1 /* 2 * OS includes and handling of OS dependencies 3 * 4 * This header exists to pull in some common system headers that 5 * most code in QEMU will want, and to fix up some possible issues with 6 * it (missing defines, Windows weirdness, and so on). 7 * 8 * To avoid getting into possible circular include dependencies, this 9 * file should not include any other QEMU headers, with the exceptions 10 * of config-host.h, config-target.h, qemu/compiler.h, 11 * sysemu/os-posix.h, sysemu/os-win32.h, glib-compat.h and 12 * qemu/typedefs.h, all of which are doing a similar job to this file 13 * and are under similar constraints. 14 * 15 * This header also contains prototypes for functions defined in 16 * os-*.c and util/oslib-*.c; those would probably be better split 17 * out into separate header files. 18 * 19 * In an ideal world this header would contain only: 20 * (1) things which everybody needs 21 * (2) things without which code would work on most platforms but 22 * fail to compile or misbehave on a minority of host OSes 23 * 24 * This work is licensed under the terms of the GNU GPL, version 2 or later. 25 * See the COPYING file in the top-level directory. 26 */ 27 #ifndef QEMU_OSDEP_H 28 #define QEMU_OSDEP_H 29 30 #include "config-host.h" 31 #ifdef NEED_CPU_H 32 #include CONFIG_TARGET 33 #else 34 #include "exec/poison.h" 35 #endif 36 37 /* 38 * HOST_WORDS_BIGENDIAN was replaced with HOST_BIG_ENDIAN. Prevent it from 39 * creeping back in. 40 */ 41 #pragma GCC poison HOST_WORDS_BIGENDIAN 42 43 /* 44 * TARGET_WORDS_BIGENDIAN was replaced with TARGET_BIG_ENDIAN. Prevent it from 45 * creeping back in. 46 */ 47 #pragma GCC poison TARGET_WORDS_BIGENDIAN 48 49 #include "qemu/compiler.h" 50 51 /* Older versions of C++ don't get definitions of various macros from 52 * stdlib.h unless we define these macros before first inclusion of 53 * that system header. 54 */ 55 #ifndef __STDC_CONSTANT_MACROS 56 #define __STDC_CONSTANT_MACROS 57 #endif 58 #ifndef __STDC_LIMIT_MACROS 59 #define __STDC_LIMIT_MACROS 60 #endif 61 #ifndef __STDC_FORMAT_MACROS 62 #define __STDC_FORMAT_MACROS 63 #endif 64 65 /* The following block of code temporarily renames the daemon() function so the 66 * compiler does not see the warning associated with it in stdlib.h on OSX 67 */ 68 #ifdef __APPLE__ 69 #define daemon qemu_fake_daemon_function 70 #include <stdlib.h> 71 #undef daemon 72 QEMU_EXTERN_C int daemon(int, int); 73 #endif 74 75 #ifdef _WIN32 76 /* as defined in sdkddkver.h */ 77 #ifndef _WIN32_WINNT 78 #define _WIN32_WINNT 0x0601 /* Windows 7 API (should be in sync with glib) */ 79 #endif 80 /* reduces the number of implicitly included headers */ 81 #ifndef WIN32_LEAN_AND_MEAN 82 #define WIN32_LEAN_AND_MEAN 83 #endif 84 #endif 85 86 /* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */ 87 #ifdef __MINGW32__ 88 #define __USE_MINGW_ANSI_STDIO 1 89 #endif 90 91 #include <stdarg.h> 92 #include <stddef.h> 93 #include <stdbool.h> 94 #include <stdint.h> 95 #include <sys/types.h> 96 #include <stdlib.h> 97 #include <stdio.h> 98 99 #include <string.h> 100 #include <strings.h> 101 #include <inttypes.h> 102 #include <limits.h> 103 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r 104 * function availability on recentish Mingw-w64 platforms. */ 105 #include <unistd.h> 106 #include <time.h> 107 #include <ctype.h> 108 #include <errno.h> 109 #include <fcntl.h> 110 #include <getopt.h> 111 #include <sys/stat.h> 112 #include <sys/time.h> 113 #include <assert.h> 114 /* setjmp must be declared before sysemu/os-win32.h 115 * because it is redefined there. */ 116 #include <setjmp.h> 117 #include <signal.h> 118 119 #ifdef CONFIG_IOVEC 120 #include <sys/uio.h> 121 #endif 122 123 #if defined(__linux__) && defined(__sparc__) 124 /* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */ 125 #include <sys/shm.h> 126 #endif 127 128 #ifndef _WIN32 129 #include <sys/wait.h> 130 #else 131 #define WIFEXITED(x) 1 132 #define WEXITSTATUS(x) (x) 133 #endif 134 135 #ifdef __APPLE__ 136 #include <AvailabilityMacros.h> 137 #endif 138 139 /* 140 * This is somewhat like a system header; it must be outside any extern "C" 141 * block because it includes system headers itself, including glib.h, 142 * which will not compile if inside an extern "C" block. 