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2019-02-16Move remaining nptl_db headers to sysdeps/nptlFlorian Weimer
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.
2019-02-14nptl: Reinstate pthread_timedjoin_np as a cancellation point (BZ#24215)Adhemerval Zanella
Patch ce7eb0e90315 ("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.
2019-02-08nptl: Avoid fork handler lock for async-signal-safe fork [BZ #24161]Florian Weimer
Commit 27761a1042daf01987e7d79636d0c41511c6df3c ("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.)
2019-01-03nptl: Cleanup cancellation macrosAdhemerval Zanella
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.
2019-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
2018-12-05Use PRINTF_FORTIFY instead of _IO_FLAGS2_FORTIFY (bug 11319)Zack Weinberg
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 7ca890b88e6ab7624afb1742a9fffb37ad5b3fc3 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.
2018-12-01Mutex: Add pthread mutex tunablesKemi Wang
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>
2018-10-17Fix race in pthread_mutex_lock while promoting to PTHREAD_MUTEX_ELISION_NP ↵Stefan Liebler
[BZ #23275] 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.
2018-08-31[BZ #20271] Add newlines in __libc_fatal calls.Paul Pluzhnikov
2018-07-25Fix ISO C threads installed header and HURD assumptionAdhemerval Zanella
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.
2018-07-25Fix C11 conformance issuesAdhemerval Zanella
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.
2018-06-29libc: Extend __libc_freeres framework (Bug 23329).Carlos O'Donell
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>
2018-05-08Fix comment typoAndreas Schwab
2018-05-04Fix blocking pthread_join. [BZ #23137]Stefan Liebler
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.
2018-04-26Increase robustness of internal dlopen() by using RTLD_NOW [BZ #22766]Tulio Magno Quites Machado Filho
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>
2018-04-03Filter out NPTL internal signals (BZ #22391)Adhemerval Zanella
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>
2018-03-07Refactor Linux ARCH_FORK implementationAdhemerval Zanella
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.
2018-03-01nptl: Move pthread_atfork to libc_nonshared.aFlorian Weimer
libpthread_nonshared.a is unused after this, so remove it from the build. There is no ABI impact because pthread_atfork was implemented using __register_atfork in libc even before this change. pthread_atfork has to be a weak alias because pthread_* names are not reserved in libc. Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2018-02-27Move NPTL-specific code to NPTL-specific headerSamuel Thibault
* sysdeps/pthread/timer_routines.c: Include <timer_routines.h> instead of <nptl/pthreadP.h> (thread_attr_compare): Move function to... * sysdeps/nptl/timer_routines.h: ... new header.
2018-02-22Refactor atfork handlersAdhemerval Zanella
Current implementation (sysdeps/nptl/fork.c) replicates the atfork handlers list backward to invoke the child handlers after fork/clone syscall. The internal atfork handlers is implemented as a single-linked list so a lock-free algorithm can be used, trading fork mulithread call performance for some code complexity and dynamic stack allocation (since the backwards list should not fail). This patch refactor it to use a dynarary instead of a linked list. It simplifies the external variables need to be exported and also the internal atfork handler member definition. The downside is a serialization of fork call in multithread, since to operate on the dynarray the internal lock should be used. However as noted by Florian, it already acquires external locks for malloc and libio so it is already hitting some lock contention. Besides, posix_spawn should be faster and more scalable to run external programs in multithread environments. Checked on x86_64-linux-gnu. * nptl/Makefile (routines): Remove unregister-atfork. * nptl/register-atfork.c (fork_handler_pool): Remove variable. (fork_handler_alloc): Remove function. (fork_handlers, fork_handler_init): New variables. (__fork_lock): Rename to atfork_lock. (__register_atfork, __unregister_atfork, libc_freeres_fn): Rewrite to use a dynamic array to add/remove atfork handlers. * sysdeps/nptl/fork.c (__libc_fork): Likewise. * sysdeps/nptl/fork.h (__fork_lock, __fork_handlers, __linkin_atfork): Remove declaration. (fork_handler): Remove next, refcntr, and need_signal member. (__run_fork_handler_type): New enum. (__run_fork_handlers): New prototype. * sysdeps/nptl/libc-lockP.h (__libc_atfork): Remove declaration.
2018-02-22Rename nptl-signals.h to internal-signals.hAdhemerval Zanella
This patch renames the nptl-signals.h header to internal-signals.h. On Linux the definitions and functions are not only NPTL related, but used for other POSIX definitions as well (for instance SIGTIMER for posix times, SIGSETXID for id functions, and signal block/restore helpers) and since generic functions will be places and used in generic implementation it makes more sense to decouple it from NPTL. Checked on x86_64-linux-gnu. * sysdeps/nptl/nptl-signals.h: Move to ... * sysdeps/generic/internal-signals.h: ... here. Adjust internal comments. * sysdeps/unix/sysv/linux/internal-signals.h: Add include guards. (__nptl_is_internal_signal): Rename to __is_internal_signal. (__nptl_clear_internal_signals): Rename to __clear_internal_signals. * sysdeps/unix/sysv/linux/raise.c: Adjust nptl-signal.h to include-signals.h rename. * nptl/pthreadP.h: Likewise. * sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Call __is_internal_signal instead of __nptl_is_internal_signal.
