/* $NetBSD: uvm_map.c,v 1.69 1999/09/12 01:17:37 chs 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. */ #include "opt_ddb.h" #include "opt_uvmhist.h" #include "opt_sysv.h" /* * uvm_map.c: uvm map operations */ #include #include #include #include #include #include #ifdef SYSVSHM #include #endif #include #include #include #define UVM_MAP #include #ifdef DDB #include #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 */ /* * 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; { entry->wired_count = 0; uvm_fault_unwire_locked(map, entry->start, entry->end); } /* * 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,"", 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) * => value meanings (4 cases): * [1] == uoffset is a hint for PMAP_PREFER * [2] == don't PMAP_PREFER * [3] == normal mapping * [4] == 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; /* wiring status must match (new area is unwired) */ if (VM_MAPENT_ISWIRED(prev_entry)) 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 (VM_MAPENT_ISWIRED(entry)) 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)) { pmap_kremove(entry->start, len); 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 (VM_MAPENT_ISWIRED(first_entry)) 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; int rv = KERN_SUCCESS; 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)) { rv = KERN_INVALID_ARGUMENT; goto out; } if ((new_prot & current->max_protection) != new_prot) { rv = KERN_PROTECTION_FAILURE; goto out; } 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)); } /* * If the map is configured to lock any future mappings, * wire this entry now if the old protection was VM_PROT_NONE * and the new protection is not VM_PROT_NONE. */ if ((map->flags & VM_MAP_WIREFUTURE) != 0 && VM_MAPENT_ISWIRED(entry) == 0 && old_prot == VM_PROT_NONE && new_prot != VM_PROT_NONE) { if (uvm_map_pageable(map, entry->start, entry->end, FALSE, UVM_LK_ENTER|UVM_LK_EXIT) != KERN_SUCCESS) { /* * If locking the entry fails, remember the * error if it's the first one. Note we * still continue setting the protection in * the map, but will return the resource * shortage condition regardless. * * XXX Ignore what the actual error is, * XXX just call it a resource shortage * XXX so that it doesn't get confused * XXX what uvm_map_protect() itself would * XXX normally return. */ rv = KERN_RESOURCE_SHORTAGE; } } current = current->next; } out: vm_map_unlock(map); UVMHIST_LOG(maphist, "<- done, rv=%d",rv,0,0,0); return (rv); } #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; } /* * XXXJRT: disallow holes? */ 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; 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. * * => wires map entries. should not be used for transient page locking. * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). * => regions sepcified as not pageable require lock-down (wired) memory * and page tables. * => map must never be read-locked * => if islocked is TRUE, map is already write-locked * => we always unlock the map, since we must downgrade to a read-lock * to call uvm_fault_wire() * => XXXCDC: check this and try and clean it up. */ int uvm_map_pageable(map, start, end, new_pageable, lockflags) vm_map_t map; vaddr_t start, end; boolean_t new_pageable; int lockflags; { vm_map_entry_t entry, start_entry, failed_entry; int rv; #ifdef DIAGNOSTIC u_int timestamp_save; #endif 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 if ((lockflags & UVM_LK_ENTER) == 0) 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) { if ((lockflags & UVM_LK_EXIT) == 0) 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))) { if ((lockflags & UVM_LK_EXIT) == 0) vm_map_unlock(map); UVMHIST_LOG(maphist, "<- done (INVALID UNWIRE ARG)",0,0,0,0); return (KERN_INVALID_ARGUMENT); } entry = entry->next; } /* * POSIX 1003.1b - a single munlock call unlocks a region, * regardless of the number of mlock calls made on