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, see <http://www.gnu.org/licenses/>. 18 */ 19 #include <stdlib.h> 20 #include <stdio.h> 21 #include <stdarg.h> 22 #include <string.h> 23 #include <unistd.h> 24 #include <errno.h> 25 #include <sys/types.h> 26 #include <sys/stat.h> 27 #include <sys/mman.h> 28 #include <linux/mman.h> 29 #include <linux/unistd.h> 30 31 #include "qemu.h" 32 #include "qemu-common.h" 33 34 //#define DEBUG_MMAP 35 36 #if defined(CONFIG_USE_NPTL) 37 static pthread_mutex_t mmap_mutex = PTHREAD_MUTEX_INITIALIZER; 38 static __thread int mmap_lock_count; 39 40 void mmap_lock(void) 41 { 42 if (mmap_lock_count++ == 0) { 43 pthread_mutex_lock(&mmap_mutex); 44 } 45 } 46 47 void mmap_unlock(void) 48 { 49 if (--mmap_lock_count == 0) { 50 pthread_mutex_unlock(&mmap_mutex); 51 } 52 } 53 54 /* Grab lock to make sure things are in a consistent state after fork(). */ 55 void mmap_fork_start(void) 56 { 57 if (mmap_lock_count) 58 abort(); 59 pthread_mutex_lock(&mmap_mutex); 60 } 61 62 void mmap_fork_end(int child) 63 { 64 if (child) 65 pthread_mutex_init(&mmap_mutex, NULL); 66 else 67 pthread_mutex_unlock(&mmap_mutex); 68 } 69 #else 70 /* We aren't threadsafe to start with, so no need to worry about locking. */ 71 void mmap_lock(void) 72 { 73 } 74 75 void mmap_unlock(void) 76 { 77 } 78 #endif 79 80 /* NOTE: all the constants are the HOST ones, but addresses are target. */ 81 int target_mprotect(abi_ulong start, abi_ulong len, int prot) 82 { 83 abi_ulong end, host_start, host_end, addr; 84 int prot1, ret; 85 86 #ifdef DEBUG_MMAP 87 printf("mprotect: start=0x" TARGET_ABI_FMT_lx 88 "len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c\n", start, len, 89 prot & PROT_READ ? 'r' : '-', 90 prot & PROT_WRITE ? 'w' : '-', 91 prot & PROT_EXEC ? 'x' : '-'); 92 #endif 93 94 if ((start & ~TARGET_PAGE_MASK) != 0) 95 return -EINVAL; 96 len = TARGET_PAGE_ALIGN(len); 97 end = start + len; 98 if (end < start) 99 return -EINVAL; 100 prot &= PROT_READ | PROT_WRITE | PROT_EXEC; 101 if (len == 0) 102 return 0; 103 104 mmap_lock(); 105 host_start = start & qemu_host_page_mask; 106 host_end = HOST_PAGE_ALIGN(end); 107 if (start > host_start) { 108 /* handle host page containing start */ 109 prot1 = prot; 110 for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { 111 prot1 |= page_get_flags(addr); 112 } 113 if (host_end == host_start + qemu_host_page_size) { 114 for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { 115 prot1 |= page_get_flags(addr); 116 } 117 end = host_end; 118 } 119 ret = mprotect(g2h(host_start), qemu_host_page_size, prot1 & PAGE_BITS); 120 if (ret != 0) 121 goto error; 122 host_start += qemu_host_page_size; 123 } 124 if (end < host_end) { 125 prot1 = prot; 126 for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { 127 prot1 |= page_get_flags(addr); 128 } 129 ret = mprotect(g2h(host_end - qemu_host_page_size), qemu_host_page_size, 130 prot1 & PAGE_BITS); 131 if (ret != 0) 132 goto error; 133 host_end -= qemu_host_page_size; 134 } 135 136 /* handle the pages in the middle */ 137 if (host_start < host_end) { 138 ret = mprotect(g2h(host_start), host_end - host_start, prot); 139 if (ret != 0) 140 goto error; 141 } 142 page_set_flags(start, start + len, prot | PAGE_VALID); 143 mmap_unlock(); 144 return 0; 145 error: 146 mmap_unlock(); 147 return ret; 148 } 149 150 /* map an incomplete host page */ 151 static int mmap_frag(abi_ulong real_start, 152 