_protection??
* (wirefault uses max?)
* XXXCDC: used to do it always if
* uvm_obj == NULL (wrong?)
*/
if ( UVM_ET_ISNEEDSCOPY(entry) &&
(entry->protection & VM_PROT_WRITE) != 0) {
amap_copy(map, entry, M_WAITOK, TRUE,
start, end);
/* XXXCDC: wait OK? */
}
}
} /* wired_count == 0 */
UVM_MAP_CLIP_START(map, entry, start);
UVM_MAP_CLIP_END(map, entry, end);
entry->wired_count++;
/*
* Check for holes
*/
if (entry->end < end && (entry->next == &map->header ||
entry->next->start > entry->end)) {
/*
* found one. amap creation actions do not need to
* be undone, but the wired counts need to be restored.
*/
while (entry != &map->header && entry->end > start) {
entry->wired_count--;
entry = entry->prev;
}
vm_map_unlock(map);
UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0);
return (KERN_INVALID_ARGUMENT);
}
entry = entry->next;
}
/*
* Pass 2.
*/
vm_map_downgrade(map);
rv = 0;
entry = start_entry;
while (entry != &map->header && entry->start < end) {
if (entry->wired_count == 1) {
rv = uvm_fault_wire(map, entry->start, entry->end,
entry->protection);
if (rv) {
/*
* wiring failed. break out of the loop.
* we'll clean up the map below, once we
* have a write lock again.
*/
break;
}
}
entry = entry->next;
}
if (rv) { /* failed? */
/*
* Get back to an exclusive (write) lock.
*/
vm_map_upgrade(map);
/*
* first drop the wiring count on all the entries
* which haven't actually been wired yet.
*/
failed = entry->start;
while (entry != &map->header && entry->start < end)
entry->wired_count--;
/*
* now, unlock the map, and unwire all the pages that
* were successfully wired above.
*/
vm_map_unlock(map);
(void) uvm_map_pageable(map, start, failed, TRUE);
UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0);
return(rv);
}
/* We are holding a read lock here. */
vm_map_unlock_read(map);
UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
return(KERN_SUCCESS);
}
/*
* uvm_map_clean: push dirty pages off to backing store.
*
* => valid flags:
* if (flags & PGO_SYNCIO): dirty pages are written synchronously
* if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean
* if (flags & PGO_FREE): any cached pages are freed after clean
* => returns an error if any part of the specified range isn't mapped
* => never a need to flush amap layer since the anonymous memory has
* no permanent home...
* => called from sys_msync()
* => caller must not write-lock map (read OK).
* => we may sleep while cleaning if SYNCIO [with map read-locked]
*/
int
uvm_map_clean(map, start, end, flags)
vm_map_t map;
vaddr_t start, end;
int flags;
{
vm_map_entry_t current;
vm_map_entry_t entry;
vsize_t size;
struct uvm_object *object;
vaddr_t offset;
UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,flags=0x%x)",
map, start, end, flags);
vm_map_lock_read(map);
VM_MAP_RANGE_CHECK(map, start, end);
if (!uvm_map_lookup_entry(map, start, &entry)) {
vm_map_unlock_read(map);
return(KERN_INVALID_ADDRESS);
}
/*
* Make a first pass to check for holes.
*/
for (current = entry; current->start < end; current = current->next) {
if (UVM_ET_ISSUBMAP(current)) {
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);
}
}
/*
* add "cleanit" flag to flags (for generic flush routine).
* then make a second pass, cleaning/uncaching pages from
* the indicated objects as we go.
*/
flags = flags | PGO_CLEANIT;
for (current = entry; current->start < end; current = current->next) {
offset = current->offset + (start - current->start);
size = (end <= current->end ? end : current->end) - start;
/*
* get object/offset. can't be submap (checked above).
*/
object = current->object.uvm_obj;
simple_lock(&object->vmobjlock);
/*
* flush pages if we've got a valid backing object.
* note that object is locked.
* XXX should we continue on an error?
*/
if (object && object->pgops) {
if (!object->pgops->pgo_flush(object, offset,
offset+size, flags)) {
simple_unlock(&object->vmobjlock);
vm_map_unlock_read(map);
return (KERN_FAILURE);
}
}
simple_unlock(&object->vmobjlock);
start += size;
}
vm_map_unlock_read(map);
return(KERN_SUCCESS);
}
/*
* uvm_map_checkprot: check protection in map
*
* => must allow specified protection in a fully allocated region.
