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Commit | Line | Data |
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54936004 FB |
1 | /* |
2 | * mmap support for qemu | |
5fafdf24 | 3 | * |
54936004 FB |
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 | |
8167ee88 | 17 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
54936004 | 18 | */ |
d39594e9 | 19 | #include "qemu/osdep.h" |
11d96056 | 20 | #include "trace.h" |
10d0d505 | 21 | #include "exec/log.h" |
54936004 | 22 | #include "qemu.h" |
3b249d26 | 23 | #include "user-internals.h" |
5423e6d3 | 24 | #include "user-mmap.h" |
8655b4c7 | 25 | #include "target_mman.h" |
54936004 | 26 | |
1e6eec8b | 27 | static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER; |
dfd3f85c | 28 | static __thread int mmap_lock_count; |
c8a706fe PB |
29 | |
30 | void mmap_lock(void) | |
31 | { | |
32 | if (mmap_lock_count++ == 0) { | |
33 | pthread_mutex_lock(&mmap_mutex); | |
34 | } | |
35 | } | |
36 | ||
37 | void mmap_unlock(void) | |
38 | { | |
39 | if (--mmap_lock_count == 0) { | |
40 | pthread_mutex_unlock(&mmap_mutex); | |
41 | } | |
42 | } | |
d5975363 | 43 | |
301e40ed AB |
44 | bool have_mmap_lock(void) |
45 | { | |
46 | return mmap_lock_count > 0 ? true : false; | |
47 | } | |
48 | ||
d5975363 PB |
49 | /* Grab lock to make sure things are in a consistent state after fork(). */ |
50 | void mmap_fork_start(void) | |
51 | { | |
52 | if (mmap_lock_count) | |
53 | abort(); | |
54 | pthread_mutex_lock(&mmap_mutex); | |
55 | } | |
56 | ||
57 | void mmap_fork_end(int child) | |
58 | { | |
59 | if (child) | |
60 | pthread_mutex_init(&mmap_mutex, NULL); | |
61 | else | |
62 | pthread_mutex_unlock(&mmap_mutex); | |
63 | } | |
c8a706fe | 64 | |
9dba3ca5 RH |
65 | /* |
66 | * Validate target prot bitmask. | |
67 | * Return the prot bitmask for the host in *HOST_PROT. | |
68 | * Return 0 if the target prot bitmask is invalid, otherwise | |
69 | * the internal qemu page_flags (which will include PAGE_VALID). | |
70 | */ | |
71 | static int validate_prot_to_pageflags(int *host_prot, int prot) | |
72 | { | |
73 | int valid = PROT_READ | PROT_WRITE | PROT_EXEC | TARGET_PROT_SEM; | |
74 | int page_flags = (prot & PAGE_BITS) | PAGE_VALID; | |
75 | ||
76 | /* | |
77 | * For the host, we need not pass anything except read/write/exec. | |
78 | * While PROT_SEM is allowed by all hosts, it is also ignored, so | |
79 | * don't bother transforming guest bit to host bit. Any other | |
80 | * target-specific prot bits will not be understood by the host | |
81 | * and will need to be encoded into page_flags for qemu emulation. | |
4eaa960d RH |
82 | * |
83 | * Pages that are executable by the guest will never be executed | |
84 | * by the host, but the host will need to be able to read them. | |
9dba3ca5 | 85 | */ |
4eaa960d RH |
86 | *host_prot = (prot & (PROT_READ | PROT_WRITE)) |
87 | | (prot & PROT_EXEC ? PROT_READ : 0); | |
9dba3ca5 | 88 | |
be5d6f48 | 89 | #ifdef TARGET_AARCH64 |
d109b46d | 90 | { |
be5d6f48 | 91 | ARMCPU *cpu = ARM_CPU(thread_cpu); |
d109b46d RH |
92 | |
93 | /* | |
94 | * The PROT_BTI bit is only accepted if the cpu supports the feature. | |
95 | * Since this is the unusual case, don't bother checking unless | |
96 | * the bit has been requested. If set and valid, record the bit | |
97 | * within QEMU's page_flags. | |
98 | */ | |
99 | if ((prot & TARGET_PROT_BTI) && cpu_isar_feature(aa64_bti, cpu)) { | |
be5d6f48 RH |
100 | valid |= TARGET_PROT_BTI; |
101 | page_flags |= PAGE_BTI; | |
102 | } | |
d109b46d RH |
103 | /* Similarly for the PROT_MTE bit. */ |
104 | if ((prot & TARGET_PROT_MTE) && cpu_isar_feature(aa64_mte, cpu)) { | |
105 | valid |= TARGET_PROT_MTE; | |
106 | page_flags |= PAGE_MTE; | |
107 | } | |
be5d6f48 RH |
108 | } |
109 | #endif | |
110 | ||
9dba3ca5 RH |
111 | return prot & ~valid ? 0 : page_flags; |
112 | } | |
113 | ||
53a5960a | 114 | /* NOTE: all the constants are the HOST ones, but addresses are target. */ |
9dba3ca5 | 115 | int target_mprotect(abi_ulong start, abi_ulong len, int target_prot) |
54936004 | 116 | { |
992f48a0 | 117 | abi_ulong end, host_start, host_end, addr; |
9dba3ca5 | 118 | int prot1, ret, page_flags, host_prot; |
54936004 | 119 | |
9dba3ca5 | 120 | trace_target_mprotect(start, len, target_prot); |
54936004 | 121 | |
9dba3ca5 | 122 | if ((start & ~TARGET_PAGE_MASK) != 0) { |
78cf3390 | 123 | return -TARGET_EINVAL; |
9dba3ca5 RH |