abi_ulong start, abi_ulong end, 153 int prot, int flags, int fd, abi_ulong offset) 154 { 155 abi_ulong real_end, addr; 156 void *host_start; 157 int prot1, prot_new; 158 159 real_end = real_start + qemu_host_page_size; 160 host_start = g2h(real_start); 161 162 /* get the protection of the target pages outside the mapping */ 163 prot1 = 0; 164 for(addr = real_start; addr < real_end; addr++) { 165 if (addr < start || addr >= end) 166 prot1 |= page_get_flags(addr); 167 } 168 169 if (prot1 == 0) { 170 /* no page was there, so we allocate one */ 171 void *p = mmap(host_start, qemu_host_page_size, prot, 172 flags | MAP_ANONYMOUS, -1, 0); 173 if (p == MAP_FAILED) 174 return -1; 175 prot1 = prot; 176 } 177 prot1 &= PAGE_BITS; 178 179 prot_new = prot | prot1; 180 if (!(flags & MAP_ANONYMOUS)) { 181 /* msync() won't work here, so we return an error if write is 182 possible while it is a shared mapping */ 183 if ((flags & MAP_TYPE) == MAP_SHARED && 184 (prot & PROT_WRITE)) 185 return -1; 186 187 /* adjust protection to be able to read */ 188 if (!(prot1 & PROT_WRITE)) 189 mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE); 190 191 /* read the corresponding file data */ 192 if (pread(fd, g2h(start), end - start, offset) == -1) 193 return -1; 194 195 /* put final protection */ 196 if (prot_new != (prot1 | PROT_WRITE)) 197 mprotect(host_start, qemu_host_page_size, prot_new); 198 } else { 199 /* just update the protection */ 200 if (prot_new != prot1) { 201 mprotect(host_start, qemu_host_page_size, prot_new); 202 } 203 } 204 return 0; 205 } 206 207 #if HOST_LONG_BITS == 64 && TARGET_ABI_BITS == 64 208 # define TASK_UNMAPPED_BASE (1ul << 38) 209 #elif defined(__CYGWIN__) 210 /* Cygwin doesn't have a whole lot of address space. */ 211 # define TASK_UNMAPPED_BASE 0x18000000 212 #else 213 # define TASK_UNMAPPED_BASE 0x40000000 214 #endif 215 abi_ulong mmap_next_start = TASK_UNMAPPED_BASE; 216 217 unsigned long last_brk; 218 219 #ifdef CONFIG_USE_GUEST_BASE 220 /* Subroutine of mmap_find_vma, used when we have pre-allocated a chunk 221 of guest address space. */ 222 static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size) 223 { 224 abi_ulong addr; 225 abi_ulong end_addr; 226 int prot; 227 int looped = 0; 228 229 if (size > RESERVED_VA) { 230 return (abi_ulong)-1; 231 } 232 233 size = HOST_PAGE_ALIGN(size); 234 end_addr = start + size; 235 if (end_addr > RESERVED_VA) { 236 end_addr = RESERVED_VA; 237 } 238 addr = end_addr - qemu_host_page_size; 239 240 while (1) { 241 if (addr > end_addr) { 242 if (looped) { 243 return (abi_ulong)-1; 244 } 245 end_addr = RESERVED_VA; 246 addr = end_addr - qemu_host_page_size; 247 looped = 1; 248 continue; 249 } 250 prot = page_get_flags(addr); 251 if (prot) { 252 end_addr = addr; 253 } 254 if (addr + size == end_addr) { 255 break; 256 } 257 addr -= qemu_host_page_size; 258 } 259 260 if (start == mmap_next_start) { 261 mmap_next_start = addr; 262 } 263 264 return addr; 265 } 266 #endif 267 268 /* 269 * Find and reserve a free memory area of size 'size'. The search 270 * starts at 'start'. 271 * It must be called with mmap_lock() held. 272 * Return -1 if error. 