On arches that set _STACK_GROWS_UP, the stacktop variable is declared
and set, but never actually used. Refactor the code a bit so that the
variable is only declared/set under _STACK_GROWS_DOWN settings.
The recently introduced TLS variables in the thread-local destructor
implementation (__cxa_thread_atexit_impl) used the default GD access
model, resulting in a call to __tls_get_addr. This causes a deadlock
with recent changes to the way TLS is initialized because DTV
allocations are delayed and hence despite knowing the offset to the
variable inside its TLS block, the thread has to take the global rtld
lock to safely update the TLS offset.
This causes deadlocks when a thread is instantiated and joined inside
a destructor of a dlopen'd DSO. The correct long term fix is to
somehow not take the lock, but that will need a lot deeper change set
to alter the way in which the big rtld lock is used.
Instead, this patch just eliminates the call to __tls_get_addr for the
thread-local variables inside libc.so, libpthread.so and rtld by
building all of their units with -mtls-model=initial-exec.
There were concerns that the static storage for TLS is limited and
hence we should not be using it. Additionally, dynamically loaded
modules may result in libc.so looking for this static storage pretty
late in static binaries. Both concerns are valid when using TLSDESC
since that is where one may attempt to allocate a TLS block from
static storage for even those variables that are not IE. They're not
very strong arguments for the traditional TLS model though, since it
assumes that the static storage would be used sparingly and definitely
not by default. Hence, for now this would only theoretically affect
ARM architectures.
The impact is hence limited to statically linked binaries that dlopen
modules that in turn load libc.so, all that on arm hardware. It seems
like a small enough impact to justify fixing the larger problem that
currently affects everything everywhere.
This still does not solve the original problem completely. That is,
it is still possible to deadlock on the big rtld lock with a small
tweak to the test case attached to this patch. That problem is
however not a regression in 2.22 and hence could be tackled as a
separate project. The test case is picked up as is from Alex's patch.
This change has been tested to verify that it does not cause any
issues on x86_64.
ChangeLog:
[BZ #18457]
* nptl/Makefile (tests): New test case tst-join7.
(modules-names): New test case module tst-join7mod.
* nptl/tst-join7.c: New file.
* nptl/tst-join7mod.c: New file.
* Makeconfig (tls-model): Pass -ftls-model=initial-exec for
all translation units in libc.so, libpthread.so and rtld.
The Linux kernel futex documentation now states that since Linux 2.6.22,
FUTEX_WAIT does return EINTR only when interrupted by a signal, and not
spuriously anymore. We only support more recent kernels, so clean up
EINTR handling in the semaphore and update the comments.
This adds new functions for futex operations, starting with wait,
abstimed_wait, reltimed_wait, wake. They add documentation and error
checking according to the current draft of the Linux kernel futex manpage.
Waiting with absolute or relative timeouts is split into separate functions.
This allows for removing a few cases of code duplication in pthreads code,
which uses absolute timeouts; also, it allows us to put platform-specific
code to go from an absolute to a relative timeout into the platform-specific
futex abstractions..
Futex operations that can be canceled are also split out into separate
functions suffixed by "_cancelable".
There are separate versions for both Linux and NaCl; while they currently
differ only slightly, my expectation is that the separate versions of
lowlevellock-futex.h will eventually be merged into futex-internal.h
when we get to move the lll_ functions over to the new futex API.
and also powerpc64 and powerpc64le. See the discussion in the thread
below for details. This change reverts the problematic bits leaving
the added test in place and marking XFAIL in anticipation of fixing
the bug in the near future.
https://sourceware.org/ml/libc-alpha/2015-07/msg00141.html
[BZ #18435]
* nptl/pthreadP.h (pthread_cleanup_push, pthread_cleanup_pop):
Revert commit ed225df3ad.
* nptl/Makefile (test-xfail-tst-once5): Define.
the initialization routine to exit by throwing an exception.
Such an execution, termed exceptional, requires call_once to
propagate the exception to its caller. A program may contain
any number of exceptional executions but only one returning
execution (which, if it exists, must be the last execution
with the same once flag).
On POSIX systems such as Linux, std::call_once is implemented
in terms of pthread_once. However, as discussed in libstdc++
bug 66146 - "call_once not C++11-compliant on ppc64le," GLIBC's
pthread_once hangs when the initialization function exits by
throwing an exception on at least arm and ppc64 (though
apparently not on x86_64). This effectively prevents call_once
from conforming to the C++ requirements since there doesn't
appear to be a thread-safe way to work around this problem in
libstdc++.
This patch changes pthread_once to handle gracefully init
functions that exit by throwing exceptions. It was successfully
tested on ppc64, ppc64le, and x86_64.
[BZ #18435]
* nptl/Makefile: Add tst-once5.cc.
* nptl/pthreadP.h (pthread_cleanup_push, pthread_cleanup_pop):
Remove macro redefinitions.
* nptl/tst-once5.cc: New test.
The probes are not provided on all architectures (and only partially by the
x86 assembly implementation), and we are not aware of actual uses of these
probes.
a need for them.
This patch combines BUSY_WAIT_NOP and atomic_delay into a new
atomic_spin_nop function and adjusts all clients. The new function is
put into atomic.h because what is best done in a spin loop is
architecture-specific, and atomics must be used for spinning. The
function name is meant to tell users that this has no effect on
synchronization semantics but is a performance aid for spinning.
mq_notify (present in POSIX by 1996) brings in references to
pthread_barrier_init and pthread_barrier_wait (new in the 2001 edition
of POSIX). This patch fixes this by making those functions into weak
aliases of __pthread_barrier_*, exporting the __pthread_barrier_*
names at version GLIBC_PRIVATE and using them in mq_notify.
Tested for x86_64 and x86 (testsuite, and comparison of installed
stripped shared libraries). Changes in addresses from dynamic symbol
table / PLT changes render most comparisons not particularly useful,
but when the addresses of subsequent code don't change there's no sign
of unexpected changes there. This patch does not remove any
linknamespace XFAILs because of other namespace issues remaining with
mqueue.h functions.