124 | } |
125 | page_flags = validate_prot_to_pageflags(&host_prot, target_prot); | |
126 | if (!page_flags) { | |
127 | return -TARGET_EINVAL; | |
128 | } | |
54936004 FB |
129 | len = TARGET_PAGE_ALIGN(len); |
130 | end = start + len; | |
46b12f46 | 131 | if (!guest_range_valid_untagged(start, len)) { |
78cf3390 | 132 | return -TARGET_ENOMEM; |
ebf9a363 | 133 | } |
9dba3ca5 | 134 | if (len == 0) { |
54936004 | 135 | return 0; |
9dba3ca5 | 136 | } |
3b46e624 | 137 | |
c8a706fe | 138 | mmap_lock(); |
83fb7adf | 139 | host_start = start & qemu_host_page_mask; |
54936004 FB |
140 | host_end = HOST_PAGE_ALIGN(end); |
141 | if (start > host_start) { | |
142 | /* handle host page containing start */ | |
9dba3ca5 RH |
143 | prot1 = host_prot; |
144 | for (addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { | |
54936004 FB |
145 | prot1 |= page_get_flags(addr); |
146 | } | |
83fb7adf | 147 | if (host_end == host_start + qemu_host_page_size) { |
9dba3ca5 | 148 | for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { |
d418c81e FB |
149 | prot1 |= page_get_flags(addr); |
150 | } | |
151 | end = host_end; | |
152 | } | |
3e8f1628 | 153 | ret = mprotect(g2h_untagged(host_start), qemu_host_page_size, |
9dba3ca5 RH |
154 | prot1 & PAGE_BITS); |
155 | if (ret != 0) { | |
c8a706fe | 156 | goto error; |
9dba3ca5 | 157 | } |
83fb7adf | 158 | host_start += qemu_host_page_size; |
54936004 FB |
159 | } |
160 | if (end < host_end) { | |
9dba3ca5 RH |
161 | prot1 = host_prot; |
162 | for (addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { | |
54936004 FB |
163 | prot1 |= page_get_flags(addr); |
164 | } | |
3e8f1628 | 165 | ret = mprotect(g2h_untagged(host_end - qemu_host_page_size), |
9dba3ca5 RH |
166 | qemu_host_page_size, prot1 & PAGE_BITS); |
167 | if (ret != 0) { | |
c8a706fe | 168 | goto error; |
9dba3ca5 | 169 | } |
83fb7adf | 170 | host_end -= qemu_host_page_size; |
54936004 | 171 | } |
3b46e624 | 172 | |
54936004 FB |
173 | /* handle the pages in the middle */ |
174 | if (host_start < host_end) { | |
3e8f1628 RH |
175 | ret = mprotect(g2h_untagged(host_start), |
176 | host_end - host_start, host_prot); | |
9dba3ca5 | 177 | if (ret != 0) { |
c8a706fe | 178 | goto error; |
9dba3ca5 | 179 | } |
54936004 | 180 | } |
aa98e2d8 | 181 | |
9dba3ca5 | 182 | page_set_flags(start, start + len, page_flags); |
aa98e2d8 IL |
183 | tb_invalidate_phys_range(start, start + len); |
184 | ret = 0; | |
185 | ||
c8a706fe PB |
186 | error: |
187 | mmap_unlock(); | |
188 | return ret; | |
54936004 FB |
189 | } |
190 | ||
191 | /* map an incomplete host page */ | |
992f48a0 BS |
192 | static int mmap_frag(abi_ulong real_start, |
193 | abi_ulong start, abi_ulong end, | |
194 | int prot, int flags, int fd, abi_ulong offset) | |
54936004 | 195 | { |
80210bcd | 196 | abi_ulong real_end, addr; |
53a5960a | 197 | void *host_start; |
54936004 FB |
198 | int prot1, prot_new; |
199 | ||
53a5960a | 200 | real_end = real_start + qemu_host_page_size; |
3e8f1628 | 201 | host_start = g2h_untagged(real_start); |
54936004 FB |
202 | |
203 | /* get the protection of the target pages outside the mapping */ | |
204 | prot1 = 0; | |
53a5960a | 205 | for(addr = real_start; addr < real_end; addr++) { |
54936004 FB |
206 | if (addr < start || addr >= end) |
207 | prot1 |= page_get_flags(addr); | |
208 | } | |
3b46e624 | 209 | |
54936004 FB |
210 | if (prot1 == 0) { |
211 | /* no page was there, so we allocate one */ | |
80210bcd TS |
212 | void *p = mmap(host_start, qemu_host_page_size, prot, |
213 | flags | MAP_ANONYMOUS, -1, 0); | |
214 | if (p == MAP_FAILED) | |
215 | return -1; | |
53a5960a | 216 | prot1 = prot; |
54936004 FB |
217 | } |
218 | prot1 &= PAGE_BITS; | |
219 | ||
220 | prot_new = prot | prot1; | |
221 | if (!(flags & MAP_ANONYMOUS)) { | |
222 | /* msync() won't work here, so we return an error if write is | |
223 | possible while it is a shared mapping */ | |
224 | if ((flags & MAP_TYPE) == MAP_SHARED && | |
225 | (prot & PROT_WRITE)) | |
ee636500 | 226 | return -1; |
54936004 FB |
227 | |
228 | /* adjust protection to be able to read */ | |
229 | if (!(prot1 & PROT_WRITE)) | |
53a5960a | 230 | mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE); |
3b46e624 | 231 | |
54936004 | 232 | /* read the corresponding file data */ |
3e8f1628 | 233 | if (pread(fd, g2h_untagged(start), end - start, offset) == -1) |
fb7e378c | 234 | return -1; |
3b46e624 | 235 | |
54936004 FB |
