This code manages the mappings of the available databases in NSS
(i.e. passwd, hosts, netgroup, etc) with the actions that should
be taken to do a query on those databases.
This is the main API between query functions scattered throughout
glibc and the underlying code (actions, modules, etc).
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Following macros: lll_futex_timed_lock_pi, lll_futex_clock_wait_bitset,
lll_futex_wait_requeue_pi, lll_futex_timed_wait_requeue_pi are not
used anymore so are eligible for removal.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
After gai_suspend and aio_suspend conversion to support 64 bit time and
hence rewriting the code to use only absolute variants of futex wait
functions (i.e. __futex_abstimed_wait64 and __futex_abstimed_wait_cancelable64)
futex_reltimed_wait{_cancelable} are not needed anymore and can be removed.
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This change uses (in gai_misc.h):
- __futex_abstimed_wait64 (instead of futex_reltimed_wait)
- __futex_abstimed_wait_cancellable64
(instead of futex_reltimed_wait_cancellable)
from ./sysdeps/nptl/futex-helpers.h
The gai_suspend() accepts relative timeout, which then is converted to
absolute one.
The i686-gnu port (HURD) do not define DONT_NEED_GAI_MISC_COND and as it
doesn't (yet) support 64 bit time it uses not converted
pthread_cond_timedwait().
The __gai_suspend() is supposed to be run on ports with __TIMESIZE !=64 and
__WORDSIZE==32. It internally utilizes __gai_suspend_time64() and hence the
conversion from 32 bit struct timespec to 64 bit one is required.
For ports supporting 64 bit time the __gai_suspend_time64() will be used
either via alias (to __gai_suspend when __TIMESIZE==64) or redirection
(when -D_TIME_BITS=64 is passed).
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
The earlier implementation of this, __lll_clocklock, calls lll_clockwait
that doesn't return the futex syscall error codes. It always tries again
if that fails.
However in the current implementation, when the futex returns EAGAIN,
__futex_clocklock64 will also return EGAIN, even if the futex is taken.
This patch fixes the EAGAIN issue and also adds a check for EINTR. As
futex syscall can return EINTR if the thread is interrupted by a signal.
In this case I'm assuming the function should continue trying to lock as
there is no mention to about it on POSIX. Also add a test for both
scenarios.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The aio_suspend function has been converted to support 64 bit time.
This change uses (in aio_misc.h):
- __futex_abstimed_wait64 (instead of futex_reltimed_wait)
- __futex_abstimed_wait_cancellable64
(instead of futex_reltimed_wait_cancellable)
from ./sysdeps/nptl/futex-helpers.h
The aio_suspend() accepts relative timeout, which then is converted to
absolute one.
The i686-gnu port (HURD) do not define DONT_NEED_AIO_MISC_COND and as it
doesn't (yet) support 64 bit time it uses not converted
pthread_cond_timedwait().
The __aio_suspend() is supposed to be run on ports with __TIMESIZE !=64 and
__WORDSIZE==32. It internally utilizes __aio_suspend_time64() and hence the
conversion from 32 bit struct timespec to 64 bit one is required.
For ports supporting 64 bit time the __aio_suspend_time64() will be used
either via alias (to __aio_suspend when __TIMESIZE==64) or redirection
(when -D_TIME_BITS=64 is passed).
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
For non null timeouts, the __futex_clocklock_wait64 creates an a
relative timeout by subtracting the current time from the input
argument. The same behavior can be obtained with FUTEX_WAIT_BITSET
without the need to calculate the relative timeout. Besides consolidate
the code it also avoid the possible relative timeout issues [1].
The __futex_abstimed_wait64 needs also to return EINVAL syscall
errors.
Checked on x86_64-linux-gnu and i686-linux-gnu.
[1] https://sourceware.org/pipermail/libc-alpha/2020-November/119881.html
Reviewed-by: Lukasz Majewski <lukma@denx.de>
And add a small optimization to avoid setting the operation for the
32-bit time fallback operation.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
It can be replaced with a __futex_abstimed_wait_cancelable64 call,
with the advantage that there is no need to further clock adjustments
to create a absolute timeout. It allows to remove the now ununsed
futex_timed_wait_cancel64 internal function.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
It is used solely on __pthread_cond_wait_common and the call can be
replaced by a __futex_abstimed_wait_cancelable64 one.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
The __futex_abstimed_wait usage was remove with 3102e28bd1 and the
__futex_abstimed_wait_cancelable by 323592fdc9 and b8d3e8fbaa.
The futex_lock_pi can be replaced by a futex_lock_pi64.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Now __thread_gscope_wait (the function behind THREAD_GSCOPE_WAIT,
formerly __wait_lookup_done) can be implemented directly in ld.so,
eliminating the unprotected GL (dl_wait_lookup_done) function
pointer.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The tls.h inclusion is not really required and limits possible
definition on more arch specific headers.
This is a cleanup to allow inline functions on sysdep.h, more
specifically on i386 and ia64 which requires to access some tls
definitions its own.
No semantic changes expected, checked with a build against all
affected ABIs.
GCC 11 introduces a -Wstringop-overflow warning for calls to functions
with an array argument passed as a pointer to memory not large enough
for that array. This includes the __sigsetjmp calls from
pthread_cleanup_push macros, because those use a structure in
__pthread_unwind_buf_t, which has a common initial subsequence with
jmp_buf but does not include the saved signal mask; this is OK in this
case because the second argument to __sigsetjmp is 0 so the signal
mask is not accessed.
To avoid this warning, use a function alias __sigsetjmp_cancel with
first argument an array of exactly the type used in the calls to the
function, if using GCC 11 or later. With older compilers, continue to
use __sigsetjmp with a cast, to avoid any issues with compilers
predating the returns_twice attribute not applying the same special
handling to __sigsetjmp_cancel as to __sigsetjmp.
Tested with build-many-glibcs.py for arm-linux-gnueabi that this fixes
the testsuite build failures.
The commit:
"y2038: nptl: Convert pthread_mutex_{clock|timed}lock to support 64 bit"
SHA1: 29e9874a04
introduced support for 64 bit timeouts. Unfortunately, it was missing the
code for bitset - i.e. lll_futex_clock_wait_bitset C preprocessor macro
was used. As a result the 64 bit struct __timespec64 was coerced to 32
bit struct timespec and regression visible as timeout was observed
(nptl/tst-robust10 on s390).
Reported-by: Stefan Liebler <stli@linux.ibm.com>
Tested-by: Stefan Liebler <stli@linux.ibm.com>
The pthread_mutex_clocklock and pthread_mutex_timedlock have been converted
to support 64 bit time.
This change uses:
- New __futex_clocklock_wait64 (instead of lll_timedwait)
from ./sysdeps/nptl/futex-helpers.c and
- New __futex_clocklock64 function (instead of lll_clocklock)
- New futex_lock_pi64
defined in sysdeps/nptl/futex-internal.h
The pthread_mutex_{clock|timed}lock only accepts absolute time.
Moreover, there is no need to check for NULL passed as *abstime pointer to the
syscalls as those calls have exported symbols marked with __nonull attribute
for abstime.
Some architectures - namely x86, powerpc and s390 - do support lock elision.
For those - adjustments have been made in arch specific elision-*.c files
to use __futex_clocklock64 instead of lll_clocklock.
The __lll_lock_elision (aliased to __lll_clocklock_elision in e.g.
sysdeps/unix/sysv/linux/s390/elision-timed.c) just uses, in this patch
provided, __futex_clocklock64.
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to pthread_mutex_{clock|timed}lock will provide support for 64
bit time
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It fixes the tst-cancelx{4,5} and tst-cancel24-{static} regression on
some platforms (arm and sparc32).
Checked on arm-linux-gnueabihf and sparcv9-linux-gnu.
This patch fixes part of bug 26647 (-Werror=array-parameter error
building with GCC 11 because of __sigsetjmp being declared using an
array parameter in one header and a pointer parameter in another).