[BZ #18544]
* nptl/pthread_barrier_init.c (pthread_barrier_init): Rename to
__pthread_barrier_init and define as weak alias of
__pthread_barrier_init.
* sysdeps/sparc/nptl/pthread_barrier_init.c
(pthread_barrier_init): Likewise.
* nptl/pthread_barrier_wait.c (pthread_barrier_wait): Rename to
__pthread_barrier_wait and define as weak alias of
__pthread_barrier_wait.
* sysdeps/sparc/nptl/pthread_barrier_wait.c
(pthread_barrier_wait): Likewise.
* sysdeps/sparc/sparc32/pthread_barrier_wait.c
(pthread_barrier_wait): Likewise.
* sysdeps/unix/sysv/linux/i386/i486/pthread_barrier_wait.S
(pthread_barrier_wait): Likewise.
* sysdeps/unix/sysv/linux/x86_64/pthread_barrier_wait.S
(pthread_barrier_wait): Likewise.
* nptl/Versions (libpthread): Export __pthread_barrier_init and
__pthread_barrier_wait at version GLIBC_PRIVATE.
* include/pthread.h (__pthread_barrier_init): Declare.
(__pthread_barrier_wait): Likewise.
* sysdeps/unix/sysv/linux/mq_notify.c (notification_function):
Call __pthread_barrier_wait instead of pthread_barrier_wait.
(helper_thread): Likewise.
(init_mq_netlink): Call __pthread_barrier_init instead of
pthread_barrier_init.
The sem_* functions bring in references to tdelete, tfind, tsearch and
twalk. But the t* functions are XSI-shaded, while sem_* aren't. This
patch fixes this by using __t* instead, exporting those functions from
libc at version GLIBC_PRIVATE (since sem_* are in libpthread) and
using libc_hidden_* for the benefit of calls within libc.
Tested for x86_64 and x86 (testsuite, and comparison of disassembly of
installed stripped shared libraries). libpthread gets changes from
PLT reordering; addresses in libc change because of PLT / dynamic
symbol table changes.
[BZ #18536]
* misc/tsearch.c (__tsearch): Use libc_hidden_def.
(__tfind): Likewise.
(__tdelete): Likewise.
(__twalk): Likewise.
* misc/Versions (libc): Add __tdelete, __tfind, __tsearch and
__twalk to GLIBC_PRIVATE.
* include/search.h (__tsearch): Use libc_hidden_proto.
(__tfind): Likewise.
(__tdelete): Likewise.
(__twalk): Likewise.
* nptl/sem_close.c (sem_close): Call __twalk instead of twalk.
Call __tdelete instead of tdelete.
* nptl/sem_open.c (check_add_mapping): Call __tfind instead of
tfind. Call __tsearch instead of tsearch.
* sysdeps/sparc/sparc32/sem_open.c (check_add_mapping): Likewise.
* conform/Makefile (test-xfail-POSIX/semaphore.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/semaphore.h/linknamespace): Likewise.
The 2008 edition of POSIX removed h_errno, but some functions still
bring in references to the h_errno external symbol. As this symbol is
not a part of the public ABI (only __h_errno_location is), this patch
fixes this by renaming the GLIBC_PRIVATE TLS symbol to __h_errno.
Tested for x86_64 and x86 (testsuite, and comparison of installed
shared libraries). Disassembly of all shared libraries using h_errno
changes because of the renaming (and changes to associated TLS / GOT
offsets in some cases); disassembly of libpthread on x86_64 changes
more substantially because the enlargement of .dynsym affects
subsequent addresses.
[BZ #18520]
* inet/herrno.c (h_errno): Rename to __h_errno.
(__libc_h_errno): Define as alias of __h_errno not h_errno.
* include/netdb.h [IS_IN_LIB && !IS_IN (libc)] (h_errno): Define
to __h_errno instead of h_errno.
* nptl/herrno.c (h_errno): Rename to __h_errno.
(__h_errno_location): Refer to __h_errno not h_errno.
* resolv/Versions (h_errno): Rename to __h_errno.
* conform/Makefile (test-xfail-XOPEN2K8/grp.h/linknamespace):
Remove variable.
(test-xfail-XOPEN2K8/pwd.h/linknamespace): Likewise.
In commit 02657da2cf, .interp section
was removed from libpthread.so. This led to an error:
$ /lib64/libpthread.so.0
Native POSIX Threads Library by Ulrich Drepper et al
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE.
Forced unwind support included.
Segmentation fault
(gdb) bt
#0 0x00000000000055a6 in _exit@plt ()
Unfortunately, there is no way to add a regression test for the bug
because .interp specifies the path to dynamic linker of the target
system.
[BZ #18479]
* nptl/pt-interp.c: New file.
* nptl/Makefile (libpthread-routines, libpthread-shared-only-routines):
Add pt-interp.
[$(build-shared) = yes] ($(objpfx)pt-interp.os): Depend on
$(common-objpfx)runtime-linker.h.
This adds wake-ups that would be missing if assuming that for a
non-writer-preferring rwlock, if one thread has acquired a rdlock and
does not release it, another thread will eventually acquire a rdlock too
despite concurrent write lock acquisition attempts. BZ 14958 is about
supporting this assumption. Strictly speaking, this isn't a valid
test case, but nonetheless worth supporting (see comment 7 of BZ 14958).
If we set up a rwlock to prefer writers (and disallow recursive rdlock
acquisitions), then readers will block for writers that are blocked to
acquire the lock (otherwise, readers could constantly enter and exit,
and the writer would never get the lock). However, the existing
implementation did not wake such readers when the writer timed out.
This patch adds the missing wake-up.
There's no similar case for writers being blocked on readers.
This patch removes the socket.S implementation for all ports and replace
it by a C implementation using socketcall. For ports that implement
the syscall directly, there is no change.
The patch idea is to simplify the socket function implementation that
uses the socketcall to be based on C implemetation instead of a pseudo
assembly implementation with arch specific parts. The patch then remove
the assembly implementatation for the ports which uses socketcall
(i386, microblaze, mips, powerpc, sparc, m68k, s390 and sh).
I have cross-build GLIBC for afore-mentioned ports and tested on both
i386 and ppc32 without regressions.
