]>
Commit | Line | Data |
---|---|---|
84778508 BS |
1 | /* |
2 | * mmap support for qemu | |
3 | * | |
4 | * Copyright (c) 2003 - 2008 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 | |
8167ee88 | 17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
84778508 | 18 | */ |
2231197c | 19 | #include "qemu/osdep.h" |
84778508 BS |
20 | |
21 | #include "qemu.h" | |
22 | #include "qemu-common.h" | |
23 | ||
24 | //#define DEBUG_MMAP | |
25 | ||
95992b67 | 26 | static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER; |
06943a62 | 27 | static __thread int mmap_lock_count; |
84778508 BS |
28 | |
29 | void mmap_lock(void) | |
30 | { | |
31 | if (mmap_lock_count++ == 0) { | |
32 | pthread_mutex_lock(&mmap_mutex); | |
33 | } | |
34 | } | |
35 | ||
36 | void mmap_unlock(void) | |
37 | { | |
38 | if (--mmap_lock_count == 0) { | |
39 | pthread_mutex_unlock(&mmap_mutex); | |
40 | } | |
41 | } | |
42 | ||
301e40ed AB |
43 | bool have_mmap_lock(void) |
44 | { | |
45 | return mmap_lock_count > 0 ? true : false; | |
46 | } | |
47 | ||
84778508 BS |
48 | /* Grab lock to make sure things are in a consistent state after fork(). */ |
49 | void mmap_fork_start(void) | |
50 | { | |
51 | if (mmap_lock_count) | |
52 | abort(); | |
53 | pthread_mutex_lock(&mmap_mutex); | |
54 | } | |
55 | ||
56 | void mmap_fork_end(int child) | |
57 | { | |
58 | if (child) | |
59 | pthread_mutex_init(&mmap_mutex, NULL); | |
60 | else | |
61 | pthread_mutex_unlock(&mmap_mutex); | |
62 | } | |
84778508 | 63 | |
84778508 BS |
64 | /* NOTE: all the constants are the HOST ones, but addresses are target. */ |
65 | int target_mprotect(abi_ulong start, abi_ulong len, int prot) | |
66 | { | |
67 | abi_ulong end, host_start, host_end, addr; | |
68 | int prot1, ret; | |
69 | ||
70 | #ifdef DEBUG_MMAP | |
6a3b9bfd WL |
71 | printf("mprotect: start=0x" TARGET_ABI_FMT_lx |
72 | "len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c\n", start, len, | |
84778508 BS |
73 | prot & PROT_READ ? 'r' : '-', |
74 | prot & PROT_WRITE ? 'w' : '-', | |
75 | prot & PROT_EXEC ? 'x' : '-'); | |
76 | #endif | |
77 | ||
78 | if ((start & ~TARGET_PAGE_MASK) != 0) | |
79 | return -EINVAL; | |
80 | len = TARGET_PAGE_ALIGN(len); | |
81 | end = start + len; | |
82 | if (end < start) | |
83 | return -EINVAL; | |
84 | prot &= PROT_READ | PROT_WRITE | PROT_EXEC; | |
85 | if (len == 0) | |
86 | return 0; | |
87 | ||
88 | mmap_lock(); | |
89 | host_start = start & qemu_host_page_mask; | |
90 | host_end = HOST_PAGE_ALIGN(end); | |
91 | if (start > host_start) { | |
92 | /* handle host page containing start */ | |
93 | prot1 = prot; | |
5be1d0b5 | 94 | for (addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
95 | prot1 |= page_get_flags(addr); |
96 | } | |
97 | if (host_end == host_start + qemu_host_page_size) { | |
5be1d0b5 | 98 | for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
99 | prot1 |= page_get_flags(addr); |
100 | } | |
101 | end = host_end; | |
102 | } | |
3e8f1628 RH |
103 | ret = mprotect(g2h_untagged(host_start), |
104 | qemu_host_page_size, prot1 & PAGE_BITS); | |
84778508 BS |
105 | if (ret != 0) |
106 | goto error; | |
107 | host_start += qemu_host_page_size; | |
108 | } | |
109 | if (end < host_end) { | |
110 | prot1 = prot; | |
5be1d0b5 | 111 | for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
112 | prot1 |= page_get_flags(addr); |
