Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
f7fbb1462b
NetBSD/sys/uvm/uvm_map.c
chuck 08a4f7fa4c fix bug in uvm_map_extract, remove case. make sure we update the loop 
variable before removing the entry from the map.
[bug was not causing problems because the remove case isn't currently
 being used ...]
1998-05-22 02:01:54 +00:00

3275 lines
85 KiB
C
Raw Blame History

/* $NetBSD: uvm_map.c,v 1.20 1998/05/22 02:01:54 chuck Exp $ */
/*
* XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!
* >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
*/
/*
* 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.
*/
#include "opt_uvmhist.h"
#include "opt_pmap_new.h"
/*
* 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>
#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>
struct uvm_cnt uvm_map_call, map_backmerge, map_forwmerge;
struct uvm_cnt uvm_mlk_call, uvm_mlk_hint;
/*
* 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
*/
/*
* 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->entries_pageable) {
MALLOC(me, vm_map_entry_t, sizeof(struct vm_map_entry),
M_VMMAPENT, M_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 kernel map entries, check MAX_KMAPENT");
me->flags = UVM_MAP_STATIC;
}
UVMHIST_LOG(maphist, "<- new entry=0x%x [pageable=%d]",
me, map->entries_pageable, 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) {
FREE(me, M_VMMAPENT);
} 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;
{
bcopy(src, dst, ((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->pmap, 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];
}
}
/*
* 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)
register vm_map_t map;
register vm_map_entry_t entry;
register vm_offset_t start;
{
register vm_map_entry_t new_entry;
vm_offset_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_ISMAP(entry)) {
uvm_map_reference(new_entry->object.share_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;
vm_offset_t end;
{
vm_map_entry_t new_entry;
vm_offset_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_ISMAP(entry)) {
uvm_map_reference(new_entry->object.share_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;
vm_offset_t *startp; /* IN/OUT */
vm_size_t size;
struct uvm_object *uobj;
vm_offset_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);
}
#if defined(PMAP_GROWKERNEL) /* hack */
{
/* locked by kernel_map lock */
static vm_offset_t maxkaddr = 0;
/*
* hack: grow kernel PTPs in advance.
*/
if (map == kernel_map && maxkaddr < (*startp + size)) {
pmap_growkernel(*startp + size);
maxkaddr = *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 (uobj->uo_refs != UVM_OBJ_KERN)
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_ISMAP(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 am_ref 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 &&
prev_entry->aref.ar_amap->am_ref != 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
*/
vm_offset_t to_add = (flags & UVM_FLAG_AMAPPAD) ?
UVM_AMAP_CHUNK * PAGE_SIZE : 0;
struct vm_amap *amap = amap_alloc(size, to_add, M_WAITOK);
new_entry->aref.ar_slotoff = 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)
register vm_map_t map;
register vm_offset_t address;
vm_map_entry_t *entry; /* OUT */
{
register vm_map_entry_t cur;
register 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;
vm_offset_t hint;
vm_size_t length;
vm_offset_t *result; /* OUT */
struct uvm_object *uobj;
vm_offset_t uoffset;
boolean_t fixed;
{
vm_map_entry_t entry, next, tmp;
vm_offset_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
* => if the "start"/"stop" range lie within a mapping of a share map,
* then the unmap takes place within the context of that share map
* rather than in the main map, unless the "mainonly" flag is set.
* (e.g. the "exit" system call would want to set "mainonly").
* => we return a list of map entries that we've remove from the map
* in "entry_list"
*/
int
uvm_unmap_remove(map, start, end, mainonly, entry_list)
vm_map_t map;
vm_offset_t start,end;
boolean_t mainonly;
vm_map_entry_t *entry_list; /* OUT */
{
int result, refs;
vm_map_entry_t entry, first_entry, next;
vm_offset_t len;
boolean_t already_removed;
struct uvm_object *uobj;
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) {
/*
* start lies within a mapped region. first check to see if
* it is within a sharemap (in which case we recurse and unmap
* within the context of the share map).
*/
if (UVM_ET_ISMAP(first_entry) &&
!UVM_ET_ISSUBMAP(first_entry) &&
mainonly == 0 && end <= first_entry->end) {
/*
* is a share map and in range ...
