sysdeps/unix/sysv/linux/kernel-features.h

   1 /* Set flags signalling availability of kernel features based on given
   2    kernel version number.
   3    Copyright (C) 1999-2014 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 #ifndef __LINUX_KERNEL_VERSION
  24 /* We assume the worst; all kernels should be supported.  */
  25 # define __LINUX_KERNEL_VERSION 0
  26 #endif
  27
  28 /* We assume for __LINUX_KERNEL_VERSION the same encoding used in
  29    linux/version.h.  I.e., the major, minor, and subminor all get a
  30    byte with the major number being in the highest byte.  This means
  31    we can do numeric comparisons.
  32
  33    In the following we will define certain symbols depending on
  34    whether the describes kernel feature is available in the kernel
  35    version given by __LINUX_KERNEL_VERSION.  We are not always exactly
  36    recording the correct versions in which the features were
  37    introduced.  If somebody cares these values can afterwards be
  38    corrected.  */
  39
  40 /* The sendfile syscall was introduced in 2.2.0.  */
  41 #define __ASSUME_SENDFILE               1
  42
  43 /* Some architectures use the socketcall multiplexer for some or all
  44    socket-related operations, via a socket.S file in glibc, instead of
  45    separate syscalls.  __ASSUME_SOCKETCALL is defined for such
  46    architectures.  */
  47 #if defined __i386__ \
  48     || defined __powerpc__ \
  49     || defined __s390__ \
  50     || defined __sh__ \
  51     || defined __sparc__
  52 # define __ASSUME_SOCKETCALL            1
  53 #endif
  54
  55 /* Linux 2.3.39 introduced IPC64.  Except for powerpc.  Linux 2.4.0 on
  56    PPC introduced a correct IPC64.  But PowerPC64 does not support a
  57    separate 64-bit syscall, already 64-bit.  */
  58 #ifndef __powerpc64__
  59 # define __ASSUME_IPC64         1
  60 #endif
  61
  62 /* The changed st_ino field appeared in 2.4.0-test6.  However, SH is lame,
  63    and still does not have a 64-bit inode field.  */
  64 #ifndef __sh__
  65 # define __ASSUME_ST_INO_64_BIT         1
  66 #endif
  67
  68 /* The getdents64 syscall was introduced in 2.4.0-test7 (but later for
  69    MIPS n32).  */
  70 #define __ASSUME_GETDENTS64_SYSCALL     1
  71
  72 /* The statfs64 syscalls are available in 2.5.74 (but not for alpha).  */
  73 #define __ASSUME_STATFS64       1
  74
  75 /* The utimes syscall has been available for some architectures
  76    forever.  For x86 it was introduced after 2.5.75, for x86-64,
  77    ppc, and ppc64 it was introduced in 2.6.0-test3, for s390 it was
  78    introduced in 2.6.21-rc5.  */
  79 #if defined __sparc__ \
  80     || defined __i386__ \
  81     || defined __x86_64__ \
  82     || defined __powerpc__ \
  83     || defined __sh__ \
  84     || (defined __s390__ && __LINUX_KERNEL_VERSION >= 0x020616)
  85 # define __ASSUME_UTIMES        1
  86 #endif
  87
  88 /* pselect/ppoll were introduced just after 2.6.16-rc1.  Due to the way
  89    the kernel versions are advertised we can only rely on 2.6.17 to have
  90    the code.  On x86_64 and SH this appeared first in 2.6.19-rc1,
  91    on ia64 in 2.6.22-rc1.  */
  92 #if __LINUX_KERNEL_VERSION >= 0x020611 \
  93     && ((!defined __x86_64__ && !defined __sh__) \
  94         || (__LINUX_KERNEL_VERSION >= 0x020613 \
  95             && (defined __x86_64__ || defined __sh__)))
  96 # define __ASSUME_PSELECT       1
  97 # define __ASSUME_PPOLL         1
  98 #endif
  99
 100 /* The *at syscalls were introduced just after 2.6.16-rc1.  Due to the way the
 101    kernel versions are advertised we can only rely on 2.6.17 to have
 102    the code.  On PPC they were introduced in 2.6.17-rc1,
 103    on SH in 2.6.19-rc1.  */
