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

/* Set flags signalling availability of kernel features based on given
   kernel version number.
   Copyright (C) 1999-2013 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/* This file must not contain any C code.  At least it must be protected
   to allow using the file also in assembler files.  */

#ifndef __LINUX_KERNEL_VERSION
/* We assume the worst; all kernels should be supported.  */
# define __LINUX_KERNEL_VERSION	0
#endif

/* We assume for __LINUX_KERNEL_VERSION the same encoding used in
   linux/version.h.  I.e., the major, minor, and subminor all get a
   byte with the major number being in the highest byte.  This means
   we can do numeric comparisons.

   In the following we will define certain symbols depending on
   whether the describes kernel feature is available in the kernel
   version given by __LINUX_KERNEL_VERSION.  We are not always exactly
   recording the correct versions in which the features were
   introduced.  If somebody cares these values can afterwards be
   corrected.  */

/* The sendfile syscall was introduced in 2.2.0.  */
#define __ASSUME_SENDFILE		1

/* Linux 2.3.39 introduced IPC64.  Except for powerpc.  Linux 2.4.0 on
   PPC introduced a correct IPC64.  But PowerPC64 does not support a
   separate 64-bit syscall, already 64-bit.  */
#ifndef __powerpc64__
# define __ASSUME_IPC64		1
#endif

/* The changed st_ino field appeared in 2.4.0-test6.  However, SH is lame,
   and still does not have a 64-bit inode field.  */
#ifndef __sh__
# define __ASSUME_ST_INO_64_BIT		1
#endif

/* The getdents64 syscall was introduced in 2.4.0-test7 (but later for
   MIPS n32).  */
#define __ASSUME_GETDENTS64_SYSCALL	1

/* The statfs64 syscalls are available in 2.5.74 (but not for alpha).  */
#define __ASSUME_STATFS64	1

/* The utimes syscall has been available for some architectures
   forever.  For x86 it was introduced after 2.5.75, for x86-64,
   ppc, and ppc64 it was introduced in 2.6.0-test3, for s390 it was
   introduced in 2.6.21-rc5.  */
#if defined __sparc__ \
    || defined __i386__ \
    || defined __x86_64__ \
    || defined __powerpc__ \
    || defined __sh__ \
    || (defined __s390__ && __LINUX_KERNEL_VERSION >= 0x020616)
# define __ASSUME_UTIMES	1
#endif

/* pselect/ppoll were introduced just after 2.6.16-rc1.  Due to the way
   the kernel versions are advertised we can only rely on 2.6.17 to have
   the code.  On x86_64 and SH this appeared first in 2.6.19-rc1,
   on ia64 in 2.6.22-rc1.  */
#if __LINUX_KERNEL_VERSION >= 0x020611 \
    && ((!defined __x86_64__ && !defined __sh__) \
	|| (__LINUX_KERNEL_VERSION >= 0x020613 \
	    && (defined __x86_64__ || defined __sh__)))
# define __ASSUME_PSELECT	1
# define __ASSUME_PPOLL		1
#endif

/* The *at syscalls were introduced just after 2.6.16-rc1.  Due to the way the
   kernel versions are advertised we can only rely on 2.6.17 to have
   the code.  On PPC they were introduced in 2.6.17-rc1,
   on SH in 2.6.19-rc1.  */
#if __LINUX_KERNEL_VERSION >= 0x020611 \
    && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020613)
# define __ASSUME_ATFCTS	1
#endif

/* Support for inter-process robust mutexes was added in 2.6.17.  */
#if __LINUX_KERNEL_VERSION >= 0x020611 \
    && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020613)
# define __ASSUME_SET_ROBUST_LIST	1
#endif

/* Pessimistically assume that 2.6.18 introduced real handling of
   large numbers of requests to readv and writev and that we don't
   need a fallback.  It likely worked for much longer.  */
#if __LINUX_KERNEL_VERSION >= 0x020612
# define __ASSUME_COMPLETE_READV_WRITEV	1
#endif

/* Support for PI futexes was added in 2.6.18.  */
#if __LINUX_KERNEL_VERSION >= 0x020612
# define __ASSUME_FUTEX_LOCK_PI	1
#endif