The fix is to split the struct __jmp_buf_tag definition out to a
separate bits/types/ header so it can be included in pthread.h, so
that pthread.h can declare __sigsetjmp with the type contents visible,
so can use an array (as in setjmp.h) rather than a pointer in the
declaration.
Note that several other build failures with GCC 11 remain. This does
not fix the jmp_buf-related -Wstringop-overflow errors (also discussed
in bug 26647), or -Warray-parameter errors for other functions (bug
26686), or -Warray-bounds errors (bug 26687).
Tested, with older compilers, natively for x86_64 and with
build-many-glibc.py for aarch64-linux-gnu. Tested with
build-many-glibcs.py with GCC mainline for aarch64-linux-gnu that this
gets past the -Warray-parameter issue for __sigsetjmp (with the next
build failure being the other one discussed in bug 26647).
This is the helper function, which uses struct __timespec64
to provide 64 bit absolute time to futex syscalls.
The aim of this function is to move convoluted pre-processor
macro code from sysdeps/nptl/lowlevellock-futex.h to C
function in futex-internal.c
The futex_abstimed_wait64 function has been put into a separate
file on the purpose - to avoid issues apparent on the m68k
architecture related to small number of available registers (there
is not enough registers to put all necessary arguments in them if
the above function would be added to futex-internal.h with
__always_inline attribute).
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This alias macro shall be moved to the beginning of the futex-internal.h
to be easily reused by other functions, which would support 64 bit time.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Similar to 64-bit time __futex_abstimed_wait_cancellable64, it should
check for overflow and convert to 32-bit timespec iff timeout is not
NULL.
It fixes some regression on i686-linux-gnu running on a 4.15 kernel.
The pthread_cond_clockwait and pthread_cond_timedwait have been converted
to support 64 bit time.
This change introduces new futex_abstimed_wait_cancelable64 function in
./sysdeps/nptl/futex-helpers.c, which uses futex_time64 where possible
and tries to replace low-level preprocessor macros from
lowlevellock-futex.h
The pthread_cond_{clock|timed}wait only accepts absolute time. Moreover,
there is no need to check for NULL passed as *abstime pointer as
__pthread_cond_wait_common() always passes non-NULL struct __timespec64
pointer to futex_abstimed_wait_cancellable64().
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to __pthread_cond_{clock|timed}wait64 will provide support
for 64 bit time
The futex_abstimed_wait_cancelable64 function has been put into a separate
file on the purpose - to avoid issues apparent on the m68k architecture
related to small number of available registers (there is not enough
registers to put all necessary arguments in them if the above function
would be added to futex-internal.h with __always_inline attribute).
In fact - new function - namely __futex_abstimed_wait_cancellable32 is
used to reduce number of needed registers (as some in-register values are
stored on the stack when function call is made).
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_cond_{clock|timed}wait64 and
__pthread_cond_{clock|timed}wait.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The pthread_clockjoin_np and pthread_timedjoin_np have been converted to
support 64 bit time.
This change introduces new futex_timed_wait_cancel64 function in
./sysdeps/nptl/futex-internal.h, which uses futex_time64 where possible
and tries to replace low-level preprocessor macros from
lowlevellock-futex.h
The pthread_{timed|clock}join_np only accept absolute time. Moreover,
there is no need to check for NULL passed as *abstime pointer as
clockwait_tid() always passes struct __timespec64.
For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to __pthread_{clock|timed}join_np64 will provide support
for 64 bit time
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
https://github.com/lmajewski/meta-y2038 and run tests:
https://github.com/lmajewski/y2038-tests/commits/master
Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_{timed|clock}join_np64 and
__pthread_{timed|clock}join_np.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This introduces the function __pthread_attr_extension to allocate the
extension space, which is freed by pthread_attr_destroy.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Also add the private type union pthread_attr_transparent, to reduce
the amount of casting that is required.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Due to the built-in tables, __NR_set_robust_list is always defined
(although it may not be available at run time).
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It is necessary to export __pthread_cond_init from libc because
the C11 condition variable needs it and is still left in libpthread.
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
It is necessary to export __pthread_cond_destroy from libc because
the C11 condition variable needs it and is still left in libpthread.
This is part of the libpthread removal project:
<https://sourceware.org/ml/libc-alpha/2019-10/msg00080.html>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
With all Linux ABIs using the expected Linux kABI to indicate
syscalls errors, the INTERNAL_SYSCALL_DECL is an empty declaration
on all ports.
This patch removes the 'err' argument on INTERNAL_SYSCALL* macro
and remove the INTERNAL_SYSCALL_DECL usage.
Checked with a build against all affected ABIs.
so it gets shared by nptl and htl. Also add htl versions of thrd_current and
thrd_yield.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Commit 1c3f9acf1f ("nptl: Add struct_mutex.h")
replaced a zero constant with the identifier PTHREAD_MUTEX_DEFAULT
in the macro PTHREAD_MUTEX_INITIALIZER. However, that constant
is not available in ISO C11 mode:
In file included from /usr/include/bits/thread-shared-types.h:74,
from /usr/include/bits/pthreadtypes.h:23,
from /usr/include/pthread.h:26,
from bug25271.c:1:
bug25271.c:3:21: error: ‘PTHREAD_MUTEX_DEFAULT’ undeclared here (not in a function)
3 | pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
| ^~~~~~~~~~~~~~~~~~~~~~~~~
This commit change the constant to the equivalent
PTHREAD_MUTEX_TIMED_NP, which is in the POSIX extension namespace
and thus always available.
The nptl: Add struct_mutex.h added a wrong initializer for
architectures that uses the generic struct_mutex.h.
Checked on sparcv9-linux-gnu (where I noted the issue with the
nptl/tst-initializers1*).
This patch adds a default pthread-offsets.h based on default
thread definitions from struct_mutex.h and struct_rwlock.h.
The idea is to simplify new ports inclusion.
Checked with a build on affected abis.
Change-Id: I7785a9581e651feb80d1413b9e03b5ac0452668a
This patch adds a default pthreadtypes-arch.h, the idea is to simpify
new ports inclusion and an override is required only if the architecture
adds some arch-specific extensions or requirement.
The default values on the new generic header are based on current
architecture define value and they are not optimal compared to current
code requirements as below.
- On 64 bits __SIZEOF_PTHREAD_BARRIER_T is defined as 32 while is
sizeof (struct pthread_barrier) is 20 bytes.
- On 32 bits __SIZEOF_PTHREAD_ATTR_T is defined as 36 while
sizeof (struct pthread_attr) is 32.
The default values are not changed so the generic header could be
used by some architectures.
Checked with a build on affected abis.
Change-Id: Ie0cd586258a2650f715c1af0c9fe4e7063b0409a
This patch adds a new generic __pthread_rwlock_arch_t definition meant
to be used by new ports. Its layout mimics the current usage on some
64 bits ports and it allows some ports to use the generic definition.
The arch __pthread_rwlock_arch_t definition is moved from
pthreadtypes-arch.h to another arch-specific header (struct_rwlock.h).
Also the static intialization macro for pthread_rwlock_t is set to use
an arch defined on (__PTHREAD_RWLOCK_INITIALIZER) which simplifies its
implementation.
The default pthread_rwlock_t layout differs from current ports with:
1. Internal layout is the same for 32 bits and 64 bits.
2. Internal flag is an unsigned short so it should not required
additional padding to align for word boundary (if it is the case
for the ABI).
Checked with a build on affected abis.
Change-Id: I776a6a986c23199929d28a3dcd30272db21cd1d0
The current way of defining the common mutex definition for POSIX and
C11 on pthreadtypes-arch.h (added by commit 06be6368da) is
not really the best options for newer ports. It requires define some
misleading flags that should be always defined as 0
(__PTHREAD_COMPAT_PADDING_MID and __PTHREAD_COMPAT_PADDING_END), it
exposes options used solely for linuxthreads compat mode
(__PTHREAD_MUTEX_USE_UNION and __PTHREAD_MUTEX_NUSERS_AFTER_KIND), and
requires newer ports to explicit define them (adding more boilerplate
code).
