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