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831b7825 TS |
1 | /* |
2 | * mmap support for qemu | |
3 | * | |
4 | * Copyright (c) 2003 Fabrice Bellard | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | #include <stdlib.h> | |
21 | #include <stdio.h> | |
22 | #include <stdarg.h> | |
23 | #include <string.h> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
26 | #include <sys/mman.h> | |
27 | ||
28 | #include "qemu.h" | |
29 | ||
30 | //#define DEBUG_MMAP | |
31 | ||
32 | /* NOTE: all the constants are the HOST ones */ | |
33 | int target_mprotect(unsigned long start, unsigned long len, int prot) | |
34 | { | |
35 | unsigned long end, host_start, host_end, addr; | |
36 | int prot1, ret; | |
37 | ||
38 | #ifdef DEBUG_MMAP | |
39 | printf("mprotect: start=0x%lx len=0x%lx prot=%c%c%c\n", start, len, | |
40 | prot & PROT_READ ? 'r' : '-', | |
41 | prot & PROT_WRITE ? 'w' : '-', | |
42 | prot & PROT_EXEC ? 'x' : '-'); | |
43 | #endif | |
44 | ||
45 | if ((start & ~TARGET_PAGE_MASK) != 0) | |
46 | return -EINVAL; | |
47 | len = TARGET_PAGE_ALIGN(len); | |
48 | end = start + len; | |
49 | if (end < start) | |
50 | return -EINVAL; | |
51 | if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC)) | |
52 | return -EINVAL; | |
53 | if (len == 0) | |
54 | return 0; | |
55 | ||
56 | host_start = start & qemu_host_page_mask; | |
57 | host_end = HOST_PAGE_ALIGN(end); | |
58 | if (start > host_start) { | |
59 | /* handle host page containing start */ | |
60 | prot1 = prot; | |
61 | for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { | |
62 | prot1 |= page_get_flags(addr); | |
63 | } | |
64 | if (host_end == host_start + qemu_host_page_size) { | |
65 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { | |
66 | prot1 |= page_get_flags(addr); | |
67 | } | |
68 | end = host_end; | |
69 | } | |
70 | ret = mprotect((void *)host_start, qemu_host_page_size, prot1 & PAGE_BITS); | |
71 | if (ret != 0) | |
72 | return ret; | |
73 | host_start += qemu_host_page_size; | |
74 | } | |
75 | if (end < host_end) { | |
76 | prot1 = prot; | |
77 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { | |
78 | prot1 |= page_get_flags(addr); | |
79 | } | |
80 | ret = mprotect((void *)(host_end - qemu_host_page_size), qemu_host_page_size, | |
81 | prot1 & PAGE_BITS); | |
82 | if (ret != 0) | |
83 | return ret; | |
84 | host_end -= qemu_host_page_size; | |
85 | } | |
86 | ||
87 | /* handle the pages in the middle */ | |
88 | if (host_start < host_end) { | |
89 | ret = mprotect((void *)host_start, host_end - host_start, prot); | |
90 | if (ret != 0) | |
91 | return ret; | |
92 | } | |
93 | page_set_flags(start, start + len, prot | PAGE_VALID); | |
94 | return 0; | |
95 | } | |
96 | ||
97 | /* map an incomplete host page */ | |
98 | int mmap_frag(unsigned long host_start, | |
99 | unsigned long start, unsigned long end, | |
100 | int prot, int flags, int fd, unsigned long offset) | |
101 | { | |
102 | unsigned long host_end, ret, addr; | |
103 | int prot1, prot_new; | |
104 | ||
105 | host_end = host_start + qemu_host_page_size; | |
106 | ||
107 | /* get the protection of the target pages outside the mapping */ | |
108 | prot1 = 0; | |
109 | for(addr = host_start; addr < host_end; addr++) { | |
110 | if (addr < start || addr >= end) | |
111 | prot1 |= page_get_flags(addr); | |
112 | } | |
113 | ||
114 | if (prot1 == 0) { | |
115 | /* no page was there, so we allocate one */ | |