This patch adds a new default __pthread_mutex_s definition meant to
be used by newer ports. Its layout mimics the current usage on both
32 and 64 bits ports and it allows most ports to use the generic
definition. Only ports that use some arch-specific definition (such
as hardware lock-elision or linuxthreads compat) requires specific
headers.
For 32 bit, the generic definitions mimic the other 32-bit ports
of using an union to define the fields uses on adaptive and robust
mutexes (thus not allowing both usage at same time) and by using a
single linked-list for robust mutexes. Both decisions seemed to
follow what recent ports have done and make the resulting
pthread_mutex_t/mtx_t object smaller.
Also the static intialization macro for pthread_mutex_t is set to use
a macro __PTHREAD_MUTEX_INITIALIZER where the architecture can redefine
in its struct_mutex.h if it requires additional fields to be
initialized.
Checked with a build on affected abis.
Change-Id: I30a22c3e3497805fd6e52994c5925897cffcfe13
The new rwlock implementation added by cc25c8b4c1 (2.25) removed
support for lock-elision. This patch removes remaining the
arch-specific unused definitions.
Checked with a build against all affected ABIs.
Change-Id: I5dec8af50e3cd56d7351c52ceff4aa3771b53cd6
Introduce pthread_clockjoin_np as a version of pthread_timedjoin_np that
accepts a clockid_t parameter to indicate which clock the timeout should be
measured against. This mirrors the recently-added POSIX-proposed "clock"
wait functions.
Checked on x86_64-linux-gnu.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch adds the generic futex_lock_pi and futex_unlock_pi to wrap
around the syscall machinery required to issue the syscall calls. It
simplifies a bit the futex code required to implement PI mutexes.
No function changes, checked on x86_64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
To help y2038 work avoid duplicate all the logic of nanosleep on
non cancellable version, the patch replace it with a new futex
operation, lll_timedwait. The changes are:
- Add a expected value for __lll_clocklock_wait, so it can be used
to wait for generic values.
- Remove its internal atomic operation and move the logic to
__lll_clocklock. It makes __lll_clocklock_wait even more generic
and __lll_clocklock slight faster on fast-path (since it won't
require a function call anymore).
- Add lll_timedwait, which uses __lll_clocklock_wait, to replace both
__pause_nocancel and __nanosleep_nocancel.
It also allows remove the sparc32 __lll_clocklock_wait implementation
(since it is similar to the generic one).
Checked on x86_64-linux-gnu, sparcv9-linux-gnu, and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
NPTL is already Linux specific, there is no need to parametrize low
level lock futex operations and add a sysdep Linux specific
implementation. This patch moves the relevant Linux code to nptl one.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
NPTL is already Linux specific, there is no need to parametrize futex
operations and add a sysdep Linux specific implementation. This patch
moves the relevant Linux code to nptl one.
Checked on x86_64-linux-gnu and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
All nptl targets have these signal definitions nowadays. This
changes also replaces the nptl-generic version of pthread_sigmask
with the Linux version.
Tested on x86_64-linux-gnu and i686-linux-gnu. Built with
build-many-glibcs.py.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
With only two exceptions (sys/types.h and sys/param.h, both of which
historically might have defined BYTE_ORDER) the public headers that
include <endian.h> only want to be able to test __BYTE_ORDER against
__*_ENDIAN.
This patch creates a new bits/endian.h that can be included by any
header that wants to be able to test __BYTE_ORDER and/or
__FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs
__LONG_LONG_PAIR. It only defines macros in the implementation
namespace.
The existing bits/endian.h (which could not be included independently
of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER)
is renamed to bits/endianness.h. I also took the opportunity to
canonicalize the form of this header, which we are stuck with having
one copy of per architecture. Since they are so short, this means git
doesn’t understand that they were renamed from existing headers, sigh.
endian.h itself is a nonstandard header and its only remaining use
from a standard header is guarded by __USE_MISC, so I dropped the
__USE_MISC conditionals from around all of the public-namespace things
it defines. (This means, an application that requests strict library
conformance but includes endian.h will still see the definition of
BYTE_ORDER.)
A few changes to specific bits/endian(ness).h variants deserve
mention:
- sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to
sysdeps/ia64/bits/endianness.h. If I remember correctly, ia64 did
have selectable endianness, but we have assembly code in
sysdeps/ia64 that assumes it’s little-endian, so there is no reason
to treat the ia64 endianness.h as linux-specific.
- The C-SKY port does not fully support big-endian mode, the compile
will error out if __CSKYBE__ is defined.
- The PowerPC port had extra logic in its bits/endian.h to detect a
broken compiler, which strikes me as unnecessary, so I removed it.
- The only files that defined __FLOAT_WORD_ORDER always defined it to
the same value as __BYTE_ORDER, so I removed those definitions.
The SH bits/endian(ness).h had comments inconsistent with the
actual setting of __FLOAT_WORD_ORDER, which I also removed.
- I *removed* copyright boilerplate from the few bits/endian(ness).h
headers that had it; these files record a single fact in a fashion
dictated by an external spec, so I do not think they are copyrightable.
As long as I was changing every copy of ieee754.h in the tree, I
noticed that only the MIPS variant includes float.h, because it uses
LDBL_MANT_DIG to decide among three different versions of
ieee854_long_double. This patch makes it not include float.h when
GCC’s intrinsic __LDBL_MANT_DIG__ is available.
* string/endian.h: Unconditionally define LITTLE_ENDIAN,
BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER. Condition byteswapping
macros only on !__ASSEMBLER__. Move the definitions of
__BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER,
and __LONG_LONG_PAIR to...
* string/bits/endian.h: ...this new file, which includes
the renamed header bits/endianness.h for the definition of
__BYTE_ORDER and possibly __FLOAT_WORD_ORDER.
* string/Makefile: Install bits/endianness.h.
* include/bits/endian.h: New wrapper.
* bits/endian.h: Rename to bits/endianness.h.
Add multiple-include guard. Rewrite the comment explaining what
the machine-specific variants of this file should do.
* sysdeps/unix/sysv/linux/ia64/bits/endian.h:
Move to sysdeps/ia64.
* sysdeps/aarch64/bits/endian.h
* sysdeps/alpha/bits/endian.h
* sysdeps/arm/bits/endian.h
* sysdeps/csky/bits/endian.h
* sysdeps/hppa/bits/endian.h
* sysdeps/ia64/bits/endian.h
* sysdeps/m68k/bits/endian.h
* sysdeps/microblaze/bits/endian.h
* sysdeps/mips/bits/endian.h
* sysdeps/nios2/bits/endian.h
* sysdeps/powerpc/bits/endian.h
* sysdeps/riscv/bits/endian.h
* sysdeps/s390/bits/endian.h
* sysdeps/sh/bits/endian.h
* sysdeps/sparc/bits/endian.h
* sysdeps/x86/bits/endian.h:
Rename to endianness.h; canonicalize form of file; remove
redundant definitions of __FLOAT_WORD_ORDER.
* sysdeps/powerpc/bits/endianness.h: Remove logic to check for
broken compilers.
* ctype/ctype.h
* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
* sysdeps/csky/nptl/bits/pthreadtypes-arch.h
* sysdeps/ia64/ieee754.h
* sysdeps/ieee754/ieee754.h
* sysdeps/ieee754/ldbl-128/ieee754.h
* sysdeps/ieee754/ldbl-128ibm/ieee754.h
* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
* sysdeps/mips/ieee754/ieee754.h
* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
* sysdeps/nptl/pthread.h
* sysdeps/riscv/nptl/bits/pthreadtypes-arch.h
* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
* sysdeps/sparc/sparc32/ieee754.h
* sysdeps/unix/sysv/linux/generic/bits/stat.h
* sysdeps/unix/sysv/linux/generic/bits/statfs.h
* sysdeps/unix/sysv/linux/sys/acct.h
* wctype/bits/wctype-wchar.h:
Include bits/endian.h, not endian.h.
* sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h.
* sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__
in ifdefs, instead of LDBL_MANT_DIG. Only include float.h
when __LDBL_MANT_DIG__ is not predefined, in which case
define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG.
In afe4de7d28, I added forwarding functions
from libc to libpthread for __pthread_cond_clockwait and
pthread_cond_clockwait to mirror those for pthread_cond_timedwait. These
are unnecessary[1], since these functions aren't (yet) being called from
within libc itself. Let's remove them.
* nptl/forward.c: Remove unnecessary __pthread_cond_clockwait and
pthread_cond_clockwait forwarding functions. There are no internal
users, so it is unnecessary to expose these functions in libc.so.
* sysdeps/nptl/pthread-functions.h (pthread_functions): Remove
unnecessary ptr___pthread_cond_clockwait member.
* nptl/nptl-init.c (pthread_functions): Remove assignment of
removed member.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
[1] https://sourceware.org/ml/libc-alpha/2017-10/msg00082.html
The only implementation of futex_supports_exact_relative_timeouts always
returns true. Let's remove it and all its callers.
* nptl/pthread_cond_wait.c: (__pthread_cond_clockwait): Remove code
that is only useful if futex_supports_exact_relative_timeouts ()
returns false.
* nptl/pthread_condattr_setclock.c: (pthread_condattr_setclock):
Likewise.
* sysdeps/nptl/futex-internal.h: Remove comment about relative
timeouts potentially being imprecise since it's no longer true.
Remove declaration of futex_supports_exact_relative_timeouts.
* sysdeps/unix/sysv/linux/futex-internal.h: Remove implementation
of futex_supports_exact_relative_timeouts.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Rename lll_timedlock to lll_clocklock and add clockid
parameter to indicate the clock that the abstime parameter should
be measured against in preparation for adding
pthread_mutex_clocklock.
The name change mirrors the naming for the exposed pthread functions:
timed => absolute timeout measured against CLOCK_REALTIME (or clock
specified by attribute in the case of pthread_cond_timedwait.)
clock => absolute timeout measured against clock specified in preceding
parameter.
* sysdeps/nptl/lowlevellock.h (lll_clocklock): Rename from
lll_timedlock and add clockid parameter. (__lll_clocklock): Rename
from __lll_timedlock and add clockid parameter.
* sysdeps/unix/sysv/linux/sparc/lowlevellock.h (lll_clocklock):
Likewise.
* nptl/lll_timedlock_wait.c (__lll_clocklock_wait): Rename from
__lll_timedlock_wait and add clockid parameter. Use __clock_gettime
rather than __gettimeofday so that clockid can be used. This means
that conversion from struct timeval is no longer required.
* sysdeps/sparc/sparc32/lowlevellock.c (lll_clocklock_wait):
Likewise.
* sysdeps/sparc/sparc32/lll_timedlock_wait.c: Update comment to
refer to __lll_clocklock_wait rather than __lll_timedlock_wait.
* nptl/pthread_mutex_timedlock.c (lll_clocklock_elision): Rename
from lll_timedlock_elision, add clockid parameter and use
meaningful names for other parameters. (__pthread_mutex_timedlock):
Pass CLOCK_REALTIME where necessary to lll_clocklock and
lll_clocklock_elision.
* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
(lll_clocklock_elision): Rename from lll_timedlock_elision and add
clockid parameter. (__lll_clocklock_elision): Rename from
__lll_timedlock_elision and add clockid parameter.
* sysdeps/unix/sysv/linux/s390/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/x86/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/elision-timed.c
(__lll_lock_elision): Call __lll_clocklock_elision rather than
__lll_timedlock_elision. (EXTRAARG): Add clockid parameter.
(LLL_LOCK): Likewise.
* sysdeps/unix/sysv/linux/s390/elision-timed.c: Likewise.
* sysdeps/unix/sysv/linux/x86/elision-timed.c: Likewise.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add:
int pthread_rwlock_clockrdlock (pthread_rwlock_t *rwlock,
clockid_t clockid,
const struct timespec *abstime)
and:
int pthread_rwlock_clockwrlock (pthread_rwlock_t *rwlock,
clockid_t clockid,
const struct timespec *abstime)
which behave like pthread_rwlock_timedrdlock and
pthread_rwlock_timedwrlock respectively, except they always measure
abstime against the supplied clockid. The functions currently support
CLOCK_REALTIME and CLOCK_MONOTONIC and return EINVAL if any other
clock is specified.
* sysdeps/nptl/pthread.h: Add pthread_rwlock_clockrdlock and
pthread_wrlock_clockwrlock.
* nptl/Makefile: Build pthread_rwlock_clockrdlock.c and
pthread_rwlock_clockwrlock.c.
* nptl/pthread_rwlock_clockrdlock.c: Implement
pthread_rwlock_clockrdlock.
* nptl/pthread_rwlock_clockwrlock.c: Implement
pthread_rwlock_clockwrlock.
* nptl/pthread_rwlock_common.c (__pthread_rwlock_rdlock_full): Add
clockid parameter and verify that it indicates a supported clock on
entry so that we fail even if it doesn't end up being used. Pass
that clock on to futex_abstimed_wait when necessary.
(__pthread_rwlock_wrlock_full): Likewise.
* nptl/pthread_rwlock_rdlock.c: (__pthread_rwlock_rdlock): Pass
CLOCK_REALTIME to __pthread_rwlock_rdlock_full even though it won't
be used because there's no timeout.
* nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock): Pass
CLOCK_REALTIME to __pthread_rwlock_wrlock_full even though it won't
be used because there is no timeout.
* nptl/pthread_rwlock_timedrdlock.c (pthread_rwlock_timedrdlock):
Pass CLOCK_REALTIME to __pthread_rwlock_rdlock_full since abstime
uses that clock.
* nptl/pthread_rwlock_timedwrlock.c (pthread_rwlock_timedwrlock):
Pass CLOCK_REALTIME to __pthread_rwlock_wrlock_full since abstime
uses that clock.
* sysdeps/unix/sysv/linux/aarch64/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/alpha/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/arm/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/csky/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/hppa/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/i386/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/ia64/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/microblaze/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/nios2/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/sh/libpthread.abilist (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libpthread.abilist
(GLIBC_2.30): Likewise.
* nptl/tst-abstime.c (th): Add pthread_rwlock_clockrdlock and
pthread_rwlock_clockwrlock timeout tests to match the existing
pthread_rwlock_timedrdloock and pthread_rwlock_timedwrlock tests.
* nptl/tst-rwlock14.c (do_test): Likewise.
* nptl/tst-rwlock6.c Invent verbose_printf macro, and use for
ancillary output throughout. (tf): Accept thread_args structure so
that rwlock, a clockid and function name can be passed to the
thread. (do_test_clock): Rename from do_test. Accept clockid
parameter to specify test clock. Use the magic clockid value of
CLOCK_USE_TIMEDLOCK to indicate that pthread_rwlock_timedrdlock and
pthread_rwlock_timedwrlock should be tested, otherwise pass the
specified clockid to pthread_rwlock_clockrdlock and
pthread_rwlock_clockwrlock. Use xpthread_create and xpthread_join.
(do_test): Call do_test_clock to test each clockid in turn.
* nptl/tst-rwlock7.c: Likewise.
* nptl/tst-rwlock9.c (writer_thread, reader_thread): Accept
thread_args structure so that the (now int) thread number, the
clockid and the function name can be passed to the thread.
(do_test_clock): Renamed from do_test. Pass the necessary
thread_args when creating the reader and writer threads. Use
xpthread_create and xpthread_join.
(do_test): Call do_test_clock to test each clockid in turn.
* manual/threads.texi: Add documentation for
pthread_rwlock_clockrdlock and pthread_rwlock_clockwrclock.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Add:
int pthread_cond_clockwait (pthread_cond_t *cond,
pthread_mutex_t *mutex,
clockid_t clockid,
const struct timespec *abstime)
which behaves just like pthread_cond_timedwait except it always measures
abstime against the supplied clockid. Currently supports CLOCK_REALTIME
and
CLOCK_MONOTONIC and returns EINVAL if any other clock is specified.
