glibc/sysdeps/unix/sysv/linux/kernel-features.h
Joseph Myers 37ad347359 Remove __ASSUME_GETDENTS64_SYSCALL.
This patch removes the __ASSUME_GETDENTS64_SYSCALL macro, as its
definition is constant given the new kernel version requirements (and
was constant anyway before those requirements except for MIPS n32).

Note that the "#ifdef __NR_getdents64" conditional *is* still needed,
because MIPS n64 only has the getdents syscall (being a 64-bit ABI,
that syscall is 64-bit; the difference between the two on 64-bit
architectures is where d_type goes).  If MIPS n64 were to gain the
getdents64 syscall and we wanted to use it conditionally on the kernel
version at runtime we'd have to revert this patch, but I think that's
unlikely (and in any case, we could follow the simpler approach of
undefining __NR_getdents64 if the syscall can't be assumed, just like
we do for accept4 / recvmmsg / sendmmsg syscalls on architectures
where socketcall support came first).

Most of the getdents.c changes are reindentation.

Tested for x86_64 and x86 that installed stripped shared libraries are
unchanged by the patch.

	* sysdeps/unix/sysv/linux/kernel-features.h
	(__ASSUME_GETDENTS64_SYSCALL): Remove macro.
	* sysdeps/unix/sysv/linux/getdents.c
	[!__ASSUME_GETDENTS64_SYSCALL]: Remove conditional code.
	[!have_no_getdents64_defined]: Likewise.
	(__GETDENTS): Remove __have_no_getdents64 conditional.
2016-03-22 00:32:20 +00:00

148 lines
5.5 KiB
C

/* Set flags signalling availability of kernel features based on given
kernel version number.
Copyright (C) 1999-2016 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 PI futexes was added in 2.6.18 (but some architectures
lack futex_atomic_cmpxchg_inatomic in some configurations). */
#define __ASSUME_FUTEX_LOCK_PI 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
2.6.23. */
#define __ASSUME_O_CLOEXEC 1
/* Support for various CLOEXEC and NONBLOCK flags was added in
2.6.27. */
#define __ASSUME_IN_NONBLOCK 1
#define __ASSUME_PIPE2 1
#define __ASSUME_DUP3 1
/* Support for accept4 functionality was added in 2.6.28, but for some
architectures using a separate syscall rather than socketcall that
syscall was only added later, and some architectures first had
socketcall support then a separate syscall. Define
__ASSUME_ACCEPT4_SOCKETCALL if glibc uses socketcall on this
architecture and accept4 is available through socketcall,
__ASSUME_ACCEPT4_SYSCALL if it is available through a separate
syscall, __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL if it became
available through a separate syscall at the same time as through
socketcall, and __ASSUME_ACCEPT4 if the accept4 function is known
to work. */
#ifdef __ASSUME_SOCKETCALL
# define __ASSUME_ACCEPT4_SOCKETCALL 1
#endif
#define __ASSUME_ACCEPT4_SYSCALL 1
#define __ASSUME_ACCEPT4 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 FUTEX_*_REQUEUE_PI was added in 2.6.31 (but some
architectures lack futex_atomic_cmpxchg_inatomic in some
configurations). */
#define __ASSUME_REQUEUE_PI 1
/* Support for recvmmsg functionality was added in 2.6.33. The macros
defined correspond to those for accept4. */
#if __LINUX_KERNEL_VERSION >= 0x020621
# ifdef __ASSUME_SOCKETCALL
# define __ASSUME_RECVMMSG_SOCKETCALL 1
# endif
# define __ASSUME_RECVMMSG_SYSCALL 1
# define __ASSUME_RECVMMSG 1
#endif
/* Support for /proc/self/task/$tid/comm and /proc/$pid/task/$tid/comm was
added in 2.6.33. */
#if __LINUX_KERNEL_VERSION >= 0x020621
# define __ASSUME_PROC_PID_TASK_COMM 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
/* Support for sendmmsg functionality was added in 3.0. The macros
defined correspond to those for accept4 and recvmmsg. */
#if __LINUX_KERNEL_VERSION >= 0x030000
# ifdef __ASSUME_SOCKETCALL
# define __ASSUME_SENDMMSG_SOCKETCALL 1
# endif
# define __ASSUME_SENDMMSG_SYSCALL 1
# define __ASSUME_SENDMMSG 1
#endif