uvm_mremap.c revision 1.7 1 1.7 drochner /* $NetBSD: uvm_mremap.c,v 1.7 2007/08/08 11:08:18 drochner Exp $ */
2 1.1 yamt
3 1.1 yamt /*-
4 1.1 yamt * Copyright (c)2006 YAMAMOTO Takashi,
5 1.1 yamt * All rights reserved.
6 1.1 yamt *
7 1.1 yamt * Redistribution and use in source and binary forms, with or without
8 1.1 yamt * modification, are permitted provided that the following conditions
9 1.1 yamt * are met:
10 1.1 yamt * 1. Redistributions of source code must retain the above copyright
11 1.1 yamt * notice, this list of conditions and the following disclaimer.
12 1.1 yamt * 2. Redistributions in binary form must reproduce the above copyright
13 1.1 yamt * notice, this list of conditions and the following disclaimer in the
14 1.1 yamt * documentation and/or other materials provided with the distribution.
15 1.1 yamt *
16 1.1 yamt * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 1.1 yamt * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 1.1 yamt * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 1.1 yamt * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 1.1 yamt * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 1.1 yamt * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 1.1 yamt * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 1.1 yamt * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 1.1 yamt * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 1.1 yamt * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 1.1 yamt * SUCH DAMAGE.
27 1.1 yamt */
28 1.1 yamt
29 1.1 yamt #include <sys/cdefs.h>
30 1.7 drochner __KERNEL_RCSID(0, "$NetBSD: uvm_mremap.c,v 1.7 2007/08/08 11:08:18 drochner Exp $");
31 1.1 yamt
32 1.1 yamt #include <sys/param.h>
33 1.5 joerg #include <sys/mman.h>
34 1.5 joerg #include <sys/syscallargs.h>
35 1.6 ad #include <sys/proc.h>
36 1.1 yamt
37 1.1 yamt #include <uvm/uvm.h>
38 1.1 yamt
39 1.1 yamt static int
40 1.1 yamt uvm_mapent_extend(struct vm_map *map, vaddr_t endva, vsize_t size)
41 1.1 yamt {
42 1.1 yamt struct vm_map_entry *entry;
43 1.1 yamt struct vm_map_entry *reserved_entry;
44 1.1 yamt struct uvm_object *uobj;
45 1.1 yamt int error = 0;
46 1.1 yamt
47 1.1 yamt vm_map_lock(map);
48 1.1 yamt if (!uvm_map_lookup_entry(map, endva, &reserved_entry)) {
49 1.1 yamt error = ENOENT;
50 1.1 yamt goto done;
51 1.1 yamt }
52 1.1 yamt if (reserved_entry->start != endva ||
53 1.1 yamt reserved_entry->end != endva + size ||
54 1.1 yamt reserved_entry->object.uvm_obj != NULL ||
55 1.1 yamt reserved_entry->aref.ar_amap != NULL) {
56 1.1 yamt error = EINVAL;
57 1.1 yamt goto done;
58 1.1 yamt }
59 1.1 yamt entry = reserved_entry->prev;
60 1.1 yamt KASSERT(&map->header != entry);
61 1.1 yamt if (entry->end != endva) {
62 1.1 yamt error = EINVAL;
63 1.1 yamt goto done;
64 1.1 yamt }
65 1.1 yamt
66 1.1 yamt /*
67 1.1 yamt * now, make reserved_entry compatible with entry, and then
68 1.1 yamt * try to merge.
69 1.1 yamt */
70 1.1 yamt
71 1.1 yamt uobj = entry->object.uvm_obj;
72 1.1 yamt if (uobj) {
73 1.1 yamt voff_t offset = entry->offset;
74 1.1 yamt voff_t newoffset;
75 1.1 yamt
76 1.1 yamt newoffset = offset + entry->end - entry->start;
77 1.1 yamt if (newoffset <= offset) {
78 1.1 yamt error = E2BIG; /* XXX */
79 1.1 yamt goto done;
80 1.1 yamt }
81 1.1 yamt simple_lock(&uobj->vmobjlock);
82 1.1 yamt KASSERT(uobj->uo_refs > 0);
83 1.1 yamt uobj->uo_refs++;
84 1.1 yamt simple_unlock(&uobj->vmobjlock);
85 1.1 yamt reserved_entry->object.uvm_obj = uobj;
86 1.1 yamt reserved_entry->offset = newoffset;
87 1.1 yamt }
88 1.1 yamt reserved_entry->etype = entry->etype;
89 1.1 yamt if (UVM_ET_ISCOPYONWRITE(entry)) {
90 1.1 yamt reserved_entry->etype |= UVM_ET_NEEDSCOPY;
91 1.1 yamt }
92 1.1 yamt reserved_entry->flags &= ~UVM_MAP_NOMERGE;
93 1.1 yamt reserved_entry->protection = entry->protection;
94 1.1 yamt reserved_entry->max_protection = entry->max_protection;
95 1.1 yamt reserved_entry->inheritance = entry->inheritance;
96 1.1 yamt reserved_entry->advice = entry->advice;
97 1.1 yamt reserved_entry->wired_count = 0; /* XXX should inherit? */
98 1.1 yamt uvm_mapent_trymerge(map, reserved_entry, 0);
99 1.1 yamt done:
100 1.1 yamt vm_map_unlock(map);
101 1.1 yamt
102 1.1 yamt return error;
103 1.1 yamt }
104 1.1 yamt
105 1.1 yamt /*
106 1.1 yamt * uvm_mremap: move and/or resize existing mappings.