273 */ 274 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size) 275 { 276 void *ptr, *prev; 277 abi_ulong addr; 278 int wrapped, repeat; 279 280 /* If 'start' == 0, then a default start address is used. */ 281 if (start == 0) { 282 start = mmap_next_start; 283 } else { 284 start &= qemu_host_page_mask; 285 } 286 287 size = HOST_PAGE_ALIGN(size); 288 289 #ifdef CONFIG_USE_GUEST_BASE 290 if (RESERVED_VA) { 291 return mmap_find_vma_reserved(start, size); 292 } 293 #endif 294 295 addr = start; 296 wrapped = repeat = 0; 297 prev = 0; 298 299 for (;; prev = ptr) { 300 /* 301 * Reserve needed memory area to avoid a race. 302 * It should be discarded using: 303 * - mmap() with MAP_FIXED flag 304 * - mremap() with MREMAP_FIXED flag 305 * - shmat() with SHM_REMAP flag 306 */ 307 ptr = mmap(g2h(addr), size, PROT_NONE, 308 MAP_ANONYMOUS|MAP_PRIVATE|MAP_NORESERVE, -1, 0); 309 310 /* ENOMEM, if host address space has no memory */ 311 if (ptr == MAP_FAILED) { 312 return (abi_ulong)-1; 313 } 314 315 /* Count the number of sequential returns of the same address. 316 This is used to modify the search algorithm below. */ 317 repeat = (ptr == prev ? repeat + 1 : 0); 318 319 if (h2g_valid(ptr + size - 1)) { 320 addr = h2g(ptr); 321 322 if ((addr & ~TARGET_PAGE_MASK) == 0) { 323 /* Success. */ 324 if (start == mmap_next_start && addr >= TASK_UNMAPPED_BASE) { 325 mmap_next_start = addr + size; 326 } 327 return addr; 328 } 329 330 /* The address is not properly aligned for the target. */ 331 switch (repeat) { 332 case 0: 333 /* Assume the result that the kernel gave us is the 334 first with enough free space, so start again at the 335 next higher target page. */ 336 addr = TARGET_PAGE_ALIGN(addr); 337 break; 338 case 1: 339 /* Sometimes the kernel decides to perform the allocation 340 at the top end of memory instead. */ 341 addr &= TARGET_PAGE_MASK; 342 break; 343 case 2: 344 /* Start over at low memory. */ 345 addr = 0; 346 break; 347 default: 348 /* Fail. This unaligned block must the last. */ 349 addr = -1; 350 break; 351 } 352 } else { 353 /* Since the result the kernel gave didn't fit, start 354 again at low memory. If any repetition, fail. */ 355 addr = (repeat ? -1 : 0); 356 } 357 358 /* Unmap and try again. */ 359 munmap(ptr, size); 360 361 /* ENOMEM if we checked the whole of the target address space. */ 362 if (addr == (abi_ulong)-1) { 363 return (abi_ulong)-1; 364 } else if (addr == 0) { 365 if (wrapped) { 366 return (abi_ulong)-1; 367 } 368 wrapped = 1; 369 /* Don't actually use 0 when wrapping, instead indicate 370 that we'd truly like an allocation in low memory. */ 371 addr = (mmap_min_addr > TARGET_PAGE_SIZE 372 ? TARGET_PAGE_ALIGN(mmap_min_addr) 373 : TARGET_PAGE_SIZE); 374 } else if (wrapped && addr >= start) { 375 return (abi_ulong)-1; 376 } 377 } 378 } 379 380 /* NOTE: all the constants are the HOST ones */ 381 abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, 382 int flags, int fd, abi_ulong offset) 383 { 384 abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; 385 unsigned long host_start; 386 387 mmap_lock(); 388 #ifdef DEBUG_MMAP 389 { 390 printf("mmap: start=0x" TARGET_ABI_FMT_lx 391 " len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c flags=", 392 start, len, 393 prot & PROT_READ ? 'r' : '-', 394 prot & PROT_WRITE ? 'w' : '-', 395 prot & PROT_EXEC ? 