1 /* $NetBSD: uvm_mremap.c,v 1.3 2006/01/31 14:03:53 yamt Exp $ */ 2 3 /*- 4 * Copyright (c)2006 YAMAMOTO Takashi, 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: uvm_mremap.c,v 1.3 2006/01/31 14:03:53 yamt Exp $"); 31 32 #include <sys/param.h> 33 34 #include <uvm/uvm.h> 35 36 static int 37 uvm_mapent_extend(struct vm_map *map, vaddr_t endva, vsize_t size) 38 { 39 struct vm_map_entry *entry; 40 struct vm_map_entry *reserved_entry; 41 struct uvm_object *uobj; 42 int error = 0; 43 44 vm_map_lock(map); 45 if (!uvm_map_lookup_entry(map, endva, &reserved_entry)) { 46 error = ENOENT; 47 goto done; 48 } 49 if (reserved_entry->start != endva || 50 reserved_entry->end != endva + size || 51 reserved_entry->object.uvm_obj != NULL || 52 reserved_entry->aref.ar_amap != NULL) { 53 error = EINVAL; 54 goto done; 55 } 56 entry = reserved_entry->prev; 57 KASSERT(&map->header != entry); 58 if (entry->end != endva) { 59 error = EINVAL; 60 goto done; 61 } 62 63 /* 64 * now, make reserved_entry compatible with entry, and then 65 * try to merge. 66 */ 67 68 uobj = entry->object.uvm_obj; 69 if (uobj) { 70 voff_t offset = entry->offset; 71 voff_t newoffset; 72 73 newoffset = offset + entry->end - entry->start; 74 if (newoffset <= offset) { 75 error = E2BIG; /* XXX */ 76 goto done; 77 } 78 simple_lock(&uobj->vmobjlock); 79 KASSERT(uobj->uo_refs > 0); 80 uobj->uo_refs++; 81 simple_unlock(&uobj->vmobjlock); 82 reserved_entry->object.uvm_obj = uobj; 83 reserved_entry->offset = newoffset; 84 } 85 reserved_entry->etype = entry->etype; 86 if (UVM_ET_ISCOPYONWRITE(entry)) { 87 reserved_entry->etype |= UVM_ET_NEEDSCOPY; 88 } 89 reserved_entry->flags &= ~UVM_MAP_NOMERGE; 90 reserved_entry->protection = entry->protection; 91 reserved_entry->max_protection = entry->max_protection; 92 reserved_entry->inheritance = entry->inheritance; 93 reserved_entry->advice = entry->advice; 94 reserved_entry->wired_count = 0; /* XXX should inherit? */ 95 uvm_mapent_trymerge(map, reserved_entry, 0); 96 done: 97 vm_map_unlock(map); 98 99 return error; 100 } 101 102 /* 103 * uvm_mremap: move and/or resize existing mappings. 104 */ 105 106 int 107 uvm_mremap(struct vm_map *oldmap, vaddr_t oldva, vsize_t oldsize, 108 struct vm_map *newmap, vaddr_t *newvap, vsize_t newsize, 109 struct proc *newproc, int flags) 110 { 111 vaddr_t dstva; 112 vsize_t movesize; 113 vaddr_t newva; 114 int error = 0; 115 const boolean_t fixed = (flags & UVM_MREMAP_FIXED) != 0; 116 117 if (fixed) { 118 newva = *newvap; 119 } else { 120 newva = 0; 121 } 122 if ((oldva & PAGE_MASK) != 0 || 123 (newva & PAGE_MASK) != 0 || 124 (oldsize & PAGE_MASK) != 0 || 125 (newsize & PAGE_MASK) != 0) { 126 return EINVAL; 127 } 128 /* XXX zero-size should be allowed? */ 129 if (oldva + oldsize <= oldva || newva + newsize <= newva) { 130 return EINVAL; 131 } 132 133 /* 134 * check the easy cases first. 135 */ 136 137 if ((!fixed || newva == oldva) && newmap == oldmap) { 138 vaddr_t va; 139 140 if (newsize == oldsize) { 141 newva = oldva; 142 goto done; 143 } 144 if (newsize < oldsize) { 145 uvm_unmap(oldmap, oldva + newsize, oldva + oldsize); 146 newva = oldva; 147 goto done; 148 } 149 va = oldva + oldsize; 150 if (uvm_map_reserve(oldmap, newsize - oldsize, 0, 0, &va, 151 UVM_FLAG_FIXED)) { 152 newva = oldva; 153 goto extend; 154 } 155 if (fixed) { 156 return ENOMEM; 157 } 158 } 159 160 /* 161 * we need to move mappings. 162 */ 163 164 if (!fixed) { 165 KASSERT(&newproc->p_vmspace->vm_map == newmap); 166 newva = newproc->p_emul->e_vm_default_addr(newproc, 167 (vaddr_t)newproc->p_vmspace->vm_daddr, newsize); 168 } 169 dstva = newva; 170 if (!uvm_map_reserve(newmap, newsize, oldva, 0, &dstva, 171 fixed ? UVM_FLAG_FIXED : 0)) { 172 return ENOMEM; 173 } 174 KASSERT(!fixed || dstva == newva); 175 newva = dstva; 176 movesize = MIN(oldsize, newsize); 177 error = uvm_map_extract(oldmap, oldva, movesize, newmap, &dstva, 178 UVM_EXTRACT_RESERVED); 179 KASSERT(dstva == newva); 180 if (error != 0) { 181 /* undo uvm_map_reserve */ 182 uvm_unmap(newmap, newva, newva + newsize); 183 return error; 184 } 185 if (newsize > oldsize) { 186 extend: 187 error = uvm_mapent_extend(newmap, newva + oldsize, 188 newsize - oldsize); 189 if (error != 0) { 190 /* undo uvm_map_reserve and uvm_map_extract */ 191 uvm_unmap(newmap, newva, newva + newsize); 192 return error; 193 } 194 } 195 196 /* 197 * now we won't fail. remove original entries. 198 */ 199 200 if (oldva != newva || oldmap != newmap) { 201 uvm_unmap(oldmap, oldva, oldva + oldsize); 202 } 203 done: 204 *newvap = newva; 205 return 0; 206 } 207