While trying to get nptl/tst-initializers1.c to include the test skeleton, I
came across a couple of speed bumps. Firstly: after making the appropriate
changes to the test, running `make check' led to this error:
> In file included from ../malloc/malloc.h:24:0,
..
> from tst-initializers1.c:60:
> ../include/stdio.h:111:1: error: unknown type name `wint_t'
> extern wint_t __getwc_unlocked (FILE *__fp);
So, `wint_t' is used before being defined. Question: Why did test-skeleton.c
not cause this error in any of the other tests that include it?
Anyway, I noticed include/stdio.h includes stddef.h, which in turn defines
`wint_t', but only if `__need_wint_t' is defined. So I put in a
`#define __need_wint_t' before the include to get rid of the error. Is that
the correct fix?
A subsequent `make && make check' led to this second error:
> from tst-initializers1-c89.c:1:
> ../test-skeleton.c: In function `main':
> ../test-skeleton.c:356:11: error: `for' loop initial declarations are only
> allowed in C99 mode
> for (struct temp_name_list *n = temp_name_list;
Although there seem to be several other C89 no-noes in test-skeleton.c, I
needed only to fix this specific one for gcc-4.8.3 to stop complaining.
sem_timedwait converts absolute timeouts to relative to pass them to
the futex syscall. (Before the recent reimplementation, on x86_64 it
used FUTEX_CLOCK_REALTIME, but not on other architectures.)
Correctly implementing POSIX requirements, however, requires use of
FUTEX_CLOCK_REALTIME; passing a relative timeout to the kernel does
not conform to POSIX. The POSIX specification for sem_timedwait says
"The timeout shall be based on the CLOCK_REALTIME clock.". The POSIX
specification for clock_settime says "If the value of the
CLOCK_REALTIME clock is set via clock_settime(), the new value of the
clock shall be used to determine the time of expiration for absolute
time services based upon the CLOCK_REALTIME clock. This applies to the
time at which armed absolute timers expire. If the absolute time
requested at the invocation of such a time service is before the new
value of the clock, the time service shall expire immediately as if
the clock had reached the requested time normally.". If a relative
timeout is passed to the kernel, it is interpreted according to the
CLOCK_MONOTONIC clock, and so fails to meet that POSIX requirement in
the event of clock changes.
This patch makes sem_timedwait use lll_futex_timed_wait_bitset with
FUTEX_CLOCK_REALTIME when possible, as done in some other places in
NPTL. FUTEX_CLOCK_REALTIME is always available for supported Linux
kernel versions; unavailability of lll_futex_timed_wait_bitset is only
an issue for hppa (an issue noted in
<https://sourceware.org/glibc/wiki/PortStatus>, and fixed by the
unreviewed
<https://sourceware.org/ml/libc-alpha/2014-12/msg00655.html> that
removes the hppa lowlevellock.h completely).
In the FUTEX_CLOCK_REALTIME case, the glibc code still needs to check
for negative tv_sec and handle that as timeout, because the Linux
kernel returns EINVAL not ETIMEDOUT for that case, so resulting in
failures of nptl/tst-abstime and nptl/tst-sem13 in the absence of that
check. If we're trying to distinguish between Linux-specific and
generic-futex NPTL code, I suppose having this in an nptl/ file isn't
ideal, but there doesn't seem to be any better place at present.
It's not possible to add a testcase for this issue to the testsuite
because of the requirement to change the system clock as part of a
test (this is a case where testing would require some form of
container, with root in that container, and one whose CLOCK_REALTIME
is isolated from that of the host; I'm not sure what forms of
containers, short of a full virtual machine, provide that clock
isolation).
Tested for x86_64. Also tested for powerpc with the testcase included
in the bug.
[BZ #18138]
* nptl/sem_waitcommon.c: Include <kernel-features.h>.
(futex_abstimed_wait)
[__ASSUME_FUTEX_CLOCK_REALTIME && lll_futex_timed_wait_bitset]:
Use lll_futex_timed_wait_bitset with FUTEX_CLOCK_REALTIME instead
of lll_futex_timed_wait.
for ChangeLog
[BZ #17090]
[BZ #17620]
[BZ #17621]
[BZ #17628]
* NEWS: Update.
* elf/dl-tls.c (_dl_update_slotinfo): Clean up outdated DTV
entries with Static TLS too. Skip entries past the end of the
allocated DTV, from Alan Modra.
(tls_get_addr_tail): Update to glibc_likely/unlikely. Move
Static TLS DTV entry set up from...
(_dl_allocate_tls_init): ... here (fix modid assertion), ...
* elf/dl-reloc.c (_dl_nothread_init_static_tls): ... here...
* nptl/allocatestack.c (init_one_static_tls): ... and here...
* elf/dlopen.c (dl_open_worker): Drop l_tls_modid upper bound
for Static TLS.
* elf/tlsdeschtab.h (map_generation): Return size_t. Check
that the slot we find is associated with the given map before
using its generation count.
* nptl_db/db_info.c: Include ldsodefs.h.
(rtld_global, dtv_slotinfo_list, dtv_slotinfo): New typedefs.
* nptl_db/structs.def (DB_RTLD_VARIABLE): New macro.
(DB_MAIN_VARIABLE, DB_RTLD_GLOBAL_FIELD): Likewise.
(link_map::l_tls_offset): New struct field.
(dtv_t::counter): Likewise.
(rtld_global): New struct.
(_rtld_global): New rtld variable.
(dl_tls_dtv_slotinfo_list): New rtld global field.
(dtv_slotinfo_list): New struct.
(dtv_slotinfo): Likewise.
* nptl_db/td_symbol_list.c: Drop gnu/lib-names.h include.
(td_lookup): Rename to...
(td_mod_lookup): ... this. Use new mod parameter instead of
LIBPTHREAD_SO.
* nptl_db/td_thr_tlsbase.c: Include link.h.
(dtv_slotinfo_list, dtv_slotinfo): New functions.
(td_thr_tlsbase): Check DTV generation. Compute Static TLS
addresses even if the DTV is out of date or missing them.
* nptl_db/fetch-value.c (_td_locate_field): Do not refuse to
index zero-length arrays.
* nptl_db/thread_dbP.h: Include gnu/lib-names.h.
(td_lookup): Make it a macro implemented in terms of...