'x' : '-'); 396 if (flags & MAP_FIXED) 397 printf("MAP_FIXED "); 398 if (flags & MAP_ANONYMOUS) 399 printf("MAP_ANON "); 400 switch(flags & MAP_TYPE) { 401 case MAP_PRIVATE: 402 printf("MAP_PRIVATE "); 403 break; 404 case MAP_SHARED: 405 printf("MAP_SHARED "); 406 break; 407 default: 408 printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE); 409 break; 410 } 411 printf("fd=%d offset=" TARGET_ABI_FMT_lx "\n", fd, offset); 412 } 413 #endif 414 415 if (offset & ~TARGET_PAGE_MASK) { 416 errno = EINVAL; 417 goto fail; 418 } 419 420 len = TARGET_PAGE_ALIGN(len); 421 if (len == 0) 422 goto the_end; 423 real_start = start & qemu_host_page_mask; 424 425 /* When mapping files into a memory area larger than the file, accesses 426 to pages beyond the file size will cause a SIGBUS. 427 428 For example, if mmaping a file of 100 bytes on a host with 4K pages 429 emulating a target with 8K pages, the target expects to be able to 430 access the first 8K. But the host will trap us on any access beyond 431 4K. 432 433 When emulating a target with a larger page-size than the hosts, we 434 may need to truncate file maps at EOF and add extra anonymous pages 435 up to the targets page boundary. */ 436 437 if ((qemu_real_host_page_size < TARGET_PAGE_SIZE) 438 && !(flags & MAP_ANONYMOUS)) { 439 struct stat sb; 440 441 if (fstat (fd, &sb) == -1) 442 goto fail; 443 444 /* Are we trying to create a map beyond EOF?. */ 445 if (offset + len > sb.st_size) { 446 /* If so, truncate the file map at eof aligned with 447 the hosts real pagesize. Additional anonymous maps 448 will be created beyond EOF. */ 449 len = (sb.st_size - offset); 450 len += qemu_real_host_page_size - 1; 451 len &= ~(qemu_real_host_page_size - 1); 452 } 453 } 454 455 if (!(flags & MAP_FIXED)) { 456 abi_ulong mmap_start; 457 void *p; 458 host_offset = offset & qemu_host_page_mask; 459 host_len = len + offset - host_offset; 460 host_len = HOST_PAGE_ALIGN(host_len); 461 mmap_start = mmap_find_vma(real_start, host_len); 462 if (mmap_start == (abi_ulong)-1) { 463 errno = ENOMEM; 464 goto fail; 465 } 466 /* Note: we prefer to control the mapping address. It is 467 especially important if qemu_host_page_size > 468 qemu_real_host_page_size */ 469 p = mmap(g2h(mmap_start), 470 host_len, prot, flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0); 471 if (p == MAP_FAILED) 472 goto fail; 473 /* update start so that it points to the file position at 'offset' */ 474 host_start = (unsigned long)p; 475 if (!(flags & MAP_ANONYMOUS)) { 476 p = mmap(g2h(mmap_start), len, prot, 477 flags | MAP_FIXED, fd, host_offset); 478 host_start += offset - host_offset; 479 } 480 start = h2g(host_start); 481 } else { 482 if (start & ~TARGET_PAGE_MASK) { 483 errno = EINVAL; 484 goto fail; 485 } 486 end = start + len; 487 real_end = HOST_PAGE_ALIGN(end); 488 489 /* 490 * Test if requested memory area fits target address space 491 * It can fail only on 64-bit host with 32-bit target. 492 * On any other target/host host mmap() handles this error correctly. 493 */ 494 if ((unsigned long)start + len - 1 > (abi_ulong) -1) { 495 errno = EINVAL; 496 goto fail; 497 } 498 499 /* worst case: we cannot map the file because the offset is not 500 aligned, so we read it */ 501 if (!(flags & MAP_ANONYMOUS) && 502 (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { 503 /* msync() won't work here, so we return an error if write is 504 possible while it is a shared mapping */ 505 if ((flags & MAP_TYPE) == MAP_SHARED && 506 (prot & PROT_WRITE)) { 507 errno = EINVAL; 508 goto fail; 509 } 510 retaddr = target_mmap(start, len, prot | PROT_WRITE, 511 MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, 512 -1, 0); 513 if (retaddr == -1) 514 goto fail; 515 if (pread(fd, g2h(start), len, offset) == -1) 516 goto fail; 517 if (!