236 | /* put final protection */ |
237 | if (prot_new != (prot1 | PROT_WRITE)) | |
53a5960a | 238 | mprotect(host_start, qemu_host_page_size, prot_new); |
54936004 | 239 | } else { |
54936004 | 240 | if (prot_new != prot1) { |
53a5960a | 241 | mprotect(host_start, qemu_host_page_size, prot_new); |
54936004 | 242 | } |
e6deac9c | 243 | if (prot_new & PROT_WRITE) { |
3e8f1628 | 244 | memset(g2h_untagged(start), 0, end - start); |
e6deac9c | 245 | } |
54936004 FB |
246 | } |
247 | return 0; | |
248 | } | |
249 | ||
14f24e14 | 250 | #if HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 64 |
aab613fb LY |
251 | #ifdef TARGET_AARCH64 |
252 | # define TASK_UNMAPPED_BASE 0x5500000000 | |
253 | #else | |
14f24e14 | 254 | # define TASK_UNMAPPED_BASE (1ul << 38) |
aab613fb | 255 | #endif |
a03e2d42 | 256 | #else |
9c9b5d7b HD |
257 | #ifdef TARGET_HPPA |
258 | # define TASK_UNMAPPED_BASE 0xfa000000 | |
259 | #else | |
14f24e14 | 260 | # define TASK_UNMAPPED_BASE 0x40000000 |
a03e2d42 | 261 | #endif |
9c9b5d7b | 262 | #endif |
59e9d91c | 263 | abi_ulong mmap_next_start = TASK_UNMAPPED_BASE; |
a03e2d42 | 264 | |
0776590d PB |
265 | unsigned long last_brk; |
266 | ||
68a1c816 PB |
267 | /* Subroutine of mmap_find_vma, used when we have pre-allocated a chunk |
268 | of guest address space. */ | |
30ab9ef2 RH |
269 | static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size, |
270 | abi_ulong align) | |
68a1c816 | 271 | { |
30ab9ef2 | 272 | abi_ulong addr, end_addr, incr = qemu_host_page_size; |
68a1c816 | 273 | int prot; |
30ab9ef2 | 274 | bool looped = false; |
68a1c816 | 275 | |
b76f21a7 | 276 | if (size > reserved_va) { |
68a1c816 PB |
277 | return (abi_ulong)-1; |
278 | } | |
279 | ||
30ab9ef2 RH |
280 | /* Note that start and size have already been aligned by mmap_find_vma. */ |
281 | ||
59e9d91c | 282 | end_addr = start + size; |
30ab9ef2 RH |
283 | if (start > reserved_va - size) { |
284 | /* Start at the top of the address space. */ | |
285 | end_addr = ((reserved_va - size) & -align) + size; | |
286 | looped = true; | |
59e9d91c | 287 | } |
59e9d91c | 288 | |
30ab9ef2 RH |
289 | /* Search downward from END_ADDR, checking to see if a page is in use. */ |
290 | addr = end_addr; | |
59e9d91c | 291 | while (1) { |
30ab9ef2 | 292 | addr -= incr; |
59e9d91c | 293 | if (addr > end_addr) { |
68a1c816 | 294 | if (looped) { |
30ab9ef2 | 295 | /* Failure. The entire address space has been searched. */ |
68a1c816 PB |
296 | return (abi_ulong)-1; |
297 | } | |
30ab9ef2 RH |
298 | /* Re-start at the top of the address space. */ |
299 | addr = end_addr = ((reserved_va - size) & -align) + size; | |
300 | looped = true; | |
301 | } else { | |
302 | prot = page_get_flags(addr); | |
303 | if (prot) { | |
304 | /* Page in use. Restart below this page. */ | |
305 | addr = end_addr = ((addr - size) & -align) + size; | |
306 | } else if (addr && addr + size == end_addr) { | |
307 | /* Success! All pages between ADDR and END_ADDR are free. */ | |
308 | if (start == mmap_next_start) { | |
309 | mmap_next_start = addr; | |
310 | } | |
311 | return addr; | |
312 | } | |
68a1c816 PB |
313 | } |
314 | } | |
68a1c816 PB |
315 | } |
316 | ||
fe3b4152 KS |
317 | /* |
318 | * Find and reserve a free memory area of size 'size'. The search | |
319 | * starts at 'start'. | |
320 | * It must be called with mmap_lock() held. | |
321 | * Return -1 if error. | |
322 | */ | |
30ab9ef2 | 323 | abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align) |
a03e2d42 | 324 | { |
14f24e14 | 325 | void *ptr, *prev; |
fe3b4152 | 326 | abi_ulong addr; |
14f24e14 | 327 | int wrapped, repeat; |
fe3b4152 | 328 | |
443b7505 RH |
329 | align = MAX(align, qemu_host_page_size); |
330 | ||
fe3b4152 | 331 | /* If 'start' == 0, then a default start address is used. */ |
14f24e14 | 332 | if (start == 0) { |
fe3b4152 | 333 | start = mmap_next_start; |
14f24e14 RH |
334 | } else { |
335 | start &= qemu_host_page_mask; | |
336 | } | |
30ab9ef2 | 337 | start = ROUND_UP(start, align); |
14f24e14 RH |
338 | |
339 | size = HOST_PAGE_ALIGN(size); | |
fe3b4152 | 340 | |
b76f21a7 | 341 | if (reserved_va) { |
30ab9ef2 | 342 | return mmap_find_vma_reserved(start, size, align); |
68a1c816 PB |
343 | } |
344 | ||
a03e2d42 | 345 | addr = start; |
14f24e14 RH |
346 | wrapped = repeat = 0; |
347 | prev = 0; | |
fe3b4152 | 348 | |
14f24e14 | 349 | for (;; prev = ptr) { |
fe3b4152 KS |
350 | /* |
