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2024-01-12Optimize pthread_cond_timedwait to avoid unnecessary call to clock_gettime ↵Justin King1-1/+1
for CLOCK_MONOTONIC
2021-08-27Fix blocking pthread_join. [BZ #23137]Stefan Liebler1-5/+8
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. (cherry picked from commit 1660901840dfc9fde6c5720a32f901af6f08f00a)
2014-03-03For b/5836136, do dlsym(0, "_Unwind..."), i.e. ignore libgcc_s.so.1 dlopen ↵Paul Pluzhnikov1-0/+9
failure.
2018-03-12Forward-port addition of __google_pthread_signal_safe_key_createStan Shebs1-0/+14
2018-01-23Work around a weird clang link failureStan Shebs1-0/+4
2018-01-25Revert Intel CET changes to __jmp_buf_tag (Bug 22743)Carlos O'Donell1-2/+5
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 Weimer1-1/+1
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 Myers27-27/+27
* 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 Weimer1-1/+0
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. Lu1-5/+2
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 Zanella3-7/+29
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 Myers1-1/+1
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 Schwab1-3/+3
2017-07-09Use generic pthread support on hppa.John David Anglin1-1/+1
2017-07-06nptl: Fix typo on __have_pthread_attr_t (BZ#21715)Matthew Krupcale1-1/+1
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 Weimer1-8/+0
2017-05-11Remove _IO_MTSAFE_IO from public headers.Zack Weinberg1-0/+1
_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 Zanella2-0/+277
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 Weinberg1-1/+1
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 Liebler1-2/+2
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 Riegel1-6/+14
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 Riegel1-68/+0
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 Myers25-25/+25
2016-12-31New condvar implementation that provides stronger ordering guarantees.Torvald Riegel2-13/+6
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 Zanella1-12/+0
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 Weinberg1-0/+1
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 Weimer1-8/+0
This removes the old mutex_t-related definitions from malloc-machine.h, too.
2016-09-14Remove the ptw-% patternsFlorian Weimer1-4/+0
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 Weimer1-3/+3
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 Weimer1-15/+38
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 Weimer1-27/+0
2016-04-14malloc: Run fork handler as late as possible [BZ #19431]Florian Weimer1-1/+12
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 Riegel1-6/+9
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.
2016-01-15Fix build errors with -DNDEBUG.Martin Sebor1-2/+4
[BZ #18755] * iconv/skeleton.c (FUNCTION_NAME): Suppress -Wunused-but-set-variable warnings. * sysdeps/nptl/gai_misc.h (__gai_start_notify_thread): Same. (__gai_create_helper_thread): Same. * nscd/nscd.c (do_exit): Suppress -Wunused-variable. * iconvdata/iso-2022-cn-ext.c (BODY): Initialize local variable to suppress -Wmaybe-uninitialized warnings.
2016-01-04Update copyright dates with scripts/update-copyrights.Joseph Myers25-25/+25
2015-12-23Do not violate mutex destruction requirements.Torvald Riegel1-4/+14
POSIX and C++11 require that a thread can destroy a mutex if no other thread owns the mutex, is blocked on the mutex, or will try to acquire it in the future. After destroying the mutex, it can reuse or unmap the underlying memory. Thus, we must not access a mutex' memory after releasing it. Currently, we can load the private flag after releasing the mutex, which is fixed by this patch. See https://sourceware.org/bugzilla/show_bug.cgi?id=13690 for more background. We need to call futex_wake on the lock after releasing it, however. This is by design, and can lead to spurious wake-ups on unrelated futex words (e.g., when the mutex memory is reused for another mutex). This behavior is documented in the glibc-internal futex API and in recent drafts of the Linux kernel's futex documentation (see the draft_futex branch of git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git).
2015-11-24Replace MUTEX_INITIALIZER with _LIBC_LOCK_INITIALIZER in generic codeFlorian Weimer2-1/+1
* sysdeps/mach/hurd/libc-lock.h (_LIBC_LOCK_INITIALIZER): Define. (__libc_lock_define_initialized): Use it. * sysdeps/nptl/libc-lockP.h (_LIBC_LOCK_INITIALIZER): Define. * malloc/arena.c (list_lock): Use _LIBC_LOCK_INITIALIZER. * malloc/malloc.c (main_arena): Likewise. * sysdeps/generic/malloc-machine.h (MUTEX_INITIALIZER): Remove. * sysdeps/nptl/malloc-machine.h (MUTEX_INITIALIZER): Remove.