(td_mod_lookup): ... this declaration.
* nptl_db/db-symbols.awk (DB_RTLD_VARIABLE): Override.
(DB_MAIN_VARIABLE): Likewise.
pthread_mutexattr_settype adds PTHREAD_MUTEX_NO_ELISION_NP to kind,
which is an internal flag that pthread_mutexattr_gettype shouldn't
expose, since pthread_mutexattr_settype wouldn't accept it.
This patch replaces unsigned long int and 1UL with uint64_t and
(uint64_t) 1 to support ILP32 targets like x32.
[BZ #17870]
* nptl/sem_post.c (__new_sem_post): Replace unsigned long int
with uint64_t.
* nptl/sem_waitcommon.c (__sem_wait_cleanup): Replace 1UL with
(uint64_t) 1.
(__new_sem_wait_slow): Replace unsigned long int with uint64_t.
Replace 1UL with (uint64_t) 1.
* sysdeps/nptl/internaltypes.h (new_sem): Replace unsigned long
int with uint64_t.
This commit fixes semaphore destruction by either using 64b atomic
operations (where available), or by using two separate fields when only
32b atomic operations are available. In the latter case, we keep a
conservative estimate of whether there are any waiting threads in one
bit of the field that counts the number of available tokens, thus
allowing sem_post to atomically both add a token and determine whether
it needs to call futex_wake.
See:
https://sourceware.org/ml/libc-alpha/2014-12/msg00155.html
Carlos reported failures in conform/ tests in environments where the
compiler used could only find headers in glibc's source and build
trees, not any previously installed headers
<https://sourceware.org/ml/libc-alpha/2014-09/msg00040.html>.
This patch moves nptl/semaphore.h to sysdeps/pthread/semaphore.h so
that it can be found by builds from all glibc subdirectories; it's not
in any way NPTL-specific. (I left the Makefile setting to install
this header in nptl/, but maybe it should move as well - it's just not
clear to me what ifeq ($(subdir),...) conditional should be used to
select the directory to associate the header with for installation
purposes. The path in the toplevel Makefile used for begin-end-check
also remains hardcoded; it's a known todo issue to rework that test to
run in each subdirectory checking the headers installed from that
subdirectory, rather than a separate hardcoded list.)
Tested for x86_64 (testsuite, and that installed stripped shared
libraries are unchanged by the patch). I did *not* test a
configuration such as that in which Carlos saw failure.
* nptl/semaphore.h: Move to ...
* sysdeps/pthread/semaphore.h: ... here.
* Makefile (installed-headers): Change nptl/semaphore.h to
sysdeps/pthread/semaphore.h.
Some pthreads functions use getrlimit and gettimeofday, but these
functions are XSI, not base POSIX; this is a namespace issue for
dynamic linking as well as static linking. This patch makes them use
__getrlimit and __gettimeofday instead - the former needed to be newly
exported from libc.so at GLIBC_PRIVATE (and so now needs
libc_hidden_proto / libc_hidden_def), the latter was already exported.
Tested for x86_64 (testsuite, and that disassembly of installed shared
libraries is unchanged by the patch).
[BZ #17682]
* resource/Versions (libc): Add __getrlimit at GLIBC_PRIVATE.
* resource/getrlimit.c (__getrlimit): Use libc_hidden_def.
* sysdeps/mach/hurd/getrlimit.c (__getrlimit): Likewise.
* include/sys/resource.h (__getrlimit): Use libc_hidden_proto.
* nptl/nptl-init.c (__pthread_initialize_minimal_internal): Use
__getrlimit instead of getrlimit.
* nptl/pthread_cond_timedwait.c (__pthread_cond_timedwait): Use
__gettimeofday instead of gettimeofday.
* nptl/pthread_rwlock_timedrdlock.c (pthread_rwlock_timedrdlock):
Likewise.
* nptl/pthread_rwlock_timedwrlock.c (pthread_rwlock_timedwrlock):
Likewise.
* sysdeps/pthread/aio_misc.c (handle_fildes_io): Likewise.
* conform/Makefile (test-xfail-POSIX2008/aio.h/linknamespace):
Remove variable.
(test-xfail-POSIX2008/pthread.h/linknamespace): Likewise.
(test-xfail-POSIX2008/time.h/linknamespace): Likewise.
This patch fixes a warning in a test that was added since my recent
warning cleanup:
tst-stack4.c: In function 'dso_process':
tst-stack4.c:64:7: warning: format '%i' expects argument of type 'int', but argument 3 has type 'uintptr_t' [-Wformat=]
The original variable has type int then is cast to uintptr_t, and from
there to void *, to pass it to a thread, so reversing the process by
casting to uintptr_t and then to int is natural; this patch does so.
Tested for x86_64.
* nptl/tst-stack4.c (dso_process): Use int not uintptr_t for t.
This patch fixes -Waddress warnings in nptl/tst-mutex1.c from
comparing the address of an object with NULL (ATTR may either be NULL,
or the address of an object when included from other tests, and the
warning arises in the latter case). A macro ATTR_NULL is defined
alongside ATTR and used for the tests.
Tested for x86_64.
* nptl/tst-mutex1.c: Include <stdbool.h>.
[!ATTR] (ATTR_NULL): New macro.
(do_test): Test !ATTR_NULL instead of ATTR != NULL.
* nptl/tst-mutexpi1.c (ATTR_NULL): New macro.
* nptl/tst-mutexpp1.c (ATTR_NULL): New macro.
This patch changes _dl_allocate_tls_init to resize DTV if the current DTV
isn't big enough. Tested on X86-64, x32 and ia32.
[BZ #13862]
* elf/dl-tls.c: Include <atomic.h>.
(oom): Remove #ifdef SHARED/#endif.
(_dl_static_dtv, _dl_initial_dtv): Moved before ...
(_dl_resize_dtv): This. Extracted from _dl_update_slotinfo.
(_dl_allocate_tls_init): Resize DTV if the current DTV isn't
big enough.
(_dl_update_slotinfo): Call _dl_resize_dtv to resize DTV.
* nptl/Makefile (tests): Add tst-stack4.
(modules-names): Add tst-stack4mod.
($(objpfx)tst-stack4): New.
