2 * OS includes and handling of OS dependencies
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).
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.
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.
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
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.
30 #include "config-host.h"
32 #include CONFIG_TARGET
34 #include "exec/poison.h"
38 * HOST_WORDS_BIGENDIAN was replaced with HOST_BIG_ENDIAN. Prevent it from
41 #pragma GCC poison HOST_WORDS_BIGENDIAN
44 * TARGET_WORDS_BIGENDIAN was replaced with TARGET_BIG_ENDIAN. Prevent it from
47 #pragma GCC poison TARGET_WORDS_BIGENDIAN
49 #include "qemu/compiler.h"
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
55 #ifndef __STDC_CONSTANT_MACROS
56 #define __STDC_CONSTANT_MACROS
58 #ifndef __STDC_LIMIT_MACROS
59 #define __STDC_LIMIT_MACROS
61 #ifndef __STDC_FORMAT_MACROS
62 #define __STDC_FORMAT_MACROS
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
69 #define daemon qemu_fake_daemon_function
72 QEMU_EXTERN_C
int daemon(int, int);
76 /* as defined in sdkddkver.h */
78 #define _WIN32_WINNT 0x0601 /* Windows 7 API (should be in sync with glib) */
80 /* reduces the number of implicitly included headers */
81 #ifndef WIN32_LEAN_AND_MEAN
82 #define WIN32_LEAN_AND_MEAN
86 /* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */
88 #define __USE_MINGW_ANSI_STDIO 1
95 #include <sys/types.h>
101 #include <inttypes.h>
103 /* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
104 * function availability on recentish Mingw-w64 platforms. */
111 #include <sys/stat.h>
112 #include <sys/time.h>
114 /* setjmp must be declared before sysemu/os-win32.h
115 * because it is redefined there. */
123 #if defined(__linux__) && defined(__sparc__)
124 /* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */
129 #include <sys/wait.h>
131 #define WIFEXITED(x) 1
132 #define WEXITSTATUS(x) (x)
136 #include <AvailabilityMacros.h>
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.
144 #include "glib-compat.h"
147 #include "sysemu/os-win32.h"
151 #include "sysemu/os-posix.h"
158 #include "qemu/typedefs.h"
161 * For mingw, as of v6.0.0, the function implementing the assert macro is
162 * not marked as noreturn, so the compiler cannot delete code following an
163 * assert(false) as unused. We rely on this within the code base to delete
164 * code that is unreachable when features are disabled.
165 * All supported versions of Glib's g_assert() satisfy this requirement.
169 #define assert(x) g_assert(x)
173 * qemu_build_not_reached()
175 * The compiler, during optimization, is expected to prove that a call
176 * to this function cannot be reached and remove it. If the compiler
177 * supports QEMU_ERROR, this will be reported at compile time; otherwise
178 * this will be reported at link time due to the missing symbol.
181 void QEMU_ERROR("code path is reachable")
182 qemu_build_not_reached_always(void);
183 #if defined(__OPTIMIZE__) && !defined(__NO_INLINE__)
184 #define qemu_build_not_reached() qemu_build_not_reached_always()
186 #define qemu_build_not_reached() g_assert_not_reached()
190 * qemu_build_assert()
192 * The compiler, during optimization, is expected to prove that the
195 #define qemu_build_assert(test) while (!(test)) qemu_build_not_reached()
198 * According to waitpid man page:
200 * This macro is not specified in POSIX.1-2001 and is not
201 * available on some UNIX implementations (e.g., AIX, SunOS).
202 * Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
205 #define WCOREDUMP(status) 0
208 * We have a lot of unaudited code that may fail in strange ways, or
209 * even be a security risk during migration, if you disable assertions
210 * at compile-time. You may comment out these safety checks if you
211 * absolutely want to disable assertion overhead, but it is not
212 * supported upstream so the risk is all yours. Meanwhile, please
213 * submit patches to remove any side-effects inside an assertion, or
214 * fixing error handling that should use Error instead of assert.