113 | } | |
3e8f1628 RH |
114 | ret = mprotect(g2h_untagged(host_end - qemu_host_page_size), |
115 | qemu_host_page_size, prot1 & PAGE_BITS); | |
84778508 BS |
116 | if (ret != 0) |
117 | goto error; | |
118 | host_end -= qemu_host_page_size; | |
119 | } | |
120 | ||
121 | /* handle the pages in the middle */ | |
122 | if (host_start < host_end) { | |
3e8f1628 | 123 | ret = mprotect(g2h_untagged(host_start), host_end - host_start, prot); |
84778508 BS |
124 | if (ret != 0) |
125 | goto error; | |
126 | } | |
127 | page_set_flags(start, start + len, prot | PAGE_VALID); | |
128 | mmap_unlock(); | |
129 | return 0; | |
130 | error: | |
131 | mmap_unlock(); | |
132 | return ret; | |
133 | } | |
134 | ||
135 | /* map an incomplete host page */ | |
136 | static int mmap_frag(abi_ulong real_start, | |
137 | abi_ulong start, abi_ulong end, | |
138 | int prot, int flags, int fd, abi_ulong offset) | |
139 | { | |
140 | abi_ulong real_end, addr; | |
141 | void *host_start; | |
142 | int prot1, prot_new; | |
143 | ||
144 | real_end = real_start + qemu_host_page_size; | |
3e8f1628 | 145 | host_start = g2h_untagged(real_start); |
84778508 BS |
146 | |
147 | /* get the protection of the target pages outside the mapping */ | |
148 | prot1 = 0; | |
5be1d0b5 | 149 | for (addr = real_start; addr < real_end; addr++) { |
84778508 BS |
150 | if (addr < start || addr >= end) |
151 | prot1 |= page_get_flags(addr); | |
152 | } | |
153 | ||
154 | if (prot1 == 0) { | |
155 | /* no page was there, so we allocate one */ | |
156 | void *p = mmap(host_start, qemu_host_page_size, prot, | |
157 | flags | MAP_ANON, -1, 0); | |
158 | if (p == MAP_FAILED) | |
159 | return -1; | |
160 | prot1 = prot; | |
161 | } | |
162 | prot1 &= PAGE_BITS; | |
163 | ||
164 | prot_new = prot | prot1; | |
165 | if (!(flags & MAP_ANON)) { | |
166 | /* msync() won't work here, so we return an error if write is | |
167 | possible while it is a shared mapping */ | |
6c173b3c | 168 | if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED && |
84778508 | 169 | (prot & PROT_WRITE)) |
059bca46 | 170 | return -1; |
84778508 BS |
171 | |
172 | /* adjust protection to be able to read */ | |
173 | if (!(prot1 & PROT_WRITE)) | |
174 | mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE); | |
175 | ||
176 | /* read the corresponding file data */ | |
3e8f1628 | 177 | pread(fd, g2h_untagged(start), end - start, offset); |
84778508 BS |
178 | |
179 | /* put final protection */ | |
180 | if (prot_new != (prot1 | PROT_WRITE)) | |
181 | mprotect(host_start, qemu_host_page_size, prot_new); | |
182 | } else { | |
183 | /* just update the protection */ | |
184 | if (prot_new != prot1) { | |
185 | mprotect(host_start, qemu_host_page_size, prot_new); | |
186 | } | |
187 | } | |
188 | return 0; | |
189 | } | |
190 | ||
84778508 | 191 | static abi_ulong mmap_next_start = 0x40000000; |
84778508 BS |
192 | |
193 | unsigned long last_brk; | |
194 | ||
195 | /* find a free memory area of size 'size'. The search starts at | |
196 | 'start'. If 'start' == 0, then a default start address is used. | |
197 | Return -1 if error. | |
198 | */ | |
199 | /* page_init() marks pages used by the host as reserved to be sure not | |
200 | to use them. */ | |
201 | static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size) | |
202 | { | |