(tst-stack4mod.sos): Likewise.
($(objpfx)tst-stack4.out): Likewise.
($(tst-stack4mod.sos)): Likewise.
(clean): Likewise.
* nptl/tst-stack4.c: New file.
* nptl/tst-stack4mod.c: Likewise.
This patch fixes "../sysdeps/nptl/pthread.h:670:26: warning:
initialization discards 'volatile' qualifier from pointer target type"
arising when building nptl/tst-cancel-self-cancelstate.c. The problem
is passing a volatile int * to a macro expecting void *; the patch
adds an explicit cast.
Tested for x86_64.
* nptl/tst-cancel-self-cancelstate.c (do_test): Cast argument of
pthread_cleanup_push to void *.
This patch removes the first column (patterns matching configuration
names) from shlib-versions, leaving shlib-versions entry selection
based purely on sysdeps directories.
An implication of this removal is that the default for any non-Linux
ports using NPTL will be the same SONAMEs for NPTL libraries as for
Linux (as those defaults, previously limited to .*-.*-linux.*, are
left in nptl/shlib-versions and nptl_db/shlib-versions).
Special host_os handling in configure.ac that was purely for
shlib-versions is removed. (The host_os setting is still used for
libc-abis - see
<https://sourceware.org/ml/libc-alpha/2014-01/msg00375.html> regarding
that - but no entries there are affected by this change.)
Tested on x86_64 and x86 that the installed shared libraries are
unchanged by this patch.
* scripts/soversions.awk: Do not handle configuration names.
* Makeconfig ($(common-objpfx)soversions.i): Do not pass cpu,
vendor and os variables to soversions.awk.
* configure.ac: Do not modify gnu-* host_os.
* configure: Regenerated
* shlib-versions: Remove first column with configuration names.
* nptl/shlib-versions: Likewise.
* nptl_db/shlib-versions: Likewise.
* sysdeps/hppa/shlib-versions: Likewise.
* sysdeps/m68k/shlib-versions: Likewise.
* sysdeps/mach/hurd/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/aarch64/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/alpha/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/arm/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/hppa/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/ia64/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/microblaze/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/mips/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/shlib-versions:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/sh/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/tile/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/shlib-versions: Likewise.
libidn/ChangeLog:
* shlib-versions: Remove first column with configuration names.
This patch eliminates another way in which ex-ports and non-ex-ports
architectures differ, by moving architecture-specific entries from the
top-level shlib-versions file and that in nptl/ to appropriate sysdeps
directories. As with my previous patch
<https://sourceware.org/ml/libc-alpha/2014-06/msg00949.html>, I do not
change the regular expressions used; even where the present
expressions seem more general, I believe they are in fact specific to
the chosen sysdeps directory, because any port that matches the
expression but not the sysdeps directory does not currently exist, and
so would use different symbol versions if added in future (and an
intended goal of these changes is to eliminate the first column in
shlib-versions completely rather than having two different mechanisms
in use for system-specific configuration).
Tested on x86_64 that this does not change the installed shared
libraries. (x86_64 of course does not provide much test coverage for
this patch - what should be architecture-specific contents in
shlib-versions for x86_64 is currently abi-*-ld-soname Makefile
settings, until gnu/lib-names.h is generated more like gnu/stubs.h so
those can move back to shlib-versions.)
* nptl/shlib-versions: Remove architecture-specific entries.
Moved to files in sysdeps.
* shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/shlib-versions: New
file.
* sysdeps/unix/sysv/linux/s390/s390-64/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/sh/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/shlib-versions: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions: Likewise.
pthread_atfork is already built in an extra-libs context, which gives
it NOT_IN_libc in its CPPFLAGS. Adding the same definition to CFLAGS
is pointless.
Verified that the code is unchanged on x86_64.
If a call to the set*id functions fails in a multi-threaded program,
the abort introduced in commit 13f7fe35ae
was triggered.
We address by checking that all calls to set*id on all threads give
the same result, and only abort if we see success followed by failure
(or vice versa).
This patch makes files using __ASSUME_* macros include
<kernel-features.h> explicitly, rather than relying on some other
header (such as tls.h, lowlevellock.h or pthreadP.h) to include it
implicitly. (I omitted cases where I've already posted or am testing
the patch that stops the file from needing __ASSUME_* at all.) This
accords with the general principle of making source files include the
headers for anything they use, and also helps make it safe to remove
<kernel-features.h> includes from any file that doesn't use
__ASSUME_* (some of those may be stray includes left behind after
increasing the minimum kernel version, others may never have been
needed or may have become obsolete after some other change).
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* nptl/pthread_cond_wait.c: Include <kernel-features.h>.
* nptl/pthread_rwlock_timedrdlock.c: Likewise.
* nptl/pthread_rwlock_timedwrlock.c: Likewise.
* nptl/sysdeps/unix/sysv/linux/lowlevelrobustlock.c: Likewise.
* nscd/nscd.c: Likewise.
* sysdeps/i386/nptl/tcb-offsets.sym: Likewise.
* sysdeps/powerpc/nptl/tcb-offsets.sym: Likewise.
* sysdeps/sh/nptl/tcb-offsets.sym: Likewise.
* sysdeps/x86_64/nptl/tcb-offsets.sym: Likewise.
This patch removes conditionals on __ASSUME_SOCK_CLOEXEC, and on
SOCK_CLOEXEC being defined, in Linux-specific code, now that all
supported Linux kernel versions can be assumed to have this
functionality. (The macro is also used in OS-independent code and is
not defined for Hurd.)
Tested x86_64 that the disassembly of installed shared libraries is
unchanged by this patch.
* nptl/sysdeps/unix/sysv/linux/mq_notify.c: Do not include
<kernel-features.h>.
(init_mq_netlink): Remove conditional have_sock_cloexec
definitions. Remove code conditional on have_sock_cloexec < 0.
(init_mq_netlink) [!SOCK_CLOEXEC]: Remove conditional code.
(init_mq_netlink) [!__ASSUME_SOCK_CLOEXEC]: Likewise.
* sysdeps/unix/sysv/linux/opensock.c: Do not include
<kernel-features.h>.
(__opensock) [SOCK_CLOEXEC]: Make code unconditional.