Includes feedback from many others. This function was originally
proposed[1] as pthread_cond_timedwaitonclock_np, but The Austin Group
preferred the new name.
* nptl/Makefile: Add tst-cond26 and tst-cond27
* nptl/Versions (GLIBC_2.30): Add pthread_cond_clockwait
* sysdeps/nptl/pthread.h: Likewise
* nptl/forward.c: Add __pthread_cond_clockwait
* nptl/forward.c: Likewise
* nptl/pthreadP.h: Likewise
* sysdeps/nptl/pthread-functions.h: Likewise
* nptl/pthread_cond_wait.c (__pthread_cond_wait_common): Add
clockid parameter and comment describing why we don't need to
check
its value. Use that value when calling
futex_abstimed_wait_cancelable rather than reading the clock
from
the flags. (__pthread_cond_wait): Pass unused clockid parameter.
(__pthread_cond_timedwait): Read clock from flags and pass it to
__pthread_cond_wait_common. (__pthread_cond_clockwait): Add new
function with weak alias from pthread_cond_clockwait.
* sysdeps/mach/hurd/i386/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/aarch64/libpthread.abilist
* (GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/alpha/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/arm/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/csky/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/hppa/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/i386/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/ia64/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/microblaze/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/nios2/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/sh/libpthread.abilist (GLIBC_2.30):
* Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libpthread.abilist
(GLIBC_2.30): Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libpthread.abilist
(GLIBC_2.30): Likewise.
* nptl/tst-cond11.c (run_test): Support testing
pthread_cond_clockwait too by using a special magic
CLOCK_USE_ATTR_CLOCK value to determine whether to call
pthread_cond_timedwait or pthread_cond_clockwait. (do_test):
Pass
CLOCK_USE_ATTR_CLOCK for existing tests, and add new tests using
all combinations of CLOCK_MONOTONIC and CLOCK_REALTIME.
* ntpl/tst-cond26.c: New test for passing unsupported and
* invalid
clocks to pthread_cond_clockwait.
* nptl/tst-cond27.c: Add test similar to tst-cond5.c, but using
struct timespec and pthread_cond_clockwait.
* manual/threads.texi: Document pthread_cond_clockwait. The
* comment
was provided by Carlos O'Donell.
[1] https://sourceware.org/ml/libc-alpha/2015-07/msg00193.html
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
In preparation for adding POSIX clockwait variants of timedwait functions,
add a clockid_t parameter to futex_abstimed_wait functions and pass
CLOCK_REALTIME from all callers for the time being.
Replace lll_futex_timed_wait_bitset with lll_futex_clock_wait_bitset
which takes a clockid_t parameter rather than the magic clockbit.
* sysdeps/nptl/lowlevellock-futex.h,
sysdeps/unix/sysv/linux/lowlevellock-futex.h: Replace
lll_futex_timed_wait_bitset with lll_futex_clock_wait_bitset that
takes a clockid rather than a special clockbit.
* sysdeps/nptl/lowlevellock-futex.h: Add
lll_futex_supported_clockid so that client functions can check
whether their clockid parameter is valid even if they don't
ultimately end up calling lll_futex_clock_wait_bitset.
* sysdeps/nptl/futex-internal.h,
sysdeps/unix/sysv/linux/futex-internal.h
(futex_abstimed_wait, futex_abstimed_wait_cancelable): Add
clockid_t parameter to indicate which clock the absolute time
passed should be measured against. Pass that clockid onto
lll_futex_clock_wait_bitset. Add invalid clock as reason for
returning -EINVAL.
* sysdeps/nptl/futex-internal.h,
sysdeps/unix/sysv/linux/futex-internal.h: Introduce
futex_abstimed_supported_clockid so that client functions can check
whether their clockid parameter is valid even if they don't
ultimately end up calling futex_abstimed_wait.
* nptl/pthread_cond_wait.c (__pthread_cond_wait_common): Remove
code to calculate relative timeout for
__PTHREAD_COND_CLOCK_MONOTONIC_MASK and just pass CLOCK_MONOTONIC
or CLOCK_REALTIME as required to futex_abstimed_wait_cancelable.
* nptl/pthread_rwlock_common (__pthread_rwlock_rdlock_full)
(__pthread_wrlock_full), nptl/sem_waitcommon (do_futex_wait): Pass
additional CLOCK_REALTIME to futex_abstimed_wait_cancelable.
* nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock):
Switch to lll_futex_clock_wait_bitset and pass CLOCK_REALTIME
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch removes the arch-specific x86 assembly implementation for
low level locking and consolidate both 64 bits and 32 bits in a
single implementation.
Different than other architectures, x86 lll_trylock, lll_lock, and
lll_unlock implements a single-thread optimization to avoid atomic
operation, using cmpxchgl instead. This patch implements by using
the new single-thread.h definitions in a generic way, although using
the previous semantic.
The lll_cond_trylock, lll_cond_lock, and lll_timedlock just use
atomic operations plus calls to lll_lock_wait*.
For __lll_lock_wait_private and __lll_lock_wait the generic implemtation
there is no indication that assembly implementation is required
performance-wise.
Checked on x86_64-linux-gnu and i686-linux-gnu.
* sysdeps/nptl/lowlevellock.h (__lll_trylock): New macro.
(lll_trylock): Call __lll_trylock.
* sysdeps/unix/sysv/linux/i386/libc-lowlevellock.S: Remove file.
* sysdeps/unix/sysv/linux/i386/lll_timedlock_wait.c: Likewise.
* sysdeps/unix/sysv/linux/i386/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/i386/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lll_timedlock_wait.c: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/x86/lowlevellock.h: New file.
* sysdeps/unix/sysv/linux/x86_64/cancellation.S: Include
lowlevellock-futex.h.
Since hppa is not an outlier anymore regarding LLL_LOCK_INITIALIZER value,
we can now assume it 0 for all architectures.
Checked on a build for all major ABIs.
* nptl/nptl-init.c (__pthread_initialize_minimal_internal): Remove
initialization for LLL_LOCK_INITIALIZER different than 0.
* nptl/old_pthread_cond_broadcast.c (__pthread_cond_broadcast_2_0):
Assume LLL_LOCK_INITIALIZER being 0.
* nptl/old_pthread_cond_signal.c (__pthread_cond_signal_2_0): Likewise.
* nptl/old_pthread_cond_timedwait.c (__pthread_cond_timedwait_2_0):
Likewise.
* nptl/old_pthread_cond_wait.c (__pthread_cond_wait_2_0): Likewise.
* sysdeps/nptl/libc-lockP.h (__libc_lock_define_initialized): Likewise.
This patch removes CLOCK_THREAD_CPUTIME_ID and CLOCK_PROCESS_CPUTIME_ID support
from clock_gettime and clock_settime generic implementation. For Linux, kernel
already provides supports through the syscall and Hurd HTL lacks
__pthread_clock_gettime and __pthread_clock_settime internal implementation.
As described in clock_gettime man-page [1] on 'Historical note for SMP
system', implementing CLOCK_{THREAD,PROCESS}_CPUTIME_ID with timer registers
is error-prone and susceptible to timing and accurary issues that the libc
can not deal without kernel support.
This allows removes unused code which, however, still incur in some runtime
overhead in thread creation (the struct pthread cpuclock_offset
initialization).
If hurd eventually wants to support them it should either either implement as
a kernel facility (or something related due its architecture) or in system
specific implementation.
Checked on aarch64-linux-gnu, x86_64-linux-gnu, and i686-linux-gnu. I also
checked on a i686-gnu build.
* nptl/Makefile (libpthread-routines): Remove pthread_clock_gettime and
pthread_clock_settime.
* nptl/pthreadP.h (__find_thread_by_id): Remove prototype.
* elf/dl-support.c [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset): Remove.
