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 0x0602 /* Windows 8 API (should be >= the one from 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 /* 92 * We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system 93 * calls since it doesn't use libc at all, so we have to emulate that despite 94 * FreeBSD 11 being EOL'd. 95 */ 96 #ifdef __FreeBSD__ 97 #define _WANT_FREEBSD11_STAT 98 #define _WANT_FREEBSD11_STATFS 99 #define _WANT_FREEBSD11_DIRENT 100 #define _WANT_KERNEL_ERRNO 101 #define _WANT_SEMUN 102 #endif 103 104 #include <stdarg.h> 105 #include <stddef.h> 106 #include <stdbool.h> 107 #include <stdint.h> 108 #include <sys/types.h> 109 #include <stdlib.h> 110 #include <stdio.h> 111 112 #include <string.h> 113 #include <strings.h> 114 #include <inttypes.h> 115 #include <limits.h> 116 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r 117 * function availability on recentish Mingw-w64 platforms. */ 118 #include <unistd.h> 119 #include <time.h> 120 #include <ctype.h> 121 #include <errno.h> 122 #include <fcntl.h> 123 #include <getopt.h> 124 #include <sys/stat.h> 125 #include <sys/time.h> 126 #include <assert.h> 127 /* setjmp must be declared before sysemu/os-win32.h 128 * because it is redefined there. */ 129 #include <setjmp.h> 130 #include <signal.h> 131 132 #ifdef CONFIG_IOVEC 133 #include <sys/uio.h> 134 #endif 135 136 #if defined(__linux__) && defined(__sparc__) 137 /* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */ 138 #include <sys/shm.h> 139 #endif 140 141 #ifndef _WIN32 142 #include <sys/wait.h> 143 #else 144 #define WIFEXITED(x) 1 145 #define WEXITSTATUS(x) (x) 146 #endif 147 148 #ifdef __APPLE__ 149 #include <AvailabilityMacros.h> 150 #endif 151 152 /* 153 * This is somewhat like a system header; it must be outside any extern "C" 154 * block because it includes system headers itself, including glib.h, 155 * which will not compile if inside an extern "C" block. 156 */ 157 #include "glib-compat.h" 158 159 #ifdef _WIN32 160 #include "sysemu/os-win32.h" 161 #endif 162 163 #ifdef CONFIG_POSIX 164 #include "sysemu/os-posix.h" 165 #endif 166 167 #ifdef __cplusplus 168 extern "C" { 169 #endif 170 171 #include "qemu/typedefs.h" 172 173 /** 174 * Mark a function that executes in coroutine context 175 * 176 * Functions that execute in coroutine context cannot be called directly from 177 * normal functions. In the future it would be nice to enable compiler or 178 * static checker support for catching such errors. This annotation might make 179 * it possible and in the meantime it serves as documentation. 180 * 181 * For example: 182 * 183 * static void coroutine_fn foo(void) { 184 * .... 185 * } 186 */ 187 #ifdef __clang__ 188 #define coroutine_fn __attribute__((__annotate__("coroutine_fn"))) 189 #else 190 #define coroutine_fn 191 #endif 192 193 /** 194 * Mark a function that can suspend when executed in coroutine context, 195 * but can handle running in non-coroutine context too. 196 */ 197 #ifdef __clang__ 198 #define coroutine_mixed_fn __attribute__((__annotate__("coroutine_mixed_fn"))) 199 #else 200 #define coroutine_mixed_fn 201 #endif 202 203 /** 204 * Mark a function that should not be called from a coroutine context. 205 * Usually there will be an analogous, coroutine_fn function that should 206 * be used instead. 207 * 208 * When the function is also marked as coroutine_mixed_fn, the function should 209 * only be called if the caller does not know whether it is in coroutine 210 * context. 211 * 212 * Functions that are only no_coroutine_fn, on the other hand, should not 213 * be called from within coroutines at all. This for example includes 214 * functions that block. 215 * 216 * In the future it would be nice to enable compiler or static checker 217 * support for catching such errors. This annotation is the first step 218 * towards this, and in the meantime it serves as documentation. 219 * 220 * For example: 221 * 222 * static void no_coroutine_fn foo(void) { 223 * .... 224 * } 225 */ 226 #ifdef __clang__ 227 #define no_coroutine_fn __attribute__((__annotate__("no_coroutine_fn"))) 228 #else 229 #define no_coroutine_fn 230 #endif 231 232 233 /* 234 * For mingw, as of v6.0.0, the function implementing the assert macro is 235 * not marked as noreturn, so the compiler cannot delete code following an 236 * assert(false) as unused. We rely on this within the code base to delete 237 * code that is unreachable when features are disabled. 