* XXX: do address transforms if share VA's != main VA's
* note: main map kept locked during share map unlock
*/
result = uvm_unmap(first_entry->object.share_map,
start, end, 0);
*entry_list = NULL;
return(result);
}
/* non-share map: 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) &&
entry->object.uvm_obj->uo_refs == UVM_OBJ_KERN) {
#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:
* - pmap_page_protect them out of all pmaps
* - uvm_pagefree the page
*
* note that in case [1] the pmap_page_protect call
* in uvm_km_pgremove may very well be redundant
* because we have already removed the mappings
* beforehand with pmap_remove (or pmap_kremove).
* in the PMAP_NEW case, the pmap_page_protect call
* may not do anything, since PMAP_NEW allows the
* kernel to enter/remove kernel mappings without
* bothing to keep track of the mappings (e.g. via
* pv_entry lists). XXX: because of this, in the
* future we should consider removing the
* pmap_page_protect from uvm_km_pgremove some time
* in the future.
*/
/*
* remove mappings from pmap
*/
#if defined(PMAP_NEW)
pmap_kremove(entry->start, len);
#else
pmap_remove(pmap_kernel(), entry->start,
entry->start+len);
#endif
/*
* remove pages from a kernel object (offsets are
* always relative to vm_map_min(kernel_map)).
*/
uvm_km_pgremove(entry->object.uvm_obj,
entry->start - vm_map_min(kernel_map),
entry->end - vm_map_min(kernel_map));
already_removed = TRUE;
/*
* null out kernel_object reference, we've just
* dropped it
*/
entry->etype &= ~UVM_ET_OBJ;
entry->object.uvm_obj = NULL; /* to be safe */
} else
already_removed = FALSE;
/*
* remove mappings now. for sharemaps, check to see if
* the reference count is one (i.e. not being shared right
* now). if so, use the cheaper pmap_remove() rather than
* the more expensive share_protect functions.
*/
if (!map->is_main_map) {
simple_lock(&map->ref_lock);
refs = map->ref_count;
simple_unlock(&map->ref_lock);
}
#if defined(sparc)
else
refs = 0; /* XXX: gcc */
#endif
if (map->is_main_map || (!map->is_main_map && refs == 1)) {
if (!already_removed)
pmap_remove(map->pmap, entry->start,
entry->end);
} else {
/* share map... must remove all mappings */
if (entry->aref.ar_amap) {
simple_lock(&entry->aref.ar_amap->am_l);
amap_share_protect(entry, VM_PROT_NONE);
simple_unlock(&entry->aref.ar_amap->am_l);
}
if (UVM_ET_ISOBJ(entry)) {
uobj = entry->object.uvm_obj;
simple_lock(&uobj->vmobjlock);
uobj->pgops->pgo_shareprot(entry, VM_PROT_NONE);
simple_unlock(&uobj->vmobjlock);
}
}
/*
* remove 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, map?=%d", first_entry,
first_entry->aref.ar_amap, first_entry->object.uvm_obj,
UVM_ET_ISMAP(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_ISMAP(first_entry)) {
uvm_map_deallocate(first_entry->object.share_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;
vm_size_t size;
vm_offset_t offset; /* hint for pmap_prefer */
vm_offset_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;
vm_offset_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;
vm_offset_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;
vm_offset_t start, *dstaddrp;
vm_size_t len;
int flags;
{
vm_offset_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;
vm_size_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 = 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_slotoff =
entry->aref.ar_slotoff + (fudge / PAGE_SIZE);
amap_ref(newentry, AMAP_SHARED |
((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0));
} else {
newentry->aref.ar_slotoff = 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, 1); /* ??? */
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;
vm_offset_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_MAP|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.
* => XXXCDC: does not work properly with share maps. rethink.
*/
#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;
vm_offset_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) {
if (UVM_ET_ISMAP(current) &&
!UVM_ET_ISSUBMAP(current)) {
/* share map? gotta go down a level */
vm_map_entry_t share_entry;
vm_offset_t share_end;
/*
* note: a share map has its own address
* space (starting at zero). current->offset
* is the offset into the share map our
* mapping starts. the length of our
* mapping is (current->end - current->start).