143 */ 144 #include "glib-compat.h" 145 146 #ifdef _WIN32 147 #include "sysemu/os-win32.h" 148 #endif 149 150 #ifdef CONFIG_POSIX 151 #include "sysemu/os-posix.h" 152 #endif 153 154 #ifdef __cplusplus 155 extern "C" { 156 #endif 157 158 #include "qemu/typedefs.h" 159 160 /* 161 * For mingw, as of v6.0.0, the function implementing the assert macro is 162 * not marked as noreturn, so the compiler cannot delete code following an 163 * assert(false) as unused. We rely on this within the code base to delete 164 * code that is unreachable when features are disabled. 165 * All supported versions of Glib's g_assert() satisfy this requirement. 166 */ 167 #ifdef __MINGW32__ 168 #undef assert 169 #define assert(x) g_assert(x) 170 #endif 171 172 /** 173 * qemu_build_not_reached() 174 * 175 * The compiler, during optimization, is expected to prove that a call 176 * to this function cannot be reached and remove it. If the compiler 177 * supports QEMU_ERROR, this will be reported at compile time; otherwise 178 * this will be reported at link time due to the missing symbol. 179 */ 180 extern G_NORETURN 181 void QEMU_ERROR("code path is reachable") 182 qemu_build_not_reached_always(void); 183 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__) 184 #define qemu_build_not_reached() qemu_build_not_reached_always() 185 #else 186 #define qemu_build_not_reached() g_assert_not_reached() 187 #endif 188 189 /** 190 * qemu_build_assert() 191 * 192 * The compiler, during optimization, is expected to prove that the 193 * assertion is true. 194 */ 195 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached() 196 197 /* 198 * According to waitpid man page: 199 * WCOREDUMP 200 * This macro is not specified in POSIX.1-2001 and is not 201 * available on some UNIX implementations (e.g., AIX, SunOS). 202 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif. 203 */ 204 #ifndef WCOREDUMP 205 #define WCOREDUMP(status) 0 206 #endif 207 /* 208 * We have a lot of unaudited code that may fail in strange ways, or 209 * even be a security risk during migration, if you disable assertions 210 * at compile-time. You may comment out these safety checks if you 211 * absolutely want to disable assertion overhead, but it is not 212 * supported upstream so the risk is all yours. Meanwhile, please 213 * submit patches to remove any side-effects inside an assertion, or 214 * fixing error handling that should use Error instead of assert. 215 */ 216 #ifdef NDEBUG 217 #error building with NDEBUG is not supported 218 #endif 219 #ifdef G_DISABLE_ASSERT 220 #error building with G_DISABLE_ASSERT is not supported 221 #endif 222 223 #ifndef O_LARGEFILE 224 #define O_LARGEFILE 0 225 #endif 226 #ifndef O_BINARY 227 #define O_BINARY 0 228 #endif 229 #ifndef MAP_ANONYMOUS 230 #define MAP_ANONYMOUS MAP_ANON 231 #endif 232 #ifndef MAP_FIXED_NOREPLACE 233 #define MAP_FIXED_NOREPLACE 0 234 #endif 235 #ifndef MAP_NORESERVE 236 #define MAP_NORESERVE 0 237 #endif 238 #ifndef ENOMEDIUM 239 #define ENOMEDIUM ENODEV 240 #endif 241 #if !defined(ENOTSUP) 242 #define ENOTSUP 4096 243 #endif 244 #if !defined(ECANCELED) 245 #define ECANCELED 4097 246 #endif 247 #if !defined(EMEDIUMTYPE) 248 #define EMEDIUMTYPE 4098 249 #endif 250 #if !defined(ESHUTDOWN) 251 #define ESHUTDOWN 4099 252 #endif 253 254 #define RETRY_ON_EINTR(expr) \ 255 (__extension__ \ 256 ({ typeof(expr) __result; \ 257 do { \ 258 __result = (expr); \ 259 } while (__result == -1 && errno == EINTR); \ 260 __result; })) 261 262 /* time_t may be either 32 or 64 bits depending on the host OS, and 263 * can be either signed or unsigned, so we can't just hardcode a 264 * specific maximum value. This is not a C preprocessor constant, 265 * so you can't use TIME_MAX in an #ifdef, but for our purposes 266 * this isn't a problem. 