238 * All supported versions of Glib's g_assert() satisfy this requirement. 239 */ 240 #ifdef __MINGW32__ 241 #undef assert 242 #define assert(x) g_assert(x) 243 #endif 244 245 /** 246 * qemu_build_not_reached() 247 * 248 * The compiler, during optimization, is expected to prove that a call 249 * to this function cannot be reached and remove it. If the compiler 250 * supports QEMU_ERROR, this will be reported at compile time; otherwise 251 * this will be reported at link time due to the missing symbol. 252 */ 253 G_NORETURN extern 254 void QEMU_ERROR("code path is reachable") 255 qemu_build_not_reached_always(void); 256 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__) 257 #define qemu_build_not_reached() qemu_build_not_reached_always() 258 #else 259 #define qemu_build_not_reached() g_assert_not_reached() 260 #endif 261 262 /** 263 * qemu_build_assert() 264 * 265 * The compiler, during optimization, is expected to prove that the 266 * assertion is true. 267 */ 268 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached() 269 270 /* 271 * According to waitpid man page: 272 * WCOREDUMP 273 * This macro is not specified in POSIX.1-2001 and is not 274 * available on some UNIX implementations (e.g., AIX, SunOS). 275 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif. 276 */ 277 #ifndef WCOREDUMP 278 #define WCOREDUMP(status) 0 279 #endif 280 /* 281 * We have a lot of unaudited code that may fail in strange ways, or 282 * even be a security risk during migration, if you disable assertions 283 * at compile-time. You may comment out these safety checks if you 284 * absolutely want to disable assertion overhead, but it is not 285 * supported upstream so the risk is all yours. Meanwhile, please 286 * submit patches to remove any side-effects inside an assertion, or 287 * fixing error handling that should use Error instead of assert. 288 */ 289 #ifdef NDEBUG 290 #error building with NDEBUG is not supported 291 #endif 292 #ifdef G_DISABLE_ASSERT 293 #error building with G_DISABLE_ASSERT is not supported 294 #endif 295 296 #ifndef O_LARGEFILE 297 #define O_LARGEFILE 0 298 #endif 299 #ifndef O_BINARY 300 #define O_BINARY 0 301 #endif 302 #ifndef MAP_ANONYMOUS 303 #define MAP_ANONYMOUS MAP_ANON 304 #endif 305 #ifndef MAP_NORESERVE 306 #define MAP_NORESERVE 0 307 #endif 308 #ifndef ENOMEDIUM 309 #define ENOMEDIUM ENODEV 310 #endif 311 #if !defined(ENOTSUP) 312 #define ENOTSUP 4096 313 #endif 314 #if !defined(ECANCELED) 315 #define ECANCELED 4097 316 #endif 317 #if !defined(EMEDIUMTYPE) 318 #define EMEDIUMTYPE 4098 319 #endif 320 #if !defined(ESHUTDOWN) 321 #define ESHUTDOWN 4099 322 #endif 323 324 #define RETRY_ON_EINTR(expr) \ 325 (__extension__ \ 326 ({ typeof(expr) __result; \ 327 do { \ 328 __result = (expr); \ 329 } while (__result == -1 && errno == EINTR); \ 330 __result; })) 331 332 /* time_t may be either 32 or 64 bits depending on the host OS, and 333 * can be either signed or unsigned, so we can't just hardcode a 334 * specific maximum value. This is not a C preprocessor constant, 335 * so you can't use TIME_MAX in an #ifdef, but for our purposes 336 * this isn't a problem. 337 */ 338 339 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from 340 * Gnulib, and are under the LGPL v2.1 or (at your option) any 341 * later version. 342 */ 343 344 /* True if the real type T is signed. */ 345 #define TYPE_SIGNED(t) (!((t)0 < (t)-1)) 346 347 /* The width in bits of the integer type or expression T. 348 * Padding bits are not supported. 349 */ 350 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT) 351 352 /* The maximum and minimum values for the integer type T. */ 353 #define TYPE_MAXIMUM(t) \ 354 ((t) (!TYPE_SIGNED(t) \ 355 ? (t)-1 \ 356 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1))) 357 358 #ifndef TIME_MAX 359 #define TIME_MAX TYPE_MAXIMUM(time_t) 360 #endif 361 362 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with 363 * the wrong type. Our replacement isn't usable in preprocessor 364 * expressions, but it is sufficient for our needs. */ 365 #ifdef HAVE_BROKEN_SIZE_MAX 366 #undef SIZE_MAX 367 #define SIZE_MAX ((size_t)-1) 368 #endif 369 370 /* 371 * Two variations of MIN/MAX macros. The first is for runtime use, and 372 * evaluates arguments only once (so it is safe even with side 373 * effects), but will not work in constant contexts (such as array 374 * size declarations) because of the '{}'. The second is for constant 375 * expression use, where evaluating arguments twice is safe because 376 * the result is going to be constant anyway, but will not work in a 377 * runtime context because of a void expression where a value is 378 * expected. Thus, both gcc and clang will fail to compile if you use 379 * the wrong macro (even if the error may seem a bit cryptic). 