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
  37 #include "qemu/compiler.h"
  38
  39 /* Older versions of C++ don't get definitions of various macros from
  40  * stdlib.h unless we define these macros before first inclusion of
  41  * that system header.
  42  */
  43 #ifndef __STDC_CONSTANT_MACROS
  44 #define __STDC_CONSTANT_MACROS
  45 #endif
  46 #ifndef __STDC_LIMIT_MACROS
  47 #define __STDC_LIMIT_MACROS
  48 #endif
  49 #ifndef __STDC_FORMAT_MACROS
  50 #define __STDC_FORMAT_MACROS
  51 #endif
  52
  53 /* The following block of code temporarily renames the daemon() function so the
  54  * compiler does not see the warning associated with it in stdlib.h on OSX
  55  */
  56 #ifdef __APPLE__
  57 #define daemon qemu_fake_daemon_function
  58 #include <stdlib.h>
  59 #undef daemon
  60 extern int daemon(int, int);
  61 #endif
  62
  63 #ifdef _WIN32
  64 /* as defined in sdkddkver.h */
  65 #ifndef _WIN32_WINNT
  66 #define _WIN32_WINNT 0x0600 /* Vista */
  67 #endif
  68 /* reduces the number of implicitly included headers */
  69 #ifndef WIN32_LEAN_AND_MEAN
  70 #define WIN32_LEAN_AND_MEAN
  71 #endif
  72 #endif
  73
  74 /* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */
  75 #ifdef __MINGW32__
  76 #define __USE_MINGW_ANSI_STDIO 1
  77 #endif
  78
  79 #include <stdarg.h>
  80 #include <stddef.h>
  81 #include <stdbool.h>
  82 #include <stdint.h>
  83 #include <sys/types.h>
  84 #include <stdlib.h>
  85 #include <stdio.h>
  86
  87 #include <string.h>
  88 #include <strings.h>
  89 #include <inttypes.h>
  90 #include <limits.h>
  91 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
  92  * function availability on recentish Mingw-w64 platforms. */
  93 #include <unistd.h>
  94 #include <time.h>
  95 #include <ctype.h>
  96 #include <errno.h>
  97 #include <fcntl.h>
  98 #include <getopt.h>
  99 #include <sys/stat.h>
 100 #include <sys/time.h>
 101 #include <assert.h>
 102 /* setjmp must be declared before sysemu/os-win32.h
 103  * because it is redefined there. */
 104 #include <setjmp.h>
 105 #include <signal.h>
 106
 107 #ifdef __OpenBSD__
 108 #include <sys/signal.h>
 109 #endif
 110
 111 #ifndef _WIN32
 112 #include <sys/wait.h>
 113 #else
 114 #define WIFEXITED(x)   1
 115 #define WEXITSTATUS(x) (x)
 116 #endif
 117
 118 #ifdef _WIN32
 119 #include "sysemu/os-win32.h"
 120 #endif
 121
 122 #ifdef CONFIG_POSIX
 123 #include "sysemu/os-posix.h"
 124 #endif
 125
 126 #include "glib-compat.h"
 127 #include "qemu/typedefs.h"
 128
 129 /*
 130  * For mingw, as of v6.0.0, the function implementing the assert macro is
 131  * not marked as noreturn, so the compiler cannot delete code following an
 132  * assert(false) as unused.  We rely on this within the code base to delete
 133  * code that is unreachable when features are disabled.
 134  * All supported versions of Glib's g_assert() satisfy this requirement.
 135  */
 136 #ifdef __MINGW32__
 137 #undef assert
 138 #define assert(x)  g_assert(x)
 139 #endif
 140
 141 /*
 142  * According to waitpid man page:
 143  * WCOREDUMP
 144  *  This  macro  is  not  specified  in POSIX.1-2001 and is not
 145  *  available on some UNIX implementations (e.g., AIX, SunOS).
 146  *  Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
 147  */
 148 #ifndef WCOREDUMP
 149 #define WCOREDUMP(status) 0
 150 #endif
 151 /*
 152  * We have a lot of unaudited code that may fail in strange ways, or
 153  * even be a security risk during migration, if you disable assertions
 154  * at compile-time.  You may comment out these safety checks if you
 155  * absolutely want to disable assertion overhead, but it is not
 156  * supported upstream so the risk is all yours.  Meanwhile, please
 157  * submit patches to remove any side-effects inside an assertion, or
 158  * fixing error handling that should use Error instead of assert.
