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 * Mark a function that executes in coroutine context 162 * 163 * Functions that execute in coroutine context cannot be called directly from 164 * normal functions. In the future it would be nice to enable compiler or 165 * static checker support for catching such errors. This annotation might make 166 * it possible and in the meantime it serves as documentation. 167 * 168 * For example: 169 * 170 * static void coroutine_fn foo(void) { 171 * .... 172 * } 173 */ 174 #define coroutine_fn 175 176 /* 177 * For mingw, as of v6.0.0, the function implementing the assert macro is 178 * not marked as noreturn, so the compiler cannot delete code following an 179 * assert(false) as unused. We rely on this within the code base to delete 180 * code that is unreachable when features are disabled. 181 * All supported versions of Glib's g_assert() satisfy this requirement. 182 */ 183 #ifdef __MINGW32__ 184 #undef assert 185 #define assert(x) g_assert(x) 186 #endif 187 188 /** 189 * qemu_build_not_reached() 190 * 191 * The compiler, during optimization, is expected to prove that a call 192 * to this function cannot be reached and remove it. If the compiler 193 * supports QEMU_ERROR, this will be reported at compile time; otherwise 194 * this will be reported at link time due to the missing symbol. 195 */ 196 extern G_NORETURN 197 void QEMU_ERROR("code path is reachable") 198 qemu_build_not_reached_always(void); 199 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__) 200 #define qemu_build_not_reached() qemu_build_not_reached_always() 201 #else 202 #define qemu_build_not_reached() g_assert_not_reached() 203 #endif 204 205 /** 206 * qemu_build_assert() 207 * 208 * The compiler, during optimization, is expected to prove that the 209 * assertion is true. 210 */ 211 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached() 212 213 /* 214 * According to waitpid man page: 215 * WCOREDUMP 216 * This macro is not specified in POSIX.1-2001 and is not 217 * available on some UNIX implementations (e.g., AIX, SunOS). 218 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif. 219 */ 220 #ifndef WCOREDUMP 221 #define WCOREDUMP(status) 0 222 #endif 223 /* 224 * We have a lot of unaudited code that may fail in strange ways, or 225 * even be a security risk during migration, if you disable assertions 226 * at compile-time. You may comment out these safety checks if you 227 * absolutely want to disable assertion overhead, but it is not 228 * supported upstream so the risk is all yours. Meanwhile, please 229 * submit patches to remove any side-effects inside an assertion, or 230 * fixing error handling that should use Error instead of assert. 231 */ 232 #ifdef NDEBUG 233 #error building with NDEBUG is not supported 234 #endif 235 #ifdef G_DISABLE_ASSERT 236 #error building with G_DISABLE_ASSERT is not supported 237 #endif 238 239 #ifndef O_LARGEFILE 240 #define O_LARGEFILE 0 241 #endif 242 #ifndef O_BINARY 243 #define O_BINARY 0 244 #endif 245 #ifndef MAP_ANONYMOUS 246 #define MAP_ANONYMOUS MAP_ANON 247 #endif 248 #ifndef MAP_FIXED_NOREPLACE 249 #define MAP_FIXED_NOREPLACE 0 250 #endif 251 #ifndef MAP_NORESERVE 252 #define MAP_NORESERVE 0 253 #endif 254 #ifndef ENOMEDIUM 255 #define ENOMEDIUM ENODEV 256 #endif 257 #if !defined(ENOTSUP) 258 #define ENOTSUP 4096 259 #endif 260 #if !defined(ECANCELED) 261 #define ECANCELED 4097 262 #endif 263 #if !defined(EMEDIUMTYPE) 264 #define EMEDIUMTYPE 4098 265 #endif 266 #if !defined(ESHUTDOWN) 267 #define ESHUTDOWN 4099 268 #endif 269 270 #define RETRY_ON_EINTR(expr) \ 271 (__extension__ \ 272 ({ typeof(expr) __result; \ 273 do { \ 274 __result = (expr); \ 275 } while (__result == -1 && errno == EINTR); \ 276 __result; })) 277 278 /* time_t may be either 32 or 64 bits depending on the host OS, and 279 * can be either signed or unsigned, so we can't just hardcode a 280 * specific maximum value. This is not a C preprocessor constant, 281 * so you can't use TIME_MAX in an #ifdef, but for our purposes 282 * this isn't a problem. 283 */ 284 285 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from 286 * Gnulib, and are under the LGPL v2.1 or (at your option) any 287 * later version. 288 */ 289 290 /* True if the real type T is signed. */ 291 #define TYPE_SIGNED(t) (!((t)0 < (t)-1)) 292 293 /* The width in bits of the integer type or expression T. 294 * Padding bits are not supported. 