116 | ret = (long)mmap((void *)host_start, qemu_host_page_size, prot, | |
117 | flags | MAP_ANONYMOUS, -1, 0); | |
118 | if (ret == -1) | |
119 | return ret; | |
120 | } | |
121 | prot1 &= PAGE_BITS; | |
122 | ||
123 | prot_new = prot | prot1; | |
124 | if (!(flags & MAP_ANONYMOUS)) { | |
125 | /* msync() won't work here, so we return an error if write is | |
126 | possible while it is a shared mapping */ | |
127 | #ifndef __APPLE__ | |
128 | if ((flags & MAP_TYPE) == MAP_SHARED && | |
129 | #else | |
130 | if ((flags & MAP_SHARED) && | |
131 | #endif | |
132 | (prot & PROT_WRITE)) | |
133 | return -EINVAL; | |
134 | ||
135 | /* adjust protection to be able to read */ | |
136 | if (!(prot1 & PROT_WRITE)) | |
137 | mprotect((void *)host_start, qemu_host_page_size, prot1 | PROT_WRITE); | |
138 | ||
139 | /* read the corresponding file data */ | |
140 | pread(fd, (void *)start, end - start, offset); | |
141 | ||
142 | /* put final protection */ | |
143 | if (prot_new != (prot1 | PROT_WRITE)) | |
144 | mprotect((void *)host_start, qemu_host_page_size, prot_new); | |
145 | } else { | |
146 | /* just update the protection */ | |
147 | if (prot_new != prot1) { | |
148 | mprotect((void *)host_start, qemu_host_page_size, prot_new); | |
149 | } | |
150 | } | |
151 | return 0; | |
152 | } | |
153 | ||
154 | /* NOTE: all the constants are the HOST ones */ | |
155 | long target_mmap(unsigned long start, unsigned long len, int prot, | |
156 | int flags, int fd, unsigned long offset) | |
157 | { | |
158 | unsigned long ret, end, host_start, host_end, retaddr, host_offset, host_len; | |
159 | #if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) | |
160 | static unsigned long last_start = 0x40000000; | |
161 | #endif | |
162 | ||
163 | #ifdef DEBUG_MMAP | |
164 | { | |
165 | printf("mmap: start=0x%lx len=0x%lx prot=%c%c%c flags=", | |
166 | start, len, | |
167 | prot & PROT_READ ? 'r' : '-', | |
168 | prot & PROT_WRITE ? 'w' : '-', | |
169 | prot & PROT_EXEC ? 'x' : '-'); | |
170 | if (flags & MAP_FIXED) | |
171 | printf("MAP_FIXED "); | |
172 | if (flags & MAP_ANONYMOUS) | |
173 | printf("MAP_ANON "); | |
174 | #ifndef MAP_TYPE | |
175 | # define MAP_TYPE 0x3 | |
176 | #endif | |
177 | switch(flags & MAP_TYPE) { | |
178 | case MAP_PRIVATE: | |
179 | printf("MAP_PRIVATE "); | |
180 | break; | |
181 | case MAP_SHARED: | |
182 | printf("MAP_SHARED "); | |
183 | break; | |
184 | default: | |
185 | printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE); | |
186 | break; | |
187 | } | |
188 | printf("fd=%d offset=%lx\n", fd, offset); | |
189 | } | |
190 | #endif | |
191 | ||
192 | if (offset & ~TARGET_PAGE_MASK) | |
193 | return -EINVAL; | |
194 | ||
195 | len = TARGET_PAGE_ALIGN(len); | |
196 | if (len == 0) | |
197 | return start; | |
198 | host_start = start & qemu_host_page_mask; | |
199 | ||
200 | if (!(flags & MAP_FIXED)) { | |
201 | #if defined(__alpha__) || defined(__sparc__) || defined(__x86_64__) | |
e91c8a77 | 202 | /* tell the kernel to search at the same place as i386 */ |
831b7825 TS |
203 | if (host_start == 0) { |
204 | host_start = last_start; | |
205 | last_start += HOST_PAGE_ALIGN(len); | |
206 | } | |
207 | #endif | |
208 | if (qemu_host_page_size != qemu_real_host_page_size) { | |
209 | /* NOTE: this code is only for debugging with '-p' option */ | |
210 | /* reserve a memory area */ | |
211 | host_len = HOST_PAGE_ALIGN(len) + qemu_host_page_size - TARGET_PAGE_SIZE; | |