2018-02-21Mechanically remove _IO_ name aliases for types and constants.Zack Weinberg
This patch mechanically removes all remaining uses, and the definitions, of the following libio name aliases: name replaced with ---- ------------- _IO_FILE FILE _IO_fpos_t __fpos_t _IO_fpos64_t __fpos64_t _IO_size_t size_t _IO_ssize_t ssize_t or __ssize_t _IO_off_t off_t _IO_off64_t off64_t _IO_pid_t pid_t _IO_uid_t uid_t _IO_wint_t wint_t _IO_va_list va_list or __gnuc_va_list _IO_BUFSIZ BUFSIZ _IO_cookie_io_functions_t cookie_io_functions_t __io_read_fn cookie_read_function_t __io_write_fn cookie_write_function_t __io_seek_fn cookie_seek_function_t __io_close_fn cookie_close_function_t I used __fpos_t and __fpos64_t instead of fpos_t and fpos64_t because the definitions of fpos_t and fpos64_t depend on the largefile mode. I used __ssize_t and __gnuc_va_list in a handful of headers where namespace cleanliness might be relevant even though they're internal-use-only. In all other cases, I used the public-namespace name. There are a tiny handful of places where I left a use of 'struct _IO_FILE' alone, because it was being used together with 'struct _IO_FILE_plus' or 'struct _IO_FILE_complete' in the same arithmetic expression. Because this patch was almost entirely done with search and replace, I may have introduced indentation botches. I did proofread the diff, but I may have missed something. The ChangeLog below calls out all of the places where this was not a pure search-and-replace change. Installed stripped libraries and executables are unchanged by this patch, except that some assertions in vfscanf.c change line numbers. * libio/libio.h (_IO_FILE): Delete; all uses changed to FILE. (_IO_fpos_t): Delete; all uses changed to __fpos_t. (_IO_fpos64_t): Delete; all uses changed to __fpos64_t. (_IO_size_t): Delete; all uses changed to size_t. (_IO_ssize_t): Delete; all uses changed to ssize_t or __ssize_t. (_IO_off_t): Delete; all uses changed to off_t. (_IO_off64_t): Delete; all uses changed to off64_t. (_IO_pid_t): Delete; all uses changed to pid_t. (_IO_uid_t): Delete; all uses changed to uid_t. (_IO_wint_t): Delete; all uses changed to wint_t. (_IO_va_list): Delete; all uses changed to va_list or __gnuc_va_list. (_IO_BUFSIZ): Delete; all uses changed to BUFSIZ. (_IO_cookie_io_functions_t): Delete; all uses changed to cookie_io_functions_t. (__io_read_fn): Delete; all uses changed to cookie_read_function_t. (__io_write_fn): Delete; all uses changed to cookie_write_function_t. (__io_seek_fn): Delete; all uses changed to cookie_seek_function_t. (__io_close_fn): Delete: all uses changed to cookie_close_function_t. * libio/iofopncook.c: Remove unnecessary forward declarations. * libio/iolibio.h: Correct outdated commentary. * malloc/malloc.c (__malloc_stats): Remove unnecessary casts. * stdio-common/fxprintf.c (__fxprintf_nocancel): Remove unnecessary casts. * stdio-common/getline.c: Use _IO_getdelim directly. Don't redefine ssize_t. * stdio-common/printf_fp.c, stdio_common/printf_fphex.c * stdio-common/printf_size.c: Don't redefine size_t or FILE. Remove outdated comments. * stdio-common/vfscanf.c: Don't redefine va_list.
2018-01-25Revert Intel CET changes to __jmp_buf_tag (Bug 22743)Carlos O'Donell
In commit cba595c350e52194e10c0006732e1991e3d0803b and commit f81ddabffd76ac9dd600b02adbf3e1dac4bb10ec, ABI compatibility with applications was broken by increasing the size of the on-stack allocated __pthread_unwind_buf_t beyond the oringal size. Applications only have the origianl space available for __pthread_unwind_register, and __pthread_unwind_next to use, any increase in the size of __pthread_unwind_buf_t causes these functions to write beyond the original structure into other on-stack variables leading to segmentation faults in common applications like vlc. The only workaround is to version those functions which operate on the old sized objects, but this must happen in glibc 2.28. Thank you to Andrew Senkevich, H.J. Lu, and Aurelien Jarno, for submitting reports and tracking the issue down. The commit reverts the above mentioned commits and testing on x86_64 shows that the ABI compatibility is restored. A tst-cleanup1 regression test linked with an older glibc now passes when run with the newly built glibc. Previously a tst-cleanup1 linked with an older glibc would segfault when run with an affected glibc build. Tested on x86_64 with no regressions. Signed-off-by: Carlos O'Donell <carlos@redhat.com>
2018-01-10nptl: Open libgcc.so with RTLD_NOW during pthread_cancel [BZ #22636]Florian Weimer
Disabling lazy binding reduces stack usage during unwinding. Note that RTLD_NOW only makes a difference if libgcc.so has not already been loaded, so this is only a partial fix. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2018-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
2017-12-20nptl: Implement pthread_self in libc.so [BZ #22635]Florian Weimer
All binaries use TLS and thus need a properly set up TCB, so we can simply return its address directly, instead of forwarding to the libpthread implementation from libc. For versioned symbols, the dynamic linker checks that the soname matches the name supplied by the link editor, so a compatibility symbol in libpthread is needed. To avoid linking against the libpthread function in all cases, we would have to bump the symbol version of libpthread in libc.so and supply a compat symbol. This commit does not do that because the function implementation is so small, so the overhead by two active copies of the same function might well be smaller than the increase in symbol table size.
2017-12-19Linux/x86: Update cancel_jmp_buf to match __jmp_buf_tag [BZ #22563]H.J. Lu
On x86, padding in struct __jmp_buf_tag is used for shadow stack pointer to support shadow stack in Intel Control-flow Enforcemen Technology. Since the cancel_jmp_buf array is passed to setjmp and longjmp by casting it to pointer to struct __jmp_buf_tag, it should be as large as struct __jmp_buf_tag. Otherwise when shadow stack is enabled, setjmp and longjmp will write and read beyond cancel_jmp_buf when saving and restoring shadow stack pointer. This patch adds bits/types/__cancel_jmp_buf_tag.h to define struct __cancel_jmp_buf_tag so that Linux/x86 can add saved_mask to cancel_jmp_buf. Tested natively on i386, x86_64 and x32. Tested hppa-linux-gnu with build-many-glibcs.py. [BZ #22563] * bits/types/__cancel_jmp_buf_tag.h: New file. * sysdeps/unix/sysv/linux/x86/bits/types/__cancel_jmp_buf_tag.h * sysdeps/unix/sysv/linux/x86/pthreaddef.h: Likewise. * sysdeps/unix/sysv/linux/x86/nptl/pthreadP.h: Likewise. * nptl/Makefile (headers): Add bits/types/__cancel_jmp_buf_tag.h. * nptl/descr.h [NEED_SAVED_MASK_IN_CANCEL_JMP_BUF] (pthread_unwind_buf): Add saved_mask to cancel_jmp_buf. * sysdeps/nptl/pthread.h: Include <bits/types/__cancel_jmp_buf_tag.h>. (__pthread_unwind_buf_t): Use struct __cancel_jmp_buf_tag with __cancel_jmp_buf. * sysdeps/unix/sysv/linux/hppa/pthread.h: Likewise.
