glibc/sysdeps/unix/sysv/linux/ia64/kernel-features.h
Joseph Myers 0e31b18ca2 Fix __ASSUME_RECVMMSG issues (bug 16610).
Similar to the issues for accept4, __ASSUME_RECVMMSG is also confused
about whether it relates to function availability or socketcall
operation availability; this is now bug 16610.

Nothing actually tests __ASSUME_RECVMMSG for function availability,
but implicit in the definition in kernel-features.h is the idea that
it makes sense when the syscall is available and socketcall is not
being used.  As with accept4, there are architectures where the
syscall was added later than the socketcall operation, meaning that
assuming glibc is built with recent enough kernel headers, it does not
attempt to use socketcall for these operations and __ASSUME_RECVMMSG
gets defined for kernels >= 2.6.33 even when the syscall was only
added later.

This patch splits the macro into separate macros like those used for
accept4; having similar macro structure in both cases (and for
sendmmsg once I've dealt with that) seems likely to be less confusing
than having a different structure on the basis of nothing actually
needing to assume the recvmmsg function works.  Appropriate
definitions are added for all architectures.

Architecture-specific note: Tile's kernel-features.h says "TILE glibc
support starts with 2.6.36", which is accurate in that 2.6.36 was the
first kernel version with Tile support, and on that basis I've made
that header define __ASSUME_RECVMMSG_SYSCALL unconditionally.
However, Tile's configure.ac has arch_minimum_kernel=2.6.32.  Since
arch_minimum_kernel is meant to reflect only kernel.org kernel
versions, I think that should change to 2.6.36.  (If using glibc with
kernel versions from before a port went in kernel.org, it's your
responsibility to change arch_minimum_kernel in a local patch, and at
the same time to adjust any __ASSUME_* definitions that may not be
correct for your older kernel; for developing the official glibc it
should only ever be necessary to consider what official kernel.org
releases support.)

Tested x86_64, including that disassembly of the installed shared
libraries is unchanged by this patch.

	[BZ #16610]
	* sysdeps/unix/sysv/linux/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621 && __ASSUME_SOCKETCALL]
	(__ASSUME_RECVMMSG_SOCKETCALL): Define.
	[(__LINUX_KERNEL_VERSION >= 0x020621 && (__i386__ || __x86_64__ ||
	__sparc__)) || (__LINUX_KERNEL_VERSION >= 0x020625 && (__powerpc__
	|| __sh__))] (__ASSUME_RECVMMSG_SYSCALL): Likewise.
	[__i386__ || __sparc__]
	(__ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL): Likewise.
	[__ASSUME_RECVMMSG_SOCKETCALL || __ASSUME_RECVMMSG_SYSCALL]
	(__ASSUME_RECVMMSG): Define instead of using previous
	[__LINUX_KERNEL_VERSION >= 0x020621] condition.
	* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
	(__ASSUME_RECVMMSG_SYSCALL): Define.
	* sysdeps/unix/sysv/linux/alpha/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/ia64/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/internal_recvmmsg.S [__ASSUME_SOCKETCALL
	&& !__ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL &&
	!__ASSUME_RECVMMSG_SYSCALL] (__NR_recvmmsg): Undefine.
	[__ASSUME_RECVMMSG]: Change condition to
	[__ASSUME_RECVMMSG_SOCKETCALL].
	* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Define.
	(__ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL): Likewise.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_RECVMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/recvmmsg.c [__ASSUME_SOCKETCALL &&
	!__ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL &&
	!__ASSUME_RECVMMSG_SYSCALL] (__NR_recvmmsg): Undefine.
	[!__ASSUME_RECVMMSG]: Change condition to
	[!__ASSUME_RECVMMSG_SOCKETCALL].
	* sysdeps/unix/sysv/linux/tile/kernel-features.h
	(__ASSUME_RECVMMSG_SYSCALL): Define.

	* sysdeps/unix/sysv/linux/hppa/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020622] (__ASSUME_RECVMMSG_SYSCALL):
	Define.
2014-02-20 17:53:08 +00:00

63 lines
2.1 KiB
C

/* Set flags signalling availability of kernel features based on given
kernel version number.
Copyright (C) 2010-2014 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/>. */
#ifndef _KERNEL_FEATURES_H
#define _KERNEL_FEATURES_H 1
/* The utimes syscall has been available for some architectures
forever. */
#define __ASSUME_UTIMES 1
/* 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. */
#if __LINUX_KERNEL_VERSION >= 0x020616
# define __ASSUME_PSELECT 1
# define __ASSUME_PPOLL 1
#endif
/* Support for various CLOEXEC and NONBLOCK flags was added in 2.6.23. */
#if __LINUX_KERNEL_VERSION >= 0x020617
# define __ASSUME_O_CLOEXEC 1
#endif
/* Support for various CLOEXEC and NONBLOCK flags was added in 2.6.27. */
#if __LINUX_KERNEL_VERSION >= 0x02061b
# 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 recvmmsg syscall was added in 2.6.33. */
#if __LINUX_KERNEL_VERSION >= 0x020621
# define __ASSUME_RECVMMSG_SYSCALL 1
#endif
/* Support for the accept4 syscall was added in 3.3. */
#if __LINUX_KERNEL_VERSION >= 0x030300
# define __ASSUME_ACCEPT4_SYSCALL 1
#endif
#include_next <kernel-features.h>
#endif /* _KERNEL_FEATURES_H */