LXR qemu/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 */
  44typedef float _Float32;
  45typedef double _Float32x;
  46typedef double _Float64;
  47typedef __float80 _Float64x;
  48typedef __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
  74extern int daemon(int, int);
  75#endif
  76
  77#ifdef _WIN32
  78/* as defined in sdkddkver.h */
  79#ifndef _WIN32_WINNT
  80#define _WIN32_WINNT 0x0600 /* Vista */
  81#endif
  82/* reduces the number of implicitly included headers */
  83#ifndef WIN32_LEAN_AND_MEAN
  84#define WIN32_LEAN_AND_MEAN
  85#endif
  86#endif
  87
  88#include <stdarg.h>
  89#include <stddef.h>
  90#include <stdbool.h>
  91#include <stdint.h>
  92#include <sys/types.h>
  93#include <stdlib.h>
  94
  95/* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */
  96#ifdef __MINGW32__
  97#define __USE_MINGW_ANSI_STDIO 1
  98#endif
  99#include <stdio.h>
 100
 101#include <string.h>
 102#include <strings.h>
 103#include <inttypes.h>
 104#include <limits.h>
 105/* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
 106 * function availability on recentish Mingw-w64 platforms. */
 107#include <unistd.h>
 108#include <time.h>
 109#include <ctype.h>
 110#include <errno.h>
 111#include <fcntl.h>
 112#include <getopt.h>
 113#include <sys/stat.h>
 114#include <sys/time.h>
 115#include <assert.h>
 116/* setjmp must be declared before sysemu/os-win32.h
 117 * because it is redefined there. */
 118#include <setjmp.h>
 119#include <signal.h>
 120
 121#ifdef __OpenBSD__
 122#include <sys/signal.h>
 123#endif
 124
 125#ifndef _WIN32
 126#include <sys/wait.h>
 127#else
 128#define WIFEXITED(x)   1
 129#define WEXITSTATUS(x) (x)
 130#endif
 131
 132#ifdef _WIN32
 133#include "sysemu/os-win32.h"
 134#endif
 135
 136#ifdef CONFIG_POSIX
 137#include "sysemu/os-posix.h"
 138#endif
 139
 140#include "glib-compat.h"
 141#include "qemu/typedefs.h"
 142
 143/*
 144 * For mingw, as of v6.0.0, the function implementing the assert macro is
 145 * not marked as noreturn, so the compiler cannot delete code following an
 146 * assert(false) as unused.  We rely on this within the code base to delete
 147 * code that is unreachable when features are disabled.
 148 * All supported versions of Glib's g_assert() satisfy this requirement.
 149 */
 150#ifdef __MINGW32__
 151#undef assert
 152#define assert(x)  g_assert(x)
 153#endif
 154
 155/*
 156 * According to waitpid man page:
 157 * WCOREDUMP
 158 *  This  macro  is  not  specified  in POSIX.1-2001 and is not
 159 *  available on some UNIX implementations (e.g., AIX, SunOS).
 160 *  Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
 161 */
 162#ifndef WCOREDUMP
 163#define WCOREDUMP(status) 0
 164#endif
 165/*
 166 * We have a lot of unaudited code that may fail in strange ways, or
 167 * even be a security risk during migration, if you disable assertions
 168 * at compile-time.  You may comment out these safety checks if you
 169 * absolutely want to disable assertion overhead, but it is not
 170 * supported upstream so the risk is all yours.  Meanwhile, please
 171 * submit patches to remove any side-effects inside an assertion, or
 172 * fixing error handling that should use Error instead of assert.
 173 */
 174#ifdef NDEBUG
 175#error building with NDEBUG is not supported
 176#endif
 177#ifdef G_DISABLE_ASSERT
 178#error building with G_DISABLE_ASSERT is not supported
 179#endif
 180
 181#ifndef O_LARGEFILE
 182#define O_LARGEFILE 0
 183#endif
 184#ifndef O_BINARY
 185#define O_BINARY 0
 186#endif
 187#ifndef MAP_ANONYMOUS
 188#define MAP_ANONYMOUS MAP_ANON
 189#endif
 190#ifndef ENOMEDIUM
 191#define ENOMEDIUM ENODEV
 192#endif
 193#if !defined(ENOTSUP)
 194#define ENOTSUP 4096
 195#endif
 196#if !defined(ECANCELED)
 197#define ECANCELED 4097
 198#endif
 199#if !defined(EMEDIUMTYPE)
 200#define EMEDIUMTYPE 4098
 201#endif
 202#if !defined(ESHUTDOWN)
 203#define ESHUTDOWN 4099
 204#endif
 205
 206/* time_t may be either 32 or 64 bits depending on the host OS, and
 207 * can be either signed or unsigned, so we can't just hardcode a
 208 * specific maximum value. This is not a C preprocessor constant,
 209 * so you can't use TIME_MAX in an #ifdef, but for our purposes
 210 * this isn't a problem.