380 * 381 * Note that neither form is usable as an #if condition; if you truly 382 * need to write conditional code that depends on a minimum or maximum 383 * determined by the pre-processor instead of the compiler, you'll 384 * have to open-code it. Sadly, Coverity is severely confused by the 385 * constant variants, so we have to dumb things down there. 386 */ 387 #undef MIN 388 #define MIN(a, b) \ 389 ({ \ 390 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 391 _a < _b ? _a : _b; \ 392 }) 393 #undef MAX 394 #define MAX(a, b) \ 395 ({ \ 396 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 397 _a > _b ? _a : _b; \ 398 }) 399 400 #ifdef __COVERITY__ 401 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b)) 402 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b)) 403 #else 404 # define MIN_CONST(a, b) \ 405 __builtin_choose_expr( \ 406 __builtin_constant_p(a) && __builtin_constant_p(b), \ 407 (a) < (b) ? (a) : (b), \ 408 ((void)0)) 409 # define MAX_CONST(a, b) \ 410 __builtin_choose_expr( \ 411 __builtin_constant_p(a) && __builtin_constant_p(b), \ 412 (a) > (b) ? (a) : (b), \ 413 ((void)0)) 414 #endif 415 416 /* 417 * Minimum function that returns zero only if both values are zero. 418 * Intended for use with unsigned values only. 419 */ 420 #ifndef MIN_NON_ZERO 421 #define MIN_NON_ZERO(a, b) \ 422 ({ \ 423 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \ 424 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \ 425 }) 426 #endif 427 428 /* 429 * Round number down to multiple. Safe when m is not a power of 2 (see 430 * ROUND_DOWN for a faster version when a power of 2 is guaranteed). 431 */ 432 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m)) 433 434 /* 435 * Round number up to multiple. Safe when m is not a power of 2 (see 436 * ROUND_UP for a faster version when a power of 2 is guaranteed). 437 */ 438 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m)) 439 440 /* Check if n is a multiple of m */ 441 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0) 442 443 /* n-byte align pointer down */ 444 #define QEMU_ALIGN_PTR_DOWN(p, n) \ 445 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n))) 446 447 /* n-byte align pointer up */ 448 #define QEMU_ALIGN_PTR_UP(p, n) \ 449 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n))) 450 451 /* Check if pointer p is n-bytes aligned */ 452 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n)) 453 454 /* 455 * Round number down to multiple. Requires that d be a power of 2 (see 456 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 457 * numbers); works even if d is a smaller type than n. 458 */ 459 #ifndef ROUND_DOWN 460 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d))) 461 #endif 462 463 /* 464 * Round number up to multiple. Requires that d be a power of 2 (see 465 * QEMU_ALIGN_UP for a safer but slower version on arbitrary 466 * numbers); works even if d is a smaller type than n. 467 */ 468 #ifndef ROUND_UP 469 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d)) 470 #endif 471 472 #ifndef DIV_ROUND_UP 473 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) 474 #endif 475 476 /* 477 * &(x)[0] is always a pointer - if it's same type as x then the argument is a 478 * pointer, not an array. 479 */ 480 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \ 481 typeof(&(x)[0]))) 482 #ifndef ARRAY_SIZE 483 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \ 484 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x))) 485 #endif 486 487 int qemu_daemon(int nochdir, int noclose); 488 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared, 489 bool noreserve); 490 void qemu_anon_ram_free(void *ptr, size_t size); 491 492 #ifdef _WIN32 493 #define HAVE_CHARDEV_SERIAL 1 494 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ 495 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \ 496 || defined(__GLIBC__) || defined(__APPLE__) 497 #define HAVE_CHARDEV_SERIAL 1 498 #endif 499 500 #if defined(__HAIKU__) 501 #define SIGIO SIGPOLL 502 #endif 503 504 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE 505 /* 506 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion 507 * about Solaris missing the madvise() prototype. 