2017-11-07nptl: Define __PTHREAD_MUTEX_{NUSERS_AFTER_KIND,USE_UNION}Adhemerval Zanella
This patch adds two new internal defines to set the internal pthread_mutex_t layout required by the supported ABIS: 1. __PTHREAD_MUTEX_NUSERS_AFTER_KIND which control whether to define __nusers fields before or after __kind. The preferred value for is 0 for new ports and it sets __nusers before __kind. 2. __PTHREAD_MUTEX_USE_UNION which control whether internal __spins and __list members will be place inside an union for linuxthreads compatibility. The preferred value is 0 for ports and it sets to not use an union to define both fields. It fixes the wrong offsets value for __kind value on x86_64-linux-gnu-x32. Checked with a make check run-built-tests=no on all afected ABIs. [BZ #22298] * nptl/allocatestack.c (allocate_stack): Check if __PTHREAD_MUTEX_HAVE_PREV is non-zero, instead if __PTHREAD_MUTEX_HAVE_PREV is defined. * nptl/descr.h (pthread): Likewise. * nptl/nptl-init.c (__pthread_initialize_minimal_internal): Likewise. * nptl/pthread_create.c (START_THREAD_DEFN): Likewise. * sysdeps/nptl/fork.c (__libc_fork): Likewise. * sysdeps/nptl/pthread.h (PTHREAD_MUTEX_INITIALIZER): Likewise. * sysdeps/nptl/bits/thread-shared-types.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New defines. (__pthread_internal_list): Check __PTHREAD_MUTEX_USE_UNION instead of __WORDSIZE for internal layout. (__pthread_mutex_s): Check __PTHREAD_MUTEX_NUSERS_AFTER_KIND instead of __WORDSIZE for internal __nusers layout and __PTHREAD_MUTEX_USE_UNION instead of __WORDSIZE whether to use an union for __spins and __list fields. (__PTHREAD_MUTEX_HAVE_PREV): Define also for __PTHREAD_MUTEX_USE_UNION case. * sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New defines. * sysdeps/alpha/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/arm/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/hppa/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/mips/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/s390/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/sh/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/sparc/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/tile/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. * sysdeps/x86/nptl/bits/pthreadtypes-arch.h (__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): Likewise. Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2017-10-05Remove add-ons mechanism.Joseph Myers
glibc has an add-ons mechanism to allow additional software to be integrated into the glibc build. Such add-ons may be within the glibc source tree, or outside it at a path passed to the --enable-add-ons configure option. localedata and crypt were once add-ons, distributed in separate release tarballs, but long since stopped using that mechanism. Linuxthreads was always an add-on. Ports spent some time as an add-on with separate release tarballs, then was first moved into the glibc source tree, then had its sysdeps files moved into the main sysdeps hierarchy so the add-ons mechanism was no longer used. NPTL spent some time as an add-on in the main glibc tree before stopping using the add-on mechanism. libidn used to have separate release tarballs but no longer does so, but still uses the add-ons mechanism within the glibc source tree. Various other software has supported building with the add-ons mechanism at times in the past, but I don't think any is still widely used. Add-ons involve significant, little-used complexity in the glibc build system, and make it hard to understand what the space of possible glibc configurations is. This patch removes the add-ons mechanism. libidn is now built via the Subdirs mechanism to cause any configuration using sysdeps/unix/inet to build libidn; HAVE_LIBIDN (which effectively means shared libraries are available) is now defined via sysdeps/unix/inet/configure. Various references to add-ons around the source tree are removed (in the case of maint.texi, the example list of sysdeps directories is still very out of date). Externally maintained ports should now put their files in the normal sysdeps directory structure rather than being arranged as add-ons; they probably need to change e.g. elf.h anyway, rather than actually being able to work just as a drop-in subtree. Hurd libpthread should be arranged similarly to NPTL, so some files might go in a hurd-pthreads (or similar) top-level directory in glibc, while sysdeps files should go in the normal sysdeps directory structure (possibly in hurd or hurd-pthreads subdirectories, just as there are nptl subdirectories in the sysdeps tree). Tested for x86_64, and with build-many-glibcs.py. * configure.ac (--enable-add-ons): Remove option. (machine): Do not mention add-ons in comment. (LIBC_PRECONFIGURE): Likewise. (add_ons): Remove variable and sanity checks and logic to locate add-ons. (add_ons_automatic): Remove variable. (configured_add_ons): Likewise. (add_ons_sfx): Likewise. (add_ons_pfx): Likewise. (add_on_subdirs): Likewise. (sysnames_add_ons): Likewise. Remove loop over add-ons and consideration of add-ons in Implies handling. (sysdeps_add_ons): Likewise. * configure: Regenerated. * libidn/configure.ac: Remove. * libidn/configure: Likewise. * sysdeps/unix/inet/configure.ac: New file. * sysdeps/unix/inet/configure: New generated file. * sysdeps/unix/inet/Subdirs: Add libidn. * Makeconfig (sysdeps-srcdirs): Remove variable. (+sysdep_dirs): Do not include $(sysdeps-srcdirs). ($(common-objpfx)config.status): Do not depend on add-on files. ($(common-objpfx)shlib-versions.v.i): Do not mention add-ons in comment. (all-subdirs): Do not include $(add-on-subdirs). * Makefile (dist-prepare): Do not use $(sysdeps-add-ons). * config.make.in (add-ons): Remove variable. (add-on-subdirs): Likewise. (sysdeps-add-ons): Likewise. * manual/Makefile (add-chapters): Remove. ($(objpfx)texis): Do not depend on $(add-chapters). (nonexamples): Do not handle $(add-chapters). (examples): Do not handle $(add-ons). (chapters.% top-menu.%): Do not pass '$(add-chapters)' to libc-texinfo.sh. * manual/install.texi (Installation): Do not mention add-ons. (--enable-add-ons): Do not document configure option. * INSTALL: Regenerated. * manual/libc-texinfo.sh: Do not handle $2 add-ons argument. * manual/maint.texi (Hierarchy Conventions): Do not mention add-ons. * scripts/build-many-glibcs.py (Glibc.build_glibc): Do not use --enable-add-ons. * scripts/gen-sorted.awk: Do not handle Subdirs files from add-ons. * scripts/test-installation.pl: Do not handle glibc-compat add-on. * sysdeps/nptl/Makeconfig: Do not mention add-ons in comment.
