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) 1999-2015 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 /* Linux 2.3.39 introduced IPC64.  Except for powerpc.  Linux 2.4.0 on
  48    PPC introduced a correct IPC64.  But PowerPC64 does not support a
  49    separate 64-bit syscall, already 64-bit.  */
  50 #define __ASSUME_IPC64          1
  51
  52 /* The changed st_ino field appeared in 2.4.0-test6.  However, SH is lame,
  53    and still does not have a 64-bit inode field.  */
  54 #define __ASSUME_ST_INO_64_BIT          1
  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 /* pselect/ppoll were introduced just after 2.6.16-rc1.  On x86_64 and
  64    SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1.  */
  65 #define __ASSUME_PSELECT        1
  66 #define __ASSUME_PPOLL          1
  67
  68 /* The *at syscalls were introduced just after 2.6.16-rc1.  On PPC
  69    they were introduced in 2.6.17-rc1, on SH in 2.6.19-rc1.  */
  70 #define __ASSUME_ATFCTS 1
  71
  72 /* Support for inter-process robust mutexes was added in 2.6.17 (but
  73    some architectures lack futex_atomic_cmpxchg_inatomic in some
  74    configurations).  */
  75 #define __ASSUME_SET_ROBUST_LIST        1
  76
  77 /* Support for PI futexes was added in 2.6.18 (but some architectures
  78    lack futex_atomic_cmpxchg_inatomic in some configurations).  */
  79 #define __ASSUME_FUTEX_LOCK_PI  1
  80
  81 /* Support for private futexes was added in 2.6.22.  */
  82 #define __ASSUME_PRIVATE_FUTEX  1
  83
  84 /* Support for fallocate was added in 2.6.23, on s390
  85    only after 2.6.23-rc1.  */
  86 #define __ASSUME_FALLOCATE      1
  87
  88 /* Support for various CLOEXEC and NONBLOCK flags was added in
  89    2.6.23.  */
  90 #define __ASSUME_O_CLOEXEC      1
  91
  92 /* Support for various CLOEXEC and NONBLOCK flags was added in
  93    2.6.27.  */
  94 #define __ASSUME_SOCK_CLOEXEC   1
  95 #define __ASSUME_IN_NONBLOCK    1
  96 #define __ASSUME_PIPE2          1
  97 #define __ASSUME_EVENTFD2       1
  98 #define __ASSUME_SIGNALFD4      1
  99 #define __ASSUME_DUP3           1
 100
 101 /* Support for accept4 functionality was added in 2.6.28, but for some
 102    architectures using a separate syscall rather than socketcall that
 103    syscall was only added later, and some architectures first had
 104    socketcall support then a separate syscall.  Define
 105    __ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
 106    architecture and accept4 is available through socketcall,
 107    __ASSUME_ACCEPT4_SYSCALL if it is available through a separate
 108    syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
 109    available through a separate syscall at the same time as through
 110    socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
 111    to work.  */
 112 #ifdef __ASSUME_SOCKETCALL
 113 # define __ASSUME_ACCEPT4_SOCKETCALL    1
 114 #endif
 115
 116 #if defined __ASSUME_ACCEPT4_SOCKETCALL || defined __ASSUME_ACCEPT4_SYSCALL
 117 # define __ASSUME_ACCEPT4       1
 118 #endif
 119
 120 /* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
 121 #define __ASSUME_FUTEX_CLOCK_REALTIME   1
 122
 123 /* Support for preadv and pwritev was added in 2.6.30.  */
 124 #define __ASSUME_PREADV 1
 125 #define __ASSUME_PWRITEV        1
 126
 127 /* Support for FUTEX_*_REQUEUE_PI was added in 2.6.31 (but some
 128    architectures lack futex_atomic_cmpxchg_inatomic in some
 129    configurations).  */
 130 #define __ASSUME_REQUEUE_PI     1
 131
 132 /* Support for recvmmsg functionality was added in 2.6.33.  The macros
 133    defined correspond to those for accept4.  */
 134 #if __LINUX_KERNEL_VERSION >= 0x020621 && defined __ASSUME_SOCKETCALL
 135 # define __ASSUME_RECVMMSG_SOCKETCALL   1
 136 #endif
 137
 138 #if defined __ASSUME_RECVMMSG_SOCKETCALL || defined __ASSUME_RECVMMSG_SYSCALL
 139 # define __ASSUME_RECVMMSG      1
 140 #endif
 141
 142 /* Support for /proc/self/task/$tid/comm and /proc/$pid/task/$tid/comm was
 143    added in 2.6.33.  */
 144 #if __LINUX_KERNEL_VERSION >= 0x020621
 145 # define __ASSUME_PROC_PID_TASK_COMM    1
 146 #endif
 147
 148 /* statfs fills in f_flags since 2.6.36.  */
 149 #if __LINUX_KERNEL_VERSION >= 0x020624
 150 # define __ASSUME_STATFS_F_FLAGS        1
 151 #endif
 152
 153 /* prlimit64 is available in 2.6.36.  */
 154 #if __LINUX_KERNEL_VERSION >= 0x020624
 155 # define __ASSUME_PRLIMIT64     1
 156 #endif
 157
 158 /* Support for sendmmsg functionality was added in 3.0.  The macros
 159    defined correspond to those for accept4 and recvmmsg.  */
 160 #if __LINUX_KERNEL_VERSION >= 0x030000 && defined __ASSUME_SOCKETCALL
 161 # define __ASSUME_SENDMMSG_SOCKETCALL   1
 162 #endif
 163
 164 #if defined __ASSUME_SENDMMSG_SOCKETCALL || defined __ASSUME_SENDMMSG_SYSCALL
 165 # define __ASSUME_SENDMMSG      1
 166 #endif