 211 */
 212
 213/* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
 214 * Gnulib, and are under the LGPL v2.1 or (at your option) any
 215 * later version.
 216 */
 217
 218/* True if the real type T is signed.  */
 219#define TYPE_SIGNED(t) (!((t)0 < (t)-1))
 220
 221/* The width in bits of the integer type or expression T.
 222 * Padding bits are not supported.
 223 */
 224#define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
 225
 226/* The maximum and minimum values for the integer type T.  */
 227#define TYPE_MAXIMUM(t)                                                \
 228  ((t) (!TYPE_SIGNED(t)                                                \
 229        ? (t)-1                                                        \
 230        : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
 231
 232#ifndef TIME_MAX
 233#define TIME_MAX TYPE_MAXIMUM(time_t)
 234#endif
 235
 236/* HOST_LONG_BITS is the size of a native pointer in bits. */
 237#if UINTPTR_MAX == UINT32_MAX
 238# define HOST_LONG_BITS 32
 239#elif UINTPTR_MAX == UINT64_MAX
 240# define HOST_LONG_BITS 64
 241#else
 242# error Unknown pointer size
 243#endif
 244
 245/* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
 246 * the wrong type. Our replacement isn't usable in preprocessor
 247 * expressions, but it is sufficient for our needs. */
 248#if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
 249#undef SIZE_MAX
 250#define SIZE_MAX ((size_t)-1)
 251#endif
 252
 253#ifndef MIN
 254#define MIN(a, b) (((a) < (b)) ? (a) : (b))
 255#endif
 256#ifndef MAX
 257#define MAX(a, b) (((a) > (b)) ? (a) : (b))
 258#endif
 259
 260/* Minimum function that returns zero only iff both values are zero.
 261 * Intended for use with unsigned values only. */
 262#ifndef MIN_NON_ZERO
 263#define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
 264                                ((b) == 0 ? (a) : (MIN(a, b))))
 265#endif
 266
 267/* Round number down to multiple */
 268#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
 269
 270/* Round number up to multiple. Safe when m is not a power of 2 (see
 271 * ROUND_UP for a faster version when a power of 2 is guaranteed) */
 272#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
 273
 274/* Check if n is a multiple of m */
 275#define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
 276
 277/* n-byte align pointer down */
 278#define QEMU_ALIGN_PTR_DOWN(p, n) \
 279    ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
 280
 281/* n-byte align pointer up */
 282#define QEMU_ALIGN_PTR_UP(p, n) \
 283    ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
 284
 285/* Check if pointer p is n-bytes aligned */
 286#define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
 287
 288/* Round number up to multiple. Requires that d be a power of 2 (see
 289 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
 290 * numbers); works even if d is a smaller type than n.  */
 291#ifndef ROUND_UP
 292#define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
 293#endif
 294
 295#ifndef DIV_ROUND_UP
 296#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 297#endif
 298
 299/*
 300 * &(x)[0] is always a pointer - if it's same type as x then the argument is a
 301 * pointer, not an array.
 302 */
 303#define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
 304                                                        typeof(&(x)[0])))
 305#ifndef ARRAY_SIZE
 306#define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
 307                       QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
 308#endif
 309
 310int qemu_daemon(int nochdir, int noclose);
 311void *qemu_try_memalign(size_t alignment, size_t size);
 312void *qemu_memalign(size_t alignment, size_t size);
 313void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared);
 314void qemu_vfree(void *ptr);
 315void qemu_anon_ram_free(void *ptr, size_t size);
 316
 317#define QEMU_MADV_INVALID -1
 318
 319#if defined(CONFIG_MADVISE)
 320
 321#define QEMU_MADV_WILLNEED  MADV_WILLNEED
 322#define QEMU_MADV_DONTNEED  MADV_DONTNEED
 323#ifdef MADV_DONTFORK
 324#define QEMU_MADV_DONTFORK  MADV_DONTFORK
 325#else
 326#define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 327#endif
 328#ifdef MADV_MERGEABLE
 329#define QEMU_MADV_MERGEABLE MADV_MERGEABLE
 330#else
 331#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 332#endif
 333#ifdef MADV_UNMERGEABLE
 334#define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
 335#else
 336#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 337#endif
 338#ifdef MADV_DODUMP
 339#define QEMU_MADV_DODUMP MADV_DODUMP
 340#else
 341#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 342#endif
 343#ifdef MADV_DONTDUMP
 344#define QEMU_MADV_DONTDUMP MADV_DONTDUMP
 345#else
 346#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 347#endif
 348#ifdef MADV_HUGEPAGE
 349#define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
 350#else
 351#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
 352#endif
 353#ifdef MADV_NOHUGEPAGE
 354#define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
 355#else
 356#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
