glibc/ports
Joseph Myers dd481ccffd Fix __ASSUME_ACCEPT4 issues (bug 16609).
In <https://sourceware.org/ml/libc-alpha/2013-12/msg00008.html>,
Aurelien noted issues with the definition of __ASSUME_ACCEPT4, which I
discussed in more detail in
<https://sourceware.org/ml/libc-alpha/2013-12/msg00014.html>; these
are now bug 16609.

As previously noted, __ASSUME_ACCEPT4 is used in two ways:

* In OS-independent code, to mean "accept4 can be assumed to work
  rather than fail with ENOSYS".  It doesn't matter whether it's
  implemented with socketcall or a separate syscall.

* In Linux-specific code, to mean "the socketcall multiplex syscall
  can be assumed to handle the accept4 operation.  When used in
  Linux-specific code, it *never* refers to anything relating to the
  accept4 syscall, only to the socketcall multiplexer.

This patch splits the macro into separate __ASSUME_ACCEPT4_SOCKETCALL,
__ASSUME_ACCEPT4_SYSCALL and __ASSUME_ACCEPT4 to clarify the different
cases involved.  A macro __ASSUME_SOCKETCALL is added for convenience
in writing logic relating to all socketcall architectures.  In
addition, to address the issue of architectures where socketcall
support for accept4 was added before a separate syscall was added (and
so the separate syscall should not be used unless known to be present
or fallback to socketcall is available), a fourth macro
__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL is added to indicate that the
syscall became available at the same time as socketcall support.  This
is then used in the relevant places in a conditional determining
whether to undefine __NR_accept4 (the simple approach to avoiding the
syscall's presence causing problems; I didn't try to implement runtime
fallback from the syscall to socketcall).

Architecture-specific note: alpha defined __ASSUME_ACCEPT4 for 2.6.33
and later, but actually the syscall was added for alpha in 3.2, so
this patch uses the correct condition for __ASSUME_ACCEPT4_SYSCALL
there.

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

	[BZ #16609]
	* sysdeps/unix/sysv/linux/kernel-features.h [__i386__ ||
	__powerpc__ || __s390__ || __sh__ || __sparc__]
	(__ASSUME_SOCKETCALL): Define.
	[__LINUX_KERNEL_VERSION && __ASSUME_SOCKETCALL]
	(__ASSUME_ACCEPT4_SOCKETCALL): Likewise.
	[(__LINUX_KERNEL_VERSION >= 0x02061c && (__x86_64__ || __sparc__))
	|| (__LINUX_KERNEL_VERSION >= 0x020625 && (__powerpc__ ||
	__sh__))] (__ASSUME_ACCEPT4_SYSCALL): Likewise.
	[__sparc__] (__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL): Likewise.
	[__ASSUME_ACCEPT4_SOCKETCALL || __ASSUME_ACCEPT4_SYSCALL]
	(__ASSUME_ACCEPT4): Define instead of using previous
	[__LINUX_KERNEL_VERSION >= 0x02061c && (__i386__ || __x86_64__ ||
	__powerpc__ || __sparc__ || __s390__)] condition.
	* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
	(__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL.
	* sysdeps/unix/sysv/linux/accept4.c [__ASSUME_SOCKETCALL &&
	!__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL &&
	!__ASSUME_ACCEPT4_SYSCALL] (__NR_accept4): Undefine.
	[!__ASSUME_ACCEPT4]: Change condition to
	[!__ASSUME_ACCEPT4_SOCKETCALL].
	* sysdeps/unix/sysv/linux/alpha/kernel-features.h
	(__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL.  Correct
	condition to [__LINUX_KERNEL_VERSION >= 0x030200].
	* sysdeps/unix/sysv/linux/arm/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020624] (__ASSUME_ACCEPT4): Change to
	__ASSUME_ACCEPT4_SYSCALL.
	* sysdeps/unix/sysv/linux/i386/accept4.S [__ASSUME_ACCEPT4]:
	Change conditions to [__ASSUME_ACCEPT4_SOCKETCALL].
	* sysdeps/unix/sysv/linux/ia64/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030300] (__ASSUME_ACCEPT4): Change to
	__ASSUME_ACCEPT4_SYSCALL.
	* sysdeps/unix/sysv/linux/internal_accept4.S [__ASSUME_SOCKETCALL
	&& !__ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL &&
	!__ASSUME_ACCEPT4_SYSCALL] (__NR_accept4): Undefine.
	[__ASSUME_ACCEPT4]: Change condition to
	[__ASSUME_ACCEPT4_SOCKETCALL].
	* sysdeps/unix/sysv/linux/m68k/kernel-features.h
	(__ASSUME_SOCKETCALL): Define.
	[__LINUX_KERNEL_VERSION >= 0x02061c] (__ASSUME_ACCEPT4): Remove.
	* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
	(__ASSUME_SOCKETCALL): Define.
	(__ASSUME_ACCEPT4): Remove.
	[__LINUX_KERNEL_VERSION >= 0x020621] (__ASSUME_ACCEPT4_SYSCALL):
	Define.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x02061f] (__ASSUME_ACCEPT4_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/tile/kernel-features.h
	(__ASSUME_ACCEPT4): Change to __ASSUME_ACCEPT4_SYSCALL.

