libc/sysdeps/linux/common/bits/kernel-features.h

   1 /* Set flags signalling availability of kernel features based on given
   2    kernel version number.
   3    Copyright (C) 1999-2003, 2004, 2005 Free Software Foundation, Inc.
   4    This file is part of the GNU C Library.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 /* This file must not contain any C code.  At least it must be protected
  21    to allow using the file also in assembler files.  */
  22
  23 #if defined __mips__
  24 # include <sgidefs.h>
  25 #endif
  26
  27 #include <linux/version.h>
  28 #define __LINUX_KERNEL_VERSION          LINUX_VERSION_CODE
  29
  30 /* We assume for __LINUX_KERNEL_VERSION the same encoding used in
  31    linux/version.h.  I.e., the major, minor, and subminor all get a
  32    byte with the major number being in the highest byte.  This means
  33    we can do numeric comparisons.
  34
  35    In the following we will define certain symbols depending on
  36    whether the describes kernel feature is available in the kernel
  37    version given by __LINUX_KERNEL_VERSION.  We are not always exactly
  38    recording the correct versions in which the features were
  39    introduced.  If somebody cares these values can afterwards be
  40    corrected.  Most of the numbers here are set corresponding to
  41    2.2.0.  */
  42
  43 /* `getcwd' system call.  */
  44 #if __LINUX_KERNEL_VERSION >= 131584
  45 # define __ASSUME_GETCWD_SYSCALL        1
  46 #endif
  47
  48 /* When was `poll' introduced?  */
  49 #if __LINUX_KERNEL_VERSION >= 131584
  50 # define __ASSUME_POLL_SYSCALL          1
  51 #endif
  52
  53 /* Real-time signal became usable in 2.1.70.  */
  54 #if __LINUX_KERNEL_VERSION >= 131398
  55 # define __ASSUME_REALTIME_SIGNALS      1
  56 #endif
  57
  58 /* When were the `pread'/`pwrite' syscalls introduced?  */
  59 #if __LINUX_KERNEL_VERSION >= 131584
  60 # define __ASSUME_PREAD_SYSCALL         1
  61 # define __ASSUME_PWRITE_SYSCALL        1
  62 #endif
  63
  64 /* When was `poll' introduced?  */
  65 #if __LINUX_KERNEL_VERSION >= 131584
  66 # define __ASSUME_POLL_SYSCALL          1
  67 #endif
  68
  69 /* The `lchown' syscall was introduced in 2.1.80.  */
  70 #if __LINUX_KERNEL_VERSION >= 131408
  71 # define __ASSUME_LCHOWN_SYSCALL        1
  72 #endif
  73
  74 /* When did the `setresuid' sysall became available?  */
  75 #if __LINUX_KERNEL_VERSION >= 131584 && !defined __sparc__
  76 # define __ASSUME_SETRESUID_SYSCALL     1
  77 #endif
  78
  79 /* The SIOCGIFNAME ioctl is available starting with 2.1.50.  */
  80 #if __LINUX_KERNEL_VERSION >= 131408
  81 # define __ASSUME_SIOCGIFNAME           1
  82 #endif
  83
  84 /* MSG_NOSIGNAL was at least available with Linux 2.2.0.  */
  85 #if __LINUX_KERNEL_VERSION >= 131584
  86 # define __ASSUME_MSG_NOSIGNAL          1
  87 #endif
  88
  89 /* On x86 another `getrlimit' syscall was added in 2.3.25.  */
  90 #if __LINUX_KERNEL_VERSION >= 131865 && defined __i386__
  91 # define __ASSUME_NEW_GETRLIMIT_SYSCALL 1
  92 #endif
  93
  94 /* On x86 the truncate64/ftruncate64 syscalls were introduced in 2.3.31.  */
  95 #if __LINUX_KERNEL_VERSION >= 131871 && defined __i386__
  96 # define __ASSUME_TRUNCATE64_SYSCALL    1
  97 #endif
  98