 159  */
 160 #ifdef NDEBUG
 161 #error building with NDEBUG is not supported
 162 #endif
 163 #ifdef G_DISABLE_ASSERT
 164 #error building with G_DISABLE_ASSERT is not supported
 165 #endif
 166
 167 #ifndef O_LARGEFILE
 168 #define O_LARGEFILE 0
 169 #endif
 170 #ifndef O_BINARY
 171 #define O_BINARY 0
 172 #endif
 173 #ifndef MAP_ANONYMOUS
 174 #define MAP_ANONYMOUS MAP_ANON
 175 #endif
 176 #ifndef ENOMEDIUM
 177 #define ENOMEDIUM ENODEV
 178 #endif
 179 #if !defined(ENOTSUP)
 180 #define ENOTSUP 4096
 181 #endif
 182 #if !defined(ECANCELED)
 183 #define ECANCELED 4097
 184 #endif
 185 #if !defined(EMEDIUMTYPE)
 186 #define EMEDIUMTYPE 4098
 187 #endif
 188 #if !defined(ESHUTDOWN)
 189 #define ESHUTDOWN 4099
 190 #endif
 191
 192 /* time_t may be either 32 or 64 bits depending on the host OS, and
 193  * can be either signed or unsigned, so we can't just hardcode a
 194  * specific maximum value. This is not a C preprocessor constant,
 195  * so you can't use TIME_MAX in an #ifdef, but for our purposes
 196  * this isn't a problem.
 197  */
 198
 199 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
 200  * Gnulib, and are under the LGPL v2.1 or (at your option) any
 201  * later version.
 202  */
 203
 204 /* True if the real type T is signed.  */
 205 #define TYPE_SIGNED(t) (!((t)0 < (t)-1))
 206
 207 /* The width in bits of the integer type or expression T.
 208  * Padding bits are not supported.
 209  */
 210 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
 211
 212 /* The maximum and minimum values for the integer type T.  */
 213 #define TYPE_MAXIMUM(t)                                                \
 214   ((t) (!TYPE_SIGNED(t)                                                \
 215         ? (t)-1                                                        \
 216         : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
 217
 218 #ifndef TIME_MAX
 219 #define TIME_MAX TYPE_MAXIMUM(time_t)
 220 #endif
 221
 222 /* HOST_LONG_BITS is the size of a native pointer in bits. */
 223 #if UINTPTR_MAX == UINT32_MAX
 224 # define HOST_LONG_BITS 32
 225 #elif UINTPTR_MAX == UINT64_MAX
 226 # define HOST_LONG_BITS 64
 227 #else
 228 # error Unknown pointer size
 229 #endif
 230
 231 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
 232  * the wrong type. Our replacement isn't usable in preprocessor
 233  * expressions, but it is sufficient for our needs. */
 234 #if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
 235 #undef SIZE_MAX
 236 #define SIZE_MAX ((size_t)-1)
 237 #endif
 238
 239 #ifndef MIN
 240 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
 241 #endif
 242 #ifndef MAX
 243 #define MAX(a, b) (((a) > (b)) ? (a) : (b))
 244 #endif
 245
 246 /* Minimum function that returns zero only iff both values are zero.
 247  * Intended for use with unsigned values only. */
 248 #ifndef MIN_NON_ZERO
 249 #define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
 250                                 ((b) == 0 ? (a) : (MIN(a, b))))
 251 #endif
 252
 253 /* Round number down to multiple */
 254 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
 255
 256 /* Round number up to multiple. Safe when m is not a power of 2 (see
 257  * ROUND_UP for a faster version when a power of 2 is guaranteed) */
 258 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
 259
 260 /* Check if n is a multiple of m */
 261 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
 262
 263 /* n-byte align pointer down */
 264 #define QEMU_ALIGN_PTR_DOWN(p, n) \
 265     ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
 266
 267 /* n-byte align pointer up */
 268 #define QEMU_ALIGN_PTR_UP(p, n) \
 269     ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
 270
 271 /* Check if pointer p is n-bytes aligned */
 272 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
 273
 274 /* Round number up to multiple. Requires that d be a power of 2 (see
 275  * QEMU_ALIGN_UP for a safer but slower version on arbitrary
 276  * numbers); works even if d is a smaller type than n.  */
 277 #ifndef ROUND_UP
 278 #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d)))
 279 #endif
 280
 281 #ifndef DIV_ROUND_UP
 282 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 283 #endif
 284
 285 /*
 286  * &(x)[0] is always a pointer - if it's same type as x then the argument is a
 287  * pointer, not an array.