(__opensock) [!__ASSUME_SOCK_CLOEXEC]: Remove conditional code.
This patch relies on the C version of the rwlocks posted earlier.
With C rwlocks it is very straight forward to do adaptive elision
using TSX. It is based on the infrastructure added earlier
for mutexes, but uses its own elision macros. The macros
are fairly general purpose and could be used for other
elision purposes too.
This version is much cleaner than the earlier assembler based
version, and in particular implements adaptation which makes
it safer.
I changed the behavior slightly to not require any changes
in the test suite and fully conform to all expected
behaviors (generally at the cost of not eliding in
various situations). In particular this means the timedlock
variants are not elided. Nested trylock aborts.
One difference of the C versions to the assembler wr/rdlock
is that the C compiler saves some registers which are unnecessary
for the fast path in the prologue of the functions. Split the
uncontended fast path out into a separate function. Only when contention is
detected is the full featured function called. This makes
the fast path code (nearly) identical to the assembler version,
and gives uncontended performance within a few cycles.
v2: Rename some functions and add space.
Various glibc build / install / test code has C locale settings that
are redundant with LC_ALL=C.
LC_ALL takes precedence over LANG, so anywhere that sets LC_ALL=C
(explicitly, or through it being in the default environment for
running tests) does not need to set LANG=C. LC_ALL=C also takes
precedence over LANGUAGE, since
2001-01-02 Ulrich Drepper <drepper@redhat.com>
* intl/dcigettext.c (guess_category_value): Rewrite so that LANGUAGE
value is ignored if the selected locale is the C locale.
* intl/tst-gettext.c: Set locale for above change.
* intl/tst-translit.c: Likewise.
and so settings of LANGUAGE=C are also redundant when LC_ALL=C is
set. One test also had LC_ALL=C in its -ENV setting, although it's
part of the default environment used for tests.
This patch removes the redundant settings. It removes a suggestion in
install.texi of setting LANGUAGE=C LC_ALL=C for "make install"; the
Makefile.in target "install" already sets LC_ALL_C so there's no need
for the user to set it (and nor should there be any need for the user
to set it).
If some build machine tool used by "make install" uses a version of
libintl predating that 2001 change, and the user has LANGUAGE set, the
removal of LANGUAGE=C from the Makefile.in "install" rule could in
principle affect the user's installation. However, I don't think we
need to be concerned about pre-2001 build tools.
Tested x86_64.
* Makefile (install): Don't set LANGUAGE.
* Makefile.in (install): Likewise.
* assert/Makefile (test-assert-ENV): Remove variable.
(test-assert-perr-ENV): Likewise.
* elf/Makefile (neededtest4-ENV): Likewise.
* iconvdata/Makefile ($(inst_gconvdir)/gconv-modules)
[$(cross-compiling) = no]: Don't set LANGUAGE.
* io/ftwtest-sh (LANG): Remove variable.
* libio/Makefile (tst-widetext-ENV): Likewise.
* manual/install.texi (Running make install): Don't refer to
environment settings for make install.
* INSTALL: Regenerated.
* nptl/tst-tls6.sh: Don't set LANG.
* posix/globtest.sh (LANG): Remove variable.
* string/Makefile (tester-ENV): Likewise.
(inl-tester-ENV): Likewise.
(noinl-tester-ENV): Likewise.
* sysdeps/s390/s390-64/Makefile ($(inst_gconvdir)/gconv-modules)
[$(cross-compiling) = no]: Don't set LANGUAGE.
* timezone/Makefile (build-testdata): Use $(built-program-cmd)
without explicit environment settings.
localedata/ChangeLog:
* tst-fmon.sh: Don't set LANGUAGE.
* tst-locale.sh: Likewise.
One wart in the original support for test wrappers for cross testing,
as noted in
<https://sourceware.org/ml/libc-alpha/2012-10/msg00722.html>, is the
requirement for test wrappers to pass a poorly-defined set of
environment variables from the build system to the system running the
glibc under test. Although some variables are passed explicitly via
$(test-wrapper-env), including LD_* variables that simply can't be
passed implicitly because of the side effects they'd have on the build
system's dynamic linker, others are passed implicitly, including
variables such as GCONV_PATH and LOCPATH that could potentially affect
the build system's libc (so effectively relying on any such effects
not breaking the wrappers). In addition, the code in
cross-test-ssh.sh for preserving environment variables is fragile (it
depends on how bash formats a list of exported variables, and could
well break for multi-line variable definitions where the contents
contain things looking like other variable definitions).
This patch moves to explicitly passing environment variables via
$(test-wrapper-env). Makefile variables that previously used
$(test-wrapper) are split up into -before-env and -after-env parts
that can be passed separately to the various .sh files used in
testing, so those files can then insert environment settings between
the two parts.
The common default environment settings in make-test-out are made into
a separate makefile variable that can also be passed to scripts,
rather than many scripts duplicating those settings (for testing an
installed glibc, it is desirable to have the GCONV_PATH setting on
just one place, so just that one place needs to support it pointing to
an installed sysroot instead of the build tree). The default settings
are included in the variables such as $(test-program-prefix), so that
if tests do not need any non-default settings they can continue to use
single variables rather than the split-up variables.
Although this patch cleans up LC_ALL=C settings (that being part of
the common defaults), various LANG=C and LANGUAGE=C settings remain.
Those are generally unnecessary and I propose a subsequent cleanup to
remove them. LC_ALL takes precedence over LANG, and while LANGUAGE
takes precedence over LC_ALL, it only does so for settings other than
LC_ALL=C. So LC_ALL=C on its own is sufficient to ensure the C
locale, and anything that gets LC_ALL=C does not need the other
settings.
While preparing this patch I noticed some tests with .sh files that
appeared to do nothing beyond what the generic makefile support for
tests can do (localedata/tst-wctype.sh - the makefiles support -ENV
variables and .input files - and localedata/tst-mbswcs.sh - just runs
five tests that could be run individually from the makefile). So I
propose another subsequent cleanup to move those to using the generic
support instead of special .sh files.
Tested x86_64 (native) and powerpc32 (cross).
* Makeconfig (run-program-env): New variable.
(run-program-prefix-before-env): Likewise.
