uvm_mremap.c revision 1.5
1 /* $NetBSD: uvm_mremap.c,v 1.5 2007/07/17 17:42:08 joerg 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 1.5 2007/07/17 17:42:08 joerg Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/mman.h> 34 #include <sys/syscallargs.h> 35 36 #include <uvm/uvm.h> 37 38 static int 39 uvm_mapent_extend(struct vm_map *map, vaddr_t endva, vsize_t size) 40 { 41 struct vm_map_entry *entry; 42 struct vm_map_entry *reserved_entry; 43 struct uvm_object *uobj; 44 int error = 0; 45 46 vm_map_lock(map); 47 if (!uvm_map_lookup_entry(map, endva, &reserved_entry)) { 48 error = ENOENT; 49 goto done; 50 } 51 if (reserved_entry->start != endva || 52 reserved_entry->end != endva + size || 53 reserved_entry->object.uvm_obj != NULL || 54 reserved_entry->aref.ar_amap != NULL) { 55 error = EINVAL; 56 goto done; 57 } 58 entry = reserved_entry->prev; 59 KASSERT(&map->header != entry); 60 if (entry->end != endva) { 61 error = EINVAL; 62 goto done; 63 } 64 65 /* 66 * now, make reserved_entry compatible with entry, and then 67 * try to merge. 68 */ 69 70 uobj = entry->object.uvm_obj; 71 if (uobj) { 72 voff_t offset = entry->offset; 73 voff_t newoffset; 74 75 newoffset = offset + entry->end - entry->start; 76 if (newoffset <= offset) { 77 error = E2BIG; /* XXX */ 78 goto done; 79 } 80 simple_lock(&uobj->vmobjlock); 81 KASSERT(uobj->uo_refs > 0); 82 uobj->uo_refs++; 83 simple_unlock(&uobj->vmobjlock); 84 reserved_entry->object.uvm_obj = uobj; 85 reserved_entry->offset = newoffset; 86 } 87 reserved_entry->etype = entry->etype; 88 if (UVM_ET_ISCOPYONWRITE(entry)) { 89 reserved_entry->etype |= UVM_ET_NEEDSCOPY; 90 } 91 reserved_entry->flags &= ~UVM_MAP_NOMERGE; 92 reserved_entry->protection = entry->protection; 93 reserved_entry->max_protection = entry->max_protection; 94 reserved_entry->inheritance = entry->inheritance; 95 reserved_entry->advice = entry->advice; 96 reserved_entry->wired_count = 0; /* XXX should inherit? */ 97 uvm_mapent_trymerge(map, reserved_entry, 0); 98 done: 99 vm_map_unlock(map); 100 101 return error; 102 } 103 104 /* 105 * uvm_mremap: move and/or resize existing mappings. 106 */ 107 108 int 109 uvm_mremap(struct vm_map *oldmap, vaddr_t oldva, vsize_t oldsize, 110 struct vm_map *newmap, vaddr_t *newvap, vsize_t newsize, 111 struct proc *newproc, int flags) 112 { 113 vaddr_t dstva; 114 vsize_t movesize; 115 vaddr_t newva; 116 vaddr_t align = 0; 117 int error = 0; 118 const bool fixed = (flags & MAP_FIXED) != 0; 119 120 if (fixed) { 121 newva = *newvap; 122 } else { 123 newva = 0; 124 } 125 if ((oldva & PAGE_MASK) != 0 || 126 (newva & PAGE_MASK) != 0 || 127 (oldsize & PAGE_MASK) != 0 || 128 (newsize & PAGE_MASK) != 0) { 129 return EINVAL; 130 } 131 /* XXX zero-size should be allowed? */ 132 if (oldva + oldsize <= oldva || newva + newsize <= newva) { 133 return EINVAL; 134 } 135 136 /* 137 * Try to see if any requested alignment can even be attemped. 138 * Make sure we can express the alignment (asking for a >= 4GB 139 * alignment on an ILP32 architecure make no sense) and the 140 * alignment is at least for a page sized quanitiy. If the 141 * request was for a fixed mapping, make sure supplied address 142 * adheres to the request alignment. 