* thus, our mapping goes from current->offset
* to share_end (which is: current->offset +
* length) in the share map's address space.
*
* thus for any share_entry we need to make
* sure that the addresses we've got fall in
* the range we want. we use:
* max(any share_entry->start, current->offset)
* min(any share_entry->end, share_end)
*
* of course to change our pmap we've got to
* convert the share * map address back to
* our map's virtual address space using:
* our_va = share_va -
* current->offset + current->start
*
* XXXCDC: protection change in sharemap may
* require use of pmap_page_protect. needs
* a rethink.
*/
vm_map_lock(current->object.share_map);
/*
* note: current->offset is offset into
* share map
*/
(void)uvm_map_lookup_entry(
current->object.share_map,
current->offset, &share_entry);
share_end = current->offset +
(current->end - current->start);
while ((share_entry !=
&current->object.share_map->header) &&
(share_entry->start < share_end)) {
pmap_protect(map->pmap,
(max(share_entry->start,
current->offset) -
current->offset + current->start),
min(share_entry->end, share_end) -
current->offset + current->start,
current->protection &
MASK(share_entry));
share_entry = share_entry->next;
}
vm_map_unlock(current->object.share_map);
} else { /* not share map! */
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.
* => XXXCDC: currently only works in main map. what about share map?
*/
int
uvm_map_inherit(map, start, end, new_inheritance)
vm_map_t map;
vm_offset_t start;
vm_offset_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_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;
vm_offset_t start, end;
boolean_t new_pageable;
{
vm_map_entry_t entry, start_entry;
vm_offset_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);
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.
*/
#if 0 /* not necessary: uvm_fault_unwire does not lock */
lock_set_recursive(&map->lock);
#endif /* XXXCDC */
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;
}
#if 0 /* XXXCDC: not necessary, see above */
lock_clear_recursive(&map->lock);
#endif
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.
*
* we don't have to do this for entries that point
* to sharing maps, because we won't hold the lock
* on the sharing map.
*/
if (!UVM_ET_ISMAP(entry)) { /* not sharing map */
/*
* 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.
*/
/*
* HACK HACK HACK HACK
*
* if we are wiring in the kernel map or a submap of it, unlock the
* map to avoid deadlocks. we trust that the kernel threads are
* well-behaved, and therefore will not do anything destructive to
* this region of the map while we have it unlocked. we cannot
* trust user threads to do the same.
*
* HACK HACK HACK HACK
*/
if (vm_map_pmap(map) == pmap_kernel()) {
vm_map_unlock(map); /* trust me ... */
} else {
vm_map_set_recursive(&map->lock);
lockmgr(&map->lock, LK_DOWNGRADE, (void *)0);
}
rv = 0;
entry = start_entry;
while (entry != &map->header && entry->start < end) {
/*
* if uvm_fault_wire fails for any page we need to undo what has
* been done. we decrement the wiring count for those pages
* which have not yet been wired (now) and unwire those that
* have * (later).
*
* XXX this violates the locking protocol on the map, needs to
* be fixed. [because we only have a read lock on map we
* shouldn't be changing wired_count?]
*/
if (rv) {
entry->wired_count--;
} else if (entry->wired_count == 1) {
rv = uvm_fault_wire(map, entry->start, entry->end);
if (rv) {
failed = entry->start;
entry->wired_count--;
}
}
entry = entry->next;
}
if (vm_map_pmap(map) == pmap_kernel()) {
vm_map_lock(map); /* relock */
} else {
vm_map_clear_recursive(&map->lock);
}
if (rv) { /* failed? */
vm_map_unlock(map);
(void) uvm_map_pageable(map, start, failed, TRUE);
UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0);
return(rv);
}
vm_map_unlock(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]
* => XXX: does this handle share maps properly?
*/
int
uvm_map_clean(map, start, end, flags)
vm_map_t map;
vm_offset_t start, end;
int flags;
{
vm_map_entry_t current;
vm_map_entry_t entry;
vm_size_t size;
struct uvm_object *object;
vm_offset_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. special case to handle share maps.