* => map must be read or write locked by caller.
*/
boolean_t
uvm_map_checkprot(map, start, end, protection)
vm_map_t map;
vaddr_t start, end;
vm_prot_t protection;
{
vm_map_entry_t entry;
vm_map_entry_t tmp_entry;
if (!uvm_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);
}
/*
* uvmspace_alloc: allocate a vmspace structure.
*
* - structure includes vm_map and pmap
* - XXX: no locking on this structure
* - refcnt set to 1, rest must be init'd by caller
*/
struct vmspace *
uvmspace_alloc(min, max, pageable)
vaddr_t min, max;
int pageable;
{
struct vmspace *vm;
UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist);
vm = pool_get(&uvm_vmspace_pool, PR_WAITOK);
uvmspace_init(vm, NULL, min, max, pageable);
UVMHIST_LOG(maphist,"<- done (vm=0x%x)", vm,0,0,0);
return (vm);
}
/*
* uvmspace_init: initialize a vmspace structure.
*
* - XXX: no locking on this structure
* - refcnt set to 1, rest must me init'd by caller
*/
void
uvmspace_init(vm, pmap, min, max, pageable)
struct vmspace *vm;
struct pmap *pmap;
vaddr_t min, max;
boolean_t pageable;
{
UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist);
memset(vm, 0, sizeof(*vm));
uvm_map_setup(&vm->vm_map, min, max, pageable ? VM_MAP_PAGEABLE : 0);
if (pmap)
pmap_reference(pmap);
else
#if defined(PMAP_NEW)
pmap = pmap_create();
#else
pmap = pmap_create(0);
#endif
vm->vm_map.pmap = pmap;
vm->vm_refcnt = 1;
UVMHIST_LOG(maphist,"<- done",0,0,0,0);
}
/*
* uvmspace_share: share a vmspace between two proceses
*
* - XXX: no locking on vmspace
* - used for vfork, threads(?)
*/
void
uvmspace_share(p1, p2)
struct proc *p1, *p2;
{
p2->p_vmspace = p1->p_vmspace;
p1->p_vmspace->vm_refcnt++;
}
/*
* uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace
*
* - XXX: no locking on vmspace
*/
void
uvmspace_unshare(p)
struct proc *p;
{
struct vmspace *nvm, *ovm = p->p_vmspace;
int s;
if (ovm->vm_refcnt == 1)
/* nothing to do: vmspace isn't shared in the first place */
return;
/* make a new vmspace, still holding old one */
nvm = uvmspace_fork(ovm);
s = splhigh(); /* make this `atomic' */
pmap_deactivate(p); /* unbind old vmspace */
p->p_vmspace = nvm;
pmap_activate(p); /* switch to new vmspace */
splx(s); /* end of critical section */
uvmspace_free(ovm); /* drop reference to old vmspace */
}
/*
* uvmspace_exec: the process wants to exec a new program
*
* - XXX: no locking on vmspace
*/
void
uvmspace_exec(p)
struct proc *p;
{
struct vmspace *nvm, *ovm = p->p_vmspace;
vm_map_t map = &ovm->vm_map;
int s;
#ifdef sparc
/* XXX cgd 960926: the sparc #ifdef should be a MD hook */
kill_user_windows(p); /* before stack addresses go away */
#endif
/*
* see if more than one process is using this vmspace...
*/
if (ovm->vm_refcnt == 1) {
/*
* if p is the only process using its vmspace then we can safely
* recycle that vmspace for the program that is being exec'd.
*/
#ifdef SYSVSHM
/*
* SYSV SHM semantics require us to kill all segments on an exec
*/
if (ovm->vm_shm)
shmexit(ovm);
#endif
/*
* now unmap the old program
*/
uvm_unmap(map, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
} else {
/*
* p's vmspace is being shared, so we can't reuse it for p since
* it is still being used for others. allocate a new vmspace
* for p
*/
nvm = uvmspace_alloc(map->min_offset, map->max_offset,
(map->flags & VM_MAP_PAGEABLE) ? TRUE : FALSE);
#if (defined(i386) || defined(pc532)) && !defined(PMAP_NEW)
/*
* allocate zero fill area in the new vmspace's map for user
* page tables for ports that have old style pmaps that keep
* user page tables in the top part of the process' address
* space.