2017-07-24Remove extra semicolons in struct pthread_mutex (bug 21804)Andreas Schwab
2017-07-09Use generic pthread support on hppa.John David Anglin
2017-07-06nptl: Fix typo on __have_pthread_attr_t (BZ#21715)Matthew Krupcale
This patch fixes some build issues when including types/sigevent_t.h along with bits/pthreadtypes.h. Checked on x86_64-linux-gnu and on a build on supported major ABIs. [BZ #21715] * sysdeps/nptl/bits/pthreadtypes.h (__have_pthread_attr_t): Fix typo on definition.
2017-05-12fork: Remove bogus parent PID assertions [BZ #21386]Florian Weimer
2017-05-11Remove _IO_MTSAFE_IO from public headers.Zack Weinberg
_IO_MTSAFE_IO controls whether stdio is *built* with support for multithreading. In the distant past it might also have worked as a feature selection macro, allowing library *users* to select thread-safe or lock-free stdio at application build time, I haven't done the archaeology. Nowadays, defining _IO_MTSAFE_IO while using the installed headers, or in _ISOMAC mode, will cause libio.h to throw syntax errors. This patch removes _IO_MTSAFE_IO from the public headers (specifically, from libio/libio.h). The most important thing it controlled in there was whether libio.h defines _IO_lock_t itself or expects stdio-lock.h to have done it, and we do still need a inter-header communication macro for that, because stdio-lock.h can only define _IO_lock_t as a typedef. I've invented _IO_lock_t_defined, which is defined by both versions of stdio-lock.h. _IO_MTSAFE_IO also controlled the definitions of a handful of macros that _might_ count as part of the public libio.h interface. They are now unconditionally given their non-_IO_MTSAFE_IO definition in libio/libio.h, and include/libio.h redefines them with the _IO_MTSAFE_IO definition. This should minimize the odds of breaking old software that actually uses those macros. I suspect that this entire mechanism is vestigial, and that glibc won't build anymore if you *don't* define _IO_MTSAFE_IO, but that's another patchset. The bulk of libio.h is internal-use-only stuff that no longer makes sense to expose (libstdc++ gave up on making a FILE the same object as a C++ filebuf *decades* ago) but that, too, is another patchset. * libio/libio.h: Condition dummy definition of _IO_lock_t on _IO_lock_t_defined, not _IO_MTSAFE_IO. Unconditionally use the non-_IO_MTSAFE_IO definitions for _IO_peekc, _IO_flockfile, _IO_funlockfile, and _IO_ftrylockfile. Only define _IO_cleanup_region_start and _IO_cleanup_region_end if not already defined. * include/libio.h: If _IO_MTSAFE_IO is defined, redefine _IO_peekc, _IO_flockfile, _IO_funlockfile, and _IO_ftrylockfile appropriately. * sysdeps/generic/stdio-lock.h, sysdeps/nptl/stdio-lock.h: Define _IO_lock_t_defined after defining _IO_lock_t.
2017-05-09Move shared pthread definitions to common headersAdhemerval Zanella
This patch removes all the replicated pthread definition accross the architectures and consolidates it on shared headers. The new organization is as follow: * Architecture specific definition (such as pthread types sizes) are place in the new pthreadtypes-arch.h header in arch specific path. * All shared structure definition are moved to a common NPTL header at sysdeps/nptl/bits/pthreadtypes.h (with now includes the arch specific one for internal definitions). * Also, for C11 future thread support, both mutex and condition definition are placed in a common header at sysdeps/nptl/bits/thread-shared-types.h. It is also a refactor patch without expected functional changes. Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64}-linux-gnu, nios2-linux-gnu, powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu, tile{pro,gx}-linux-gnu, and x86_64-linux-gnu). * posix/Makefile (headers): Add pthreadtypes-arch.h and thread-shared-types.h. * sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h: New file: arch specific thread definition. * sysdeps/alpha/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/arm/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/hppa/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/mips/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/sh/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/sparc/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/tile/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/x86/nptl/bits/pthreadtypes-arch.h: Likewise. * sysdeps/nptl/bits/thread-shared-types.h: New file: shared thread definition between POSIX and C11. * sysdeps/aarch64/nptl/bits/pthreadtypes.h.: Remove file. * sysdeps/alpha/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/arm/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/hppa/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/mips/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/powerpc/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/s390/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/sh/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/sparc/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/tile/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/x86/nptl/bits/pthreadtypes.h: Likewise. * sysdeps/nptl/bits/pthreadtypes.h: New file: common thread definitions shared across all architectures.
