include/qemu/osdep.h

   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.h"
  33 #else
  34 #include "exec/poison.h"
  35 #endif
  36 #ifdef __COVERITY__
  37 /* Coverity does not like the new _Float* types that are used by
  38  * recent glibc, and croaks on every single file that includes
  39  * stdlib.h.  These typedefs are enough to please it.
  40  *
  41  * Note that these fix parse errors so they cannot be placed in
  42  * scripts/coverity-model.c.
  43  */
  44 typedef float _Float32;
  45 typedef double _Float32x;
  46 typedef double _Float64;
  47 typedef __float80 _Float64x;
  48 typedef __float128 _Float128;
  49 #endif
  50
  51 #include "qemu/compiler.h"
  52
  53 /* Older versions of C++ don't get definitions of various macros from
  54  * stdlib.h unless we define these macros before first inclusion of
  55  * that system header.
  56  */
  57 #ifndef __STDC_CONSTANT_MACROS
  58 #define __STDC_CONSTANT_MACROS
  59 #endif
  60 #ifndef __STDC_LIMIT_MACROS
  61 #define __STDC_LIMIT_MACROS
  62 #endif
  63 #ifndef __STDC_FORMAT_MACROS
  64 #define __STDC_FORMAT_MACROS
  65 #endif
  66
  67 /* The following block of code temporarily renames the daemon() function so the
  68  * compiler does not see the warning associated with it in stdlib.h on OSX
  69  */
  70 #ifdef __APPLE__
  71 #define daemon qemu_fake_daemon_function
  72 #include <stdlib.h>
  73 #undef daemon
  74 extern int daemon(int, int);
  75 #endif
  76
  77 #include <stdarg.h>
  78 #include <stddef.h>
  79 #include <stdbool.h>
  80 #include <stdint.h>
  81 #include <sys/types.h>
  82 #include <stdlib.h>
  83 #include <stdio.h>
  84 #include <string.h>
  85 #include <strings.h>
  86 #include <inttypes.h>
  87 #include <limits.h>
  88 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
  89  * function availability on recentish Mingw-w64 platforms. */
  90 #include <unistd.h>
  91 #include <time.h>
  92 #include <ctype.h>
  93 #include <errno.h>
  94 #include <fcntl.h>
  95 #include <sys/stat.h>
  96 #include <sys/time.h>
  97 #include <assert.h>
  98 /* setjmp must be declared before sysemu/os-win32.h
  99  * because it is redefined there. */
 100 #include <setjmp.h>
 101 #include <signal.h>
 102
 103 #ifdef __OpenBSD__
 104 #include <sys/signal.h>
 105 #endif
 106
 107 #ifndef _WIN32
 108 #include <sys/wait.h>
 109 #else
 110 #define WIFEXITED(x)   1
 111 #define WEXITSTATUS(x) (x)
 112 #endif
 113
 114 #ifdef _WIN32
 115 #include "sysemu/os-win32.h"
 116 #endif
 117
 118 #ifdef CONFIG_POSIX
 119 #include "sysemu/os-posix.h"
 120 #endif
 121
 122 #include "glib-compat.h"
 123 #include "qemu/typedefs.h"
 124
 125 /*
 126  * For mingw, as of v6.0.0, the function implementing the assert macro is
 127  * not marked as noreturn, so the compiler cannot delete code following an
 128  * assert(false) as unused.  We rely on this within the code base to delete
 129  * code that is unreachable when features are disabled.
 130  * All supported versions of Glib's g_assert() satisfy this requirement.
 131  */
 132 #ifdef __MINGW32__
 133 #undef assert
 134 #define assert(x)  g_assert(x)
 135 #endif
 136
 137 /*
 138  * According to waitpid man page:
 139  * WCOREDUMP
 140  *  This  macro  is  not  specified  in POSIX.1-2001 and is not
 141  *  available on some UNIX implementations (e.g., AIX, SunOS).