212 | host_start = (long)mmap((void *)host_start, host_len, PROT_NONE, | |
213 | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); | |
214 | if (host_start == -1) | |
215 | return host_start; | |
216 | host_end = host_start + host_len; | |
217 | start = HOST_PAGE_ALIGN(host_start); | |
218 | end = start + HOST_PAGE_ALIGN(len); | |
219 | if (start > host_start) | |
220 | munmap((void *)host_start, start - host_start); | |
221 | if (end < host_end) | |
222 | munmap((void *)end, host_end - end); | |
223 | /* use it as a fixed mapping */ | |
224 | flags |= MAP_FIXED; | |
225 | } else { | |
226 | /* if not fixed, no need to do anything */ | |
227 | host_offset = offset & qemu_host_page_mask; | |
228 | host_len = len + offset - host_offset; | |
229 | start = (long)mmap((void *)host_start, host_len, | |
230 | prot, flags, fd, host_offset); | |
231 | if (start == -1) | |
232 | return start; | |
233 | /* update start so that it points to the file position at 'offset' */ | |
234 | if (!(flags & MAP_ANONYMOUS)) | |
235 | start += offset - host_offset; | |
236 | goto the_end1; | |
237 | } | |
238 | } | |
239 | ||
240 | if (start & ~TARGET_PAGE_MASK) | |
241 | return -EINVAL; | |
242 | end = start + len; | |
243 | host_end = HOST_PAGE_ALIGN(end); | |
244 | ||
245 | /* worst case: we cannot map the file because the offset is not | |
246 | aligned, so we read it */ | |
247 | if (!(flags & MAP_ANONYMOUS) && | |
248 | (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { | |
249 | /* msync() won't work here, so we return an error if write is | |
250 | possible while it is a shared mapping */ | |
251 | #ifndef __APPLE__ | |
252 | if ((flags & MAP_TYPE) == MAP_SHARED && | |
253 | #else | |
254 | if ((flags & MAP_SHARED) && | |
255 | #endif | |
256 | (prot & PROT_WRITE)) | |
257 | return -EINVAL; | |
258 | retaddr = target_mmap(start, len, prot | PROT_WRITE, | |
259 | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, | |
260 | -1, 0); | |
261 | if (retaddr == -1) | |
262 | return retaddr; | |
263 | pread(fd, (void *)start, len, offset); | |
264 | if (!(prot & PROT_WRITE)) { | |
265 | ret = target_mprotect(start, len, prot); | |
266 | if (ret != 0) | |
267 | return ret; | |
268 | } | |
269 | goto the_end; | |
270 | } | |
271 | ||
272 | /* handle the start of the mapping */ | |
273 | if (start > host_start) { | |
274 | if (host_end == host_start + qemu_host_page_size) { | |
275 | /* one single host page */ | |
276 | ret = mmap_frag(host_start, start, end, | |
277 | prot, flags, fd, offset); | |
278 | if (ret == -1) | |
279 | return ret; | |
280 | goto the_end1; | |
281 | } | |
282 | ret = mmap_frag(host_start, start, host_start + qemu_host_page_size, | |
283 | prot, flags, fd, offset); | |
284 | if (ret == -1) | |
285 | return ret; | |
286 | host_start += qemu_host_page_size; | |
287 | } | |
288 | /* handle the end of the mapping */ | |
289 | if (end < host_end) { | |
290 | ret = mmap_frag(host_end - qemu_host_page_size, | |
291 | host_end - qemu_host_page_size, host_end, | |
292 | prot, flags, fd, | |
293 | offset + host_end - qemu_host_page_size - start); | |
294 | if (ret == -1) | |
295 | return ret; | |
296 | host_end -= qemu_host_page_size; | |
297 | } | |
298 | ||
299 | /* map the middle (easier) */ | |
300 | if (host_start < host_end) { | |
301 | unsigned long offset1; | |
302 | if (flags & MAP_ANONYMOUS) | |
303 | offset1 = 0; | |
304 | else | |
305 | offset1 = offset + host_start - start; | |