2017-03-01Narrowing the visibility of libc-internal.h even further.Zack Weinberg
posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar to what was done with libc-diag.h, I have split the definitions of cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN to a new header, libc-pointer-arith.h. It then occurred to me that the remaining declarations in libc-internal.h are mostly to do with early initialization, and probably most of the files including it, even in the core code, don't need it anymore. Indeed, only 19 files actually need what remains of libc-internal.h. 23 others need libc-diag.h instead, and 12 need libc-pointer-arith.h instead. No file needs more than one of them, and 16 don't need any of them! So, with this patch, libc-internal.h stops including libc-diag.h as well as losing the pointer arithmetic macros, and all including files are adjusted. * include/libc-pointer-arith.h: New file. Define cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN here. * include/libc-internal.h: Definitions of above macros moved from here. Don't include libc-diag.h anymore either. * posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h. Don't include libc-internal.h. * debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c * io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c * nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c * string/strcoll_l.c, sysdeps/nacl/brk.c * sysdeps/unix/clock_settime.c * sysdeps/unix/sysv/linux/i386/get_clockfreq.c * sysdeps/unix/sysv/linux/ia64/get_clockfreq.c * sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c * sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c: Don't include libc-internal.h. * elf/get-dynamic-info.h, iconv/loop.c * iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h * misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h * nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c * soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c * sysdeps/ieee754/dbl-64/e_lgamma_r.c * sysdeps/ieee754/dbl-64/k_rem_pio2.c * sysdeps/ieee754/flt-32/e_lgammaf_r.c * sysdeps/ieee754/flt-32/k_rem_pio2f.c * sysdeps/ieee754/ldbl-128/k_tanl.c * sysdeps/ieee754/ldbl-128ibm/k_tanl.c * sysdeps/ieee754/ldbl-96/e_lgammal_r.c * sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h: Include libc-diag.h instead of libc-internal.h. * elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c * nptl/nptl-init.c, string/strcspn.c, string/strspn.c * malloc/malloc.c, sysdeps/i386/nptl/tls.h * sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h * sysdeps/unix/sysv/linux/spawni.c * sysdeps/x86_64/nptl/tls.h: Include libc-pointer-arith.h instead of libc-internal.h. * elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h * sysdeps/x86_64/atomic-machine.h: Add multiple include guard.
2017-02-06Add __glibc_unlikely hint in lll_trylock, lll_cond_trylock.Stefan Liebler
The macros lll_trylock, lll_cond_trylock are extended by an __glibc_unlikely hint. Now the trylock macros are based on the same assumption about a free/busy lock as lll_lock. With the hint gcc emits code in e.g. pthread_mutex_trylock which does not use jumps if the lock is free. Without the hint it had to jump away if the lock is free. Tested on s390x, ppc. ChangeLog: * sysdeps/nptl/lowlevellock.h (lll_trylock, lll_cond_trylock): Add __glibc_unlikely hint.
2017-01-13Clear list of acquired robust mutexes in the child process after forking.Torvald Riegel
Robust mutexes acquired at the time of a call to fork() do not remain acquired by the forked child process. We have to clear the list of acquired robust mutexes before registering this list with the kernel; otherwise, if some of the robust mutexes are process-shared, the parent process can alter the child's robust mutex list, which can lead to deadlocks or even modification of memory that may not be occupied by a mutex anymore. [BZ #19402] * sysdeps/nptl/fork.c (__libc_fork): Clear list of acquired robust mutexes.
2017-01-13robust mutexes: Fix broken x86 assembly by removing itTorvald Riegel
lll_robust_unlock on i386 and x86_64 first sets the futex word to FUTEX_WAITERS|0 before calling __lll_unlock_wake, which will set the futex word to 0. If the thread is killed between these steps, then the futex word will be FUTEX_WAITERS|0, and the kernel (at least current upstream) will not set it to FUTEX_OWNER_DIED|FUTEX_WAITERS because 0 is not equal to the TID of the crashed thread. The lll_robust_lock assembly code on i386 and x86_64 is not prepared to deal with this case because the fastpath tries to only CAS 0 to TID and not FUTEX_WAITERS|0 to TID; the slowpath simply waits until it can CAS 0 to TID or the futex_word has the FUTEX_OWNER_DIED bit set. This issue is fixed by removing the custom x86 assembly code and using the generic C code instead. However, instead of adding more duplicate code to the custom x86 lowlevellock.h, the code of the lll_robust* functions is inlined into the single call sites that exist for each of these functions in the pthread_mutex_* functions. The robust mutex paths in the latter have been slightly reorganized to make them simpler. This patch is meant to be easy to backport, so C11-style atomics are not used. [BZ #20985] * nptl/Makefile: Adapt. * nptl/pthread_mutex_cond_lock.c (LLL_ROBUST_MUTEX_LOCK): Remove. (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. * nptl/pthread_mutex_lock.c (LLL_ROBUST_MUTEX_LOCK): Remove. (LLL_ROBUST_MUTEX_LOCK_MODIFIER): New. (__pthread_mutex_lock_full): Inline lll_robust* functions and adapt. * nptl/pthread_mutex_timedlock.c (pthread_mutex_timedlock): Inline lll_robust* functions and adapt. * nptl/pthread_mutex_unlock.c (__pthread_mutex_unlock_full): Likewise. * sysdeps/nptl/lowlevellock.h (__lll_robust_lock_wait, __lll_robust_lock, lll_robust_cond_lock, __lll_robust_timedlock_wait, __lll_robust_timedlock, __lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_robust_lock, lll_robust_cond_lock, lll_robust_timedlock, lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_robust_lock, lll_robust_cond_lock, lll_robust_timedlock, lll_robust_unlock): Remove. * sysdeps/unix/sysv/linux/sparc/lowlevellock.h (__lll_robust_lock_wait, __lll_robust_lock, lll_robust_cond_lock, __lll_robust_timedlock_wait, __lll_robust_timedlock, __lll_robust_unlock): Remove. * nptl/lowlevelrobustlock.c: Remove file. * nptl/lowlevelrobustlock.sym: Likewise. * sysdeps/unix/sysv/linux/i386/lowlevelrobustlock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevelrobustlock.S: Likewise.