  99 /* On x86 the mmap2 syscall was introduced in 2.3.31.  */
 100 #if __LINUX_KERNEL_VERSION >= 131871 && defined __i386__
 101 # define __ASSUME_MMAP2_SYSCALL 1
 102 #endif
 103
 104 /* On x86 the stat64/lstat64/fstat64 syscalls were introduced in 2.3.34.  */
 105 #if __LINUX_KERNEL_VERSION >= 131874 && defined __i386__
 106 # define __ASSUME_STAT64_SYSCALL        1
 107 #endif
 108
 109 /* On sparc and ARM the truncate64/ftruncate64/mmap2/stat64/lstat64/fstat64
 110    syscalls were introduced in 2.3.35.  */
 111 #if __LINUX_KERNEL_VERSION >= 131875 && (defined __sparc__ || defined __arm__)
 112 # define __ASSUME_TRUNCATE64_SYSCALL    1
 113 # define __ASSUME_MMAP2_SYSCALL         1
 114 # define __ASSUME_STAT64_SYSCALL        1
 115 #endif
 116
 117 /* I know for sure that getrlimit are in 2.3.35 on powerpc.  */
 118 #if __LINUX_KERNEL_VERSION >= 131875 && defined __powerpc__
 119 # define __ASSUME_NEW_GETRLIMIT_SYSCALL 1
 120 #endif
 121
 122 /* I know for sure that these are in 2.3.35 on powerpc. But PowerPC64 does not
 123    support separate 64-bit syscalls, already 64-bit */
 124 #if __LINUX_KERNEL_VERSION >= 131875 && defined __powerpc__ \
 125     && !defined __powerpc64__
 126 # define __ASSUME_TRUNCATE64_SYSCALL    1
 127 # define __ASSUME_STAT64_SYSCALL        1
 128 #endif
 129
 130 /* Linux 2.3.39 introduced 32bit UID/GIDs.  Some platforms had 32
 131    bit type all along.  */
 132 #if __LINUX_KERNEL_VERSION >= 131879 || defined __powerpc__ || defined __mips__
 133 # define __ASSUME_32BITUIDS             1
 134 #endif
 135
 136 /* Linux 2.3.39 sparc added setresuid.  */
 137 #if __LINUX_KERNEL_VERSION >= 131879 && defined __sparc__
 138 # define __ASSUME_SETRESUID_SYSCALL     1
 139 #endif
 140
 141 #if __LINUX_KERNEL_VERSION >= 131879
 142 # define __ASSUME_SETRESGID_SYSCALL     1
 143 #endif
 144
 145 /* Linux 2.3.39 introduced IPC64.  Except for powerpc.  */
 146 #if __LINUX_KERNEL_VERSION >= 131879 && !defined __powerpc__
 147 # define __ASSUME_IPC64         1
 148 #endif
 149
 150 /* MIPS platforms had IPC64 all along.  */
 151 #if defined __mips__
 152 # define __ASSUME_IPC64         1
 153 #endif
 154
 155 /* We can use the LDTs for threading with Linux 2.3.99 and newer.  */
 156 #if __LINUX_KERNEL_VERSION >= 131939
 157 # define __ASSUME_LDT_WORKS             1
 158 #endif
 159
 160 /* Linux 2.4.0 on PPC introduced a correct IPC64. But PowerPC64 does not
 161    support a separate 64-bit sys call, already 64-bit */
 162 #if __LINUX_KERNEL_VERSION >= 132096 && defined __powerpc__ \
 163     && !defined __powerpc64__
 164 # define __ASSUME_IPC64                 1
 165 #endif
 166
 167 /* SH kernels got stat64, mmap2, and truncate64 during 2.4.0-test.  */
 168 #if __LINUX_KERNEL_VERSION >= 132096 && defined __sh__
 169 # define __ASSUME_TRUNCATE64_SYSCALL    1
 170 # define __ASSUME_MMAP2_SYSCALL         1
 171 # define __ASSUME_STAT64_SYSCALL        1
 172 #endif
 173
 174 /* The changed st_ino field appeared in 2.4.0-test6.  But we cannot
 175    distinguish this version from other 2.4.0 releases.  Therefore play
 176    save and assume it available is for 2.4.1 and up.  However, SH is lame,
 177    and still does not have a 64-bit inode field.  */