 104 #if __LINUX_KERNEL_VERSION >= 0x020611 \
 105     && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020613)
 106 # define __ASSUME_ATFCTS        1
 107 #endif
 108
 109 /* Support for inter-process robust mutexes was added in 2.6.17.  */
 110 #if __LINUX_KERNEL_VERSION >= 0x020611 \
 111     && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020613)
 112 # define __ASSUME_SET_ROBUST_LIST       1
 113 #endif
 114
 115 /* Pessimistically assume that 2.6.18 introduced real handling of
 116    large numbers of requests to readv and writev and that we don't
 117    need a fallback.  It likely worked for much longer.  */
 118 #if __LINUX_KERNEL_VERSION >= 0x020612
 119 # define __ASSUME_COMPLETE_READV_WRITEV 1
 120 #endif
 121
 122 /* Support for PI futexes was added in 2.6.18.  */
 123 #if __LINUX_KERNEL_VERSION >= 0x020612
 124 # define __ASSUME_FUTEX_LOCK_PI 1
 125 #endif
 126
 127 /* Support for utimensat syscall was added in 2.6.22, on SH
 128    only after 2.6.22-rc1.  */
 129 #if __LINUX_KERNEL_VERSION >= 0x020616 \
 130     && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020617)
 131 # define __ASSUME_UTIMENSAT     1
 132 #endif
 133
 134 /* Support for private futexes was added in 2.6.22.  */
 135 #if __LINUX_KERNEL_VERSION >= 0x020616
 136 # define __ASSUME_PRIVATE_FUTEX 1
 137 #endif
 138
 139 /* Support for fallocate was added in 2.6.23, on s390
 140    only after 2.6.23-rc1.  */
 141 #if __LINUX_KERNEL_VERSION >= 0x020617 \
 142     && (!defined __s390__ || __LINUX_KERNEL_VERSION >= 0x020618)
 143 # define __ASSUME_FALLOCATE     1
 144 #endif
 145
 146 /* Support for various CLOEXEC and NONBLOCK flags was added for x86,
 147    x86-64, PPC, IA-64, SPARC< and S390 in 2.6.23.  */
 148 #if __LINUX_KERNEL_VERSION >= 0x020617 \
 149     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 150         || defined __sparc__ || defined __s390__)
 151 # define __ASSUME_O_CLOEXEC     1
 152 #endif
 153
 154 /* From 2.6.23 onwards the value of ARG_MAX depends on the stack
 155    size.  */
 156 #define __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL  0x020617
 157 #if __LINUX_KERNEL_VERSION >= __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL
 158 # define __ASSUME_ARG_MAX_STACK_BASED   1
 159 #endif
 160
 161 /* Support for ADJ_OFFSET_SS_READ was added in 2.6.24.  */
 162 #if __LINUX_KERNEL_VERSION >= 0x020618
 163 # define __ASSUME_ADJ_OFFSET_SS_READ    1
 164 #endif
 165
 166 /* Support for various CLOEXEC and NONBLOCK flags was added for x86,
 167    x86-64, PPC, IA-64, and SPARC in 2.6.27.  */
 168 #if __LINUX_KERNEL_VERSION >= 0x02061b \
 169     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 170         || defined __sparc__ || defined __s390__)
 171 # define __ASSUME_SOCK_CLOEXEC  1
 172 # define __ASSUME_IN_NONBLOCK   1
 173 # define __ASSUME_PIPE2         1
 174 # define __ASSUME_EVENTFD2      1
 175 # define __ASSUME_SIGNALFD4     1
 176 # define __ASSUME_DUP3          1
 177 #endif
 178
 179 /* Support for accept4 functionality was added in 2.6.28, but for some
 180    architectures using a separate syscall rather than socketcall that
 181    syscall was only added later, and some architectures first had
 182    socketcall support then a separate syscall.  Define
 183    __ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
 184    architecture and accept4 is available through socketcall,
 185    __ASSUME_ACCEPT4_SYSCALL if it is available through a separate
 186    syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
 187    available through a separate syscall at the same time as through
 188    socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
 189    to work.  */