2017-01-01Update copyright dates with scripts/update-copyrights.Joseph Myers
2016-12-31New condvar implementation that provides stronger ordering guarantees.Torvald Riegel
This is a new implementation for condition variables, required after http://austingroupbugs.net/view.php?id=609 to fix bug 13165. In essence, we need to be stricter in which waiters a signal or broadcast is required to wake up; this couldn't be solved using the old algorithm. ISO C++ made a similar clarification, so this also fixes a bug in current libstdc++, for example. We can't use the old algorithm anymore because futexes do not guarantee to wake in FIFO order. Thus, when we wake, we can't simply let any waiter grab a signal, but we need to ensure that one of the waiters happening before the signal is woken up. This is something the previous algorithm violated (see bug 13165). There's another issue specific to condvars: ABA issues on the underlying futexes. Unlike mutexes that have just three states, or semaphores that have no tokens or a limited number of them, the state of a condvar is the *order* of the waiters. A waiter on a semaphore can grab a token whenever one is available; a condvar waiter must only consume a signal if it is eligible to do so as determined by the relative order of the waiter and the signal. Therefore, this new algorithm maintains two groups of waiters: Those eligible to consume signals (G1), and those that have to wait until previous waiters have consumed signals (G2). Once G1 is empty, G2 becomes the new G1. 64b counters are used to avoid ABA issues. This condvar doesn't yet use a requeue optimization (ie, on a broadcast, waking just one thread and requeueing all others on the futex of the mutex supplied by the program). I don't think doing the requeue is necessarily the right approach (but I haven't done real measurements yet): * If a program expects to wake many threads at the same time and make that scalable, a condvar isn't great anyway because of how it requires waiters to operate mutually exclusive (due to the mutex usage). Thus, a thundering herd problem is a scalability problem with or without the optimization. Using something like a semaphore might be more appropriate in such a case. * The scalability problem is actually at the mutex side; the condvar could help (and it tries to with the requeue optimization), but it should be the mutex who decides how that is done, and whether it is done at all. * Forcing all but one waiter into the kernel-side wait queue of the mutex prevents/avoids the use of lock elision on the mutex. Thus, it prevents the only cure against the underlying scalability problem inherent to condvars. * If condvars use short critical sections (ie, hold the mutex just to check a binary flag or such), which they should do ideally, then forcing all those waiter to proceed serially with kernel-based hand-off (ie, futex ops in the mutex' contended state, via the futex wait queues) will be less efficient than just letting a scalable mutex implementation take care of it. Our current mutex impl doesn't employ spinning at all, but if critical sections are short, spinning can be much better. * Doing the requeue stuff requires all waiters to always drive the mutex into the contended state. This leads to each waiter having to call futex_wake after lock release, even if this wouldn't be necessary. [BZ #13165] * nptl/pthread_cond_broadcast.c (__pthread_cond_broadcast): Rewrite to use new algorithm. * nptl/pthread_cond_destroy.c (__pthread_cond_destroy): Likewise. * nptl/pthread_cond_init.c (__pthread_cond_init): Likewise. * nptl/pthread_cond_signal.c (__pthread_cond_signal): Likewise. * nptl/pthread_cond_wait.c (__pthread_cond_wait): Likewise. (__pthread_cond_timedwait): Move here from pthread_cond_timedwait.c. (__condvar_confirm_wakeup, __condvar_cancel_waiting, __condvar_cleanup_waiting, __condvar_dec_grefs, __pthread_cond_wait_common): New. (__condvar_cleanup): Remove. * npt/pthread_condattr_getclock.c (pthread_condattr_getclock): Adapt. * npt/pthread_condattr_setclock.c (pthread_condattr_setclock): Likewise. * npt/pthread_condattr_getpshared.c (pthread_condattr_getpshared): Likewise. * npt/pthread_condattr_init.c (pthread_condattr_init): Likewise. * nptl/tst-cond1.c: Add comment. * nptl/tst-cond20.c (do_test): Adapt. * nptl/tst-cond22.c (do_test): Likewise. * sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_cond_t): Adapt structure. * sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/x86/bits/pthreadtypes.h (pthread_cond_t): Likewise. * sysdeps/nptl/internaltypes.h (COND_NWAITERS_SHIFT): Remove. (COND_CLOCK_BITS): Adapt. * sysdeps/nptl/pthread.h (PTHREAD_COND_INITIALIZER): Adapt. * nptl/pthreadP.h (__PTHREAD_COND_CLOCK_MONOTONIC_MASK, __PTHREAD_COND_SHARED_MASK): New. * nptl/nptl-printers.py (CLOCK_IDS): Remove. (ConditionVariablePrinter, ConditionVariableAttributesPrinter): Adapt. * nptl/nptl_lock_constants.pysym: Adapt. * nptl/test-cond-printers.py: Adapt. * sysdeps/unix/sysv/linux/hppa/internaltypes.h (cond_compat_clear, cond_compat_check_and_clear): Adapt. * sysdeps/unix/sysv/linux/hppa/pthread_cond_timedwait.c: Remove file ... * sysdeps/unix/sysv/linux/hppa/pthread_cond_wait.c (__pthread_cond_timedwait): ... and move here. * nptl/DESIGN-condvar.txt: Remove file. * nptl/lowlevelcond.sym: Likewise. * nptl/pthread_cond_timedwait.c: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i486/pthread_cond_wait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i586/pthread_cond_wait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/i386/i686/pthread_cond_wait.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_broadcast.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S: Likewise.