(_dl_non_dynamic_init): Remove _dl_cpuclock_offset setting.
* elf/rtld.c (_dl_start_final): Likewise.
* nptl/allocatestack.c (__find_thread_by_id): Remove function.
* sysdeps/generic/ldsodefs.h [!HP_TIMING_NOAVAIL] (_dl_cpuclock_offset):
Remove.
* sysdeps/mach/hurd/dl-sysdep.c [!HP_TIMING_NOAVAIL]
(_dl_cpuclock_offset): Remove.
* nptl/descr.h (struct pthread): Rename cpuclock_offset to
cpuclock_offset_ununsed.
* nptl/nptl-init.c (__pthread_initialize_minimal_internal): Remove
cpuclock_offset set.
* nptl/pthread_create.c (START_THREAD_DEFN): Likewise.
* sysdeps/nptl/fork.c (__libc_fork): Likewise.
* nptl/pthread_clock_gettime.c: Remove file.
* nptl/pthread_clock_settime.c: Likewise.
* sysdeps/unix/clock_gettime.c (hp_timing_gettime): Remove function.
[HP_TIMING_AVAIL] (realtime_gettime): Remove CLOCK_THREAD_CPUTIME_ID
and CLOCK_PROCESS_CPUTIME_ID support.
* sysdeps/unix/clock_settime.c (hp_timing_gettime): Likewise.
[HP_TIMING_AVAIL] (realtime_gettime): Likewise.
* sysdeps/posix/clock_getres.c (hp_timing_getres): Likewise.
[HP_TIMING_AVAIL] (__clock_getres): Likewise.
* sysdeps/unix/clock_nanosleep.c (CPUCLOCK_P, INVALID_CLOCK_P):
Likewise.
(__clock_nanosleep): Remove CPUCLOCK_P and INVALID_CLOCK_P usage.
[1] http://man7.org/linux/man-pages/man2/clock_gettime.2.html
This patch assumes realtime clock support for nptl and thus removes
all the associated code.
For __pthread_mutex_timedlock the fallback usage for the case where
lll_futex_timed_wait_bitset it not set define is also removed. The
generic lowlevellock-futex.h always define it, so for NPTL code the
check always yield true.
Checked on x86_64-linux-gnu and i686-linux-gnu.
* nptl/nptl-init.c (__have_futex_clock_realtime,
__have_futex_clock_realtime): Remove definition.
(__pthread_initialize_minimal_internal): Remove FUTEX_CLOCK_REALTIME
check test for !__ASSUME_FUTEX_CLOCK_REALTIME.
* nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock): Assume
__ASSUME_FUTEX_CLOCK_REALTIME support.
* sysdeps/unix/sysv/linux/i386/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_FUTEX_CLOCK_REALTIME): Remove.
* sysdeps/nptl/lowlevellock-futex.h (lll_futex_timed_wait_bitset):
Adjust comment.
sys/procfs.h was already using this sysdeps directory.
This avoids the need for nptl-specific wrapper headers under
include/, a generic location in the source tree.
Patch ce7eb0e903 ("nptl: Cleanup cancellation macros") changed the
join sequence for internal common __pthread_timedjoin_ex to use the
new macro lll_wait_tid. The idea was this macro would issue the
cancellable futex operation depending whether the timeout is used or
not. However if a timeout is used, __lll_timedwait_tid is called and
it is not a cancellable entrypoint.
This patch fixes it by simplifying the code in various ways:
- Instead of adding the cancellation handling on __lll_timedwait_tid,
it moves the generic implementation to pthread_join_common.c (called
now timedwait_tid with some fixes to use the correct type for pid).
- The llvm_wait_tid macro is removed, along with its replication on
x86_64, i686, and sparc arch-specific lowlevellock.h.
- sparc32 __lll_timedwait_tid is also removed, since the code is similar
to generic one.
- x86_64 and i386 provides arch-specific __lll_timedwait_tid which is
also removed since they are similar in functionality to generic C code
and there is no indication it is better than compiler generated code.
New tests, tst-join8 and tst-join9, are provided to check if
pthread_timedjoin_np acts as a cancellation point.
Checked on x86_64-linux-gnu, i686-linux-gnu, sparcv9-linux-gnu, and
aarch64-linux-gnu.
[BZ #24215]
* nptl/Makefile (lpthread-routines): Remove lll_timedwait_tid.
(tests): Add tst-join8 tst-join9.
* nptl/lll_timedwait_tid.c: Remove file.
* sysdeps/sparc/sparc32/lll_timedwait_tid.c: Likewise.
* sysdeps/unix/sysv/linux/i386/lll_timedwait_tid.c: Likewise.
* sysdeps/sysv/linux/x86_64/lll_timedwait_tid.c: Likewise.
* nptl/pthread_join_common.c (timedwait_tid): New function.
(__pthread_timedjoin_ex): Act as cancellation entrypoint is block
is set.
* nptl/tst-join5.c (thread_join): New function.
(tf1, tf2, do_test): Use libsupport and add pthread_timedjoin_np
check.
* nptl/tst-join8.c: New file.
* nptl/tst-join9.c: Likewise.
* sysdeps/nptl/lowlevellock-futex.h (lll_futex_wait_cancel,
lll_futex_timed_wait_cancel): Add generic macros.
* sysdeps/nptl/lowlevellock.h (__lll_timedwait_tid, lll_wait_tid):
Remove definitions.
* sysdeps/unix/sysv/linux/i386/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Likewise.
* sysdeps/sparc/sparc32/lowlevellock.c (__lll_timedwait_tid):
Remove function.
* sysdeps/unix/sysv/linux/i386/lowlevellock.S (__lll_timedwait_tid):
Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
* sysdeps/unix/sysv/linux/lowlevellock-futex.h
(lll_futex_timed_wait_cancel): New macro.
Commit 27761a1042 ("Refactor atfork
handlers") introduced a lock, atfork_lock, around fork handler list
accesses. It turns out that this lock occasionally results in
self-deadlocks in malloc/tst-mallocfork2:
(gdb) bt
#0 __lll_lock_wait_private ()
at ../sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:63
#1 0x00007f160c6f927a in __run_fork_handlers (who=(unknown: 209394016),
who@entry=atfork_run_prepare) at register-atfork.c:116
#2 0x00007f160c6b7897 in __libc_fork () at ../sysdeps/nptl/fork.c:58
#3 0x00000000004027d6 in sigusr1_handler (signo=<optimized out>)
at tst-mallocfork2.c:80
#4 sigusr1_handler (signo=<optimized out>) at tst-mallocfork2.c:64
#5 <signal handler called>
#6 0x00007f160c6f92e4 in __run_fork_handlers (who=who@entry=atfork_run_parent)
at register-atfork.c:136
#7 0x00007f160c6b79a2 in __libc_fork () at ../sysdeps/nptl/fork.c:152
#8 0x0000000000402567 in do_test () at tst-mallocfork2.c:156
#9 0x0000000000402dd2 in support_test_main (argc=1, argv=0x7ffc81ef1ab0,
config=config@entry=0x7ffc81ef1970) at support_test_main.c:350
#10 0x0000000000402362 in main (argc=<optimized out>, argv=<optimized out>)
at ../support/test-driver.c:168
If no locking happens in the single-threaded case (where fork is
expected to be async-signal-safe), this deadlock is avoided.
(pthread_atfork is not required to be async-signal-safe, so a fork
call from a signal handler interrupting pthread_atfork is not
a problem.)
This patch wraps all uses of *_{enable,disable}_asynccancel and
and *_CANCEL_{ASYNC,RESET} in either already provided macros
(lll_futex_timed_wait_cancel) or creates new ones if the
functionality is not provided (SYSCALL_CANCEL_NCS, lll_futex_wait_cancel,
and lll_futex_timed_wait_cancel).
Also for some generic implementations, the direct call of the macros
are removed since the underlying symbols are suppose to provide
cancellation support.
This is a priliminary patch intended to simplify the work required
for BZ#12683 fix. It is a refactor change, no semantic changes are
expected.