295 */ 296 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT) 297 298 /* The maximum and minimum values for the integer type T. */ 299 #define TYPE_MAXIMUM(t) \ 300 ((t) (!TYPE_SIGNED(t) \ 301 ? (t)-1 \ 302 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1))) 303 304 #ifndef TIME_MAX 305 #define TIME_MAX TYPE_MAXIMUM(time_t) 306 #endif 307 308 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with 309 * the wrong type. Our replacement isn't usable in preprocessor 310 * expressions, but it is sufficient for our needs. */ 311 #ifdef HAVE_BROKEN_SIZE_MAX 312 #undef SIZE_MAX 313 #define SIZE_MAX ((size_t)-1) 314 #endif 315 316 /* 317 * Two variations of MIN/MAX macros. The first is for runtime use, and 318 * evaluates arguments only once (so it is safe even with side 319 * effects), but will not work in constant contexts (such as array 320 * size declarations) because of the '{}'. The second is for constant 321 * expression use, where evaluating arguments twice is safe because 322 * the result is going to be constant anyway, but will not work in a 323 * runtime context because of a void expression where a value is 324 * expected. Thus, both gcc and clang will fail to compile if you use 325 * the wrong macro (even if the error may seem a bit cryptic). 326 * 327 * Note that neither form is usable as an #if condition; if you truly 328 * need to write conditional code that depends on a minimum or maximum 329 * determined by the pre-processor instead of the compiler, you'll 330 * have to open-code it. Sadly, Coverity is severely confused by the 331 * constant variants, so we have to dumb things down there. 332 */ 333 #undef MIN 334 #define MIN(a, b) \ 335 ({ \ 336 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 337 _a < _b ? _a : _b; \ 338 }) 339 #undef MAX 340 #define MAX(a, b) \ 341 ({ \ 342 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 343 _a > _b ? _a : _b; \ 344 }) 345 346 #ifdef __COVERITY__ 347 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b)) 348 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b)) 349 #else 350 # define MIN_CONST(a, b) \ 351 __builtin_choose_expr( \ 352 __builtin_constant_p(a) && __builtin_constant_p(b), \ 353 (a) < (b) ? (a) : (b), \ 354 ((void)0)) 355 # define MAX_CONST(a, b) \ 356 __builtin_choose_expr( \ 357 __builtin_constant_p(a) && __builtin_constant_p(b), \ 358 (a) > (b) ? (a) : (b), \ 359 ((void)0)) 360 #endif 361 362 /* 363 * Minimum function that returns zero only if both values are zero. 364 * Intended for use with unsigned values only. 365 */ 366 #ifndef MIN_NON_ZERO 367 #define MIN_NON_ZERO(a, b) \ 368 ({ \ 369 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 370 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \ 371 }) 372 #endif 373 374 /* 375 * Round number down to multiple. Safe when m is not a power of 2 (see 376 * ROUND_DOWN for a faster version when a power of 2 is guaranteed). 377 */ 378 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m)) 379 380 /* 381 * Round number up to multiple. Safe when m is not a power of 2 (see 382 * ROUND_UP for a faster version when a power of 2 is guaranteed). 383 */ 384 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m)) 385 386 /* Check if n is a multiple of m */ 387 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0) 388 389 /* n-byte align pointer down */ 390 #define QEMU_ALIGN_PTR_DOWN(p, n) \ 391 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n))) 392 393 /* n-byte align pointer up */ 394 #define QEMU_ALIGN_PTR_UP(p, n) \ 395 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n))) 396 397 /* Check if pointer p is n-bytes aligned */ 398 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n)) 399 400 /* 401 * Round number down to multiple. Requires that d be a power of 2 (see 402 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 403 * numbers); works even if d is a smaller type than n. 404 */ 405 #ifndef ROUND_DOWN 406 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d))) 407 #endif 408 409 /* 410 * Round number up to multiple. Requires that d be a power of 2 (see 411 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 412 * numbers); works even if d is a smaller type than n. 413 */ 414 #ifndef ROUND_UP 415 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d)) 416 #endif 417 418 #ifndef DIV_ROUND_UP 419 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) 420 #endif 421 422 /* 423 * &(x)[0] is always a pointer - if it's same type as x then the argument is a 424 * pointer, not an array. 