 142  *  Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
 143  */
 144 #ifndef WCOREDUMP
 145 #define WCOREDUMP(status) 0
 146 #endif
 147 /*
 148  * We have a lot of unaudited code that may fail in strange ways, or
 149  * even be a security risk during migration, if you disable assertions
 150  * at compile-time.  You may comment out these safety checks if you
 151  * absolutely want to disable assertion overhead, but it is not
 152  * supported upstream so the risk is all yours.  Meanwhile, please
 153  * submit patches to remove any side-effects inside an assertion, or
 154  * fixing error handling that should use Error instead of assert.
 155  */
 156 #ifdef NDEBUG
 157 #error building with NDEBUG is not supported
 158 #endif
 159 #ifdef G_DISABLE_ASSERT
 160 #error building with G_DISABLE_ASSERT is not supported
 161 #endif
 162
 163 #ifndef O_LARGEFILE
 164 #define O_LARGEFILE 0
 165 #endif
 166 #ifndef O_BINARY
 167 #define O_BINARY 0
 168 #endif
 169 #ifndef MAP_ANONYMOUS
 170 #define MAP_ANONYMOUS MAP_ANON
 171 #endif
 172 #ifndef ENOMEDIUM
 173 #define ENOMEDIUM ENODEV
 174 #endif
 175 #if !defined(ENOTSUP)
 176 #define ENOTSUP 4096
 177 #endif
 178 #if !defined(ECANCELED)
 179 #define ECANCELED 4097
 180 #endif
 181 #if !defined(EMEDIUMTYPE)
 182 #define EMEDIUMTYPE 4098
 183 #endif
 184 #if !defined(ESHUTDOWN)
 185 #define ESHUTDOWN 4099
 186 #endif
 187
 188 /* time_t may be either 32 or 64 bits depending on the host OS, and
 189  * can be either signed or unsigned, so we can't just hardcode a
 190  * specific maximum value. This is not a C preprocessor constant,
 191  * so you can't use TIME_MAX in an #ifdef, but for our purposes
 192  * this isn't a problem.
 193  */
 194
 195 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
 196  * Gnulib, and are under the LGPL v2.1 or (at your option) any
 197  * later version.
 198  */
 199
 200 /* True if the real type T is signed.  */
 201 #define TYPE_SIGNED(t) (!((t)0 < (t)-1))
 202
 203 /* The width in bits of the integer type or expression T.
 204  * Padding bits are not supported.
 205  */
 206 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
 207
 208 /* The maximum and minimum values for the integer type T.  */
 209 #define TYPE_MAXIMUM(t)                                                \
 210   ((t) (!TYPE_SIGNED(t)                                                \
 211         ? (t)-1                                                        \
 212         : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
 213
 214 #ifndef TIME_MAX
 215 #define TIME_MAX TYPE_MAXIMUM(time_t)
 216 #endif
 217
 218 /* HOST_LONG_BITS is the size of a native pointer in bits. */
 219 #if UINTPTR_MAX == UINT32_MAX
 220 # define HOST_LONG_BITS 32
 221 #elif UINTPTR_MAX == UINT64_MAX
 222 # define HOST_LONG_BITS 64
 223 #else
 224 # error Unknown pointer size
 225 #endif
 226
 227 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
 228  * the wrong type. Our replacement isn't usable in preprocessor
 229  * expressions, but it is sufficient for our needs. */
 230 #if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
 231 #undef SIZE_MAX
 232 #define SIZE_MAX ((size_t)-1)
 233 #endif
 234
 235 #ifndef MIN
 236 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 237 #endif
 238 #ifndef MAX
 239 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
 240 #endif
 241
 242 /* Minimum function that returns zero only iff both values are zero.