267 */ 268 269 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from 270 * Gnulib, and are under the LGPL v2.1 or (at your option) any 271 * later version. 272 */ 273 274 /* True if the real type T is signed. */ 275 #define TYPE_SIGNED(t) (!((t)0 < (t)-1)) 276 277 /* The width in bits of the integer type or expression T. 278 * Padding bits are not supported. 279 */ 280 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT) 281 282 /* The maximum and minimum values for the integer type T. */ 283 #define TYPE_MAXIMUM(t) \ 284 ((t) (!TYPE_SIGNED(t) \ 285 ? (t)-1 \ 286 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1))) 287 288 #ifndef TIME_MAX 289 #define TIME_MAX TYPE_MAXIMUM(time_t) 290 #endif 291 292 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with 293 * the wrong type. Our replacement isn't usable in preprocessor 294 * expressions, but it is sufficient for our needs. */ 295 #ifdef HAVE_BROKEN_SIZE_MAX 296 #undef SIZE_MAX 297 #define SIZE_MAX ((size_t)-1) 298 #endif 299 300 /* 301 * Two variations of MIN/MAX macros. The first is for runtime use, and 302 * evaluates arguments only once (so it is safe even with side 303 * effects), but will not work in constant contexts (such as array 304 * size declarations) because of the '{}'. The second is for constant 305 * expression use, where evaluating arguments twice is safe because 306 * the result is going to be constant anyway, but will not work in a 307 * runtime context because of a void expression where a value is 308 * expected. Thus, both gcc and clang will fail to compile if you use 309 * the wrong macro (even if the error may seem a bit cryptic). 310 * 311 * Note that neither form is usable as an #if condition; if you truly 312 * need to write conditional code that depends on a minimum or maximum 313 * determined by the pre-processor instead of the compiler, you'll 314 * have to open-code it. Sadly, Coverity is severely confused by the 315 * constant variants, so we have to dumb things down there. 316 */ 317 #undef MIN 318 #define MIN(a, b) \ 319 ({ \ 320 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 321 _a < _b ? _a : _b; \ 322 }) 323 #undef MAX 324 #define MAX(a, b) \ 325 ({ \ 326 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 327 _a > _b ? _a : _b; \ 328 }) 329 330 #ifdef __COVERITY__ 331 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b)) 332 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b)) 333 #else 334 # define MIN_CONST(a, b) \ 335 __builtin_choose_expr( \ 336 __builtin_constant_p(a) && __builtin_constant_p(b), \ 337 (a) < (b) ? (a) : (b), \ 338 ((void)0)) 339 # define MAX_CONST(a, b) \ 340 __builtin_choose_expr( \ 341 __builtin_constant_p(a) && __builtin_constant_p(b), \ 342 (a) > (b) ? (a) : (b), \ 343 ((void)0)) 344 #endif 345 346 /* 347 * Minimum function that returns zero only if both values are zero. 348 * Intended for use with unsigned values only. 349 */ 350 #ifndef MIN_NON_ZERO 351 #define MIN_NON_ZERO(a, b) \ 352 ({ \ 353 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 354 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \ 355 }) 356 #endif 357 358 /* 359 * Round number down to multiple. Safe when m is not a power of 2 (see 360 * ROUND_DOWN for a faster version when a power of 2 is guaranteed). 