2015-10-27Remove sysdeps/nptl/configure.ac.Joseph Myers3-117/+0
sysdeps/nptl/configure.ac tests for forced unwind support and the C cleanup attribute, giving errors if either is unsupported. It does nothing beyond running those two tests. Both the attribute, and _Unwind_GetCFA which is used in the forced unwind test, were added in GCC 3.3. Thus these tests are long obsolete, and this patch removes the configure fragment running them, along with associated conditionals. Tested for x86_64 and x86 (testsuite, and that installed stripped shared libraries are unchanged by the patch). * sysdeps/nptl/configure.ac: Remove file. * sysdeps/nptl/configure: Remove generated file. * configure.ac (libc_cv_forced_unwind): Do not substitute. * configure: Regenerated. * config.h.in (HAVE_FORCED_UNWIND): Remove #undef. * config.make.in (have-forced-unwind): Remove variable. * nptl/Makefile [$(have-forced-unwind) = yes]: Make code unconditional. * nptl/descr.h [HAVE_FORCED_UNWIND]: Likewise. * nptl/unwind.c [HAVE_FORCED_UNWIND]: Likewise. (__pthread_unwind) [!HAVE_FORCED_UNWIND]: Remove conditional code. * nptl/version.c [HAVE_FORCED_UNWIND]: Make code unconditional. * sysdeps/nptl/Makefile [$(have-forced-unwind) = yes]: Make code unconditional.
2015-10-17malloc: Rewrite with explicit TLS access using __threadFlorian Weimer1-10/+0
2015-10-15Remove NPTL configure errors based on top-level configure tests.Joseph Myers2-18/+0
sysdeps/nptl/configure.ac has code to give errors if certain tests in the top-level configure failed. However, all those failure conditions also produce errors in the top-level configure, so the errors in the NPTL configure are completely redundant; this patch removes them. (As suggested in <https://sourceware.org/ml/libc-alpha/2015-10/msg00510.html>, I think the top-level tests in question can be completely removed as unnecessary given the version tests. But even without that there is clearly no point in duplicating code that gives an error if the test fails.) Tested for x86_64 (testsuite, and that installed shared libraries are unchanged by the patch). * sysdeps/nptl/configure.ac: Do not give errors based on the results of top-level configure tests. * sysdeps/nptl/configure: Regenerated.
2015-09-18Use __libc_ptf_call in _longjmp_unwindH.J. Lu1-9/+3
Use __libc_ptf_call in _longjmp_unwind to avoid duplicated logic. On x86-64, I got jmp-unwind.os: _longjmp_unwind: movl __libc_pthread_functions_init(%rip), %eax testl %eax, %eax jne .L4 rep ret .L4: movq 304+__libc_pthread_functions(%rip), %rax movq %rsp, %rsi ror $2*8+1, %rax xor %fs:48, %rax jmp *%rax jmp-unwind.o: _longjmp_unwind: movl $__pthread_cleanup_upto, %eax testq %rax, %rax je .L1 movq %rsp, %rsi jmp __pthread_cleanup_upto .L1: rep ret * sysdeps/nptl/jmp-unwind.c: Include <libc-lock.h> instead of <nptl/pthreadP.h>. (_longjmp_unwind): Use __libc_ptf_call. * sysdeps/unix/sysv/linux/s390/jmp-unwind.c: Likewise.
2015-09-17Use __pthread_setcancelstate in libc.aH.J. Lu2-3/+4
This patch references __pthread_setcancelstate instead of pthread_setcancelstate in libc.a. [BZ #18970] * misc/error.c (error): Replace pthread_setcancelstate with __pthread_setcancelstate. (error_at_line): Likewise. * posix/wordexp.c (parse_comm): Likewise. * stdlib/fmtmsg.c (fmtmsg): Likewise. * nptl/forward.c (pthread_setcancelstate): Renamed to ... (__pthread_setcancelstate): This. (pthread_setcancelstate): Add an alias. * nptl/nptl-init.c (pthread_functions): Replace ptr_pthread_setcancelstate with ptr___pthread_setcancelstate. * sysdeps/nptl/pthread-functions.h (pthread_functions): Likewise. * nptl/pthreadP.h (__pthread_setcancelstate): Mark it with hidden_proto. * nptl/pthread_setcancelstate.c (__pthread_setcancelstate): Mark it with hidden_def. * sysdeps/nptl/libc-lockP.h (__pthread_setcancelstate): New. (pthread_setcancelstate): Renamed to ... (__pthread_setcancelstate): This. * sysdeps/unix/sysv/linux/fatal-prepare.h (FATAL_PREPARE): Use __libc_ptf_call with __pthread_setcancelstate.