351 | * Reserve needed memory area to avoid a race. | |
352 | * It should be discarded using: | |
353 | * - mmap() with MAP_FIXED flag | |
354 | * - mremap() with MREMAP_FIXED flag | |
355 | * - shmat() with SHM_REMAP flag | |
356 | */ | |
3e8f1628 | 357 | ptr = mmap(g2h_untagged(addr), size, PROT_NONE, |
fe3b4152 KS |
358 | MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0); |
359 | ||
360 | /* ENOMEM, if host address space has no memory */ | |
14f24e14 | 361 | if (ptr == MAP_FAILED) { |
fe3b4152 | 362 | return (abi_ulong)-1; |
14f24e14 RH |
363 | } |
364 | ||
365 | /* Count the number of sequential returns of the same address. | |
366 | This is used to modify the search algorithm below. */ | |
367 | repeat = (ptr == prev ? repeat + 1 : 0); | |
368 | ||
369 | if (h2g_valid(ptr + size - 1)) { | |
370 | addr = h2g(ptr); | |
fe3b4152 | 371 | |
30ab9ef2 | 372 | if ((addr & (align - 1)) == 0) { |
14f24e14 RH |
373 | /* Success. */ |
374 | if (start == mmap_next_start && addr >= TASK_UNMAPPED_BASE) { | |
375 | mmap_next_start = addr + size; | |
376 | } | |
377 | return addr; | |
378 | } | |
fe3b4152 | 379 | |
14f24e14 RH |
380 | /* The address is not properly aligned for the target. */ |
381 | switch (repeat) { | |
382 | case 0: | |
383 | /* Assume the result that the kernel gave us is the | |
384 | first with enough free space, so start again at the | |
385 | next higher target page. */ | |
30ab9ef2 | 386 | addr = ROUND_UP(addr, align); |
14f24e14 RH |
387 | break; |
388 | case 1: | |
389 | /* Sometimes the kernel decides to perform the allocation | |
390 | at the top end of memory instead. */ | |
30ab9ef2 | 391 | addr &= -align; |
14f24e14 RH |
392 | break; |
393 | case 2: | |
394 | /* Start over at low memory. */ | |
395 | addr = 0; | |
396 | break; | |
397 | default: | |
398 | /* Fail. This unaligned block must the last. */ | |
399 | addr = -1; | |
400 | break; | |
401 | } | |
402 | } else { | |
403 | /* Since the result the kernel gave didn't fit, start | |
404 | again at low memory. If any repetition, fail. */ | |
405 | addr = (repeat ? -1 : 0); | |
406 | } | |
407 | ||
408 | /* Unmap and try again. */ | |
fe3b4152 | 409 | munmap(ptr, size); |
fe3b4152 | 410 | |
14f24e14 | 411 | /* ENOMEM if we checked the whole of the target address space. */ |
d0b3e4f5 | 412 | if (addr == (abi_ulong)-1) { |
a03e2d42 | 413 | return (abi_ulong)-1; |
14f24e14 RH |
414 | } else if (addr == 0) { |
415 | if (wrapped) { | |
416 | return (abi_ulong)-1; | |
417 | } | |
418 | wrapped = 1; | |
419 | /* Don't actually use 0 when wrapping, instead indicate | |
8186e783 | 420 | that we'd truly like an allocation in low memory. */ |
14f24e14 RH |
421 | addr = (mmap_min_addr > TARGET_PAGE_SIZE |
422 | ? TARGET_PAGE_ALIGN(mmap_min_addr) | |
423 | : TARGET_PAGE_SIZE); | |
424 | } else if (wrapped && addr >= start) { | |
425 | return (abi_ulong)-1; | |
426 | } | |
a03e2d42 | 427 | } |
a03e2d42 FB |
428 | } |
429 | ||
54936004 | 430 | /* NOTE: all the constants are the HOST ones */ |
9dba3ca5 | 431 | abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, |
992f48a0 | 432 | int flags, int fd, abi_ulong offset) |
54936004 | 433 | { |
f93b7695 IL |
434 | abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len, |
435 | passthrough_start = -1, passthrough_end = -1; | |
9dba3ca5 | 436 | int page_flags, host_prot; |
54936004 | 437 | |
c8a706fe | 438 | mmap_lock(); |
9dba3ca5 | 439 | trace_target_mmap(start, len, target_prot, flags, fd, offset); |
54936004 | 440 | |
38138fab | 441 | if (!len) { |
e89f07d3 | 442 | errno = EINVAL; |
c8a706fe | 443 | goto fail; |
e89f07d3 | 444 | } |
54936004 | 445 | |
9dba3ca5 RH |
446 | page_flags = validate_prot_to_pageflags(&host_prot, target_prot); |
447 | if (!page_flags) { | |
448 | errno = EINVAL; | |
449 | goto fail; | |
450 | } | |
451 | ||
38138fab | 452 | /* Also check for overflows... */ |
54936004 | 453 | len = TARGET_PAGE_ALIGN(len); |
38138fab AB |
454 | if (!len) { |
455 | errno = ENOMEM; | |
456 | goto fail; | |
457 | } | |
458 | ||
459 | if (offset & ~TARGET_PAGE_MASK) { | |
460 | errno = EINVAL; | |
461 | goto fail; | |
462 | } | |
463 | ||
228168cb RH |
464 | /* |
465 | * If we're mapping shared memory, ensure we generate code for parallel | |
466 | * execution and flush old translations. This will work up to the level | |
467 | * supported by the host -- anything that requires EXCP_ATOMIC will not | |