 288  */
 289 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
 290                                                         typeof(&(x)[0])))
 291 #ifndef ARRAY_SIZE
 292 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
 293                        QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
 294 #endif
 295
 296 int qemu_daemon(int nochdir, int noclose);
 297 void *qemu_try_memalign(size_t alignment, size_t size);
 298 void *qemu_memalign(size_t alignment, size_t size);
 299 void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared);
 300 void qemu_vfree(void *ptr);
 301 void qemu_anon_ram_free(void *ptr, size_t size);
 302
 303 #define QEMU_MADV_INVALID -1
 304
 305 #if defined(CONFIG_MADVISE)
 306
 307 #define QEMU_MADV_WILLNEED  MADV_WILLNEED
 308 #define QEMU_MADV_DONTNEED  MADV_DONTNEED
 309 #ifdef MADV_DONTFORK
 310 #define QEMU_MADV_DONTFORK  MADV_DONTFORK
 311 #else
 312 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 313 #endif
 314 #ifdef MADV_MERGEABLE
 315 #define QEMU_MADV_MERGEABLE MADV_MERGEABLE
 316 #else
 317 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 318 #endif
 319 #ifdef MADV_UNMERGEABLE
 320 #define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
 321 #else
 322 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 323 #endif
 324 #ifdef MADV_DODUMP
 325 #define QEMU_MADV_DODUMP MADV_DODUMP
 326 #else
 327 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 328 #endif
 329 #ifdef MADV_DONTDUMP
 330 #define QEMU_MADV_DONTDUMP MADV_DONTDUMP
 331 #else
 332 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 333 #endif
 334 #ifdef MADV_HUGEPAGE
 335 #define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
 336 #else
 337 #define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
 338 #endif
 339 #ifdef MADV_NOHUGEPAGE
 340 #define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
 341 #else
 342 #define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
 343 #endif
 344 #ifdef MADV_REMOVE
 345 #define QEMU_MADV_REMOVE MADV_REMOVE
 346 #else
 347 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 348 #endif
 349
 350 #elif defined(CONFIG_POSIX_MADVISE)
 351
 352 #define QEMU_MADV_WILLNEED  POSIX_MADV_WILLNEED
 353 #define QEMU_MADV_DONTNEED  POSIX_MADV_DONTNEED
 354 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 355 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 356 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 357 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 358 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 359 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 360 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 361 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 362
 363 #else /* no-op */
 364
 365 #define QEMU_MADV_WILLNEED  QEMU_MADV_INVALID
 366 #define QEMU_MADV_DONTNEED  QEMU_MADV_INVALID
 367 #define QEMU_MADV_DONTFORK  QEMU_MADV_INVALID
 368 #define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
 369 #define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
 370 #define QEMU_MADV_DODUMP QEMU_MADV_INVALID
 371 #define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
 372 #define QEMU_MADV_HUGEPAGE  QEMU_MADV_INVALID
 373 #define QEMU_MADV_NOHUGEPAGE  QEMU_MADV_INVALID
 374 #define QEMU_MADV_REMOVE QEMU_MADV_INVALID
 375
 376 #endif
 377
 378 #ifdef _WIN32
 379 #define HAVE_CHARDEV_SERIAL 1
 380 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
 381     || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
 382     || defined(__GLIBC__) || defined(__APPLE__)
 383 #define HAVE_CHARDEV_SERIAL 1
 384 #endif
 385