143 */ 144 align = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT; 145 if (align) { 146 if (align >= sizeof(vaddr_t) * NBBY) 147 return(EINVAL); 148 align = 1L << align; 149 if (align < PAGE_SIZE) 150 return(EINVAL); 151 if (align >= vm_map_max(oldmap)) 152 return(ENOMEM); 153 if (flags & MAP_FIXED) { 154 if ((*newvap & (align-1)) != 0) 155 return(EINVAL); 156 align = 0; 157 } 158 } 159 160 /* 161 * check the easy cases first. 162 */ 163 164 if ((!fixed || newva == oldva) && newmap == oldmap && 165 (align == 0 || (oldva & ~(align - 1)) == 0)) { 166 vaddr_t va; 167 168 if (newsize == oldsize) { 169 newva = oldva; 170 goto done; 171 } 172 if (newsize < oldsize) { 173 uvm_unmap(oldmap, oldva + newsize, oldva + oldsize); 174 newva = oldva; 175 goto done; 176 } 177 va = oldva + oldsize; 178 if (uvm_map_reserve(oldmap, newsize - oldsize, 0, 0, &va, 179 UVM_FLAG_FIXED)) { 180 newva = oldva; 181 goto extend; 182 } 183 if (fixed) { 184 return ENOMEM; 185 } 186 } 187 188 /* 189 * we need to move mappings. 190 */ 191 192 if (!fixed) { 193 KASSERT(&newproc->p_vmspace->vm_map == newmap); 194 newva = newproc->p_emul->e_vm_default_addr(newproc, 195 (vaddr_t)newproc->p_vmspace->vm_daddr, newsize); 196 } 197 dstva = newva; 198 if (!uvm_map_reserve(newmap, newsize, oldva, align, &dstva, 199 fixed ? UVM_FLAG_FIXED : 0)) { 200 return ENOMEM; 201 } 202 KASSERT(!fixed || dstva == newva); 203 newva = dstva; 204 movesize = MIN(oldsize, newsize); 205 error = uvm_map_extract(oldmap, oldva, movesize, newmap, &dstva, 206 UVM_EXTRACT_RESERVED); 207 KASSERT(dstva == newva); 208 if (error != 0) { 209 /* undo uvm_map_reserve */ 210 uvm_unmap(newmap, newva, newva + newsize); 211 return error; 212 } 213 if (newsize > oldsize) { 214 extend: 215 error = uvm_mapent_extend(newmap, newva + oldsize, 216 newsize - oldsize); 217 if (error != 0) { 218 /* undo uvm_map_reserve and uvm_map_extract */ 219 uvm_unmap(newmap, newva, newva + newsize); 220 return error; 221 } 222 } 223 224 /* 225 * now we won't fail. remove original entries. 226 */ 227 228 if (oldva != newva || oldmap != newmap) { 229 uvm_unmap(oldmap, oldva, oldva + oldsize); 230 } 231 done: 232 *newvap = newva; 233 return 0; 234 } 235 236 /* 237 * sys_mremap: mremap system call. 238 */ 239 240 int 241 sys_mremap(struct lwp *l, void *v, register_t *retval) 242 { 243 struct sys_mremap_args /* { 244 syscallarg(void *) old_address; 245 syscallarg(size_t) old_size; 246 syscallarg(void *) new_address; 247 syscallarg(size_t) new_size; 248 syscallarg(int) flags; 249 } */ *uap = v; 250 251 struct proc *p; 252 struct vm_map *map; 253 vaddr_t oldva; 254 vaddr_t newva; 255 size_t oldsize; 256 size_t newsize; 257 int flags; 258 int error; 259 260 flags = SCARG(uap, flags); 261 oldva = (vaddr_t)SCARG(uap, old_address); 262 oldsize = (vsize_t)(SCARG(uap, old_size)); 263 newva = (vaddr_t)SCARG(uap, new_address); 264 newsize = (vsize_t)(SCARG(uap, new_size)); 265 266 if ((flags & ~(MAP_FIXED | MAP_ALIGNMENT_MASK)) != 0) { 267 error = EINVAL; 268 goto done; 269 } 270 271 p = l->l_proc; 272 map = &p->p_vmspace->vm_map; 273 error = uvm_mremap(map, oldva, oldsize, map, &newva, newsize, p, 274 flags); 275 276 done: 277 *retval = (error != 0) ? 0 : (register_t)newva; 278 return error; 279 280 } 281
Indexes created Fri Sep 26 08:10:20 GMT 2025