*/
if (UVM_ET_ISMAP(current)) { /* share map? */
register vm_map_t smap;
vm_map_entry_t tentry;
vm_size_t tsize;
smap = current->object.share_map;
vm_map_lock_read(smap);
(void) uvm_map_lookup_entry(smap, offset, &tentry);
tsize = tentry->end - offset;
if (tsize < size)
size = tsize;
object = tentry->object.uvm_obj;
offset = tentry->offset + (offset - tentry->start);
simple_lock(&object->vmobjlock);
vm_map_unlock_read(smap);
} else {
object = current->object.uvm_obj;
simple_lock(&object->vmobjlock);
}
/*
* flush pages if writing is allowed. note that object is
* locked.
* XXX should we continue on an error?
*/
if (object && object->pgops &&
(current->protection & VM_PROT_WRITE) != 0) {
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;
vm_offset_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)
vm_offset_t min, max;
int pageable;
{
struct vmspace *vm;
UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist);
MALLOC(vm, struct vmspace *, sizeof(struct vmspace), M_VMMAP, M_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;
vm_offset_t min, max;
boolean_t pageable;
{
UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist);
bzero(vm, sizeof(*vm));
uvm_map_setup(&vm->vm_map, min, max, pageable);
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, 0);
} 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->entries_pageable);
#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
*/
{
vm_offset_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,
TRUE, &dead_entries);
if (dead_entries != NULL)
uvm_unmap_detach(dead_entries, 0);
}
pmap_destroy(vm->vm_map.pmap);
vm->vm_map.pmap = NULL;
FREE(vm, M_VMMAP);
}
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->entries_pageable);
bcopy(&vm1->vm_startcopy, &vm2->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)");
else if (UVM_ET_ISMAP(old_entry)) {
if (UVM_ET_ISNEEDSCOPY(old_entry))
panic("fork: encountered a share map entry that needs_copy (illegal)");
if (UVM_ET_ISCOPYONWRITE(old_entry))
panic("fork: encountered a copy_on_write share map entry (illegal)");
if (old_entry->aref.ar_amap)
panic("fork: detected share map entry that has an amap (illegal)");
} else {
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 objects backing the map
*/
if (UVM_ET_ISMAP(new_entry)) { /* share map? */
uvm_map_reference(old_entry->object.share_map);
} else {
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)
*/
/*
* share maps: we special case it (handled by
* uvm_map_sharemapcopy)
*/
if (UVM_ET_ISMAP(old_entry)) { /* share map? */
uvm_map_sharemapcopy(old_map, old_entry,
new_map);
break;
}
/*
* not a share map. 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 ((old_entry->aref.ar_amap->am_flags &
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
*/
{
vm_offset_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
UVMHIST_LOG(maphist,"<- done",0,0,0,0);
return(vm2);
}
/*
* uvm_map_sharemapcopy: handle the copying of a share map during a
* fork. this is a helper function for uvmspace_fork. it is called
* when we are doing a fork and we have encountered a map entry which
* has two attributes: [1] its inherit code is VM_INHERIT_COPY, and
* [2] it points to a share map (i.e. is_a_map is true). in this case
* we must traverse the area of the share map pointed to by the
* old_entry and make private copies of the map entries in the share
* map. this is somewhat similar to what happens in the non-share map
* case in fork, but it has to handle multiple map entries which may
* not be the proper size. it was seperated out into its own function
* in order to make the main body of the fork code easier to read and
* understand!
*
* main_entry->offset = starting VA in share map for our mapping
*
* => main map is locked by caller.
* => we lock share map.
* => new map isn't in use yet (still being set up for the first time).
*/
void
uvm_map_sharemapcopy(main_map, main_entry, new_map)
vm_map_t main_map, new_map;
vm_map_entry_t main_entry;
{
vm_map_t share_map = main_entry->object.share_map;
vm_map_entry_t share_entry, new_entry;
vm_offset_t shend = main_entry->offset +
(main_entry->end - main_entry->start);
int refs;
/*
* lock share map. find first map entry of interest. clip if needed.