*
* XXXCDC: this should go away once all pmaps are fixed
*/
{
vaddr_t addr = VM_MAXUSER_ADDRESS;
if (uvm_map(&nvm->vm_map, &addr, VM_MAX_ADDRESS - addr,
NULL, UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL,
UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_NORMAL,
UVM_FLAG_FIXED|UVM_FLAG_COPYONW)) != KERN_SUCCESS)
panic("vm_allocate of PT page area failed");
}
#endif
/*
* install new vmspace and drop our ref to the old one.
*/
s = splhigh();
pmap_deactivate(p);
p->p_vmspace = nvm;
pmap_activate(p);
splx(s);
uvmspace_free(ovm);
}
}
/*
* uvmspace_free: free a vmspace data structure
*
* - XXX: no locking on vmspace
*/
void
uvmspace_free(vm)
struct vmspace *vm;
{
vm_map_entry_t dead_entries;
UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist);
UVMHIST_LOG(maphist,"(vm=0x%x) ref=%d", vm, vm->vm_refcnt,0,0);
if (--vm->vm_refcnt == 0) {
/*
* lock the map, to wait out all other references to it. delete
* all of the mappings and pages they hold, then call the pmap
* module to reclaim anything left.
*/
vm_map_lock(&vm->vm_map);
if (vm->vm_map.nentries) {
(void)uvm_unmap_remove(&vm->vm_map,
vm->vm_map.min_offset, vm->vm_map.max_offset,
&dead_entries);
if (dead_entries != NULL)
uvm_unmap_detach(dead_entries, 0);
}
pmap_destroy(vm->vm_map.pmap);
vm->vm_map.pmap = NULL;
pool_put(&uvm_vmspace_pool, vm);
}
UVMHIST_LOG(maphist,"<- done", 0,0,0,0);
}
/*
* F O R K - m a i n e n t r y p o i n t
*/
/*
* uvmspace_fork: fork a process' main map
*
* => create a new vmspace for child process from parent.
* => parent's map must not be locked.
*/
struct vmspace *
uvmspace_fork(vm1)
struct vmspace *vm1;
{
struct vmspace *vm2;
vm_map_t old_map = &vm1->vm_map;
vm_map_t new_map;
vm_map_entry_t old_entry;
vm_map_entry_t new_entry;
pmap_t new_pmap;
boolean_t protect_child;
UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist);
#if (defined(i386) || defined(pc532)) && !defined(PMAP_NEW)
/*
* avoid copying any of the parent's pagetables or other per-process
* objects that reside in the map by marking all of them non-inheritable
* XXXCDC: should go away
*/
(void) uvm_map_inherit(old_map, VM_MAXUSER_ADDRESS, VM_MAX_ADDRESS,
VM_INHERIT_NONE);
#endif
vm_map_lock(old_map);
vm2 = uvmspace_alloc(old_map->min_offset, old_map->max_offset,
(old_map->flags & VM_MAP_PAGEABLE) ? TRUE : FALSE);
memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy,
(caddr_t) (vm1 + 1) - (caddr_t) &vm1->vm_startcopy);
new_map = &vm2->vm_map; /* XXX */
new_pmap = new_map->pmap;
old_entry = old_map->header.next;
/*
* go entry-by-entry
*/
while (old_entry != &old_map->header) {
/*
* first, some sanity checks on the old entry
*/
if (UVM_ET_ISSUBMAP(old_entry))
panic("fork: encountered a submap during fork (illegal)");
if (!UVM_ET_ISCOPYONWRITE(old_entry) &&
UVM_ET_ISNEEDSCOPY(old_entry))
panic("fork: non-copy_on_write map entry marked needs_copy (illegal)");
switch (old_entry->inheritance) {
case VM_INHERIT_NONE:
/*
* drop the mapping
*/
break;
case VM_INHERIT_SHARE:
/*
* share the mapping: this means we want the old and
* new entries to share amaps and backing objects.