2015-09-08Move bits/libc-lock.h and bits/libc-lockP.h out of bits/ (bug 14912).Joseph Myers4-8/+8
It was noted in <https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the bits/*.h naming scheme should only be used for installed headers. This patch renames bits/libc-lock.h to plain libc-lock.h and bits/libc-lockP.h to plain libc-lockP.h to follow that convention. Note that I don't know where libc-lockP.h comes from for Hurd (the Hurd libc-lock.h includes libc-lockP.h, but the only libc-lockP.h in the glibc source tree is for NPTL) - some unmerged patch? - but I updated the #include in the Hurd libc-lock.h anyway. Tested for x86_64 (testsuite, and that installed stripped shared libraries are unchanged by the patch). [BZ #14912] * bits/libc-lock.h: Move to ... * sysdeps/generic/libc-lock.h: ...here. (_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H. * sysdeps/mach/hurd/bits/libc-lock.h: Move to ... * sysdeps/mach/hurd/libc-lock.h: ...here. (_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H. [_LIBC]: Include <libc-lockP.h> instead of <bits/libc-lockP.h>. * sysdeps/mach/bits/libc-lock.h: Move to ... * sysdeps/mach/libc-lock.h: ...here. (_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H. * sysdeps/nptl/bits/libc-lock.h: Move to ... * sysdeps/nptl/libc-lock.h: ...here. (_BITS_LIBC_LOCK_H): Rename macro to _LIBC_LOCK_H. * sysdeps/nptl/bits/libc-lockP.h: Move to ... * sysdeps/nptl/libc-lockP.h: ...here. (_BITS_LIBC_LOCKP_H): Rename macro to _LIBC_LOCKP_H. * crypt/crypt_util.c: Include <libc-lock.h> instead of <bits/libc-lock.h>. * dirent/scandir-tail.c: Likewise. * dlfcn/dlerror.c: Likewise. * elf/dl-close.c: Likewise. * elf/dl-iteratephdr.c: Likewise. * elf/dl-lookup.c: Likewise. * elf/dl-open.c: Likewise. * elf/dl-support.c: Likewise. * elf/dl-writev.h: Likewise. * elf/rtld.c: Likewise. * grp/fgetgrent.c: Likewise. * gshadow/fgetsgent.c: Likewise. * gshadow/sgetsgent.c: Likewise. * iconv/gconv_conf.c: Likewise. * iconv/gconv_db.c: Likewise. * iconv/gconv_dl.c: Likewise. * iconv/gconv_int.h: Likewise. * iconv/gconv_trans.c: Likewise. * include/link.h: Likewise. * inet/getnameinfo.c: Likewise. * inet/getnetgrent.c: Likewise. * inet/getnetgrent_r.c: Likewise. * intl/bindtextdom.c: Likewise. * intl/dcigettext.c: Likewise. * intl/finddomain.c: Likewise. * intl/gettextP.h: Likewise. * intl/loadmsgcat.c: Likewise. * intl/localealias.c: Likewise. * intl/textdomain.c: Likewise. * libidn/idn-stub.c: Likewise. * libio/libioP.h: Likewise. * locale/duplocale.c: Likewise. * locale/freelocale.c: Likewise. * locale/newlocale.c: Likewise. * locale/setlocale.c: Likewise. * login/getutent_r.c: Likewise. * login/getutid_r.c: Likewise. * login/getutline_r.c: Likewise. * login/utmp-private.h: Likewise. * login/utmpname.c: Likewise. * malloc/mtrace.c: Likewise. * misc/efgcvt.c: Likewise. * misc/error.c: Likewise. * misc/fstab.c: Likewise. * misc/getpass.c: Likewise. * misc/mntent.c: Likewise. * misc/syslog.c: Likewise. * nis/nis_call.c: Likewise. * nis/nis_callback.c: Likewise. * nis/nss-default.c: Likewise. * nis/nss_compat/compat-grp.c: Likewise. * nis/nss_compat/compat-initgroups.c: Likewise. * nis/nss_compat/compat-pwd.c: Likewise. * nis/nss_compat/compat-spwd.c: Likewise. * nis/nss_nis/nis-alias.c: Likewise. * nis/nss_nis/nis-ethers.c: Likewise. * nis/nss_nis/nis-grp.c: Likewise. * nis/nss_nis/nis-hosts.c: Likewise. * nis/nss_nis/nis-network.c: Likewise. * nis/nss_nis/nis-proto.c: Likewise. * nis/nss_nis/nis-pwd.c: Likewise. * nis/nss_nis/nis-rpc.c: Likewise. * nis/nss_nis/nis-service.c: Likewise. * nis/nss_nis/nis-spwd.c: Likewise. * nis/nss_nisplus/nisplus-alias.c: Likewise. * nis/nss_nisplus/nisplus-ethers.c: Likewise. * nis/nss_nisplus/nisplus-grp.c: Likewise. * nis/nss_nisplus/nisplus-hosts.c: Likewise. * nis/nss_nisplus/nisplus-initgroups.c: Likewise. * nis/nss_nisplus/nisplus-network.c: Likewise. * nis/nss_nisplus/nisplus-proto.c: Likewise. * nis/nss_nisplus/nisplus-pwd.c: Likewise. * nis/nss_nisplus/nisplus-rpc.c: Likewise. * nis/nss_nisplus/nisplus-service.c: Likewise. * nis/nss_nisplus/nisplus-spwd.c: Likewise. * nis/ypclnt.c: Likewise. * nptl/libc_pthread_init.c: Likewise. * nss/getXXbyYY.c: Likewise. * nss/getXXent.c: Likewise. * nss/getXXent_r.c: Likewise. * nss/nss_db/db-XXX.c: Likewise. * nss/nss_db/db-netgrp.c: Likewise. * nss/nss_db/nss_db.h: Likewise. * nss/nss_files/files-XXX.c: Likewise. * nss/nss_files/files-alias.c: Likewise. * nss/nsswitch.c: Likewise. * posix/regex_internal.h: Likewise. * posix/wordexp.c: Likewise. * pwd/fgetpwent.c: Likewise. * resolv/res_hconf.c: Likewise. * resolv/res_libc.c: Likewise. * shadow/fgetspent.c: Likewise. * shadow/lckpwdf.c: Likewise. * shadow/sgetspent.c: Likewise. * socket/opensock.c: Likewise. * stdio-common/reg-modifier.c: Likewise. * stdio-common/reg-printf.c: Likewise. * stdio-common/reg-type.c: Likewise. * stdio-common/vfprintf.c: Likewise. * stdio-common/vfscanf.c: Likewise. * stdlib/abort.c: Likewise. * stdlib/cxa_atexit.c: Likewise. * stdlib/fmtmsg.c: Likewise. * stdlib/random.c: Likewise. * stdlib/setenv.c: Likewise. * string/strsignal.c: Likewise. * sunrpc/auth_none.c: Likewise. * sunrpc/bindrsvprt.c: Likewise. * sunrpc/create_xid.c: Likewise. * sunrpc/key_call.c: Likewise. * sunrpc/rpc_thread.c: Likewise. * sysdeps/arm/backtrace.c: Likewise. * sysdeps/generic/ldsodefs.h: Likewise. * sysdeps/generic/stdio-lock.h: Likewise. * sysdeps/generic/unwind-dw2-fde.c: Likewise. * sysdeps/i386/backtrace.c: Likewise. * sysdeps/ieee754/ldbl-opt/nldbl-compat.c: Likewise. * sysdeps/m68k/backtrace.c: Likewise. * sysdeps/mach/hurd/cthreads.c: Likewise. * sysdeps/mach/hurd/dirstream.h: Likewise. * sysdeps/mach/hurd/malloc-machine.h: Likewise. * sysdeps/nptl/malloc-machine.h: Likewise. * sysdeps/nptl/stdio-lock.h: Likewise. * sysdeps/posix/dirstream.h: Likewise. * sysdeps/posix/getaddrinfo.c: Likewise. * sysdeps/posix/system.c: Likewise. * sysdeps/pthread/aio_suspend.c: Likewise. * sysdeps/s390/s390-32/backtrace.c: Likewise. * sysdeps/s390/s390-64/backtrace.c: Likewise. * sysdeps/unix/sysv/linux/check_pf.c: Likewise. * sysdeps/unix/sysv/linux/if_index.c: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/getutent_r.c: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/getutid_r.c: Likewise. * sysdeps/unix/sysv/linux/s390/s390-32/getutline_r.c: Likewise. * sysdeps/unix/sysv/linux/shm-directory.c: Likewise. * sysdeps/unix/sysv/linux/system.c: Likewise. * sysdeps/x86_64/backtrace.c: Likewise. * time/alt_digit.c: Likewise. * time/era.c: Likewise. * time/tzset.c: Likewise. * wcsmbs/wcsmbsload.c: Likewise. * nptl/tst-initializers1.c (do_test): Refer to <libc-lock.h> instead of <bits/libc-lock.h> in comment.