 178 #if __LINUX_KERNEL_VERSION >= 132097 && !defined __alpha__ && !defined __sh__
 179 # define __ASSUME_ST_INO_64_BIT         1
 180 #endif
 181
 182 /* To support locking of large files a new fcntl() syscall was introduced
 183    in 2.4.0-test7.  We test for 2.4.1 for the earliest version we know
 184    the syscall is available.  */
 185 #if __LINUX_KERNEL_VERSION >= 132097 && (defined __i386__ || defined __sparc__)
 186 # define __ASSUME_FCNTL64               1
 187 #endif
 188
 189 /* The AT_CLKTCK auxiliary vector entry was introduction in the 2.4.0
 190    series.  */
 191 #if __LINUX_KERNEL_VERSION >= 132097
 192 # define __ASSUME_AT_CLKTCK             1
 193 #endif
 194
 195 /* Arm got fcntl64 in 2.4.4, PowerPC and SH have it also in 2.4.4 (I
 196    don't know when it got introduced).  But PowerPC64 does not support
 197    separate FCNTL64 call, FCNTL is already 64-bit */
 198 #if __LINUX_KERNEL_VERSION >= 132100 \
 199     && (defined __arm__ || defined __powerpc__ || defined __sh__) \
 200     && !defined __powerpc64__
 201 # define __ASSUME_FCNTL64               1
 202 #endif
 203
 204 /* The getdents64 syscall was introduced in 2.4.0-test7.  We test for
 205    2.4.1 for the earliest version we know the syscall is available.  */
 206 #if __LINUX_KERNEL_VERSION >= 132097
 207 # define __ASSUME_GETDENTS64_SYSCALL    1
 208 #endif
 209
 210 /* When did O_DIRECTORY became available?  Early in 2.3 but when?
 211    Be safe, use 2.3.99.  */
 212 #if __LINUX_KERNEL_VERSION >= 131939
 213 # define __ASSUME_O_DIRECTORY           1
 214 #endif
 215
 216 /* Starting with one of the 2.4.0 pre-releases the Linux kernel passes
 217    up the page size information.  */
 218 #if __LINUX_KERNEL_VERSION >= 132097
 219 # define __ASSUME_AT_PAGESIZE           1
 220 #endif
 221
 222 /* Starting with at least 2.4.0 the kernel passes the uid/gid unconditionally
 223    up to the child.  */
 224 #if __LINUX_KERNEL_VERSION >= 132097
 225 # define __ASSUME_AT_XID                1
 226 #endif
 227
 228 /* Starting with 2.4.5 kernels PPC passes the AUXV in the standard way
 229    and the vfork syscall made it into the official kernel.  */
 230 #if __LINUX_KERNEL_VERSION >= (132096+5) && defined __powerpc__
 231 # define __ASSUME_STD_AUXV              1
 232 # define __ASSUME_VFORK_SYSCALL         1
 233 #endif
 234
 235 /* Starting with 2.4.5 kernels the mmap2 syscall made it into the official
 236    kernel.  But PowerPC64 does not support a separate MMAP2 call.  */
 237 #if __LINUX_KERNEL_VERSION >= (132096+5) && defined __powerpc__ \
 238     && !defined __powerpc64__
 239 # define __ASSUME_MMAP2_SYSCALL         1
 240 #endif
 241
 242 /* Starting with 2.4.21 PowerPC implements the new prctl syscall.
 243    This allows applications to get/set the Floating Point Exception Mode.  */
 244 #if __LINUX_KERNEL_VERSION >= (132096+21) && defined __powerpc__
 245 # define __ASSUME_NEW_PRCTL_SYSCALL             1
 246 #endif
 247
 248 /* Starting with 2.4.21 the PowerPC32 clone syscall works as expected.  */
 249 #if __LINUX_KERNEL_VERSION >= (132096+21) && defined __powerpc__ \
 250     && !defined __powerpc64__
 251 # define __ASSUME_FIXED_CLONE_SYSCALL           1
 252 #endif
 253
 254 /* Starting with 2.4.21 PowerPC64 implements the new rt_sigreturn syscall.