361 */ 362 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m)) 363 364 /* 365 * Round number up to multiple. Safe when m is not a power of 2 (see 366 * ROUND_UP for a faster version when a power of 2 is guaranteed). 367 */ 368 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m)) 369 370 /* Check if n is a multiple of m */ 371 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0) 372 373 /* n-byte align pointer down */ 374 #define QEMU_ALIGN_PTR_DOWN(p, n) \ 375 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n))) 376 377 /* n-byte align pointer up */ 378 #define QEMU_ALIGN_PTR_UP(p, n) \ 379 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n))) 380 381 /* Check if pointer p is n-bytes aligned */ 382 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n)) 383 384 /* 385 * Round number down to multiple. Requires that d be a power of 2 (see 386 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 387 * numbers); works even if d is a smaller type than n. 388 */ 389 #ifndef ROUND_DOWN 390 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d))) 391 #endif 392 393 /* 394 * Round number up to multiple. Requires that d be a power of 2 (see 395 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 396 * numbers); works even if d is a smaller type than n. 397 */ 398 #ifndef ROUND_UP 399 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d)) 400 #endif 401 402 #ifndef DIV_ROUND_UP 403 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) 404 #endif 405 406 /* 407 * &(x)[0] is always a pointer - if it's same type as x then the argument is a 408 * pointer, not an array. 409 */ 410 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \ 411 typeof(&(x)[0]))) 412 #ifndef ARRAY_SIZE 413 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \ 414 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x))) 415 #endif 416 417 int qemu_daemon(int nochdir, int noclose); 418 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, 419 bool noreserve); 420 void qemu_anon_ram_free(void *ptr, size_t size); 421 422 #ifdef _WIN32 423 #define HAVE_CHARDEV_SERIAL 1 424 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 425 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \ 426 || defined(__GLIBC__) || defined(__APPLE__) 427 #define HAVE_CHARDEV_SERIAL 1 428 #endif 429 430 #if defined(__HAIKU__) 431 #define SIGIO SIGPOLL 432 #endif 433 434 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE 435 /* 436 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion 437 * about Solaris missing the madvise() prototype. 438 */ 439 extern int madvise(char *, size_t, int); 440 #endif 441 442 #if defined(CONFIG_LINUX) 443 #ifndef BUS_MCEERR_AR 444 #define BUS_MCEERR_AR 4 445 #endif 446 #ifndef BUS_MCEERR_AO 447 #define BUS_MCEERR_AO 5 448 #endif 449 #endif 450 451 #if defined(__linux__) && \ 452 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \ 453 || defined(__powerpc64__)) 454 /* Use 2 MiB alignment so transparent hugepages can be used by KVM. 455 Valgrind does not support alignments larger than 1 MiB, 456 therefore we need special code which handles running on Valgrind. */ 457 # define QEMU_VMALLOC_ALIGN (512 * 4096) 458 #elif defined(__linux__) && defined(__s390x__) 459 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ 460 # define QEMU_VMALLOC_ALIGN (256 * 4096) 461 #elif defined(__linux__) && defined(__sparc__) 462 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA) 463 #else 464 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size() 465 #endif 466 467 #ifdef CONFIG_POSIX 468 struct qemu_signalfd_siginfo { 469 uint32_t ssi_signo; /* Signal number */ 470 int32_t ssi_errno; /* Error number (unused) */ 471 int32_t ssi_code; /* Signal code */ 472 uint32_t ssi_pid; /* PID of sender */ 473 uint32_t