217 #error building with NDEBUG is not supported
219 #ifdef G_DISABLE_ASSERT
220 #error building with G_DISABLE_ASSERT is not supported
224 #define O_LARGEFILE 0
229 #ifndef MAP_ANONYMOUS
230 #define MAP_ANONYMOUS MAP_ANON
232 #ifndef MAP_FIXED_NOREPLACE
233 #define MAP_FIXED_NOREPLACE 0
235 #ifndef MAP_NORESERVE
236 #define MAP_NORESERVE 0
239 #define ENOMEDIUM ENODEV
241 #if !defined(ENOTSUP)
244 #if !defined(ECANCELED)
245 #define ECANCELED 4097
247 #if !defined(EMEDIUMTYPE)
248 #define EMEDIUMTYPE 4098
250 #if !defined(ESHUTDOWN)
251 #define ESHUTDOWN 4099
254 #define TFR(expr) do { if ((expr) != -1) break; } while (errno == EINTR)
256 /* time_t may be either 32 or 64 bits depending on the host OS, and
257 * can be either signed or unsigned, so we can't just hardcode a
258 * specific maximum value. This is not a C preprocessor constant,
259 * so you can't use TIME_MAX in an #ifdef, but for our purposes
260 * this isn't a problem.
263 /* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
264 * Gnulib, and are under the LGPL v2.1 or (at your option) any
268 /* True if the real type T is signed. */
269 #define TYPE_SIGNED(t) (!((t)0 < (t)-1))
271 /* The width in bits of the integer type or expression T.
272 * Padding bits are not supported.
274 #define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
276 /* The maximum and minimum values for the integer type T. */
277 #define TYPE_MAXIMUM(t) \
278 ((t) (!TYPE_SIGNED(t) \
280 : ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
283 #define TIME_MAX TYPE_MAXIMUM(time_t)
286 /* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
287 * the wrong type. Our replacement isn't usable in preprocessor
288 * expressions, but it is sufficient for our needs. */
289 #ifdef HAVE_BROKEN_SIZE_MAX
291 #define SIZE_MAX ((size_t)-1)
295 * Two variations of MIN/MAX macros. The first is for runtime use, and
296 * evaluates arguments only once (so it is safe even with side
297 * effects), but will not work in constant contexts (such as array
298 * size declarations) because of the '{}'. The second is for constant
299 * expression use, where evaluating arguments twice is safe because
300 * the result is going to be constant anyway, but will not work in a
301 * runtime context because of a void expression where a value is
302 * expected. Thus, both gcc and clang will fail to compile if you use
303 * the wrong macro (even if the error may seem a bit cryptic).
305 * Note that neither form is usable as an #if condition; if you truly
306 * need to write conditional code that depends on a minimum or maximum
307 * determined by the pre-processor instead of the compiler, you'll
308 * have to open-code it. Sadly, Coverity is severely confused by the
309 * constant variants, so we have to dumb things down there.
314 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
320 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
325 # define MIN_CONST(a, b) ((a) < (b) ? (a) : (b))
326 # define MAX_CONST(a, b) ((a) > (b) ? (a) : (b))
328 # define MIN_CONST(a, b) \
329 __builtin_choose_expr( \
330 __builtin_constant_p(a) && __builtin_constant_p(b), \
331 (a) < (b) ? (a) : (b), \
333 # define MAX_CONST(a, b) \
334 __builtin_choose_expr( \
335 __builtin_constant_p(a) && __builtin_constant_p(b), \
336 (a) > (b) ? (a) : (b), \
341 * Minimum function that returns zero only if both values are zero.
342 * Intended for use with unsigned values only.
345 #define MIN_NON_ZERO(a, b) \
347 typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
348 _a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \
353 * Round number down to multiple. Safe when m is not a power of 2 (see
354 * ROUND_DOWN for a faster version when a power of 2 is guaranteed).
356 #define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
359 * Round number up to multiple. Safe when m is not a power of 2 (see
360 * ROUND_UP for a faster version when a power of 2 is guaranteed).
362 #define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
364 /* Check if n is a multiple of m */
365 #define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
367 /* n-byte align pointer down */
368 #define QEMU_ALIGN_PTR_DOWN(p, n) \
369 ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
371 /* n-byte align pointer up */
372 #define QEMU_ALIGN_PTR_UP(p, n) \
373 ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
375 /* Check if pointer p is n-bytes aligned */
376 #define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
379 * Round number down to multiple. Requires that d be a power of 2 (see
380 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
381 * numbers); works even if d is a smaller type than n.
384 #define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d)))
388 * Round number up to multiple. Requires that d be a power of 2 (see
389 * QEMU_ALIGN_UP for a safer but slower version on arbitrary
390 * numbers); works even if d is a smaller type than n.