 255    The new rt_sigreturn takes an ucontext pointer allowing rt_sigreturn
 256    to be used in the set/swapcontext implementation.  */
 257 #if __LINUX_KERNEL_VERSION >= (132096+21) && defined __powerpc64__
 258 # define __ASSUME_NEW_RT_SIGRETURN_SYSCALL              1
 259 #endif
 260
 261 /* On x86, the set_thread_area syscall was introduced in 2.5.29, but its
 262    semantics was changed in 2.5.30, and again after 2.5.31.  */
 263 #if __LINUX_KERNEL_VERSION >= 132384 && defined __i386__
 264 # define __ASSUME_SET_THREAD_AREA_SYSCALL       1
 265 #endif
 266
 267 /* The vfork syscall on x86 and arm was definitely available in 2.4.  */
 268 #if __LINUX_KERNEL_VERSION >= 132097 && (defined __i386__ || defined __arm__)
 269 # define __ASSUME_VFORK_SYSCALL         1
 270 #endif
 271
 272 /* There are an infinite number of PA-RISC kernel versions numbered
 273    2.4.0.  But they've not really been released as such.  We require
 274    and expect the final version here.  */
 275 #ifdef __hppa__
 276 # define __ASSUME_32BITUIDS             1
 277 # define __ASSUME_TRUNCATE64_SYSCALL    1
 278 # define __ASSUME_MMAP2_SYSCALL         1
 279 # define __ASSUME_STAT64_SYSCALL        1
 280 # define __ASSUME_IPC64                 1
 281 # define __ASSUME_ST_INO_64_BIT         1
 282 # define __ASSUME_FCNTL64               1
 283 # define __ASSUME_GETDENTS64_SYSCALL    1
 284 #endif
 285
 286 /* Alpha switched to a 64-bit timeval sometime before 2.2.0.  */
 287 #if __LINUX_KERNEL_VERSION >= 131584 && defined __alpha__
 288 # define __ASSUME_TIMEVAL64             1
 289 #endif
 290
 291 #if defined __mips__ && _MIPS_SIM == _ABIN32
 292 # define __ASSUME_FCNTL64               1
 293 #endif
 294
 295 /* The late 2.5 kernels saw a lot of new CLONE_* flags.  Summarize
 296    their availability with one define.  The changes were made first
 297    for i386 and the have to be done separately for the other archs.
 298    For i386 we pick 2.5.50 as the first version with support.  */
 299 #if __LINUX_KERNEL_VERSION >= 132402 && defined __i386__
 300 # define __ASSUME_CLONE_THREAD_FLAGS    1
 301 #endif
 302
 303 /* Support for various CLOEXEC and NONBLOCK flags was added for x86,
 304    x86-64, PPC, IA-64, SPARC< and S390 in 2.6.23.  */
 305 #if __LINUX_KERNEL_VERSION >= 0x020617 \
 306     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 307         || defined __ia64__ || defined __sparc__ || defined __s390__)
 308 # define __ASSUME_O_CLOEXEC 1
 309 #endif
 310
 311 /* Support for various CLOEXEC and NONBLOCK flags was added for x86,
 312  *    x86-64, PPC, IA-64, and SPARC in 2.6.27.  */
 313 #if (__LINUX_KERNEL_VERSION >= 0x02061b \
 314      && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 315          || defined __ia64__ || defined __sparc__ || defined __s390__) \
 316         ) || (__LINUX_KERNEL_VERSION >= 0x020621 && defined __alpha__) \
 317         || defined __aarch64__ || defined __tile__
 318 /* # define __ASSUME_SOCK_CLOEXEC  1 */
 319 /* # define __ASSUME_IN_NONBLOCK   1 */
 320 # define __ASSUME_PIPE2         1
 321 /* # define __ASSUME_EVENTFD2      1 */
 322 /* # define __ASSUME_SIGNALFD4     1 */
 323 /* # define __ASSUME_DUP3               1 */
 324 #endif
 325
 326 /* These features were surely available with 2.4.12.  */
 327 #if __LINUX_KERNEL_VERSION >= 132108 && defined __mc68000__
 328 # define __ASSUME_MMAP2_SYSCALL         1
 329 # define __ASSUME_TRUNCATE64_SYSCALL    1
 330 # define __ASSUME_STAT64_SYSCALL        1
 331 # define __ASSUME_FCNTL64               1
 332 # define __ASSUME_VFORK_SYSCALL         1
 333 #endif
 334
 335 /* Beginning with 2.5.63 support for realtime and monotonic clocks and
 336    timers based on them is available.  */
 337 #if __LINUX_KERNEL_VERSION >= 132415
 338 # define __ASSUME_POSIX_TIMERS          1
 339 #endif
 340
 341 /* Beginning with 2.6.12 the clock and timer supports CPU clocks.  */
 342 #if __LINUX_KERNEL_VERSION >= 0x2060c
 343 # define __ASSUME_POSIX_CPU_TIMERS      1
 344 #endif
 345
 346 /* The late 2.5 kernels saw a lot of new CLONE_* flags.  Summarize
 347    their availability with one define.  The changes were made first
 348    for i386 and the have to be done separately for the other archs.