that * region. */ entry = start_entry; while ((entry != &map->header) && (entry->start < end)) { UVM_MAP_CLIP_END(map, entry, end); if (VM_MAPENT_ISWIRED(entry)) uvm_map_entry_unwire(map, entry); entry = entry->next; } if ((lockflags & UVM_LK_EXIT) == 0) 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 == 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 (VM_MAPENT_ISWIRED(entry) == 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 */ if (UVM_ET_ISNEEDSCOPY(entry) && ((entry->protection & VM_PROT_WRITE) || (entry->object.uvm_obj == NULL))) { amap_copy(map, entry, M_WAITOK, TRUE, start, end); /* XXXCDC: wait OK? */ } } } UVM_MAP_CLIP_START(map, entry, start); UVM_MAP_CLIP_END(map, entry, end); entry->wired_count++; /* * Check for holes */ if (entry->protection == VM_PROT_NONE || (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; } if ((lockflags & UVM_LK_EXIT) == 0) vm_map_unlock(map); UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); return (KERN_INVALID_ARGUMENT); } entry = entry->next; } /* * Pass 2. */ #ifdef DIAGNOSTIC timestamp_save = map->timestamp; #endif vm_map_busy(map); 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); vm_map_unbusy(map); #ifdef DIAGNOSTIC if (timestamp_save != map->timestamp) panic("uvm_map_pageable: stale map"); #endif /* * first drop the wiring count on all the entries * which haven't actually been wired yet. */ failed_entry = entry; while (entry != &map->header && entry->start < end) { entry->wired_count--; entry = entry->next; } /* * now, unwire all the entries that were successfully * wired above. */ entry = start_entry; while (entry != failed_entry) { entry->wired_count--; if (VM_MAPENT_ISWIRED(entry) == 0) uvm_map_entry_unwire(map, entry); entry = entry->next; } if ((lockflags & UVM_LK_EXIT) == 0) vm_map_unlock(map); UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0); return(rv); } /* We are holding a read lock here. */ if ((lockflags & UVM_LK_EXIT) == 0) { vm_map_unbusy(map); vm_map_unlock_read(map); } else { /* * Get back to an exclusive (write) lock. */ vm_map_upgrade(map); vm_map_unbusy(map); } UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); return(KERN_SUCCESS); } /* * uvm_map_pageable_all: special case of uvm_map_pageable - affects * all mapped regions. * * => map must not be locked. * => if no flags are specified, all regions are unwired. * => XXXJRT: has some of the same problems as uvm_map_pageable() above. */ int uvm_map_pageable_all(map, flags, limit) vm_map_t map; int flags; vsize_t limit; { vm_map_entry_t entry, failed_entry; vsize_t size; int rv; #ifdef DIAGNOSTIC u_int timestamp_save; #endif UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist); UVMHIST_LOG(maphist,"(map=0x%x,flags=0x%x)", map, flags, 0, 0); #ifdef DIAGNOSTIC if ((map->flags & VM_MAP_PAGEABLE) == 0) panic("uvm_map_pageable_all: map %p not pageable", map); #endif vm_map_lock(map); /* * handle wiring and unwiring separately. */ if (flags == 0) { /* unwire */ /* * POSIX 1003.1b -- munlockall unlocks all regions, * regardless of how many times mlockall has been called. */ for (entry = map->header.next; entry != &map->header; entry = entry->next) { if (VM_MAPENT_ISWIRED(entry)) uvm_map_entry_unwire(map, entry); } vm_map_modflags(map, 0, VM_MAP_WIREFUTURE); vm_map_unlock(map); UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); return (KERN_SUCCESS); /* * end of unwire case! */ } if (flags & MCL_FUTURE) { /* * must wire all future mappings; remember this. */ vm_map_modflags(map, VM_MAP_WIREFUTURE, 0); } if ((flags & MCL_CURRENT) == 0) { /* * no more work to do! */ UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); vm_map_unlock(map); return (KERN_SUCCESS); } /* * wire case: in three passes [XXXCDC: ugly block of code here] * * 1: holding the write lock, count all pages mapped by non-wired * entries. if this would cause us to go over our limit, we fail. * * 2: still holding the write lock, we