2016-11-24Remove cached PID/TID in cloneAdhemerval Zanella
This patch remove the PID cache and usage in current GLIBC code. Current usage is mainly used a performance optimization to avoid the syscall, however it adds some issues: - The exposed clone syscall will try to set pid/tid to make the new thread somewhat compatible with current GLIBC assumptions. This cause a set of issue with new workloads and usecases (such as BZ#17214 and [1]) as well for new internal usage of clone to optimize other algorithms (such as clone plus CLONE_VM for posix_spawn, BZ#19957). - The caching complexity also added some bugs in the past [2] [3] and requires more effort of each port to handle such requirements (for both clone and vfork implementation). - Caching performance gain in mainly on getpid and some specific code paths. The getpid performance leverage is questionable [4], either by the idea of getpid being a hotspot as for the getpid implementation itself (if it is indeed a justifiable hotspot a vDSO symbol could let to a much more simpler solution). Other usage is mainly for non usual code paths, such as pthread cancellation signal and handling. For thread creation (on stack allocation) the code simplification in fact adds some performance gain due the no need of transverse the stack cache and invalidate each element pid. Other thread usages will require a direct getpid syscall, such as cancellation/setxid signal, thread cancellation, thread fail path (at create_thread), and thread signal (pthread_kill and pthread_sigqueue). However these are hardly usual hotspots and I think adding a syscall is justifiable. It also simplifies both the clone and vfork arch-specific implementation. And by review each fork implementation there are some discrepancies that this patch also solves: - microblaze clone/vfork does not set/reset the pid/tid field - hppa uses the default vfork implementation that fallback to fork. Since vfork is deprecated I do not think we should bother with it. The patch also removes the TID caching in clone. My understanding for such semantic is try provide some pthread usage after a user program issue clone directly (as done by thread creation with CLONE_PARENT_SETTID and pthread tid member). However, as stated before in multiple discussions threads, GLIBC provides clone syscalls without further supporting all this semantics. I ran a full make check on x86_64, x32, i686, armhf, aarch64, and powerpc64le. For sparc32, sparc64, and mips I ran the basic fork and vfork tests from posix/ folder (on a qemu system). So it would require further testing on alpha, hppa, ia64, m68k, nios2, s390, sh, and tile (I excluded microblaze because it is already implementing the patch semantic regarding clone/vfork). [1] https://codereview.chromium.org/800183004/ [2] https://sourceware.org/ml/libc-alpha/2006-07/msg00123.html [3] https://sourceware.org/bugzilla/show_bug.cgi?id=15368 [4] http://yarchive.net/comp/linux/getpid_caching.html * sysdeps/nptl/fork.c (__libc_fork): Remove pid cache setting. * nptl/allocatestack.c (allocate_stack): Likewise. (__reclaim_stacks): Likewise. (setxid_signal_thread): Obtain pid through syscall. * nptl/nptl-init.c (sigcancel_handler): Likewise. (sighandle_setxid): Likewise. * nptl/pthread_cancel.c (pthread_cancel): Likewise. * sysdeps/unix/sysv/linux/pthread_kill.c (__pthread_kill): Likewise. * sysdeps/unix/sysv/linux/pthread_sigqueue.c (pthread_sigqueue): Likewise. * sysdeps/unix/sysv/linux/createthread.c (create_thread): Likewise. * sysdeps/unix/sysv/linux/getpid.c: Remove file. * nptl/descr.h (struct pthread): Change comment about pid value. * nptl/pthread_getattr_np.c (pthread_getattr_np): Remove thread pid assert. * sysdeps/unix/sysv/linux/pthread-pids.h (__pthread_initialize_pids): Do not set pid value. * nptl_db/td_ta_thr_iter.c (iterate_thread_list): Remove thread pid cache check. * nptl_db/td_thr_validate.c (td_thr_validate): Likewise. * sysdeps/aarch64/nptl/tcb-offsets.sym: Remove pid offset. * sysdeps/alpha/nptl/tcb-offsets.sym: Likewise. * sysdeps/arm/nptl/tcb-offsets.sym: Likewise. * sysdeps/hppa/nptl/tcb-offsets.sym: Likewise. * sysdeps/i386/nptl/tcb-offsets.sym: Likewise. * sysdeps/ia64/nptl/tcb-offsets.sym: Likewise. * sysdeps/m68k/nptl/tcb-offsets.sym: Likewise. * sysdeps/microblaze/nptl/tcb-offsets.sym: Likewise. * sysdeps/mips/nptl/tcb-offsets.sym: Likewise. * sysdeps/nios2/nptl/tcb-offsets.sym: Likewise. * sysdeps/powerpc/nptl/tcb-offsets.sym: Likewise. * sysdeps/s390/nptl/tcb-offsets.sym: Likewise. * sysdeps/sh/nptl/tcb-offsets.sym: Likewise. * sysdeps/sparc/nptl/tcb-offsets.sym: Likewise. * sysdeps/tile/nptl/tcb-offsets.sym: Likewise. * sysdeps/x86_64/nptl/tcb-offsets.sym: Likewise. * sysdeps/unix/sysv/linux/aarch64/clone.S: Remove pid and tid caching. * sysdeps/unix/sysv/linux/alpha/clone.S: Likewise. * sysdeps/unix/sysv/linux/arm/clone.S: Likewise. * sysdeps/unix/sysv/linux/hppa/clone.S: Likewise. * sysdeps/unix/sysv/linux/i386/clone.S: Likewise. * sysdeps/unix/sysv/linux/ia64/clone2.S: Likewise. * sysdeps/unix/sysv/linux/mips/clone.S: Likewise. * sysdeps/unix/sysv/linux/nios2/clone.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/clone.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/clone.S: Likewise. * sysdeps/unix/sysv/linux/sh/clone.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/clone.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/clone.S: Likewise. * sysdeps/unix/sysv/linux/tile/clone.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/clone.S: Likewise. * sysdeps/unix/sysv/linux/aarch64/vfork.S: Remove pid set and reset. * sysdeps/unix/sysv/linux/alpha/vfork.S: Likewise. * sysdeps/unix/sysv/linux/arm/vfork.S: Likewise. * sysdeps/unix/sysv/linux/i386/vfork.S: Likewise. * sysdeps/unix/sysv/linux/ia64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/m68k/clone.S: Likewise. * sysdeps/unix/sysv/linux/m68k/vfork.S: Likewise. * sysdeps/unix/sysv/linux/mips/vfork.S: Likewise. * sysdeps/unix/sysv/linux/nios2/vfork.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc32/vfork.S: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/vfork.S: Likewise. * sysdeps/unix/sysv/linux/s390/s390-64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/sh/vfork.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc32/vfork.S: Likewise. * sysdeps/unix/sysv/linux/sparc/sparc64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/tile/vfork.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/vfork.S: Likewise. * sysdeps/unix/sysv/linux/tst-clone2.c (f): Remove direct pthread struct access. (clone_test): Remove function. (do_test): Rewrite to take in consideration pid is not cached anymore.