 386 #if defined(__linux__) || defined(__FreeBSD__) ||               \
 387     defined(__FreeBSD_kernel__) || defined(__DragonFly__)
 388 #define HAVE_CHARDEV_PARPORT 1
 389 #endif
 390
 391 #if defined(CONFIG_LINUX)
 392 #ifndef BUS_MCEERR_AR
 393 #define BUS_MCEERR_AR 4
 394 #endif
 395 #ifndef BUS_MCEERR_AO
 396 #define BUS_MCEERR_AO 5
 397 #endif
 398 #endif
 399
 400 #if defined(__linux__) && \
 401     (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
 402      || defined(__powerpc64__))
 403    /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
 404       Valgrind does not support alignments larger than 1 MiB,
 405       therefore we need special code which handles running on Valgrind. */
 406 #  define QEMU_VMALLOC_ALIGN (512 * 4096)
 407 #elif defined(__linux__) && defined(__s390x__)
 408    /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
 409 #  define QEMU_VMALLOC_ALIGN (256 * 4096)
 410 #elif defined(__linux__) && defined(__sparc__)
 411 #include <sys/shm.h>
 412 #  define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size, SHMLBA)
 413 #else
 414 #  define QEMU_VMALLOC_ALIGN qemu_real_host_page_size
 415 #endif
 416
 417 #ifdef CONFIG_POSIX
 418 struct qemu_signalfd_siginfo {
 419     uint32_t ssi_signo;   /* Signal number */
 420     int32_t  ssi_errno;   /* Error number (unused) */
 421     int32_t  ssi_code;    /* Signal code */
 422     uint32_t ssi_pid;     /* PID of sender */
 423     uint32_t ssi_uid;     /* Real UID of sender */
 424     int32_t  ssi_fd;      /* File descriptor (SIGIO) */
 425     uint32_t ssi_tid;     /* Kernel timer ID (POSIX timers) */
 426     uint32_t ssi_band;    /* Band event (SIGIO) */
 427     uint32_t ssi_overrun; /* POSIX timer overrun count */
 428     uint32_t ssi_trapno;  /* Trap number that caused signal */
 429     int32_t  ssi_status;  /* Exit status or signal (SIGCHLD) */
 430     int32_t  ssi_int;     /* Integer sent by sigqueue(2) */
 431     uint64_t ssi_ptr;     /* Pointer sent by sigqueue(2) */
 432     uint64_t ssi_utime;   /* User CPU time consumed (SIGCHLD) */
 433     uint64_t ssi_stime;   /* System CPU time consumed (SIGCHLD) */
 434     uint64_t ssi_addr;    /* Address that generated signal
 435                              (for hardware-generated signals) */
 436     uint8_t  pad[48];     /* Pad size to 128 bytes (allow for
 437                              additional fields in the future) */
 438 };
 439
 440 int qemu_signalfd(const sigset_t *mask);
 441 void sigaction_invoke(struct sigaction *action,
 442                       struct qemu_signalfd_siginfo *info);
 443 #endif
 444
 445 int qemu_madvise(void *addr, size_t len, int advice);
 446 int qemu_mprotect_rwx(void *addr, size_t size);
 447 int qemu_mprotect_none(void *addr, size_t size);
 448
 449 int qemu_open(const char *name, int flags, ...);
 450 int qemu_close(int fd);
 451 int qemu_unlink(const char *name);
 452 #ifndef _WIN32
 453 int qemu_dup(int fd);
 454 #endif
 455 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
 456 int qemu_unlock_fd(int fd, int64_t start, int64_t len);
 457 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
 458 bool qemu_has_ofd_lock(void);
 459
 460 #if defined(__HAIKU__) && defined(__i386__)
 461 #define FMT_pid "%ld"
 462 #elif defined(WIN64)
 463 #define FMT_pid "%" PRId64
 464 #else
 465 #define FMT_pid "%d"
 466 #endif
 467
 468 bool qemu_write_pidfile(const char *pidfile, Error **errp);
 469
 470 int qemu_get_thread_id(void);
 471
 472 #ifndef CONFIG_IOVEC
 473 struct iovec {
 474     void *iov_base;
 475     size_t iov_len;
 476 };
 477 /*
 478  * Use the same value as Linux for now.
