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Author SHA1 Message Date
Will Newton 37d3500738 aarch64: Re-implement setcontext without rt_sigreturn syscall 
The current implementation of setcontext uses rt_sigreturn to restore
the contents of registers. This contrasts with the way most other
architectures implement setcontext:

  powerpc64, mips, tile:

  Call rt_sigreturn if context was created by a call to a signal handler,
  otherwise restore in user code.

  powerpc32:

  Call swapcontext system call and don't call sigreturn or rt_sigreturn.

  x86_64, sparc, hppa, sh, ia64, m68k, s390, arm:

  Only support restoring "synchronous" contexts, that is contexts
  created by getcontext, and restoring in user code and don't call
  sigreturn or rt_sigreturn.

  alpha:

  Call sigreturn (but not rt_sigreturn) in all cases to do the restore.

The text of the setcontext manpage suggests that the requirement to be
able to restore a signal handler created context has been dropped from
SUSv2:

  If  the context was obtained by a call to a signal handler, then old
  standard text says that "program execution continues with the program
  instruction following the instruction interrupted by the signal".
  However, this sentence was removed in SUSv2, and the present verdict
  is "the result is unspecified".

Implementing setcontext by calling rt_sigreturn unconditionally causes
problems when used with sigaltstack as in BZ #16629. On this basis it
seems that aarch64 is broken and that new ports should only support
restoring contexts created with getcontext and do not need to call
rt_sigreturn at all.

This patch re-implements the aarch64 setcontext function to restore
the context in user code in a similar manner to x86_64 and other ports.

ChangeLog:

2014-04-17  Will Newton  <will.newton@linaro.org>

	[BZ #16629]
	* sysdeps/unix/sysv/linux/aarch64/setcontext.S (__setcontext):
	Re-implement to restore registers in user code and avoid
	rt_sigreturn system call.
 2014-04-17 11:38:50 +01:00
Torvald Riegel 36875b06e0 Fixed and unified pthread_once. 
[BZ #15215] This unifies various pthread_once architecture-specific
implementations which were using the same algorithm with slightly different
implementations.  It also adds missing memory barriers that are required for
correctness.
 2014-04-11 15:54:19 +02:00
Adhemerval Zanella 01f8eac224 Move __PTHREAD_SPINS definition to architecture specific header 
This patch moves the __PTHREAD_SPINS definition to arch specific header
since pthread_mutex_t layout is also arch specific.  This leads to no
need to defining __PTHREAD_MUTEX_HAVE_ELISION and thus removing of the
undefined compiler warning.
 2014-04-09 06:41:44 -05:00
Will Newton fede7a5ffa aarch64: Remove inaccurate comment from sysdep.h 
This comment appears to have been copied from the ARM port where it
makes more sense.

2014-03-18  Will Newton  <will.newton@linaro.org>

	* sysdeps/unix/sysv/linux/aarch64/sysdep.h: Remove
	inaccurate comment.
 2014-03-18 11:50:39 +00:00
Joseph Myers 67737b8f07 Don't define __ASSUME_UTIMES for linux-generic architectures. 
The __ASSUME_UTIMES macro describes whether the utimes syscall is
present.  For linux-generic architectures, it isn't (utimensat is
instead), so the macro should not be defined for them; this patch
removes the spurious definitions for such architectures.  (Those
definitions don't actually cause any user-visible bug, because
futimes.c doesn't use __ASSUME_UTIMES if __ASSUME_UTIMENSAT is
defined, and futimesat.c and utimes.c are overridden for
linux-generic, but the definitions are still logically incorrect.)

	* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
	(__ASSUME_UTIMES): Remove.
	* sysdeps/unix/sysv/linux/tile/kernel-features.h
	(__ASSUME_UTIMES): Likewise.
 2014-03-06 14:13:18 +00:00
Joseph Myers bc688c1029 Fix __ASSUME_SENDMMSG issues (bug 16611). 
Similar to the issues for accept4 and recvmmsg, __ASSUME_SENDMMSG is
also confused about whether it relates to function availability or
socketcall operation availability, and the conditions for the
definition are always wrong (sendmmsg appeared in Linux kernel 3.0,
not 2.6.39); this is now bug 16611.

This patch splits the macro into separate macros like those for
accept4 and recvmmsg, defining them for appropriate kernel versions.

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

	[BZ #16611]
	* sysdeps/unix/sysv/linux/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030000 && __ASSUME_SOCKETCALL]
	(__ASSUME_SENDMMSG_SOCKETCALL): Define.
	[__LINUX_KERNEL_VERSION >= 0x030000 && (__i386__ || __x86_64__ ||
	__powerpc__ || __sh__ || __sparc__)] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	[__i386__ || __powerpc__ || __sh__ || __sparc__]
	(__ASSUME_SENDMMSG_SYSCALL_WITH_SOCKETCALL): Likewise.
	[__ASSUME_SENDMMSG_SOCKETCALL || __ASSUME_SENDMMSG_SYSCALL]
	(__ASSUME_SENDMMSG): Define instead of using previous
	[__LINUX_KERNEL_VERSION >= 0x020627] condition.
	* sysdeps/unix/sysv/linux/aarch64/kernel-features.h
	(__ASSUME_SENDMMSG_SYSCALL): Define.
	* sysdeps/unix/sysv/linux/alpha/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030200] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/ia64/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/internal_sendmmsg.S [__ASSUME_SOCKETCALL
	&& !__ASSUME_SENDMMSG_SYSCALL_WITH_SOCKETCALL &&
	!__ASSUME_SENDMMSG_SYSCALL] (__NR_sendmmsg): Undefine.
	[__ASSUME_SENDMMSG]: Change conditionals to
	[__ASSUME_SENDMMSG_SOCKETCALL].
	* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030300] (__ASSUME_SENDMMSG_SYSCALL):
	Define.
	* sysdeps/unix/sysv/linux/mips/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030100] (__ASSUME_SENDMMSG_SYSCALL):
	Likewise.
	* sysdeps/unix/sysv/linux/sendmmsg.c [__ASSUME_SOCKETCALL &&
	!__ASSUME_SENDMMSG_SYSCALL_WITH_SOCKETCALL &&
	!__ASSUME_SENDMMSG_SYSCALL] (__NR_sendmmsg): Undefine.
	[!__ASSUME_SENDMMSG]: Change conditional to
	[!__ASSUME_SENDMMSG_SOCKETCALL].
	* sysdeps/unix/sysv/linux/tile/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030000] (__ASSUME_SENDMMSG_SYSCALL):
	Define.

	* sysdeps/unix/sysv/linux/hppa/kernel-features.h
	[__LINUX_KERNEL_VERSION >= 0x030100] (__ASSUME_SENDMMSG_SYSCALL):
	Define.
 2014-02-20 17:55:35 +00:00
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
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
Marcus Shawcroft 75eff3fe90 Relocate AArch64 from ports to libc. 
This patch moves the AArch64 port to the main sysdeps hierarchy.  The
move is essentially:

  git mv ports/sysdeps/aarch64 sysdeps/aarch64
  git mv ports/sysdeps/unix/sysv/linux/aarch64 sysdeps/unix/sysv/linux/aarch64

The README is updated and I've updated ChangeLog.aarch64 along the
lines of the ARM move.  The AArch64 build has been tested to confirm
that there were no changes in objdump -dr output or the shared
objects.
 2014-02-11 11:36:00 +00:00