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 #define __ASSUME_UTIMES 1
  80
  81 /* pselect/ppoll were introduced just after 2.6.16-rc1.  On x86_64 and
  82    SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1.  */
  83 #define __ASSUME_PSELECT        1
  84 #define __ASSUME_PPOLL          1
  85
  86 /* The *at syscalls were introduced just after 2.6.16-rc1.  On PPC
  87    they were introduced in 2.6.17-rc1, on SH in 2.6.19-rc1.  */
  88 #define __ASSUME_ATFCTS 1
  89
  90 /* Support for inter-process robust mutexes was added in 2.6.17 (but
  91    some architectures lack futex_atomic_cmpxchg_inatomic in some
  92    configurations).  */
  93 #if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)
  94 # define __ASSUME_SET_ROBUST_LIST       1
  95 #endif
  96
  97 /* Pessimistically assume that 2.6.18 introduced real handling of
  98    large numbers of requests to readv and writev and that we don't
  99    need a fallback.  It likely worked for much longer.  */
 100 #define __ASSUME_COMPLETE_READV_WRITEV  1
 101
 102 /* Support for PI futexes was added in 2.6.18 (but some architectures
 103    lack futex_atomic_cmpxchg_inatomic in some configurations).  */
 104 #if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)
 105 # define __ASSUME_FUTEX_LOCK_PI 1
 106 #endif
 107
 108 /* Support for utimensat syscall was added in 2.6.22, on SH
 109    only after 2.6.22-rc1.  */
 110 #define __ASSUME_UTIMENSAT      1
 111
 112 /* Support for private futexes was added in 2.6.22.  */
 113 #define __ASSUME_PRIVATE_FUTEX  1
 114
 115 /* Support for fallocate was added in 2.6.23, on s390
 116    only after 2.6.23-rc1.  */
 117 #define __ASSUME_FALLOCATE      1
 118
 119 /* Support for various CLOEXEC and NONBLOCK flags was added in
 120    2.6.23.  */
 121 #define __ASSUME_O_CLOEXEC      1
 122
 123 /* Support for ADJ_OFFSET_SS_READ was added in 2.6.24.  */
 124 #define __ASSUME_ADJ_OFFSET_SS_READ     1
 125
 126 /* Support for various CLOEXEC and NONBLOCK flags was added in
 127    2.6.27.  */
 128 #define __ASSUME_SOCK_CLOEXEC   1
 129 #define __ASSUME_IN_NONBLOCK    1
 130 #define __ASSUME_PIPE2          1
 131 #define __ASSUME_EVENTFD2       1
 132 #define __ASSUME_SIGNALFD4      1
 133 #define __ASSUME_DUP3           1
 134
 135 /* Support for accept4 functionality was added in 2.6.28, but for some
 136    architectures using a separate syscall rather than socketcall that
 137    syscall was only added later, and some architectures first had
 138    socketcall support then a separate syscall.  Define
 139    __ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
 140    architecture and accept4 is available through socketcall,
 141    __ASSUME_ACCEPT4_SYSCALL if it is available through a separate
 142    syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
 143    available through a separate syscall at the same time as through
 144    socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
 145    to work.  */
 146 #ifdef __ASSUME_SOCKETCALL
 147 # define __ASSUME_ACCEPT4_SOCKETCALL    1
 148 #endif
 149
 150 /* The accept4 syscall was added for x86_64 and SPARC in 2.6.28, and
 151    for PowerPC and SH in 2.6.37.  */
 152 #if (defined __x86_64__ || defined __sparc__)           \
 153     || (__LINUX_KERNEL_VERSION >= 0x020625              \
 154         && (defined __powerpc__ || defined __sh__))
 155 # define __ASSUME_ACCEPT4_SYSCALL       1
 156 #endif
 157 #ifdef __sparc__
 158 # define __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL       1
 159 #endif
 160
 161 #if defined __ASSUME_ACCEPT4_SOCKETCALL || defined __ASSUME_ACCEPT4_SYSCALL