	* sysdeps/unix/sysv/linux/hppa/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x020622] (__ASSUME_ACCEPT4_SYSCALL):
	Define.
2014-02-20 17:50:31 +00:00
..
sysdeps Fix __ASSUME_ACCEPT4 issues (bug 16609). 2014-02-20 17:50:31 +00:00
ChangeLog rename configure.in to configure.ac 2013-10-30 17:32:08 +10:00
ChangeLog.aarch64 Relocate AArch64 from ports to libc. 2014-02-11 11:36:00 +00:00
ChangeLog.aix Move all files into ports/ subdirectory in preparation for merge with glibc 2012-07-01 13:06:41 +00:00
ChangeLog.alpha ia64: relocate out of ports/ subdir 2014-02-16 01:12:38 -05:00
ChangeLog.am33 Remove am33 port. 2014-02-08 00:16:57 +00:00
ChangeLog.arm Move arm from ports to libc. 2014-02-08 01:49:39 +00:00
ChangeLog.cris Move all files into ports/ subdirectory in preparation for merge with glibc 2012-07-01 13:06:41 +00:00
ChangeLog.hppa Fix __ASSUME_ACCEPT4 issues (bug 16609). 2014-02-20 17:50:31 +00:00
ChangeLog.ia64 ia64: relocate out of ports/ subdir 2014-02-16 01:12:38 -05:00
ChangeLog.linux-generic Move tilegx, tilepro, and linux-generic from ports to libc. 2014-02-10 11:04:39 -05:00
ChangeLog.m68k Move m68k from ports to libc 2014-02-10 20:22:40 +01:00
ChangeLog.microblaze [MicroBlaze]: Move MicroBlaze from ports to sysdeps. 2014-02-17 11:08:21 +10:00
ChangeLog.mips ia64: relocate out of ports/ subdir 2014-02-16 01:12:38 -05:00
ChangeLog.powerpc Move powerpc ports pieces to libc. 2013-10-04 16:02:33 +00:00
ChangeLog.tile Move tilegx, tilepro, and linux-generic from ports to libc. 2014-02-10 11:04:39 -05:00
README rename configure.in to configure.ac 2013-10-30 17:32:08 +10:00

This is the glibc ports add-on, an add-on for the GNU C Library (glibc).
It contains code that is not maintained in the official glibc source tree.

This includes working ports to GNU/Linux on some machine architectures that
are not maintained in the official glibc source tree.  It also includes
some code once used by old libc ports now defunct, which has been abandoned
but may be useful for some future porter to examine.  It may also include
some optimized functions tailored for specific CPU implementations of an
architecture, to be selected using --with-cpu.

The ports add-on is cooperatively maintained by volunteers on the
<libc-ports@sourceware.org> mailing list, and housed in the ports
subdirectory of the glibc git repository.  See
http://www.gnu.org/software/libc/download.html for details on using
git.  To report a bug in code housed in the ports add-on, please go to
http://sourceware.org/bugzilla/ and file a bug report under the glibc
"ports" component.

An add-on for an individual port can be made from just the sysdeps/
subdirectories containing the port's code.  You may want to include a
README and Banner of your own talking about your port's code in particular,
rather than the generic ones here.

The real source code for any ports is found in the sysdeps/ subdirectories.
These should be exactly what would go into the main libc source tree if you
were to incorporate it directly.  The only exceptions are the files
sysdeps/*/preconfigure and sysdeps/*/preconfigure.ac; these are fragments
used by this add-on's configure fragment.  The purpose of these is to set
$base_machine et al when the main libc configure's defaults are not right
for some machine.  Everything else can and should be done from a normal
sysdeps/.../configure fragment that is used only when the configuration
selects that sysdeps subdirectory.  Each port that requires some special
treatment before the sysdeps directory list is calculated, should add a
sysdeps/CPU/preconfigure file; this can either be written by hand or
generated by Autoconf from sysdeps/CPU/preconfigure.ac, and follow the
rules for glibc add-on configure fragments.  No preconfigure file should do
anything on an unrelated configuration, so that disparate ports can be put
into a single add-on without interfering with each other.

Like all glibc add-ons, this must be used by specifying the directory in
the --enable-add-ons option when running glibc's configure script.

The GNU C Library is free software.  See the file COPYING.LIB in the
libc repository for copying conditions, and LICENSES for notices about
a few contributions that require these additional notices to be
distributed.  License copyright years may be listed using range
notation, e.g., 2000-2013, indicating that every year in the range,
inclusive, is a copyrightable year that would otherwise be listed
individually.