306 | ret = (long)mmap((void *)host_start, host_end - host_start, | |
307 | prot, flags, fd, offset1); | |
308 | if (ret == -1) | |
309 | return ret; | |
310 | } | |
311 | the_end1: | |
312 | page_set_flags(start, start + len, prot | PAGE_VALID); | |
313 | the_end: | |
314 | #ifdef DEBUG_MMAP | |
315 | printf("target_mmap: ret=0x%lx\n", (long)start); | |
316 | page_dump(stdout); | |
317 | printf("\n"); | |
318 | #endif | |
319 | return start; | |
320 | } | |
321 | ||
322 | int target_munmap(unsigned long start, unsigned long len) | |
323 | { | |
324 | unsigned long end, host_start, host_end, addr; | |
325 | int prot, ret; | |
326 | ||
327 | #ifdef DEBUG_MMAP | |
328 | printf("munmap: start=0x%lx len=0x%lx\n", start, len); | |
329 | #endif | |
330 | if (start & ~TARGET_PAGE_MASK) | |
331 | return -EINVAL; | |
332 | len = TARGET_PAGE_ALIGN(len); | |
333 | if (len == 0) | |
334 | return -EINVAL; | |
335 | end = start + len; | |
336 | host_start = start & qemu_host_page_mask; | |
337 | host_end = HOST_PAGE_ALIGN(end); | |
338 | ||
339 | if (start > host_start) { | |
340 | /* handle host page containing start */ | |
341 | prot = 0; | |
342 | for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { | |
343 | prot |= page_get_flags(addr); | |
344 | } | |
345 | if (host_end == host_start + qemu_host_page_size) { | |
346 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { | |
347 | prot |= page_get_flags(addr); | |
348 | } | |
349 | end = host_end; | |
350 | } | |
351 | if (prot != 0) | |
352 | host_start += qemu_host_page_size; | |
353 | } | |
354 | if (end < host_end) { | |
355 | prot = 0; | |
356 | for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { | |
357 | prot |= page_get_flags(addr); | |
358 | } | |
359 | if (prot != 0) | |
360 | host_end -= qemu_host_page_size; | |
361 | } | |
362 | ||
363 | /* unmap what we can */ | |
364 | if (host_start < host_end) { | |
365 | ret = munmap((void *)host_start, host_end - host_start); | |
366 | if (ret != 0) | |
367 | return ret; | |
368 | } | |
369 | ||
370 | page_set_flags(start, start + len, 0); | |
371 | return 0; | |
372 | } | |
373 | ||
374 | /* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED | |
375 | blocks which have been allocated starting on a host page */ | |
376 | long target_mremap(unsigned long old_addr, unsigned long old_size, | |
377 | unsigned long new_size, unsigned long flags, | |
378 | unsigned long new_addr) | |
379 | { | |
380 | #ifndef __APPLE__ | |
381 | /* XXX: use 5 args syscall */ | |
382 | new_addr = (long)mremap((void *)old_addr, old_size, new_size, flags); | |
383 | if (new_addr == -1) | |
384 | return new_addr; | |
385 | prot = page_get_flags(old_addr); | |
386 | page_set_flags(old_addr, old_addr + old_size, 0); | |
387 | page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); | |
388 | return new_addr; | |
389 | #else | |
390 | qerror("target_mremap: unsupported\n"); | |
391 | #endif | |
392 | ||
393 | } | |
394 | ||
395 | int target_msync(unsigned long start, unsigned long len, int flags) | |
396 | { | |
397 | unsigned long end; | |
398 | ||
399 | if (start & ~TARGET_PAGE_MASK) | |
400 | return -EINVAL; | |
401 | len = TARGET_PAGE_ALIGN(len); | |
402 | end = start + len; | |
403 | if (end < start) | |
404 | return -EINVAL; | |
405 | if (end == start) | |
406 | return 0; | |
407 | ||
408 | start &= qemu_host_page_mask; | |
409 | return msync((void *)start, end - start, flags); | |
410 | } |