1 | /* $NetBSD: uvm_mremap.c,v 1.18 2015/11/26 13:15:34 martin Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c)2006,2007,2009 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 1.18 2015/11/26 13:15:34 martin Exp $" ); |
31 | |
32 | #include <sys/param.h> |
33 | #include <sys/mman.h> |
34 | #include <sys/sched.h> |
35 | #include <sys/syscallargs.h> |
36 | #include <sys/proc.h> |
37 | #include <sys/atomic.h> |
38 | |
39 | #include <uvm/uvm.h> |
40 | |
41 | static int |
42 | uvm_mapent_extend(struct vm_map *map, vaddr_t endva, vsize_t size) |
43 | { |
44 | struct vm_map_entry *entry; |
45 | struct vm_map_entry *reserved_entry; |
46 | struct uvm_object *uobj; |
47 | int error = 0; |
48 | |
49 | vm_map_lock(map); |
50 | if (!uvm_map_lookup_entry(map, endva, &reserved_entry)) { |
51 | error = ENOENT; |
52 | goto done; |
53 | } |
54 | if (reserved_entry->start != endva || |
55 | reserved_entry->end != endva + size || |
56 | reserved_entry->object.uvm_obj != NULL || |
57 | reserved_entry->aref.ar_amap != NULL || |
58 | reserved_entry->protection != VM_PROT_NONE) { |
59 | error = EINVAL; |
60 | goto done; |
61 | } |
62 | entry = reserved_entry->prev; |
63 | if (&map->header == entry || entry->end != endva) { |
64 | error = EINVAL; |
65 | goto done; |
66 | } |
67 | |
68 | /* |
69 | * now, make reserved_entry compatible with entry, and then |
70 | * try to merge. |
71 | */ |
72 | |
73 | uobj = entry->object.uvm_obj; |
74 | if (uobj) { |
75 | voff_t offset = entry->offset; |
76 | voff_t newoffset; |
77 | |
78 | newoffset = offset + entry->end - entry->start; |
79 | if (newoffset <= offset) { |
80 | error = E2BIG; /* XXX */ |
81 | goto done; |
82 | } |
83 | mutex_enter(uobj->vmobjlock); |
84 | KASSERT(uobj->uo_refs > 0); |
85 | atomic_inc_uint(&uobj->uo_refs); |
86 | mutex_exit(uobj->vmobjlock); |
87 | reserved_entry->object.uvm_obj = uobj; |
88 | reserved_entry->offset = newoffset; |
89 | } |
90 | reserved_entry->etype = entry->etype; |
91 | if (UVM_ET_ISCOPYONWRITE(entry)) { |
92 | reserved_entry->etype |= UVM_ET_NEEDSCOPY; |
93 | } |
94 | reserved_entry->flags &= ~UVM_MAP_NOMERGE; |
95 | reserved_entry->protection = entry->protection; |
96 | reserved_entry->max_protection = entry->max_protection; |
97 | reserved_entry->inheritance = entry->inheritance; |
98 | reserved_entry->advice = entry->advice; |
99 | reserved_entry->wired_count = 0; /* XXX should inherit? */ |
100 | uvm_mapent_trymerge(map, reserved_entry, 0); |
101 | done: |
102 | vm_map_unlock(map); |
103 | |
104 | return error; |
105 | } |
106 | |
107 | /* |
108 | * uvm_mremap: move and/or resize existing mappings. |
109 | */ |
110 | |
111 | int |
112 | uvm_mremap(struct vm_map *oldmap, vaddr_t oldva, vsize_t oldsize, |
113 | struct vm_map *newmap, vaddr_t *newvap, vsize_t newsize, |
114 | struct proc *newproc, int flags) |
115 | { |
116 | vaddr_t dstva; |
117 | vsize_t movesize; |
118 | vaddr_t newva; |
119 | int alignshift; |
120 | vaddr_t align = 0; |
121 | int error = 0; |
122 | const bool fixed = (flags & MAP_FIXED) != 0; |
123 | |
124 | if (fixed) { |
125 | newva = *newvap; |
126 | } else { |
127 | newva = 0; |
128 | } |
129 | if ((oldva & PAGE_MASK) != 0 || |
130 | (newva & PAGE_MASK) != 0 || |
131 | (oldsize & PAGE_MASK) != 0 || |
132 | (newsize & PAGE_MASK) != 0) { |
133 | return EINVAL; |
134 | } |
135 | /* XXX zero-size should be allowed? */ |
136 | if (oldva + oldsize <= oldva || newva + newsize <= newva) { |
137 | return EINVAL; |
138 | } |
139 | |
140 | /* |
141 | * Try to see if any requested alignment can even be attempted. |
142 | * Make sure we can express the alignment (asking for a >= 4GB |
143 | * alignment on an ILP32 architecure make no sense) and the |
144 | * alignment is at least for a page sized quanitiy. If the |
145 | * request was for a fixed mapping, make sure supplied address |
146 | * adheres to the request alignment. |
147 | */ |
148 | alignshift = (flags & MAP_ALIGNMENT_MASK) >> MAP_ALIGNMENT_SHIFT; |
149 | if (alignshift != 0) { |
150 | if (alignshift >= sizeof(vaddr_t) * NBBY) |