(run-program-prefix-after-env): Likewise.
(run-program-prefix): Define in terms of new variables.
(built-program-cmd-before-env): New variable.
(built-program-cmd-after-env): Likewise.
(built-program-cmd): Define in terms of new variables.
(test-program-prefix-before-env): New variable.
(test-program-prefix-after-env): Likewise.
(test-program-prefix): Define in terms of new variables.
(test-program-cmd-before-env): New variable.
(test-program-cmd-after-env): Likewise.
(test-program-cmd): Define in terms of new variables.
* Rules (make-test-out): Use $(run-program-env).
* scripts/cross-test-ssh.sh (env_blacklist): Remove variable.
(help): Do not mention environment variables. Mention
--timeoutfactor option.
(timeoutfactor): New variable.
(blacklist_exports): Remove function.
(exports): Remove variable.
(command): Do not include ${exports}.
* manual/install.texi (Configuring and compiling): Do not mention
test wrappers preserving environment variables. Mention that last
assignment to a variable must take precedence.
* INSTALL: Regenerated.
* benchtests/Makefile (run-bench): Use $(run-program-env).
* catgets/Makefile ($(objpfx)test1.cat): Use
$(built-program-cmd-before-env), $(run-program-env) and
$(built-program-cmd-after-env).
($(objpfx)test2.cat): Do not specify environment variables
explicitly.
($(objpfx)de/libc.cat): Use $(built-program-cmd-before-env),
$(run-program-env) and $(built-program-cmd-after-env).
($(objpfx)test-gencat.out): Use $(test-program-cmd-before-env),
$(run-program-env) and $(test-program-cmd-after-env).
($(objpfx)sample.SJIS.cat): Do not specify environment variables
explicitly.
* catgets/test-gencat.sh: Use test_program_cmd_before_env,
run_program_env and test_program_cmd_after_env arguments.
* elf/Makefile ($(objpfx)tst-pathopt.out): Use $(run-program-env).
* elf/tst-pathopt.sh: Use run_program_env argument.
* iconvdata/Makefile ($(objpfx)iconv-test.out): Use
$(test-wrapper-env) and $(run-program-env).
* iconvdata/run-iconv-test.sh: Use test_wrapper_env and
run_program_env arguments.
* iconvdata/tst-table.sh: Do not set GCONV_PATH explicitly.
* intl/Makefile ($(objpfx)tst-gettext.out): Use
$(test-program-prefix-before-env), $(run-program-env) and
$(test-program-prefix-after-env).
($(objpfx)tst-gettext2.out): Likewise.
* intl/tst-gettext.sh: Use test_program_prefix_before_env,
run_program_env and test_program_prefix_after_env arguments.
* intl/tst-gettext2.sh: Likewise.
* intl/tst-gettext4.sh: Do not set environment variables
explicitly.
* intl/tst-gettext6.sh: Likewise.
* intl/tst-translit.sh: Likewise.
* malloc/Makefile ($(objpfx)tst-mtrace.out): Use
$(test-program-prefix-before-env), $(run-program-env) and
$(test-program-prefix-after-env).
* malloc/tst-mtrace.sh: Use test_program_prefix_before_env,
run_program_env and test_program_prefix_after_env arguments.
* math/Makefile (run-regen-ulps): Use $(run-program-env).
* nptl/Makefile ($(objpfx)tst-tls6.out): Use $(run-program-env).
* nptl/tst-tls6.sh: Use run_program_env argument. Set LANG=C
explicitly with each use of ${test_wrapper_env}.
* posix/Makefile ($(objpfx)wordexp-tst.out): Use
$(test-program-prefix-before-env), $(run-program-env) and
$(test-program-prefix-after-env).
* posix/tst-getconf.sh: Do not set environment variables
explicitly.
* posix/wordexp-tst.sh: Use test_program_prefix_before_env,
run_program_env and test_program_prefix_after_env arguments.
* stdio-common/tst-printf.sh: Do not set environment variables
explicitly.
* stdlib/Makefile ($(objpfx)tst-fmtmsg.out): Use
$(test-program-prefix-before-env), $(run-program-env) and
$(test-program-prefix-after-env).
* stdlib/tst-fmtmsg.sh: Use test_program_prefix_before_env,
run_program_env and test_program_prefix_after_env arguments.
Split $test calls into $test_pre and $test.
* timezone/Makefile (build-testdata): Use
$(built-program-cmd-before-env), $(run-program-env) and
$(built-program-cmd-after-env).
localedata/ChangeLog:
* Makefile ($(addprefix $(objpfx),$(CTYPE_FILES))): Use
$(built-program-cmd-before-env), $(run-program-env) and
$(built-program-cmd-after-env).
($(objpfx)sort-test.out): Use $(test-program-prefix-before-env),
$(run-program-env) and $(test-program-prefix-after-env).
($(objpfx)tst-fmon.out): Use $(run-program-prefix-before-env),
$(run-program-env) and $(run-program-prefix-after-env).
($(objpfx)tst-locale.out): Use $(built-program-cmd-before-env),
$(run-program-env) and $(built-program-cmd-after-env).
($(objpfx)tst-trans.out): Use $(run-program-prefix-before-env),
$(run-program-env), $(run-program-prefix-after-env),
$(test-program-prefix-before-env) and
$(test-program-prefix-after-env).
($(objpfx)tst-ctype.out): Use $(test-program-cmd-before-env),
$(run-program-env) and $(test-program-cmd-after-env).
($(objpfx)tst-wctype.out): Likewise.
($(objpfx)tst-langinfo.out): Likewise.
($(objpfx)tst-langinfo-static.out): Likewise.
* gen-locale.sh: Use localedef_before_env, run_program_env and
localedef_after_env arguments.
* sort-test.sh: Use test_program_prefix_before_env,
run_program_env and test_program_prefix_after_env arguments.
* tst-ctype.sh: Use tst_ctype_before_env, run_program_env and
tst_ctype_after_env arguments.
* tst-fmon.sh: Use run_program_prefix_before_env, run_program_env
and run_program_prefix_after_env arguments.
* tst-langinfo.sh: Use tst_langinfo_before_env, run_program_env
and tst_langinfo_after_env arguments.
