Adjust kernel-features.h defaults for socket syscalls.

This patch adjusts the defaults for kernel-features.h macros relating
to availability of accept4, recvmmsg and sendmmsg.  It is not intended
to affect which macros end up getting defined in any configuration.

At present, all architectures with syscalls for those functions need
to define __ASSUME_*_SYSCALL macros; in particular, any new
architecture needs its own kernel-features.h file for that purpose,
though it may not otherwise need such a header.  Those macros are then
used together with __ASSUME_SOCKETCALL to define macros for whether
the functions in question are available.

This patch changes the defaults so that the syscalls are assumed to be
available by default with recent-enough kernels, and it is the
responsibility of architecture headers to undefine the macros if they
are unavailable in supported kernels at least as recent as the version
where the architecture-independent functionality was introduced.  The
__ASSUME_<function> macros are defaulted similarly instead of being
defined based on other macros (defining based on other macros would no
longer work because the #undefs appear after the generic header is
included), so where the syscall being unavailable means the function
is unavailable this means the architecture header has to undefine the
__ASSUME_<function> macro; this only affects __ASSUME_ACCEPT4 for
ia64, as other cases where the syscalls were added late enough to be
relevant with current kernel version requirements are all on
socketcall architectures.

As a consequence, the AArch64 and Nios II kernel-features.h header
files are removed, and others simplified.  When the minimum kernel
version becomes 4.3 or later on all architectures, the syscalls in
question can just be assumed unconditionally, permitting further
simplification.

Tested for x86_64, x86 and powerpc (that installed shared libraries
are unchanged by the patch, and testsuite for x86_64 and x86).

	* sysdeps/unix/sysv/linux/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Define unconditionally.
	(__ASSUME_ACCEPT4): Likewise.
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Define.
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG):
	Likewise.
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG):
	Likewise.
	* sysdeps/unix/sysv/linux/aarch64/kernel-features.h: Remove file.
	* sysdeps/unix/sysv/linux/nios2/kernel-features.h: Likewise.
	* sysdeps/unix/sysv/linux/alpha/kernel-features.h
	(__ASSUME_RECVMMSG_SYSCALL): Do not define.
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/arm/kernel-features.h
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/hppa/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/i386/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Likewise.
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	(__ASSUME_ACCEPT4_SYSCALL): Undefine if [__LINUX_KERNEL_VERSION <
	0x040300] instead of defining if [__LINUX_KERNEL_VERSION >=
	0x040300].
	* sysdeps/unix/sysv/linux/ia64/kernel-features.h
	(__ASSUME_RECVMMSG_SYSCALL): Do not define.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	(__ASSUME_ACCEPT4_SYSCALL): Undefine if [__LINUX_KERNEL_VERSION <
	0x030300] instead of defining if [__LINUX_KERNEL_VERSION >=
	0x030300].
	[__LINUX_KERNEL_VERSION < 0x030300] (__ASSUME_ACCEPT4): Undefine.
	* sysdeps/unix/sysv/linux/m68k/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Undefine if [__LINUX_KERNEL_VERSION <
	0x040300] instead of defining if [__LINUX_KERNEL_VERSION >=
	0x040300].
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Do not define.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Undefine if [__LINUX_KERNEL_VERSION <
	0x030300] instead of defining if [__LINUX_KERNEL_VERSION >=
	0x030300].
	* sysdeps/unix/sysv/linux/mips/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Do not define.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/s390/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Undefine if [__LINUX_KERNEL_VERSION <
	0x040300] instead of defining if [__LINUX_KERNEL_VERSION >=
	0x040300].
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/sh/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Do not define.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/sparc/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/tile/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	(__ASSUME_RECVMMSG_SYSCALL): Likewise.
	(__ASSUME_SENDMMSG_SYSCALL): Likewise.
	* sysdeps/unix/sysv/linux/x86_64/kernel-features.h
	(__ASSUME_ACCEPT4_SYSCALL): Likewise.
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Likewise.
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.

1 files changed, 0 insertions, 31 deletions

diff --git a/sysdeps/unix/sysv/linux/aarch64/kernel-features.h b/sysdeps/unix/sysv/linux/aarch64/kernel-features.h
deleted file mode 100644
index 556ba733aa..0000000000
--- a/sysdeps/unix/sysv/linux/aarch64/kernel-features.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/* Set flags signalling availability of kernel features based on given
-   kernel version number.
-
-   Copyright (C) 2009-2016 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/>.  */
-
-#include <linux/version.h>
-
-/* AArch64 support starts with 3.7.0, guaranteeing many kernel
-   features.  */
-
-#define __ASSUME_ACCEPT4_SYSCALL        1
-#define __ASSUME_RECVMMSG_SYSCALL       1
-#define __ASSUME_SENDMMSG_SYSCALL       1
-
-#include_next <kernel-features.h>