2015-09-04Rename bits/stdio-lock.h to stdio-lock.h (bug 14912).Joseph Myers2-4/+4
It was noted in <https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the bits/*.h naming scheme should only be used for installed headers. This patch renames bits/stdio-lock.h to plain stdio-lock.h to follow that convention. Tested for x86_64 (testsuite, and that installed stripped shared libraries are unchanged by the patch). [BZ #14912] * bits/stdio-lock.h: Move to ... * sysdeps/generic/stdio-lock.h: ...here. (_BITS_STDIO_LOCK_H): Rename macro to _STDIO_LOCK_H. * sysdeps/nptl/bits/stdio-lock.h: Move to ... * sysdeps/nptl/stdio-lock.h: ...here. (_BITS_STDIO_LOCK_H): Rename macro to _STDIO_LOCK_H. * include/libio.h: Include <stdio-lock.h> instead of <bits/stdio-lock.h>. * sysdeps/nptl/fork.c: Likewise. * sysdeps/pthread/flockfile.c: Likewise. * sysdeps/pthread/ftrylockfile.c: Likewise. * sysdeps/pthread/funlockfile.c: Likewise.
2015-09-03Rename bits/libc-tsd.h to libc-tsd.h (bug 14912).Joseph Myers1-1/+1
It was noted in <https://sourceware.org/ml/libc-alpha/2012-09/msg00305.html> that the bits/*.h naming scheme should only be used for installed headers. This patch renames bits/libc-tsd.h to plain libc-tsd.h to follow that convention. Tested for x86_64 (testing, and that installed stripped shared libraries are unchanged by the patch). [BZ #14912] * bits/libc-tsd.h: Move to ... * sysdeps/generic/libc-tsd.h: ...here. (_GENERIC_BITS_LIBC_TSD_H): Rename macro to _GENERIC_LIBC_TSD_H. * sysdeps/mach/hurd/bits/libc-tsd.h: Move to ... * sysdeps/mach/hurd/libc-tsd.h: ...here. (_BITS_LIBC_TSD_H): Rename macro to _LIBC_TSD_H. * include/ctype.h: Include <libc-tsd.h> instead of <bits/libc-tsd.h>. * include/rpc/rpc.h: Likewise. * locale/localeinfo.h: Likewise. * sunrpc/rpc_thread.c: Likewise. * sysdeps/mach/hurd/malloc-machine.h: Likewise. * sysdeps/nptl/malloc-machine.h: Likewise.
2015-07-10Add and use new glibc-internal futex API.Torvald Riegel4-17/+221
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.
2015-06-24Use unsigned types for counters in getaddrinfo_a code.Roland McGrath1-2/+2
2015-06-24Use unsigned types for counters in AIO code.Roland McGrath1-2/+2
2015-03-28NPTL: Remove duplicate definition of PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NPMartin Galvan1-2/+0
The PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP macro was defined twice with the same values in pthread.h; this removes the second definition.
2015-01-29Include <signal.h> in sysdeps/nptl/allocrtsig.cAndreas Schwab1-0/+1
Architectures which don't use hp-timing-common.h don't include <signal.h> via <sys/param.h>.