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 /* Linux 2.3.39 introduced IPC64.  Except for powerpc.  Linux 2.4.0 on
  44    PPC introduced a correct IPC64.  But PowerPC64 does not support a
  45    separate 64-bit syscall, already 64-bit.  */
  46 #ifndef __powerpc64__
  47 # define __ASSUME_IPC64         1
  48 #endif
  49
  50 /* The changed st_ino field appeared in 2.4.0-test6.  However, SH is lame,
  51    and still does not have a 64-bit inode field.  */
  52 #ifndef __sh__
  53 # define __ASSUME_ST_INO_64_BIT         1
  54 #endif
  55
  56 /* The getdents64 syscall was introduced in 2.4.0-test7 (but later for
  57    MIPS n32).  */
  58 #define __ASSUME_GETDENTS64_SYSCALL     1
  59
  60 /* The statfs64 syscalls are available in 2.5.74 (but not for alpha).  */
  61 #define __ASSUME_STATFS64       1
  62
  63 /* The utimes syscall has been available for some architectures
  64    forever.  For x86 it was introduced after 2.5.75, for x86-64,
  65    ppc, and ppc64 it was introduced in 2.6.0-test3, for s390 it was
  66    introduced in 2.6.21-rc5.  */
  67 #if defined __sparc__ \
  68     || defined __i386__ \
  69     || defined __x86_64__ \
  70     || defined __powerpc__ \
  71     || defined __sh__ \
  72     || (defined __s390__ && __LINUX_KERNEL_VERSION >= 0x020616)
  73 # define __ASSUME_UTIMES        1
  74 #endif
  75
  76 /* pselect/ppoll were introduced just after 2.6.16-rc1.  Due to the way
  77    the kernel versions are advertised we can only rely on 2.6.17 to have
  78    the code.  On x86_64 and SH this appeared first in 2.6.19-rc1,
  79    on ia64 in 2.6.22-rc1.  */
  80 #if __LINUX_KERNEL_VERSION >= 0x020611 \
  81     && ((!defined __x86_64__ && !defined __sh__) \
  82         || (__LINUX_KERNEL_VERSION >= 0x020613 \
  83             && (defined __x86_64__ || defined __sh__)))
  84 # define __ASSUME_PSELECT       1
  85 # define __ASSUME_PPOLL         1
  86 #endif
  87
  88 /* The *at syscalls were introduced just after 2.6.16-rc1.  Due to the way the
  89    kernel versions are advertised we can only rely on 2.6.17 to have
  90    the code.  On PPC they were introduced in 2.6.17-rc1,
  91    on SH in 2.6.19-rc1.  */
  92 #if __LINUX_KERNEL_VERSION >= 0x020611 \
  93     && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020613)
  94 # define __ASSUME_ATFCTS        1
  95 #endif
  96
  97 /* Support for inter-process robust mutexes was added in 2.6.17.  */
  98 #if __LINUX_KERNEL_VERSION >= 0x020611 \
  99     && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020613)
 100 # define __ASSUME_SET_ROBUST_LIST       1
 101 #endif
 102
 103 /* Pessimistically assume that 2.6.18 introduced real handling of
 104    large numbers of requests to readv and writev and that we don't
 105    need a fallback.  It likely worked for much longer.  */
 106 #if __LINUX_KERNEL_VERSION >= 0x020612
 107 # define __ASSUME_COMPLETE_READV_WRITEV 1
 108 #endif
 109
 110 /* Support for PI futexes was added in 2.6.18.  */
 111 #if __LINUX_KERNEL_VERSION >= 0x020612
 112 # define __ASSUME_FUTEX_LOCK_PI 1
 113 #endif
 114
 115 /* Support for utimensat syscall was added in 2.6.22, on SH
 116    only after 2.6.22-rc1.  */
 117 #if __LINUX_KERNEL_VERSION >= 0x020616 \
 118     && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020617)
 119 # define __ASSUME_UTIMENSAT     1
 120 #endif
 121
 122 /* Support for private futexes was added in 2.6.22.  */
 123 #if __LINUX_KERNEL_VERSION >= 0x020616
 124 # define __ASSUME_PRIVATE_FUTEX 1
 125 #endif
 126
 127 /* Support for fallocate was added in 2.6.23, on s390
 128    only after 2.6.23-rc1.  */
 129 #if __LINUX_KERNEL_VERSION >= 0x020617 \