 349    For ia64, s390*, PPC, x86-64 we pick 2.5.64 as the first version
 350    with support.  */
 351 #if __LINUX_KERNEL_VERSION >= 132416 \
 352     && (defined __ia64__ || defined __s390__ || defined __powerpc__ \
 353         || defined __x86_64__ || defined __sh__)
 354 # define __ASSUME_CLONE_THREAD_FLAGS    1
 355 #endif
 356
 357 /* With kernel 2.4.17 we always have netlink support.  */
 358 #if __LINUX_KERNEL_VERSION >= (132096+17)
 359 # define __ASSUME_NETLINK_SUPPORT       1
 360 #endif
 361
 362 /* The requeue futex functionality was introduced in 2.5.70.  */
 363 #if __LINUX_KERNEL_VERSION >= 132422
 364 # define __ASSUME_FUTEX_REQUEUE 1
 365 #endif
 366
 367 /* The statfs64 syscalls are available in 2.5.74.  */
 368 #if __LINUX_KERNEL_VERSION >= 132426
 369 # define __ASSUME_STATFS64      1
 370 #endif
 371
 372 /* Starting with at least 2.5.74 the kernel passes the setuid-like exec
 373    flag unconditionally up to the child.  */
 374 #if __LINUX_KERNEL_VERSION >= 132426
 375 # define __ASSUME_AT_SECURE     1
 376 #endif
 377
 378 /* The utimes syscall has been available for some architectures
 379    forever.  For x86 it was introduced after 2.5.75, for x86-64,
 380    ppc, and ppc64 it was introduced in 2.6.0-test3.  */
 381 #if defined __alpha__ || defined __ia64__ || defined __hppa__ \
 382     || defined __sparc__ \
 383     || (__LINUX_KERNEL_VERSION > 132427 && defined __i386__) \
 384     || (__LINUX_KERNEL_VERSION > 132609 && defined __x86_64__) \
 385     || (__LINUX_KERNEL_VERSION >= 132609 && defined __powerpc__) \
 386     || (__LINUX_KERNEL_VERSION >= 132609 && defined __sh__)
 387 # define __ASSUME_UTIMES        1
 388 #endif
 389
 390 // XXX Disabled for now since the semantics we want is not achieved.
 391 #if 0
 392 /* The CLONE_STOPPED flag was introduced in the 2.6.0-test1 series.  */
 393 #if __LINUX_KERNEL_VERSION >= 132609
 394 # define __ASSUME_CLONE_STOPPED 1
 395 #endif
 396 #endif
 397
 398 /* The fixed version of the posix_fadvise64 syscall appeared in
 399    2.6.0-test3.  At least for x86.  Powerpc support appeared in
 400    2.6.2, but for 32-bit userspace only.  */
 401 #if (__LINUX_KERNEL_VERSION >= 132609 && defined __i386__) \
 402     || (__LINUX_KERNEL_VERSION >= 132610 && defined __powerpc__ \
 403        && !defined __powerpc64__)
 404 # define __ASSUME_FADVISE64_64_SYSCALL  1
 405 #endif
 406
 407 /* The PROT_GROWSDOWN/PROT_GROWSUP flags were introduced in the 2.6.0-test
 408    series.  */
 409 #if __LINUX_KERNEL_VERSION >= 132609
 410 # define __ASSUME_PROT_GROWSUPDOWN      1
 411 #endif
 412
 413 /* Starting with 2.6.0 PowerPC adds signal/swapcontext support for Vector
 414    SIMD (AKA Altivec, VMX) instructions and register state.  This changes
 415    the overall size of the sigcontext and adds the swapcontext syscall.  */
 416 #if __LINUX_KERNEL_VERSION >= 132608 && defined __powerpc__
 417 # define __ASSUME_SWAPCONTEXT_SYSCALL   1
 418 #endif
 419
 420 /* The CLONE_DETACHED flag is not necessary in 2.6.2 kernels, it is
 421    implied.  */
 422 #if __LINUX_KERNEL_VERSION >= 132610
 423 # define __ASSUME_NO_CLONE_DETACHED     1
 424 #endif
 425
 426 /* Starting with version 2.6.4-rc1 the getdents syscall returns d_type
 427    information as well and in between 2.6.5 and 2.6.8 most compat wrappers
 428    were fixed too.  Except s390{,x} which was fixed in 2.6.11.  */
 429 #if (__LINUX_KERNEL_VERSION >= 0x020608 && !defined __s390__) \
 430     || (__LINUX_KERNEL_VERSION >= 0x02060b && defined __s390__)
 431 # define __ASSUME_GETDENTS32_D_TYPE     1
 432 #endif
 433
 434 /* Starting with version 2.5.3, the initial location returned by `brk'
 435    after exec is always rounded up to the next page.  */
 436 #if __LINUX_KERNEL_VERSION >= 132355
 437 # define __ASSUME_BRK_PAGE_ROUNDED      1
 438 #endif
 439
 440 /* Starting with version 2.6.9, the waitid system call is available.