203 | abi_ulong addr, addr1, addr_start; | |
204 | int prot; | |
205 | unsigned long new_brk; | |
206 | ||
207 | new_brk = (unsigned long)sbrk(0); | |
208 | if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) { | |
209 | /* This is a hack to catch the host allocating memory with brk(). | |
210 | If it uses mmap then we loose. | |
211 | FIXME: We really want to avoid the host allocating memory in | |
212 | the first place, and maybe leave some slack to avoid switching | |
213 | to mmap. */ | |
214 | page_set_flags(last_brk & TARGET_PAGE_MASK, | |
215 | TARGET_PAGE_ALIGN(new_brk), | |
216 | PAGE_RESERVED); | |
217 | } | |
218 | last_brk = new_brk; | |
219 | ||
220 | size = HOST_PAGE_ALIGN(size); | |
221 | start = start & qemu_host_page_mask; | |
222 | addr = start; | |
223 | if (addr == 0) | |
224 | addr = mmap_next_start; | |
225 | addr_start = addr; | |
5be1d0b5 | 226 | for (;;) { |
84778508 | 227 | prot = 0; |
5be1d0b5 | 228 | for (addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) { |
84778508 BS |
229 | prot |= page_get_flags(addr1); |
230 | } | |
231 | if (prot == 0) | |
232 | break; | |
233 | addr += qemu_host_page_size; | |
234 | /* we found nothing */ | |
235 | if (addr == addr_start) | |
236 | return (abi_ulong)-1; | |
237 | } | |
238 | if (start == 0) | |
239 | mmap_next_start = addr + size; | |
240 | return addr; | |
241 | } | |
242 | ||
243 | /* NOTE: all the constants are the HOST ones */ | |
244 | abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, | |
245 | int flags, int fd, abi_ulong offset) | |
246 | { | |
247 | abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; | |
248 | unsigned long host_start; | |
249 | ||
250 | mmap_lock(); | |
251 | #ifdef DEBUG_MMAP | |
252 | { | |
6a3b9bfd WL |
253 | printf("mmap: start=0x" TARGET_ABI_FMT_lx |
254 | " len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c flags=", | |
84778508 BS |
255 | start, len, |
256 | prot & PROT_READ ? 'r' : '-', | |
257 | prot & PROT_WRITE ? 'w' : '-', | |
258 | prot & PROT_EXEC ? 'x' : '-'); | |
6a3b9bfd WL |
259 | if (flags & MAP_ALIGNMENT_MASK) { |
260 | printf("MAP_ALIGNED(%u) ", (flags & MAP_ALIGNMENT_MASK) | |
261 | >> MAP_ALIGNMENT_SHIFT); | |
262 | } | |
263 | #if MAP_GUARD | |
264 | if (flags & MAP_GUARD) { | |
265 | printf("MAP_GUARD "); | |
266 | } | |
267 | #endif | |
268 | if (flags & MAP_FIXED) { | |
84778508 | 269 | printf("MAP_FIXED "); |
6a3b9bfd WL |
270 | } |
271 | if (flags & MAP_ANONYMOUS) { | |
84778508 | 272 | printf("MAP_ANON "); |
6a3b9bfd WL |
273 | } |
274 | #ifdef MAP_EXCL | |
275 | if (flags & MAP_EXCL) { | |
276 | printf("MAP_EXCL "); | |
277 | } | |
278 | #endif | |
279 | if (flags & MAP_PRIVATE) { | |
84778508 | 280 | printf("MAP_PRIVATE "); |
6a3b9bfd WL |
281 | } |
282 | if (flags & MAP_SHARED) { | |
84778508 | 283 | printf("MAP_SHARED "); |
84778508 | 284 | } |
6a3b9bfd WL |
285 | if (flags & MAP_NOCORE) { |
286 | printf("MAP_NOCORE "); | |
287 | } | |
288 | #ifdef MAP_STACK | |
289 | if (flags & MAP_STACK) { | |
290 | printf("MAP_STACK "); | |
291 | } | |
292 | #endif | |
293 | printf("fd=%d offset=0x%llx\n", fd, offset); | |
84778508 BS |
294 | } |
295 | #endif | |
296 | ||
297 | if (offset & ~TARGET_PAGE_MASK) { | |
298 | errno = EINVAL; | |
299 | goto fail; | |
300 | } | |
301 | ||
302 | len = TARGET_PAGE_ALIGN(len); | |
303 | if (len == 0) | |