 130     && (!defined __s390__ || __LINUX_KERNEL_VERSION >= 0x020618)
 131 # define __ASSUME_FALLOCATE     1
 132 #endif
 133
 134 /* Support for various CLOEXEC and NONBLOCK flags was added for x86,
 135    x86-64, PPC, IA-64, SPARC< and S390 in 2.6.23.  */
 136 #if __LINUX_KERNEL_VERSION >= 0x020617 \
 137     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 138         || defined __sparc__ || defined __s390__)
 139 # define __ASSUME_O_CLOEXEC     1
 140 #endif
 141
 142 /* From 2.6.23 onwards the value of ARG_MAX depends on the stack
 143    size.  */
 144 #define __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL  0x020617
 145 #if __LINUX_KERNEL_VERSION >= __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL
 146 # define __ASSUME_ARG_MAX_STACK_BASED   1
 147 #endif
 148
 149 /* Support for ADJ_OFFSET_SS_READ was added in 2.6.24.  */
 150 #if __LINUX_KERNEL_VERSION >= 0x020618
 151 # define __ASSUME_ADJ_OFFSET_SS_READ    1
 152 #endif
 153
 154 /* Support for various CLOEXEC and NONBLOCK flags was added for x86,
 155    x86-64, PPC, IA-64, and SPARC in 2.6.27.  */
 156 #if __LINUX_KERNEL_VERSION >= 0x02061b \
 157     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 158         || defined __sparc__ || defined __s390__)
 159 # define __ASSUME_SOCK_CLOEXEC  1
 160 # define __ASSUME_IN_NONBLOCK   1
 161 # define __ASSUME_PIPE2         1
 162 # define __ASSUME_EVENTFD2      1
 163 # define __ASSUME_SIGNALFD4     1
 164 # define __ASSUME_DUP3          1
 165 #endif
 166
 167 /* Support for the accept4 syscall was added in 2.6.28.  */
 168 #if __LINUX_KERNEL_VERSION >= 0x02061c \
 169     && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
 170         || defined __sparc__ || defined __s390__)
 171 # define __ASSUME_ACCEPT4       1
 172 #endif
 173
 174 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 175 #if __LINUX_KERNEL_VERSION >= 0x02061d
 176 # define __ASSUME_FUTEX_CLOCK_REALTIME  1
 177 #endif
 178
 179 /* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29.  */
 180 #if __LINUX_KERNEL_VERSION >= 0x02061d
 181 # define __ASSUME_AT_RANDOM     1
 182 #endif
 183
 184 /* Support for preadv and pwritev was added in 2.6.30.  */
 185 #if __LINUX_KERNEL_VERSION >= 0x02061e
 186 # define __ASSUME_PREADV        1
 187 # define __ASSUME_PWRITEV       1
 188 #endif
 189
 190 /* Support for FUTEX_*_REQUEUE_PI was added in 2.6.31.  */
 191 #if __LINUX_KERNEL_VERSION >= 0x02061f
 192 # define __ASSUME_REQUEUE_PI    1
 193 #endif
 194
 195 /* Support for F_GETOWN_EX was introduced in 2.6.32.  */
 196 #if __LINUX_KERNEL_VERSION >= 0x020620
 197 # define __ASSUME_F_GETOWN_EX   1
 198 #endif
 199
 200 /* Support for the recvmmsg syscall was added in 2.6.33.  */
 201 #if __LINUX_KERNEL_VERSION >= 0x020621
 202 # define __ASSUME_RECVMMSG      1
 203 #endif
 204
 205 /* statfs fills in f_flags since 2.6.36.  */
 206 #if __LINUX_KERNEL_VERSION >= 0x020624
 207 # define __ASSUME_STATFS_F_FLAGS        1
 208 #endif
 209
 210 /* prlimit64 is available in 2.6.36.  */
 211 #if __LINUX_KERNEL_VERSION >= 0x020624
 212 # define __ASSUME_PRLIMIT64     1
 213 #endif
 214
 215 /* sendmmsg is available in 2.6.39.  */
 216 #if __LINUX_KERNEL_VERSION >= 0x020627
 217 # define __ASSUME_SENDMMSG      1
 218 #endif
 219
 220 /* getcpu is a syscall for x86-64 since 3.1.  */
 221 #if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
 222 # define __ASSUME_GETCPU_SYSCALL        1
 223 #endif
 224
 225 /* 2.6.29 removed the XFS restricted_chown sysctl, so it is pointless looking
 226    for it in newer kernels.  */
 227 #if __LINUX_KERNEL_VERSION >= 0x02061d
 228 # define __ASSUME_XFS_RESTRICTED_CHOWN 1
 229 #endif