* tst-locale.sh: Use localedef_before_env, run_program_env and
localedef_after_env arguments.
* tst-mbswcs.sh: Do not set environment variables explicitly.
* tst-numeric.sh: Likewise.
* tst-rpmatch.sh: Likewise.
* tst-trans.sh: Use run_program_prefix_before_env,
run_program_env, run_program_prefix_after_env,
test_program_prefix_before_env and test_program_prefix_after_env
arguments.
* tst-wctype.sh: Use tst_wctype_before_env, run_program_env and
tst_wctype_after_env arguments.
glibc's Makeconfig defines some variables such as $(libm) and $(libdl)
for linking with libraries built by glibc, and nptl/Makeconfig
(included by the toplevel Makeconfig) defines others such as
$(shared-thread-library).
In some places glibc's Makefiles use those variables when linking
against the relevant libraries, but in other places they hardcode the
location of the libraries in the build tree. This patch cleans up
various places to use the variables that already exist (in the case of
libm, replacing several duplicate definitions of a $(link-libm)
variable in subdirectory Makefiles). (It's not necessarily exactly
equivalent to what the existing code does - in particular,
$(shared-thread-library) includes libpthread_nonshared, but is
replacing places that just referred to libpthread.so. But I think
that change is desirable on the general principle of linking things as
close as possible to the way in which they would be linked with an
installed library, unless there is a clear reason not to do so.)
To support running tests with an installed copy of glibc without
needing the full build tree from when that copy was built, I think it
will be useful to use such variables more generally and systematically
- every time the rules for building a test refer to some file from the
build tree that's also installed by glibc, use a makefile variable so
that the installed-testing case can point those variables to installed
copies of the files. This patch just deals with straightforward cases
where such variables already exist.
It's quite possible some uses of $(shared-thread-library) should
actually be a new $(thread-library) variable that's set appropriately
in the --disable-shared case, if those uses would in fact work without
shared libraries. I didn't change the status quo that those cases
hardcode use of a shared library whether or not it's actually needed
(but other uses such as $(libm) and $(libdl) would now get the static
library if the shared library isn't built, when some previously
hardcoded use of the shared library - if they actually need shared
libraries, the test itself needs an enable-shared conditional anyway).
Tested x86_64.
* benchtests/Makefile
($(addprefix $(objpfx)bench-,$(bench-math))): Depend on $(libm),
not $(common-objpfx)math/libm.so.
($(addprefix $(objpfx)bench-,$(bench-pthread))): Depend on
$(shared-thread-library), not $(common-objpfx)nptl/libpthread.so.
* elf/Makefile ($(objpfx)noload): Depend on $(libdl), not
$(common-objpfx)dlfcn/libdl.so.
($(objpfx)tst-audit8): Depend on $(libm), not
$(common-objpfx)math/libm.so.
* malloc/Makefile ($(objpfx)libmemusage.so): Depend on $(libdl),
not $(common-objpfx)dlfcn/libdl.so.
* math/Makefile
($(addprefix $(objpfx),$(filter-out $(tests-static),$(tests)))):
Depend on $(libm), not $(objpfx)libm.so. Do not condition on
[$(build-shared) = yes].
($(objpfx)test-fenv-tls): Depend on $(shared-thread-library), not
$(common-objpfx)nptl/libpthread.so.
* misc/Makefile ($(objpfx)tst-tsearch): Depend on $(libm), not
$(common-objpfx)math/libm.so$(libm.so-version) or
$(common-objpfx)math/libm.a depending on [$(build-shared) = yes].
* nptl/Makefile ($(objpfx)tst-unload): Depend on $(libdl), not
$(common-objpfx)dlfcn/libdl.so.
* setjmp/Makefile (link-libm): Remove variable.
($(objpfx)tst-setjmp-fp): Depend on $(libm), not $(link-libm).
* stdio-common/Makefile (link-libm): Remove variable.
($(objpfx)tst-printf-round): Depend on $(libm), not $(link-libm).
* stdlib/Makefile (link-libm): Remove variable.
($(objpfx)bug-getcontext): Depend on $(libm), not $(link-libm).
($(objpfx)tst-strtod-round): Likewise.
($(objpfx)tst-tininess): Likewise.
($(objpfx)tst-strtod-underflow): Likewise.
($(objpfx)tst-strtod6): Likewise.
($(objpfx)tst-tls-atexit): Depend on $(shared-thread-library) and
$(libdl), not $(common-objpfx)nptl/libpthread.so and
$(common-objpfx)dlfcn/libdl.so.
Added support for TX lock elision of pthread mutexes on s390 and
s390x. This may improve lock scaling of existing programs on TX
capable systems. The lock elision code is only built with
--enable-lock-elision=yes and then requires a GCC version supporting
the TX builtins. With lock elision default mutexes are elided via
__builtin_tbegin, if the cpu supports transactions. By default lock
elision is not enabled and the elision code is not built.
lll_unlock() will be called again if it goes to "wake_all" in
pthread_cond_broadcast(). This may make another thread which is
waiting for lock in pthread_cond_timedwait() unlock. So there are
more than one threads get the lock, it will break the shared data.
It's introduced by commit 8313cb997d2d("FUTEX_*_REQUEUE_PI support for
non-x86 code")
This patch removes the arch specific powerpc implementation and instead
uses the linux default one. Although the current powerpc implementation
already constains the required memory barriers for correct
initialization, the default implementation shows a better performance on
newer chips.
[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.
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.
At this point, we can only abort the process because we have already
switched credentials on other threads. Returning an error would still
leave the process in an inconsistent state.
The new xtest needs root privileges to run.
When profiling programs with lock problems with perf record -g dwarf,
libunwind can currently not backtrace through the futex and unlock
functions in pthread. This is because they use out of line sections,
and those are not correctly described in dwarf2 (I believe needs
dwarf3 or 4).
This patch first removes the out of line sections. They only save a
single jump, but cause a lot of pain. Then it converts the now inline
lock code to use the now standard gas .cfi_* commands.
With these changes libunwind/perf can backtrace through the futex
functions now.
Longer term it would be likely better to just use C futex() functions
on x86 like all the other architectures. This would clean the code up
even more.