304 | goto the_end; | |
305 | real_start = start & qemu_host_page_mask; | |
306 | ||
307 | if (!(flags & MAP_FIXED)) { | |
308 | abi_ulong mmap_start; | |
309 | void *p; | |
310 | host_offset = offset & qemu_host_page_mask; | |
311 | host_len = len + offset - host_offset; | |
312 | host_len = HOST_PAGE_ALIGN(host_len); | |
313 | mmap_start = mmap_find_vma(real_start, host_len); | |
314 | if (mmap_start == (abi_ulong)-1) { | |
315 | errno = ENOMEM; | |
316 | goto fail; | |
317 | } | |
318 | /* Note: we prefer to control the mapping address. It is | |
319 | especially important if qemu_host_page_size > | |
320 | qemu_real_host_page_size */ | |
3e8f1628 | 321 | p = mmap(g2h_untagged(mmap_start), |
84778508 BS |
322 | host_len, prot, flags | MAP_FIXED, fd, host_offset); |
323 | if (p == MAP_FAILED) | |
324 | goto fail; | |
325 | /* update start so that it points to the file position at 'offset' */ | |
326 | host_start = (unsigned long)p; | |
327 | if (!(flags & MAP_ANON)) | |
328 | host_start += offset - host_offset; | |
329 | start = h2g(host_start); | |
330 | } else { | |
331 | int flg; | |
332 | target_ulong addr; | |
333 | ||
334 | if (start & ~TARGET_PAGE_MASK) { | |
335 | errno = EINVAL; | |
336 | goto fail; | |
337 | } | |
338 | end = start + len; | |
339 | real_end = HOST_PAGE_ALIGN(end); | |
340 | ||
5be1d0b5 | 341 | for (addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
342 | flg = page_get_flags(addr); |
343 | if (flg & PAGE_RESERVED) { | |
344 | errno = ENXIO; | |
345 | goto fail; | |
346 | } | |
347 | } | |
348 | ||
349 | /* worst case: we cannot map the file because the offset is not | |
350 | aligned, so we read it */ | |
351 | if (!(flags & MAP_ANON) && | |
352 | (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { | |
353 | /* msync() won't work here, so we return an error if write is | |
354 | possible while it is a shared mapping */ | |
6c173b3c | 355 | if ((flags & TARGET_BSD_MAP_FLAGMASK) == MAP_SHARED && |
84778508 BS |
356 | (prot & PROT_WRITE)) { |
357 | errno = EINVAL; | |
358 | goto fail; | |
359 | } | |
360 | retaddr = target_mmap(start, len, prot | PROT_WRITE, | |
361 | MAP_FIXED | MAP_PRIVATE | MAP_ANON, | |
362 | -1, 0); | |
363 | if (retaddr == -1) | |
364 | goto fail; | |
3e8f1628 | 365 | pread(fd, g2h_untagged(start), len, offset); |
84778508 BS |
366 | if (!(prot & PROT_WRITE)) { |
367 | ret = target_mprotect(start, len, prot); | |
368 | if (ret != 0) { | |
369 | start = ret; | |
370 | goto the_end; | |
371 | } | |
372 | } | |
373 | goto the_end; | |
374 | } | |
375 | ||
376 | /* handle the start of the mapping */ | |
377 | if (start > real_start) { | |
378 | if (real_end == real_start + qemu_host_page_size) { | |
379 | /* one single host page */ | |
380 | ret = mmap_frag(real_start, start, end, | |
381 | prot, flags, fd, offset); | |
382 | if (ret == -1) | |
383 | goto fail; | |
384 | goto the_end1; | |
385 | } | |
386 | ret = mmap_frag(real_start, start, real_start + qemu_host_page_size, | |
387 | prot, flags, fd, offset); | |
388 | if (ret == -1) | |
389 | goto fail; | |
390 | real_start += qemu_host_page_size; | |
391 | } | |
392 | /* handle the end of the mapping */ | |
393 | if (end < real_end) { | |
394 | ret = mmap_frag(real_end - qemu_host_page_size, | |
395 | real_end - qemu_host_page_size, real_end, | |
396 | prot, flags, fd, | |