Checked on x86_64-linux-gnu and i686-linux-gnu.
* nptl/pthread_join_common.c (__pthread_timedjoin_ex): Use
lll_wait_tid with timeout.
* nptl/sem_wait.c (__old_sem_wait): Use lll_futex_wait_cancel.
* sysdeps/nptl/aio_misc.h (AIO_MISC_WAIT): Use
futex_reltimed_wait_cancelable for cancelabla mode.
* sysdeps/nptl/gai_misc.h (GAI_MISC_WAIT): Likewise.
* sysdeps/posix/open64.c (__libc_open64): Do not call cancelation
macros.
* sysdeps/posix/sigwait.c (__sigwait): Likewise.
* sysdeps/posix/waitid.c (__sigwait): Likewise.
* sysdeps/unix/sysdep.h (__SYSCALL_CANCEL_CALL,
SYSCALL_CANCEL_NCS): New macro.
* sysdeps/nptl/lowlevellock.h (lll_wait_tid): Add timeout argument.
(lll_timedwait_tid): Remove macro.
* sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_wait_tid):
Likewise.
(lll_timedwait_tid): Likewise.
* sysdeps/unix/sysv/linux/sparc/lowlevellock.h (lll_wait_tid):
Likewise.
(lll_timedwait_tid): Likewise.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_wait_tid):
Likewise.
(lll_timedwait_tid): Likewise.
* sysdeps/unix/sysv/linux/clock_nanosleep.c (__clock_nanosleep):
Use INTERNAL_SYSCALL_CANCEL.
* sysdeps/unix/sysv/linux/futex-internal.h
(futex_reltimed_wait_cancelable): Use LIBC_CANCEL_{ASYNC,RESET}
instead of __pthread_{enable,disable}_asynccancel.
* sysdeps/unix/sysv/linux/lowlevellock-futex.h
(lll_futex_wait_cancel): New macro.
The _chk variants of all of the printf functions become much simpler.
This is the last thing that we needed _IO_acquire_lock_clear_flags2
for, so it can go as well. I took the opportunity to make the headers
included and the names of all local variables consistent across all the
affected files.
Since we ultimately want to get rid of __no_long_double as well, it
must be possible to get all of the nontrivial effects of the _chk
functions by calling the _internal functions with appropriate flags.
For most of the __(v)xprintf_chk functions, this is covered by
PRINTF_FORTIFY plus some up-front argument checks that can be
duplicated. However, __(v)sprintf_chk installs a custom jump table so
that it can crash instead of overflowing the output buffer. This
functionality is moved to __vsprintf_internal, which now has a
'maxlen' argument like __vsnprintf_internal; to get the unsafe
behavior of ordinary (v)sprintf, pass -1 for that argument.
obstack_printf_chk and obstack_vprintf_chk are no longer in the same
file.
As a side-effect of the unification of both fortified and non-fortified
vdprintf initialization, this patch fixes bug 11319 for __dprintf_chk
and __vdprintf_chk, which was previously fixed only for dprintf and
vdprintf by the commit
commit 7ca890b88e
Author: Ulrich Drepper <drepper@redhat.com>
Date: Wed Feb 24 16:07:57 2010 -0800
Fix reporting of I/O errors in *dprintf functions.
This patch adds a test case to avoid regressions.
Tested for powerpc and powerpc64le.
This patch does not have any functionality change, we only provide a spin
count tunes for pthread adaptive spin mutex. The tunable
glibc.pthread.mutex_spin_count tunes can be used by system administrator to
squeeze system performance according to different hardware capabilities and
workload characteristics.
The maximum value of spin count is limited to 32767 to avoid the overflow
of mutex->__data.__spins variable with the possible type of short in
pthread_mutex_lock ().
The default value of spin count is set to 100 with the reference to the
previous number of times of spinning via trylock. This value would be
architecture-specific and can be tuned with kinds of benchmarks to fit most
cases in future.
I would extend my appreciation sincerely to H.J.Lu for his help to refine
this patch series.
* manual/tunables.texi (POSIX Thread Tunables): New node.
* nptl/Makefile (libpthread-routines): Add pthread_mutex_conf.
* nptl/nptl-init.c: Include pthread_mutex_conf.h
(__pthread_initialize_minimal_internal) [HAVE_TUNABLES]: Call
__pthread_tunables_init.
* nptl/pthreadP.h (MAX_ADAPTIVE_COUNT): Remove.
(max_adaptive_count): Define.
* nptl/pthread_mutex_conf.c: New file.
* nptl/pthread_mutex_conf.h: New file.
* sysdeps/generic/adaptive_spin_count.h: New file.
* sysdeps/nptl/dl-tunables.list: New file.
* nptl/pthread_mutex_lock.c (__pthread_mutex_lock): Use
max_adaptive_count () not MAX_ADAPTIVE_COUNT.
* nptl/pthread_mutex_timedlock.c (__pthrad_mutex_timedlock):
Likewise.
Suggested-by: Andi Kleen <andi.kleen@intel.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Signed-off-by: Kemi.wang <kemi.wang@intel.com>
The race leads either to pthread_mutex_destroy returning EBUSY
or triggering an assertion (See description in bugzilla).
This patch is fixing the race by ensuring that the elision path is
used in all cases if elision is enabled by the GLIBC_TUNABLES framework.
The __kind variable in struct __pthread_mutex_s is accessed concurrently.
Therefore we are now using the atomic macros.
The new testcase tst-mutex10 is triggering the race on s390x and intel.
Presumably also on power, but I don't have access to a power machine
with lock-elision. At least the code for power is the same as on the other
two architectures.
ChangeLog:
[BZ #23275]
* nptl/tst-mutex10.c: New File.
* nptl/Makefile (tests): Add tst-mutex10.
(tst-mutex10-ENV): New variable.
* sysdeps/unix/sysv/linux/s390/force-elision.h: (FORCE_ELISION):
Ensure that elision path is used if elision is available.
* sysdeps/unix/sysv/linux/powerpc/force-elision.h (FORCE_ELISION):
Likewise.
* sysdeps/unix/sysv/linux/x86/force-elision.h: (FORCE_ELISION):
Likewise.
* nptl/pthreadP.h (PTHREAD_MUTEX_TYPE, PTHREAD_MUTEX_TYPE_ELISION)
(PTHREAD_MUTEX_PSHARED): Use atomic_load_relaxed.
* nptl/pthread_mutex_consistent.c (pthread_mutex_consistent): Likewise.
* nptl/pthread_mutex_getprioceiling.c (pthread_mutex_getprioceiling):
Likewise.
* nptl/pthread_mutex_lock.c (__pthread_mutex_lock_full)
(__pthread_mutex_cond_lock_adjust): Likewise.
* nptl/pthread_mutex_setprioceiling.c (pthread_mutex_setprioceiling):
Likewise.
* nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock): Likewise.
* nptl/pthread_mutex_trylock.c (__pthread_mutex_trylock): Likewise.
* nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full): Likewise.
* sysdeps/nptl/bits/thread-shared-types.h (struct __pthread_mutex_s):
Add comments.
* nptl/pthread_mutex_destroy.c (__pthread_mutex_destroy):
Use atomic_load_relaxed and atomic_store_relaxed.
* nptl/pthread_mutex_init.c (__pthread_mutex_init):
Use atomic_store_relaxed.
Set installed NPTL header as the expected one (instead of an
internal one for glibc testsuite) and add a hurd specific
stdc-predef with __STDC_NO_THREADS__.
Checked on both i686-linux-gnu and i686-gnu that both threads.h
and stdc-predef.h are the expected ones.
* nptl/threads.h: Move to ...
* sysdeps/nptl/threads.h: ... here.
* sysdeps/hurd/stdc-predef.h: New file.
Remove conformace assumption of NPTL implementation for ISO C threads
and revert wrong libcrypt addition on linknamespace-libs-XPG4.