508 */ 509 extern int madvise(char *, size_t, int); 510 #endif 511 512 #if defined(CONFIG_LINUX) 513 #ifndef BUS_MCEERR_AR 514 #define BUS_MCEERR_AR 4 515 #endif 516 #ifndef BUS_MCEERR_AO 517 #define BUS_MCEERR_AO 5 518 #endif 519 #endif 520 521 #if defined(__linux__) && \ 522 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \ 523 || defined(__powerpc64__)) 524 /* Use 2 MiB alignment so transparent hugepages can be used by KVM. 525 Valgrind does not support alignments larger than 1 MiB, 526 therefore we need special code which handles running on Valgrind. */ 527 # define QEMU_VMALLOC_ALIGN (512 * 4096) 528 #elif defined(__linux__) && defined(__s390x__) 529 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */ 530 # define QEMU_VMALLOC_ALIGN (256 * 4096) 531 #elif defined(__linux__) && defined(__sparc__) 532 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA) 533 #else 534 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size() 535 #endif 536 537 #ifdef CONFIG_POSIX 538 struct qemu_signalfd_siginfo { 539 uint32_t ssi_signo; /* Signal number */ 540 int32_t ssi_errno; /* Error number (unused) */ 541 int32_t ssi_code; /* Signal code */ 542 uint32_t ssi_pid; /* PID of sender */ 543 uint32_t ssi_uid; /* Real UID of sender */ 544 int32_t ssi_fd; /* File descriptor (SIGIO) */ 545 uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */ 546 uint32_t ssi_band; /* Band event (SIGIO) */ 547 uint32_t ssi_overrun; /* POSIX timer overrun count */ 548 uint32_t ssi_trapno; /* Trap number that caused signal */ 549 int32_t ssi_status; /* Exit status or signal (SIGCHLD) */ 550 int32_t ssi_int; /* Integer sent by sigqueue(2) */ 551 uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */ 552 uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */ 553 uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */ 554 uint64_t ssi_addr; /* Address that generated signal 555 (for hardware-generated signals) */ 556 uint8_t pad[48]; /* Pad size to 128 bytes (allow for 557 additional fields in the future) */ 558 }; 559 560 int qemu_signalfd(const sigset_t *mask); 561 void sigaction_invoke(struct sigaction *action, 562 struct qemu_signalfd_siginfo *info); 563 #endif 564 565 /* 566 * Don't introduce new usage of this function, prefer the following 567 * qemu_open/qemu_create that take an "Error **errp" 568 */ 569 int qemu_open_old(const char *name, int flags, ...); 570 int qemu_open(const char *name, int flags, Error **errp); 571 int qemu_create(const char *name, int flags, mode_t mode, Error **errp); 572 int qemu_close(int fd); 573 int qemu_unlink(const char *name); 574 #ifndef _WIN32 575 int qemu_dup_flags(int fd, int flags); 576 int qemu_dup(int fd); 577 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive); 578 int qemu_unlock_fd(int fd, int64_t start, int64_t len); 579 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive); 580 bool qemu_has_ofd_lock(void); 581 #endif 582 583 #if defined(__HAIKU__) && defined(__i386__) 584 #define FMT_pid "%ld" 585 #elif defined(WIN64) 586 #define FMT_pid "%" PRId64 587 #else 588 #define FMT_pid "%d" 589 #endif 590 591 bool qemu_write_pidfile(const char *pidfile, Error **errp); 592 593 int qemu_get_thread_id(void); 594 595 #ifndef CONFIG_IOVEC 596 struct iovec { 597 void *iov_base; 598 size_t iov_len; 599 }; 600 /* 601 * Use the same value as Linux for now. 602 */ 603 #define IOV_MAX 1024 604 605 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt); 606 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt); 607 #endif 608 609 #ifdef _WIN32 610 static inline void qemu_timersub(const struct timeval *val1, 611 const struct timeval *val2, 612 struct timeval *res) 613 { 614 res->tv_sec = val1->tv_sec - val2->tv_sec; 615 if (val1->tv_usec < val2->tv_usec) { 616 res->tv_sec--; 617 res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000; 618 } else { 619 res->tv_usec = val1->tv_usec - val2->tv_usec; 620 } 621 } 622 #else 623 #define qemu_timersub timersub 624 #endif 625 626 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 627 G_GNUC_WARN_UNUSED_RESULT; 628 629 void qemu_set_cloexec(int fd); 630 631 /* Return a dynamically allocated directory path that is appropriate for storing 632 * local state. 