397 | offset + real_end - qemu_host_page_size - start); | |
398 | if (ret == -1) | |
399 | goto fail; | |
400 | real_end -= qemu_host_page_size; | |
401 | } | |
402 | ||
403 | /* map the middle (easier) */ | |
404 | if (real_start < real_end) { | |
405 | void *p; | |
406 | unsigned long offset1; | |
407 | if (flags & MAP_ANON) | |
408 | offset1 = 0; | |
409 | else | |
410 | offset1 = offset + real_start - start; | |
3e8f1628 | 411 | p = mmap(g2h_untagged(real_start), real_end - real_start, |
84778508 BS |
412 | prot, flags, fd, offset1); |
413 | if (p == MAP_FAILED) | |
414 | goto fail; | |
415 | } | |
416 | } | |
417 | the_end1: | |
418 | page_set_flags(start, start + len, prot | PAGE_VALID); | |
419 | the_end: | |
420 | #ifdef DEBUG_MMAP | |
6a3b9bfd | 421 | printf("ret=0x" TARGET_ABI_FMT_lx "\n", start); |
84778508 BS |
422 | page_dump(stdout); |
423 | printf("\n"); | |
424 | #endif | |
425 | mmap_unlock(); | |
426 | return start; | |
427 | fail: | |
428 | mmap_unlock(); | |
429 | return -1; | |
430 | } | |
431 | ||
432 | int target_munmap(abi_ulong start, abi_ulong len) | |
433 | { | |
434 | abi_ulong end, real_start, real_end, addr; | |
435 | int prot, ret; | |
436 | ||
437 | #ifdef DEBUG_MMAP | |
6a3b9bfd WL |
438 | printf("munmap: start=0x" TARGET_ABI_FMT_lx " len=0x" |
439 | TARGET_ABI_FMT_lx "\n", | |
440 | start, len); | |
84778508 BS |
441 | #endif |
442 | if (start & ~TARGET_PAGE_MASK) | |
443 | return -EINVAL; | |
444 | len = TARGET_PAGE_ALIGN(len); | |
445 | if (len == 0) | |
446 | return -EINVAL; | |
447 | mmap_lock(); | |
448 | end = start + len; | |
449 | real_start = start & qemu_host_page_mask; | |
450 | real_end = HOST_PAGE_ALIGN(end); | |
451 | ||
452 | if (start > real_start) { | |
453 | /* handle host page containing start */ | |
454 | prot = 0; | |
5be1d0b5 | 455 | for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
456 | prot |= page_get_flags(addr); |
457 | } | |
458 | if (real_end == real_start + qemu_host_page_size) { | |
5be1d0b5 | 459 | for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
460 | prot |= page_get_flags(addr); |
461 | } | |
462 | end = real_end; | |
463 | } | |
464 | if (prot != 0) | |
465 | real_start += qemu_host_page_size; | |
466 | } | |
467 | if (end < real_end) { | |
468 | prot = 0; | |
5be1d0b5 | 469 | for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { |
84778508 BS |
470 | prot |= page_get_flags(addr); |
471 | } | |
472 | if (prot != 0) | |
473 | real_end -= qemu_host_page_size; | |
474 | } | |
475 | ||
476 | ret = 0; | |
477 | /* unmap what we can */ | |
478 | if (real_start < real_end) { | |
3e8f1628 | 479 | ret = munmap(g2h_untagged(real_start), real_end - real_start); |
84778508 BS |
480 | } |
481 | ||
482 | if (ret == 0) | |
483 | page_set_flags(start, start + len, 0); | |
484 | mmap_unlock(); | |
485 | return ret; | |
486 | } | |
487 | ||
488 | int target_msync(abi_ulong start, abi_ulong len, int flags) | |
489 | { | |
490 | abi_ulong end; | |
491 | ||
492 | if (start & ~TARGET_PAGE_MASK) | |
493 | return -EINVAL; | |
494 | len = TARGET_PAGE_ALIGN(len); | |
495 | end = start + len; | |
496 | if (end < start) | |
497 | return -EINVAL; | |
498 | if (end == start) | |
499 | return 0; | |
500 | ||
501 | start &= qemu_host_page_mask; | |
3e8f1628 | 502 | return msync(g2h_untagged(start), end - start, flags); |
84778508 | 503 | } |