ssi_uid; /* Real UID of sender */ 474 int32_t ssi_fd; /* File descriptor (SIGIO) */ 475 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */ 476 uint32_t ssi_band; /* Band event (SIGIO) */ 477 uint32_t ssi_overrun; /* POSIX timer overrun count */ 478 uint32_t ssi_trapno; /* Trap number that caused signal */ 479 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */ 480 int32_t ssi_int; /* Integer sent by sigqueue(2) */ 481 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */ 482 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */ 483 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */ 484 uint64_t ssi_addr; /* Address that generated signal 485 (for hardware-generated signals) */ 486 uint8_t pad[48]; /* Pad size to 128 bytes (allow for 487 additional fields in the future) */ 488 }; 489 490 int qemu_signalfd(const sigset_t *mask); 491 void sigaction_invoke(struct sigaction *action, 492 struct qemu_signalfd_siginfo *info); 493 #endif 494 495 /* 496 * Don't introduce new usage of this function, prefer the following 497 * qemu_open/qemu_create that take an "Error **errp" 498 */ 499 int qemu_open_old(const char *name, int flags, ...); 500 int qemu_open(const char *name, int flags, Error **errp); 501 int qemu_create(const char *name, int flags, mode_t mode, Error **errp); 502 int qemu_close(int fd); 503 int qemu_unlink(const char *name); 504 #ifndef _WIN32 505 int qemu_dup_flags(int fd, int flags); 506 int qemu_dup(int fd); 507 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); 508 int qemu_unlock_fd(int fd, int64_t start, int64_t len); 509 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); 510 bool qemu_has_ofd_lock(void); 511 #endif 512 513 #if defined(__HAIKU__) && defined(__i386__) 514 #define FMT_pid "%ld" 515 #elif defined(WIN64) 516 #define FMT_pid "%" PRId64 517 #else 518 #define FMT_pid "%d" 519 #endif 520 521 bool qemu_write_pidfile(const char *pidfile, Error **errp); 522 523 int qemu_get_thread_id(void); 524 525 #ifndef CONFIG_IOVEC 526 struct iovec { 527 void *iov_base; 528 size_t iov_len; 529 }; 530 /* 531 * Use the same value as Linux for now. 532 */ 533 #define IOV_MAX 1024 534 535 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt); 536 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt); 537 #endif 538 539 #ifdef _WIN32 540 static inline void qemu_timersub(const struct timeval *val1, 541 const struct timeval *val2, 542 struct timeval *res) 543 { 544 res->tv_sec = val1->tv_sec - val2->tv_sec; 545 if (val1->tv_usec < val2->tv_usec) { 546 res->tv_sec--; 547 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000; 548 } else { 549 res->tv_usec = val1->tv_usec - val2->tv_usec; 550 } 551 } 552 #else 553 #define qemu_timersub timersub 554 #endif 555 556 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 557 G_GNUC_WARN_UNUSED_RESULT; 558 559 void qemu_set_cloexec(int fd); 560 561 /* Return a dynamically allocated directory path that is appropriate for storing 562 * local state. 563 * 564 * The caller is responsible for releasing the value returned with g_free() 565 * after use. 566 */ 567 char *qemu_get_local_state_dir(void); 568 569 /** 570 * qemu_getauxval: 571 * @type: the auxiliary vector key to lookup 572 * 573 * Search the auxiliary vector for @type, returning the value 574 * or 0 if @type is not present. 575 */ 576 unsigned long qemu_getauxval(unsigned long type); 577 578 void qemu_set_tty_echo(int fd, bool echo); 579 580 typedef struct ThreadContext ThreadContext; 581 582 /** 583 * qemu_prealloc_mem: 584 * @fd: the fd mapped into the area, -1 for anonymous memory 585 * @area: start address of the are to preallocate 586 * @sz: the size of the area to preallocate 587 * @max_threads: maximum number of threads to use 588 * @errp: returns an error if this function fails 589 * 590 * Preallocate memory (populate/prefault page tables writable) for the virtual 591 * memory area starting at @area with the size of @sz. After a successful call, 592 * each page in the area was faulted in writable at least once, for example, 593 * after allocating file blocks for mapped files. 