 243  * Intended for use with unsigned values only. */
 244 #ifndef MIN_NON_ZERO
 245 #define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
 246                                 ((b) == 0 ? (a) : (MIN(a, b))))
 247 #endif
 248
 249 /* Round number down to multiple */
 250 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
 251
 252 /* Round number up to multiple. Safe when m is not a power of 2 (see
 253  * ROUND_UP for a faster version when a power of 2 is guaranteed) */
 254 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
 255
 256 /* Check if n is a multiple of m */
 257 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
 258
 259 /* n-byte align pointer down */
 260 #define QEMU_ALIGN_PTR_DOWN(p, n) \
 261     ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
 262
 263 /* n-byte align pointer up */
 264 #define QEMU_ALIGN_PTR_UP(p, n) \
 265     ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
 266
 267 /* Check if pointer p is n-bytes aligned */
 268 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
 269
 270 /* Round number up to multiple. Requires that d be a power of 2 (see
 271  * QEMU_ALIGN_UP for a safer but slower version on arbitrary
 272  * numbers); works even if d is a smaller type than n.  */
 273 #ifndef ROUND_UP
 274 #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
 275 #endif
 276
 277 #ifndef DIV_ROUND_UP
 278 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 279 #endif
 280
 281 /*
 282  * &(x)[0] is always a pointer - if it's same type as x then the argument is a
 283  * pointer, not an array.
 284  */
 285 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
 286                                                         typeof(&(x)[0])))
 287 #ifndef ARRAY_SIZE
 288 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
 289                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
 290 #endif
 291
 292 int qemu_daemon(int nochdir, int noclose);
 293 void *qemu_try_memalign(size_t alignment, size_t size);
 294 void *qemu_memalign(size_t alignment, size_t size);
 295 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared);
 296 void qemu_vfree(void *ptr);
 297 void qemu_anon_ram_free(void *ptr, size_t size);
 298
 299 #define QEMU_MADV_INVALID -1
 300
 301 #if defined(CONFIG_MADVISE)
 302
 303 #define QEMU_MADV_WILLNEED  MADV_WILLNEED
 304 #define QEMU_MADV_DONTNEED  MADV_DONTNEED
 305 #ifdef MADV_DONTFORK
 306 #define QEMU_MADV_DONTFORK  MADV_DONTFORK
 307 #else
 308 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 309 #endif
 310 #ifdef MADV_MERGEABLE
 311 #define QEMU_MADV_MERGEABLE MADV_MERGEABLE
 312 #else
 313 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 314 #endif
 315 #ifdef MADV_UNMERGEABLE
 316 #define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
 317 #else
 318 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 319 #endif
 320 #ifdef MADV_DODUMP
 321 #define QEMU_MADV_DODUMP MADV_DODUMP
 322 #else
 323 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 324 #endif
 325 #ifdef MADV_DONTDUMP
 326 #define QEMU_MADV_DONTDUMP MADV_DONTDUMP
 327 #else
 328 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 329 #endif
 330 #ifdef MADV_HUGEPAGE
 331 #define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
 332 #else
 333 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
 334 #endif
 335 #ifdef MADV_NOHUGEPAGE
 336 #define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
 337 #else
 338 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
 339 #endif
 340 #ifdef MADV_REMOVE
 341 #define QEMU_MADV_REMOVE MADV_REMOVE
 342 #else
 343 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 344 #endif
 345
 346 #elif defined(CONFIG_POSIX_MADVISE)
 347
 348 #define QEMU_MADV_WILLNEED  POSIX_MADV_WILLNEED
 349 #define QEMU_MADV_DONTNEED  POSIX_MADV_DONTNEED
 350 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 351 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 352 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 353 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 354 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 355 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 356 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 357 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 358
 359 #else /* no-op */
 360
 361 #define QEMU_MADV_WILLNEED  QEMU_MADV_INVALID