 441    Except for powerpc and powerpc64, where it is available in 2.6.12.  */
 442 #if (__LINUX_KERNEL_VERSION >= 0x020609 && !defined __powerpc__) \
 443     || (__LINUX_KERNEL_VERSION >= 0x02060c && defined __powerpc__)
 444 # define __ASSUME_WAITID_SYSCALL        1
 445 #endif
 446
 447 /* Starting with version 2.6.9, SSI_IEEE_RAISE_EXCEPTION exists.  */
 448 #if __LINUX_KERNEL_VERSION >= 0x020609 && defined __alpha__
 449 #define __ASSUME_IEEE_RAISE_EXCEPTION   1
 450 #endif
 451
 452 /* Support for the accept4 syscall was added in 2.6.28.  */
 453 #if __LINUX_KERNEL_VERSION >= 0x02061c \
 454     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 455         || defined __sparc__ || defined __s390__)
 456 # define __ASSUME_ACCEPT4       1
 457 #endif
 458
 459 /* Support for the accept4 syscall for alpha was added after 2.6.33-rc1.  */
 460 #if __LINUX_KERNEL_VERSION >= 0x020621 && defined __alpha__
 461 # define __ASSUME_ACCEPT4       1
 462 #endif
 463
 464 /* Support for the recvmmsg/sendmmsg syscall was added in 2.6.33  */
 465 #if __LINUX_KERNEL_VERSION >= 0x020621
 466 #define __ASSUME_RECVMMSG_SYSCALL       1
 467 #define __ASSUME_SENDMMSG_SYSCALL       1
 468 #endif
 469
 470 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 471 #if __LINUX_KERNEL_VERSION >= 0x02061d
 472 # define __ASSUME_FUTEX_CLOCK_REALTIME  1
 473 #endif
 474
 475 /* Support for PI futexes was added in 2.6.18.  */
 476 #if __LINUX_KERNEL_VERSION >= 0x020612
 477 # define __ASSUME_FUTEX_LOCK_PI 1
 478 #endif
 479
 480 /* Support for private futexes was added in 2.6.22.  */
 481 #if __LINUX_KERNEL_VERSION >= 0x020616
 482 # define __ASSUME_PRIVATE_FUTEX 1
 483 #endif
 484
 485 /* Support for fallocate was added in 2.6.23,
 486    on s390 only after 2.6.23-rc1, on alpha only after 2.6.33-rc1.  */
 487 #if __LINUX_KERNEL_VERSION >= 0x020617 \
 488     && (!defined __s390__ || __LINUX_KERNEL_VERSION >= 0x020618) \
 489     && (!defined __alpha__ || __LINUX_KERNEL_VERSION >= 0x020621)
 490 # define __ASSUME_FALLOCATE 1
 491 #endif
 492
 493 /* prlimit64 is available in 2.6.36.  */
 494 #if __LINUX_KERNEL_VERSION >= 0x020624
 495 # define __ASSUME_PRLIMIT64    1
 496 #endif
 497
 498 /* getcpu is a syscall for x86-64 since 3.1.  */
 499 #if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
 500 # define __ASSUME_GETCPU_SYSCALL        1
 501 #endif
 502
 503 /* getrandom syscall (widely) appeared around 4.0.0 */
 504 #if __LINUX_KERNEL_VERSION >= 0x040000
 505 # define __ASSUME_GETRANDOM_SYSCALL 1
 506 #endif