393 #define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
397 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
401 * &(x)[0] is always a pointer - if it's same type as x then the argument is a
402 * pointer, not an array.
404 #define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
407 #define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
408 QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
411 int qemu_daemon(int nochdir
, int noclose
);
412 void *qemu_anon_ram_alloc(size_t size
, uint64_t *align
, bool shared
,
414 void qemu_anon_ram_free(void *ptr
, size_t size
);
417 #define HAVE_CHARDEV_SERIAL 1
418 #elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
419 || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
420 || defined(__GLIBC__) || defined(__APPLE__)
421 #define HAVE_CHARDEV_SERIAL 1
424 #if defined(__linux__) || defined(__FreeBSD__) || \
425 defined(__FreeBSD_kernel__) || defined(__DragonFly__)
426 #define HAVE_CHARDEV_PARPORT 1
429 #if defined(__HAIKU__)
430 #define SIGIO SIGPOLL
433 #ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE
435 * See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion
436 * about Solaris missing the madvise() prototype.
438 extern int madvise(char *, size_t, int);
441 #if defined(CONFIG_LINUX)
442 #ifndef BUS_MCEERR_AR
443 #define BUS_MCEERR_AR 4
445 #ifndef BUS_MCEERR_AO
446 #define BUS_MCEERR_AO 5
450 #if defined(__linux__) && \
451 (defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
452 || defined(__powerpc64__))
453 /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
454 Valgrind does not support alignments larger than 1 MiB,
455 therefore we need special code which handles running on Valgrind. */
456 # define QEMU_VMALLOC_ALIGN (512 * 4096)
457 #elif defined(__linux__) && defined(__s390x__)
458 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
459 # define QEMU_VMALLOC_ALIGN (256 * 4096)
460 #elif defined(__linux__) && defined(__sparc__)
461 # define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA)
463 # define QEMU_VMALLOC_ALIGN qemu_real_host_page_size()
467 struct qemu_signalfd_siginfo
{
468 uint32_t ssi_signo
; /* Signal number */
469 int32_t ssi_errno
; /* Error number (unused) */
470 int32_t ssi_code
; /* Signal code */
471 uint32_t ssi_pid
; /* PID of sender */
472 uint32_t ssi_uid
; /* Real UID of sender */
473 int32_t ssi_fd
; /* File descriptor (SIGIO) */
474 uint32_t ssi_tid
; /* Kernel timer ID (POSIX timers) */
475 uint32_t ssi_band
; /* Band event (SIGIO) */
476 uint32_t ssi_overrun
; /* POSIX timer overrun count */
477 uint32_t ssi_trapno
; /* Trap number that caused signal */
478 int32_t ssi_status
; /* Exit status or signal (SIGCHLD) */
479 int32_t ssi_int
; /* Integer sent by sigqueue(2) */
480 uint64_t ssi_ptr
; /* Pointer sent by sigqueue(2) */
481 uint64_t ssi_utime
; /* User CPU time consumed (SIGCHLD) */
482 uint64_t ssi_stime
; /* System CPU time consumed (SIGCHLD) */
483 uint64_t ssi_addr
; /* Address that generated signal
484 (for hardware-generated signals) */
485 uint8_t pad
[48]; /* Pad size to 128 bytes (allow for
486 additional fields in the future) */
489 int qemu_signalfd(const sigset_t
*mask
);
490 void sigaction_invoke(struct sigaction
*action
,
491 struct qemu_signalfd_siginfo
*info
);
495 * Don't introduce new usage of this function, prefer the following
496 * qemu_open/qemu_create that take an "Error **errp"
498 int qemu_open_old(const char *name
, int flags
, ...);
499 int qemu_open(const char *name
, int flags
, Error
**errp
);
500 int qemu_create(const char *name
, int flags
, mode_t mode
, Error
**errp
);
501 int qemu_close(int fd
);
502 int qemu_unlink(const char *name
);
504 int qemu_dup_flags(int fd
, int flags
);
505 int qemu_dup(int fd
);
506 int qemu_lock_fd(int fd
, int64_t start
, int64_t len
, bool exclusive
);
507 int qemu_unlock_fd(int fd
, int64_t start
, int64_t len
);
508 int qemu_lock_fd_test(int fd
, int64_t start
, int64_t len
, bool exclusive
);
509 bool qemu_has_ofd_lock(void);
512 #if defined(__HAIKU__) && defined(__i386__)
513 #define FMT_pid "%ld"
515 #define FMT_pid "%" PRId64
520 bool qemu_write_pidfile(const char *pidfile
, Error
**errp
);
522 int qemu_get_thread_id(void);
530 * Use the same value as Linux for now.