468 | * be atomic with respect to an external process. | |
469 | */ | |
470 | if (flags & MAP_SHARED) { | |
471 | CPUState *cpu = thread_cpu; | |
472 | if (!(cpu->tcg_cflags & CF_PARALLEL)) { | |
473 | cpu->tcg_cflags |= CF_PARALLEL; | |
474 | tb_flush(cpu); | |
475 | } | |
476 | } | |
477 | ||
53a5960a | 478 | real_start = start & qemu_host_page_mask; |
a5e7ee46 RH |
479 | host_offset = offset & qemu_host_page_mask; |
480 | ||
481 | /* If the user is asking for the kernel to find a location, do that | |
482 | before we truncate the length for mapping files below. */ | |
483 | if (!(flags & MAP_FIXED)) { | |
484 | host_len = len + offset - host_offset; | |
485 | host_len = HOST_PAGE_ALIGN(host_len); | |
30ab9ef2 | 486 | start = mmap_find_vma(real_start, host_len, TARGET_PAGE_SIZE); |
a5e7ee46 RH |
487 | if (start == (abi_ulong)-1) { |
488 | errno = ENOMEM; | |
489 | goto fail; | |
490 | } | |
491 | } | |
54936004 | 492 | |
54c5a2ae EI |
493 | /* When mapping files into a memory area larger than the file, accesses |
494 | to pages beyond the file size will cause a SIGBUS. | |
495 | ||
496 | For example, if mmaping a file of 100 bytes on a host with 4K pages | |
497 | emulating a target with 8K pages, the target expects to be able to | |
498 | access the first 8K. But the host will trap us on any access beyond | |
499 | 4K. | |
500 | ||
501 | When emulating a target with a larger page-size than the hosts, we | |
502 | may need to truncate file maps at EOF and add extra anonymous pages | |
503 | up to the targets page boundary. */ | |
504 | ||
8e3b0cbb | 505 | if ((qemu_real_host_page_size() < qemu_host_page_size) && |
35f2fd04 MAL |
506 | !(flags & MAP_ANONYMOUS)) { |
507 | struct stat sb; | |
54c5a2ae EI |
508 | |
509 | if (fstat (fd, &sb) == -1) | |
510 | goto fail; | |
511 | ||
512 | /* Are we trying to create a map beyond EOF?. */ | |
513 | if (offset + len > sb.st_size) { | |
514 | /* If so, truncate the file map at eof aligned with | |
515 | the hosts real pagesize. Additional anonymous maps | |
516 | will be created beyond EOF. */ | |
0c2d70c4 | 517 | len = REAL_HOST_PAGE_ALIGN(sb.st_size - offset); |
54c5a2ae EI |
518 | } |
519 | } | |
520 | ||
54936004 | 521 | if (!(flags & MAP_FIXED)) { |
a5e7ee46 | 522 | unsigned long host_start; |
a03e2d42 | 523 | void *p; |
a5e7ee46 | 524 | |
a03e2d42 FB |
525 | host_len = len + offset - host_offset; |
526 | host_len = HOST_PAGE_ALIGN(host_len); | |
a5e7ee46 | 527 | |
a03e2d42 FB |
528 | /* Note: we prefer to control the mapping address. It is |
529 | especially important if qemu_host_page_size > | |
530 | qemu_real_host_page_size */ | |
3e8f1628 | 531 | p = mmap(g2h_untagged(start), host_len, host_prot, |
a5e7ee46 | 532 | flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0); |
9dba3ca5 | 533 | if (p == MAP_FAILED) { |
c8a706fe | 534 | goto fail; |
9dba3ca5 | 535 | } |
a03e2d42 FB |
536 | /* update start so that it points to the file position at 'offset' */ |
537 | host_start = (unsigned long)p; | |
54c5a2ae | 538 | if (!(flags & MAP_ANONYMOUS)) { |
3e8f1628 | 539 | p = mmap(g2h_untagged(start), len, host_prot, |
54c5a2ae | 540 | flags | MAP_FIXED, fd, host_offset); |
8384274e | 541 | if (p == MAP_FAILED) { |
3e8f1628 | 542 | munmap(g2h_untagged(start), host_len); |
8384274e JB |
543 | goto fail; |
544 | } | |
a03e2d42 | 545 | host_start += offset - host_offset; |
54c5a2ae | 546 | } |
a03e2d42 | 547 | start = h2g(host_start); |
f93b7695 IL |
548 | passthrough_start = start; |
549 | passthrough_end = start + len; | |
a03e2d42 FB |
550 | } else { |
551 | if (start & ~TARGET_PAGE_MASK) { | |
e89f07d3 | 552 | errno = EINVAL; |
c8a706fe | 553 | goto fail; |
e89f07d3 | 554 | } |
a03e2d42 FB |
555 | end = start + len; |
556 | real_end = HOST_PAGE_ALIGN(end); | |
7ab240ad | 557 | |
7d37435b PB |
558 | /* |
559 | * Test if requested memory area fits target address space | |
560 | * It can fail only on 64-bit host with 32-bit target. | |
561 | * On any other target/host host mmap() handles this error correctly. | |
562 | */ | |
46b12f46 | 563 | if (end < start || !guest_range_valid_untagged(start, len)) { |
ebf9a363 | 564 | errno = ENOMEM; |
45bc1f52 AJ |
565 | goto fail; |
566 | } | |
567 | ||
a03e2d42 FB |
568 | /* worst case: we cannot map the file because the offset is not |
569 | aligned, so we read it */ | |
570 | if (!(flags & MAP_ANONYMOUS) && | |
571 | (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { | |
572 | /* msync() won't work here, so we return an error if write is | |
573 | possible while it is a shared mapping */ | |
574 | if ((flags & MAP_TYPE) == MAP_SHARED && | |
9dba3ca5 | 575 | (host_prot & PROT_WRITE)) { |
a03e2d42 | 576 | errno = EINVAL; |
c8a706fe | 577 | goto fail; |
a03e2d42 | 578 | } |
9dba3ca5 | 579 | retaddr = target_mmap(start, len, target_prot | PROT_WRITE, |
a03e2d42 FB |
580 | MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, |
581 | -1, 0); | |
582 | if (retaddr == -1) | |
c8a706fe | 583 | goto fail; |
3e8f1628 | 584 | if (pread(fd, g2h_untagged(start), len, offset) == -1) |
fb7e378c | 585 | goto fail; |
9dba3ca5 RH |
586 | if (!(host_prot & PROT_WRITE)) { |
587 | ret = target_mprotect(start, len, target_prot); | |
86abac06 | 588 | assert(ret == 0); |
a03e2d42 FB |
589 | } |
590 | goto the_end; | |
54936004 | 591 | } |
a03e2d42 FB |
592 | |
593 | /* handle the start of the mapping */ | |
594 | if (start > real_start) { | |
595 | if (real_end == real_start + qemu_host_page_size) { | |
596 | /* one single host page */ | |
597 | ret = mmap_frag(real_start, start, end, | |
9dba3ca5 | 598 | host_prot, flags, fd, offset); |
a03e2d42 | 599 | if (ret == -1) |
c8a706fe | 600 | goto fail; |
a03e2d42 FB |
601 | goto the_end1; |
602 | } | |
603 | ret = mmap_frag(real_start, start, real_start + qemu_host_page_size, | |
9dba3ca5 | 604 | host_prot, flags, fd, offset); |
54936004 | 605 | if (ret == -1) |
c8a706fe | 606 | goto fail; |
a03e2d42 FB |
607 | real_start += qemu_host_page_size; |
608 | } | |
609 | /* handle the end of the mapping */ | |
610 | if (end < real_end) { | |
611 | ret = mmap_frag(real_end - qemu_host_page_size, | |
530c0032 | 612 | real_end - qemu_host_page_size, end, |
9dba3ca5 | 613 | host_prot, flags, fd, |
a03e2d42 FB |
614 | offset + real_end - qemu_host_page_size - start); |
615 | if (ret == -1) | |
c8a706fe | 616 | goto fail; |
a03e2d42 | 617 | real_end -= qemu_host_page_size; |
54936004 | 618 | } |
3b46e624 | 619 | |
a03e2d42 FB |
620 | /* map the middle (easier) */ |
621 | if (real_start < real_end) { | |
622 | void *p; | |
623 | unsigned long offset1; | |
624 | if (flags & MAP_ANONYMOUS) | |
625 | offset1 = 0; | |
626 | else | |
627 | offset1 = offset + real_start - start; | |
3e8f1628 | 628 | p = mmap(g2h_untagged(real_start), real_end - real_start, |
9dba3ca5 | 629 | host_prot, flags, fd, offset1); |
a03e2d42 | 630 | if (p == MAP_FAILED) |
c8a706fe | 631 | goto fail; |
f93b7695 IL |
632 | passthrough_start = real_start; |
633 | passthrough_end = real_end; | |
a03e2d42 | 634 | } |
54936004 FB |
635 | } |
636 | the_end1: | |
26bab757 RH |
637 | if (flags & MAP_ANONYMOUS) { |
638 | page_flags |= PAGE_ANON; | |
639 | } | |
d9c58585 | 640 | page_flags |= PAGE_RESET; |
f93b7695 IL |
641 | if (passthrough_start == passthrough_end) { |
642 | page_set_flags(start, start + len, page_flags); | |
643 | } else { | |
644 | if (start < passthrough_start) { | |
645 | page_set_flags(start, passthrough_start, page_flags); | |
646 | } | |
647 | page_set_flags(passthrough_start, passthrough_end, | |
648 | page_flags | PAGE_PASSTHROUGH); | |
649 | if (passthrough_end < start + len) { | |
650 | page_set_flags(passthrough_end, start + len, page_flags); | |
651 | } | |
652 | } | |
54936004 | 653 | the_end: |
d0e165ae | 654 | trace_target_mmap_complete(start); |
10d0d505 | 655 | if (qemu_loglevel_mask(CPU_LOG_PAGE)) { |
93756fdc RH |
656 | FILE *f = qemu_log_trylock(); |
657 | if (f) { | |
658 | fprintf(f, "page layout changed following mmap\n"); | |
659 | page_dump(f); | |
660 | qemu_log_unlock(f); | |
661 | } | |
10d0d505 | 662 | } |
35865339 | 663 | tb_invalidate_phys_range(start, start + len); |
c8a706fe | 664 | mmap_unlock(); |
54936004 | 665 | return start; |
c8a706fe PB |
666 | fail: |
667 | mmap_unlock(); | |
668 | return -1; | |
54936004 FB |
669 | } |
670 | ||
68a1c816 PB |
671 | static void mmap_reserve(abi_ulong start, abi_ulong size) |
672 | { | |
673 | abi_ulong real_start; | |
674 | abi_ulong real_end; | |
675 | abi_ulong addr; | |
676 | abi_ulong end; | |
677 | int prot; | |
678 | ||
679 | real_start = start & qemu_host_page_mask; | |
680 | real_end = HOST_PAGE_ALIGN(start + size); | |
681 | end = start + size; | |
682 | if (start > real_start) { | |
683 | /* handle host page containing start */ | |
684 | prot = 0; | |
685 | for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { | |
686 | prot |= page_get_flags(addr); | |
687 | } | |
688 | if (real_end == real_start + qemu_host_page_size) { | |
689 | for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { | |
690 | prot |= page_get_flags(addr); | |
691 | } | |
692 | end = real_end; | |
693 | } | |
694 | if (prot != 0) | |
695 | real_start += qemu_host_page_size; | |
696 | } | |
697 | if (end < real_end) { | |
698 | prot = 0; | |
699 | for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { | |
700 | prot |= page_get_flags(addr); | |
701 | } | |
702 | if (prot != 0) | |
703 | real_end -= qemu_host_page_size; | |
704 | } | |
705 | if (real_start != real_end) { | |
3e8f1628 | 706 | mmap(g2h_untagged(real_start), real_end - real_start, PROT_NONE, |
68a1c816 PB |
707 | MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, |
708 | -1, 0); | |
709 | } | |
710 | } | |
711 | ||
992f48a0 | 712 | int target_munmap(abi_ulong start, abi_ulong len) |
54936004 | 713 | { |
992f48a0 | 714 | abi_ulong end, real_start, real_end, addr; |
54936004 FB |
715 | int prot, ret; |
716 | ||
b7b18d26 AB |
717 | trace_target_munmap(start, len); |
718 | ||
54936004 | 719 | if (start & ~TARGET_PAGE_MASK) |
78cf3390 | 720 | return -TARGET_EINVAL; |
54936004 | 721 | len = TARGET_PAGE_ALIGN(len); |
46b12f46 | 722 | if (len == 0 || !guest_range_valid_untagged(start, len)) { |
78cf3390 | 723 | return -TARGET_EINVAL; |
ebf9a363 MF |
724 | } |
725 | ||
c8a706fe | 726 | mmap_lock(); |
54936004 | 727 | end = start + len; |
53a5960a PB |
728 | real_start = start & qemu_host_page_mask; |
729 | real_end = HOST_PAGE_ALIGN(end); | |
54936004 | 730 | |
53a5960a | 731 | if (start > real_start) { |
54936004 FB |
732 | /* handle host page containing start */ |
733 | prot = 0; | |
53a5960a | 734 | for(addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { |
54936004 FB |
735 | prot |= page_get_flags(addr); |
736 | } | |
53a5960a PB |
737 | if (real_end == real_start + qemu_host_page_size) { |
738 | for(addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { | |
d418c81e FB |
739 | prot |= page_get_flags(addr); |
740 | } | |
53a5960a | 741 | end = real_end; |
d418c81e | 742 | } |
54936004 | 743 | if (prot != 0) |
53a5960a | 744 | real_start += qemu_host_page_size; |
54936004 | 745 | } |
53a5960a | 746 | if (end < real_end) { |
54936004 | 747 | prot = 0; |
53a5960a | 748 | for(addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { |
54936004 FB |
749 | prot |= page_get_flags(addr); |
750 | } | |
751 | if (prot != 0) | |
53a5960a | 752 | real_end -= qemu_host_page_size; |
54936004 | 753 | } |
3b46e624 | 754 | |
c8a706fe | 755 | ret = 0; |
54936004 | 756 | /* unmap what we can */ |
53a5960a | 757 | if (real_start < real_end) { |
b76f21a7 | 758 | if (reserved_va) { |
68a1c816 PB |
759 | mmap_reserve(real_start, real_end - real_start); |
760 | } else { | |
3e8f1628 | 761 | ret = munmap(g2h_untagged(real_start), real_end - real_start); |
68a1c816 | 762 | } |
54936004 FB |
763 | } |
764 | ||
77a8f1a5 | 765 | if (ret == 0) { |
c8a706fe | 766 | page_set_flags(start, start + len, 0); |
35865339 | 767 | tb_invalidate_phys_range(start, start + len); |
77a8f1a5 | 768 | } |
c8a706fe PB |
769 | mmap_unlock(); |
770 | return ret; | |
54936004 FB |
771 | } |
772 | ||
992f48a0 BS |
773 | abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, |
774 | abi_ulong new_size, unsigned long flags, | |
775 | abi_ulong new_addr) | |
54936004 FB |
776 | { |
777 | int prot; | |
f19412a2 | 778 | void *host_addr; |
54936004 | 779 | |
46b12f46 | 780 | if (!guest_range_valid_untagged(old_addr, old_size) || |
ebf9a363 | 781 | ((flags & MREMAP_FIXED) && |
46b12f46 | 782 | !guest_range_valid_untagged(new_addr, new_size)) || |
ccc5ccc1 | 783 | ((flags & MREMAP_MAYMOVE) == 0 && |
46b12f46 | 784 | !guest_range_valid_untagged(old_addr, new_size))) { |
ebf9a363 MF |
785 | errno = ENOMEM; |
786 | return -1; | |
787 | } | |
788 | ||
c8a706fe | 789 | mmap_lock(); |
f19412a2 | 790 | |
68a1c816 | 791 | if (flags & MREMAP_FIXED) { |
3e8f1628 RH |
792 | host_addr = mremap(g2h_untagged(old_addr), old_size, new_size, |
793 | flags, g2h_untagged(new_addr)); | |
68a1c816 | 794 | |
b76f21a7 | 795 | if (reserved_va && host_addr != MAP_FAILED) { |
68a1c816 PB |
796 | /* If new and old addresses overlap then the above mremap will |
797 | already have failed with EINVAL. */ | |
798 | mmap_reserve(old_addr, old_size); | |
799 | } | |
800 | } else if (flags & MREMAP_MAYMOVE) { | |