633 * 634 * The caller is responsible for releasing the value returned with g_free() 635 * after use. 636 */ 637 char *qemu_get_local_state_dir(void); 638 639 /** 640 * qemu_getauxval: 641 * @type: the auxiliary vector key to lookup 642 * 643 * Search the auxiliary vector for @type, returning the value 644 * or 0 if @type is not present. 645 */ 646 unsigned long qemu_getauxval(unsigned long type); 647 648 void qemu_set_tty_echo(int fd, bool echo); 649 650 typedef struct ThreadContext ThreadContext; 651 652 /** 653 * qemu_prealloc_mem: 654 * @fd: the fd mapped into the area, -1 for anonymous memory 655 * @area: start address of the are to preallocate 656 * @sz: the size of the area to preallocate 657 * @max_threads: maximum number of threads to use 658 * @errp: returns an error if this function fails 659 * 660 * Preallocate memory (populate/prefault page tables writable) for the virtual 661 * memory area starting at @area with the size of @sz. After a successful call, 662 * each page in the area was faulted in writable at least once, for example, 663 * after allocating file blocks for mapped files. 664 */ 665 void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads, 666 ThreadContext *tc, Error **errp); 667 668 /** 669 * qemu_get_pid_name: 670 * @pid: pid of a process 671 * 672 * For given @pid fetch its name. Caller is responsible for 673 * freeing the string when no longer needed. 674 * Returns allocated string on success, NULL on failure. 675 */ 676 char *qemu_get_pid_name(pid_t pid); 677 678 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even 679 * when intptr_t is 32-bit and we are aligning a long long. 680 */ 681 static inline uintptr_t qemu_real_host_page_size(void) 682 { 683 return getpagesize(); 684 } 685 686 static inline intptr_t qemu_real_host_page_mask(void) 687 { 688 return -(intptr_t)qemu_real_host_page_size(); 689 } 690 691 /* 692 * After using getopt or getopt_long, if you need to parse another set 693 * of options, then you must reset optind. Unfortunately the way to 694 * do this varies between implementations of getopt. 695 */ 696 static inline void qemu_reset_optind(void) 697 { 698 #ifdef HAVE_OPTRESET 699 optind = 1; 700 optreset = 1; 701 #else 702 optind = 0; 703 #endif 704 } 705 706 int qemu_fdatasync(int fd); 707 708 /** 709 * Sync changes made to the memory mapped file back to the backing 710 * storage. For POSIX compliant systems this will fallback 711 * to regular msync call. Otherwise it will trigger whole file sync 712 * (including the metadata case there is no support to skip that otherwise) 713 * 714 * @addr - start of the memory area to be synced 715 * @length - length of the are to be synced 716 * @fd - file descriptor for the file to be synced 717 * (mandatory only for POSIX non-compliant systems) 718 */ 719 int qemu_msync(void *addr, size_t length, int fd); 720 721 /** 722 * qemu_get_host_physmem: 723 * 724 * Operating system agnostic way of querying host memory. 725 * 726 * Returns amount of physical memory on the system. This is purely 727 * advisery and may return 0 if we can't work it out. At the other 728 * end we saturate to SIZE_MAX if you are lucky enough to have that 729 * much memory. 730 */ 731 size_t qemu_get_host_physmem(void); 732 733 /* 734 * Toggle write/execute on the pages marked MAP_JIT 735 * for the current thread. 736 */ 737 #if defined(MAC_OS_VERSION_11_0) && \ 738 MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0 739 static inline void qemu_thread_jit_execute(void) 740 { 741 pthread_jit_write_protect_np(true); 742 } 743 744 static inline void qemu_thread_jit_write(void) 745 { 746 pthread_jit_write_protect_np(false); 747 } 748 #else 749 static inline void qemu_thread_jit_write(void) {} 750 static inline void qemu_thread_jit_execute(void) {} 751 #endif 752 753 /** 754 * Platforms which do not support system() return ENOSYS 755 */ 756 #ifndef HAVE_SYSTEM_FUNCTION 757 #define system platform_does_not_support_system 758 static inline int platform_does_not_support_system(const char *command) 759 { 760 errno = ENOSYS; 761 return -1; 762 } 763 #endif /* !HAVE_SYSTEM_FUNCTION */ 764 765 #ifdef __cplusplus 766 } 767 #endif 768 769 #endif 770