*/
/*
* if the old_entry needs a new amap (due to prev fork)
* then we need to allocate it now so that we have
* something we own to share with the new_entry. [in
* other words, we need to clear needs_copy]
*/
if (UVM_ET_ISNEEDSCOPY(old_entry)) {
/* get our own amap, clears needs_copy */
amap_copy(old_map, old_entry, M_WAITOK, FALSE,
0, 0);
/* XXXCDC: WAITOK??? */
}
new_entry = uvm_mapent_alloc(new_map);
/* old_entry -> new_entry */
uvm_mapent_copy(old_entry, new_entry);
/* new pmap has nothing wired in it */
new_entry->wired_count = 0;
/*
* gain reference to object backing the map (can't
* be a submap, already checked this case).
*/
if (new_entry->aref.ar_amap)
/* share reference */
amap_ref(new_entry, AMAP_SHARED);
if (new_entry->object.uvm_obj &&
new_entry->object.uvm_obj->pgops->pgo_reference)
new_entry->object.uvm_obj->
pgops->pgo_reference(
new_entry->object.uvm_obj);
/* insert entry at end of new_map's entry list */
uvm_map_entry_link(new_map, new_map->header.prev,
new_entry);
/*
* pmap_copy the mappings: this routine is optional
* but if it is there it will reduce the number of
* page faults in the new proc.
*/
pmap_copy(new_pmap, old_map->pmap, new_entry->start,
(old_entry->end - old_entry->start),
old_entry->start);
break;
case VM_INHERIT_COPY:
/*
* copy-on-write the mapping (using mmap's
* MAP_PRIVATE semantics)
*
* allocate new_entry, adjust reference counts.
* (note that new references are read-only).
*/
new_entry = uvm_mapent_alloc(new_map);
/* old_entry -> new_entry */
uvm_mapent_copy(old_entry, new_entry);
if (new_entry->aref.ar_amap)
amap_ref(new_entry, 0);
if (new_entry->object.uvm_obj &&
new_entry->object.uvm_obj->pgops->pgo_reference)
new_entry->object.uvm_obj->pgops->pgo_reference
(new_entry->object.uvm_obj);
/* new pmap has nothing wired in it */
new_entry->wired_count = 0;
new_entry->etype |=
(UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY);
uvm_map_entry_link(new_map, new_map->header.prev,
new_entry);
/*
* the new entry will need an amap. it will either
* need to be copied from the old entry or created
* from scratch (if the old entry does not have an
* amap). can we defer this process until later
* (by setting "needs_copy") or do we need to copy
* the amap now?
*
* we must copy the amap now if any of the following
* conditions hold:
* 1. the old entry has an amap and that amap is
* being shared. this means that the old (parent)
* process is sharing the amap with another
* process. if we do not clear needs_copy here
* we will end up in a situation where both the
* parent and child process are refering to the
* same amap with "needs_copy" set. if the
* parent write-faults, the fault routine will
* clear "needs_copy" in the parent by allocating
* a new amap. this is wrong because the
* parent is supposed to be sharing the old amap
* and the new amap will break that.
*
* 2. if the old entry has an amap and a non-zero
* wire count then we are going to have to call
* amap_cow_now to avoid page faults in the
* parent process. since amap_cow_now requires
* "needs_copy" to be clear we might as well
* clear it here as well.
*
*/
if (old_entry->aref.ar_amap != NULL) {
if ((amap_flags(old_entry->aref.ar_amap) &
AMAP_SHARED) != 0 ||
old_entry->wired_count != 0) {
amap_copy(new_map, new_entry, M_WAITOK, FALSE,
0, 0);
/* XXXCDC: M_WAITOK ... ok? */
}
}
/*
* if the parent's entry is wired down, then the
* parent process does not want page faults on
* access to that memory. this means that we
* cannot do copy-on-write because we can't write
* protect the old entry. in this case we
* resolve all copy-on-write faults now, using
* amap_cow_now. note that we have already
* allocated any needed amap (above).
*/
if (old_entry->wired_count != 0) {
/*
* resolve all copy-on-write faults now
* (note that there is nothing to do if
* the old mapping does not have an amap).
* XXX: is it worthwhile to bother with pmap_copy
* in this case?
*/
if (old_entry->aref.ar_amap)
amap_cow_now(new_map, new_entry);
} else {
/*
* setup mappings to trigger copy-on-write faults
* we must write-protect the parent if it has
* an amap and it is not already "needs_copy"...
* if it is already "needs_copy" then the parent
* has already been write-protected by a previous
* fork operation.