(prot & PROT_WRITE)) { 518 ret = target_mprotect(start, len, prot); 519 if (ret != 0) { 520 start = ret; 521 goto the_end; 522 } 523 } 524 goto the_end; 525 } 526 527 /* handle the start of the mapping */ 528 if (start > real_start) { 529 if (real_end == real_start + qemu_host_page_size) { 530 /* one single host page */ 531 ret = mmap_frag(real_start, start, end, 532 prot, flags, fd, offset); 533 if (ret == -1) 534 goto fail; 535 goto the_end1; 536 } 537 ret = mmap_frag(real_start, start, real_start + qemu_host_page_size, 538 prot, flags, fd, offset); 539 if (ret == -1) 540 goto fail; 541 real_start += qemu_host_page_size; 542 } 543 /* handle the end of the mapping */ 544 if (end < real_end) { 545 ret = mmap_frag(real_end - qemu_host_page_size, 546 real_end - qemu_host_page_size, real_end, 547 prot, flags, fd, 548 offset + real_end - qemu_host_page_size - start); 549 if (ret == -1) 550 goto fail; 551 real_end -= qemu_host_page_size; 552 } 553 554 /* map the middle (easier) */ 555 if (real_start < real_end) { 556 void *p; 557 unsigned long offset1; 558 if (flags & MAP_ANONYMOUS) 559 offset1 = 0; 560 else 561 offset1 = offset + real_start - start; 562 p = mmap(g2h(real_start), real_end - real_start, 563 prot, flags, fd, offset1); 564 if (p == MAP_FAILED) 565 goto fail; 566 } 567 } 568 the_end1: 569 page_set_flags(start, start + len, prot | PAGE_VALID); 570 the_end: 571 #ifdef DEBUG_MMAP 572 printf("ret=0x" TARGET_ABI_FMT_lx "\n", start); 573 page_dump(stdout); 574 printf("\n"); 575 #endif 576 tb_invalidate_phys_range(start, start + len, 0); 577 mmap_unlock(); 578 return start; 579 fail: 580 mmap_unlock(); 581 return -1; 582 } 583 584 static void mmap_reserve(abi_ulong start, abi_ulong size) 585 { 586 abi_ulong real_start; 587 abi_ulong real_end; 588 abi_ulong addr; 589 abi_ulong end; 590 int prot; 591 592 real_start = start & qemu_host_page_mask; 593 real_end = HOST_PAGE_ALIGN(start + size); 594 end = start + size; 595 if (start > real_start) { 596 /* handle host page containing start */ 597 prot = 0; 598 for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { 599 prot |= page_get_flags(addr); 600 } 601 if (real_end == real_start + qemu_host_page_size) { 602 for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { 603 prot |= page_get_flags(addr); 604 } 605 end = real_end; 606 } 607 if (prot != 0) 608 real_start += qemu_host_page_size; 609 } 610 if (end < real_end) { 611 prot = 0; 612 for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { 613 prot |= page_get_flags(addr); 614 } 615 if (prot != 0) 616 real_end -= qemu_host_page_size; 617 } 618 if (real_start != real_end) { 619 mmap(g2h(real_start), real_end - real_start, PROT_NONE, 620 MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, 621 -1, 0); 622 } 623 } 624 625 int target_munmap(abi_ulong start, abi_ulong len) 626 { 627 abi_ulong end, real_start, real_end, addr; 628 int prot, ret; 629 630 #ifdef DEBUG_MMAP 631 printf("munmap: start=0x" TARGET_ABI_FMT_lx " len=0x" 632 TARGET_ABI_FMT_lx "\n", 633 start, len); 634 #endif 635 if (start & ~TARGET_PAGE_MASK) 636 return -EINVAL; 637 len = TARGET_PAGE_ALIGN(len); 638 if (len == 0) 639 return -EINVAL; 640 mmap_lock(); 641 end = start + len; 642 real_start = start & qemu_host_page_mask; 643 real_end = HOST_PAGE_ALIGN(end); 644 645 if (start > real_start) { 646 /* handle host page containing start */ 647 prot = 0; 648 for(addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { 649 prot |= page_get_flags(addr); 650 } 651 if (real_end == real_start + qemu_host_page_size) { 652 for(addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { 653 prot |= page_get_flags(addr); 654 } 655 end = real_end; 656 } 657 if (prot != 0) 658 real_start += qemu_host_page_size; 659 } 660 if (end < real_end) { 661 prot = 0; 662 for(addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { 663 prot |= page_get_flags(addr); 664 } 665 if (prot != 0) 666 real_end -= qemu_host_page_size; 667 } 668 669 ret = 0; 670 /* unmap what we can */ 671 if (real_start < real_end) { 672 if (RESERVED_VA) { 673 mmap_reserve(real_start, real_end - real_start); 674 } else { 675 ret = munmap(g2h(real_start), real_end - real_start); 676 } 677 } 678 679 if (ret == 0) { 680 page_set_flags(start, start + len, 0); 681 tb_invalidate_phys_range(start, start + len, 0); 682 } 683 mmap_unlock(); 684 return ret; 685 } 686 687 abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, 688 abi_ulong new_size, unsigned long flags, 689 abi_ulong new_addr) 690 { 691 int prot; 692 void *host_addr; 693 694 mmap_lock(); 695 696 if (flags & MREMAP_FIXED) { 697 host_addr = (void *) syscall(__NR_mremap, g2h(old_addr), 698 old_size, new_size, 699 flags, 700 g2h(new_addr)); 701 702 if (RESERVED_VA && host_addr != MAP_FAILED) { 703 /* If new and old addresses overlap then the above mremap will 704 already have failed with EINVAL. */ 705 mmap_reserve(old_addr, old_size); 706 } 707 } else if (flags & MREMAP_MAYMOVE) { 708 abi_ulong mmap_start; 709 710 mmap_start = mmap_find_vma(0, new_size); 711 712 if (mmap_start == -1) { 713 errno = ENOMEM; 714 host_addr = MAP_FAILED; 715 } else { 716 host_addr = (void *) syscall(__NR_mremap, g2h(old_addr), 717 old_size, new_size, 718 flags | MREMAP_FIXED, 719 g2h(mmap_start)); 720 if ( RESERVED_VA ) { 721 mmap_reserve(old_addr, old_size); 722 } 723 } 724 } else { 725 int prot = 0; 726 if (RESERVED_VA && old_size < new_size) { 727 abi_ulong addr; 728 for (addr = old_addr + old_size; 729 addr < old_addr + new_size; 730 addr++) { 731 prot |= page_get_flags(addr); 732 } 733 } 734 if (prot == 0) { 735 host_addr = mremap(g2h(old_addr), old_size, new_size, flags); 736 if (host_addr != MAP_FAILED && RESERVED_VA && old_size > new_size) { 737 mmap_reserve(old_addr + old_size, new_size - old_size); 738 } 739 } else { 740 errno = ENOMEM; 741 host_addr = MAP_FAILED; 742 } 743 /* Check if address fits target address space */ 744 if ((unsigned long)host_addr + new_size > (abi_ulong)-1) { 745 /* Revert mremap() changes */ 746 host_addr = mremap(g2h(old_addr), new_size, old_size, flags); 747 errno = ENOMEM; 748 host_addr = MAP_FAILED; 749 } 750 } 751 752 if (host_addr == MAP_FAILED) { 753 new_addr = -1; 754 } else { 755 new_addr = h2g(host_addr); 756 prot = page_get_flags(old_addr); 757 page_set_flags(old_addr, old_addr + old_size, 0); 758 page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); 759 } 760 tb_invalidate_phys_range(new_addr, new_addr + new_size, 0); 761 mmap_unlock(); 762 return new_addr; 763 } 764 765 int target_msync(abi_ulong start, abi_ulong len, int flags) 766 { 767 abi_ulong end; 768 769 if (start & ~TARGET_PAGE_MASK) 770 return -EINVAL; 771 len = TARGET_PAGE_ALIGN(len); 772 end = start + len; 773 if (end < start) 774 return -EINVAL; 775 if (end == start) 776 return 0; 777 778 start &= qemu_host_page_mask; 779 return msync(g2h(start), end - start, flags); 780 } 781