 357#endif
 358#ifdef MADV_REMOVE
 359#define QEMU_MADV_REMOVE MADV_REMOVE
 360#else
 361#define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 362#endif
 363
 364#elif defined(CONFIG_POSIX_MADVISE)
 365
 366#define QEMU_MADV_WILLNEED  POSIX_MADV_WILLNEED
 367#define QEMU_MADV_DONTNEED  POSIX_MADV_DONTNEED
 368#define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 369#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 370#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 371#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 372#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 373#define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 374#define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 375#define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 376
 377#else /* no-op */
 378
 379#define QEMU_MADV_WILLNEED  QEMU_MADV_INVALID
 380#define QEMU_MADV_DONTNEED  QEMU_MADV_INVALID
 381#define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 382#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 383#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 384#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 385#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 386#define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 387#define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 388#define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 389
 390#endif
 391
 392#ifdef _WIN32
 393#define HAVE_CHARDEV_SERIAL 1
 394#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
 395    || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
 396    || defined(__GLIBC__)
 397#define HAVE_CHARDEV_SERIAL 1
 398#endif
 399
 400#if defined(__linux__) || defined(__FreeBSD__) ||               \
 401    defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 402#define HAVE_CHARDEV_PARPORT 1
 403#endif
 404
 405#if defined(CONFIG_LINUX)
 406#ifndef BUS_MCEERR_AR
 407#define BUS_MCEERR_AR 4
 408#endif
 409#ifndef BUS_MCEERR_AO
 410#define BUS_MCEERR_AO 5
 411#endif
 412#endif
 413
 414#if defined(__linux__) && \
 415    (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
 416     || defined(__powerpc64__))
 417   /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
 418      Valgrind does not support alignments larger than 1 MiB,
 419      therefore we need special code which handles running on Valgrind. */
 420#  define QEMU_VMALLOC_ALIGN (512 * 4096)
 421#elif defined(__linux__) && defined(__s390x__)
 422   /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 423#  define QEMU_VMALLOC_ALIGN (256 * 4096)
 424#elif defined(__linux__) && defined(__sparc__)
 425#include <sys/shm.h>
 426#  define QEMU_VMALLOC_ALIGN MAX(getpagesize(), SHMLBA)
 427#else
 428#  define QEMU_VMALLOC_ALIGN getpagesize()
 429#endif
 430
 431#ifdef CONFIG_POSIX
 432struct qemu_signalfd_siginfo {
 433    uint32_t ssi_signo;   /* Signal number */
 434    int32_t  ssi_errno;   /* Error number (unused) */
 435    int32_t  ssi_code;    /* Signal code */
 436    uint32_t ssi_pid;     /* PID of sender */
 437    uint32_t ssi_uid;     /* Real UID of sender */
 438    int32_t  ssi_fd;      /* File descriptor (SIGIO) */
 439    uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
 440    uint32_t ssi_band;    /* Band event (SIGIO) */
 441    uint32_t ssi_overrun; /* POSIX timer overrun count */
 442    uint32_t ssi_trapno;  /* Trap number that caused signal */
 443    int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
 444    int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
 445    uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
 446    uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
 447    uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
 448    uint64_t ssi_addr;    /* Address that generated signal
 449                             (for hardware-generated signals) */
 450    uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
 451                             additional fields in the future) */
 452};
 453
 454int qemu_signalfd(const sigset_t *mask);
 455void sigaction_invoke(struct sigaction *action,
 456                      struct qemu_signalfd_siginfo *info);
 457#endif
 458
 459int qemu_madvise(void *addr, size_t len, int advice);
 460int qemu_mprotect_rwx(void *addr, size_t size);
 461int qemu_mprotect_none(void *addr, size_t size);
 462
 463int qemu_open(const char *name, int flags, ...);
 464int qemu_close(int fd);
 465#ifndef _WIN32
 466int qemu_dup(int fd);
 467#endif
 468int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
 469int qemu_unlock_fd(int fd, int64_t start, int64_t len);
 470int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
 471bool qemu_has_ofd_lock(void);
 472
 473#if defined(__HAIKU__) && defined(__i386__)
 474#define FMT_pid "%ld"
 475#elif defined(WIN64)
 476#define FMT_pid "%" PRId64
 477#else
 478#define FMT_pid "%d"
 479#endif
 480
 481bool qemu_write_pidfile(const char *pidfile, Error **errp);
 482
 483int qemu_get_thread_id(void);
 484
 485#ifndef CONFIG_IOVEC
 486struct iovec {
 487    void *iov_base;
 488    size_t iov_len;
 489};
 490/*
 491 * Use the same value as Linux for now.