107 1.1 yamt */
108 1.1 yamt
109 1.1 yamt int
110 1.3 yamt uvm_mremap(struct vm_map *oldmap, vaddr_t oldva, vsize_t oldsize,
111 1.3 yamt struct vm_map *newmap, vaddr_t *newvap, vsize_t newsize,
112 1.3 yamt struct proc *newproc, int flags)
113 1.1 yamt {
114 1.1 yamt vaddr_t dstva;
115 1.1 yamt vsize_t movesize;
116 1.1 yamt vaddr_t newva;
117 1.5 joerg vaddr_t align = 0;
118 1.1 yamt int error = 0;
119 1.5 joerg const bool fixed = (flags & MAP_FIXED) != 0;
120 1.1 yamt
121 1.1 yamt if (fixed) {
122 1.1 yamt newva = *newvap;
123 1.1 yamt } else {
124 1.1 yamt newva = 0;
125 1.1 yamt }
126 1.1 yamt if ((oldva & PAGE_MASK) != 0 ||
127 1.1 yamt (newva & PAGE_MASK) != 0 ||
128 1.1 yamt (oldsize & PAGE_MASK) != 0 ||
129 1.1 yamt (newsize & PAGE_MASK) != 0) {
130 1.1 yamt return EINVAL;
131 1.1 yamt }
132 1.1 yamt /* XXX zero-size should be allowed? */
133 1.1 yamt if (oldva + oldsize <= oldva || newva + newsize <= newva) {
134 1.1 yamt return EINVAL;
135 1.1 yamt }
136 1.1 yamt
137 1.1 yamt /*
138 1.5 joerg * Try to see if any requested alignment can even be attemped.
139 1.5 joerg * Make sure we can express the alignment (asking for a >= 4GB
140 1.5 joerg * alignment on an ILP32 architecure make no sense) and the
141 1.5 joerg * alignment is at least for a page sized quanitiy. If the
142 1.5 joerg * request was for a fixed mapping, make sure supplied address
143 1.5 joerg * adheres to the request alignment.
144 1.5 joerg */
145 1.5 joerg align = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT;
146 1.5 joerg if (align) {
147 1.5 joerg if (align >= sizeof(vaddr_t) * NBBY)
148 1.5 joerg return(EINVAL);
149 1.5 joerg align = 1L << align;
150 1.5 joerg if (align < PAGE_SIZE)
151 1.5 joerg return(EINVAL);
152 1.5 joerg if (align >= vm_map_max(oldmap))
153 1.5 joerg return(ENOMEM);
154 1.5 joerg if (flags & MAP_FIXED) {
155 1.5 joerg if ((*newvap & (align-1)) != 0)
156 1.5 joerg return(EINVAL);
157 1.5 joerg align = 0;
158 1.5 joerg }
159 1.5 joerg }
160 1.5 joerg
161 1.5 joerg /*
162 1.1 yamt * check the easy cases first.
163 1.1 yamt */
164 1.1 yamt
165 1.5 joerg if ((!fixed || newva == oldva) && newmap == oldmap &&
166 1.5 joerg (align == 0 || (oldva & ~(align - 1)) == 0)) {
167 1.1 yamt vaddr_t va;
168 1.1 yamt
169 1.1 yamt if (newsize == oldsize) {
170 1.2 yamt newva = oldva;
171 1.2 yamt goto done;
172 1.1 yamt }
173 1.1 yamt if (newsize < oldsize) {
174 1.1 yamt uvm_unmap(oldmap, oldva + newsize, oldva + oldsize);
175 1.2 yamt newva = oldva;
176 1.2 yamt goto done;
177 1.1 yamt }
178 1.1 yamt va = oldva + oldsize;
179 1.1 yamt if (uvm_map_reserve(oldmap, newsize - oldsize, 0, 0, &va,
180 1.1 yamt UVM_FLAG_FIXED)) {
181 1.1 yamt newva = oldva;
182 1.1 yamt goto extend;
183 1.1 yamt }
184 1.1 yamt if (fixed) {
185 1.1 yamt return ENOMEM;
186 1.1 yamt }
187 1.1 yamt }
188 1.1 yamt
189 1.1 yamt /*
190 1.1 yamt * we need to move mappings.