*/
vm_map_lock(share_map);
if (uvm_map_lookup_entry(share_map, main_entry->offset, &share_entry))
UVM_MAP_CLIP_START(share_map, share_entry, main_entry->offset);
while (share_entry != &share_map->header &&
share_entry->start < shend) {
/*
* at this point we have a map entry that we need to make a
* copy of.
*/
/* may need to clip? */
UVM_MAP_CLIP_END(share_map, share_entry, shend);
new_entry = uvm_mapent_alloc(new_map);
/* share_entry -> new_entry */
uvm_mapent_copy(share_entry, new_entry);
/* convert share map addresses back to main map addresses */
new_entry->start = main_entry->start +
(new_entry->start - main_entry->offset);
new_entry->end = main_entry->start +
(new_entry->end - main_entry->offset);
/* gain references */
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);
/* init rest of new entry and insert at end of new map */
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);
/*
* don't bother trying to defer the copy in the share map case
*/
/* XXXCDC: WAITOK? */
amap_copy(new_map, new_entry, M_WAITOK, FALSE, 0, 0);
/* just like non-share case: can't COW wired memory */
if (share_entry->wired_count != 0 &&
UVM_ET_ISCOPYONWRITE(share_entry)) {
amap_cow_now(new_map, new_entry);
} else {
/* just like non-share case */
if (UVM_ET_ISCOPYONWRITE(share_entry)) {
if (!UVM_ET_ISNEEDSCOPY(share_entry)) {
/*
* must write protect pages. if we
* have the sole reference to the share
* map we can use good old pmap_protect.
* if we don't, then we have to use
* pmap_page_protect. note that the VA
* new_entry->start (starting entry of
* this segment of the share map in
* child process) is the same virtual
* address it is mapped in in the parent
* (thus we can mix main_map and
* new_entry in the pmap_protect call
* below).
*/
simple_lock(&share_map->ref_lock);
refs = share_map->ref_count;
simple_unlock(&share_map->ref_lock);
if (refs == 1) {
pmap_protect(main_map->pmap,
new_entry->start,
new_entry->end,
share_entry->protection &
~VM_PROT_WRITE);
} else {
if (share_entry->aref.ar_amap) {
simple_lock(
&share_entry->aref.ar_amap->am_l);
amap_share_protect(share_entry,
share_entry->protection &
~VM_PROT_WRITE);
simple_unlock(
&share_entry->aref.ar_amap->am_l);
}
if (share_entry->object.uvm_obj)
{
#ifdef DIAGNOSTIC
if (!share_entry->object.uvm_obj->pgops->
pgo_shareprot)
panic("fork: share_entry with no prot function");
#endif
simple_lock(
&share_entry->object.uvm_obj->vmobjlock);
share_entry->object.uvm_obj->pgops->
pgo_shareprot(share_entry,
share_entry->protection & ~VM_PROT_WRITE);
simple_unlock(
&share_entry->object.uvm_obj->vmobjlock);
}
}
share_entry->etype |= UVM_ET_NEEDSCOPY;
}
}
/*
* now copy the mappings: note address are the same
* in both main_map and new_map
*/
pmap_copy(new_map->pmap, main_map->pmap,
new_entry->start,
(new_entry->end - new_entry->start),
new_entry->start);
/* just like non-share case */
if (!UVM_ET_ISCOPYONWRITE(share_entry)) {
pmap_protect(new_map->pmap, new_entry->start,
new_entry->end,
new_entry->protection & ~VM_PROT_WRITE);
}
}
/* next entry in share map, please */
share_entry = share_entry->next;
}
/* done! */
}
#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;
void (*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, main=%c, version=%d\n",
map->nentries, map->size, map->ref_count,
(map->is_main_map) ? 'T' : 'F', map->timestamp);
#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_slotoff);
(*pr)(
"\tmap=%c, submap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, wc=%d, adv=%d\n",
(entry->etype & UVM_ET_MAP) ? 'T' : 'F',
(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;
void (*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 (uobj->uo_refs == UVM_OBJ_KERN)
(*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;
void (*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, 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;
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
Reference in New Issue View Git Blame Copy Permalink