425 */ 426 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \ 427 typeof(&(x)[0]))) 428 #ifndef ARRAY_SIZE 429 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \ 430 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x))) 431 #endif 432 433 int qemu_daemon(int nochdir, int noclose); 434 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, 435 bool noreserve); 436 void qemu_anon_ram_free(void *ptr, size_t size); 437 438 #ifdef _WIN32 439 #define HAVE_CHARDEV_SERIAL 1 440 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 441 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \ 442 || defined(__GLIBC__) || defined(__APPLE__) 443 #define HAVE_CHARDEV_SERIAL 1 444 #endif 445 446 #if defined(__HAIKU__) 447 #define SIGIO SIGPOLL 448 #endif 449 450 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE 451 /* 452 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion 453 * about Solaris missing the madvise() prototype. 454 */ 455 extern int madvise(char *, size_t, int); 456 #endif 457 458 #if defined(CONFIG_LINUX) 459 #ifndef BUS_MCEERR_AR 460 #define BUS_MCEERR_AR 4 461 #endif 462 #ifndef BUS_MCEERR_AO 463 #define BUS_MCEERR_AO 5 464 #endif 465 #endif 466 467 #if defined(__linux__) && \ 468 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \ 469 || defined(__powerpc64__)) 470 /* Use 2 MiB alignment so transparent hugepages can be used by KVM. 471 Valgrind does not support alignments larger than 1 MiB, 472 therefore we need special code which handles running on Valgrind. */ 473 # define QEMU_VMALLOC_ALIGN (512 * 4096) 474 #elif defined(__linux__) && defined(__s390x__) 475 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ 476 # define QEMU_VMALLOC_ALIGN (256 * 4096) 477 #elif defined(__linux__) && defined(__sparc__) 478 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA) 479 #else 480 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size() 481 #endif 482 483 #ifdef CONFIG_POSIX 484 struct qemu_signalfd_siginfo { 485 uint32_t ssi_signo; /* Signal number */ 486 int32_t ssi_errno; /* Error number (unused) */ 487 int32_t ssi_code; /* Signal code */ 488 uint32_t ssi_pid; /* PID of sender */ 489 uint32_t ssi_uid; /* Real UID of sender */ 490 int32_t ssi_fd; /* File descriptor (SIGIO) */ 491 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */ 492 uint32_t ssi_band; /* Band event (SIGIO) */ 493 uint32_t ssi_overrun; /* POSIX timer overrun count */ 494 uint32_t ssi_trapno; /* Trap number that caused signal */ 495 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */ 496 int32_t ssi_int; /* Integer sent by sigqueue(2) */ 497 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */ 498 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */ 499 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */ 500 uint64_t ssi_addr; /* Address that generated signal 501 (for hardware-generated signals) */ 502 uint8_t pad[48]; /* Pad size to 128 bytes (allow for 503 additional fields in the future) */ 504 }; 505 506 int qemu_signalfd(const sigset_t *mask); 507 void sigaction_invoke(struct sigaction *action, 508 struct qemu_signalfd_siginfo *info); 509 #endif 510 511 /* 512 * Don't introduce new usage of this function, prefer the following 513 * qemu_open/qemu_create that take an "Error **errp" 514 */ 515 int qemu_open_old(const char *name, int flags, ...); 516 int qemu_open(const char *name, int flags, Error **errp); 517 int qemu_create(const char *name, int flags, mode_t mode, Error **errp); 518 int qemu_close(int fd); 519 int qemu_unlink(const char *name); 520 #ifndef _WIN32 521 int qemu_dup_flags(int fd, int flags); 522 int qemu_dup(int fd); 523 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); 524 int qemu_unlock_fd(int fd, int64_t start, int64_t len); 525 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); 526 bool qemu_has_ofd_lock(void); 527 #endif 528 529 #if defined(__HAIKU__) && defined(__i386__) 530 #define FMT_pid "%ld" 531 #elif defined(WIN64) 532 #define FMT_pid "%" PRId64 533 #else 534 #define FMT_pid "%d" 535 #endif 536 537 bool qemu_write_pidfile(const char *pidfile, Error **errp); 538 539 int qemu_get_thread_id(void); 540 541 #ifndef CONFIG_IOVEC 542 struct iovec { 543 void *iov_base; 544 size_t iov_len; 545 }; 546 /* 547 * Use the same value as Linux for now. 548 */ 549 #define IOV_MAX 1024 550 551 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt); 552 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt); 553 #endif 554 555 #ifdef _WIN32 556 static inline void qemu_timersub(const struct timeval *val1, 557 const struct timeval *val2, 558 struct timeval *res) 559 { 560 res->tv_sec = val1->tv_sec - val2->tv_sec; 561 if (val1->tv_usec < val2->tv_usec) { 562 res->tv_sec--; 563 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000; 564 } else { 565 res->tv_usec = val1->tv_usec - val2->tv_usec; 566 } 567 } 568 #else 569 #define qemu_timersub timersub 570 #endif 571 572 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 573 G_GNUC_WARN_UNUSED_RESULT; 574 575 void qemu_set_cloexec(int fd); 576 577 /* Return a dynamically allocated directory path that is appropriate for storing 578 * local state. 