2016-09-23Installed-header hygiene (BZ#20366): time.h types.Zack Weinberg
Many headers are expected to expose a subset of the type definitions in time.h. time.h has a whole bunch of messy logic for conditionally defining some its types and structs, but, as best I can tell, this has never worked 100%. In particular, __need_timespec is ineffective if _TIME_H has already been defined, which means that if you compile #include <time.h> #include <sched.h> with e.g. -fsyntax-only -std=c89 -Wall -Wsystem-headers, you will get In file included from test.c:2:0: /usr/include/sched.h:74:57: warning: "struct timespec" declared inside parameter list will not be visible outside of this definition or declaration extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW; ^~~~~~~~ And if you want to _use_ sched_rr_get_interval in a TU compiled that way, you're hosed. This patch replaces all of that with small bits/types/TYPE.h headers as introduced earlier. time.h and bits/time.h are now *much* simpler, and a lot of other headers are slightly simpler. * time/time.h, bits/time.h, sysdeps/unix/sysv/linux/bits/time.h: Remove all logic conditional on __need macros. Move all the conditionally defined types to their own headers... * time/bits/types/clock_t.h: Define clock_t here. * time/bits/types/clockid_t.h: Define clockid_t here. * time/bits/types/struct_itimerspec.h: Define struct itimerspec here. * time/bits/types/struct_timespec.h: Define struct timespec here. * time/bits/types/struct_timeval.h: Define struct timeval here. * time/bits/types/struct_tm.h: Define struct tm here. * time/bits/types/time_t.h: Define time_t here. * time/bits/types/timer_t.h: Define timer_t here. * time/Makefile: Install the new headers. * bits/resource.h, io/fcntl.h, io/sys/poll.h, io/sys/stat.h * io/utime.h, misc/sys/select.h, posix/sched.h, posix/sys/times.h * posix/sys/types.h, resolv/netdb.h, rt/aio.h, rt/mqueue.h * signal/signal.h, pthread/semaphore.h, sysdeps/nptl/pthread.h * sysdeps/unix/sysv/linux/alpha/bits/resource.h * sysdeps/unix/sysv/linux/alpha/sys/acct.h * sysdeps/unix/sysv/linux/bits/resource.h * sysdeps/unix/sysv/linux/bits/timex.h * sysdeps/unix/sysv/linux/mips/bits/resource.h * sysdeps/unix/sysv/linux/net/ppp_defs.h * sysdeps/unix/sysv/linux/sparc/bits/resource.h * sysdeps/unix/sysv/linux/sys/acct.h * sysdeps/unix/sysv/linux/sys/timerfd.h * sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h * time/sys/time.h, time/sys/timeb.h Use the new bits/types headers. * include/time.h: Remove __need logic. * include/bits/time.h * include/bits/types/clock_t.h, include/bits/types/clockid_t.h * include/bits/types/time_t.h, include/bits/types/timer_t.h * include/bits/types/struct_itimerspec.h * include/bits/types/struct_timespec.h * include/bits/types/struct_timeval.h * include/bits/types/struct_tm.h: New wrapper headers.
2016-09-21malloc: Manual part of conversion to __libc_lockFlorian Weimer
This removes the old mutex_t-related definitions from malloc-machine.h, too.
2016-09-14Remove the ptw-% patternsFlorian Weimer
Nothing depends on the PTW macro anymore, so the mechanism to define PTW for recompliations of libc routines is no longer needed. The source files are still recompiled for the nptl directory, just without the “ptw-” prefix. (Reducing the number of pattern rules in sysd-rules is critical for improving make performance.)
2016-08-26malloc: Simplify static malloc interposition [BZ #20432]Florian Weimer
Existing interposed mallocs do not define the glibc-internal fork callbacks (and they should not), so statically interposed mallocs lead to link failures because the strong reference from fork pulls in glibc's malloc, resulting in multiple definitions of malloc-related symbols.
2016-05-12Increase fork signal safety for single-threaded processes [BZ #19703]Florian Weimer
This provides a band-aid and addresses the scenario where fork is called from a signal handler while the process is in the malloc subsystem (or has acquired the libio list lock). It does not address the general issue of async-signal-safety of fork; multi-threaded processes are not covered, and some glibc subsystems have fork handlers which are not async-signal-safe.
2016-04-14malloc: Remove unused definitions of thread_atfork, thread_atfork_staticFlorian Weimer
2016-04-14malloc: Run fork handler as late as possible [BZ #19431]Florian Weimer
Previously, a thread M invoking fork would acquire locks in this order: (M1) malloc arena locks (in the registered fork handler) (M2) libio list lock A thread F invoking flush (NULL) would acquire locks in this order: (F1) libio list lock (F2) individual _IO_FILE locks A thread G running getdelim would use this order: (G1) _IO_FILE lock (G2) malloc arena lock After executing (M1), (F1), (G1), none of the threads can make progress. This commit changes the fork lock order to: (M'1) libio list lock (M'2) malloc arena locks It explicitly encodes the lock order in the implementations of fork, and does not rely on the registration order, thus avoiding the deadlock.
2016-01-15New pthread_barrier algorithm to fulfill barrier destruction requirements.Torvald Riegel
The previous barrier implementation did not fulfill the POSIX requirements for when a barrier can be destroyed. Specifically, it was possible that threads that haven't noticed yet that their round is complete still access the barrier's memory, and that those accesses can happen after the barrier has been legally destroyed. The new algorithm does not have this issue, and it avoids using a lock internally.