create any anonymous maps that * need to be created. then we increment its wiring count. * * 3: we downgrade to a read lock, and call uvm_fault_wire to fault * in the pages for any newly wired area (wired_count == 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. */ for (size = 0, entry = map->header.next; entry != &map->header; entry = entry->next) { if (entry->protection != VM_PROT_NONE && VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ size += entry->end - entry->start; } } if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { vm_map_unlock(map); return (KERN_NO_SPACE); /* XXX overloaded */ } /* XXX non-pmap_wired_count case must be handled by caller */ #ifdef pmap_wired_count if (limit != 0 && (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { vm_map_unlock(map); return (KERN_NO_SPACE); /* XXX overloaded */ } #endif /* * Pass 2. */ for (entry = map->header.next; entry != &map->header; entry = entry->next) { if (entry->protection == VM_PROT_NONE) continue; if (VM_MAPENT_ISWIRED(entry) == 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 */ if (UVM_ET_ISNEEDSCOPY(entry) && ((entry->protection & VM_PROT_WRITE) || (entry->object.uvm_obj == NULL))) { amap_copy(map, entry, M_WAITOK, TRUE, entry->start, entry->end); /* XXXCDC: wait OK? */ } } } entry->wired_count++; } /* * Pass 3. */ #ifdef DIAGNOSTIC timestamp_save = map->timestamp; #endif vm_map_busy(map); vm_map_downgrade(map); rv = KERN_SUCCESS; for (entry = map->header.next; entry != &map->header; entry = entry->next) { 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; } } } if (rv) { /* failed? */ /* * Get back an exclusive (write) lock. */ vm_map_upgrade(map); vm_map_unbusy(map); #ifdef DIAGNOSTIC if (timestamp_save != map->timestamp) panic("uvm_map_pageable_all: stale map"); #endif /* * first drop the wiring count on all the entries * which haven't actually been wired yet. * * Skip VM_PROT_NONE entries like we did above. */ failed_entry = entry; for (/* nothing */; entry != &map->header; entry = entry->next) { if (entry->protection == VM_PROT_NONE) continue; entry->wired_count--; } /* * now, unwire all the entries that were successfully * wired above. * * Skip VM_PROT_NONE entries like we did above. */ for (entry = map->header.next; entry != failed_entry; entry = entry->next) { if (entry->protection == VM_PROT_NONE) continue; entry->wired_count--; if (VM_MAPENT_ISWIRED(entry)) uvm_map_entry_unwire(map, entry); } vm_map_unlock(map); UVMHIST_LOG(maphist,"<- done (RV=%d)", rv,0,0,0); return (rv); } /* We are holding a read lock here. */ vm_map_unbusy(map); vm_map_unlock_read(map); UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); return (KERN_SUCCESS); } /* * uvm_map_clean: clean out a map range * * => valid flags: * if (flags & PGO_CLEANIT): dirty pages are cleaned first * 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, but may deactivate pages there * => called from sys_msync() and sys_madvise() * => caller must not write-lock map (read OK). * => we may sleep while cleaning if SYNCIO [with map read-locked] */ int amap_clean_works = 1; /* XXX for now, just in case... */ int uvm_map_clean(map, start, end, flags) vm_map_t map; vaddr_t start, end; int flags; { vm_map_entry_t current, entry; struct uvm_object *uobj; struct vm_amap *amap; struct vm_anon *anon; struct vm_page *pg; vaddr_t offset; vsize_t size; int rv, error, refs; 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); #ifdef DIAGNOSTIC if ((flags & (PGO_FREE|PGO_DEACTIVATE)) == (PGO_FREE|PGO_DEACTIVATE)) panic("uvm_map_clean: FREE and DEACTIVATE"); #endif vm_map_lock_read(map); VM_MAP_RANGE_CHECK(map, start, end); if (uvm_map_lookup_entry(map, start, &entry) == FALSE) { 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); } } error = KERN_SUCCESS; for (current = entry; current->start < end; current = current->next) { amap = current->aref.ar_amap; /* top layer */ uobj = current->object.uvm_obj; /* bottom layer */ #ifdef DIAGNOSTIC if (start < current->start) panic("uvm_map_clean: hole"); #endif /* * No amap cleaning necessary if: * * (1) There's no amap. * * (2) We're not deactivating or freeing pages. */ if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) goto flush_object; /* XXX for now, just in case... */ if (amap_clean_works == 0) goto flush_object; amap_lock(amap); offset = start - current->start; size = (end <= current->end ? end : current->end) - start; for (/* nothing */; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { anon = amap_lookup(¤t->aref, offset); if (anon == NULL) continue; simple_lock(&anon->an_lock); pg = anon->u.an_page; if (pg == NULL) { simple_unlock(&anon->an_lock); continue; } switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { /* * XXX In these first 3 cases, we always just * XXX deactivate the page. We may want to * XXX handle the different cases more * XXX specifically, in the future. */ case PGO_CLEANIT|PGO_FREE: case PGO_CLEANIT|PGO_DEACTIVATE: case PGO_DEACTIVATE: deactivate_it: /* skip the page if it's loaned or wired */ if (pg->loan_count != 0 || pg->wire_count != 0) { simple_unlock(&anon->an_lock); continue; } uvm_lock_pageq(); /* * skip the page if it's not actually owned * by the anon (may simply be loaned to the * anon). */ if ((pg->pqflags & PQ_ANON) == 0) { #ifdef DIAGNOSTIC if (pg->uobject != NULL) panic("uvm_map_clean: " "page anon vs. object " "inconsistency"); #endif uvm_unlock_pageq(); simple_unlock(&anon->an_lock); continue; } #ifdef DIAGNOSTIC if (pg->uanon != anon) panic("uvm_map_clean: anon " "inconsistency"); #endif /* zap all mappings for the page. */ pmap_page_protect(pg, VM_PROT_NONE); /* ...and deactivate the page. */ uvm_pagedeactivate(pg); uvm_unlock_pageq(); simple_unlock(&anon->an_lock); continue; case PGO_FREE: /* * If there are multiple references to * the amap, just deactivate the page. */ if (amap_refs(amap) > 1) goto deactivate_it; /* XXX skip the page if it's wired */ if (pg->wire_count != 0) { simple_unlock(&anon->an_lock); continue; } amap_unadd(¤t->aref, offset); refs = --anon->an_ref; simple_unlock(&anon->an_lock); if (refs == 0) uvm_anfree(anon); continue; default: panic("uvm_map_clean: wierd flags"); } #ifdef DIAGNOSTIC panic("uvm_map_clean: unreachable code"); #endif } amap_unlock(amap); flush_object: /* * flush pages if we've got a valid backing object. */ offset = current->offset + (start - current->start); size = (end <= current->end ? end : current->end) - start; if (uobj != NULL) { simple_lock(&uobj->vmobjlock); rv = uobj->pgops->pgo_flush(uobj, offset, offset + size, flags); simple_unlock(&uobj->vmobjlock); if (rv == FALSE) error = KERN_FAILURE; } start += size; } vm_map_unlock_read(map); return (error); } /* * 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 pmap = pmap_create(); 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 /* * POSIX 1003.1b -- "lock future mappings" is revoked * when a process execs another program image. */ vm_map_lock(map); vm_map_modflags(map, 0, VM_MAP_WIREFUTURE); vm_map_unlock(map); /* * 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); /* * 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); 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 || VM_MAPENT_ISWIRED(old_entry)) { 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 (VM_MAPENT_ISWIRED(old_entry)) { /* * 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); #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; 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, 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=<>)\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; 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 (UVM_OBJ_IS_KERN_OBJECT(uobj)) (*pr)("refs=\n"); else (*pr)("refs=%d\n", uobj->uo_refs); if (!full) return; (*pr)(" PAGES :\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, (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