579 * 580 * The caller is responsible for releasing the value returned with g_free() 581 * after use. 582 */ 583 char *qemu_get_local_state_dir(void); 584 585 /** 586 * qemu_getauxval: 587 * @type: the auxiliary vector key to lookup 588 * 589 * Search the auxiliary vector for @type, returning the value 590 * or 0 if @type is not present. 591 */ 592 unsigned long qemu_getauxval(unsigned long type); 593 594 void qemu_set_tty_echo(int fd, bool echo); 595 596 typedef struct ThreadContext ThreadContext; 597 598 /** 599 * qemu_prealloc_mem: 600 * @fd: the fd mapped into the area, -1 for anonymous memory 601 * @area: start address of the are to preallocate 602 * @sz: the size of the area to preallocate 603 * @max_threads: maximum number of threads to use 604 * @errp: returns an error if this function fails 605 * 606 * Preallocate memory (populate/prefault page tables writable) for the virtual 607 * memory area starting at @area with the size of @sz. After a successful call, 608 * each page in the area was faulted in writable at least once, for example, 609 * after allocating file blocks for mapped files. 610 */ 611 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, 612 ThreadContext *tc, Error **errp); 613 614 /** 615 * qemu_get_pid_name: 616 * @pid: pid of a process 617 * 618 * For given @pid fetch its name. Caller is responsible for 619 * freeing the string when no longer needed. 620 * Returns allocated string on success, NULL on failure. 621 */ 622 char *qemu_get_pid_name(pid_t pid); 623 624 /** 625 * qemu_fork: 626 * 627 * A version of fork that avoids signal handler race 628 * conditions that can lead to child process getting 629 * signals that are otherwise only expected by the 630 * parent. It also resets all signal handlers to the 631 * default settings. 632 * 633 * Returns 0 to child process, pid number to parent 634 * or -1 on failure. 635 */ 636 pid_t qemu_fork(Error **errp); 637 638 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even 639 * when intptr_t is 32-bit and we are aligning a long long. 640 */ 641 static inline uintptr_t qemu_real_host_page_size(void) 642 { 643 return getpagesize(); 644 } 645 646 static inline intptr_t qemu_real_host_page_mask(void) 647 { 648 return -(intptr_t)qemu_real_host_page_size(); 649 } 650 651 /* 652 * After using getopt or getopt_long, if you need to parse another set 653 * of options, then you must reset optind. Unfortunately the way to 654 * do this varies between implementations of getopt. 655 */ 656 static inline void qemu_reset_optind(void) 657 { 658 #ifdef HAVE_OPTRESET 659 optind = 1; 660 optreset = 1; 661 #else 662 optind = 0; 663 #endif 664 } 665 666 int qemu_fdatasync(int fd); 667 668 /** 669 * Sync changes made to the memory mapped file back to the backing 670 * storage. For POSIX compliant systems this will fallback 671 * to regular msync call. Otherwise it will trigger whole file sync 672 * (including the metadata case there is no support to skip that otherwise) 673 * 674 * @addr - start of the memory area to be synced 675 * @length - length of the are to be synced 676 * @fd - file descriptor for the file to be synced 677 * (mandatory only for POSIX non-compliant systems) 678 */ 679 int qemu_msync(void *addr, size_t length, int fd); 680 681 /** 682 * qemu_get_host_physmem: 683 * 684 * Operating system agnostic way of querying host memory. 685 * 686 * Returns amount of physical memory on the system. This is purely 687 * advisery and may return 0 if we can't work it out. At the other 688 * end we saturate to SIZE_MAX if you are lucky enough to have that 689 * much memory. 690 */ 691 size_t qemu_get_host_physmem(void); 692 693 /* 694 * Toggle write/execute on the pages marked MAP_JIT 695 * for the current thread. 696 */ 697 #if defined(MAC_OS_VERSION_11_0) && \ 698 MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 699 static inline void qemu_thread_jit_execute(void) 700 { 701 pthread_jit_write_protect_np(true); 702 } 703 704 static inline void qemu_thread_jit_write(void) 705 { 706 pthread_jit_write_protect_np(false); 707 } 708 #else 709 static inline void qemu_thread_jit_write(void) {} 710 static inline void qemu_thread_jit_execute(void) {} 711 #endif 712 713 /** 714 * Platforms which do not support system() return ENOSYS 715 */ 716 #ifndef HAVE_SYSTEM_FUNCTION 717 #define system platform_does_not_support_system 718 static inline int platform_does_not_support_system(const char *command) 719 { 720 errno = ENOSYS; 721 return -1; 722 } 723 #endif /* !HAVE_SYSTEM_FUNCTION */ 724 725 #ifdef __cplusplus 726 } 727 #endif 728 729 #endif 730