f19412a2 AJ |
801 | abi_ulong mmap_start; |
802 | ||
30ab9ef2 | 803 | mmap_start = mmap_find_vma(0, new_size, TARGET_PAGE_SIZE); |
f19412a2 AJ |
804 | |
805 | if (mmap_start == -1) { | |
806 | errno = ENOMEM; | |
807 | host_addr = MAP_FAILED; | |
68a1c816 | 808 | } else { |
3e8f1628 RH |
809 | host_addr = mremap(g2h_untagged(old_addr), old_size, new_size, |
810 | flags | MREMAP_FIXED, | |
811 | g2h_untagged(mmap_start)); | |
b76f21a7 | 812 | if (reserved_va) { |
c65ffe6d | 813 | mmap_reserve(old_addr, old_size); |
814 | } | |
68a1c816 | 815 | } |
3af72a4d | 816 | } else { |
68a1c816 | 817 | int prot = 0; |
b76f21a7 | 818 | if (reserved_va && old_size < new_size) { |
68a1c816 PB |
819 | abi_ulong addr; |
820 | for (addr = old_addr + old_size; | |
821 | addr < old_addr + new_size; | |
822 | addr++) { | |
823 | prot |= page_get_flags(addr); | |
824 | } | |
825 | } | |
826 | if (prot == 0) { | |
3e8f1628 RH |
827 | host_addr = mremap(g2h_untagged(old_addr), |
828 | old_size, new_size, flags); | |
56d19084 TK |
829 | |
830 | if (host_addr != MAP_FAILED) { | |
831 | /* Check if address fits target address space */ | |
46b12f46 | 832 | if (!guest_range_valid_untagged(h2g(host_addr), new_size)) { |
56d19084 | 833 | /* Revert mremap() changes */ |
3e8f1628 RH |
834 | host_addr = mremap(g2h_untagged(old_addr), |
835 | new_size, old_size, flags); | |
56d19084 TK |
836 | errno = ENOMEM; |
837 | host_addr = MAP_FAILED; | |
838 | } else if (reserved_va && old_size > new_size) { | |
839 | mmap_reserve(old_addr + old_size, old_size - new_size); | |
840 | } | |
68a1c816 PB |
841 | } |
842 | } else { | |
843 | errno = ENOMEM; | |
844 | host_addr = MAP_FAILED; | |
845 | } | |
f19412a2 AJ |
846 | } |
847 | ||
848 | if (host_addr == MAP_FAILED) { | |
c8a706fe PB |
849 | new_addr = -1; |
850 | } else { | |
851 | new_addr = h2g(host_addr); | |
852 | prot = page_get_flags(old_addr); | |
853 | page_set_flags(old_addr, old_addr + old_size, 0); | |
d9c58585 RH |
854 | page_set_flags(new_addr, new_addr + new_size, |
855 | prot | PAGE_VALID | PAGE_RESET); | |
c8a706fe | 856 | } |
35865339 | 857 | tb_invalidate_phys_range(new_addr, new_addr + new_size); |
c8a706fe | 858 | mmap_unlock(); |
54936004 FB |
859 | return new_addr; |
860 | } | |
892a4f6a IL |
861 | |
862 | static bool can_passthrough_madv_dontneed(abi_ulong start, abi_ulong end) | |
863 | { | |
864 | ulong addr; | |
865 | ||
866 | if ((start | end) & ~qemu_host_page_mask) { | |
867 | return false; | |
868 | } | |
869 | ||
870 | for (addr = start; addr < end; addr += TARGET_PAGE_SIZE) { | |
f93b7695 | 871 | if (!(page_get_flags(addr) & PAGE_PASSTHROUGH)) { |
892a4f6a IL |
872 | return false; |
873 | } | |
874 | } | |
875 | ||
876 | return true; | |
877 | } | |
878 | ||
879 | abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice) | |
880 | { | |
881 | abi_ulong len, end; | |
882 | int ret = 0; | |
883 | ||
884 | if (start & ~TARGET_PAGE_MASK) { | |
885 | return -TARGET_EINVAL; | |
886 | } | |
887 | len = TARGET_PAGE_ALIGN(len_in); | |
888 | ||
889 | if (len_in && !len) { | |
890 | return -TARGET_EINVAL; | |
891 | } | |
892 | ||
893 | end = start + len; | |
894 | if (end < start) { | |
895 | return -TARGET_EINVAL; | |
896 | } | |
897 | ||
898 | if (end == start) { | |
899 | return 0; | |
900 | } | |
901 | ||
902 | if (!guest_range_valid_untagged(start, len)) { | |
903 | return -TARGET_EINVAL; | |
904 | } | |
905 | ||
906 | /* | |
907 | * A straight passthrough may not be safe because qemu sometimes turns | |
908 | * private file-backed mappings into anonymous mappings. | |
909 | * | |
910 | * This is a hint, so ignoring and returning success is ok. | |
911 | * | |
912 | * This breaks MADV_DONTNEED, completely implementing which is quite | |
f93b7695 IL |
913 | * complicated. However, there is one low-hanging fruit: mappings that are |
914 | * known to have the same semantics in the host and the guest. In this case | |
915 | * passthrough is safe, so do it. | |
892a4f6a IL |
916 | */ |
917 | mmap_lock(); | |
8655b4c7 | 918 | if (advice == TARGET_MADV_DONTNEED && |
892a4f6a IL |
919 | can_passthrough_madv_dontneed(start, end)) { |
920 | ret = get_errno(madvise(g2h_untagged(start), len, MADV_DONTNEED)); | |
dbbf8975 VB |
921 | if (ret == 0) { |
922 | page_reset_target_data(start, start + len); | |
923 | } | |
892a4f6a IL |
924 | } |
925 | mmap_unlock(); | |
926 | ||
927 | return ret; | |
928 | } |