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