/* Support for utimensat syscall was added in 2.6.22, on SH
   only after 2.6.22-rc1.  */
#if __LINUX_KERNEL_VERSION >= 0x020616 \
    && (!defined __sh__ || __LINUX_KERNEL_VERSION >= 0x020617)
# define __ASSUME_UTIMENSAT	1
#endif

/* Support for private futexes was added in 2.6.22.  */
#if __LINUX_KERNEL_VERSION >= 0x020616
# define __ASSUME_PRIVATE_FUTEX	1
#endif

/* Support for fallocate was added in 2.6.23, on s390
   only after 2.6.23-rc1.  */
#if __LINUX_KERNEL_VERSION >= 0x020617 \
    && (!defined __s390__ || __LINUX_KERNEL_VERSION >= 0x020618)
# define __ASSUME_FALLOCATE	1
#endif

/* Support for various CLOEXEC and NONBLOCK flags was added for x86,
   x86-64, PPC, IA-64, SPARC< and S390 in 2.6.23.  */
#if __LINUX_KERNEL_VERSION >= 0x020617 \
    && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
	|| defined __sparc__ || defined __s390__)
# define __ASSUME_O_CLOEXEC	1
#endif

/* From 2.6.23 onwards the value of ARG_MAX depends on the stack
   size.  */
#define __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL	0x020617
#if __LINUX_KERNEL_VERSION >= __LINUX_ARG_MAX_STACK_BASED_MIN_KERNEL
# define __ASSUME_ARG_MAX_STACK_BASED	1
#endif

/* Support for ADJ_OFFSET_SS_READ was added in 2.6.24.  */
#if __LINUX_KERNEL_VERSION >= 0x020618
# define __ASSUME_ADJ_OFFSET_SS_READ	1
#endif

/* Support for various CLOEXEC and NONBLOCK flags was added for x86,
   x86-64, PPC, IA-64, and SPARC in 2.6.27.  */
#if __LINUX_KERNEL_VERSION >= 0x02061b \
    && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
	|| defined __sparc__ || defined __s390__)
# define __ASSUME_SOCK_CLOEXEC	1
# define __ASSUME_IN_NONBLOCK	1
# define __ASSUME_PIPE2		1
# define __ASSUME_EVENTFD2	1
# define __ASSUME_SIGNALFD4	1
# define __ASSUME_DUP3		1
#endif

/* Support for the accept4 syscall was added in 2.6.28.  */
#if __LINUX_KERNEL_VERSION >= 0x02061c \
    && (defined __i386__ || defined __x86_64__ || defined __powerpc__ \
	|| defined __sparc__ || defined __s390__)
# define __ASSUME_ACCEPT4	1
#endif

/* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29.  */
#if __LINUX_KERNEL_VERSION >= 0x02061d
# define __ASSUME_FUTEX_CLOCK_REALTIME	1
#endif

/* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29.  */
#if __LINUX_KERNEL_VERSION >= 0x02061d
# define __ASSUME_AT_RANDOM	1
#endif

/* Support for preadv and pwritev was added in 2.6.30.  */
#if __LINUX_KERNEL_VERSION >= 0x02061e
# define __ASSUME_PREADV	1
# define __ASSUME_PWRITEV	1
#endif

/* Support for F_GETOWN_EX was introduced in 2.6.32.  */
#if __LINUX_KERNEL_VERSION >= 0x020620
# define __ASSUME_F_GETOWN_EX	1
#endif

/* Support for the recvmmsg syscall was added in 2.6.33.  */
#if __LINUX_KERNEL_VERSION >= 0x020621
# define __ASSUME_RECVMMSG	1
#endif

/* statfs fills in f_flags since 2.6.36.  */
#if __LINUX_KERNEL_VERSION >= 0x020624
# define __ASSUME_STATFS_F_FLAGS	1
#endif

/* prlimit64 is available in 2.6.36.  */
#if __LINUX_KERNEL_VERSION >= 0x020624
# define __ASSUME_PRLIMIT64	1
#endif

/* sendmmsg is available in 2.6.39.  */
#if __LINUX_KERNEL_VERSION >= 0x020627
# define __ASSUME_SENDMMSG	1
#endif

/* getcpu is a syscall for x86-64 since 3.1.  */
#if defined __x86_64__ && __LINUX_KERNEL_VERSION >= 0x030100
# define __ASSUME_GETCPU_SYSCALL	1
#endif