glibc/sysdeps/unix/sysv/linux/kernel-features.h
Florian Weimer bad7a0c81f copy_file_range: New function to copy file data
The semantics are based on the Linux system call, but a very close
emulation in user space is provided.
2017-12-22 10:55:40 +01:00

118 lines
4.4 KiB
C

/* Set flags signalling availability of kernel features based on given
kernel version number.
Copyright (C) 1999-2017 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
/* Some architectures use the socketcall multiplexer for some or all
socket-related operations instead of separate syscalls.
__ASSUME_SOCKETCALL is defined for such architectures. */
/* 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. */
#define __ASSUME_ST_INO_64_BIT 1
/* The statfs64 syscalls are available in 2.5.74 (but not for alpha). */
#define __ASSUME_STATFS64 1
/* pselect/ppoll were introduced just after 2.6.16-rc1. On x86_64 and
SH this appeared first in 2.6.19-rc1, on ia64 in 2.6.22-rc1. */
#define __ASSUME_PSELECT 1
/* The *at syscalls were introduced just after 2.6.16-rc1. On PPC
they were introduced in 2.6.17-rc1, on SH in 2.6.19-rc1. */
#define __ASSUME_ATFCTS 1
/* Support for inter-process robust mutexes was added in 2.6.17 (but
some architectures lack futex_atomic_cmpxchg_inatomic in some
configurations). */
#define __ASSUME_SET_ROBUST_LIST 1
/* Support for private futexes was added in 2.6.22. */
#define __ASSUME_PRIVATE_FUTEX 1
/* Support for various CLOEXEC and NONBLOCK flags was added in
2.6.27. */
#define __ASSUME_IN_NONBLOCK 1
/* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29. */
#define __ASSUME_FUTEX_CLOCK_REALTIME 1
/* Support for preadv and pwritev was added in 2.6.30. */
#define __ASSUME_PREADV 1
#define __ASSUME_PWRITEV 1
/* Support for sendmmsg functionality was added in 3.0. */
#define __ASSUME_SENDMMSG 1
/* On most architectures, most socket syscalls are supported for all
supported kernel versions, but on some socketcall architectures
separate syscalls were only added later. */
#define __ASSUME_SENDMSG_SYSCALL 1
#define __ASSUME_RECVMSG_SYSCALL 1
#define __ASSUME_ACCEPT_SYSCALL 1
#define __ASSUME_CONNECT_SYSCALL 1
#define __ASSUME_RECVFROM_SYSCALL 1
#define __ASSUME_SENDTO_SYSCALL 1
#define __ASSUME_ACCEPT4_SYSCALL 1
#define __ASSUME_RECVMMSG_SYSCALL 1
#define __ASSUME_SENDMMSG_SYSCALL 1
/* Support for SysV IPC through wired syscalls. All supported architectures
either support ipc syscall and/or all the ipc correspondent syscalls. */
#define __ASSUME_DIRECT_SYSVIPC_SYSCALLS 1
/* Support for p{read,write}v2 was added in 4.6. However Linux default
implementation does not assume the __ASSUME_* and instead use a fallback
implementation based on p{read,write}v and returning an error for
non supported flags. */
/* Support for the execveat syscall was added in 3.19. */
#if __LINUX_KERNEL_VERSION >= 0x031300
# define __ASSUME_EXECVEAT 1
#endif
#if __LINUX_KERNEL_VERSION >= 0x040400
# define __ASSUME_MLOCK2 1
#endif
#if __LINUX_KERNEL_VERSION >= 0x040500
# define __ASSUME_COPY_FILE_RANGE 1
#endif