 362 #define QEMU_MADV_DONTNEED  QEMU_MADV_INVALID
 363 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 364 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 365 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 366 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 367 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 368 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 369 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 370 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 371
 372 #endif
 373
 374 #ifdef _WIN32
 375 #define HAVE_CHARDEV_SERIAL 1
 376 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
 377     || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
 378     || defined(__GLIBC__)
 379 #define HAVE_CHARDEV_SERIAL 1
 380 #endif
 381
 382 #if defined(__linux__) || defined(__FreeBSD__) ||               \
 383     defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 384 #define HAVE_CHARDEV_PARPORT 1
 385 #endif
 386
 387 #if defined(CONFIG_LINUX)
 388 #ifndef BUS_MCEERR_AR
 389 #define BUS_MCEERR_AR 4
 390 #endif
 391 #ifndef BUS_MCEERR_AO
 392 #define BUS_MCEERR_AO 5
 393 #endif
 394 #endif
 395
 396 #if defined(__linux__) && \
 397     (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
 398      || defined(__powerpc64__))
 399    /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
 400       Valgrind does not support alignments larger than 1 MiB,
 401       therefore we need special code which handles running on Valgrind. */
 402 #  define QEMU_VMALLOC_ALIGN (512 * 4096)
 403 #elif defined(__linux__) && defined(__s390x__)
 404    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 405 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
 406 #elif defined(__linux__) && defined(__sparc__)
 407 #include <sys/shm.h>
 408 #  define QEMU_VMALLOC_ALIGN MAX(getpagesize(), SHMLBA)
 409 #else
 410 #  define QEMU_VMALLOC_ALIGN getpagesize()
 411 #endif
 412
 413 #ifdef CONFIG_POSIX
 414 struct qemu_signalfd_siginfo {
 415     uint32_t ssi_signo;   /* Signal number */
 416     int32_t  ssi_errno;   /* Error number (unused) */
 417     int32_t  ssi_code;    /* Signal code */
 418     uint32_t ssi_pid;     /* PID of sender */
 419     uint32_t ssi_uid;     /* Real UID of sender */
 420     int32_t  ssi_fd;      /* File descriptor (SIGIO) */
 421     uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
 422     uint32_t ssi_band;    /* Band event (SIGIO) */
 423     uint32_t ssi_overrun; /* POSIX timer overrun count */
 424     uint32_t ssi_trapno;  /* Trap number that caused signal */
 425     int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
 426     int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
 427     uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
 428     uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
 429     uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
 430     uint64_t ssi_addr;    /* Address that generated signal
 431                              (for hardware-generated signals) */
 432     uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
 433                              additional fields in the future) */
 434 };
 435
 436 int qemu_signalfd(const sigset_t *mask);
 437 void sigaction_invoke(struct sigaction *action,
 438                       struct qemu_signalfd_siginfo *info);
 439 #endif
 440
 441 int qemu_madvise(void *addr, size_t len, int advice);
 442 int qemu_mprotect_rwx(void *addr, size_t size);
 443 int qemu_mprotect_none(void *addr, size_t size);
 444
 445 int qemu_open(const char *name, int flags, ...);
 446 int qemu_close(int fd);
 447 #ifndef _WIN32
 448 int qemu_dup(int fd);
 449 #endif
 450 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
 451 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
 452 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
 453 bool qemu_has_ofd_lock(void);
 454
 455 #if defined(__HAIKU__) && defined(__i386__)
 456 #define FMT_pid "%ld"
 457 #elif defined(WIN64)
 458 #define FMT_pid "%" PRId64
 459 #else
 460 #define FMT_pid "%d"
 461 #endif
 462
 463 bool qemu_write_pidfile(const char *pidfile, Error **errp);
 464
 465 int qemu_get_thread_id(void);
 466
 467 #ifndef CONFIG_IOVEC
 468 struct iovec {
 469     void *iov_base;
 470     size_t iov_len;
 471 };
 472 /*
 473  * Use the same value as Linux for now.