594 */ 595 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, 596 ThreadContext *tc, Error **errp); 597 598 /** 599 * qemu_get_pid_name: 600 * @pid: pid of a process 601 * 602 * For given @pid fetch its name. Caller is responsible for 603 * freeing the string when no longer needed. 604 * Returns allocated string on success, NULL on failure. 605 */ 606 char *qemu_get_pid_name(pid_t pid); 607 608 /** 609 * qemu_fork: 610 * 611 * A version of fork that avoids signal handler race 612 * conditions that can lead to child process getting 613 * signals that are otherwise only expected by the 614 * parent. It also resets all signal handlers to the 615 * default settings. 616 * 617 * Returns 0 to child process, pid number to parent 618 * or -1 on failure. 619 */ 620 pid_t qemu_fork(Error **errp); 621 622 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even 623 * when intptr_t is 32-bit and we are aligning a long long. 624 */ 625 static inline uintptr_t qemu_real_host_page_size(void) 626 { 627 return getpagesize(); 628 } 629 630 static inline intptr_t qemu_real_host_page_mask(void) 631 { 632 return -(intptr_t)qemu_real_host_page_size(); 633 } 634 635 /* 636 * After using getopt or getopt_long, if you need to parse another set 637 * of options, then you must reset optind. Unfortunately the way to 638 * do this varies between implementations of getopt. 639 */ 640 static inline void qemu_reset_optind(void) 641 { 642 #ifdef HAVE_OPTRESET 643 optind = 1; 644 optreset = 1; 645 #else 646 optind = 0; 647 #endif 648 } 649 650 int qemu_fdatasync(int fd); 651 652 /** 653 * Sync changes made to the memory mapped file back to the backing 654 * storage. For POSIX compliant systems this will fallback 655 * to regular msync call. Otherwise it will trigger whole file sync 656 * (including the metadata case there is no support to skip that otherwise) 657 * 658 * @addr - start of the memory area to be synced 659 * @length - length of the are to be synced 660 * @fd - file descriptor for the file to be synced 661 * (mandatory only for POSIX non-compliant systems) 662 */ 663 int qemu_msync(void *addr, size_t length, int fd); 664 665 /** 666 * qemu_get_host_physmem: 667 * 668 * Operating system agnostic way of querying host memory. 669 * 670 * Returns amount of physical memory on the system. This is purely 671 * advisery and may return 0 if we can't work it out. At the other 672 * end we saturate to SIZE_MAX if you are lucky enough to have that 673 * much memory. 674 */ 675 size_t qemu_get_host_physmem(void); 676 677 /* 678 * Toggle write/execute on the pages marked MAP_JIT 679 * for the current thread. 680 */ 681 #if defined(MAC_OS_VERSION_11_0) && \ 682 MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 683 static inline void qemu_thread_jit_execute(void) 684 { 685 pthread_jit_write_protect_np(true); 686 } 687 688 static inline void qemu_thread_jit_write(void) 689 { 690 pthread_jit_write_protect_np(false); 691 } 692 #else 693 static inline void qemu_thread_jit_write(void) {} 694 static inline void qemu_thread_jit_execute(void) {} 695 #endif 696 697 /** 698 * Platforms which do not support system() return ENOSYS 699 */ 700 #ifndef HAVE_SYSTEM_FUNCTION 701 #define system platform_does_not_support_system 702 static inline int platform_does_not_support_system(const char *command) 703 { 704 errno = ENOSYS; 705 return -1; 706 } 707 #endif /* !HAVE_SYSTEM_FUNCTION */ 708 709 #ifdef __cplusplus 710 } 711 #endif 712 713 #endif 714