*
* if we do not write-protect the parent, then
* we must be sure to write-protect the child
* after the pmap_copy() operation.
*
* XXX: pmap_copy should have some way of telling
* us that it didn't do anything so we can avoid
* calling pmap_protect needlessly.
*/
if (old_entry->aref.ar_amap) {
if (!UVM_ET_ISNEEDSCOPY(old_entry)) {
if (old_entry->max_protection & VM_PROT_WRITE) {
pmap_protect(old_map->pmap,
old_entry->start,
old_entry->end,
old_entry->protection &
~VM_PROT_WRITE);
}
old_entry->etype |= UVM_ET_NEEDSCOPY;
}
/*
* parent must now be write-protected
*/
protect_child = FALSE;
} else {
/*
* we only need to protect the child if the
* parent has write access.
*/
if (old_entry->max_protection & VM_PROT_WRITE)
protect_child = TRUE;
else
protect_child = FALSE;
}
/*
* copy the mappings
* XXX: need a way to tell if this does anything
*/
pmap_copy(new_pmap, old_map->pmap,
new_entry->start,
(old_entry->end - old_entry->start),
old_entry->start);
/*
* protect the child's mappings if necessary
*/
if (protect_child) {
pmap_protect(new_pmap, new_entry->start,
new_entry->end,
new_entry->protection &
~VM_PROT_WRITE);
}
}
break;
} /* end of switch statement */
old_entry = old_entry->next;
}
new_map->size = old_map->size;
vm_map_unlock(old_map);
#if (defined(i386) || defined(pc532)) && !defined(PMAP_NEW)
/*
* allocate zero fill area in the new vmspace's map for user
* page tables for ports that have old style pmaps that keep
* user page tables in the top part of the process' address
* space.
*
* XXXCDC: this should go away once all pmaps are fixed
*/
{
vaddr_t addr = VM_MAXUSER_ADDRESS;
if (uvm_map(new_map, &addr, VM_MAX_ADDRESS - addr, NULL,
UVM_UNKNOWN_OFFSET, UVM_MAPFLAG(UVM_PROT_ALL,
UVM_PROT_ALL, UVM_INH_NONE, UVM_ADV_NORMAL,
UVM_FLAG_FIXED|UVM_FLAG_COPYONW)) != KERN_SUCCESS)
panic("vm_allocate of PT page area failed");
}
#endif
#ifdef SYSVSHM
if (vm1->vm_shm)
shmfork(vm1, vm2);
#endif
#ifdef PMAP_FORK
pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap);
#endif
UVMHIST_LOG(maphist,"<- done",0,0,0,0);
return(vm2);
}
#if defined(DDB)
/*
* DDB hooks
*/
/*
* uvm_map_print: print out a map
*/
void
uvm_map_print(map, full)
vm_map_t map;
boolean_t full;
{
uvm_map_printit(map, full, printf);
}
/*
* uvm_map_printit: actually prints the map
*/
void
uvm_map_printit(map, full, pr)
vm_map_t map;
boolean_t full;
int (*pr) __P((const char *, ...));
{
vm_map_entry_t entry;
(*pr)("MAP %p: [0x%lx->0x%lx]\n", map, map->min_offset,map->max_offset);
(*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=0x%x\n",
map->nentries, map->size, map->ref_count, map->timestamp,
map->flags);
#ifdef pmap_resident_count
(*pr)("\tpmap=%p(resident=%d)\n", map->pmap,
pmap_resident_count(map->pmap));
#else
/* XXXCDC: this should be required ... */
(*pr)("\tpmap=%p(resident=<<NOT SUPPORTED!!!>>)\n", map->pmap);
#endif
if (!full)
return;
for (entry = map->header.next; entry != &map->header;
entry = entry->next) {
(*pr)(" - %p: 0x%lx->0x%lx: obj=%p/0x%x, amap=%p/%d\n",
entry, entry->start, entry->end, entry->object.uvm_obj,
entry->offset, entry->aref.ar_amap, entry->aref.ar_pageoff);
(*pr)(
"\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, wc=%d, adv=%d\n",
(entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F',
(entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F',
(entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F',
entry->protection, entry->max_protection,
entry->inheritance, entry->wired_count, entry->advice);
}
}
/*
* uvm_object_print: print out an object
*/
void
uvm_object_print(uobj, full)
struct uvm_object *uobj;
boolean_t full;
{
uvm_object_printit(uobj, full, printf);
}
/*
* uvm_object_printit: actually prints the object
*/
void
uvm_object_printit(uobj, full, pr)
struct uvm_object *uobj;
boolean_t full;
int (*pr) __P((const char *, ...));
{
struct vm_page *pg;
int cnt = 0;
(*pr)("OBJECT %p: pgops=%p, npages=%d, ", uobj, uobj->pgops,
uobj->uo_npages);
if (UVM_OBJ_IS_KERN_OBJECT(uobj))
(*pr)("refs=<SYSTEM>\n");
else
(*pr)("refs=%d\n", uobj->uo_refs);
if (!full) return;
(*pr)(" PAGES <pg,offset>:\n ");
for (pg = uobj->memq.tqh_first ; pg ; pg = pg->listq.tqe_next, cnt++) {
(*pr)("<%p,0x%lx> ", pg, pg->offset);
if ((cnt % 3) == 2) (*pr)("\n ");
}
if ((cnt % 3) != 2) (*pr)("\n");
}
/*
* uvm_page_print: print out a page
*/
void
uvm_page_print(pg, full)
struct vm_page *pg;
boolean_t full;
{
uvm_page_printit(pg, full, printf);
}
/*
* uvm_page_printit: actually print the page
*/
void
uvm_page_printit(pg, full, pr)
struct vm_page *pg;
boolean_t full;
int (*pr) __P((const char *, ...));
{
struct vm_page *lcv;
struct uvm_object *uobj;
struct pglist *pgl;
(*pr)("PAGE %p:\n", pg);
(*pr)(" flags=0x%x, pqflags=0x%x, vers=%d, wire_count=%d, pa=0x%lx\n",
pg->flags, pg->pqflags, pg->version, pg->wire_count, (long)pg->phys_addr);
(*pr)(" uobject=%p, uanon=%p, offset=0x%lx loan_count=%d\n",
pg->uobject, pg->uanon, pg->offset, pg->loan_count);
#if defined(UVM_PAGE_TRKOWN)
if (pg->flags & PG_BUSY)
(*pr)(" owning process = %d, tag=%s\n",
pg->owner, pg->owner_tag);
else
(*pr)(" page not busy, no owner\n");
#else
(*pr)(" [page ownership tracking disabled]\n");
#endif
if (!full)
return;
/* cross-verify object/anon */
if ((pg->pqflags & PQ_FREE) == 0) {
if (pg->pqflags & PQ_ANON) {
if (pg->uanon == NULL || pg->uanon->u.an_page != pg)
(*pr)(" >>> ANON DOES NOT POINT HERE <<< (%p)\n",
(pg->uanon) ? pg->uanon->u.an_page : NULL);
else
(*pr)(" anon backpointer is OK\n");
} else {
uobj = pg->uobject;
if (uobj) {
(*pr)(" checking object list\n");
for (lcv = uobj->memq.tqh_first ; lcv ;
lcv = lcv->listq.tqe_next) {
if (lcv == pg) break;
}
if (lcv)
(*pr)(" page found on object list\n");
else
(*pr)(" >>> PAGE NOT FOUND ON OBJECT LIST! <<<\n");
}
}
}
/* cross-verify page queue */
if (pg->pqflags & PQ_FREE)
pgl = &uvm.page_free[uvm_page_lookup_freelist(pg)];
else if (pg->pqflags & PQ_INACTIVE)
pgl = (pg->pqflags & PQ_SWAPBACKED) ?
&uvm.page_inactive_swp : &uvm.page_inactive_obj;
else if (pg->pqflags & PQ_ACTIVE)
pgl = &uvm.page_active;
else
pgl = NULL;
if (pgl) {
(*pr)(" checking pageq list\n");
for (lcv = pgl->tqh_first ; lcv ; lcv = lcv->pageq.tqe_next) {
if (lcv == pg) break;
}
if (lcv)
(*pr)(" page found on pageq list\n");
else
(*pr)(" >>> PAGE NOT FOUND ON PAGEQ LIST! <<<\n");
}
}
#endif
![[BACK]](/icons/back.gif){kind=icon}
Return to uvm_map.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / sys / uvm