151 | return EINVAL; |
152 | align = 1L << alignshift; |
153 | if (align < PAGE_SIZE) |
154 | return EINVAL; |
155 | if (align >= vm_map_max(oldmap)) |
156 | return ENOMEM; |
157 | if ((flags & MAP_FIXED) != 0) { |
158 | if ((*newvap & (align - 1)) != 0) |
159 | return EINVAL; |
160 | align = 0; |
161 | } |
162 | } |
163 | |
164 | /* |
165 | * check the easy cases first. |
166 | */ |
167 | |
168 | if ((!fixed || newva == oldva) && newmap == oldmap && |
169 | (align == 0 || (oldva & (align - 1)) == 0)) { |
170 | vaddr_t va; |
171 | |
172 | if (newsize == oldsize) { |
173 | newva = oldva; |
174 | goto done; |
175 | } |
176 | if (newsize < oldsize) { |
177 | uvm_unmap(oldmap, oldva + newsize, oldva + oldsize); |
178 | newva = oldva; |
179 | goto done; |
180 | } |
181 | va = oldva + oldsize; |
182 | if (uvm_map_reserve(oldmap, newsize - oldsize, 0, 0, &va, |
183 | UVM_FLAG_FIXED)) { |
184 | newva = oldva; |
185 | goto extend; |
186 | } |
187 | if (fixed) { |
188 | return ENOMEM; |
189 | } |
190 | } |
191 | |
192 | /* |
193 | * we need to move mappings. |
194 | */ |
195 | |
196 | if (!fixed) { |
197 | KASSERT(&newproc->p_vmspace->vm_map == newmap); |
198 | newva = newproc->p_emul->e_vm_default_addr(newproc, |
199 | (vaddr_t)newproc->p_vmspace->vm_daddr, newsize, |
200 | newproc->p_vmspace->vm_map.flags & VM_MAP_TOPDOWN); |
201 | } |
202 | dstva = newva; |
203 | if (!uvm_map_reserve(newmap, newsize, oldva, align, &dstva, |
204 | fixed ? UVM_FLAG_FIXED : 0)) { |
205 | return ENOMEM; |
206 | } |
207 | KASSERT(!fixed || dstva == newva); |
208 | newva = dstva; |
209 | movesize = MIN(oldsize, newsize); |
210 | error = uvm_map_extract(oldmap, oldva, movesize, newmap, &dstva, |
211 | UVM_EXTRACT_RESERVED); |
212 | KASSERT(dstva == newva); |
213 | if (error != 0) { |
214 | /* |
215 | * undo uvm_map_reserve. |
216 | */ |
217 | uvm_unmap(newmap, newva, newva + newsize); |
218 | return error; |
219 | } |
220 | if (newsize > oldsize) { |
221 | extend: |
222 | error = uvm_mapent_extend(newmap, newva + oldsize, |
223 | newsize - oldsize); |
224 | if (error != 0) { |
225 | /* |
226 | * undo uvm_map_reserve and uvm_map_extract. |
227 | */ |
228 | if (newva == oldva && newmap == oldmap) { |
229 | uvm_unmap(newmap, newva + oldsize, |
230 | newva + newsize); |
231 | } else { |
232 | uvm_unmap(newmap, newva, newva + newsize); |
233 | } |
234 | return error; |
235 | } |
236 | } |
237 | |
238 | /* |
239 | * now we won't fail. |
240 | * remove original entries unless we did in-place extend. |
241 | */ |
242 | |
243 | if (oldva != newva || oldmap != newmap) { |
244 | uvm_unmap(oldmap, oldva, oldva + oldsize); |
245 | } |
246 | done: |
247 | *newvap = newva; |
248 | return 0; |
249 | } |
250 | |
251 | /* |
252 | * sys_mremap: mremap system call. |
253 | */ |
254 | |
255 | int |
256 | sys_mremap(struct lwp *l, const struct sys_mremap_args *uap, register_t *retval) |
257 | { |
258 | /* { |
259 | syscallarg(void *) old_address; |
260 | syscallarg(size_t) old_size; |
261 | syscallarg(void *) new_address; |
262 | syscallarg(size_t) new_size; |
263 | syscallarg(int) flags; |
264 | } */ |
265 | |
266 | struct proc *p; |
267 | struct vm_map *map; |
268 | vaddr_t oldva; |
269 | vaddr_t newva; |
270 | size_t oldsize; |
271 | size_t newsize; |
272 | int flags; |
273 | int error; |
274 | |
275 | flags = SCARG(uap, flags); |
276 | oldva = (vaddr_t)SCARG(uap, old_address); |
277 | oldsize = (vsize_t)(SCARG(uap, old_size)); |
278 | newva = (vaddr_t)SCARG(uap, new_address); |
279 | newsize = (vsize_t)(SCARG(uap, new_size)); |
280 | |
281 | if ((flags & ~(MAP_FIXED | MAP_ALIGNMENT_MASK)) != 0) { |
282 | error = EINVAL; |
283 | goto done; |
284 | } |
285 | |
286 | oldsize = round_page(oldsize); |
287 | newsize = round_page(newsize); |
288 | |
289 | p = l->l_proc; |
290 | map = &p->p_vmspace->vm_map; |
291 | error = uvm_mremap(map, oldva, oldsize, map, &newva, newsize, p, flags); |
292 | |
293 | done: |
294 | *retval = (error != 0) ? 0 : (register_t)newva; |
295 | return error; |
296 | } |
297 | |