534 ssize_t
readv(int fd
, const struct iovec
*iov
, int iov_cnt
);
535 ssize_t
writev(int fd
, const struct iovec
*iov
, int iov_cnt
);
539 static inline void qemu_timersub(const struct timeval
*val1
,
540 const struct timeval
*val2
,
543 res
->tv_sec
= val1
->tv_sec
- val2
->tv_sec
;
544 if (val1
->tv_usec
< val2
->tv_usec
) {
546 res
->tv_usec
= val1
->tv_usec
- val2
->tv_usec
+ 1000 * 1000;
548 res
->tv_usec
= val1
->tv_usec
- val2
->tv_usec
;
552 #define qemu_timersub timersub
555 ssize_t
qemu_write_full(int fd
, const void *buf
, size_t count
)
556 G_GNUC_WARN_UNUSED_RESULT
;
558 void qemu_set_cloexec(int fd
);
560 /* Return a dynamically allocated directory path that is appropriate for storing
563 * The caller is responsible for releasing the value returned with g_free()
566 char *qemu_get_local_state_dir(void);
570 * @type: the auxiliary vector key to lookup
572 * Search the auxiliary vector for @type, returning the value
573 * or 0 if @type is not present.
575 unsigned long qemu_getauxval(unsigned long type
);
577 void qemu_set_tty_echo(int fd
, bool echo
);
579 void os_mem_prealloc(int fd
, char *area
, size_t sz
, int smp_cpus
,
584 * @pid: pid of a process
586 * For given @pid fetch its name. Caller is responsible for
587 * freeing the string when no longer needed.
588 * Returns allocated string on success, NULL on failure.
590 char *qemu_get_pid_name(pid_t pid
);
595 * A version of fork that avoids signal handler race
596 * conditions that can lead to child process getting
597 * signals that are otherwise only expected by the
598 * parent. It also resets all signal handlers to the
601 * Returns 0 to child process, pid number to parent
604 pid_t
qemu_fork(Error
**errp
);
606 /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
607 * when intptr_t is 32-bit and we are aligning a long long.
609 static inline uintptr_t qemu_real_host_page_size(void)
611 return getpagesize();
614 static inline intptr_t qemu_real_host_page_mask(void)
616 return -(intptr_t)qemu_real_host_page_size();
620 * After using getopt or getopt_long, if you need to parse another set
621 * of options, then you must reset optind. Unfortunately the way to
622 * do this varies between implementations of getopt.
624 static inline void qemu_reset_optind(void)
634 int qemu_fdatasync(int fd
);
637 * Sync changes made to the memory mapped file back to the backing
638 * storage. For POSIX compliant systems this will fallback
639 * to regular msync call. Otherwise it will trigger whole file sync
640 * (including the metadata case there is no support to skip that otherwise)
642 * @addr - start of the memory area to be synced
643 * @length - length of the are to be synced
644 * @fd - file descriptor for the file to be synced
645 * (mandatory only for POSIX non-compliant systems)
647 int qemu_msync(void *addr
, size_t length
, int fd
);
650 * qemu_get_host_physmem:
652 * Operating system agnostic way of querying host memory.
654 * Returns amount of physical memory on the system. This is purely
655 * advisery and may return 0 if we can't work it out. At the other
656 * end we saturate to SIZE_MAX if you are lucky enough to have that
659 size_t qemu_get_host_physmem(void);
662 * Toggle write/execute on the pages marked MAP_JIT
663 * for the current thread.
665 #if defined(MAC_OS_VERSION_11_0) && \
666 MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0
667 static inline void qemu_thread_jit_execute(void)
669 pthread_jit_write_protect_np(true);
672 static inline void qemu_thread_jit_write(void)
674 pthread_jit_write_protect_np(false);
677 static inline void qemu_thread_jit_write(void) {}
678 static inline void qemu_thread_jit_execute(void) {}
682 * Platforms which do not support system() return ENOSYS
684 #ifndef HAVE_SYSTEM_FUNCTION
685 #define system platform_does_not_support_system
686 static inline int platform_does_not_support_system(const char *command
)
691 #endif /* !HAVE_SYSTEM_FUNCTION */