 479  */
 480 #define IOV_MAX 1024
 481
 482 ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
 483 ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
 484 #else
 485 #include <sys/uio.h>
 486 #endif
 487
 488 #ifdef _WIN32
 489 static inline void qemu_timersub(const struct timeval *val1,
 490                                  const struct timeval *val2,
 491                                  struct timeval *res)
 492 {
 493     res->tv_sec = val1->tv_sec - val2->tv_sec;
 494     if (val1->tv_usec < val2->tv_usec) {
 495         res->tv_sec--;
 496         res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
 497     } else {
 498         res->tv_usec = val1->tv_usec - val2->tv_usec;
 499     }
 500 }
 501 #else
 502 #define qemu_timersub timersub
 503 #endif
 504
 505 void qemu_set_cloexec(int fd);
 506
 507 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
 508  * instead of QEMU_VERSION, so setting hw_version on MachineClass
 509  * is no longer mandatory.
 510  *
 511  * Do NOT change this string, or it will break compatibility on all
 512  * machine classes that don't set hw_version.
 513  */
 514 #define QEMU_HW_VERSION "2.5+"
 515
 516 /* QEMU "hardware version" setting. Used to replace code that exposed
 517  * QEMU_VERSION to guests in the past and need to keep compatibility.
 518  * Do not use qemu_hw_version() in new code.
 519  */
 520 void qemu_set_hw_version(const char *);
 521 const char *qemu_hw_version(void);
 522
 523 void fips_set_state(bool requested);
 524 bool fips_get_state(void);
 525
 526 /* Return a dynamically allocated pathname denoting a file or directory that is
 527  * appropriate for storing local state.
 528  *
 529  * @relative_pathname need not start with a directory separator; one will be
 530  * added automatically.
 531  *
 532  * The caller is responsible for releasing the value returned with g_free()
 533  * after use.
 534  */
 535 char *qemu_get_local_state_pathname(const char *relative_pathname);
 536
 537 /* Find program directory, and save it for later usage with
 538  * qemu_get_exec_dir().
 539  * Try OS specific API first, if not working, parse from argv0. */
 540 void qemu_init_exec_dir(const char *argv0);
 541
 542 /* Get the saved exec dir.
 543  * Caller needs to release the returned string by g_free() */
 544 char *qemu_get_exec_dir(void);
 545
 546 /**
 547  * qemu_getauxval:
 548  * @type: the auxiliary vector key to lookup
 549  *
 550  * Search the auxiliary vector for @type, returning the value
 551  * or 0 if @type is not present.
 552  */
 553 unsigned long qemu_getauxval(unsigned long type);
 554
 555 void qemu_set_tty_echo(int fd, bool echo);
 556
 557 void os_mem_prealloc(int fd, char *area, size_t sz, int smp_cpus,
 558                      Error **errp);
 559
 560 /**
 561  * qemu_get_pid_name:
 562  * @pid: pid of a process
 563  *
 564  * For given @pid fetch its name. Caller is responsible for
 565  * freeing the string when no longer needed.
 566  * Returns allocated string on success, NULL on failure.
 567  */
 568 char *qemu_get_pid_name(pid_t pid);
 569
 570 /**
 571  * qemu_fork:
 572  *
 573  * A version of fork that avoids signal handler race
 574  * conditions that can lead to child process getting
 575  * signals that are otherwise only expected by the
 576  * parent. It also resets all signal handlers to the
 577  * default settings.
 578  *
 579  * Returns 0 to child process, pid number to parent
 580  * or -1 on failure.
 581  */
 582 pid_t qemu_fork(Error **errp);
 583
 584 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
 585  * when intptr_t is 32-bit and we are aligning a long long.
 586  */
 587 extern uintptr_t qemu_real_host_page_size;
 588 extern intptr_t qemu_real_host_page_mask;
 589
 590 extern int qemu_icache_linesize;
 591 extern int qemu_icache_linesize_log;
 592 extern int qemu_dcache_linesize;
 593 extern int qemu_dcache_linesize_log;
 594
 595 /*
 596  * After using getopt or getopt_long, if you need to parse another set
 597  * of options, then you must reset optind.  Unfortunately the way to
 598  * do this varies between implementations of getopt.
 599  */
 600 static inline void qemu_reset_optind(void)
 601 {
 602 #ifdef HAVE_OPTRESET
 603     optind = 1;
 604     optreset = 1;
 605 #else
 606     optind = 0;
 607 #endif
 608 }
 609
 610 #endif