 492 */
 493#define IOV_MAX 1024
 494
 495ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 496ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
 497#else
 498#include <sys/uio.h>
 499#endif
 500
 501#ifdef _WIN32
 502static inline void qemu_timersub(const struct timeval *val1,
 503                                 const struct timeval *val2,
 504                                 struct timeval *res)
 505{
 506    res->tv_sec = val1->tv_sec - val2->tv_sec;
 507    if (val1->tv_usec < val2->tv_usec) {
 508        res->tv_sec--;
 509        res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
 510    } else {
 511        res->tv_usec = val1->tv_usec - val2->tv_usec;
 512    }
 513}
 514#else
 515#define qemu_timersub timersub
 516#endif
 517
 518void qemu_set_cloexec(int fd);
 519
 520/* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
 521 * instead of QEMU_VERSION, so setting hw_version on MachineClass
 522 * is no longer mandatory.
 523 *
 524 * Do NOT change this string, or it will break compatibility on all
 525 * machine classes that don't set hw_version.
 526 */
 527#define QEMU_HW_VERSION "2.5+"
 528
 529/* QEMU "hardware version" setting. Used to replace code that exposed
 530 * QEMU_VERSION to guests in the past and need to keep compatibility.
 531 * Do not use qemu_hw_version() in new code.
 532 */
 533void qemu_set_hw_version(const char *);
 534const char *qemu_hw_version(void);
 535
 536void fips_set_state(bool requested);
 537bool fips_get_state(void);
 538
 539/* Return a dynamically allocated pathname denoting a file or directory that is
 540 * appropriate for storing local state.
 541 *
 542 * @relative_pathname need not start with a directory separator; one will be
 543 * added automatically.
 544 *
 545 * The caller is responsible for releasing the value returned with g_free()
 546 * after use.
 547 */
 548char *qemu_get_local_state_pathname(const char *relative_pathname);
 549
 550/* Find program directory, and save it for later usage with
 551 * qemu_get_exec_dir().
 552 * Try OS specific API first, if not working, parse from argv0. */
 553void qemu_init_exec_dir(const char *argv0);
 554
 555/* Get the saved exec dir.
 556 * Caller needs to release the returned string by g_free() */
 557char *qemu_get_exec_dir(void);
 558
 559/**
 560 * qemu_getauxval:
 561 * @type: the auxiliary vector key to lookup
 562 *
 563 * Search the auxiliary vector for @type, returning the value
 564 * or 0 if @type is not present.
 565 */
 566unsigned long qemu_getauxval(unsigned long type);
 567
 568void qemu_set_tty_echo(int fd, bool echo);
 569
 570void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
 571                     Error **errp);
 572
 573/**
 574 * qemu_get_pmem_size:
 575 * @filename: path to a pmem file
 576 * @errp: pointer to a NULL-initialized error object
 577 *
 578 * Determine the size of a persistent memory file.  Besides supporting files on
 579 * DAX file systems, this function also supports Linux devdax character
 580 * devices.
 581 *
 582 * Returns: the size or 0 on failure
 583 */
 584uint64_t qemu_get_pmem_size(const char *filename, Error **errp);
 585
 586/**
 587 * qemu_get_pid_name:
 588 * @pid: pid of a process
 589 *
 590 * For given @pid fetch its name. Caller is responsible for
 591 * freeing the string when no longer needed.
 592 * Returns allocated string on success, NULL on failure.
 593 */
 594char *qemu_get_pid_name(pid_t pid);
 595
 596/**
 597 * qemu_fork:
 598 *
 599 * A version of fork that avoids signal handler race
 600 * conditions that can lead to child process getting
 601 * signals that are otherwise only expected by the
 602 * parent. It also resets all signal handlers to the
 603 * default settings.
 604 *
 605 * Returns 0 to child process, pid number to parent
 606 * or -1 on failure.
 607 */
 608pid_t qemu_fork(Error **errp);
 609
 610/* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
 611 * when intptr_t is 32-bit and we are aligning a long long.
 612 */
 613extern uintptr_t qemu_real_host_page_size;
 614extern intptr_t qemu_real_host_page_mask;
 615
 616extern int qemu_icache_linesize;
 617extern int qemu_icache_linesize_log;
 618extern int qemu_dcache_linesize;
 619extern int qemu_dcache_linesize_log;
 620
 621/*
 622 * After using getopt or getopt_long, if you need to parse another set
 623 * of options, then you must reset optind.  Unfortunately the way to
 624 * do this varies between implementations of getopt.
 625 */
 626static inline void qemu_reset_optind(void)
 627{
 628#ifdef HAVE_OPTRESET
 629    optind = 1;
 630    optreset = 1;
 631#else
 632    optind = 0;
 633#endif
 634}
 635
 636#endif
 637