 474  */
 475 #define IOV_MAX 1024
 476
 477 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 478 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
 479 #else
 480 #include <sys/uio.h>
 481 #endif
 482
 483 #ifdef _WIN32
 484 static inline void qemu_timersub(const struct timeval *val1,
 485                                  const struct timeval *val2,
 486                                  struct timeval *res)
 487 {
 488     res->tv_sec = val1->tv_sec - val2->tv_sec;
 489     if (val1->tv_usec < val2->tv_usec) {
 490         res->tv_sec--;
 491         res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
 492     } else {
 493         res->tv_usec = val1->tv_usec - val2->tv_usec;
 494     }
 495 }
 496 #else
 497 #define qemu_timersub timersub
 498 #endif
 499
 500 void qemu_set_cloexec(int fd);
 501
 502 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
 503  * instead of QEMU_VERSION, so setting hw_version on MachineClass
 504  * is no longer mandatory.
 505  *
 506  * Do NOT change this string, or it will break compatibility on all
 507  * machine classes that don't set hw_version.
 508  */
 509 #define QEMU_HW_VERSION "2.5+"
 510
 511 /* QEMU "hardware version" setting. Used to replace code that exposed
 512  * QEMU_VERSION to guests in the past and need to keep compatibility.
 513  * Do not use qemu_hw_version() in new code.
 514  */
 515 void qemu_set_hw_version(const char *);
 516 const char *qemu_hw_version(void);
 517
 518 void fips_set_state(bool requested);
 519 bool fips_get_state(void);
 520
 521 /* Return a dynamically allocated pathname denoting a file or directory that is
 522  * appropriate for storing local state.
 523  *
 524  * @relative_pathname need not start with a directory separator; one will be
 525  * added automatically.
 526  *
 527  * The caller is responsible for releasing the value returned with g_free()
 528  * after use.
 529  */
 530 char *qemu_get_local_state_pathname(const char *relative_pathname);
 531
 532 /* Find program directory, and save it for later usage with
 533  * qemu_get_exec_dir().
 534  * Try OS specific API first, if not working, parse from argv0. */
 535 void qemu_init_exec_dir(const char *argv0);
 536
 537 /* Get the saved exec dir.
 538  * Caller needs to release the returned string by g_free() */
 539 char *qemu_get_exec_dir(void);
 540
 541 /**
 542  * qemu_getauxval:
 543  * @type: the auxiliary vector key to lookup
 544  *
 545  * Search the auxiliary vector for @type, returning the value
 546  * or 0 if @type is not present.
 547  */
 548 unsigned long qemu_getauxval(unsigned long type);
 549
 550 void qemu_set_tty_echo(int fd, bool echo);
 551
 552 void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
 553                      Error **errp);
 554
 555 /**
 556  * qemu_get_pid_name:
 557  * @pid: pid of a process
 558  *
 559  * For given @pid fetch its name. Caller is responsible for
 560  * freeing the string when no longer needed.
 561  * Returns allocated string on success, NULL on failure.
 562  */
 563 char *qemu_get_pid_name(pid_t pid);
 564
 565 /**
 566  * qemu_fork:
 567  *
 568  * A version of fork that avoids signal handler race
 569  * conditions that can lead to child process getting
 570  * signals that are otherwise only expected by the
 571  * parent. It also resets all signal handlers to the
 572  * default settings.
 573  *
 574  * Returns 0 to child process, pid number to parent
 575  * or -1 on failure.
 576  */
 577 pid_t qemu_fork(Error **errp);
 578
 579 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
 580  * when intptr_t is 32-bit and we are aligning a long long.
 581  */
 582 extern uintptr_t qemu_real_host_page_size;
 583 extern intptr_t qemu_real_host_page_mask;
 584
 585 extern int qemu_icache_linesize;
 586 extern int qemu_icache_linesize_log;
 587 extern int qemu_dcache_linesize;
 588 extern int qemu_dcache_linesize_log;
 589
 590 #endif