 162 # define __ASSUME_ACCEPT4       1
 163 #endif
 164
 165 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 166 #define __ASSUME_FUTEX_CLOCK_REALTIME   1
 167
 168 /* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29.  */
 169 #define __ASSUME_AT_RANDOM      1
 170
 171 /* Support for preadv and pwritev was added in 2.6.30.  */
 172 #define __ASSUME_PREADV 1
 173 #define __ASSUME_PWRITEV        1
 174
 175 /* Support for FUTEX_*_REQUEUE_PI was added in 2.6.31 (but some
 176    architectures lack futex_atomic_cmpxchg_inatomic in some
 177    configurations).  */
 178 #if !(defined __sparc__ && !defined __arch64__ && !defined __sparc_v9__)
 179 # define __ASSUME_REQUEUE_PI    1
 180 #endif
 181
 182 /* Support for F_GETOWN_EX was introduced in 2.6.32.  */
 183 #define __ASSUME_F_GETOWN_EX    1
 184
 185 /* Support for recvmmsg functionality was added in 2.6.33.  The macros
 186    defined correspond to those for accept4.  */
 187 #if __LINUX_KERNEL_VERSION >= 0x020621 && defined __ASSUME_SOCKETCALL
 188 # define __ASSUME_RECVMMSG_SOCKETCALL   1
 189 #endif
 190
 191 /* The recvmmsg syscall was added for i386, x86_64 and SPARC in
 192    2.6.33, and for PowerPC and SH in 2.6.37.  */
 193 #if (__LINUX_KERNEL_VERSION >= 0x020621                 \
 194      && (defined __i386__ || defined __x86_64__ || defined __sparc__))  \
 195     || (__LINUX_KERNEL_VERSION >= 0x020625              \
 196         && (defined __powerpc__ || defined __sh__))
 197 # define __ASSUME_RECVMMSG_SYSCALL      1
 198 #endif
 199 #if defined __i386__ || defined __sparc__
 200 # define __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL      1
 201 #endif
 202
 203 #if defined __ASSUME_RECVMMSG_SOCKETCALL || defined __ASSUME_RECVMMSG_SYSCALL
 204 # define __ASSUME_RECVMMSG      1
 205 #endif
 206
 207 /* Support for /proc/self/task/$tid/comm and /proc/$pid/task/$tid/comm was
 208    added in 2.6.33.  */
 209 #if __LINUX_KERNEL_VERSION >= 0x020621
 210 # define __ASSUME_PROC_PID_TASK_COMM    1
 211 #endif
 212
 213 /* statfs fills in f_flags since 2.6.36.  */
 214 #if __LINUX_KERNEL_VERSION >= 0x020624
 215 # define __ASSUME_STATFS_F_FLAGS        1
 216 #endif
 217
 218 /* prlimit64 is available in 2.6.36.  */
 219 #if __LINUX_KERNEL_VERSION >= 0x020624
 220 # define __ASSUME_PRLIMIT64     1
 221 #endif
 222
 223 /* Support for sendmmsg functionality was added in 3.0.  The macros
 224    defined correspond to those for accept4 and recvmmsg.  */
 225 #if __LINUX_KERNEL_VERSION >= 0x030000 && defined __ASSUME_SOCKETCALL
 226 # define __ASSUME_SENDMMSG_SOCKETCALL   1
 227 #endif
 228
 229 /* The sendmmsg syscall was added for i386, x86_64, PowerPC, SH and
 230    SPARC in 3.0.  */
 231 #if __LINUX_KERNEL_VERSION >= 0x030000                                  \
 232     && (defined __i386__ || defined __x86_64__ || defined __powerpc__   \
 233         || defined __sh__ || defined __sparc__)
 234 # define __ASSUME_SENDMMSG_SYSCALL      1
 235 #endif
 236 #if defined __i386__ || defined __powerpc__ || defined __sh__ \
 237     || defined __sparc__
 238 # define __ASSUME_SENDMMSG_SYSCALL_WITH_SOCKETCALL      1
 239 #endif
 240
 241 #if defined __ASSUME_SENDMMSG_SOCKETCALL || defined __ASSUME_SENDMMSG_SYSCALL
 242 # define __ASSUME_SENDMMSG      1
 243 #endif
 244
 245 /* getcpu is a syscall for x86-64 since 3.1.  */
 246 #if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
 247 # define __ASSUME_GETCPU_SYSCALL        1
 248 #endif
 249
 250 /* 2.6.29 removed the XFS restricted_chown sysctl, so it is pointless looking
 251    for it in newer kernels.  */
 252 #define __ASSUME_XFS_RESTRICTED_CHOWN 1