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) 1999-2016 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 instead of separate syscalls.
  45    __ASSUME_SOCKETCALL is defined for such architectures.  */
  46
  47 /* The changed st_ino field appeared in 2.4.0-test6.  However, SH is lame,
  48    and still does not have a 64-bit inode field.  */
  49 #define __ASSUME_ST_INO_64_BIT          1
  50
  51 /* The statfs64 syscalls are available in 2.5.74 (but not for alpha).  */
  52 #define __ASSUME_STATFS64       1
  53
  54 /* pselect/ppoll were introduced just after 2.6.16-rc1.  On x86_64 and
  55    SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1.  */
  56 #define __ASSUME_PSELECT        1
  57
  58 /* The *at syscalls were introduced just after 2.6.16-rc1.  On PPC
  59    they were introduced in 2.6.17-rc1, on SH in 2.6.19-rc1.  */
  60 #define __ASSUME_ATFCTS 1
  61
  62 /* Support for inter-process robust mutexes was added in 2.6.17 (but
  63    some architectures lack futex_atomic_cmpxchg_inatomic in some
  64    configurations).  */
  65 #define __ASSUME_SET_ROBUST_LIST        1
  66
  67 /* Support for PI futexes was added in 2.6.18 (but some architectures
  68    lack futex_atomic_cmpxchg_inatomic in some configurations).  */
  69 #define __ASSUME_FUTEX_LOCK_PI  1
  70
  71 /* Support for private futexes was added in 2.6.22.  */
  72 #define __ASSUME_PRIVATE_FUTEX  1
  73
  74 /* Support for various CLOEXEC and NONBLOCK flags was added in
  75    2.6.23.  */
  76 #define __ASSUME_O_CLOEXEC      1
  77
  78 /* Support for various CLOEXEC and NONBLOCK flags was added in
  79    2.6.27.  */
  80 #define __ASSUME_IN_NONBLOCK    1
  81 #define __ASSUME_PIPE2          1
  82 #define __ASSUME_DUP3           1
  83
  84 /* Support for accept4 functionality was added in 2.6.28, but for some
  85    architectures using a separate syscall rather than socketcall that
  86    syscall was only added later, and some architectures first had
  87    socketcall support then a separate syscall.  Define
  88    __ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
  89    architecture and accept4 is available through socketcall,
  90    __ASSUME_ACCEPT4_SYSCALL if it is available through a separate
  91    syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
  92    available through a separate syscall at the same time as through
  93    socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
  94    to work.  */
  95 #ifdef __ASSUME_SOCKETCALL
  96 # define __ASSUME_ACCEPT4_SOCKETCALL    1
  97 #endif
  98 #define __ASSUME_ACCEPT4_SYSCALL        1
  99 #define __ASSUME_ACCEPT4        1
 100
 101 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 102 #define __ASSUME_FUTEX_CLOCK_REALTIME   1
 103
 104 /* Support for preadv and pwritev was added in 2.6.30.  */
 105 #define __ASSUME_PREADV 1
 106 #define __ASSUME_PWRITEV        1
 107
 108 /* Support for FUTEX_*_REQUEUE_PI was added in 2.6.31 (but some
 109    architectures lack futex_atomic_cmpxchg_inatomic in some
 110    configurations).  */
 111 #define __ASSUME_REQUEUE_PI     1
 112
 113 /* Support for recvmmsg functionality was added in 2.6.33.  The macros
 114    defined correspond to those for accept4.  */
 115 #if __LINUX_KERNEL_VERSION >= 0x020621
 116 # ifdef __ASSUME_SOCKETCALL
 117 #  define __ASSUME_RECVMMSG_SOCKETCALL  1
 118 # endif
 119 # define __ASSUME_RECVMMSG_SYSCALL      1
 120 # define __ASSUME_RECVMMSG      1
 121 #endif
 122
 123 /* Support for /proc/self/task/$tid/comm and /proc/$pid/task/$tid/comm was
 124    added in 2.6.33.  */
 125 #if __LINUX_KERNEL_VERSION >= 0x020621
 126 # define __ASSUME_PROC_PID_TASK_COMM    1
 127 #endif
 128
 129 /* statfs fills in f_flags since 2.6.36.  */
 130 #if __LINUX_KERNEL_VERSION >= 0x020624
 131 # define __ASSUME_STATFS_F_FLAGS        1
 132 #endif
 133
 134 /* prlimit64 is available in 2.6.36.  */
 135 #if __LINUX_KERNEL_VERSION >= 0x020624
 136 # define __ASSUME_PRLIMIT64     1
 137 #endif
 138
 139 /* Support for sendmmsg functionality was added in 3.0.  The macros
 140    defined correspond to those for accept4 and recvmmsg.  */
 141 #if __LINUX_KERNEL_VERSION >= 0x030000
 142 # ifdef __ASSUME_SOCKETCALL
 143 #  define __ASSUME_SENDMMSG_SOCKETCALL  1
 144 # endif
 145 # define __ASSUME_SENDMMSG_SYSCALL      1
 146 # define __ASSUME_SENDMMSG      1
 147 #endif
 148
 149 /* On most architectures, most socket syscalls are supported for all
 150    supported kernel versions, but on some socketcall architectures
 151    separate syscalls were only added later.  */
 152 #define __ASSUME_SENDMSG_SYSCALL        1
 153 #define __ASSUME_RECVMSG_SYSCALL        1