The i686-gnu target now shows two new conformance failures:
FAIL: conform/ISO11/threads.h/conform
FAIL: conform/ISO11/threads.h/linknamespace
It is expected due missing HTL ISO C threads support and both conformance
.out files indicates the reason ("#error "HTL does not implement ISO C
threads").
Checked on i686-linux-gnu and i686-gnu.
* include/threads.h: Move to ...
* sysdeps/nptl/threads.h: ... here.
* sysdeps/htl/threads.h: New file.
* conform/Makefile (linknamespace-libs-ISO11): Use
static-thread-library instead of linking libpthread.
(linknamespace-libs-XPG4): Revert wrong libcrypt.a addition.
The __libc_freeres framework does not extend to non-libc.so objects.
This causes problems in general for valgrind and mtrace detecting
unfreed objects in both libdl.so and libpthread.so. This change is
a pre-requisite to properly moving the malloc hooks out of malloc
since such a move now requires precise accounting of all allocated
data before destructors are run.
This commit adds a proper hook in libc.so.6 for both libdl.so and
for libpthread.so, this ensures that shm-directory.c which uses
freeit () to free memory is called properly. We also remove the
nptl_freeres hook and fall back to using weak-ref-and-check idiom
for a loaded libpthread.so, thus making this process similar for
all DSOs.
Lastly we follow best practice and use explicit free calls for
both libdl.so and libpthread.so instead of the generic hook process
which has undefined order.
Tested on x86_64 with no regressions.
Signed-off-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
On s390 (31bit) if glibc is build with -Os, pthread_join sometimes
blocks indefinitely. This is e.g. observable with
testcase intl/tst-gettext6.
pthread_join is calling lll_wait_tid(tid), which performs the futex-wait
syscall in a loop as long as tid != 0 (thread is alive).
On s390 (and build with -Os), tid is loaded from memory before
comparing against zero and then the tid is loaded a second time
in order to pass it to the futex-wait-syscall.
If the thread exits in between, then the futex-wait-syscall is
called with the value zero and it waits until a futex-wake occurs.
As the thread is already exited, there won't be a futex-wake.
In lll_wait_tid, the tid is stored to the local variable __tid,
which is then used as argument for the futex-wait-syscall.
But unfortunately the compiler is allowed to reload the value
from memory.
With this patch, the tid is loaded with atomic_load_acquire.
Then the compiler is not allowed to reload the value for __tid from memory.
ChangeLog:
[BZ #23137]
* sysdeps/nptl/lowlevellock.h (lll_wait_tid):
Use atomic_load_acquire to load __tid.
Prevent random runtime crashes due to missing symbols caused by mixed
libnss_* versions.
[BZ #22766]
* include/dlfcn.h [__libc_dl_open]: Replace RTLD_LAZY with RTLD_NOW.
* sysdeps/gnu/unwind-resume.c (__lib_gcc_s_init): Replace
__libc_dlopen_mode() using RTLD_NOW with __libc_dlopen.
* sysdeps/nptl/unwind-forcedunwind.c: Likewise.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
This patch filters out the internal NPTL signals (SIGCANCEL/SIGTIMER and
SIGSETXID) from signal functions. GLIBC on Linux requires both signals to
proper implement pthread cancellation, posix timers, and set*id posix
thread synchronization.
And not filtering out the internal signal is troublesome:
- A conformant program on a architecture that does not filter out the
signals might inadvertently disable pthread asynchronous cancellation,
set*id synchronization or posix timers.
- It might also to security issues if SIGSETXID is masked and set*id
functions are called (some threads might have effective user or group
id different from the rest).
The changes are basically:
- Change __is_internal_signal to bool and used on all signal function
that has a signal number as input. Also for signal function which accepts
signals sets (sigset_t) it assumes that canonical function were used to
add/remove signals which lead to some input simplification.
- Fix tst-sigset.c to avoid check for SIGCANCEL/SIGTIMER and SIGSETXID.
It is rewritten to check each signal indidually and to check realtime
signals using canonical macros.
- Add generic __clear_internal_signals and __is_internal_signal
version since both symbols are used on generic implementations.
- Remove superflous sysdeps/nptl/sigfillset.c.
- Remove superflous SIGTIMER handling on Linux __is_internal_signal
since it is the same of SIGCANCEL.
- Remove dangling define and obvious comment on nptl/sigaction.c.
Checked on x86_64-linux-gnu.
[BZ #22391]
* nptl/sigaction.c (__sigaction): Use __is_internal_signal to
check for internal nptl signals.
* nptl/sigaction.c (__sigaction): Likewise.
* signal/sigaddset.c (sigaddset): Likewise.
* signal/sigdelset.c (sigdelset): Likewise.
* sysdeps/posix/signal.c (__bsd_signal): Likewise.
* sysdeps/posix/sigset.c (sigset): Call and check sigaddset return
value.
* signal/sigfillset.c (sigfillset): User __clear_internal_signals
to filter out internal nptl signals.
* signal/tst-sigset.c (do_test): Check ech signal indidually and
also check realtime signals using standard macros.
* sysdeps/generic/internal-signals.h (__clear_internal_signals,
__is_internal_signal, __libc_signal_block_all,
__libc_signal_block_app, __libc_signal_restore_set): New functions.
* sysdeps/nptl/sigfillset.c: Remove file.
* sysdeps/unix/sysv/linux/internal-signals.h (__is_internal_signal):
Change return to bool.
(__clear_internal_signals): Remove SIGTIMER clean since it is
equal to SIGCANEL on Linux.
* sysdeps/unix/sysv/linux/sigtimedwait.c (__sigtimedwait): Assume
signal set was constructed using standard functions.
Reported-by: Yury Norov <ynorov@caviumnetworks.com>
This patch refactors the ARCH_FORK macro and the required architecture
specific header to simplify the required architecture definitions
to provide the fork syscall semantic and proper document current
Linux clone ABI variant.
Instead of require the reimplementation of arch-fork.h header, this
patch changes the ARCH_FORK to an inline function with clone ABI
defined by kernel-features.h define. The generic kernel ABI meant
for newer ports is used as default and redefine if the architecture
requires.
Checked on x86_64-linux-gnu and i686-linux-gnu. Also with a build
for all the afected ABIs.
* sysdeps/nptl/fork.c (ARCH_FORK): Replace by auch_fork.
* sysdeps/unix/sysv/linux/alpha/arch-fork.h: Remove file.
* sysdeps/unix/sysv/linux/riscv/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/aarch64/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/arm/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/hppa/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/i386/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/ia64/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/m68k/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/microblaze/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/mips/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/nios2/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/s390/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/sh/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/tile/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/x86_64/arch-fork.h: Likewise.
* sysdeps/unix/sysv/linux/arch-fork.h (arch_fork): New function.
* sysdeps/unix/sysv/linux/aarch64/kernel-features.h: New file.
* sysdeps/unix/sysv/linux/riscv/kernel-features.h: Likewise.
* sysdeps/unix/sysv/linux/arm/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Define.
* sysdeps/unix/sysv/linux/createthread.c (ARCH_CLONE): Define to
__clone2 if __NR_clone2 is defined.
* sysdeps/unix/sysv/linux/hppa/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Likewise.
* sysdeps/unix/sysv/linux/i386/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Likewise.
* sysdeps/unix/sysv/linux/ia64/kernel-features.h
(__ASSUME_CLONE2): Likewise.
* sysdeps/unix/sysv/linux/microblaze/kernel-features.h
(__ASSUME_CLONE_BACKWARDS3): Likewise.
* sysdeps/unix/sysv/linux/kernel-features.h: Document possible clone
variants and the define architecture can use.
(__ASSUME_CLONE_DEFAULT): Define as default.
* sysdeps/unix/sysv/linux/mips/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Likewise.
* sysdeps/unix/sysv/linux/powerpc/kernel-features.h
(__ASSUME_CLONE_BACKWARDS): Likewise.
* sysdeps/unix/sysv/linux/s390/kernel-features.h
(__ASSUME_CLONE_BACKWARDS2): Likewise.