191 1.1 yamt */
192 1.1 yamt
193 1.1 yamt if (!fixed) {
194 1.1 yamt KASSERT(&newproc->p_vmspace->vm_map == newmap);
195 1.1 yamt newva = newproc->p_emul->e_vm_default_addr(newproc,
196 1.3 yamt (vaddr_t)newproc->p_vmspace->vm_daddr, newsize);
197 1.1 yamt }
198 1.1 yamt dstva = newva;
199 1.5 joerg if (!uvm_map_reserve(newmap, newsize, oldva, align, &dstva,
200 1.1 yamt fixed ? UVM_FLAG_FIXED : 0)) {
201 1.1 yamt return ENOMEM;
202 1.1 yamt }
203 1.1 yamt KASSERT(!fixed || dstva == newva);
204 1.1 yamt newva = dstva;
205 1.1 yamt movesize = MIN(oldsize, newsize);
206 1.1 yamt error = uvm_map_extract(oldmap, oldva, movesize, newmap, &dstva,
207 1.1 yamt UVM_EXTRACT_RESERVED);
208 1.1 yamt KASSERT(dstva == newva);
209 1.1 yamt if (error != 0) {
210 1.1 yamt /* undo uvm_map_reserve */
211 1.1 yamt uvm_unmap(newmap, newva, newva + newsize);
212 1.1 yamt return error;
213 1.1 yamt }
214 1.1 yamt if (newsize > oldsize) {
215 1.1 yamt extend:
216 1.1 yamt error = uvm_mapent_extend(newmap, newva + oldsize,
217 1.1 yamt newsize - oldsize);
218 1.1 yamt if (error != 0) {
219 1.1 yamt /* undo uvm_map_reserve and uvm_map_extract */
220 1.1 yamt uvm_unmap(newmap, newva, newva + newsize);
221 1.1 yamt return error;
222 1.1 yamt }
223 1.1 yamt }
224 1.1 yamt
225 1.1 yamt /*
226 1.1 yamt * now we won't fail. remove original entries.
227 1.1 yamt */
228 1.1 yamt
229 1.1 yamt if (oldva != newva || oldmap != newmap) {
230 1.1 yamt uvm_unmap(oldmap, oldva, oldva + oldsize);
231 1.1 yamt }
232 1.2 yamt done:
233 1.1 yamt *newvap = newva;
234 1.1 yamt return 0;
235 1.1 yamt }
236 1.5 joerg
237 1.5 joerg /*
238 1.5 joerg * sys_mremap: mremap system call.
239 1.5 joerg */
240 1.5 joerg
241 1.5 joerg int
242 1.5 joerg sys_mremap(struct lwp *l, void *v, register_t *retval)
243 1.5 joerg {
244 1.5 joerg struct sys_mremap_args /* {
245 1.5 joerg syscallarg(void *) old_address;
246 1.5 joerg syscallarg(size_t) old_size;
247 1.5 joerg syscallarg(void *) new_address;
248 1.5 joerg syscallarg(size_t) new_size;
249 1.5 joerg syscallarg(int) flags;
250 1.5 joerg } */ *uap = v;
251 1.5 joerg
252 1.5 joerg struct proc *p;
253 1.5 joerg struct vm_map *map;
254 1.5 joerg vaddr_t oldva;
255 1.5 joerg vaddr_t newva;
256 1.5 joerg size_t oldsize;
257 1.5 joerg size_t newsize;
258 1.5 joerg int flags;
259 1.5 joerg int error;
260 1.5 joerg
261 1.5 joerg flags = SCARG(uap, flags);
262 1.5 joerg oldva = (vaddr_t)SCARG(uap, old_address);
263 1.5 joerg oldsize = (vsize_t)(SCARG(uap, old_size));
264 1.5 joerg newva = (vaddr_t)SCARG(uap, new_address);
265 1.5 joerg newsize = (vsize_t)(SCARG(uap, new_size));
266 1.5 joerg
267 1.5 joerg if ((flags & ~(MAP_FIXED | MAP_ALIGNMENT_MASK)) != 0) {
268 1.5 joerg error = EINVAL;
269 1.5 joerg goto done;
270 1.5 joerg }
271 1.5 joerg
272 1.7 drochner oldsize = round_page(oldsize);
273 1.7 drochner newsize = round_page(newsize);
274 1.7 drochner
275 1.5 joerg p = l->l_proc;
276 1.5 joerg map = &p->p_vmspace->vm_map;
277 1.5 joerg error = uvm_mremap(map, oldva, oldsize, map, &newva, newsize, p,
278 1.5 joerg flags);
279 1.5 joerg
280 1.5 joerg done:
281 1.5 joerg *retval = (error != 0) ? 0 : (register_t)newva;
282 1.5 joerg return error;
283 1.5 joerg
284 1.5 joerg }
285