 190 #if __LINUX_KERNEL_VERSION >= 0x02061c && defined __ASSUME_SOCKETCALL
 191 # define __ASSUME_ACCEPT4_SOCKETCALL    1
 192 #endif
 193
 194 /* The accept4 syscall was added for x86_64 and SPARC in 2.6.28, and
 195    for PowerPC and SH in 2.6.37.  */
 196 #if (__LINUX_KERNEL_VERSION >= 0x02061c                 \
 197      && (defined __x86_64__ || defined __sparc__))      \
 198     || (__LINUX_KERNEL_VERSION >= 0x020625              \
 199         && (defined __powerpc__ || defined __sh__))
 200 # define __ASSUME_ACCEPT4_SYSCALL       1
 201 #endif
 202 #ifdef __sparc__
 203 # define __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL       1
 204 #endif
 205
 206 #if defined __ASSUME_ACCEPT4_SOCKETCALL || defined __ASSUME_ACCEPT4_SYSCALL
 207 # define __ASSUME_ACCEPT4       1
 208 #endif
 209
 210 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 211 #if __LINUX_KERNEL_VERSION >= 0x02061d
 212 # define __ASSUME_FUTEX_CLOCK_REALTIME  1
 213 #endif
 214
 215 /* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29.  */
 216 #if __LINUX_KERNEL_VERSION >= 0x02061d
 217 # define __ASSUME_AT_RANDOM     1
 218 #endif
 219
 220 /* Support for preadv and pwritev was added in 2.6.30.  */
 221 #if __LINUX_KERNEL_VERSION >= 0x02061e
 222 # define __ASSUME_PREADV        1
 223 # define __ASSUME_PWRITEV       1
 224 #endif
 225
 226 /* Support for FUTEX_*_REQUEUE_PI was added in 2.6.31.  */
 227 #if __LINUX_KERNEL_VERSION >= 0x02061f
 228 # define __ASSUME_REQUEUE_PI    1
 229 #endif
 230
 231 /* Support for F_GETOWN_EX was introduced in 2.6.32.  */
 232 #if __LINUX_KERNEL_VERSION >= 0x020620
 233 # define __ASSUME_F_GETOWN_EX   1
 234 #endif
 235
 236 /* Support for recvmmsg functionality was added in 2.6.33.  The macros
 237    defined correspond to those for accept4.  */
 238 #if __LINUX_KERNEL_VERSION >= 0x020621 && defined __ASSUME_SOCKETCALL
 239 # define __ASSUME_RECVMMSG_SOCKETCALL   1
 240 #endif
 241
 242 /* The recvmmsg syscall was added for i386, x86_64 and SPARC in
 243    2.6.33, and for PowerPC and SH in 2.6.37.  */
 244 #if (__LINUX_KERNEL_VERSION >= 0x020621                 \
 245      && (defined __i386__ || defined __x86_64__ || defined __sparc__))  \
 246     || (__LINUX_KERNEL_VERSION >= 0x020625              \
 247         && (defined __powerpc__ || defined __sh__))
 248 # define __ASSUME_RECVMMSG_SYSCALL      1
 249 #endif
 250 #if defined __i386__ || defined __sparc__
 251 # define __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL      1
 252 #endif
 253
 254 #if defined __ASSUME_RECVMMSG_SOCKETCALL || defined __ASSUME_RECVMMSG_SYSCALL
 255 # define __ASSUME_RECVMMSG      1
 256 #endif
 257
 258 /* Support for /proc/self/task/$tid/comm and /proc/$pid/task/$tid/comm was
 259    added in 2.6.33.  */
 260 #if __LINUX_KERNEL_VERSION >= 0x020621
 261 # define __ASSUME_PROC_PID_TASK_COMM    1
 262 #endif
 263
 264 /* statfs fills in f_flags since 2.6.36.  */
 265 #if __LINUX_KERNEL_VERSION >= 0x020624
 266 # define __ASSUME_STATFS_F_FLAGS        1
 267 #endif
 268
 269 /* prlimit64 is available in 2.6.36.  */
 270 #if __LINUX_KERNEL_VERSION >= 0x020624
 271 # define __ASSUME_PRLIMIT64     1
 272 #endif
 273
 274 /* sendmmsg is available in 2.6.39.  */
 275 #if __LINUX_KERNEL_VERSION >= 0x020627
 276 # define __ASSUME_SENDMMSG      1
 277 #endif
 278
 279 /* getcpu is a syscall for x86-64 since 3.1.  */
 280 #if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
 281 # define __ASSUME_GETCPU_SYSCALL        1
 282 #endif
 283
 284 /* 2.6.29 removed the XFS restricted_chown sysctl, so it is pointless looking
 285    for it in newer kernels.  */
 286 #if __LINUX_KERNEL_VERSION >= 0x02061d
 287 # define __ASSUME_XFS_RESTRICTED_CHOWN 1
 288 #endif